WO2007138873A1 - Resist composition for immersion exposure, and method for formation of resist pattern - Google Patents

Abstract

Disclosed is a resist composition for immersion exposure, comprising: a resin component (A) whose alkali solubility can be changed by the action of an acid; and an acid-generator component (B) which can generate an acid upon being exposed to light, wherein the acid-generator component (B) comprises an acid-generator (B1) having a cationic moiety represented by the general formula (b1-1). (b1-1) wherein R42 and R43 independently represent an alkyl group, an alkoxy group or a hydroxyl group; and n2 and n3 independently represent an integer ranging from 0 to 2.

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 resist pattern formation method used for a resist pattern forming method including immersion exposure (immersion lithography).

 This application claims priority based on Japanese Patent Application No. 2006-148172 filed with the Japan Patent Office on May 29, 2006, the contents of which are incorporated herein by reference.

 Background art

 [0002] A lithography method is frequently used to manufacture a fine structure in various electronic devices such as semiconductor devices and liquid crystal devices. However, as the device structure becomes finer, the resist pattern becomes finer in the lithography process. It is requested.

 At present, it is possible to form a fine resist pattern with a line width of about 90 nm in the most advanced region using, for example, an ArF excimer laser by a lithography method. Formation is required.

In order to achieve such a fine pattern formation, the development of an exposure apparatus and a corresponding resist is the first.

 As a resist, a chemically amplified resist that achieves high resolution while achieving high resolution, and can use the catalytic reaction and chain reaction of acid generated by irradiation of radiation, with a quantum yield of 1 or more. Is attracting attention and is being actively developed.

 Until now, the base resin of chemically amplified resists has high transparency to KrF excimer laser (248 nm), and polyhydroxystyrene (PHS) and its hydroxyl groups are protected with acid-dissociable, dissolution-inhibiting groups ( PHS resin) and excellent transparency to ArF excimer laser (near 193 nm) The carboxyl group of the resin (acrylic resin) having a structural unit derived from (meth) acrylic ester ester in the main chain In general, a succinate protected with a dissociable, dissolution inhibiting group is used.

Examples of acid dissociable, dissolution inhibiting groups include acetals such as ethoxyethyl groups. Groups, tertiary alkyl groups such as tert butyl group, tert butoxycarbonyl group, tert-butoxycarbonylmethyl group and the like are known. For example, as a structural unit having an acid dissociable, dissolution inhibiting group in a resin component of a conventional ArF resist composition, as shown in Patent Document 1 below, 2-alkyl 2-adamantyl (meth) acrylate, etc. ( A structural unit derived from a tertiary ester compound of (meth) acrylic acid is generally used.

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

[0004] On the other hand, in an exposure apparatus, it is common to shorten the wavelength of a light source to be used, increase the numerical aperture (ΝΑ) of a lens, or increase the aperture. For example, in general, when the resist resolution is about 0.5 μm, the main spectral force of the mercury lamp is about 436 nm. The g-line force of S436 nm is about 0.5 to 0.30 μm. The 248nm KrF excimer laser beam is used at about 0.30 to 0. The ArF excimer laser beam at 193nm is used at about 0.30 and below.

 For further miniaturization, F excimer laser (157nm) and Ar excimer laser

 2 2 The use of 1V (126nm), EUV (extreme ultraviolet light; 13.5nm), EB (electron beam), X-ray, etc. is being studied.

 However, shortening the light source wavelength requires a new expensive exposure apparatus. Also, with high NA, there is a problem that the depth of focus decreases even if the resolution is increased because the resolution and the depth of focus are in a trade-off relationship.

[0005] In such circumstances, a method called immersion exposure (immersion lithography) has been reported (for example, see Non-Patent Documents 1 to 3).

This method uses a solvent having a refractive index larger than the refractive index of air at the time of exposure between a lens, which has been filled with an inert gas such as air or nitrogen, and the resist film on the wafer. It is a method that has a step of performing exposure (immersion exposure) in a state filled with (immersion medium). is there.

 According to such immersion exposure, even when a light source with the same exposure wavelength is used, the same high resolution as when using a light source with a shorter wavelength or using a high NA lens can be achieved, and moreover, It is said that there is no drop in the depth of the point. In addition, immersion exposure can be performed using an existing exposure apparatus. For this reason, immersion exposure is expected to be able to form resist patterns with low cost, high resolution, and excellent depth of focus.In the manufacture of semiconductor devices that require large capital investment, In terms of cost and lithography characteristics such as resolution, it has attracted a great deal of attention as having a great effect on the semiconductor industry. At present, water is mainly considered as the immersion medium.

 In the method of immersion exposure, the resist film is used to prevent penetration of the immersion medium into the resist film formed on the wafer and lens contamination of the exposure apparatus due to sublimation substances from the resist film. A method of forming a resist pattern by providing a top coat (hereinafter sometimes referred to as “protective film”) on top is also performed.

Patent Document 1: JP-A-10-161313

Non-Patent Document 1: Journal of Vacuum Science & Technology B (USA), 1999, No. 17, No. 6, pages 3306-3309.

Non-Patent Document 2: Journal of Vacuum Science & Technology B (USA), 2001, 19th, No. 6, 2353-2 356.

Non-Patent Document 3: Proceedings of SPIE (USA) 2002, 4691, 459-465.

Disclosure of the invention

Problems to be solved by the invention

 However, in immersion exposure, it is actually difficult to form a fine pattern with many unknown points at a level where it can actually be used.

In a conventional resist composition for immersion exposure, as described above, when a top coat is provided on a resist film to form a resist pattern, there are adverse effects on lithography properties. For example, there are problems such as surface roughness of the resist pattern and line width roughness (hereinafter abbreviated as “LWR”) in which the line width of the line pattern becomes non-uniform.

 The present invention has been made in view of the above circumstances, and a resist composition and a resist pattern for immersion exposure that provide good lithography characteristics even when a resist pattern is formed by providing a top coat on a resist film. The problem is to provide a forming method.

 Means for solving the problem

 [0007] The present inventors propose the following means in order to solve the above problems.

 That is, the first aspect (aspect) of the present invention is an immersion liquid containing a resin component (A) whose alkali solubility is changed by the action of an acid and an acid generator component (B) which generates an acid upon exposure. A resist composition for exposure, wherein the acid generator component (B) comprises an acid generator (B1) having a cation moiety represented by the following general formula (bl-1): It is a resist composition for exposure.

 [0008] [Chemical 1]

[Wherein, R ⁴² and R ^4d each independently represent an alkyl group, an alkoxy group or a hydroxy group; n ² and n ³ each independently represent an integer of 0 to 2. ]

Further, the second aspect (aspect) of the present invention is to form a resist film on a substrate using the resist composition for immersion exposure according to the first aspect, to subject the resist film to immersion exposure, A resist pattern forming method including developing a resist film to form a resist pattern. In the present specification and claims, the “structural unit” means a monomer unit (monomer unit) constituting the resin component (polymer).

 “Exposure” is a concept that includes radiation exposure in general.

 Unless otherwise specified, the “alkyl group” includes linear, branched and cyclic monovalent saturated hydrocarbon groups.

 The “lower alkyl group” means an alkyl group having 1 to 5 carbon atoms.

 The invention's effect

 According to the present invention, there are provided a resist composition for immersion exposure and a method for forming a resist pattern, which can provide good lithography characteristics even when a resist pattern is formed by providing a top coat on a resist film.

 BEST MODE FOR CARRYING OUT THE INVENTION

 [0012] «Resist composition for immersion exposure >>

 The resist composition for immersion exposure according to the present invention comprises a resin component (A) whose alkali solubility is changed by the action of an acid (hereinafter referred to as component (A)) and an acid generator component that generates an acid upon exposure. (B) (hereinafter referred to as component (B)), wherein the component (B) contains an acid generator (B1) having a cation moiety represented by the general formula (bl-1)

 [0013] The resist composition for immersion exposure according to 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, the component (A) is an alkali-soluble resin, and a crosslinking agent (C) is further blended in the negative resist composition.

 In a negative resist composition, when an acid is generated from the component (B) by exposure during resist pattern formation, the exposed portion acts to crosslink between the alkali-soluble resin and the crosslinking agent. Occurs and changes to alkali-insoluble.

 As the alkali-soluble coconut resin, the coconut resin having a unit derived from at least one of a- (hydroxyalkyl) acrylic acid or α- (hydroxyalkyl) acrylic acid also having a lower alkyl ester power is selected. A good resist pattern can be formed.

,preferable. In addition, (X (hydroxyalkyl) acrylic acid has a carboxy group bonded to it. Acrylic acid, in which a hydrogen atom is bonded to the α-position carbon atom, and a hydroxyalkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) are bonded to the α-position carbon atom (X-hydroxy Indicates one or both of alkyl acrylic acid α- (Hydroxyalkyl) Atalylate is an arylate in which a hydrogen atom is bonded to the α-position carbon atom to which the carbonyl group is bonded, and a hydroxy group to the α-position carbon atom. One or both of α-hydroxyalkyl acrylates to which an alkyl group (preferably a hydroxyalkyl group having 1 to 5 carbon atoms) is bonded are shown.

