Resist top coating composition and method of forming pattern using the same

Abstract

A resist topcoat composition and a method of forming a pattern using the composition are provided. The resist topcoat composition includes: a copolymer including a first structural unit represented by Chemical Formula M-1, a second structural unit represented by Chemical Formula M-2; at least one acidic compound selected from the group consisting of sulfonic acid compounds containing at least one fluorine, sulfimide compounds containing at least one fluorine, and carboxylic acid compounds containing at least one fluorine; and a solvent.

Description

[0001] Citations of Related Applications

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2023-0113817 filed in the Korean Intellectual Property Office on August 29, 2023, the disclosure of which is incorporated herein in its entirety by reference. Technical Field

[0003] Embodiments of the present disclosure relate to a resist topcoat composition and a method of forming a pattern using the composition. Background Art

[0004] Recently, the semiconductor industry has developed ultra-micro technology that provides patterns with sizes ranging from several nanometers to tens of nanometers. This ultra-micro technology should be accompanied by an efficient photolithography process.

[0005] The existing photolithography process involves forming a material layer on a semiconductor substrate, coating a photoresist layer thereon, exposing and developing to form a photoresist pattern, and then etching the material layer using the photoresist pattern as a mask.

[0006] As photolithography processes develop, the degree of pattern integration is increasing, and research is being conducted on materials and techniques for solving various problems arising in the process.

[0007] For example, if extreme ultraviolet light (EUV) is irradiated onto a photoresist, due to the high energy of each photon of EUV light, there may be areas where a large amount of light or a small amount of light is randomly irradiated (this may be referred to as photo shot noise), or the difference in EUV absorption between the top and bottom of the photoresist may cause pattern dispersion degradation such as pattern roughness (e.g., LER: line edge roughness, LWR: line width roughness) and / or IPU (in-point uniformity), so further development of technology to improve such pattern dispersion degradation will be useful. Summary of the invention

[0008] Some embodiments of the present disclosure provide a resist top coating composition capable of reducing pattern scatter by preventing or reducing pattern degradation.

[0009] Some embodiments provide methods of forming patterns using a resist topcoat composition.

[0010] Some embodiments provide a resist top coating composition comprising: a copolymer including a first structural unit represented by chemical formula M-1, a second structural unit represented by chemical formula M-2; at least one acidic compound selected from a sulfonic acid compound containing at least one fluorine, a sulfonimide compound containing at least one fluorine, and a carboxylic acid compound containing at least one fluorine; and a solvent.

[0011]

[0012] In Chemical Formula M-1 and Chemical Formula M-2,

[0013] R 1 and R 2 are each independently hydrogen or substituted or unsubstituted C1 to C10 alkyl,

[0014] L 1 and L 2 are each independently a single bond (eg, a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, or a combination thereof,

[0015] X 1 is a single bond (e.g., a single covalent bond), -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO)-, -O(CO)O-, -NR a -(where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl) or a combination thereof,

[0016] R 3 is hydrogen, fluorine, hydroxy, substituted or unsubstituted C1 to C20 alkyl or a combination thereof,

[0017] R 4 is hydrogen or C(=O)R b ,

[0018] R b is a substituted or unsubstituted C1 to C10 alkyl group,

[0019] Selected from R 3 , L 1 and L 2 at least one of which includes fluorine and hydroxyl,

[0020] R 5 is hydrogen, halogen, hydroxy, substituted or unsubstituted C1 to C10 alkyl, or a combination thereof,

[0021] m1 is an integer from 1 to 4, and

[0022] * is the point of attachment (eg, point of attachment to another part of the copolymer).

[0023] Some embodiments provide a method for forming a pattern, comprising coating and heating a photoresist composition on a substrate to form a photoresist layer, coating and heating the above-mentioned resist top coating composition on the photoresist layer to form a top coating layer, and exposing and developing the top coating layer and the photoresist layer to form a resist pattern.

[0024] The resist top coating composition according to some embodiments can remove excess activated acid from the top of the photoresist if exposed to EUV to prevent or reduce pattern distribution degradation, such as roughness (LER, LWR) and / or IPU of the pattern due to EUV absorption differences between the top and bottom of the photoresist, thereby improving pattern distribution, significantly improving the IPU of the columnar pattern and facilitating the formation of a fine pattern of the photoresist. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The drawings, together with the specification, illustrate embodiments of the presently disclosed subject matter, and, together with the description, serve to explain principles of the embodiments of the presently disclosed subject matter.

[0026] Figure 1 is a schematic diagram illustrating a method of forming a pattern using a resist top coating composition according to some embodiments.

[0027] Description of Reference Numerals

[0028] 1: Forming a photoresist layer

[0029] 2: Forming a photoresist top coat

[0030] 3: Expose and develop the photoresist layer and photoresist top coat to form a resist pattern

[0031] 30: Photoresist top coating

[0032] 100: Substrate

[0033] 101: Photoresist layer

[0034] 102b: Photoresist pattern DETAILED DESCRIPTION

[0035] Hereinafter, the embodiments of the present disclosure will be described in detail so that those skilled in the art can easily implement the subject matter of the present disclosure. However, the present disclosure can be embodied in many different forms and should not be construed as being limited to the exemplary embodiments described herein.

[0036] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity, and the same reference numerals represent the same elements throughout the text. It will be understood that if an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element, or there can be intermediate elements. In some embodiments, if an element is referred to as being "directly on" another element, there are no intermediate elements.

