KR20240052148A - Photoacid generator and photoresist composition comprising the same - Google Patents

Abstract

The photoacid generator according to embodiments of the present invention includes a compound containing a naphthalimide group to which a sulfonic acid group is bonded at both ends. The photoresist composition containing the photoacid generator has excellent photosensitivity and can implement high-resolution patterns.

Description

Photoacid generator and photoresist composition containing the same {PHOTOACID GENERATOR AND PHOTORESIST COMPOSITION COMPRISING THE SAME}

The present invention provides a photoacid generator and a photoresist composition containing the same.

As the recent development of the semiconductor industry requires high integration of semiconductor devices, processing technology to implement ultra-fine patterns with a line width of 100 nm or less is emerging. The processing technology for forming the pattern has mainly been a photo-lithography process using photoresist, a photoresist. The photolithography process forms a photoresist pattern by performing a photoresist film forming process, an alignment/exposure process of a pattern to be formed on the photoresist film, and a photoresist development process.

The photoresist applied to form such a pattern is a positive photoresist in which the part exposed to light is photodenatured and dissolved and removed by development, and the part exposed to light is photocrosslinked and insolubilized, and the part other than the light irradiated part is developed. There are two types of negative photoresists.

A typical photoresist composition includes a polymer resin, a photoacid generator, an organic solvent, etc. According to the reaction mechanism of this photoresist, the photoacid generator (PAG) generates acid when light is irradiated, and the polymer resin reacts with the acid generated in the light irradiated area and is decomposed or crosslinked, changing the polarity of the polymer. do. This change in polarity results in a difference in solubility in the developer between the irradiated exposed and unexposed areas, thereby forming a positive or negative image of the pattern on the substrate.

In the photoresist composition, the energy sensitivity of the photoacid generator to the exposure light must be excellent to form a fine pattern. However, if only a normal photoacid generator is used, the sensitivity of the photoresist cannot be satisfied. There is a problem where it cannot be increased by that much.

Republic of Korea Patent Publication No. 10-2009-0009655 discloses an acid amplifier having an acetal group and a photoresist composition containing the same, which can improve the energy sensitivity of photoresist.

However, a photoacid generator that can improve the verticality and solubility of the photoresist pattern along with improved sensitivity and a photoresist composition containing the same have not yet been developed.

Republic of Korea Patent Publication No. 10-2009-0009655

One object of the present invention is to provide a photoacid generator with high photosensitivity.

One object of the present invention is to provide a photoresist composition containing the photoacid generator.

According to exemplary embodiments, a photoacid generator containing a compound represented by the following Chemical Formula 1 is provided.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a substituted or unsubstituted C1 to C10 alkyl group, a C1 to C10 perfluoroalkyl group, or a substituted or unsubstituted C6 to C12 aryl group, and R ₃ is a substituted or unsubstituted C6 to C12 aryl group. Unsubstituted C1 to C10 alkylene group; Substituted or unsubstituted C6 to C12 arylene group; Alternatively, it is a substituted or unsubstituted C2 to C10 hydrocarbon group containing at least one selected from the group consisting of an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group.

According to exemplary embodiments, R ₁ and R ₂ may independently be a C1 to C8 perfluoroalkyl group.

According to exemplary embodiments, R ₃ may be a C2 to C5 linear or branched alkylene group.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ether groups.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ester groups.

According to exemplary embodiments, the compound may include a compound represented by any one of the following formulas 2 to 4.

[Formula 2]

[Formula 3]

[Formula 4]

According to exemplary embodiments, a photoresist composition containing the photoacid generator is provided.

According to exemplary embodiments, the content of the photo acid generator may be 0.01 parts by weight to 15 parts by weight based on 100 parts by weight of solid content of the photoresist composition.

The photoacid generator according to exemplary embodiments includes a naphthalimide-based sulfonic acid derivative compound represented by Chemical Formula 1, has excellent solubility in a photoresist solvent, and can improve thermal stability.

The photoacid generator according to exemplary embodiments has a very high sensitivity to photolithography light, such as i-line (365 nm) wavelength light, and has excellent developability, taper angle, and It is possible to provide patterns with high stability, etc.

In addition, photoresist compositions according to exemplary embodiments can minimize outgassing generated from photoacid generators during exposure and post-bake processes, thereby reducing contamination and minimizing product defects that may occur due to this.

A photoacid generator and a photoresist composition containing the same according to an embodiment of the present invention are provided.

With reference to the drawings below, embodiments of the present invention will be described in more detail. However, the following drawings attached to this specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention along with the contents of the above-described invention, so the present invention is described in such drawings. It should not be interpreted as limited to the specifics.

Terms such as “upper surface”, “bottom surface”, “upper part”, “bottom”, “lower surface”, “bottom”, etc. used in this specification are used in a relative sense to distinguish the positions of components, and specify absolute positions. It's not about doing it.

According to exemplary embodiments, a photoacid generator containing a compound represented by the following Chemical Formula 1 is provided.

[Formula 1]

In Formula 1, R ₁ and R ₂ are each independently a substituted or unsubstituted C1 to C10 alkyl group, a C1 to C10 perfluoroalkyl group, or a substituted or unsubstituted C6 to C12 aryl group, and R ₃ is a substituted or unsubstituted C6 to C12 aryl group. Unsubstituted C1 to C10 alkylene group; Substituted or unsubstituted C6 to C12 arylene group; Alternatively, it is a substituted or unsubstituted C2 to C10 hydrocarbon group containing at least one selected from the group consisting of an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group.

