KR101361623B1 - Photoacid generator and resist composition comprising same - Google Patents

Abstract

The present invention relates to a photoacid generator represented by chemical formula 1 and resist composition including the same, wherein the photoacid generator can reduce line edge roughness at the boundary of a non-exposure interface and an exposure interface by controlling the diffusion of acid to a non-exposure area from an exposure area during the formation of a resist film. In chemical formula 1, each substituent is the same as that defined in the specification.

Description

[0001] PHOTOACID GENERATOR AND RESIST COMPOSITION COMPRISING SAME [0002]

The present invention relates to a novel photoacid generator that can reduce line edge roughness at an unexposed interface and an exposure interface by controlling acid diffusion from an exposed area to a non-exposed area when forming a resist film, and a resist composition comprising the same. will be.

The chemically amplified positive resist composition used in semiconductor microfabrication including a lithography process contains a photoacid generator comprising a compound that generates an acid by irradiation of light.

The onium salt mainly used as the photoacid generator has a cation side degraded into a radical form to exist as a molecule of another type, and an anion side generates an acid to cause diffusion on the resist film during baking of the wafer after irradiation. do. In this process, the photoacid generator can be used to absorb light, acid generation efficiency due to light absorption, acid diffusion ability in anions, acid strength of anions, and so on. It will have a direct impact on roughness.

Recently, lithography technology is actively progressing high volumn manufacturing (HVM) by ArF immersion (liquid immersion lithography) technology, and the development of technology for implementing line widths of 50 nm or less is being progressed. As the line width to be realized becomes narrower, it is possible to obtain a high resolution for resist, sufficient margin (energy margin, focus margin) to be applied to the process, and sufficient resistance to etch due to the decrease in the line width and the thickness thereof. Physical properties are required, and in particular, improvement of the line edge roughness characteristics is required.

The line edge roughness means the uniformity of the interface between the exposure area and the non-exposure area. Recently, the roughness in the ArF liquid immersion exposure method is required to be about 2 to 3 nm in precision.

The factors affecting such line edge roughness are various, but among them, the photoacid generator is considered to be the main factor because it affects the acid diffusion distance and acid strength during exposure after exposure to acid or during PEB. Accordingly, studies to obtain good line edge roughness characteristics by controlling acid diffusion of photoacid generators have been mainly conducted. In addition, it is known that roughness due to the diffusion of acid in the border region of non-exposure / exposure can be reduced when the acid diffusion is slower than when the diffusion of acid is faster. Therefore, as a method for reducing acid diffusion, And the diffusion is controlled when the acid is generated.

Patent Document 1: Korean Patent Publication No. 2010-0014433 (published on August 26, 2010) Patent Document 2: Korean Patent Publication No. 2006-0030950 (published on October 13, 2006) Patent Document 3: Korean Patent Laid-Open Publication No. 2010-7022640 (published on December 22, 2010) Patent Document 4: Korean Patent Laid-Open No. 2010-0051591 (Published Dec. 24, 2011)

It is an object of the present invention to prevent diffusion of acid from an exposed area to an unexposed area when forming a resist film, thereby reducing line edge roughness at the non-exposed interface and exposure interface. "").

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 a structure represented by the following Formula 1:

[Formula 1]

In 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.

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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,

Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, c is an integer of 1 to 3, and d is an integer of 1 to 3, and

A + is an organic counterion.

Preferably, in Chemical Formula 1, X is a carbonyl group (CO).

More preferably, in Formula 1, Q ₁ and Q ₁ ′ are each independently a fluoro group, Q ₂ and Q ₂ ′ are each independently a hydrogen atom or a fluoro group, and R is a hydrogen atom or a methyl group. Wherein V ₁ and V ₂ are each independently an oxygen atom or a sulfur atom, and W ₁ and W ₂ are each independently selected from the group consisting of a methyl group, an ethyl group, a cyclopropyl group, a phenyl group, a methoxy group and an ethoxy group X is a carbonyl group, and a is an integer of 1 to 3, b is an integer of 0 to 2, c is an integer of 1 or 2, and d may be an integer of 1 or 2.