[0037] As used herein, if no definition is provided otherwise, "substituted" means that a hydrogen atom of a compound is replaced by a substituent selected from the group consisting of a halogen atom (F, Br, Cl or I), a hydroxyl group, a thiol group, a nitro group, a cyano group, an amino group, a substituted or unsubstituted C1 to C30 amine group, an azido group, an amidine group, a hydrazine group, a hydrazone group, a carbonyl group, a carbamoyl group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphate group or a salt thereof, a vinyl group, a C C1 to C20 alkyl, C2 to C20 alkenyl, C2 to C20 alkynyl, C6 to C30 aryl, C7 to C30 arylalkyl, C6 to C30 allyl, C1 to C30 alkoxy, C1 to C30 thioether, C1 to C20 heteroalkyl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, C3 to C30 heterocycloalkyl, and combinations thereof.

[0038] As used herein, if no definition is otherwise provided, the term "alkyl" refers to a straight or branched aliphatic hydrocarbon group. The alkyl group may be a "saturated alkyl group" without any double or triple bonds (eg, the alkyl group does not include any double or triple bonds).

[0039] The alkyl group may be a C1 to C8 alkyl group. In some embodiments, the alkyl group may be a C1 to C10 alkyl group or a C1 to C6 alkyl group. For example, the term C1 to C5 alkyl group may refer to an alkyl chain containing 1 to 5 carbon atoms and is selected from methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl and tert-butyl.

[0040] The alkyl group may include examples such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, and the like.

[0041] In the chemical formulas described herein, t-Bu refers to tert-butyl.

[0042] As used herein, if no definition is otherwise provided, "cycloalkyl" refers to a monovalent cyclic aliphatic hydrocarbon group.

[0043] The term cycloalkyl refers to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl and / or the like.

[0044] The cycloalkyl group may be a C3 to C10 cycloalkyl group, for example, a C3 to C8 cycloalkyl group, a C3 to C7 cycloalkyl group, or a C3 to C6 cycloalkyl group. For example, the cycloalkyl group may be a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group, but is not limited thereto.

[0045] As used herein, unless otherwise defined, the term "alkenyl" refers to an aliphatic unsaturated alkenyl group that is a straight or branched aliphatic hydrocarbon group containing at least one double bond.

[0046] As used herein, unless otherwise defined, the term "alkynyl" refers to an aliphatic unsaturated alkynyl group that is a straight or branched aliphatic hydrocarbon group containing at least one triple bond.

[0047] As used herein, the term "aryl" refers to a substituent in which all atoms in a cyclic substituent have p-orbitals and the p-orbitals are conjugated, and may include monocyclic or fused-ring polycyclic functional groups (e.g., rings that share adjacent pairs of carbon atoms).

[0048] As used herein, “hetero” refers to a group including 1 to 3 heteroatoms selected from N, O, S, Se and P if no definition is otherwise provided.

[0049] In the present disclosure, if a definition is not otherwise provided, the term "heterocycloalkyl group" refers to a cycloalkyl group containing at least one heteroatom selected from N, O, S, P and Si.

[0050] In the present disclosure, the term "heteroaryl" refers to an aryl group including at least one heteroatom selected from N, O, S, P and Si. Two or more heteroaryl groups are directly connected by a sigma bond, or if the heteroaryl group includes two or more rings, the two or more rings may be fused together. If the heteroaryl group is a fused ring, each ring may include 1 to 3 heteroatoms.

[0051] Unless otherwise specified in this specification, the weight average molecular weight can be measured by dissolving a powder sample in tetrahydrofuran (THF) and then using a 1200 series gel permeation chromatograph (GPC) from Agilent Technologies (the column can be LF-804 from Shodex and the standard sample can be polystyrene from Shodex).

[0052] In some embodiments, unless otherwise defined in the specification, "*" indicates a point of attachment of a structural unit of a compound or a compound moiety.

[0053] Hereinafter, a resist top coating composition according to some embodiments is described.

[0054] The present disclosure relates to a photoresist topcoat composition capable of improving the IPU (intra-dot uniformity) of a C / H (contact hole) pattern, the LER (line edge roughness) / LWR (line width roughness) of an L / S (line and space) pattern, and the IPU of a columnar pattern by improving the sensitivity of the photoresist during a fine pattern forming process of a photolithography method using high-energy rays such as EUV (extreme ultraviolet light; wavelength: about 13.5 nm) and / or the like and selectively reducing the acid concentration in an upper portion of the photoresist in parallel (e.g., simultaneously); and a method for forming a photoresist pattern by using the topcoat.

[0055] According to some embodiments, the photoresist top coating composition includes: a copolymer, the copolymer including a first structural unit represented by Chemical Formula M-1, a second structural unit represented by Chemical Formula M-2; at least one acidic compound selected from a sulfonic acid compound containing at least one fluorine, a sulfonimide compound containing at least one fluorine, and a carboxylic acid compound containing at least one fluorine; and a solvent.

