Resist underlayer composition and method of forming pattern using the same

Abstract

Disclosed are a resist underlayer composition and a method of forming a pattern using the same, the resist underlayer composition including a polymer including a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, and a structural unit represented by Chemical Formula 3, and a solvent. [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3]

Description

[0001] Cross-reference of related applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2024-0073313, filed on June 4, 2024, with the Korean Intellectual Property Office, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to a resist underlay composition and a method of forming a pattern using the resist underlay composition. Background Technology

[0004] Recently, the semiconductor industry has developed ultra-fine technology with patterns ranging from several nanometers to tens of nanometers in size. This ultra-fine technology essentially requires efficient photolithography techniques.

[0005] Photolithography is a process that includes the following operations: coating a photoresist film onto a semiconductor substrate (e.g., a silicon wafer) to form a thin film; irradiating the photoresist film with activating radiation (e.g., ultraviolet light) through a mask pattern on which a device pattern is drawn; developing the resulting material to obtain a photoresist pattern; and using the photoresist pattern as a protective layer to etch the substrate to form a fine pattern corresponding to the pattern on the surface of the substrate.

[0006] As semiconductor patterns become increasingly intricate, the photoresist layer needs to be thin, and therefore, the resist underlayer also needs to be thin. Even when thin, the resist underlayer should not cause the photoresist pattern to collapse; it should have good adhesion to the photoresist and be formed at a uniform thickness. Furthermore, the resist underlayer is required to have a high refractive index and a low extinction coefficient for the light used in photolithography, and to have a faster etching rate than the photoresist layer. Summary of the Invention

[0007] The resist underlay composition according to some exemplary embodiments provides a resist underlay with improved patterning performance and energy efficiency by preventing resist pattern collapse even in fine patterning processes and improving sensitivity to exposure light sources.

[0008] Some exemplary embodiments provide a method for forming patterns using a resist underlayer composition.

[0009] The underlying composition according to some exemplary embodiments comprises a polymer and a solvent, said polymer comprising at least one of structural units represented by chemical formula 1, structural units represented by chemical formula 2, and structural units represented by chemical formula 3:

[0010] [Chemical Formula 1]

[0011]

[0012] [Chemical Formula 2]

[0013]

[0014] [Chemical Formula 3]

[0015]

[0016] In chemical formulas 1 to 3

[0017] A is a heterocyclic group that includes a nitrogen atom in the ring.

[0018] L 1 To L 8 Each of these can be independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 ynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof.

[0019] X 1 To X 7 Each of these can be independently represented as a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR a -(where R) a (which may be hydrogen, deuterium, or C1 to C10 alkyl), or combinations thereof.

[0020] Y 1 and Y 2 Each of the following is independently a hydroxyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a group represented by Formula 4, or a combination thereof, with the limitation being Y. 1 and Y 2 At least one of them is a group represented by chemical formula 4.

[0021] Y 3 and Y 4 Each is an independent group represented by chemical formula 4.

[0022] R 1 To R 3Each is independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, and

[0023] * indicates a connection point.

[0024] [Chemical Formula 4]

[0025]

[0026] In chemical formula 4,

[0027] M 1 It is a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C20 alkenyl group, -O-, -NH-, or a combination thereof.

[0028] Z 1 and Z 2 Each can be independently -C(=O)- or -C(OH)-.

[0029] M 2 For single bonds, double bonds, *-C(R) c ) = *(where R c It is hydrogen, deuterium, or C1 to C5 alkyl, and * is related to Z. 1 or Z 2 (the junction point), or substituted or unsubstituted C1 to C3 alkylene groups,

[0030] M 3 It can be hydroxyl, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C2 to C20 alkenyl, or substituted or unsubstituted C6 to C20 aryl.

[0031] M 1 With M 3 Or M 2 With M 3 They can optionally be connected to each other to form a loop, and

[0032] * indicates a connection point.

[0033] The letter A in chemical formulas 1 and 2 can be represented by any of the chemical formulas A-1 to A-5:

[0034] [Chemical Formula A-1]

[0035]

[0036] [Chemical Formula A-2]

[0037]

[0038] [Chemical Formula A-3]

[0039]

[0040] [Chemical Formula A-4]

[0041]

[0042] [Chemical Formula A-5]

[0043]

[0044] In chemical formulas A-3 and A-4

[0045] R x and R y Each of the following is independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl, a substituted or unsubstituted C2 to C10 alkenyl, a substituted or unsubstituted C2 to C10 alkynyl, a substituted or unsubstituted C1 to C10 heteroalkyl, a substituted or unsubstituted C1 to C10 heteroalkenyl, a substituted or unsubstituted C1 to C10 heteroalkynyl, a substituted or unsubstituted C3 to C20 cycloalkyl, a substituted or unsubstituted C2 to C20 heterocycloalkyl, a substituted or unsubstituted C6 to C20 aryl, a substituted or unsubstituted C1 to C20 heteroaryl, or a combination thereof, and

[0046] * indicates a connection point.

[0047] In chemical formula 1, A can be chemical formula A-1, L 1 and L 2 Each can be an independent single bond, or a substituted or unsubstituted C1 to C10 alkylene group, and X 1 and X 2 Each can be a single key independently:

[0048] [Chemical Formula A-1]

[0049]

[0050] In chemical formula 3, L 7 and L 8 Each can be an independent single bond, or a substituted or unsubstituted C1 to C10 alkylene group, X 6 and X 7 Each can be an independent single bond or -(CO)O-, and R 1 To R 3 Each can be independently hydrogen, deuterium, or substituted or unsubstituted C1 to C5 alkyl groups.

[0051] The polymer may also include structural units represented by chemical formula 5 or chemical formula 6:

[0052] [Chemical Formula 5]

[0053]

[0054] [Chemical Formula 6]

[0055]

[0056] In chemical formulas 5 and 6

[0057] L 9 To L 11 Each of these can be independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 ynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof.

[0058] X 8 To X 11 Each of these can be independently represented as a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR b -(where R) b (which may be hydrogen, deuterium, or C1 to C10 alkyl), or combinations thereof.

[0059] Y 5 To Y 7 Each of the following is independently hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 heterocycloalkyl, or substituted or unsubstituted C6 to C20 aryl.

[0060] R 4 and R 5 Each is independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, and

[0061] * indicates a connection point.

[0062] In chemical formula 5, L 9 and L 10 Each can be an independent single bond or a substituted or unsubstituted C1 to C10 alkylene group, X 8 and X 9 Each can be an independent single bond, and Y 5 and Y 6Each can be independently hydroxyl, substituted or unsubstituted C1 to C10 alkyl, or substituted or unsubstituted C2 to C10 alkenyl.

[0063] In chemical formula 6, L 11 It can be a single-bonded, substituted or unsubstituted C1 to C10 alkylene group, X 10 and X 11 Each can be an independent single bond or -(CO)O-, and Y 7 It may be hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C20 heterocyclic alkyl, or substituted or unsubstituted C6 to C20 aryl.