More preferably, the anion moiety in Formula 1 may be selected from the group consisting of the following Formulas 2a to 2f:

(2a)

(2b)

[Chemical Formula 2c]

(2d)

[Formula 2e]

(2f)

Also preferably, in Formula 1, A + may be an organic counterion selected from the group consisting of sulfonium-based, iodonium-based, phosphonium-based, diazonium-based, pyridinium-based, and imide-based compounds, more preferably A + May be an organic counterion represented by Formula 3a or 3b:

[Chemical Formula 3]

(3b)

In Chemical Formulas 3a and 3b,

X ₁ , X ₂ , Y ₁ and Y ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, a perfluoroalkyl group having 1 to 10 carbon atoms, a benzyl group, an aryl group having 6 to 30 carbon atoms, And X ₁ and X ₂ , and Y ₁ and Y ₂ may combine with each other to form a saturated or unsaturated hydrocarbon ring having 3 to 30 carbon atoms, and

X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen group, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, Thiophenoxy group, thioalkoxy group having 1 to 30 carbon atoms, alkoxycarbonylmethoxy group having 1 to 20 carbon atoms, and combinations thereof.

Even more preferably, A + may be an organic counterion having a structure represented by Formulas 4a to 4v:

According to another embodiment of the present invention, the compound of formula 7 is carbonyl diimidazole (carbonyl diimidazole), N-halosuccinic imide (N-halosuccinic imide), potassium iodide (potassium iodide), thi Preparing a compound of Chemical Formula 9 by reacting with a compound selected from the group consisting of onyl chloride and mixtures thereof; Preparing a compound of formula 11 by reacting the compound of formula 9 prepared above with a compound of formula 10; In addition, it provides a method for producing a photoacid generator of Formula 1 comprising the step of reacting the compound of Formula 11 prepared above with a compound of Formula 12:

[Formula 7]

[Chemical Formula 9]

[Formula 10]

[Formula 11]

[Chemical Formula 12]

In Chemical Formulas 7 to 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 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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,

Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, c is an integer of 1 to 3, and d is an integer of 1 to 3,

A + is an organic counterion,

M + is any one selected from the group consisting of Li +, Na + and K +,

Q ₃ is selected from the group consisting of imidazolyl, fluoro, chloro, bromo and iodo, and

Z- is (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 -are any one selected from the group consisting of.

According to another embodiment of the present invention there is provided a compound of formula 11:

 [Formula 11]

In the above 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.

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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,

Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, 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 +.

According to another embodiment of the present invention, there is provided a resist composition comprising the photoacid generator.

Other details of the embodiments of the present invention are included in the following detailed description.

The photoacid generator according to the present invention can reduce the line edge roughness at the non-exposed interface and the exposure interface by preventing the diffusion of acid from the exposed area to the non-exposed area when forming the resist film.

1 is a graph showing the 1H NMR observation results for the trimethyl dioxane carboxylic acid (i) prepared in Synthesis Example 1.
2 is a graph showing the 1H NMR observation results for the compound (iii) prepared in Step 1 of Example 1.
3 is a graph showing the results of 1 H NMR observation for the compound (v) prepared in Step 2 of Example 1. FIG.
4 is a graph showing the results of 1 H NMR observation for the compound (vii) in the solid phase prepared in Step 3 of Example 1. FIG.

Hereinafter, embodiments of the present invention will be described in detail. However, this is presented as an example, by which the present invention is not limited and the present invention is defined only by the scope of the claims to be described later.

Unless otherwise specified herein, the term "halogen group" means any one selected from the group consisting of fluorine, chloro, bromo, and isoiodo.

Unless otherwise specified herein, the term "alkyl group" means an alkyl group having 1 to 30 carbon atoms, which is linear or branched, 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, but are not limited to, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group and a t-butyl group.

Unless otherwise specified, the term "cycloalkyl group" means a cycloalkyl group having 3 to 30 carbon atoms, and includes a monocyclic, bicyclic, tricyclic, and sicyclic group. Further, it includes a polycyclic cycloalkyl group containing an adamantyl group, a norbornyl group, and a norbornyl group.

Unless otherwise specified herein, an "aryl group" means a compound including a benzene ring and derivatives thereof, for example, two or more benzene rings, such as toluene or xylene having an alkyl side chain attached to a benzene ring, , Naphthalene or anthracene condensed with two or more benzene rings such as fluorene, xanthene, or anthraquinone in which two or more benzene rings are bonded through a cycloalkyl group or a heterocycloalkyl group, and the like. Unless otherwise specified in the specification, the aryl group means an aryl group having 6 to 30 carbon atoms.

In the present specification, all the compounds or substituents may be substituted or unsubstituted unless otherwise specified. The term "substituted" as used herein refers to a group in which hydrogen is replaced by 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, Means a substituted one selected from the group consisting of an acyl group, an acyl group, an aldehyde group, a cycloalkyl group, a heterocycle group, an allyl group, an aryl group, a derivative thereof, and a combination thereof.

