TWI465418B - Compound, polymer comprising the compound, and chemically amplified resist composition comprising the polymer - Google Patents

Description

Compound, polymer containing the same, and chemically amplified photoresist composition containing the same

The present invention relates to a novel compound, a polymer containing the same, and a chemically amplified resist composition containing the same, which uses the compound and a polymer produced by polymerizing the compound as a monomer to make the composition uniform It is dispersed and suitable for forming a fine pattern having characteristics such as high adhesion, high sensitivity, and high thermal stability while reducing the amount of gas generated, and can improve resolution and line edge roughness. More particularly, the present invention relates to a novel compound useful for the manufacture of photoresists capable of using various radiations such as KrF excimer lasers, ArF excimer lasers and the like, far infrared radiation, X a pattern formed by radiation (such as synchrotron radiation) and charged particle radiation (such as electron beam), and thus can be used for micro-processing; a polymer obtained by polymerizing a compound as a monomer; and a chemically amplified light containing the polymer Blocking composition.

Since lithography used in the semiconductor industry and similar industries has recently been replaced by sub-50 nanotechnology, it is expected that new and improved technologies will emerge. Although lithography using far ultraviolet radiation is an important technique for such patterning, the technique of achieving a sub-32 nm pattern requires a very difficult process. The use of a 193 nm wavelength lithography technique is considered to be an important way to implement the technique of manufacturing a sub-32 nm pattern in the future, and this technique can be made possible by increasing the numerical aperture (NA).

According to Rayleigh's equation, the numerical aperture can be increased to increase the refractive index of the immersion fluid or immersion photoresist, and the resolution can be Increase at the same time. In addition, an increase in refractive index can increase the depth of focus (DOF).

R = (K1. λ ) / (NA), NA = n sin θ, R = resolution, λ = wavelength, NA = numerical aperture, n = refractive index, θ = angle of incidence.

There is a constant need to improve novel photoresist compositions such as resolution, sensitivity, refractive index, and line edge roughness (LER), and to increase the refractive index of the active photoresist and to obtain higher sensitivity photoresist Research on technology is already underway. However, the results of these studies are unsatisfactory in achieving a finer semiconductor integrated circuit, and there is a problem that the speed of light is lowered.

Furthermore, the demand for chemically amplified photoresist compositions with high resolution and low line edge roughness is increasing for the introduction of photoacid generators with higher sensitivity and higher stability while reducing gas emissions. .

It is an object of the present invention to provide novel compounds which can be used as photoacid generators or monomers in chemically amplified photoresists. Another object of the present invention is to provide a polymer containing the above compound as a monomer which can be used in a chemically amplified photoresist composition. The chemically amplified photoresist composition has excellent sensitivity and high stability while reducing gas emissions, and also has high resolution and low line edge roughness.

In order to achieve the above object, a compound of one aspect of the present invention is represented by the formula (1): In the formula (1), R ₁₁ represents a group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. Any one of Q ₁ and Q ₂ independently represents any one selected from the group consisting of a hydrogen atom and a halogen atom; and A ⁺ represents an organic counter ion.

Another aspect of the invention polymer comprises a repeating unit represented by formula (2): In the formula (2), R ₁₁ , R ₄₁ and R ₄₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkyl group having 1 to 10 carbon atoms. Any one selected from the group consisting of oxy groups; Q ₁ and Q ₂ each independently represent any one selected from the group consisting of a hydrogen atom and a halogen atom; and A ⁺ represents an organic counter ion.

The polymer may be a polymer represented by the following formula (3): Wherein in the formula (3), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ and R ₄₈ each independently represent a hydrogen atom, Any one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms; and Q ₁ and Q ₂ each independently represent hydrogen Any one selected from the group consisting of an atom and a halogen atom; R ₂₁ , R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an alkyl group, a heteroalkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, or a hetero group. Any one selected from the group consisting of aryl groups and combinations thereof; A ⁺ represents an organic counter ion; X represents a polymer unit derived from an olefin monomer; and l, m, n, o, and p are each in the following ranges: 0<l 0.4,0<m 0.5,0 n 0.5,0 o 0.5 and 0<p 0.2, while l+m+n+o+p=1.

The above polymer may have a weight average molecular weight of 2,000 to 100,000 and may have a molecular weight distribution of 1 to 5.

Another chemically amplified photoresist composition of the present invention comprises a polymer comprising a repeating unit of the formula (2).

The invention will be described in more detail below.

The terms used in the description of the present invention are defined as follows.

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

Unless otherwise specifically stated herein, examples of alkyl groups include primary alkyl, secondary alkyl, and tertiary alkyl.

