Photoresist pattern trimming composition and method of trimming a photoresist pattern

Abstract

A photoresist pattern trimming composition comprising: a polymer comprising as a polymerized unit a monomer containing an acid-decomposable group, decomposition of which forms a carboxylic acid group on the polymer; a non-polymeric acid or a non-polymeric thermal acid generator; and an organic-based solvent system comprising one or more organic solvents. A method of trimming a photoresist pattern includes applying such a photoresist pattern trimming composition to a photoresist pattern formed from a photoresist composition comprising a photo-acid generator and a polymer containing an acid-decomposable group. The photoresist pattern trimming composition and pattern forming method are particularly useful in forming fine lithographic patterns in the semiconductor manufacturing industry.

Description

Photoresist pattern trimming composition and method for trimming photoresist patterns Background Technology Technical Field

[0001] 1. Field of Invention

[0002] This invention generally relates to the manufacture of electronic devices. More specifically, the invention relates to photoresist patterning compositions and methods for using such compositions to pattern photoresist. The compositions and methods are particularly useful for forming fine photolithographic patterns for manufacturing semiconductor devices.

[0003] 2. Related technical specifications

[0004] In the semiconductor manufacturing industry, photoresist layers are used to transfer images onto one or more underlying layers disposed on a semiconductor substrate, such as metal, semiconductor, or dielectric layers, as well as the substrate itself. To increase the integration density of semiconductor devices and enable the formation of structures with dimensions in the nanometer range, photoresist compositions and lithography tools with high-resolution capabilities have been and continue to be developed.

[0005] Positive chemically enhanced photoresist compositions are commonly used for high-resolution processing. Such compositions typically utilize a photoacid generator (PAG) and a polymer with acid-indestabilizing groups. A layer formed from this photoresist composition is patterned and exposed to activating radiation, causing the PAG to generate acid. During post-exposure baking, the acid breaks down the acid-indestabilizing groups in the exposed areas of the photoresist layer. This creates a difference in solubility properties between the exposed and unexposed areas of the layer in the developer solution. During positive development (PTD), the exposed areas of the photoresist layer dissolve in the developer and are removed from the substrate surface, while the unexposed areas, insoluble in the developer, are retained after development to form a positive image. The resulting embossed image allows for selective processing of the substrate.

[0006] Photolithographic scaling is typically achieved by increasing the numerical aperture of the optical exposure tool and using a shorter exposure wavelength. To form finer photoresist patterns than those achievable solely through direct imaging, photoresist pattern trimming processes have been proposed, for example, in US Patent Application Publications US 2013 / 0171574 A1, US 2013 / 0171825 A1, US 2014 / 0186772 A1, and US 2016 / 0187783A1. Photoresist pattern trimming processes typically involve contacting a photoresist pattern comprising a polymer with acid-labile groups with a trimming composition containing the polymer and an acid or a hot acid-generating agent. The acid in the trimming composition, or the generated acid, causes deprotection of the photoresist polymer in surface areas of the photoresist pattern, which are then removed by contact with an rinsing agent such as a water-based developer (e.g., TMAH) solution. This allows for the refinement of the photoresist pattern, resulting in, for example, finer resist lines or pillar patterns compared to when only direct imaging is used.

[0007] KrF (248 nm) and extreme ultraviolet (EUV) photoresist materials typically comprise vinyl aromatic compounds, such as hydroxyl styrene-based polymers. These materials generally offer advantageous etch resistance, etch selectivity, and sensitivity properties, as well as low cost. These benefits are superior to conventional ArF (193 nm) photoresist materials, which typically contain (meth)acrylate polymers and are essentially free of aromatic groups due to their high absorption at ArF exposure wavelengths. Given the significantly different polymer chemistry of ArF compared to KrF and EUV photoresist compositions, pattern trimming compositions designed for ArF photoresist patterns may be incompatible with KrF and EUV photoresist patterns. This incompatibility can manifest, for example, as severe pattern damage due to the removal of the dissolved resist pattern in the casting solvent of the trimming composition. To address this issue, a nonpolar hydrophobic casting solvent can be used in the trimming composition. However, this imposes additional limitations on the trimming composition polymer, which must be soluble in both the casting solvent and the rinsing agent. The insolubility of the finishing polymer in the casting solvent can lead to uneven coating and pattern defects, while its insolubility in the rinsing agent can lead to pattern defects and ineffective finishing. These insolubility issues can adversely affect the performance and / or yield of the resulting electronic devices.

[0008] There is a need in the art for improved photoresist patterning compositions and patterning methods that address one or more problems associated with the prior art. Summary of the Invention

[0009] According to a first aspect of the invention, a photoresist patterning composition is provided. The composition comprises: a polymer containing a monomer having an acid-degradable group as a polymerization unit, the decomposition of which forms a carboxylic acid group on the polymer; a non-polymeric acid or a non-polymeric hot acid generator; and an organic-based solvent system comprising one or more organic solvents.

[0010] A method for trimming a photoresist pattern is also provided. The method includes: (a) providing a semiconductor substrate; (b) forming a photoresist pattern on the semiconductor substrate, wherein the photoresist pattern is formed from a photoresist composition comprising a photoacid generator and a polymer containing acid-degradable groups; (c) applying a pattern trimming composition as described in any one of claims 1 to 9 onto the photoresist pattern; (d) heating the coated photoresist pattern; and (e) rinsing the coated and heated photoresist pattern with a rinsing agent to remove surface areas of the photoresist pattern. Attached Figure Description

[0011] The invention will be described with reference to the following drawings, in which similar reference numerals denote similar features, and in the drawings:

[0012] Figures 1A-H illustrate exemplary process flows for forming patterns according to the present invention. Detailed Implementation

[0013] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. Unless the context otherwise indicates, the singular forms “a / an” and “the” are intended to include both singular and plural forms. The full scope disclosed herein includes endpoints, and these endpoints can be independently combined with each other. When an element is referred to as being “on” or “on” another element, it may be in direct contact with said other element or there may be an intervening element between them. Conversely, when an element is referred to as being “directly on” another element, there is no intervening element.

[0014] As used herein, an "acid-degradable group" refers to a group in which a 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 (e.g., a carboxylic acid or alcohol group) on the polymer and, optionally and typically, the portion connected to the broken bond detaches from the polymer. Acid-degradable 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-degradable groups are also commonly referred to in the art as "acid-crackable groups," "acid-crackable protecting groups," "acid-unstable groups," "acid-unstable protecting groups," "acid-leaving groups," and "acid-sensitive groups."

[0015] Unless otherwise stated, a "substituted" group refers to a group in which one or more of its hydrogen atoms are replaced by one or more substituents. Exemplary substituent groups include, but are not limited to, hydroxyl (-OH), halogens (e.g., -F, -Cl, -I, -Br), C 1-18 Alkyl, C 1-8 Haloalkyl, C 3-12 cycloalkyl, C having at least one aromatic ring 6-12 Aryl (e.g., phenyl, biphenyl, naphthyl, etc., each ring being substituted or unsubstituted aromatic), C having at least one aromatic ring 7-19 Arylalkyl, C 7-12 Alkyl aryl groups and combinations thereof. For the purpose of determining the carbon number, when the group is substituted, the number of carbon atoms in the group is the total number of carbon atoms in the group, excluding those with any substituents.