In the present specification, "a combination thereof" means that two or more substituents are bonded to each other through a single bond or a linking group, or two or more substituents are condensed and connected to each other.

According to the present invention, unlike the conventional photoacid generators, which rely on the size of the anion to reduce roughness due to the diffusion of acid in the non-exposure and exposure regions, alcohols are partially decomposed by the acid generated after irradiation. The group is produced, and the line roughness is reduced by remarkably reducing the diffusion of the acid by the hydrogen bonding of the alcohol group and the acid.

That is, the photoacid generator according to the embodiment of the present invention may be represented by the following Chemical Formula 1:

[Formula 1]

In the anion moiety of Formula 1,

Q ₁ and Q ₁ ′ may be each independently a halogen group, preferably each independently a fluoro group.

Q ₂ and Q ₂ ′ may each independently be a hydrogen atom or a halogen group, preferably each independently may be a hydrogen atom or a fluoro group.

The R may be a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, preferably a hydrogen atom or a methyl group.

V ₁ and V ₂ may be each independently an oxygen atom (O) or a sulfur atom (S), preferably an oxygen atom.

W ₁ and W ₂ are each independently selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 It may be, preferably each independently may be selected from the group consisting of methyl group, ethyl group, cyclopropyl group, phenyl group, methoxy group and ethoxy group.

X may be any one selected from the group consisting of alkanediyl, alkenediyl, NR ′, S, O, CO, and a combination thereof, wherein R ′ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Preferably, X is a carbonyl group (CO).

A is an integer of 1 to 4, b is an integer of 0 to 5, c is an integer of 1 to 3, and d may be an integer of 1 to 3, B is an integer of 0 to 2, c is an integer of 1 or 2, and d may be an integer of 1 or 2.

Preferably, the anion moiety of Formula 1a in Formula 1 may be selected from the group consisting of Formulas 2a to 2f:

[Formula 1a]

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

(2a) (2b) (2c)

(2d) (2e) (2f)

On the other hand, in the cation part of the above formula (1), A is an organic counter ion, specifically, a cation selected from the group consisting of a sulfonium type, an iodonium type, a phosphonium type, a diazonium type, a pyridinium type, .

When A + is a sulfonium-based organic counterion, it may be preferable that A + is an organic cation represented by the following Chemical Formula 3a or 3b:

[Chemical Formula 3]

(3b)

In Chemical Formulas 3a and 3b,

X ₁ , X ₂ , Y ₁ and Y ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, a perfluoroalkyl group having 1 to 10 carbon atoms, a benzyl group, an aryl group having 6 to 30 carbon atoms, And X ₁ and X ₂ , and Y ₁ and Y ₂ may combine with each other to form a saturated or unsaturated hydrocarbon ring having 3 to 30 carbon atoms, and

X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen group, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, Thiophenoxy group, thioalkoxy group having 1 to 30 carbon atoms, alkoxycarbonylmethoxy group having 1 to 20 carbon atoms, and combinations thereof.

More preferably, A + may be an organic counterion having a structure represented by Formulas 4a to 4v:

In addition, when A is an iodonium-based organic counterion, it may be preferable that A + is an organic cation represented by Formula 5a or 5b:

[Chemical Formula 5a]

[Chemical Formula 5b]

In the above formulas (5a) and (5b)

R ₁₁ to R ₁₃ and R ₂₁ to R ₂₃ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, a perfluoroalkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 30 carbon atoms, and a combination thereof It may be any one selected from the group consisting of,

R ₁₄ and R ₂₄ are each independently a halogen group, an alkyl group having 1 to 30 carbon atoms, 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, It may be any one selected from the group consisting of alkoxycarbonylmethoxy group having 1 to 20 carbon atoms and combinations thereof.

More preferably, A + may be an organic counterion having a structure represented by the following Chemical Formulas 6a to 6i:

Of the above organic counterions, sulfone based organic counter ions are even more preferred.

