WO2008041476A1

WO2008041476A1 - Resist protective film forming composition and process for the formation of resist patterns

Info

Publication number: WO2008041476A1
Application number: PCT/JP2007/068100
Authority: WO
Inventors: Yoko Takebe; Naoko Shirota; Osamu Yokokoji
Original assignee: Asahi Glass Company, Limited
Priority date: 2006-09-29
Filing date: 2007-09-18
Publication date: 2008-04-10
Also published as: JP2009300463A

Abstract

The invention provides a composition for the formation of resist protective films and a process for the formation of resist patterns. A composition for the formation of resist protective films which comprises both a fluoropolymer (F)-containing and alkali -soluble material for resist protective films and a solvent containing at least one fluorine-containing solvent (S) selected from the group consisting of hydrofluorocarbon solvents and hydrofluoro ether solvents and which is to be applied to the surface of a photoresist layer containing a resist polymer (R) which can be enhanced in the solubility in alkali by the action of an acid and has a fluorine content lower than that of the fluoropolymer (F).

Description

Specification

Resist protective film forming composition and resist pattern forming method

Technical field

TECHNICAL FIELD [0001] The present invention relates to a resist protective film forming composition and a method for forming a resist pattern.

Yes

Background art

In the manufacture of integrated circuits such as semiconductors, a mask pattern image obtained by irradiating light from an exposure light source onto a mask is projected onto a photosensitive resist on a substrate, and the pattern image is formed on the photosensitive resist. A transfer lithography method is used. Usually, the pattern image is projected by the scan method. That is, the pattern image is projected by projecting the pattern image onto the photosensitive resist via a projection lens that moves relative to the photosensitive resist. The resolution of the pattern image transferred to the photosensitive resist increases as the light from the exposure light source becomes shorter wavelength light. Therefore, short wavelength light of less than 220 nm (ArF excimer laser, F excimer laser, etc.) is being studied as an exposure light source.

2

[0003] Furthermore, an immersion lithography method that utilizes the phenomenon that the wavelength of light in a liquid medium becomes the reciprocal of the refractive index of the liquid medium, that is, between the lower part of the projection lens and the upper part of the photosensitive resist. In recent years, a method of projecting a mask pattern image onto a photosensitive resist through a projection lens while being filled with a high refractive index liquid medium (hereinafter also referred to as an immersion liquid) has been studied.

In the immersion lithography method, since the space between the projection lens and the photosensitive resist is filled with the immersion liquid, the components of the photosensitive resist (such as a photoacid generator) are eluted in the immersion liquid. There is a concern that the photosensitive resist is swollen by the immersion liquid. Therefore, there is an attempt to suppress elution and swelling of the photosensitive resist by providing a resist protective film layer on the surface of the photosensitive resist in the immersion lithography method.

[0005] As a material for a resist protective film, a fluorine-containing material having a specific contact angle with respect to water and containing a repeating unit formed by polymerization of an acyclic polyfluoroalkyl group-containing acrylate. Polymers are known. For example, the following compound (f ^P l) and the following compound Objects copolymer (b ^P l), or a copolymer of the following compound (fl) and the following compound (b ^P 2), the resist protective film for polymer (see Patent Documents 1 to 3.) Is known It has been.

CH = CH-C (0) 0- (CH) One (CF) CF (fl),

2 2 2 2 7 3

CH = C (CH) -C (0) OH (b ^P l),

twenty three

CH = C (CH) —CH (CH) CH—C (CF) (OH) (b ^P 2).

[0006] In addition, it was obtained by polymerizing a monomer having a C (CF) (OH) group such as the following compounds:

3 2

A resist protective film composition containing an alkali-soluble polymer for a resist protective film and a fluorosurfactant is known (see Patent Document 4).

[0007] [Chemical 1

CH ₂ = CHC (0) 0 ~ ^ Vc (CF ₃ ) ₂ OH

[0008] The resist protective film materials of Patent Documents 1 to 4 are usually prepared in a liquid resist protective film-forming composition by dissolving in a fluorine atom-free organic solvent (alcohol, ester, ketone, etc.). Used. Usually, the resist protective film layer, which is a material strength for the resist protective film, is formed by applying the resist protective film-forming composition onto the surface of the photosensitive resist layer, further removing the organic solvent by heat treatment, This is because it is formed on the surface. Patent Document 2 describes a perfluoroether solvent such as perfluoro-2-ptyltetrahydrofuran as the organic solvent.

Patent Document 5 discloses a fluorine-containing resist protective film-forming composition obtained by dissolving a resist protective film material having an alkali-soluble fluorine-containing polymer power in a specific fluorine-containing alkyl ether or a specific fluorine-containing alkyl ester. Are listed.

Patent Document 6 describes a fluorine-containing resist protective film-forming composition obtained by dissolving a resist protective film material having an alkali-soluble fluoropolymer power in a specific fluorine-containing acetal.

Patent Document 1: Japanese Patent Laid-Open No. 2006-193687

Patent Document 2: International Publication No. 2006/070695

Patent Document 3: Japanese Unexamined Patent Publication No. 2006-243308

Patent Document 4: JP 2005-352384 A Patent Document 5: International Publication No. 2007/007780 Pamphlet

Patent Document 6: Japanese Unexamined Patent Application Publication No. 2007-126582

Disclosure of the invention

Problems to be solved by the invention

[0010] However, none of Patent Documents 1 to 4 has sufficiently studied the influence of the organic solvent in the resist protective film-forming composition on the photosensitive resist layer. For example, Patent Document 1 merely describes a mixed solvent composed of an alcohol and another organic solvent containing no fluorine atom as the organic solvent. According to the study by the present inventors, when the resist protective film layer is provided using the resist protective film forming composition described in Patent Document 1, the accuracy of the resist pattern formed on the photosensitive resist layer is determined. There was a case where the

Further, according to the study by the present inventors, the alkali-soluble resist protective film material containing a fluoropolymer is a stable resist having low compatibility with a perfluoroether solvent. In some cases, the protective film forming composition was not formed.

Patent Document 5 or 6 discusses the influence of a resist protective film-forming composition using a specific fluorine-containing solvent on the photosensitive resist layer. However, the fluorine-containing solvents that have been studied are only specific fluorine-containing organic solvents (fluorine-containing acetals, fluorine-containing alkyl ethers, or fluorine-containing alkyl esters).

[0012] Furthermore, when a resist protective film layer is provided on the surface of the photosensitive resist layer in the immersion lithography method, the immersion liquid follows the projection lens that moves at high speed on the surface of the resist protective film layer. This is desirable from the viewpoint of high-speed implementation of the immersion lithography method. However, there is no known resist protective film material having dynamic and liquid repellency having strength and strength.

The present invention provides a material for a resist protective film, which has excellent dynamic liquid repellency and has strength and strength, from the viewpoint of increasing the speed of an immersion lithography method and forming a resist pattern with high shape accuracy. For the purpose.

Means for solving the problem

[0013] The present inventors provide a specific resist protective film material on the surface of a specific photosensitive resist layer. Acquired knowledge that a resist pattern can be formed with high shape accuracy by an immersion lithography method provided with a resist protective film layer formed from a resist protective film forming composition containing a specific fluorine-based solvent. . Furthermore, the present inventors have found a stable resist protective film forming composition capable of forming a resist protective film layer having excellent dynamic liquid repellency.

That is, the present invention has the following gist.

<1> A resist protective film-forming composition comprising the following resist protective film material and the following solvent, and applied to the surface of the following photosensitive resist layer.

Photosensitive resist layer: A layer containing a resist polymer (R) whose fluorine content is lower than that of the following fluoropolymer (F) and whose alkali solubility is increased by the action of an acid.

Resist protective film material: An alkali-soluble material containing a fluoropolymer (F). Solvent: A solvent containing at least one fluorine-based solvent (S) selected from the group consisting of a noble mouth fluorocarbon solvent and a hyde mouth fluoroether solvent.

<2> The resist protective film-forming composition according to <1>, wherein the resist polymer (R) is a resist polymer containing no fluorine atom.

<3> A monomer in which the resist protective film material has at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, a sulfonic acid group, a sulfonylamide group, an amino group, and a phosphoric acid group The resist protective film-forming composition according to <1> or <2>, comprising an alkali-soluble fluoropolymer (F ^P ) containing a repeating unit (B ^u ) formed by polymerization of (b ^M ).

[0017] <4> Material strength for resist protective film Formula CF = CF— Q ^BM1 — CH = CH

twenty two

Q ^BM1 is formed by polymerization of a polymer (provided that it is a group having a hydroxy group or a carboxy group, an alkylene group or a fluoroalkylene group and having a carbon number;! To 8). <1> to <3>! /, Wherein the composition for forming a resist protective film comprises a fluorine-containing polymer (F ^P1 ) containing repeating units.

[0018] <5> The resist protective film material is a monomer having a fluorine-containing ring structure or a monomer that forms a repeating unit having a fluorine-containing ring structure by cyclopolymerization, The resist protective film-forming composition according to <1> to <3>, comprising a fluorine-containing polymer containing a repeating unit formed by polymerization of S50 to 76% by mass of a monomer. [0019] <6> The resist protective film-forming composition according to any one of <1> to <5>, wherein the solvent is a mixed solvent containing a fluorine-based solvent (S) and an organic solvent not containing a fluorine atom. .