According to exemplary embodiments, when the photoacid generator includes a compound represented by Formula 1, it has high solubility in a photoresist solvent such as propylene glycol monomethyl ether (PGMEA) or cyclohexane, and has high solubility in photoresist solvents such as propylene glycol monomethyl ether (PGMEA) or cyclohexane. Sensitivity to can be very high.

Accordingly, even if the photoacid generator is used in a small amount in the photoresist composition, a pattern with excellent developability, taper angle, high stability, etc. can be provided.

The "substitution" means that any hydrogen of the moiety is a halogen atom, a C1-C6 alkyl group, a C2-C6 alkenyl group, a C2-C6 alkynyl group, a C1-C6 alkoxy group, a C6-C12 phenoxy group, It may mean being substituted with at least one of a hydroxy group, a nitro group, and a cyano group.

A photoacid generator containing the compound represented by Formula 1 can generate acid upon light irradiation. For example, in Formula 1, the bond between the trifluoromethane sulfonic group at both ends and the nitrogen atom may be dissociated to produce trifluoromethane sulfonic acid.

According to exemplary embodiments, the photoacid generator containing the compound represented by Formula 1 includes naphthalimide groups to which a sulfonic acid group is bonded at both ends, so that a large amount of sulfonic acid can be generated even when less light is irradiated. . Accordingly, a photoresist composition with excellent light sensitivity can be implemented.

According to exemplary embodiments, R ₁ and R ₂ may each independently be a substituted or unsubstituted C1 to C10 alkyl group, a C1 to C10 perfluoroalkyl group, or a substituted or unsubstituted C6 to C12 aryl group. For example, R ₁ and R ₂ may each independently be a C1 to C8 perfluoroalkyl group, for example, a trifluoromethyl group.

When R ₁ and R ₂ are trifluoromethyl groups, the photoacid generator may be decomposed by light to produce trifluoromethane sulfonic acid, a strong acid. When a strong acid is generated, the developability of the polymer resin in the exposed area can be changed more strongly, and the photoresist composition can implement a pattern with high resolution.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C1 to C10 alkylene group. Alternatively, R ₃ may be a C2 to C5 linear or branched alkylene group.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C6 to C12 arylene group. For example, R ₃ may be a phenylene group.

According to exemplary embodiments, R ₃ may be an unsubstituted C1 to C10 alkylene group, or an unsubstituted C6 to C12 arylene group. When R ₃ is the unsubstituted hydrocarbon group, the photoacid generator may be hydrophobic. In this case, the photoacid generator may have excellent compatibility with the hydrophobic polymer resin included in the photoresist. In addition, dispersibility in photoresists containing hydrophobic polymer resins may be excellent.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C2 to C10 hydrocarbon group containing at least one selected from the group consisting of an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group.

The hydrocarbon group may be a saturated or unsaturated, linear or branched hydrocarbon group. Alternatively, the hydrocarbon group may include a saturated or unsaturated hydrocarbon ring within the chain or in a branched form.

Any methylene group (-CH ₂ -) of the substituted or unsubstituted C2 to C10 hydrocarbon group may be substituted with an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group.

The ether group, thioether group, carbonate group, carbonyl group, or ester group is a polar group and may have excellent compatibility with the hydrophilic polymer resin included in the photoresist. In addition, dispersibility in photoresists containing hydrophilic polymer resins may be excellent.

According to exemplary embodiments, R ₃ may include at least one selected from the group consisting of an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group. For example, R ₃ may include three ether groups and one ester group.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ether groups. Alternatively, R ₃ may be a substituted or unsubstituted C5 to C9 hydrocarbon group containing 1 to 3 ether groups.

When R ₃ contains 1 to 3 ether groups, the hydrophilicity of the photoacid generator is further improved and it can be uniformly dispersed in the photoresist.

According to exemplary embodiments, R ₃ may be a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ester groups. Alternatively, R ₃ may be a substituted or unsubstituted C5 to C9 hydrocarbon group containing 1 to 3 ester groups.

When R ₃ contains 1 to 3 ester groups, the carbonyl group of the ester group protruding from the main chain can further improve the hydrophilicity of the photoacid generator.

According to exemplary embodiments, the compound may have a symmetric structure. When the compound has a symmetrical structure, acid may be generated in more uniform areas upon exposure of the photoresist composition. Accordingly, it may be possible to implement a fine pattern with improved verticality.

According to exemplary embodiments, the compound may be represented by the following formula 1-1.

[Formula 1-1]

According to exemplary embodiments, the compound may be represented by the following formula 1-2.

[Formula 1-2]

In Formula 1-1, R ₃ may be as described above.

According to exemplary embodiments, the compound may include a compound represented by any one of the following formulas 2 to 4.

[Formula 2]

[Formula 3]

[Formula 4]

According to exemplary embodiments, the photoacid generator is not particularly limited as long as it can synthesize the compound represented by Formula 1, but can be prepared, for example, by the following method.

