Resist underlayer composition, and method of forming patterns using the composition

Abstract

The present invention relates to a resist underlayer composition comprising: a polymer including a structural unit represented by chemical formula 1 and having an electron affinity of 1.0-3.0 eV; and a solvent, and to a method of forming patterns using the resist underlayer composition. [Chemical formula 1] Chemical formula 1 is as defined in the specification.

Description

Composition for resist underlayer film and pattern forming method using the same

[0001] The present invention relates to a composition for a resist underlayer film and a pattern forming method using the same.

[0002] The semiconductor industry is currently evolving from patterns measuring hundreds of nanometers to ultra-fine technologies with patterns measuring several to tens of nanometers. To realize this ultra-fine technology, effective lithographic techniques are essential.

[0003] The lithographic technique is a processing method that forms a thin film by coating a photoresist film on a semiconductor substrate such as a silicon wafer, and then irradiating the thin film with an activating ray such as ultraviolet rays through a mask pattern on which a device pattern is drawn, and then developing the thin film, and then etching the substrate using the obtained photoresist pattern as a protective film to form a fine pattern corresponding to the pattern on the surface of the substrate.

[0004] As semiconductor patterns become increasingly finer, the thickness of the photoresist layer becomes increasingly thinner, and consequently, the thickness of the resist underlayer also becomes increasingly thin. The resist underlayer must not cause the photoresist pattern to collapse even at a thin thickness, must exhibit excellent adhesion to the photoresist, and must form a film of uniform thickness. Furthermore, the resist underlayer must possess a high refractive index and low absorption coefficient for the light used in photolithography, while also exhibiting a faster etching speed than the photoresist layer.

[0005] A composition for a resist underlayer film according to one embodiment provides a resist underlayer film having high patterning selectivity and capable of implementing a fine pattern.

[0006] Another embodiment provides a pattern forming method using the composition for the resist underlayer film.

[0007] A composition for a resist underlayer film according to one embodiment comprises a polymer having a structural unit represented by the following chemical formula 1 and an electron affinity of 1.0 eV to 3.0 eV, and a solvent:

[0008] [Chemical Formula 1]

[0009]

[0010] In the above chemical formula 1,

[0011] R 1 Inland R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group,

[0012] L 1 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C2 to C10 heteroalkenylene group, or a combination thereof,

[0013] X 1 is a single bond, -O-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a - (Here, R a is hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group), or a combination thereof,

[0014] L 2 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof,

[0015] Y 1is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a nitro group, a cyano group, -S(=O)2OH, -C(=O)OR x (Here, R x is a substituted or unsubstituted C1 to C10 alkyl group.) or -NR b R c (Here, R b and R c are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, and R b and R c are optionally interconnected to form a ring.)

[0016] * is a connection point.

[0017] X of the above chemical formula 1 1 This single bond can be -(CO)O-, or -NH-.

[0018] L of the above chemical formula 1 1 is a C1 to C10 alkylene group substituted with a hydroxy group, and L 2 may be a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof.

[0019] The electron affinity of the polymer may be 1.2 eV to 2.5 eV.

[0020] The polymer may further include a structural unit represented by the following chemical formula 2:

[0021] [Chemical Formula 2]

[0022]

[0023] In the above chemical formula 2,

[0024] R 4 Inland R 6 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group,

[0025] X 2 and X 3 are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR d - (Here, R d is hydrogen, deuterium, or a C1 to C10 alkyl group), or a combination thereof,

[0026] L 3 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene 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, a substituted or unsubstituted C2 to C20 heteroarylene group, or a combination thereof,

[0027] Y 2 is hydrogen, deuterium, halogen atom, hydroxyl group, nitro group, cyano group, -COOH, -NR e R f (Here, R e and R fare each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl 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 C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C10 heteroalkenyl group, a substituted or unsubstituted C2 to C10 heteroalkynyl 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, or a substituted or unsubstituted C2 to C20 heteroaryl group,

[0028] * is a connection point.

[0029] The above polymer may include at least one structural unit represented by the following chemical formula 1-1 or the following chemical formula 1-2.