[0020] <7> The fluorine-based solvent (S) is a hydrated fluorocarbon-based solvent.

The resist protective film forming composition according to any one of the above items.

<8> The resist protective film forming composition according to any one of 1> to <7>, wherein the fluorinated solvent (S) is 1,3 bis (trifluoromethyl) benzene.

<9> A method for forming a resist pattern by an immersion lithography method, comprising a polymer whose alkali solubility is increased by the action of an acid on the surface of a substrate, from a fluorine-containing polymer (F). Low fluorine content! / Resist polymer (R) -containing photosensitive resist layer forming step, resist protective film containing the following resist protective film material and the following solvent on the surface of the photosensitive resist layer A step of applying the forming composition, further removing the solvent to form a resist protective film layer on the surface of the photosensitive resist layer, an immersion lithography step, and a step of developing the photosensitive resist layer are performed in this order. By this, the resist pattern formation method of obtaining the base material in which the resist pattern was formed.

Resist protective film material: A material containing an alkali-soluble fluoropolymer (F). Solvent: A solvent containing at least one fluorine-based solvent (S) selected from the group consisting of a noble mouth fluorocarbon solvent and a hyde mouth fluoroether solvent.

The invention's effect

[0023] According to the present invention, a stable resist protective film-forming composition that has excellent resist protective film characteristics (characteristics that suppress swelling and elution of the photosensitive resist, etc.), and that is difficult to denature the photosensitive resist layer, A resist protective film-forming composition having excellent dynamic liquid repellency is provided. According to the present invention, it is possible to implement an immersion lithography method capable of forming a highly accurate resist pattern at high speed.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present specification, the compound represented by the formula (a) is referred to as the compound CFa (CF) (

twenty three

The group represented by OH) (CH) — is also referred to as —CF C (CF) (OH) (CH) —. Other

2 mr 2 3 2 mr

The compound and other groups are described similarly. Further, symbols in the group are as defined above unless otherwise specified. [0025] The present invention is a resist protective film forming composition used by being applied to the surface of the following photosensitive resist layer, comprising the following resist protective film material and the following solvent. I will provide a.

Photosensitive resist layer: A polymer whose alkali solubility is increased by the action of an acid and has a lower fluorine content than the fluorine-containing polymer (F) /, and a layer containing the resist polymer (R).

[0026] The resist protective film forming composition of the present invention makes it possible to form a resist pattern with high shape accuracy. The reason for this is not necessarily clear, but it is considered that the fluorinated solvent (S) is hardly compatible with the resist polymer (R). Therefore, when the composition for forming a resist protective film of the present invention is applied to the surface of the photosensitive resist layer, it is considered that the photosensitive resist layer is not easily modified (swelled, dissolved, etc.) by the solvent. In addition, the fluorinated solvent (S) is a fluorinated solvent partially having a hydrogen atom and is considered highly compatible with the fluorinated polymer (F). Therefore, it is considered that the resist protective film-forming composition of the present invention can easily form a stable liquid composition suitable for forming a uniform coating film.

[0027] The resist polymer (R) in the present invention is a polymer whose alkali solubility is increased by the action of an acid, and has a lower fluorine content than the fluoropolymer (F) /. It is not particularly limited. The resist polymer (R) may be a polymer containing a fluorine atom or a polymer containing no fluorine atom. In the former case, the fluorine content of the resist polymer (R) is preferably 60% by mass or less, particularly preferably less than 30% by mass. Further, the lower limit of the fluorine content is preferably more than 0% by mass.

[0028] The resist polymer (R) has the following groups (r— 1), the following groups (r— 2), — C (CF) (OZ ^R ) (hereinafter,

3 2

Also called group (r-3). ), And —C (CF) (OZ ^R ) — (hereinafter also referred to as group (r-4)).

Three

Polymers having at least one group (r) selected from the group are preferred! /.

[0029] [Chemical 2]

The symbols in the formula have the following meanings (the same applies hereinafter).

^: An alkyl group having 1 to 6 carbon atoms.

Y ^R1 : a divalent group having 4 to 20 carbon atoms that forms a cyclic hydrocarbon group together with the carbon atom in the formula.

X ^R2 : an alkyl group having 1 to 20 carbon atoms, and three X ^R2 groups may be the same or different.

Z ^R : an alkyl group, an alkoxyalkyl group, an alkoxycarbonyl group or an alkyl group, a sulfonyl group having 1 to 20 carbon atoms.

^{^{However, x R1, Y R1, x}} R2 or carbon atoms in the z ^R - is between the carbon atoms - o-, c (o) o- or a c (o) - is also be揷入Yogumata , X ^R1 , Y ^R1 , x ^R2 or z ^R may be bonded to a fluorine atom, a hydroxy group or a carboxy group.

[0030] The polymer is a polymer whose alkali solubility is increased by the action of an acid. The polymer having the group (r 1) or the group (r 2) is considered to increase alkali solubility because the carboxylate moiety is cleaved by the action of an acid to form a carboxy group. In addition, in the polymer having the group (r 3) or the group (r 4), the ether moiety is cleaved by the action of an acid to form —C (CF) (OH) or —C (CF) (OH) —. Increased alkali solubility

3 2 3

It is considered large.

[0031] X ^R1 in the present specification is particularly preferably a methyl group or an ethyl group, preferably an alkyl group having 1 to 6 carbon atoms or an alkyl group having 1 to 6 carbon atoms containing an etheric oxygen atom.

Yes

In the present specification, the divalent group formed by Y ^R1 and the carbon atom in the formula is particularly preferably a saturated aliphatic group, which is preferably an aliphatic group. The divalent group may be a monocyclic hydrocarbon group or a polycyclic hydrocarbon group. The divalent group is a polycyclic hydrocarbon. Particularly preferred are bridged ring hydrocarbon groups where the group is preferred.

In the present specification, ^XR2 is a force in which all three are alkyl groups having 1 to 3 carbon atoms, 2 is an alkyl group having 3 carbon atoms;! 3 is an alkyl group and 1 is a ring hydrocarbon group having 4 to 20 carbon atoms. Preferred groups (r 1) are represented by the following formula! /, And any group is preferred! /.

[0032] [Chemical 3]

The group (r 2) is represented by the following formula! /, And any group is preferred! /.

[0033] [Chemical 4]

[0034] The group (r-3) is -C (CF) (OCH OZ ^K1 ) (where Ζ ^Κ1 is a carbon number ^{;! To} 12 hydrocarbons

3 2 2

Indicates a group. The same applies below. ) -C (CF) (OCH OCH), -C (CF) (OCH

3 2 2 3 3 2

OCH CH), -C (CF) (OCH 0 C (CH)) or any of the following groups

2 2 3 3 2 2 3 3

preferable.

[0035] [Chemical 5]

[0036] The group (r-4) is preferably C (CF) (OCH OZ)-, C (CF) (OCH OCH)

3 2 3 2 3 -C (CF) (OCH OCH CH) C (CF) (OCH OC (CH)) —or down

3 2 2 3 3 2 3 3

Of the! /, The base of the difference is particularly preferred! /.

[0037] [Chemical 6] CF ₃ OCH _a O

[0038] The resist polymer (R) is obtained by polymerization of at least one monomer (r ^M ) selected from the group consisting of the following compound (rl), the following compound (r2), and the following compound (r3) force. Polymers containing the recurring units (R ^U ) formed are preferred! /.

[0039] [Chemical 7]

[0040] T ^R: a hydrogen atom, a fluorine atom, an alkyl group or Furuo port alkyl group having 1 to 3 carbon atoms having 1 to 3 carbon atoms.

Q ^R1 : a group represented by the formula — CF C (CF) (OZ ^R ) (CH) — or a formula — CH CH ((CH

2 3 2 mr 2

) C (CF) (OZ ^R )) (CH) —

nr 3 2 2 mr

mr and nr: 0, 1 or 2 independently.

T ^R is particularly preferably a hydrogen atom or a methyl group, preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group! / '

, R1 Rl,

The mr in Q ^K1 is preferably 1. Nr in Q ^Ki is preferably 0. Q ^Ki — CF C (CF)

(OCH OZ) CH— or one CH CH (C (CF) (OCH OZ)) CH— is preferred! The compound (rl) is preferably the following compound (rll), the following compound (rl2), the following compound (rl3), the following compound (rl4) or the following compound (rl 5)!

[Chemical 8] CH

The compound (r2) is preferably the following compound (r21) or the following compound (r22)! /

[0042] [Chemical 9]

C

[0043] The compound (r3) is CF = CFCF C (CF) (OCH OZ) CH CH = CH or CF

2 2 3 2 2 2

= CFCH CH (C (CF) (OCH OZ R1)) CH CH = CH are preferred.

[0044] Specific examples of the compound (rl) include the following compounds.

[0045] [Chemical 10]

Specific examples of the compound (r2) include the following compounds.

