WO2008044741A1

WO2008044741A1 - Resist composition for use in lithography method utilizing electron beam, x-ray or euv light

Info

Publication number: WO2008044741A1
Application number: PCT/JP2007/069881
Authority: WO
Inventors: Takasi Sasaki; Osamu Yokokoji
Original assignee: Asahi Glass Company, Limited
Priority date: 2006-10-12
Filing date: 2007-10-11
Publication date: 2008-04-17
Also published as: JPWO2008044741A1; TW200832057A

Abstract

Disclosed is a resist composition for use in a lithography method utilizing electron beam, X-ray or EUV light. Specifically disclosed is a resist composition for use in a lithography method utilizing electron beam, X-ray or EUV light, comprising: a fluorinated polymer (F) which has a repeating unit (F) having a fluorinated aromatic ring structure in a side chain and whose alkali solubility can be increased by the action of an acid; and a compound capable of generating an acid. For example, the repeating unit (F) is a repeating unit (FV) [wherein RF represents a hydrogen atom, a halogen atom, a methyl group, or a halomethyl group (provided that three pieces of RF's may be the same as or different from one another); YF represents an acid-degradable group having 1 to 20 carbon atoms or a hydrogen atom; and p, q and r independently represent an integer of 0 to 5, provided that the sum total of p, q and r is 1 to 5].

Description

Specification

Resist composition used in lithography method using electron beam, X-ray or EUV light

Technical field

TECHNICAL FIELD [0001] The present invention relates to a resist composition used in a lithography method using electron beam, X-ray or EUV light, and a resist forming composition containing the resist composition and an organic solvent.

Yes

Background art

In the manufacture of integrated circuits such as semiconductors, a mask pattern obtained by irradiating a mask with exposure light source light is projected onto a photosensitive resist film on a substrate, and the pattern is formed on the photosensitive resist film. A transfer lithography method is used. As the exposure light source has a shorter wavelength, the transferred pattern can be made finer. Therefore, ArF excimer laser light (wavelength 193 nm) and F excimer laser light (wavelength 157 nm) have been studied as exposure light sources. And

2

The force of the acid used in the lithography method using F excimer laser light

2

As resist composition Li solubility is increased, the resist composition comprising a fluoropolymer comprising the following repeating units (G ^ ¹⁾ is known as following repeating unit (FVL ¹⁾ (see Patent Document 1.) .

[0003] [Chemical 1]

(F ^V 1 ¹ ) (G ^V 2 ¹ ) On the other hand, as a next-generation lithography method for forming finer patterns, a lithography method using electron beam, X-ray or EUV light as an exposure light source has attracted attention in recent years. ing. In the lithography method, a resist composition containing a polymer whose alkali solubility is increased by the action of an acid and a compound capable of generating an acid (acid generator) is usually used. The polymer has a non-acid-decomposable group and does not have a fluorine atom! /, And a polymer containing a repeating unit of styrenes (the following repeating unit (P ^V1 ) and the like) (see Patent Document 2). ) And a polymer containing a repeating unit having a fluorine-containing aliphatic ring structure (the following repeating unit ( ^FANb ) etc.) (see Patent Document 3) is known.

[0005] [Chemical 2]

[0006] Further, in Non-Patent Documents 1 and 2, a resist composition containing a polymer containing a repeating unit of styrenes having a chlorine atom or a bromine atom does not contain the repeating unit! / It has been reported that the sensitivity to electron beams is higher than that of the resist composition. However, Non-Patent Documents 1 and 2 describe a fluorine-containing polymer containing a repeating unit of styrenes having a fluorine atom.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-002925

Patent Document 2: JP 2005-266801 A

Patent Document 3: Japanese Patent Laid-Open No. 2005-275283

Non-Patent Document l: Jpn. J. Appl. Phys. 43 (6B), 2004, pp. 3971— 3973

Non-Patent Document 2: Jpn. J. Appl. Phys. 44 (26), 2005, pp. L842-L844

Disclosure of the invention

Problems to be solved by the invention

[0008] The resist composition used in the lithography method is preferably highly sensitive to electron beams, X-rays or EUV light from the viewpoint of forming a very fine pattern. In order to prepare such a resist composition, a polymer that easily generates ionized screening or secondary electrons by electron beam, X-ray or EUV light and has increased alkali solubility by the action of an acid is used. However, it is useful as a technique for promoting the acid generation of the acid generator in the resist composition. In addition, the resist film formed from the resist composition on the substrate is preferably excellent in etching resistance from the viewpoint of forming a very fine pattern on the substrate!

There is no known resist composition that satisfies these characteristics.

An object of the present invention is to provide a resist composition excellent in etching resistance desired from the viewpoint of forming an ultrafine pattern with high sensitivity to electron beam, X-ray or EUV light.

Means for solving the problem

That is, the present invention has the following gist.

[1] A battery comprising a fluorine-containing polymer (F) whose alkali solubility is increased by the action of an acid containing a repeating unit (F) having a fluorine-containing aromatic ring structure in the side chain, and a compound capable of generating an acid. A resist composition used in a lithography method using a core beam, X-ray or EUV light.

[0010] The composition according to claim 1, wherein the repeating unit (F) is a repeating unit represented by the following formula (F ^v ).

[0011] [Chemical 3]

[0012] Symbols in the formula have the following meanings.

R ^F : a hydrogen atom, a halogen atom, a methyl group or a halomethyl group, and three R ^F may be the same or different.

