TWI519512B - Photoacid compound,photoacid generator and preparation method thereof,and resist composition comprising photoacid generator - Google Patents

Description

Photoacid compound, photoacid generator, preparation method thereof, and resist composition containing the photoacid generator

The present invention relates to a novel photoacid generator and a resist composition comprising the photoacid generator, which regulates acid diffusion from an exposed region to a non-exposed region during formation of a resist film, thereby being capable of reducing Line edge roughness on non-exposed and exposed surfaces.

The chemically amplified positive resist composition applied to semiconductor fine processing including photolithography processes contains a photoacid generator containing a compound which generates an acid by light irradiation.

As the photoacid generator, a sulfonium salt is mainly used, and a cation portion thereof is degraded into a radical form and exists as a molecule of another form, and when an anion portion is baked after the acid is formed and irradiated, the wafer is baked. The acid diffuses on the resist film. In this process, the resolution of the photoacid generator to the resist is due to, for example, the ability to absorb light, the efficiency of generation of acid generated by light, the diffusion ability of an acid generated by an anion, the strength of an anion acid, and the like. Line edge roughness, etc. directly Image.

Recently, photolithography technology is actively pursuing high-volume manufacturing (HVM) using ArF liquid immersion (immersion exposure) technology, and mainly develops technologies for achieving line widths of 50 nm or less. Thus, as the line width to be realized becomes smaller, the resist needs to have high resolution, sufficient protection for the process (energy support, focal length guarantee), line width reduction, and corresponding energy. It is necessary to cope with properties such as sufficient etch resistance of thickness reduction, and among them, it is particularly required to improve the characteristics of line edge roughness.

The line edge roughness means the uniformity of the surface between the exposed area and the non-exposed area, and the requirement for line edge roughness of the ArF immersion exposure method is recently fine to about 2 nm to 3 nm.

As described above, there are many reasons for affecting the edge roughness of the wire, and among them, the diffusion distance of the acid and the acidity of the photoacid generator due to exposure to acid after exposure or Post Exposure Bake (PEB) The influence is therefore considered as a main factor affecting the roughness of the line edge, and therefore, research for obtaining better line edge roughness characteristics by adjusting the diffusion of the acid of the photoacid generator is mainly performed. In addition, as it is recognized that the acid diffusion is slower than when the acid diffusion is slow, the edge roughness caused by acid diffusion can be reduced in the non-exposed and exposed adjacent regions, as a method of reducing acid diffusion, by expanding the anion The way in which the size regulates the diffusion when acid is formed is being studied extensively.

[Previous Technical Literature] [Patent Literature]

Patent Document 1: Korean Patent Publication No. 2010-0014433 (published on 2010.08.27)

Patent Document 2: Korean Patent Publication No. 2006-0030950 (published on June 31, 2013)

Patent Document 3: Korean Patent Publication No. 2010-7022640 (published on 2010.12.02)

Patent Document 4: Korean Patent Publication No. 2010-0051591 (2011.12.07 publication)

An object of the present invention is to provide a photoacid generator (hereinafter referred to as "PAG") which can reduce non-acid diffusion from an exposed region to a non-exposed region during formation of a resist film. Line edge roughness on exposed and exposed surfaces.

Another object of the present invention is to provide a resist composition comprising the photoacid generator.

In order to achieve the above object, a photoacid generator according to an embodiment of the present invention is a compound having the structure of the following Chemical Formula 1.

In the chemical formula 1, Q ₁ and Q ₁ ' are each independently a halogen group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen group; and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ; V ₁ and V ₂ are each independently an oxygen atom (O) or a sulfur atom (S); W ₁ and W ₂ are each independently selected from an alkyl group having 1 to 10 carbon atoms and having 3 to 30 carbon atoms; a group consisting of a cycloalkyl group, an aryl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; and X is selected from an alkyl group, an alkenyl group, and an NR group. In the group consisting of ', S, O, CO, and a combination thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is an integer of 1 to 4, and b is an integer of 0 to 5. c is an integer from 1 to 3, d is an integer from 1 to 3; A+ is an organic counter ion.

Preferably, X in the chemical formula 1 is a carbonyl group (CO).

More preferably, in the chemical formula 1, Q ₁ and Q ₁ ' are each independently a fluorine group, and Q ₂ and Q ₂ ' are each independently a hydrogen atom or a fluorine group, and R is a hydrogen atom or a methyl group, and V ₁ and V _{2 are respectively} Each is independently an oxygen atom or a sulfur atom, and W ₁ and W ₂ are each independently selected from the group consisting of methyl, ethyl, cyclopropyl, phenyl, methoxy, and ethoxy, and X is a carbonyl group. , a is an integer from 1 to 3, b is an integer from 0 to 2, c is an integer of 1 or 2, and d is an integer of 1 or 2.

More preferably, the anion moiety in Chemical Formula 1 may be selected from the group consisting of Chemical Formula 2a to Chemical Formula 2f below.

[Chemical Formula 2b]

Further, preferably, A+ in the chemical formula 1 may be selected from the group consisting of thioindigo and iodine. More preferably, the organic counter ion in the group consisting of anthraquinones, phosphoniums, diazonium salts, pyridiniums, and quinones is an organic counter ion represented by the following chemical formula 3a or chemical formula 3b. .