Photoacid generator according to an embodiment of the present invention having the structure as described above is a compound of formula (7), carbonyl diimidazole of formula (8a), N-halosuccinic imide of formula (8b) (N-halosuccinic imide), potassium iodide of formula (8c), thionyl chloride of formula (8d), and mixtures thereof to react with a compound selected from the group consisting of Preparing (step 1); Preparing a compound of formula 11 by reacting the compound of formula 9 prepared above with a compound of formula 10 (step 2); In addition, the compound of Chemical Formula 11 prepared in the step may be prepared by a method comprising the step of preparing a compound of Chemical Formula 1 by following the reaction of the compound of Chemical Formula 12 (Step 3):

[Formula 1]

[Formula 7]

[Chemical Formula 8a]

[Formula 8b]

[Chemical Formula 8c]

[Chemical Formula 8d]

[Chemical Formula 9]

[Formula 10]

[Formula 11]

[Chemical Formula 12]

In Formulas 1 and 7 to 12, 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 same as defined above. and,

M + is any one selected from the group consisting of Li +, Na +, and K +

Q ₃ is a functional group derived from a compound of Formulas 8a to 8d, and is specifically selected from the group consisting of imidazolyl group, fluoro, chloro, bromo and iodo,

Y is a halogen group selected from the group consisting of fluoro, chloro, bromo and iodo,

Z- is (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 -are any one selected from the group consisting of.

The following scheme shows a reaction step for the preparation of a photoacid generator according to an embodiment of the present invention. Scheme 1 below is only an example for describing the present invention, and the present invention is not limited thereto.

[Reaction Scheme 1]

Substituents in each compound in Scheme 1 are the same as defined above.

Hereinafter, with reference to Scheme 1 will be described in detail for each step.

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

The compound of Formula 7 may be obtained commercially, or may be prepared according to a known method. Specifically, as shown in Scheme 2, a dihydroxy compound (13) such as (2,2-bis (hydroxymethyl) propionic acid) or the like is selected from p-toluene sulfonic acid. (7a) by reacting with a dialkoxy alkane compound (14) such as 2,2-dimethoxy propane under an acid catalyst such as (p-toluene sulfonic acid, p-TSA). ) Can be prepared.

[Reaction Scheme 2]

Specifically, as the compound of Formula 7, trimethyl dioxane carboxylic acid may be used.

In addition, N-halosuccinic imide, such as N-bromosuccinic imide, potassium iodide in place of the carbonyl diimidazole of Formula 8a in step 1 of Scheme 1 (potassium iodide), thionyl chloride or mixtures thereof may be used.

In the reaction of Step 1, the compound of Formula 8a to 8d, which may react with the compound of Formula 7, is preferably reacted in a molar ratio of 1: 1 to 1: 1.2 in terms of purification and yield improvement.

The reaction of step 1 may be carried out in a solvent such as tetrahydrofuran (THF) and the like.

Carbon dioxide gas is generated during the reaction in step 1, and the compound of formula 9 is included together with imidazole in the reactant obtained as a result of the reaction. Accordingly, the resultant reactant may be subjected to additional separation and purification steps in a conventional manner to separate the compound of formula 9, and the reaction product of step 1 may be used for the reaction of the next step without any separate separation step. It may be.

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

Specifically, the compound of Formula 10 is 1,1-difluoromethyl-2-hydroxy-ethane sulfonic acid (1,1-difluoromethyl-2-hydroxy-ethanesulfonic acid), 1,1-difluoromethyl-2 Hydroxy-propane sulfonic acid (1,1-difluoromethyl-2-hydroxy-propanesulfonic acid), or 1,1-difluoromethyl-2-hydroxy-butane sulfonic acid (1,1-difluoromethyl-2-hydroxy-butanesulfonic lithium salts such as acid), sodium or sodium salts may be used.

The reaction of step 2 may be carried out in a solvent, wherein any one selected from the group consisting of esters, ethers, lactones, ketones, amides, alcohols and combinations thereof may be used. Preferably, the solvent may be any one selected from the group consisting of dichloromethane, chloroform, dichloroethane, acetonitrile, toluene, and combinations thereof.

It is preferable that the compound of Formula 9 and the compound of Formula 10 react with each other in a molar ratio of 1: 1 to 1: 1.2.

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

Specifically, as the compound of Formula 12, triphenylsulfonium triflate, diphenyl alkylphenyl sulfonium triflate, triphenyl sulfonium chloride, and the like may be used.

In the reaction of Step 3, reacting the compound of Formula 11 and the compound of Formula 12 in a molar ratio of 1: 1 to 1: 2 may minimize reaction treatment time and suppress side reactions due to excessive use of reactants. It is preferable that the compound of formula 1 can be prepared in a high yield.

The substitution reaction may be a method of solidifying and recovering by using a recrystallization method or a mixture of a solvent (good solvent) that dissolves well with a solvent (poor solvent) that does not dissolve well. The method can also be used.

