WO2008023555A1

WO2008023555A1 - Resist composition for liquid immersion lithography, and method for formation of resist pattern

Info

Publication number: WO2008023555A1
Application number: PCT/JP2007/065149
Authority: WO
Inventors: Yoshiyuki Utsumi; Makiko Irie
Original assignee: Tokyo Ohka Kogyo Co., Ltd.
Priority date: 2006-08-23
Filing date: 2007-08-02
Publication date: 2008-02-28
Also published as: JP2008051967A

Abstract

A resist composition for liquid immersion lithography, comprising: (A) a base component whose alkali solubility can vary by the action of an acid and which does not have a constitutional unit (c1) represented by the general formula (c1-1) [wherein R represents a hydrogen atom, a lower alkyl group, a halogen atom or a halogenated lower alkyl group; R21 and R22 independently represent a hydrogen atom or a lower alkyl group; a represents an integer ranging from 0 to 3; R23 represents an aliphatic cyclic group having a structure (I) represented by the general formula (I-1)]; (B) an acid generator component which can generate an acid when exposed to light; and (C) a fluorinated resin component having the constitutional unit (c1).

Description

Specification

Resist composition for immersion exposure and method for forming resist pattern

Technical field

The present invention relates to a resist composition for immersion exposure and a method for forming a resist pattern, which are used for immersion exposure (Liquid Immersion Lithography).

We claim priority based on Japanese Patent Application No. 2006-226950 filed on this application (August 2006, 23, 2006), which is incorporated herein by reference.

Background art

In lithography technology, for example, a resist film made of a resist material is formed on a substrate, and the resist film is irradiated with radiation such as light or an electron beam through a mask on which a predetermined pattern is formed. A step of forming a resist pattern having a predetermined shape on the resist film is performed by performing selective exposure and developing.

Along with the miniaturization of semiconductor elements, the exposure light source has become shorter in wavelength and the projection lens has a higher numerical aperture (high Ν Α). Currently, an ArF excimer laser having a wavelength of 193 nm is used as the light source. An exposure machine has been developed. As the exposure light source becomes shorter in wavelength, the resist material is required to have improved lithographic characteristics such as sensitivity to the exposure light source and resolution capable of reproducing a pattern with fine dimensions. As a resist material satisfying such requirements, a chemically amplified resist containing a base resin whose alkali solubility is changed by the action of an acid and an acid generator that generates an acid upon exposure is used.

Currently, the base resin of the chemically amplified resist used in ArF excimer laser lithography etc. is excellent in transparency around 193 nm, so the structural unit derived from (meth) acrylic acid ester is the main chain. In general, resins (acrylic resins) are used. Here, “(meth) acrylic acid” means one or both of acrylic acid having a hydrogen atom bonded to the α-position and methacrylic acid having a methyl group bonded to the a-position. “(Meth) acrylic acid ester” means either an acrylic acid ester with a hydrogen atom bonded to the α-position or a methacrylate ester with a methyl group bonded to the a-position! “(Meth) atalylate” means one or both of an acrylate with a hydrogen atom bonded to the α-position and a meta-acrylate with a methyl group bonded to the α-position.

[0003] As one of the methods for further improving the resolution, exposure is performed by interposing a liquid (immersion medium) having a refractive index higher than that of air between the objective lens of the exposure machine and the sample. There is known a lithography method for performing immersion exposure (so-called “Liquid Immersion Lithography”, hereinafter referred to as “immersion exposure”) (for example, see Non-Patent Document 1).

With immersion exposure, the same high resolution can be achieved with a light source with the same exposure wavelength as when using a light source with a shorter wavelength or with a high NA lens. It is said that there is no decrease in depth. Moreover, immersion exposure can be performed using an existing exposure apparatus. Therefore, immersion exposure is expected to be able to form a resist pattern with low cost, high resolution, and excellent depth of focus, and in the manufacture of semiconductor devices that require large capital investment. It is attracting a great deal of attention as having a great effect on the semiconductor industry in terms of cost and lithography characteristics such as resolution!

Immersion exposure is effective in the formation of all types of pattern shapes, and it is also considered that it can be combined with super-resolution techniques such as the phase shift method and modified illumination method that are currently under investigation! Yes. At present, as an immersion exposure technique, a technique mainly using an ArF excimer laser as a light source is being actively researched. Currently, water is mainly considered as the immersion medium.

[0004] In recent years, with respect to fluorine-containing compounds, attention has been paid to characteristics such as water repellency and transparency, and research and development in various fields has been actively conducted. For example, in the field of resist materials, an acid such as a methoxymethyl group, a tert-butyl group, or a tert-butyloxycarbonyl group is added to a fluorine-containing polymer compound for use as a base resin for a positive chemically amplified resist. Introducing labile groups. However, when such a fluorine-based polymer compound is used as the base resin of a positive resist composition, a large amount of outgas is generated after exposure, or the resistance to dry etching gas (etching resistance) is sufficient. There are drawbacks.

Recently, fluorine-containing polymer compounds having acid labile groups containing cyclic hydrocarbon groups have been reported as fluorine-containing polymer compounds having excellent etching resistance (for example, Non-Patent Document 2).

Non-Patent Document 1: Proceedings of SPIE, Vol. 5754, 119-128 (2005).

Non-Patent Document 2: Proceedings of SPIE, Volume 4690, 76-83 (2002).

Disclosure of the invention

Problems to be solved by the invention

[0005] In immersion exposure, a resist material having characteristics corresponding to immersion exposure technology in addition to normal lithography characteristics (sensitivity, resolution, etching resistance, etc.) is required. For example, when the immersion medium is water and the immersion exposure is performed using a scanning immersion exposure machine as described in Non-Patent Document 1, the immersion medium is a lens. Water tracking is required to follow the movement of the water. If water followability is low, the exposure speed will decrease, which may affect productivity. This water followability is a force that can be improved by increasing the hydrophobicity of the resist film (hydrophobizing). On the other hand, simply hydrophobizing the resist film has an adverse effect on lithography properties. There is a tendency for image quality and sensitivity to decrease, and to increase the amount of scum.

Thus, in immersion exposure, the development of materials with moderate hydrophobicity becomes an important issue.

However, at present, few materials are known that have both lithographic characteristics and characteristics required for immersion exposure.

The present invention has been made in view of the above circumstances, and provides a resist composition for immersion exposure and a method for forming a resist pattern that have good lithography characteristics and have hydrophobicity suitable for immersion exposure. The purpose is to do.

Means for solving the problem

[0006] The first aspect (aspect) of the present invention for solving the above-mentioned problems is that the alkali solubility is changed by the action of an acid and the structural unit (c 1 1) represented by the following general formula (c 1 1) 1), a substrate component (A), an acid generator component (B) that generates an acid upon exposure, and a fluororesin component (C) having the structural unit (cl). A resist composition for immersion exposure. [0007] [Chemical 1]

[In the formula (cl 1), R represents a hydrogen atom, a lower alkyl group, a halogen atom or a halogenated lower alkyl group; R ²¹ and R ²² each independently represent a hydrogen atom or a lower alkyl group; Is an integer of 0 to 3, and R ²³ is an aliphatic cyclic group having the structure (I) represented by the following general formula (I 1). ]

[0008] [Chemical 2]

[In Formula (1-1), R ²⁴ and R ²⁵ each independently represent a fluorine atom or a fluorinated alkyl group, and X ²¹ and X ²² each represent a ring of an aliphatic cyclic group having the structure (I). It is a carbon atom that constitutes the skeleton. ]

[0009] A second aspect of the present invention is a step of forming a resist film on a support using the resist composition for immersion exposure according to the first aspect (aspect). A resist pattern forming method including a step of immersion exposure and a step of developing the resist film to form a resist pattern.

In the present specification and claims, an “alkyl group” means a straight chain unless otherwise specified.

, Including branched and cyclic monovalent saturated hydrocarbon groups.

A “lower alkyl group” is an alkyl group having 1 to 5 carbon atoms. The same applies to the “alkyl group” in the “halogenated lower alkyl group”. The “alkylene group” includes linear, branched and cyclic divalent saturated hydrocarbon groups unless otherwise specified.

“Structural unit” means a monomer unit (monomer unit) constituting a resin (polymer).

“Exposure” is a concept that includes general irradiation of radiation.

The invention's effect

[0011] According to the present invention, it is possible to provide a resist composition for immersion exposure and a method for forming a resist pattern, which have good lithography characteristics and hydrophobicity suitable for immersion exposure.

[0012] FIG. 1 is a diagram for explaining an advancing angle (Θ), a receding angle (Θ), and a falling angle (Θ).

one two Three

[Fig. 2] In Example, (C) Component ratio (% by mass) and contact angle of resist film before exposure, etc. [Fig. 3] In Example, (C) Component ratio (% by mass) and after exposure Explanation of sign with contact angle of resist film

[0013] 1 drop; la bottom of drop 1; lb top of drop 1; 2 plane; Θ advance angle; Θ

1 2 Receding angle; Θ Tipping angle

Three

BEST MODE FOR CARRYING OUT THE INVENTION

The resist composition for immersion exposure according to the present invention does not have the structural unit (cl) represented by the above general formula (cl 1), whose alkali solubility is changed by the action of an acid, and is a base material component (A) (hereinafter referred to as component (A)), an acid generator component (B) (hereinafter referred to as component (B)) that generates an acid upon exposure, and the above general formula (cl 1). And a fluorine-containing resin component (C) having the structural unit (cl) (hereinafter referred to as component (C)).

[0015] <(A) component>

The component (A) is not particularly limited as long as it does not contain the structural unit (cl). Many substrate components for amplification resist compositions, such as resist compositions for ArF excimer lasers, resist compositions for KrF excimer lasers (preferably for ArF excimer lasers), etc., have been proposed. Choose from any of the powers! The structural unit (c 1) will be described in the section of the component (C) described later.

Here, “base material component” means an organic compound having film-forming ability.

Preferable base material components include organic compounds having a molecular weight of 500 or more. When the molecular weight of the organic compound is 500 or more, the film forming ability is improved, and a nano-level pattern can be easily formed.

The organic compound having a molecular weight of 500 or more is largely classified into a low molecular weight organic compound (hereinafter referred to as a low molecular compound) having a molecular weight of 500 or more and less than 2000 and a high molecular weight resin (polymer) having a molecular weight of 2000 or more. Separated. As the low molecular weight compound, a non-polymer is usually used. In the case of a resin (polymer), the “molecular weight” is the weight average molecular weight in terms of polystyrene measured by GPC (gel permeation chromatography). Hereinafter, in the case of simply “resin”, it means a resin having a molecular weight of 2000 or more.

The component (A) may be a low molecular compound whose alkali solubility is changed by the action of an acid, or a mixture of these, which may be a resin whose alkali solubility is changed by the action of an acid. May be.

The resist composition for immersion exposure of the present invention may be a negative resist composition or a positive resist composition! /.

When the resist composition for immersion exposure of the present invention is a negative resist composition, as the component (A), a base material component whose alkali solubility is lowered by the action of an acid is used. As the base material component, an alkali-soluble resin is usually used.

In the case of the negative type, the resist composition further contains a crosslinking agent component. In such a resist composition, when an acid is generated from the component (B) by exposure during resist pattern formation, the acid acts to cause crosslinking between the component (A) and the cross-linking agent, and the alkali-soluble resin is alkali-insoluble. It changes to. Therefore, in the formation of a resist pattern, when a resist film obtained by applying the resist composition on a substrate is selectively exposed, the exposed portion turns into alkali-insoluble while the unexposed portion becomes alkali-soluble. Remains strange Therefore, a resist pattern can be formed by alkali development.

Examples of the alkali-soluble resin include: a (hydroxyalkyl) acrylic acid, or α (hydroxyalkyl) acrylic acid, a lower alkyl ester power, a resin power having a unit derived from at least one selected from A resist pattern can be formed, which is preferable. Α (Hydroxyalkyl) acrylic acid is composed of 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. ~ 5 hydroxyalkyl groups) are attached! /, Which represents one or both of a-hydroxyalkylacrylic acids.