[0030] [Chemical Formula 1-1]

[0031]

[0032] In the above chemical formula 1-1,

[0033] R 7 is hydrogen, deuterium, methyl group, or -CF3,

[0034] L 4 is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof,

[0035] Y 3 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a nitro group, a cyano group, -S(=O)2OH, -C(=O)OR x (Here, R x is a substituted or unsubstituted C1 to C5 alkyl group), or -NR g Rh (Here, R g and R h are each independently hydrogen, deuterium, or a C1 to C5 alkyl group,

[0036] * is a connection point:

[0037] [Chemical Formula 1-2]

[0038]

[0039] In the above chemical formula 1-2,

[0040] R 8 is hydrogen, deuterium, methyl group, or -CF3,

[0041] Y 4 is -NR i R j and the above R i and R j are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group containing nitrogen in the ring, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group containing nitrogen in the ring, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group containing nitrogen in the ring, and R i and R j are optionally interconnected to form a ring,

[0042] * is a connection point.

[0043] The above polymer may include one or more of the structural units represented by the following chemical formulas 1-3 to 1-13.

[0044] [Chemical Formula 1-3]

[0045]

[0046] [Chemical Formula 1-4]

[0047]

[0048] [Chemical Formula 1-5]

[0049]

[0050] [Chemical Formula 1-6]

[0051]

[0052] [Chemical Formula 1-7]

[0053]

[0054] [Chemical Formula 1-8]

[0055]

[0056] [Chemical Formula 1-9]

[0057]

[0058] [Chemical Formula 1-10]

[0059]

[0060] [Chemical Formula 1-11]

[0061]

[0062] [Chemical Formula 1-12]

[0063]

[0064] [Chemical Formula 1-13]

[0065]

[0066] The structural unit represented by the above chemical formula 1 may be 40 wt% to 100 wt% based on the total weight of the polymer.

[0067] The weight average molecular weight of the above polymer may be 1,000 g / mol to 300,000 g / mol.

[0068] The polymer may be included in an amount of 0.1 wt% to 50 wt% based on the total weight of the composition for the resist underlayer film.

[0069] The above composition may further include one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glucouryl resins, and melamine resins.

[0070] The composition may further comprise an additive that is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0071] According to another embodiment, a method for forming a pattern is provided, comprising: forming an etching target film on a substrate; applying a composition for a resist underlayer film according to one embodiment to form a resist underlayer film on the etching target film; forming a photoresist pattern on the resist underlayer film; and sequentially etching the resist underlayer film and the etching target film using the photoresist pattern as an etching mask.

[0072] A composition for a resist underlayer film according to one embodiment can provide a resist underlayer film having improved sensitivity to an exposure light source and improved pattern selectivity and uniformity even in a fine patterning process.

[0073] Figure 1 is a cross-sectional view illustrating a pattern forming method using a composition for a resist underlayer film according to one embodiment.

[0074] <Explanation of symbols>

[0075] 100: Substrate 102: Thin film

[0076] 104: Resist underlayer 106: Photoresist film

[0077] 106a: Exposure area 106b: Non-exposure area

[0078] 108: Photoresist pattern 110: Mask

[0079] 112: Organic film pattern 114: Thin film pattern

[0080] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0081] To clearly illustrate various layers and regions in the drawings, their thicknesses are enlarged, and similar parts are designated by the same drawing reference numerals throughout the specification. When an element such as a layer, film, region, or plate is said to be "on" another element, this includes not only the case where it is "directly on" the other element, but also the case where there is another element in between. Conversely, when an element is said to be "directly on" another element, it means that there is no other element in between.

[0082] Hereinafter, unless otherwise defined, 'substituted' means a compound in which a hydrogen atom is substituted with a deuterium, a halogen atom (F, Br, Cl, or I), a hydroxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 It means substituted with a substituent selected from a cycloalkynyl group, a C2 to C30 heterocyclic group, and a combination thereof.