[0064] Polymers may include any one or more of the structural units represented by chemical formulas 1-1, 2-1, and 3-1 to 3-8:

[0065] [Chemical Formula 1-1]

[0066]

[0067] [Chemical Formula 2-1]

[0068]

[0069] [Chemical Formula 3-1]

[0070]

[0071] [Chemical Formula 3-2]

[0072]

[0073] [Chemical Formula 3-3]

[0074]

[0075] [Chemical Formula 3-4]

[0076]

[0077] [Chemical Formula 3-5]

[0078]

[0079] [Chemical Formula 3-6]

[0080]

[0081] [Chemical Formula 3-7]

[0082]

[0083] [Chemical Formula 3-8]

[0084]

[0085] The weight-average molecular weight of the polymer can range from about 1,000 g / mol to about 300,000 g / mol.

[0086] The polymer may be contained in an amount from about 0.1% to about 50% by weight, based on the total weight of the resist underlayer composition.

[0087] The composition may also contain one or more polymers selected from acrylic resins, epoxy resins, phenolic varnish resins, glycourea resins, and melamine resins.

[0088] The composition may also contain additives, such as surfactants, thermal acid generators, photoacid generators, plasticizers, or combinations thereof.

[0089] According to some exemplary embodiments, a method of forming a pattern includes: forming an etch target layer on a substrate; forming a resist underlayer by applying a resist underlayer composition according to some exemplary embodiments; forming a photoresist pattern on the resist underlayer; and sequentially etching the resist underlayer and the etch target layer using the photoresist pattern as an etch mask.

[0090] The resist underlay composition according to some exemplary embodiments can provide a resist underlay that does not cause resist pattern collapse even in fine patterning processes and has improved sensitivity to exposure light sources, thereby improving patterning performance and energy efficiency. Attached Figure Description

[0091] Figures 1A to 1F This is a cross-sectional view illustrating a method of forming a pattern using a resist underlayer composition according to some exemplary embodiments.

[0092] Explanation of icon numbers

[0093] 100: Substrate / Semiconductor Substrate

[0094] 102: Film

[0095] 104: Resist underlayer

[0096] 106: Photoresist film

[0097] 106a: Exposure Zone

[0098] 106b: Unexposed area

[0099] 108: Photoresist pattern

[0100] 110: Mask

[0101] 112: Organic membrane pattern

[0102] 114: Thin Film Pattern Detailed Implementation

[0103] Exemplary embodiments of this disclosure will be set forth in more detail below, and those skilled in the art will readily practice them. However, this disclosure may be implemented in many different forms and is not to be construed as limited to the exemplary embodiments set forth herein.

[0104] In the accompanying drawings, the thickness of layers, films, panels, regions, etc., is exaggerated for clarity, and the same reference numerals denote the same elements throughout this specification. It should be understood that when an element (e.g., a layer, film, region, or substrate) is referred to as being "on" another element, the element may be directly on the other element, or there may be intermediate elements present. In contrast, when an element is referred to as being "directly on" another element, there are no intermediate elements.

[0105] Unless otherwise defined, “substituted” as used herein means that the hydrogen atom of a compound is replaced by a substituent selected from the following: deuterium, halogen (F, Br, Cl, or I), hydroxyl, nitro, cyano, amino, azide, formamidinyl, hydrazine, hydrazine, carbonyl, carbamoyl, thiol, ester, carboxyl or a salt thereof, sulfonic acid or a salt thereof, phosphate or a salt thereof, C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C7 to C30 arylalkyl, C1 to C30 alkoxy, C1 to C20 heteroalkyl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, C2 to C30 heterocyclic, and combinations thereof.

[0106] Additionally, two adjacent substituents may fuse together to form a ring: substituted halogen atom (F, Br, Cl, or I), hydroxyl, nitro, cyano, amino, azide, formamidinyl, hydrazine, hydrazine, carbonyl, carbamoyl, thiol, ester, carboxyl or its salt, sulfonic acid or its salt, phosphate or its salt, C1 to C30 alkyl, C2 to C30 alkenyl, C2 to C30 alkynyl, C6 to C30 aryl, C7 to C30 arylalkyl, C1 to C30 alkoxy, C1 to C20 heteroalkyl, C3 to C20 heteroarylalkyl, C3 to C30 cycloalkyl, C3 to C15 cycloalkenyl, C6 to C15 cycloalkynyl, or C2 to C30 heterocyclic.

[0107] As used herein, "heterocyclic group" includes heteroaryl groups and cyclic groups comprising at least one heteroatom selected from N, O, S, P, and Si to replace the carbon (C) of a cyclic compound, such as aryl, cycloalkyl, their fused rings, or combinations thereof. When the heterocyclic group is a fused ring, each ring or the entire ring of the heterocyclic group may comprise at least one heteroatom.

[0108] More specifically, the substituted or unsubstituted aryl and / or substituted or unsubstituted heterocyclic groups can be substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthraquinone, substituted or unsubstituted phenanthyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted pyrene, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted trefyl, substituted or unsubstituted triphenylene, substituted or unsubstituted triphenylene, substituted... Or unsubstituted peryl, substituted or unsubstituted indole, substituted or unsubstituted furanyl, substituted or unsubstituted thiophene, substituted or unsubstituted pyrrole, substituted or unsubstituted pyrazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted triazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxadiazolyl, substituted or unsubstituted thiadiazolyl, substituted or unsubstituted pyridyl, substituted or unsubstituted pyrimidinyl, substituted or unsubstituted pyrimidinyl Substituted or unsubstituted pyrazinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiopheneyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted quinolinyl, substituted or unsubstituted isoquinolinyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted naphthidyl, substituted or unsubstituted benzoxazinyl, substituted or unsubstituted benzothiophene Azinyl, substituted or unsubstituted acridineyl, substituted or unsubstituted phenazinyl, substituted or unsubstituted phenothiazinyl, substituted or unsubstituted phenotoxazinyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothiophenyl, substituted or unsubstituted carbazoyl, pyridinodolyl, benzopyridinooxazinyl, benzopyridinothiazinyl, 9,9-dimethyl-9,10-dihydroacridinyl, combinations thereof, or combinations of the foregoing groups, but not limited to these.

[0109] Unless otherwise defined, the term “combination” as used in this document refers to a mixture or copolymerization.

[0110] In addition, the term "polymer" as used herein may include both oligomers and polymers.

[0111] Unless otherwise stated in this specification, the weight-average molecular weight was determined by dissolving the powder sample in tetrahydrofuran (THF) and then using Agilent Technologies' Series 1200 gel permeation chromatography (GPC) with a Showa Company LF-804 column and Showa Company polystyrene as the standard sample.

[0112] In addition, unless otherwise defined in the specification, "*" indicates the connection point of a structural unit or part of a polymer.