As the crosslinking agent component, 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. The blending amount of the crosslinking agent component is preferably in the range of! To 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

[0017] When the resist composition for immersion exposure of the present invention is a positive resist composition, the component (A) has an acid dissociable, dissolution inhibiting group, and the alkali solubility is increased by the action of an acid. Base material components are used. The resist composition containing such a base material component is insoluble before exposure, and when acid is generated from component (B) upon exposure during resist pattern formation, the acid dissociable dissolution is suppressed by the action of the acid. The group dissociates and the component (A) changes to alkali-soluble. Therefore, in the formation of the resist pattern, if the resist film obtained by applying the positive resist composition on the substrate is selectively exposed, the exposed portion turns to be soluble in the Al force, while the unexposed portion becomes Since it remains insoluble in alkali and does not change, a resist pattern can be formed by re-developing.

[0018] In the resist composition for immersion exposure according to the present invention, the component (A) is preferably a substrate component whose alkali solubility is increased by the action of an acid, in addition to being excellent in the effects of the present invention. . That is, the resist composition for immersion exposure according to the present invention is preferably a positive resist composition.

The substrate component may be a resin (A1) having an acid dissociable, dissolution inhibiting group and increasing alkali solubility by the action of an acid (hereinafter sometimes referred to as (A1) component). Low molecular weight compound whose alkali solubility is increased by the action of (A2) (hereinafter sometimes referred to as component (A2). ).

In consideration of miscibility with component (C), availability, etc., component (A) is preferably component (A1).

[0019] [(A1) component]

The component (A1) is not particularly limited, and any one that has been proposed as a base resin for positive chemically amplified resists so far can be used. For example, a resin in which a part or all of the alkali-soluble group in a resin having an alkali-soluble group (hydroxyl group, carboxy group, etc.) is protected with an acid dissociable, dissolution inhibiting group can be mentioned. Examples of the resin having an alkali-soluble group include a nopolak resin, a resin having a structural unit derived from hydroxystyrene (polyhydroxystyrene, hydroxystyrene-styrene copolymer, etc.), and a structural unit derived from an acrylate ester. And resins having a structural unit derived from cycloolefin.

In the present invention, the component (A1) is preferably a resin having a structural unit that also induces acrylate power. Such a resin can be suitably used in lithography using an ArF excimer laser, which is particularly highly transparent to an ArF excimer laser.

In the component (A1), the proportion of the structural unit derived from the acrylate ester is preferably 20 mol% or more with respect to the total of all the structural units constituting the component (A1). % or more may be further a preferred fixture 100 mole ^_0/0 more preferably tool 80 mole ^_0/0 or

[0020] Here, in the present specification and claims, the "structural unit derived from an acrylate ester" means a structural unit constituted by cleavage of an ethylenic double bond of an acrylate ester. To do.

“Acrylic acid esters” have a hydrogen atom bonded to the carbon atom at the α-position! /, And a substituent (an atom or group other than a hydrogen atom) bonded to the carbon atom at the α-position. It is a concept including what is. Examples of the substituent include a halogen atom, a lower alkyl group, a hydrogenated, a logenated lower alkyl group, and the like. Halogen atoms include fluorine atoms and salts Elemental atoms, bromine atoms, iodine atoms and the like can be mentioned. The _α- position ( _α- position carbon atom) of a structural unit derived from an acrylate ester is a carbon atom bonded to a carbonyl group unless otherwise specified.

In the acrylate ester, the lower alkyl group as a substituent at the α-position is specifically a methyl group, an ethyl group, a propyl group, an isopropyl group, a η-butyl group, an isobutanol group, a tert-butyl group, or a pentyl group. And a lower linear or branched alkyl group such as an isopentyl group and a neopentyl group.

The halogenated lower alkyl group as a substituent at the a position is a group in which at least one or all of the hydrogen atoms of the lower alkyl group are substituted with the halogen atoms.

In the present invention, the α-position of the acrylate ester is preferably a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and preferably a hydrogen atom or a lower alkyl group. Is more preferably a hydrogen atom or a methyl group from the viewpoint of easy industrial availability.

[0021] “Structural Unit (a l)”

In the present invention, the component (A1) preferably has a structural unit (a l) that also induces an acrylate ester having an acid dissociable, dissolution inhibiting group! /.

The acid dissociable, dissolution inhibiting group in the structural unit (al) has an alkali dissolution inhibiting property that makes the entire resin (A1) insoluble to alkali before dissociation, and after dissociation, the entire resin (A1) changes to become alkali soluble. So far, it has been proposed as an acid dissociable, dissolution inhibiting group for base resins for chemically amplified resists! In general, a group that forms a cyclic or chain tertiary alkyl ester with a carboxy group in (meth) acrylic acid or the like; an acetal type acid dissociable, dissolution inhibiting group such as an alkoxyalkyl group is widely known. ing.

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

[0023] Here, the term "aliphatic" in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean groups, compounds, and the like that do not have aromaticity.

“Aliphatic branched” means that it has no aromaticity and has a branched structure. The structure of the “aliphatic branched acid dissociable, dissolution inhibiting group” is not limited to a group consisting of carbon and hydrogen (a hydrocarbon group), but is preferably a hydrocarbon group. Further, the “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated.

As the aliphatic branched acid dissociable, dissolution inhibiting group, a tertiary alkyl group having 4 to 8 carbon atoms is preferred. Specifically, a tert-butyl group, a tert-amyl group, a tert-heptyl group, etc. Can be mentioned.

[0024] The "aliphatic cyclic group" indicates that it has no aromaticity! /, A monocyclic group or a polycyclic group.

The “aliphatic cyclic group” in the structural unit (al) may or may not have a substituent. Examples of the substituent include a lower alkyl group having 1 to 5 carbon atoms, a fluorine atom, a carbon atom substituted with a fluorine atom; a fluorinated lower alkyl group having! To 5 carbon atoms, an oxygen atom (= 0), and the like.

The basic ring structure excluding the substituent of “aliphatic cyclic group” is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but is preferably a hydrocarbon group. The “hydrocarbon group” may be either saturated or unsaturated, but is usually preferably saturated. The “aliphatic cyclic group” is preferably a polycyclic group.

Specific examples of the aliphatic cyclic group include, for example, a lower alkyl group, a fluorine atom, or a fluorinated alkyl group substituted! /, May! /, And may / cannot be! /, Polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, tetracycloalkane Examples include groups in which one or more hydrogen atoms have been removed. Specifically, cyclopentane

And monocycloalkanes such as cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group. Specifically, 2-methyl-2 Examples include —adamantyl group and 2-ethyl-2-adamantyl group. Or, in a structural unit represented by the following general formula (al "), an aliphatic cyclic group such as an adamantyl group such as a group bonded to an oxygen atom of a carbonyloxy group (one C (O) -0-) And a group having a group and a branched alkylene group having a tertiary carbon atom bonded thereto.

[0025] [Chemical 3]

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹⁵ and R ¹⁶ are alkyl groups (both linear and branched, preferably carbon number) 1 to 5). ]

[0026] In the formula (al "), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is the halogen atom or lower alkyl group mentioned as the substituent at the α-position in the description of the acrylate ester. Or the same as the halogenated lower alkyl group

Yes

[0027] "Acetal-type acid dissociable, dissolution inhibiting group" is generally a carboxy group, a hydroxyl group or the like. It replaces the hydrogen atom at the end of the Lucari soluble group and is bonded to the oxygen atom. When an acid is generated by exposure, the acid acts to break the bond between the acetal type acid dissociable, dissolution inhibiting group and the oxygen atom to which the acetal type acid dissociable, dissolution inhibiting group is bonded. . Examples of the acetal type acid dissociable, dissolution inhibiting group include a group represented by the following general formula (pi).

[0028] [Chemical 4]

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

[0029] In the above formula, n is preferably an integer of 0 to 2, 0 or 1 is more preferable, and 0 is most preferable.

Examples of the lower alkyl group for R ¹ ′ and R ² ′ include the same lower alkyl groups as those described above for R, and a methyl group that is preferably a methyl group or an ethyl group is most preferable.

In the present invention, it is preferable that at least one of R ¹ ′ and R ² ′ is a hydrogen atom. That is, the acid dissociable, dissolution inhibiting group (pi) force is preferably a group represented by the following general formula (pi-1).

[0030] [Chemical 5]

... c ί-1)

[Wherein R ¹ ′, η and 、 are the same as R ¹ ′, n and Y in the general formula (pi). ]

[0031] Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.

Yes

The aliphatic cyclic group for Y can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups that have been conventionally proposed in a number of ArF resists and the like. Examples thereof include those similar to the “aliphatic cyclic group”.

[0032] The acetal type acid dissociable, dissolution inhibiting group includes a group represented by the following general formula (p2).

[0033] [Chemical 6]

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

[0034] In R ^17, R ^18, carbon atoms in the alkyl group is preferably 1 to; of 15, linear, branched either Yogu Echiru group, is preferred instrument methyl group methyl group is most preferable. In particular, it is preferable that one of R ¹⁷ and R ¹⁸ is a hydrogen atom and the other is a methyl group.

R ¹⁹ is a linear, branched or cyclic alkyl group, preferably having 1 to 15 carbon atoms, and may be linear, branched or cyclic.

When R ¹⁹ is linear or branched, it preferably has 1 to 5 carbon atoms, more preferably an ethyl group or a methyl group, and most preferably an ethyl group! /.

When R ¹⁹ is cyclic, the force is preferably 4 to 15 carbon atoms, preferably S, and more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, one or more polycycloalkanes such as monocycloalkane, bicycloalkane, tricycloalkane, and tetracycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group. And the like, in which a hydrogen atom is removed. Specific examples include monocycloalkanes such as cyclopentane and cyclohexane, and groups obtained by removing one or more hydrogen atoms from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. It is done. Among them, a group in which one or more hydrogen atoms are removed from adamantane is preferable. In the above formula, R ¹⁷ and R ¹⁹ are each independently a linear or branched alkylene group (preferably an alkylene group having 1 to 5 carbon atoms), and the end of R ^{19 and} the end of R ¹⁷ The end may be bonded.

In this case, a cyclic group is formed by R ¹⁷ and R ¹⁹ , the oxygen atom to which R ¹⁹ is bonded, and the carbon atom to which the oxygen atom and R ¹⁷ are bonded. As the cyclic group, a 4- to 7-membered ring is preferable, and a 4- to 6-membered ring is more preferable. Specific examples of the cyclic group include a tetrahydrobilanyl group and a tetrahydrofurayl group.

[0035] The structural unit (al) is selected from the group consisting of structural units represented by the following general formula (al-0-1) and structural units represented by the following general formula (al-0-2). It is preferable to use one or more.

[0036] [Chemical 7]

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

[Chemical 8]

, * * (A 1 ~ 0-2)

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

[0038] In the general formula (al-0-1), the halogen atom, lower alkyl group, or halogenated lower alkyl group of R is a halogen atom, lower alkyl group, or may be bonded to the α-position of the acrylate ester. The same as the halogenated lower alkyl group.

X ¹ is not particularly limited as long as it is an acid dissociable, dissolution inhibiting group, and examples thereof include the above-described tertiary alkyl ester type acid dissociable, dissolution inhibiting group and acetal type acid dissociable, dissolution inhibiting group. Tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred! /.

In the general formula (al-0-2), R is the same as R in the general formula (al-0-1).

X ² is the same as X ¹ in the formula (al- 0- 1).

Y ² is preferably an alkylene group having 1 to 4 carbon atoms or a divalent aliphatic cyclic group, except that a group in which two or more hydrogen atoms are removed is used as the aliphatic cyclic group. The same as the explanation of the “aliphatic cyclic group” can be used.

[0040] Specific examples of the structural unit (al) include structural units represented by the following general formulas (al- :!) to (al-4).

[0041] [Chemical 9]

C 1-1) 4) [In the above formula, X represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group; Y represents a lower alkyl group having 1 to 5 carbon atoms or an aliphatic cyclic group; n represents 0 to 3 M represents 0 or 1; R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; R ¹ ′ and R ² ′ each independently represent a hydrogen atom or a carbon number ;! Represents a lower alkyl group of 5 to 5. ]

[0042] R in the general formulas (al- ;!) to (al-4) is the same as R in the general formulas (al-0-1) to (al-0-2).