Y ^F : a hydrogen atom or an acid-decomposable group having 1 to 20 carbon atoms.

p, q and r are each independently an integer of 0 to 5, and the sum of p, q and r is an integer of!

[0013] [3] The repeating unit (F) is at least one selected from the group consisting of repeating units represented by the following formula (F ^v l), the following formula (F ^v ¾, and the following formula (F ^v 3): The resist composition according to [1] or [2], which is a seed repeating unit (F ^v n). [0014] [Chemical 4]

(F ^V D (F ^V 2) (F ^V 3)

[0015] Symbols in the formula have the following meanings.

rl, r2 and ql: each independently; an integer between!

Y ^F2 : an acid-decomposable group having carbon number;

[4] The weight average molecular weight of the fluoropolymer (F) is from 1000 to 100,000. ] To [3] V, a resist composition according to any one of the above.

[5] The ratio of the weight average molecular weight to the number average molecular weight of the fluoropolymer (F) is 2.2 or less! .

[6] The resist composition according to [1] to [5], wherein the ratio of the weight average molecular weight to the number average molecular weight of the fluoropolymer (F) is 1.5 or less.

[0018] [7] The fluoropolymer (F) is at least selected from the group consisting of repeating units represented by the following formula (G ^v l), the following formula (G ^v 2) and the following formula (G ^v 3): The resist composition according to any one of [1] to [6], further including one type of repeating unit (G ^v n).

[0019] [Chemical 5]

[0020] Symbols in the formula have the following meanings.

R ^G : A hydrogen atom, a halogen atom, a methyl group or a halomethyl group, and the three R ^G may be the same or different.

T ^G : a hydrogen atom, a halogen atom, a methyl group or a halomethyl group.

Z ^e and W ^e : each independently an acid-decomposable group having 1 to 20 carbon atoms. _g: An integer from ₁ to 4.

[8] [8] The fluoropolymer (F) is represented by the following formula (Q ^v l), the following formula (Q ^v 2), the following formula (Q ^v 3), and the following formula (Q ^v 4) The resist composition according to any one of [1] to [7], further comprising at least one repeating unit (Q ^V n) selected from the group consisting of units.

[0022] [Chemical 6]

(Q ^v 1) (Q 2) (Q ^v 3) (Q 4)

[0023] Symbols in the formula have the following meanings.

R ^Q : A hydrogen atom, a halogen atom, a methyl group or a halomethyl group, and the three R ^Qs may be the same or different.

T ^Q: hydrogen atom, a halogen atom, a methyl group or a halomethyl group.

q _: An integer from ₁ to 4.

[9] The acid generating compound is a diazonium salt, a phosphonium salt, a sulfonium salt, an iodine salt, an imide sulfonate, oxime sulfonate, diazodisulfone, disulfone, or o-nitrobenzil sulfonate, In addition, the resist according to any one of [1] to [8], wherein the acid generating compound is contained in an amount of 0 to 20% by mass based on the total mass of the fluoropolymer (F). Composition.

[0025] [10] [;! ] The resist formation composition used for the lithography method using an electron beam, an X-ray, or EUV light containing the resist composition in any one of [9], and an organic solvent.

[11] The resist forming composition according to [10], wherein the organic solvent is an alcohol compound, a ketone compound, an ester compound, an aromatic hydrocarbon compound, an ether compound, or an amide compound.

The invention's effect

[0026] According to the present invention, a resist set used in a lithography method using electron beam, X-ray or EUV light, which has high sensitivity to electron beam, X-ray or EUV light and excellent etching resistance. A composition is provided.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present specification, symbols in groups are as defined above unless otherwise specified.

In this specification, the compound represented by the formula (f) is the compound (f), the repeating unit represented by the formula (F) is the repeating unit (F), the formula — C (CF) (OY) — C (CF) (

3 2 3 2

OY). Other compounds and other groups are also described in the same manner.

The exposure in the present invention is a concept including electron beam irradiation.

[0028] The present invention relates to a fluorine-containing polymer (F) whose alkali solubility is increased by the use of an acid containing a repeating unit (F) having a fluorine-containing aromatic ring structure in the side chain, and a compound capable of generating an acid. There is provided a resist composition for use in a lithography method using an electron beam, an X-ray or EUV light (hereinafter also simply referred to as a lithography method), which comprises (an acid generator).

[0029] Since the fluorine-containing polymer (F) in the present invention has a fluorine atom having a large absorption cross section for electron beam, X-ray or EUV light, is it easily ionized by electron beam, X-ray or EUV light? It is thought that secondary electrons are likely to be emitted. In particular, since the fluoropolymer (F) has a fluorinated aromatic ring structure having π electrons, it emits secondary electrons as compared with a fluorinated polymer having a fluorinated aliphatic ring structure. It is considered easy. Therefore, in the resist composition of the present invention, it is considered that the fluorine-containing polymer (F) is immediately activated by electron beam, X-ray or EUV light and promotes acid generation of the acid generator. Therefore, the resist composition of the present invention is considered to be highly sensitive to electron beams, X-rays or EU V light, where the acid generating efficiency of the acid generator is high.

[0030] Furthermore, since the fluorinated polymer (F) contains the repeating unit (F) having a fluorinated aromatic ring structure, it is compared with the fluorinated polymer containing a repeating unit having a fluorinated aliphatic ring structure. Etching resistance is excellent. Therefore, by using the resist composition of the present invention, it is possible to form a very fine pattern by a lithography method using electron beam, X-ray or EUV light.

[0031] The repeating unit (F) in the fluoropolymer (F) may be composed of only one kind or two or more kinds! /, May! /.