[0113] In the semiconductor industry, there has always been a demand to reduce chip size. To meet this trend, the linewidth of the patterned resist in photolithography should be reduced to the tens of nanometers level, and the pattern formed in this way is used to transfer the pattern to the underlying material through an etching process on the substrate. However, as the pattern size of the resist becomes smaller, the height (aspect ratio) of the resist that can withstand the linewidth is limited, and therefore, the resist may not have sufficient resistance in the etching step. Therefore, when using thin resist materials, when the substrate to be etched is thick, or when deep patterns are required, a resist underlayer has been used to compensate for this.

[0114] As the resist thickness becomes thinner, the resist underlayer must also become thinner, and even if the resist underlayer is a thin photoresist pattern, it should not collapse. Therefore, the resist underlayer should have excellent adhesion to the photoresist. Furthermore, when forming a thin resist underlayer, the uniformity of the resist underlayer composition and the flatness of the resist underlayer produced from said composition should be improved, and the sensitivity to the exposure light source should be improved to enhance pattern formability and energy efficiency.

[0115] The resist underlayer composition according to some exemplary embodiments comprises a polymer and a solvent, said polymer comprising at least one of structural units represented by chemical formula 1, structural units represented by chemical formula 2, and structural units represented by chemical formula 3:

[0116] [Chemical Formula 1]

[0117]

[0118] [Chemical Formula 2]

[0119]

[0120] [Chemical Formula 3]

[0121]

[0122] In chemical formulas 1 to 3

[0123] A is a heterocyclic group that includes a nitrogen atom in the ring.

[0124] L 1 To L 8 Each of these can be independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 ynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof.

[0125] X 1 To X 7 Each of these can be independently represented as a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR a -(where R) a (which may be hydrogen, deuterium, or C1 to C10 alkyl), or combinations thereof.

[0126] Y 1 and Y 2 Each of the following is independently a hydroxyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a group represented by Formula 4, or a combination thereof, with the limitation being Y. 1 and Y 2 At least one of them is a group represented by chemical formula 4.

[0127] Y 3 and Y 4 Each is an independent group represented by chemical formula 4.

[0128] R 1 To R 3 Each is independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, and

[0129] * indicates a connection point.

[0130] [Chemical Formula 4]

[0131]

[0132] In chemical formula 4,

[0133] M1 It is a single bond, a substituted or unsubstituted C1 to C20 alkylene group, a substituted or unsubstituted C2 to C20 alkenyl group, -O-, -NH-, or a combination thereof.

[0134] Z 1 and Z 2 Each can be independently -C(=O)- or -C(OH)-.

[0135] M 2 For single bonds, double bonds, *-C(R) c ) = *(where R c It is hydrogen, deuterium, or C1 to C5 alkyl, and * is related to Z. 1 or Z 2 (the junction point), or substituted or unsubstituted C1 to C3 alkylene groups,

[0136] M 3 It is a hydroxyl group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

[0137] M 1 With M 3 Or M 2 With M 3 They can optionally be connected to each other to form a loop, and

[0138] * indicates a connection point.

[0139] In the resist underlayer composition according to some exemplary embodiments, the structural units represented by Formula 1 and Formula 2 include heterocycles, which include nitrogen atoms in the ring, such that the polymer comprising these structural units can have sp... 2 -sp 2 This allows the polymer to have a high electron density. If the resist underlayer composition contains a polymer with a high electron density, the resist underlayer composition according to some exemplary embodiments can be implemented as an ultrathin film with a dense structure. In addition, the high electron density of the polymer can improve light absorption efficiency when the resist underlayer composition is exposed. Furthermore, by including a heterocyclic backbone, etching selectivity is improved, and energy efficiency can be improved when patterning is formed after exposure using high-energy rays (e.g., extreme ultraviolet (EUV) (wavelength 13.5 nm) and electron beams (E-Beam)).

[0140] The polymer contained in the composition comprises structural units having groups at their ends represented by Formula 4. Formula 4 includes two or more -(C=O)- or -C(OH)- groups at adjacent positions to form coordination bonds with inorganic materials in the photoresist and to improve the adhesion between the resist substrate and the photoresist film formed from the composition.

[0141] The letter A in chemical formulas 1 and 2 can be represented by any of the chemical formulas A-1 to A-5:

[0142] [Chemical Formula A-1]

[0143]

[0144] [Chemical Formula A-2]

[0145]

[0146] [Chemical Formula A-3]

[0147]

[0148] [Chemical Formula A-4]

[0149]

[0150] [Chemical Formula A-5]

[0151]

[0152] In chemical formulas A-3 and A-4

[0153] R x and R y Each of the following is independently hydrogen, a substituted or unsubstituted C1 to C10 alkyl, a substituted or unsubstituted C2 to C10 alkenyl, a substituted or unsubstituted C2 to C10 alkynyl, a substituted or unsubstituted C1 to C10 heteroalkyl, a substituted or unsubstituted C1 to C10 heteroalkenyl, a substituted or unsubstituted C1 to C10 heteroalkynyl, a substituted or unsubstituted C3 to C20 cycloalkyl, a substituted or unsubstituted C2 to C20 heterocycloalkyl, a substituted or unsubstituted C6 to C20 aryl, a substituted or unsubstituted C1 to C20 heteroaryl, or a combination thereof, and

[0154] * indicates a connection point.

[0155] In some exemplary embodiments, the A in chemical formula 1 is, for example, chemical formula A-1, but is not limited to this.

[0156] L of chemical formula 1 1 and L 2Each is independently, for example, a single bond, a substituted or unsubstituted C1 to C10 heteroalkylene, or a substituted or unsubstituted C1 to C10 alkylene, such as a single bond, or a substituted or unsubstituted C1 to C10 alkylene, such as a single bond, or a substituted or unsubstituted C1 to C5 alkylene, but is not limited thereto.

[0157] In chemical formula 1, X 1 and X 2 Each can be a single bond, -O-, -C(=O)-, or -(CO)O-, for example, a single bond, but not limited to these.

[0158] In chemical formula 1, Y 1 and Y 2 Each of these groups is independently a hydroxyl group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, or a group represented by Formula 4, such as a hydroxyl group, or a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, or a group represented by Formula 4, such as a substituted or unsubstituted C2 to C10 alkenyl group, but not limited to these. In the above, Y 1 and Y 2 At least one of them is a group represented by chemical formula 4.

[0159] In some exemplary embodiments, A in Formula 2 is, for example, Formula A-1 or Formula A-5, but is not limited to these. 3 To L 6 Each is independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C1 to C10 heteroalkylene group, such as a single bond, or a substituted or unsubstituted C1 to C10 alkylene group, such as a single bond, or a substituted or unsubstituted C1 to C5 alkylene group, but is not limited thereto. 3 To X 5 Each can be independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, for example, a single bond, -O-, -C(=O)-, -(CO)O-, for example, a single bond, but not limited to these. Y 3 It is a group represented by chemical formula 4.