R ¹ ′ and R ² ′ are preferably at least one hydrogen atom, more preferably a hydrogen atom. n is preferably 0 or 1.

[0043] X, is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified in X ¹ above.

Examples of the aliphatic cyclic group of Y include those similar to those exemplified in the description of the “aliphatic cyclic group” above.

[0044] Specific examples of the structural units represented by the general formulas (a l- ;!) to (al-4) are shown below.

[0045] [Chemical 10]

[ΐΐ¾] [9W) 0]

/ X3d Li ] [] 007412

[n ^ l [6 00]

Κΐ¾] [8 ^ 00]

f / X3J 61- iSS £ Z0 / 800i OAV [] (A0050 l

† 2 H. Hcif

Medium cH & i-

[[STS0

[ΐ¾] [2900]

iC90 / L00rdf / I3d

[Prophet s∞

[OZ ^] [9900]

93

(al-4-28) (a1-4-2?) (el -4-28) Cal- -28) (at--30) As the structural unit (al), one type may be used alone. Two or more types may be used in combination.

Among them, the structural unit represented by the general formula (al-1) is specifically preferred (al-1 1 ;!) to (al-1 16) or (al-1 35) to (al— It is more preferable to use at least one selected from structural units represented by 1 41). Furthermore, as the structural unit (al), in particular, the formula (al—l—l) to the formula (al—:

Including the following general formula (al — 1 01) and formula (al —

41) The following general formula (al — 102) that includes the structural unit is also preferred.

[0057] [Chemical 21]

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ¹¹ represents a lower alkyl group.)

[0058] [Chemical 22]

-(a 1-1 1 02)

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, R ¹² represents a lower alkyl group, h represents an integer of 1 to 3)

In the general formula (al-1-01),! /, And R! / Are the same as R in the general formula (al-1). The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group.

[0060] In the general formula (al-1-02),! /, And R! / Are the same as R in the general formula (al-1). The lower alkyl group for R ^{12 is the same as} the lower alkyl group for R, and a methyl group or an ethyl group is preferred, and an ethyl group is most preferred. h is preferably 1 or 2. 2 is most preferred. [0061] (Al), the amount of the structural unit (al) is against the total of all the structural units that constitute the copolymer (A1), 10 to 80 Monore ^_0/0 Ca Preferably, 20-70 Monore ^_0/0 more preferably Ca, preferably 25 to 50 Monore ^_0/0 Ca is found. By setting it to the lower limit value or more, a pattern can be easily obtained when the resist composition is used, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

[0062] · Structural unit ( _a 2)

In addition to the structural unit (al), the component (Al) preferably further has a structural unit ( _a2 ) derived from an acrylate ester containing a latathone-containing cyclic group! /.

Here, the ratatone-containing cyclic group refers to a cyclic group containing one ring (lataton ring) containing a -o-c (o) structure. The rataton ring is counted as the first ring, and if it is only a rataton ring, it is called a monocyclic group, and if it has another ring structure, it is called a polycyclic group regardless of the structure.

When the (A1) component is used to form the resist film, the lathetone-containing cyclic group in the structural unit ( _a 2) increases the adhesion of the resist film to the substrate, increases the hydrophilicity, This is effective for increasing the affinity with the developer contained.

[0063] The structural unit (a2) is not particularly limited, and any unit can be used.

Specifically, examples of the latatatone-containing monocyclic group include groups in which one hydrogen atom has been removed from γ-petit-latatotone. In addition, examples of the latathone-containing polycyclic group include groups in which one hydrogen atom is removed from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane having a latathone ring.

[0064] More specifically, examples of the structural unit (a2) include structural units represented by the following general formulas (a2;;!) To (a2-5).

[0065] [Chemical 23]

[Wherein, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group, and R ′ is independently a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms. , M is an integer of 0 or 1, and A is an alkylene group having 1 to 5 carbon atoms or an oxygen atom. ]

[0066] R in the general formulas (a2-1) to (a2-5) is the same as R in the general formula (al ") of the structural unit (al).

The lower alkyl group for R ′ is the same as the lower alkyl group for R in the structural unit (al).

Specific examples of the alkylene group of A to C having 5 to 5 carbon atoms include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group.

In general formulas (a2-1) to (a2-5), R ′ is preferably a hydrogen atom in view of industrial availability.

Specific examples of the structural units of the general formulas (a2-1) to (a2-5) are shown below.

[0067] [Chemical 24]

[0068]

[6900]

6Μδ90 / Ζ.00ί <ΙΓ / Χ3ί OS SSS £ Z0 / 800Z OAV

[o oo]

6MS90 / .00Zdf / X3d

£ S £ CZ0 / 800r O

[8] [UOO]

flS90 / L00rdf / I3d SSS 0/800 OAV

[0072] Among these, it is preferable to use at least one selected from the general formulas (a2— ;!) to (a2-5). The general formulas (a2— ;!) to (a2-3) are preferred. It is preferable to use at least one selected from Specifically, chemical formulas (a2 — 1— 1), (a2 — 1— 2), (a2— 2— 1), (a2— 2— 2), (a2— 3— l), (a2— 3) — It is preferable to use at least one selected from (2), (& 2-3-9) and (& 2-3-10).

[0073] In the component (A1), as the structural unit (a2), one type may be used alone, or two or more types may be used in combination.

(A1), the amount of the structural units within the component (a2) is, (A1) relative to the combined total of all structural units constituting the component 5 to 60 Monore ^_0/0 Ca Preferably, 10-60 Monore ^_0/0 Kayori preferably, 20 to 55 Monore ^_0/0 force S more preferred. By containing the structural unit (a2) by setting it to the lower limit value or more, the effects described above can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to obtain a tolerance with other structural units.

[0074] · Structural unit (a3)

The component (Al) is in addition to the structural unit (al) or the structural unit (al) and the structural unit. In addition to (a2), it is preferable to further have a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group! /. By having the structural unit (a3), the hydrophilicity of the component (A1) is increased, the affinity with the developer is increased, the alkali solubility in the exposed area is improved, and the resolution is improved. To do.

Examples of the polar group include a hydroxyalkyl group (fluorinated alkyl alcohol) in which at least one hydrogen atom of a hydroxyl group, cyan group, carboxy group, or alkyl group is substituted with a fluorine atom, and a hydroxyl group is particularly preferable.

Aliphatic hydrocarbon groups include straight-chain or branched hydrocarbon groups (preferably alkylene groups) having a carbon number;! To 10 or polycyclic aliphatic hydrocarbon groups (polycyclic groups). Can be mentioned. As the polycyclic group, for example, a resin for a resist composition for ArF excimer laser can be appropriately selected from among many proposed ones. The polycyclic group preferably has 7 to 30 carbon atoms! /.

Among them, an acrylate ester containing an aliphatic polycyclic group containing a hydroxyalkyl group in which at least one hydrogen atom of a hydroxyl group, a cyano group, a carboxy group, or an alkyl group is substituted with a fluorine atom is induced. The structural unit is more preferable. Examples of the polycyclic group include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane. Among these polycyclic groups, a group obtained by removing two or more hydrogen atoms from adamantane, a group obtained by removing two or more hydrogen atoms from norbornane !, and a group obtained by removing two or more hydrogen atoms from tetracyclododecane. ! / ヽ is industrially preferred.

[0075] As the structural unit (a3), when the hydrocarbon group in the polar group-containing aliphatic hydrocarbon group is a linear or branched hydrocarbon group having 1 to 10 carbon atoms, hydroxy group of acrylic acid is used. A structural unit derived from an ethyl ester is preferred. When the hydrocarbon group is a polycyclic group, a structural unit represented by the following formula (a3-1), a structural unit represented by (a3-2) The structural unit represented by (a3-3) is preferred.

[0076] [Chemical 29]

{aS-3

(In the formula, R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated alkyl group, j is an integer from !! to 3, k is an integer from 1 to 3, and t 'is from 1 to 3 1 is an integer from 1 to 5, and s is an integer from 1 to 3.)

[0077] In the general formulas (a3— ;!) to (a3-3), the halogen atom, lower alkyl group or halogenated lower alkyl group of R is bonded to the α-position of the acrylate ester to form V. Y! /, The same as a halogen atom, a lower alkyl group or a halogenated lower alkyl group.

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

Among these, j is preferably 1, and a hydroxyl group bonded to the 3-position of the adamantyl group is particularly preferable.

In formula (a3-2), k is preferably 1. It is preferred that the cyan group is bonded to the 5th or 6th position of the norbornyl group! / ,!

In formula (a3-3), t ′ is preferably 1. 1 is preferably 1. s is preferably 1. It is preferable that 2-norbornyl group or 3-norbornyl group is bonded to the end of the carboxy group of acrylic acid! /. The fluorinated alkyl alcohol is preferably bonded to the 5th or 6th position of the norbornyl group. Here, the fluorinated alkyl alcohol refers to [(CH) C (C F) OH] bonded to the norbornyl group.

1 + lt 'represents the site. As the structural unit (a3), one type may be used alone, or two or more types may be used in combination.

In the component (A1), the proportion of the structural unit (a3) is preferably 5 to 50 mol% with respect to all the structural units constituting the component (A1). 5 to 25 mol% is even more preferable.

[0081] · Unit ( _a 4)

The copolymer (Al) includes other structural units (a4) other than the structural units (al) to (a3) as long as the effects of the present invention are not impaired.

The structural unit _(a 4) is Do is classified as one of the above structural units (al) ~ (a3)! /, Other structural units are long if limited in particular for an ArF excimer laser Nag, for KrF excimer laser (preferably Can be used for many resists that are conventionally used for resist resins such as ArF excimer laser).

As the structural unit (a4), for example, a structural unit derived from an acrylate ester force containing a non-acid-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those similar to those exemplified in the case of the structural unit (al), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser). A number of hitherto known materials can be used as the resin component of the resist composition.

In particular, at least one selected from a tricyclodecanyl group, an adamantyl group, a tetracyclododecanyl group, an isobornyl group, and a norbornyl group is preferable in terms of industrial availability. These polycyclic groups have a linear or branched alkyl group having 1 to 5 carbon atoms as a substituent! /, Or may be /.

Specifically, as the structural unit (a4), it is possible to display the structures of the following general formulas (a4— ;!) to (a4-5).

[0082] [Chemical 30]

(In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group.)

[0083] The halogen atom, lower alkyl group or halogenated lower alkyl group of the above (a4— ;!) to (a4—R) is a halogen atom or lower alkyl which may be bonded to the α-position of the acrylate ester. When the structural unit (a4) is contained in the component (A1), the structural unit (A1) is added to the total of all the structural units constituting the component (A1). It is preferable that a4) is contained in an amount of 1 to 30 mol%, preferably 10 to 20 mol%.

In the present invention, the component (A1) is preferably a copolymer having the structural units (al), (a2) and (a3). Examples of the force and the copolymer include, for example, a copolymer composed of the structural units (al), (a 2) and (a3), and the structural units (al), (a2), (a3) and (a4). Examples of such a copolymer include:

[0085] The component (A1) is particularly preferably a copolymer having three structural units represented by the following general formula (A-11).

[0086] [Chemical 31]

[0087] In the formula, R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated alkyl group, R ^{1 ()} is a lower alkyl group. ]

In the above general formula (A1-11), it is bonded to the halogen atom, lower alkyl group or halogenated lower alkyl group of R! /, And bonded to the α-position of the acrylate ester! /, , No, a rogen atom, a lower alkyl group or a halogenated lower alkyl group.

The lower alkyl group for R ^{1 () is the same as} the lower alkyl group for R, and a methyl group, most preferably a methyl group or an ethyl group, is most preferred.

[0088] The component (A1) is obtained by polymerizing a monomer that derives each structural unit by a known radical polymerization using a radical polymerization initiator such as azobisisobutyronitrile (AIBN). You can get the power by S.

In addition, the component (A1) includes, for example, HS—CH—CH—CH—C (C

2 2 2

By using a chain transfer agent such as F) OH in combination, C (CF) — O

3 2 3 2

An H group may be introduced. In this way, copolymers in which a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms are introduced have reduced development defects and LER (Line Edge Roughness: uneven unevenness on the line sidewalls). ).