In the chemical formula 3a and the chemical formula 3b, X ₁ , X ₂ , Y ₁ and Y ₂ are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, and 1 to 1 carbon atom. Any one of the group consisting of a perfluoroalkyl group of 10, a benzyl group, an aryl group having 6 to 30 carbon atoms, and a combination thereof, X ₁ and X ₂ and Y ₁ and Y ₂ may be bonded to each other to form a carbon. a saturated or unsaturated hydrocarbon ring having an atomic number of 3 to 30; X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ may be an alkane each independently selected from a hydrogen atom and having 1 to 30 carbon atoms a group, a halogen group, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a thiophenoxy group, and a thioalkoxy group having 1 to 30 carbon atoms Any of a group consisting of (thioalkoxy), an alkoxycarbonylmethoxy having 1 to 20 carbon atoms, and a combination thereof.

Still more preferably, A+ may be an organic counter ion having a structure represented by the following Chemical Formula 4a to Chemical Formula 4v.

According to another embodiment of the present invention, there is provided a process for producing the photoacid generator of Chemical Formula 1, which comprises the steps of: reacting a compound of the following Chemical Formula 7 with Selected from the group consisting of carbonyl diimidazole, N-halosuccinic imide, potassium iodide, thionyl chloride, and mixtures thereof a step of preparing a compound of the following chemical formula 9 by reacting a compound; a step of preparing a compound of the following chemical formula 11 by reacting a compound of the chemical formula 9 prepared as described above with a compound of the following chemical formula 10; and a chemical formula 11 prepared by the above step The step of reacting a compound with a compound of the following Chemical Formula 12.

[Chemical Formula 11]

[Chemical Formula 12] A+Z-

In the chemical formula 7 and the chemical formula 9 to the chemical formula 12, Q ₁ and Q ₁ ' are each independently a halogen group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen group; R is a hydrogen atom or the number of carbon atoms is An alkyl group of 1 to 4; V ₁ and V ₂ are each independently an oxygen atom (O) or a sulfur atom (S); and W ₁ and W ₂ are each independently selected from an alkyl group having 1 to 10 carbon atoms, carbon. a group consisting of a cycloalkyl group having 3 to 30 atoms, an aryl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; X is selected from an alkyl group In the group consisting of alkenyl groups, NR', S, O, CO, and combinations thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is an integer of 1 to 4, b Is an integer from 0 to 5, c is an integer from 1 to 3, d is an integer from 1 to 3; A+ is an organic counter ion; M+ is any one selected from the group consisting of Li+, Na+, and K+; Q ₃ Selected from the group consisting of imidazolyl, fluorine, chlorine, bromine and iodine; and Z- is selected from (OSO ₂ CF ₃ )-, (OSO ₂ C ₄ F ₉ )-, (OSO ₂ C ₈ F ₁₇ )-, (N(CF ₃ ) ₂ )-, (N(C ₂ F ₅ ) ₂ )-, (N(C ₄ F ₉ ) ₂ )-, (C(CF ₃ ) ₃ )-, (C( C ₂ F ₅ ) ₃ )-, (C(C ₄ F ₉ ) ₃ )-, F-, Cl-, Br-, I-, BF ₄ -, AsF ₆ - and PF ₆ - One.

Another embodiment of the present invention provides the photoacid compound of the following Chemical Formula 11.

In the formula 11, Q ₁ and Q ₁ ' are each independently a halogen group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen group; and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ; V ₁ and V ₂ are each independently an oxygen atom (O) or a sulfur atom (S); and W ₁ and W ₂ are each independently selected from an alkyl group having 1 to 10 carbon atoms and having 3 to 30 carbon atoms; a group consisting of a cycloalkyl group, an aryl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; and X is selected from an alkyl group, an alkenyl group, and an NR group. In the group consisting of ', S, O, CO, and a combination thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is an integer of 1 to 4, and b is 0 to An integer of 5, c is an integer of 1 to 3, d is an integer of 1 to 3; and M+ is any one selected from the group consisting of Li+, Na+, and K+.

Another embodiment of the present invention provides a resist composition comprising the photoacid generator.

Specific matters of other embodiments of the present invention are included in the following description.

The photoacid generator of the present invention prevents the slave during the formation of the resist film The diffusion of acid from the exposed area to the non-exposed area enables the line edge roughness on the non-exposed surface and the exposed surface to be reduced.

Fig. 1 is a graph showing the results of 1H NMR observation of trimethyldioxanecarboxylic acid (i) prepared in Synthesis Example 1.

2 is a graph showing the results of 1H NMR observation of the compound (iii) prepared in the first step of Example 1.

Fig. 3 is a graph showing the results of 1H NMR observation of the compound (v) prepared in the second step of Example 1.

4 is a graph showing the results of 1H NMR observation of the solid compound (vii) prepared in the third step of Example 1.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited thereto, and the scope of the present invention should be determined by the scope of the patent application.

Unless otherwise stated in the specification, a halogen group means any one selected from the group consisting of fluorine, chlorine, bromine and iodine.

Unless otherwise stated in the specification, an alkyl group means a straight or branched alkyl group having 1 to 30 carbon atoms, and the alkyl group includes a primary alkyl group, a secondary alkyl group, and a tertiary alkyl group. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, and a third butyl group. However, the present invention is not limited thereto.

Unless otherwise specified in the specification, a cycloalkyl group means a cycloalkyl group having 3 to 30 carbon atoms, and includes a monocyclic, bicyclic, tricyclic or tetracyclic ring. Further, it includes an adamantyl group, a norbornyl group, and a polycyclic cycloalkyl group having a norbornyl group.