 As the crosslinking agent (C), for example, it is usually preferable to use an amino crosslinking agent such as glycoluril having a methylol group or an alkoxymethyl group, which can form a good resist pattern with little swelling. . The amount of the crosslinking agent (C) is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the alkali-soluble resin.

 [0014] When the resist composition for immersion exposure according to the present invention is a positive resist composition, the component (ii) is an alkali-insoluble one having a so-called acid dissociable, dissolution inhibiting group, and at the time of forming the resist pattern. When an acid is generated from the component (Β) by exposure, the acid dissociates the acid dissociable, dissolution inhibiting group, so that the component (Α) becomes alkali-soluble. For this reason, in the formation of the resist pattern, when the resist film obtained by applying the positive resist composition on the substrate is selectively exposed, the exposed portion turns to alkali-soluble while being unexposed. Since the light part remains insoluble in alkali, it can be developed with alkali.

 [0015] In the resist composition for immersion exposure according to the present invention, the component (榭) is a resin component (A1) (hereinafter referred to as the component (A1)) in which the solubility of alcohol is increased by the action of an acid. It is preferable. That is, the resist composition for immersion exposure according to the present invention is preferably a positive resist composition.

 Next, the component (A1) that is preferably used in the positive resist composition for immersion exposure will be described with examples.

[0016] <(Α1) component>

The component (A1) preferably used in a positive resist composition for immersion exposure has a structural unit (al) derived from an acrylate ester group containing an acid dissociable, dissolution inhibiting group. It is preferable. In addition, it is preferable that the (Al) component further has a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group.

 In addition, the component (A1) preferably further has a structural unit (a3) from which an ester ester acrylate containing a polar group-containing aliphatic hydrocarbon group is also derived.

[0017] Here, in the present specification and claims, the "structural unit derived from an acrylate ester force" means a structural unit formed by cleavage of an ethylenic double bond of an acrylate ester. To do.

 “Acrylic acid ester” has a hydrogen atom bonded to the carbon atom at position a, and in addition to the acrylic acid ester, a substituent (atom or group other than a hydrogen atom) is bonded to the carbon atom at position a. It is a concept including things.

 Examples of the substituent include a halogen atom, a lower alkyl group, and a halogenated lower alkyl group. 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.

 In addition, the α position of the structural unit from which the acrylate power is also derived (the carbon atom at the position) means a carbon atom to which a carbo group is bonded, unless otherwise specified. In the acrylate ester, as the lower alkyl group as the substituent at the α-position, specifically, methyl group, ethyl group, propyl group, isopropyl group, η-butyl group, isopropyl group, tert-butyl group, pentyl group And a linear or branched lower alkyl group such as an isopentyl group and a neopentyl group. Examples of the halogenated lower alkyl group as the substitution at the a-position include those in which at least one hydrogen atom is substituted with a halogen atom in the above specific examples of the lower alkyl group.

 In the present invention, it is preferable that a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group is bonded to the α-position of the acrylate ester, and a hydrogen atom, a fluorine atom, a lower alkyl group or A fluorinated lower alkyl group is more preferred, and a hydrogen atom or a methyl group is most preferred from the viewpoint of industrial availability.

[0018] · Unit (al)

The structural unit (al) is derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group. It is a structural unit.

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

Here, the “tertiary alkyl ester” is an ester formed by substitution with a hydrogen atom of a carboxy group, 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 1 C (O) —0—). In this tertiary alkyl ester, when an acid acts, 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.

[0020] Here, the term "aliphatic" in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, compound, or the like that does 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 a carbon atom and a hydrogen atom (hydrocarbon group), but is preferably a hydrocarbon group. Yes.

 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 Specific examples include tert butyl group, tert-amyl group, tert-heptyl group, and the like.

 [0021] The "aliphatic cyclic group" indicates that it is not aromatic !, a monocyclic group or a polycyclic group.

 The “aliphatic cyclic group” in the structural unit (al) preferably has 4 to 20 carbon atoms, and 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 fluorinated lower alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, an oxygen atom (= 0), and the like.

 Except for the substituents of the “aliphatic cyclic group”, the basic ring structure is not limited to a group consisting of carbon and hydrogen (hydrocarbon group), but may be a hydrocarbon group. Favored ,. 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 having 1 to 5 carbon atoms. However, polycycloalkane forces such as monocycloalkanes, bicycloalkanes, tricycloalkanes, and tetracycloalkanes also include groups in which at least one hydrogen atom has been removed. Specifically, monocycloalkanes such as cyclopentane and cyclohexane, groups obtained by removing at least one hydrogen atom from polycycloalkanes such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane. Is mentioned.

 Examples of the acid dissociable, dissolution inhibiting group containing an aliphatic cyclic group include a group having a tertiary carbon atom on the ring skeleton of a cyclic alkyl group, specifically, 2-methyl 2-adamantyl. Group, 2-ethyl-2-adamantyl group and the like. 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 carbo-oxy group (-C (O)-0-) And a group having a group and a branched alkylene group having a tertiary carbon atom bonded thereto.

[0022] [Chemical 2]

[Wherein, R is an atom or atomic group bonded to the α-position carbon atom of the acrylate ester, and is a hydrogen atom, a halogen atom, a lower alkyl group, or a halogenated lower alkyl group; ¹⁵ and R ^{16 each} represents an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). ]

 [0023] "Acetal type acid dissociable, dissolution inhibiting group" is generally bonded to an oxygen atom by substituting a hydrogen atom at the terminal of an alkali-soluble group such as a carboxy group or a hydroxyl group. When an acid is generated by exposure, the acid acts to break the bond between the acetal 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).

 [0024] [Chemical 3]

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

In the above formula, n is preferably an integer of 0 to 2, and 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. Most preferred is a methyl group, preferably a methyl group or an ethyl group.

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) is preferably a group represented by the following general formula (pi-1).

 Examples of the lower alkyl group for Y include the same as the lower alkyl group for R above.

As the aliphatic cyclic group for Y, a number of conventionally proposed monocyclic or polycyclic aliphatic cyclic groups can be appropriately selected from ArF resists and the like. Its carbon atom number is preferably 4-20!

[0026] [Chemical 4]

… ( _P 1 1)

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

[0027] Examples of the lower alkyl group for Y include the same lower alkyl groups as those described above for R.

As the aliphatic cyclic group for Y, many conventionally proposed ArF resists and the like can be appropriately selected from monocyclic or polycyclic aliphatic cyclic groups. Examples thereof are the same as the “aliphatic cyclic group”.

[0028] Further, the acetal type acid dissociable, dissolution inhibiting group includes a group represented by the following general formula (p2).

 [0029] [Chemical 5]

[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. Or R ¹⁷ R ¹⁹ 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 be bonded to form a ring. ]

In R ¹⁷ and R ¹⁸ , the alkyl group preferably has 1 to 15 carbon atoms, and is preferably a straight chain or branched chain ethyl group, and a methyl group is preferred. . In particular, one of R ¹⁷ and R ¹⁸ is preferably a hydrogen atom and the other is a katyl 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, and most preferably a methyl group, more preferably a methyl group.

When R ¹⁹ is cyclic, it is preferably 4 to 15 carbon atoms, more preferably 4 to 12 carbon atoms, and most preferably 5 to 10 carbon atoms. Specifically, it is substituted with a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms !, may! /, Or !!, or not !, monocycloalkane, bicycloalkane, tricyclo Examples thereof include groups in which one or more hydrogen atoms have been removed from a polycycloalkane such as alkane or tetracycloalkane. More specifically, a group in which one or more hydrogen atoms have been removed from a monocycloalkane such as cyclopentane or cyclohexane, or a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane. Etc. Among them, the group is preferred by removing one or more hydrogen atoms from adamantane.

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 tetrahydrobiranyl group and a tetrahydrofuran group.

As the structural unit (al), a structural unit represented by the following general formula (al—0—1) and a structural unit force represented by the following general formula (al—0—2) are selected. It is preferable to use one or more. [0032] [Chemical 6]

[Wherein, R is the same as above; X ¹ represents an acid dissociable, dissolution inhibiting group. ]

[0033] [Chemical 7]

[Wherein, R is the same as above; X ² represents an acid dissociable, dissolution inhibiting group; Y ² represents an alkylene group or an aliphatic cyclic group. ]

 [0034] 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 which may be bonded to the α-position of the acrylate ester or This is the same as the halogeno 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, acetal type acid dissociable, dissolution inhibiting group, and the like. Tertiary alkyl ester type acid dissociable, dissolution inhibiting groups are preferred ヽ

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

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, and the aliphatic cyclic group is the above except that a group in which two or more hydrogen atoms are removed is used. "fat The thing similar to description of a "group cyclic group" can be used.

[0036] Specific examples of the structural unit (al) include structural units represented by the following general formulas (al-1) to (al-4).