A method for producing a photoacid generator according to an exemplary embodiment includes preparing a compound of Formula 7 by reacting a compound of Formula 5 below with a compound of Formula 6 below; Preparing a compound of Formula 8 by reacting a compound of Formula 7 below with a hydroxylamine-based compound; And reacting the compound of formula 8 below with a trifluoromethyl sulfonic acid compound to prepare a photoacid generator containing the compound represented by formula 1.

[Formula 5]

[Formula 6]

HS-R-SH

[Formula 7]

[Formula 8]

In Formula ₅ , Substituted or unsubstituted C6 to C12 arylene group; Alternatively, it is a substituted or unsubstituted C2 to C10 hydrocarbon group containing at least one selected from the group consisting of an ether group, a thioether group, a carbonate group, a carbonyl group, or an ester group.

According to exemplary embodiments, a compound of Formula 7 can be prepared by first reacting a naphthalic anhydride compound of Formula 5 with a dithiol compound of Formula 6. An acid compound may be produced as a by-product by combining the halogen atom (X) of Formula 5 and the hydrogen of the dithiol group of Formula 6. Additionally, a compound of Formula 7 can be produced by combining the site where the halogen atom of the naphthalic anhydride compound of Formula 5 is dissociated and the sulfur atom of Formula 6.

The compound of Formula 5 may have an equivalent ratio to the compound of Formula 6 of 1.95 to 2.05. The compound of Formula 5 is bonded to both ends of the compound of Formula 6, and when the compounds are reacted at an equivalence ratio within the above range, the compound of Formula 7 can be obtained in high yield.

The compound of Formula 5 may include a compound of Formula 5-1 below.

[Formula 5-1]

The compound of Formula 5 and the compound of Formula 6 may react in a solvent. For example, the reaction may proceed after dissolving or dispersing the compound of Formula 5 and the compound of Formula 6 in a solvent. The solvent is not particularly limited, but for example, the solvent may include dimethyl sulfoxide.

The compound of Formula 5 and the compound of Formula 6 may react in the presence of a basic nucleophilic catalyst. For example, the basic nucleophilic catalyst is 1,4-diazabicyclo[2.2.2]octane, 1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5,7-triazabi Cyclo[4.4.0]dec-5-ene, diphenyl guanidine, N,N-dimethyl-4-aminopyridine, 4-pyrrolidinopyridine and 1,3-di-tert-butylimidazol-2-yl It may include one or more types selected from the group consisting of den.

The reaction between the compound of Formula 5 and the compound of Formula 6 may be carried out at a temperature of 20°C to 50°C or 30°C to 40°C.

According to exemplary embodiments, the compound of Formula 8 may be prepared by reacting the compound of Formula 7 with a hydroxylamine-based compound. In the naphthalic anhydride group of the compound of Formula 7, the oxygen atom between the carbonyl groups may be replaced with a hydroxylamine group.

The hydroxylamine-based compound may be hydroxylamine hydrochloride, but is not limited thereto.

The compound of Formula 7 and the hydroxylamine-based compound may react in a solvent. For example, the reaction may proceed after dissolving or dispersing the compound of Formula 7 and the hydroxylamine-based compound in a solvent. The solvent may be a polar solvent and may include, for example, ethanol.

The compound of Formula 7 and the hydroxylamine-based compound may react in the presence of a weakly basic compound. For example, the weakly basic compound may include sodium bicarbonate.

The reaction of the compound of Formula 7 and the hydroxylamine-based compound may be performed under reflux conditions. Refluxing refers to introducing unreacted reactants contained in the product back into the reactor, which can improve the yield of the compound of Formula 8 produced.

The compound of Formula 7 may include a compound of Formula 7-1 below.

[Formula 7-1]

According to exemplary embodiments, a photo acid generator containing the compound represented by Formula 1 may be prepared by reacting the compound of Formula 8 with a trifluoromethyl sulfonic acid compound. A photo acid generator containing the compound represented by Formula 1 can be prepared by combining the hydroxyl group of the compound of Formula 8 with a trifluoromethyl sulfonic acid compound.

The trifluoromethyl sulfonic acid compound may be trifluoromethyl sulfonic acid anhydride, or trifluoromethyl sulfonic acid halide. For example, the trifluoromethyl sulfonic acid compound may include trifluoromethyl sulfonic acid chloride, trifluoromethyl sulfonic acid fluoride, trifluoromethyl sulfonic acid iodide, etc.

The compound of Formula 8 and the trifluoromethyl sulfonic acid compound may react in a solvent. For example, the reaction may proceed after dissolving or dispersing the compound of Formula 8 and the trifluoromethyl sulfonic acid compound in a solvent. The solvent is not particularly limited, but may include, for example, pyridine.

The reaction between the compound of Formula 8 and the trifluoromethyl sulfonic acid compound may be carried out at a temperature of -10°C to 30°C or 0°C to 25°C.

[Formula 8-1]

According to exemplary embodiments, a photoresist composition containing the photoacid generator is provided.

The photoresist composition includes the photoacid generator and can form a fine pattern through a photolithography process, and the boundary between exposed and unexposed areas is clear, so the verticality of the pattern can be excellent.

The photoresist composition may be a composition applied on an object to form a pattern. The photoresist composition may include the photoacid generator, a polymer resin that reacts with the acid generated from the photoacid generator, and a solvent.

The photoresist composition contains a photoacid generator, and the solubility in the developer of the exposed and unexposed areas may vary by heating after exposure.

