Salt compound, acid diffusion inhibitor containing same, and photoresist composition

Abstract

The present invention relates to a salt compound containing an anion having a specific structure represented by Chemical Formula 1 and a cation represented by Chemical Formula 2, and an acid diffusion inhibitor and photoresist composition containing the same.

Description

[Technical Field]

[0001] The present invention relates to a salt compound, an acid diffusion inhibitor (quencher) containing the same, and a photoresist composition. More particularly, the present invention relates to a novel photosensitive salt compound used in chemically amplified resist materials, an acid diffusion inhibitor (quencher) containing the same, and a photoresist composition. [Background technology]

[0002] Lithography is a technology in which a resist film is formed by applying a photosensitive resist material to a substrate, and then a mask with a pattern formed on the resist film is used to transfer the mask pattern onto the resist film by exposing it to a selected light source and developing it.

[0003] Semiconductor devices manufactured using lithography technology use short wavelength light sources to enable the creation of finer patterns on semiconductor elements. For example, near ultraviolet (g-line (436nm), i-line (365nm)) was used in the past, but now deep ultraviolet (KrF (248nm), ArF (193nm) excimer lasers are used, and ArF immersion and the multi-patterning method using this are widely used in the mass production of semiconductor elements. Recently, lithography technology using extreme ultraviolet (EUV (13.5nm)) wavelengths has begun to be introduced into mass production processes.

[0004] Resist materials are required to have characteristics such as sensitivity to the exposure light source and resolution that can reproduce fine mask patterns. Resist components that can exhibit these characteristics include chemically amplified photoresist (CAR) compositions, which contain a photoacid generator that generates acid during the exposure process, a polymer resin whose solubility in alkaline developers changes due to the action of the generated acid, an acid diffusion inhibitor that can adjust the acid diffusion distance, and a solvent that can dissolve each component.

[0005] In the field of conventional chemically amplified resist compositions, nitrogen-containing organic substances such as amines and amides have been used to control the diffusion distance of the acid generated from a photoacid generator in order to improve resist performance.

[0006] However, recently, instead of nitrogen-containing organic compounds, photodegradable acid diffusion inhibitors have been developed that have a structure similar to that of photoacid generators and are decomposed by an exposure source. These photodegradable acid diffusion inhibitors act as quenchers that suppress acid diffusion in unexposed areas and are photodecomposed into acid in exposed areas, maintaining a relatively high acid concentration in the exposed areas and increasing the acid distribution contrast between exposed and unexposed areas, thereby improving lithography properties.

[0007] However, the formation of a pattern of a desired size from a resist material has not yet reached an ideal level. From this perspective, there remains a need to develop a photosensitive acid diffusion inhibitor having a new structure in order to ensure high contrast during the formation of a fine pattern. Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention provides a salt compound that can provide a photoresist composition having improved polarity, which shortens the diffusion length of anions generated upon exposure, ensuring high contrast and improving limiting resolution, as well as low sensitivity, LER value, and a wide process margin. The present invention also provides an acid diffusion inhibitor containing the salt compound. Furthermore, the present invention provides a photoresist composition containing the salt compound. [Means for solving the problem]

[0009] Provided herein is a salt compound comprising an anion represented by the following Chemical Formula 1 and a cation represented by the following Chemical Formula 2: [Chemical formula 1] JPEG0007824417000001.jpg35170[Chemical formula 2] JPEG0007824417000002.jpg16170

[0010] Also provided herein is an acid diffusion inhibitor comprising the salt compound. Further provided herein is a photoresist composition comprising the salt compound. The present specification also provides a method for forming a photoresist pattern using the photoresist composition.

[0011] Hereinafter, salt compounds and acid diffusion inhibitors containing the same, photoresist compositions, and methods for forming photoresist patterns according to specific embodiments of the present invention will be described in more detail.

[0012] In this specification, when a part "comprises" a certain component, this does not mean that it can further include other components, unless otherwise specified.

[0013] In this specification, the term polymer is used interchangeably with the terms macromolecule and polymer.

[0014] In this specification, examples of the substituents are explained below, but the present invention is not limited to these.

[0015] In this specification, the term "substituted" means that another atom or functional group is bonded in place of a hydrogen atom or a carbon atom in a compound, and the substitution position is not limited as long as it is a substitution position of a hydrogen atom or a carbon atom, that is, a position that can be substituted by a substituent, and when two or more substituents are substituted, the two or more substituents may be the same or different from each other.

[0016] As used herein, the term "substituted or unsubstituted" means substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium, halogen, cyano, nitro, hydroxy, carbonyl, ester, imide, amide, amino, carboxy, sulfonic acid, sulfonamide, phosphine oxide, alkoxy, alkylcarbonyl, alkoxycarbonyl, sulfonyloxy, aryloxy, alkylthioxy, arylthioxy, alkylsulfoxy, arylsulfoxy, silyl, and boron; or substituted or unsubstituted with two or more of the above-listed substituents linked together. For example, a "substituent linked to two or more substituents" may be a biphenyl group. In other words, a biphenyl group may be an aryl group or may be interpreted as a substituent linked to two phenyl groups.

[0017] In this specification, JPEG0007824417000003.jpg10170, or JPEG0007824417000004.jpg7170 denotes a bond that is connected to another substituent.

[0018] As used herein, examples of halogen include fluorine, chlorine, bromine or iodine.

[0019] In this specification, the number of carbon atoms of the imide group is not particularly limited, but may be 1 to 30. Specifically, the imide group may have a compound with the following structure, but is not limited thereto. [ka]

[0020] In this specification, the nitrogen of the amide group may be substituted with hydrogen, a linear, branched, or cyclic alkyl group having 1 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms. Specifically, the amide group may be a compound having the following structural formula, but is not limited thereto. [ka]

[0021] In this specification, the number of carbon atoms in the carbonyl group is not particularly limited, and may be 1 to 30. Specifically, the carbonyl group may have a structure as shown below, but is not limited thereto. [ka]

[0022] In this specification, the oxygen of the ester group may be substituted with a linear, branched, or cyclic alkyl group having 1 to 25 carbon atoms, or an aryl group having 6 to 25 carbon atoms. Specifically, the ester group may be a compound having the following structural formula, but is not limited thereto. [ka]

[0023] In this specification, the sulfonamide group may be -SONR'R", wherein R' and R" may be the same or different and are each independently selected from the group consisting of hydrogen; deuterium; halogen; a nitrile group; a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 30 carbon atoms; a substituted or unsubstituted linear or branched alkyl group having 1 to 30 carbon atoms; a substituted or unsubstituted monocyclic or polycyclic aryl group having 6 to 30 carbon atoms; and a substituted or unsubstituted monocyclic or polycyclic heteroaryl group having 2 to 30 carbon atoms.

[0024] In this specification, the alkyl group may be linear or branched, and the number of carbon atoms in the linear alkyl group is not particularly limited, but may be 1 to 20. The number of carbon atoms in the branched alkyl group is 3 to 20. Exemplary alkyl groups include, but are not limited to, methyl, ethyl, propyl, n-propyl, isopropyl, butyl, n-butyl, isobutyl, tert-butyl, sec-butyl, 1-methylbutyl, 1-ethylbutyl, pentyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, hexyl, n-hexyl, 1-methylpentyl, 2-methylpentyl, 4-methyl-2-pentyl, 3,3-dimethylbutyl, 2-ethylbutyl, heptyl, n-heptyl, 1-methylhexyl, cyclopentylmethyl, cyclohexylmethyl, octyl, n-octyl, tert-octyl, 1-methylheptyl, 2-ethylhexyl, 2-propylpentyl, n-nonyl, 2,2-dimethylheptyl, 1-ethylpropyl, 1,1-dimethylpropyl, isohexyl, 2-methylpentyl, 4-methylhexyl, 5-methylhexyl, and the like. The alkyl group may be substituted or unsubstituted, and when substituted, examples of the substituent are as described above.