[0032] The fluorine-containing aromatic ring structure of the repeating unit (F) is an aromatic ring structure having a fluorine atom. Is not particularly limited, and may be a monocyclic fluorine-containing aromatic ring structure or a polycyclic fluorine-containing aromatic ring structure, or preferably the following fluorine-containing aromatic ring structure. (Note that the position of the carbon atom of the benzene ring to which —CF F -C (CF) OY ^F is bonded is

3 3 2

There is no particular limitation. ).

[0033] [Chemical 7]

[0034] Further, the fluorinated aromatic ring structure has a linking group (one C (0) on the side chain of the fluorinated polymer (F) which may be directly bonded to the main chain of the fluorinated polymer (F). ) 0 O— etc.).

[0035] repeating unit (F) is the following repeating unit (F ^v) are preferred (Note that, - CF - F - C (

Three

The position of the carbon atom of the benzene ring to which CF) OY ^F is bonded is not particularly limited. ).

[0036] [Chemical 8]

[0037] The three R ^F in the repeating unit (F ^v ) are preferably hydrogen atoms.

Y ^F is an acid-decomposable group having a carbon number of 1 20 is not particularly limited, Y ^F2 a and even preferable instrument later group (Y ^F21) described later, below the group (Y ^F22) or later group (Y ^F23 ) is particularly preferred.

The sum of p q and r is preferably an integer of 13.

It is preferable that one of p q and r is an integer of 13 and the remaining two are 0.

[0038] The fluoropolymer (F) containing the repeating unit (F ^v ) is preferably produced by polymerization of the following compound (f). [0039] [Chemical 9]

[0040] The repeating unit (F) is at least one repeating unit selected from the group consisting of the following repeating unit (F ^v l), the following repeating unit (F ^v 2) and the following repeating unit (F ^v 3) ( F ^v n) (in each repeating unit, CF F or C

The position of the carbon atom of the benzene ring to which (CF) OY ^ is bonded is not particularly limited. ) <

[0041] [Chemical 10]

(F ^V D (F ^V 2) (F ^V 3)

[0042] Y ^F2 is not particularly limited, and is represented by the formula — a group represented by C (Y ^A ) (Y ^ OY): a group (Y ^F21 ), a formula — (O) C (Y ^D ). group: group (Y ^F22) or formula - C (Y ^D) a group represented by: group (Y ^{F 23)} preferably Ru der.

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

Y ^A , Υ ^Β : each independently a hydrogen atom or a hydrocarbon group having 1 to 8 carbon atoms. Y ^E : a hydrocarbon group having 1 to 16 carbon atoms.

Y ^D : a hydrocarbon group having! To 16 carbon atoms, and three Y ^D on the same carbon atom may be the same or different. Also, two Y ^D is to form a jointly with the carbon atom cyclic hydrocarbon group in the formula! /, It is good les.

[0043] Specific examples of the group (Y ^F21 ) include the following groups.

[0044] [Chemical 11] → ^)

-CH ₂ OC (CH ₃ ) ₃

CH _2- <^;; ^

[0045] Specific examples of the group (Y ^ include the following groups _c

[0046] [Chemical 12]

[0047] Specific examples of the group (Y ^F23 ) include the following groups _c

[0048] [Chemical 13]

Examples of [0049] the repeating units (F ^v l), include the following repeating units.

[0050] [Chemical 14]

[0051] Specific examples of the repeating unit (F ^v 2) include the following repeating units _c [0052] [Chemical Formula 15]

[0053] Specific examples of the repeating unit (F ^v 3) include the following repeating units _c

[0054] [Chemical 16]

[0055] The fluoropolymer (F) preferably contains 1 mol% or more of repeating units ( ^Fvn ) with respect to all repeating units. The upper limit of the repeating unit (F ^vn ) is not particularly limited and is preferably 80 mol% or less. Repeating units (F ^v n) is particularly preferably 1 to 50 mol% containing Murrell on all repeating units.

[0056] The fluoropolymer (F) is a fluoropolymer whose alkali solubility is increased by the action of an acid. The fluoropolymer (F) preferably contains a repeating unit having an acid-decomposable group. The following repeating unit (G ^V 1), the following repeating unit (G ^V 2) and the following repeating unit (G ^V 3) are preferred. It is particularly preferred to include at least one repeating unit (G ^V n) selected from the group consisting of

[0057] [Chemical 17]

Three R ^G in the repeating unit (G 1) and (G ^V 2) is the is not preferable a hydrogen atom.

T ^G is in the repeating unit (G ^V 3), a hydrogen atom, a fluorine atom, is preferably a methyl group or a triflate Oromechiru group! /,.

Z in the repeating units (G ^V 1) and (G ^V 2) and W in the repeating unit (G ^V 3) are each independently preferably Y ^F2 , and the group (Y ^F21 ), group (Y ^F22 ) or Group (Y ^F23 ) is particularly preferred Good.

Repeating unit (G ^v l) and in (G ^v 2) g is preferably 1.

Examples of [0059] the repeating units (G ^v l), include the following repeating units.

[0060] [Chemical 18]

Examples of [0061] the repeating units (G ^v 2), include the following repeating units.

[0062] [Chemical 19]

[0063] Specific examples of the repeating unit (G ^V 3) include the following repeating units.

[Chemical 20]

[0064] The fluoropolymer (F) preferably contains 1 mol% or more of repeating units (G ^V n) having an acid-decomposable group based on all repeating units! /. The upper limit of the repeating unit (G ^V n) is not particularly limited and is preferably 80 mol% or less.