[0016] Photoresist pattern finishing composition

[0017] The photoresist patterning composition of the present invention comprises: a polymer containing a monomer having an acid-degradable group as a polymerization unit, the decomposition of the group forming a carboxylic acid group on the polymer; a non-polymeric acid or a non-polymeric hot acid generator; and an organic-based solvent system containing one or more organic solvents, and may contain one or more optional additional components.

[0018] The polymer allows the composition to be coated onto a photoresist pattern in the form of a layer of desired thickness. The polymer should have good solubility in an organic-based solvent system for the finishing composition. The polymer should also have good solubility in the rinsing agent to be used in the patterning process. For example, the polymer can be soluble in alkaline aqueous solutions, such as those typically used as photoresist developers, preferably aqueous solutions of quaternary ammonium hydroxide, such as tetramethylammonium hydroxide (TMAH). To minimize residual defects originating from the pattern finishing composition, the dissolution rate of the dried layer of the finishing composition in the rinsing agent to be applied should be greater than the dissolution rate of the photoresist pattern in the rinsing agent. The polymer typically exhibits good solubility in the rinsing agent (preferably a 0.26N TMAH solution). Or higher, preferred Or a higher dissolution rate. The polymer is preferably free of strong acid groups, such as sulfonic acid (-SO3H) and carboxylic acid (-CO2H) groups, as these groups generally reduce the solubility of the polymer in the nonpolar solvents used to finish the composition. In some respects, the polymer may also be free of fluoroalkyl and / or fluoroalcohol groups.

[0019] The acid-degradable group that forms a carboxylic acid group on the polymer after decomposition is preferably an acid-degradable group having the formula -C(O)OC(R). 1 )3 tertiary ester group or having the formula -C(O)OC(R 2 )2OR 3 The acetal group, wherein: R 1 Each is a straight chain C independently. 1-20 Alkyl, branched C 3-20 alkyl, monocyclic or polycyclic C 3-20 cycloalkyl, straight-chain C 2-20 Alkenyl, branched C 3-20 alkenyl, monocyclic or polycyclic C 3-20 Cycloalkenyl, monocyclic or polycyclic C 6-20 Aryl, or monocyclic or polycyclic C 2-20 Heteroaryl groups, preferably linear C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 Cycloalkyl groups, each of which is substituted or unsubstituted, each R 1 Optionally, it includes one or more groups selected from -O-, -C(O)-, -C(O)-O-, or -S- as part of its structure, and any two R 1 The groups may optionally form a ring together; R 2 Independently, it is hydrogen, fluorine, and straight-chain C. 1-20 Alkyl, branched C 3-20 alkyl, monocyclic or polycyclic C 3-20 cycloalkyl, straight-chain C 2-20 Alkenyl, branched C 3-20 alkenyl, monocyclic or polycyclic C 3-20 Cycloalkenyl, monocyclic or polycyclic C 6-20 aryl, or monocyclic or polycyclic C 2-20 Heteroaryl groups, preferably hydrogen or straight-chain C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 Cycloalkyl groups, each of which is substituted or unsubstituted, each R 2 Optionally, it includes one or more groups selected from -O-, -C(O)-, -C(O)-O-, or -S- as part of its structure, and R 2 The groups optionally form a ring together; and R 3 It is a straight chain C 1-20 Alkyl, branched C 3-20 alkyl, monocyclic or polycyclic C 3-20 cycloalkyl, straight-chain C 2-20 Alkenyl, branched C 3-20 alkenyl, monocyclic or polycyclic C 3-20 Cycloalkenyl, monocyclic or polycyclic C6-20 aryl, or monocyclic or polycyclic C 2-20 Heteroaryl groups, preferably linear C 1-6 Alkyl, branched C 3-6 Alkyl, or monocyclic or polycyclic C 3-10 Cycloalkyl, each of which is substituted or unsubstituted, R 3 Optionally, it includes one or more groups selected from -O-, -C(O)-, -C(O)-O-, or -S- as part of its structure, and an R 2 With R 3 They can optionally form a ring together. Such monomers are typically vinyl aromatic compounds, (meth)acrylates, or norbornel monomers.

[0020] Suitable monomers containing such acid-degradable groups include monomers having the following formulas (1a), (1b), (1c), and (1d):

[0021]

[0022] Where: R is hydrogen, fluorine, C 1-5 Alkyl, or C 1-5 Fluoroalkyl, typically hydrogen or methyl; R 1 R 2 and R 3 It is as defined above; L 1 It is a single bond or an m+1 valence linking group containing at least one carbon atom, typically C 1-10 linear, C 3-10 branched, or C 3-10 Cyclic, each of which may be substituted or unsubstituted, and may include one or more heteroatoms; P is a polymerizable group selected from vinyl or norbornel; L 2 It is a single bond or a divalent linker containing at least one carbon atom, typically C. 1-10 linear, C 3-10 branched, or C 3-10 Cyclic, each of which may be substituted or unsubstituted, and may include one or more heteroatoms, provided that L is vinyl. 2 It is not a single bond; m is 1 or 2; and n is 0 or 1.

[0023] Suitable monomers containing acid-degradable groups include, for example, the following:

[0024]

[0025]

[0026]

[0027] Where R is as defined above. The total content of polymeric units containing acid-degradable groups that form carboxylic acid groups on the polymer is typically 10 to 100 mol%, more typically 10 to 90 mol%, or 30 to 70 mol% based on the total number of polymeric units in the polymer.

[0028] The polymer may further comprise monomers containing acid-degradable groups as polymerization units, the decomposition of which forms alcohol or fluorohydrin groups on the polymer. Suitable such groups include, for example, those having the formula -COC(R 2 )2OR 3 The monomer has an acetal group or a carbonate group having the formula -OC(O)O-. Such monomers are typically vinyl aromatic compounds, (meth)acrylates, or norbornyl monomers.

[0029] Suitable monomers containing acid-degradable groups that form alcohol or fluorohydrin groups include, for example, the following:

[0030]

[0031]

[0032] Where R is as defined above. The total content of polymeric units containing acid-degradable groups (the decomposition of which forms alcohol or fluorohydrin groups on the polymer) is typically 10 to 90 mol% based on the total number of polymeric units in the polymer, more typically 30 to 70 mol%.

[0033] The polymer preferably further comprises neutral, solubility-enhancing monomers as polymerization units. Such monomers are typically vinyl aromatic compounds, (meth)acrylates, or norbornyl monomers. Suitable neutral, solubility-enhancing monomers include, for example, the following:

[0034]

[0035]

[0036] Where R is as defined above. The total content of the polymeric units of the neutral, highly soluble monomer, if present in the polymer, is typically 10 to 90 mol%, more typically 30 to 70 mol%, based on the total polymeric units of the polymer.