Unless otherwise specified in the specification, the aryl group means a compound containing a benzene ring and a derivative thereof, and for example, may be a toluene or xylene having an alkyl side chain attached to a benzene ring, or two or more benzene rings. A single-bonded biphenyl or the like, two or more benzene rings, a naphthyl or an anthracene having a cycloalkyl group or a heterocycloalkyl group as a medium, two or more benzene rings condensed naphthalene or an anthracene. Unless otherwise stated in the specification, the aryl group is an aryl group having 6 to 30 carbon atoms.

Unless otherwise stated in the specification, all compounds or substituents may be substituted or unsubstituted. Here, substituted means that hydrogen is selected from the group consisting of a halogen atom, an alkyl group, a perfluoroalkyl group, a perfluoroalkoxy group, a hydroxyl group, a carboxyl group, a carbonyl group, a cyano group, a nitrile group, a nitro group, an amine group, a thio group, an alkane group. A substitution selected from the group consisting of a thio group, an alkoxy group, a decyl group, an aldehyde group, a cycloalkyl group, a heterocyclic group, an allyl group, an aryl group, a derivative thereof, and a combination thereof.

Further, unless otherwise stated in the specification, a combination thereof means that two or more substituents are condensed and bonded by a single bond or a linker group or two or more substituents.

The present invention and the existing photoacid generator reduce the line edge roughness caused by acid diffusion in the adjacent regions of non-exposure and exposure by depending on the size of the anion, and a part of the anion is decomposed by the acid generated after the light irradiation. The alcohol group is formed, and this alcohol group can significantly reduce the diffusion of the acid by hydrogen bonding with the acid, thereby reducing the line edge roughness.

That is, the photoacid generator of one embodiment of the present invention can have the following chemical formula 1 indicates.

In the anion portion of the chemical formula 1, Q ₁ and Q ₁ ' may each independently be a halogen group, preferably may each independently be a fluorine group; and Q ₂ and Q ₂ ' may each independently be a hydrogen atom or a halogen group, preferably Each may be independently a hydrogen atom or a fluorine group; R may be a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group; and V ₁ and V ₂ may each independently be an oxygen atom ( O) or a sulfur atom (S), preferably may be an oxygen atom; W ₁ and W ₂ may each independently be selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, and carbon. The group consisting of an aryl group having 3 to 30 atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof may preferably be independently selected from a methyl group, an ethyl group, a cyclopropyl group, and a benzene group. a group consisting of a group consisting of a methoxy group and an ethoxy group; X may be any one selected from the group consisting of an alkyl group, an alkenyl group, an NR', an S, an O, a CO, and a combination thereof. In this case, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Preferably, X is a carbonyl group (CO); in addition, a may be an integer of 1 to 4, b may be an integer of 0 to 5, c may be an integer of 1 to 3, d may be an integer of 1 to 3, preferably a may be An integer of 1 to 3, b may be an integer of 0 to 2, c may be an integer of 1 or 2, and d may be an integer of 1 or 2; preferably, the anion portion of the following chemical formula 1a in Chemical Formula 1 may be selected from It is a group consisting of the following Chemical Formula 2a to Chemical Formula 2f.

The definition of each substituent in the chemical formula 1a is the same as defined above.

Further, in the cationic portion of Chemical Formula 1, the A+ is an organic counter ion, and specifically may be selected from the group consisting of thioindigos, iodoniums, phosphonium salts, diazonium salts, a cation in a group consisting of pyridinium and quinone.

When the A+ is a sulfonium-based organic counter ion, the A+ may preferably be an organic cation represented by the following Chemical Formula 3a or Chemical Formula 3b.

In the chemical formula 3a and the chemical formula 3b, X ₁ , X ₂ , Y ₁ and Y ₂ are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, and 1 to 1 carbon atom. Any one of the group consisting of a perfluoroalkyl group of 10, a benzyl group, an aryl group having 6 to 30 carbon atoms, and a combination thereof, X ₁ and X ₂ and Y ₁ and Y ₂ may be bonded to each other to form a carbon. a saturated or unsaturated hydrocarbon ring having an atomic number of 3 to 30; X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ may be independently selected from a hydrogen atom and an alkane having 1 to 30 carbon atoms. a group, a halogen group, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a thiophenoxy group, and a thioalkoxy group having 1 to 30 carbon atoms Any one of a group consisting of (thioalkoxy), an alkoxycarbonylmethoxy having 1 to 20 carbon atoms, and a combination thereof; further preferably, the A+ may have the following chemical formula 4a The organic counter ion of the structure represented by the chemical formula 4v.

Further, when the A+ is an iodonium-based organic counter ion, the A+ may preferably be an organic cation represented by the following Chemical Formula 5a or Chemical Formula 5b.

In the chemical formula 5a and the chemical formula 5b, R ₁₁ to R ₁₃ and R ₂₁ to R ₂₃ may each independently be selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, and 1 carbon atom. Any one of the group consisting of -10 perfluoroalkyl group, aryl group having 6 to 30 carbon atoms, and combinations thereof; R ₁₄ and R ₂₄ may each independently be selected from a halogen group, a carbon number An alkyl group of 1 to 30, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, a thiophenoxy group, and a thioalkoxy group having 1 to 30 carbon atoms Any one of the group consisting of an alkoxycarbonylmethoxy group having 1 to 20 carbon atoms and a combination thereof; more preferably, the A+ is an organic compound having the structure represented by the following Chemical Formula 6a to Chemical Formula 6i Counter ion.

Further more preferably, the organic counter ion is a sulfonium-based organic counter ion.

