Photoresist composition containing amide compound and pattern forming method using the same

Abstract

This document discloses a photoresist composition comprising a first polymer containing an acid-instable group; a photoacid generator; and an acid diffusion controller comprising a trialkylamide compound having a lipophilicity (logP) value greater than 11.

Description

Technical Field

[0001] This invention generally relates to the manufacture of electronic devices. More specifically, this invention relates to photoresist compositions and photolithography processes that allow the formation of fine patterns using negative development processes. Background Technology

[0002] Significant efforts have been made to expand the practical resolving power of positive development in immersion lithography, both in terms of materials and processing. One example involves negative development (NTD), an image inversion technique that allows the printing of critical dark layers using the superior imaging quality achieved through brightfield masks. NTD resists typically use resins with acid-indestabilized groups and photoacid generators. Exposure to photochemical radiation causes the photoacid generator to form acid, which breaks down the acid-indestabilized groups in the resin during post-exposure baking. As a result, a difference in the solubility properties of the organic developer is created between the exposed and unexposed areas of the resist, causing the unexposed areas of the resist to be removed by the developer, leaving a pattern formed by the insoluble exposed areas. This process is described, for example, in U.S. Patent No. 6,790,579 to Goodall et al. For the resist chemicals described, the exposed areas of the resist layer can be selectively removed with an alkaline developer, or alternatively, the unexposed areas can be selectively removed by treatment with a suitable nonpolar solvent for negative development.

[0003] The inventors have observed that surface inhibition of photoresist in NTD processes can lead to "necking" of contact holes or "T-tops" in line and trench patterns within the developed resist pattern. The presence of necking and T-tops typically results in a poorer process window, including depth of focus and exposure latitude. These problems can lead to, for example, randomly missing contact holes or microbridging defects when forming narrow trench or line patterns, thus adversely affecting device yield.

[0004] U.S. Patent Publication No. US 2011 / 0294069 A1 by Bae et al. discloses a photoresist composition comprising an acid-sensitive matrix polymer; a specific additive polymer having a surface energy lower than that of a first polymer; a photoacid generator; and a solvent. While this document acknowledges the problems associated with surface inhibition, further improved solutions to these problems remain needed.

[0005] There is a persistent need in the art for improved compositions and lithography methods for negative development that allow for the formation of fine patterns in electronic device manufacturing and address one or more problems associated with the prior art. Summary of the Invention

[0006] This document discloses a photoresist composition comprising a first polymer containing an acid-instable group; a photoacid generator; and an acid diffusion controller comprising a trialkylamide compound having a lipophilicity (logP) value greater than 11. Detailed Implementation

[0007] As used herein, the terms “a / an” and “the” do not indicate a limitation of quantity and are to be construed as including both the singular and plural unless otherwise indicated herein or clearly contradicted by the context. Unless otherwise explicitly stated, “or” means “and / or”.

[0008] As used herein, an "acid-indestructible group" refers to a group in which the bond is broken by the catalytic action of an acid (optionally and typically in conjunction with heat treatment), resulting in the formation of a polar group (such as a carboxylic acid or alcohol group) on the polymer, and optionally and typically, a portion attached to the broken bond that is disconnected from the polymer. Such acids are typically photogenerated acids where bond breaking occurs during post-exposure baking. Suitable acid-indestructible groups include, for example, tertiary alkyl ester groups, secondary or tertiary aryl ester groups, secondary or tertiary ester groups having a combination of alkyl and aryl groups, tertiary alkoxy groups, acetal groups, or ketal groups. Acid-indestructible groups are also commonly referred to in the art as "acid-crackable groups," "acid-crackable protecting groups," "acid-indestructible protecting groups," "acid-leaving groups," "acid-decomposable groups," and "acid-sensitive groups."

[0009] This document discloses a photoresist composition comprising a polymer containing an acid-indestabilizing group; a photoacid generator; and an acid diffusion controller, wherein the acid diffusion controller comprises a trialkylamide compound having a lipophilicity (logP) value greater than 11. Each alkyl chain of the trialkyl functional group may contain substituted or unsubstituted C7 to C8 groups and may be linear, cyclic, or branched. 20 alkyl.

[0010] The use of straight-chain or branched trialkyl-substituted amide compounds in photoresists can significantly improve the contours of embossed images, such as contact holes. In particular, the use of trialkyl-substituted amide compounds, in which each alkyl chain has 7 to 20 carbon atoms, shows improved lithographic results compared to other photoresists containing amide complexes with shorter alkyl chain lengths or other types of basic additives such as amine compounds.

[0011] Lipophilicity is most often referred to as LogP, which represents the concentration ratio of a compound between two phases (oil and liquid phases) at equilibrium. The LogP value is a constant defined as follows: LogP = log10 (partition coefficient), where partition coefficient P = [organic] / [aqueous], and the square brackets “[]” indicate the concentration of the solute in the organic and aqueous portions.

[0012] The photoresist composition comprises one or more matrix polymers containing acid-indestructible groups. Acid-indestructible groups are chemical moieties that readily undergo deprotection reactions in the presence of acid. The solubility of the matrix polymer, which is part of the photoresist composition layer, changes in the developer as a result of reactions with acids generated by photoacid generators after soft baking, exposure to activated radiation, and post-exposure baking. This is due to the cleavage of the photoacid-induced acid-indestructible groups, leading to a change in the polarity of the matrix polymer. The acid-indestructible groups can be selected, for example, from tertiary alkyl carbonates, tertiary alkyl esters, tertiary alkyl ethers, acetals, and ketals. Preferably, the acid-indestructible group is an ester group containing a tertiary acyclic alkyl carbon or a tertiary alicyclic carbon covalently linked to the carboxyl oxygen of the ester in the matrix polymer. Cleavage of such acid-indestructible groups results in the formation of carboxylic acid groups.

