KR20030028103A - Polymer for photoresist thereof and photoresist composition thereby - Google Patents

Abstract

PURPOSE: A polymer for photoresist and a chemical amplification photoresist composition using the polymer are provided, to improve the formation of micropattern and the transparency under the light source with a wavelength of 157 nm. CONSTITUTION: The polymer is represented by the formula 1, wherein R1 is H, F, an alkyl group of C1-C10 or a fluoroalkyl group; R2 is F, an alkyl group of C1-C10 or a fluoroalkyl group; R3 and R4 are the same or different and independent each other and are an alkyl group of C1-C10 or a fluoroalkyl group; R5 is a substituent deprotected by an acid, and is a linear, branched or cyclic alkyl, haloalkyl or alkylalkoxy group of C1-C12, a carbonyl alkyl group, an alkoxycarbonyl group, a phenyl group or a naphthyl group; 0<=p<3, 0<=q<3, and 0 <p+q<3; and 0<n/(n+m)<=1 and 0<=m/(n+m)<1. The photoresist composition comprises the polymer of the formula 1; a photoacid generator; and a solvent.

Description

Photoresist polymer and photoresist composition using the same

The present invention relates to a photoresist polymer and a photoresist composition using the same in the case of forming a fine pattern on the surface of a semiconductor device by using ultraviolet (UV) or deep ultraviolet (Deep UV).

With the recent development of large scale integration (LSI) technology, the number of bits of memory integrated in an IC chip reaches the mega bit level, and as the size of the line and space becomes smaller, Submicron rules are required. Therefore, not only the wavelength region of the lithography light source is shifted from the long wavelength to the short wavelength but also the etching process during the LSI process is mainly performed by dry etching by PF plasma. The resist material accompanying this process technique requires photosensitivity, transparency, etching resistance, etc. with respect to the wavelength used. Photoresists that meet these requirements, especially resists used in g-line and i-line lithography techniques, are novel blocks with good light transmission and plasma etching resistance to the wavelength of the light source used. (Novolak) based aromatic resins were used. However, when using the same light source (mercury lamp), ArF or KrF light is much weaker than g-ray or i-ray. Therefore, when such far ultraviolet rays are applied to photolithography, sufficient exposure sensitivity cannot be obtained for conventional resists of g-ray and i-ray. . In addition, the development of a new kind of resist material is being progressed due to problems such as light transmittance being lowered in far ultraviolet rays.

In order to solve this problem, instead of the conventional type of resist material, a chemical amplification resist was proposed by H. Ito of IBM Corporation in the early 1980s and widely studied. Based on the concept of chemical amplification, a resist using a light source of KrF and ArF as a light source was developed, and it is now possible to realize a fine pattern up to 100 nm (Line / Space). A representative example of the implementation of the micropattern using a KrF excimer laser light source is Japanese Patent (Patent No. 10-53621) of Wako Corporation, and a resist technology using an ArF excimer laser light source is IBM's resist using an acrylic resin. And the combination of the two structures to improve the resolution and technology of Lucent, IBM, and JSR, which introduced alicyclic structures such as norbornene and maleic acid to the polymer backbone to improve the etching resistance. And resists such as Fujitsu.

However, in order to realize a micropattern of 70 nm (Line / Space) or less, the two light sources cannot be used because the wavelength is too large. Therefore, in order to realize a fine pattern of 80 nm or less, F2 emitting light having a wavelength of 157 nm, which is shorter than the two light sources, is adopted as a light source. When the existing KrF or ArF resists are used as the light source of 157nm, the development of a new resist is required because the transmittance is poor in the 157nm region, that is, the absorption is severe and cannot be used in the 157nm region.