Unless otherwise specifically stated herein, a perfluoroalkyl group means an alkyl group in which a part of a hydrogen atom or all hydrogen atoms are replaced by a fluorine atom.

Unless otherwise specifically stated herein, perfluoroalkoxy means a partial hydrogen atom or an alkoxy group in which all hydrogen atoms are replaced by a fluorine atom.

Unless otherwise specifically stated herein, all compounds and substituents may Substituted or unsubstituted. Herein, substituted means that the hydrogen atom has been replaced by any one selected from the group consisting of a halogen atom, a hydroxyl group, a carboxyl group, a cyano group, a nitro group, an amine group, a thio group, a methylthio group, and an alkyl group. Oxyl, nitrile, aldehyde, epoxy, ether, ester, carbonyl, acetal, keto, alkyl, perfluoroalkyl, cycloalkyl, heterocycloalkyl, allyl, benzene Methyl, aryl, heteroaryl, derivatives thereof, and combinations thereof.

Unless otherwise specifically stated herein, the word "hetero" means that a carbon atom is substituted with one or three heteroatoms selected from the group consisting of N, O, S, and P. For example, heteroalkyl means that one to three carbon atoms in the carbon atom of the alkyl group are substituted with a hetero atom.

Unless otherwise specifically stated herein, alkyl means a straight or branched alkyl group having 1 to 30 carbon atoms; heteroalkyl refers to a heteroalkyl group having 1 to 3 carbon atoms; and alkoxy means 1 to 10 carbon atoms. Alkoxy; perfluoroalkyl refers to a perfluoroalkyl group having 1 to 10 carbon atoms; perfluoroalkoxy refers to a perfluoroalkoxy group having 1 to 10 carbon atoms; and cycloalkyl refers to a cycloalkane having 3 to 32 carbon atoms. A heterocycloalkyl group means a heterocycloalkyl group having 2 to 32 carbon atoms; an aryl group means an aryl group having 6 to 30 carbon atoms; and a heteroaryl group means a heteroaryl group having 2 to 30 carbon atoms.

Unless otherwise specifically stated herein, examples of cycloalkyl groups include monocyclic, bicyclic, tricyclic, and tetracyclic cycloalkyl groups. Examples of cycloalkyl groups also include adamantyl, norbornyl, and polycyclic cycloalkyl groups containing norbornyl groups.

Unless otherwise specifically stated herein, aryl means a compound containing a benzene ring or a derivative thereof, and examples of the aryl group include toluene and xylene, wherein an alkyl side chain is bonded to a benzene ring; biphenyl, wherein two or more benzenes are present The ring is linked by a single bond; xanthene and anthracene, wherein two or more benzene rings are bonded by a cycloalkyl group or a heterocycloalkyl group; and naphthalene and an anthracene, wherein two or more benzene rings are combined.

Unless otherwise specifically stated herein, an olefin means an unsaturated hydrocarbon compound containing a double bond, and examples thereof include, but are not limited to, an olefin, an acrylate, a styrene, a norbornene, an indene, an anthracene, and a furandione. .

The compound of one aspect of the present invention is represented by the following formula (1).

In the formula (1), R ₁₁ represents a group selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. Any one of them may preferably be selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms; and Q ₁ and Q ₂ are each independently Any one selected from the group consisting of a hydrogen atom and a halogen atom, and preferably a fluorine atom; and A ⁺ represents an organic counter ion, which may preferably be represented by the following formula (5) or (6) Group: Wherein in the formula (5), R ₁ , R ₂ and R ₃ each independently represent a group selected from the group consisting of an alkyl group, a heteroalkyl group, a perfluoroalkyl group, an alkoxy group, an aryl group and a heteroaryl group; R ₄ -|-R ₅ (6) wherein R ₄ and R ₅ each independently represent a group consisting of an alkyl group, a heteroalkyl group, a perfluoroalkyl group, an alkoxy group, an aryl group and a heteroaryl group. Any one selected.

The formula (5) may be any one selected from the group consisting of the following formulas (5-i) to (5-xxii):

Equation (6) may be any one selected from the group consisting of the following formulas (6-i) to (6-ix):

The compound of the formula (1) serves as a monomer as well as a photoacid generator. In this case, the resolution and the characteristics of the LER can be improved by adjusting the carbon number of the main chain of the compound (1), thereby ensuring that the polymer obtained by polymerizing the compound (1) is exposed to generate an acid. The space is also adjusted for the acid diffusion distance of the pattern.

Another aspect of the polymer of the present invention contains a repeating unit of the following formula (2).