[0056]

[0057] In Chemical Formula M-1 and Chemical Formula M-2,

[0058] R 1 and R 2 are each independently hydrogen or substituted or unsubstituted C1 to C10 alkyl,

[0059] L 1 and L 2 are each independently a single bond (eg, a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, or a combination thereof,

[0060] X 1 is a single bond (e.g., a single covalent bond), -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO)-, -O(CO)O-, -NR a -(where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl) or a combination thereof,

[0061] R 3 is hydrogen, fluorine, hydroxy, substituted or unsubstituted C1 to C20 alkyl, or a combination thereof,

[0062] R 4 is hydrogen or C(=O)R b ,

[0063] R b is a substituted or unsubstituted C1 to C10 alkyl group,

[0064] Selected from R 3 , L 1 and L 2 at least one of which includes fluorine and hydroxyl,

[0065] R 5 is hydrogen, halogen, hydroxyl, substituted or unsubstituted C1 to C10 alkyl, or a combination thereof, m1 is an integer from 1 to 4, and

[0066] * is the point of attachment (eg, point of attachment to another part of the copolymer).

[0067] The photoresist top coating composition according to some embodiments may be coated on top of a photoresist layer to significantly improve LER / LWR of an L / S pattern, IPU of a C / H pattern, and IPU of a pillar pattern, and improve sensitivity of the photoresist.

[0068] The first structural unit included in the copolymer of the composition has the property of being almost unreactive with the photoresist but well soluble in the solvent, and thus can protect the photoresist while minimizing or reducing the influence on the photoresist, while the second structural unit can increase EUV absorption to improve sensitivity.

[0069] Therefore, the copolymer may have excellent solubility in a solvent, may be uniformly (or substantially uniformly) coated on a pattern, and minimize or reduce the influence on a resist.

[0070] In some embodiments, the acidic compound included in the composition is an acidic compound containing at least one fluorine, and may be, for example, selected from sulfonic acid compounds containing at least one fluorine, sulfonimide compounds containing at least one fluorine, and carboxylic acid compounds containing at least one fluorine.

[0071] In some embodiments, resist defects can be selectively removed by adding an acidic compound containing at least one fluorine. In some embodiments, the IPU or LWR of a pattern can be improved by dissolving and removing a deteriorated area (e.g., a circular outline area of ​​an upper layer of a photoresist) of the pattern that occurs during an exposure process during a development process, making it rectangular.

[0072] If the photoresist topcoat composition remains after development, it may cause scum defects in the L / S pattern and / or not-open defects in the C / H pattern, thereby resulting in reduced product yield.

[0073] However, the photoresist top coating composition according to some embodiments may be removed during a development process and thus may not (or substantially not) cause defects in various suitable patterns.

[0074] The copolymer and the acidic compound may be included in a weight ratio of about 3:1 to about 30:1.

[0075] The resist top coating composition according to some embodiments may prevent or reduce pattern degradation and reduce pattern dispersion by including the copolymer and the acidic compound in the above weight ratio.

[0076] The copolymer may be included in an amount of about 1 wt % to about 10 wt % based on the total weight of the resist top coating composition.

[0077] The acidic compound may be included in an amount of about 0.1 wt % to about 10 wt % based on the total weight of the resist top coating composition.

[0078] Within the above range, the resist top coat layer can be easily removed.

[0079] As an example, the copolymer may include a first structural unit represented by Chemical Formula M-1 and a second structural unit represented by Chemical Formula M-2.

[0080] In the chemical formula M-2, if m1 is 2 or greater, each OR 4 May be the same as or different from each other.

[0081] In the chemical formula M-2, if 5-m1 is 2 or greater, each R 5 May be the same as or different from each other.

[0082] R 3 , L 1 and L 2 The meanings of at least one including fluorine and hydroxyl may include the following cases, wherein:

[0083] R 3 may be a C1 to C20 alkyl group substituted with at least one fluorine group and at least one hydroxyl group, or

[0084] Selected from L 1 and L 2 At least one of may be a C1 to C10 alkylene group substituted with one or more fluorine and one or more hydroxyl groups, or

[0085] Selected from L 1 and L 2 One of the may be a C1 to C10 alkylene group substituted by one or more fluorine groups, and the other may be a C1 to C10 alkylene group substituted by one or more hydroxy groups, or

[0086] R 3 may be fluorine and is selected from L 1 and L 2 At least one of may be a C1 to C10 alkylene group substituted with one or more hydroxyl groups, or

[0087] R 3 may be hydroxyl and is selected from L 1 and L 2 At least one of may be a C1 to C10 alkylene group substituted with one or more fluorines, or

[0088] R 3 may be a C1 to C10 alkyl group substituted with one or more fluorine groups and one or more hydroxy groups, or

[0089] R 3 It may be a C1 to C10 alkyl group substituted with one or more hydroxyl groups and one or more C1 to C10 fluoroalkyl groups.

[0090] As an example, the first structural unit may be represented by Chemical Formula 1.

[0091] [Chemical formula 1]

[0092]

[0093] In Chemical Formula 1,

[0094] R 1 is hydrogen or substituted or unsubstituted C1 to C10 alkyl,

[0095] R k , R l , R m , R n and R 3 are each independently hydrogen, fluorine, hydroxyl, substituted or unsubstituted C1 to C20 alkyl, or a combination thereof,

[0096] m2 and m3 are each independently an integer from 1 to 10,

[0097] X 1 is a single bond (e.g., a single covalent bond), -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO)-, -O(CO)O-, -NR a -(where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl) or a combination thereof, and

[0098] Selected from R k , R l , R m , Rn and R 3 At least one of includes fluorine and hydroxyl.

[0099] In Formula 1, if m2 is 2 or greater, each R k May be the same as or different from each other.

[0100] In Formula 1, if m2 is 2 or greater, each R l May be the same as or different from each other.

[0101] In Formula 1, if m3 is 2 or greater, each R m May be the same as or different from each other.