Preferably, the solution may be dissolved in dichloromethane and water to form two layers, followed by stirring to cause a substitution reaction. The use of this two-layer reaction method is advantageous in that no additional method for separation of the product is required. The stirring may be performed for 2 to 6 hours, or for 2 to 4 hours. When the reaction is carried out within the time range described above, the effect of the present invention can be maximized.

When the compound represented by Chemical Formula 1 is prepared through the above process, the compound represented by Chemical Formula 1 may be prepared in an efficient and simple manner.

The photoacid generator of Formula 1 prepared by the above manufacturing method, when applied to the resist composition, when the light is sufficiently irradiated, acid is generated and acid diffuses rapidly, but as the acid-containing anions are decomposed by these acids, 1 Two alcohol groups are generated per molecule, and the generated alcohol groups reduce acid diffusion by hydrogen bonding with other acids. As a result, the penetration of acid from the exposed area to the non-exposed area is prevented, thereby maximizing the effect of reducing line etch roughness.

The following Reaction Scheme 3 schematically shows the acid diffusion reduction effect of the photoacid generator according to the present invention upon exposure. The present invention is not limited thereto.

Scheme 3

For example, when using the compound A as a resist composition according to the present invention, when the photoion is decomposed by light irradiation, the anion forms an acid such as B. The produced acid B undergoes diffusion of acid B when PEB (post exposure baking) is performed in the lithography process, and the diffusion rate is relatively high at an early stage. The dioxane group is decomposed to form a diol such as C in an anion containing an acid. At this time, the diffusion of acid is abruptly reduced by hydrogen bonding of diol, and it prevents the diffusion of acid from the exposure area to the non-exposure area, thereby reducing the line edge roughness at the non-exposure / exposure interface.

Accordingly, according to another embodiment of the present invention, a resist composition comprising the photoacid generator is provided.

Specifically, the resist composition includes the photoacid generator, the base copolymer and the solvent.

The photoacid generators are the same as those described above, and may be used alone or in combination of two or more. The acid generator may be included in an amount of 0.3 to 15 parts by weight, preferably 0.5 to 10 parts by weight, more preferably 2 to 10 parts by weight, based on 100 parts by weight of the polymer solid content. When the content of the acid generator is more than 15 parts by weight, the perpendicularity of the pattern is remarkably decreased. When the content of the acid generator is less than 0.3 parts by weight, the flexibility of the pattern may be lowered.

The base copolymer for resist can be used without any particular limitation as long as it is used as a base resin at the time of forming a resist film. Specific examples thereof include polymers obtained by a ring-opening metathesis reaction of a (meth) acrylic acid ester polymer, (? -Trifluoromethyl) acrylic acid ester-maleic anhydride copolymer, cycloolefin-maleic anhydride copolymer, polynorbornene and cycloolefin (Meth) acrylic acid ester derivatives, styrene, vinylnaphthalene, vinyl anthracene, vinyl pyrene, hydroxyvinyl naphthalene, hydroxyvinyl (meth) acrylate, and the like. A polymer compound obtained by copolymerizing any one of anthracene, indene, hydroxyindene, acenaphthylene, and norbornadiene, a novolak resin, and a mixture thereof.

The base copolymer may be contained in an amount of 3 to 20% by weight based on the total weight of the resist composition. If the content of the polymer is less than 3% by weight, the viscosity of the composition becomes too low to form a film having a desired thickness, and there is a problem that the pattern loss is increased by a relatively large amount of the photoacid generator. If the weight% is exceeded, the thickness of the film becomes too thick, the transmittance of the radiation becomes poor, and it is difficult to obtain a vertical pattern.

In order to obtain a uniform and flat resist coating film, it is preferable to use the copolymer and the photoacid generator dissolved in a solvent having a suitable evaporation rate and viscosity. Examples of the solvent usable in the present invention include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, methyl cellosolve acetate, ethyl cellosolve acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether Esters such as acetate and propylene glycol monopropyl ether acetate; Ketones such as methyl isopropyl ketone, cyclohexanone, methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, 2-heptanone, ethyl lactate and gamma-butyrolactone. They may be used singly or in combination of two or more.

The amount of the solvent to be used can be appropriately controlled depending on the physical properties of the solvent, such as volatility, viscosity, etc., so that a uniform resist film can be formed.

In addition, the resist composition according to the present invention may further contain additives in accordance with the purpose of improving the coatability and the like.

