Photosensitive polymer and resist composition containing the same

Abstract

The present invention discloses a photosensitive polymer comprising a repeating unit derived from a vinyl heteroaromatic compound of Chemical Formula 1 or Chemical Formula 2 and a resist composition comprising the photosensitive polymer. [Chemical Formula 1] [Chemical Formula 2] In the Chemical Formula 1 or 2, R 1 , R 2 is hydrogen or methyl, X is a carbon, sulfur or nitrogen atom, and n represents 1 or 2.

Description

Technical Field

[0001] The present disclosure relates to a photosensitive polymer and a resist composition comprising the same. The photosensitive polymer comprises a repeating unit derived from a vinyl heteroaromatic compound. Background Art

[0002] As semiconductor manufacturing processes become more complex and the integration of semiconductor elements increases, it is necessary to form fine patterns. As for resist materials, ArF excimer laser (193nm) is used instead of the existing KrF excimer laser (248nm) resist, and ArF excimer laser uses a short wavelength.

[0003] However, in semiconductor elements with a capacity of 16 Gigabit or more, the thickness of the resist film gradually becomes smaller because the design rules require the pattern size to be less than 70 nm. As the process margin decreases in the process of etching the lower film layer, the use of resist materials using ArF excimer lasers is increasingly restricted.

[0004] Compared with existing resist materials, this resist material used in lithography using ArF excimer laser has many problems in commercialization. The most typical problem is the resistance of the resist to dry etching.

[0005] As the existing ArF resist known so far, acrylic acid or methacrylic acid polymers are mainly used, and the most commonly used polymer materials are poly (methacrylate) polymer materials. A serious problem of these polymers is that they have very poor resistance to dry etching. In other words, since these materials have too low a selectivity in the dry etching process using plasma gas in the semiconductor device manufacturing process, it is difficult to perform the etching process.

[0006] Therefore, in order to increase the resistance to dry etching, a method of introducing alicyclic compounds, which are substances with strong resistance to dry etching, has been adopted, such as isobornyl group, adamantyl group, tricyclodecanyl group, etc. as substituents of polymers. However, in order to meet the solubility in the developer and the adhesion properties to the lower film layer, their polymer forms mainly have a structure above a terpolymer, in which the alicyclic group occupies a very small part, so the resistance to dry etching is still poor. In addition, since alicyclic compounds are hydrophobic, when a lot of alicyclic compounds are included in the terpolymer structure as described above, the adhesion properties of the resist film to the lower film layer will deteriorate.

[0007] As another prior art polymer, COMA (cycloolefin-maleic anhydride) alternating polymers are proposed. In the preparation of COMA-type copolymers, the raw material cost is low, but there are still problems in the synthesis yield and resolution when preparing the polymer.

[0008] In addition, the polymer synthesized into the above structure has a highly hydrophobic alicyclic group as a skeleton, and thus has poor adhesion to the film layer. In addition, the COMA type photosensitive resin has a disadvantage in terms of storage stability of the resist composition. Summary of the invention

[0009] Technical issues

[0010] The present disclosure aims to provide a photosensitive polymer comprising a repeating unit derived from a vinyl heteroaromatic compound and having excellent resistance to dry etching.

[0011] The present disclosure aims to provide a resist composition which has extremely excellent dry etching characteristics compared with KrF and ArF resist materials and is suitable for manufacturing future next-generation semiconductors.

[0012] Technical Solution

[0013] The photosensitive polymer according to an embodiment includes a repeating unit derived from the vinyl heteroaromatic compound of Chemical Formula 1 or Chemical Formula 2.

[0014] [Chemical formula 1]

[0015]

[0016] [Chemical formula 2]

[0017]

[0018] In the chemical formula 1 or 2, R 1 , R 2 is hydrogen or methyl, X is a carbon, sulfur or nitrogen atom,

[0019] n represents 1 or 2.

[0020] The resist composition according to an embodiment includes the photosensitive polymer including the repeating unit derived from the vinyl heteroaromatic compound of Chemical Formula 1 or Chemical Formula 2, a photoacid generator, and an organic solvent.

