TWI490241B - Additive for resist and resist composition comprising same - Google Patents

Description

Resist additive and resist composition containing the same

The present invention relates to a resist additive and a resist composition comprising the same, which improves the hydrophobicity of the surface of the resist film to prevent the material in the resist film from being leached in water during the immersion lithography process, And a resist film micropattern having excellent sensitivity and high resolution is formed.

With the recent high level integration and higher speed of large scale integrated circuits (LSIs), accurate micropatterning of photoresist is required. As an exposure light source used in forming a resist pattern, a g-line (436 nm) or an i-line (365 nm) from a mercury lamp has been widely used.

However, since the resolution obtained by adjusting the exposure wavelength is improved to approach the physical limit, a method using a shorter wavelength is introduced as a patterning technique of a finer photoresist. For example, a KrF excimer laser (248 nm) having a shorter wavelength than the i-line (365 nm), an ArF excimer laser, or the like is being used.

In the ArF immersion lithography method using an ArF excimer laser as a light source, the space between the projection lens and the wafer substrate is filled with water. According to this method, even if a lens having an NA of 1.0 or more is used, a refractive index of water at 193 nm can be used to form a pattern, and this method is generally called an immersion lithography method. However, since the resist film is directly in contact with water, the amine compound as a quencher contained in the acid or resist film produced by the photoacid generator can be easily dissolved in water. Therefore, the resist pattern may be deformed or may collapse due to swelling, or may cause various defects such as bubbles and water. Printed.

Therefore, a method of forming a protective film or an overcoat film between a resist film and water to prevent the resist film from coming into contact with a medium such as water has been proposed. Such a resist protective film needs to be formed on a resist film while having sufficient light transmittance at an exposure wavelength without intermixing with the resist film so as not to interrupt the exposure, requiring liquid immersion lithography It has stability in the process and is maintained without being leached by a medium such as water, and needs to be easily dissolved in an alkali solution as a developer during development.

current technology

Patent Document 1: Korean Patent Application Publication No. 2006-0029280 (published on Apr. 5, 2006)

Patent Document 2: Korean Patent Application Publication No. 2009-0108935 (published on October 19, 2009)

Patent Document 3: Korean Patent Application Publication No. 2011-0084848 (published on July 26, 2011)

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a resist additive which improves the hydrophobicity of a surface of a resist film to prevent a resist film during a immersion lithography process The material in the material is leached in the water. Although the resist additive is dissolved in the developer together with the resist in the exposed region, the resist additive remains patterned together with the resist and is converted to be hydrophilic by the developer in the non-exposed regions.

Another object of the present invention is to provide an additive comprising the same A resist composition of the agent, and a method of forming a resist pattern using the composition.

According to the present invention, the above and other objects can be achieved by providing a resist additive represented by the following formula 1.

In Formula 1, R ₁ and R ₂ may each independently be a hydrogen atom or a C1-C8 alkyl group.

R ₃ may be selected from C 1 -C 20 alkylene, C 2 -C 20 alkenylene, C 1 -C 20 heteroalkylene, C 2 -C 20 heteroalkenylene, C ₃ -C 30 cycloalkanediyl, C ₃ -C 30 cycloalkenyl a C2-C30 heterocycloalkanediyl group and a C3-C30 heterocycloalkanediyl group, wherein at least one hydrogen atom is selected from a group selected from the group consisting of a C1-C10 alkyl group, a C1-C20 halogenated alkyl group, and a C3-C30 cycloalkyl group. Substituted or unsubstituted.

R ₄ may be a hydrophobic group selected from the group consisting of a C1-C20 haloalkyl group, an organic oxime group, and a C3-C20 hydrocarbon group.

R ₅ may be selected from , with

An acid labile group. Here, R _a , R _b , R _c and R _d may each independently be selected from a C1-C20 alkyl group, a C3-C30 cycloalkyl group, a (C1-C10 alkyl)cycloalkyl group, a hydroxyalkyl group, a C1- C20 alkoxy, (C1-C10 alkoxy)alkyl, ethyl fluorenyl, ethoxyalkyl, carboxyl, (C1-C10 alkyl)carboxy, (C3-C18 cycloalkyl)carboxy and C3-C30 a cycloalkyl group, or an adjacent group fused together to form a C3-C30 saturated or unsaturated hydrocarbon ring or a C2-C30 heterocyclic group, p may be an integer from 0 to 3, and q may be from 0 to 10 Integer.

Here, l, m, and n are the number of repeating units in the main chain, respectively, where l+m+n=1, 0<l/(l+m+n)<0.99, 0<m/(l+m+ n) 0.99 and 0 < n / (l + m + n) < 0.20.

Here, o is an integer of 0 or 1. If o is 0, then R ₄ is an organic sulfonium group, and if o is 1, then R ₄ is a C1-C20 haloalkyl group or a C3-C20 hydrocarbyl group.

R ₃ may be selected from a C1-C10 alkylene group, a C2-C10 alkenylene group, a C1-C10 heteroalkylene group, a C2-C10 heteroalkenylene group, a C3-C18 cycloalkanediyl group, a C3-C18 cycloalkenylene group. And a C2-C18 heterocycloalkanediyl group and a C3-C18 heterocycloalkanediyl group, wherein at least one hydrogen atom is substituted or unsubstituted by a C1-C10 alkyl group or a C1-C10 haloalkyl group.

R ₄ may be selected from a C1-C10 fluoroalkyl group, a germyl group, a C1-C10 alkyl formamyl group, a C3-C10 linear or branched alkyl group, a C3-C14 monocyclic cycloalkyl group, a C8-C18 bicyclic ring. Cycloalkyl, C10-C30 tricyclic cycloalkyl and C10-C30 tetracyclic cycloalkyl.

R ₄ may be selected from the group consisting of t-butyl, trifluoromethyl, trimethylmethane alkyl, bis(trifluoromethyl)isopropyl, pentafluoroethyl and heptafluoropropyl.

R ₅ can be selected from , with .

Here, R _a , R _b , R _c and R _d may each independently be selected from a C1-C10 alkyl group, a C3-C14 monocyclic cycloalkyl group, a C8-C20 bicyclic cycloalkyl group, a C10-C30 tricyclic ring. Alkyl, C10-C30 tetracyclic cycloalkyl, (C1-C5 alkyl)cycloalkyl, hydroxyalkyl, C1-C10 alkoxy, (C1-C5 alkoxy)alkyl, ethyl thiol, B a decyl group, a carboxyl group, a (C1-C5 alkyl)carboxy group, and a (C3-C10 cycloalkyl)carboxy group, or fused together between adjacent groups to form a C6-C18 saturated or unsaturated hydrocarbon ring or C5- The C18 heterocyclic group, p may be an integer of 0 to 3, and q may be an integer of 0 to 5.

R ₅ may be selected from the group consisting of t-butyl, trimethylmethyl decyl, hydroxy-2-ethyl, 1-methoxypropyl, 1-methoxy-1-methylethyl, 1-ethoxy propyl , 1-ethoxy-1-methylethyl, 1-methoxy-1-ethyl, 1-ethoxy-1-ethyl, tert-butoxy-2-ethyl, 1-iso Butoxy-1-ethyl and a group represented by the following formula 2a-2k:

In Formulae 2a-2k, R', R" and R''' may each independently be a hydrogen atom or a C1-C10 alkyl group, and a and e may each independently be an integer from 0 to 15, and b may be 0- An integer of 11, c and d may each independently be an integer from 0 to 9, and f may be an integer from 0 to 7, and g and i may each independently be an integer of 0-6, and h may be an integer of 0-4. 0 c+d 17 and 0 c+f 15.