[0037] The polymer may contain one or more additional types of polymeric units. Suitable additional units may contain one or more groups selected from, for example, alkyl, hydroxyl, fluoroalkyl, fluoroalcohol, ester, ether, imide, sulfonamide, oxoalkyl ester groups, and combinations thereof. Such additional units are typically formed from monomers selected from, for example, vinyl aromatic compounds, (meth)acrylates, or norbornyl monomers. Exemplary suitable additional monomers include the following:

[0038]

[0039]

[0040] Where R is as defined above. The content of such additional polymeric units, if present in the polymer, can vary widely and can exist, for example, in amounts from 2 to 20 mol% based on the total polymeric units of the polymer.

[0041] Suitable polymers according to the invention include homopolymers or copolymers comprising two, three, or more different repeating units. Suitable homopolymers include polymeric units formed from monomers containing acid-degradable groups that form carboxylic acids, as described above. Suitable copolymers include, for example, the following:

[0042]

[0043]

[0044]

[0045] The total molar ratio of units in each polymer is 100 mol%, and can be selected within the range described above.

[0046] The finishing composition typically comprises a single polymer, but may optionally contain one or more additional polymers. The polymer content in the composition will depend, for example, on the target thickness of the layer, with a higher polymer content used when a thicker layer is desired. The polymer is typically present in the pattern finishing composition in an amount of 80 to 99.9 wt%, more typically 90 to 99 wt%, or 95 to 99 wt% based on the total solids of the finishing composition. The weight-average molecular weight (Mw) of the polymer is typically less than 400,000, preferably 3,000 to 50,000, more preferably 3,000 to 25,000, as measured by GPC relative to a polystyrene standard. Typically, the polymer will have a polydispersity index (PDI = Mw / Mn) of 3 or less, preferably 2 or less, where Mw and Mn are measured by GPC relative to a polystyrene standard.

[0047] Suitable polymers for finishing compositions are commercially available and / or readily prepared by those skilled in the art. For example, polymers can be synthesized by dissolving selected monomers corresponding to polymer units in an organic solvent, adding a free radical polymerization initiator thereto, and thermally polymerizing to form the polymer. Examples of suitable organic solvents that can be used for polymer polymerization include, for example, toluene, benzene, tetrahydrofuran, diethyl ether, dioxane, ethyl lactate, and methyl isobutyl methanol. Suitable polymerization initiators include, for example, 2,2′-azobisisobutyronitrile (AIBN), 2,2′-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide.

[0048] The finishing composition further comprises a non-polymeric acid or a non-polymeric thermal acid generator (TAG). The acid, or the acid generated in the case of a TAG, should be sufficient to break the bonds of the acid-degradable groups of the polymer in the surface region of the photoresist pattern by heating, thereby increasing the solubility of the photoresist polymer in the rinsing solution to be applied. The acid or TAG is in a non-polymeric form compared to polymeric acids and TAGs, so as to better diffuse into the photoresist pattern during processing. The finishing composition preferably does not contain polymeric acids or polymeric TAGs. The non-polymeric acid or non-polymeric TAG is typically present in the composition in an amount of about 0.01 to 20 wt% based on the total solids of the finishing composition.

[0049] Preferred nonpolymer acids are organic acids including both non-aromatic and aromatic acids, each of which may optionally have fluorine substitution. Suitable organic acids include, for example: carboxylic acids, such as alkyl acids, including formic acid, acetic acid, propionic acid, butyric acid, dichloroacetic acid, trichloroacetic acid, perfluoroacetic acid, perfluorooctanoic acid, oxalic acid, malonic acid, and succinic acid; hydroxyalkyl acids, such as citric acid; aromatic carboxylic acids, such as benzoic acid, fluorobenzoic acid, hydroxybenzoic acid, and naphtholic acid; organophosphoric acids, such as dimethylphosphoric acid and dimethylphosphonic acid; and sulfonic acids, such as optionally fluorinated alkylsulfonic acids, including methanesulfonic acid, trifluoromethanesulfonic acid, ethanesulfonic acid, 1-butanesulfonic acid, 1-perfluorobutanesulfonic acid, 1,1,2,2-tetrafluorobutane-1-sulfonic acid, 1,1,2,2-tetrafluoro-4-hydroxybutane-1-sulfonic acid, 1-pentanesulfonic acid, 1-hexanesulfonic acid, and 1-heptanesulfonic acid.

[0050] Suitable TAGs include those capable of generating nonpolymeric acids as described above. TAGs can be nonionic or ionic. Suitable nonionic thermal acid generators include, for example, cyclohexyl trifluoromethanesulfonate, methyl trifluoromethanesulfonate, cyclohexyl p-toluenesulfonate, methyl p-toluenesulfonate, cyclohexyl 2,4,6-triisopropylbenzenesulfonate, nitrobenzyl ester, benzoin toluenesulfonate, 2-nitrobenzyl toluenesulfonate, tris(2,3-dibromopropyl)-1,3,5-triazine-2,4,6-trione, alkyl esters of organic sulfonic acids, p-toluenesulfonic acid, dodecylbenzenesulfonic acid, and oxaliplatin. Acids, phthalic acid, phosphoric acid, camphor sulfonic acid, 2,4,6-trimethylbenzenesulfonic acid, triisopropylnaphthalenesulfonic acid, 5-nitro-o-toluenesulfonic acid, 5-sulfosalicylic acid, 2,5-dimethylbenzenesulfonic acid, 2-nitrobenzenesulfonic acid, 3-chlorobenzenesulfonic acid, 3-bromobenzenesulfonic acid, 2-fluorodecanoylnaphthalenesulfonic acid, dodecylbenzenesulfonic acid, 1-naphthol-5-sulfonic acid, 2-methoxy-4-hydroxy-5-benzoyl-benzenesulfonic acid, and their salts, and combinations thereof. Suitable ionic thermal acid generators include, for example, triethylamine dodecylbenzenesulfonate, triethylamine dodecylbenzene disulfonic acid, ammonium p-toluenesulfonate, pyridinium p-toluenesulfonate, and sulfonates (such as carbocyclic aryl and heteroaryl sulfonates, aliphatic sulfonates, and benzenesulfonates). Compounds that produce sulfonic acids upon activation are generally suitable. Preferred thermal acid generators include ammonium p-toluenesulfonate and heteroaryl sulfonates.

[0051] Preferably, the TAG is ionic, wherein the reaction scheme for generating sulfonic acid is as follows:

[0052]

[0053] Among them RSO3 - It is a TAG anion and X + It is a TAG cation, preferably an organic cation. The cation can be a nitrogen-containing cation having the general formula (I):

[0054] (BH) + (I)

[0055] It is the unprotonated form of a nitrogen-containing base B. Suitable nitrogen-containing base B includes, for example: optionally substituted amines, such as ammonia, difluoromethylamine, C1-20 alkylamines, and C3-30 arylamines, such as nitrogen-containing heteroaromatic bases, such as pyridine or substituted pyridines (e.g., 3-fluoropyridine), pyrimidines, and pyrazines; nitrogen-containing heterocyclic groups, such as oxazoles, oxazolines, or thiazolines. The aforementioned nitrogen-containing base B may be optionally substituted, for example, by one or more groups selected from alkyl, aryl, halogen atoms (preferably fluorine), cyano, nitro, and alkoxy groups. Among these, base B is preferably a heteroaromatic base.