[0021] The photosensitive polymer further includes one or more repeating units derived from a compound selected from the group consisting of the following Chemical Formula 3, Chemical Formula 4, and Chemical Formula 5.

[0022] [Chemical formula 3]

[0023]

[0024] [Chemical formula 4]

[0025]

[0026] [Chemical formula 5]

[0027]

[0028] In the chemical formula 3, chemical formula 4 and chemical formula 5,

[0029] R 3 and R 5 are each independently hydrogen or methyl,

[0030] R 4 It is an acid-labile group or lactone derivative of C4 to C20 that decomposes in the presence of an acid catalyst.

[0031] R 6 is an alkyl or cycloalkyl group containing a polar group selected from the group consisting of hydrogen, hydroxyl, carboxyl and combinations thereof,

[0032] R 7 It is an alkyl group or a cycloalkyl group containing a polar group selected from the group consisting of hydrogen, hydroxyl, carboxyl, sulfonyl and combinations thereof.

[0033] Beneficial Effects

[0034] The photosensitive polymer according to the embodiment includes a repeating unit derived from a vinyl heteroaromatic compound and thus has low manufacturing cost, excellent dry etching resistance and adhesion properties to an underlying film layer, and exhibits an anti-corrosion function in a film layer composed of a metal material.

[0035] The resist composition according to the embodiment has much better dry etching properties than existing resist materials for KrF and ArF, and also has excellent adhesion properties to underlying film layers, and is therefore very suitable for use in manufacturing future next-generation semiconductor devices. DETAILED DESCRIPTION

[0036] Hereinafter, the embodiments will be described in detail so that those skilled in the art can easily implement them. The embodiments can be implemented in various ways and are not limited to the specific embodiments described herein.

[0037] Unless some terms used in the present disclosure are defined otherwise below, all technical and scientific terms used in the application have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs.

[0038] Unless otherwise specified, "alkyl" refers to a C1 to C 20 The alkyl group is more preferably C1 to C 12 "lower alkyl" refers to C1 to C4 alkyl, and "alkoxy" refers to C1 to C 20 The alkoxy group is preferably C1 to C 12 The alkoxy group, "alkylene" refers to C1 to C 20 The alkylene group is more preferably C1 to C 12 "Aryl" refers to C6 to C 20 The aryl group is more preferably C6 to C 12 "Cycloalkyl" refers to C3 to C 14 of a cycloalkyl group.

[0039] A photosensitive polymer according to an embodiment of the present invention includes a repeating unit derived from a vinyl heteroaromatic compound of the following Chemical Formula 1 or Chemical Formula 2.

[0040] [Chemical formula 1]

[0041]

[0042] [Chemical formula 2]

[0043]

[0044] In the chemical formula, R 1 , R 2 is hydrogen or methyl, X is a carbon, sulfur or nitrogen atom, and n represents 1 or 2.

[0045] The vinyl heteroaromatic compound may preferably be any one selected from the group consisting of the following compounds.

[0046]

[0047] The vinyl heteroaromatic compound can be easily synthesized into a photosensitive polymer (copolymer) by free radical polymerization with a (meth)acrylic monomer or a styrene monomer having various functional substituents.

[0048] The photosensitive polymer prepared by the method described above has etching resistance to dry etching, and at the same time has excellent adhesion properties to the underlying film layer, and has an anti-corrosion function in the film layer composed of metal materials, which is very conducive to forming a resist pattern. Therefore, the shortcomings of the existing KrF or ArF resist materials in terms of resistance to dry etching and adhesion properties to the underlying film layer are overcome, and the role of the etching mask can be fully exerted in semiconductor devices requiring higher resolution.

[0049] The photosensitive polymer includes the repeating unit derived from the vinyl heteroaromatic compound and one or more repeating units derived from a compound selected from the group consisting of the following Chemical Formula 3, Chemical Formula 4 and Chemical Formula 5.