[0025] In this specification, the cycloalkyl group is not particularly limited, but may have 3 to 60 carbon atoms. According to one embodiment, the cycloalkyl group has 3 to 30 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 20 carbon atoms. According to another embodiment, the cycloalkyl group has 3 to 6 carbon atoms. Specific examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, and cyclooctyl. The cycloalkyl group may be substituted or unsubstituted. If substituted, examples of the substituent are as described above.

[0026] As used herein, the term "alkoxy group" refers to a functional group in which the aforementioned alkyl group is bonded to one end of an ether group (-O-). The same explanation as for the alkyl group is applicable, except that the alkoxy group is a functional group bonded to an ether group (-O-). For example, the alkoxy group may be linear, branched, or cyclic. The number of carbon atoms in the alkoxy group is not particularly limited, but may be 1 to 20. Specific examples include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, i-propyloxy, n-butoxy, isobutoxy, tert-butoxy, sec-butoxy, n-pentyloxy, neopentyloxy, isopentyloxy, n-hexyloxy, 3,3-dimethylbutyloxy, 2-ethylbutyloxy, n-octyloxy, n-nonyloxy, n-decyloxy, cycloheptoxy, benzyloxy, and p-methylbenzyloxy. The alkoxy group may be substituted or unsubstituted. If substituted, examples of the substituent are as described above.

[0027] In this specification, the amine group can be selected from the group consisting of -NH2, a monoalkylamine group, a dialkylamine group, an N-alkylarylamine group, a monoarylamine group, a diarylamine group, an N-arylheteroarylamine group, an N-alkylheteroarylamine group, a monoheteroarylamine group, and a diheteroarylamine group, and the number of carbon atoms is not particularly limited, but may be 1 to 30. Specific examples of the amine group include, but are not limited to, methylamine, dimethylamine, ethylamine, diethylamine, phenylamine, naphthylamine, biphenylamine, anthracenylamine, 9-methylanthracenylamine, diphenylamine, ditolylamine, N-phenylbiphenylamine, N-phenylnaphthylamine, N-biphenylnaphthylamine, ditolylamine, N-phenyltolylamine, triphenylamine, N-naphthylfluorenylamine, N-phenylphenanthrenylamine, N-biphenylphenanthrenylamine, N-phenylfluorenylamine, N-phenylterphenylamine, N-phenanthrenylfluorenylamine, and N-biphenylfluorenylamine. The amine group may be substituted or unsubstituted, and if substituted, examples of the substituents are as described above.

[0028] As used herein, an N-alkylarylamine group refers to an amine group in which the N of the amine group is substituted with an alkyl group and an aryl group. As used herein, an N-arylheteroarylamine group refers to an amine group in which the N of the amine group is substituted with an aryl group and a heteroaryl group. As used herein, an N-alkylheteroarylamine group refers to an amine group in which the N of the amine group is substituted with an alkyl group and a heteroarylamine group.

[0029] In this specification, the alkyl groups in the monoalkylamine group, dialkylamine group, N-arylalkylamine group, alkylthioxy group, alkylsulfoxy group, and N-alkylheteroarylamine group are the same as the examples of the alkyl group described above. Specific examples of the alkylthioxy group include methylthioxy group, ethylthioxy group, tert-butylthioxy group, hexylthioxy group, and octylthioxy group, and examples of the alkylsulfoxy group include mesyl, ethylsulfoxy group, propylsulfoxy group, and butylsulfoxy group, but are not limited to these.

[0030] In this specification, the alkenyl group may be linear or branched, and the number of carbon atoms is not particularly limited, but may be 2 to 40. The above description of the alkyl group is applicable to the alkenyl group, except that the alkenyl group contains at least one unsaturated bond (double bond or triple bond) in the functional group. According to one embodiment, the alkenyl group has 2 to 20 carbon atoms. According to another embodiment, the alkenyl group has 2 to 10 carbon atoms. According to another embodiment, the alkenyl group has 2 to 6 carbon atoms. Specific examples include, but are not limited to, vinyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 3-methyl-1-butenyl, 1,3-butadienyl, allyl, 1-phenylvinyl-1-yl, 2-phenylvinyl-1-yl, 2,2-diphenylvinyl-1-yl, 2-phenyl-2-(naphthyl-1-yl)vinyl-1-yl, 2,2-bis(diphenyl-1-yl)vinyl-1-yl, stilbenyl, styrenyl, etc. The alkenyl group may be substituted or unsubstituted, and if substituted, examples of the substituents are as described above.

[0031] In this specification, the cycloalkenyl group may have 3 to 60 carbon atoms, and according to one embodiment, the cycloalkenyl group has 3 to 30 carbon atoms. According to another embodiment, the cycloalkenyl group has 3 to 20 carbon atoms. According to another embodiment, the cycloalkenyl group has 3 to 6 carbon atoms. The above description of the cycloalkyl group is applicable to the cycloalkenyl group, except that the cycloalkenyl group contains at least one unsaturated bond (double bond or triple bond) in the functional group. The cycloalkenyl group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0032] In this specification, specific examples of the silyl group include, but are not limited to, a trimethylsilyl group, a triethylsilyl group, a t-butyldimethylsilyl group, a vinyldimethylsilyl group, a propyldimethylsilyl group, a triphenylsilyl group, a diphenylsilyl group, a phenylsilyl group, etc. The silyl group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0033] In this specification, specific examples of the boron group include, but are not limited to, a trimethyl boron group, a triethyl boron group, a t-butyldimethyl boron group, a triphenyl boron group, a phenyl boron group, etc. The boron group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0034] In this specification, specific examples of the phosphine oxide group include, but are not limited to, a diphenylphosphine oxide group, a dinaphthylphosphine oxide group, etc. The phosphine oxide group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0035] In this specification, the aryl group is not particularly limited, but may have 6 to 60 carbon atoms, and may be a monocyclic aryl group or a polycyclic aryl group. According to one embodiment, the aryl group has 6 to 30 carbon atoms. According to one embodiment, the aryl group has 6 to 20 carbon atoms. As the monocyclic aryl group, the aryl group may be, but is not limited to, a phenyl group, a biphenyl group, a terphenyl group, etc. As the polycyclic aryl group, the aryl group may be, but is not limited to, a naphthyl group, an anthracenyl group, etc. The aryl group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0036] In this specification, the aryl group in the monoarylamine group, diarylamine group, aryloxy group, arylthioxy group, arylsulfoxy group, N-arylalkylamine group, N-arylheteroarylamine group and arylphosphine group is the same as the above-mentioned examples of the aryl group. Specific examples of aryloxy groups include phenoxy, p-tolyloxy, m-tolyloxy, 3,5-dimethyl-phenoxy, 2,4,6-trimethylphenoxy, p-tert-butylphenoxy, 3-biphenyloxy, 4-biphenyloxy, 1-naphthyloxy, 2-naphthyloxy, 4-methyl-1-naphthyloxy, 5-methyl-2-naphthyloxy, 1-anthryloxy, 2-anthryloxy, 9-anthryloxy, 1-phenanthryloxy, 3-phenanthryloxy, and 9-phenanthryloxy groups. Examples of arylthioxy groups include phenylthioxy, 2-methylphenylthioxy, and 4-tert-butylphenylthioxy groups. Examples of arylsulfoxy groups include benzenesulfoxy and p-toluenesulfoxy groups, but are not limited to these.

[0037] In this specification, the heterocyclic group is a heterocyclic group containing one or more heteroelements selected from O, N, Se and S, and the number of carbon atoms is not particularly limited, but may be 2 to 60 carbon atoms. Examples of heterocyclic groups include, but are not limited to, thiophene, furan, pyrrole, imidazole, thiazole, oxazole, oxadiazole, triazole, pyridyl, bipyridyl, pyrimidyl, triazine, acridyl, pyridazine, pyrazinyl, quinolinyl, quinazoline, quinoxalinyl, phthalazinyl, pyridopyrimidinyl, pyridopyrazinyl, pyrazinopyrazinyl, isoquinoline, indole, carbazole, benzoxazole, benzimidazole, benzothiazole, benzocarbazole, benzothiophene, dibenzothiophene, benzofuranyl, phenanthroline, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, and dibenzofuranyl groups.