According to exemplary embodiments, the content of the photo acid generator may be 0.01 parts by weight to 15 parts by weight based on 100 parts by weight of solid content of the photoresist composition. When the photoresist composition contains a photoacid generator in an amount within the above range, sensitivity to light can be improved and the physical properties of the insoluble portion can be exhibited well with respect to an alkaline developer.

The polymer resin included in the photoresist composition may be positive or negative.

For example, if the polymer resin is a positive polymer resin, it may be decomposed under the action of acid, thereby increasing the solubility of the photoresist in an alkaline developer. The positive polymer resin is insoluble or poorly soluble in an alkaline developer, but the acid generated after light irradiation changes polarity through a deprotection reaction of the polymer side chain, and may become soluble in an alkaline developer.

Alternatively, if the polymer resin is a negative polymer resin, it may be crosslinked or its polarity may change under the action of acid, making the photoresist insoluble in an alkaline developer. The negative polymer resin is soluble in an alkaline developer, but the acid generated after light irradiation changes the polarity of the resin due to a crosslinking reaction, and may become insoluble or poorly soluble in an alkaline developer.

The positive polymer resin may include a first resin that is an alkali-soluble resin containing an acidic functional group, and a second resin that is a protective group-introduced resin in which some or all of the hydrogen atoms of the acidic functional group of the first resin are replaced with acid-dissociable groups. there is. Alternatively, the positive polymer resin may be composed of a second resin.

Examples of the first resin include phenolic hydroxyl group-containing resin, carboxyl group-containing resin, and sulfonic acid group-containing resin. These can be used individually or in combination of two or more types.

There is no particular limitation as to the phenolic hydroxyl group-containing resin as long as it is a resin containing a phenolic hydroxyl group, for example, novolak resin, polyhydroxystyrene, copolymer of hydroxystyrene, copolymer of hydroxystyrene and styrene, and hygrostyrene. Roxystyrene, copolymers of styrene and (meth)acrylic acid derivatives, phenol-xylylene glycol condensation resin, cresol-xylylene glycol condensation resin, polyimide containing phenolic hydroxyl group, polyamic acid containing phenolic hydroxyl group, phenol- Dicyclopentadiene condensation resin, etc. are used. Among these, novolac resin, polyhydroxystyrene, copolymer of polyhydroxystyrene, copolymer of hydroxystyrene and styrene, copolymer of hydroxystyrene, styrene and (meth)acrylic acid derivative, and phenol-xylylene glycol condensation. Resin is preferred. These may be used individually by 1 type, or 2 or more types may be mixed and used.

The novolak resin can be obtained, for example, by condensing phenols and aldehydes in the presence of a catalyst.

Examples of the phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-butylphenol, m-butylphenol, and p-butyl. Phenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, Examples include 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, catechol, resorcinol, pyrogallol, α-naphthol, and β-naphthol.

Additionally, the aldehydes include formaldehyde, paraformaldehyde, acetaldehyde, and benzaldehyde.

Specific examples of novolak resins include phenol/formaldehyde condensation novolak resins, cresol/formaldehyde condensation novolak resins, and phenol-naphthol/formaldehyde condensation novolak resins.

Additionally, the phenolic hydroxyl group-containing resin may contain a phenolic low molecular weight compound as part of the components.

Examples of the phenolic low-molecular-weight compounds include 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, tris(4-hydroxyphenyl)methane, and 1,1-bis. (4-hydroxyphenyl)-1-phenylethane, tris(4-hydroxyphenyl)ethane, 1,3-bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 1,4- Bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 4,6-bis[1-(4-hydroxyphenyl)-1-methylethyl]-1,3-dihydroxybenzene, 1,1-bis(4-hydroxyphenyl)-1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethane, 1,1,2,2-tetra(4- Hydroxyphenyl)ethane, 4,4'-{1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylidene}bisphenol, etc. are mentioned. These phenolic low molecular compounds may be used individually, or may be used in mixture of two or more types.

The content of the phenolic low molecular weight compound in the phenolic hydroxyl group-containing resin may be 40 parts by weight or less, or 1 to 30 parts by weight, based on 100 parts by weight of the phenolic hydroxyl group-containing resin.

The weight average molecular weight of the phenolic hydroxyl group-containing resin may be 2000 or more, or may be 2000 to 20000. When the phenolic hydroxyl group-containing resin has a weight average molecular weight within the above range, an insulating film with excellent thermal shock resistance, heat resistance, residual film rate, etc. can be implemented.

The carboxyl group-containing resin is not particularly limited as long as it is a polymer having a carboxyl group. For example, it is obtained by vinyl polymerizing a carboxyl group-containing vinyl monomer and, if necessary, a hydrophobic group-containing vinyl monomer.

Examples of carboxyl group-containing vinyl monomers include unsaturated monocarboxylic acids [(meth)acrylic acid, crotonic acid, and cinnamic acid, etc.], unsaturated polyvalent (2-4) carboxylic acids [(anhydrous) maleic acid, itaconic acid, and fumaric acid. and citraconic acid, etc.], unsaturated polyhydric carboxylic acid alkyl (alkyl group having 1 to 10 carbon atoms) esters [maleic acid monoalkyl ester, fumaric acid monoalkyl ester, and citraconic acid monoalkyl ester, etc.], and their salts [alkali metal salts] (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), amine salts, ammonium salts, etc.].