[0037] [Chemical 8]

[In the above formula, X ′ represents a tertiary alkyl ester type acid dissociable, dissolution inhibiting group, Y is the same as above; n represents an integer of 0 to 3; m represents 0 or 1; R Is the same as above, and R ¹ ′ and R ² each independently represents a hydrogen atom or a lower alkyl group having 1 to 5 carbon atoms. ]

[0038] At least one of R ¹ 'and R ² ' is preferably a hydrogen atom, and more preferably a hydrogen atom. n is preferably 0 or 1.

[0039] X, is the same as the tertiary alkyl ester type acid dissociable, dissolution inhibiting group exemplified for X ¹ above.

 Examples of the aliphatic cyclic group for Y include the same groups as those exemplified above in the explanation of the “aliphatic cyclic group”.

[0040] Specific examples of the structural units represented by the general formulas (al-1) to (al-4) are shown below.

[0041] [Chemical 9]

ccl

Ten]

] Dimensions 0

[[] Εi

 .

 (丄

.丄 2- CH ₃

[0047] [Chemical 15]

To] [s (48i00) 3 end

[¾3004

 (a1-3-13) (a-3-14) (al-3-15) (a1-3-16)

(a 1-3-21) (al-3-22) (a 1-3-23) (31-3-24)]

]

~ ^4_21) Ca1-4-22) Ca1-4-23) Ca1-4-24) (a1-4-25)

 -4-30) As the structural unit (al), one type may be used alone, or two or more types may be used in combination.

Among these, the structural unit represented by the general formula (al-1) is specifically preferred (al-1 1 1) to (al-1 1-6) or (al-1 35) to (al — It is more preferable to use at least one selected from the constituent unit forces represented by 1-41). Furthermore, as the structural unit (al), in particular, those represented by the following general formula (al-1 01) including structural units of the formula (al 1 1) to the formula (al 1-4), and the formula (al — The following general formula (a 1—102) including the structural units of (1 35) to (al— 1 -41) is also preferred.

[0053] [Chemical 20]

[Wherein, R is as defined above, and R ¹¹ represents a lower alkyl group. ]

 [Chemical 21]

[Wherein, R is the same as defined above, and R represents a lower alkyl group. h represents an integer of 1 to 3 o]

[0055] In general formula (al-1-01), R is the same as described above. The lower alkyl group for R ^{11 is the same as} the lower alkyl group for R, and is preferably a methyl group or an ethyl group! /.

In the general formula (al-1 02), R is the same as described above. Lower alkyl group of R ¹² is the same as the lower alkyl group for R, and most preferably preferred instrument Echiru group is a methyl group or Echiru group. h is preferably 1 or 2, and most preferably 2.

[0057] (A1) the amount of the structural units in the component (al) is, (A1) relative to the total structural units constituting the component 10-80 Monore _^0/0 force S Preferably, 20-70 Monore _^0/0 force more preferably S, 25~50 Monore _^0/0 force S further preferable. By setting it to the lower limit value or more, a pattern can be easily obtained when the positive resist composition for immersion exposure is used, and by setting the upper limit value or less, it is possible to balance with other structural units. .

[0058] · Structural unit (a2)

 In the present invention, the component (A1) preferably has a structural unit (a2) derived from an acrylate ester containing a latathone-containing cyclic group, in addition to the structural unit (al).

 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 component (A1) is used for forming a resist film, the rataton cyclic group in the structural unit (a2) can increase the adhesion of the resist film to the substrate or can have an affinity for a developer containing water. It is effective for raising the level.

As the structural unit (a2), any unit can be used without any particular limitation.

 Specifically, examples of the latatatone-containing monocyclic group include groups in which y-peptidyl latatone force one hydrogen atom is removed. In addition, examples of the latathone-containing polycyclic group include groups obtained by removing one hydrogen atom from a polycycloalkane such as a bicycloalkane, tricycloalkane, or tetracycloalkane having a latathone ring.

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

[0061] [Chemical 22]

[Wherein, R is the same as defined above, R ′ is independently a hydrogen atom, a lower alkyl group, or an alkoxy group having 1 to 5 carbon atoms, and m is an integer of 0 or 1. ]

[0062] R in the general formulas (a2-l) to (a2-5) is the same as R in 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).

 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.

[0063] [Chemical 23]

[0064] [Chemical 24]

iuoe o e7: 120021/090

9009

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§] §] 0

[0068] Among these, it is preferable to use at least one selected from general formulas (& 2-1) to (& 2-5) V, and general formulas (a2-1) to (a2— It is more preferable to use at least one selected from 3). Specifically, the chemical formulas (a2—1—1), (a2—l—2), (a2—2—1), (a2—2—2), (a2—3—l), (a2—3) — It is preferable to use at least one selected from 2), (a2-3-9) and (a2-3-10) U.

 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) based on the combined total of all structural units constituting the component 5 to 60 Monore _^0/0 force S Preferably, 10-50 Monore _^0/0 power S More preferably, it is more preferably 20-50 monole ⁰ / ₀ %. By setting it to the lower limit value or more, the effect of containing the structural unit (a2) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units.

 [0070] · Structural unit (a3)

In the present invention, the component (A1) is added to the structural unit (al) or the structural unit. In addition to the positions (al) and (a2), it is preferable to further have _a structural unit (a3) derived from an acrylate ester group 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.

 Examples of the polar group include a hydroxyl group, a cyano group, a carboxy group, and a hydroxyalkyl group in which at least one hydrogen atom of an alkyl group having 1 to 5 carbon atoms is substituted with a fluorine atom. A hydroxyl group is particularly preferable.

 Examples of the aliphatic hydrocarbon group include a linear or branched hydrocarbon group having 1 to 10 carbon atoms (preferably an alkylene group), and a polycyclic aliphatic hydrocarbon group having 4 to 20 carbon atoms (polycyclic). Formula group). As the polycyclic group, for example, many resins proposed for resist compositions for ArF excimer lasers can be appropriately selected from those used.

 Among them, an acrylic acid 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 having 1 to 5 carbon atoms is substituted with a fluorine atom A structural unit derived from Esterca is more preferred. Examples of the polycyclic group include groups obtained by removing one or more hydrogen atoms from a polycycloalkane such as bicycloalkane, tricycloalkane, and tetracycloalkane. Specific examples include groups in which one or more hydrogen atoms have been removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, or the like. 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, a group obtained by removing two or more hydrogen atoms from tetracyclododecane, These groups are industrially preferred.

 [0071] 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: LO carbon atoms, the hydroxy group of acrylic acid is used. Preferred structural units derived from tilesters 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.

[0072] [Chemical 28]

[Wherein R is the same as above, j is an integer of 1 to 3, k is an integer of 1 to 3, t 'is an integer of 1 to 3, and 1 is an integer of 1 to 5] And s is an integer from 1 to 3. ]

 [0073] In the formula (a3-l), j is preferably 1 or 2, and more preferably 1. When j is 2, it is preferable that the hydroxyl group is bonded to the 3rd and 5th positions of the adamantyl group. When j is 1, a hydroxyl group is preferably bonded to the 3rd position of the adamantyl group.

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

 [0074] In the formula (a3-2), k is preferably 1. The cyan group is preferably bonded to the 5th or 6th position of the norbornyl group.

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

 In the component (A1), as the structural unit (a3), 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 (a3) is, (A1) against the total of all structural units constituting the component 5 to 50 mol _^0/0 is it is preferred instrument 40 mol _^0/0 power Ri preferably, more preferably 5 to 25 mol _^0/0 power. By setting it to the lower limit value or more, the effect of containing the structural unit (a3) can be sufficiently obtained, and by setting it to the upper limit value or less, it is possible to balance with other structural units. [0077] 'Unit (a4)

 The component (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 (a4) is not classified into the above structural units (al) to (a3)! However, other structural units are not particularly limited. Many of them are known to be used in resist resins such as for ArF excimer laser and KrF excimer laser (preferably for ArF excimer laser). Things can be used.

 As the structural unit (a4), for example, a structural unit that is also capable of inducing acrylate ester power including an acid non-dissociable aliphatic polycyclic group is preferable. Examples of the polycyclic group include those exemplified in the case of the structural unit (al), for ArF excimer laser, for KrF excimer laser (preferably for ArF excimer laser). A large number of conventionally known strengths can be used as the oil component of the resist composition.

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

 Specific examples of the structural unit (a4) include those represented by the following general formulas (a4-l) to (a4-5).

[0078] [Chemical 29]

[0079] When the structural unit (a4) is included in the component (A1), the proportion of the structural unit (a4) is (A1 ) It is preferably 1 to 30 mol% with respect to the total of all the structural units constituting the component 10

And more preferably it is 20 mol _^0/0! /,.

[0080] In the present invention, the component (A1) is a resin component (polymer) whose alkali solubility is increased by the action of an acid, and is suitable as a powerful resin component (polymer). Is a copolymer having structural units (al), (a2) and (a3), for example,

For example, the structural units (al), (a2) and (a3)

Examples thereof include copolymers consisting of 2), (a3) and (a4).

[0081] In the present invention, the component (A) is particularly preferably a copolymer (A1-1) containing a combination of structural units represented by the following general formula (A1-1). ,.