[0046] [Chemical 11]

C

Specific examples of the compound (r3) include the following compounds.

[0047] [Chemical 12] CF ₂ = CFCF ₂ C (CF ₃ ) (OCH ₂ OCH ₃ ) CH ₂ CH = CH ₂

CF ₂ = CFCF ₂ C <CF ₃ ) (OCH ₂ OCH ₂ CH ₃ ) CH ₂ CH = CH ₂

CF2 = CFCF ₂ C (CF ₃ ) (OCH ₂ OC (CH ₃ ) ₃ ) CH ₂ CH = CH ₂

CF ₂ = CFCH ₂ CH (C (CF ₃ ) ₂ OCH ₂ OCH ₃ ) CH ₂ CH = CH ₂

CF ₂ = CFCH ₂ CH (C (CF ₃ ) ₂ OCH ₂ OCH ₂ CH ₃ ) CH ₂ CH = CH ₂

CF ₂ = CFCH ₂ CH (C (CF ₃ ) ₂ OCH ₂ OC (CH ₃ ) ₃ ) CH ₂ CH = CH ₂

[0048] The resist polymer (R) preferably contains 10 to 90 mol% of repeating units (R ^U ), more preferably 30 to 60 mol%, based on all repeating units. In this case, it is easy to remove the exposed portion of the resist polymer (R) with an alkaline solution!

[0049] The resist polymer (R) may contain a repeating unit other than the repeating unit (R ^u ) (hereinafter also referred to as other unit (R u)). In this case, the resist polymer (R) preferably contains 20 to 60 mol% of other units (R ^U ) with respect to all repeating units! /.

[0050] The other unit (R ^U ) is not particularly limited, and at least one compound (q) selected from the following compound (ql) and the following compound (q2) and / or the following compound (pi) and A repeating unit formed by polymerization of at least one compound (p) selected from the following compound (p2) is preferred.

[0051] [Chemical 13]

The symbols in the formula have the following meanings (the same applies hereinafter). [0052] T ^Q and T ^P : each independently a hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, or a fluoroalkyl group having 1 to 3 carbon atoms.

Y ^Q1 : A trivalent group having 4 to 20 carbon atoms that forms a bridged cyclic hydrocarbon group together with the carbon atom in the formula.

Y ^Q2 : A divalent group having 4 to 20 carbon atoms that forms a cyclic hydrocarbon group together with the carbon atom in the formula.

Y ^P1 : a trivalent group having 5 to 20 carbon atoms that forms a bridged ring hydrocarbon group in cooperation with a carbon atom in the formula, wherein a hydroxy group or a carboxy group is bonded to the carbon atom in the group. Group.

Υ ^Ρ2 : A divalent group of 4 to 20 carbon atoms that forms a cyclic hydrocarbon group in cooperation with the carbon atom in the formula, and a hydroxy group or a carboxy group is bonded to the carbon atom in the group Base

Yes

However, between carbon atoms in Y ^Q1 , Y ^Q2 , Y ^p1 or Y ^P2 — between carbon atoms — o—, c (o

) O or C (O) is purchased!

[0053] Each of T ^Q and T ^P is particularly preferably a hydrogen atom or a methyl group, preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

The trivalent group formed by ^YQ1 and the carbon atom in the formula is particularly preferably a saturated aliphatic group, which is preferably an aliphatic group.

[0054] The divalent group formed by ^YQ2 and the carbon atom in the formula is particularly preferably a saturated aliphatic group, which is preferably an aliphatic group. The divalent group may be a monocyclic hydrocarbon group or a polycyclic hydrocarbon group.

The trivalent group formed by ^YP1 and the carbon atom in the formula is particularly preferably a saturated aliphatic group, which is preferably an aliphatic group.

The divalent group formed by ^{Ρ 2} and the carbon atom in the formula is particularly preferably a saturated aliphatic group, which is preferably an aliphatic group. The divalent group may be a monocyclic hydrocarbon group or a polycyclic hydrocarbon group.

[0055] carbon atoms in Y ^Q1 , Y ^Q2 , Υ ^Ρ1 or Υ ^Ρ2 between carbon atoms, C (Ο) Ο or C (

If O)-is purchased! /, Then C (O) O is purchased! /, It is preferable! The compound (ql) is preferably the following compound (ql l), the following compound (ql2) or the following compound (ql3).

[0056] [Chemical 14]

The compound (q2) includes the following compound (q21), the following compound (q22), the following compound (q23), the following compound (q24), the following compound (q25), the following compound (q27), and the following compound (q28). Or the following compound (29) is preferable.

[0058] [Chemical 15]

(q27) (q28) (q29) As the compound (pl), the following compound (pi 1), the following compound (pi ² ) or the following compound (Pl3) is preferable, and the following compound (P 12) is particularly preferable.

[0059] [Chemical 16] CH.

c

Specific examples of the compound (ql) include the following compounds.

[0060] [Chemical 17]

,

CH ₂ CH ₂ CH ₂ = C '

£

Specific examples of the compound (q2) include the following compounds c

[0061] [Chemical 18]

Specific examples of the compound (pi) include the following compounds c

[0062] [Chemical 19]

The weight average molecular weight of the resist polymer (R) is preferably 1000 to 100000 force S, particularly preferably 100O 000. A preferred embodiment of the resist polymer (R), based on all repeating units, the repeating unit of (R ^u) and comprises 10 to 60 mol%, the polymer containing other units (R ^u) 40 to 90 mol% Is mentioned.

[0064] The repeating unit (R ^u ) in the above embodiment is particularly preferably a repeating unit formed by polymerization of the compound (rl). The other unit (R ^U ) in the above embodiment is a repeating unit formed by the polymerization of the compound (q2) and the compound (pi) preferred by the repeating unit formed by the polymerization of the compound (q) and the compound (P). Units are particularly preferred.

As for the weight average molecular weight of the polymer in the said aspect, 1000-30000 are preferable.

[0065] The photosensitive resist layer in the present invention particularly preferably contains 0.;! To 10% by mass of a photoacid generator with respect to the resist polymer (R) which preferably contains a photoacid generator. .

The photoacid generator is not particularly limited as long as it is a compound having a group capable of generating an acid upon irradiation with active light (active light means a broad concept including radiation). The compound may be a non-polymer compound or a polymer compound. One photoacid generator may be used, or two or more photoacid generators may be used! /, Or may be used.

The photoacid generator is selected from the group consisting of onium salts, halogen-containing compounds, diazoketones, sulfonate compounds, sulfonic acid compounds, diazodisulfones, diazoketosulfones, iminosulfonates and disulfones. At least one photoacid generator is preferred.

[0066] Specific examples of the photoacid generator include diphenyl nitronium triflate, diphenyl dolom piransnorephonate, diphene oleodonium hexafanoleo oral antimonate, difenil Donumdodecyl benzene sulfonate, bis (4-tert-butylphenol) iodine triflate, bis (4 tert-butylphenyl) odonum dodecyl benzene sulphonate, triphenylenosenorephonium triflate Fret, trifenenoles nore hononyumnonate, trifenenores norehonom perfu nore octane norephonate, trifenenoles norehonium hexaph noreo oral antimonate, trifenenores nore honofane naphthalene nore honate, Trifenenolesnorehonium Trifnoreolomethanesuno Rehonate, Triphenylenoleshonum camphorsulfonium, 1 (Naphthylacetomethinole) thiolanium triflate, Cyclohexylmethyl (2-oxocyclohexyleno) sulfonium triflate, Dicyclohexa Sil (2oxocyclohexyl) sulfonium triflate, dimethyl (4-hydroxynaphthinole) snorephonum tosylate, dimethylenole (4-hydroxynaphthonole) snorephonium dodecino benzenesulfonate, dimethyl (4-hydroxynaphthyl) sulphonium Munaphthalene norphonate, triphenylsulfonium camphorsulfonate, (4-hydroxyphenyl) benzylmethylsulfonium toluenesulfonate, (4-methoxyphenyl) phenol monodonium trifluoromethanesulfonate, bis (t-butylphenolate) ) Jodonium trif Nororomethane sulfonate, phenyl bis (trichloromethyl) s triazine, methoxy phenyl mono bis (trichloromethyl) s triazine, naphthyl mono bis (tri Chloromethyl) s triazine, 1, 1-bis (4-chlorophenenole) 1, 2, 2, 2-trichloroethane, 4-trisphenacyl sulfone, mesitylphenacyl sulfone, bis (phenylsulfoninole) ) Methane, benzoin tosylate, 1,8-naphthalenedicarboxylic imide triflate.

[0067] The material for the resist protective film in the present invention is an alkali-soluble material containing a fluoropolymer (F) that has the required optical properties and can suppress swelling and elution of the photosensitive resist layer. If so, there is no particular limitation!

The fluoropolymer (F) in the present invention is not particularly limited as long as it is a fluoropolymer having a higher fluorine content than the resist polymer (R). The fluorine content of the fluoropolymer (F) is preferably 5% by mass or more, particularly preferably 30% by mass or more. The upper limit of the fluorine content is preferably 76% by mass or less.