The repeating unit 1 may be selected from the repeating units represented by the following formulas 3a to 3i:

The repeating unit m may be selected from the repeating units represented by the following formulas 4a to 4d: .

The repeating unit n of Formula 1 may be included in the resist additive copolymer in an amount of 5 to 15 mol%.

The resist additive may be selected from the compounds represented by the following formulas 5-16:

Equation 8

Equation 16

In Equations 5-16, l, m, and n are the number of repeating units in the main chain, respectively, where l+m+n=1, 0<l/(l+m+n)<0.99, 0<m/( l+m+n) 0.99 and 0 < n / (l + m + n) < 0.20.

The polystyrene equivalent weight average molecular weight of the resist additive measured by gel permeation chromatography may be in the range of 1,000 to 500,000 g/mol.

The ratio of the weight average molecular weight / number average molecular weight of the resist additive may be in the range of 1-5.

According to an aspect of the invention, the above and other objects are achieved by providing a resist composition comprising a resist additive, a resist base polymer, an acid generator, and a solvent.

The amount of the resist additive may be in the range of 0.05 to 5% by weight based on the total weight of the resist composition.

The acid generator may include at least one compound selected from the group consisting of compounds represented by the following formulas 20 and 21:

Equation 21

In Formulae 20 and 21, X ₁ , X ₂ , Y ₁ and Y ₂ may each independently be selected from a hydrogen atom, a C1-C10 alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group, a C6-C30 aryl group. And any combination thereof, wherein X ₁ and X _{2 are} fused to form a C3-C30 saturated or unsaturated hydrocarbon ring, and Y ₁ and Y _{2 are} fused to form a C3-C30 saturated or unsaturated hydrocarbon ring.

X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ may each independently be selected from a hydrogen atom, a C1-C30 alkyl group, a halogen group, a C1-C30 alkoxy group, a C6-C30 aryl group, a sulfur Phenoxy, C1-C30 thioalkoxy, C1-C20 alkoxycarbonylmethoxy, and any combination thereof.

Z representing an anion may be OSO ₂ CF ₃ , OSO ₂ C ₄ F ₉ , OSO ₂ C ₈ F ₁₇ , N(CF ₃ ) ₂ , N(C ₂ F ₅ ) ₂ , N(C ₄ F ₉ ) ₂ , C(CF ₃ ) ₃ , C(C ₂ F ₅ ) ₃ , C(C ₄ F ₉ ) ₃ or a functional group represented by the following formula 22:

In Formula 22, V ₁ and V ₂ may each independently be a halogen atom,

W ₁ may be -(C=O)- or -(SO ₂ )-.

W ₂ may be a C1-C10 alkylene group.

W ₃ may be selected from the group consisting of C3-C30 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl, C6-C30 aryloxy, C6-C30 arylthio and C5-C30 heterocyclic.

W ₄ may be selected from a hydrogen atom, a halogen group, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C1-C10 haloalkyl group, a C1-C10 alkylthio group, a C6-C30 aryl group, and any combination thereof.

Here, o is an integer of 0-1, and p is an integer of 0-2.

The amount of the acid generator may be in the range of 0.3 to 10 parts by weight based on 100 parts by weight of the resist composition solid.

The resist composition may further comprise an additive selected from the group consisting of an alkali soluble quencher, an acid diffusion quencher, a surfactant, and any mixture thereof.

According to another aspect of the present invention, a method of forming a resist pattern is provided, the method comprising forming a resist film by applying a resist composition on a substrate, heating the resist film, and heating the resist film The film is exposed to form a predetermined pattern, and the exposed pattern is developed.

The exposure can be performed using a light source selected from the group consisting of KrF excimer lasers, ArF excimer lasers, extreme ultraviolet lasers, X-rays, and electron beams.

Other aspects, features, and advantages of the present invention will be apparent from the following detailed description.

The invention will be described in detail below. However, the description of the exemplary embodiments is provided for the purpose of illustration only and should not be construed as limiting the scope and spirit of the invention. The detailed description of the present invention is intended to provide a further explanation of the claimed invention.

The term "halogen" or "halogen atom" as used herein, refers to a fluorine, chlorine, bromine or iodine atom unless otherwise stated.

The term "hetero" as used herein is intended to cover 1-3 selected from N, O, S and The hetero atom of the substituted carbon atom of P unless otherwise stated. For example, the term "heteroalkyl" refers to an alkyl group wherein one to three carbon atoms are replaced by a heteroatom.

The term "alkyl" as used herein, refers to a straight or branched C1-C30 alkyl group which, unless otherwise stated, includes primary alkyl groups, secondary alkyl groups, and tertiary alkyl groups. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a t-butyl group, but are not limited thereto.

The term "cycloalkyl" as used herein, refers to a C3-C30 cycloalkyl group, unless otherwise stated, and includes monocyclic, bicyclic, tricyclic, and tetracyclic alkyl groups. The cycloalkyl group also includes an adamantyl group, a norbornyl group, and a polycyclic cycloalkyl group containing a norbornyl group.

As used herein, the term "alkylene" refers to a divalent by the removal of two hydrogen atoms, a group derived from an alkane and by the general formula -C _n H _2n - represented. The term "alkenylene" as used herein, refers to a divalent atom radical derived by the removal of two hydrogen atoms from an olefin and may be represented by the formula -C _n H _n -.

The term "aryl" as used herein refers to a group including a benzene ring and derivatives thereof, unless otherwise stated. For example, the aryl group includes toluene or xylene composed of a benzene ring and an alkyl side chain, a biphenyl group composed of at least two benzene rings via a single bond, and at least two benzene rings via a cycloalkyl or heterocycloalkane. The base is composed of ruthenium, osmium or iridium, and naphthalene or anthracene composed of at least two benzene rings condensed with each other. Unless otherwise stated herein, aryl refers to C6-C30 aryl.

The term "hydrocarbyl" as used herein refers to a C3-C20 monovalent hydrocarbon group consisting of carbon and hydrogen, unless otherwise stated, and may include aliphatic straight or branched chain hydrocarbon groups and alicyclic hydrocarbon groups. Examples of the hydrocarbon group include hexyl, heptyl, octyl, decyl, decyl, undecyl, dodecyl, cyclohexyl, phenyl, toluene Base, xylyl, mesityl, benzyl, diphenylmethyl, triphenylmethyl, styryl, biphenyl and naphthyl.

The term "heterocyclyl" as used herein, refers to a group of 4 to 20 ring atoms derived by substituting one or more, for example 1, 2, 3 or 4, carbon atoms with a hetero atom such as N, O, P or S. Cyclic groups unless otherwise stated. The heterocyclic group includes a saturated ring, a partially unsaturated ring, and an aromatic ring, that is, a heteroaromatic ring having an oxidized or quaternized hetero atom to form, for example, an N-oxide or a quaternary ammonium salt. Substituted heterocyclic groups include carbonyl and heterocyclic rings substituted with any of the substituents disclosed herein.