[0050] [Chemical formula 3]

[0051]

[0052] [Chemical formula 4]

[0053]

[0054] [Chemical formula 5]

[0055]

[0056] In the chemical formula 3, chemical formula 4 and chemical formula 5, R 3 and R 5 are each independently hydrogen or methyl, R 4 It is a C4 to C 20 Acid-labile group or lactone derivative.

[0057] The acid-sensitive group is preferably selected from the group consisting of norbornyl, isobornyl, cyclodecyl, adamantyl, norbornyl substituted by a lower alkyl group, isobornyl substituted by a lower alkyl group, cyclodecyl substituted by a lower alkyl group, adamantyl substituted by a lower alkyl group, alkoxycarbonyl, alkoxycarbonylalkyl, pentyloxycarbonyl, pentyloxycarbonylalkyl, 2-tetrahydropyranyloxycarbonylalkyl, 2-tetrahydrofuranyloxycarbonylalkyl, tertiary alkyl and acetal group, and more preferably selected from the group consisting of 2-methyl-2-norbornyl, 2-ethyl-2-norbornyl, 2-methyl-2-isobornyl, 2-ethyl The invention also includes the group consisting of 2-isobornyl, 8-methyl-8-tricyclodecanyl, 8-ethyl-8-tricyclodecanyl, 2-methyl-2-adamantyl, 2-ethyl-2-adamantyl, 2-propyl-2-adamantyl, tert-butoxycarbonyl, tert-butoxycarbonylmethyl, t-pentyloxycarbonyl, t-pentyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylalkyl, 2-tetrahydrofuranyloxycarbonylalkyl, tert-butyl, triethylcarbyl, 1-methylcyclohexyl, 1-ethylcyclopentyl, tert-pentyl and acetal.

[0058] In addition, for the lactone derivative, preferably, as the lactone derivative group, substituents having structures of the following Chemical Formula 6 and Chemical Formula 7 can be cited.

[0059] [Chemical formula 6]

[0060]

[0061] Two of X1 to X4 are each independently C=O and O, and except for C=O and O, the others are CR8, and R8 is hydrogen, an alkyl group, or an alkylene group forming a condensed ring with the five-membered ring.

[0062] [Chemical formula 7]

[0063]

[0064] Two of X5 to X9 are independently C=O and O, and except for C=O and O, the others are CR9, and R9 is hydrogen, an alkyl group, or an alkylene group forming a condensed ring with a six-membered ring, or,

[0065] X5 to X9 are all CR9, R9 is hydrogen, an alkyl group, or an alkylene group containing an ester group that forms a condensed ring with a six-membered ring,

[0066] At least two R9 groups are linked to each other to form a lactone ring.

[0067] More preferably, R4 is selected from the group consisting of butyrolactone, valerolactonyl, 1,3-cyclohexanecarbolactonyl, 2,6-norbonanecarbolacton-5-yl and 7-oxa-2,6-norbornanecarbolacton-5-yl.

[0068] R6 is an alkyl or cycloalkyl group containing a polar group selected from the group consisting of hydrogen, hydroxyl, carboxyl and combinations thereof. 14 The alkyl group and cycloalkyl group are C3 to C 14 Preferably, it may be 2-hydroxyethyl, 3-hydroxy-1-adamantyl, or the like.

[0069] R7 is an alkyl or cycloalkyl group containing a polar group selected from the group consisting of hydrogen, hydroxyl, carboxyl, sulfonyl and combinations thereof. 14 The alkyl group and cycloalkyl group are C3 to C 14 Preferably, it may be hydrogen, hydroxy, fluorine, methyl, methoxy, etc.

[0070] That is, the photosensitive polymer may have a random copolymer form of the vinyl heteroaromatic compound of Chemical Formula 1 or Chemical Formula 2 and the compounds of Chemical Formulas 3 to 5. Preferably, the photosensitive polymer has a weight average molecular weight (Mw) of 3,000 to 30,000. More preferably, it has a weight average molecular weight (Mw) of 5,000 to 20,000.

[0071] In addition, the photosensitive polymer preferably has a dispersion degree (Mw / Mn) of 1.5 to 2.5. Within the above range, excellent etching resistance and resolution can be exhibited.