In the formula (2), R ₁₁ , R ₄₁ and R ₄₂ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. Any one selected from the group consisting of a group, and preferably any one selected from the group consisting of a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. ; Q ₁ and Q ₂ each independently represent any one selected from the group consisting of a hydrogen atom and a halogen atom, and may preferably be a fluorine atom; and A ⁺ represents an organic counter ion, which is defined with respect to formula (1) The same is true and therefore will not be repeated for further description.

The polymer is produced by directly polymerizing a compound of the formula (1) which has a photoacid generator in the polymer and introduces a large amount of the photoacid generator. Therefore, it is possible to produce a higher exposure sensitivity to the photoresist containing the same A polymer with a higher degree of stability and a reduced amount of exhaust gas produced by simultaneous low LER exposure.

The polymer is a multicomponent copolymer and may be a block copolymer, a scrambled copolymer or a graft copolymer. Further, the polymer containing the repeating unit represented by the formula (2) may be a polymer containing any one of the repeating units selected from the following repeating units: a repeating unit having an acid labile group, and a hydroxyl group Repeating unit, repeating unit containing an adhesive group of a lactone ring, and combinations thereof.

More specifically, the polymer may be a polymer represented by the following formula (3):

In the formula (3), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ and R ₄₈ each independently represent a hydrogen atom or a carbon. Any one selected from the group consisting of an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms, and preferably a hydrogen atom or a trifluoro group. Any one selected from the group consisting of a methyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms; and Q ₁ and Q ₂ each independently represent a group selected from a hydrogen atom and a halogen atom; One, and preferably a fluorine atom; A ⁺ represents an organic counter ion, and since its definition is the same as that described for A+ in the formula (1), it will not be further described; the symbols l, m, n, o and p points are in the following range: 0<l 0.4,0<m 0.5,0 n 0.5,0 o 0.5 and 0<p 0.2, while l+m+n+o+p=1; and X represents a polymer unit derived from an olefin monomer.

The olefin monomer may preferably be any one selected from the group consisting of acrylate, styrene, norbornene, hydrazine, hydrazine, furanedione and derivatives thereof.

X may preferably be a polymerization unit represented by one of the following formulae (3-a) to (3-f):

In the formulae (3-a) to (3-f), R ₁₅ , R ₄₉ and R ₅₀ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, and a perfluoroalkyl group having 1 to 10 carbon atoms. And any one selected from the group consisting of alkoxy groups having a carbon number of 1 to 10, and each of them may preferably be a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 5 carbon atoms, and a carbon number of 1 to 5. Any one selected from the group consisting of alkoxy groups; R ₃₁ and R ₃₂ each independently represent any one selected from the group consisting of a halogen atom, a hydroxyl group, a cyano group, a carboxyl group, a nitrile group, an aldehyde group, and an epoxy group. Base, nitro, amine, thio, methylthio, alkyl, alkoxy, perfluoroalkoxy, hydroxyalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, COOR' And COR', wherein R' represents any one selected from the group consisting of an alkyl group, a perfluoroalkyl group, a cycloalkyl group, an aryl group and a cyclic aryl group; a represents an integer from 0 to 5, and b represents 0~ An integer of 5, an integer of c to 0 to 8, an integer of 0 to 4 of d, an integer of 0 to 3 of e, and f represents an integer of 0 to 3.

In the formula (3), R ₂₁ , R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an alkyl group, a heteroalkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group and a combination thereof. Any one selected among the ethnic groups, and may preferably be any one selected from the group consisting of the following formulas (3-i) to (3-ix):

In the formulae (3-i) to (3-ix), R ₃₃ to R ₃₅ each independently represent any one selected from the group consisting of a hydrogen atom, an alkyl group, an alkoxy group, and a perfluoroalkane. a base, a perfluoroalkoxy group, a hydroxyalkyl group, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amine group, a thio group, a methylthio group, an ether group and a methoxy group, and preferably, R ₃₃ to R ₃₅ Each of them may be independently selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, and a perfluoroalkyl group having 1 to 4 carbon atoms. a perfluoroalkoxy group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amine group, a thio group, a methylthio group and a methoxy group.

The symbol g represents an integer from 0 to 9, h represents an integer from 0 to 9, i represents an integer from 0 to 5, j represents an integer from 0 to 15, k represents an integer from 0 to 15, and q represents an integer from 0 to 17, and r represents an integer from 0 to 11.

The polymer may preferably be a polymer represented by the following formula (4):

Wherein in the formula (4), R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ , R ₄₈ , Q ₁ , Q ₂ , The definitions of A ⁺ , R ₂₁ , R ₂₂ , R ₂₃ , l, m, n, o, and p are the same as those described for the formula (3), respectively, and thus will not be further described.