[0013] Suitable units containing acid-instable groups include, for example, acid-instable (alkyl)acrylate units, such as tert-butyl (meth)acrylate, 1-methylcyclopentyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-isopropylcyclopentyl (meth)acrylate, 1-propylcyclopentyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclohexyl (meth)acrylate, 1-isopropylcyclohexyl (meth)acrylate, 1-propylcyclohexyl (meth)acrylate, tert-butylmethyladamantyl (meth)acrylate, ethyl fentanyl (meth)acrylate, etc., as well as other cyclic and acyclic (alkyl) acrylates, including alicyclic ones. The unstable groups in acetals and ketals can be substituted by the terminal hydrogen atom of a base-soluble group, such as a carboxyl or hydroxyl group, thereby bonding with an oxygen atom. When an acid is formed, the acid breaks the bond between the acetal or ketal group and the oxygen atom, which then bonds to a dissociable, dissolution-inhibiting group of the acetal acid. Exemplary examples of such acid-indestructible groups are described, for example, in U.S. Patent Nos. US 6057083, US 6136501, and US 8206886, and European Patent Publications EP 01008913 A1 and EP 00930542 A1. Acetal and ketal groups, which are part of sugar-derived structures, are also suitable, the cleavage of which results in the formation of carboxyl groups, such as those described in U.S. Patent Application No. US 2012 / 0064456A1.

[0014] For wavelengths of 200 nm or greater, such as 248 nm, suitable resin materials include, for example, phenolic resins containing acid-labile groups. Particularly preferred resins of this class include: (i) polymers containing vinylphenol and acid-labile (alkyl)acrylate polymeric units as described above, such as those described in U.S. Patent Nos. 6,042,997 and 5,492,793; (ii) polymers containing vinylphenol, optionally substituted vinylphenyl (e.g., styrene) without hydroxyl or carboxyl ring substituents, and acid-labile (alkyl)acrylate polymers as described above, such as those described in U.S. Patent No. 6,042,997; (iii) polymers containing repeating units comprising acetal or ketal moieties that react with photoacids and optionally aromatic repeating units such as phenyl or phenolic groups; such polymers are described in U.S. Patent Nos. 5,929,176 and 6,090,526; and blends of (i) and / or (ii) and / or (iii).

[0015] For imaging at wavelengths less than 200 nm, such as 193 nm, the matrix polymer is typically substantially free (e.g., less than 15 mol%), and preferably completely free of phenyl, benzyl, or other aromatic groups, which highly absorb radiation. Suitable polymers substantially or completely free of aromatic groups are disclosed in European Patent Publication No. EP930542A1 and U.S. Patent Nos. 6,692,888 and 6,680,159.

[0016] Other suitable matrix polymers include, for example, those containing polymeric units of non-aromatic cyclic olefins (inner ring double bonds), such as optionally substituted norbornene, for example, the polymers described in U.S. Patent Nos. 5,843,624 and 6,048,664. Other suitable matrix polymers include polymers containing polymeric anhydride units, particularly polymeric maleic anhydride units and / or itaconic anhydride units, as disclosed in European Publication Application EP01008913 A1 and U.S. Patent No. 6,048,662.

[0017] Also suitable as matrix polymers are resins containing repeating units that contain heteroatoms, particularly oxygen and / or sulfur (but not acid anhydrides, i.e., the units do not contain ketone ring atoms). Heterocyclic units can be fused to the polymer backbone and can comprise fused carbocyclic units (such as those provided by polymerization of norbornene groups) and / or acid anhydride units (such as those provided by polymerization of maleic anhydride or itaconic anhydride). Such polymers are described in International Publication No. WO 0186353A1 and U.S. Patent No. 6,306,554. Other suitable matrix polymers containing heteroatom-containing groups include polymers containing polymeric carbocyclic aryl units (e.g., hydroxynaphthyl) substituted with one or more heteroatom-containing (e.g., oxygen or sulfur) groups, as disclosed in U.S. Patent No. 7,244,542.

[0018] For wavelengths less than 200 nm, such as 193 nm, and EUV (e.g., 13.5 nm), the matrix polymer typically further comprises units containing a lactone moiety to control the dissolution rate of the matrix polymer and photoresist composition. Monomers suitable for matrix polymers containing a lactone moiety include, for example, the following:

[0019]

[0020]

[0021] This matrix polymer further typically comprises units containing polar groups, which enhance the etch resistance of the matrix polymer and photoresist composition and provide an additional means of controlling the dissolution rate of the matrix polymer and photoresist composition. Monomers used to form such units include, for example, the following:

[0022]

[0023] The matrix polymer may contain one or more additional units of the type described above. Typically, the additional units for the matrix polymer will include the same or similar polymerizable groups as those used in the monomers used to form other units of the polymer, but may include other different polymerizable groups in the same polymer backbone.

[0024] The matrix polymer has a higher surface energy than the additive polymers described below, and should be substantially immiscible with the additive polymers. Due to the difference in surface energy, the additive polymers separate from the matrix polymers during spin coating. Suitable matrix polymers typically have surface energies from 20 to 50 mN / m, preferably from 30 to 40 mN / m.

