KR20020080736A - Polymer for photoresist, producing method thereof and photoresist composition thereby - Google Patents

Abstract

PURPOSE: Provided are a chemically amplified photoresist polymer excellent in physical property, such as micropattern forming property and improved transparency, a method for preparing the same, and a photoresist composition comprising the same. CONSTITUTION: The photoresist polymer is represented by formula 1. In the formula 1, n is 1-4; X is cyclohexyl or phenyl, naphthyl; R1, which is a functional group capable of being deprotected by acid, is an alkyl group, alkylalkoxy group, alkylester group or alkyl acetyl group; R2 is hydrogen or trifluoromethyl group; Z is nitrile group or carboxylic acid; p and q are not 0, at least one of p and q is not 0, 0.4<=p/(p+q+r)<=0.9, 0<=q/(p+q+r)<=0.5, 0<=r(p+q+r)<=0.5. The composition comprises (a) the photoresist polymer, (b) a photo acid generator, and (c) solvent capable of dissolving the components(a) and (b).

Description

Polymer for photoresist, preparation method thereof and photoresist composition using same {Polymer for photoresist, producing method

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

With the recent development of the Large Scale Intergration (LSI) technology, the number of bits of the memory integrated in the IC chip reaches the mega bit level, and as a result of the miniaturization between the line and space intervals, the submicron A rule is required. Therefore, not only the wavelength region of the light source for lithography 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. 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 studied by the G.Willson group of the University of Texas at Austin, USA. Hexafluoro isopropyl alcohol having an acidity similar to that of phenol pKa (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 the alpha-trifluoromethyl vinyl acetate polymer and introduced a protecting group which is 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, or to replace the hydroxyl group of the vinyl polymer containing a fluorinated hydroxy compound having excellent transmittance at 157nm with a functional group which is partially deprotected by an acid, or To provide a polymer copolymerized with an acrylic acid or acrylonitrile-based monomer known to have excellent permeability, to provide a novel chemically amplified photoresist polymer having excellent physical properties such as fine pattern formation and improved permeability, and a composition thereof.

That is, the present invention provides a polymer for photoresist of the formula (1).

[Formula 1]

N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkylalkoxy group, an alkylester group or an alkylacetyl group as a functional group deprotectable by an acid; R ₂ represents hydrogen or trifluoromethyl group; Z represents a nitrile group or carboxylic acid. In p, q and r, p and q are not 0, at least one of q and r is not 0, and 0.4≤p / (p + q + r) ≤0.9, 0≤q / (p + q + r) It is a value which satisfies ≤ 0.5, 0 ≤ r / (p + q + r) ≤ 0.5.

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

Another aspect of the present invention is a partial hydrolysis after radical or anionic polymerization of a vinyl monomer containing a fluorinated hydroxy compound represented by the following formula (2) alone or together with the monomer represented by the following formula (3) It provides a method for producing a photoresist polymer according to the formula (1) comprising the step of.

[Formula 2]

N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R <_1> represents a C1-C6 alkyl group, an alkylalkoxy group, an alkylester group, or an alkylacetyl group as a functional group which can be deprotected by an acid.

[Formula 3]

In which R ₂ represents hydrogen or a trifluoromethyl group; Z represents a nitrile group or carboxylic acid.

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, a preparation method thereof and a photoresist composition using the same.

The photoresist polymer is represented by a polymer including a substituent that can be easily deprotected by an acid as shown in the following Chemical Formula 1.

N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkylalkoxy group, an alkylester group or an alkylacetyl group as a functional group deprotectable by an acid; R ₂ represents hydrogen or trifluoromethyl group; Z represents a nitrile group or carboxylic acid. In p, q and r, p and q are not 0, at least one of q and r is not 0, and 0.4≤p / (p + q + r) ≤0.9, 0≤q / (p + q + r) It is a value which satisfies ≤ 0.5, 0 ≤ r / (p + q + r) ≤ 0.5.

The polymer of Formula 1 is a radical or anionic polymerization of a vinyl monomer containing a fluorinated hydroxy compound as shown in the following formula 2 alone or together with the monomer represented by the formula (3), and then partially hydrolyzed to the formula (1) A polymer such as can be obtained.

N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R <_1> represents a C1-C6 alkyl group, an alkylalkoxy group, an alkylester group, or an alkylacetyl group as a functional group which can be deprotected by an acid.

In which R ₂ represents hydrogen or a trifluoromethyl group; Z represents a nitrile group or carboxylic acid.