[0038] In this specification, a heteroaryl group includes one or more non-carbon atoms, i.e., heteroatoms, and specifically, the heteroatoms may include one or more atoms selected from the group consisting of O, N, Se, S, etc. The number of carbon atoms is not particularly limited, but may be 2 to 60, and the heteroaryl group may be monocyclic or polycyclic. Examples of the heteroaryl group include a thiophene group, a furanyl group, a pyrrole group, an imidazolyl group, a thiazolyl group, an oxazolyl group, an oxadiazolyl group, a pyridyl group, a bipyridyl group, a pyrimidyl group, a triazinyl group, a triazolyl group, an acridyl group, a pyridazinyl group, a pyrazinyl group, a quinolinyl group, a quinazolinyl group, a quinoxalinyl group, a phthalazinyl group, a pyridopyrimidyl group, a pyridopyrazinyl group, a pyrazinopyrazinyl group, an isoquinolinyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a benzimidazolyl group, a benzothiazolyl group, a benzocarbazolyl group, a benzothiophene group, a dibenzothiophene group, Examples of heteroaryl groups include, but are not limited to, benzofuranyl, phenanthrolinyl, thiazolyl, isoxazolyl, oxadiazolyl, thiadiazolyl, benzothiazolyl, phenothiazinyl, aziridyl, azaindolyl, isoindolyl, indazolyl, purine, pteridyl, beta-carbolyl, naphthyridine, ter-pyridyl, phenazinyl, imidazopyridyl, pyropyridyl, azepine, pyrazolyl, and dibenzofuranyl. The heteroaryl group may be substituted or unsubstituted, and if substituted, examples of the substituents are as described above.

[0039] In this specification, examples of the heteroaryl group in the monoheteroarylamine group, diheteroarylamine group, N-arylheteroarylamine group and N-alkylheteroarylamine group can be selected from the examples of the heteroaryl group described above.

[0040] In this specification, an alkylene group is a divalent functional group derived from an alkane, and may be, for example, a linear or branched chain, such as a methylene group, an ethylene group, a propylene group, an isobutylene group, a sec-butylene group, a tert-butylene group, a pentylene group, a hexylene group, etc. The alkylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0041] In this specification, the haloalkylene group refers to a functional group in which a halogen group is substituted on the above-mentioned alkylene group, and may be, for example, perfluoropropane-2,2-diyl.

[0042] In this specification, the alkenylene group is a divalent functional group derived from alkenyl, and the above description of the alkenyl group is applicable except that it is a divalent functional group. The alkenylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0043] In this specification, the cycloalkylene group is a divalent functional group derived from a cycloalkane, and the above description of the cycloalkyl group is applicable except that it is a divalent functional group. The cycloalkylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0044] In this specification, a cycloalkenylene group is a divalent functional group derived from cycloalkenyl, and the above description of the cycloalkenyl group is applicable except that it is a divalent functional group. The cycloalkenylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0045] In this specification, an arylene group refers to an aryl group having two bonding positions, i.e., a divalent functional group. The above description of the aryl group is applicable except that each of these is a divalent functional group. The arylene group may be substituted or unsubstituted, and if substituted, examples of the substituent are as described above.

[0046] 1. Salt compounds According to one embodiment of the present invention, there is provided a salt compound containing an anion represented by the following Chemical Formula 1 and a cation represented by the following Chemical Formula 2: [Chemical formula 1] JPEG0007824417000009.jpg35170[Chemical formula 2] JPEG0007824417000010.jpg16170

[0047] In the above Chemical Formulas 1 and 2, R1 and R2 are the same or different and each independently represent an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, or a combination thereof; X represents a direct bond, an alkylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, or a combination thereof; M + is one of an onium ion or a metal ion.

[0048] The combination of functional groups in R1, R2, and X means a combined functional group containing two or more functional groups, such as an arylalkyl group that contains both an aryl group and an alkyl group.

[0049] At least one hydrogen atom contained in the alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, aryl group, alkylene group, alkenylene group, cycloalkylene group, cycloalkenylene group, and arylene group is each independently substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium; halogen; cyano group; nitro group; hydroxy group; carbonyl group; ester group; imide group; amide group; amino group; carboxy group; sulfonic acid group; sulfonamide group; phosphine oxide group; alkoxy group; alkylcarbonyl group; alkoxycarbonyl group; sulfonyloxy group; aryloxy group; alkylthioxy group; arylthioxy group; alkylsulfoxy group; arylsulfoxy group; silyl group; and boron group;

[0050] at least one or more carbon atoms contained in the alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, aryl group, alkylene group, alkenylene group, cycloalkylene group, cycloalkenylene group, and arylene group are each independently substituted or unsubstituted with a heteroatom; the alkyl group, alkenyl group, alkylene group, and alkenylene group are each independently linear or branched; The cycloalkyl group, cycloalkenyl group, aryl group, cycloalkylene group, cycloalkenylene group, and arylene group are each independently monocyclic or polycyclic.

[0051] The present inventors have confirmed through experiments that the salt compound of one embodiment, as represented by Chemical Formula 1, is more polar due to the sulfonyloxy group (—SO3—) contained in the anion structure, thereby shortening the diffusion length of anions generated from the acid diffusion inhibitor during exposure, thereby ensuring high contrast, improving limiting resolution, and achieving low sensitivity, LER value, and high process margin, and have completed the invention.

[0052] In contrast, when a sulfonyl group (-SO2-) is contained instead of the above-mentioned sulfonyloxy group (-SO3-), the polarity is reduced due to the reduction in oxygen atoms, and there is a limit to how short the diffusion length of the anions generated from the acid diffusion inhibitor is during exposure.

[0053] In addition, in the anion structure of the salt compound of one embodiment, when the sulfonyloxy group (—SO—) and the nitrogen (N) atom are bonded via an intermediary functional group represented by X rather than directly, miscibility with other components constituting the resist is improved, resulting in improved distribution uniformity within the resist thin film. In addition, due to an increased acid diffusion suppression effect, the contrast between exposed and unexposed areas is improved, resulting in improved line width roughness.

[0054] On the other hand, when the sulfonyloxy group (-SO3-) is directly bonded to the nitrogen (N) atom, or when two sulfonyl groups (-SO2-) are directly bonded to a nitrogen (N) atom, the polarity decreases due to the decrease in oxygen atoms, which reduces the acid diffusion inhibition efficiency and reduces miscibility with the resist components, resulting in poor distribution uniformity within the thin film. As a result, the contrast between exposed and unexposed areas becomes insufficient, which can lead to reduced process margins and increased line width roughness.

[0055] Specifically, in the anion represented by Chemical Formula 1, X may be one of a direct bond, an alkylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, an arylene group, or a combination thereof. Specifically, in Chemical Formula 1, X may be one of an alkylene group having 1 to 30 carbon atoms, an alkenylene group having 1 to 30 carbon atoms, a cycloalkylene group having 3 to 30 carbon atoms, a cycloalkenylene group having 3 to 30 carbon atoms, or an arylene group having 6 to 30 carbon atoms.

[0056] Specifically, X may be an alkylene group or an alkenylene group, in which case the reactivity is excellent and a high yield can be obtained. The alkylene group having 1 to 30 carbon atoms may be an alkylene group having 1 to 20 carbon atoms, or 1 to 10 carbon atoms, or 1 to 8 carbon atoms, or 1 to 3 carbon atoms, or 2 to 6 carbon atoms. More specifically, in Chemical Formula 1, X is an alkylene group having 2 to 3 carbon atoms.