[0160] In some exemplary embodiments, L in chemical formula 3 7 It can be a single bond, or a substituted or unsubstituted C1 to C10 alkylene group, such as a single bond, but not limited to this. L 8Each is independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C2 to C10 alkenyl group, such as a single bond, or a substituted or unsubstituted C1 to C10 alkylene group, such as a single bond, or a substituted C1 to C10 alkylene group, such as a single bond, or a hydroxylated C1 to C5 alkylene group, but is not limited thereto.

[0161] In chemical formula 3, X 6 and X 7 Each can be a single bond, -O-, -C(=O)-, or -(CO)O-, for example, a single bond or -(CO)O-, but is not limited to these.

[0162] In chemical formula 3, R 1 To R 3 It is hydrogen, deuterium, or substituted or unsubstituted C1 to C5 alkyl, such as hydrogen, methyl, or ethyl, but not limited to these.

[0163] In some exemplary embodiments, M of chemical formula 4 1 It may be a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, -O-, -NH- or a combination thereof, such as a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenyl group, -O-, -NH- or a combination thereof, such as a substituted or unsubstituted C1 to C5 alkylene group, such as -N-, such as a combination of -O- and C1 to C5 alkylene groups, such as a combination of -O- and C2 to C5 alkenyl groups, but is not limited thereto.

[0164] In chemical formula 4, Z 1 and Z 2 They can each be independently -C(=O)- or -C(OH)-, for example, Z. 1 and Z 2 Each can be -C(=O)-, for example, Z 1 and Z 2 Each can be -C(OH)-, and for example, Z 1 and Z 2 One of them can be -C(=O)- and the other can be -C(OH)-.

[0165] In chemical formula 4, M 2 It can be a single bond, a double bond, or *-C(R) c ) = *(where R cIt is a hydrogen, deuterium, or C1 to C5 alkyl group, or a substituted or unsubstituted C1 to C3 alkylene group, such as a single bond, double bond, *-CH=*, *-C(CH3)=*, or a substituted or unsubstituted methylene group, but not limited to these. In *-C(R c In )=*, ** is related to Z 1 or Z 2 The connection point.

[0166] If M 2 If Z has more carbon atoms than the options above, then 1 With Z 2 The large distance between them makes it difficult to effectively form coordination bonds with the inorganic materials in the photoresist, and also results in poor adhesion to the photoresist film. In other words, if M... 2 For single bonds, double bonds, *-C(R) c The presence of substituted or unsubstituted C1 to C3 alkylene groups can effectively increase the adhesion between the resist substrate made from the resist substrate composition and the photoresist film.

[0167] In chemical formula 4, M 3 It may be hydroxyl, substituted or unsubstituted C1 to C20 alkyl, substituted or unsubstituted C2 to C20 alkenyl, or substituted or unsubstituted C6 to C20 aryl, such as hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, or substituted or unsubstituted C6 to C10 aryl, such as hydroxyl, substituted or unsubstituted C1 to C5 alkyl, substituted or unsubstituted C2 to C5 alkenyl, or phenyl, but is not limited thereto.

[0168] M of chemical formula 4 1 With M 3 、 or M 2 With M 3 They can independently connect with each other to form rings. That is, in chemical formula 4, M 1 With M 3 They can optionally be connected to form a loop, or M 2 With M 3 They can optionally be connected to each other to form a loop. For example, M 1 and M 3 They can exist independently, M 1 With M 3 They can be connected to form a loop, and M 2 and M 3 They can exist independently, and M 2 With M 3 They can be connected to each other to form a ring.

[0169] In some exemplary embodiments, the polymer may further include structural units represented by Formula 5 or Formula 6:

[0170] [Chemical Formula 5]

[0171]

[0172] [Chemical Formula 6]

[0173]

[0174] In chemical formulas 5 and 6

[0175] L 9 To L 11 Each of these can be independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 ynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof.

[0176] X 8 To X 11 Each of these can be independently represented as a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR b -(where R) b (which may be hydrogen, deuterium, or C1 to C10 alkyl), or combinations thereof.

[0177] Y 5 To Y 7 Each of the following is independently hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 heterocycloalkyl, or substituted or unsubstituted C6 to C20 aryl.

[0178] R 4 and R 5 Each is independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, and

[0179] * indicates a connection point.

[0180] In some exemplary embodiments, in chemical formula 5, L 9 and L 10Each can be a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, such as a single bond, or a substituted or unsubstituted C1 to C10 alkylene group, such as a substituted or unsubstituted C1 to C5 alkylene group, but is not limited thereto.

[0181] In chemical formula 5, X 8 and X 9 Each can be a single bond, -O-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, such as a single bond, -O-, -C(=O)-, -(CO)O-, or a combination thereof, such as a single bond, but not limited to these.

[0182] In chemical formula 5, Y 5 and Y 6 Each of these can be independently hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, or substituted or unsubstituted C2 to C20 heterocyclic alkyl, such as hydroxyl, substituted or unsubstituted C1 to C10 alkyl, or substituted or unsubstituted C2 to C10 alkenyl, such as hydroxyl, or substituted or unsubstituted C2 to C5 alkenyl, but is not limited thereto.

[0183] In some exemplary embodiments, in chemical formula 6, L 11 It may be a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenyl group, or a substituted or unsubstituted C6 to C14 arylene group, such as a single bond, a substituted or unsubstituted C1 to C10 alkylene group, or a substituted or unsubstituted C6 to C10 arylene group, such as a single bond, a substituted or unsubstituted C1 to C5 alkylene group, or a substituted or unsubstituted phenylene group, but is not limited thereto.

[0184] In chemical formula 6, X 10 and X 11 Each can be a single bond, -O-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, such as a single bond or -(CO)O-, but is not limited to these.

[0185] In chemical formula 6, Y 7It may be hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C20 heterocyclic alkyl, or substituted or unsubstituted C6 to C20 aryl, such as hydroxyl, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 heterocyclic alkyl, or substituted or unsubstituted C6 to C10 aryl, such as hydroxyl, epoxy, substituted or unsubstituted phenyl, but is not limited thereto.

[0186] In some exemplary embodiments, the polymer includes any one or more of the structural units represented by chemical formulas 1-1, 2-1, and 3-1 to 3-8:

[0187] [Chemical Formula 1-1]

[0188]

[0189] [Chemical Formula 2-1]

[0190]

[0191] [Chemical Formula 3-1]

[0192]

[0193] [Chemical Formula 3-2]

[0194]

[0195] [Chemical Formula 3-3]

[0196]

[0197] [Chemical Formula 3-4]

[0198]

[0199] [Chemical Formula 3-5]

[0200]

[0201] [Chemical Formula 3-6]

[0202]

[0203] [Chemical Formula 3-7]

[0204]

[0205] [Chemical Formula 3-8]

[0206]

[0207] The polymer may have a weight-average molecular weight of about 1,000 g / mol to about 300,000 g / mol, for example about 3,000 g / mol to about 200,000 g / mol, for example about 3,000 g / mol to about 100,000 g / mol, for example about 3,000 g / mol to about 90,000 g / mol, for example about 3,000 g / mol to about 70,000 g / mol, for example about 3,000 g / mol to about 50,000 g / mol, for example about 5,000 g / mol to about 50,000 g / mol, for example about 5,000 g / mol to about 30,000 g / mol, but is not limited to these. By keeping the weight-average molecular weight within the above ranges, the carbon content and solubility in solvents of the resist underlayer composition containing the polymer can be adjusted and optimized.