Specific examples of Chemical Formula 3 include acrylonitrile, trifluoromethyl acrylonitrile, trifluoromethyl acrylate, acrylate, and the like.

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 Formulas 4 to 10, and an acid is generated upon 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 ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group.

Specific examples of Chemical Formula 4 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.

Wherein R ₄ 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 <_5> is a C1-C10 linear, branched or cyclic alkyl group, an alkylphenyl group, or a haloalkyl group.

Specific examples of Formula 5 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 ₆ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a trifluoromethyl group; R ₇ 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 6 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 7a or 7b.

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 7 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 7a and 7b; 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 (8a).

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 8 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 (9) are 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 10, 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

Fluorine compounds such as (Japan Ink), Fluorad FC-430 (Japan Ink) and MEGAFACE LS-11 (Japan 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

Preparation of poly [(2-fluoro) -4-hydroxystyrene (70 mol%)-co- (2-fluoro) -p-tbutoxycarbonyloxystyrene (30%)]

250 g of 2-fluoro-4- (t-butoxycarbonyloxystyrene) was dissolved in anhydrous tetrahydrofuran solvent, 0.4 g of normal butyl lithium was added thereto, charged with nitrogen, and then polymerized at -70 ° C. for 24 hours. Next, the obtained polymer was added to water, washed several times, dried in vacuo and dissolved in THF solvent, 0.3 g of hydrochloric acid was added thereto, hydrolyzed for 3 minutes, precipitated in distilled water, and washed again with distilled water to obtain the polymer.

The weight average molecular weight of the polymer thus obtained was 25,000, the molecular weight distribution was 1.9, and as shown in FIG. 2, the polymer exhibited excellent light transmittance at 157 nm.

Preparation Example 2

Poly [(2,6-difluoro) -4-hydroxystyrene (70 mol%)-co- (2,6-difluoro) -4-butoxycarbonyloxystyrene (20 mol%)-co -α-trifluoromethyl acrylonitrile (10 mol%)]

After dissolving 212 g of 2,6-fluoro-4- (t-butoxycarbonyloxystyrene) in anhydrous THF solvent, 12 g of α-trifluoromethylacrylonitrile was added thereto and stirred, followed by normal butyl. 0.4 g of lithium was charged with nitrogen, and then polymerized at -70 ° C. for 24 hours. The obtained polymer was poured into water, washed several times, dried in vacuo, dissolved in THF solvent, 0.5 g of hydrochloric acid was added, and stirred for 2 minutes. Decomposed and precipitated in distilled water and washed again with distilled water to obtain the polymer.

The weight molecular weight of the polymer obtained at this time was 15,000, the molecular weight distribution is 2.3, it can be seen that the polymer shown in the UV spectrum as shown in Figure 2 excellent light transmittance at 157nm.

Preparation Example 3

Preparation of poly [(6-fluoro) -4-hydroxystyrene (75 mol%)-co- (6-fluoro) -4-acetoxy styrene (25 mol%)]

After dissolving 260 g of 6-fluoro-4-acetoxy styrene in anhydrous THF, nitrogen-filled, 3 g of 2,2'-azobisisobutyronitrile (AIBN) was added thereto, followed by degassing several times. After reacting for 10 hours, 20 ml of methanol was added thereto to terminate the reaction. The reaction was poured into distilled water, washed several times, filtered and dried in vacuo. The vacuum dried polymer was dissolved in THF solvent, 0.3 g of hydrochloric acid was added thereto, and hydrolyzed for 10 minutes to obtain the polymer. The weight average molecular weight of the obtained polymer was 40,000, and the molecular weight distribution was 2.8.

Preparation Example 4

Poly [(6-fluoro) -4-hydroxystyrene (65 mol%)-co- (6-fluoro) -4-acetoxystyrene (25 mol%)-co-α-trifluoromethyl acrylo Nitrile (10 mol%)] Preparation

260 g of 6-fluoro-4-acetoxy styrene was dissolved in anhydrous THF, and 12 g of α-trifluoromethyl acrylonitrile and 3 g of 2,2'-azobisisobutyronitrile (AIBN) were added thereto, followed by degassing. After several times of reaction, the reaction temperature was adjusted to 70 ° C. for 18 hours, and 30 ml of methanol was added thereto to terminate the reaction. The reaction was poured into distilled water, washed several times, and filtered and dried in vacuo. The vacuum dried polymer was dissolved in THF solvent, and 0.4 g of hydrochloric acid was added thereto, followed by hydrolysis for 8 minutes to obtain the polymer. The weight average molecular weight of the obtained polymer was 35,000, and the molecular weight distribution was 2.7.