[0068] The fluoropolymer (F) has a weight average molecular weight of 1000 to 100,000, preferably 1000 to 50,000, and particularly preferably.

The fluoropolymer (F) is a monomer having at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, a sulfonic acid group, a sulfonylamide group, an amino group and a phosphoric acid group (b ^M ) Is preferably a fluorine-containing polymer (F ^P ) containing repeating units (B ^u ) formed by polymerization! Since the fluoropolymer (F ^P ) contains repeating units (B ^u ), it is an alkali-soluble fluoropolymer, and the resist protective film material containing the fluoropolymer (F ^P ) is an alkali-soluble material. It is. The hydroxy group may be an alcoholic hydroxy group or a phenolic hydroxy group.

[0069] The monomer (b ^M ) in the present specification is a monomer having a hydroxy group or a carboxy group. Is preferred -C (CF) (OH), -C (CF) (OH) — or a single quantity with COOH

3 2 3

The following compound (bl), the following compound (b2), the following compound (b3), or the following compound (b4), which the body prefers, are particularly preferred! /.

[0070] [Chemical 20]

CF ₂ = CF— Q ^BM1 -CH = CH ₂ ( ^b1 )

CH ₂ = CR ^BM2 C (0) 0-a ^BM2 (-C (CF ₃ ) ₂ OH) _rb (b2)

CH ₂ = CH 1 Q ^BM3 (-C (CF ₃ ) ₂ OH) _rb (b3)

[0071] Q ^BM1 : a group having a hydroxy group or a carboxy group, an alkylene group or a fluoroalkylene group, and a carbon number;

R ^BM2 : A hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, or a fluoroalkyl group having 1 to 3 carbon atoms.

Q ^BM2 and Q ^BM3 _: each independently a (Λ + 1) -valent hydrocarbon group having 1 to 20 carbon atoms. rb: l or 2.

Q ^BM4 : A single bond or a divalent hydrocarbon group having 1 to 10 carbon atoms.

However, the hydrogen atom in Q ^BM2 , Q ^BM3 or Q ^BM4 may be substituted with a fluorine atom.

[0072] Q ^BM1 of the compound (M) is a group represented by the formula —CF 2 C (CF 3) (OH) (CH 2) 1, a formula —C

2 3 2 mb

H CH ((CH) C (CF) (OH)) (CH) A group represented by the formula CF CH (COOH)

2 2 nb 3 2 2 mb 2

(CH 3) a group represented by one, formula CF C (COOH) (CH 2) a group or formula represented by one

2 mb 2 2 2 mb

— CH 2 CH (COOH) 2 (CH 3) — is preferable.

2 2 mb

And nb each independently represents 0, 1 or 2. )

Q is preferably 1 for mb in ^BM1 . Q in ^BM1 is preferably 0. Q ^BM1 is CF C (

2

CF) (OH) CH CH CH (C (CF) (〇H)) CH CF CH (C〇H) CH

3 2 2 3 2 2 2

CF C (COOH) CH— or one CH CH (COOH) CH— is preferred.

2 2 2 2 2 2

[0073] Specific examples of the compound (bl) include the following compounds. [0074] [Chemical 21]

CF ₂ = CF— CF ₂ C (CF ₃ ) (OH) CH ₂ — CH = CH ₂

CF ₂ = CF— CH ₂ CH (C (CF ₃ ) ₂ OH) CH ₂ — CH = CH ₂

CF ₂ = CF_CH ₂ CH (CH ₂ C (CF ₃ ) ₂ OH) CH ₂ — CH 2 CH ₂

CF ₂ = CF— CH ₂ CH (COOH) CH ₂ — CH = CH ₂

CF ₂ = CF— CF ₂ CH (COOH) CH ₂ — CH = CH ₂

CF ₂ = CF— CF ₂ C (COOH) ₂ CH ₂ —— CH = CH ₂ R ^BM2 of the compound (b2) is a hydrogen atom, a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group preferred. A methyl group is particularly preferred.

[0075] The (rb + 1) -valent hydrocarbon group in Q ^BM2 of compound (b2) and Q ^BM3 of compound (b3) are each independently an (rb + 1) -valent cyclic hydrocarbon having 1 to 20 carbon atoms. Groups are preferred. The cyclic hydrocarbon group may be a group consisting of only a cyclic hydrocarbon group or a group containing a cyclic hydrocarbon group in the group. The ring hydrocarbon group may be an aliphatic group or an aromatic group. The ring hydrocarbon group may be a monocyclic hydrocarbon group or a polycyclic hydrocarbon group. The polycyclic hydrocarbon group may be a bridged ring hydrocarbon group.

[0076] Q ^BM2 and Q ^BM3 are particularly preferably any of the following groups.

[0077] [Chemical 22]

Specific examples of the compound (b2) include the following compounds.

[0078] [Chemical 23]

CH ₂ = CHC (0) 0 ~ (^ ~ C (CF ₃ ) ₂ OH CH ₂ = C (CH ₃ ) C (0) 0 ^^) ~ C (CF ₃ ) ₂ OH

CH ₂ = CHC (0) OH ^) ^ CH ₂ C (CF ₃ ) ₂ OH CH ₂ = C (CH ₃ ) C (0) 0 ~ (^ "CH ₂ C (CF ₃ ) ₂ OH

Specific examples of the compound (b3) include the following compounds.

[0079] [Chemical 24]

CH ₂ = CH "(厂 Vc (CF ₃ ) ₂ OH CH ₂ = CH-<^ CH ₂ C (CF ₃ ) ₂ OH Q ^BM4 of the compound (b4) is preferably a single bond or a methylene group! / '

Specific examples of the compound (b4) include the following compounds.

[0080] [Chemical 25]

[0081] The weight average molecular weight of the fluoropolymer (F ^P ) is preferably 1000 to 100,000 force s, particularly preferably 1000 to 50,000.

[0082] The fluorine-containing polymer (F ^P ) may be a fluorine-containing polymer consisting only of the repeating unit (B ^u ), and may be a repeating unit (Β ^υ ) and other than the repeating unit (Β ^υ ). It may be a fluorine-containing polymer containing repeating units.

The resist protective film-forming material in the present invention includes a fluorine-containing polymer containing a repeating unit formed by polymerization of a fluorine-containing monomer (単量体) other than a monomer (b ^M ) having a fluorine atom. Is preferred.

[0084] The fluorine-containing monomer (f ^M ) is preferably a monomer having a fluorine content of 30 to 76% by mass. A monomer having a fluorine content of 50 to 76% by mass is particularly preferable.

The fluorine-containing monomer (f ^M ) is a monomer having a fluorine-containing ring structure, or is contained by cyclopolymerization. A monomer that forms a repeating unit having a fluorine ring structure is preferred.

The fluorine-containing polymer in this case is a fluorine-containing polymer having a fluorine-containing ring structure derived from a fluorine-containing monomer (f ^M ) and excellent in dynamic water and oil repellency, and further having a repeating unit (B ^u ) When it contains, it is an alkali-soluble fluoropolymer.

Therefore, in the immersion lithography method provided with a resist protective film layer formed from the resist protective film forming composition in this case, swelling and dissolution of the photosensitive resist layer are suppressed. The immersion liquid will follow the projection lens moving at high speed over the resist protective film layer. Therefore, it is possible to perform the immersion lithography method at high speed, which can transfer the mask pattern image with high accuracy.

The fluorine-containing monomer (f ^M ) is preferably the following compound (f 1), the following compound (f 2), the following compound (f 3) or the following compound (f4)!

[0087] [Chemical 26]

R ™: a hydrogen atom, a fluorine atom, an alkyl group having 1 to 3 carbon atoms, or a fluoroalkyl group having 1 to 3 carbon atoms.

"^: Fluorine-containing saturated hydrocarbon group having 4 to 20 carbon atoms and a fluorine-containing ring structure. However, OC (O) or c (o) o- is inserted between carbon atoms in w ^FM . May be.

Q ^FM : At least one group selected from the group consisting of a methylene group, a dimethylene group, a trimethylene group, a tetramethylene group, an oxymethylene group, an oxydimethylene group, and an oxytrimethylene group. However, the hydrogen atom in the group is substituted with at least one group having 1 to 12 carbon atoms selected from the group consisting of an alkyl group, a fluoroalkyl group, an alkoxy group, and a fluoroalkoxy group, or a fluorine atom. May be.

X ^FM : Hydrogen atom or fluorine atom, and three X ^FMs may be the same or different. It may be.

Y ^FM : A fluorine atom or a perfluoroalkoxy group having 1 to 3 carbon atoms.

[0089] Z ^FM1 Z ^FM2 Z ™ ³ and Z ^FM4 _: each independently a fluorine atom or a perfluoroalkyl group having 16 carbon atoms.

[0090] R ™ of the compound (f 1) is particularly preferably a hydrogen atom or a methyl group, preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

The compound (fl) is preferably the following compound (fll), the following compound (fl2a), the following compound (fl2b), or the following compound (f13)!

[0091] [Chemical 27]

(f11) (f12a) (f12b) (f13) Symbols in the formulas have the following meanings (the same shall apply hereinafter) _t

[0092] Q ^tM1 : Single bond or methylene group.

f: a fluorine atom or a trifluoromethyl group.