As the additive, any additive which is usually applied to a resist composition can be used without any particular limitation, and specific examples thereof include an alkali dissolution inhibitor, an acid diffusion inhibitor, and a surfactant, and one kind or two or more kinds thereof .

The above-mentioned alkali dissolution inhibitor can be applied as long as it is an alkali dissolution inhibitor generally applied to a resist composition. Specific examples thereof include phenol and carboxylic acid derivatives.

The acid diffusion inhibitor acts to control the diffusion phenomenon when the acid generated from the photo-acid generator diffuses into the resist film by light irradiation and to suppress the chemical reaction in the unexposed area. By using such an acid diffusion inhibitor, it is possible to improve the storage stability of the radiation-sensitive resin composition and to further improve the resolution of the resist, and to improve the resolution of the resist pattern by changing the line width of the resist pattern The change can be suppressed.

Examples of such an acid diffusion inhibitor include basic compounds such as ammonia, methylamine, isopropylamine, n-hexylamine, cyclopentylamine, methylenediamine, ethylenediamine, dimethylamine, diisopropylamine, N, N ', N', N ', N'-tetramethylmethylenediamine, N, N'-dimethylethylenediamine, N, N-dimethylethylenediamine, trimethylamine, N, N, N ', N'-tetramethyltetraethylenepentamine, dimethylethylamine, methylethylpropylamine, benzylamine, phenethylamine, benzyldimethylamine, tetramethylammonium hydroxide Aniline, aniline, aniline, N, N-dimethyltoluidine triphenylamine, phenylenediamine, pyrrole, oxazole, isoxazole, thiazole, isothiazole, imidazole, pyrazole, pyrroline, pyrrolidine, imidazoline Derivatives, imidazolidine derivatives, pyridine derivatives, pyridazine derivatives Amines such as pyrimidine derivatives, pyrazine derivatives, pyrazoline derivatives, pyrazolidine derivatives, piperidine derivatives, piperazine derivatives and morpholine; (2-hydroxypyridine, 2-hydroxypyridine, aminocresol, 2,4-quinolinone, and the like) Diol, 2- (2-hydroxyethyl) pyridine, 1- (2-hydroxyethyl) piperazine; Amide derivatives such as formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide and benzamide; And imide derivatives such as phthalimide, succinimide and maleimide.

The acid diffusion inhibitor may be contained in an amount of 0.01 to 5 parts by weight, preferably 0.1 to 1 part by weight, based on 100 parts by weight of the polymer solid content. When the content of the acid diffusion inhibitor is less than 0.01 part by weight, the influence of the retardation after exposure is increased, which may affect the shape of the pattern. If the content is more than 5 parts by weight, the resolution and sensitivity may decrease.

Specific examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene, and polyethylene glycol dilaurate. However, the surfactant is not limited thereto. It is not.

The resist composition according to the present invention having such a composition as described above can be included as a photoacid generator having an acid diffusion inhibiting effect to reduce the line edge roughness due to the diffusion of acid in the border region of the non-exposure / exposure during the resist film formation .

Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

[ Synthetic example ]

Into a round bottom flask, spin bar was dissolved and 100 g of (2,2-bis (hydroxymethyl) propionic acid) was dissolved in 500 ml of acetone while stirring. 116 g of 2,2-dimethoxy propane was added to dissolve, and the resulting mixture was continuously added with 7 g of p-toluene sulfonic acid (p-TSA) as an acid catalyst with continuous stirring. After confirming the completion of the reaction by NMR, the resulting reaction was distilled under reduced pressure to remove acetone as a solvent, and the resulting reaction was dissolved in dichloromethane, followed by aqueous ammonia (NH). ₄ OH, 35 wt%) was added to remove p-TSA.

The resulting reaction was washed three times with distilled water, and then the organic layers were collected and distilled under reduced pressure to obtain trimethyl dioxane carboxylic acid (i), which is the target compound in the reaction scheme (110 g, yield: 63%).

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

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

[ Example  One]

Step 1

Carbonyl diimidazole (ii) was prepared by dissolving 50 g of trimethyl dioxane carboxylic acid (i) prepared in Synthesis Example 1 in 250 ml of tetrahydrofuran (THF) while stirring at room temperature. 46 g was slowly added dropwise and stirred at room temperature for 4 hours. At this time, the generation of carbon dioxide gas was visually confirmed. It was confirmed by 1 H NMR whether the reaction of the resulting reaction proceeds. The results are shown in Fig. For the two-step reaction, the conversion to compound (iii) was confirmed without work up, and the reaction of the next step was carried out.