Examples of the hydrophobic group-containing vinyl monomer include (meth)acrylic acid ester and aromatic hydrocarbon monomer.

Examples of (meth)acrylic acid esters include alkyl (meth)acrylates having 1 to 20 carbon atoms in the alkyl group [e.g., methyl (meth)acrylate, ethyl (meth)acrylate, and n-propyl (meth)acrylate. , isopropyl (meth)acrylate, n-butyl (meth)acrylate, n-hexyl (meth)acrylate and 2-ethylhexyl (meth)acrylate, etc.] and alicyclic group-containing (meth)acrylate [dicyclo Fentanyl (meth)acrylate, dicyclopentenyl (meth)acrylate, isobornyl (meth)acrylate, etc.].

Examples of aromatic hydrocarbon monomers include hydrocarbon monomers having a styrene skeleton [e.g., styrene, α-methylstyrene, vinyltoluene, 2,4-dimethylstyrene, ethylstyrene, isopropylstyrene, butylstyrene, phenylstyrene, cyclo hexyl styrene and benzyl styrene] and vinyl naphthalene.

The sulfonic acid group-containing resin is not particularly limited as long as it is a polymer having a sulfonic acid group. For example, it is obtained by vinyl polymerizing a sulfonic acid group-containing vinyl monomer and, if necessary, a hydrophobic group-containing vinyl monomer.

As the hydrophobic group-containing vinyl monomer, the same ones as those described above can be used.

Examples of vinyl monomers containing a sulfonic acid group include vinyl sulfonic acid, (meth)allylsulfonic acid, styrene sulfonic acid, α-methylstyrene sulfonic acid, 2-(meth)acryloylamide-2-methylpropane sulfonic acid, and salts thereof. You can. Salts include alkali metal (sodium and potassium, etc.) salts, alkaline earth metal (calcium and magnesium, etc.) salts, primary to tertiary amine salts, ammonium salts, and quaternary ammonium salts.

The second resin itself may be insoluble or poorly soluble in an alkaline developer.

The acid dissociable group of the second resin is a group that can dissociate in the presence of an acid generated from a photoacid generator. For example, substituted methyl group, 1-substituted ethyl group, 1-branched alkyl group, silyl group, germyl group, alkoxycarbonyl group, acyl group, and cyclic acid dissociable group. These may be used individually by 1 type, or may be used in combination of 2 or more types.

1-Substituted methyl groups include, for example, methoxymethyl group, methylthiomethyl group, ethoxymethyl group, ethylthiomethyl group, methoxyethoxymethyl group, benzyloxymethyl group, benzylthiomethyl group, phenacyl group, bromophenacyl group, and methoxy. Phenacyl group, methylthiophenacyl group, α-methylphenacyl group, cyclopropylmethyl group, benzyl group, diphenylmethyl group, triphenylmethyl group, bromobenzyl group, nitrobenzyl group, methoxybenzyl group, methylthiobenzyl group, ethoxy Benzyl group, ethylthiobenzyl group, piperonyl group, methoxycarbonylmethyl group, ethoxycarbonylmethyl group, n-propoxycarbonylmethyl group, i-propoxycarbonylmethyl group, n-butoxycarbonylmethyl group, tert- Butoxycarbonylmethyl group, etc. are mentioned.

Examples of 1-substituted ethyl groups include 1-methoxyethyl group, 1-methylthioethyl group, 1,1-dimethoxyethyl group, 1-ethoxyethyl group, 1-ethylthioethyl group, 1,1-diethoxyethyl group, 1-Ethoxypropyl group, 1-propoxyethyl group, 1-cyclohexyloxyethyl group, 1-phenoxyethyl group, 1-phenylthioethyl group, 1,1-diphenoxyethyl group, 1-benzyloxyethyl group, 1-benzyl Thioethyl group, 1-cyclopropylethyl group, 1-phenylethyl group, 1,1-diphenylethyl group, 1-methoxycarbonylethyl group, 1-ethoxycarbonylethyl group, 1-n-propoxycarbonylethyl group, 1- Examples include isopropoxycarbonylethyl group, 1-n-butoxycarbonylethyl group, and 1-tert-butoxycarbonylethyl group.

Examples of the 1-branched alkyl group include i-propyl group, sec-butyl group, tert-butyl group, 1,1-dimethylpropyl group, 1-methylbutyl group, 1,1-dimethylbutyl group, etc. there is.

Silyl groups include, for example, trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl group, and tri-i-propylsilyl group. , tricarbyl silyl groups such as tert-butyldimethylsilyl group, methyldi-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, and triphenylsilyl group. .

Germyl groups include, for example, trimethyl germyl group, ethyldimethyl germyl group, methyl diethyl germyl group, triethyl germyl group, isopropyl dimethyl germyl group, methyl di-i-propyl germyl group, and tri-i-propyl germyl group. , tert-butyldimethylgermyl group, methyldi-tert-butylgermyl group, tri-tert-butylgermyl group, phenyldimethylgermyl group, methyldiphenylgermyl group, and tricarbylgermyl group such as triphenylgermyl group. there is.

Examples of the alkoxycarbonyl group include methoxycarbonyl group, ethoxycarbonyl group, i-propoxycarbonyl group, and tert-butoxycarbonyl group.