The repeating unit having an acid-decomposable group (G ^V n) is 10 to 50 moles relative to all repeating units.

It is especially preferred to contain%.

[0065] The fluoropolymer (F) is a group consisting of the following repeating units (Q ^v l), the following repeating units (Q ^V 2), the following repeating units (Q ^v 3), and the following repeating units (Q ^v 4). It also contains at least one repeating unit (Q ^v n) selected from

[0066] [Chemical 21]

^{^{(Q V D (Q V 2}} ) (Q 3) (Q v 4)

[0067] repeating units (Q ^v:!) ~ Three in ^(Q ^v 3) R Q is preferably a hydrogen atom.

T ^Q in the repeating unit (Q ^v 4) is preferably a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group! /.

Q in the repeating units (Q ^V 1) and (Q ^V 2) is preferably 1.

[0068] Specific examples of the repeating unit (Q ^v l) include the following compounds. [0069] [Chemical 22]

[0070] Specific examples of the repeating unit (Q ^v 2) include the following compounds.

[0071] [Chemical 23]

[0072] Specific examples of the repeating unit (Q ^V 3) include the following compounds _c

[0073] [Chemical 24]

[0074] Specific examples of the repeating unit (Q ^v 4) include the following compounds.

[Chemical 25]

[0075] The fluoropolymer (F), based on all repeating units preferably contains repeating units (Q ^v n) 1 mol% or more. Moreover, the upper limit of the repeating unit (Q ^V n) is not particularly limited, and is preferably 80 mol% or less. It is particularly preferable that the repeating unit (Q ^V n) is contained in an amount of 10 to 50 mol% based on the total repeating unit! /.

[0076] The weight average molecular weight of the fluoropolymer (F) is preferably 1000 to 100,000, more preferably 1,000 to 20,000 force S. In this case, it is easy to remove the photosensitive portion of the resist film in the development process. [0077] The fluorine-containing polymer (F) is preferably a polymer having a narrow molecular weight distribution! /. The ratio of the weight average molecular weight to the number average molecular weight of the fluorine-containing polymer (F) (weight average molecular weight / number average molecular weight) is preferably 2.2 or less, particularly preferably 1.5 or less. The lower limit of the ratio is not particularly limited and is 1.0 or more.

In this case, the fluoropolymer (F) is highly transparent and sensitive to electron beams, X-rays or EUV light, has a particularly high etching resistance, and is highly soluble in a developer. The composition can be prepared more easily.

The fluorine-containing polymer (F) having a narrow molecular weight distribution is preferably produced by riving radical polymerization of a monomer that forms the repeating unit (F).

However, the living radical polymerization in the present invention only means radical polymerization in which the activity of the polymerization terminal is always maintained in the polymerization of the monomer and the polymerization terminal is inactivated and the polymerization terminal is activated. It also means quasi-living polymerization in which polymerization proceeds while equilibrium with the generated species.

[0078] Living radical polymerization is a method using a reversible addition-cleavage chain transfer agent such as a thiocarbonylthio compound (for example, a method described in WO 1998/001478 pamphlet); a radical such as a cobalt porphyrin complex or a nitroxide compound. A method using a scavenger; it is preferably carried out by an atom transfer radical polymerization method using an organic halide or the like as an initiator and a transition metal complex as a catalyst.

[0079] Preferable embodiment and mode of the fluoropolymer (F) includes a repeating unit (F ^v n) and a repeating unit (G ^v n), and the repeating unit (F ^v Examples thereof include fluorine-containing polymers containing 5 to 50 mol% of n) and 10 to 80 mol% of repeating units (G ^v n). It said containing fluorocarbon polymer may be 5 to 50 mole% containing Ndei against further repeating units (Q ^V n) of all repeating units.

The repeating unit (G ^v n) in the fluoropolymer is preferably a repeating unit (G ^v l). When containing the fluorine-containing polymer repeat units (Q ^V n), the repeating units (Q ^V n) are recurring units (Q ^v 3) and / or q is a repeating unit (Q ^v l) is preferred is 1 That's right.

The weight average molecular weight of the fluoropolymer is preferably 1000 to 30000. Above The ratio of the weight average molecular weight to the number average molecular weight of the fluoropolymer is preferably 2.2 or less, particularly preferably 1.5 or less.

[0080] The acid generator in the present invention is a compound that generates an acid by the action of an electron beam, X-rays or EUV light (hereinafter also referred to as a photoacid generator). Alternatively, it is a compound that generates an acid when a chemical bond is cleaved by irradiation with EUV light. The compound may be a non-polymer compound or a polymer compound.

[0081] The photoacid generator is not particularly limited, and examples thereof include diazonium salts, phosphonium salts, sulfonium salts, iodonium salts, imide sulfonates, oxime sulfonates, diazodisulfones, disulfones, and o ditrobenzyl sulfonates. It is done. The photoacid generator is preferably a compound that generates sulfonic acid when irradiated with active light! Examples of the compound include sulfonium salts, iodine salts, imidonosulfonates, oxime sulfonates, diazodisulfones, and disulfones.