[0025] Although not limited thereto, exemplary matrix polymers include, for example, the following:

[0026]

[0027] Other exemplary copolymers that can be used as the first polymer include, for example, the following:

[0028]

[0029]

[0030]

[0031] Suitable matrix polymers for use in the photoresist compositions of the present invention are commercially available and can be readily prepared by those skilled in the art. The matrix polymer is present in the photoresist composition in an amount sufficient to make the exposed coating of the photoresist developable in a suitable developer solution. Typically, the matrix polymer is present in the composition in an amount from 70 to 95 wt% based on the total solids of the photoresist composition. The weight-average molecular weight M of the matrix polymer is... w Typically less than 100,000, for example from 4,000 to 100,000, more typically from 4,000 to 15,000. Blends of two or more of the matrix polymers described above may be suitably used in the photoresist compositions of the present invention.

[0032] The photosensitive composition further comprises a photoacid generator (PAG), used in an amount sufficient to generate a latent image in the coating of the composition upon exposure to activating radiation. For example, the photoacid generator will suitably be present in an amount from about 1 to 30 wt% of the total solids of the photoresist composition. Typically, smaller amounts of the photoactive component will be suitable for chemically reinforced resists.

[0033] The photoresist composition further comprises one or more photoacid generators (PAGs). Suitable photoacid generator compounds may have the formula G. + A - G + It is an organic cation and A- is typically an organic anion containing a sulfonate group, such as a sulfonamide anion, a sulfonamide anion, or a methyl anion. Suitable organic anions include, for example, fluoroalkyl and alkyl sulfonates, fluoro-cycloalkyl and cycloalkyl sulfonates.

[0034]

[0035] Suitable organic cations include, for example, iodonium cations substituted with two alkyl, aryl, or combinations of alkyl and aryl groups; and sulfonium cations substituted with three alkyl, aryl, or combinations of alkyl and aryl groups. In some embodiments, G +It is an iodonium cation substituted with two alkyl, aryl, or a combination of alkyl and aryl groups; or a sulfonium cation substituted with three alkyl, aryl, or a combination of alkyl and aryl groups. In some embodiments, G + It is a substituted sulfonium cation having formula (2A):

[0036]

[0037] Among them, each R aa C is independent 1-20 Alkyl, C 1-20 fluoroalkyl, C 3-20 cycloalkyl, C 3-20 Fluorocycloalkyl, C 2-20 alkenyl, C 2-20 Fluoroolefin, C 6-30 Aryl, C 6-30 Fluoroaryl, C 6-30 Iodoaryl, C 1-30 heteroaryl, C 7-20 Arylalkyl, C 7-20 Fluoroarylalkyl, C 2-20 heteroarylalkyl, or C 2-20 Fluoroarylalkyl groups, each of which is substituted or unsubstituted, wherein each R aa It is attached to another group R independently or via a single bond or divalent linker. aa Form a loop. Each R aa Optionally, it may include one or more groups selected from the following as part of its structure: -O-, -C(O)-, -C(O)-O-, -C 1-12 -, -O-(C) 1-12 (-, -C(O)-O-(C) 1-12 (Hydroalkyl)- and -C(O)-O-(C 1-12 (Hydroxy)-O-. Each R aa Independently, it may optionally contain an acid-instable group selected from, for example, the following: tertiary alkyl ester group, secondary or tertiary aryl ester group, secondary or tertiary ester group having a combination of alkyl and aryl groups, tertiary alkoxy group, acetal group, or ketal group. Suitable for connecting R aa The divalent linking group of the group includes, for example, -O-, -S-, -Te-, -Se-, -C(O)-, -C(S)-, -C(Te)-, or -C(Se)-, substituted or unsubstituted C- groups. 1-5 Alkylenes and combinations thereof.

[0038] Exemplary sulfonium cations having formula (2A) include the following:

[0039]

[0040]

[0041] Suitable PAGs include, for example: onium salts, such as triphenylsulfonium trifluoromethane sulfonate, (p-tert-butoxyphenyl)diphenylsulfonium trifluoromethane sulfonate, tri(p-tert-butoxyphenyl)sulfonium trifluoromethane sulfonate, and triphenylsulfonium p-toluene sulfonate; nitrobenzyl derivatives, such as 2-nitrobenzyl p-toluene sulfonate, 2,6-dinitrobenzyl p-toluene sulfonate, and 2,4-dinitrobenzyl p-toluene sulfonate; sulfonates, such as 1,2,3-tris(methanesulfonyloxy)benzene, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, and 1,2,3-tris(p-toluenesulfonyloxy)benzene; and diazomethane derivatives, such as bis( (benzenesulfonyl)diazomethane, bis(p-toluenesulfonyl)diazomethane; dioxime derivatives, such as bis-O-(p-toluenesulfonyl)-α-dimethyldioxime, and bis-O-(n-butanesulfonyl)-α-dimethyldioxime; sulfonate derivatives of N-hydroxyimide compounds, such as N-hydroxysuccinimide methanesulfonate, N-hydroxysuccinimide trifluoromethanesulfonate; and halogenated triazine compounds, such as 2-(4-methoxyphenyl)-4,6-bis(trichloromethyl)-1,3,5-triazine, and 2-(4-methoxynaphthyl)-4,6-bis(trichloromethyl)-1,3,5-triazine. One or more of these PAGs may be used.