FM2

Q -CF— or — C (CF) —, which may be the same up to 2 Q ^tM

3 2

It's okay! / '

W ^Md : A hydrogen atom, a fluorine atom, an alkyl group having 16 carbon atoms or a fluoroalkyl group having 16 carbon atoms.

Q ™ ³ : a C 3 11 perfluoroalkylene group that forms a fluorine-containing monocyclic hydrocarbon group in combination with the carbon atom in the formula.

[0093] Among the compounds (fll), a compound in which Q ^FM1 is a methylene group is a novel compound. The compound (fll) is obtained by reacting the following compound (pf 11) with water to obtain the following compound (qf 11), and then reacting the compound (qf 11) with H-CHO to produce the following compound ( rf 11) is obtained, and then it can be produced by reacting the compound (rfll) with CH 2 = CR ^FM COCl.

2 [0094] [Chemical 28]

[0095]

[0096]

[0097]

(of 12a) (pf12a) (qf12a) (rf12a) (sf12a) The symbols in the formula have the following meanings (the same applies hereinafter).

R ^f : an etheric oxygen atom having 1 to 20 carbon atoms! /, May! /, A perfluoroalkyl group.

w ^HM2 : w A group corresponding to ^FM2 , which is a hydrogen atom or a methyl group. Q A group corresponding to ^HM , -en— or C (CH 3) —. The compound (f 12b) is a novel compound. Compound (f12b) can be produced in the same manner except that the following compound (of 12b) is used in place of compound (of 12a).

[0099] [Chemical 31]

Specific examples of the compound (f 12a) and the compound (f 12b) include the following compounds.

[0100] [Chemical 32]

[0101]

[0102]

Q ^F of compound (f2) is CH CH (T ^FM1 ) CH ―, — OCF CF ―, — OCF (T ™ ² )

twenty two

CF _q —or one OCF _Q CF (T ™ ² ) — is preferred. However, T ^FM1 has carbon number; An alkyl group of ~ 6 or a fluoroalkyl group of 1 to 6 carbon atoms, T ™ ² is a perfluoro having 1 to 6 carbon atoms An o-alkyl group is shown (the same applies hereinafter).

[0104] The compound (f2) is preferably the following compound (f21), the following compound (f22), the following compound (f23) or the following compound (f 24).

CF = CFCH CH (T) CH CH = CH (f21)

2 2 2 2

CF = CFOCF CF C (X ™) = C (X ™) (f 22),

2 2 2 2

CF = CFOCF CF (T ™ ² ) C (X ™) = C (X ™) (f 23),

2 2 2

CF = CFOCF (T ™ ² ) CF C (X ™) = C (X ™) (f 24)

[0105] Specific examples of the compound (f2) (excluding the compound (f21) described below) include the following compounds.

[0106] [Chemical 34]

CF ₂ = CF-CF ₂ CF ₂ CH— CH = CH ₂

CF ₂ = CF-CF (CF ₃ ) CF ₂ CH ₂ -CH 2 CH ₂

CF ₂ = CF— CF ₂ CF (CF ₃ ) CH ₂ -CH 2 CH ₂

CF ₂ = CF— OCF ₂ CF ₂ -CF 2 CF ₂

CF ₂ = CF— OCF (CF ₃ ) CF ₂ -CF = CF ₂

CF ₂ = CF— OCF ₂ CF (CF ₃ )-CF 2 CF ₂

CF ₂ = CF— OCF ₂ CF ₂ _CH = CF ₂

CF ₂ = CF-OCF (CF ₃ ) CF ₂ -CH 2 CF ₂

CF ₂ = CF-OCF ₂ CF (CF ₃ )-CH = CF ₂

CF ₂ = CF— OCF ₂ CF ₂ — CH = CH ₂

CF ₂ = CF-OCF (CF ₃ ) CF ₂ -CH = CH ₂

CF ₂ = CF-OCF ₂ CF (CF ₃ )-CH = CH ₂

[0107] Compound (f21) is a novel compound. Compound (f21) consists of the following compound (pf 21) and CF C

2

ICFCII is reacted to obtain the following compound (qf 21), and then the following compound (qf21) and CH

2

= CHCH MgCl is reacted to obtain the following compound (rf21), then the compound (rf21) is converted to Z

2

It can be produced by dechlorination reaction in the presence of n.

CH = CHT ^FM1 (pf21),

2

CF C1CFC1CH CHIT ™ ¹ (qf21),

twenty two

CF C1CFC1CH CH (T ^FM1 ) CH CH CH (rf21) _G

2 2 2 2

Specific examples of the compound (f21) include the following compounds.

[0108] [Chemical 35] CF ₂ = CFCH ₂ — CH (CH ₂ CH ₃ ) CH ₂ — CH = CH ₂

CF ₂ = CFCH ₂ — CH ((CH ₂ ) ₃ CH ₃ ) CH ₂ -CH = CH ₂

Co / F ₂ = CFCH ₂ — CH (CH ₂ CH (CH ₃ ) ₂ ) — CH = CH ₂

CF ₂ = CFCH ₂ — CH ((CH ₂ ) ₅ CH ₃ ) CH ₂ -CH = CH ₂

CF ₂ = CFCH ₂ — CH (CH ₂ CF ₃ ) CH ₂ — CH = CH ₂

CF ₂ = C \ oFCH ₂ — CH (CH ₂ CF ₂ CF ₃ ) CH ₂ — CH = CH ₂

CF ₂ = CFCH ₂ — CH (CH ₂ (CF ₂ ½CF ₃ ) — CH = CH ₂

CF ₂ = CFCH ₂ — CH (CH ₂ CF (CF ₃ ) ₂ ) CH ₂ — CH = CH ₂

CF ₂ = CFCH ₂ — CH (CH ₂ (CF ₂ > ₃ CF ₃ ) —— CH = CH ₂

CF ₂ = CFCH ₂ _CH (CF ₃ ) CH ₂ CH = CH ₂

CF ₂ = CFCH ₂ — CH (CF ₂ CF ₃ ) CH ₂ CH = CH ₂

_{_{CF 2 = CFCH 2 - CH (}} CF 2 CF 2 CF 3) CH 2 - Specific examples of the CH = CH ₂ Compound (f 3) include the following compounds

[0109] [Chemical 36]

Specific examples of CF, CF ₃ compound (f4) include the following compounds:

[0110] [Chemical 37]

_y ⁰ ₂

CF ₂ I

ヽ₀ — CF ₂

[0111] As a first preferred embodiment of the resist protective film material in the present invention, a resist protective film material composed only of a fluoropolymer containing a repeating unit (B ^u ) can be mentioned. Before Ki含fluoropolymer, repeating units (beta ^upsilon) consisting only force ,, repeating unit (beta ^upsilon) fluorine-containing containing monomer and (f ^M) repeating units formed by polymerization of (F ^u) A fluorine-containing polymer containing is preferable.

[0112] The latter polymer also has a fluorinated polymer (F ^PG ) force containing 10 mol% or more of repeating units ( ^Bu ) and 1 mol% or more of repeating units ( ^Fu ) with respect to all repeating units. I prefer to be! / The fluorine-containing polymer (F ^Pe ) may be a polymer composed only of the repeating unit (F ^u ) and the repeating unit (B ^u ), or may be a polymer including other units. In the fluoropolymer (F ^P ^e ), the repeating unit (F ^u ) is usually one kind, and the repeating unit (B ^u ) is also usually one kind.

[0113] The fluoropolymer (F ^Pe ) contains 1 to 70 moles of repeating units (F ^u ) with respect to all repeating units. It is preferable to contain at least 1%. The fluoropolymer (F ^P), based on all repeating units, the repetition units (B ^u), preferably to include 30 to 99 mole ^_0/0! /,.

The fluorine content of the fluoropolymer (F ^PG ) is preferably 20% by mass or more!

The weight average molecular weight of the fluorine-containing polymer (F ^PG ) is from 1000 to 100000 force S, preferably from 1000 to 50,000.

The preferred form and mode of the fluoropolymer (F ^rc ) is composed of only the repeating unit (F ^u ) and the repeating unit (B ^u ), and the repeating unit (F ^u ) is 1 to Examples thereof include a polymer containing 30 mol% and 70 to 99 mol% of repeating units (B ^u ).

[0114] The repeating unit (F ^u ) in the above embodiment is preferably a repeating unit formed by polymerization of the compound (fl) or the compound (f 2).

The repeating unit (B ^u ) in the above embodiment is preferably a repeating unit formed by polymerization of the compound (bl), the compound (b2), the compound (b3) or the compound (b4)! /.

The polymer of the above embodiment preferably has a weight average molecular weight of 1000 to 30000.

[0115] As a second preferred embodiment of the resist protective film material in the present invention, an alkali-soluble fluoropolymer (F ^Q ) and a fluoropolymer (F ^R ) containing a repeating unit (F ^u ). The resist protective film composition containing these is mentioned. The resist protective film composition preferably contains 1 to 10% by mass of a fluoropolymer (F ^R ) with respect to the fluoropolymer (F ^Q ). In this case, the fluoropolymer (F ^Q ) and the fluoropolymer (F ^R ) are easily compatible with each other, and the film forming property of the resist protective film composition is excellent.