¹ H NMR (CDCl ₃ , internal standard: tetramethylsilane): (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

Sodium salt of 1,1-difluoromethyl-2-hydroxy-ethane sulfonic acid (sodium 1,1-difluoromethyl-2) in the mixed solution (compound (iii) and imidazole) completed in step 1 After adding a solution prepared by dissolving -hydroxy-ethanesulfonic acid (iv) in water, the bath was heated to 75 ° C and stirred and refluxed for 4 hours. The progress of the reaction (confirmation of conversion (95%) to compound (v) by 1 H NMR) was confirmed using 1 H NMR for the resulting reaction product. The results are shown in Fig.

¹ H NMR (CDCl ₃ , internal standard: tetramethylsilane): (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 (compound (v) and imidazole) obtained in step 2 was distilled under reduced pressure to remove THF, and dissolved in distilled water again. To the resulting solution, a solution prepared by dissolving triphenylsulfonium triflate (vi) in dichloromethane was added and stirred vigorously for 2 hours. ¹⁹ F NMR was used to confirm the degree of substitution of the anion and the completion of the reaction. After the reaction was completed, the organic layer was separated, washed three times with distilled water, and the organic layers were collected and distilled under reduced pressure to obtain a solid powder (vii).

The obtained solid powder structure was confirmed using 1 H NMR. The results are shown in Fig.

¹ H NMR (CDCl ₃ , internal standard: tetramethylsilane): (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)

Test Example  One

After the resist pattern was formed using the photoacid generator prepared in Example 1, various evaluations were performed on the prepared resist pattern.

Specifically, as the base resin, the compound represented by the following formula (Mw: 8,500 g / mol, Mw / Mn: 1.75, and the molar ratio (x: y: z: w) of each repeating unit is 1: 1: 1: 1) 100 parts by weight, 0.5, 1 or 1.5 parts by weight of the compound prepared in Example 1 as a photoacid generator, and 0.5 parts by weight of tetramethyl ammonium hydroxide as basic additives are dissolved in 1,000 parts by weight of propylene glycol methyl ether acetate. After filtering with a 0.2um membrane filter to prepare a resist composition (preparation examples 1, 2 and 3) according to the content of the photoacid generator.

[Chemical Formula 13]

The resist composition thus obtained was applied to a substrate using a spinner and dried at 110 DEG C for 90 seconds to form a coating having a thickness of 0.20 mu m. The formed film was exposed using an ArF excimer laser stepper (lens numerical aperture: 0.78), and then heat-treated at 110 DEG C for 90 seconds. Then, the resist was developed, washed and dried with a 2.38 wt% tetramethylammonium hydroxide aqueous solution for 40 seconds to form a resist pattern.

Various evaluations were performed on the resist pattern thus prepared, and the results are shown in Table 1 below.

In Table 1 below, the exposure amount for forming a 0.10-μm line-and-space (L / S) pattern formed after development with a line width of 1: 1 is defined as an optimum exposure amount, and the optimum exposure amount is defined as sensitivity. Resolution.

Also, in the case of the line width roughness (LWR), the illuminance of the pattern was observed with respect to the 0.10um line-and-space (L / S) pattern formed after the development and the LWR was measured.

Photoacid generator Sensitivity
(mJ / cm ² ) resolution
(nm) LWR (mm) Production Example 1 Example 1
(0.5 parts by weight) 30 65 2.5 Production Example 2 Example 1
(1.0 parts by weight) 34 65 2.4 Production Example 3 Example 1
(1.5 parts by weight) 39 70 2.7 Comparative Example Triphenyl sulfonium triflate
(1.5 parts by weight) 15 75 3.0

As shown in Table 1, the resist compositions of Preparation Examples 1 to 3 exhibited improved properties compared to the resist compositions of Comparative Examples in terms of resolution and LWR. On the other hand, the sensitivity was lower than the resist of the comparative example, but this low sensitivity is due to the slow diffusion rate of the acid. However, due to the slow acid diffusion rate, better LWRs can be obtained.

Test Example  2

The diffusion rate of acid generated after exposure in forming a resist pattern using the photoacid generator prepared in Example 1 was measured using a Modified Fick's equation. At this time, triphenylsulfonium adamantane carboxylic acid 2,2-difluoro-2-sulfoethyl ester (triphenylsulfonium adamantane), a photoacid generator containing an adamantane group as a bulky functional group in the anion portion of the photoacid generator, for comparison The acid diffusion rate was also measured for the carboxylic acid 2,2-difluoro-2-sulo ethyl ester).