[0072] The photosensitive polymer according to an embodiment of the present invention is in the form of a polymer (copolymer) containing repeating units derived from a vinyl heteroaromatic compound having a novel function, and has the advantage that a resist composition having very excellent resistance to dry etching and metal corrosion can be obtained compared to existing resist materials.

[0073] When the resist composition obtained in this way is applied to a photolithography process, very excellent photolithography performance can be obtained.

[0074] According to another embodiment of the present invention, a resist composition comprising the photosensitive polymer is provided.

[0075] Specifically, the resist composition includes (a) a photosensitive polymer, (b) a photoacid generator (PAG) and (c) a solvent.

[0076] Hereinafter, each component included in the resist composition according to one embodiment of the present invention will be described in detail.

[0077] (a) Photosensitive polymer

[0078] The photosensitive polymer is as described above. The photosensitive polymer is preferably included in an amount of 5 to 50 parts by weight relative to 100 parts by weight of the resist composition. When the content of the photosensitive polymer included in the resist composition is within the above range, excellent etching resistance and adhesion properties can be obtained.

[0079] (b) Photo Acid Generator (PAG)

[0080] The photoacid generator may be selected from the group consisting of inorganic onium salts, organic sulfonates, and mixtures thereof. Specifically, a sulfonium salt or iodonium salt selected from triarylsulfonium salts, diaryliodonium salts, sulfonates, or mixtures thereof may be used. More preferably, the photoacid generator may be selected from the group consisting of triarylsulfonium trifluoromethanesulfonate, diaryliodonium trifluoromethanesulfonate, triarylsulfonium perfluorobutylsulfonate, diaryliodonium perfluorobutylsulfonate, succinimide trifluoromethanesulfonate, 2,6-dinitrobenzylsulfonate, and mixtures thereof.

[0081] The photoacid generator is preferably included in an amount of 1 to 10 parts by weight relative to 100 parts by weight of the photosensitive polymer. If the content of the photoacid generator is less than 1 part by weight, the exposure amount of the resist composition may be excessively increased, and if the content of the photoacid generator is greater than 10 parts by weight, there may be a problem of insufficient penetration of the resist composition.

[0082] (c) Organic solvent

[0083] As the organic solvent, one or more selected from the group consisting of propylene glycol methyl ether acetate (PGMEA), propylene glycol methyl ether (PGME), ethyl lactate (EL), cyclohexanone, 2-heptanone, γ-butyrolactone (GBL), etc. can be used.

[0084] The organic solvent is contained in the resist composition as a remaining component, and the content thereof is not particularly limited, but is preferably contained in an amount of 50 to 95 parts by weight relative to 100 parts by weight of the resist composition.

[0085] (d) Acid quencher

[0086] The resist composition may further include an organic base in addition to the components (a) to (c) in order to control the exposure amount and form a resist profile.

[0087] The organic base is mainly in the form of trivalent amines, for example, an amine compound selected from triethylamine, triisobutylamine, trioctylamine, triisodecylamine, triethanolamine or a mixture thereof can be used.

[0088] The content of the organic base is preferably 0.01 to 1 part by weight relative to 100 parts by weight of the photosensitive polymer. If the content of the organic base is less than 0.01 parts by weight, the desired effect cannot be expected, and if the content of the organic base is greater than 1 part by weight, the exposure amount will be excessively increased, and even a pattern may not be formed.

[0089] The following process is employed to form a desired pattern using the resist composition having the above-mentioned components.

[0090] A bare silicon wafer or a silicon wafer having a silicon oxide layer, a silicon nitride layer, a silicon oxynitride layer or a metal-containing lower film layer formed on the upper surface is prepared, and the silicon wafer is subjected to HMDS treatment or organic anti-reflection layer treatment. Then, the resist composition is coated on the silicon wafer with a thickness of about 100 to 500 nm to form a resist film.

[0091] The silicon wafer on which the resist film is formed is pre-baked (SB) at a temperature of about 90 to 150° C. for about 60 to 120 seconds to remove the solvent, and is exposed using various exposure light sources such as KrF, ArF or EUV (extreme ultraviolet), electron beam, etc., and then post-exposure baked (PEB) is performed at a temperature of about 90 to 120° C. for about 60 to 120 seconds to cause a chemical reaction in the exposed area of ​​the resist film.