Examples of the heterocyclic group include pyridyl, dihydropyridyl, tetrahydropyridyl (acridinyl), thiazolyl, tetrahydrothiophenyl, tetrahydrothiophenylthione, pyrimidinyl, furyl, thienyl, pyrrolyl , pyrazolyl, imidazolyl, tetrazolyl, benzofuranyl, thioindolyl, fluorenyl, indolenyl, quinolyl, isoquinolyl, benzimidazolyl, acridinyl , 4-acridone, pyrrolidinyl, 2-pyrrolidone, pyrrolinyl, tetrahydrofuranyl, tetrahydroquinolyl, tetrahydroisoquinolinyl, decahydroquinolinyl, octahydroisoquinolinyl, Azocinyl, triazinyl, 6H-1,2,5-thiadiazinyl, 2H,6H-1,5,2-dithiazinyl, thienyl, thiophenyl, pyran , isobenzofuranyl, chromenyl, xanthene, phenoxathinyl, 2H-pyrrolyl, isothiazolyl, isoxazolyl, pyrazinyl, pyridazinyl, pyridazinyl, iso Indenyl, 3H-indenyl, 1H-carbazolyl, fluorenyl, 4H-quinazinyl, pyridazinyl, naphthyridinyl, quinoxalinyl, quinazolinyl, porphyrinyl, acridinyl , 4aH-carbazolyl, carbazolyl, β-carbolinyl, phenanthryl , acridinyl, pirimidinyl, phenanthroline, phenazine, phenothiazine, Furoxan, phenoxazinyl, isochroman, chromanyl, imidazolidinyl, imidazolinyl, pyrazolidinyl, pyrazolinyl, pyridazinyl, indanyl, isoindoline Base, quinuclidinyl, morpholinyl, oxazolidinyl, benzotriazolyl, benzoisoxazolyl, hydroxydecyl, benzoxazolinyl, isatinoyl And bis-tetrahydrofuranyl, which may be substituted or unsubstituted, their N-oxides (for example, pyridyl N-oxide and quinolinyl N-oxide) or their quaternary ammonium salts, but are not limited thereto this.

All compounds or substituents used herein may be substituted or unsubstituted unless otherwise stated. In this regard, the term "substituted" means that the hydrogen is selected from the group consisting of a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an amino group, a thio group, a methylthio group, an alkoxy group, a nitrile group, an aldehyde group, an epoxy group. , ether, ester, carbonyl, acetal, keto, alkyl, perfluoroalkyl, cycloalkyl, heterocycloalkyl, allyl, benzyl, aryl, heteroaryl, any of them The derivative and one of any combination thereof are substituted.

The term "combination thereof" as used herein refers to at least two substituents bonded to each other by a single bond or a linking group or at least two substituents condensed with each other unless otherwise specified.

Conventionally, when a resist pattern is formed by ArF immersion lithography, water is used in the optical path on the resist film to increase the refractive index. However, the acid or amine compound contained in the resist film is dissolved in water disposed between the projection lens and the wafer substrate, so the projection lens may be contaminated, the resist pattern may be deformed or collapsed due to swelling, or may be generated Various defects such as bubbles and watermarks.

According to the present invention, there is provided a protective film for use as a resist film and Conversion to a hydrophilic additive copolymer. The acrylic acid-derived repeating unit and the maleic anhydride-derived repeating unit contained in the copolymer main chain form a carboxyl group by a developer in a non-exposed area, thereby improving the hydrophilicity of the surface of the resist film, thereby suppressing defects of the copolymer. During the exposure process, the hydrophobic group contained at one end of the side chain of the copolymer improves the hydrophobicity of the surface of the resist film to prevent the material of the resist film from being leached during the immersion lithography process and is converted during development. It is a hydrophilic group to provide hydrophilicity to the copolymer.

That is, the copolymer according to one embodiment of the present invention is a multi-block copolymer represented by the following formula 1:

In Formula 1, R ₁ and R ₂ may each independently be a hydrogen atom or a C1-C8 alkyl group.

R ₃ may be selected from C 1 -C 20 alkylene, C 2 -C 20 alkenylene, C 1 -C 20 heteroalkylene, C 2 -C 20 heteroalkenylene, C ₃ -C 30 cycloalkanediyl, C ₃ -C 30 cycloalkenyl a C2-C30 heterocycloalkanediyl group and a C3-C30 heterocycloalkanediyl group, wherein at least one hydrogen atom is selected from a group selected from the group consisting of a C1-C10 alkyl group, a C1-C20 halogenated alkyl group, and a C3-C30 cycloalkyl group. Substituted or unsubstituted.

R ₄ may be a hydrophobic group selected from the group consisting of a C1-C20 haloalkyl group, an organic oxime group, and a C3-C20 hydrocarbon group.

R ₅ may be selected from , with in

Acid labile group. In this regard, R _a , R _b , R _c and R _d may each independently be selected from C 1 -C 20 alkyl, C 3 -C 30 cycloalkyl, (C 1 -C 10 alkyl)cycloalkyl, hydroxyalkyl, C 1 . -C20 alkoxy, (C1-C10 alkoxy)alkyl, ethyl fluorenyl, ethinyl, carboxy, (C1-C10 alkyl)carboxy, (C3-C18 cycloalkyl)carboxy and C3-C30 a heterocycloalkyl group, or an entangled group of adjacent groups to form a C3-C30 saturated or unsaturated hydrocarbon ring or a C2-C30 heterocyclic group, p may be an integer from 0 to 3, and q may be from 0 to 10. The integer.

Here, l, m, and n are the number of repeating units in the main chain, respectively, where l+m+n=1, 0<l/(l+m+n)<0.99, 0<m/(l+m+ n) 0.99 and 0 < n / (l + m + n) < 0.20.

Here, o is an integer of 0 or 1. If o is 0, then R ₄ is an organic sulfonium group, and if o is 1, then R ₄ is a C1-C20 halogenated alkyl group or a C3-C20 hydrocarbon group.

In Formula 1, R ₁ and R ₂ may each independently be a hydrogen atom or a C1-C4 alkyl group, preferably a hydrogen atom or a methyl group.