[0116] A preferred embodiment of the fluoropolymer (F ^Q ) is a fluoropolymer containing a repeating unit (B ^u ).

The fluoropolymer (F ^Q ) in the above embodiment preferably contains 5 mol% or more of repeating units (B ^u ) from the viewpoint of alkali solubility, and more preferably contains 25 mol% or more. It is especially preferred to consist only of the return unit (Β ^υ )!

The repeating unit (Β ^υ ) in the above embodiment is more preferably a fluorine-containing polymer consisting only of repeating units formed by polymerization of the compound (bl), the compound (b2), the compound (b3) or the compound (b4). A fluorine-containing polymer consisting only of repeating units formed by polymerization of the compound (bl) is particularly preferred. The weight average molecular weight of the fluoropolymer in the above embodiment is preferably 1000 to 50000.

[0117] Preferable embodiments of the fluoropolymer (F ^R ) include the following fluoropolymer (F ^RH ) and the following fluoropolymer (F ^Re ).

Fluoropolymer (F ^RH ): ^{Fluoropolymer} composed solely of repeating units (F ^u ). Fluoropolymer (F ^Re): repeating includes units and (F ^u) and other units (F ^u), based on all the repeating units of 1 to 70 mol ^_0/0 includes a repeating unit (F ^u) Other units (F ^u ) 30-99 mol

% Fluorine-containing polymer.

The repeating unit (F ^u ) in the above embodiment is preferably the compound (fl) or the compound (f 2). The other unit (F ^u ) in the above embodiment is the compound (bl) in which the repeating unit (B ^u ) is preferred, A repeating unit formed by polymerization of the compound (b2), the compound (b3) or the compound (b4) is particularly preferred.

The weight average molecular weight of the fluoropolymer in the above embodiment is preferably 1000 to 50000.

[0118] The solvent in the present invention is a solvent containing at least one fluorine-based solvent (S) selected from the group consisting of a hyde mouth fluorocarbon solvent and a hyde mouth fluorocarbon solvent, The solvent is preferably contained.

[0119] The nodyl fluorocarbon solvent means a compound which is composed of only hydrogen, fluorine and carbon atoms and is liquid at 25 ° C. The boiling point of the compound is preferably 60 to 160 ° C. In addition, the carbon atom in the compound may form an alicyclic ring or an aromatic ring.

[0120] The nodyl fluoroether solvent means a compound which is composed of only etheric oxygen atoms, hydrogen atoms, fluorine atoms and carbon atoms and is liquid at 25 ° C. The boiling point of the compound is preferably 60 to 160 ° C. In addition, the carbon atom in the compound may form an alicyclic ring or aromatic ring. In the compound, two or more etheric oxygen atoms may be present.

[0121] Preferably, the ido-fluoro ether solvent is R ^EF — O— R ^EH (where R ^EF is carbon A polyfluoroalkyl group which may contain an etheric oxygen atom having 4 to 12 carbon atoms, and R ^EH represents an alkyl group having 1 to 8 carbon atoms. ). R ^EF and R ^EH may each be a linear group or a branched group.

[0122] R ^EF is preferably a perfluoroalkyl group having 4 to 8 carbon atoms or a perfluoro (alkoxyalkyl) group having 4 to 8 carbon atoms! /.

R ^EH is preferably a methyl group or an ethyl group.

Specific examples of the hyde mouth fluorocarbon solvent include CF CHFCHFCF CF, CF

3 2 3 3

(CF) H, CF (CF) CH CH, CF (CF) CH CH, CF (CF) CH CH, 1,

2 5 3 2 3 2 3 3 2 5 2 3 3 2 7 2 3

3-bis (trifluoromethyl) benzene and the following compounds may be mentioned.

[0123] [Chemical 38]

, CF ₂

CF ₂ ^N CF ₂

\ I

CH ₂ — CHF

[0124] Specific examples of the hydrated fluoroether solvent include CF (CF) OCH, CF (CF

3 2 3 3 3 2

) OCH, F (CF) OCH, F (CF) OCH, F (CF) OCH, F (CF) OCH, F (

5 3 2 6 3 2 7 3 2 8 3 2 9 3

CF) OCH, H (CF) OCH, F (CF) OCF (CF) CF OCH, F (CF) OCF (

2 10 3 2 6 3 2 3 3 2 3 2 3

CF) CF OCF (CF) CF OCH, F (CF) OCH CH CH, (CF) CFCF CF O

3 2 3 2 3 2 8 2 2 3 3 2 2 2

CH, F (CF) 0 (CF) OCH CH, (CF) CFCF (CF) CF OCH, (CF) CF

3 2 2 2 4 2 3 3 2 3 2 3 3 2

CF (CF CF) OCH, CF CH OCF CHF

2 3 3 3 2 2 2

The fluorine-based solvent (S) is preferably 1,3-bis (trifluoromethyl) benzene.

[0125] The solvent in the present invention may be a solvent composed of only the fluorine-based solvent (S), or an organic solvent other than the fluorine-based solvent (S) and the fluorine-based solvent (S) (hereinafter referred to as other organic solvents). It may be a mixed solvent. In the present invention, the fluorinated solvent (S) is usually one kind.

From the viewpoint of compatibility with the resist protective film material, the solvent in the present invention is an organic solvent other than the fluorine-based solvent (S) and the fluorine-based solvent (S) (hereinafter also referred to as other organic solvent). ) Is preferred.

[0127] The mixed solvent is based on the total mass of the fluorinated solvent (S) and the other organic solvent (fluorinated solvent ( 50% by mass or more and less than 100% by mass, preferably 90% by mass or more and less than 100% by mass, and other organic solvents more than 0% by mass and less than 50% by mass, preferably 0% by mass or more and less than 10% by mass. Is preferred.

[0128] The other organic solvent may be a fluorine-based organic solvent other than the fluorine-based solvent (S), or may be a non-fluorinated organic solvent containing no fluorine atom. I like it. The boiling point of the other organic solvent is 60 to 160 ° C, preferably 60 to 120 ° C.

[0129] Specific examples of fluorinated organic solvents other than fluorinated solvent (S) include CC1 FCH, CF C

2 3 3

F CHC1 CC1F CF CHC1F, etc. Hyde mouth black mouth fluorocarbon solvents;

2 2 2 2

Fluoroketone solvent: Hyd mouth fluoroalcohol solvent such as CHF CF CHOH

2 2 2

Can be mentioned.

[0130] Specific examples of non-fluorinated organic solvents include 1 propanol, isopropanol, n-prono norole, n butanol, 2-butanol, tert butanol, 1 pentanol, 2 pentanol, 3 Pentanol, n-hexanol, cyclohexanol, 2 methylolene 2 butanol, 3 methyl-2 butanol, 2 methyl-1-butanol, 3 methyl-1-butanol, 2-methyl-1 pentanol, 2-methyl-2-pen Tanol, 2-Methyl-3-pentanol, 3-Methyl-l-Pentanol, 3-Methyl-2-Pentanol, 3-Methyl-3-Pentanol, 4-Methyl-l-Pentanol, 4-Methinore 2-Pentanol, 2,2-Dimethyl-3 Pentanol 2, 3 Dimethyl-3-pentanol, 2, 4 Dimethyl-3 pentanol, 4, 4 Di Chile-2-pentanol, 3-ethyl-3-pentanol, 1-heptanol, 2-heptanol, 3-heptanol, 2-methyl-2-hexanol, 2-methyl-3-hexanol, 5-methyl-1-hexanol and 5-methylol 2 Hexanol, 1 Ethanol, 1 Mexanol, 4 Methanol, Heptanol, 6 Methyl-2-Heptanol, 1-Octanol, 2-Otanol, 3 Octanol, 2 Propyl 1 Pentananol, 2, 4, 4 Trimethyl 1 Nore, 2, 6 dimethyl-4 heptanonole, 3 ethyl-2, 2 dimethylpentanol, 1-nonanonole, 2 nonanonore, 3, 5, 5 trimethyl-1, 1-hexanol, 1-decanol, 2 decanol, 4-decanol 3, 7 Dimethyl 1-Ottatanol 3, 7 Dimethyl 2-Ottatanol Hydrocarbon alcohols and the like; acetone, main Hydrocarbon ketones such as tilisobutylketone, cyclohexanone, cyclopentanone, 2-heptanone, N-methylpyrrolidone, and γ-butyrolatatone; propylene glycol monomethylenoatenoacetate, propyleneglycolonemethenoleatenorepropio Naphthalate, propylene glycol monoethyl ether acetate, carbitol acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate , Hydrocarbon esters such as 2-ethoxyethyl acetate, isoamyl acetate, methyl lactate, and ethyl lactate; aromatic hydrocarbons such as toluene and xylene; propylene glycol methyl ether acetate, propylene glycol Remonomethinoatenore, Propyleneglycolenomethinoleetenore, Ethyleneglycolenolemonoisopropinoreatenore, Diethyleneglycolmonoremonomethinoreatenore, Diethyleneglycolenoresinomethenoreatenore, Propyleneglycolenoremonotenore Hydrocarbon ethers such as ethers; hydrocarbon amides such as N, N dimethylformamide and N, N dimethylacetamide.