[0082] Specific examples of the photoacid generator include diphenyl nitronium triflate, diphenyl dolom pirans norephonate, diphen ylrenodon hexafnoreo oral antimonate, difenil Donumdodecyl benzene sulfonate, bis (4-tert-butylphenol) iodine triflate, bis (4 tert-butylphenyl) odonum dodecyl benzene sulphonate, triphenylenosenorephonium triflate Fret, trifeninores norehononyumanonate, trifenenoresnorehonom perfunoleo octanes norephonate, trifenenoles norehonium hexafnoreo antimonate, trifenenoresnoreno naphthalene norenoate, Trifenenolesnorehonium Trifnoreolomethanesuno Rehonate, triphenylenosrephonicum camphor sulfone, 1 (naphthylacetomethinole) thiolanium triflate, cyclohexylmethyl (2-oxocyclohexyleno) sulfonium triflate, dicyclohexyl (2 Oxocyclohexyl) sulfonium triflate, dimethyl (4-hydroxynaphthinole) snorefonymutosylate, dimethylenole (4-hydroxynaphthonole) snorephonum dodecino benzenesulfonate, dimethyl (4-hydroxynaphthyl) sulphonium naphthalene Nolephonate, Triphenylsulfonium camphorsulfonate, (4-Hydroxyphenyl) benzylmethylsulfonyltoluenesulfonate, (4-Methoxyphenyl) phenol nitromethane Honate, Bis (t-butylphenol) Nororomethanesulfonate, phenylrubis (trichloromethyl) S triazine, methoxyphenyl monobis (trichloromethyl) S triazine, naphthyl monobis (trichloromethyl) s triazine, 1, 1-bis (4-crophine phenol) 1, 2, 2-trichloroethane, 4-tris phenacyl sulfone, mesityl phenacyl sulfone, bis (phenylsulfoninole) methane, benzoin tosylate, 1,8-naphthalenedicarboxylic imide triflate, etc. Be

Yes

[0083] The resist composition of the present invention preferably contains 0.;! To 20% by mass of an acid generator based on the total mass of the fluoropolymer (F). % Is particularly preferable.

[0084] In application to an electron beam, X-ray or EUV lithography method, the resist composition of the present invention is usually applied to a substrate surface and dried to form a film. Preferably it is prepared.

The present invention provides a resist forming composition comprising the resist composition of the present invention and an organic solvent. The resist-forming composition of the present invention preferably contains 100 to 10,000 mass% of an organic solvent with respect to the total mass of the fluoropolymer (F).

[0085] The organic solvent is not particularly limited as long as it has high compatibility with the fluoropolymer (F) and the acid generator and is a solvent. The organic solvent may be a fluorine-based organic solvent or may not contain fluorine atoms! /, Or may be a non-fluorine-based organic solvent! /.

[0086] Specific examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, and diacetone alcohol; acetone, methyl isobutyl ketone, cyclohexanone, cyclopentanone, 2-heptanone, N-methylpyrrolidone, and _{butyrololataton} Ketones: propylene glycolenomono methinore ethenore acetate, propylene glycol eno mono methino ethenore propionate, propylene glycol eno mono ethino enoate acetate, canolebitol acetate, methyl 3-methoxypropionate, 3- Ethyl ethoxypropionate, methyl β-methoxyisobutyrate, ethyl butyrate, propyl butyrate, methyl isobutyl ketone, ethyl acetate, 2-ethoxyethyl acetate, isoamyl acetate, methyl lactate, ethyl lactate, etc. Ters; aromatic hydrocarbons such as toluene and xylene; propylene glycol methyl etherate acetate, propylene glycol methanol monomethenoate alcohol, propylene glycol monomer noethino etherenole, ethylene glycol monomer monopropynoleateol, Diethylene glycol Examples include ethers such as noremonomethylenoatenore, diethyleneglycolinomethinereatenore, and propylene glycol monomethyl ether; amides such as N, N-dimethylformamide and N, N-dimethylacetamide.

[0087] The method of forming a resist pattern by the lithography method using an electron beam, X-ray or EUV light using the resist forming composition of the present invention is not particularly limited! /.

As the method for forming the resist pattern, a step of forming a resist film formed from the resist composition of the present invention on the substrate by removing the organic solvent after applying the resist forming composition of the present invention on the substrate. In this order, the resist film on which the resist pattern is formed is obtained by exposing the resist film on the substrate to electron beam, X-ray or EUV light, and developing the resist film to remove the exposed portion. The pattern formation method is listed. In the forming method, a heating process, a rinsing process, and a drying process may be combined as appropriate.

Exposure is a concept that includes irradiation with electron beams, X-rays, or EUV light.

[0088] The substrate is not particularly limited, and examples thereof include a silicon substrate whose surface is coated with silicon dioxide, a glass substrate, an ITO substrate, and a quartz substrate whose surface is coated with chromium oxide.

The development process is performed until an alkaline solution is contacted from the resist film side and the exposed portion of the resist film is removed.

[0089] Specific examples of the alkaline solution include an aqueous alkaline solution containing an alkaline compound selected from the group consisting of sodium hydroxide, potassium hydroxide, ammonium hydroxide, tetramethyl ammonium hydroxide and triethylamine. It is done.

Example

[0090] Power to specifically explain the present invention by way of examples The present invention should not be construed as being limited thereto.

In the examples, the weight average molecular weight is Mw, the number average molecular weight is Mn, and the ratio of Mw to Mn is Mw / Mn. Azobisisobutyronitrile is referred to as AIBN, propylene glycol methyl ether acetate as PGMEA, tetrahydrofuran as THF, and polystyrene as PSt.

As the acid generator, triphenylsulfonium nonaflate, which is a photoacid generator, was used. Yes

In order to produce a polymer, the following compound! / Was used.

[0091] [Chemical 26]

(q ^v 3i)

[0092] The following compound (xl) was used as a reversible addition-cleavage chain transfer agent used in living radical polymerization.