[0057] In Chemical Formula 1, specific examples of X are not particularly limited, but include ethylene and propylene. When X in Chemical Formula 1 is an alkylene group having 2 to 3 carbon atoms, crystallinity is improved during purification, allowing a high-purity material to be obtained in high yield. However, when X in Chemical Formula 1 is an alkylene group having more than 3 carbon atoms, purification can be difficult due to side reactions and gel-like properties, resulting in reduced yields. Specific examples of X in the above chemical formula 1 include butylene, pentylene, hexylene, heptylene, and octylene.

[0058] Meanwhile, in the anion represented by Chemical Formula 1, R1 and R2 may be the same or different and each independently represent one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a halogen, or a combination thereof.

[0059] Specifically, in the above Chemical Formula 1, R1 may be an alkyl group having 1 to 30 carbon atoms and in which the hydrogen atoms are not substituted. Specific examples of the alkyl group having 1 to 30 carbon atoms and in which the hydrogen atoms are not substituted are not particularly limited, but include, for example, one of methyl, ethyl, and propyl.

[0060] Furthermore, in the above Chemical Formula 1, R1 may be an aryl group having 6 to 30 carbon atoms and having an unsubstituted hydrogen atom. Specific examples of the aryl group having 6 to 30 carbon atoms and having an unsubstituted hydrogen atom are not particularly limited, but one example is phenyl.

[0061] Furthermore, in the above Chemical Formula 1, R1 may be a halogen. Specific examples of the halogen are not particularly limited, but include fluorine, chlorine, bromine, and iodine.

[0062] Furthermore, in Chemical Formula 1, R1 may be a cycloalkyl group having 3 to 30 carbon atoms and having an unsubstituted hydrogen atom. Specific examples of the cycloalkyl group having 3 to 30 carbon atoms and having an unsubstituted hydrogen atom are not particularly limited, but examples include cyclohexyl and adamantyl.

[0063] In addition, in Chemical Formula 1, R1 may be an alkyl group having 1 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogen, or an aryl group having 6 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogen, or an aryl group having 1 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogenated alkyl group, thereby increasing the absorption efficiency of the exposure light source and improving the resolution.

[0064] Specific examples of the alkyl group having 1 to 30 carbon atoms in which at least one hydrogen atom has been substituted with a halogen are not particularly limited, but include trifluoromethyl.

[0065] Specific examples of the aryl group having 6 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogen are not particularly limited, but include, for example, one of 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,5-difluorophenyl, 2,4-difluorophenyl, 4-(trifluoromethyl)phenyl, and 1,2,3,4,5-pentafluorophenyl.

[0066] Specifically, in Chemical Formula 1, R1 may be one of an alkyl group having 1 to 30 carbon atoms in which 2 to 6 hydrogen atoms are substituted with halogen, or an aryl group having 6 to 30 carbon atoms in which 2 to 6 hydrogen atoms are substituted with halogen. This increases the efficiency of absorption of the exposure light source in the exposed area, thereby increasing the acid diffusion suppression efficiency, which may improve the contrast between the exposed area and the non-exposed area, thereby increasing the resolving power.

[0067] Specific examples of the alkyl group having 1 to 30 carbon atoms in which 2 to 6 hydrogen atoms have been substituted with halogen are not particularly limited, but include one of the following: trifluoromethyl.

[0068] Specific examples of the aryl group having 6 to 30 carbon atoms in which at least 2 but no more than 6 hydrogen atoms have been substituted with halogen are not particularly limited, but include, for example, one of 4-trifluoromethylphenyl, 4-fluorophenyl, 2,5-difluorophenyl, 2,4-difluorophenyl, 4-(trifluoromethyl)phenyl, and 1,2,3,4,5-pentafluorophenyl.

[0069] Specifically, in Chemical Formula 1, R1 may be one of methyl, ethyl, propyl, halogen, trifluoromethyl, cyclohexyl, adamantyl, phenyl, 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 4-(trifluoromethyl)phenyl, or 1,2,3,4,5-pentafluorophenyl.

[0070] Meanwhile, in the above Chemical Formula 1, R2 may be a substituted or unsubstituted aryl group. When the unsaturated aromatic group R2 in the above Chemical Formula 1 is selected and substituted, the electron beam or EUV photon absorption increases, so that more secondary electrons can be generated in the resist thin film, thereby improving sensitivity.

[0071] Specifically, R2 may be one of an aryl group in which at least one hydrogen atom is substituted with a halogen, an aryl group in which no hydrogen atoms are substituted, or an aryl group in which at least one hydrogen atom is substituted with a heteroalkyl group.

[0072] Preferably, R2 may be an aryl group in which at least one hydrogen atom is substituted with a halogen. Among halogen elements, iodine is particularly preferred in terms of improving secondary electron generation efficiency. Specific examples of the aryl group in which at least one hydrogen atom is substituted with a halogen include, but are not limited to, 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,5-difluorophenyl, 2,4-difluorophenyl, and 1,2,3,4,5-pentafluorophenyl.

[0073] On the other hand, R2 may be an aryl group in which a hydrogen atom is unsubstituted. Specific examples of the aryl group in which a hydrogen atom is unsubstituted include, but are not limited to, 1-naphthyl, 2-naphthyl, 4-pyridinyl, 6-benzoxazolyl, 5-phthalanyl, 1,4-benzodioxan-6-yl, acetyl-4-piperidinyl, and tert-butoxycarbonyl-4-piperidinyl.

[0074] Furthermore, R2 may be an aryl group in which at least one hydrogen atom is substituted with a heteroalkyl group. Specific examples of the heteroalkyl group include an alkoxy group, and specific examples of the aryl group in which at least one hydrogen atom is substituted with a heteroalkyl group include, but are not limited to, 4-methoxyphenyl.

[0075] Meanwhile, R2 may be one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, or a combination thereof. More specifically, the alkyl group, alkenyl group, cycloalkyl group, and cycloalkenyl group may have unsubstituted hydrogen atoms. Specific examples of the unsubstituted alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, or a combination thereof include, but are not limited to, methyl, ethyl, propyl, trifluoromethyl, cyclohexyl, adamantyl, and 1,4-dioxane-2-ylethyl.

[0076] Furthermore, R2 may be one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, or a combination thereof, in which at least one hydrogen atom is substituted with a heteroalkyl group. Specific examples of the heteroalkyl group include an alkoxy group.

[0077] More specifically, in Chemical Formula 1, R2 may be one of methyl, ethyl, propyl, trifluoromethyl, cyclohexyl, adamantyl, acetyl-4-piperidinyl, tert-butoxycarbonyl-4-piperidinyl, 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,5-difluorophenyl, 2,4-difluorophenyl, 1,2,3,4,5-pentafluorophenyl, 4-methoxyphenyl, 1-naphthyl, 2-naphthyl, 4-pyridinyl, 6-benzoxazolyl, 5-phthalanyl, 1,4-dioxan-2-ylethyl, and 1,4-benzodioxan-6-yl.

[0078] Specific examples of the anion represented by Chemical Formula 1 are not particularly limited, but may be any one selected from the group consisting of the following: [ka] [ka]

[0079] On the other hand, in the above-mentioned chemical formula 2, M + may be one of an onium ion or a metal ion. Specifically, in the above Chemical Formula 2, M + may be one of the onium ions sulfonium ion, iodonium ion, or ammonium ion.

[0080] Specific examples of the cation represented by Chemical Formula 2 are not particularly limited, but may be any one selected from the group consisting of the following: [ka] [ka]

[0081] Although the specific example of the method for synthesizing the salt compound is not particularly limited, the salt compound can be synthesized by the following reaction formula 1, for example. [Reaction Scheme 1] JPEG0007824417000015.jpg42170

[0082] In the reaction formula 1, R1, R2, X, and M are the same as R1, R2, X (chemical formula 1), and M (chemical formula 2) of the salt compound, respectively. Y is a counter anion, and Base is a base.