The basic characteristics of the resist which can be applied in the 157 nm region should have a functional group having an excellent transmittance in the 157 nm region and an appropriate acidity (pKa) so that it can be developed in a basic developer. Based on this basic concept, various studies have recently been attempted. A representative example is a technique being studied by the G.Willson group of the University of Texas at Austin, USA. Hexafluoro isopropyl alcohol having an acidity similar to the pKa of phenol. (hexafluoro isopropylalcohol; HFIPA) was introduced into the norbornene polymer backbone to improve permeability and dissolve in TMAH base solution. (Solid State Technology, 2000, March, pp. 41-48; Proc. SPIE, 2000, Vol. 3999, pp 365-372; J. Phototpolymer Sci. Technol., 2000, Vol. 13 (4), pp.657 -664)

In addition, IBM proposed a resist with improved permeability and physicochemical properties at 157 nm by copolymerizing HFIPA-containing norbornene or styrene monomers with alphatri-fluoromethyl acrylate monomers. Cornell University, on the other hand, hydrolyzed alpha-trifluoromethyl vinyl acetate polymer and introduced a protecting group decomposed by an acid to prepare a polyvinylacetate polymer having relatively improved permeability (J. Photopolymer Sci. Tech., 2000, Vol. 13 (3), pp. 451-458), and Matsushida, Japan, synthesized another PVA derivative containing norbornene alcohol and t-butyl group (Japanese Patent Laid-Open No. JP 2000-89465). Excellent results were obtained at (157 nm) with (alpha-methyl-p-hydroxystyrene-co-methylmethacrylonitrile) -based polymer, and the reason for synthesizing the copolymer using acrylonitrile as a monomer was to increase permeability. (J. Photopolymer Sci. Tech., 2000, Vol., 13 (3), pp.459-466)

Agfa, on the other hand, published a PVA-based polymer in which an acetal group and a carboxylic acid group were introduced, proving that the butyral polymer is as permeable as PVA at 157 nm (EP-993966, published).

On the other hand, Kansai Research Institute of Japan has introduced the development of resists with improved etching properties and excellent transmittance at 157nm by introducing SiO2 nanoparticles into existing ArF and KrF resists (Japanese Patent Laid-Open No. 11-327125).

However, in the above-mentioned techniques, HFIPA-based polymers are difficult to introduce a protecting group which is deprotected by acid, and thus, the introduction of various protecting groups is limited and the permeability is further required. .

The present invention is to solve the problems of the prior art as described above to introduce a protecting group partially deprotected by acid in the styrene polymer having a fluorinated main chain and a fluorinated alkyl alcohol group in order to exhibit excellent transmittance at 157 nm The present invention provides a new chemically amplified photoresist polymer having excellent physical properties such as fine pattern formation and improved permeability by providing a polymer, and a composition thereof.

That is, one aspect of the present invention relates to a photoresist polymer represented by the following formula (1).

[Formula 1]

R ₁ in the formula is hydrogen, fluorine, alkyl group having 1 to 10 carbon atoms, or fluoroalkyl group; R ₂ represents fluorine, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group, R ₃ and R ₄ are the same or each independently represent an alkyl group or fluoroalkyl group having 1 to 10 carbon atoms, and R ₅ is an acid group. As a deprotected substituent, C1-C12 linear, branched or cyclic alkyl group, haloalkyl group or alkylalkoxy group, carbonylalkyl group, alkoxycarbonyl group, phenyl group, or naphthyl group are each represented by p and q. p <3, 0 ≦ q <3, 0 <p + q <3, and n and m are each 0 <n / (n + m) ≤1,0≤m / (n + m) < The value satisfies 1.

Another aspect of the invention is (a) the polymer; (b) photo acid generators; And (c) relates to a composition for a photoresist comprising a solvent capable of dissolving the (a) and (b).

1 is a flowchart illustrating an image forming process using a photoresist composition, and

2 is a graph showing the results of ultraviolet absorption analysis of the polymer according to the preparation example.

Hereinafter, the present invention will be described in detail.

The present invention relates to a novel photoresist polymer and a photoresist composition using the same.

The photoresist polymer is represented by a polymer substituted with a functional group which can be easily deprotected by an acid partially to a styrene polymer having a fluorinated main chain and a fluorinated alkyl alcohol group as shown in the following Chemical Formula 1.