[0092] Then, the resist film is developed with a 2.38 wt % tetramethylammonium hydroxide (TMAH) solution. At this time, the exposed portion shows a very large solubility in the alkaline aqueous developer, so it is easily dissolved and removed during development. When the exposure light source used is an ArF excimer laser, it can be developed at about 5 to 30 mJ / cm 2 A line and space pattern of 80 to 100 nm is formed at a dose of .

[0093] The resist pattern obtained through the above process is used as a mask, and a specific etching gas such as halogen gas or CxFy gas plasma is used to etch the lower film layer. Then, the resist pattern remaining on the wafer is removed with a stripper, so that a desired pattern can be formed.

[0094] Hereinafter, the present invention will be further described in detail with reference to examples. However, the following examples are only preferred examples of the present invention, and the present invention is not limited to the following examples.

[0095] Example-1) Synthesis of photosensitive polymer

[0096]

[0097] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), γ-butyrolactone methacrylate (GBLMA) (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were placed in a round-bottom flask and dissolved in a dioxane solvent (3 times the total weight of the monomers), and BPO (2% of the monomer concentration) was added as a polymerization initiator, and purged with nitrogen for about 20 minutes, and then polymerized at a temperature of 80°C for about 20 hours.

[0098] After the polymerization is completed, the reactants are slowly precipitated in an excess of methanol / water co-solvent, the resulting precipitate is filtered, and then dissolved in an appropriate amount of THF and re-precipitated in a methanol / water co-solvent. The resulting precipitate is then dried in a vacuum oven at 80°C for about 24 hours to synthesize a polymer (yield: 80%).

[0099] The weight average molecular weight (Mw) of the synthesized polymer was 14,900, and the dispersion degree (Mw / Mn) was 1.7.

[0100] Example-2) Synthesis of photosensitive polymer

[0101]

[0102] 1-vinyl-1,2,4-triazole (20 mmol), tert-butyl methacrylate (40 mmol), γ-butyrolactone methacrylate (GBLMA) (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0103] At this time, the weight average molecular weight (Mw) of the obtained polymer was 14,600, and the degree of dispersion (Mw / Mn) was 1.7.

[0104] Example-3) Synthesis of photosensitive polymer

[0105]

[0106] 4-Vinylpyridine (20 mmol), tert-butyl methacrylate (40 mmol), γ-butyrolactone methacrylate (GBLMA) (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0107] At this time, the weight average molecular weight (Mw) of the obtained polymer was 15,500, and the degree of dispersion (Mw / Mn) was 1.7.

[0108] Example-4) Synthesis of photosensitive polymer

[0109]

[0110] 2-Vinylpyrazine (20 mmol), tert-butyl methacrylate (40 mmol), γ-butyrolactone methacrylate (GBLMA) (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0111] At this time, the weight average molecular weight (Mw) of the obtained polymer was 14,500, and the degree of dispersion (Mw / Mn) was 1.8.

[0112] Example-5) Synthesis of photosensitive polymer

[0113]

[0114] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), styrene (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0115] At this time, the weight average molecular weight (Mw) of the obtained polymer was 14,800, and the degree of dispersion (Mw / Mn) was 1.7.

[0116] Example-6) Synthesis of photosensitive polymer

[0117]

[0118] 1-vinyl-1,2,4-triazole (20 mmol), tert-butyl methacrylate (40 mmol), styrene (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 70%).

[0119] At this time, the weight average molecular weight (Mw) of the obtained polymer was 14,600, and the degree of dispersion (Mw / Mn) was 1.7.

[0120] Example-7) Synthesis of photosensitive polymer

[0121]

[0122] 4-Vinylpyridine (20 mmol), tert-butyl methacrylate (40 mmol), styrene (20 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0123] At this time, the weight average molecular weight (Mw) of the obtained polymer was 14,800, and the degree of dispersion (Mw / Mn) was 1.7.