In the formula (4), b represents an integer of 0 to 5, and c represents an integer of 0 to 8.

In the formula (4), R ₁₅ and R ₄₉ each independently represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms. Any one selected from the group, and preferably, R ₁₅ and R ₄₉ are each independently a hydrogen atom, a trifluoromethyl group, an alkyl group having 1 to 5 carbon atoms, and an alkoxy group having 1 to 5 carbon atoms. Any one of the selected ethnic groups.

In the formula (4), R ₃₁ represents any one selected from the group consisting of a halogen atom, a hydroxyl group, a cyano group, a carboxyl group, a nitrile group, an aldehyde group, an epoxy group, a nitro group, an amine group, Thio, methylthio, alkyl, alkoxy, perfluoroalkoxy, hydroxyalkyl, cycloalkyl, heterocycloalkyl, aryl, heteroaryl, COOR' and COR', wherein R' represents Any one selected from the group consisting of an alkyl group, a perfluoroalkyl group, a cycloalkyl group, an aryl group, and a cyclic aryl group.

R ₃₁ may preferably be any one selected from the group consisting of an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a perfluoroalkyl group having 1 to 4 carbon atoms, and carbon. a fluoroalkyloxy group having 1 to 4, a hydroxyalkyl group having 1 to 6 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, a nitro group, an amine group, a thio group and a methylthio group, and more preferably R ₃₁ Any one selected from the group consisting of a hydrogen atom and a group consisting of: (3-x):

When a photoresist is produced using a polymer containing a (meth)acrylic polymer, the amount of light absorption is small, but there is a problem that the polymer has poor etching resistance as compared with the aromatic compound. However, in the case where the carbon number of the cyclic olefin introduced as shown in the formula (4) is larger than that of the (meth)acrylic polymer introduced into the main chain, the etching resistance can be highly improved, and the acid instability portion is even After pretreatment (soft baking), it does not completely vaporize and partially remains in the photoresist film. Therefore, the fluidity of the acid generated by the acid generator at the time of exposure is improved, and thus the patterning characteristics are greatly improved.

The polymer may be any one selected from the group consisting of: (a) to (4-l):

In the formulae (4-a) to (4-l), the symbols l, m, n, o, and p are respectively in the following ranges: 0 < l 0.4,0<m 0.5,0 n 0.5,0 o 0.5 and 0<p 0.2, while l+m+n+o+p=1; A ⁺ represents an organic counter ion, and since its definition is the same as that described for A+ in the formula (1), further description will not be repeated.

The polymer containing the repeating unit of the formula (2) preferably has a weight average molecular weight of from 2,000 to 100,000 as measured by gel permeation chromatography (GPC) with respect to polystyrene standards, and a molecular weight distribution of from 1 to 5, More preferably, it has a weight average molecular weight of 3,000 to 30,000 and a molecular weight distribution of 1.50 to 3. If the weight average molecular weight is more than 100,000, when the polymer is used in the photoresist composition, the solubility of the polymer may be poor, and the line edge roughness may be poor. If the weight average molecular weight is less than 2,000, the mechanical strength of the resin is poor, and a pattern (pattern crack) may not be satisfactorily formed. Further, if the molecular weight distribution is more than 5, the line edge roughness may be poor. Therefore, when a polymer having a weight average molecular weight and a molecular weight distribution within the above range is used in the photoresist composition, the photoresist composition can exhibit appropriate characteristics in terms of developability, coatability, and heat resistance.

The compound represented by the formula (1) can be produced by the method described below.

The compound represented by the formula (1) can be produced by a method comprising the steps of reacting a compound represented by the following formula (7) with a compound represented by the following formula (8), and reacting the reaction product produced in the first step The second step of performing a substitution reaction with a compound represented by the following formula (9).

A+Z- (9).

In the formulae (7) to (9), M ⁺ represents any one selected from the group consisting of Li ⁺ , Na ⁺ and K ⁺ ; Z ^- represents any one selected from the group consisting of: :(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 -; and the definitions of A+, R ₁₁ , Q ₁ and Q ₂ are the same as those described for the compound represented by the formula (1), respectively, and therefore Further description will be repeated.

The reaction of the first step can be carried out in a solvent, and any one selected from the group consisting of esters, ethers, lactones, ketones, decylamines, alcohols, and a combination thereof can be used as a solvent. Preferably, dichloromethane, chloroform, dichloroethane, acetonitrile, toluene, benzene, 1,4-dioxane and the like can be used.