R ₁ in the formula is hydrogen, fluorine, alkyl group having 1 to 10 carbon atoms, or fluoroalkyl group; R ₂ represents fluorine, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group, R ₃ and R ₄ represent the same or each independently a C 1-10 alkyl group or a fluoroalkyl group, and R ₅ represents an acid. As a deprotected substituent, C1-C12 linear, branched or cyclic alkyl group, haloalkyl group or alkylalkoxy group, carbonylalkyl group, alkoxycarbonyl group, phenyl group, or naphthyl group are each represented by p and q. p <3, 0 ≦ q <3, 0 <p + q <3, and n and m are 0 <n / (n + m) ≤1, 0≤m / (n + m) < The value satisfies 1.

The polymer of Chemical Formula 1 may be obtained by polymerizing a monomer represented by Chemical Formula 2 by a radical polymerization method and substituting a portion of an alkyl alcohol group with a protecting group which is easily deprotected by an acid.

R ₁ in the formula is hydrogen, fluorine, alkyl group having 1 to 10 carbon atoms, fluoroalkyl group; R ₂ is fluorine, an alkyl group having 1 to 10 carbon atoms, a fluoroalkyl group; R ₃ and R ₄ are the same or each independently represent an alkyl group or a fluoroalkyl group having 1 to 10 carbon atoms, and p and q satisfy 0≤p <3, 0≤q <3 and 0 <p + q <3 It is a value.

Substituents deprotected by an acid include linear, branched or cyclic alkyl groups, haloalkyl groups or alkylalkoxy groups having 1 to 12 carbon atoms, carbonylalkyl groups, alkoxycarbonyl groups, phenyl groups or naphthyl groups. Specific examples thereof include ethoxymethoxy, methoxymethylethyl, ethoxyethyl, methoxyethyl, butoxyethyl, isobutoxyethyl, 1,1-dimethylethoxy-1-methylethyl, 1,1- (dimethyl Methoxy) ethyl, 1- (2-chloroethoxy) ethyl, 1- (2-ethylhexyloxy) ethyl, 1-ethoxy-1-methylethyl, 1-n-propoxyethyl, 1-methyl-1 -n-propoxyethyl, 1-ethoxypropyl, 1-methoxybutyl, 1-methoxycyclohexyl, mensyloxymethyl, phenoxyoxyethyl, isobornyloxyethyl, acetyloxy-1-methylethyl, 1-hydride Oxy-α-methyl, 1-phenoxyethyl group, t-butyloxycarbonyl group, n-butyloxycarbonyl group, t-butylcarbonyl group, n-butylcarbonyl group, or haloalkyl group or alkoxycarbonyl group or naphthyloxyethyl group have.

The weight average molecular weight of the said polymer is 5,000-50,000, and molecular weight distribution is 1.0-3.0.

The present invention also provides a photoresist composition comprising (a) the novel photoresist polymer, (b) photoacid generator, and (c) a solvent capable of dissolving the (a) and (b).

The photo acid generator uses at least one compound selected from the group consisting of the following Chemical Formulas 3 to 9, and an acid is generated during exposure by the photoacid generator. The content of the photoacid generator is appropriate to be 0.05 to 15% by weight relative to 100% by weight of the polymer used.

In the above formula, R ₆ and R ₇ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group.

Specific examples of Formula 3 include 1-cyclohexylsulfonyl-1- (1,1-dimethylethylsulfonyl) diazomethane, bis (cyclohexylsulfonyl) diazomethane, 1-cyclohexylsulfonyl-1- Cyclohexylcarbonyldiazomethane, 1-diazo-1-cyclohexylsulfonyl-3,3'-dimethylbutan-2-non, 1-diazo-1-methylsulfonyl-4-phenylbutan-2- Paddy, diazo-1- (1,1-dimethylethylsulfonyl) 3,3-dimethyl-2-butanone, 1-acetyl-1- (1-methylethylsulfonyl) diazomethane, and the like.

In which R ₈ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, an alkoxy group or a haloalkyl group; R ₉ is a C1-C10 linear, branched or cyclic alkyl group, an alkylphenyl group or a haloalkyl group.

Specific examples of Chemical Formula 4 include bis (p-toluenesulfonyl) diazomethane, methylsulfonyl-p-toluenesulfonyldiazomethane, 1-diazo-1- (p-toluenesulfonyl) -3,3 '-Dimethyl-2-butanone, bis (p-chlorobenzenesulfonyl) diazomane, cyclohexylsulfonyl-p-toluenesulfonyldiazomethane, and the like.