[0124] Example-8) Synthesis of photosensitive polymer

[0125]

[0126] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), styrene (20 mmol) and 4-hydroxystyrene (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 70%).

[0127] At this time, the weight average molecular weight (Mw) of the obtained polymer was 16100, and the degree of dispersion (Mw / Mn) was 1.7.

[0128] Example-9) Synthesis of photosensitive polymer

[0129]

[0130] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), styrene (20 mmol) and γ-butyrolactone methacrylate (GBLMA) (20 mmol) were polymerized in the same manner as in Example-1) to synthesize a polymer (yield: 75%).

[0131] At this time, the weight average molecular weight (Mw) of the obtained polymer was 15100, and the degree of dispersion (Mw / Mn) was 1.7.

[0132] Example-10) Synthesis of photosensitive polymer

[0133]

[0134] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), 4-hydroxystyrene (20 mmol) and γ-butyrolactone methacrylate (GBLMA) (20 mmol) were polymerized in the same manner as in Example-1) to synthesize a polymer (yield: 75%).

[0135] At this time, the weight average molecular weight (Mw) of the obtained polymer was 16,200, and the degree of dispersion (Mw / Mn) was 1.7.

[0136] Example-11) Synthesis of photosensitive polymer

[0137]

[0138] 1-vinylimidazole (20 mmol), tert-butyl methacrylate (40 mmol), 4-hydroxystyrene (20 mmol) and 1-adamantyl acrylate (20 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0139] At this time, the weight average molecular weight (Mw) of the obtained polymer was 15,500, and the degree of dispersion (Mw / Mn) was 1.7.

[0140] Example-12) Synthesis of photosensitive polymer

[0141]

[0142] 1-vinylimidazole (20 mmol), γ-butyrolactone methacrylate (20 mmol), styrene (20 mmol) and 2-methyl-2-adamantyl methacrylate (40 mmol) were polymerized by the same method as in Example-1) to synthesize a polymer (yield: 75%).

[0143] At this time, the weight average molecular weight (Mw) of the obtained polymer was 15,300, and the degree of dispersion (Mw / Mn) was 1.7.

[0144] Comparative Example) Synthesis of Photosensitive Polymer

[0145]

[0146] By the same method as in Example -1), tert-butyl methacrylate (40 mmol), γ-butyrolactone methacrylate (GBLMA) (40 mmol) and 3-hydroxy-1-adamantyl methacrylate (HAMA) (20 mmol) were polymerized to synthesize a polymer (yield: 80%).

[0147] At this time, the weight average molecular weight (Mw) of the obtained polymer was 15,900, and the degree of dispersion (Mw / Mn) was 1.7.

[0148] Example-13) Preparation of resist composition and lithographic performance

[0149] Each photosensitive polymer (1 g) synthesized in Examples 1 to 12 and Comparative Examples was dissolved in PGMEA / EL (6 / 4) (17 g) together with triphenylsulfonium perfluorobutanesulfonate (0.02 g), and then an organic base triethanolamine (1 mg) was added to completely dissolve it to prepare each resist composition.

[0150] Example-14) Evaluation of resist resolution

[0151] Each resist solution prepared in the embodiment 13) was filtered using a 0.1 μm membrane filter. The filtered resist solution was coated on a silicon wafer treated with an organic BARC (AR46, Rhom & Hass Company) with a thickness of 600 Å at a thickness of 140 nm, and then pre-baked (soft baking: SB) at a temperature of 130 degrees for 60 seconds.

[0152] An ArF scanner (0.78NA, dipole) was used with a concentration of 20-50 mj / cm 2 After exposure, PEB (post-exposure bake) was performed at 110 degrees for 60 seconds, and then developed in a 2.38 wt% TMAH solution for 60 seconds. As a result, a clean L / S pattern of 90 to 100 nm was obtained as shown in Table 1 below, and the resolution was better than that of the polymer in the comparative example.