The photoacid generator of one embodiment of the present invention having the structure as described above can be produced by the following preparation steps: a compound of the following chemical formula 7 and a carbonyl diimidazole selected from the following Chemical Formula 8a, the following chemical formula a group consisting of N-halosuccinic imide of 8b, potassium iodide of the following chemical formula 8c, thionyl chloride of the following chemical formula 8d, and a mixture thereof a step of preparing a compound of the following chemical formula 9 by reacting a compound in the group (step 1); a step of preparing a compound of the following chemical formula 11 by reacting the compound of the chemical formula 9 prepared in the above step with a compound of the following chemical formula 10 (step 2); and a step (Step 3) of preparing a compound of the following Chemical Formula 1 by reacting the compound of Chemical Formula 11 prepared in the above step with a compound of the following Chemical Formula 12.

[Chemical Formula 1]

[Chemical Formula 8c] K ⁺ I ^-

[Chemical Formula 12] A+Z-

In the chemical formula 1 and the chemical formula 7 to the chemical formula 12, the definitions of A+, Q ₁ , Q ₁ ', Q ₂ , Q ₂ ', V ₁ , V ₂ , W ₁ , W ₂ , R, X and a to d are The foregoing definitions are the same; M+ is any one selected from the group consisting of Li+, Na+, and K+; Q ₃ is a functional group derived from the compound of Chemical Formula 8a to Chemical Formula 8d, specifically selected from the group consisting of imidazolyl, fluorine, chlorine, and bromine And a group consisting of iodine; Y is a halogen group selected from the group consisting of fluorine, chlorine, bromine and iodine; Z- is selected from (OSO ₂ CF ₃ )-, (OSO ₂ C ₄ F ₉ )-, (OSO ₂ C ₈ F ₁₇ )-, (N(CF ₃ ) ₂ )-, (N(C ₂ F ₅ ) ₂ )-, (N(C ₄ F ₉ ) ₂ )-, (C( CF ₃ ) ₃ )-, (C(C ₂ F ₅ ) ₃ )-, (C(C ₄ F ₉ ) ₃ )-, F-, Cl-, Br-, I-, BF ₄ -, AsF ₆ - And any one of the groups consisting of PF ₆ -.

The following reaction formula is a reaction step for indicating the preparation of the photoacid generator of one embodiment of the present invention, and the following Reaction Formula 1 is merely an example for explaining the present invention, and the present invention is not limited thereto.

In the above Reaction Scheme 1, the definition of the substituent of each compound is the same as defined above.

Each step will be described in detail below with reference to Reaction Formula 1.

Step 1 is a step of preparing a compound of the chemical formula 9 by reacting a compound of Chemical Formula 7 with a carbonyl diimidazole of the Chemical Formula 8a.

The compound of the chemical formula 7 is commercially available or can be used according to the disclosure. Method preparation. Specifically, as in Reaction Scheme 2, a dihydroxy compound (13) such as (2,2-bis(hydroxymethyl)propionic acid) is used in p-toluenesulfonic acid (p- By the action of an acid catalyst such as toluene sulfonic acid, p-TSA), it can be reacted with a dialkoxy alkane compound (14) such as 2,2-dimethoxypropane to prepare a chemical formula 7 Compound (7a).

Specific examples of the compound of Chemical Formula 7 include trimethyl dioxane carboxylic acid and the like.

Further, in the step 1 of the reaction formula 1, for example, N-halogenated diimenimine such as N-bromosuccinic imide, potassium iodide or sulfoxide may be used. Instead of the carbonyl diimidazole of the chemical formula 8a, thionyl chloride or a mixture thereof.

In terms of refining or improvement in yield, in the above reaction step 1, it is preferred that the compound of Chemical Formula 7 reacts with the reactable compound of Chemical Formula 8a to Chemical Formula 8d at a molar ratio of 1:1 to 1:1.2, as described above. The reaction of the step 1 can be carried out in a solvent such as tetrahydrofuran (THF).

Carbon dioxide gas is generated during the reaction of the above step 1, and the compound of Chemical Formula 9 is contained together with the imidazole in the reactant obtained as a result of the above reaction. Thus, the resulting reactants can be attached by a general method. The separation and refining steps are carried out to separate the resulting compound of Chemical Formula 9, or the reactant of Step 1 can be used directly in the reaction of the next step without additional separation steps.

Step 2 is a step of preparing a compound of Chemical Formula 11 by reacting the compound of Chemical Formula 9 prepared in Step 1 with the compound of Chemical Formula 10.

As the compound of the chemical formula 10, specifically, 1,1-difluoromethyl-2-hydroxy-ethanesulfonic acid, 1,1-difluoromethyl- 1,1-difluoromethyl-2-hydroxy-propanesulfonic acid, or 1,1-difluoromethyl-2-hydroxy-butanesulfonic acid Lithium salt, sodium or sodium salt, etc.

The reaction of the above step 2 can be carried out in a solvent. In this case, the solvent can be any one selected from the group consisting of esters, ethers, lactones, ketones, guanamines, alcohols, and combinations thereof. One, preferably the solvent may be any one selected from the group consisting of dichloromethane, chloroform, dichloroethane, acetonitrile, toluene, and combinations thereof.

For ease of refining, it is preferred that the compound of the formula 9 is reacted with the compound of the formula 10 in a molar ratio of 1:1 to 1:1.2.

Step 3 is a step of preparing the chemical formula 1 by reacting the compound of Chemical Formula 11 prepared in Step 2 with the compound of Chemical Formula 12.

Specific examples of the compound of Chemical Formula 12 include triphenylsulfur trifluoromethanesulfonate, diphenylalkylphenylthiotrichloromethanesulfonate, triphenylsulfur trichloromethanesulfonate, and the like.