Wherein R ₁₀ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a trifluoromethyl group; R ₁₁ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an alkylphenyl group or a haloalkyl group, a phenyl alkyl group, a linear or branched alkoxy, phenyl group having 1 to 5 carbon atoms, or a tolyl group.

Specific examples of Chemical Formula 5 include 1-p-toluenesulfonyl-1-cyclohexyl carbonyl diazomethane, 1-diazo-1- (p-toluenesulfonyl) -3,3-dimethylbutan-2-non , 1-diazo-1-benzenesulfonyl-3,3-dimethylbutan-2-non, and 1-diazo-1- (p-toluenesulfonyl) -3-methylbutan-2-non.

In the formula, R ₁₂ has the same structure as in Chemical Formula 6a or 6b.

Wherein R ₁₃ , R ₁₄ and R ₁₅ are each independently a hydrogen atom or a halogen atom; k is 0 or an integer of 1-3.

In the above formula, R ₁₆ to R ₂₀ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms or an alkoxy group, a trifluoromethyl group, a hydroxy group, a trifluoromethoxy group or a nitro group.

Specific examples of Chemical Formula 6 include 1,2,3-tris (trifluoro methanesulfonyloxy) benzene, 1,2,3-tris (2,2,2-trifluoroethanesulfonyloxy) benzene, 1 , 2,3-tris (2-chloroethanesulfonyloxy) benzene, 1,2,3-tris (p-trifluoro benzene sulfonyloxy) benzene, 1,2,3-tris (p-nitrobenzenesul Ponyloxy) benzene, 1,2,3-tris (2,3,4,5-pentafluorobenzenesulfonyloxy) benzene, 1,2,3-tris (p-fluoro benzene sulfonyloxy) benzene, 1,2,3-tris (methanesulfonyloxy) benzene, 1,2,4-tris (p-trifluoro methyloxybenzenesulfonyloxy) benzene, 1,2,4-tris (2,2,2 -Trifluoro ethanesulfonyloxy) benzene, 1,2,4-tris (2-thienylsulfonyloxy) benzene, 1,3,5-tris (methanesulfonyloxy) benzene, 1,3,5-tris (Trifluoromethanesulfonyloxy) benzene, 1,3,5-tris (2,2,2-trifluoroethanesulfonyloxy) benzene, 1,3,5-tris (p-nitrobenzene sulfonyloxy ) Benzene, 1,3,5-tris (2 , 3,4,5,6-pentafluorobenzenesulfonyloxy) benzene, 1,3,5-tris (p-fluorobenzenesulfonyloxy) benzene, 1,3,5-tris (2-chloroethane Sulfonyloxy) benzene and the like.

Wherein R ₁₂ has the same structure as in Formulas 6a and 6b; R ₂₁ is a hydrogen atom, a hydroxy group, or R ₁₂ SO ₂ O; R ₂₂ has a structure such as a linear or branched alkyl group having 1 to 5 carbon atoms or the following formula (7a).

In the above formula, R ₂₃ and R ₃₁ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or R ₁₂ SO ₂ O.

Specific examples of Chemical Formula 7 include 2,3,4-tris (p-fluorobenzenesulfonyloxy) benzophenone 2,3,4-tris (trifluolmethanesulfonyloxy) benzophenone, 2,3,4- Tris (2-chloroethanesulfonyloxy) benzophenone, 2,3,4-tris (p-trifluoromethylbenzenesulfonyloxy) benzophenone, 2,3,4-tris (p-nitrobenzene sulfonyl oxy ) Benzophenone, 2,3,4-tris (p-fluorobenzenesulfonyloxy) acetophenone, 2,3,4-tris (2,3,4,5,6-pentafluorobenzenesulfonyloxy) Acetophenone, 2,3,4-tris (2-nitrobenzenesulfonyloxy) acetophenone, 2,3,4-tris (2,5-dichlorobenzenesulfonyloxy) acetophenone 2,3,4-tris ( 2,3,4-trichlorobenzenesulfonyloxy) acetophenone, 2,2 ', 4,4'-tetra (methanesulfonyloxy) benzophenone, 2,2', 4,4'-tetra (2, 2,2-trifluoroethanesulfonyloxy) benzophenone, 2,2 ', 4,4'-tetra (2-chloroethanesulfonyloxy) benzophenone 2,2', 4,4'-tetra (2 , 5-dichlorobenzenesulfo Oxy) benzophenone, 2,2 ', 4,4'-tetra (2,4,6-trimethylbenzenesulfonyloxy) benzophenone, 2,2', 4,4'-tetra (m-trifluoromethyl Benzenesulfonyloxy) benzophenone and the like.