In Formula 1, R ₃ may be selected from a C1-C10 alkylene group, a C2-C10 alkenylene group, a C1-C10 heteroalkylene group, a C2-C10 heteroalkenylene group, a C3-C18 cycloalkanediyl group, a C3- a C18 cycloalkenyldiyl group, a C2-C18 heterocycloalkanediyl group, and a C3-C18 heterocycloalkanediyl group, wherein at least one hydrogen atom is substituted or unsubstituted by a C1-C10 alkyl group or a C1-C10 haloalkyl group. More preferably, R ₃ may be selected from the group consisting of methylene, ethylene, 1,3-propylene, 1,2-propylene, tetramethylene, pentamethylene, 2,2-dimethyl Pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecyl, dodecamethylene, thirteenmethylene, fourteen Methyl, pentadecyl, hexadecyl, heptamethylene, octamethylidene, ninth methylene, 1-methyl-1,3-propylene, 2-methyl -1,3-propylene, 2-methyl-1,2-propylene, 1-methyl-1,4-butylene, 2-methyl-1,4-butylene, methylene, Propylene, 2-propylene, 1,3-cyclobutylene, 1,3-cyclopentylene, 1,4-cyclohexylene, 1,5-cyclooctylene, 1,4-亚Norborn, 2,5-norbornyl, 1,5-adamantyl, 2,6-adamantyl, -OCH ₂ -, -OCH(Cl)-, -CO-, -COCH ₂ -, -COCH ₂ CH ₂ -, -CH ₂ -O-CH ₂ -, -CH ₂ -O-CH ₂ CH ₂ -, -CH ₂ CH ₂ -O-CH ₂ -, -CH ₂ -O-CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ -O-CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -O-CH ₂ -, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₃ ) CH ₂ -, -CH(CH ₂ CH ₃ )-, -CH(OCH ₃ )-, -C(CF ₃ ) ( OCH ₃ )-, -CH ₂ -S-CH ₂ -, -CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ -, -CH ₂ -S-CH ₂ CH ₂ CH ₂ -, -CH ₂ CH ₂ -S-CH ₂ CH ₂ -, -CH ₂ CH ₂ CH ₂ -S-CH ₂ -, -CH(CH ₂ )CH-, -C(CH ₂ CH ₂ )-, -CH ₂ CO-, -CH ₂ CH ₂ CO-, -CH(CH ₃ )CH ₂ CO-, -CH(OH)-, -C(OH)(CH ₃ )-, -CH(Br)-, -CH(Br)CH(Br)-, -CH=CH-, -CH ₂ CH=CH-, -CH=CHCH ₂ -, -CH=CHCO-, -C ₇ H ₉ - and -C ₁₀ H ₁₄ - wherein at least one of the hydrogen atoms is substituted or unsubstituted by a C1-C4 alkyl group or a perfluoroalkyl group.

In Formula 1, R ₄ may be selected from a C1-C10 fluoroalkyl group, a germyl group, a C1-C10 alkyl formamyl group, a C3-C10 linear or branched alkyl group, a C3-C14 monocyclic cycloalkyl group, a C8-C18 bicyclic cycloalkyl group, a C10-C30 tricyclic cycloalkyl group, and a C10-C30 tetracyclic cycloalkyl group, more preferably selected from the group consisting of t-butyl, trifluoromethyl, trimethylmethanealkyl, and di(III) Fluoromethyl)isopropyl, pentafluoroethyl and heptafluoropropyl.

Further, in Formula 1, R ₅ may be selected from , with .

Here, R _a , R _b , R _c and R _d may each independently be selected from a C1-C10 alkyl group, a C3-C14 monocyclic cycloalkyl group, a C8-C20 bicyclic cycloalkyl group, a C10-C30 tricyclic ring. Alkyl, C10-C30 tetracyclic cycloalkyl, (C1-C5 alkyl)cycloalkyl, hydroxyalkyl, C1-C10 alkoxy, (C1-C5 alkoxy)alkyl, ethyl thiol, B a decyl group, a carboxyl group, a (C1-C5 alkyl)carboxy group, and a (C3-C10 cycloalkyl)carboxy group, or fused together between adjacent groups to form a C6-C18 saturated or unsaturated hydrocarbon ring or C5- The C18 heterocyclic group, p may be an integer of 0 to 3, and q may be an integer of 0 to 5.

More preferably, R ₅ may be selected from the group consisting of t-butyl, trimethylmethane alkyl, hydroxy-2-ethyl, 1-methoxypropyl, 1-methoxy-1-methylethyl, 1- Ethoxypropyl, 1-ethoxy-1-methylethyl, 1-methoxy-1-ethyl, 1-ethoxy-1-ethyl, tert-butoxy-2-ethyl , 1-isobutoxy-1-ethyl and a group represented by the following formula 2a-2k:

In Formulae 2a-2k, R', R" and R''' may each independently be a hydrogen atom or a C1-C10 alkyl group, and a and e may each independently be an integer from 0 to 15, and b may be 0- An integer of 11, c and d may each independently be an integer from 0 to 9, and f may be an integer from 0 to 7, and g and i may each independently be an integer of 0-6, and h may be an integer of 0-4. 0 c+d 17 and 0 c+f 15.

When a resist film is formed by using a resist composition containing a resist additive having the above structure according to the present invention, the additive is dissolved in the developer together with the resist in the exposed region, but is not exposed The additive is converted to hydrophilic in the region by the base and is not soluble in the developer. Specifically, the maleic anhydride derived heavy weight of the additive in the non-exposed area The complex unit is opened by a developer to form a carboxyl group, thereby improving the hydrophilicity of the surface of the resist film. Therefore, defects caused in the hydrophobic surface can be reduced. When a resist film is formed using the resist composition containing the additive, the additive is disposed on the surface of the resist film, and the resist film is formed as a separate protective film formed on the resist film To improve the hydrophobicity of the surface of the resist film, thereby preventing the material of the resist film from being leached in water during liquid immersion lithography.

Each repeating unit constituting the resist additive copolymer according to the present invention will hereinafter be described in more detail. The acrylonitrile-derived repeating unit 1 includes a hydrophobic group having an electron withdrawing group to provide hydrophobicity to the copolymer. The copolymer is self-isolated due to its hydrophobicity during the preparation of the photoresist composition and acts as a protective film on the photoresist film to prevent leaching in water during liquid immersion lithography. In addition, in the exposure region, the repeating unit 1 is dissolved in the developer together with the resist, and forms a pattern together with the resist which is not dissolved in the developer in the unexposed region. However, the hydrophobic group is stripped by the base to be converted into a hydroxyl group as a hydrophilic group, as shown in the following Reaction Scheme 1. However, the following Reaction Scheme 1 is exemplary, and the present invention is not limited thereto.

Specifically, the acrylonitrile-derived repeating unit 1 may have one of the following structures represented by the following formulas 3a to 3i:

The acid labile group contained at one end of another propylene fluorene-derived repeat unit m is converted from a hydrophobic group to a hydrophilic group by an acid-induced deprotection reaction in the exposed region, as shown in Reaction Scheme 2. As a result, the addition The agent can be easily dissolved in the developer. However, the following Reaction Scheme 2 is exemplary, and the present invention is not limited thereto.

Specifically, the propylenefluorene-derived repeating unit m may have one of the following structures represented by Formulas 4a to 4d:

Further, the maleic anhydride-derived repeating unit n does not exert any effect in the exposed region, but is opened by a developer in a non-exposed region to form a carboxyl group, as shown in the following Reaction Scheme 3, thereby improving the hydrophilicity of the surface of the resist film. . Since the modified surface has the same characteristics as the developer, it is advantageous for the developing process. Therefore, defects caused in the hydrophobic surface can be reduced. However, the following Reaction Scheme 3 is exemplary, and the present invention is not limited thereto.

Reaction route 3

Here, l, m and n represent not only the content of each repeating unit contained in the main chain of the copolymer but also the substitution ratio as the degree of dissolution of the copolymer in the developer. The copolymer according to the invention comprises repeating units l, m and n, provided that l+m+n=1, where 0<l/(l+m+n)<0.99,0<m/(l+m+n ) 0.99 and 0 < n / (l + m + n) < 0.20.