[0083] In addition, two adjacent groups among the substituted halogen atom (F, Br, Cl, or I), hydroxy group, nitro group, cyano group, amino group, azido group, amidino group, hydrazino group, hydrazono group, carbonyl group, carbamyl group, thiol group, ester group, carboxyl group or salt thereof, sulfonic acid group or salt thereof, phosphoric acid or salt thereof, C1 to C30 alkyl group, C2 to C30 alkenyl group, C2 to C30 alkynyl group, C6 to C30 aryl group, C7 to C30 arylalkyl group, C1 to C30 alkoxy group, C1 to C20 heteroalkyl group, C3 to C20 heteroarylalkyl group, C3 to C30 cycloalkyl group, C3 to C15 cycloalkenyl group, C6 to C15 cycloalkynyl group, or C2 to C30 heterocyclic group Substituents may also be fused to form rings.

[0084] In this specification, the term "heterocyclic group" refers to a concept including a heteroaryl group, and in addition, means a group containing at least one heteroatom selected from N, O, S, P, and Si instead of carbon (C) in a ring compound such as an aryl group, a cycloalkyl group, a fused ring thereof, or a combination thereof. When the heterocyclic group is a fused ring, the heterocyclic group as a whole or each ring may contain one or more heteroatoms.

[0085] More specifically, the substituted or unsubstituted aryl group and / or the substituted or unsubstituted heterocyclic group is a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted naphthacenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted quaterphenyl group, a substituted or unsubstituted chrysenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted indenyl group, a substituted or unsubstituted furanyl group, a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted pyrrolyl group, a substituted or unsubstituted pyrazolyl group, a substituted or unsubstituted imidazolyl group, a substituted or unsubstituted triazolyl group, a substituted or unsubstituted oxazolyl group, a substituted or unsubstituted Thiazolyl group, substituted or unsubstituted oxadiazolyl group, substituted or unsubstituted thiadiazolyl group, substituted or unsubstituted pyridinyl group, substituted or unsubstituted pyrimidinyl group, substituted or unsubstituted pyrazinyl group, substituted or unsubstituted triazinyl group, substituted or unsubstituted benzofuranyl group, substituted or unsubstituted benzothiophenyl group, substituted or unsubstituted benzimidazolyl group, substituted or unsubstituted indolyl group, substituted or unsubstituted quinolinyl group, substituted or unsubstituted isoquinolinyl group, substituted or unsubstituted quinazolinyl group, substituted or unsubstituted quinoxalinyl group, substituted or unsubstituted naphthyridinyl group, substituted or unsubstituted benzoxazinyl group, substituted or unsubstituted benzthiazinyl group, substituted or unsubstituted acridinyl group, substituted or unsubstituted phenazinyl group, substituted or unsubstituted phenothiazinyl group, substituted Or it may be an unsubstituted phenoxazinyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted carbazolyl group, a pyridoindolyl group, a benzopyridoxazinyl group, a benzopyridothiazinyl group, a 9,9-dimethyl-9,10-dihydroacridinyl group, a combination thereof, or a fused form of a combination thereof,but is not limited to this,

[0086] Unless otherwise specified herein, “combination” means mixing or copolymerization.

[0087] Additionally, in this specification, “polymer” may include both oligomers and polymers.

[0088] Unless otherwise specified herein, “weight average molecular weight” is the value obtained by dissolving a powder sample in tetrahydrofuran (THF) and measuring it using Agilent Technologies’ 1200 series Gel Permeation Chromatography (GPC) (column: Shodex LF-804, standard sample: Shodex polystyrene).

[0089] Also, in this specification, “electron affinity” refers to the conduction band energy (E) in the energy band of a polymer. c ) and vacuum level energy (E vac ) and is a value calculated from the energy difference between the ground state of a molecule or atom and its corresponding anion. The electron affinity of the polymer in the text was obtained by calculating the electron affinity (unit: eV) using the density functional theory (DFT) using the static and dynamic models of each polymer.

[0090] Additionally, unless otherwise defined herein, '*' indicates a structural unit of a polymer or a connecting point of a moiety of a polymer.

[0091] The semiconductor industry is constantly seeking to reduce chip size. To meet this trend, the line width of the resist patterned in lithography must be reduced to tens of nanometers. This pattern is then transferred to the underlying substrate through an etching process. However, as the resist pattern size decreases, the resist height (aspect ratio) that can withstand the line width becomes limited. Consequently, resists sometimes lack sufficient etching resistance. Therefore, a resist underlayer has been used to compensate for this in situations such as when the resist material is thin, the substrate to be etched is thick, or a deep pattern is required.