[0056] Base B typically has a pKa of 0 to 5.0, or 0 to 4.0, or 0 to 3.0, or 1.0 to 3.0. As used herein, the term "pK" is... a "pKa" is used according to its generally accepted meaning in the field, namely, the conjugate acid (BH) of the basic portion (B) in aqueous solution at approximately room temperature. + The negative logarithm of the dissociation constant (base 10). In some embodiments, base B has a boiling point of less than about 170°C, or less than about 160°C, 150°C, 140°C, 130°C, 120°C, 110°C, 100°C, or 90°C.

[0057] A suitable nitrogen-containing cation (BH) is an example. + Including NH4 + CF2HNH2 + CF3CH2NH3 + (CH3)3NH + (C2H5)3NH + (CH3)2(C2H5)NH + And the following:

[0058]

[0059] Wherein Y is an alkyl group, preferably methyl or ethyl.

[0060] The trimming composition further comprises an organic-based solvent system containing one or more organic solvents. The term "organic-based" means that the solvent system includes organic solvents comprising more than 50 wt% of the total solvent in the trimming composition, and more typically more than 90 wt%, more than 95 wt%, more than 99 wt%, or 100 wt% of the total solvent in the trimming composition. Suitable solvent materials for formulating and casting the trimming composition should exhibit good solubility characteristics for the non-solvent components of the trimming composition without significantly dissolving the underlying photoresist pattern, thereby minimizing mixing with the photoresist pattern.

[0061] When the photoresist pattern to be trimmed is formed from a vinyl aromatic compound-based polymer (such as a styrene- or hydroxystyrene-containing polymer typically used for KrF and EUV photoresists), the solvent system preferably comprises one or more nonpolar organic solvents. Preferably, the solvent system is nonpolar organic-based. The term "nonpolar organic-based" means that the solvent system comprises a combination of nonpolar organic solvents comprising more than 50 wt% of the total solvent of the trimmed composition, more typically more than 70 wt%, more than 85 wt%, or 100 wt% of the total solvent of the trimmed composition. The nonpolar organic solvent is typically present in the solvent system in an amount of 70 to 98 wt%, preferably 80 to 95 wt%, more preferably 85 to 98 wt% of the solvent system. It is believed that using a nonpolar organic-based solvent system can provide low top loss characteristics when processing vinyl aromatic compound-based photoresist patterns. As used herein, “vinyl aromatic compound” means a polymeric unit formed by a monomer in which an aromatic group is directly bonded to a vinyl group, such as styrene, hydroxystyrene, and vinylnaphthalene. “Polymer based on vinyl aromatic compound” means a polymer containing more than 50 mol% of total polymeric units, more typically 60 to 100 mol% or 80 to 100 mol% of total polymeric units.

[0062] Suitable nonpolar solvents include, for example, ethers, hydrocarbons, and combinations thereof, with ethers being preferred. Suitable ether solvents include, for example, alkyl monoethers and aromatic monoethers, particularly those having a total carbon number of 6 to 16. Suitable alkyl monoethers include, for example, 1,4-cineole, 1,8-cineole, pinene oxide, di-n-propyl ether, diisopropyl ether, di-n-butyl ether, di-n-pentyl ether, diisopentyl ether, dihexyl ether, diheptyl ether, and dioctyl ether, with diisopentyl ether being preferred. Suitable aromatic monoethers include, for example, anisole, ethyl benzyl ether, diphenyl ether, dibenzyl ether, and phenethyl ether, with anisole being preferred. Suitable aliphatic hydrocarbons include, for example, n-heptane, 2-methylheptane, 3-methylheptane, 3,3-dimethylhexane, 2,3,4-trimethylpentane, n-octane, n-nonane, n-decane, and fluorinated compounds such as perfluoroheptane. Suitable aromatic hydrocarbons include, for example, benzene, toluene, and xylene.

[0063] The solvent system preferably further comprises one or more alcohols and / or ester solvents. For certain trimming compositions, alcohols and / or ester solvents can provide enhanced solubility of the solid components of the trimming composition. Suitable alcohol solvents include, for example, straight-chain, branched, or cyclic C454-hydroxyl groups. 4-9Monohydric alcohols, such as 1-butanol, 2-butanol, isobutanol, tert-butanol, 3-methyl-1-butanol, 1-pentanol, 2-pentanol, 4-methyl-2-pentanol, 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, 2,2,3,3,4,4-hexafluoro-1-butanol, 2,2,3,3,4,4,5,5-octafluoro-1-pentanol, and 2,2,3,3,4,4,5,5,6,6-decafluoro-1-hexanol; and C 5-9 Fluorinated diols, such as 2,2,3,3,4,4-hexafluoro-1,5-pentanediol, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol, and 2,2,3,3,4,4,5,5,6,6,7,7-dodecano-1,8-octanediol. The preferred alcohol solvent is C10. 4-9 Monohydric alcohols, of which 4-methyl-2-pentanol is preferred. Suitable ester solvents include, for example, alkyl esters having a total carbon number of 4 to 10, such as alkyl propionates like n-butyl propionate, n-pentyl propionate, n-hexyl propionate, and n-heptyl propionate, and alkyl butyrate esters like n-butyl butyrate, isobutyl butyrate, and isobutyl isobutyrate. If used in a solvent system, one or more alcohols and / or ester solvents are typically present in a combined amount of 2 to 50 wt% based on the solvent system, more typically in an amount of 2 to 30 wt%.

[0064] The solvent system may contain one or more additional solvents selected from, for example, one or more of the following: ketones, such as 2,5-dimethyl-4-hexanone and 2,6-dimethyl-4-heptanone; and polyethers, such as dipropylene glycol monomethyl ether and tripropylene glycol monomethyl ether. Such additional solvents (if used) are typically present in a combined amount of 1 to 20 wt% based on the solvent system.

[0065] Particularly preferred organic-based solvent systems comprise one or more monoether solvents in a combined amount of 70 to 98 wt% of the solvent system, and one or more alcohols and / or ester solvents in a combined amount of 2 to 30 wt% of the solvent system. The solvent system is typically present in the outer coating composition in an amount of 90 to 99 wt%, preferably 95 to 99 wt%, based on the outer coating composition.