R ₂₄ is a linear or branched alkyl group having 1 to 6 carbon atoms, a phenyl group or a substituted phenylalkyl group; R ₂₅ is a hydrogen atom, a halogen atom or a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms; X is a linear, branched or cyclic alkyl sulfonate having 1 to 8 carbon atoms, perfluoroalkyl sulfonate, naphthyl sulfonate, 10-camphor sulfonate, phenyl sulfonate, tolyl sulfonate, dichloro Phenyl sulfonate, trichlorophenyl sulfonate, trifluoromethylphenyl sulfonate, Cl, Br, SbF ₆ , BF ₄ , PF ₆ or AsF ₆ .

Specific examples of the formula (8) include triphenylsulfonium trifluoro methane sulfonate, triphenylsulfonium perfluorooctanesulfonate, triphenylsulfonium perfluorobutanesulfonate, diphenyl-p-tolylsulfonium perfluor Rooctanesulfonate, tris (p-tolyl) sulfonium perfluorooctanesulfonate, tris (p-chlorobenzene) sulfonium trifluoromethanesulfonate, tris (p-tolyl) sulfonium trifluoromethane sulfonate , Trimethylsulfonium trifluoromethanesulfonate, dimethylphenylsulfonium trifluoromethanesulfonate, dimethyltorylsulfonium trifluoromethanesulfonate, dimethyltorylsulfonium perfluorooctanesulfonate, triphenylsulfonium p- Toluenesulfonate, triphenylsulfonium methanesulfonate, triphenylsulfonium butanesulfonate, triphenylsulfonium n-octanesulfonate, triphenylsulfonium 1-naphthalenesul , Triphenylsulfonium 2-naphthalenesulfonate, triphenylsulfonium 10-camphorsulfonate, triphenylsulfonium 2,5-dichlorobenzenesulfonate, diphenyltorylsulfonium 1,3,4-trichlorobenzenesulfo Nitrate, dimethyl torylsulfonium p-toluenesulfonate, diphenyl toryl sulfonium 2,5-dichlorobenzenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroacetate, triphenylsulfonium chloride, etc. There is this.

Wherein X is a linear, branched or cyclic alkyl sulfonate having 1 to 8 carbon atoms, perfluoroalkyl sulfonate, naphthyl sulfonate, 10-camphor sulfonate, phenyl sulfonate, tolyl sulfonate , Dichlorophenyl sulfonate, trichlorophenyl sulfonate, trifluoromethylphenyl sulfonate, F, Cl, Br, SbF ₆ , BF ₄ , PF ₆ or AsF ₆ ; D 1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; D2 is a C1-C10 alkyl group or 2-vinyloxyethyl group.

As a specific example of Formula 9, X is methanesulfonate, trifluoro methane sulfonate, p -toluenesulfonate, 10-camphorsulfonate, cyclohexane sulfamate, perfluoro-1-butanesulfonate, perfluor Rooctanesulfonate, F, Cl, Br, SbF ₆ , BF ₄ , PF ₆ or AsF ₆ , where D1 is hydrogen or methyl group, D2 is methyl group or vinyloxyethyl group.

In addition, the photoresist composition of the present invention may include at least one or more basic substances as an additive as necessary in order to further improve pattern characteristics. Basic materials include all monomers, polymers and phosphine oxide derivatives and hydrazine derivatives containing amine groups in the structure. The amount used is suitably such that each of the basic substances added to 100% by weight of the binder polymer is 10% by weight or less.