Preferably, in the reaction of the above step 3, the compound of the chemical formula 11 and The compound of the chemical formula 12 is reacted at a molar ratio of 1:1 to 1:1.2, thereby minimizing the reaction time, suppressing side reactions caused by using too much reactant, and preparing the chemical formula 1 in high yield. compound of.

The above-mentioned substitution reaction may be carried out by using a recrystallization method or a solvent (good solvent) capable of sufficiently dissolving the obtained salt and a solvent (poor solvent) in which the obtained salt is not sufficiently dissolved, and then recovering the solution after solidification, or using a solvent. To extract or concentrate the method of recovery.

Preferably, it is dissolved in dichloromethane and water to form two reaction layers, followed by stirring to cause a substitution reaction to occur. An advantage of this two-layer reaction process is that no additional methods for separating the product are needed. The above agitation may be carried out for 2 hours to 6 hours, and may also be carried out for 2 hours to 4 hours. When the reaction is carried out in the above-mentioned time range, the yield of the product can be maximized.

When the compound represented by Chemical Formula 1 is produced by the above process, the compound represented by Chemical Formula 1 can be obtained by a method which is both efficient and simple.

When the photoacid generator of Chemical Formula 1 prepared by the above-described preparation method is applied to a resist composition, if sufficient light is irradiated, an acid is formed, and the generated acid rapidly diffuses, and an acid-containing anion passes through these acids. Decomposition is carried out to form two alcohol groups per molecule, and the resulting alcohol group is bonded to hydrogen bonds with other acids to reduce the diffusion of acid. As a result, the penetration of acid from the non-exposed area to the exposed area is prevented, so that the line edge roughness can be minimized.

The following Reaction Formula 3 schematically shows the effect of reducing the acid diffusion by exposure of the photoacid generator of the present invention. However, the reaction formula is merely an example for explaining the present invention, and the present invention is not limited thereto.

[Reaction formula 3]

As an example, when Compound A is used as the photoacid generator of the present invention in a resist composition, light ions are decomposed by light, and an anion such as B acid is generated. When the generated acid B is subjected to post-exposure baking (PEB) in the photolithography step, the diffusion process of the acid B is carried out, the initial acid diffusion rate is relatively slow, and then the acid B itself is used as the acid. The trimethyl dioxane group of the labile group is decomposed so that a diol such as C is formed in the acid-containing anion. At this time, the diffusion of the acid is rapidly reduced by the hydrogen bonding of the diol, and the line edge roughness on the non-exposed surface and the exposed surface is reduced by preventing the diffusion of the acid from the non-exposed area to the exposed area.

Thus, another embodiment of the present invention provides a resist composition comprising the photoacid generator.

Specifically, the resist composition contains the photoacid generator, a base polymer, and a solvent.

The photoacid generator may be used singly or in combination of two or more as described above. Further, the photoacid generator is contained in an amount of from 0.3 part by weight to 15 parts by weight, based on 100 parts by weight of the polymer solid component; preferably from 0.5 part by weight to 10 parts by weight; more preferably from 2 parts by weight to 10 parts by weight. When the content of the photoacid generator exceeds 15 parts by weight, the perpendicularity of the pattern is remarkably lowered; and when it is less than 0.3 parts by weight, the plasticity of the pattern May be reduced.

The raw material polymer for a resist can be used as long as it is used as a raw material resin in forming a resist film, and is not particularly limited. Specific examples are that the raw material polymer for resist may be selected from the group consisting of: (meth) acrylate polymer; (α-trifluoromethyl) acrylate-maleic anhydride copolymer; a cycloolefin-maleic anhydride copolymer; a polynorbornene; a polymer compound obtained by ring-opening metathesis reaction of a cycloolefin; a polymer compound obtained by adding a hydrogen to a polymer obtained by ring-opening metathesis reaction of a cycloolefin; hydroxystyrene And (meth) acrylate derivatives; selected from the group consisting of styrene, vinyl naphthalate, vinyl fluorene, vinyl hydrazine, hydroxy vinyl naphthyl ester, hydroxy vinyl hydrazine, hydrazine, hydroxy hydrazine, decene, norbornadiene A polymer compound obtained by copolymerization of any of the classes; a phenol resin; and a mixture thereof.

The base polymer may contain from 3% by weight to 20% by weight based on the total weight of the resist composition. When the content of the polymer is less than 3% by weight, the viscosity of the composition is too low to form a film of a desired thickness, and pattern loss is severe due to a relatively large amount of photoacid generator; When the weight is %, the thickness of the film is too thick, and the transmittance of radiation is lowered, so that it is difficult to obtain a vertical pattern.

In order to obtain a uniform and flat resist coating film, it is preferred to dissolve the polymer and photoacid generator in a solvent having an appropriate evaporation rate and viscosity. Solvents which can be used in the present invention are ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, methoxyethyl acetate, ethoxyethyl acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether. Esters such as acetate, propylene glycol monopropyl ether acetate; methyl isopropanone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-heptanone, ethyl lactate, γ-butyl One type of ketones such as a lactone may be used alone or in combination of two or more.

The solvent can be appropriately adjusted in accordance with physical properties of the solvent, that is, volatility, viscosity, and the like, so that a uniform resist film can be formed.

Further, the resist composition of the present invention may further contain an additive for the purpose of improving coatability and the like.

The additive is not particularly limited as long as it is an additive generally used in a resist composition, and specifically may be an alkali dissolution inhibitor, an acid scavenger, a surfactant, or the like, and may include one of the additives or Two or more kinds of additives are mixed.