[0093] [Chemical 27]

[0094] Mw and Mn of the polymer were measured by gel permeation chromatography (developing solvent: THF, internal standard: PSt).

Specifically, a SEC column (trade name: TSKgel SuperHZ—2000, 3000, and 4000) manufactured by Tosoh Corporation is used as an analytical column, and an Mw / Mn force of 1.15 or less as an internal standard for molecular weight measurement. Thus, 12 types of PSt (Mw495 force, et al. Mwl ll.000) with different Mw were used. The flow rate of the mobile phase (developing solvent: THF) was 0.35 ml / min, and the column temperature was 40 ° C.

[0095] [Example 1] Production example of fluoropolymer (F) [Example 1 1] Production example of polymer (1)

In a pressure-resistant reaction vessel (internal volume 100 mL, glass), compound (f ^v ll) (7. lg), compound (g ^v l 1) (3. Og), compound (q ^v 31) (l. Og) and Toluene (25 · 8 g) was charged, and then AIBN (0.8 g) was charged as a polymerization initiator.

After freezing and degassing the reactor, the reactor was sealed, and polymerization was carried out at a reactor internal temperature of 60 ° C for 18 hours. Next, the solid content obtained by dripping the solution in the reactor into hexane was collected, vacuum-dried at 80 ° C for 24 hours, and a white powder of amorphous heavy weight at 25 ° C. Combined (1) (8. lg) was obtained. Polymer (1) was soluble in toluene, acetone, THF, and PGMEA, respectively.

[0096] Mn of the polymer (1) was 4600, Mw was 9000, and Mw / Mn was 1 · 96.

As a result of analyzing the polymer (1) using ¹⁹ F-NMR and ¹ H-NMR, the polymer (1) was found to contain 40 mol% of the following repeating units (F ^v ll) with respect to all repeating units. , following repeating unit (G ^V 11) 30 mol ^_0/0, it was confirmed that the fluorine-containing polymer containing 30 mol% of the following repeating units (Q ^V 31).

[0097] [Chemical 28]

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

A pressure-resistant reaction vessel (internal volume 30 mL, glass) is charged with compound (f ^v ll) (3. Og), compound (q ^v 31) (0.4 g), and toluene (7.8 g), and then polymerized ΑΙΒΝ (0 · 3g as initiator

).

After freezing and degassing the reactor, the reactor was sealed, and polymerization was carried out at a reactor internal temperature of 60 ° C for 18 hours. Next, the solid content obtained by dripping the solution in the reactor into hexane was collected, vacuum-dried at 80 ° C for 24 hours, and a white powder of amorphous heavy weight at 25 ° C. Combined (p2) (2.7 g) was obtained. Polymer (p2) is soluble in toluene, acetone, THF, and PGMEA Met.

[0099] A polymer (p2) (2 g) and methanol (10 g) were charged into a round bottom flask (internal volume 50 mL, glass), and a methanol solution (2.2 g) containing 6 mass% sodium hydroxide was further added. After the preparation, the inside of the flask was stirred at 25 ° C for 8 hours under a nitrogen gas atmosphere. Next, the solvent of the solution in the flask was distilled off, and dehydrated THF (20 mL) and CH OCH C1 (0.26 g) were prepared in the flask.

3 2

Then, the reaction was carried out at 25 ° C for 12 hours. In order to remove the inorganic salt precipitated during the reaction, the solution in the flask was filtered, and the filtrate was dropped into hexane to recover the solid content. The solid content was vacuum-dried at 80 ° C. for 12 hours to obtain a white powdery non-crystalline polymer (2) (1.8 g) at 25 ° C. The polymer (2) was soluble in toluene, acetone, THF, and PGME A, respectively.

[0100] Mn of the polymer (2) was 5800, Mw was 11000, and Mw / Mn was 1 · 90.

As a result of analyzing the polymer (2) using ¹⁹ F-NMR and ¹ H-NMR, the polymer (2) was repetitively 28 mol% of the following repeating unit (F ^v 21) with respect to all repeating units. It was confirmed to be a fluoropolymer containing 42 mol% of units (F ^v ll) and 30 mol% of repeating units (Q ^v 31).

[0101] [Chemical 29]

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

In a pressure-resistant reaction vessel (internal volume 100 mL, glass), compound (f31) (1.5 g), compound (g ^v 3 1) (3.0 g), compound (q ^v ll) (l. 7 g), and toluene (5 · 0 g) was charged, and then AIBN (0.8 g) was charged as a polymerization initiator.

After freezing and degassing the reactor, the reactor was sealed, and polymerization was carried out at a reactor internal temperature of 60 ° C for 18 hours. Next, the solid content obtained by dripping the solution in the reactor into hexane was collected, vacuum-dried at 80 ° C for 24 hours, and a white powder of amorphous heavy weight at 25 ° C. The union (3) (2.lg) was obtained. Polymer (3) is soluble in toluene, acetone, THF, and PGMEA, respectively. there were.

[0103] Mn of the polymer (3) was 5200, Mw was 11000, and Mw / Mn was 2 · 12.

As a result of analyzing the polymer (3) using ¹⁹ F-NMR and ¹ Η-NMR, the polymer (3) was found to contain 19 mol% of the following repeating unit (F ^v 31) with respect to all repeating units. repeating unit (G ^v 31) 45 mole ^_0/0, it was confirmed that the fluorine-containing polymer below containing repeating units (Q ^V 11) 36 mol ^_0/0.