[0066] The trimming composition may further include one or more additional, optional components, such as surfactants. Typical surfactants include those that exhibit amphiphilic properties, meaning they can be both hydrophilic and hydrophobic. Amphiphilic surfactants have one or more hydrophilic head groups (which have a strong affinity for water) and a long hydrophobic tail (which is organophilic and repels water). Suitable surfactants can be ionic (i.e., anionic, cationic) or nonionic. Other examples of surfactants include silicone surfactants, poly(oxyethylene) surfactants, and fluorinated surfactants. Suitable nonionic surfactants include, but are not limited to, octyl and nonylphenol ethoxylates, such as... X-114, X-100, X-45, X-15, and branched secondary alcohol ethoxylates, such as TERGITOL TM TMN-6 (Dow Chemical Company, Midland, Michigan, USA). Other exemplary surfactants include alcohol (primary and secondary alcohols) ethoxylates, amine ethoxylates, glucosides, glucosamine, polyethylene glycol, poly(ethylene glycol-co-propylene glycol), or other surfactants disclosed in the North American edition of McCutcheon's Emulsifiers and Detergents, published in 2000 by Manufacturers Confectioners Publishing Co., Glen Rock, NJ. Nonionic surfactants that are acetylenic diol derivatives may also be suitable. Such surfactants are commercially available from Air Products and Chemicals, Inc. of Allentown, PA, and are marketed under the trade name... and For sale. Other suitable surfactants include other polymer compounds, such as triblock EO-PO-EO copolymers. 25R2, L121, L123, L31, L81, L101, and P123 (BASF, Inc.). If used, these surfactants and other optional additives are typically present in the composition in small amounts, such as 0.01 to 10 wt%, based on the total solids of the trimming composition. The trimming composition preferably does not contain crosslinking agents or other materials that could lead to an increase in the size of the photoresist pattern.

[0067] The trimming composition can be prepared according to known procedures. For example, the composition can be prepared by dissolving the solid components of the composition in a solvent component. The desired total solids content of the composition will depend on factors such as the desired final layer thickness. Preferably, the solids content of the trimming composition is 1 to 10 wt% based on the total weight of the composition, more preferably 1 to 5 wt%.

[0068] Pattern Formation Method

[0069] The process according to the invention will now be described with reference to FIG1A-H, which illustrates an exemplary process flow of the patterning method according to the invention. Although the process flow shown describes a patterning process in which a photoresist pattern is transferred to an underlying substrate using a single photoresist mask, it should be understood that the method can be used for other lithography processes, such as for dual patterning processes, such as photolithography-etching (LLE), photolithography-etching-photolithography-etching (LELE), or self-aligned dual patterning (SADP), such as ion implantation masks, or any other lithography process in which such photoresist patterning would be beneficial.

[0070] Figure 1A depicts a cross-section of a substrate 100 that may include various layers and features. The substrate may be a material such as a semiconductor, such as silicon or a compound semiconductor (e.g., III-V or II-VI), glass, quartz, ceramic, copper, etc. Typically, the substrate is a semiconductor wafer, such as a single-crystal silicon or compound semiconductor wafer, and may have one or more layers formed on its surface, as well as patterned features. One or more layers 102 to be patterned may be provided on the substrate 100. Optionally, for example, when it is desired to form trenches in the substrate material, the underlying base substrate material itself may be patterned. In the case of patterning the base substrate material itself, the pattern should be considered to be formed within the layers of the substrate.

[0071] The layers may include, for example, one or more conductive layers such as aluminum, copper, molybdenum, tantalum, titanium, tungsten, alloys of these metals, nitrides or silicides, layers of doped amorphous silicon or doped polycrystalline silicon; one or more dielectric layers such as silicon oxide, silicon nitride, silicon oxynitride, or metal oxide layers; semiconductor layers such as single-crystal silicon; and combinations thereof. The layers to be etched can be formed using various techniques, such as chemical vapor deposition (CVD), such as plasma-enhanced CVD (PECVD), low-pressure CVD (LPCVD), or epitaxial growth; physical vapor deposition (PVD), such as sputtering or evaporation; or electroplating. The specific thickness of the one or more layers 102 to be etched will vary depending on the material and the specific apparatus used for formation.

[0072] Depending on the specific layer to be etched, the film thickness, and the photolithography material and process to be used, it may be desirable to arrange a hard mask layer 103 and / or a bottom anti-reflective coating (BARC) 104 on layer 102, upon which a photoresist layer 106 is coated. For example, a hard mask layer may be necessary for very thin resist layers where the layer to be etched requires significant etch depth, and / or where a particular etchant has poor resist selectivity. When using a hard mask layer, the resist pattern to be formed can be transferred to the hard mask layer 103, which can then be used as a mask for etching the underlying layer 102. Suitable hard mask materials and formation methods are known in the art. Typical materials include, for example, tungsten, titanium, titanium nitride, titanium oxide, zirconium oxide, aluminum oxide, aluminum oxynitride, hafnium oxide, amorphous carbon, spin-coated carbon (SOC), silicon oxynitride, and silicon nitride. The hard mask layer may comprise a single layer or multiple layers of different materials. The hard mask layer can be formed, for example, by CVD, PVD, or spin-coating techniques.

[0073] A bottom anti-reflective coating may be desirable when the substrate and / or underlying layer reflect a significant amount of incident radiation during photoresist exposure, adversely affecting the quality of the formed pattern. Such coatings can improve depth of focus, exposure latitude, linewidth uniformity, and CD control. Anti-reflective coatings are typically used when the photoresist is exposed to deep ultraviolet radiation (300 nm or less), such as KrF (248 nm), ArF (193 nm), or EUV (13.5 nm) radiation. Anti-reflective coatings may comprise a single layer or multiple distinct layers. Suitable anti-reflective materials and formation methods are known in the art. Anti-reflective materials are commercially available, for example, those from DuPont (Wilmington, Delaware, USA) using AR... TM Those products sold under the brand name, such as AR TM 3. AR TM 40A and AR TM 124 Anti-reflective material.

[0074] The photoresist layer 106 is formed from a photoresist composition, typically a chemically enhanced photosensitive composition comprising a polymer having acid-indestabilizing groups, a photoacid generator, and a solvent. Suitable photoresist compositions are well known in the art. Preferably, the photoresist polymer is formed from monomers selected from vinyl aromatic compounds (e.g., styrene and hydroxystyrene), (meth)acrylates, norbornene, and combinations thereof. In a preferred aspect, the photoresist polymer is based on vinyl aromatic compounds, wherein more than 50 mol% of the polymeric units, typically more than 80 mol% of the polymeric units, are formed from vinyl aromatic monomers.

[0075] A photoresist layer is disposed on a substrate above the antireflective layer 104 (if present). The photoresist composition can be applied to the substrate by spin coating, dip coating, roll coating, or other conventional coating techniques. Spin coating is typical. For spin coating, the solids content of the coating solution can be adjusted to provide the desired film thickness based on the specific coating equipment used, the viscosity of the solution, the speed of the coating tool, and the allowable rotation time. The typical thickness of the photoresist layer 106 is about 500 nm.

[0076] Next, the photoresist layer 106 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 can be performed on a heated plate or in an oven, with a heated plate being typical. The soft baking temperature and time will depend on, for example, the specific material and thickness of the photoresist. Typical soft baking is performed at temperatures between approximately 90°C and 150°C for approximately 30 to 90 seconds.