The alkali dissolution inhibitor may be used as long as it is an alkali dissolution inhibitor which is generally used for a resist composition, and specifically may be a phenol or a carboxylic acid derivative or the like.

The acid scavenger can prevent the diffusion phenomenon of the acid generated by the photoacid generator from diffusing into the resist film due to light irradiation, and suppress the chemical reaction of the unexposed portion. The use of such an acid scavenger can improve the storage stability of the photosensitive resin composition, and at the same time further improve the resolution of the resist, and can also suppress the line of the resist pattern caused by the change in time (PED) between exposure processes. Wide change.

As the acid scavenger as described above, a basic compound can be used, and specifically, an amine, methylamine, isopropylamine, n-hexylamine, cyclopentylamine, methylenediamine, ethylenediamine, dimethylamine, diisopropylamine can be used. , diethyldiamine, N,N-dimethyldiamine, N,N-dimethylethylenediamine, trimethylamine, triethylamine, N,N,N',N'-tetramethyl Methylenediamine, N,N,N',N'-tetramethylethylenediamine, N,N,N',N'-tetramethyltetraethylpentamine, dimethylethylamine, methylethyl Propylamine, benzylamine, phenylethylamine, benzyldimethylamine, tetramethylammonium hydroxide, aniline, N,N-dimethyltoluidine, triphenylamine (acid scavenger), p-phenylenediamine, pyrrole , oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole, pyrroline, pyrrolidine, imidazoline derivative, pyridine derivative, pyridazine derivative, pyrimidine derivative, A pyrazine derivative, a pyrazoline derivative, a pyrazolidine derivative, a piperidine derivative, a piperazine derivative, an amine such as morpholine; an aminobenzoic acid, an anthracene carboxylic acid, an amino acid derivative (for example) , niacin, alanine, arginine, aspartic acid, etc.), 3-pyridinesulfonic acid, p-toluenesulfonic acid pyridine, 2-hydroxypyridine, aminomethylphenol, 2,4-quinolinediol, a nitrogen-containing compound such as 2-(2-hydroxyethyl)pyridine or 1-(2-hydroxyethyl)piperidine; formamide, N-methylformamide, N,N-dimethylformamide, a decylamine derivative such as acetamide, N-methylacetamide, N,N-dimethylacetamide, acetamide or benzamide; or phthalimide or amber An imine derivative such as an amine or maleimide.

The acid scavenger is contained in an amount of from 0.01 part by weight to 5 parts by weight, based on 100 parts by weight of the solid content of the polymer, preferably from 0.1 part by weight to 1 part by weight. If the content of the acid scavenger is less than 0.01 parts by weight, the influence of the delay time after exposure is greater, which affects the shape of the pattern; if it is more than 5 parts by weight, the resolution and photosensitivity may be lowered.

The surfactant is used for improving coating properties, developing properties, etc., and specifically may be polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene. ), polyethylene glycol dilaurate, etc., but is not limited thereto.

The resist composition of the present invention having the composition as described above contains a photoacid generator having an acid diffusion suppressing effect, and can reduce line edge roughness caused by acid diffusion of non-exposure/exposure adjacent portions when a resist film is formed. .

Hereinafter, the embodiments of the present invention will be described in detail so as to be easily implemented by those skilled in the art. However, the invention may be embodied in a variety of different forms and is not limited to the embodiments described herein.

[Synthesis example]

The round bottom flask was placed in a spin bar and stirred, and 100 g of 2,2-bis(hydroxymethyl)propionic acid was dissolved in 500 ml of acetone, and then added. 116 g of 2,2-dimethoxy propane was dissolved. The mixture thus obtained was continuously stirred while 7 g of p-toluene sulfonic acid (p-TSA) as an acid catalyst was added to the solution, and stirred at normal temperature for 3 hours. After confirming the completion of the reaction by nuclear magnetic resonance (NMR), the obtained reactant was subjected to distillation under reduced pressure to remove acetone as a solvent, and the thus obtained reactant was dissolved in dichloromethane, and 10 ml of ammonium hydroxide was added thereto. (NH ₄ OH, 35 wt%), p-TSA was removed.

After the obtained reactant was washed three times with distilled water, the organic layer was collected and subjected to distillation under reduced pressure to obtain the objective compound - trimethyl dioxane carboxylic acid (i) (110 g, in the above reaction formula, Yield: 63%).

The structure of the obtained compound was confirmed by 1H NMR, and the results are shown in Fig. 1.

1H NMR (CDCl ₃ , internal standard: tetramethyl decane): (ppm) 1.20 (s, 3H), 1.4 (2s, 6H), 3.6 (d, 2H), 4.2 (d, 2H)

[Example 1]

step 1

50 g of the trimethyldioxanecarboxylic acid (i) prepared in the synthesis example 1 was dissolved in 250 ml of tetrahydrofuran (THF), and the prepared solution was stirred at normal temperature, and 46 g of carbonyldiimidazole (carbonyl) was slowly added. After diiamidazole (ii), it was stirred at normal temperature for 4 hours. At this time, the generation of carbon dioxide gas was confirmed with the naked eye. The progress of the reaction of the obtained reactant was confirmed by 1H NMR, and the results are shown in Fig. 2. For the reaction of the step 2, the reaction of the next step was carried out without confirming the conversion of the compound (iii) without work up.