[0208] The polymer may be included in an amount from about 0.1% to about 50% by weight, based on the total weight of the resist underlayer composition. More specifically, the polymer may be included in an amount from about 0.1% to about 40% by weight, for example from about 0.1% to about 30% by weight, for example from about 0.1% to about 20% by weight, for example from about 0.2% to about 20% by weight, based on the total weight of the resist underlayer composition, but is not limited thereto. By including the polymer within the above range in the composition, the thickness, surface roughness, and flatness of the resist underlayer can be adjusted.

[0209] The resist underlayer composition according to some exemplary embodiments may contain a solvent. According to some exemplary embodiments, the solvent is not particularly limited, provided it has sufficient solubility and / or dispersibility for the polymer and compound; however, the solvent may be, for example, propylene glycol, propylene glycol diacetate, methoxypropylene glycol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate (EL), γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, or combinations thereof.

[0210] In addition to polymers and solvents, the resist underlayer compositions according to some exemplary embodiments may also contain one or more polymers selected from acrylic resins, epoxy resins, phenolic varnish resins, urea resins and melamine resins, but are not limited thereto.

[0211] The resist underlayer composition according to some exemplary embodiments may also include additives, including surfactants, hot acid generators, plasticizers, or combinations thereof.

[0212] Surfactants can be used to improve coating defects caused by increased solids content when forming a resist underlayer, and can be, for example, alkylbenzene sulfonates, alkylpyridinium salts, polyethylene glycol, quaternary ammonium salts, etc., but are not limited to these.

[0213] The heat-generating agent can be an acidic compound, such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, p-toluenesulfonic acid pyridinium, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalene carbonate or / and benzointosylate, 2-nitrobenzyltosylate, and other organic alkyl sulfonates, but is not limited to these.

[0214] There are no particular restrictions on plasticizers, and a wide variety of known plasticizers can be used. Examples of plasticizers may include low molecular weight compounds (such as phthalates, adipates, phosphates, trimellitates, citrates, etc.), polyether compounds, polyester compounds, polyacetal compounds, etc.

[0215] Based on 100 parts by weight of the resist underlayer composition, the additive may be included in an amount from about 0.0001 parts by weight to about 40 parts by weight. Within this range, solubility can be improved without altering the optical properties of the resist underlayer composition.

[0216] According to some exemplary embodiments, a resist underlayer manufactured using the aforementioned resist underlayer composition is provided. The resist underlayer can be formed by coating the aforementioned resist underlayer composition onto, for example, a substrate and then curing it by a heat treatment process.

[0217] In the following text, refer to Figures 1A to 1F A method for forming patterns using the aforementioned resist underlayer composition is described. Figures 1A to 1F This is a cross-sectional view illustrating a method for forming a pattern using a resist underlayer composition according to the present invention.

[0218] Reference Figure 1A Prepare the etching target. The etching target may be a thin film 102 formed on the semiconductor substrate 100. In the following, the etching target is limited to the thin film 102. Clean the entire surface of the thin film 102 to remove impurities and the like remaining on the surface. The thin film 102 may be, for example, a silicon nitride layer, a polysilicon layer, or a silicon oxide layer.

[0219] Subsequently, the aforementioned resist underlayer composition was applied to the surface of the cleaned film 102 by spin coating.

[0220] The coated composition is then dried and baked to form a resist underlayer 104 on the film 102. Baking can be performed at about 100°C to about 500°C, for example, about 100°C to about 300°C. Specifically, the resist underlayer composition has been described in detail above, and therefore will not be described again.

[0221] Reference Figure 1B A photoresist film 106 is formed by coating photoresist onto a resist substrate 104.

[0222] Examples of photoresists include: positive photoresists containing naphthoquinone diazide compound and phenolic varnish resin; chemically-amplified positive photoresists containing an acid-generating agent capable of dissociating acid upon exposure, a compound that decomposes in the presence of acid and has enhanced solubility in alkaline aqueous solutions, and an alkali-soluble resin; and chemically-amplified positive photoresists containing an alkali-soluble resin capable of applying a resin that enhances solubility in alkaline aqueous solutions.

[0223] Then, the substrate 100 having the photoresist film 106 is subjected to preliminary baking. The preliminary baking can be performed at about 90°C to about 120°C.

[0224] Reference Figure 1C The photoresist film 106 can be selectively exposed. Exposure of the photoresist film 106 can be performed, for example, by positioning an exposure mask with a predetermined pattern on the mask stage of the exposure apparatus and aligning the exposure mask 110 with the photoresist film 106. Subsequently, by radiating light into the exposure mask 110, predetermined areas of the photoresist film 106 formed on the substrate 100 selectively react with the light passing through the exposure mask.

[0225] For example, the light used during exposure may include short-wavelength light, such as i-line with a wavelength of 365 nm, KrF excimer laser with a wavelength of 248 nm, and ArF excimer laser with a wavelength of 193 nm. Alternatively, extreme ultraviolet (EUV) light with a wavelength of 13.5 nm, corresponding to extreme ultraviolet light, may be used.

[0226] Compared to the photoresist film in the unexposed area 106b, the photoresist film in the exposed area 106a is relatively hydrophilic. Therefore, the exposed area 106a and the unexposed area 106b of the photoresist film can have different solubilities.

[0227] Subsequently, the substrate 100 undergoes a second baking process. This second baking can be performed at approximately 90°C to approximately 150°C. Due to the second baking, the exposed areas of the photoresist film become more readily soluble relative to the predetermined solvent.

[0228] Reference Figure 1D Specifically, the photoresist film corresponding to the exposure area 106a is dissolved, and then the photoresist film is removed using tetra-methyl ammonium hydroxide (TMAH) or the like. The remaining photoresist film after development, i.e. the unexposed area 106b, forms the photoresist pattern 108.

[0229] Subsequently, the photoresist pattern 108 is used as an etching mask to etch the resist underlayer 104. The above etching process forms a layer as shown in the image. Figure 1E The organic film pattern 112 is shown. Etching can be, for example, dry etching using an etching gas, and the etching gas can be, for example, CHF3, CF4, Cl2, O2, and mixtures thereof. As described above, since the resist underlayer formed from the resist underlayer composition according to the embodiment has a fast etching rate, a smooth etching process can be performed in a short time.