[0042] Suitable photoacid generators are further described in U.S. Patent No. 8,431,325 to Hashimoto et al., in column 37, lines 11-47 and 41-91. Other suitable sulfonate PAGs include sulfonated esters and sulfonyloxy ketones, nitrobenzyl esters, s-triazine derivatives, benzoin toluene sulfonate, α-(p-toluenesulfonyloxy)-tert-butylphenyl acetate, and α-(p-toluenesulfonyloxy)-tert-butyl acetate; as described in U.S. Patent Nos. 4,189,323 and 8,431,325. Typically, the photoacid generator is present in the photoresist composition in an amount of 1 to 30 wt%, more typically 5 to 27 wt%, and more preferably 8 to 25 wt%, based on the total solids of the photoresist composition.

[0043] Suitable solvents for use in the photoresist compositions of the present invention include, for example: glycol ethers, such as 2-methoxyethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; propylene glycol monomethyl ether acetate; lactates, such as methyl lactate and ethyl lactate; propionates, such as methyl propionate, ethyl propionate, ethoxypropionate, and methyl-2-hydroxyisobutyrate; cellosol esters, such as methyl cellosol acetate; aromatic hydrocarbons, such as toluene and xylene; and ketones, such as methyl ethyl ketone, cyclohexanone, and 2-heptanone. Blends of solvents, such as blends of two, three, or more of the solvents described above, are also suitable. The solvents are typically present in the composition in an amount of 90 to 99 wt%, more typically 95 to 98 wt%, based on the total weight of the photoresist composition.

[0044] Other optional additives for use in photoresist compositions include, for example, photochemical dyes and contrast dyes, anti-stripping agents, plasticizers, speed enhancers, sensitizers, etc. If used, such optional additives are typically present in the composition in small amounts, for example, from 0.1 to 10 wt% based on the total solids of the photoresist composition, but fillers and dyes may be present in larger amounts, for example, from 5 to 30 wt% based on the total solids of the photoresist composition.

[0045] A preferred optional additive in the resist composition of the present invention is an added base, which can improve the resolution of the developed resist embossed pattern. Suitable alkaline quenchers include, for example: linear and cyclic amides and their derivatives, such as N,N-bis(2-hydroxyethyl)palmitamide, N,N-diethylacetamide, N1,N1,N3,N3-tetrabutylmalonamide, 1-methylazacycloheptan-2-one, 1-allylazacycloheptan-2-one, and tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propyl-2-ylcarbamate; aromatic amines, such as pyridine and di-tert-butylpyridine; aliphatic amines, such as triisopropanolamine, n-tert-butyldiethanolamine, tris(2-acetoxy-ethyl)amine, 2,2',2",2"'-(ethane-1,2-diylbis(azaalkyltri))amine, and 2,2',2",2"'-(ethane-1,2-diylbis(azaalkyltri))amine. Alkaline quenchers include 2-(dibutylamino)ethanol, 2,2',2'-nitrotriethanol; cyclic aliphatic amines such as 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, tert-butyl 1-pyrrolidinecarboxylate, tert-butyl 2-ethyl-1H-imidazolium-1-carboxylate, di-tert-butyl piperazine-1,4-dicarboxylate, and N-(2-acetoxy-ethyl)morpholine. Among these basic quenchers, 1-(tert-butoxycarbonyl)-4-hydroxypiperidine and triisopropanolamine are preferred. The added base is suitable for use in relatively small amounts, for example from 1 to 30 wt% relative to PAG, more typically from 5 to 15 wt% relative to PAG.

[0046] The photoresist composition further comprises an acid diffusion control agent comprising a trialkylamide compound having a lipophilicity (logP) value greater than 11, greater than 12, greater than 13, and greater than 15. The trialkylamide compound has the structure of formula (1).

[0047] Where R 1 R 2 and R 3 At least one of them is independently a linear, cyclic, or branched C7 to C8 chain. 20 An alkyl group, which may be substituted or unsubstituted. In one embodiment, preferably, R 1 R 2 and R 3 Each of the C7 to C8 molecules is independently a linear, cyclic, or branched chain. 20 An alkyl group, which may be substituted or unsubstituted. A substituted alkyl group is one in which at least one alkylene group is substituted by N, S, or O.

[0048] In the embodiment, R 1 R 2 Or R 3 It can be independently an alkyl group having 7 to 15 carbon atoms, a cycloalkyl group having 7 to 15 carbon atoms, or an alkyl group having at least one of the -CH2- groups having 7 to 15 carbon atoms substituted with N, S, or O.

[0049] In the embodiment, R 1 R 2 and R 3 It is an alkyl or cycloalkyl group having the same or different numbers of carbon atoms. In the examples, R 1 With R 2 Or R 3 Different numbers of carbon atoms, and R 2 and R 3 They have the same number of carbon atoms. In the examples, R 1 It is a straight-chain or branched alkyl or cycloalkyl group having 7 to 13 carbon atoms, while R 2 and R 3 They are straight-chain or branched alkyl or cycloalkyl groups, each having the same number of carbon atoms. In the examples, R 2 and R 3 They are straight-chain or branched alkyl or cycloalkyl groups, each having the same number of carbon atoms, from 7 to 15, preferably 8 to 13. In the examples, R 1 It is a straight-chain or branched alkyl or cycloalkyl group with an odd number of carbon atoms, while R 2 and R 3 It is a straight-chain or branched alkyl or cycloalkyl group having an even number of carbon atoms.