[0104] [Chemical 30]

(F ^v 31) (G ^v 31) (Q ^v 11)

[0105] [Example 1 4] Production example of polymer (4)

Compound (f ^v 31) (0.33g), compound (g ^v 21) (1. Og), compound (pq ^v ll) (1 · 6g) and toluene in a pressure-resistant reaction vessel (internal volume 100mL, glass) (2.2 g) was charged, followed by ΑΙΒN (0. Olg) and compound (χ ¹ ) (0.004 g).

After freezing and degassing the inside of the reactor, the reactor was sealed and living radical polymerization was carried out at a reactor internal temperature of 80 ° C for 18 hours. Next, the solid content obtained by dripping the solution in the reactor into methanol was recovered and vacuum-dried at 80 ° C for 24 hours to obtain a pink powdery amorphous polymer (p4) (2 8g) was obtained. A glass reactor is charged with polymer (p4) (2.8 g) and THF (lOmL), and then charged with a THF solution (25 mL) containing 1 · Omol / L of tetraptyl ammonium fluoride. The reaction was performed at a reactor internal temperature of 25 ° C for 4 hours.

[0106] Next, the solid content obtained by dripping the solution in the reactor into water was collected and vacuum-dried at 80 ° C for 24 hours to obtain a brown powdery amorphous polymer (4 ) (1.8 g) was obtained. The polymer (4) was soluble in toluene, acetone, THF, and PGMEA, respectively.

[0107] Mn of the polymer (4) was 8800, Mw was 12000, and Mw / Mn was 1.36.

As a result of analyzing the polymer (4) using ¹⁹ F-NMR and ¹ H-NMR, the polymer (4) was found to contain 9 mol% of the repeating unit (F ^v 31) with respect to all repeating units. The following repeating unit (G ^V 21) is 46 It was confirmed that the polymer contained 45% by mole of the repeating unit (Q ^v l 1).

[0108] [Chemical 31]

[Example 1 5 (Comparative Production Example)] Production Example of Polymer (c)

In a pressure-resistant reaction vessel (internal volume 100 mL, glass), compound (g ^v 31) (3. Og), compound (q ^v 31) (0.8 g), compound (q ^v ll) (1.7 g) and toluene (10 g) was charged, and then AIBN (0.6 g) was charged as a polymerization initiator.

After freezing and degassing the reactor, the reactor was sealed, and polymerization was carried out at a reactor internal temperature of 60 ° C for 18 hours. Next, the solid content obtained by dripping the solution in the reactor into hexane was collected, vacuum-dried at 80 ° C for 24 hours, and a white powder of amorphous heavy weight at 25 ° C. Combined (c) (3.5 g) was obtained. The polymer (c) was soluble in toluene, acetone, THF, and PGMEA, respectively.

[0110] Mn of the polymer (c) was 7300, Mw was 12000, and Mw / Mn was 1 · 64.

Polymer (c) a ¹⁹ F- NMR and ¹ H - NMR of Yore, was analyzed Te, relative to the polymer (c) the total repetition units, the repeating units (Q ^v ll) 33 mol ⁰ / ₀ , a polymer containing 42 mol% of repeating units (G ^v 31) and 25 mol% of repeating units (Q ^v 31) was confirmed.

[0111] [Example 2] EUV light exposure evaluation example

The solution obtained by dissolving polymer (1) (lg) and acid generator (0. lg) in PGMEA (20 g) was filtered through a 0.2 Hm filter (made of PTFE). Thus, a resist-forming composition (1) was obtained.

The resist-forming composition (1) is spin-coated on a silicon substrate surface-treated with hexamethyldisilazane, and the silicon substrate is heated at 100 ° C. for 90 seconds to form a resist-forming composition (1) force. A silicon substrate having a resist film (thickness 0.15 ΐη) was obtained.

[0112] Each EUV light having an exposure intensity of 0 · 1, 0.5, 1, 2, 3, 5, 8, 10 mJ / cm ² is exposed to a specific portion of the resist film of the silicon substrate. did. EUV light exposure For this, EUVES-7000 manufactured by RISOTEC JAPAN was used.

Next, the silicon substrate was heated at 100 ° C. for 90 seconds, and the resist film was developed with an alkaline solution to remove the resist film exposed to EUV light. Next, the remaining film thickness of the resist film was measured according to the exposure intensity of the exposed EUV light.

Further, an EUV exposure test was conducted in the same manner except that the polymer (c) was used instead of the polymer (1).

Table 1 summarizes the remaining resist film thickness (unit: nm) for each EUV exposure test according to the exposure intensity of the exposed EUV light.

[table 1]

[0114] Also, in the case of conducting an EUV exposure test in the same manner except that the polymer (2), (3) or (4) is used instead of the polymer (1), the resist film is completely exposed. The exposure intensity of EUV light necessary for removal by development is 1. OmJ / cm ² or less.

From the above results, the resist film formed from the fluorine-containing polymer (polymers (1) to (4)) containing a repeating unit having a fluorine-containing aromatic ring structure does not contain the repeating unit. Compared to a resist film formed from a polymer (polymer (c)), it is completely exposed to low-intensity EUV light, indicating that it is highly sensitive to EUV light.

[0116] [Example 3] Example of evaluation of etching resistance

A solution obtained by dissolving the polymer (1) (lg) in PGMEA (15 g) was filtered through a filter (PTFE) having a pore size of 0.2 m to obtain a polymer solution. The polymer solution is The silicon substrate was spin-coated on the recon substrate, and the silicon substrate was heated at 100 ° C. for 90 seconds to obtain a silicon substrate having a polymer (1) thin film (film thickness 0.2 ίη).