[0089] The mass average molecular weight (Mw) of the component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000 < 5,000 to 20000 most preferred. If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

Further, the dispersity (Mw / Mn) is preferably 1 · 0 to 5 · 0 force S, more preferably 1 · 0 to 3 · 0, and further preferably 1.2 to 2.5. Μη represents the number average molecular weight.

[0090] [(Α2) component]

Component (ii) is preferably a low molecular compound having a molecular weight of 500 or more and 2000 or less and having an acid dissociable, dissolution inhibiting group and a hydrophilic group as exemplified in the description of component (A1) above. 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. The component (A2) is, for example, a part of the hydrogen atom of the hydroxyl group of a low molecular weight phenolic compound known as a heat sensitizer in non-chemically amplified g-line or i-line resist. Anything substituted with a dissolution-inhibiting group is preferred.

Examples of such low molecular weight phenolic compounds include bis (4-hydroxyphenyl) methane, bis (2,3,4 trihydroxyphenyl) methane, 2- (4-hydroxyphenol) -2 ( 4, -Hydroxyphenol) propane, 2- (2, 3, 4 trihydroxyphenyl) -2- (2 ', 3', 4'-trihydroxyphenyl) propane, Tris (4-hydroxyphenol) methane Bis (4hydroxy-1,3,5 dimethylphenyl) 1-2 hydroxyphenylmethane, bis (4-hydroxy-2,5 dimethylphenyl) 1-2 hydroxyphenylmethane, bis (4hydroxy-1,3,5-dimethylphenyl) 1) 1,4-Dihydroxyphenylmethane, bis (4-hydroxy-1,2,5 dimethylphenyl) 1,3,4 Dihydroxyphenylmethane, bis (4hydroxy-3-methyl) Phenyl) 1,3,4-dihydroxyphenylmethane, bis (3-cyclohexyl 4-hydroxy-1-6-methylphenyl) 4-hydroxyphenylmethane, bis (3-cyclohexyl 4-hydroxy-1-6-methylphenyl) ) 3, 4-Dihydroxyphenolinomethane, (4-Hydroxyphenol) isopropyl] — 4— [1, 1-Bis (4-hydroxyphenenole) ethinore] benzene, phenol, m-crezo monole, p Crezo mono Examples include 2, 3, and 4 nuclei of formalin condensates of phenols such as nore or 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.

[0091] As the component (A), one type may be used alone, or two or more types may be used in combination.

In the present invention, the component (A) preferably has no fluorine atom. When the component (A) does not contain a fluorine atom, the effects of the present invention are improved, and in particular, the lithography properties are improved.

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

[0092] <(B) component>

Component (B) is not particularly limited, and has so far been used as an acid generator for chemically amplified resists. Can be used. Examples of such acid generators include onium salt-based acid generators such as odonium salts and sulfonium salts; oxime sulfonate-based acid generators; bisalkyl or bisarylsulfonyldiazomethanes, (Screw

Various types are known, such as nitrobenzyl sulfonate acid generators; imino sulfonate acid generators; disulfone acid generators.

[0093] Examples of the onium salt-based acid generator include an acid generator represented by the following general formula (b-0).

[0094] [Chemical 32]

[Wherein R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group; R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, a straight Chain or branched alkyl group, linear or branched alkyl halide group

Or a linear or branched alkoxy group; R ⁵³ is an optionally substituted aryl group; u "is an integer of 1 to _3. ] General formula (b-0 In the formula (1), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a linear, branched or cyclic fluorinated alkyl group.

The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. . The cyclic alkyl group preferably has 4 to 12 carbon atoms, preferably 5 to 10 carbon atoms, more preferably 6 to 10 carbon atoms, and most preferably 10 to 10 carbon atoms.

The linear or branched fluorinated alkyl group has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Most preferred.

The cyclic alkyl group preferably has 4 to 12 carbon atoms, preferably 5 to 10 carbon atoms, more preferably 6 to 10 carbon atoms, and most preferably 10 to 10 carbon atoms. The fluorination rate of the fluorinated alkyl group (ratio of the number of substituted fluorine atoms to the total number of hydrogen atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. In particular, all hydrogen atoms substituted with fluorine atoms are preferred because the strength of the acid increases.

R ⁵¹ is most preferably a linear alkyl group or a linear fluorinated alkyl group.

[0096] R ⁵² represents a hydrogen atom, a hydroxyl group, a halogen atom, a linear or branched alkyl group, a linear or branched alkyl halide group, or a linear or branched alkoxy group. .

In R ⁵² , examples of the halogen atom include a fluorine atom, a bromine atom, a chlorine atom, and an iodine atom, and a fluorine atom is preferable.

In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably;!-5, in particular;!-4, and more preferably 1-3.

In R ⁵² , the halogenated alkyl group is a group in which at least one or all of the hydrogen atoms in the alkyl group are substituted with halogen atoms. Examples of the alkyl group herein are the same as the “alkyl group” in ² above. Examples of the halogen atom to be substituted are the same as those described above for “no, rogen atom”. In the halogenated alkyl group, 50 to 100% of the total number of hydrogen atoms is substituted with a halogen atom. S Desirable, all substituted!

In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, particularly preferably !! to 4, and more preferably 1 to 3.

Among these, R ⁵² is preferably a hydrogen atom.

[0097] R ⁵³ has a substituent! /, May! /, An aryl group, and the structure of the basic ring (matrix ring) is a naphthyl group or a phenyl group. And anthracenyl group. From the viewpoint of the effect of the present invention and the absorption of exposure light such as ArF excimer laser, a phenyl group is desirable.

Examples of the substituent include a hydroxyl group and a lower alkyl group (straight chain or branched chain, preferably having 1 to 5 carbon atoms, and more preferably a methyl group). it can.

The aryl group of R ⁵³ has no substituent! /, More preferably! / ,.

u "is an integer from 1 to 3, preferably 2 or 3, more preferably 3.

[0098] Preferable examples of the acid generator represented by the general formula (b—O) include the following.

[0099] [Chemical 33]

[0100] Other examples of the onium salt-based acid generator represented by the general formula (b-0) include those represented by the following general formula (b-1) or (b-2). Compounds.

[0101] [Chemical 34]

ε R> 4 "" SO-»(b-2)

[Wherein, “˜”, R ⁵ ”and R ⁶ ” each independently represent an aryl group or an alkyl group; R ⁴ ”represents a linear, branched or cyclic alkyl group or a linear or branched chain Or a cyclic fluorinated alkyl group; 1 ^ "to 1 ^" ⁽ ) represents a single group,

) Represents a single group. ]

[0102] In the formula (b— 1), ¹ “˜! ^” Each independently represents an aryl group or an alkyl group. R ~ ³ "represents at least one aryl group. Of ¹ " ~! ^ ³ ", two or more are preferably aryl groups. All" ~ "are aryl groups. Is most preferred The aryl group of Ri "to" is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms, in which at least one or all of the hydrogen atoms are alkyl groups or alkoxy groups. , It may or may not be substituted with a halogen atom or the like. As the aryl group, an aryl group having 6 to 10 carbon atoms is preferable because it can be synthesized at low cost. Specific examples include a phenyl group and a naphthyl group.

Examples of the alkyl group that may be substituted with a hydrogen atom of the aryl group include a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group, which are preferably alkyl groups having 1 to 5 carbon atoms. Most preferred.

As the alkoxy group, a methoxy group and an ethoxy group are preferred, and an alkoxy group having! To 5 carbon atoms is preferred.

When the hydrogen atom of the aryl group is substituted! /, The halogen atom is preferably a fluorine atom.

R1 as alkyl group "to R ^3", Nag particularly limited for example, the number of carbon atoms;! A ~ 10 linear

And a branched or cyclic alkyl group. 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 Noel group, and a decanyl group. It is. Especially, it is preferable that it is C1-C5 from the point which is excellent in resolution. A methyl group can be mentioned as a more preferable one because it is excellent in resolution and can be synthesized at low cost.

Among these, ¹ “˜! ^” Are most preferably each independently a phenyl group or a naphthyl group.

R ⁴ ″ represents a linear, branched or cyclic alkyl group or a linear, branched or cyclic fluorinated alkyl group.

The linear or branched alkyl group preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and still more preferably 1 to 4 carbon atoms. . The cyclic alkyl group is a cyclic group as indicated by R ¹ ″ and preferably has 4 to 10 carbon atoms, more preferably 4 to 10 carbon atoms. 6 to 6 carbon atoms; 10 Most preferably.

The cyclic fluorinated alkyl group is a cyclic group as shown in the above R ¹ ″, and preferably has 4 to 15 carbon atoms, preferably 4 to 10 carbon atoms. The preferred number of carbons is 6 to 10;

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%. This is because the strength of the acid is increased.

R ⁴ ″ is most preferably a linear or cyclic alkyl group, or a linear or cyclic fluorinated alkyl group.

In formula (b-2), R ⁵ ″ and R ⁶ ″ each independently represent an aryl group or an alkyl group.

At least one of R ⁵ "and R ⁶ " represents an aryl group. It is preferred that all of R ⁵ "and R ⁶ " are aryl groups.

The Ariru group for R ⁵ "and ^{^{R 6", 1 "~!}} ^" Are the same as those described Ariru group

Examples of the alkyl group represented by R ⁵ "and R ⁶ " include the same alkyl groups as those represented by ¹ "~! ^".

Of these, it is most preferred that R ⁵ ″ and R ⁶ ″ are all phenyl groups. "The R ⁴ in the formula (b-1)" Formula (b-2) R ⁴ in the same groups as those described above for.

[0105] Specific examples of the onion salt-based acid generators represented by the formulas (b-1) and (b-2) include diphenols.

Bis (4 tert butylphenyl) odonitrium trifluoromethanesulfonate or

Norefonate, tri (4 methylphenyl) sulfurium trifluoromethanesulfonate, Monophenyl dimethyl sulfone trifluoromethanesulfonate, its heptafunole

Norephonate or its nonafluorobutane sulfonate, (4 methylphenolinole) diphenylate or its nonafluorobutanesulfonate, (4-methoxyphenyl) diphenylate or its nonafnolebutanesulfonate (4 tert butynole) phenenolesnore or its nonafluorobutane sulfonate, diphenyl (1- (4-methoxy) naphthyl) ate or its nonafluorobutane sulfonate, di (1 naphthinore) phenyl sulphonyl is its nonafluorobutane sulfonate Etc. Further, onium salts in which the anion portion of these onium salts is replaced by methanesulfonate, n-propanesulfonate, or n-butanesulfonate Kn-octanesulfonate can also be used.

[0106] Further, in the general formula (b-1) or (b-2), an anion salt system in which the anion part is replaced with an anion part represented by the following general formula (b-3) or (b-4) An acid generator can also be used (the cation moiety is the same as (b-1) or (b-2)).

[0107] [Chemical 35]

... (O ^)

[In the formula, X "represents an alkylene group having 2 to 6 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom; Υ" and Ζ "are each independently at least one hydrogen atom is fluorine. Represents an alkyl group having from 10 to 10 carbon atoms substituted by an atom; ]

[0108] 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 carbon atoms. ~ 5, most preferably 3 carbon atoms.

Υ "and Ζ" 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, Preferably it is C1-C7, More preferably, it is C1-C3.

The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of “アルキル” and “Ζ” is preferably as small as possible within the range of the above-mentioned carbon number for reasons such as good solubility in a resist solvent.

In addition, in the alkylene group of X "or the alkyl group of Υ" and Ζ ", the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength and the higher the energy 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%. Most preferably, it is a perfluoroalkylene group or a perfluoroalkyl group in which all hydrogen atoms are substituted with fluorine atoms.

[0109] In addition, a sulfonium salt having a cation moiety represented by the following general formula (b-5) or (b-6) can also be used as an onion salt-based acid generator.

[0110] [Chemical 36]

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

6

In [0111] R ⁴¹ ~R ^46, alkyl group, even if signaling preferred is a lower alkyl group of 1 to 5 carbon atoms straight-chain or branched alkyl group is more preferred instrument methyl group, Echiru group, Even more preferred are propyl, isopropyl, n-butyl, or tert-butyl.