[0092] The resist underlayer film is required to become thinner as the resist thickness decreases, and the photoresist pattern must not collapse even with the thin resist underlayer film. To this end, the resist underlayer film must have excellent adhesion to the photoresist. Furthermore, when forming a thin resist underlayer film, the coating uniformity of the resist underlayer film composition and the flatness of the resist underlayer film produced therefrom must be improved, and the sensitivity to the exposure light source must be improved to improve pattern formation and energy efficiency.

[0093] A composition for a resist underlayer film according to one embodiment comprises a polymer having a structural unit represented by the following chemical formula 1 and an electron affinity of 1.0 eV to 3.0 eV, and a solvent:

[0094] [Chemical Formula 1]

[0095]

[0096] In the above chemical formula 1,

[0097] R 1 Inland R 3are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group,

[0098] L 1 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C2 to C10 heteroalkenylene group, or a combination thereof,

[0099] X 1 is a single bond, -O-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a - (Here, R a is hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group), or a combination thereof,

[0100] L 2 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof,

[0101] Y 1 is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a nitro group, a cyano group, -S(=O)2OH, -C(=O)OR x (Here, R x is a substituted or unsubstituted C1 to C10 alkyl group), or -NR b R c (Here, R b and R care each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, and R b and R c are optionally interconnected to form a ring.)

[0102] * is a connection point.

[0103] The polymer included in the composition according to one embodiment has an electron affinity value within a certain range, so that the composition can control secondary electrons diffusing to a non-exposed area during exposure, increase selectivity between the exposed area and the non-exposed area, and an underlayer film manufactured therefrom can secure a clear pattern.

[0104] In one embodiment, the electron affinity of the polymer may be from 1.0 eV to 3.0 eV, for example, from 1.0 eV to 2.9 eV, from 1.0 eV to 2.8 eV, from 1.0 eV to 2.7 eV, from 1.0 eV to 2.6 eV, from 1.0 eV to 2.5 eV, from 1.1 eV to 3.0 eV, from 1.2 eV to 3.0 eV, from 1.1 eV to 2.9 eV, from 1.1 eV to 2.8 eV, from 1.1 eV to 2.7 eV, from 1.1 eV to 2.6 eV, from 1.1 eV to 2.5 eV, from 1.2 eV to 2.9 eV, from 1.2 eV to 2.8 eV, from 1.2 eV to 2.7 eV, It can be 1.2 eV to 2.6 eV, or 1.2 eV to 2.5 eV, but is not limited thereto. Since the polymer has an electron affinity in the above range, a composition including the polymer can control secondary electrons that diffuse to the non-exposed area during exposure because it has a higher electron affinity than the photoacid generator in the photoresist, and can increase the selectivity between the exposed area and the non-exposed area. Therefore, the LER (Line edge roughness) or LWR (Line width roughness) of the resist underlayer film pattern formed from the composition can be improved.

[0105] In one embodiment, R of the above formula 1 1 Inland R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C5 alkyl group, for example, hydrogen, deuterium, a methyl group, an ethyl group, or a C1 to C5 alkyl group substituted with a halogen atom, for example, hydrogen, a methyl group, or -CF3, but are not limited thereto.

[0106] In one embodiment, L of the above chemical formula 1 1 is a single bond, a substituted or unsubstituted C1 to C7 alkylene group, a substituted or unsubstituted C2 to C7 alkenylene group, a substituted or unsubstituted C2 to C7 alkynylene group, a substituted or unsubstituted C1 to C7 heteroalkylene group, a substituted or unsubstituted C2 to C7 heteroalkenylene group, or a combination thereof, for example, a single bond, a substituted or unsubstituted C1 to C7 alkylene group, a substituted or unsubstituted C2 to C7 alkenylene group, or a combination thereof, for example, a substituted or unsubstituted C1 to C10 alkylene group, for example, a C1 to C10 alkylene group substituted with a hydroxy group, but is not limited thereto.