[0082] [Chemical 30]

[Wherein, R is the same as defined above. Is a lower alkyl group. ]

[0083] In the formula (A1-1), R is the same as described above, and most preferably a hydrogen atom or a methyl group.

R ² is a lower alkyl group, preferably a methyl group or an ethyl group, and most preferably a methyl group.

[0084] In the component (A), as the copolymer (A1-1), one kind may be used alone, or two or more kinds may be used in combination.

 The content of the copolymer (A1-1) in the component (A) is preferably 70% by mass or more, more preferably 80% by mass or more, and most preferably 100% by mass. . By being above the lower limit of the range, the lithographic characteristics are further improved when a positive resist composition for immersion exposure is obtained.

[0085] Component (A1) is a monomer derived from each structural unit, such as It can be obtained by polymerizing by a known radical polymerization method using a radical polymerization initiator such as Ru (AIBN).

 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 together, the end of — C (CF) —OH group

3 2 3 2 May be introduced. In this way, a copolymer in which a hydroxyalkyl group in which at least one hydrogen atom of the alkyl group is substituted with a fluorine atom is introduced can reduce development defects and LER (line edge roughness: uneven unevenness of the line side wall ( effective in reducing roughness))

[0086] The weight average molecular weight (Mw) of component (A1) (polystyrene conversion standard by gel permeation chromatography) is not particularly limited, but 2,000 to 50,000 is preferred <, 3,000 to 30,000 force Preferable <, 5,000 to 20,000 power is the most preferred! When it is smaller than the upper limit of this range, it has sufficient solubility in a resist solvent to be used as a resist, and when it is larger than the lower limit of this range, dry etching resistance and resist pattern cross-sectional shape are good.

 Further, the degree of dispersion (Mw / Mn) i is preferably 1.0 to 5.0 force S, more preferably 1.0 to 3.0 force S, and most preferably 1.2 to 2.5. Mn represents a number average molecular weight.

 Further, as the component (A1), an alkali-soluble resin component other than the copolymer (A1-1), for example, other high molecular compounds used in conventional positive resist compositions can be used. .

 In the positive resist composition for immersion exposure according to the present invention, the content of the component (A1) should be adjusted according to the resist film thickness to be formed.

[0087] <Component (B)>

 In the resist composition for immersion exposure according to the present invention, the component (B) is an acid generator (B1) having a cation moiety represented by the general formula (bl-1) (hereinafter referred to as the component (B1)). Is included. By including the component (B1), when a resist composition for immersion exposure is used, even if a resist pattern is formed by providing a top coat on the resist film, good lithographic characteristics can be obtained.

Further, the component (B1) can be added in a large amount in the resist composition for immersion exposure. This is thought to be due to the high transparency (suppression of light absorption) in the exposure wavelength band (especially the wavelength band of ArF excimer laser).

In the general formula (bl-1), R ⁴² and R ⁴³ each independently represents an alkyl group, an alkoxy group, or a hydroxy group.

R ⁴² and R ^{43 In} this, the alkyl group is preferably a lower alkyl group having 1 to 5 carbon atoms, and more preferably a linear or branched alkyl group, a methyl group, an ethyl group, or a propyl group. Particularly preferred are a group, n-butyl group and tert-butyl group.

 The alkoxy group is particularly 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.

n ² and n ³ are each independently an integer of 0 to 2, preferably each independently 0 or 1, more preferably 0.

When n ² or n ³ is 2, two R ⁴² or two R ⁴³ may be the same or different from each other.

[0089] The key-on part in the component (B1) is not particularly limited, and any known part of the salt-based acid generator may be used as appropriate.

For example, the general formula “R” SO_ (R ¹⁴ represents a linear, branched or cyclic alkyl group.

 Three

 Or represents a fluorinated alkyl group. ;) ”, A charon part represented by the following general formula (b-3), a charon part represented by the following general formula (b-4), etc. may be used. it can

[0090] [Chemical 31]

[0091] [wherein X "represents a C 2-6 alkylene group in which at least one hydrogen atom is substituted with a fluorine atom; Υ", Ζ "each independently represents at least one hydrogen Represents an alkyl group having 1 to 10 carbon atoms in which the atom is substituted with a fluorine atom.

[0092] In the general formula "R ¹⁴ SO" j, R ¹⁴ represents a linear, branched or cyclic alkyl. Or a fluorinated alkyl group.

The linear or branched alkyl group as R ¹⁴ preferably has 1 to 8 carbon atoms, more preferably 1 to 8 carbon atoms, and more preferably 1 to 4 carbon atoms. Is most preferred.

Most preferably, the cyclic alkyl group as R ¹⁴ has 4 to 15 carbon atoms, preferably 4 to 10 carbon atoms, and more preferably 6 to 10 carbon atoms.

When the fluorinated alkyl group as R ¹⁴ is linear or branched, it is preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms. Most preferably, it has 1 to 4 carbon atoms. When the fluorinated alkyl group is cyclic, it is most preferably 4 to 10 carbon atoms, more preferably 4 to 10 carbon atoms, and most preferably 6 to 10 carbon atoms. The fluorination rate of the fluorinated alkyl group (the ratio of the number of fluorine atoms substituted by fluorination to the total number of hydrogen atoms in the alkyl group before fluorination, the same shall apply hereinafter) is preferably 10 to 100%, more preferably 50 to 100%, especially the force in which all hydrogen atoms are replaced with fluorine atoms.

R ¹⁴ is most preferably a linear or cyclic alkyl group or a fluorinated alkyl group.

 In the general formula (b-3), X ″ is a linear or branched alkylene group in which at least one hydrogen atom is replaced with a fluorine atom, and the alkylene group preferably has carbon number. 2 to 6, more preferably 3 to 5 carbon atoms, and most preferably 3 carbon atoms In the general formula (b-4), Y "and Ζ" each independently represent at least one hydrogen atom. Is a linear or branched alkyl group substituted with a fluorine atom, and the alkyl group preferably has 1 to: LO, more preferably 1 to 7 carbon atoms, and most preferably It has 1 to 3 carbon atoms.

 The carbon number of the alkylene group of X ″ or the carbon number of the alkyl group of Υ ″ and Ζ ″ is preferably as small as possible because the solubility in the resist solvent is good within the above carbon number range.

In addition, the alkylene group of X "or the alkyl group of Υ" and Ζ "is substituted with a fluorine atom. The larger the number of hydrogen atoms, the better the strength of the acid and the better the transparency to high-energy light and electron beams of 200 nm or less. The fluorination rate of the alkylene group or alkyl group is preferably 70 to 100%, more preferably 90 to 100%, and most preferably a perfluoro group in which all hydrogen atoms are substituted with fluorine atoms. An alkylene group or a perfluoroalkyl group;

[0094] As the key-on part of the component (B1), the key-on part represented by the general formula "R ¹⁴ SO" J is

 Three

Preferred R ¹⁴ is more preferably a fluorinated alkyl group.

[0095] Preferred examples of component (B1) are listed below.

[0096] [Chemical 32]

Among these, at least one selected from the acid generator powers represented by the chemical formulas (bl-01) to (bl-03) is particularly preferable.

 Component (B1) can be used alone or in combination.

 In the resist composition for immersion exposure according to the present invention, the content of the component (B1) in the entire component (B) is preferably 40% by mass or more, more preferably 70% by mass or more. Most preferably, it is 100 mass%. By being above the lower limit of the range, the lithography characteristics are improved particularly when a resist pattern is formed by providing a top coat on the resist film.

In the resist composition for immersion exposure according to the present invention, the content of the component (B1) is preferably 1 to 30 parts by mass with respect to 100 parts by mass of the component (A). More preferably, it is 7 to 18 parts by mass. By being above the lower limit of the range, a resist pattern is formed by providing a top coat on the resist film. In this case, the lithography characteristics are improved. On the other hand, storage stability becomes better by being below the upper limit.

 [0098] In component (B), an acid generator (B2) (hereinafter referred to as component (B2)) other than component (B1) may be used in combination with component (B1). Good.

 The component (B2) is not particularly limited as long as it is other than the component (B1), and those that have been proposed as acid generators for chemically amplified resists can be used. Examples of such acid generators include onium salt-based acid generators such as iodine salts and sulfo-um salts; oxime sulfonate-based acid generators; bisalkyl or bisarylsulfol-diazomethanes, Diazomethane acid generators such as (bissulfol) diazomethanes; Nitrobenzyl sulfonate acid generators; Iminosulfonate acid generators

Various kinds such as disulfone-based acid generators are known.

[0099] As the form salt-based acid generator, for example, an acid generator represented by the following general formula (b-0) can be suitably used.

[0100] [Chemical 33]

[Wherein ¹ 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 linear or branched alkyl group, a linear or branched halogenated alkyl group (hereinafter sometimes referred to as a halogenated alkyl group), or a linear or branched chain An alkoxy group; R ⁵³ has a substituent and may be an aryl group; u ″ is an integer of 1 to 3.]

[0102] In the general formula (b- 0), R ⁵¹ represents a linear, branched or cyclic alkyl group, or a straight-chain, 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 most preferably 1 to 4 carbon atoms. The cyclic alkyl group preferably has 4 to 12 carbon atoms, more preferably 5 to 10 carbon atoms, and still more preferably 6 to carbon atoms: LO.