The alkoxy group is more preferably a methoxy group or an ethoxy group, more preferably a linear or branched alkoxy group, even more preferably an alkoxy group having 1 to 5 carbon atoms. Examples of the hydroxyalkyl group include a hydroxymethyl group, a hydroxyethyl group, and a hydroxypropyl group, which are preferably groups in which at least one hydrogen atom of the alkyl group is substituted with a hydroxy group.

n is preferably 1 or 2, more preferably 1.

n and n are preferably each independently 0 or 1, more preferably 0.

twenty three

n is preferably 1 or 2, more preferably 1.

Four

n is preferably 0 or 1, more preferably 0.

Five

n is preferably 0 or 1, more preferably 1.

6

[0112] 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 the anion part of the onium salt-based acid generators proposed so far It may be the same. For example, the anion portion of the onium salt acid generator represented by the general formula (b—0) (R ⁵¹ — SO—), the general formula (b—l)

Three

Or the anion portion (R ⁴ "— SO or above) of the onium salt-based acid generator represented by (b-2)

3 The anion part etc. which are represented by the general formula (b-3) or (b-4) are mentioned.

Preferred examples of sulfonium salts having a cation moiety represented by the formula (b-5) or (b-6) are given below.

[0113] [Chemical 37]

[0114] [Chemical 38]

[0115] [Chemical 39]

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. It is. Such oxime sulfonate

Since it is widely used for width resist compositions, it can be arbitrarily selected and used.

[0117] [Chemical 40]

(In the formula (B—l), R ³¹ and R ³² each independently represents an organic group.)

[0118] The organic group of R ³¹ and R ^{32 is} a group containing a carbon atom, and an atom other than a carbon atom (for example, a hydrogen atom, an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom (a fluorine atom, a chlorine atom, etc. ) Etc.).

The organic group for R ³¹ is preferably a linear, branched or cyclic alkyl group or aryl group. These alkyl groups and aryl groups may have a substituent. Examples of the substituent include, but are not particularly limited to, a fluorine atom, a linear, branched or cyclic alkyl group having 6 to 6 carbon atoms. Here, “having a substituent” means that at least one or all of the hydrogen atoms of the alkyl group or aryl group are substituted with a substituent. Means.

The alkyl group as the organic group of R ³¹ is preferably 1 to 20 carbon atoms, preferably 10 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 6 to 6 carbon atoms. Most preferred is carbon number;! ~ 4. Among these, as the alkyl group of the organic group of R ³¹ , a partially or completely halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group! /) May be particularly preferable. The partially halogenated alkyl group means an alkyl group in which at least one hydrogen atom is substituted with a halogen atom, and the fully halogenated alkyl group means that all the hydrogen atoms are halogenated. An alkyl group substituted with an atom. 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 as the organic group for R ³¹ is most preferably 4 to 20 carbon atoms, preferably 6 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms. As the aryl group, a partially or completely halogenated aryl group is particularly preferable. A partially halogenated aryl group means an aryl group in which at least one of the hydrogen atoms is replaced with a halogen atom, and a fully halogenated aryl group means a hydrogen atom. This means an aryl group in which all are replaced by halogen atoms. 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.

R ³¹ is particularly preferably an alkyl group having 1 to 4 carbon atoms having no substituent or a fluorinated alkyl group having 1 to 4 carbon atoms! /.

As the organic group for R ³² , a linear, branched or cyclic alkyl group, aryl group, or cyan group is preferable. Examples of the alkyl group and aryl group for R ³² include the same alkyl groups and aryl groups as those described above for R ³¹ .

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.

[0120] As an oxime sulfonate-based acid generator, more preferred are those represented by the following general formula (

Examples thereof include compounds represented by B-2) or (B-3).

[0121] [Chemical 41] R ^ —Q ^ ~~ O― S0 ₂ —— ^3S

R ³³ • (B-2>

[In the formula (B-2), R ^dd 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. ]

[Chemical 42]

[In the formula (Β-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. R ³⁸ is an alkyl group having no substituent or a halogenated alkyl group. p "is 2 or 3.]

[0123] In the general formula (B- 2), alkyl or halogenated alkyl group which includes no substituent R ³³ has a carbon number of 1 to; C1-8 is preferable instrument carbon 10 Is more preferred. Carbon number 1 to 6 is most preferred. Examples of the halogen atom in the halogenated alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ³³ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

Yes

The fluorinated alkyl group for R ³³ preferably has 50% or more of the hydrogen atom of the alkyl group, more preferably 70% or more, and even more preferably 90% or more. .

[0124] The aryl group of R ³⁴ is a hydrogen atom from an aromatic hydrocarbon ring such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, a phenanthryl group, or the like. And a heteroaryl group in which a part of the 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. An alkyl group in the substituent, The alkyl group or alkoxy group preferably has 1 to 8 carbon atoms;! To 4 forces S, more preferably. Examples of the halogen atom in the halogenated alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The halogenated alkyl group is preferably a fluorinated alkyl group.

[0125] The alkyl group or halogenated alkyl group having no substituent for R ³⁵ has a carbon number of !! to 10 and preferably 1 to 8 and more preferably 1 to 6 Is most preferred. Examples of the halogen atom in the halogenated alkyl group include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ³⁵ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group.

Yes

The fluorinated alkyl group in R ³⁵ preferably has a hydrogen atom of the alkyl group of 50% or more fluorinated, more preferably 70% or more, and still more preferably 90% or more. This is preferable because the strength of the generated acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

[0126] In the general formula (B- 3), the alkyl group or halogenated alkyl group having no substituent group R ^36, it! / No substituent of the R ^33, an alkyl group or halogenated Examples are the same as the alkyl group.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups obtained by further removing 1 or 2 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 those similar to the alkyl group or halogenated alkyl group having no substituent of the above ⁵ .

P "is preferably 2.

[0127] Specific examples of the oxime sulfonate acid generator include α (ρ toluenesulfonyloxyimino) benzyl cyanide, α (ρ chlorobenzenesulfonyloxyimino) benzyl cyanide, α- (4 Benzenesulfonyloxymino) Benzyl cyanide, α (4 12 tallow 2 trifluoromethylbenzenesulfonyloxymino) benzyl cyanide, α (benzenesulfonyloxymino) -4 Nido, α- (Benzenesulfonyloxyimino) -2,4-dichlorodiphenylcyanide, α (benzenesulfonyloxyimino) -2,6-dichlorodiphenylcyanide, α (Benzenesulfonyloxy) Simino) -4-methoxybenzyl cyanide, α (2-chlorobenzylenoxymino) 4-methoxybenzylcyanide, α (benzenesulfonoxyximino) Chen 2-ilacetonitrile, α (4- Dodecylbenzenesulfonyloxymino) Benzyl cyanide, α (ρ Toluenesulfonyloxyimino) 4-methoxyphenoxy] acetonitrile, α [(Dodecylbenzenesulfonyloxyimino) 4-methoxyphenyl] acetonitrile, a (Tosyloxy) Simino) -4 Chelanicyanide, α (Methylsulfonyloxyimino) 1-cyclo Tert-acetonitrile, α (methylsulfonyloxyximino) 1-cyclohexenylacetonitrile, a (methylsulfonyloxyximino) 1-cycloheptulacetonitrile, α (methylsulfonoxyximino) 1-cyclooctatur Acetonitrile, α (trifluoromethylsulfonyloxymino) 1-cyclopentenylacetonitrile, _α (trifluoromethylsulfonyloxymino) -cyclohexylacetonitrile, α (ethylsulfonyloxy) Simino) -ethylacetonitrile, a (propylsulfonyloxyximino) propylacetonitolinole, α (cyclohexylsulfonyloxyimino) -cyclopentylacetonitrinole, α (cyclohexylsulfonyloxyimino) -cyclo Hexylacetonite A (Cyclohexylsulfonyloximino) 1-cyclopentenylacetonitrile, a (Ethylsulfonyloxyimino) 1-Cyclopentenylacetonitrile, α- (Isopropylsulfonyloxyimino) 1-Cyclopentenylrucetonitrile, α- (η-Butylsulfonyloxymino) 1-cyclopentenylacetonitrile, α (Ethylsulfonyloxymino) 1-Cyclohexenylacetonitrile, α (Isopropylsulfonyloxymino) 1-Cyclohexenyla Cetonitrile, α- (η butylsulfonyloxyimino) 1-cyclohexenylacetonitrile, α (methylsulfonyloxyimino) phenylenoacetononitrile, α (methylsulfonyloxyimino) ρ methoxyphenylacetonitrile, a ( bird Ruo b methylsulfonyl O key Consequences mino) Fuenirua acetonitrile, _a (triflate Ruo b methylsulfonyl O key Consequences mino) p-methoxyphenyl Asetonitorinore, alpha (E chill sulfonyl O key Consequences mino) [rho Metokishifue two Ruasetonito Yl, α- (propylsulfonyloxyimino) p methylphenylacetonitrile, α (methylsulfonyloxyimino) ρ bromophenylacetonitrile, etc. Also, JP-A-9 208554 (paragraphs [0012] to [0014] ] [Chemical Formula 18] to [Chemical Formula 19]), oxime sulfonate-based acid generators disclosed in WO2004 / 074242A2 (Examples on pages 65 to 85, examples;! To 40) A system acid generator can also be suitably used.

Moreover, the following can be illustrated as a suitable thing.

[Chemical 43]

[0129] Further, more preferable examples of the oxime sulfonate generator include the following four compounds.

[0130] [Chemical 44]

H3C ~ Q ^ fi ™ OSO2 《CH ₂ GHs

— H

[0131] Among the diazomethane acid generators, specific examples of bisalkyl or bisarylsulfonyldiazomethanes include bis (isopropylsulfonyl) diazomethane, bis (p-toluenenolehoninore) diazomethane, bis (1, 1 -Dimethinoleethinoresnorehoninore) diazomethane, bis (cyclohexenolesnorehoninore) diazomethane, bis (2,4 dimethinolefuinorenorehoninore) 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) pronone, 1,4-bis (disclosed in JP-A-11 322707. Fenenolesno rehonino regiozome chinore les nore hononole) butane, 1, 6-bis (fuenino les reno zoino linole reno inno re) hexane, 1, 10-bis Phonyldiazomethylsulfoninole) decane, 1,2-bis (cyclohexylsulfonyldiazomethylsulfoninole) ethane, 1,3-bis (cyclohexylsulfonyldiazomethylsulphoninole) propane, 1, 6-bis (cyclohexylenoresnorenoinoresinazomethinolesnorehoninole) hexane, 1,10-bis (cyclohexylsulfonyldiazomethylsulfo) Norre) decane, and so on can be force S mentioned.

[0132] As the component (B), one type of these acid generators may be used alone, or two or more types may be used in combination.

In the present invention, it is preferable to use, as the component (B), an onium salt having a fluorinated alkylsulfonic acid anion as an anion among the above.

The content of component (B) is 0.5 to 30 parts by mass, preferably 1 to 10 parts by mass, with respect to 100 parts by mass of component (A). By setting it within the above range, pattern formation is sufficiently performed. Also, A uniform solution is obtained and storage stability is good, which is preferable.

[0133] <Component (C)>

The component (C) has a structural unit (cl) represented by the following general formula (cl 1).

[0134] [Chemical 45]

… [C]

[0135] [Chem 46]

[0136] In the formula (cl 1), the lower alkyl group, halogen atom or halogenated lower alkyl group of R is the same as R in the general formula (al ") in the component (A1) of the component (A). That is, the same as the halogen atom, lower alkyl group or halogenated lower alkyl group mentioned as the substituent at the α-position of the acrylate ester.

R is a hydrogen atom, a fluorine atom, a lower alkyl group or a fluorinated alkyl group. A hydrogen atom or a methyl group is preferable in terms of easy industrial availability, etc.

Yes

Specific examples of the lower alkyl group for R ²¹ and R ²² include a methyl group, an ethyl group, a propylene group, an isopropyl group, an n butyl group, an isobutyl group, a tert butyl group, a pentyl group, an isopentyl group, and a neopentyl group. A linear or branched lower alkyl group can be mentioned, and a methyl group is most preferred, preferably a methyl group or an ethyl group.