[0083] First, compound 1-a can be reacted with compound 1-b or compound 1-c to obtain compound 1-d. Compound 1-d can be reacted again with compound 1-e or compound 1-f to obtain compound 1-g, where compounds 1-e and 1-f can be the same as or different from compounds 1-b and 1-c. Compound 1-g can be reacted with compound 1-h to obtain compound A.

[0084] During the above reaction, the nucleophilic reaction of the amine group occurs more frequently than the nucleophilic reaction of the alcohol group in the synthesis reaction to obtain compound 1-d. Alternatively, to induce the amine group substitution reaction, compound 1-b or compound 1-c can be added slowly dropwise while maintaining the reaction temperature below -40°C and above -78°C. When compound 1-b and compound 1-e have the same structure, it is sufficient to add compound 1-b or 1-e slowly dropwise at 0°C, and then slowly raise the temperature to room temperature. Compound 1-g can also be obtained in a similar manner.

[0085] The method for obtaining a salt compound by reacting compound 1-g with compound 1-h is not particularly limited. The salt compound can be obtained by dissolving compound 1-g in a suitable organic solvent and water in the presence of a suitable alkali metal hydroxide, adding compound 1-h, and then stirring the mixture so that the organic layer and the aqueous layer are well mixed.

[0086] The alkali metal hydroxide used in the reaction is not particularly limited, and common alkali metal hydroxides such as sodium hydroxide and potassium hydroxide can be used. The amount used is 1 mole or more and 2 moles or less per mole of compound 1-g.

[0087] In the reaction, the organic solvent may be a solvent that dissolves the product salt compound well, such as dichloromethane or chloroform, and the amount used may be 15 parts by mass or more and 20 parts by mass or less based on compound 1-g.

[0088] The amount of compound 1-h used in the reaction may usually be 1 mole or more and 3 moles or less per mole of compound 1-g, the reaction time may vary depending on the reactivity, reaction concentration, etc., but may generally be 10 hours or more and 24 hours or less, and the reaction temperature may be 20°C or more and 50°C or less.

[0089] After the reaction is completed, the aqueous layer and the organic layer are separated, and the compound A dissolved in the organic layer can be purified by a method selected from conventionally known purification methods such as solvent extraction, concentration, chromatography, crystallization, and recrystallization, either singly or in combination. This method can be applied to purify not only the final compound A but also the compounds 1-d, 1-g, and 1-h synthesized in each step.

[0090] 2. Acid diffusion inhibitor Meanwhile, according to another embodiment of the present invention, there is provided an acid diffusion inhibitor (quencher) comprising the salt compound of the above embodiment. The content regarding the salt compound includes the content described above regarding the one embodiment.

[0091] The acid diffusion inhibitor is a substance capable of controlling the acid diffusion distance, and acts as a quencher that inhibits acid diffusion in non-exposed areas, and is photodecomposed to act as an acid in exposed areas, thereby maintaining a relatively high acid concentration in the exposed areas and increasing the acid distribution contrast between the exposed and non-exposed areas, thereby improving lithography properties.

[0092] In addition to the above-mentioned salt compounds, the acid diffusion inhibitor used in the present invention can be any conventional photoresist acid diffusion inhibitor that can be added and mixed without any restrictions. Examples of the conventional photoresist acid diffusion inhibitor include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates.

[0093] 3. Photoresist composition Meanwhile, according to yet another embodiment of the present invention, there is provided a photoresist composition comprising the salt compound of the above embodiment; a photoacid generator; a base polymer; and an organic solvent.

[0094] The content of the salt compound includes the content described above in relation to the embodiment. The content of the salt compound or the acid diffusion inhibitor containing the salt compound may be 0.01 to 30 parts by weight, or 0.1 to 23 parts by weight, relative to 100 parts by weight of the base polymer. If the content of the salt compound or the acid diffusion inhibitor containing the salt compound exceeds the above range, a large amount of acid may be generated, resulting in a pattern with an unsatisfactory cross section and reduced pattern contrast.

[0095] Meanwhile, the base polymer has a property that its solubility in a developer changes under the action of an acid, and photosensitive polymers used in conventional photoresist compositions can be used without any restrictions.

[0096] As a specific example, the base polymer may contain a repeating unit represented by the following chemical formula a or chemical formula b. The base polymer may be a homopolymer consisting of one type of repeating unit represented by the chemical formula a, a homopolymer consisting of one type of repeating unit represented by the chemical formula b, a copolymer consisting of two or more types of repeating units represented by the chemical formula a, a copolymer consisting of two or more types of repeating units represented by the chemical formula b, or a copolymer consisting of one or more types of repeating units represented by the chemical formula a and one or more types of repeating units represented by the chemical formula b. [Chemical formula a] JPEG0007824417000016.jpg24170

[0097] In the above chemical formula (a), R3 may be hydrogen or a methyl group, and Ar may be an aryl group in which at least one hydrogen atom is substituted or unsubstituted. The aryl group may be monocyclic or polycyclic. Examples of the substituent are not particularly limited, and include one or more substituents selected from the group consisting of deuterium, halogen, cyano, nitro, hydroxy, carbonyl, ester, imide, amide, amino, carboxy, sulfonic acid, sulfonamide, phosphine oxide, alkoxy, alkylcarbonyl, alkoxycarbonyl, sulfonyloxy, aryloxy, alkylthioxy, arylthioxy, alkylsulfoxy, arylsulfoxy, silyl, and boron. More specifically, the substituent may be a halogen or a hydroxy group. [Chemical formula b] JPEG0007824417000017.jpg45170

[0098] In the formula (b), R4 is hydrogen or a methyl group, and R5 may be one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, and an aryl group. At least one hydrogen atom contained in the alkyl group, the alkenyl group, the cycloalkyl group, the cycloalkenyl group, and the aryl group may each independently be substituted or unsubstituted with one or more substituents selected from the group consisting of deuterium, halogen, cyano group, nitro group, hydroxy group, carbonyl group, ester group, imide group, amide group, amino group, carboxy group, sulfonic acid group, sulfonamide group, phosphine oxide group, alkoxy group, alkylcarbonyl group, alkoxycarbonyl group, sulfonyloxy group, aryloxy group, alkylthioxy group, arylthioxy group, alkylsulfoxy group, arylsulfoxy group, silyl group, and boron group.

[0099] At least one carbon atom contained in the alkyl group, alkenyl group, cycloalkyl group, cycloalkenyl group, and aryl group may be independently substituted or unsubstituted with a heteroatom.

[0100] The alkyl group and alkenyl group may each independently be linear or branched, and the cycloalkyl group, cycloalkenyl group, and aryl group may each independently be monocyclic or polycyclic.

[0101] More specifically, the base polymer may be a photosensitive polymer (base resin) represented by the following chemical formula c: [Chemical formula c] JPEG0007824417000018.jpg46170

[0102] In the chemical formula c, R6 to R8 are the same or different and each independently represent a hydrogen atom or a methyl group; Ar represents an aryl group in which at least one hydrogen atom is substituted or unsubstituted; R9 and R 10 are the same or different and may each independently be one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, or an aryl group. Ar is the same as Ar in Formula a, and R and R 10 is the same as R5 in the above chemical formula b.

[0103] More specifically, in the above chemical formula c, Ar may be a monocyclic aryl group having 6 to 11 carbon atoms in which at least one hydrogen atom has been substituted with a hydroxy group.

[0104] In the chemical formula c, R9 may be a monocyclic or polycyclic cycloalkyl group in which at least one carbon atom is substituted with a heteroatom, or a polycyclic cycloalkyl group in which at least one hydrogen atom is substituted with a hydroxy group. In the chemical formula c, the R 10 may be a monocyclic or polycyclic cycloalkyl group.