Subsequently, the silicon substrate was subjected to an etching test, and the etching rate of the polymer (1) thin film was measured. The etching test was performed using RIE-10NR manufactured by Samco (etching conditions: pressure: 2 Pa, etching gas: CF (80% by volume) and O (20% by volume)).

4 2

Mixed gas, output: 70W, time: 60 seconds. ).

[0117] A similar etching test was conducted using a thin film of polymer (c) or poly-p-hydroxystyrene (Mw8000) instead of polymer (1), and polymer (c) and poly-p-hydroxystyrene were used. The etching rate (unit: nm / min) of len was measured.

Table 2 summarizes the etching rate ratio of the polymer (1) or the polymer (c) to the etching rate of poly (p-hydroxystyrene).

[0118] [Table 2]

[0119] Also, in the case where an etching test is performed in the same manner except that the polymer (2), (3) or (4) is used instead of the polymer (1), the etching rate of poly (P-hydroxystyrene) is The etching rate ratio of the polymer (2), (3) or (4) is around 1.1.

[0120] From the above results, it can be seen that the fluorine-containing polymer (polymers (1) to (4)) containing a repeating unit having a fluorine-containing aromatic ring structure has sufficient etching resistance.

Industrial applicability

[0121] According to the present invention, the sensitivity to electron beam, X-ray or EUV light used in the lithography method using electron beam, X-ray or EUV light is high, and the etching resistance is excellent. A resist composition is provided. The resist composition of the present invention has high sensitivity and high resolution, good pattern shape, and line edge roughness (the edge between the pattern formed on the photosensitive resist material and the substrate interface fluctuates in the direction perpendicular to the line direction). And a positive resist composition satisfying the above-mentioned phenomenon that the edges appear to be uneven. By using the resist composition of the present invention, the above-mentioned lithography method is used. A fine pattern can be formed. The specifications, claims, and claims of Japanese patent application 2006-278841 filed on October 12, 2006 and Japanese Patent Application 2007-151687 filed on June 7, 2007, and The entire content of the abstract is hereby incorporated by reference as a disclosure of the specification of the present invention.

Claims

The scope of the claims

[1] A fluorine-containing polymer (F) whose alkali solubility is increased by the action of an acid containing a repeating unit (F) having a fluorine-containing aromatic ring structure in the side chain, and a compound capable of generating an acid, A resist composition used in a lithography method using electron beam, X-ray or EUV light.

[2] The resist composition according to claim 1, wherein the repeating unit (F) is a repeating unit represented by the following formula (F ^v ).

[Chemical 1]

The symbols in the formula have the following meanings.

[3] The repeating unit (F) is at least one selected from the group consisting of repeating units represented by the following formula (F ^v l), the following formula (F ^v 2), and the following formula (F ^v 3). repeating units (F ^v n) resist composition according to claim 1 or 2 which is a.

[Chemical 2]

(F ^V D (F ^V 2) (F ^V 3) Symbols in the formula have the following meanings.

rl, r2 and ql: each independently an integer of '3. Y: an acid-decomposable group having 1 to 20 carbon atoms.

[4] The weight average molecular weight of the fluoropolymer (F) is 1000 to 100000;

V, the resist composition according to any one of the above.

[5] The resist composition according to any one of [1] to [4], wherein the ratio of the weight average molecular weight to the number average molecular weight of the fluoropolymer (F) is 2.2 or less.

6. The resist composition according to any one of claims 1 to 5, wherein the ratio of the weight average molecular weight to the number average molecular weight of the fluoropolymer (F) is 1.5 or less.

[7] The fluoropolymer (F) is at least one selected from the group consisting of repeating units represented by the following formula (G ^V 1), the following formula (G ^V 2), and the following formula (G ^V 3). of repeating further comprises a unit (G ^V n), the resist composition according to any one of claims 1 to 6.

[Chemical 3]

(G ^V 1) (G ^V 2) (G ^v 3) The symbols in the formula have the following meanings.

T ^G : a hydrogen atom, a halogen atom, a methyl group or a halomethyl group.

Z ^e and W ^e : each independently an acid-decomposable group having 1 to 20 carbon atoms.

g _: An integer from ₁ to 4.

The fluoropolymer (F) is selected from the group consisting of repeating units represented by the following formula (Q ^v l), the following formula (Q ^v 2), the following formula (Q ^v 3) and the following formula (Q ^V 4). The resist composition according to claim 7, further comprising at least one repeating unit (Q ^V n).

[Chemical 4]

(Q ^v 1) (Q ^v 2) (Q ^v 3) (Q ^v 4) The symbols in the formula have the following meanings.

T ^Q: hydrogen atom, a halogen atom, a methyl group or a halomethyl group.

q _: An integer from ₁ to 4.

[9] The acid-generating compound is a diazonium salt, a phosphonium salt, a sulfonium salt, a sodium salt, an imide sulfonate, an oxime sulfonate, a diazodisulfone, a disulfone, or o-nitrobenzil sulfonate, The resist composition according to any one of claims 8 to 10, wherein the compound that generates an acid is contained in an amount of 0 .;

[10] A resist forming composition for use in a lithography method using an electron beam, an X-ray or EUV light, comprising the resist composition according to any one of claims 1 to 9 and an organic solvent.

11. The resist forming composition according to claim 10, wherein the organic solvent is an alcohol compound, a ketone compound, an ester compound, an aromatic hydrocarbon compound, an ether compound, or an amide compound.