When the repeating unit satisfies the above conditions, the resist film may have hydrophobicity in the liquid immersion lithography process. Specifically, when the content of the maleic anhydride-derived repeating unit n is less than 20 mol%, the CA value may be lowered, thereby causing defects. If the content of the maleic anhydride-derived repeating unit n is more than 20 mol%, the additive in the non-exposed area can be dissolved by the developer. More preferably, the content of the maleic anhydride-derived repeating unit n may be in the range of 5 to 15 mol%.

The copolymer having the structure shown above according to the present invention may be a block copolymer, a random copolymer or a graft copolymer.

Examples of the copolymer may include a compound represented by the following formula 5-16. In the structural formula, the order of the repeating units can be changed.

Equation 10

Equation 13

In Formula 5-16, l, m, and n are the number of repeating units in the main chain, respectively. Here, l+m+n=1, 0<l/(l+m+n)<0.99, 0<m/(l+m+n) 0.99 and 0 < n / (l + m + n) < 0.20.

The polystyrene equivalent weight average molecular weight (Mw) of the copolymer according to the present invention as measured by gel permeation chromatography (GPC) may be in the range of 1,000 to 500,000 g/mol. If the Mw of the copolymer is too low, mutual mixing may occur or elution with pure water may occur during immersion lithography. On the other hand, if the Mw of the copolymer is too high, the film may not be formed properly or the alkali solubility may be lowered. Preferably, the Mw of the copolymer may be in the range of from 2000 to 100,000 g/mol to have excellent solubility in the developer without being eluted in pure water.

Further, the molecular weight distribution of the copolymer, that is, the weight average molecular weight/number average molecular weight (Mw/Mn) may be from 1 to 5, more preferably from 1 to 3. If the molecular weight distribution is more than 5, the line edge roughness characteristics may be deteriorated. Therefore, a copolymer having a Mw and a molecular weight distribution within the above range is used as a photoresist composition to provide excellent developability, coatability, and heat resistance can be obtained.

The copolymer having the above structure according to the present invention may use an acryl-based group-based monomer represented by the following formula 17, an acryl-based group-based monomer represented by the following formula 18, and a maleic anhydride single represented by the following formula 19. The body is prepared by known polymerization methods such as bulk polymerization, solution polymerization, suspension polymerization, bulk suspension polymerization and emulsion polymerization: Formula 17

In the formulae 17-19, R _{1 -} R ₅ and o are as defined above.

Preferably, the copolymer according to the invention can be polymerized by free radical polymerization. In this regard, any radical polymerization initiator commonly used in the art, such as azobisisobutyronitrile (AIBN), benzammonium peroxide (BPO), laurel peroxide, azobisisohexonitrile, or the like, may be used. Azobisisovaleronitrile and t-butyl hydroperoxide are not limited thereto.

Further, a polymerization solvent including at least one compound selected from the group consisting of benzene, toluene, xylene, halogenated benzene, diethyl ether, tetrahydrofuran, ester, ether, lactone, ketone, decylamine, and alcohol may be used.

In the polymerization process, the polymerization temperature can be appropriately selected depending on the type of the catalyst to be employed. In addition, the molecular weight distribution of the prepared polymer can be It is adjusted by changing the amount of the polymerization initiator and the reaction time. After the completion of the polymerization, solvent precipitation can be utilized to remove unreacted monomers and by-products remaining in the reaction mixture.

The copolymer according to the present invention prepared by adjusting the type and amount of the monomer according to the above production method has a suitable hydrophobicity. Therefore, when a resist additive is added to the resist composition, the resist film formed therefrom is transparent to the exposed light and immiscible with the liquid used for exposure in the liquid immersion lithography process, This can reduce various defects that may be caused during the exposure process.

According to another embodiment of the present invention, a resist composition comprising a resist additive is provided.

Specifically, the resist composition contains a resist additive, a resist base polymer, an acid generator, and a solvent.

The resist additive is the same as described above, and the content in the resist composition may be 0.05 to 5% by weight based on the total weight of the resist composition. When the amount of the resist additive is within the above range, an appropriate degree of hydrophobicity is obtained, and thus a resist pattern having high resolution and sensitivity can be formed.

The resist base polymer may be any polymer used as a base resin in the formation of a resist film without limitation. Examples of the resist base polymer may include (meth) acrylate polymer, (α-trifluoromethyl) acrylate-maleic anhydride copolymer, cycloolefin-maleic anhydride copolymer, polynorbornene, Ring-opening exchange polymerization (ROMP) polymer, hydrogenated cyclic olefin ROMP polymer, hydroxystyrene and selected from (meth) acrylate derivatives, styrene, vinyl naphthalene, vinyl anthracene, vinyl anthracene, hydroxy Vinyl a copolymer of one of naphthalene, hydroxyvinyl hydrazine, hydrazine, hydroxy hydrazine, decene and norbornadiene, a novolac resin, and mixtures thereof.

The amount of the base polymer contained in the resist composition may range from 3 to 20% by weight. If the amount of the base polymer is less than 3% by weight, a film having a desired thickness may not be formed due to a too low viscosity of the composition, and pattern loss may be increased due to the presence of a relatively large amount of photoacid generator. On the other hand, if the amount of the base polymer is more than 20% by weight, the film is too thick, so that the transmittance to radiation is lowered and a vertical pattern may not be obtained.

The acid generator as a photoacid generator (PAG) may include a phosphonium salt such as an iodonium salt, a phosphonium salt, a phosphonium salt, a diazonium salt, a pyridinium salt or a quinone imine, preferably a phosphonium salt represented by the formulas 20 and 21. At least one of them, more preferably a triphenylsulfonium perfluorobutanesulfonate:

In Formulae 20 and 21, X ₁ , X ₂ , Y ₁ and Y ₂ may each independently be selected from a hydrogen atom, a C1-C10 alkyl group, an allyl group, a C1-C10 perfluoroalkyl group, a benzyl group, a C6- group. C30 aryl group and any combination thereof. X ₁ and X ₂ may be fused to form a C3-C30 saturated or unsaturated hydrocarbon ring, and Y ₁ and Y ₂ may be fused to form a C3-C30 saturated or unsaturated hydrocarbon ring.

X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ may each independently be selected from a hydrogen atom, a C1-C30 alkyl group, a halogen group, a C1-C30 alkoxy group, a C6-C30 aryl group, a sulfur Phenoxy, C1-C30 thioalkoxy, C1-C20 alkoxycarbonylmethoxy, and any combination thereof.

Z representing an anion may be OSO ₂ CF ₃ , OSO ₂ C ₄ F ₉ , OSO ₂ C ₈ F ₁₇ , N(CF ₃ ) ₂ , N(C ₂ F ₅ ) ₂ , N(C ₄ F ₉ ) ₂ , C(CF ₃ ) ₃ , C(C ₂ F ₅ ) ₃ , C(C ₄ F ₉ ) ₃ or a functional group represented by the following formula 22:

In Formula 22, V ₁ and V ₂ may each independently be a halogen atom,

W ₁ may be -(C=O)- or -(SO ₂ )-.

W ₂ may be a C1-C10 alkylene group.

W ₃ may be selected from the group consisting of C3-C30 cycloalkyl, C6-C30 aryl, C7-C30 aralkyl, C6-C30 aryloxy, C6-C30 arylthio and C5-C30 heterocyclic.

W ₄ may be selected from a hydrogen atom, a halogen group, a C1-C10 alkyl group, a C1-C10 alkoxy group, a C1-C10 haloalkyl group, a C1-C10 alkylthio group, a C6-C30 aryl group, and any combination thereof.