[0105] In formula c, the a, b, and c listed under the repeating unit represent the molar percentage of each repeating unit relative to the total monomers (repeating units) constituting the polymer, where a may be 10 mol% to 60 mol%, or 35 mol% to 40 mol%, b may be 1 mol% to 30 mol%, or 5 mol% to 20 mol%, and c may be 30 mol% to 60 mol%, or 40 mol% to 55 mol%. If the molar percentage of the repeating units exceeds the above range, the physical properties of the photoresist film may be degraded, or the photoresist film may be difficult to form, resulting in reduced pattern contrast. Typically, the weight-average molecular weight (Mw) of the photosensitive polymer may be 2,000 to 20,000, or 3,000 to 12,000.

[0106] More specific examples of the photosensitive polymer (base resin) represented by the above chemical formula c include photosensitive polymers (base resins) represented by the following chemical formulas d, e, f, and g. [Chemical formula d] JPEG0007824417000019.jpg24170[Chemical formula e] JPEG0007824417000020.jpg27170[Chemical formula f] JPEG0007824417000021.jpg25170[Chemical formula g] JPEG0007824417000022.jpg26170

[0107] The content of the base polymer may be 2 to 30% by weight, or 4 to 10% by weight, based on the total weight of the photoresist composition. If the content of the base polymer is less than 2% by weight, it may be difficult to form a photoresist film and a pattern. If the content of the base polymer is more than 30% by weight, the thickness distribution of the pattern formed on the wafer may not be uniform.

[0108] Examples of photoacid generators include onium salts such as sulfonium salts and iodonium salts, diazomethanes, oximes, nitrobenzylsulfonates, iminosulfonates, and disulfones, and these can be used alone or in combination of two or more.

[0109] The content of the photoacid generator may be 0.05 to 30 parts by weight, or 0.1 to 15 parts by weight, relative to 100 parts by weight of the base polymer. If the content of the photoacid generator is less than 0.05 parts by weight relative to 100 parts by weight of the base polymer, the photoresist may become less sensitive to light and the acid diffusion distance may become longer. If the content of the photoacid generator is more than 30 parts by weight, the photoacid generator may absorb too much far ultraviolet light, generating too much acid and resulting in a defective cross-section of the pattern.

[0110] The organic solvent used in the present invention can be any organic solvent that is used in ordinary photoresist compositions and that can easily dissolve the base polymer, photoacid generator, salt compound, and other additives. For example, ketones such as cyclohexanone and methyl amyl ketone; alcohols such as 2-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and diethyl glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; and lactones such as γ-butyrolactone. These solvents can be used alone or in combination of two or more, but are not limited thereto. Examples of the organic solvent are not particularly limited, but one example may be any one of PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), EL (ethyl lactate), and CyH (cyclohexanone), which have the best solubility for the acid diffusion inhibitor, or a mixture thereof.

[0111] The content of the organic solvent is the remainder excluding the content of the photoresist composition excluding the base polymer, photoacid generator, salt compound, and other additives, relative to 100% by weight of the entire photoresist composition.

[0112] Examples of the additives are not particularly limited, but may include additional resins, stabilizers, surfactants, thickeners, antifoaming agents, adhesion agents, antioxidants, and dissolution inhibitors.

[0113] According to yet another embodiment of the present invention, there is provided a method for forming a photoresist pattern, including the steps of applying and heating the photoresist composition of the other embodiment to form a photoresist film, exposing the photoresist film to light, and developing the exposed photoresist film to form a photoresist pattern. The content relating to the photoresist composition includes the content described above in relation to the other embodiments.

[0114] The pattern formation method can be performed using known techniques, for example, by applying a photoresist using a spinner or the like, exposing the photoresist to high-energy rays with a wavelength of 300 nm or less using a predetermined photomask, and developing the exposed photoresist film with a conventional developer (for example, an alkaline aqueous solution such as a 0.1 wt % to 10 wt % aqueous solution of tetramethylammonium hydroxide).

[0115] The high-energy radiation having a wavelength of 300 nm or less is not particularly limited, but examples thereof include ultraviolet radiation, far ultraviolet radiation, extreme ultraviolet radiation (EUV), electron beams, X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. For the formation of fine patterns of 70 nm or less, it is preferable to use an exposure apparatus equipped with a source of short-wavelength high-energy radiation such as an ArF excimer laser, a KrF excimer laser, or EUV.

[0116] More specifically, the high energy exposure source can be selected from KrF having a wavelength of 248 nm, ArF having a wavelength of 193 nm, an electron beam (e-beam), and EUV having a wavelength of 13.5 nm. [Effects of the Invention]

[0117] According to the present invention, there are provided a salt compound and an acid diffusion inhibitor containing the same, which can provide a photoresist composition having improved polarity, shortening the diffusion length of anions generated during exposure, ensuring high contrast and improving limiting resolution, thereby achieving low sensitivity, LER value, and a high process margin. DETAILED DESCRIPTION OF THE INVENTION

[0118] Hereinafter, an example will be presented to help understand the present invention. However, the following example is provided merely to facilitate understanding of the present invention, and is not intended to limit the scope of the present invention.

[0119] Example 1: Preparation of salt compounds The structures of the salt compounds obtained in Examples 1-1 to 1-12 and Comparative Examples 1-1 to 1-3 are shown in Table 1 below.

[0120] [Table 1] JPEG0007824417000024.jpg213170

[0121] Example 1-1: Salt Compound 1 Step 1) Preparation of 1,1,1-trifluoro-N-(2-hydroxyethyl)methanesulfoneamide [ka]

[0122] Ethanolamine (20 g) was dissolved in dichloromethane (150 g) to prepare mixture 1, which was then cooled to -78°C and stirred. Trifluoromethanesulfonic anhydride (97 g) and dichloromethane (150 g) were then mixed to prepare mixture 2, which was then slowly added dropwise to mixture 1 for approximately 1 hour. After the addition was completed, the temperature was maintained at -78°C for an additional hour, then gradually increased to 0°C and stirred for an additional 5 hours. The reaction was terminated with distilled water, and the organic layer was washed three times with distilled water to remove unreacted materials. The mixture was then concentrated under reduced pressure and purified by column chromatography to obtain 1,1,1-trifluoro-N-(2-hydroxyethyl)methanesulfonamide (35.7 g, 56.4% yield). 1 H-NMR (CDCl3, TMS (standard material), 600MHz): 8.2(NH, s, 1H), 4.5(CH2, t, 2H), 3.7(CH2, t, 2H), 1.3(OH, s, 1H)

[0123] Step 2) Preparation of 2-(trifluoromethylsulfonamido)ethyl 4-iodobenzenesulfonate [ka]

[0124] 1,1,1-trifluoro-N-(2-hydroxyethyl)methanesulfonamide (30 g) obtained in step 1) was dissolved in dichloromethane (200 g). While stirring, a mixture of 4-iodobenzene-1-sulfonylchloride (50 g) and dichloromethane (200 g) was slowly added dropwise and allowed to react for 3 hours. The organic layer was then washed with distilled water until it became neutral (approximately pH 6-7). The organic layer was then concentrated under reduced pressure to give 2-(trifluoromethylsulfonamido)ethyl 4-iodobenzenesulfonate (62.3 g, 87.3% yield). 1 H-NMR(CDCl3, TMS, 600MHz): 8.5(NH, s, 1H), 8.2(CH, d, 2H), 7.5(CH, d, 2H), 4.5(CH2, t, 2H), 3.9(CH2, t, 2H)

[0125] Step 3) Preparation of triphenylsulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 1) [ka]

[0126] 2-(trifluoromethylsulfonamido)ethyl 4-iodobenzenesulfonate (30 g) obtained in Step 2 was dissolved in acetonitrile (200 g), and 10% aqueous sodium hydroxide (28 g) was slowly added. The mixture was stirred at room temperature for 3 hours and then distilled under reduced pressure to obtain sodium (2-(4-iodophenylsulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide salt (approximately 30.1 g, 98.54% yield). Triphenylsulfonium chloride (20.56 g), distilled water (200 g), and dichloromethane (300 g) were then added, along with tetrabutylammonium fluoride (0.5 g) as a catalyst, and the mixture was thoroughly stirred at room temperature for approximately 12 hours. The organic layer was separated, washed with distilled water until neutral (approximately pH 6-7), and then concentrated under reduced pressure. Ethyl acetate (100 g) was added to the resulting concentrate, and the mixture was stirred. The organic solvent was then removed, and this process was repeated three times. The mixture was then concentrated under reduced pressure to give triphenylsulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 1) (39 g, 87.2% yield). 1 H-NMR(CDCl3, TMS, 600MHz): 8.24(CH, d, 2H), 7.54(CH, d, 2H), 7.27-7.78(CH, m, 15H), 4.5(CH2, t, 2H), 3.7(CH2, t, 2H)

[0127] Example 1-2: Salt Compound 2 The compound was prepared in the same manner as in Example 1-1, except that in step 2), adamantanesulfonyl chloride was used instead of 4-iodobenzene-1-sulfonyl chloride, and triphenylsulfonium(2-(adamantanesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 2) was obtained by ion exchange reaction.