[0107] In one embodiment, X of the above formula 1 1 This single bond may be -O-, -C(=O)-, -(CO)O-, or -NH-, for example, but not limited to, a single bond, -(CO)O-, or -NH-.

[0108] In one embodiment, L of the above chemical formula 1 2is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof, and may be, for example, a single bond, an unsubstituted C1 to C5 alkylene group, a combination of an unsubstituted C1 to C5 alkylene group and an unsubstituted C2 to C5 alkenylene group, a combination of a vinylene group and a methylene group, or a combination of a vinylene group and a phenylene group, but is not limited thereto.

[0109] In one implementation, Y 1 is 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 heterocycloalkyl group, a substituted or unsubstituted C2 to C10 heterocycloalkenyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C2 to C20 heteroaryl group, a nitro group, a cyano group, -S(=O)2OH, or -NR b R c (Here, R b and R c are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C5 alkyl group, or a substituted or unsubstituted C6 to C10 aryl group, and R b and R c are optionally linked to each other to form a ring), but are not limited thereto. For example, the heterocycloalkyl group, heterocycloalkenyl group, or heteroaryl group may include nitrogen, oxygen, or sulfur within the ring, but are not limited thereto.

[0110] For example, the polymer may include one or more of the structural units represented by the following chemical formula 1-1 or the following chemical formula 1-2:

[0111] [Chemical Formula 1-1]

[0112]

[0113] In the above chemical formula 1-1, R 7 is hydrogen, deuterium, methyl, or -CF3, and L 4 is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof, and Y 3 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a nitro group, a cyano group, -S(=O)2OH, or -NR g R h (Here, R g and R h are each independently hydrogen, deuterium, or a C1 to C5 alkyl group, and * is a connecting point.

[0114] [Chemical Formula 1-2]

[0115]

[0116] In the above chemical formula 1-2, R 8 is hydrogen, deuterium, methyl group, or -CF3, and Y 4 is -NR i R j and the above R i and R j are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group containing nitrogen in the ring, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group containing nitrogen in the ring, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group containing nitrogen in the ring, and R i and R j are optionally connected to each other to form a ring, and * is a connection point.

[0117] For example, the polymer may include one or more of the structural units represented by the following chemical formulas 1-3 to 1-13, but is not limited thereto.

[0118] [Chemical Formula 1-3]

[0119]

[0120] [Chemical Formula 1-4]

[0121]

[0122] [Chemical Formula 1-5]

[0123]

[0124] [Chemical Formula 1-6]

[0125]

[0126] [Chemical Formula 1-7]

[0127]

[0128] [Chemical Formula 1-8]

[0129]

[0130] [Chemical Formula 1-9]

[0131]

[0132] [Chemical Formula 1-10]

[0133]

[0134] [Chemical Formula 1-11]

[0135]

[0136] [Chemical Formula 1-12]

[0137]

[0138] [Chemical Formula 1-13]

[0139]

[0140] In one embodiment, the structural unit represented by the above chemical formula 1 may be included in an amount of 40 wt% to 100 wt% based on the total weight of the polymer, for example, 40 wt% to 95 wt%, 40 wt% to 90 wt%, 40 wt% to 85 wt%, 40 wt% to 80 wt%, 40 wt% to 75 wt%, 40 wt% to 70 wt%, 45 wt% to 80 wt%, 50 wt% to 80 wt%, 45 wt% to 75 wt%, 50 wt% to 75 wt%, 50 wt% to 70 wt%, but is not limited thereto. When the structural unit represented by the above chemical formula 1 is included in the above range, the composition can maximize the control function of secondary electrons, and the selectivity of the resist underlayer film pattern formed from the composition can be further improved.

[0141] The polymer may have a weight average molecular weight of from 1,000 g / mol to 300,000 g / mol, for example, from about 3,000 g / mol to 200,000 g / mol, for example, from 3,000 g / mol to 100,000 g / mol, for example, from 3,000 g / mol to 90,000 g / mol, for example, from 3,000 g / mol to 70,000 g / mol, for example, from 3,000 g / mol to 50,000 g / mol, for example, from 5,000 g / mol to 50,000 g / mol, for example, from 5,000 g / mol to 30,000 g / mol, but is not limited thereto. By having a weight average molecular weight within the above range, the carbon content and solubility in a solvent of a composition for a resist underlayer film including the polymer can be controlled and optimized.