[0131] As the non-fluorinated organic solvent, a monovalent alcohol having 4 to 8 carbon atoms, which is preferably a monohydric alcohol, is particularly preferable. N Butanol, 2-methyl-1-propanol, or 4-methyl-2- Pentanol is particularly preferred.

[0132] The present invention relates to a method for forming a resist pattern by an immersion lithography method, the step of forming a photosensitive resist layer containing a resist polymer (R) on the surface of a substrate, the photosensitive property Applying the resist protective film-forming composition of the present invention to the surface of the resist layer, further removing the solvent to form a resist protective film layer on the surface of the photosensitive resist layer, an immersion lithography process, and Then, a resist pattern forming method for obtaining a substrate on which a resist pattern is formed is provided by performing the steps of developing the photosensitive resist layer in this order.

A base material is not specifically limited, A silicon wafer is mentioned. The substrate may be a substrate surface-treated with an antireflection film or the like!

[0133] The method for forming the photosensitive resist layer is not particularly limited. For example, resist polymer

A positive photosensitive resist forming composition obtained by dissolving (R) and a photoacid generator in an organic solvent is applied onto a desired substrate and then heated to remove the organic solvent, Base A photosensitive resist layer can be formed on the surface of the material.

[0134] Examples of the method for applying the photosensitive resist composition include a roll coating method, a casting method, a dipping method, a spin coating method, a water casting method, a die coating method, and a Langmuir'Blodgett method. Heating is performed until the organic solvent is distilled off at a temperature equal to or higher than the boiling point of the organic solvent, and is usually performed at 80 to 130 ° C for 60 to 90 seconds.

[0135] The method for applying the resist protective film-forming composition of the present invention to the surface of the photosensitive resist layer is not particularly limited. Examples of the method for applying the resist protective film-forming composition of the present invention include a roll coating method, a casting method, a dip method, a spin coating method, a water casting method, a die coating method, and a Langmuir-Projet method. The solvent is removed by heating and drying until the solvent is distilled off at a temperature not lower than the boiling point of the solvent. Usually, heat drying is performed at 80 to 130 ° C for 60 to 90 seconds.

[0136] The resist protective film-forming composition of the present invention comprises the resist protective film material of the present invention and the above solvent in a mass ratio of (resist protective film material / the above solvent) of 5 to 100, preferably Contains 10-50.

[0137] In the immersion lithography process, a fine pattern image obtained by irradiating a mask having a desired fine pattern with exposure light source light is passed between the projection lens and the resist protective film layer via the projection lens. If it is a process of projecting to the desired position of the substrate while moving the projection lens while filling with immersion liquid, there is no particular limitation! /.

[0138] Exposure light source is g-line (wavelength 436nm), i-line (wavelength 365nm), KrF excimer laser light

(Wavelength 248nm), ArF excimer laser light (wavelength 193nm) or F excimer laser

2

Light (wavelength 157nm) is preferred ArF excimer laser light or F excimer laser light

2

An ArF excimer laser beam is particularly preferable because of its high power.

[0139] The immersion liquid is not particularly limited as long as it has a high light transmittance and a high refractive index with respect to the exposure light source light.

The light transmittance of the immersion liquid is preferably 70% or more, more preferably 90% or more, at the wavelength of the exposure light source light. However, the light transmittance means the light transmittance per lmm of the optical path length in the immersion liquid of the exposure light source light.

[0140] The refractive index of the immersion liquid is preferably more than 1.0 in the wavelength light of the exposure light source. Above The upper limit of the refractive index is not particularly limited, and is preferably 2.0 or less.

The immersion liquid may be an aqueous liquid medium or a non-aqueous liquid medium. The aqueous liquid medium is preferably ultrapure water.

[0141] The non-aqueous liquid medium is particularly preferably an alicyclic compound in which an alicyclic compound or an organosiloxane compound is preferred.

Specific examples of non-aqueous liquid media include cis decalin, trans decalin, spiro [5,5] undecane, exo tetrahydrodicyclopentagen, 5-silacyclo [4,4] nonane, 1

Examples include tricycloheptylmethane, dicyclohexyl, isopoxy pinolecyclohexane, cyclooctane, cycloheptane, and hexamethinoresisiloxane.

[0142] The step of developing the photosensitive resist layer is performed until the resist protective film layer and the exposed portion of the photosensitive resist layer are removed by contacting an alkali solution from the resist protective film layer side.

[0143] Specific examples of the alkaline solution include at least one alkaline compound selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethylammonium hydroxide, and triethylamine. An alkaline aqueous solution is used. In the formation method of the present invention, a beta step and a rinse step may be further combined.

Example

[0144] The present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

In the examples, the gel permeation chromatography method is the GPC method, the weight average molecular weight is Mw, the number average molecular weight is Mn, dichloropentafluoropropane is R225, diisopropyl peroxydicarbonate is IPP, Propylene glycol methyl ether acetate is indicated as PGMEA, tetrahydrofuran as THF, methyl ethyl ketone as MEK, cyclopentanone as CP, and tetramethyl ammonium hydroxide as TMAH.

[0145] [Example 1] Production example of resist polymer (R)

[Example 1 1] Production example of polymer (R ¹ )

In the reactor, the following compound (r ¹ ) (10.4 g), the following compound (q ¹ ) (3.7 g), the following compound (p ¹ ) (8. Og) and ΜΕΚ (76.5 g) were charged. Next, isopropanol (6.3 g) was used as a chain transfer agent, and IPP (11. Og) diluted to 50% by mass with R225 was charged as a polymerization initiator. After freezing and degassing the reactor, a polymerization reaction was carried out at 40 ° C for 18 hours.

[0146] [Chemical 39]

[0147] After the polymerization reaction, the solution in the reactor is dropped into hexane to recover the aggregated solid, and the solid is vacuum-dried at 90 ° C for 24 hours to contain no fluorine atoms. Resist polymer; Polymer (R ¹ ) (15.9 g) was obtained.

[0148] The polymer (R ¹ ) was a white powdery amorphous polymer at 25 ° C. Mn based on the polymer was 2870, and Mw was 6600. As a result of measurement by ¹³ C-NMR method, the polymer (R ¹ ) was found to contain 40 mol% of the repeating unit of the compound (r ¹ ) and 40 mol of the repeating unit of the compound (q ¹ ) with respect to all repeating units. ^_0/0 and compounds of repeating units of (p ¹⁾ was 20 mol ^_0/0 including polymers.

The polymer (R ¹ ) was soluble in THF, PGMEA, and CP, respectively.

[0149] [Example 1 2] Production example of polymer (R ² )

In the same manner except that the fine adjustment of the polymerization conditions and the amount of compound of Example 1 1, compound (37 moles of repeating units of r ^_0/0, the compound (q ¹⁾ repeating units 43 mole ^_0/0, and the compounds of An Mw7100 polymer (R ² ) containing 20 mol% of the repeating unit (p ¹ ) was obtained.

[0150] [Example 2] Evaluation example of solvent solubility of resist polymer

[Example 2 1] Solvent solubility evaluation example of polymer (R ¹ )

A PGMEA solution containing polymer (R ¹ ) is spin-coated on a silicon wafer, and then heated at 100 ° C for 90 seconds to form a polymer (R ¹ ) thin film (thickness 150 nm) on the surface. A silicon wafer was obtained.

1.5 hours of thin film when the silicon wafer is immersed in various solvents shown in Table 1 below The film reduction rate after 18 hours and the film reduction rate after 18 hours were measured. The measurement was performed using F20 manufactured by Filmetrics. The results are summarized in Table 1.

The film reduction rate (%) after a certain time is calculated by the following formula. Thinning rate (%) = ((Thin film thickness after a certain time (unit: _nm ) — 150) Z150 X 100

[table 1]

However, C ₅ H ₃ F ₇ are the following compounds.

[0152] [Chemical 40]

[Example 2—2] Example of solvent solubility evaluation of polymer (R ² )

90 mass of PGMEA. Polymer () was dissolved in a mixed solvent containing 10% by mass of / ₀ and CP to obtain a resin solution containing 10% by mass of polymer (R ² ). The resin solution is spin-coated on a silicon wafer, heated on a hot plate at 100 ° C for 90 seconds, and a thin film (unit: nm) of a polymer (R ² ) with a predetermined initial film thickness is formed on the surface. A formed silicon wafer was obtained.

The thin film of the silicon wafer was brought into contact with various solvents shown in Table 2 below for a predetermined time, and the film thickness after the solvent was purged was measured. The results are summarized in Table 2.