[0102] In Formula 1, if m3 is 2 or greater, each R n May be the same as or different from each other.

[0103] Selected from R k , R l , R m , R n and R 3 The description that at least one of includes fluorine and hydroxyl may include the following embodiments, wherein:

[0104] Selected from R k , R l , R m , R n and R 3 At least one of each independently is fluorine and hydroxyl, or

[0105] Selected from R k , R l , R m , R n and R 3 At least one of each independently comprises a C1 to C10 alkyl group substituted by one or more fluorine groups and a C1 to C10 alkyl group substituted by one or more hydroxy groups, or

[0106] Selected from R k , R l , R m , R n and R 3 At least one of each independently comprises a C1 to C10 alkyl group substituted by one or more hydroxyl groups and one or more fluorine groups, or

[0107] Selected from R k , R l , R m , R n and R 3At least one of each independently comprises a C1 to C5 alkyl group substituted with one or more hydroxyl groups and one or more C1 to C5 fluoroalkyl groups, or

[0108] Selected from R k , R l , R m , R n and R 3 At least one of them is fluorine, and at least one of the others is hydroxyl, or

[0109] Selected from R k , R l , R m , R n and R 3 At least one of them is fluorine, and at least one of the others includes a C1 to C10 alkyl group substituted with one or more hydroxyl groups, or

[0110] Selected from R k , R l , R m , R n and R 3 At least one of them is a hydroxyl group, and at least one of the others includes a C1 to C10 alkyl group substituted with one or more fluorine groups, or

[0111] Selected from R k , R l , R m , R n and R 3 At least one of the groups is a C1 to C20 alkyl group substituted by one or more fluorine groups, and at least one of the groups selected from the others is a C1 to C20 alkyl group substituted by one or more hydroxy groups.

[0112] For example, R 1 can be hydrogen or methyl,

[0113] X 1 It can be a single bond (e.g., a single covalent bond), -O-, or -NR a -(where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl), and

[0114] R 3 It may be fluorine, hydroxyl, a C1 to C10 alkyl group substituted by at least one fluorine group, or a C1 to C10 alkyl group substituted by at least one hydroxyl group.

[0115] As an example, in Chemical Formula 1, R m , R n and R 3 At least one of may include fluorine and hydroxyl groups.

[0116] As an example, in Chemical Formula 1, R m and R n At least one of them may be fluorine or a C1 to C10 alkyl group substituted with at least one fluorine, and R 3 It may be a hydroxy group or a C1 to C10 alkyl group substituted with at least one hydroxy group.

[0117] As an example, in Chemical Formula 1, R m and R n At least one of them may be a hydroxyl group or a C1 to C10 alkyl group substituted with at least one hydroxyl group, and R 3 It may be fluorine or a C1 to C10 alkyl group substituted with at least one fluorine.

[0118] As an example, in Chemical Formula 1, R m It may be a hydroxyl group or a C1 to C10 alkyl group substituted with at least one hydroxyl group, R n may be fluorine or a C1 to C10 alkyl group substituted with at least one fluorine, and R 3 It may be a hydroxy group, a fluorine group, or a C1 to C10 alkyl group substituted with at least one of a fluorine group and a hydroxy group.

[0119] As an example, in Chemical Formula 1, R m and R n At least one of them may be fluorine or a C1 to C10 alkyl group substituted with at least one fluorine, and R 3 It may be a hydroxy group or a C1 to C5 alkyl group substituted with at least one selected from a hydroxy group and a C1 to C5 fluoroalkyl group.

[0120] For example, the first structural unit may be selected from Group I.

[0121] [Group I]

[0122]

[0123] In Group I,

[0124] R 1 Each is independently hydrogen or methyl, and * is a point of attachment (eg, * is a point of attachment to another part of the copolymer).

[0125] As an example, the second structural unit may be represented by any one selected from Chemical Formula 2-1 to Chemical Formula 2-4.

[0126]

[0127] In Chemical Formula 2-1 to Chemical Formula 2-4,

[0128] R 2is hydrogen or methyl,

[0129] R 4 , R 4a and R 4b are independently hydrogen or C(=O)R b ,

[0130] R b is a substituted or unsubstituted C1 to C5 alkyl group,

[0131] R 5a , R 5b , R 5c and R 5d are each independently hydrogen, halogen, hydroxy, substituted or unsubstituted C1 to C10 alkyl, or a combination thereof, and

[0132] * is the point of attachment (eg, * is the point of attachment to another part of the copolymer).

[0133] As an example, R 5 At least one of may be a halogen.

[0134] As an example, R 5 At least one of the second structural unit may be an iodine group. If the second structural unit includes an iodine group, the sensitivity may be further improved. For example, the second structural unit may be selected from Group II.

[0135] [Group II]

[0136]

[0137] In Group II,

[0138] R 2 Each is independently hydrogen or methyl, and * is a point of attachment (eg, * is a point of attachment to another part of the copolymer).

[0139] The copolymer may include about 30 mol % to about 95 mol % of the first structural unit and about 5 mol % to about 70 mol % of the second structural unit.

[0140] For example, the copolymer may include about 50 mol % to about 90 mol % of the first structural unit, about 10 mol % to about 50 mol % of the second structural unit, more specifically about 60 mol % to about 85 mol % of the first structural unit, and about 15 mol % to about 40 mol % of the second structural unit.

[0141] If the molar ratio of each structural unit included in the copolymer is within the above range, solubility in an organic solvent is improved, and a pattern may be uniformly (or substantially uniformly) coated.