[0142] The polymer may be included in an amount of 0.1 wt% to 50 wt% based on the total weight of the composition for a resist underlayer film. More specifically, the polymer may be included in an amount of, for example, 1 wt% to 50 wt%, 10 wt% to 50 wt%, 15 wt% to 50 wt%, 20 wt% to 50 wt%, 1 wt% to 45 wt%, 1 wt% to 40 wt%, 10 wt% to 45 wt%, 10 wt% to 40 wt%, 15 wt% to 40 wt%, 20 wt% to 40 wt%, based on the total weight of the composition for a resist underlayer film, but is not limited thereto. By including the polymer in the composition in the above range, the thickness, surface roughness, and degree of planarization of the resist underlayer film can be controlled.

[0143] A composition for a resist underlayer film according to one embodiment may include a solvent. The solvent is not particularly limited as long as it has sufficient solubility and / or dispersibility for the polymer and compound according to one embodiment, and may include, but is not limited to, for example, propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, gamma-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, or a combination thereof.

[0144] A composition for a resist underlayer film according to one embodiment may further include, in addition to the polymer, compound, and solvent, one or more polymers selected from an acrylic resin, an epoxy resin, a novolak resin, a glycoluril resin, and a melamine resin, but is not limited thereto.

[0145] According to another embodiment, the composition for a resist underlayer film may further include an additive including a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0146] The above surfactant can be used to improve coating defects that occur as the solid content increases during the formation of a resist underlayer film, and examples thereof include, but are not limited to, alkylbenzenesulfonic acid salts, alkylpyridinium salts, polyethylene glycol, and quaternary ammonium salts.

[0147] The above-mentioned thermal acid generator may be, but is not limited to, acidic compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid, and / or benzoin tosylate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters.

[0148] The above plasticizer is not particularly limited, and various types of known plasticizers can be used. Examples of plasticizers include low-molecular-weight compounds such as phthalic acid esters, adipic acid esters, phosphoric acid esters, trimellitic acid esters, and citric acid esters, as well as compounds such as polyethers, polyesters, and polyacetals.

[0149] The above additive may be included in an amount of 0.001 to 40 parts by weight per 100 parts by weight of the composition for the resist underlayer film. By including it in the above range, the solubility can be improved without changing the optical properties of the composition for the resist underlayer film.

[0150] According to another embodiment, a resist underlayer film is provided, which is manufactured using the composition for a resist underlayer film described above. The resist underlayer film may be in a form that is cured, for example, by coating the composition for a resist underlayer film described above on a substrate and then performing a heat treatment process.

[0151] A method for forming a pattern using the composition for the resist underlayer film described below is described with reference to FIG. 1.

[0152] Figure 1 is a cross-sectional view illustrating a pattern forming method using a composition for a resist underlayer film according to the present invention.

[0153] Referring to Fig. 1(a), first, an etching target is prepared. An example of the etching target may be a thin film (102) formed on a semiconductor substrate (100). The following description will be limited to the case where the etching target is a thin film (102). The surface of the thin film (102) is pre-cleaned to remove contaminants remaining on the thin film (102). The thin film (102) may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0154] Next, the composition for the resist underlayer film described above is coated on the surface of the cleaned thin film (102) using a spin coating method.

[0155] Thereafter, a drying and baking process is performed to form a resist underlayer film (104) on the thin film. The baking process is performed at a temperature of 100°C to 500°C, and may be performed at, for example, 100°C to 300°C. A more specific description of the composition for the resist underlayer film is omitted to avoid duplication, as it has been described in detail above.

[0156] Referring to Fig. 1(b), a photoresist film (106) is formed by coating photoresist on the resist lower layer film (104).