[0050] Trialkylamide compounds are present in the photoresist composition in an amount from 0.3 to 5 wt%, more typically from 0.8 to 2 wt%, based on the total solids of the photoresist composition.

[0051] The photoresist used according to the present invention is generally prepared according to known procedures. For example, the photoresist of the present invention can be prepared into a coating composition by dissolving the components of the photoresist in a suitable solvent, such as one or more of the following: glycol ethers, such as 2-methoxyethyl ether (diethylene glycol dimethyl ether), ethylene glycol monomethyl ether, propylene glycol monomethyl ether; propylene glycol monomethyl ether acetate; lactate esters, such as ethyl lactate or methyl lactate, wherein ethyl lactate is preferred; propionate esters, particularly methyl propionate, ethyl propionate and ethoxypropionate; cellosol esters, such as methyl cellosol acetate; aromatic hydrocarbons, such as toluene or xylene; or ketones, such as methyl ethyl ketone, cyclohexanone and 2-heptanone. The desired total solids content of the photoresist will depend on various factors such as the specific polymer in the composition, the final layer thickness and the exposure wavelength. Typically, the solid content of photoresist varies from 1 wt% to 10 wt% based on the total weight of the photoresist composition, and more typically from 2 wt% to 5 wt%.

[0052] The photoresist composition may further include one or more additional optional additives. For example, optional additives may include one or more photodegradable quenchers (also called photodegradable bases), basic quenchers other than the diamide quencher compounds described above, surfactants, resist stabilizers, photochemical dyes and contrast dyes, anti-stripping agents, plasticizers, speed enhancers, photosensitizers, etc., or combinations thereof. Unless otherwise stated below, optional additives are typically present in the photoresist composition in an amount of 0.01 to 10 wt% based on the total solids of the photoresist composition.

[0053] Photodegradable quenchers produce weak acids upon irradiation. The acids produced by photodegradable quenchers are not strong enough to react rapidly with acid-instable groups present in the resist matrix. Exemplary photodegradable quenchers include, for example, photodegradable cations, and are preferably also used to prepare strong acid-generating compounds but react with weak acids (pKa > 1) (e.g., C). 1-20 Carboxylic acid or C 1-20 Those anionic pairs of sulfonic acids. Exemplary carboxylic acids include formic acid, acetic acid, propionic acid, tartaric acid, succinic acid, cyclohexanecarboxylic acid, benzoic acid, salicylic acid, etc. Exemplary carboxylic acids include p-toluenesulfonic acid, camphorsulfonic acid, etc. In a preferred embodiment, the photodegradable quencher is a photodegradable organic zwitterionic compound, such as diphenyliodonium-2-carboxylic acid ester.

[0054] Exemplary alkaline quenchers include, for example: straight-chain aliphatic amines such as tributylamine, trioctylamine, triisopropanolamine, tetra(2-hydroxypropyl)ethylenediamine, n-tert-butyldiethanolamine, tris(2-acetoxy-ethyl)amine, 2,2',2",2"'-(ethane-1,2-diylbis(azanetriyl))tetraethanol, 2-(dibutylamino)ethanol, and 2,2',2"-nitrotriethanol; cyclic aliphatic amines, such as 1 -(tert-butoxycarbonyl)-4-hydroxypiperidine, tert-butyl 1-pyrrolidinecarboxylate, tert-butyl 2-ethyl-1H-imidazolium-1-carboxylate, di-tert-butyl piperazine-1,4-dicarboxylate, and N-(2-acetoxy-ethyl)morpholine; aromatic amines such as pyridine, di-tert-butylpyridine, and pyridinium; linear and cyclic amides and their derivatives such as N,N-bis(2-hydroxyethyl)palmitamide, N,N-diethylacetamide, N... 1 N 1 N 3 N 3 -Tetrabutylmalonamide, 1-methylazacycloheptan-2-one, 1-allylazacycloheptan-2-one and tert-butyl 1,3-dihydroxy-2-(hydroxymethyl)propyl-2-ylcarbamate; ammonium salts, such as quaternary ammonium salts of sulfonates, aminosulfonates, carboxylates and phosphonates; imines, such as primary and secondary aldehyde imines and ketimines; diazines, such as optionally substituted pyrazines, piperazines and phenazines; diazoles, such as optionally substituted pyrazoles, thiadiazoles and imidazoles; and optionally substituted pyrrolidones, such as 2-pyrrolidone and cyclohexylpyrrolidine.

[0055] Exemplary surfactants include fluorinated and nonfluorinated surfactants and can be ionic or nonionic, with nonionic surfactants being preferred. Exemplary fluorinated nonionic surfactants include perfluorinated C4 surfactants, such as FC-4430 and FC-4432 surfactants available from 3M Corporation; and fluorinated glycols, such as POLYFOX PF-636, PF-6320, PF-656, and PF-6520 fluorinated surfactants from Omnova. In this aspect, the photoresist composition further comprises a surfactant polymer containing fluorinated repeating units.

[0056] Photoresist compositions can be prepared according to known procedures. For example, a composition can be prepared by dissolving the solid (non-solvent) component of the composition in one or more solvent components.