[0128] Examples 1-3: Salt Compound 3 The compound was prepared in the same manner as in Example 1-1, except that in step 2, 4-iodobenzene-1-sulfonyl chloride was replaced with 4-methoxybenzenesulfonyl chloride, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(4-methoxyphenylsulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 3).

[0129] Examples 1-4: Salt Compound 4 The compound was prepared in the same manner as in Example 1-1, except that in step 2), benzo-1,4-dioxanesulfonyl chloride was used instead of 4-iodobenzene-1-sulfonyl chloride, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(benzo-1,4-dioxanesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 4).

[0130] Examples 1-5: Salt Compound 5 The compound was prepared in the same manner as in Example 1-1, except that in step 2, 2,3,4,5,6-pentafluoro-N-(2-hydroxyethyl)benzenesulfoneamide was used instead of 1,1,1-trifluoro-N-(2-hydroxyethyl)methanesulfonamide, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(trifluorobenzenesulfonyl)amide (salt compound 5).

[0131] Examples 1-6: Salt Compound 6 The compound was prepared in the same manner as in Example 1-1, except that in step 2, naphthalene-sulfonyl chloride was used instead of 4-iodobenzene-1-sulfonyl chloride, and triphenylsulfonium(2-(naphthalenesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 6) was obtained by ion exchange reaction.

[0132] Examples 1-7: Salt Compound 7 The compound was prepared in the same manner as in Example 1-1, except that in step 3, diphenyl(4-(1-iodobenzene-4-sulfonyloxy)phenyl)sulfonium chloride was used instead of triphenylsulfonium chloride, and an ion exchange reaction was carried out to obtain diphenyl(4-(1-iodobenzene-4-sulfonyloxy)phenyl)sulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (Diphenyl(4-(4-iodobenzene-1-sulfonyloxy)phenyl)sulfonium(2-(naphthalenesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide, salt compound 7.

[0133] Examples 1-8: Salt Compound 8 The compound was prepared in the same manner as in Example 1-1, except that in step 2, propanesulfonyl chloride was used instead of 4-iodobenzene-1-sulfonyl chloride, and triphenylsulfonium(2-(propanesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 8) was obtained by ion exchange reaction.

[0134] Examples 1-9: Salt Compound 9 The compound was prepared in the same manner as in Example 1-1, except that in step 2), 2-(1,4-dioxan-2-yl)ethanesulfonyl chloride was used instead of 4-iodobenzene-1-sulfonyl chloride, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(1,4-dioxan-2-yl)ethanesulfonyloxy)ethyl)(trifluoromethanesulfonyl)amide (salt compound 9).

[0135] Examples 1-10: Salt Compound 10 The compound was prepared in the same manner as in Example 1-1, except that in step 2, N-(2-hydroxyethyl)propanesulfoneamide was used instead of trifluoro-N-(2-hydroxyethyl)methanesulfonamide, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(propanesulfonyl)amide (salt compound 10).

[0136] Examples 1-11: Salt Compound 11 The compound was prepared in the same manner as in Example 1-1, except that in step 2, N-(2-hydroxyethyl)benzenesulfoneamide was used instead of trifluoro-N-(2-hydroxyethyl)methanesulfonamide, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(4-iodophenylsulfonyloxy)ethyl)(benzenesulfonyl)amide (salt compound 11).

[0137] Examples 1-12: Salt Compound 12 The compound was prepared in the same manner as in Example 1-1, except that in step 2, trifluoro-N-(2-hydroxybutyl)methanesulfonamide (1,1,1-trifluoro-N-(2-hydroxybutyl)methanesulfoneamide) was used instead of trifluoro-N-(2-hydroxyethyl)methanesulfonamide, and an ion exchange reaction was carried out to obtain triphenylsulfonium(2-(4-iodophenylsulfonyloxy)butyl)(trifluoromethanesulfone)amide (salt compound 12).

[0138] Comparative Example 1-1: Salt Compound 13 The salt compound 13 was used, which has the following structure: [ka]

[0139] Comparative Example 1-2: Salt Compound 14 The salt compound 14 was used, which has the following structure: [ka]

[0140] Comparative Example 1-3: Salt Compound 15 The salt compound 15 was used, which has the following structure: [ka]

[0141] <Synthesis example: production of base polymer> Synthesis Example 1: Preparation of Polymer 1 Monomers were combined according to the repeating units listed in Table 2 below and dissolved in tetrahydrofuran (THF) to prepare a reaction solution, which was then copolymerized. The reaction solution was then added dropwise to a mixed solvent of methanol, n-hexane, hexane / isopropyl alcohol, or methanol / water to remove small molecules and solidify the polymer. The polymer was then repeatedly washed with the same solvent, separated, and dried to prepare a base polymer (referred to as Polymer 1). For monomers containing hydroxystyrene groups, these were used in a state protected with an acetoxy group, and after primary polymerization, a secondary hydrolysis reaction was additionally performed, followed by a process of precipitation in water.

[0142] Synthesis Examples 2 to 4: Preparation of Polymers 2 to 4 Polymers 2 to 4 were produced in the same manner as in Synthesis Example 1, except that the types and amounts of monomers were changed according to the repeating units shown in Table 2 below.

[0143] After drying the base polymers produced in Synthesis Examples 1 to 4, 1 H or 13 The monomer components were analyzed by C-NMR spectroscopy, and the Mw and PDI (polydispersity index, expressed as Mw / Mn) were analyzed by gel permeation chromatography (GPC). The molecular weight (Mw) of the polymer was calculated in terms of standard polystyrene using THF solvent. The types of repeating units and analytical results of polymers 1 to 4 are listed in Table 2 below.

[0144] [Table 2]

[0145] Example 2: Preparation of photoresist composition The photoresist compositions of Examples 2-1 to 2-25 and Comparative Examples 2-1 to 2-6 were prepared by dissolving a base polymer, a photoacid generator, and an acid diffusion inhibitor in an organic solvent using the components listed in Table 3 below, and filtering the solution through a polytetrafluoroethylene (PTFE) filter with 0.2 μm pores.

[0146] <<Base polymer>> In Examples 2-1 to 2-25 and Comparative Examples 2-1 to 2-6, one of the polymers 1 to 4 produced in the above Synthesis Examples 1 to 4 was selected and used as the base polymer.

[0147] <<Photoacid generator>> In Examples 2-1 to 2-25 and Comparative Examples 2-1 to 2-6, one of the compounds having the following structure was selected and used as the photoacid generator (PAG). [ka]

[0148] <<Acid diffusion inhibitor>> In Examples 2-1 to 2-25, salt compounds 1 to 12 prepared in Examples 1-1 to 1-12 were used as acid diffusion inhibitors (quenchers). In Comparative Examples 2-1 to 2-6, salt compounds 13 to 15 described in Comparative Examples 1-1 to 1-3 were used as acid diffusion inhibitors.