Here, o may be an integer of 0-1, and p may be an integer of 0-2.

In the acid generator, the diffusion length of the acid in the resist film may be appropriately It is kept short, and the resist film can have high transmittance by introducing a cycloalkyl group into the anion. As a result, a resist having a high resolution can be obtained.

Preferably, Z representing an anion in Formula 22 may be selected from the functional groups represented by the following formulas 23-1 to 23-36:

Further, in Formulas 20 and 21, the cationic moiety may be represented by the following formulas 24-1 to 24-16:

The acid generators may be used singly or in combination of at least two of them. Further, the amount of the acid generator may be in the range of 0.3 to 15 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 2 to 10 parts by weight based on 100 parts by weight of the polymer solid. If the amount of the acid generator is more than 15 parts by weight, the perpendicularity of the pattern may be significantly lowered. On the other hand, if the amount of the acid generator is less than 0.3 parts by weight, the flexibility of the pattern may be deteriorated.

In order to uniformly and smoothly apply the resist composition, the polymer and the acid generator may be dissolved in a solvent having an appropriate evaporation rate and viscosity. Examples of the solvent may include: esters such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol Monomethyl ether acetate, propylene glycol monoethyl ether acetate, and propylene glycol monopropyl ether acetate; and ketones such as methyl isopropyl ketone, cyclohexanone, methyl 2-hydroxypropionate, 2-hydroxy propyl Ethyl acetate, 2-heptanone, ethyl lactate and γ-butyrolactone. These solvents may be used singly or in combination of at least two of them.

The amount of the solvent can be appropriately adjusted depending on the physical properties of the solvent, that is, the volatility, viscosity, and the like.

The resist composition according to the present invention may further contain an additive depending on the application, for example, to improve coatability.

The additive may be any additive commonly used in the resist composition without limitation. Examples of the additive may include an alkali-soluble quencher, an acid diffusion quencher, a surfactant, and a sensitizer, and the additives may be used singly or in combination of at least two of them.

The alkali soluble quencher can be any alkali soluble quencher commonly used in resist compositions. Examples of the alkali soluble quencher may include a phenol or a carboxylic acid derivative.

The acid diffusion quencher inhibits the acid generated by the acid generator from diffusing during exposure to the resist film and chemical reactions in the unexposed regions. By using the acid diffusion quencher, the storage stability of the radiation-sensitive resin composition can be improved, the resolution of the resist can be improved, and the line width variation of the resist pattern during exposure to development can be suppressed.

The acid diffusion quencher can be a basic compound. Examples of the acid diffusion quencher may include: an amine such as ammonia, methylamine, isopropylamine, n-hexylamine, cyclopentylamine, methyldiamine, ethylenediamine, dimethylamine, diisopropylamine, diethylenediamine, N , N-dimethylmethyldiamine, N,N-dimethylethylenediamine, trimethylamine, triethylamine, N,N,N',N'-tetramethylformamide, N,N,N ',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyltetraethylenepentylamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine , benzyl dimethylamine, tetramethylammonium hydroxide, aniline, N,N-dimethyltoluidine, triphenylamine, phenylenediamine, pyrrole, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyridyl Azole, pyrroline, pyrrolidine, imidazoline derivative, imidazolidine derivative, pyridine derivative, pyridazine derivative, pyrimidine derivative, pyrazine derivative, pyrazoline derivative, pyrididine derivative, Pyridazine derivatives and morpholines; nitrogen-containing compounds such as aminobenzoic acid, hydrazine carboxylic acid, amino acid derivatives (such as niacin, alanine, arginine and aspartic acid), 3-pyridine sulfonic acid, Pyridinium p-toluenesulfonate, 2-hydroxypyridine, aminocresol 2,4-quinolinediol, 2-(2-hydroxyethyl)pyridine and 1-(2-hydroxyethyl)pyridazine; indoleamine derivatives such as formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, acetamide and benzamide; or quinone derivatives, For example, phthalimide, amber imine, and maleimide.

The amount of the basic compound may be in the range of 0.01 to 5 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the polymer solid. If the amount of the basic compound is less than 0.01 parts by weight, the pattern may be deformed due to an increase in delay time after exposure. On the other hand, if the amount of the basic compound is more than 5 parts by weight, the resolution and sensitivity may be deteriorated.

Surfactants are used to improve coatability, developability, and the like. Examples of the surfactant may include, but are not limited to, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene, and polyethylene glycol dilaurate.

The resist pattern formed using the resist composition according to the present invention has improved line width roughness characteristics and high resolution in both C/H and L/S patterns. In addition, the wide process window provides an excellent pattern profile regardless of the type of substrate and improved contrast. Therefore, the resist composition is suitable for far ultraviolet light, X-rays such as synchrotron radiation generated by far ultraviolet light such as KrF excimer laser, ArF excimer laser or F ₂ excimer laser. And a positive chemically amplified photoresist composition having charged photosensitivity such as extreme ultraviolet (EUV) light sensitivity.

According to another embodiment of the present invention, a method of forming a resist pattern using a resist composition is provided.

Specifically, the method includes forming a resist film by applying a resist composition on a substrate, heating the resist film, and exposing the resist film to form a predetermined pattern, and exposing the exposed pattern development.

The substrate may be a wafer substrate, and the coating may be performed on the substrate by spin coating, flow coating, roll coating, or the like.

Specifically, the resist composition is coated on a substrate such as a germanium wafer. The thickness is in the range of 0.3-2.0 μm, and the coating is prebaked at 60-150 ° C for 1-10 minutes, preferably at 80-130 ° C for 1-5 minutes.

The resist film is then partially exposed to the radiation to form a micropattern. In this regard, examples of radiation may include ultraviolet light such as I-line, far ultraviolet light such as KrF excimer laser, ArF excimer laser, and far ultraviolet light generated by F ₂ excimer laser, X-rays and charged particle rays such as electron beams are not limited thereto. The radiation can be appropriately adjusted depending on the type of acid generator.

Specifically, the exposure is carried out at an exposure amount of from about 1 to about 200 mJ/m ² , preferably from about 10 to about 100 mJ/m ² . This is followed by post-exposure bake (PEB), which is carried out at 60-150 ° C for 1-5 minutes, preferably at 80-130 ° C for 1-3 minutes.

After exposure, the exposed resist pattern is developed with a developer for 0.1 to 3 minutes, preferably 0.5 to 2 minutes, by any conventional technique such as dipping, pulverizing, and spraying techniques. As a result, a desired pattern is formed on the substrate. The developer may be composed of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium citrate, sodium methyl citrate, ammonia, ethylamine, n-propylamine, triethylamine, tetramethylammonium hydroxide, tetraethyl hydroxide Ammonium or the like is preferably an aqueous solution of tetramethylammonium hydroxide.

Optionally, the developer may also contain additives such as surfactants or water soluble alcohols.

According to the method of forming a pattern using the resist composition according to the present invention, a micro resist pattern having excellent sensitivity and high resolution can be obtained.

Hereinafter, the present invention will be more fully described with reference to the following examples. but It is to be understood that the following examples are in the form of modifications and alternatives and are not intended to limit the embodiments.