[0142] The copolymer may have a weight average molecular weight (Mw) of about 1,000 g / mol to about 50,000 g / mol. For example, the copolymer may have a weight average molecular weight of about 2,000 g / mol to about 30,000 g / mol, such as about 3,000 g / mol to about 20,000 g / mol, but is not limited thereto. If the weight average molecular weight of the copolymer is within the above range, the carbon content of the resist top coating composition containing the copolymer and the solubility in the solvent can be improved.

[0143] The copolymer may be included in an amount of about 1 wt % to about 10 wt % based on the total weight of the resist top coating composition.Within the above range, the resist top coating may be easily removed.

[0144] In some embodiments, the copolymer may be selected from those listed in Group III.

[0145] [Group III]

[0146]

[0147] In Group III, x:y can be about 65:35, about 70:30, or about 75:25.

[0148] As an example, the acidic compound may be at least one selected from the compounds represented by Chemical Formula 3 to Chemical Formula 6.

[0149] [Chemical formula 3]

[0150]

[0151] [Chemical formula 6]

[0152]

[0153] In Chemical Formulae 3 to 6,

[0154] R 7 To R 10 each independently represents fluorine, a C1 to C20 alkyl group substituted by at least one fluorine, a C2 to C20 alkenyl group substituted by at least one fluorine, a C2 to C20 alkynyl group substituted by at least one fluorine, a C3 to C20 cycloalkyl group substituted by at least one fluorine, a C3 to C20 cycloalkenyl group substituted by at least one fluorine, a C3 to C20 cycloalkynyl group substituted by at least one fluorine, a C6 to C20 aryl group substituted by at least one fluorine, a C1 to C20 heteroaryl group substituted by at least one fluorine, or a combination thereof, and

[0155] L 3It is a C1 to C10 alkylene group substituted by at least one fluorine group, a C3 to C20 cycloalkylene group substituted by at least one fluorine group, a C6 to C20 arylene group substituted by at least one fluorine group, a C1 to C20 heteroarylene group substituted by at least one fluorine group, or a combination thereof.

[0156] As an example, R in Chemical Formulae 3 to 6 7 To R 10 are each independently a C1 to C10 alkyl group substituted by at least one fluorine group, a C6 to C20 aryl group substituted by at least one fluorine group, or a combination thereof, and

[0157] L 3 It may be a C1 to C5 alkylene group substituted with at least one fluorine group.

[0158] For example, the acidic compound may be at least one selected from the compounds listed in Group IV.

[0159] [Group IV]

[0160]

[0161] In some embodiments, the resist top coating composition may further include at least one other polymer selected from the group consisting of epoxy-based resin, novolac resin, glycoluril-based resin, and melamine-based resin, but is not limited thereto.

[0162] The resist top coating composition may further include an additive including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

[0163] The surfactant may be, for example, alkylbenzene sulfonate, alkyl pyridinium salt, polyethylene glycol, quaternary ammonium salt, and / or the like, but is not limited thereto.

[0164] The thermal acid generator can be, for example, an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluene sulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthoic acid and / or benzoin tosylate, 2-nitrobenzyl tosylate and / or other organic alkyl sulfonates, but is not limited thereto.

[0165] The amounts of these additives can be easily adjusted and may be omitted depending on the appropriate or desired physical properties.

[0166] The solvent may be an ether solvent represented by Chemical Formula 7.

[0167] [Chemical formula 7]

[0168]

[0169] In Chemical Formula 7,

[0170] R 11 and R 12 Each is independently a substituted or unsubstituted C3 to C20 alkyl group.

[0171] For example, the ether solvent can be selected from diisopropyl ether, dipropyl ether, diisoamyl ether, diamyl ether, dibutyl ether, diisobutyl ether, disec-butyl ether, dihexyl ether, bis(2-ethylhexyl) ether, didecyl ether, didedecyl ether, didedecyl ether, didedecyl ether, didetradecyl ether, hexadecyl ether, butyl methyl ether, butyl ethyl ether, butyl propyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert-butyl propyl ether, di-tert-butyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, cyclopentyl ethyl ether, cyclohexyl ethyl ether, cyclopentyl propyl ether, cyclopentyl-2-propyl ether, cyclohexyl propyl ether, cyclohexyl-2-propyl ether, cyclopentyl butyl ether, cyclopentyl tert-butyl ether, cyclohexyl butyl ether, cyclohexyl tert-butyl ether, 2-octanone, 4-heptanone and combinations thereof.

[0172] For the above composition, the ether solvent may have suitable or sufficient solubility and / or dispersibility.

[0173] According to some exemplary embodiments, a method of forming a pattern using the above-mentioned photoresist top coating composition may be provided. For example, the fabricated pattern may be a photoresist pattern.

[0174] The method of forming a pattern according to some exemplary embodiments includes coating and heating a photoresist composition on a substrate to form a photoresist layer, coating and heating the above-mentioned photoresist top coating composition on the photoresist layer to form a top coating layer, and exposing and developing the top coating layer and the photoresist layer to form a resist pattern.

[0175] Hereinafter, a method of forming a pattern using the above-mentioned photoresist top coating composition will be described with reference to the accompanying drawings. Figure 1 is a schematic diagram illustrating a method of forming a pattern using a photoresist top coating composition according to the present disclosure.