[0057] A patterning method using the photoresist composition of the present invention will now be described. Suitable substrates on which the photoresist composition can be coated include electronic device substrates. A wide variety of electronic device substrates can be used in the present invention, such as: semiconductor wafers; polycrystalline silicon substrates; packaging substrates, such as multi-chip modules; flat panel display substrates; substrates for light-emitting diodes (LEDs) including organic light-emitting diodes (OLEDs); etc., wherein semiconductor wafers are typical. Such substrates are typically composed of one or more of silicon, polycrystalline silicon, silicon oxide, silicon nitride, silicon oxynitride, silicon germanide, gallium arsenide, aluminum, sapphire, tungsten, titanium, titanium-tungsten, nickel, copper, and gold. Suitable substrates can be in the form of wafers, such as those used for manufacturing integrated circuits, optical sensors, flat panel displays, integrated optical circuits, and LEDs. Such substrates can be of any suitable size. Typical wafer substrate diameters are 200 to 300 millimeters (mm), although wafers with smaller and larger diameters can be suitably used according to the present invention. The substrate may include one or more layers or structures that may optionally include active or operable portions of the formed device.

[0058] Typically, prior to coating the photoresist composition of the present invention, one or more photolithographic layers, such as hard mask layers (e.g., spin-coated carbon (SOC), amorphous carbon, or metal hard mask layers), CVD layers (e.g., silicon nitride (SiN), silicon oxide (SiO), or silicon oxynitride (SiON) layers), organic or inorganic underlayers, or combinations thereof, are provided on the upper surface of the substrate. These layers, together with the externally coated photoresist layer, form a photolithographic material stack.

[0059] Optionally, an adhesion promoter layer may be applied to the substrate surface prior to coating the photoresist composition. If an adhesion promoter is desired, any suitable adhesion promoter for polymer films may be used, such as silanes, typically organosilanes like trimethoxyvinylsilane, triethoxyvinylsilane, hexamethyldisilazane, or aminosilane coupling agents like γ-aminopropyltriethoxysilane. Particularly suitable adhesion promoters include those sold from DuPont Electronics & Imaging (Marlborough, Massachusetts) under the names AP 3000, AP 8000, and AP 9000S.

[0060] The photoresist composition can be coated onto a substrate by any suitable method, including spin coating, spraying, dip coating, blade coating, etc. For example, applying a photoresist layer can be accomplished by spin coating the photoresist in a solvent using a coating track, wherein the photoresist is dispensed onto a rotating wafer. During the dispensing process, the wafer is typically rotated at a speed of up to 4,000 rpm, for example 200 to 3,000 rpm, or for example 1,000 to 2,500 rpm, for 15 to 120 seconds to obtain a photoresist composition layer on the substrate. The thickness of the coated layer can be adjusted by changing the rotation speed and / or the solids content of the composition. The thickness of the photoresist layer formed by the composition of the present invention can vary widely depending on the application. For some applications, the resist can have a dried layer thickness of 10 to 400 nanometers (nm), preferably 15 to 200 nm, and more preferably 50 to 100 nm.

[0061] Next, the photoresist composition is typically soft-baked to minimize the solvent content in the layer, thereby forming a non-stick coating and improving the layer's adhesion to the substrate. Soft baking is typically performed, for example, on a heated plate or in an oven, with a heated plate being typical. The soft baking temperature and time will depend, for example, on the specific photoresist composition and thickness. Soft baking temperatures are typically from 70°C to 170°C, for example from 70°C to 150°C. Soft baking times are typically from 10 seconds to 20 minutes, for example from 1 minute to 10 minutes, or from 1 minute to 5 minutes. Those skilled in the art can readily determine the heating time based on the composition's components.

[0062] Next, the photoresist layer is patterned and exposed to activating radiation to create a solubility difference between the exposed and unexposed areas. The exposure of the photoresist composition to activating radiation, as described herein, indicates that radiation can form a latent image within the photoresist composition. Exposure is typically performed using a patterned photomask having optically transparent and optically opaque regions corresponding to the areas of the photoresist layer to be exposed and the areas of the photoresist layer to be unexposed, respectively. Alternatively, this exposure can be performed without a photomask in a direct-write method, typically used in electron beam lithography. The activating radiation typically has wavelengths less than 400 nm, less than 300 nm, or less than 200 nm, with wavelengths of 248 nm (KrF), 193 nm (ArF), and 13.5 nm (EUV) preferred, or in electron beam lithography. This method can be used in immersion or dry (non-immersion) lithography techniques. Exposure energy is typically 1 to 200 millijoules per square centimeter (mJ / cm²). 2 Preferably 10 to 100 mJ / cm 2 And more preferably 20 to 50 mJ / cm 2This depends on the composition of the exposed tool and the photoresist composition.

[0063] After the photoresist layer is exposed, post-exposure baking (PEB) of the exposed photoresist layer is performed. PEB can be performed, for example, on a heated plate or in an oven, with a heated plate being typical. The conditions of PEB will depend, for example, on the specific photoresist composition and layer thickness. PEB is typically performed at temperatures ranging from 80°C to 150°C for times ranging from 30 to 120 seconds. A latent image is formed in the photoresist, defined by polarity-converted regions (exposed regions) and non-polarity-converted regions (unexposed regions).