Preparation Example: Synthesis of Polymer

Polymer Synthesis Example 1

By 10 g of 3-(2,2,2-trifluoro-ethoxycarbonyl)-adamantan-1-yl methacrylate, 1 g of maleic anhydride and 15 g of 2-methyl-acrylic acid 1 a solution prepared by dissolving isopropylcyclohexyl ester in 255 g of 1,4-dioxane and 1 g of dimethylazobisbutyronitrile (DMAB) as an initiator was added to the jacketed reactor and stirred. . The temperature of the reactor was gradually raised by setting the temperature of the circulator to 65 ° C, and the reactor was stirred at 65 ° C for 8 hours. After the reaction was terminated, the reaction solution was precipitated by adding 3.4 L of n-hexane thereto. The precipitate was filtered off and dried in vacuo to give a polymer I represented by the formula. The polystyrene equivalent weight average molecular weight (Mw) of the polymer I was 7,500 g/mol.

Polymer Synthesis Example 2

The polymer II represented by the following formula was prepared in the same manner as in the polymer synthesis example 1, except that 2-methyl-acrylic acid 2-isopropyl-adamantan-2-yl ester was used instead of the polymer synthesis example. 2-Methyl-acrylic acid 1-isopropyl-cyclohexyl ester. The polystyrene equivalent Mw of polymer II is 8000 g/mol.

Polymer Synthesis Example 3

The polymer III represented by the following formula was prepared in the same manner as in the polymer synthesis example 1, except that 2-methyl-acrylic acid 1-methyl-cyclohexyl ester was used instead of the polymer in Synthesis Example 1 Methyl-1-isopropyl-cyclohexyl acrylate. The polystyrene equivalent Mw of the polymer III was 9,200 g/mol.

Polymer Synthesis Example 4

The polymer IV represented by the following formula was prepared in the same manner as in the polymer synthesis example 1, except that 2-methyl-acrylic acid 2-methyl-adamantan-2-yl ester was used instead of the polymer synthesis example 1. 2-Methyl-acrylic acid 1-isopropyl-cyclohexyl ester. The polystyrene equivalent Mw of the polymer IV was 7100 g/mol.

Evaluation Example 1: Evaluation of additive hydrophobicity

1.0 g of each of the polymers synthesized in Polymer Synthesis Examples 1-4 was dissolved in 25 g of 4-methylpentanol, and the solution was filtered with a 0.2 μm polypropylene filter to prepare a resist protective film. combination. In order to compare the effects with the additive according to the present invention, the polymer V represented by the following formula was used in Comparative Example 1.

Each of the prepared resist protective film compositions was spin-coated on a ruthenium substrate and baked at 100 ° C for 60 seconds to form a resist protective film having a thickness of 50 nm.

The sliding angle and the receding contact angle of the resist protective film were measured, respectively.

Specifically, 50 μl of pure water was added dropwise to form droplets on a crucible substrate having a resist protective film maintained at a level. While the base of the crucible is gradually inclined, measure the angle (sliding angle) at which the droplet starts to slide down and the receding contact angle. The results are shown in Table 1 below.

Referring to Table 1, the resist protective film containing the polymer prepared in Polymer Synthesis Examples 1-4 has high water repellency, low solubility in water, and high solubility in an alkali solution, and can be easily developed. It is removed by an alkali developer during the process. Further, it was confirmed that the sliding angle or the receding contact angle of the polymer prepared in Polymer Synthesis Examples 1-4 was not adversely affected.

Experimental Example: Formation of Resist Film and Measurement of Resist Film Properties

Examples 1-4

5 g of the resist polymer represented by the following formula 20 (Mw: 8500 g/mol, Mw/Mn: 1.75, molar ratio of repeating unit: x: y: z: w = 1:1: 1:1) 1.0 g of each of the polymers prepared in Synthesis Examples 1-5, 0.31 g of the photoacid generator represented by the following formula 21, and 0.07 g of triisopropanolamine as a quencher were added to 80 g of propylene glycol alone. The solution was filtered in diethyl ether acetate (PGMEA) using a 0.2 μm polypropylene filter to form a photoresist film composition.

A 90 nm thick bottom anti-reflective coating (BARC) was formed on the tantalum substrate, and the photoresist film composition prepared as described above was coated on the substrate having BARC. Bake the substrate at 110 ° C for 60 seconds to shape A photoresist film having a thickness of 120 nm.

Then, in order to achieve liquid immersion lithography, the exposed film was rinsed with pure water for 5 minutes. That is, exposure was performed using an ArF scanner 306C (Nikon Corp., NA = 0.78, 6% halftone mask), and the substrate was rinsed with pure water for 5 minutes. The exposure was carried out at 110 ° C for 60 seconds, PEB was carried out, followed by development using a 2.38 wt% TMAH developer for 60 seconds.

Comparative Example 2

A resist film was formed in the same manner as in Example 1, except that a resist additive was not used.

The ruthenium substrate having the resist films prepared in Examples 1-4 and Comparative Example 2 was cut to evaluate the sensitivity. The sensitivity corresponds to an exposure amount for forming a 65 nm line and space (L/S) pattern at a 1:1 resolution. The results are shown in Table 2 below.

Referring to Table 2, when a resist film not including a protective film was formed as described in Comparative Example 2 and washed with pure water after exposure, since the generated acid was dissolved in water, a T-top shape resist was formed. Agent pattern. However, in Examples 1-4 using the polymer prepared in Synthesis Examples 1-4 as a resist additive, the resist pattern was not deformed.

As apparent from the above description, the present invention provides a resist additive which, when added to a resist composition, can improve the hydrophobicity of the surface of the resist film to prevent leaching in water during exposure of the immersion lithography process, and It is possible to form a micro resist pattern having excellent sensitivity and high resolution.

Although the preferred embodiment of the present invention has been disclosed for illustrative purposes, it will be appreciated by those skilled in the art .

Claims (19)