[0176] Referring to the accompanying drawings, first, an object to be etched is prepared. An example of the object to be etched may be a thin film on a semiconductor substrate. Hereinafter, only the case where the object to be etched is a thin film is described. The surface of the thin film is cleaned to remove contaminants remaining on the thin film. The thin film may be, for example, a silicon nitride film, a polysilicon film, and / or a silicon oxide film.

[0177] A photoresist composition is coated on the thin film 100 and heated to form a photoresist layer 101 (stage 1). Subsequently, a photoresist topcoat composition is coated on the photoresist layer and heated to form a photoresist topcoat layer 30 (stage 2).

[0178] The heating may be performed at a temperature of about 80°C to about 500°C.

[0179] The photoresist topcoat and photoresist layer are then exposed to high energy radiation.

[0180] For example, high-energy radiation that may be used in the exposure process may include light having a high-energy wavelength, such as EUV (extreme ultraviolet light; wavelength: 13.5 nm) and / or E-beam (electron beam).

[0181] A post-exposure thermal treatment (PEB) is then performed. The post-exposure thermal treatment may be performed at a temperature of about 80° C. to about 200° C. By performing the post-exposure thermal treatment, the exposed region of the photoresist layer (e.g., the region not covered by the patterned mask) becomes soluble in the developer, so that the exposed region has a different solubility from the unexposed region of the photoresist layer.

[0182] The photoresist pattern 102b may be formed by dissolving and removing the photoresist layer and the photoresist top coat layer corresponding to the exposed area using a developer (stage 3).

[0183] In some embodiments, the developer may be an alkaline developer or a developer containing an organic solvent (hereinafter referred to as an organic-based developer).

[0184] As the alkaline developer, a quaternary ammonium salt such as tetramethylammonium hydroxide may be used, but an alkaline aqueous solution such as an inorganic base, a primary to tertiary amine, an alcoholamine and / or a cyclic amine may also be used.

[0185] In some embodiments, the alkaline developer may include an appropriate amount or a suitable amount of alcohol and / or a surfactant. The alkaline developer may have an alkali concentration of, for example, about 0.1% to about 20% by mass, and a pH of, for example, about 10 to about 15.

[0186] The organic-based developer may be a developer containing at least one organic solvent selected from the group consisting of a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, an ether solvent, and a hydrocarbon solvent.

[0187] Examples of the ketone solvent may include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonyl acetone, ionone, diacetonyl alcohol, acetyl carbinol, acetophenone, methyl naphthyl ketone, isophorone, propylene carbonate, and the like.

[0188] Examples of the ester solvents may include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, amyl acetate, isoamyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butyrate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, butyl propionate, and the like.

[0189] Any suitable solvent generally used in the art may be used as the alcohol solvent, the amide solvent, the ether solvent and / or the hydrocarbon solvent.

[0190] A plurality of the solvents may be mixed together, or may be mixed with a solvent other than the above solvents or water. As the developer as a whole, the water content may be appropriately or desirably less than about 50 wt %, less than about 20 wt %, less than about 10 wt %, or the developer may be substantially free of or completely free of water.

[0191] The organic solvent may be appropriately or desirably included in an amount of about 50 wt % to about 100 wt %, about 80 wt % to about 100 wt %, about 90 wt % to about 100 wt %, or about 95 wt % to about 100 wt %, based on the total amount of the organic developer.

[0192] The organic developer may include any suitable surfactant in a suitable amount or a suitable amount as required.

[0193] The surfactant may be included in an amount of about 0.001 wt % to about 5 wt %, about 0.005 wt % to about 2 wt %, or about 0.01 wt % to about 0.5 wt %, based on the total amount of the developer.

[0194] Organic developers may include inhibitors.

[0195] Subsequently, the exposed thin film is etched by using the photoresist pattern as an etching mask, thereby forming the thin film into a thin film pattern.

[0196] The thin film may be etched, for example, by dry etching using an etching gas, and the etching gas may be, for example, CHF 3 , CF 4 , Cl 2 , BCl 3 , or a mixture thereof.

[0197] In the exposure process performed above, the thin film pattern formed by the photoresist pattern formed by the exposure process performed with the EUV light source can have a width corresponding to the photoresist pattern. For example, the photoresist pattern can have a width of about 5nm to about 100nm. For example, the thin film pattern formed by the exposure process performed with the EUV light source can have a width of about 5nm to about 90nm, about 5nm to about 80nm, about 5nm to about 70nm, about 5nm to about 60nm, about 5nm to about 50nm, about 5nm to about 40nm, about 5nm to about 30nm, about 5nm to about 20nm, or can have a width less than or equal to about 20nm, which is similar to the width of the photoresist pattern.

[0198] Hereinafter, embodiments of the present disclosure will be described in more detail through examples involving the synthesis of the above-mentioned polymer and the preparation of a photoresist top coating composition including the polymer. However, the present disclosure is not technically limited to the following examples.

[0199] Synthesis example

[0200] Synthesis Example 1: Synthesis of Compound 1a

[0201] Under nitrogen atmosphere, 20g (59.86mmol) of hexafluoro-2,3-bis (trifluoromethyl) -2,3-butanediol (perfluoropinacol), 7.79g (59.86mmol) of 2- (hydroxyethyl) methacrylate and 18.84g (71.84mmol) of triphenylphosphine (PH3P) were mixed together in 110ml of ether and then stirred. After stirring for 30 minutes, the obtained mixture was cooled to 0°C, and another mixture of 14.52g (71.84mmol) of diisopropyl azodicarboxylate (DIAD) and 35ml of ether was slowly added thereto over 2 hours. Subsequently, the obtained mixture was stirred at room temperature (23°C) for 24 hours and then concentrated. The concentrated mixture was dissolved in dichloromethane and then treated by column chromatography using silica gel to separate the synthesized substance. The separated substance was distilled under reduced pressure to obtain 2-[3,3,3-trifluoro-2-hydroxy-1,1,2-tris(trifluoromethyl)propoxy]ethyl 2-methyl-2-propionate represented by Chemical Formula 1a.