1H NMR (CDCl ₃ , internal standard: tetramethyl decane): (ppm) 1.4 (s, 3H), 1.5 (2s, 6H), 3.8 (d, 2H), 4.3 (d, 2H), 7.0 (s, 1H), 7.6 (s, 1H), 8.3 (s, 1H)

Step 2

Addition to the mixed solution (comprising compound (iii) and imidazole) completed in the above step 1 a solution prepared by dissolving sodium 1,1-difluoromethyl-2-hydroxy-ethanesulfonic acid (iv) in water to form a bath (bath) After the temperature was raised to 75 ° C, stirring and commutation were carried out for 4 hours. The degree of progress of the reaction of the obtained reactant was confirmed by 1H NMR (conversion rate (95%) converted to the compound (v) was confirmed by 1H NMR), and the results are shown in Fig. 3.

1H NMR (CDCl ₃ , internal standard: tetramethyl decane): (ppm) 1.4 (s, 3H), 1.5 (2s, 6H), 3.8 (d, 2H), 4.3 (d, 2H), 4.8 (t, 2H)

Step 3

The reaction solution (containing the compound (v) and imidazole) obtained in the above step 2 was subjected to distillation under reduced pressure, and the THF was removed and dissolved again in distilled water. To the solution thus obtained, a solution prepared by dissolving triphenylsulfofyltrifluoromethane sulfate (vi) in dichloromethane was added, followed by vigorous stirring for 2 hours. The degree of substitution of the anion and the completion of the reaction were confirmed by 19F NMR. After the organic layer was separated from the reaction material in which the reaction was completed, it was washed three times with distilled water, and the organic layer was collected and distilled under reduced pressure to obtain a solid powder (vii).

The structure of the obtained solid powder was confirmed by 1H NMR, and the results are shown in Fig. 4.

1H NMR (CDCl ₃ , internal standard: tetramethyl decane): (ppm) 1.2 (s, 3H), 1.4 (2s, 6H), 3.6 (d, 2H), 4.2 (d, 2H), 4.8 (t, 2H), 7.7 (m, 15H)

Experimental example 1

Forming a resist pattern using the photo-acid generator prepared in the above Example 1, and then The prepared resist pattern was subjected to various evaluations.

Specifically, a compound represented by the following Chemical Formula 13 as a raw material resin (Mw: 8500 g/mol, Mw/Mn: 1.75, and molar ratio (x: y: z: w) of each repeating unit is 1:1:1). : 1) 100 parts by weight, respectively, 0.5 parts by weight, 1 part by weight or 1.5 parts by weight of the compound as the photoacid generator prepared in the above Example 1, and 0.5 parts by weight of tetramethylhydrogen as a basic additive The tetramethyl ammonium hydroxide was dissolved in 1000 parts by weight of propylene glycol monoethyl ether acetate (PGMEA), and then filtered through a 0.2 μm membrane filter to prepare a resist corresponding to the photoacid generator content. Composition (Preparation Example 1, Preparation Example 2, and Preparation Example 3).

The obtained resist composition was applied onto a substrate by a spiner, and dried at 110 ° C for 90 seconds to form a film having a thickness of 0.20 μm. The formed film was exposed to light using an ArF excimer laser stepper (prism numerical aperture: 0.78), and then heat-treated at 110 ° C for 90 seconds. Next, development was carried out for 40 seconds using a 2.38 wt% aqueous solution of tetramethylammonium hydroxide, followed by washing and drying to form a resist pattern.

Various evaluations were made on the prepared resist pattern, and the results were shown below. in FIG. 1.

The photosensitivity in Table 1 below is the exposure amount formed by the line width and pitch (L/S) pattern of 0.10 μm formed after development at a line width of 1 to 1, which is the optimum exposure amount, and the exposure amount is In the case of photosensitivity, the size of the smallest pattern of development is taken as the resolution.

Further, for the line width roughness (LWR), the line width and the pitch (L/S) pattern thickness of 0.10 μm formed after development were observed, and the LWR was measured (the smaller the value, the LWR) The more excellent).

As shown in Table 1, the resist compositions of Preparation Examples 1 to 3 exhibited improved characteristics in terms of resolution and LWR with respect to the resist composition of the comparative example. On the contrary, the characteristics of the resist lower than that of the comparative example were exhibited in terms of photosensitivity. This low sensitivity is caused by the slower rate of acid diffusion. However, a more excellent LWR can be obtained by a slower acid diffusion rate.

Experimental example 2

The diffusion rate of the acid formed after exposure by the resist of the photo-acid generator prepared in the above Example 1 at the time of pattern formation was measured by a modified Fick's equation. At this time, for comparison, a photoacid generator containing adamantyl group as a bulky functional group in the anion portion was determined by the same method - triphenylphosphonnadamanecarboxylic acid-2,2-difluoro-2-sulfonic acid The rate of acid diffusion of triphenylsulfonium adamantane carboxylic acid-2, 2-difluoro-2-sulfo ethyl ester.

As a result of the measurement, the acid diffusion rate of the photoacid generator of Example 1 was 15.6 nm ² /sec, and the rate of diffusion of the acid as a photoacid generator for comparison was 33.1 nm ² /sec.

As described above, the photoacid generator of the present invention exhibits a slower acid diffusion rate although its anion is remarkably small, and as a result, it is predicted that a more excellent LWR can be exhibited when a resist pattern is formed.

The preferred embodiments of the present invention have been described in detail above, but the scope of the present invention is not limited thereto, and various modifications and improvements of the basic concepts of the present invention as defined in the appended claims are also included. The scope of the patent application of the invention.