The reaction of the first step can be carried out in the presence of a basic catalyst, and the basic catalyst can be composed of triethylamine, diethylamine, pyridine, diethylisopropylamine, aniline, diisopropylethylamine and combinations thereof. Any one of the ethnic groups selected. When the reaction of the first step is carried out in the presence of a basic catalyst, the reaction time can be shortened, the conversion ratio can be increased, and the side reaction can be reduced.

The compound represented by the formula (8) can be obtained by reduction of the formula represented by the following formula (10):

In the formula (10), M ⁺ represents any one selected from the group consisting of Li ⁺ , Na ⁺ and K ⁺ ; R ₆ represents any one selected from the group consisting of: hydrogen atom, carbon An alkyl group having 1 to 10 alkyl groups and a heteroalkyl group in which 1 to 3 hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are substituted by a halogen atom, and may be any one selected from the group consisting of: a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a trifluoromethyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group; and Q ₁ and Q ₂ are each defined as a compound represented by the formula (1) The same is true and therefore will not be repeated for further description.

The process for reducing the compound represented by the formula (10) to give the compound represented by the formula (8) may specifically comprise the steps of: dissolving the compound of the formula (8) in tetrahydrofuran and an alcohol solvent; slowly reducing the reducing agent in an ice bath Adding dropwise to the solution; after completion of the dropwise addition, raising the temperature to 40 to 100 ° C to prepare a liquid of the reaction mixture; reacting the liquid of the reaction mixture under stirring; then terminating the reaction of the liquid of the reaction mixture; removing the solvent; The reaction product was crystallized. For the method of crystallization, any crystallization method conventionally used may be used, but in particular, a method comprising the steps of: acidifying the reaction mixture of the removed solvent with a strong acid to pH 5-6; concentrating the resulting mixture; then adding the alcohol The resulting concentrate was slurried; the slurry was filtered, and the filtrate was washed again with hexane; then the filtrate was concentrated again; and the product was crystallized from diethyl ether.

A polymer containing a repeating unit of the formula (2) can be conventionally produced to produce a polymer. The method is to polymerize, but a radical polymerization method is preferably used. The polymerization initiator for radical polymerization may be used from azobisisobutyronitrile (AIBN), benzammonium peroxide (BPO), lauryl peroxide, azobisisohexanenitrile, azobisisovaleronitrile, hydrogen. Any one selected from the group consisting of tributyl peroxide and combinations thereof. The polymerization can be achieved by methods such as bulk polymerization, solution polymerization, suspension polymerization, bulk suspension polymerization, and emulsion polymerization. The solvent for polymerization may be one or more selected from the group consisting of benzene, toluene, xylene, benzene halide, diethyl ether, tetrahydrofuran, 1,2-dichloroethane, ester, ether, lactone, ketone and decylamine. After the completion of the polymerization reaction, the unreacted monomers and by-products remaining in the liquid of the reaction mixture can be removed by a conventional method for removing these monomers and by-products, and it is preferred to use a solvent by a precipitation method. To remove these substances.

A chemically amplified resist composition according to another aspect of the present invention comprises a polymer comprising a repeating unit of the formula (2), wherein the monomer represented by the formula (1) is used in an amount relative to 100 parts by weight of the total solids of the polymer. The content may be from 0.5 to 15 parts by weight. If the amount of the monomer represented by the formula (1) is within the above range, better sensitivity and higher stability can be obtained, and the amount of gas emission can be reduced.

The photoresist composition may contain a polymer containing a repeating unit of the formula (2) in an amount of 3% by weight or more, and preferably 5% by weight or more based on the total amount of the photoresist composition. When the content of the polymer is 3% by weight or less, the effect of including the polymer may not be sufficiently exhibited. The photoresist composition may contain, in addition to the polymer, conventional constituents constituting the photoresist composition, such as an additive or a solvent.

The photoresist composition comprising the repeating unit of the formula (2) can be used for pattern formation, and the pattern forming method comprises the steps of: coating the photoresist composition on the substrate; and heat-treating the applied photoresist composition, and High energy a step of exposing the photoresist composition to radiation; and a step of developing the photoresist composition using a developer.

Higher energy ray in the range of 13.5 to 250 nm is preferred because it increases resolution and reduces LER.

When the novel compound of the present invention and a polymer containing the same are used in a chemically amplified photoresist composition, the photoresist composition can have good sensitivity and high stability while reducing gas emissions, and can have Higher resolution and lower line edge roughness.

[Better Embodiment]

The present invention will be described in detail below, so that those skilled in the art can readily implement the present invention. However, the invention can be implemented in a variety of different embodiments, and is not limited to the examples described below.