[0077] Next, the photoresist layer 106 is exposed to activating radiation 108 through a photomask 110 to create a solubility difference between the exposed and unexposed areas. The exposure of the photoresist composition to radiation that activates the composition, as described herein, demonstrates that radiation can form a latent image in the photoresist composition. The photomask has optically transparent and optically opaque areas, corresponding to the areas in the resist layer to be exposed and unexposed by the activating radiation, respectively. Exposure wavelengths are typically below 400 nm, below 300 nm (e.g., deep UV (248 nm)), 193 nm, or EUV wavelengths (e.g., 13.5 nm). In a preferred aspect, the exposure wavelength is deep UV or EUV lithography. Exposure energy is typically about 10 to 80 mJ / cm². 2 This depends on, for example, the components of the exposure tool and the photosensitive composition.

[0078] After exposure of the photoresist layer 106, post-exposure baking (PEB) is typically performed. PEB can be performed, for example, on a heated plate or in an oven. The conditions of PEB will depend on, for example, the specific photoresist composition and the layer thickness. PEB is typically performed at a temperature of about 80°C to 150°C for about 30 to 90 seconds. This forms a latent image defined by the boundary between polarity-converted and unconverted regions (corresponding to exposed and unexposed regions, respectively).

[0079] Next, the photoresist layer 106 is developed to remove the exposed areas of the layer, leaving unexposed areas to form a resist pattern 106' with multiple features as shown in FIG. 1B. These features are not limited to and may include, for example, multiple line, pillar, and / or contact hole patterns, which allow such patterns to be formed in the underlying layer to be patterned. The formed resist pattern has an initial size shown in L1, a linewidth for the line pattern, a pillar diameter for the pillar pattern, or a sidewall width for the contact hole pattern.

[0080] As shown in Figure 1C, a layer 112 of a photoresist pattern trimming composition as described herein is formed on a photoresist pattern 106'. The trimming composition is typically applied to the substrate by spin coating. The solids content of the coating solution can be adjusted to provide the desired film thickness based on the specific coating equipment used, the viscosity of the solution, the speed of the coating tool, and the amount of time allowed for rotation. The typical thickness of the pattern trimming composition layer 112 is typically 200 to [missing value] mm, measured on an unpatterned substrate.

[0081] As shown in Figure 1D, the substrate is then baked to remove the solvent from the trimming composition layer. Baking also allows the acid in the trimming composition to diffuse to the surface of the resist pattern 106′, inducing a polarity-changing reaction in the resist pattern surface region 114. Baking can be performed using a heated plate or an oven, with a heated plate being typical. Suitable baking temperatures are greater than 50°C, such as greater than 70°C, greater than 90°C, greater than 120°C, or greater than 150°C, with temperatures between 70°C and 160°C and times of approximately 30 to 90 seconds being typical. While a single baking step is typical, multi-step baking can be used and can be employed for resist contouring.

[0082] Next, the photoresist pattern is brought into contact with a rinsing agent (typically a developing solution) to remove residual trimming composition layer 112 and, typically, surface areas 114 of the photoresist pattern, wherein the resulting pattern 106” is shown in FIG. 1E. The rinsing agent is typically an aqueous alkaline developing agent, such as a quaternary ammonium hydroxide solution, such as a tetraalkylammonium hydroxide solution, like 0.26 equivalent concentration (N) (2.38 wt%) tetramethylammonium hydroxide (TMAH). The rinsing agent may further be water or contain water. The resulting structure is shown in FIG. 1E. The photoresist pattern after trimming has a smaller size (L2) compared to the feature size before trimming.

[0083] Using a resist pattern 106” as an etching mask, the BARC layer 104 is selectively etched to form a BARC pattern 104′ exposing the underlying hard mask layer 103, as shown in FIG1F. Next, the hard mask layer is selectively etched, again using the resist pattern as an etching mask, to produce patterned BARC and hard mask layers 103′, as shown in FIG1G. Suitable etching techniques and chemicals for etching the BARC and hard mask layers are known in the art and will depend on, for example, the specific materials of these layers. Dry etching processes such as reactive ion etching are typical. Next, using known techniques such as oxygen plasma ashing, the resist pattern 106” and patterned BARC layer 104′ are removed from the substrate. Then, using the hard mask pattern 103′ as an etching mask, one or more layers 102 are selectively etched. Suitable etching techniques and chemicals for etching the underlying layer 102 are known in the art, wherein dry etching processes such as reactive ion etching are typical. Next, known techniques, such as dry etching processes like reactive ion etching or wet stripping, can be used to remove the patterned hard mask layer 103' from the substrate surface. The resulting structure is a pattern of etched features 102', as shown in FIG1H. In an alternative exemplary method, it may be desirable to directly pattern layer 102 using a photoresist pattern 106″ without using the hard mask layer 103. Whether direct patterning using a photoresist pattern is feasible will depend on factors such as the materials involved, photoresist selectivity, photoresist pattern thickness, and pattern size.

[0084] The following non-limiting examples illustrate the present invention.

[0085] Example

[0086] Polymer Synthesis

[0087] Polymers were synthesized using the following monomers according to the procedure described below:

[0088]

[0089] Example 1 (Polymer P1) )

[0090] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 20.0 g of monomer M1, 20.0 g of monomer M4, and 1.44 g of V-601 radical initiator (from Wako Chemical Company) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P1) was precipitated by adding the reaction mixture dropwise to a methanol / water 20 / 80 (wt%), collected by filtration, and dried under vacuum to produce 32 g of solids (80% yield). For this example and subsequent examples, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) were determined by polystyrene equivalents as measured by gel permeation chromatography (GPC), and polydispersity was calculated as PDI = Mw / Mn. The monomer ratios and molecular weights in the polymers of this polymer synthesis example and subsequent polymer synthesis examples are shown in Table 1.

[0091] Example 2 (Polymer P2) )

[0092] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 20.0 g of monomer M2, 20.0 g of monomer M4, and 1.44 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P2) was precipitated by dropwise addition of the reaction mixture to a 25 / 75 wt% methanol / water mixture, collected by filtration, and dried under vacuum to yield 31.5 g of solids (78.75% yield).

[0093] Example 3 (Polymer P3) )

[0094] The feed solution was prepared by combining 17.32 g of propylene glycol monomethyl ether acetate (PGMEA), 15.0 g of monomer M3, 15.0 g of monomer M4, and 1.42 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 22 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P3) was precipitated by dropwise addition of the reaction mixture to a 25 / 75 wt% methanol / water mixture, collected by filtration, and dried under vacuum to produce 22 g of solids (73.3% yield).

[0095] Example 4 (Polymer P4) )

[0096] The feed solution was prepared by combining 23.20 g of propylene glycol monomethyl ether acetate (PGMEA), 25.0 g of monomer M2, 25.0 g of monomer M5, and 1.80 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 25 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P4) was precipitated by dropwise addition of the reaction mixture to a 25 / 75 wt% methanol / water mixture, collected by filtration, and dried under vacuum to yield 42 g of solids (84% yield).