Acyl groups include, for example, acetyl group, propionyl group, butyryl group, heptanoyl group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauroyl group, myristoyl group, palmitoyl group, stearoyl group, Oxalyl group, malonyl group, succinyl group, glutaryl group, adipoyl group, piperoyl group, suberoyl group, azelaoyl group, sebacoyl group, acryloyl group, propioloyl group, methacryloyl group, crotonoyl group Diary, oleoyl group, maleoyl group, fumaroyl group, mesaconyl group, camphoroyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluoyl group, hydroatrophoyl group, Examples include atropoyl group, cinnamoyl group, furoyl group, thenoyl group, nicotinoyl group, isonicotinoyl group, p-toluenesulfonyl group, and mesyl group.

Examples of cyclic acid-dissociable groups include cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclohexenyl group, 4-methoxycyclohexyl group, tetrahydropyranyl group, tetrahydrofuranyl group, and tetrahydrothiopyranyl group. , tetrahydrothiofuranyl group, 3-bromotetrahydropyranyl group, 4-methoxytetrahydropyranyl group, 4-methoxytetrahydrothiopyranyl group, 3-tetrahydrothiophene-1,1-dioxide group, etc. I can hear it.

The positive polymer resin may include a first resin and a second resin, and the content of the first resin may be 50 parts by weight or less with respect to 100 parts by weight of the positive polymer resin. That is, the content of the second resin may be 50 to 100 parts by weight based on 100 parts by weight of the positive polymer resin.

The negative polymer resin may include a phenolic hydroxyl group-containing resin. The phenolic hydroxyl group-containing resin may be as described above.

The content of the polymer resin may be 50 to 95 parts by weight based on 100 parts by weight of solid content of the photoresist composition. When the polymer resin is included in an amount within the above range, a film can be appropriately formed from the photoresist composition, and while the film has sufficient developability with an alkaline developer, a high-resolution fine pattern can be realized upon light irradiation.

The solvent included in the photoresist composition is not particularly limited as long as it can dissolve the polymer resin and the photoacid generator, has an appropriate drying speed, and can form a coating film with a uniform and smooth surface after evaporation of the solvent.

For example, glycol ether esters such as ethyl cellosolve acetate, methyl cellosolve acetate, propylene glycol monomethyl ether acetate, and propylene glycol monoethyl ether acetate; Glycol ethers such as ethyl cellosolve, methyl cellosolve, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; esters such as ethyl acetate, butyl acetate, amyl acetate, and ethyl pyruvate; Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, 2-heptone, and cyclohexanone; and cyclic esters such as γ-butyrolacetone, ethyl lactate; Known solvents such as N-methylpyrrolidone, N,N-dimethylformamide, dimethyl sulfoxide, toluene, ethanol, cyclohexanone, methanol, methyl ethyl ketone, and xylene can be used.

The content of the solvent may be 30 to 1000 parts by weight, or 50 to 800 parts by weight, based on 100 parts by weight of solid content of the photoresist composition.

Additionally, the photoresist composition may include a crosslinking agent. The crosslinking agent is not particularly limited as long as it is a compound that can crosslink the negative polymer resin with an acid generated from a photo acid generator upon light irradiation.

Examples of the crosslinking agent include bisphenol A-based epoxy compounds, bisphenol F-based epoxy compounds, bisphenol S-based epoxy compounds, novolac resin-based epoxy compounds, resol resin-based epoxy compounds, poly(hydroxystyrene)-based epoxy compounds, and oxetane compounds. , melamine compound containing methylol group, benzoguanamine compound containing methylol group, urea compound containing methylol group, phenol compound containing methylol group, melamine compound containing alkoxyalkyl group, benzoguanamine compound containing alkoxyalkyl group, urea compound containing alkoxyalkyl group, containing alkoxyalkyl group. Phenol compound, melamine resin containing carboxymethyl group, benzoguanamine resin containing carboxymethyl group, urea resin containing carboxymethyl group, phenol resin containing carboxymethyl group, melamine compound containing carboxymethyl group, benzoguanamine compound containing carboxymethyl group, urea compound containing carboxymethyl group and carboxymethyl group containing and methyl group-containing phenol compounds.

The content of the crosslinking agent may be 0.1 to 10 parts by weight based on 100 parts by weight of solid content of the photoresist composition. Alternatively, the content of the crosslinking agent may be 5 to 60 mol% based on the total acidic functional groups of the negative polymer resin.

The photoresist composition may also include optional additives. Additives include benzotriazole-based, triazine-based, and benzoate-based ultraviolet absorbers; Phenolic, phosphorus, and sulfur-based antioxidants; Antistatic agents consisting of cationic surfactants, anionic surfactants, nonionic surfactants, and amphoteric surfactants; Flame retardants such as halogen-based compounds, phosphoric acid ester-based compounds, phosphoric acid amide-based compounds, melamine-based compounds, fluororesins or metal oxides, melamine (poly) phosphate, and piperazine (poly) phosphate; Hydrocarbon-based, fatty acid-based, fatty alcohol-based, fatty ester-based, aliphatic amide-based or metallic soap-based lubricants; Colorants such as dyes, pigments, and carbon black; Fumed silica, particulate silica, silica, diatomaceous earth, clay, kaolin, diatomaceous earth, silica gel, calcium silicate, sericite, kaolinite, flint, feldspar powder, vermiculite, attapulgite, talc, mica, silicic acid-based inorganic additives such as minnesite, pyrophyllite, and silica; Fillers such as glass fiber and calcium carbonate; Examples include crystallizing agents such as nucleating agents and crystal accelerators, silane coupling agents, rubber elasticity imparting agents such as flexible polymers, and sensitizers.