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

 The cyclic fluorinated alkyl group preferably has 4 to 12 carbon atoms, preferably 5 to carbon atoms, more preferably 6 to LO, and most preferably LO.

 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%. The most preferable is that all hydrogen atoms are substituted with fluorine atoms because the strength of the acid is increased.

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

R ⁵² is 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 among them, a fluorine atom is preferred.

In R ⁵² , the alkyl group is linear or branched, and the carbon number thereof is preferably 1 to 5, more preferably 1 to 4, and still more preferably 1 to 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 a halogen atom. 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 the “halogen atom”. In the halogenalkyl group, 50 to 100% of the total number of hydrogen atoms are preferably substituted with halogen atoms, more preferably all are substituted! /.

In R ⁵² , the alkoxy group is linear or branched, and the carbon number thereof is preferably 1 to 5, more preferably 1 to 4, and still more preferably 1 to 3. Among these, a hydrogen atom is preferable.

[0104] R ⁵³ may have a substituent but may be an aryl group, and the structure of the basic ring (matrix ring) may be a naphthyl group, a phenyl group, an anthracene group. In view of the effects of the present invention and the absorption of exposure light such as ArF excimer laser, a phenyl group is preferred.

 Examples of the substituent include a hydroxyl group and a lower alkyl group (straight or branched chain, preferably 5 or less carbon atoms, particularly preferably a methyl group).

As the aryl group for R ⁵³ , those having no substituent are more preferable.

 u "is an integer of 1 to 3, 2 or 3 is preferred, and 3 is more preferred.

 [0105] Preferred examples of the acid generator represented by the general formula (b-0) include the following.

 [0106] [Chemical 34]

[0107] The acid generators represented by the general formula (b—O) can be used alone or in combination of two or more.

 [0108] In addition, other acid salt-based acid generators of the acid generator represented by the general formula (b—O) are represented by, for example, the following general formula (b-1) or (b-2). The compound to be used is also preferably used.

[0109] [Chemical 35] R 'S03 ~ _(b -2)

[Wherein, ,, to ", R ⁵ " and R ⁶ "each independently represents an aryl group or an alkyl group; R ⁴ " represents a linear, branched or cyclic alkyl group or a fluorinated group. Represents an alkyl group; at least one of R ^{lw to} R ³ ″ represents an aryl group, and at least one of R ⁵ ″ and R ⁶ ″ represents an aryl group.]

In the formula (b— 1), ,, and “" each independently represent an aryl group or an alkyl group. Of R ¹ "to R ³ ", at least one represents an aryl group. It is preferred that the above is an aryl group. Most preferably, all of R ^{lw to} R ³ "are aryl groups.

The aryl group of R ^{lw to} R ³ ″ is not particularly limited, for example, an aryl group having 6 to 20 carbon atoms, and in the aryl group, at least one or all of the hydrogen atoms are alkyl groups, The aryl group may or may not be substituted with an alkoxy group, a halogen atom, etc. The aryl group is preferably an aryl group having 6 to: LO, since it can be synthesized at low cost. Examples thereof include a phenol group and a naphthyl group.

 Examples of the alkyl group on which the hydrogen atom of the aryl group may be substituted 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. That is the most preferred.

 As the alkoxy group that may be substituted with a hydrogen atom of the aryl group, a methoxy group and an ethoxy group are preferred, with an alkoxy group having 1 to 5 carbon atoms being preferred.

The halogen atom that may be substituted for the hydrogen atom of the aryl group is preferably a fluorine atom.

The “˜” alkyl group is not particularly limited, and examples thereof include a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms. From the viewpoint of excellent resolution, the number of carbon atoms is preferably 1 to 5. Specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, cyclopentyl, hexyl, cyclohexyl, nonyl, -Group, etc. In addition, a methyl group is preferable because it can be synthesized at low cost. Among these, R ^{lw to} R ³ ″ are most preferably a phenyl group or a naphthyl group, respectively.

[0111] 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 shown by the above R ¹ ″, preferably a carbon number of 4 to 15 carbon atoms, more preferably a carbon number of 4 to 10 carbon atoms. Most preferably, the number is from 6 to 10.

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

The cyclic fluorinated alkyl group is a cyclic group as shown in the above R ¹ ″, more preferably 4 to 15 carbon atoms, and further preferably 4 to 10 carbon atoms. Most preferably, it has 6 to 10 carbon atoms.

 The fluorination rate of the fluorinated alkyl group (ratio of fluorine atoms in the alkyl group) is preferably 10 to 100%, more preferably 50 to 100%. It is most preferable because the strength of the acid becomes stronger.

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. Above all, it is preferable that all of R ⁵ "and R ⁶ " are aryl groups!

Examples of the aryl groups of R ⁵ "and R ⁶ " include the same as the aryl groups of,, ~.

As the alkyl group for R ⁵ ″ and R ⁶ ″, the same as the alkyl groups for. Of these, R ⁵ ″ and R ⁶ ″ are most preferably a phenol group.

Examples of R ⁴ ″ in formula (b-2) include the same as “in formula (b-1)”.

[0113] Specific examples of the sodium salt acid generators represented by the formulas (b-1) and (b-2) include trifluoromethanesulfonate or nonafluorobutanesulfonate of diphlo-rhodonium, Bis (4-tert-butylphenol) trifluoromethanesulfonate or nonafluorobutanesulfonate, trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorolob Tansusulfonate, tri (4 methylphenol) sulfurium trifluoromethanesulfonate, heptafluoropropanesulfonate or nonafluorobutanesulfonate, dimethyl (4-hydroxynaphthyl) sulfotrifluoromethane Lomethanesulfonate and its heptafluoropropanesulfonate Or its nonafluorobutane sulfonate, monophenyl dimethyl sulfone trifluoromethane sulfonate, its heptafluoropropane sulfonate or its nonafluorobutane sulfonate, diphenol mono methinores noreform trifno Leolomethanesulphonate, its heptafluoropropanol sulphonate or its nonafluorobutane sulphonate, (4-methylphenol) diphenylsulphotrifluoromethanesulphonate, its heptafluoropropane sulphonate or Its nonafluorobutane sulfonate, (4-methoxyphenyl) diphenyl trifonoreomethane sulphonate of snorephonium, its heptafluororeopropane sulphonate or its nonafluorobutane sulphonate, Li (4 tert-butyl) phenolsulfurium trifanololeomethanesulphonate, its heptafluororenopropane sulphonate or its nonafluorobutane sulphonate, diphenol (1 (4-methoxy ) Naphthyl) snorephonium trifonoleolomethane sulphonate, its hepta-fluoro-propanes sulphonate or its nonafluorobutane sulphonate, di (1 naphthyl) -phenyl sulpho-trifluoromethane sulphonate, Examples include heptafluoropropane sulfonate and its nonafluorobutane sulfonate. In addition, ohmic salts in which the ionic part of these ohmic salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

[0114] In addition, in the general formula (b-1) or (b-2), an anion is represented by the general formula (b-3). ) Or (b-4) can be used as an acid salt acid generator substituted with the cation moiety (cation part is the same as (b-1) or (b-2)) .

 [0115] 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 generates an acid upon irradiation with radiation. It has characteristics. Such oxime sulfonate acid generators are widely used for chemically amplified resist compositions and can be arbitrarily selected and used.

 [0116] [Chemical 36]

—— C == N― 0― S0 ₂ —— R ³¹

R ³² , ■. (B-1)

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

[0117] 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. The substituent is not particularly limited, and examples thereof include a fluorine atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms. Here, “having a substituent” means that at least one hydrogen atom of the alkyl group or aryl group is substituted with a substituent.

As the alkyl group, 1 to 20 carbon atoms are preferable. 1 to 10 carbon atoms are more preferable. 1 to 8 carbon atoms are more preferable. 1 to 6 carbon atoms are more preferable. 1 to 6 carbon atoms are more preferable. 4 is most preferred. As the alkyl group, a halogenated alkyl group in which at least one hydrogen atom is replaced with a halogen atom is particularly preferable. More preferably, it is a norogenyl alkyl group in which all of the hydrogen atoms are substituted with a halogen 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 has 4 to 20 carbon atoms that are preferred 4 to: 6 to 1 carbon atoms that LO is more preferred

0 is most preferred. As the aryl group, a halogen aryl group in which at least one hydrogen atom is substituted with a halogen atom is particularly preferable. More preferably, it is a noroalkyl group in which all of the hydrogen atoms are substituted with 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.

As R ³¹ , in particular, an alkyl group having 1 to 4 carbon atoms having no substituent, or 1 carbon atom

~ 4 fluorinated alkyl groups are preferred.

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.

[0119] 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).

[0120] [Chemical 37]

R ³ "--C— N—0 S0 ₂ — R ³⁵

R ³³ (B-2)

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

[0121] [Chemical 38]

P '-·--(B-3)

[In the formula (B-3), R ³⁶ represents a cyano group, an alkyl group having no substituent, or a halogenal. Kill 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.]