Compound synthesis example

1) Synthesis of sodium difluorohydroxypropane sulfonate

83 g of sodium 3,3-difluoro-3-sulfopropionate sodium salt was dissolved in 160 ml of methanol and 1.2 liters of tetrahydrofuran (THF) in an ice bath, and 44 g of sodium borohydride was slowly added dropwise to In solution. After completion of the dropwise addition, the reaction mixture was removed from the ice bath and heated to 60 °C. The reaction mixture was stirred at the same temperature for about 4 hours.

The thus stirred reaction mixture liquid was quenched with distilled water, and the solvent was removed. The reaction mixture obtained after removing the solvent was again dissolved in distilled water, and the resulting solution was acidified to pH 5-6 with concentrated hydrochloric acid.

The acidified reaction mixture was concentrated again, and methanol was added thereto to obtain a slurry. The slurry was filtered to remove the inorganic salt, and the filtrate was washed twice with hexane. The methanol layer was again concentrated, followed by crystallization using diethyl ether.

The white solid obtained by crystallization was dried in vacuo, and the structure of the solid was determined by ¹ H-NMR. Thus, 68.5 g (yield 95%) of difluorohydroxypropane sulfonate sodium salt represented by the formula [A] in the following reaction scheme (1) (3-ethoxy-1,1-difluoro-3) was obtained. - Sodium oxypropane-1-sulfonate).

¹ H-NMR (chloroform-d3, internal standard: tetramethyl decane): δ (ppm) 3.3 (t, 2H), 4.58 - 4.68 (t, 2H).

In the reaction scheme 1, Me represents a methyl group, and Et represents an ethyl group.

2) Synthesis of sodium 2-methacrylate 2-,2-difluoro-2-sulfopropyl ester

68 g of sodium difluorohydroxypropane sulfonate (3-ethoxy-1,1-difluoro-3) represented by the formula [A] in the reaction scheme (1) produced in Synthesis Example 1) of the compound -Sodium oxypropane-1-sulfonate) and 54.6 ml of methacrylic acid chlorochloride were mixed with 500 ml of dichloromethane (MC), and the resulting mixture was stirred. Subsequently, 3.2 g of N,N'-dimethylaminopyridine (DMAP) and 50 mg of a polymerization inhibitor (hydroquinone monomethyl ether (MEHQ)) were added to the mixture at 15 to 25 ° C, and the resulting mixture was mixed. 104 ml of triethylamine (Et ₃ N) placed in a dropping funnel was slowly added dropwise to the mixture at 15 to 25 ° C to prepare a reaction mixture. The reaction mixture liquid was stirred at 15 to 25 ° C for 3 hours, and then the degree of the reaction was confirmed by NMR, and the reaction was terminated.

After the reaction of the reaction mixture was terminated, distillation under reduced pressure was carried out to remove dichloromethane as a reaction solvent, and 300 ml of distilled water was added thereto. Subsequently, potassium carbonate was added to the reaction mixture to obtain a saturated solution. After stirring the saturated solution for 2 hours, the solid thus obtained was filtered to obtain 81 g (yield: 86%) of 2-methyl-acrylic acid-2,2-difluoro represented by the formula [B] in the reaction scheme 2. Sodium sulfo-propyl ester (sodium 1,1-difluoro-3-(methacryloxy)propane-1-sulfonate). The structure of the salt was determined by ¹ H-NMR.

¹ H-NMR (DMSO, internal standard: tetramethyl decane): δ (ppm) 1.91 (s, 3H), 3.3 (t, 2H), 4.57-4.67 (t, 2H), 5.77 (s, 1H), 6.11 (s, 1H).

In the reaction scheme 2, Et represents an ethyl group.

3) Synthesis of 2-methyl 2-methacrylate 2-benzoyl phenyl sulfonate

31 g of sodium 2-methacrylic acid-2,2-difluoro-2-sulfopropyl ester (1,1-difluoro-3-(methacrylofluorene) produced in Synthesis Example 2) of the compound Base) sodium propane-1-sulfonate) and 35 g of the benzhydrylphenylphosphonium trifluoromethane salt represented by the formula [C] in the following Reaction Scheme 3 dissolved in 300 ml of dichloromethane (MC) and 300 The reaction mixture was prepared in milliliters of distilled water, and the reaction mixture was subjected to a two-layer reaction under vigorous stirring for 3 hours.

After completion of the stirring, an aliquot of the organic layer was obtained to examine the degree of reaction by ¹⁹ F-NMR, and the reaction was terminated. After the reaction was terminated, the organic layer of the reaction mixture was collected, and the solvent was removed. The organic layer was washed with dichloromethane (as a good solvent) and hexane (as a poor solvent), and the solvent was removed to obtain crystals.