[0064] The exposed photoresist layer is then developed with a suitable developer to selectively remove areas of the layer that are soluble in the developer while retaining insoluble areas, forming the resulting photoresist pattern relief image. In the case of a positive development (PTD) process, the exposed areas of the photoresist layer are removed during development, while the unexposed areas are retained. Conversely, in a negative development (NTD) process, the exposed areas of the photoresist layer are retained during development, while the unexposed areas are removed. The application of the developer can be accomplished by any suitable method, as described above regarding the application of the photoresist composition, with spin coating being typical. The development time is the period of time during which the soluble areas of the photoresist are effectively removed, typically 5 to 60 seconds. Development is typically performed at room temperature.

[0065] Suitable developers for PTD processes include aqueous alkaline developers, such as quaternary ammonium hydroxide solutions, such as tetramethylammonium hydroxide (TMAH) (preferably 0.26 standard (N) TMAH), tetraethylammonium hydroxide, tetrabutylammonium hydroxide, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc. Suitable developers for NTD processes are based on organic solvents, meaning that the cumulative content of organic solvents in the developer is 50 wt% or more, typically 95 wt% or more, 95 wt% or more, 98 wt% or more, or 100 wt% based on the total weight of the developer. Suitable organic solvents for NTD developers include, for example, those selected from ketones, esters, ethers, hydrocarbons, and mixtures thereof. Typical developers are 2-heptanone or n-butyl acetate.

[0066] The coated substrate can be formed from the photoresist composition of the present invention. Such a coated substrate comprises: (a) a substrate having one or more layers to be patterned on its surface; and (b) a photoresist composition layer on said one or more layers to be patterned.

[0067] Photoresist patterns can be used, for example, as etching masks to transfer patterns to one or more sequentially arranged underlying layers using known etching techniques, typically dry etching (such as reactive ion etching). Photoresist patterns can also be used, for example, to transfer patterns to an underlying hard mask layer, which in turn serves as an etching mask for transferring patterns to one or more layers below it. In another aspect, photoresist patterns can be used as masks for ion implantation processes, for example, to selectively introduce dopants onto a substrate surface. If the photoresist pattern is not lost during the patterning or implantation process, it can be removed from the substrate using known techniques such as oxygen plasma ashing. When used in one or more such patterning processes, photoresist compositions can be used to manufacture semiconductor devices such as memory devices, processor chips (CPUs), graphics chips, optoelectronic chips, LEDs, OLEDs, and other electronic devices.

[0068] The photoresist compositions disclosed herein are illustrated by the following non-limiting examples.

[0069] Example

[0070] Example 1

[0071] This example details the synthesis of a trialkyl-substituted amide. Octanoyl chloride (17.6 g, 0.1 mol) was added dropwise to a solution of triethylamine (Et3N) (20.3 g, 0.3 mol) and dioctylamine (36.1 g, 0.15 mol) in dichloromethane (DCM) (250 mL) at 0 °C. The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a clear oil of trioctylamine (TOAm) was given (28.4 g, yield: 77%). The reaction is shown below.

[0072]

[0073] At 0 °C, myristoyl chloride (24.6 g, 0.1 mol) was added dropwise to a solution of Et3N (20.3 g, 0.3 mol) and dioctylamine (36.1 g, 0.15 mol) in DCM (250 mL). The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a clear oily substance of MDOAm was given (40.1 g, yield: 89%). The reaction is as described above.

[0074] Synthesis of octanoyl didecylamine (ODDAm)

[0075]

[0076] At 0 °C, octanoyl chloride (3.5 g, 20 mmol) was added dropwise to a solution of Et3N (2.5 g, 25 mmol) and didecylamine (5.95 g, 20 mmol) in DCM (30 mL). The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a clear oily substance of ODDAM was given (6.9 g, yield: 81%). The reaction is as described above.

[0077] Synthesis of octanoyl didodecylamine (ODDDAm)

[0078]

[0079] At 0 °C, octanoyl chloride (3.5 g, 20 mmol) was added dropwise to a solution of Et3N (2.5 g, 25 mmol) and dodecylamine (7.1 g, 20 mmol) in DCM (30 mL). The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a clear oily substance of ODDDAm was given (7.3 g, yield: 73%). The reaction is as described above.

[0080] Synthesis of Myristoyl Didecylamine (MDDAm)

[0081]

[0082] At 0 °C, myristoyl chloride (3.5 g, 20 mmol) was added dropwise to a solution of Et3N (2.5 g, 25 mmol) and didecylamine (5.95 g, 20 mmol) in DCM (30 mL). The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a clear oily substance of MDDAM was given (9.2 g, yield: 92%). The reaction is as described above.

[0083] Synthesis of Myristoyl Didodecylamine (MDDDAm)

[0084]

[0085] At 0 °C, myristoyl chloride (3.5 g, 20 mmol) was added dropwise to a solution of Et3N (2.5 g, 25 mmol) and dodecylamine (7.1 g, 20 mmol) in DCM (30 mL). The reaction mixture was stirred at room temperature for 6 h. After stirring, volatiles were removed under vacuum. The crude product was diluted with heptane and purified through a silica filter. After solvent removal, a white powder of MDDDAm was given (7.6 g, yield: 67%). The reaction was as described above.