[0122] Te you, the general formula (B- 2), Do no substituent of R ^33, an alkyl group or a halogenated alkyl group, 1 to carbon atoms: preferably be a L0 device carbon Numbers 1-8 are more preferred Carbon numbers 1-6 are 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.

The fluorinated alkyl group in R ³³ is preferably fluorinated with 50% or more of the hydrogen atom of the alkyl group, more preferably 70% or more, and even more preferably 90% or more. Is preferred!

[0123] The aryl group of R ³ includes aromatic carbon such as a phenyl group, a biphenyl group, a fluorenyl group, a naphthyl group, an anthracyl group, and a phenanthryl group. Hydrogen ring force A group with one hydrogen atom removed, and a heteroaryl group in which some of the carbon atoms constituting the ring of these groups are substituted with a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom. Etc. 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. 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 alkyl group or halogenoalkyl group in the substituent is preferably 1 to 8 carbon atoms, more preferably 1 to 4 carbon atoms. The halogenoalkyl group is preferably a fluorinated alkyl group. The alkoxy group in the substituent preferably has 1 to 5 carbon atoms.

[0124] The alkyl group or halogenated alkyl group having no substituent of R ³⁵ preferably has 1 to 10 carbon atoms, preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms. Most preferred. Examples of the halogen atom in the above-mentioned halogenoalkyl group include a fluorine atom, a chlorine atom, an odor atom, and an iodine atom.

R ³⁵ is more preferably a fluorinated alkyl group, preferably a halogenated alkyl group. The fluorinated alkyl group in R ^d5 preferably has 50% or more of the hydrogen atom of the alkyl group fluorinated, more preferably 70% or more, and even more preferably 90% or more. This is preferable because the strength of the acid is increased. Most preferably, it is a fully fluorinated alkyl group in which a hydrogen atom is 100% fluorine-substituted.

[0125] In the general formula (B-3), the alkyl group or the halogenated alkyl group having no substituent of R ³⁶ is an alkyl group or a group having no substituent of R ³³ described above. Examples thereof are the same as the halogenalkyl group.

Examples of the divalent or trivalent aromatic hydrocarbon group for R ³⁷ include groups in which the aryl group strength of R ³⁴ is one or two hydrogen atoms removed.

Do no substituent of R ^38, the alkyl group or Harogeni spoon alkyl group, the same alkyl group or Harogeni spoon alkyl group containing no substituent group of the ⁵ like et be.

 P "is preferably 2.

[0126] Specific examples of oxime sulfonate-based acid generators include α- (p-toluenesulfo-oxyximino) monobenzyl cyanide, α- (ρ chlorobenzene-sulfo-oxyoximino) -benzyl cyanide, α- ( 4-Nitrobenzenesulfo-luoxyimino) -Benzyl cyanide, Hiichi (4-troo 2 trifluoromethylbenzenesulfo-ruximino) Benzyl cyanide, α- (Benzenesulfo-ruximino) —4-Clorobenzoylcia-do , Α (Benzenesulfo-ruximino) — 2, 4 dichlorobenzil cyanide, α — (Benzenesulfo-ruximino) — 2, 6 dichlorobenzil cyanide, α (Benzenesulfo-ruximino) 4-methoxybenzyl cyanide , Α-(2-Clorobenzobenzo-Luximinomino) -4-methoxybenzyl cyanide, α-(Benzene Sulfone-ruximino) —Chen—2-ylacetonitrile, at- (4-dodecylbenzenesulfo-ruximino) —benzyl cyanide, α-[(ρ Toluenesulfo-roximino) -4-methoxyphenyl] acetonitrile, α [(Dodecylbenzenesulfo-luoxyimino) -4-methoxyphenyl] acetonitrile, at- (tosyloximino) -4-cercia-do, α (methylsulfo-ruximino) — 1-cyclopente-rucetonitrile, α -(Methylsulfo-ruximino) — 1-cyclohex-l-acetonitrile, α- (Methylsulfo-ruximino) 1-cycloheptulacetonitrile, α (methylsulfo-ruximino) — 1-cyclootatulacetonitrile, at- (Trifluoromethylsulfoxy-mino)-1-cyclopentelucacetonitrile, _α- (Trifluoromethylsulfo-oxyximino) -cyclohexylacetonitrile, α (ethylsulfo-oxyximino) -ethylacetonitrile, OC- (propylsulfo-oxyximino) -propylaceto-tolyl, _α- (cyclohexylsulfo-oxyximino) -cyclopentylacetonitrile, a- (cyclohexylsulfo-oxyximino) -cyclohexylacetonitrile, a- (cyclo Hexylsulfo-Luo Xyimino) — 1-cyclopenteracetonitrile, a- (ethylsulfo-ruximino) — 1-cyclopenteruacetonitrile, α (isopropylsulfo-ruxitimino) — 1-cyclopente-rucetonitrile, a- (η-butylsulfonyloxyimino) ) 1 Shikuropente two Ruasetonitoriru, alpha (Echirusu sulfo - Ruokishiimino) - 1-cyclohexane xenon - Ruasetonitoriru, alpha - (isopropylsulfanyl e - Ruokishiimino) xenon to 1 Shikuro - Ruasetonitoriru, arsenic _(eta - Buchirusuruho - Ruokishiimino) xenon to 1 Shikuro -Lucetonitrile, α (Methylsulfo-Luoxyimino) —Phenolacetonitrile, OC-(Methylsulfo-Luoxyimino) —ρ-Methoxyphenylacetonitrile, α- (Trifluoromethylsulfo-Luoxyimino) —Fuee -Luaceto-tolyl, _α- (trifluoromethylsulfo-ruximino) -p-methoxyphenylacetonitrile, at- (ethylsulfonyloxy-imino) -p-methoxyphenylacetonitrile, α- (propylsulfo- (Luoxyimino) p-methylphenolacetonitrile, α (methylsulfo-Luoxyimino) ρ bromophenylacetonitrile, and the like.

Further, as disclosed in JP-A-9-208554 (paragraphs [0012] to [0014], [Chemical Formula 18] to [Chemical Formula 19]), Ruoxime sulfonate-based acid generator, International Publication No. 04-074242 Pamphlet An oxime sulfonate-based acid generator disclosed in (Examples 40 to 65 on pages 65 to 85) can also be suitably used.

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

[Chemical 39]

[0128] Of the above exemplified compounds, the following four compounds are preferred:

[0129] [Chemical 40]

H ₃ C—— C = N— OS0 ₂ —— (CH ₂ ) ₃ CH ₃

H ₃ C—— C = —— OS0 ₂ (CH ₂ ) ₃ CH3

[0130] Among diazomethane acid generators, specific examples of bisalkyl or bisarylsulfol diazomethanes include bis (isopropylsulfol) diazomethane, bis (p toluenesulfol) diazomethane, bis (1 , 1-dimethylethylsulfol) diazomethane, bis (cyclohexylsulfol) diazomethane, bis (2,4 dimethylphenylsulfol) 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 (bissulfol) diazomethanes include 1,3 bis (phenylsulfol diazomethylsulfol) pronone, 1, 4 disclosed in JP-A-11 322707. Bis (phenylsulfodiazomethylsulfol) butane, 1,6-bis (phenolsulfodiazomethylsulfol) hexane, 1,10-bis (phenolsulfoldiol) Zomethylsulfo) decane, 1,2-bis (cyclohexylsulfodiazomethylsulfo) ethane, 1,3 bis (cyclohexylsulfodiazomethylsulfo) propane, 1,6 bis (cyclohexylsulfo-) (Luazomethylsulfol) hexane, 1,10-bis (cyclohexylsulfoldiazomethylsulfol) decane, and the like.

 [0131] As the component (B2), one type of acid generator may be used alone, or two or more types may be used in combination.

[0132] The content of the component (B) in the resist composition for immersion exposure according to the present invention is 0.5 to 30 parts by mass, preferably 1 to 20 parts by mass with respect to 100 parts by mass of the component (A). The By making it in the above range, pattern formation is sufficiently performed. In addition, a uniform solution is obtained and storage stability is good. It is preferable because it is favorable.

<(D) component>

 In the resist composition for immersion exposure according to the present invention, in order to improve the resist pattern shape, post exposure stability of the latent image formed oy the pattern-wise exposure of the resist layer, etc. Furthermore, it is preferable to contain a nitrogen-containing organic compound (D) (hereinafter referred to as “component (D)”) as an optional component.

 Since a wide variety of components (D) have already been proposed, aliphatic amines, particularly secondary aliphatic amines and tertiary aliphatic amines, can be used arbitrarily from known ones. Is preferred. Here, “aliphatic” in the claims and the specification is a relative concept with respect to aromatics, and is defined to mean a group, a compound, or the like that does not have aromaticity.

 The “aliphatic cyclic group” means a monocyclic group or polycyclic group having no aromaticity. Aliphatic amines contain at least one hydrogen atom of ammonia NH and have 12 or more carbon atoms.

 Three

Examples include amines substituted with alkyl groups or hydroxyalkyl groups below (alkylamines or alkylalcoholamines) or cyclic amines.

 Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-xylamine, n-ptylamine, n-octylamine, n-norlamin, n-decylamine; jetylamine, di-n-propylamine, di-n Dialkylamines such as ptylamine, di-n-octylamine, dicyclohexylamine; —Trialkylamines such as otatylamamine, tri-n-noramine, tri-n-de-ramine, tri-n-dodecylamine; diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine Emissions, di one n- O click pentanol § Min, alkyl alcohols § Min and triethylene one n- Okutanoru Amin like. Among these, tri-n-pentylamine having 5 10 carbon atoms is preferable, and tri-n-pentylamine having tri-n-octylamine is more preferable.

Examples of cyclic amines include heterocyclic compounds containing a nitrogen atom as a hetero atom. Can be mentioned. 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, such as 1, 5 — diazabicyclo [4. 3. 0] — 5-nonene, 1, 8 — diazabicyclo [5 4. 0] — 7-undecene, hexamethylenetetramine, 1,4-diazabicyclo [2.2.2] octane.

 These can be used alone or in combination of two or more.

 Component (D) is usually used in the range of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

<Optional ingredients>

 The resist composition for immersion exposure according to the present invention includes post exposure stability of the latent image formed Dy the pattern-wise exposure of the resist. At least one compound (E) (hereinafter referred to as the (E) component) selected as an optional component for the purpose of improving the resist layer, etc. It can be included. 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 derivatives of phosphorus oxoacids include esters in which the hydrogen atom of the oxoacid 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 phosphoric acid esters such as di-n-butyl phosphate and diphenyl phosphate.

Examples of the phosphonic acid derivatives include phosphonic acid esters such as phosphonic acid dimethyl ester, phosphonic acid diol n-butenoresestenole, phenolinophosphonic acid, phosphonic acid diphenolinoestenole, and phosphonic acid dibenzyl ester. Examples of 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.

 As the component (E), an organic carboxylic acid is preferred, and salicylic acid is particularly preferred. Component (E) is used in a proportion of 0.01 to 5.0 parts by mass per 100 parts by mass of component (A).

[0135] The resist composition for immersion exposure according to the present invention further contains a miscible additive as desired, for example, an additional grease for improving the performance of the resist film, and a surface activity for improving the coating property. 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.

[0136] The resist composition for immersion exposure according to the present invention can be produced by dissolving the material in an organic solvent (hereinafter sometimes referred to as the component (S)).

 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-butyrolatatane; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-η-amyl ketone, methyl isoamyl ketone, 2-heptanone; ethylene glycol, diethylene glycol, propylene glycol, dipropylene Polyhydric alcohols such as glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate or dipropylene glycol monoacetate; the polyhydric alcohols or having the ester bond Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether, etc., or ethers such as monophenyl ether Derivatives of polyhydric alcohols such as compounds having a combination [in these, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME) are preferred]; cyclic ethers such as dioxane Esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; Ether, cresylmethi Aromatic organic solvents such as Noleyatenore, Diphenylenoatenore, Dipenzinoleethenole, Phenene Monore, Butynophenol Ether, Ethylbenzene, Jetylbenzene, Amylbenzene, Isopropylbenzene, Toluene, Xylene, Cymene, Mesitylene, etc. Can be mentioned.

 These organic solvents can 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), EL, and y-butyrolatone are preferred.

 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, but is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. Within range.

 More specifically, when EL is blended as a polar solvent, the mass ratio of PGMEA: EL is preferably 1: 9 to 9: 1, more preferably 2: 8 to 8: 2. 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 among PGMEA and EL and γ-petit-mouth rataton is also preferable. In this case, the mixing ratio of the former and the latter is preferably 70: 30-95: 5.

 Furthermore, as the component (S), the above-mentioned mixed solvent of PGMEA and PGME and the mixed solvent of γ-butyrolattone are also preferred.

 The amount of component (S) used is not particularly limited, but it is a concentration that can be applied to a substrate, etc., and can be appropriately set according to the coating film thickness. It is used so as to be in the range of 20% by mass, preferably 5 to 15% by mass.

 According to the resist composition for immersion exposure of the present invention, good lithography characteristics can be obtained even when a resist pattern is formed by providing a top coat on a resist film.

The reason for this is not clear, but the acid generator (B1) represented by the general formula (bl-1) used in the present invention is light-sensitive in the exposure wavelength band (especially the wavelength band of ArF excimer laser). It is considered that the absorption of is effectively suppressed. For this reason, the resist composition for immersion exposure according to the present invention suppresses light absorption by blending the component (B1), and the resist It is considered that the transparency of the composition is increased.

 Further, it is considered that the component (B1) has good dispersibility in the resist film and is more uniformly distributed in the resist film than a conventional acid generator. For this reason, it is presumed that the acid generated from the component (B1) by exposure can diffuse more uniformly in the resist film than when a conventional acid generator is used.

 For the above reasons, it is considered that good lithography characteristics can be obtained even when a resist pattern is formed by providing a top coat on a resist film.

 According to the resist composition for immersion exposure of the present invention, for example, line width roughness (LWR), resist pattern shape (especially resist pattern surface roughness), mask error factor (MEF), exposure amount margin (EL margin), etc. Resist patterns with good lithography characteristics can be formed.

 The MEF is a parameter that indicates how faithfully a mask pattern of different size can be reproduced when the mask size (line width and space width) is changed with the same exposure amount and a fixed pitch. Yes, the closer the MEF value is to 1, the better the mask reproducibility.

 The EL margin is a parameter indicating the amount of change in the pattern size accompanying the change in exposure amount. The larger the value, the smaller the amount of change.

[0138] <Method for forming resist pattern>

 Next, the resist pattern forming method according to the second aspect of the present invention will be described. The resist pattern forming method according to the present invention uses the resist composition for immersion exposure according to the first aspect of the present invention. It is a method including forming a resist film on a substrate, performing immersion exposure on the resist film, and developing the resist film to form a resist pattern.

[0139] 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 substrate such as a silicon wafer with a spinner and the like, and then subjected to pre-beta (post-apply beta (PAB) treatment) to form a resist film. Form.

At this time, between the substrate and the coating layer of the resist composition, organic or inorganic reflection It is also possible to form a two-layer laminate by providing a protective film.

 Further, a top coat can be provided on the resist film to form a two-layer laminate, and further, a three-layer laminate in which a lower antireflection film is provided can be formed.

[0140] The top coat is not particularly limited, and those usually used for immersion exposure can be used. For example, protective films disclosed in WO05Z019937 pamphlet, WO04 / 074937 pamphlet; Q—NH—SO—R ⁵ (however,

 2

Q is a linear or branched alkylene group having 1 to 5 carbon atoms, and R ⁵ is a fluorinated alkyl group. ), CO—O—R ⁷ (wherein R ⁷ is a fluorinated alkyl group). A main chain cyclic type resin containing a group represented by an organic solvent (an alcohol solvent such as isobutanol) is dissolved. And a protective film formed on the composition cover.

 Here, the term “main chain cyclic type” means that the structural unit constituting the type of resin has a monocyclic or polycyclic ring structure, and preferably at least one ring on the ring structure, preferably Means that two or more carbon atoms have a structural unit constituting the main chain (hereinafter referred to as “main-chain cyclic structural unit”).

 Examples of the main chain cyclic structural unit include a structural unit derived from polycycloolefin (polycyclic olefin), a dicarboxylic acid anhydride-containing structural unit, and the like. Among them, it is preferable to have a structural unit derived from polycycloolefin (polycyclic olefin, preferably norbornene, etc.) in the main chain.

[0141] The topcoat provided on the resist film is preferably soluble in an alkali developer.

 The steps so far can be performed using a known method. 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.

[0142] Next, the resist film obtained as described above is selectively subjected to liquid immersion lithography (Liquid Immersion Lithography) through a desired mask pattern. At this time, the space between the resist film (or top coat) and the lens at the lowest position of the exposure apparatus is filled with a solvent (immersion medium) having a refractive index larger than that of air in advance, and exposure (immersion exposure) is performed in this state. )I 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. Immersion exposure according to the present invention

2

Resist yarn composition for KrF excimer laser or ArF excimer laser, especially ArF Effective for excimer lasers.

 [0143] As described above, in the resist pattern forming method of the present invention, during exposure, the space between the resist film (or top coat) and the lens at the lowest position of the exposure apparatus is filled with the immersion medium, and exposure is performed in this state ( Immersion exposure) is performed.

 At this time, as the immersion medium, a solvent having a refractive index larger than that of air and having a refractive index of a resist film formed by using a resist composition for immersion exposure is preferable. The refractive index of 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 the refractive index of air and smaller than the refractive index of the resist film include water, a fluorine-based inert liquid, a silicon-based solvent, and the like.

[0144] Specific examples of the fluorinated inert liquid include C HC F, C F OCH, C F OC H, C

 3 12 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

 The thing of 80-160 degreeC is more preferable. If the fluorinated inert liquid has a boiling point in the above range, it is preferable that the medium used for immersion can be removed by a simple method after the exposure is completed.