[0153]

Table 1

[0154]

[0155] Example-15) Evaluation of etching resistance

[0156] In order to evaluate the etching characteristics of each resist composition prepared in the embodiment-13), bulk etching evaluation was performed under CF4 gas (components; power 100W, pressure 5Pa, flow rate 30ml / min) according to RIE (reactive ion etching) method. At this time, the reference value adopted was normalized based on the etching rate of polyhydroxystyrene (PHS) polymer (polymer for KrF), a resist for KrF, as a reference value for evaluation. The measurement results are shown in Table 2. In the case of the polymer of the present invention, the etching rate was about 1.1 times (normalized) relative to the polymer for KrF, and in the case of the polymer of the comparative example, the etching rate was about 1.5 times. It can be confirmed that the polymer of the present invention has a strong etching resistance.

[0157]

Table 2

[0158]

[0159] In the above, various embodiments have been described, but the scope of rights is not limited to the above embodiments. The implemented methods can be implemented in various ways within the scope of the description, which naturally also fall within the scope of rights.

Claims

1. A photosensitive polymer comprising repeating units derived from a vinyl heteroaromatic compound, The vinyl heteroaromatic compound is any one selected from the group consisting of compounds having the following structures, In the above chemical formula, R 1 is hydrogen or methyl.

2. A photosensitive polymer comprising a first repeating unit, a second repeating unit, a third repeating unit and a fourth repeating unit, The first repeating unit is composed of a vinyl heteroaromatic compound selected from the group consisting of compounds having the following structure, In the above chemical formula, R 1 is hydrogen or methyl; The second repeating unit is composed of the following chemical formula: In the chemical formula, R 3 is hydrogen or methyl, R 4 It is a C4 to C 20 Acid-sensitive groups; The third repeating unit is composed of the following chemical formula: In the chemical formula, R 3 is hydrogen or methyl, R 4 is a lactone derivative group; The fourth repeating unit is composed of the following chemical formula: In the chemical formula, R 5 is hydrogen or methyl, R 6 It is a cycloalkyl group containing a polar group selected from the group consisting of a hydroxyl group, a carboxyl group, and a combination thereof.

3. The photosensitive polymer according to claim 2, wherein The acid-sensitive group is any one selected from the group consisting of norbornyl, isobornyl, cyclodecyl, adamantyl, norbornyl substituted by a lower alkyl group, isobornyl substituted by a lower alkyl group, cyclodecyl substituted by a lower alkyl group, adamantyl substituted by a lower alkyl group, alkoxycarbonyl, alkoxycarbonylalkyl, pentyloxycarbonyl, pentyloxycarbonylalkyl, 2-tetrahydropyranyloxycarbonylalkyl, 2-tetrahydrofuranyloxycarbonylalkyl, tertiary alkyl and acetal group.

4. The photosensitive polymer according to claim 2, wherein The lactone derivative group is a substituent having a structure of the following Chemical Formula 6, [Chemical formula 6] In the chemical formula 6, two of X1 to X4 are independently C=O and O, and except for C=O and O, the others are CR8, and R8 is hydrogen, an alkyl group, or an alkylene group forming a condensed ring with a five-membered ring.

5. The photosensitive polymer according to claim 4, wherein The lactone derivative group is a butyrolactone group, a valerolactone group, a 1,3-cyclohexane carbolactone group, a 2,6-norbornane carbolactone-5-yl group or a 7-oxa-2,6-norbornane carbolactone-5-yl group.

6. The photosensitive polymer according to claim 2, wherein The molecular weight of the photosensitive polymer is a weight average molecular weight (Mw) of 3,000 to 30,000.

7. A resist composition comprising: (a) The photosensitive polymer according to any one of claims 1 to 6; (b) a photoacid generator (PAG); and (c) Organic solvents.

8. The resist composition according to claim 7, wherein The photosensitive polymer includes 5 to 50 parts by weight based on 100 parts by weight of the resist composition.

9. The resist composition according to claim 7, wherein The photoacid generator includes 1 to 10 parts by weight relative to 100 parts by weight of the photosensitive polymer.

10. The resist composition according to claim 7, wherein The resist composition includes 0.01 to 1 parts by weight of an organic base relative to 100 parts by weight of the photosensitive polymer.

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