In the present invention, it is most preferable that both Sig R ²¹ and R ²² preferred that at least one is a hydrogen atom of R ²¹ and R ²² are hydrogen atoms.

a is preferably an integer of 0 to 2, more preferably 0 or 1, and most preferably 0.

R ²³ is an aliphatic cyclic group having the structure (I) represented by the general formula (I 1).

In the formula (1-1), the fluorinated alkyl group represented by R ²⁴ and R ²⁵ preferably has 1 to 5 carbon atoms, and most preferably 1 to 3 carbon atoms, more preferably 1 to 3 carbon atoms.

The fluorinated alkyl group has a fluorination rate (ratio (%) of “the number of fluorine atoms” to “the total number of fluorine atoms and the number of hydrogen atoms” in the fluorinated alkyl group); 0% is preferred 70-; 100% strength is more preferred, and 100% is most preferred.

R ²⁴ and R ²⁵ are particularly preferably a trifluoromethyl group, preferably a fluorinated alkyl group.

X ²¹ and X ²² are each a carbon atom constituting the ring skeleton of the aliphatic cyclic group having the structure (I).

That is, in the aliphatic cyclic group of R ²³ , part or all of the ring skeleton is constituted by X ²¹ OC—X ²² in the structure (I).

The aliphatic cyclic group for R ²³ is preferably a polycyclic group which may be a monocyclic group or a polycyclic group! /.

Here, a monocyclic group in the aliphatic cyclic group for R ²³ are part of the ring skeleton or all, one aliphatic ring (hereinafter constituted by X ²¹ OC-X ²² in the structure (I) Is a group obtained by removing one or more hydrogen atoms from a specific ring. The polycyclic group is a group obtained by removing one or more hydrogen atoms from a condensed ring composed of the specific ring and an aliphatic ring sharing two or more carbon atoms with the specific ring. As the specific ring structure (I) in X ²¹ OC- all parts of the ring skeleton by X ²² is constructed ring (four-membered ring) and a X ²¹ in Yogu structure (I) also OC- X ²² may be a ring (a ring of 5 or more members) that constitutes part of the ring skeleton! /.

Examples of the five-membered ring or more include, for example, four consecutive carbon atom (CCCC) forces among the carbon atoms constituting the ring skeleton of a monocycloalkane having 5 or more carbon atoms such as cyclopentane and cyclohexane. A ring substituted with X ²¹ OC—X ²² in structure (I) is listed.

The specific ring is preferably a 4- to 6-membered ring.

[0139] In case the aliphatic cyclic group for R ²³ is a polycyclic group, wherein the aliphatic ring constituting a fused ring together with a specific ring, even Yogu polycyclic be monocyclic Good. In addition, the aliphatic ring is preferably saturated, whether saturated or unsaturated. Specific examples of the saturated aliphatic ring include, for example, monocycloalkanes such as cyclopentane and cyclohexane; polycycloalkanes such as norbornane, isobornane, adamantane, tricyclodecane and tetracyclodecane. Among these, cyclohexane or norbornane is preferable, and norbornane is particularly preferable.

[0140] The aliphatic cyclic group of R ²³ has a substituent! /, May! /. Here, “having a substituent” means that a hydrogen atom bonded to the ring skeleton of the aliphatic cyclic group is substituted with a substituent. Examples of the substituent include a lower alkyl group.

[0141] When the aliphatic cyclic group of R ²³ is a polycyclic group, an atom adjacent to R ²³ (when it is a force SO, it is an oxygen atom, and a is an integer from !! to 3 Is a carbon atom.) Is preferably bonded to the carbon atom constituting the aliphatic ring constituting the condensed ring together with the specific ring other than the specific ring.

[0142] In the present invention, R ²³ is preferably a group represented by the following general formula (II 1).

[0143] [Chemical 47]

XJ>,

[In formula (II-l), R ⁴ and are each independently 8 fluorine atoms or fluorinated alkyls.

^ One (

A Le group, R ²⁶ is aralkyl RF Killen group having 1 to 5 carbon atoms, b is an integer of 0 to 2, c is 0 to 2 integer, and b + c is from 0 to 2 It is an integer and d is 0 or 1. ]

In formula (II-1), R ²⁴ and R ²⁵ are the same as R ²⁴ and R ²⁵ in the formula (1-1). R ²⁶ is an alkylene group having 1 to 5 carbon atoms, preferably an alkylene group having 1 to 3 carbon atoms, such as a methylene group, an ethylene group, an n-propylene group, an isopropylene group (one C (CH 3)

3 2

And a linear or branched alkylene group such as Of these, a methylene group is particularly preferable.

b and c are each independently an integer of 0 to 2, and +. Any value that is an integer between 0 and 2 is acceptable. It is most preferable that b = 0 and c = 0, that is, b + c = 0. d is 0 or 1, and preferably 1.

[0145] The group represented by the general formula (II 1) may have a substituent on the ring skeleton. Examples of the substituent include those described above for the aliphatic cyclic group for R ²³ ! /, May! /, And the same as those described as the substituent.

In the present invention, as the structural unit (c l), the following general formula (c l-1 -1) or (cl-1)

The group represented by 2) is particularly preferred, and the group represented by the formula (cl 1 1) is preferred.

[0147] [Chemical 48]

In the formulas (cl 1 1) and (cl 1 2), R is a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group. R ²⁷ and R ²⁸ are each independently a fluorine atom or a fluorinated lower alkyl group, and examples thereof include the same as R ²⁴ and R ²⁵ described above. Most preferably, each of R ²⁷ and R ²⁸ is a trifluoromethyl group.

R ²⁹ is an alkyl group having 1 to 5 carbon atoms. If R ²⁹ there are a plurality, the plurality of R ²⁹ may be different from each Yogu be the same.

f is an integer of 0 to 2, preferably 0 to 1, and most preferably 0.

[0149] (C), the amount of the structural unit (cl) based on the combined total of all structural units constituting the component (C), 50; that mosquitoes preferably 100 Monore ^_0/0, 70; 100 more preferably Monore ^_0/0 Ca, may be 100 Monore ^_0/0. When the proportion of the structural unit (cl) is 50 mol% or more, the effect of the present invention is improved.

[0150] The component (C) may contain a constituent unit other than the constituent unit (cl) (hereinafter referred to as constituent unit (c2)) as long as the effects of the present invention are not impaired.

As the structural unit ( _C2 ), any monomer may be used as long as the monomer that induces the structural unit can be copolymerized with the monomer that induces the structural unit (cl). Specifically, for example, the above (A1

And the structural units (al) to (a4) mentioned in the component).

[0151] Component (C) is a monomer derived from each structural unit, such as azobisisobutyronitrile ( It can be obtained by polymerization by known radical polymerization using a radical polymerization initiator such as AIBN).

In addition, the component (C) includes, for example, HS—CH—CH—CH—C (CF

2 2 2

) C (CF) — OH at the end by using a chain transfer agent such as OH together

3 2 3 2 groups may be introduced. In this way, copolymers introduced with hydroxyalkyl groups in which some of the hydrogen atoms in the alkyl group have been replaced with fluorine atoms reduce development defects and LER (Line Edge Roughness: uneven unevenness on the line sidewalls). ).

[0152] The mass average molecular weight (Mw) of component (C) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but is preferably 2000 to 50000, more preferably 3000 to 30000 < 5,000 to 20000 most preferred. If it is smaller than the upper limit of this range, it is sufficiently soluble in a resist solvent to be used as a resist, and if it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

[0153] As the component (C), any one of these may be used alone, or two or more may be used in combination.

The content of the component (C) in the resist composition for immersion exposure according to the present invention is preferably in the range of 0.;! To 10 parts by mass with respect to 100 parts by mass of the component (i). ; ~ 5 parts by mass are more preferred. When it is at least the lower limit of the above range, the effect of improving the hydrophobicity of the resist composition is excellent, and when it is at most the upper limit, the lithography properties are improved.

[0154] <Optional component>

The resist composition for immersion exposure according to the present invention preferably further contains a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component. This improves the shape of the resist pattern and the post exposure stability of the latent image formed by the pattern-wise exposure of the resist layer.

Since a wide variety of components (D) have already been proposed, aliphatic amines, particularly secondary aliphatic amines, especially tertiary aliphatic amines, can be used arbitrarily from known ones. 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.

As an aliphatic amine, at least one hydrogen atom of ammonia NH has 1 or more carbon atoms.

Three

Examples include amines substituted with up to 12 alkyl groups or hydroxyalkyl groups (alkylamines or alkylalcoholamines) or cyclic amines.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, n-decylamine; jetylamine, gen-n-propylamine, gen-n-heptylamine, di-alkylamine. Dialkylamines such as n-octylamine, dicyclohexylamine; trimethinolemine, 卜 Lucinolemine, 卜 Lyn propynoleamine, 卜 Lyn フ noleamine, 卜 Lyn n-hexyllamine, Toly n-pentylamine, Toly n heptylamine, Toly n Trialkylamines such as otatylamamine, tri-n noninoreamine, tri-n-decaninoleamine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropan Examples thereof include alkyl alcohol amines such as luminamine, di-n-octanolamine, tri-n-octanolamine, etc. Among these, alkyl alcoholamine and trialkylamine are preferred, and alkyl alcoholamine is more preferred. Among the alkyl alcoholamines, triethanolamine and / or triisopropanolamine are most preferred, with alkyl alcoholamines having an alkyl group having 2 to 5 carbon atoms in the alkyl group being 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 ammine) or polycyclic (aliphatic polycyclic ammine).

Specific examples of the aliphatic monocyclic amine include piperidine and piperazine. Aliphatic polycyclic amines having 6 to 10 carbon atoms are preferred. 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.

Component (D) may be used alone or in combination, or two or more may be used in combination. May be.

When component (D) is contained in the resist composition, component (D) is usually used in the range of 0.01 to 5.0 parts by mass with respect to 100 parts by mass of component (A).

[0155] The resist composition for immersion exposure of the present invention includes an organic carboxylic acid as an optional component for the purpose of preventing sensitivity deterioration and improving the resist pattern shape, stability with time, etc. In addition, at least one compound (E) selected from the group consisting of oxalic acid of phosphorus and its derivatives (hereinafter referred to as component (E)) can be contained.

As the organic carboxylic acid, for example, acetic acid, malonic acid, citrate, malic acid, succinic acid, benzoic acid, salicylic acid and the like are suitable.

Examples of phosphorus oxoacids include phosphoric acid, phosphonic acid, and phosphinic acid. Among these, phosphonic acid is particularly preferred.

Examples of the derivative of oxo acid of phosphorus include esters in which the hydrogen atom of the oxo acid is substituted with a hydrocarbon group. Examples of the hydrocarbon group include an alkyl group having 1 to 5 carbon atoms and a carbon number of 6 ~; 15 aryl groups and the like.

Examples of phosphoric acid derivatives include phosphate esters such as di-n-butyl phosphate and diphenyl phosphate.

Examples of phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethylolestenole, phosphonic acid diol n-butyl ester, fenenorephosphonic acid, phosphonic acid diphenenoresestenole, and phosphonic acid dibenzyl ester.

Examples of the phosphinic acid derivatives include phosphinic acid esters such as phenylphosphinic acid.

As the component (E), one type may be used alone, or two or more types may be used in combination.

When component (E) is contained in the resist composition, component (E) is usually used at a ratio of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0156] The resist composition for immersion exposure according to the present invention further contains a miscible additive, for example, an additional resin for improving the performance of the resist film, a surface activity for improving the coating property, if desired. An agent, a dissolution inhibitor, a plasticizer, a stabilizer, a colorant, an antihalation agent, a dye, and the like can be appropriately added and contained. The resist composition for immersion exposure according to the present invention can be produced by dissolving a material in an organic solvent (hereinafter, sometimes referred to as (S) component).

As the component (S), it is sufficient if each component to be used can be dissolved into a uniform solution. Any one of conventionally known solvents for chemically amplified resists can be used. Two or more kinds can be appropriately selected and used.