 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: Perfluorotributylamine (boiling point 174 ° C.).

 [0145] The resist composition for immersion exposure according to the present invention is particularly sensitive to water and is excellent in sensitivity and resist pattern profile shape. Therefore, water is used as a solvent having a refractive index higher than that of air. Preferably used. Water also likes cost, safety, environmental issues and versatility.

[0146] Next, after finishing the immersion exposure step, post-exposure heating (post exposure beta (P EB) treatment) is performed, followed by development using an alkaline developer comprising an alkaline aqueous solution. To process. And preferably, water rinsing is performed using pure water. In the water rinse, for example, water is dropped or sprayed on the surface of the substrate while rotating the substrate to wash away the developing solution on the substrate and the resist composition for immersion exposure dissolved by the image solution. 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 in a shape corresponding to the mask pattern.

 Example

 [0147] Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these examples.

[0148] <Resin component (A)>

 Polymer (A) -1 of component (A) used in the examples and comparative examples is shown below. The mass average molecular weight (Mw) and dispersity (MwZMn) of the following polymer (A) -1 are also shown. The mass average molecular weight (Mw) and dispersity (MwZMn) were determined on the basis of polystyrene conversion by gel permeation chromatography (GPC).

 The composition ratio was calculated by carbon NMR. In the chemical formula, the number attached to the lower right of the structural unit indicates the ratio (mol%) of each structural unit in the polymer.

[0149] [Chemical 41]

(Mw: 10000, Mw / Mn: 2.0; synthesized by a known drop polymerization method using monomers for deriving each structural unit.)

<Preparation of positive resist composition solution for immersion exposure>

 (Examples 1-2, Comparative Examples 1-2)

Each component shown in Table 1 was mixed and dissolved to prepare a positive resist composition solution for immersion exposure. In addition, "one" in a table | surface represents not containing. [0151] [Table 1]

[0152] Each abbreviation in Table 1 has the following meaning. The numerical value in [] is the blending amount (part by mass).

 (B) —1: An acid generator represented by the following chemical formula (b l-01).

[0153] [Chemical 42]

 (bi -01)

[0154] (B) —2: Di (1 naphthyl) phenolsulfo-munonafluorobutanesulfonate.

 (B) —3: Triphenylsulfo-munonafluorobutane sulfonate.

 (B) 4: (4 Methylphenol) diphenylsulfo trifluoromethanesulfonate

(D) 1: Tree n—pentylamine.

 (D) -2: Triethanolamine.

 (E) — 1:: Salicylic acid.

 (S) — 1: Ύ Butyrolatathon.

 (S)-2: Mixed solvent with PGMEA / PGME = 6,4 (mass ratio).

 <Evaluation of lithography characteristics>

A resist pattern was formed using the obtained positive resist composition solution for immersion exposure. The following lithography properties were evaluated.

 In addition, the evaluation of the lithographic properties is performed when the top coat is not provided on the resist film (Examples 1 and 2, Comparative Examples 1 and 2) and when the top coat is provided (Example 1 and Comparative Example 1). The resist patterns formed in each were performed.

 Table 2 shows the results without the top coat, and Table 3 shows the results with the top coat.

 [0156] [Resist pattern formation]

 An organic antireflective coating composition “ARC29A” (trade name, manufactured by Brew 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. Then, an organic antireflection film having a thickness of 77 nm was formed. Then, on the antireflection film, the positive resist composition solution for immersion exposure obtained above was applied using a spinner, and each temperature shown in Table 2 and Table 3 was applied on a hot plate. Then, a pre-beta (PAB) treatment was performed under the conditions for 60 seconds and dried to form a resist film having a thickness of 150 nm.

 [0157] Next, when a top coat is provided, a coating liquid 1 for forming a protective film is applied onto the resist film using a spinner and heated at 90 ° C for 60 seconds to obtain a film having a thickness of 35 nm. A top coat was formed.

 Here, the “coating liquid 1 for forming a protective film” is a composition obtained by dissolving, in isobutanol, a resin having a structural unit derived from norbornenka containing a sulfonamide group, represented by the following chemical formula: (Solid content concentration 4% by mass).

[0158] [Chemical 43]

(Mw = 5000, Mw / Mn = l.5; manufactured by Promeras) [0159] Next, ArF excimer laser (193nm) is selectively passed through the mask pattern using ArF exposure system NSR-S302 (Nikon Corporation; NA (numerical aperture) = 0.60, 2/3 ring illumination) Irradiated. Then, at each temperature shown in Tables 2 and 3, carried out after exposure for 60 seconds and pressurized heat (PEB) treatment, further 〖this 23 ° C 〖iron 2.38 mass _^0/0 tetramethylammonium - Line and space (1: 1) resist pattern (LZS pattern) is developed with an aqueous solution of humhydroxide (TMAH) for 30 seconds, rinsed with pure water for 30 seconds, and then shaken and dried. ), And the optimum exposure (sensitivity: Eop, mjZcm ² ) for forming an LZS pattern with a line width of 120 nm and a pitch of 240 nm was determined.

 [0160] [Line Wise Roughness (LWR)]

 In the LZS pattern line width of 120 nm and pitch 240 nm formed by the Eop, five points were measured in the longitudinal direction of the line by the side length SEM (trade name: S-9220, manufactured by Hitachi, Ltd.). The resulting force was also calculated as a measure of LWR, which is 3 times the standard deviation (s) (3s). The results are shown in Table 23.

 The smaller the value of 3s, the smaller the line width roughness, and the more uniform the resist pattern was obtained.

 [0161] [Table 2]

 [0162] [Table 3]

From the results in Table 2, it was confirmed that when no topcoat was provided, Example 12 according to the present invention had a smaller LWR value and a resist pattern with a uniform width than Comparative Example 2. Further, it was confirmed that the LWR value of Example 1 was the same level as that of Comparative Example 1. From the results in Table 3, when a top coat is provided, Example 1 according to the present invention is compared with Comparative Example 1. In addition, it was confirmed that a resist pattern having a uniform width can be obtained with a smaller LWR value. From the results in Tables 2 and 3, L in the case where the top coat is provided in Example 1 according to the present invention.

The WR value was smaller than the LWR value without the top coat, and it was confirmed that the LWR was suppressed even with the top coat.

 On the other hand, in Comparative Example 1, the LWR value when the top coat was provided was larger, and it was confirmed that the LWR was deteriorated by providing the top coat.

[0164] Further, when the shape of the resist pattern surface formed when the top coat was provided was observed with a scanning electron microscope (SEM), Example 1 according to the present invention showed a resist pattern as compared with Comparative Example 1. It was confirmed that the surface roughness was small.

[0165] Also, the mask error factor (MEF) and exposure margin (EL margin)! /, L

In the same manner as WR, the resist pattern formed when the top coat is not provided (Examples 1 and 2, Comparative Examples 1 and 2) and when the top coat is provided (Example 1 and Comparative Example 1), respectively. As a result of evaluation, it was confirmed that Examples 1 and 2 according to the present invention were at the same level as Comparative Examples 1 and 2, respectively.

 [0166] From the above results, it was confirmed that in Example 1 which is effective in the present invention, good lithography characteristics can be obtained even when a resist pattern is formed by providing a top coat on a resist film.

 Industrial applicability

[0167] According to the present invention, there are provided a resist composition for immersion exposure and a method for forming a resist pattern, which can provide good lithography characteristics even when a resist pattern is formed by providing a topcoat on a resist film. Therefore, the present invention is extremely useful in industry.

Claims

A resist composition for immersion exposure comprising a resin component (A) whose alkali solubility is changed by the action of an acid and an acid generator component (B) that generates an acid upon exposure, wherein the acid The generator component (B) has the following general formula (bl— 1)

 [Chemical 1]

[Wherein, R ⁴² and R ^4d each independently represent an alkyl group, an alkoxy group or a hydroxy group; n ² and n ³ each independently represent an integer of 0 to 2. A resist composition for immersion exposure comprising an acid generator (B1) having a cation moiety represented by the formula:

[2] The resist composition for immersion exposure according to claim 1, wherein the content of the acid generator (B1) is in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the resin component (A). object.

[3] The resist composition for immersion exposure according to claim 1 or 2, wherein the resin component (A) is a resin component (A1) whose alkali solubility is increased by the action of an acid.

4. The resist composition for immersion exposure according to claim 3, wherein the resin component (A1) has a structural unit (al) derived from an acrylate ester containing an acid dissociable, dissolution inhibiting group.

[5] The resist composition for immersion exposure according to claim 4, wherein the resin component (A1) further comprises a structural unit (a2) that also induces an acrylate ester-containing force containing a latathone-containing cyclic group.

[6] The resist composition for immersion exposure according to claim 4, wherein the resin component (A1) further comprises a structural unit (a3) derived from an acrylate ester containing a polar group-containing aliphatic hydrocarbon group. object.

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

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

 [9] A resist film is formed on a substrate using the resist composition for immersion exposure according to any one of claims 1 to 8, immersion exposure of the resist film, and the resist film A resist pattern forming method including developing and forming a resist pattern.