[0230] Reference Figure 1F The exposed thin film 102 is etched using a photoresist pattern 108 as an etching mask. Thus, the thin film is formed into a thin film pattern 114. In previously implemented exposure processes, the thin film pattern 114 formed by exposure processes using short-wavelength light sources (e.g., i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm)) can have a width of tens to hundreds of nanometers, and the thin film pattern 114 formed by exposure processes using EUV light sources can have a width of less than or equal to about 20 nm.

[0231] The present disclosure is illustrated in more detail below by way of examples relating to the synthesis of polymers and the preparation of resist underlayer compositions comprising said polymers. However, the present disclosure is not technically limited to the examples below.

[0232] Polymer Synthesis

[0233] Synthesis example 1

[0234] A reaction solution was prepared by adding 7.5 g of ethyl 2-acetylacetoxymethacrylate (Tokyo Chemical Industry, TCI), 4.9 g of glycidyl methacrylate (TCI), 4.8 g of dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 64 g of propylene glycol methyl etheracetate (PGMEA) to a 500 ml three-necked round-bottom flask, which was then connected to a condenser. The reaction was carried out by heating the reaction solution at 90 °C for 1 hour, and then cooling the reaction solution to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g of heptane while stirring to produce a gel, which was then dissolved in 90 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 3-1 and 6-2 was obtained. (Weight-average molecular weight (Mw): 4,000 g / mol)

[0235]

[0236] Synthesis example 2

[0237] 1.46 g glycidyl methacrylate (TCI), 1.81 g 4-vinylphenyl acetate (TCI), 2.43 g benzoic acid, 2-hydroxy-2-[(1-oxo-2-propenyl)oxy]ethyl ester, 1.06 g 2,2'-azobis(2-methylpropionic acid) dimethyl ester (V-601; TCI) and 22 g propylene glycol methyl ether acetate (PGMEA) were added to a 100 ml two-necked round-bottom flask to prepare the reaction solution, and a condenser was connected.

[0238] The reaction was initiated by heating the reaction solution at 90°C for 3 hours, followed by cooling to room temperature. Then, while stirring, the reaction solution was added dropwise to a beaker containing 450 g of toluene to produce a gel, which was then dissolved in 90 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 3-2, 6-2, and 6-3 was obtained. (Mw: 5,000 g / mol)

[0239]

[0240]

[0241] Synthesis example 3

[0242] 5.86 g of 2-hydroxyethyl methacrylate (TCI), 9.1 g of 1-[2-[(1-oxo-2-propen-1-yl)oxy]ethyl]malonate (Hong Kong Chem), 3.1 g of dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 35 g of propylene glycol methyl ether acetate (PGMEA) were added to a 500 ml three-necked round-bottom flask, which was then connected to a condenser. The reaction was initiated by heating the reaction solution at 90 °C for 2.5 hours, followed by cooling to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g of heptane while stirring to produce a gel, which was then dissolved in 90 g of PGMEA. Ultimately, a polymer composed of structural units represented by chemical formulas 3-3 and 6-4 was obtained. (Mw: 6,500 g / mol)

[0243]

[0244] Synthesis example 4

[0245] 6.49 g of 2-hydroxy-5-(2-propen-1-yl)-2,4,6-cycloheptatrien-1-one (Aurora), 4.9 g of glycidyl methacrylate (TCI), 4.8 g of dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 64 g of propylene glycol methyl ether acetate (PGMEA) were added to a 200 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 80 °C for 2 hours, and while stirring, it was added dropwise to a beaker containing 450 g of heptane to produce a gel. The gel was then dissolved in 90 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 3-4 and 6-2 was obtained. (Mw: 5,000 g / mol)

[0246]

[0247] Synthesis example 5

[0248] 21.3 g glycidyl methacrylate (TCI), 5.1 g dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 50 g propylene glycol methyl ether acetate (PGMEA) were added to a 250 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 90 °C for 1 hour, and while stirring, it was added dropwise to a beaker containing 450 g heptane to produce a gel. The gel was then dissolved in 100 g PGMEA to obtain a polymer composed of structural units represented by chemical formula 6-2.

[0249] 5.4 g of the above polymer, 0.7 g of indigo (TCI), 0.04 g of pyridine, 0.011 g of dibutylhydroxytoluene (BHT), and 7.55 g of dimethyl formamide (DMF) were added to a 100 ml two-necked round-bottom flask, which was then connected to a condenser. The reaction solution was heated at 100 °C for 1 hour, and while stirring, the reaction solution was added dropwise to a beaker containing 450 g of heptane to produce a gel. The gel was then dissolved in 100 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 6-2 and 3-5 was obtained. (Mw: 8,000 g / mol)

[0250]

[0251] Synthesis example 6

[0252] 21.3 g glycidyl methacrylate (TCI), 5.1 g dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 50 g propylene glycol methyl ether acetate (PGMEA) were added to a 250 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 90 °C for 1 hour, and while stirring, it was added dropwise to a beaker containing 450 g heptane to produce a gel. The gel was then dissolved in 100 g PGMEA to obtain a polymer composed of structural units represented by chemical formula 6-2.

[0253] 5.4 g of polymer, 0.62 g of 1H-indole-2,3-diol (Aurora Chemicals), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF were added to a 100 ml two-necked round-bottom flask, which was then connected to a condenser. The reaction solution was heated at 100 °C for 1 hour, and while stirring, the solution was added dropwise to a beaker containing 450 g of heptane to produce a gel. The gel was then dissolved in 100 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 6-2 and 3-6 was obtained. (Mw: 8,000 g / mol)

[0254]

[0255] Synthesis Example 7

[0256] 21.3 g glycidyl methacrylate (TCI), 5.1 g dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 50 g propylene glycol methyl ether acetate (PGMEA) were added to a 250 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 90 °C for 1 hour, and while stirring, it was added dropwise to a beaker containing 450 g heptane to produce a gel. The gel was then dissolved in 100 g PGMEA to obtain a polymer composed of structural units represented by chemical formula 6-2.

[0257] 5.4 g of polymer, 0.68 g of 3-hydroxy-4(1H)-quinolinone (Aurora Chemicals), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF were added to a 100 ml two-necked round-bottom flask, which was then connected to a condenser. The reaction solution was heated at 100 °C for 1 hour, and while stirring, the reaction solution was added dropwise to a beaker containing 450 g of heptane to produce a gel. The gel was then dissolved in 100 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 6-2 and 3-7 was obtained. (Mw: 8,000 g / mol)

[0258]

[0259]

[0260] Synthesis example 8

[0261] 21.3 g glycidyl methacrylate (TCI), 5.1 g dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 50 g propylene glycol methyl ether acetate (PGMEA) were added to a 250 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 90 °C for 1 hour, and while stirring, it was added dropwise to a beaker containing 450 g heptane to produce a gel. The gel was then dissolved in 100 g PGMEA to obtain a polymer composed of structural units represented by chemical formula 6-2.