For example, latones such as γ-butyrolatatatone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-η-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycolol, diethylene glycolol, propylene glycol Polyhydric alcohols such as Nole and dipropylene glycol and derivatives thereof; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; Monoanol ethers such as alcohols or compounds having an ester bond such as monomethyl ether, monoethino ethenore, monopropino oleenore, monobutino ree enore, etc. Is a derivative of a polyhydric alcohol such as a compound having an ether bond such as monophenyl ether; a cyclic ether such as dioxane; methyl lactate, ethyl lactate (Ε L), methyl acetate, ethyl acetate, butyl acetate, pyrubin Esters such as methyl acid, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisonole, ethinolevenoreinoatenore, crezinoremethinoreatenore, diphenenoreethenore, dibenzenore Examples include aromatic organic solvents such as etherenole, phenenole, butinoleenoleetenole, ethinorebenzene, jetinolebenzene, amylbenzene, isopropylenobenzene, toluene, xylene, cymene and mesitylene.

These organic solvents may be used alone or as a mixed solvent of two or more. Of these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and EL are preferable.

A mixed solvent in which PGMEA and a polar solvent are mixed is preferable. The mixing 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. Preferably within range! /.

More specifically, when EL is used as a polar solvent, the mass ratio of PGMEA: EL is The ratio is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. When PGM E is blended as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2, more preferably 3: 7 to 7: Three.

In addition, as the component (S), a mixed solvent of at least one selected from the medium strengths of PGMEA and EL and a γ-bubble outlet is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

The amount of component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate and the like, and is appropriately set according to the coating film thickness. In general, the solid content concentration of the resist composition is 2 -20% by mass, preferably 5 to 15% by mass.

[0158] The material can be dissolved in the component (S) by, for example, mixing and stirring each of the above-mentioned components in a usual manner. If necessary, a dissolver, a homogenizer, a three-roll mill, etc. You may disperse and mix using a disperser. Also, after mixing, you can further filter using a mesh or membrane filter!

[0159] The resist composition for immersion exposure according to the present invention has good lithography characteristics, which are characteristics required for a resist composition used for immersion exposure, and water repellency suitable for immersion exposure. For this reason, it is preferably used for immersion exposure.

In other words, as described above, in the immersion exposure, the portion between the lens and the resist film on the wafer that has been conventionally filled with an inert gas such as air or nitrogen during the exposure is refracted by air. It is a method having a step of performing exposure (immersion exposure) in a state filled with a solvent (immersion medium) having a refractive index larger / than the refractive index. In immersion exposure, when the resist film and the immersion solvent come into contact with each other, elution (substance dissolution) of substances ((B) component, (D) component, etc.) in the resist film into the immersion solvent occurs. Substance elution causes phenomena such as alteration of the resist layer and change in the refractive index of the immersion solvent, and deteriorates lithography properties. The amount of this substance elution is affected by the characteristics of the resist film surface (for example, hydrophilicity / hydrophobicity). For this reason, for example, the elution of the substance is presumed to be reduced by increasing the hydrophobicity of the resist film surface.

Since the resist composition for immersion exposure of the present invention contains a component (C) having a specific structural unit (c 1) containing a fluorine atom, compared to the case where it does not contain the component (C), The resist film formed using the resist composition has high hydrophobicity. Therefore, the present invention According to the positive resist composition, substance elution during immersion exposure can be suppressed.

In addition, the resist composition for immersion exposure according to the present invention also has various lithographic properties as shown in Examples described later. For example, by using the resist composition for immersion exposure according to the present invention, a fine resist pattern having a line width of a line and space (L / S) pattern of 120 nm or less can be formed. In addition, since the component (C) has an aliphatic cyclic group, it has excellent etching resistance, and the etching resistance is particularly high in the aliphatic cyclic group at R ²³ in the general formula (1-1). Is particularly good when is a polycyclic group.

The resist film formed by using the resist composition for immersion exposure according to the present invention contains the component (C), so that the hydrophobicity of the resist film is higher than when the component (C) is not contained. In other words, the contact angle against water, for example, the static contact angle (the angle between the surface of the water droplet on the resist film in the horizontal state and the resist film surface), the dynamic contact angle (when the resist film is tilted, Contact angle when it begins to fall: There are contact angle (forward angle) at the end point in front of the drop direction of water droplets and contact angle (retreat angle) at the end point behind the fall direction), fall angle (resist film) The tilt angle of the resist film changes when the water droplets start to fall when tilted. For example, the higher the hydrophobicity of the resist film, the larger the static contact angle and dynamic contact angle, while the smaller the falling angle.

Here, as shown in FIG. 1, the advancing angle is such that when the plane 2 on which the droplet 1 is placed is gradually tilted, the droplet 1 moves (falls) on the plane 2. The angle Θ between the droplet surface at the lower end la of the droplet 1 and the plane 2 when starting. At this time (when the droplet 1 starts to move (drop) on the plane 2), the angle Θ between the droplet surface at the upper end lb of the droplet 1 and the plane 2 is the receding angle, The tilt angle Θ of plane 2 is the falling angle.

twenty three

In this specification, the static contact angle, the dynamic contact angle, and the sliding angle are measured as follows.

First, a resist composition solution is spin-coated on a silicon substrate, and then heated at 90 ° C. for 90 seconds to form a resist film.

Next, DROP MASTER-700 (manufactured by Kyowa Interface Science Co., Ltd.), AUTO SLIDING ANGLE: SA-30DM (manufactured by Kyowa Interface Science Co., Ltd.), AUTO DIS PENSER: AD- 31 (manufactured by Kyowa Interface Science Co., Ltd.) ) Using a commercially available measuring device such as And force S.

[0161] In the resist composition for immersion exposure according to the present invention, the measured value of the receding angle in the resist film obtained using the resist composition is preferably 55 to 150 degrees. More preferably, 55 to 130 degrees, even more preferably 60 to 100 degrees. When the receding angle is 55 degrees or more, the substance elution suppression effect during immersion exposure is improved. The reason is not clear, but one of the main factors may be related to the hydrophobicity of the resist film. In other words, since the immersion medium is water or other water-based material, it is highly hydrophobic, so that after immersion exposure is performed, the immersion medium is quickly removed from the resist film surface when the immersion medium is removed. It is speculated that the media can be removed! In addition, when the receding angle is 150 degrees or less, the lithography characteristics and the like are good.

For the same reason, the resist composition for immersion exposure according to the present invention preferably has a measured value of the advance angle in a resist film obtained by using the resist composition of 80 ° or more, 85 to 100 °. A certain force is preferable, and it is particularly preferable that the angle is 85 to 95 degrees.

For the same reason, the resist composition for immersion exposure according to the present invention preferably has a measured value of a static contact angle in a resist film obtained by using the resist composition of 70 degrees or more. It is more preferable that the angle is 80 to 90 degrees. The resist composition for immersion exposure according to the present invention preferably has a measured value of the falling angle in a resist film obtained by using the resist composition of 36 ° or less and 10 to 36 °. It is preferable, and it is most preferably 15 to 25 degrees, and most preferably 12 to 30 degrees. If the sliding angle is 36 degrees or less, the substance elution suppression effect during immersion exposure is improved. In addition, when the falling angle is 10 degrees or more, the lithography characteristics and the like are good.

[0162] The above-mentioned various angles (static contact angle, dynamic contact angle (advance angle, receding angle), drop angle, etc.) are determined depending on the composition of the resist composition for immersion exposure, for example, component (C). It can be adjusted by adjusting the blending amount, the proportion of the structural unit (c 1), the type of component (A) and the like. For example, the higher the structural unit (cl) in component (C) and the higher the content of component (C), the higher the hydrophobicity of the resulting resist composition. The angle increases and the falling angle decreases.

[0163] Further, in the present invention, as described above, the liquid is dissolved from the resist film during the immersion exposure. Material elution into the medium is suppressed. Therefore, in the immersion exposure, by using the resist composition for immersion exposure according to the present invention, it is possible to suppress the alteration of the resist film and the change in the refractive index of the immersion solvent. Therefore, the shape of the resist pattern to be formed is improved, for example, by suppressing fluctuations in the refractive index of the immersion solvent.

Further, the contamination of the lens of the exposure apparatus can be reduced, and therefore, it is possible to contribute to the simplification of the process and the exposure apparatus that do not require protective measures against them.

Furthermore, as described above, when immersion exposure is performed using a scanning-type immersion exposure machine as described in Non-Patent Document 1, the immersion medium moves following the movement of the lens. In the present invention, the water followability is high because the hydrophobicity of the resist film is high. In addition, the resist composition for immersion exposure according to the present invention has good lithography properties, and can be used to form a resist pattern without any practical problems when used as a resist in immersion exposure.

Thus, the resist composition for immersion exposure of the present invention has good lithography properties (sensitivity, resolution, etching resistance, etc.), hydrophobicity, substance elution suppression ability, water followability, etc.) It also has the characteristics required for resist materials in immersion exposure.

[0164] <Resist pattern formation method>

Next, the resist pattern forming method of the present invention will be described.

The resist pattern forming method of the present invention includes a step of forming a resist film on a support using the resist composition for immersion exposure of the present invention, a step of immersing the resist film, and the resist film. And developing to form a resist pattern.

A preferred example of the method for forming a resist pattern of the present invention is shown below.

First, the resist composition for immersion exposure of the present invention is applied onto a support with a spinner or the like, and then subjected to pre-beta (post-apply beta (PAB) treatment) to form a resist film.

The support is not particularly limited, and a conventionally known one can be used. For example, a substrate for an electronic component or a substrate on which a predetermined wiring pattern is formed can be exemplified. More specifically, silicon eno, copper, chromium, iron, aluminum, etc. And a glass substrate. As a material for the wiring pattern, for example, copper, ano-remium, nickel, gold or the like can be used.

In addition, the support may be a substrate in which an inorganic and / or organic film is provided on the substrate as described above. An inorganic antireflection film (inorganic BAR C (Bottom Anti-Reflective Coating)) is an example of the inorganic film. Examples of organic films include organic antireflection films (organic BARC) and organic films such as lower organic films in the multilayer resist method. Here, the multilayer resist method refers to at least one organic film (lower layer) on a substrate. Organic film) and at least one resist film (upper resist film) are provided, and the pattern of the lower organic film is patterned using the resist pattern formed on the upper resist film as a mask to form a pattern with a high aspect ratio. It is supposed to be possible. That is, according to the multilayer resist method, the required thickness can be secured by the lower organic film, so that the resist film can be thinned and a fine pattern with a high aspect ratio can be formed.

In the multilayer resist method, basically, a method of making a two-layer structure of an upper resist film and a lower organic film (two-layer resist method) and one or more intermediate layers between the upper resist film and the lower organic film (Three-layer resist method) that is divided into three or more layers (metal thin film etc.)

[0166] After the resist film is formed, an organic antireflection film may be further provided on the resist film to form a three-layer laminate including a support, a resist film, and an antireflection film. The antireflection film provided on the resist film is preferably soluble in an alkali developer.

[0167] The steps up to here can be performed using a known technique. The operating conditions and the like are preferably set as appropriate according to the composition and characteristics of the resist composition for immersion exposure to be used.

[0168] Next! /, The resist film obtained above is selectively subjected to liquid immersion lithography through a desired mask pattern. At this time, the space between the resist film and the lens at the lowest position of the exposure apparatus is previously filled with a solvent (immersion medium) having a refractive index larger than the refractive index of air, and exposure (immersion exposure) is performed in this state. Do.

The wavelength used for the exposure is not particularly limited, and can be performed using radiation such as an ArF excimer laser, a KrF excimer laser, or an F laser. Resist group which is effective in the present invention The composition is effective for KrF or ArF excimer lasers, especially ArF excimer lasers.

[0169] As the immersion medium, a solvent having a refractive index that is larger than the refractive index of air and smaller than the refractive index of the resist film formed by using the resist composition for immersion exposure V. I like it. The refractive index of the solvent and the solvent is not particularly limited as long as it is within the above range.

Examples of the solvent having a refractive index larger than that of air and smaller than that of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and a hydrocarbon-based solvent.

Specific examples of fluorinated inert liquids include c HC1 F, C F OCH, C F OC H, C

3 2 5 4 9 3 4 9 2 5

Examples include liquids mainly composed of fluorine-based compounds such as HF, and boiling point of 70 to 180 ° C.