[0097] Example 5 (Polymer P5) )

[0098] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 28.0 g of monomer M1, 12.0 g of monomer M6, and 1.44 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P5) was precipitated by dropwise addition of the reaction mixture to a 35 / 65 wt% methanol / water mixture, collected by filtration, and dried under vacuum to yield 30.7 g of solids (76.75% yield).

[0099] Example 6 (Polymer P6) )

[0100] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 12.0 g of monomer M1, 28.0 g of monomer M6, and 1.44 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P6) was precipitated by dropwise addition of the reaction mixture to a 15 / 85 wt% methanol / water mixture, collected by filtration, and dried under vacuum to produce 32 g of solids (80% yield).

[0101] Example 7 (Polymer P7) )

[0102] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 16.0 g of monomer M2, 20.0 g of monomer M4, 4.0 g of monomer M6, and 1.44 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P7) was precipitated by adding the reaction mixture dropwise to a 25 / 75 wt% methanol / water mixture, collected by filtration, and dried under vacuum to produce 33 g of solids (82.5% yield).

[0103] Example 8 (Polymer P8) )

[0104] The feed solution was prepared by combining 18.56 g of propylene glycol monomethyl ether acetate (PGMEA), 16.0 g of monomer M1, 20.0 g of monomer M4, 4.0 g of monomer M6, and 1.44 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 20 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P8) was precipitated by dropwise addition of the reaction mixture to a 25 / 75 wt% methanol / water mixture, collected by filtration, and dried under vacuum to yield 30.5 g of solids (76% yield).

[0105] Example 9 (Polymer P9) )

[0106] The feed solution was prepared by combining 23.20 g of propylene glycol monomethyl ether acetate (PGMEA), 20.0 g of monomer M2, 25.0 g of monomer M4, 5.0 g of monomer M7, and 1.80 g of V-601 radical initiator (from Photochemi) in a vessel and stirring the mixture to dissolve the components. 25 g of PGMEA was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 95°C with stirring. The feed solution was then introduced into the reaction vessel and fed over a 2-hour period. The reaction vessel was maintained at 95°C with stirring for an additional three hours and then allowed to cool to room temperature. The polymer (P9) was precipitated by adding the reaction mixture dropwise to a 40 / 60 (wt%) methanol / water mixture, collected by filtration, and dried under vacuum to produce 42 g of solids (82% yield).

[0107] Example 10 (Polymer CP1) )

[0108] The monomer feed solution was prepared by mixing 7.56 g of 4-methyl-2-pentanol (MIBC) and 40.50 g of monomer M4 in a vessel. The initiator feed solution was prepared by combining 3.52 g of V-601 radical initiator (from Photochemi) and 23.57 g of MIBC in a vessel and stirring the mixture to dissolve the initiator. 14.85 g of MIBC was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 88 °C with stirring. Simultaneously, the monomer feed solution and the initiator feed solution were introduced into the reaction vessel. The monomer feed solution was fed over a 1.5-hour period and the initiator feed solution over a 2-hour period. The reaction vessel was maintained at 88 °C with stirring for an additional 3 hours and then allowed to cool to room temperature. The polymer (CP1) was precipitated by adding the reaction mixture dropwise to heptane, collected by filtration, and dried under vacuum to produce 30 g of solids (74% yield).

[0109] Example 11 (Polymer CP2) )

[0110] The monomer feed solution was prepared by mixing 6.13 g of 4-methyl-2-pentanol (MIBC), 20.25 g of monomer M4, and 20.25 g of monomer M8 in a vessel. The initiator feed solution was prepared by combining 7.13 g of V-601 radical initiator (from Heguang Chemical Company) and 21.39 g of MIBC in a vessel and stirring the mixture to dissolve the initiator. 14.85 g of MIBC was introduced into the reaction vessel and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 88 °C with stirring. Simultaneously, the monomer feed solution and the initiator feed solution were introduced into the reaction vessel. The monomer feed solution was fed over a 1.5-hour period, and the initiator feed solution was fed over a 2-hour period. The reaction vessel was maintained at 88 °C with stirring for an additional 3 hours and then allowed to cool to room temperature. The polymer (CP2) was precipitated by adding the reaction mixture dropwise to heptane, collected by filtration, and dried under vacuum to produce 30 g of solids (74% yield).

[0111] Example 12 (Polymer CP3) )

[0112] The monomer feed solution was prepared by mixing 2.83 g of propylene glycol monomethyl ether (PGME), 27.20 g of monomer M6, and 4.80 g of monomer M8 in a vessel. The initiator feed solution was prepared by combining 1.48 g of Vazo-67 radical initiator (EI du Pont de Nemours and Company) and 19.69 g of PGME in a vessel and stirring the mixture to dissolve the initiator. 24.00 g of PGME was introduced into the reaction vessel, and the vessel was purged with nitrogen for 30 minutes. The reaction vessel was then heated to 90 °C with stirring. Simultaneously, the monomer feed solution and the initiator feed solution were introduced into the reaction vessel. The monomer feed solution was fed over a 2-hour period, and the initiator feed solution over a 3-hour period. The reaction vessel was maintained at 90 °C with stirring for an additional 7 hours, and then allowed to cool to room temperature. The polymer (CP3) was precipitated by adding the reaction mixture dropwise to heptane, collected by filtration, and dried under vacuum to produce 25 g of solids (78% yield).

[0113] Table 1

[0114]

[0115] Synthesis of Thermal Acid Generator (TAG)

[0116] Example 13 (TAG1) )

[0117] 2,3-Difluoropyridine (7.25 g, 0.063 mol) was added to a solution of 4-dodecylbenzenesulfonic acid (16.00 g, 0.049 mol) in methanol (250 mL). The resulting mixture was stirred overnight at room temperature. The resulting reaction mixture was concentrated under reduced pressure to produce a crude solid product, which was then washed with heptane (300 mL). The solid was filtered and washed with methyl tert-butyl ether (100 mL) to produce the acid-generating agent TAG1 in 90% yield.

[0118]

[0119] Example 14 (TAG2) )

[0120] 3-Fluoropyridine (6.12 g, 0.063 mol) was added to a solution of 4-dodecylbenzenesulfonic acid (16.00 g, 0.049 mol) in methanol (250 mL). The resulting mixture was stirred overnight at room temperature. The resulting reaction mixture was concentrated under reduced pressure to produce a crude solid product, which was then washed with heptane (300 mL). The solid was filtered and washed with methyl tert-butyl ether (100 mL) to produce the acid-generating agent TAG2 in 92% yield.

[0121]

[0122] Preparation of pattern trimming composition

[0123] The photoresist patterning composition (PTC) was prepared by dissolving the solid components in a solvent using the materials and amounts listed in Table 2. The resulting mixture, prepared in batches of 14–30 g, was shaken on a mechanical vibrator for 3–24 hours and then filtered through a PTFE disc filter with a pore size of 0.2 micrometers.