[0157] Examples of the photoresist include a positive photoresist containing a naphthoquinone diazide compound and a novolak resin, a chemically amplified positive photoresist containing an acid generator capable of dissociating an acid upon exposure, a compound that decomposes in the presence of an acid to increase solubility in an alkaline aqueous solution, and an alkali-soluble resin, and a chemically amplified positive photoresist containing an acid generator and an alkali-soluble resin having a group capable of providing a resin that decomposes in the presence of an acid to increase solubility in an alkaline aqueous solution, etc.

[0158] Next, a first baking process is performed to heat the substrate (100) on which the photoresist film (106) is formed. The first baking process can be performed at a temperature of 90°C to 120°C.

[0159] Referring to Fig. 1(c), the photoresist film (106) is selectively exposed. As an example, an exposure process for exposing the photoresist film (106) is described. An exposure mask having a predetermined pattern formed thereon is positioned on a mask stage of an exposure device, and the exposure mask (110) is aligned on the photoresist film (106). Then, by irradiating light onto the mask (110), a predetermined portion of the photoresist film (106) formed on the substrate (100) selectively reacts with the light transmitted through the exposure mask.

[0160] For example, examples of light that can be used in the above exposure process include short-wavelength light such as an activating irradiance i-line having a wavelength of 365 nm, a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, and in addition, EUV (Extreme ultraviolet) having a wavelength of 13.5 nm corresponding to extreme ultraviolet light.

[0161] The photoresist film (106a) of the exposed portion becomes relatively hydrophilic compared to the photoresist film (106b) of the non-exposed portion. Accordingly, the photoresist films of the exposed portion (106a) and the non-exposed portion (106b) have different solubilities.

[0162] Next, a second baking process is performed on the substrate (100). The second baking process can be performed at a temperature of 90° C. to 150° C. By performing the second baking process, the photoresist film corresponding to the exposed area becomes easily soluble in a specific solvent.

[0163] Referring to FIG. 1(d), specifically, by dissolving and then removing the photoresist film (106a) corresponding to the exposed area using tetramethyl ammonium hydroxide (TMAH) or the like, the photoresist film (106b) remaining after development forms a photoresist pattern (108).

[0164] Next, the resist underlayer film (104) is etched using the photoresist pattern (108) as an etching mask. An organic film pattern (112) as shown in Fig. 1(e) is formed by the etching process described above. The etching can be performed by, for example, dry etching using an etching gas, and the etching gas can be, for example, CHF3, CF4, Cl2, O2, or a mixed gas thereof. As described above, since the resist underlayer film formed by the resist underlayer film composition according to one embodiment has a fast etching speed, a smooth etching process can be performed in a short period of time.

[0165] Referring to Fig. 1(f), the photoresist pattern (108) is applied as an etching mask to etch the exposed thin film (102). As a result, the thin film is formed into a thin film pattern (114). In the exposure process performed previously, the thin film pattern (114) formed by the exposure process performed using a short-wavelength light source such as an activating irradiance i-line (wavelength 365 nm), a KrF excimer laser (wavelength 248 nm), or an ArF excimer laser (wavelength 193 nm) may have a width of several tens to several hundred nm, and the thin film pattern (114) formed by the exposure process performed using an EUV light source may have a width of 20 nm or less.

[0166] Hereinafter, the present invention will be described in more detail through examples relating to the synthesis of the above-described polymer and the preparation of a composition for a resist underlayer film comprising the same. However, the present invention is not technically limited by the following examples.

[0167]

[0168] Synthetic example

[0169] Synthesis Example 1

[0170] Into a 500 ml three-necked round flask, add 28.4 g of poly(glycidyl methacrylate), 33.8 g of monomethyl fumarate, 1.6 g of pyridine, 4.4 g of BHT (butylated hydroxytoluene), and 103 g of PGMEA, and connect a condenser. After the reaction is carried out at 90°C for 16 hours, the reaction solution is cooled to room temperature (23°C). Afterwards, the reaction solution is transferred to a 1 L wide-mouth bottle, and 500 g of heptane is poured in with stirring to generate gum, which is then dissolved in 100 g of tetrahydrofuran (THF). The dissolved resin solution forms a precipitate with heptane, and single and low molecules are removed to obtain the final product having the following chemical formula. A polymer composed of structural units represented by 1-7 is obtained. The weight average molecular weight of the polymer is 1,700 g / mol, and the electron affinity is 1.67 eV.