[0262] 5.4 g of the above polymer, 0.7 g of 1,2-dihydro-2-hydroxy-3H-indol-3-one (ACCEL), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF were added to a 100 ml two-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 100 °C for 1 hour, and while stirring, it was added dropwise to a beaker containing 450 g of heptane to produce a gel. The gel was then dissolved in 100 g of PGMEA. Finally, a polymer composed of structural units represented by chemical formulas 6-2 and 3-8 was obtained. (Mw: 8,000 g / mol)

[0263]

[0264] Comparative Synthesis Example 1

[0265] 2.8 g glycidyl methacrylate (TCI), 2.1 g dimethyl 2,2'-azobis(2-methylpropionic acid) (V-601; TCI), and 7 g propylene glycol methyl ether acetate (PGMEA) were added to a 500 ml three-necked round-bottom flask to prepare a reaction solution, which was then connected to a condenser. The reaction was initiated by heating the reaction solution at 85 °C for 2 hours, followed by cooling to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g heptane while stirring to produce a gel, which was then dissolved in 90 g PGMEA. Finally, a polymer composed of structural units represented by chemical formula 6-2 was obtained. (Mw: 3,000 g / mol)

[0266] [Chemical Formula 6-2]

[0267]

[0268] Preparation of resist underlayer composition

[0269] Examples 1 to 8 and Comparative Example 1

[0270] 1.2 g of each polymer obtained in Synthetic Examples 1 to 8 and Comparative Synthetic Example 1, 0.4 g of PL1174 (crosslinking agent) and 0.04 g of ammonium trifluoromethanesulfonate (AOTf) were mixed with 15 g of propylene glycol monomethyl ether, completely dissolved, and diluted with another solvent to prepare each resist underlayer composition according to Examples 1 to 8 and Comparative Example 1 containing 0.45% by weight of polymer on a total weight basis.

[0271] Evaluation 1: Evaluation of Exposure Characteristics

[0272] The compositions prepared in Examples 1 to 8 and Comparative Example 1 were spin-coated and then heat-treated on a hot plate at 205°C for 60 seconds to form a thickness of [missing information]. A resist underlayer was then applied. Subsequently, a photoresist solution was spin-coated onto this underlayer, and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The photoresist layer was then exposed to 200 μC / cm using an electron beam lithography machine (Elionix, Inc.). 2 Up to 2000 μC / cm 2 The photoresist layer was exposed to light within the specified range and then heat-treated at 150°C for 60 seconds. Subsequently, the photoresist layer was developed using a 2.38% (w / w) TMAH aqueous solution and rinsed with pure water for 15 seconds to form a 50 nm line and spacing (L / S) photoresist pattern. The photoresist pattern was then evaluated relative to the optimal exposure dose.

[0273] Evaluation 2: Evaluation of Line Width Roughness (LWR)

[0274] Each of the compositions according to Examples 1 to 8 and Comparative Example 1 was spin-coated and heat-treated on a hot plate at 205°C for 60 seconds to form A thick resist underlayer was then applied. A photoresist solution was subsequently spin-coated onto this underlayer and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The resist layer was exposed using an electron beam lithography machine (manufactured by Elionis, accelerating voltage 100 keV) with a line width of 30 nm and a line spacing of 30 nm. The exposed resist layer was then heat-treated at 95°C for 60 seconds, developed with a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, and rinsed with pure water for 15 seconds to form the resist pattern.

[0275] Pattern collapse was observed using a scanning electron microscope (SEM) S-9260 (manufactured by Hitachi). In Table 1, cases where pattern collapse was observed are represented as O, and cases where pattern collapse was not observed are represented as X.

[0276] Line width roughness (LWR) was observed on a pattern formed with a width of 30 nm using a scanning electron microscope (SEM) S-9260 (manufactured by Hitachi). The distance from the reference line to the position where the edge should be located was measured within 2 μm of the edge in the longitudinal direction of the pattern. The results are shown in Table 1, and a smaller line width roughness (LWR) value is better.

[0277] The exposure dose and LWR of the examples and comparative examples were converted into ratios based on the exposure dose or LWR of Comparative Example 1 as a reference, and the results are shown in Table 1. The smaller the exposure dose and linewidth roughness (LWR) values, the better the pattern formation and sensitivity.

[0278] * Exposure dose (or LWR) (%) = (Exposure dose (or LWR) according to each experimental example - Exposure dose (or LWR) according to Comparative Example 1) / Exposure dose (or LWR) according to Comparative Example 1 × 100

[0279] (Table 1)

[0280] Exposure dose (Eop, %) Has the pattern collapsed? LWR(nm) Example 1 -4.5％ X -5.4％ Example 2 -1.2％ X -2.2％ Example 3 -4.2％ X -5.1％ Example 4 -2.5％ X -2.8％ Example 5 -5.5％ X -4.7％ Example 6 -5.2％ X -4.8％ Example 7 -4.5％ X -4.8％ Example 8 -5.2％ X -5.0％ Comparative Example 1 refer to O refer to

[0281] Referring to Table 1, compared with Comparative Example 1, the resist substrates according to Examples 1 to 8 exhibit superior formability and sensitivity of fine patterns (50 nm L / S). Furthermore, in the case of the resist substrates according to Examples 1 to 8, the LWR is lower than that of Comparative Example 1, indicating a more uniform pattern.

[0282] Specific embodiments of this disclosure have been described and illustrated above. However, it will be apparent to those skilled in the art that this disclosure is not limited to the described embodiments, and various modifications and variations can be made without departing from the spirit and scope of this disclosure. Therefore, modified or varied embodiments may be understood without separating them from the technical concept and aspects of this disclosure, and the modified embodiments are within the scope of the claims of this disclosure.

Claims

1. A resist underlayer composition comprising: a polymer including at least one of a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, and a structural unit represented by Chemical Formula 3; and a solvent: [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] wherein in Chemical Formulas 1 to 3, A is a heterocyclic group including a nitrogen atom in a ring, L 1 to L 8 each independently a single bond, substituted or unsubstituted Ci to C10alkylene, substituted or unsubstituted C2to C10alkenylene, substituted or unsubstituted C2to C10alkynylene, substituted or unsubstituted C3to C20cycloalkylene, substituted or unsubstituted C2to C20heterocycloalkylene, substituted or unsubstituted C6to C20arylene, or a combination thereof, X 1 to X 7 each independently is a single bond, -0-, -S-, -S(=0)-, -S(=0)2-, -C(=0)-, -(CO)0-, -0(CO)0-, -C(=0)NH-, -NR a -, or a combination thereof, wherein R a is hydrogen, deuterium, or Ci to C10alkyl, Y 1 and Y 2 each independently is hydroxyl, substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C10alkenyl, substituted or unsubstituted C2to C10alkynyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20heterocycloalkyl, substituted or unsubstituted C6to C20aryl, a group represented by Chemical Formula 4, or a combination thereof, provided that at least one of Y 1 and Y 2 is a group represented by Chemical Formula 4, Y 3 and Y 4 each independently is a group represented by Chemical Formula 4, R 1 to R 3 each independently is hydrogen, deuterium, or substituted or unsubstituted C1 to C10 alkyl, and * is a connecting point, [Chemical Formula 4] wherein, in Chemical Formula 4, M 1 R1is a single bond, substituted or unsubstituted C1to C20alkylene, substituted or unsubstituted C2to C20alkenylene, -O-, -NH-, or a combination thereof, Z 1 and Z 2 each independently is -C(=O)- or -C(OH)-, M 2 is a single bond, a double bond, *-C(R c )=*, or a substituted or unsubstituted C1to C3alkylene, wherein R c is hydrogen, deuterium, or C1to C5alkyl, and * is the point of attachment to Z 1 or Z 2 , M 3 hydrogen, halogen, -CN, -NO2, -SF5, -NHOH, -ONH2, -NNH2, -OH, substituted or unsubstituted C1to C20alkyl, substituted or unsubstituted C2to C20alkenyl, or substituted or unsubstituted C6to C20aryl, M 1 with M 3 or M 2 with M 3 are optionally connected to each other to form a ring, and * is a connecting point.