The crystals thus obtained were dried under reduced pressure to obtain 40 g (yield: 96%) of 2-methyl bromo-2,2-difluoro-2- represented by the formula [D] in the following Reaction Scheme 3. Sulfopropyl benzhydrin. The structure of the salt was determined by ¹ H-NMR.

¹ H-NMR (chloroform-d3, internal standard: tetramethyl decane): δ (ppm) 1.95 (s, 3H), 2.43 (s, 3H), 3.3 (t, 2H), 4.82 (t, 2H), 5.60 (s, 1H), 6.22 (s, 1H), 7.43-7.80 (m, 14H).

Polymer synthesis example

(Example 1)

As a monomer for polymerization, 13 g of 2-methyl-2-adamantyl acrylate, 8.4 g of γ-butyrolactone-based methacrylate, and 11.6 g of 3-hydroxy-1-adamantyl methacrylate were used. And 1 g of 2-methyl methacrylate-2,2-difluoro-2-sulfopropyl ester diphenylmethylphenyl sulfonium salt represented by the formula [D] in the above Reaction Scheme 3 is dissolved in 58 g of 1,2 In the case of dichloroethane, a monomer mixture is thus obtained.

3.7 g of norbornene, 2.5 g of azobisisobutyronitrile (AIBN) (as a polymerization initiator) and 117 g of 1,2-dichloroethane (as a polymerization solvent) were added to a 250 ml flask to provide a reaction. Bath and introduce nitrogen into the reaction bath. The mixture was stirred for 1 hour while maintaining the temperature at 15 to 25 °C.

When the temperature of the reaction bath was 65 ° C, the above monomer mixture was slowly added dropwise to the reaction bath over 1 hour to prepare a reaction mixture, and the reaction mixture was allowed to react for 16 hours. After completion of the polymerization, the reaction mixture was cooled to 15 to 25 ° C, and the reaction product was precipitated with hexane, and the precipitate was filtered. The precipitate was washed several times with the same solvent as during the filtration process, and the crystals thus obtained were dried under reduced pressure to obtain 37 g (yield: 79%) of the polymer of the formula 1 represented by the formula (11). . In the polymer of Example 1 represented by the following formula (11), l = 0.24, m = 0.25, n = 0.30, o = 0.20 and p = 0.01.

The polymer of Example 1 had a polystyrene-equivalent weight average molecular weight (Mw) of 1,190 and a molecular weight distribution of 1.57 (ratio of weight average molecular weight to number average molecular weight, Mw/Mn).

(Example 2)

Polymerization was carried out in the same manner as in Example 1 except that the individual amounts of the monomers used for the polymerization were adjusted to change the values of l, m, n, o and p in the formula (11). Compound. The values of l, m, n, o and p in the formula (11) of the polymer of Example 2 were as follows: l = 0.24, m = 0.25, n = 0.30, o = 0.18 and p = 0.03.

(Example 3)

The polymer was produced in the same manner as in Example 1 except that the individual amounts of the monomers used for the polymerization were adjusted to change the values of 1, 10, n, o and p in the formula (11). The values of l, m, n, o and p in the formula (11) of the polymer of Example 3 were as follows: l = 0.24, m = 0.25, n = 0.30, o = 0.16 and p = 0.05.

(Example 4)

The polymer was produced in the same manner as in Example 1 except that the individual amounts of the monomers used for the polymerization were adjusted to change the values of 1, 10, n, o and p in the formula (11). The values of l, m, n, o and p in the formula (11) of the polymer of Example 4 were as follows: l = 0.24, m = 0.25, n = 0.30, o = 0.14 and p = 0.07.

(Comparative example)

As a monomer for polymerization, 10.0 g of 2-methyl-2-adamantyl methacrylate, 7.3 g of γ-butyrolactone-based methacrylate, and 10.1 g of 3-hydroxy-1-gold methacrylate were mixed. The alkyl ester was dissolved in 82 g of 1,4-dioxane to prepare a monomer mixture. The bath temperature was slowly raised to 65 °C.

3.7 g of norbornene, 2.5 g of azobisisobutyronitrile (AIBN) (as a polymerization initiator) and 117 g of 1,2-dichloroethane (as a polymerization solvent) were added to a 250 ml flask to provide a reaction. Bath and introduce nitrogen into the reaction bath. The mixture was stirred for 1 hour while maintaining the temperature at 15 to 25 °C.