Claims (10)

A photoacid generator of the following chemical formula 1: In the chemical formula 1, Q ₁ and Q ₁ ' are each independently a halogen group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen group; and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ; V ₁ and V ₂ are each independently an oxygen atom (O); W ₁ and W ₂ are each independently selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, and carbon. a group consisting of an aryl group having 3 to 30 atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; X is selected from the group consisting of an alkyl group, an alkenyl group, NR', S, O, In the group consisting of CO and a combination thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is an integer of 1 to 4, b is an integer of 0 to 5, and c is 1 to 3 An integer, d is an integer from 1 to 3; A+ is an organic counterion. The photoacid generator according to claim 1, wherein X is a carbonyl group. The photoacid generator according to claim 1, wherein Q ₁ and Q ₁ ' are each independently a fluorine group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a fluorine group; and R is a hydrogen atom. Or methyl; V ₁ and V ₂ are each independently an oxygen atom; W ₁ and W ₂ are each independently selected from the group consisting of methyl, ethyl, cyclopropyl, phenyl, methoxy and ethoxy. In the group; X is a carbonyl group; a is an integer from 1 to 3, b is an integer from 0 to 2, c is an integer of 1 or 2, and d is an integer of 1 or 2. The photoacid generator according to claim 1, wherein the anion moiety in the chemical formula 1 is selected from the group consisting of the following chemical formula 2a to chemical formula 2e: The photoacid generator according to claim 1, wherein A+ is an organic counter ion selected from the group consisting of sulfoniums and iodoniums. The photoacid generator according to claim 1, wherein A+ is an organic counter ion represented by the following Chemical Formula 3a or Chemical Formula 3b, [Chemical Formula 3b] In the chemical formula 3a and the chemical formula 3b, X ₁ , X ₂ , Y ₁ and Y ₂ are each independently selected from a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a benzyl group, and 6 carbon atoms. Any one of the group consisting of aryl groups of -30 and combinations thereof, X ₁ and X ₂ and Y ₁ and Y ₂ may be bonded to each other to form a saturated or unsaturated hydrocarbon ring having 3 to 30 carbon atoms; ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ are each independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen group, and an alkoxy group having 1 to 30 carbon atoms. An aryl group having 6 to 30 carbon atoms, a thiophenoxy group, a thioalkoxy group having 1 to 30 carbon atoms, an alkoxycarbonylmethoxy group having 1 to 20 carbon atoms, and the like Combine any of the groups consisting of. The photoacid generator according to claim 1, wherein A+ is an organic counter ion having a structure represented by the following Chemical Formula 4a to Chemical Formula 4v: A method for producing a photoacid generator of the following Chemical Formula 1, which comprises the steps of: reacting a compound of the following Chemical Formula 7 with a group selected from the group consisting of carbonyldiimidazole, N-halobutylimine, potassium iodide, sulfoxide, and a step of preparing a compound of the following chemical formula 9 by reacting a compound in a group consisting of the mixture thereof; and a step of preparing a compound of the following chemical formula 11 by reacting the compound of the chemical formula 9 prepared as described above with the compound of the following chemical formula 10; And a step of reacting the compound of Chemical Formula 11 prepared as described above with the compound of the following Chemical Formula 12, [Chemical Formula 10] [Chemical Formula 12] A + Z - In Chemical Formula 1 and Chemical Formula 7, Chemical Formula 9 to Chemical Formula 12, Q ₁ and Q ₁ ' are each independently a halogen group; and Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen. R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; V ₁ and V ₂ are each independently an oxygen atom (O); and W ₁ and W ₂ are each independently selected from a carbon number of 1 to 10 a group consisting of an alkyl group, a cycloalkyl group having 3 to 30 carbon atoms, an aryl group having 3 to 30 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; X In the group consisting of a free alkyl group, an alkenyl group, NR', S, O, CO, and a combination thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is 1 to An integer of 4, b is an integer from 0 to 5, c is an integer from 1 to 3, d is an integer from 1 to 3; A+ is an organic counter ion; M+ is selected from the group consisting of Li+, Na+, and K+ Any one; Q _{3 is} selected from the group consisting of imidazolyl, fluorine, chlorine, bromine and iodine; Z- is selected from (OSO ₂ CF ₃ )-, (OSO ₂ C ₄ F ₉ )-, (OSO ₂ C ₈ F ₁₇ )-, (N(CF ₃ ) ₂ )-, (N(C ₂ F ₅ ) ₂ )-, (N(C ₄ F ₉ ) ₂ )-, (C(CF ₃ ) ₃ ) -, (C(C ₂ F ₅ ) ₃ )-, (C(C ₄ F ₉ ) ₃ )-, F-, Cl-, Br-, I-, BF ₄ -, AsF ₆ - and PF ₆ - Any of the grouped groups. a photoacid compound of the following chemical formula 11, In the formula 11, Q ₁ and Q ₁ ' are each independently a halogen group; Q ₂ and Q ₂ ' are each independently a hydrogen atom or a halogen group; and R is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; ; V ₁ and V ₂ are each independently an oxygen atom (O); W ₁ and W ₂ are each independently selected from an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, and carbon. a group consisting of an aryl group having 3 to 30 atoms, an alkoxy group having 1 to 10 carbon atoms, and a combination thereof; X is selected from the group consisting of an alkyl group, an alkenyl group, NR', S, O, In the group consisting of CO and a combination thereof, R' is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms; a is an integer of 1 to 4, b is an integer of 0 to 5, and c is 1 to 3 An integer, d is an integer from 1 to 3; M+ is any one selected from the group consisting of Li+, Na+, and K+. A resist composition comprising the photoacid generator according to any one of claims 1 to 7.