A resist additive is represented by the following formula 1: Wherein R ₁ and R ₂ are each independently a hydrogen atom or a C1-C8 alkyl group, and R _{3 is} selected from the group consisting of C1-C20 alkylene, C2-C20 alkenylene, C1-C20 heteroalkylene, C2-C20 hetero An alkenylene group, a C3-C30 cycloalkanediyl group, a C3-C30 cycloalkenyldiyl group, a C2-C30 heterocycloalkanediyl group, and a C3-C30 heterocycloalkanediyl group, wherein at least one hydrogen atom is selected from a C1-C10 alkane a group of a C1-C20 haloalkyl group and a C3-C30 cycloalkyl group substituted or unsubstituted, R ₄ is a hydrophobic group selected from a C1-C20 haloalkyl group, and R ₅ is selected from the group consisting of , with An acid labile group, wherein R _a , R _b , R _c and R _d are each independently selected from C 1 -C 20 alkyl, C 3 -C 30 cycloalkyl, (C 1 -C 10 alkyl)cycloalkyl, hydroxy Alkyl, C1-C20 alkoxy, (C1-C10 alkoxy)alkyl, ethyl fluorenyl, ethoxyalkyl, carboxyl, (C1-C10 alkyl)carboxy, (C3-C18 cycloalkyl)carboxyl And a C3-C30 heterocycloalkyl group, or an adjacent group of R _a , R _b , R _c and R _d fused together to form a C3-C30 saturated or unsaturated hydrocarbon ring or a C2-C30 heterocyclic group. , p is an integer of 0-3, q is an integer of 0-10, l, m, and n are the number of repeating units in the main chain, respectively, where l+m+n=1, 0<l/(l+m+ n)<0.99,0<m/(l+m+n) 0.99 and 0 < n / (l + m + n) < 0.20, and o is an integer of 1. The resist additive of claim 1, wherein R _{3 is} selected from the group consisting of C1-C10 alkylene, C2-C10 alkenylene, C1-C10 heteroalkylene, C2-C10 heteroalkenylene, a C3-C18 cycloalkanediyl group, a C3-C18 cycloalkenyldiyl group, a C2-C18 heterocycloalkanediyl group, and a C3-C18 heterocycloalkanediyl group, wherein at least one of the hydrogen atoms is a C1-C10 alkyl group or a C1-C10 alkyl halide Substituted or unsubstituted. The resist additive of claim 1, wherein R ₄ is a C1-C10 fluoroalkyl group. The resist additive of claim 1, wherein R _{4 is} selected from the group consisting of trifluoromethyl, bis(trifluoromethyl)isopropyl, pentafluoroethyl, and heptafluoropropyl. The resist additive of claim 1, wherein R _{5 is} selected from the group consisting of , with Wherein R _a , R _b , R _c and R _d are each independently selected from C 1 -C 10 alkyl, C 3 -C 14 monocyclic cycloalkyl, C 8 -C 20 bicyclic cycloalkyl, C 10 -C 30 tricyclic cycloalkyl , C10-C30 tetracyclic cycloalkyl, (C1-C5 alkyl)cycloalkyl, hydroxyalkyl, C1-C10 alkoxy, (C1-C5 alkoxy)alkyl, ethyl hydrazine, ethane oxide a group, a carboxyl group, a (C1-C5 alkyl)carboxy group and a (C3-C10 cycloalkyl)carboxy group, or _a contiguous group of R _a , R _b , R _c and R _d fused together to form a C6-C18 A saturated or unsaturated hydrocarbon ring or a C5-C18 heterocyclic group, p is an integer of 0-3, and q is an integer of 0-5. The resist additive of claim 1, wherein R _{5 is} selected from the group consisting of t-butyl, trimethylmethyl sulfonyl, hydroxy-2-ethyl, 1-methoxypropyl, 1-methoxy 1-methylethyl, 1-ethoxypropyl, 1-ethoxy-1-methylethyl, 1-methoxy-1-ethyl, 1-ethoxy-1-ethyl a group, a tert-butoxy-2-ethyl group, a 1-isobutoxy-1-ethyl group, and a group represented by the following formula 2a-2k: Wherein R', R" and R''' are each independently a hydrogen atom or a C1-C10 alkyl group, a and e are each independently an integer from 0 to 15, and b is an integer from 0 to 11, and c and d are each independently The ground is an integer of 0-9, f is an integer of 0-7, g and i are each independently an integer of 0-6, and h is an integer of 0-4, 0 c+d 17 and 0 c+f 15. The resist additive according to claim 1, wherein the repeating unit 1 is selected from the repeating units represented by the following formulas 3a to 3c: The resist additive according to claim 1, wherein the repeating unit m is selected from the repeating units represented by the following formulas 4a to 4d: The resist additive according to claim 1, wherein the repeating unit n of the formula 1 is contained in the copolymer of the resist additive in an amount of 5 to 15 mol%. The resist additive according to claim 1, wherein the resist additive is selected from the compounds represented by the following formulas 5-16: Equation 9 Equation 12 Equation 16 Where l, m and n are the number of repeating units in the main chain, respectively, where l+m+n=1, 0<l/(l+m+n)<0.99, 0<m/(l+m+n ) 0.99 and 0 < n / (l + m + n) < 0.20. The resist additive according to claim 1, wherein the resist additive having a polystyrene equivalent weight average molecular weight measured by gel permeation chromatography is in the range of 1,000 to 500,000 g/mol. The resist additive according to claim 1, wherein the ratio of the weight average molecular weight/number average molecular weight of the resist additive is in the range of 1-5. A resist composition comprising a resist additive, a resist base polymer, an acid generator, and a solvent according to any one of claims 1 to 12. The resist composition of claim 13, wherein the amount of the resist additive is in the range of 0.05 to 5% by weight based on the total weight of the resist composition. The resist composition according to claim 13, wherein the acid generator comprises at least one compound selected from the compounds represented by the following formulas 20 and 21: Formula 20 Wherein X ₁ , X ₂ , Y ₁ and Y ₂ are each independently selected from the group consisting of a hydrogen atom, a C1-C10 alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group, a C6-C30 aryl group, and any combination thereof. Wherein X ₁ and X _{2 are} fused to form a C3-C30 saturated or unsaturated hydrocarbon ring, and Y ₁ and Y _{2 are} fused to form a C3-C30 saturated or unsaturated hydrocarbon ring, X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ are each independently selected from a hydrogen atom, a C1-C30 alkyl group, a halogen group, a C1-C30 alkoxy group, a C6-C30 aryl group, a thiophenoxy group, a C1-C30 thioalkane. Oxy, C1-C20 alkoxycarbonylmethoxy and any combination thereof, wherein the Z of the anion is OSO ₂ CF ₃ , OSO ₂ C ₄ F ₉ , OSO ₂ C ₈ F _{17 ,} N(CF ₃ ) ₂ , N (C ₂ F ₅ ) ₂ , N(C ₄ F ₉ ) ₂ , C(CF ₃ ) ₃ , C(C ₂ F ₅ ) ₃ , C(C ₄ F ₉ ) ₃ or a functional group represented by the following formula 22: Wherein, V ₁ and V ₂ are each independently a halogen atom, W ₁ is -(C=O)- or -(SO ₂ )-, W ₂ is a C1-C10 alkylene group, and W _{3 is} selected from a C3-C30 subunit. a cycloalkyl group, a C6-C30 arylene group and a C5-C30 heterocycloalkylene group, and W _{4 is} selected from the group consisting of a hydrogen atom, a halogen group, a C1-C10 alkyl group, a C2-C20 alkenyl group, a C1-C10 alkoxy group, C1-C10 haloalkyl, (C1-C10 alkyl)thio, C3-C30 cycloalkyl, C6-C30 aryl, (C6-C30 aryl)oxy, (C6-C30 aryl)thio, C5 a -C30 heterocyclic group and any combination thereof, o is an integer of 0-1, and p is an integer of 0-2. The resist composition according to claim 13, wherein the amount of the acid generator is in the range of 0.3 to 10 parts by weight based on 100 parts by weight of the solid of the resist composition. The resist composition of claim 13, further comprising an additive selected from the group consisting of an alkali-soluble quencher, an acid diffusion quencher, a surfactant, and any mixture thereof. A method of forming a resist pattern, the method comprising: forming a resist film by coating a resist composition as described in claim 13 on a substrate; heating the resist film and The resist film is exposed to form a predetermined pattern; and the exposed pattern is developed. Forming a resist pattern as described in claim 18 The method wherein the exposure is performed using a light source selected from the group consisting of a KrF excimer laser, an ArF excimer laser, an extreme ultraviolet laser, an X-ray, and an electron beam.