[0124] Table 2

[0125]

[0126] B1 = diisopentyl ether; B2 = 4-methyl-2-pentanol; B3 = tripropylene glycol monomethyl ether; A1 = 4-dodecylbenzenesulfonic acid (King Industries, Inc.); all amounts are provided as a percentage by weight (wt%) of the total pattern-finishing composition.

[0127] Solubility evaluation

[0128] Examples 27-38 (Polymer solubility in organic solvents)

[0129] The polymers of Examples 1-12 were combined with isopentyl ether / 4-methyl-2-pentanol (97 / 3 weight ratio) at a concentration of 10 wt% of the total solution. The solutions were shaken for 2 hours, and polymer solubility was assessed both visually and using an Orbeco-Hellige turbidimeter. The polymer was considered soluble in the ether-based solvent if the solution was visually clear and exhibited a turbidity of <1 NTU. The results are shown in Table 3, where "yes" or "no" indicates whether the polymer is soluble or insoluble in the solvent.

[0130] Examples 39-50 (Membrane solubility in rinsing agents)

[0131] Using a TEL Clean Track Act 8 coating tool, the pattern trimming compositions of Examples 15-26 were applied to the respective 8-inch silicon wafers at a rotation speed of 1500 rpm. The coated wafers were baked at 100°C for 60 seconds to a dried film thickness of 40 nm, as measured by a Therma-Wave Opti-Probe 5230 measuring tool. The wafers were then rinsed with a 0.26N TMAH solution. The film thickness was measured again after the rinse. The film thickness change (ΔFT) before and after TMAH rinsing was calculated using the following equation:

[0132] ΔFT = FT i -FT f

[0133] Among them FT i This refers to the membrane thickness before TMAH rinsing, and FT. f This is the membrane thickness after rinsing. The results are shown in Table 3, where "yes" or "no" indicates whether the membrane is soluble or insoluble in TMAH rinsing agent, respectively.

[0134] Table 3

[0135]

[0136] Evaluation of photoresist pattern finishing compositions

[0137] Pattern Repair Evaluation

[0138] On the TEL Clean Track Act 8 coating tool, a 600nm BARC layer (AR) will be coated. TM 3. Anti-reflection: DuPont Electronics & Imaging spin-coated 8-inch silicon wafers with UV217 photoresist (DuPont Electronics & Imaging) and soft-baked at 130°C for 60 seconds to provide... The resist layer thickness was determined. The wafer was exposed using a Canon ES4 FPA 5000 scanner with NA = 0.68 and normal illumination (0.75σ) and a mask with a 1:1 line-spacer pattern of 140 nm dual feature size. After exposure at 125°C, the wafer was baked for 60 seconds and developed with 0.26N TMAH solution to form a photoresist pattern with a 1:1 line-spacer pattern of 140 nm (duty cycle = 1:1). The CD linewidth of the formed pattern was measured using a Hitachi High Technologies Co. CG4000 CD-SEM to obtain initial CD values.

[0139] Next, the coating is applied to the wafer using a TEL Clean Track Act 8 coating tool at a rotation speed of 1500 rpm. The corresponding pattern-trimming composition was baked at the temperatures described in Table 4 for 60 seconds, rinsed with a 0.26N TMAH aqueous solution for 30 seconds, rinsed with distilled water, and then rotated to dry. The resist pattern of the treated wafer was then measured using CD to obtain the final CD value. The CD change (ΔCD) of the treated pattern for each wafer was calculated according to the following equation:

[0140] ΔCD=CD i -CD f

[0141] CD f It is the average CD measurement value after pattern trimming, and CD i This is the average CD measurement value before pattern finishing. The results are shown in Table 4. The wafer was also examined using an optical microscope to determine if any residue remained in the gaps between the lines of the resist pattern.

[0142] Table 4

[0143] Example Pattern Trimming Composition Baking Temperature (°C) ΔCD (nm) Residue Example 39 PTC-11 10 35.0 None Example 40 PTC-21 10 27.4 None Example 41 PTC-3 100 35.5 None Example 42 PTC-4 100 28.9 None Example 43 PTC-5 110 33.7 None Example 44 PTC-6 100 36.2 None Example 45 PTC-7 100 23.5 None Example 46 PTC-8 110 34.3 None Example 47 PTC-9 110 36.4 None Example 48 (Comparison) PTC-10 80 -6 2.0 Yes Example 49 (Comparison) PTC-11 N / AN / AN / A Example 50 (Comparison) PTC-12 100* Yes surface

[0144] *The CD cannot be measured due to the extent of residue.

Claims

1. A method for modifying photoresist patterns, comprising: (a) Providing a semiconductor substrate; (b) Forming a photoresist pattern on the semiconductor substrate, wherein the photoresist pattern is formed from a photoresist composition comprising a photoacid generator and a polymer containing acid-degradable groups, wherein the photoresist composition comprises a polymer based on a vinyl aromatic compound; (c) Applying a photoresist pattern trimming composition to the photoresist pattern, wherein the photoresist pattern trimming composition comprises: a polymer comprising monomers containing acid-degradable groups as polymerization units, wherein the decomposition of the groups forms carboxylic acid groups on the polymer; a non-polymeric acid or a non-polymeric thermal acid generator; and an organic-based solvent system comprising one or more organic solvents, wherein the polymer of the photoresist pattern trimming composition does not contain acid groups, and the organic-based solvent system comprises one or more non-polar organic solvents; (d) Heating the coated photoresist pattern; and (e) Rinsing the coated and heated photoresist pattern with a rinsing agent to remove surface areas of the photoresist pattern.

2. The method as described in claim 1, wherein, The acid-degradable group in the photoresist pattern trimming composition is a tertiary alkyl ester.

3. The method as described in claim 1, wherein, The acid-degradable group in the photoresist pattern-correcting composition is an acetal group.

4. The method according to any one of claims 1 to 3, wherein, The polymer in the photoresist patterning composition further comprises monomers containing the following groups as polymerization units: (i) fluorohydrin groups, or (ii) acid-degradable groups, wherein the decomposition of the groups forms fluorohydrin groups on the polymer.

5. The method according to any one of claims 1 to 3, wherein, The polymer in the photoresist patterning composition further comprises monomers as unsubstituted C1-C10 alkyl (meth)acrylate monomers as polymerization units.

6. The method according to any one of claims 1 to 3, wherein, In the photoresist patterning composition, the combined content of all polymeric units containing acid-degradable groups is 30 to 100 mol% based on the total number of polymeric units of the polymer, and the decomposition of the groups forms carboxylic acid groups on the polymer.

7. The method according to any one of claims 1 to 3, wherein, The organic-based solvent system includes a single ether.

8. The method of claim 7, wherein, The organic-based solvent system further comprises alcohols and / or esters.

9. The method according to any one of claims 1 to 3, wherein, The rinsing agent is an aqueous solution of tetramethylammonium hydroxide.

10. The method according to any one of claims 1 to 3, wherein, The photoresist pattern is formed by KrF or EUV lithography.

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