[0086] Example 2

[0087] Preparation of reference NTD sample A

[0088] This example details the preparation of a reference NTD photoresist composition. The reference photoresist composition was prepared as follows: by mixing the following components: 2.98 g polymer-A, 0.26 g PAG-A, 0.09 g WPAG-A (weak photoacid generator), 0.07 g EBL-A (EBL-embedded barrier layer), 48.30 g propylene glycol methyl ether acetate (PGMEA), 9.66 g γ-butyrolactone (aGBLMA), and 38.64 g methyl-2-hydroxyisobutyrate, and then filtering the mixture using a 0.2-micron nylon filter. Polymer A comprises 1-isopropyl-adamantyl methacrylate (IPAMA), 1-isopropylcyclopentyl methacrylate (IPCPMA), α-methacryloyloxy-γ-butyrolactone (aGBLMA), and 2-oxo-2-((2-oxohexahydro-2H-3,5-methanecyclopenten[b]furan-6-yl)oxo)ethyl methacrylate (MNLMA) in a molar ratio of 20:25:40:15.

[0089]

[0090] Polymer-A

[0091]

[0092] Preparation of reference NTD sample B

[0093] This example also details the preparation of the reference NTD photoresist composition. The reference photoresist composition is prepared as follows: by mixing the following components: 2.98 g polymer-A, 0.26 g PAG-A, 0.09 g WPAG-A, 0.04 g quencher-A, 0.07 g EBL-A, 48.30 g propylene glycol methyl ether acetate, 9.66 g γ-butyrolactone (aGBLMA) and 38.64 g methyl-2-hydroxyisobutyrate, and then filtering the mixture using a 0.2-micron nylon filter.

[0094]

[0095] Preparation of Examples 1 to 8

[0096] The structure of quencher BI is shown below, and it is used to prepare a photoresist as described below. The photoresist composition of the present invention is prepared as follows: by mixing the following components: 2.98 g polymer-A, 0.26 g PAG-A, 0.09 g WPAG-A, 0.04 g one of the quenchers shown below (quencher BI), 0.07 g EBL-A, 48.30 g propylene glycol methyl ether acetate, 9.66 g γ-butyrolactone (aGBLMA) and 38.64 g methyl-2-hydroxyisobutyrate, and then filtering the mixture with a 0.2-micron nylon filter.

[0097]

[0098]

[0099] Example 3

[0100] This series of examples demonstrates the effectiveness of trialkylamide quenchers with a LogP greater than 11 in photoresist compositions. Comparative compositions and compositions of this disclosure are shown in the table below and are described in detail below for creating trenches.

[0101] On TEL CLEAN TRACK LITHIUS i+ (coating and developing tools), use AR TM A 300mm thick silicon wafer is spin-coated with a 40% antireflective agent (DuPont Electronics & Industrial) and a 300mm thick hexamethyldisilazane (HMDZ) primer to form a first bottom antireflective coating (BARC), followed by a baking process at 205°C for 60 seconds to provide a thickness of [missing information]. The first BARC layer. The test sample is spin-coated onto the BARC layer to form... The thickness is then subjected to a baking process at 90°C for 60 seconds.

[0102] The fabricated film was then exposed through a mask using a Nikon S610C ArF immersion scanner under the following illumination conditions: 1.3 NA, with cross-polarity of azimuth polarization, δ 0.90–0.59. The exposed film was then baked at 85°C for 60 seconds, followed by development with n-butyl acetate using TEL CLEAN TRAC LITHIUS i+ for 18 seconds, yielding a pattern with negative development. The critical dimension (CD) of the 54 nm 10⁸ pitch trench pattern through a 6% PSM mask was measured on a Hitachi CG4000 CD SEM. The results are shown in the table below.

[0103] In the table below, reference AE is a comparative composition in which the alkane amide quencher has a LogP value of less than 11, while examples 1-5 represent compositions of the present invention in which the trialkylamide has a LogP value of greater than 11.

[0104] surface

[0105]

[0106] The results in the table show that the photoresist compositions of Examples 1-5 (which have LogP values ​​greater than 11) produced good square trench profiles.

Claims

1. A photoresist composition comprising: The first polymer containing acid-labile groups; Photoacid generator; and An acid diffusion control agent comprising a trialkylamide compound having a lipophilicity value greater than 11, wherein, The trialkylamide compound comprises substituted or unsubstituted straight-chain, cyclic, or branched C7 to C8 atoms. 20 Alkyl groups, wherein the lipophilicity value is expressed as logP.

2. The photoresist composition of claim 1, wherein, The trialkylamide compound has the structure of formula (1). (1), where R 1 R 2 and R 3 C7 to C8 are independently linear, cyclic, or branched chains. 20 An alkyl group, which may be substituted or unsubstituted.

3. The photoresist composition of claim 2, wherein, R 1 With R 2 and R 3 Different numbers of carbon atoms.

4. The photoresist composition of claim 3, wherein, R 2 and R 3 have the same number of carbon atoms.

5. The photoresist composition of claim 2 wherein, R 1 It is a straight-chain alkyl group having 7 to 13 carbon atoms, and wherein R 2 and R 3 It has the same number of carbon atoms and is a straight-chain alkyl group having 7 to 15 carbon atoms.

6. The photoresist composition of claim 1, wherein, The first polymer is derived from the polymerization of at least two of the following monomers: , , and .

7. A method for forming a pattern, comprising: (a) Applying a layer of the photoresist composition as described in claim 1 onto a substrate; (b) Exposing the photoresist composition layer to activated radiation in a patterned manner; and (c) Develop the exposed photoresist composition layer to provide a photoresist relief image.

8. The pattern forming method of claim 7, further comprising transferring the pattern of the resist embossed image onto the substrate.

9. The pattern forming process according to claim 7, wherein The exposed photoresist composition layer is developed using an organic solvent-based developer.

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