When the temperature of the reaction bath was 65 ° C, the above monomer mixture was slowly added dropwise to the reaction bath over 1 hour to prepare a reaction mixture, and the reaction mixture was allowed to react for 16 hours. After the polymerization is completed, the reaction is mixed. The liquid was cooled to 15 to 25 ° C, and the reaction product was precipitated with hexane, and the precipitate was filtered. The precipitate was washed several times with the same solvent as during the filtration process, and the crystals thus obtained were dried under reduced pressure to give 25 g (yield: 91%) of a polymer represented by the following formula (12).

In the following formula (12), l = 0.28, m = 0.24, n = 0.24, and o = 0.24.

The polymer represented by the following formula (12) has a polystyrene-equivalent weight average molecular weight (Mw) of 1,780 and a molecular weight distribution (Mw/Mn) of 1.68.

Preparation of photoresist and characterization

(Example 1)

100 parts by weight of the polymer of Example 1 and 0.75 parts by weight of tetramethylammonium hydroxide as a basic additive were dissolved in 1,000 parts by weight of propylene glycol methyl ether acetate, and the solution was filtered through a 0.2 micron membrane filter to obtain a photoresist. liquid.

The photoresist was applied onto the substrate using a spinner and dried at 110 ° C for 90 seconds to form a film having a thickness of 0.2 μm. The thus formed film was exposed using an ArF excimer laser stepper (lens numerical aperture: 0.75), followed by heat treatment of the film at 120 ° C for 90 seconds. The heat-treated substrate was developed with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide for 40 seconds, and the substrate was washed and dried. Thereby, a photoresist pattern is formed on the substrate.

(Examples 2~4)

In addition to the use of 100 parts by weight of each polymer synthesized in Synthesis Examples 2 to 4 of the polymer instead of 100 parts by weight of the polymer of Example 1 for the preparation of photoresist and property evaluation, in Example 1 for the preparation of photoresist and characteristics evaluation A photoresist pattern was formed in the same manner, and the characteristics of the photoresist pattern were evaluated.

(Comparative examples 1 to 3)

A photoresist pattern was formed in the same manner as in Example 1 for preparing photoresist and property evaluation, except that the polymer of the comparative example represented by the above formula (12) was used to produce a photoresist having the composition shown in the following Table 1, and the light was evaluated. The characteristics of the resistance pattern.

The characteristics of Examples 1 to 4 and Comparative Examples 1 to 3 were evaluated in terms of sensitivity, resolution, and LER, and the results are shown in Table 2 below.

When evaluating the sensitivity, an exposure amount capable of forming a 0.10 μm line/space (L/S) pattern having a 1:1 line width after development is defined as an optimum exposure amount, and the optimum exposure amount is defined as sensitivity. . The minimum pattern size resolved at this time is defined as the resolution.

LER is measured by critical dimension scanning electron microscopy (CD SEM) and is based on 5 levels (eg 1 (very poor), 2 (poor), 3 (medium), 4 (Good) and 5 (excellent) to rate the assessment results.

According to Table 2, Examples 1 to 4 generally exhibited better sensitivity than Comparative Examples 1 to 3, and also exhibited better resolution. Especially in the case of LER, Examples 1 to 4 exhibited much better results than the comparative examples.

Therefore, the preferred embodiments of the present invention have been described in detail, but the scope of the present invention is not intended to be limited thereto, and various modifications and improvements may be made by those skilled in the art using the basic concepts of the invention as defined in the following claims. Within the scope of the invention.

Claims (3)

A polymer which is represented by the following formula (4): Wherein in the formula (4), each of R ₁₁ , R ₁₂ , R ₁₃ , R ₁₄ , R ₁₅ , R ₄₁ , R ₄₂ , R ₄₃ , R ₄₄ , R ₄₅ , R ₄₆ , R ₄₇ , R ₄₈ and R ₄₉ Any one selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, a perfluoroalkyl group having 1 to 10 carbon atoms, and an alkoxy group having 1 to 10 carbon atoms; Q ₁ and Q; ₂ each independently represents a halogen atom; R ₂₁ , R ₂₂ and R ₂₃ each independently represent a hydrogen atom, an alkyl group, a heteroalkyl group, a cycloalkyl group, a heterocycloalkyl group, an aryl group, a heteroaryl group, and combinations thereof. Any one selected from the group; A ⁺ represents an organic counter ion; the symbols l, m, n, o, and p are respectively in the following ranges: 0 < l 0.4,0<m 0.5,0 n 0.5,0 o 0.5 and 0<p 0.2, while l+m+n+o+p=1; R ₃₁ represents a hydrogen atom; and b represents an integer of 0-5, and c represents an integer of 0-8. The polymer of claim 1, which has a weight average molecular weight of from 2,000 to 100,000 and a molecular weight distribution of from 1.5 to 5. A chemically amplified photoresist composition comprising the polymer of claim 1 of the patent application.