The additive may be used in an amount that does not inhibit the reaction of the photoacid generator and the polymer resin.

The photoresist composition can be used to form a photoresist pattern. The method of forming a pattern using the photoresist composition includes forming a photoresist film using a photoresist composition on a substrate, selectively exposing the photoresist film to light using a mask, and developing the exposed photoresist film. Steps may be included.

The step of forming the photoresist film can be performed using conventional methods such as spin coating, dipping, spraying, and rotation. The photoresist film may be prebaked at a temperature of 20 to 100° C., and the prebake may be performed to evaporate the solvent without thermally decomposing the solid components in the photoresist composition. Line baking can be performed until most of the solvent has evaporated and a thin coating film remains on the substrate.

The exposure step can be performed by selectively exposing the photoresist film using a mask. After performing the exposure process, post exposure bake (PEB) may be performed.

In the exposure process, the photoacid generator may be decomposed to generate sulfonic acid. The light source used in the exposure is not particularly limited as long as it can decompose the photoacid generator. For example, low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high pressure mercury lamp, xenon lamp, metal halide lamp, electron beam irradiation device, X-ray irradiation device, laser (argon laser, dye laser, nitrogen laser, LED, helium cadmium laser, etc.) etc. can be used as a light source, or light with an i-line (365 nm) wavelength can be used as a light source.

The post-exposure bake (PEB) temperature may be, for example, 40 to 200°C, or 50 to 190°C. Additionally, heating after exposure may be performed for 1 to 120 minutes, or may be performed for 2 to 90 minutes. When heating is performed after exposure at a temperature and time within the above range, a sufficient difference in solubility between the exposed and unexposed areas can be achieved while ensuring productivity.

The development step of the selectively exposed photoresist film includes sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, triethylamine, tetramethylammonium hydroxide, and tetraethyl This can be done using an alkaline developer such as ammonium hydroxide or (2-hydroxyethyl)trimethylammonium hydroxide.

As a development method, an appropriate method can be adopted among a dip method using an alkaline developer, a shower method, and a spray method.

After the substrate on which the photoresist pattern is formed is removed from the developer, a hardbake process may be performed to improve the adhesion and chemical resistance of the photoresist film. The post-bending process is preferably performed at a temperature below the softening point of the photoresist film, and is preferably performed at a temperature of about 100 to 150° C.

Hereinafter, embodiments of the present invention will be further described with reference to specific experimental examples. The examples and comparative examples included in the experimental examples only illustrate the present invention and do not limit the scope of the appended patent claims, and various changes and modifications to the examples are possible within the scope and technical idea of the present invention. It is obvious to those skilled in the art, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

Example 1

Manufacturing of photoacid generators

The compound of Formula 3 was prepared according to Scheme 1 below.

[Scheme 1]

(1) 1,2-bis(2-mercaptoethoxy)ethane 1 of the above formula 6-1 in dimethyl sulfoxide solvent in the presence of 1,4-diaza-bicyclo[2,2,2]octane. The compound of Formula 7-2 was prepared by reacting the equivalent with 2 equivalents of 4-bromo-1,8-naphthalic anhydride of Formula 5-2 for 30 to 40 minutes.

(2) The compound of Formula 8-2 was prepared by reacting 1 equivalent of the compound of Formula 7-2 with 2 equivalents of hydroxylamine hydrochloride under reflux for 30 minutes in an ethanol solvent in the presence of sodium bicarbonate.

(3) In a pyridine solvent, 1 equivalent of the compound of Formula 8-2 was reacted with 2 equivalents of trifluoromethyl sulfonic anhydride at a temperature of 0 to 25° C. for about 2 hours to prepare the compound of Formula 3.

Preparation of binder resin

After adding 200 ml of propylene glycol monomethyl ether acetate (PGMEA) and 1.5 g of azobisisobutyronitrile (AIBN) to a 500 ml polymerization vessel, acetoxystyrene, styrene, and t-butoxymethacrylate were added at 50% each. A binder resin was prepared by adding solid content to 40% by weight at a molar ratio of 25:25 and polymerizing it with stirring at 70°C for 5 hours under a nitrogen atmosphere. The weight average molecular weight of the copolymer prepared in this way was confirmed to be 25,000, and the degree of dispersion was confirmed to be 2.0.

Preparation of photoresist compositions

In a reaction mixing tank equipped with a UV screen and a stirrer, 97 parts by weight of the binder resin prepared above, 0.4 parts by weight of the compound of formula 3 prepared above as a photoacid generator, and FC-430 (leveling agent from 3M, 0.02 parts by weight) %) 0.1 part by weight was sequentially added, stirred at room temperature, and then PGMEA was added as a solvent to a solid content of 50% by weight to prepare a photoresist composition.