[0202] * 1 H-NMR (acetone-d6): δ1.90 (3H, t), 4.36 (4H, m), 5.63 (1H, t), 6.09 (1H, t), 8.34 (1H, s)

[0203] * 19 F-NMR (acetone-d6):δ-70.12(6F,m),-65.38(6F,m)

[0204] [Chemical formula 1a]

[0205]

[0206] Synthesis Example 2: Preparation of Copolymer R1

[0207] In a 250 mL 2-necked round-bottom flask, a compound represented by Chemical Formula 1a (21.06 g, 59 mmol), a compound represented by Chemical Formula 1b (DIHS (di-iodine hydroxylstyrene), Daejeong Chemical Co., Ltd.) (12.20 g, 41 mmol) were added under a nitrogen atmosphere, and then heated to 100° C. When the internal temperature reached 100° C., 18.42 g of a 25 wt% V-601 / DIAE solution (V-601, 4.61 g, 30 mmol) was slowly added thereto, and after 6 hours, the obtained reaction solution was cooled to room temperature and then concentrated to have a solid content of 50%. 270 g of heptane was added to the concentrated solution, and the polymer produced therefrom was filtered. The filtered polymer was completely dissolved in 34 g of DIAE, and 270 g of heptane was added thereto for precipitation, which was repeated twice to obtain a precipitate, and the precipitate was completely dried, thereby preparing a final copolymer R1 (Mw=5,000).

[0208] [Chemical formula 1b]

[0209]

[0210] Synthesis Example 3: Preparation of Copolymer R2

[0211] Copolymer R2 (Mw=5,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Chemical Formula 1b was not used.

[0212]

[0213] Preparation of resist topcoat composition

[0214] Examples 1 to 7 and Comparative Examples 1 to 11

[0215] The copolymers R1 and R2 prepared in Synthesis Examples 2 and 3, the acidic compounds represented by A1 to A11, and diisoamyl ether (DIAE) were mixed together in the amounts shown in Table 1, stirred at room temperature (23° C.) for 24 hours, and filtered through a Teflon filter having a pore size of 0.45 μm, thereby preparing resist top coating compositions according to Examples 1 to 7 and Comparative Examples 1 to 11, respectively.

[0216] *Acidic compounds

[0217]

[0218] Table 1

[0219]

[0220]

[0221] Evaluation 1: Solubility evaluation

[0222] 1 g of each copolymer of Synthesis Examples 2 to 3 was taken and added to 50 g of DIAE (2 wt %), followed by stirring for 24 hours, and whether a precipitate was generated was checked with naked eyes, and the results are shown in Table 2.

[0223] (No precipitation—solubility ○, with precipitation—solubility X)

[0224] Evaluation 2: Development evaluation

[0225] Each photoresist top coating composition according to the embodiment and the comparative example was spin-coated on a silicon substrate and heat-treated on a hot plate at 110° C. for 1 minute to form a photoresist top coating layer of about 5 nm thick. The substrate having the top coating layer formed thereon was developed with a 2.38% tetramethylammonium hydroxide aqueous solution and heat-treated again on a hot plate at 110° C. for 1 minute, and then, the thickness change of the top coating layer was measured, and the results are shown in Table 2.

[0226] [Evaluation criteria]

[0227] *Residual film after development (%) = [Top coating thickness before development (nm) - Top coating thickness after development (nm)] x 100 / Top coating thickness before development (nm)

[0228] (Residual film after development ≤ 20% - developability O, residual film after development > 20% - developability X)

[0229] Evaluation 3: Pattern Evaluation

[0230] A resist lower layer (thickness: ) and photoresist films for electron beams (thickness: ), each of the photoresist top coating compositions according to the examples and comparative examples was spin-coated and then heat-treated on a hot plate at 110° C. for 1 minute to form a photoresist top coating layer of about 5 nm in thickness.

[0231] The wafer on which the photoresist top coating was formed was line-printed in a focal energy matrix (FEM) format using an electron beam apparatus (JEOL JBX-9300FS). The optimum sensitivity capable of forming a critical dimension (CD) of 50 nm was confirmed using an interpolation method, and the results are shown in Table 2.

[0232] After checking the optimal sensitivity, the line width roughness (LWR) dispersion under the corresponding energy shot was measured by using a CD-SEM device manufactured by Hitatchi Ltd., and the same pattern at 500 points within the beam was measured to obtain the reliability of the dispersion, and its final average value is shown in Table 2.

[0233] Table 2

[0234]

[0235] Referring to Table 2, if the resist top coating compositions according to Examples 1 to 7 were applied, superior solubility, developability, sensitivity, and LWR improvement effects were obtained compared to applying the resist top coating compositions according to Comparative Examples 1 to 11.

[0236] In the above, exemplary embodiments of the present disclosure have been described and illustrated, but it is clear to those skilled in the art that the present disclosure is not limited to the described embodiments, and they can be changed and transformed differently without departing from the spirit and scope of the present disclosure. Therefore, the embodiments thus changed or transformed cannot be understood separately from the technical ideas and aspects of the present disclosure, and the changed embodiments are within the scope of the claims of the present disclosure.