Example 1

Poly [(2-fluoro) -4-hydroxystyrene (70 mol%)-co- (2-fluoro) -pt-butoxycarbonyloxystyrene synthesized in Preparation Example 1 as a binder resin (30 Mol%) 100 g of polymer, 0.4 g of triphenylsulfonium p-toluenesulfonate, 0.1 g of 1,2,3-tris (trifluoro methanesulfonyloxy) benzene and 1-diazo-1- (p-toluene 0.6 g of sulfonyl) -3-methylbutan-2-non was dissolved in 630 g of propylene glycol methylether acetate to form a photoresist composition.

After spin-coating the photoresist composition on a silicon wafer, the photoresist composition was preheated at 90 ° C. for 90 seconds to form a 0.2 μm thick resist film. 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 110 ° 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 [(2,6-difluoro) -4-hydroxystyrene (70 mol%)-co- (2,6-difluoro) -4-butoxycarbonyloxystyrene (synthesized in Preparation Example 2 20 mole%)-co-α-trifluoromethylacrylonitrile (10 mole%)] A polymer was used in the same manner as in Example 1, except that 110 g of a binder resin was used. As a result of evaluation in the same manner as in Example 1, a positive pattern of 0.17 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 [(6-fluoro) -4-hydroxystyrene (75 mol%)-co- (6-fluoro) -4-acetoxystyrene (25 mol%)] polymer synthesized in Preparation Example 3 with binder resin 200 g of the photoresist composition was dissolved in 0.8 g of bis (p-toluene sulfonyl) diazomethane and 2 g of dimethyltoryl sulfonium perfluorooctane sulfonate in 620 g of a mixed solvent of ethyl cellosolve acetate and methyl ethyl ketone. Made.

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.

Example 4

Poly [(6-fluoro) -4-hydroxystyrene (65 mol%)-co- (6-fluoro) -4-acetoxystyrene (25 mol%)-co synthesized in Preparation Example 4 with a binder resin -α-trifluoromethyl acrylonitrile (10 mol%)] The same procedure as in Example 1 was carried out except that 160 g was used.

As a result of evaluation in the same manner as in Example 1, a positive pattern of 0.16 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.

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 (6)

To a photoresist polymer of the formula (1). [Formula 1] N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R ₁ represents an alkyl group having 1 to 6 carbon atoms, an alkylalkoxy group, an alkylester group or an alkylacetyl group as a functional group deprotectable by an acid; R ₂ represents hydrogen or trifluoromethyl group; Z represents a nitrile group or carboxylic acid. In p, q and r, p and q are not 0, at least one of q and r is not 0, and 0.4≤p / (p + q + r) ≤0.9, 0≤q / (p + q + r) It is a value which satisfies ≤ 0.5, 0 ≤ r / (p + q + r) ≤ 0.5. (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 5 to 11. [Formula 4] In the above formula, R ₂ and R ₃ are each independently a linear or branched alkyl group having 1 to 10 carbon atoms or a cycloalkyl group. [Formula 5] Wherein R ₄ 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 <_5> is a C1-C10 linear, branched or cyclic alkyl group, an alkylphenyl group, or a haloalkyl group. [Formula 6] R ₆ is hydrogen, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, or a trifluoromethyl group; R ₇ 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 7] In the formula, R ₁₂ has the same structure as in Chemical Formula 7a or 7b. [Formula 7a] 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 7b] 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 8] R ₁₂ is the same as in Formula 7a or 7b; 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 (8a). [Formula 8a] 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 9] 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 10] 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. A first method comprising the step of partially or hydrolyzing a vinyl-based monomer comprising a fluorinated hydroxy compound represented by the following formula (2), alone or together with the monomer represented by the following formula (3), and then partially hydrolyzing: It provides a method for producing a polymer for photoresist according to the paragraph. [Formula 2] N is 1 to 4; X is cyclohexyl or phenyl, naphthyl; R <_1> represents a C1-C6 alkyl group, an alkylalkoxy group, an alkylester group, or an alkylacetyl group as a functional group which can be deprotected by an acid. [Formula 3] In which R ₂ represents hydrogen or a trifluoromethyl group; Z represents a nitrile group or carboxylic acid.