Example 2

As a photoacid generator, instead of 1,2-bis(2-mercaptoethoxy)ethane of Chemical Formula 6-1, the compound of Chemical Formula 2 prepared using 1,2-ethanedithiol was used. A photoresist composition was prepared in the same manner as Example 1.

Example 3

As a photoacid generator, Example 1 and A photoresist composition was prepared in the same manner.

Comparative example

A photoresist composition was prepared in the same manner as in Example 1, except that as a photoacid generator, a compound of the following formula 9 was used instead of 1,2-bis(2-mercaptoethoxy)ethane of the formula 6-1. did.

[Formula 9]

Experimental Example 1: Evaluation of solubility of photoacid generator

Solubility at room temperature (weight of saturated solution) of compounds represented by Chemical Formulas 3, 2, 4, and 9, which are photoacid generators used in the photoresist compositions of Examples and Comparative Examples, in propylene glycol monomethyl ether (PGMEA) and cyclohexane %) were measured respectively and are shown in Table 1 below.

compound Solubility (% by weight) PGMEA cyclohexane Formula 2 5.3 12.5 Formula 3 8.8 22.4 Formula 4 7.5 20.1 Formula 9 1.5 5.3

Referring to Table 1, the compounds corresponding to the examples of Formula 1 have high solubility in PGMEA and cyclohexane, which are solvents mainly used in photoresist compositions, but the compounds of Formula 9 containing only one naphthalimide group are PGMEA and It can be seen that the solubility in cyclohexane is very low.

Experimental Example 2: Evaluation of photoresist composition

Evaluation of the photoresist compositions of the above Examples and Comparative Examples was conducted on a silicon wafer substrate, and the pattern stability and taper angle of the photoresist composition were measured, and the evaluation results are shown in Table 2 below. The specific experimental method is as follows.

1) Pattern stability

The photoresist composition was spin coated on a silicon wafer substrate, dried on a hot plate at 90°C for 1 minute, and then exposed to i-line (365 nm) wavelength light for 1 minute using a line-space (10μm-10μm) step mask. Afterwards, it went through a post-exposure bake process and was then developed in a 2.384% aqueous solution of trimethylammonium hydroxide (TMAH). After development, the width of the pattern in the space portion was measured.

In addition, the values of the examples were expressed as a ratio based on the values measured for the photoresist composition of the comparative example.

2) Taper angle

The photoresist composition was spin-coated on a silicon wafer substrate, dried on a hot plate at 90°C for 1 minute, and then exposed to i-line (365 nm) wavelength light for 1 minute using a line-space (10μm-10μm) step mask. Afterwards, it went through a post-exposure bake process and was then developed in a 2.384% TMAH aqueous solution. After development, the taper angle of the space portion was measured and evaluated according to the following criteria.

- Above 85° and below 90°: Good

- Less than 85° or more than 91°: defective

photoresist
composition Width of space CD pattern ( ) Value compared to comparative example Taper angle state Example 1 11.5 1.03 Good Example 2 11.9 1.06 Good Example 3 11.8 1.05 Good Comparative example 11.2 1.00 error

Referring to Table 2, it can be seen that even when light is irradiated under the same conditions, the width of the space CD pattern in the photoresist compositions of the Examples is formed larger than that of the photoresist compositions in the Comparative Examples.

In addition, it can be confirmed that the taper angle of the pattern formed with the photoresist composition of the examples was also 85 to 90 °, thereby realizing the verticality of the pattern.

In the case of the comparative example, it can be seen that the sensitivity to the same light irradiation is somewhat low because the space CD pattern is formed with a narrow width compared to the width of the space CD pattern of the examples, and the verticality of the pattern is somewhat inferior beyond the good taper angle range. You can check that.

That is, when a photoacid generator containing the compound represented by Formula 1 is included in the photoresist composition, sensitivity is excellent, making it possible to form fine patterns and implement patterns with improved verticality.

Claims (8)

A photoacid generator containing a compound represented by the following formula (1):
[Formula 1]

(In Formula 1, R ₁ and R ₂ are each independently a substituted or unsubstituted C1 to C10 alkyl group, a C1 to C10 perfluoroalkyl group, or a substituted or unsubstituted C6 to C12 aryl group, and R ₃ is a substituted or a substituted or unsubstituted C1 to C10 alkylene group; a substituted or unsubstituted C6 to C12 arylene group; or at least one selected from the group consisting of an ether group, a thioether group, a carbonyl group, or an ester group. It is a hydrocarbon group of C2 to C10 of the ring).
The photoacid generator according to claim 1, wherein R ₁ and R ₂ are independently C1 to C8 perfluoroalkyl groups.
The photoacid generator according to claim 1, wherein R ₃ is a C2 to C5 linear or branched alkylene group.
The photoacid generator according to claim 1, wherein R ₃ is a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ether groups.
The photoacid generator according to claim 1, wherein R ₃ is a substituted or unsubstituted C3 to C10 hydrocarbon group containing 1 to 3 ester groups.
The photoacid generator according to claim 1, wherein the compound includes a compound represented by any one of the following formulas 2 to 4:
[Formula 2]

[Formula 3]

[Formula 4]
.
A photoresist composition comprising the photoacid generator according to any one of claims 1 to 6.
The photoresist composition of claim 7, wherein the content of the photoacid generator is 0.01 to 15 parts by weight based on 100 parts by weight of solid content of the photoresist composition.