Claims

1. A resist top coating composition comprising: A copolymer comprising a first structural unit represented by Chemical Formula M-1 and a second structural unit represented by Chemical Formula M-2; at least one acidic compound selected from the group consisting of a sulfonic acid compound containing at least one fluorine, a sulfonimide compound containing at least one fluorine, and a carboxylic acid compound containing at least one fluorine; and Solvents, In Chemical Formula M-1 and Chemical Formula M-2, R 1 and R 2 are each independently hydrogen or substituted or unsubstituted C1 to C10 alkyl, L 1 and L 2 are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, or a combination thereof, X 1 Is a single bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO)-, -O(CO)O-, -NR a - or a combination thereof, where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl, R 3 is hydrogen, fluorine, hydroxyl, substituted or unsubstituted C1 to C20 alkyl, or a combination thereof, R 4 is hydrogen or C(=O)R b , R b is a substituted or unsubstituted C1 to C10 alkyl group, Selected from R 3 , L 1 and L 2 at least one of which includes fluorine and hydroxyl, R 5 is hydrogen, halogen, hydroxyl, substituted or unsubstituted C1 to C10 alkyl, or a combination thereof, m1 is an integer from 1 to 4, and * is the connection point.

2. The resist top coating composition according to claim 1, wherein The copolymer and the acidic compound are included in a weight ratio of 3:1 to 30:

1.

3. The resist top coating composition according to claim 1, wherein The copolymer is included in an amount of about 1 wt % to about 10 wt % based on the total weight of the resist top coating composition.

4. The resist top coating composition according to claim 1, wherein The acidic compound is included in an amount of about 0.1 wt % to about 3 wt % based on the total weight of the resist top coating composition.

5. The resist top coating composition according to claim 1, wherein The first structural unit is represented by Chemical Formula 1: [Chemical formula 1] In Chemical Formula 1, R 1 is hydrogen or substituted or unsubstituted C1 to C10 alkyl, R k , R l , R m , R n and R 3 are each independently hydrogen, fluorine, hydroxyl, substituted or unsubstituted C1 to C20 alkyl, or a combination thereof, m2 and m3 are each independently an integer from 1 to 10, X 1 Is a single bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO)-, -O(CO)O-, -NR a - or a combination thereof, where R a is hydrogen, deuterium or substituted or unsubstituted C1 to C10 alkyl, and Selected from R k , R l , R m , R n and R 3 At least one of includes fluorine and hydroxyl.

6. The resist top coating composition according to claim 1, wherein The first structural unit is at least one selected from Group I: [Group I] In Group I, R 1 Each is independently hydrogen or methyl, and * is the point of attachment.

7. The resist top coating composition according to claim 1, wherein The second structural unit is represented by any one selected from Chemical Formula 2-1 to Chemical Formula 2-4: In Chemical Formula 2-1 to Chemical Formula 2-4, R 2 is hydrogen or methyl, R 4 , R 4a and R 4b are each independently hydrogen or C(=O)R b , R b is a substituted or unsubstituted C1 to C5 alkyl group, R 5a , R 5b , R 5c and R 5d are each independently hydrogen, halogen, hydroxy, substituted or unsubstituted C1 to C10 alkyl, or a combination thereof, and * is the connection point.

8. The resist topcoat composition according to claim 1, wherein the second structural unit is at least one selected from Group II: [Group II] In Group II, R 2 Each is independently hydrogen or methyl, and * is the point of attachment.

9. The resist top coating composition according to claim 1, wherein The copolymer includes 30 mol % to 95 mol % of the first structural unit and 5 mol % to 70 mol % of the second structural unit.

10. The resist top coating composition according to claim 1, wherein The copolymer has a weight average molecular weight of about 1,000 to about 50,000 g / mol.

11. The resist top coating composition according to claim 1, wherein The acidic compound is at least one selected from the compounds represented by Chemical Formula 3 to Chemical Formula 6: [Chemical formula 3] [Chemical formula 6] In Chemical Formulae 3 to 6, R 7 To R 10 each independently represents fluorine, a C1 to C20 alkyl group substituted by at least one fluorine, a C2 to C20 alkenyl group substituted by at least one fluorine, a C2 to C20 alkynyl group substituted by at least one fluorine, a C3 to C20 cycloalkyl group substituted by at least one fluorine, a C3 to C20 cycloalkenyl group substituted by at least one fluorine, a C3 to C20 cycloalkynyl group substituted by at least one fluorine, a C6 to C20 aryl group substituted by at least one fluorine, a C1 to C20 heteroaryl group substituted by at least one fluorine, or a combination thereof, and L 3 It is a C1 to C10 alkylene group substituted by at least one fluorine group, a C3 to C20 cycloalkylene group substituted by at least one fluorine group, a C6 to C20 arylene group substituted by at least one fluorine group, a C1 to C20 heteroarylene group substituted by at least one fluorine group, or a combination thereof.

12. The resist top coating composition according to claim 1, wherein The acidic compound is at least one selected from the compounds listed in Group IV: [Group IV] 13. A method for forming a pattern, comprising: coating and heating a photoresist composition on a substrate to form a photoresist layer, coating and heating the resist top coating composition according to any one of claims 1 to 12 on the photoresist layer to form a top coating layer, and The top coating layer and the photoresist layer are exposed and developed to form a resist pattern.

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