5 3 7

Those of 80 to 160 ° C are more preferred. If the fluorinated inert liquid has a boiling point in the above range, the medium used for immersion can be removed after exposure by a simple method, which is preferable.

As the fluorinated inert liquid, a perfluorinated alkyl compound in which all the hydrogen atoms of the alkyl group are replaced with fluorine atoms is particularly preferred! /. Specific examples of the perfluorinated alkyl compound include perfluoroalkyl ether compounds and perfluoroalkylamine compounds.

More specifically, examples of the perfluoroalkyl ether compound include perfluoro (2-butyl monotetrahydrofuran) (boiling point: 102 ° C.). Examples of the perfluoroalkylamine compound include: Raising perfluorotributylamine (boiling point 174 ° C) with force S.

Since the resist composition for immersion exposure according to the present invention is particularly excellent in sensitivity and resist pattern profile shape that are not easily affected by water, water is preferably used as the immersion medium in the present invention. Water is also preferable from the viewpoints of cost, safety, environmental problems, and versatility.

[0170] Next, after the immersion exposure step is completed, post-exposure heating (post exposure beta (P EB)) is performed, followed by development using an alkali developer composed of an alkaline aqueous solution. And preferably, water rinsing is performed using pure water. Water rinse, for example, turn the substrate It can be carried out by dripping or spraying water onto the substrate surface while rolling to wash away the developer on the substrate and the resist composition for immersion exposure dissolved by the developer. Then, drying is performed to obtain a resist pattern in which a resist film (a coating film of a resist composition for immersion exposure) is patterned into a shape corresponding to a mask pattern.

Example

[0171] Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

Resin (A) -1 used as component (A) in the following Examples 1 to 4 and Comparative Example 1 is copolymerized using the following monomers (1) to (3) using a known dropping polymerization method. I got it.

[0172]

[0173] The obtained resin was subjected to GPC measurement, and the mass average molecular weight (Mw) and the dispersity (Mw / Mn) were determined. The Mw of (A) -1 was 10000, and the Mw / Mn was 2.0. Met.

The structure of (A) -1 is shown below. In the formula, the number attached to the lower right of () indicates the ratio (mol%) of each constituent unit to the total of all constituent units constituting the resin.

[0174] [Chemical 50]

[0175] Further, in the following examples;! To 4, as the component (C), the tree essence represented by the following formula (C) 1 (C) -l (Mw = 14300 Mw / Mn = l. .) Was used.

Resin (C) -1 uses a monomer represented by the following chemical formula (C) -0 (manufactured by Central Glass Co., Ltd.) and refers to JP-A-2005-232095 and JP-A-2005-316352. It is a synthesized homopolymer.

[0176] [Chemical 51]

[0177] Examples;! To 4, Comparative Example 1

Each component shown in Table 1 was mixed and dissolved to prepare a positive composition. In the table, “one” indicates no compounding.

[0178] [Table 1]

[0179] Each abbreviation in Table 1 has the following meaning, and the number in [] is the blending amount (part by mass).

(B) -l: a compound represented by the following formula (B) -1: (B) -2: A compound represented by the following formula (B) -2.

(D) — 1: Triethanolamine.

(S) — 1: Mixed solvent with PGMEA / PGME = 60/40 (mass ratio).

[0180] [Chemical 52]

[0181] The following evaluation was performed using the obtained resist composition.

Use the following procedure to measure the static contact angle, dynamic contact angle (advance angle and receding angle), and fall angle (hereinafter collectively referred to as contact angle, etc.) of the resist film surface before and after exposure. Thus, the hydrophobicity of the resist film was evaluated.

The organic anti-reflective coating composition “ARC-29A” (trade name, manufactured by Pruss Science Co., Ltd.) was applied onto an 8-inch silicon wafer using a spinner and baked on a hot plate at 205 ° C. for 60 seconds. By drying, an organic antireflection film having a thickness of 77 nm was formed. On the antireflection film, the resist compositions of Examples 1 to 4 and Comparative Example 1 are applied using a spinner, pre-betaed on a hot plate at 115 ° C. for 60 seconds, and dried. Thus, a resist film having a thickness of 150 nm was formed.

Water was added dropwise to the surface of the resist film (resist film before exposure), and the contact angle and the like were measured using DROP MASTER-700 manufactured by Kyowa Interface Science Co., Ltd.

In addition, a resist film was formed in the same manner as described above, and ArF exposure apparatus NSR-S-302 (manufactured by Nikon Corporation; NA (numerical aperture) = 0 · 60, σ = 0.75) was used. Excimer laser (193 nm) was used for open frame exposure (through a mask! /, Exposure)! /, (Exposure 20 mj / cm ² ), and PEB treatment at 115 ° C for 60 seconds. After PEB treatment, the contact angle on the surface of the resist film (resist film after exposure) was measured in the same manner as described above. [0183] Tables 2 to 3 show the measurement results such as the contact angle of the resist film before and after exposure. In Tables 2 to 3, the ratio of the amount of component (C) to the amount of component (A) in each resist composition (hereinafter simply referred to as “(C) component ratio”. Unit: mass% ).

Also, from these results, a graph was prepared for each of before and after exposure, with the (C) component ratio (mass%) on the horizontal axis and the angle (°) such as contact angle on the vertical axis. This graph is shown in Figs.

As shown in these results, in Examples 1 to 4 in which (A) -1 and (C) -1 were used in combination! /, Compared with Comparative Example 1 in which (C) 1 was not blended As a result, the static contact angle and the dynamic contact angle increased both before and after exposure, and the sliding angle decreased. Also, the difference in contact angle before and after exposure was getting smaller. From these results, it was confirmed that the resist film strength S obtained using the resist compositions of Examples;! To 4 was higher than the resist film obtained using the resist composition of Comparative Example 1. did it.

[0184] [Table 2]

[0185] [Table 3]

<Lithography characterization> "Resolution 'sensitivity"

About the resist composition of Examples 1-2 and Comparative Example 1, the resist pattern was formed in the following procedures, respectively.

A resist film is formed in the same procedure as shown in the hydrophobicity evaluation above, and an ArF exposure device NSR-S-302 (manufactured by Nikon; ΝΑ (numerical aperture) = 0 · 60, 2 / 3 ring illumination), selectively irradiate ArF excimer laser (193nm) through the mask pattern. I shot. Then, PEB processing was performed at 115 ° C for 60 seconds, and further development processing was performed for 30 seconds with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution at 23 ° C. Even in the example using the resist composition, a space-and-line resist pattern (hereinafter referred to as S / L pattern) having a space width of 120 nm and a line width of 120 nm (pitch 240 nm) was formed.

At this time, the optimum exposure dose (Eop) (unit: mj / cm ² (energy amount per unit area)), that is, sensitivity, in which an S / L pattern having a space width of 120 nm and a pitch of 240 nm was formed was obtained. As a result, the sensitivity of Examples ;! to 2 and Comparative Example 1 was 18. Omj / cm ² , which was the same. With each S / L pattern formed by the above Eop! /, Side width SEM (scanning electron microscope, acceleration voltage 800V, product name: S-9220, manufactured by Hitachi, Ltd.) Was measured at five points in the longitudinal direction of the line, and as a result, the force was also calculated as a measure of LWR, which was 3 times the standard deviation (s) (3s). As a result, the value of 3 s was equal to 10 nm in any of the examples using the resist composition. The smaller the value of 3s, the smaller the line width roughness, and the more uniform S / L pattern was obtained.

"MEF (Mask Error Factor)"

In the above Eop, an S / L pattern is formed using a mask pattern that targets an S / L pattern with a line width of 120 nm and a pitch of 260 nm and a mask pattern that targets an S / L pattern with a line width of 130 nm and a pitch of 260 nm. The MEF value was obtained from the following equation.

MEF = I CD CD I / I MD — MD |

130 120 130 120

In the above formula, CD and CD have a line width of 120 nm and a line width of 130 nm, respectively.

130 120

This is the actual line width (nm) of the S / L pattern formed using the target mask pattern. MD and MD are the lines targeted by the mask pattern.

130 120

The width (nm) is MD = 130 and MD = 120. MEF is a fixed pitch.

130 120

When faithfully reapplying mask patterns with different line widths and apertures with the same exposure, This parameter indicates the force that can be expressed and (mask reproducibility). The closer the MEF is to 1, the better the mask reproducibility.

As a result, the MEF was almost the same in any of the resist compositions.

[0189] "Exposure Latitude Margin (EL margin)"

An S / L pattern was formed in the same manner as above except that the exposure amount was changed, and the obtained S / L pattern was observed with a SEM (scanning electron microscope). In each S / L pattern, the space width was , determine the exposure dose that can be formed in the target dimension (120 nm) within a range of ± 5% (i.e. in the range of 114～126Nm), said exposure light quantity and calculates how is within what percentage of that obtained in the above £ ₀ . The larger the value is, the better the EL margin is because the dimensional change of the pattern to be formed is smaller than the exposure change. Note that the EL margin is a range of exposure that can form a resist pattern with a dimension within which the deviation from the target dimension is within a predetermined range when exposure is performed with varying exposure, that is, a resist pattern that is faithful to the mask. It is the range of the exposure amount to be produced.

As a result, the EL margins of Examples 1 and 2 and Comparative Example 1 were almost equal.

[0190] As shown in the above results, the resist compositions of Examples 1 and 2 had the same level of good performance as the resist composition of Comparative Example 1 with respect to various lithography characteristics. From these results, the resist compositions of Examples 1 to 4 containing the component (A), the component (B), and the component (C) can form a resist film with high hydrophobicity, and the lithography properties. It was confirmed that it was also good.

Industrial applicability

[0191] The present invention can provide a resist composition for immersion exposure and a method for forming a resist pattern, which have good lithography properties and have hydrophobicity suitable for immersion exposure. Therefore, the present invention is extremely useful industrially.

Claims

Claims The alkali solubility is changed by the action of an acid, and does not have the structural unit (c 1) represented by the following general formula (cl 1). A resist composition for immersion exposure comprising an acid generator component (B) that is generated and a fluororesin component (C) having the structural unit (cl). [Chemical 1]

[Chemical 2]

[In Formula (1-1), and are each independently a fluorine atom or a fluorinated alkyl group, and X ²¹ and X ²² each constitute a ring skeleton of an aliphatic cyclic group having the structure (I). It is a carbon atom. ]

The resist composition for immersion exposure according to claim 1, wherein R ²³ in the formula (cl 1) is a group represented by the following general formula (II 1). 3]

[In the formula (II-l), R ⁴ and each independently represent a fluorine atom or a fluorinated alkynole group, R ²⁶ represents an alkylene group having 1 to 5 carbon atoms, and b represents an integer of 0 to 2. Yes, c is 0

Is an integer of ˜2, and b + c is an integer of 0 to 2, and d is 0 or 1. ]

[3] The content of the fluororesin component (C) is 0.;! To 10 mass with respect to the substrate component (A).

2. The resist composition for immersion exposure according to claim 1, wherein the resist composition is in the range of%.

[4] The resist composition for immersion exposure according to claim 1, wherein the substrate component (A) is a resin (A1) having an acid dissociable, dissolution inhibiting group and having increased alkali solubility by the action of an acid. .

5. The resist composition for immersion exposure according to claim 4, wherein the resin (A1) has a structural unit (a 1) derived from an acrylate ester having an acid dissociable, dissolution inhibiting group.

6. The resist composition for immersion exposure according to claim 5, further comprising a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

[7] The resist composition for immersion exposure according to claim 5, wherein the resin (A1) further comprises a structural unit (a3) derived from an acrylic ester containing a polar group-containing aliphatic hydrocarbon group. .

[8] The resist composition for immersion exposure according to [6], wherein the resin (A1) further has a structural unit (a3) derived from an acrylic ester containing a polar group-containing aliphatic hydrocarbon group. .

[9] The resist composition for immersion exposure according to claim 1, further comprising a nitrogen-containing organic compound (D).

[10] A support using the resist composition for immersion exposure according to any one of claims;! To 9 A resist pattern forming method including a step of forming a resist film thereon, a step of immersing the resist film, and a step of developing the resist film to form a resist pattern