In addition, as an additive, a surfactant, a sensitizer, an adhesion aid, a storage stabilizer, etc. may be included as necessary. As surfactant, ether compounds, such as polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene nonyl phenyl ether, MEGAFACE R-08 (Japanese ink), Fluorad FC-430 Fluorine compounds such as (Japan Nippon Ink) and MEGAFACE LS-11 (Japan Nippon Ink) are representatively used, but not limited thereto. As the sensitizer, the adhesion aid, and the storage stabilizer, an amine compound or the like can be used. The composition of each additive is suitably used at 5% by weight or less relative to 100% by weight of the binder polymer.

As a solvent which melt | dissolves each component of the photoresist composition of this invention, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl Ether, propylene glycol methyl ether acetate, propylene glycol propyl ether acetate, diethylene glycol dimethyl ether, ethyl lactate, toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone, 4- Heptanone etc. can be used individually or in mixture of 2 or more types. If necessary, N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, alcohols and the like can be used as cosolvents. . At this time, the amount of the solvent is appropriately adjusted so that the amount of the polymer is 5 to 25% by weight relative to 100% by weight of the solvent, the co-solvent is suitable to use less than 10% by weight relative to 100% by weight of the solvent.

1 is a flowchart illustrating a method for implementing a micropattern using the resist composition of the present invention as described above. First, the resist composition 20 is coated and dried on a substrate 10 such as a silicon wafer. Thereafter, the F2 excimer laser light 40 of 300 nm or less is exposed through the mask 30, and developed using an alkali developer to form a desired pattern shape.

The following describes an embodiment of the present invention. The following examples are only for illustrating the present invention in more detail, but the present invention is not limited to the following examples.

Preparation Example 1

Poly [α, β, β-trifluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol (80%)-co- α, β, β-trifluorovinyl (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) -t-butyloxycarbonyl propylate (20%) ] Produce

60 g of α, β, β-trifluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol with 200 g of THF After putting together, 0.4 g of AIBN was added thereto and reacted at 70 ° C. for 8 hours. After the reaction was completed, the reaction product was cooled, poured into water to form a precipitate, washed with water several times, and dried under filtration vacuum. After dissolving 34 g of the vacuum-dried polymer in 150 g of THF solvent, 8 g of triethylamine and 10 g of di-t-butyl dicarbonate were added thereto and reacted at room temperature for 24 hours. Then, the reactant was poured into water to form a precipitate, which was filtered. After washing several times with water, filtration and vacuum drying to obtain the polymer.

The synthesized polymer has a weight average molecular weight of 18,000, a molecular weight distribution of 2.5, and shows excellent light transmittance at 157 nm as shown in the UV spectrum of FIG. 1.

Preparation Example 2

Poly [α, β, β-trifluorovinyl- (2,3-difluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol (75%) -co-α, β, β-trifluorovinyl (2,3-difluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) -t-butyloxycarbonyl Propylate (25%)] manufacture

80 g of α, β, β-trifluorovinyl- (2,3-difluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol in a 2 L reaction vessel After putting together 300 g of THF, 0.5 g of AIBN was added thereto and reacted at 70 ° C. for 8 hours. After the reaction was completed, the reaction product was cooled, poured into water to form a precipitate, washed several times with water, and then filtered and dried under vacuum. 40 g of the vacuum-dried polymer was dissolved in 200 g of a THF solvent, and 9 g of triethylamine and 12 g of di-t-butyl dicarbonate were added thereto, and reacted at room temperature for 24 hours. The polymer was obtained by filtration vacuum drying after washing several times.

The weight average molecular weight of the polymer thus obtained was 21,000, the molecular weight distribution was 2.4 and it can be seen that it shows excellent light transmittance at 157 nm as shown in the UV spectrum in FIG.