[0154] [Table 2] Solvent type Thin film thickness (nm)

Initial film thickness 1 minute later 2 minutes later 5 minutes later 10 minutes later

1, 3-Bis (Trifluoro ¹ til) 2 6 2 2 6 2 2 6 2 2 6 1 2 6 1

2-Methyl-toff 'mouth', reel 2 5 8 2 5 3 2 4 8 2 4 0 2 3 8

4 Cyl-2-hexane 2 6 0 2 5 5 2 5 2 2 5 0 2 4 5

3 Chill -1 -F 2 Tal 2 5 9 2 5 3 2 5 1 2 4 5 2 3 8 Hex 2 6 0 2 5 3 2 5 0 2 4 1 2 3 1 [0155] From the above results, it can be seen that the resist polymer (R) is hardly denatured by a fluorine-based solvent (S) such as 1,3-.

[0156] [Example 3] Production example of fluoropolymer

[Example 3 1] Production example of polymer (F ¹ )

CF = CFCH CH (C (CF) OH) CH CH = CH; Cyclopolymerization of compound (bl ¹ )

2 2 3 2 2 2

As a result, a Mwl 1000 fluoropolymer; polymer (F ¹ ) composed of the following repeating unit (B ^U1 ) was obtained.

[0157] [Chemical 41]

[Example 4] Production example of resist protective film forming composition

[Example 4 1] Production example of composition (1)

Obtained by dissolving the polymer (F ¹ ) in a mixed solvent containing 99.5% by mass of 1,3 bis (trifluoromethylenole) benzene and 0.5% by mass of 2-methyl-1-ol The solution was filtered through a 0.2 m pore size filter (manufactured by PTFE) to obtain a 3.5 mass% polymer (a solution of a mixed solvent containing F 2; composition (1)).

[0159] [Example 4 2] Production example of composition (2)

The same procedure is applied except that the mixed solvent in Example 4-1 is changed to a mixed solvent containing 95.1 mass% of 1,3-bis (trifluoromethyl) benzene and 4.9 mass% of 2 methyl-1 propanol. Thus, a mixed solvent solution containing 4.5% by mass of the polymer (F ¹ ) was obtained.

A solution of the above mixed solvent (2.097 g) and a 1,3 bis (trifluoromethyl) benzene solution (1.366 g) containing 0.38% by mass of a homopolymer of the following compound (fl l ¹ ) A solution containing 5.5% by mass of the homopolymer based on the polymer (F ¹ ) after mixing, filtering through a filter having a pore size of 0.2 111 (made of PTFE); Composition (2) Got.

[0160] [Chemical 42]

[0161] [Example 4 3 (Comparative)] Production Example of Composition (X)

The solution obtained by dissolving the polymer (F ¹ ) in 2-methyl-1-propanol was filtered through a 0.2 μm filter (made of PTFE) to obtain 3.5% by mass. A solution of 2-methyl-1 propanol containing the polymer (F ¹ ); composition (X) was obtained.

[0162] [Example 5] Evaluation example of intermixing of resist protective film forming composition

A resin solution containing a polymer (R ² ) is spin-coated on a silicon wafer, and then heated at 100 ° C. for 90 seconds to give a predetermined initial film thickness (unit: polymer) of the polymer (R ² ) on the surface. nm) was obtained.

The composition (2) is spin-coated on the surface of the thin film, and then heated at 100 ° C. for 90 seconds to form a silicon wafer, a polymer (R ² ) thin film, and a polymer (F ¹ ) thin film. A silicon wafer formed in this order was obtained.

The silicon wafer was immersed in an alkaline aqueous solution containing 2.38% by mass of TMAH for 60 seconds and rinsed with ultrapure water for 10 seconds to remove the polymer (F ¹ ) thin film (R The film thickness (late film thickness) of ² ) was measured. In addition, the change in the thin film surface of the polymer (R ² ) after removing the thin film of the polymer (F ¹ ) was observed. The same measurement was performed using composition (X) instead of composition (2). The results are summarized in Table 3.

[0163] [Table 3]

[Example 6] Example of resist pattern formation

Polymer (R ¹ ) (lg) and photoacid generator triphenylsulfonium triflate HO. 05g) are dissolved in PGMEA (lOmL) and filtered through a 0.2m filter (PTFE). To obtain a photosensitive resist composition. The photosensitive resist composition is spin-coated on the surface of a silicon wafer with an antireflection film (trade name AR26 manufactured by ROHM AHD HAAS Electronic Materials) on the surface, and then at 100 ° C for 90 seconds, further 130 ° A silicon wafer having a photosensitive resist layer (thickness 150 nm) formed on the surface was obtained by heat treatment at C for 120 seconds.

[0165] Furthermore, after the composition (1) was spin-coated on the surface of the photosensitive resist layer of the silicon wafer, the substrate, the photosensitive resist layer, and the substrate were subjected to heat treatment at 100 ° C for 90 seconds. Then, a resist protective film layer strength S made of the polymer (F ¹ ) and a silicon wafer formed in this order were obtained.

[0166] An exposure test of 90 nmL / S of the silicon wafer was performed using an immersion lithography process using a two-beam interference exposure apparatus (light source: laser light with a wavelength of 193 nm) (an immersion liquid: ultrapure water.) It went by. Subsequently, the silicon wafer was heated at 130 ° C. for 60 seconds. Furthermore, the silicon wafer photosensitive resist layer was developed using an alkaline aqueous solution containing 2.38 mass% of TMAH at 23 ° C to form a silicon wafer on which a resist pattern formed from the photosensitive resist layer was formed. Got.

[0167] A silicon wafer on which a resist pattern was formed was obtained in the same manner except that the composition (X) was used instead of the composition (1). Table 4 summarizes the results of confirming the shape of the resist pattern formed on each silicon wafer using SEM images.

[0168] [Table 4]

[0169] From the above results, the alkali-soluble resist protective film material (polymer (F ¹ ), etc.) containing the fluorine-containing polymer (F) and the fluorine-based solvent (S) (1, 3-bis (Trifluoromethyl) benzene etc.) and a resist resist film comprising a resist polymer (R) (polymer (R ¹ ) etc.) It can be seen that a resist pattern with high shape accuracy can be obtained by forming on the surface.

Industrial applicability

[0170] According to the present invention, there is provided a stable resist protective film-forming composition that enables high-speed implementation of an immersion lithography method capable of forming a highly accurate resist pattern. The entire contents of the specification, claims and abstract of the Japanese Patent Application No. 2006-266679 filed on September 29, 2006 are cited here as the disclosure of the specification of the present invention. Incorporated.

Claims

The scope of the claims

[1] A resist protective film-forming composition comprising the following resist protective film material and the following solvent, and applied to the surface of the following photosensitive resist layer.

[2] The resist protective film-forming composition according to claim 1, wherein the resist polymer (R) is a resist polymer containing no fluorine atom.

[3] A monomer in which the resist protective film material has at least one functional group selected from the group consisting of a hydroxy group, a carboxy group, a sulfonic acid group, a sulfonylamide group, an amino group, and a phosphoric acid group ( The resist protective film-forming composition according to claim 1 or 2, comprising an alkali-soluble fluoropolymer (F ^P ) containing a repeating unit (B ^u ) formed by polymerization of b ^M ).

[4] The resist protective film material is a compound represented by the formula CF = CF-Q ^BM1 -CH = CH

twenty two

However, Q ^BM1 represents an alkylene group or a fluorinated alkylene group having a hydroxy group or a carboxy group, and the remaining portion excluding the hydroxy group or the carboxy group has a carbon number of 1 to 5. The resist protective film-forming composition according to any one of claims 1 to 3, comprising a fluorine-containing polymer (F ^P1 ) containing a repeating unit formed by polymerization of

[5] The resist protective film material is a monomer having a fluorine-containing ring structure or a monomer that forms a repeating unit having a fluorine-containing ring structure by cyclopolymerization, and has a fluorine content of 50 The resist protective film-forming composition according to any one of claims 1 to 3, comprising a fluorine-containing polymer containing a repeating unit formed by polymerization of ~ 76% by mass of a monomer.

6. The resist protective film-forming composition according to any one of claims 1 to 5, wherein the solvent is a mixed solvent containing a fluorine-based solvent (S) and an organic solvent not containing a fluorine atom.

[7] The resist protective film-forming composition according to any one of [1] to [6], wherein the fluorine-based solvent (S) is a hydrated fluorocarbon-based solvent.

[8] The fluorinated solvent (S) is 1,3-bis (trifluoromethyl) benzene; The composition for forming a resist protective film according to any one of the above.

A resist pattern forming method using an immersion lithography method, which is a polymer whose alkali solubility is increased by the action of an acid on the surface of a substrate and has a fluorine content higher than that of the fluoropolymer (F). A step of forming a photosensitive resist layer containing a low resist polymer (R), and applying a resist protective film forming composition containing the following resist protective film material and the following solvent on the surface of the photosensitive resist layer Further, by removing the solvent and forming a resist protective film layer on the surface of the photosensitive resist layer, an immersion lithography step, and a step of developing the photosensitive resist layer in this order, A resist pattern forming method for obtaining a base material on which a resist pattern is formed.

Resist protective film material: An alkali-soluble material containing a fluoropolymer (F).

Solvent: A solvent containing at least one fluorine-based solvent (S) selected from the group consisting of a noble mouth fluorocarbon solvent and a hyde mouth fluoroether solvent.