2. The resist underlayer composition according to claim 1, wherein A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of Chemical Formula A-1 to Chemical Formula A-5: [Chemical Formula A-1] [Chemical Formula A-2] [Chemical Formula A-3] [Chemical Formula A-4] [Chemical Formula A-5] wherein In Chemical Formula A-3 and Chemical Formula A-4, R x and R y each independently is hydrogen, substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C10alkenyl, substituted or unsubstituted C2to C10alkynyl, substituted or unsubstituted C1to C10heteroalkyl, substituted or unsubstituted C1to C10heteroalkenyl, substituted or unsubstituted C1to C10heteroalkynyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20heterocycloalkyl, substituted or unsubstituted C6to C20aryl, substituted or unsubstituted C1to C20heteroaryl, or a combination thereof, and * is a connecting point.

3. The resist underlayer composition of claim 1, wherein A in Chemical Formula 1 is Chemical Formula A-1, L 1 and L 2 each independently is a single bond, or a substituted or unsubstituted C1to C10alkylene, and X 1 and X 2 each independently is a single bond: [Chemical Formula A-1] 4. The resist underlayer composition of claim 1, wherein in Chemical Formula 3, L 7 and L 8 each independently is a single bond, or a substituted or unsubstituted C1to C10alkylene, X 6 and X 7 each independently is a single bond, or -(CO)O-, and R 1 to R 3 each independently is hydrogen, deuterium, or a substituted or unsubstituted C1to C5alkyl.

5. The resist underlayer composition according to claim 1, wherein the polymer further includes a structural unit represented by Chemical Formula 5, or a structural unit represented by Chemical Formula 6: [Chemical Formula 5] [Chemical Formula 6] wherein, in Chemical Formulas 5 and 6, L 9 to L 11 each independently a single bond, substituted or unsubstituted Ci to C10alkylene, substituted or unsubstituted C2to C10alkenylene, substituted or unsubstituted C2to C10alkynylene, substituted or unsubstituted C3to C20cycloalkylene, substituted or unsubstituted C2to C20heterocycloalkylene, substituted or unsubstituted C6to C20arylene, or a combination thereof, X 8 to X 11 each independently a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR b -, or a combination thereof, wherein R b is hydrogen, deuterium, or Ci to C10alkyl, Y 5 to Y 7 each independently hydroxyl, substituted or unsubstituted C1to C10alkyl, substituted or unsubstituted C2to C10alkenyl, substituted or unsubstituted C2to C10alkynyl, substituted or unsubstituted C3to C20cycloalkyl, substituted or unsubstituted C2to C20heterocycloalkyl, or substituted or unsubstituted C6to C20aryl, R 4 and R 5 each independently is hydrogen, deuterium, or substituted or unsubstituted C1to C10alkyl, and * is a connecting point.

6. The resist underlayer composition of claim 5, wherein in Chemical Formula 5, L 9 and L 10 each independently is a single bond, or a substituted or unsubstituted C1to C10alkylene, X 8 and X 9 each independently is a single bond, and Y 5 and Y 6 each independently is a hydroxyl group, a substituted or unsubstituted C1to C10alkyl group, or a substituted or unsubstituted C2to C10alkenyl group.

7. The resist underlayer composition of claim 5, wherein in Chemical Formula 6, L is a single bond, substituted or unsubstituted C1 to C10 alkylene, or substituted or unsubstituted C6 to C10 arylene, X is -O-, -S-, -NR1-, -SiR1R2-, -PR1-, -BR1-, or a single bond, Y is -O-, -S-, -NR1-, -SiR1R2-, -PR1-, -BR1-, or a single bond, and X and Y are each independently a single bond, or -(CO)O-. 11 10 11 7 is a single bond, substituted or unsubstituted C1 to C10 alkylene, or substituted or unsubstituted C6 to C10 arylene, X is -O-, -S-, -NR1-, -SiR1R2-, -PR1-, -BR1-, or a single bond, Y is -O-, -S-, -NR1-, -SiR1R2-, -PR1-, -BR1-, or a single bond, and X and Y are each independently a single bond, or -(CO)O-, Y is a single bond, substituted or unsubstituted C1 to C10 alkylene, or substituted or unsubstituted C6 to C10 arylene, and Z is a single bond, substituted or unsubstituted C1 to C10 alkylene, or substituted or unsubstituted C6 to C10 arylene.​​​ 8. The resist underlayer composition according to claim 1, wherein the polymer includes any one or more of structural units represented by Chemical Formula 1-1, Chemical Formula 2-1, and Chemical Formula 3-1 to Chemical Formula 3-8: [Chemical Formula 1-1] [Chemical Formula 2-1] [Chemical Formula 3-1] [Chemical Formula 3-2] [Chemical Formula 3-3] [Chemical Formula 3-4] [Chemical Formula 3-5] [Chemical Formula 3-6] [Chemical Formula 3-7] [Chemical Formula 3-8] 9. The resist underlayer composition according to claim 1, wherein the weight average molecular weight of the polymer is 1,000 g / mol to 300,000 g / mol.

10. The resist underlayer composition according to claim 1, wherein the polymer is included in an amount of 0.1 to 50 wt% based on the total weight of the resist underlayer composition.

11. The resist underlayer composition according to claim 1, wherein the resist underlayer composition further includes one or more polymers selected from the group consisting of acrylic resins, epoxy resins, novolak resins, glycoluril resins, and melamine resins.

12. The resist underlayer composition according to claim 1, wherein the resist underlayer composition further includes an additive of a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

13. A method of forming a pattern, comprising: forming an etching target layer on a substrate; forming a resist underlayer by applying the resist underlayer composition according to any one of claims 1 to 12 on the etching target layer; forming a photoresist pattern on the resist underlayer; and sequentially etching the resist underlayer and the etching target layer using the photoresist pattern as an etching mask.

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