My Art 3

Poly [β, β-difluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol (80%)-co-β, β-difluorovinyl (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) -t-butyloxycarbonyl propylate (25%)]

70 g of β, β-difluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol together with 240 g of THF were added to a 2 L reaction vessel. After that, 0.5 g of AIBN was added thereto and reacted at 70 ° C. for 8 hours. After the reaction was completed, the reaction product was cooled, poured into water to form a precipitate, and washed again with water several times, followed by filtration and vacuum drying. After dissolving 29 g of the vacuum-dried polymer in 200 g of THF solvent, 8 g of triethylamine and 7 g of di-t-butyl dicarbonate were added thereto and reacted at room temperature for 24 hours. Then, the reactant was poured into water to form a precipitate, which was then filtered. Was washed several times with water and dried under filtration and vacuum to obtain the polymer.

The obtained polymer had a mass average molecular weight of 13,000 and a molecular weight distribution of 2.3, and the UV spectrum showed that the polymer exhibited excellent light transmittance at 157 nm.

Example 1

Poly [α, β, β-trifluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) polymerized in Preparation Example 1 with a binder resin Isopropyl alcohol (80%)-co-α, β, β-trifluorovinyl (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) -t- Butyloxycarbonyl propylate (20%)] 30 g of polymer, 0.5 g of triphenylsulfonium p-toluenesulfonate, 0.2 g of 1,2,3-tris (trifluoro methanesulfonyloxy) benzene and 1-diazo 0.7 g of -1- (p-toluenesulfonyl) -3-methylbutan-2-non was dissolved in 600 g of propylene glycol methyl ether acetate to form a photoresist composition.

The photoresist composition was spin-coated on a silicon wafer and then heated at 110 ° C. for 90 seconds before exposure to form a resist film having a thickness of 0.12 μm. The film was subjected to reduced projection exposure with a F2 excimer laser (157 nm) stepper via a mask with a pattern, which was heated after exposure at 120 ° C. for 90 seconds. Puddle development was then carried out in 2.38 wt% aqueous tetramethylammonium hydroxide (TMAH) solution for 1 minute, followed by spin drying with ultrapure water. As a result, a positive pattern of 0.18 μm Line and Space was developed with a good pattern cross section. No residual film loss was observed in the unexposed part, and no residue was observed after development of the exposed part.

Example 2

Poly [α, β, β-trifluorovinyl- (2,3-difluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) iso synthesized in Preparation Example 2 Propyl Alcohol (75%)-co-α, β, β-trifluorovinyl (2,3-difluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro)- t-butyloxycarbonyl propylate (25%)] The same process as in Example 1 was conducted except that 90 g of a polymer was used as the binder resin. As a result of evaluation in the same manner as in Example 1, a positive pattern of 0.13 μm line and space was developed with a good pattern cross-sectional shape. No residual film loss was observed in the unexposed part, and no post-development residue was observed in the exposed part.

Example 3

Poly [β, β-difluorovinyl- (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) isopropyl alcohol synthesized in Preparation Example 3 with binder resin (80%)-co-β, β-difluorovinyl (2-fluoro) phenyl-4- (1,1,1,3,3,3-hexafluoro) -t-butyloxycarbonyl propyl (25%)] 120 g of a polymer was mixed with 0.8 g of bis (p-toluenesulfonyl) diazomethane and 2 g of dimethyltoryl sulfonium perfluorooctanesulfonate, and a mixed solvent of 620 g of ethyl cellosolve acetate and methyl ethyl ketone. Was dissolved in to form a photoresist composition.

As a result of evaluation in the same manner as in Example 1, a positive pattern of 0.18 μm line and space was developed with a good pattern cross-sectional shape. No residual film loss was observed in the unexposed portion, and no post-development residue was observed in the exposed portion.

The present invention is to provide a new photoresist polymer of fluorinated polyvinyl-based to provide a chemically amplified photoresist composition with improved physical properties such as the formation of fine patterns and transmittance under a light source of 157nm.