[0149] <<Organic solvents>> In Examples 2-1 to 2-25 and Comparative Examples 2-1 to 2-6, one or more of PGMEA (propylene glycol monomethyl ether acetate), PGME (propylene glycol monomethyl ether), EL (ethyl lactate), and CyH (cyclohexanone) was selected and used as the organic solvent.

[0150] [Table 3] JPEG0007824417000034.jpg144170

[0151] <Experimental Example> Experimental Example 1: Resist pattern formation experiment To analyze resist pattern characteristics, silicon wafers were coated with a resist underlayer organic thin film to prepare substrates. The photoresist compositions of Examples 2-1 to 2-20 and Comparative Examples 2-1 to 2-6 were spin-coated onto the substrates to form resist thin films. The substrates were then prebaked at 100°C to 130°C for 60 seconds using a hot plate. (i) The wafers were then exposed to light using an ASML NXE:3400 EUV exposure tool with a numerical aperture (NA) of 0.33, followed by post-exposure baking at 100°C to 130°C for 60 seconds. The prebaked wafers were then developed for 30 seconds in a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution to form 1:1 line and space (L / S) patterns with a film thickness of 40 nm and a line width of 20 nm.

[0152] Experimental Example 2: Resist pattern characteristic evaluation The pattern size of the patterned wafer of Experimental Example 1 was measured using a Hitachi High-Technologies Corp. Critical Dimension Scanning Electron Microscope (CD-SEM, product name: CG-5000) to measure the pattern size, and the sensitivity, line edge roughness (LER), and process margin (EL and DOF) were evaluated as follows.

[0153] (1) Sensitivity evaluation The optimum exposure energy, Eop (mJ / cm), at which a resist pattern having the same size space (pitch 40 nm) as the resist line width of 20 nm is formed. 2 The lower the sensitivity value, the lower the LER, and the larger the process margin (EL, DOF), the better the product can be evaluated.

[0154] (2) LER evaluation (Line Edge Roughness) The line edge roughness was measured at 200 measurement points in the longitudinal direction of the line width pattern for a 20 nm pattern formed at the optimum exposure energy (Eop), and the average value was calculated for three times the standard deviation (s) (3s). The lower the LER value, the better the evaluation.

[0155] (3) EL margin evaluation (Exposure Latitude, unit: %) The EL margin was calculated using the following formula, using the exposure energy value when a 20nm size pattern formed with the optimum exposure energy (Eop) is formed within a line width range of 20nm ±5% (19nm to 21nm).The higher the EL margin value, the better it can be evaluated. EL margin (%) = (|E1-E2| / Eop) x 100 E1: Exposure energy value when forming a line width 19 nm pattern (mJ / cm 2 ) E2: Exposure energy value when forming a line width 21 nm pattern (mJ / cm 2 )

[0156] (4) DOF margin evaluation (Depth of focus, unit: nm) The change in depth of focus (DOF) at the optimum exposure energy (Eop) was calculated as a value within the range of ±1.5% (19.7 nm to 20.3 nm) of the 20 nm pattern line width of 20 nm. The formula for this is as follows. The higher the DOF margin value, the better the evaluation. DOF margin (nm) = D1 + D2 Where D1: When a pattern is formed within line width ±1.5% + depth of focus value (nm) D2: Depth of focus (nm) when a pattern with a line width of ±1.5% is formed The results of the above-mentioned evaluation of the resist pattern characteristics are listed in Table 4 below.

[0157] [Table 4] JPEG0007824417000036.jpg99170

[0158] Referring to Table 4, when the photoresist compositions according to Examples 2-1 to 2-25 were used, the radiation intensity was 55 mJ / cm 2 More than 74mJ / cm 2 The results showed a sensitivity of 2.34 nm or more and an LER of 2.84 nm or less, an EL margin of 9.1% or more and 12.4% or less, and a DOF margin of 80 nm or more and 100 nm or less.

[0159] In contrast, when the photoresist compositions of Comparative Examples 2-1 to 2-5 were used, the radiation intensity was 79 mJ / cm 2 More than 86mJ / cm 2 The comparative examples 2-6, which used salt compound 14, exhibited excellent sensitivity, an LER of 3.25 nm to 3.58 nm, an EL margin of 9.3% to 11.9%, and a DOF margin of 70 nm to 80 nm, demonstrating poorer physical properties than the examples. In particular, comparative example 2-6, which used salt compound 14, exhibited excellent sensitivity, but exhibited poorer physical properties than the examples, with an LER of 3.61 nm and a DOF margin of 60 nm.

Claims

1. A salt compound containing an anion represented by the following chemical formula 1 and a cation represented by the following chemical formula 2: [Chemical formula 1] [Chemical formula 2] In the above Chemical Formulas 1 and 2, R １ and R ２ are the same or different and each independently represent one of an alkyl group, an alkenyl group, a cycloalkyl group, a cycloalkenyl group, an aryl group, a halogen, or a combination thereof; X is one of an alkylene group, an alkenylene group, a cycloalkylene group, a cycloalkenylene group, or a combination thereof; M ＋ is one of an onium ion or a metal ion.

2. The salt compound according to claim 1 , wherein X is an alkylene group or an alkenylene group.

3. 2. The salt compound according to claim 1, wherein X is an alkylene group having 2 to 3 carbon atoms.

4. The R １ is one of an alkyl group having 1 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogen, an aryl group having 6 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogen, or an aryl group having 6 to 30 carbon atoms in which at least one hydrogen atom is substituted with a halogenated alkyl group.

5. The R １ is one of an alkyl group having 1 to 30 carbon atoms in which two or more and six or less hydrogen atoms are substituted with halogen, and an aryl group having 6 to 30 carbon atoms in which two or more and six or less hydrogen atoms are substituted with halogen.

6. The R ２ The salt compound of claim 1 , wherein is a substituted or unsubstituted aryl group.

7. The R ２ is one of an aryl group in which at least one hydrogen atom is substituted with a halogen, an aryl group in which no hydrogen atom is substituted, or an aryl group in which at least one hydrogen atom is substituted with a heteroalkyl group.

8. The R ２ The salt compound according to claim 1 , wherein is an aryl group in which at least one hydrogen atom is substituted with a halogen.

9. The R １ is selected from the group consisting of methyl, ethyl, propyl, halogen, trifluoromethyl, cyclohexyl, adamantyl, phenyl, 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,4-difluorophenyl, 2,5-difluorophenyl, 4-(trifluoromethyl)phenyl, and 1,2,3,4,5-pentafluorophenyl. The salt compound of claim 1, wherein

10. The R ２ is one of methyl, ethyl, propyl, trifluoromethyl, cyclohexyl, adamantyl, acetyl-4-piperidinyl, tert-butoxycarbonyl-4-piperidinyl, 4-fluorophenyl, 4-bromophenyl, 4-iodophenyl, 2,5-difluorophenyl, 2,4-difluorophenyl, 1,2,3,4,5-pentafluorophenyl, 4-methoxyphenyl, 1-naphthyl, 2-naphthyl, 4-pyridinyl, 6-benzoxazolyl, 5-phthalanyl, 1,4-dioxan-2-ylethyl, or 1,4-benzodioxan-6-yl.

11. Said M ＋ 2. The salt compound of claim 1, wherein is one of a sulfonium ion, an iodonium ion, or an ammonium ion.

12. The salt compound according to claim 1, wherein the anion represented by Chemical Formula 1 is any one selected from the group consisting of: 【Transformation 5】 【Transformation 6】

13. The salt compound according to claim 1, wherein the cation represented by Chemical Formula 2 is any one selected from the group consisting of: 【Transformation 7】 【Transformation 8】

14. An acid diffusion inhibitor comprising the salt compound of claim 1.

15. A salt compound according to claim 1; Photoacid generator; a base polymer; and A photoresist composition comprising an organic solvent.

Images