As a result, the acid diffusion rate of the photoacid generator of Example 1 was 15.6 nm ² / sec, while the acid diffusion rate of the photoacid generator used in comparison was 33.1 nm ² / sec.

As described above, the photoacid generator according to the present invention exhibited a slower acid diffusion rate even though the size of the anion part was much smaller, and it can be expected from this result that the LWR can be improved.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of right.

Claims (10)

A photo acid generator represented by the following formula (1)
[Chemical Formula 1]

In 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.
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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,
Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, c is an integer of 1 to 3, and d is an integer of 1 to 3, and
A is an organic counterion. The method of claim 1,
And X is a carbonyl group. The method of claim 1,
Q ₁ and Q ₁ ′ are each independently a fluoro group,
Q ₂ and Q ₂ ′ are each independently a hydrogen atom or a fluoro group,
R is a hydrogen atom or a methyl group,
V ₁ and V ₂ are each independently an oxygen atom or a sulfur atom,
W ₁ and W ₂ are each independently selected from the group consisting of methyl group, ethyl group, cyclopropyl group, phenyl group, methoxy group and ethoxy group,
X is a carbonyl group,
Wherein a is an integer of 1 to 3, b is an integer of 0 to 2, c is an integer of 1 or 2, and d is an integer of 1 or 2. The method of claim 1,
The anion moiety in Chemical Formula 1 is selected from the group consisting of the following Chemical Formulas 2a to 2f:
(2a)

(2b)

[Chemical Formula 2c]

(2d)

[Formula 2e]

(2f)

The method of claim 1,
Wherein A + is an organic counter ion selected from the group consisting of a sulfonium-based, iodonium-based, phosphonium-based, diazonium-based, pyridinium-based and imide-based. The method of claim 1,
A + is a photoacid generator which is an organic cation represented by the following Chemical Formula 3a or 3b:
[Chemical Formula 3]

(3b)

In Chemical Formulas 3a and 3b,
X ₁ , X ₂ , Y ₁ and Y ₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an allyl group, a perfluoroalkyl group having 1 to 10 carbon atoms, a benzyl group, an aryl group having 6 to 30 carbon atoms, And X ₁ and X ₂ , and Y ₁ and Y ₂ may combine with each other to form a saturated or unsaturated hydrocarbon ring having 3 to 30 carbon atoms, and
X ₃ , X ₄ , X ₅ , Y ₃ , Y ₄ and Y ₅ each independently represent a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a halogen group, an alkoxy group having 1 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, Thiophenoxy group, thioalkoxy group having 1 to 30 carbon atoms, alkoxycarbonylmethoxy group having 1 to 20 carbon atoms, and combinations thereof. The method of claim 1,
A + is a photoacid generator which is an organic counter ion having a structure represented by the following Chemical Formulas 4a to 4v:

To the compound of formula 7 carbonyl diimidazole (carbonyl diimidazole), N-halosuccinic imide (N-halosuccinic imide), potassium iodide (potassium iodide), thionyl chloride (thionyl chloride) and mixtures thereof Reacting with a compound selected from the group consisting of preparing a compound of Formula 9;
Preparing a compound of formula 11 by reacting the compound of formula 9 prepared above with a compound of formula 10; And,
Reacting the compound of Chemical Formula 11 prepared above with a compound of Chemical Formula 12
Method for producing a photoacid generator of the formula 1 comprising a:
[Chemical Formula 1]

(7)

[Chemical Formula 9]

[Formula 10]

(11)

[Chemical Formula 12]

In Chemical Formulas 1 and 7, 9 to 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 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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,
Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, c is an integer of 1 to 3, and d is an integer of 1 to 3,
A + is an organic counterion.
M + is any one selected from the group consisting of Li +, Na + and K +,
Q ₃ is selected from the group consisting of imidazolyl, fluoro, chloro, bromo and iodo
Z- is (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 -are any one selected from the group consisting of. A compound of formula (11)
(11)

In Chemical 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.
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 the group consisting of an alkyl group having 1 to 10 carbon atoms, 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 Will,
Wherein X is selected from the group consisting of alkandiyl, alkenediyl, NR ', S, O, CO and combinations thereof, wherein 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, c is an integer of 1 to 3, and d is an integer of 1 to 3, and
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.

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