Claims (5)

A photoresist polymer represented by the following formula (1). [Formula 1] R ₁ in the formula is hydrogen, fluorine, alkyl group having 1 to 10 carbon atoms, or fluoroalkyl group; R ₂ represents fluorine, an alkyl group having 1 to 10 carbon atoms, or a fluoroalkyl group, R ₃ and R ₄ are the same or each independently represent an alkyl group or fluoroalkyl group having 1 to 10 carbon atoms, and R ₅ is an acid group. As a deprotected substituent, C1-C12 linear, branched or cyclic alkyl group, haloalkyl group or alkylalkoxy group, carbonylalkyl group, alkoxycarbonyl group, phenyl group, or naphthyl group are each represented by p and q. p <3, 0 ≦ q <3, 0 <p + q <3, and n and m are each 0 <n / (n + m) ≤1, 0≤m / (n + m) < The value satisfies 1. (a) the polymer according to claim 1; (b) photo acid generators; And (c) a solvent capable of dissolving (a) and (b); Photoresist composition comprising a. The photosensitive composition for photoresist according to claim 2, wherein the photoacid generator uses at least one compound selected from the group consisting of the following Chemical Formulas 3 to 9. [Formula 3] In the above formula, R ₆ and R ₇ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. [Formula 4] R ₈ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, an alkoxy group or a haloalkyl group; R ₉ is a linear, branched or cyclic alkyl group, alkylphenyl group or haloalkyl group having 1 to 10 carbon atoms. [Formula 5] R ₁₀ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a trifluoromethyl group; R ₁₁ is a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an alkylphenyl group or a haloalkyl group, a phenyl alkyl group, a linear or branched alkoxy group having 1 to 5 carbon atoms, a phenyl group or a tolyl group. [Formula 6] In the formula, R ₁₂ has the same structure as in Chemical Formula 6a or 6b. [Formula 6a] R ₁₃ , R ₁₄ and R ₁₅ are each independently a hydrogen atom or a halogen atom; k is 0 or an integer of 1-3. [Formula 6b] In the above formula, R ₁₆ to R ₂₀ are each independently a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms or an alkoxy group, a trifluoromethyl group, a hydroxy group, a trifluoromethoxy group or a nitro group. [Formula 7] R ₁₂ is the same as in Chemical Formula 6a or 6b; R ₂₁ is a hydrogen atom, a hydroxy group, or R ₁₂ SO ₂ O; R ₂₂ has a structure such as a linear or branched alkyl group having 1 to 5 carbon atoms or the following formula (7a). [Formula 7a] In the above formula, R ₂₃ and R ₃₁ are each independently a hydrogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or R ₁₂ SO ₂ O. [Formula 8] R ₂₄ is a linear or branched alkyl group having 1 to 6 carbon atoms, a phenyl group, or a substituted phenylalkyl group; R ₂₅ is a hydrogen atom, a halogen atom, or a linear, branched or cyclic alkyl group having 1 to 4 carbon atoms; X is a linear, branched or cyclic alkyl sulfonate having 1 to 8 carbon atoms, perfluoroalkyl sulfonate, naphthyl sulfonate, 10-camphor sulfonate, phenyl sulfonate, tolyl sulfonate, dichloro Phenyl sulfonate, trichlorophenyl sulfonate, trifluoromethylphenyl sulfonate, Cl, Br, SbF ₆ , BF 4, PF ₆ or AsF ₆ . [Formula 9] Wherein X is a linear, branched or cyclic alkylsulfonate having 1 to 8 carbon atoms, perfluoroalkyl sulfonate, naphthyl sulfonate, 10-camphor sulfonate, phenyl sulfonate, tolyl sulfonate , Dichlorophenyl sulfonate, trichlorophenyl sulfonate, trifluoromethylphenylsulfonate, toluene sulfonate, perfluorooctane sulfonate, perfluoro-1-butane sulfonate, cyclohexane sulfamate, F, Cl, Br , SbF ₆ , BF ₄ , PF ₆ or AsF ₆ ; D 1 is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; D2 is a C1-C10 alkyl group or 2-vinyloxyethyl group. The method of claim 2, wherein the solvent is ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol methyl Group consisting of ether acetate, propylene glycol propyl ether acetate, diethylene glycol dimethyl ether, ethyl lactate, toluene, xylene, methyl ethyl ketone, cyclohexanone, 2-heptanone, 3-heptanone and 4-heptanone Photoresist composition, characterized in that at least one selected from. The solvent according to claim 4, wherein the solvent consists of N-methylformamide, N, N-dimethylformamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide and alcohols. The photoresist composition further comprises at least one selected from the group as a co-solvent.