[0171] [Chemical Formula 1-7]

[0172]

[0173]

[0174] Synthesis Example 2

[0175] A polymer composed of a structural unit represented by the following chemical formula 1-3 is obtained by performing the same procedure as in Synthesis Example 1, except that 36.4 g of 2-(Trifluoromethyl)acrylic acid is used instead of monomethyl fumarate. The weight average molecular weight of the polymer is 1,700 g / mol, and the electron affinity is 1.20 eV.

[0176] [Chemical Formula 1-3]

[0177]

[0178]

[0179] Synthesis Example 3

[0180] A polymer composed of a structural unit represented by the following chemical formula 1-4 is obtained by performing the same procedure as in Synthesis Example 1, except that 49.4 g of 3-(4-Nitro benzoyl)acrylic acid is used instead of monomethyl fumarate. The weight average molecular weight of the polymer is 2,000 g / mol, and the electron affinity is 2.57 eV.

[0181] [Chemical Formula 1-4]

[0182]

[0183]

[0184] Synthesis Example 4

[0185] A polymer composed of a structural unit represented by the following chemical formula 1-11 is obtained by performing the same procedure as in Synthesis Example 1, except that 71.0 g of 5-Iodoisatin is used instead of monomethyl fumarate. The weight average molecular weight of the polymer is 4,200 g / mol, and the electron affinity is 2.41 eV.

[0186] [Chemical Formula 1-11]

[0187]

[0188]

[0189] Synthesis Example 5

[0190] A polymer composed of a structural unit represented by the following chemical formula 1-8 is obtained by performing the same procedure as in Synthesis Example 1, except that 44.0 g of 2-Amino-5-trifluoromethyl-1,3,4-thiadiazole is used instead of monomethyl fumarate. The weight average molecular weight of the polymer is 3,100 g / mol, and the electron affinity is 1.61 eV.

[0191] [Chemical Formula 1-8]

[0192]

[0193]

[0194] Synthesis Example 6

[0195] Except that 44.0 g of Isatine was used instead of monomethyl fumarate, the same procedure as in Synthesis Example 1 was repeated to obtain a polymer composed of structural units represented by the following chemical formula 1-13. The polymer has a weight-average molecular weight of 1,900 g / mol and an electron affinity of 2.06 eV.

[0196] [Chemical Formula 1-13]

[0197]

[0198]

[0199] Comparative synthesis example 1

[0200] Except that 12.0 g of formic acid was used instead of monomethyl fumarate, the same procedure as in Synthesis Example 1 was repeated to obtain a polymer composed of structural units represented by the following chemical formula 3. The polymer has a weight-average molecular weight of 1,180 g / mol and an electron affinity of 0.20 eV.

[0201] [Chemical Formula 3]

[0202]

[0203]

[0204] Comparative synthesis example 2

[0205] A polymer composed of a structural unit represented by the following chemical formula 4 is obtained by performing the same procedure as in Synthesis Example 1, except that 18.7 g of acrylic acid is used instead of monomethyl fumarate. The weight average molecular weight of the polymer is 1,200 g / mol, and the electron affinity is 0.51 eV.

[0206] [Chemical Formula 4]

[0207]

[0208]

[0209] Comparative synthesis example 3

[0210] In a nitrogen atmosphere, add 33.17 g of PGMEA to a 500 ml three-necked round flask, connect a condenser, and raise the temperature to 90℃. Dissolve 71.08 g, 500 mmol; Samchun Pure Chemicals Co., Ltd. and V-601 (17.27 g, 75 mmol; Wako Co., Ltd.) in 132.67 g of PGMEA and add the solution dropwise using an Easy-Loader for 1 hour. After the feeding is finished, heat and react for 3 hours, and then cool the reaction solution to room temperature. After that, transfer the reaction solution to a 1 L wide-mouth bottle and pour in 450 g of heptane while stirring to form a gum, which is then dissolved in 150 g of tetrahydrofuran (THF). The dissolved resin solution forms a precipitate with heptane, and single and small molecules are removed to finally obtain a polymer composed of structural units represented by the following chemical formula 5. The weight average molecular weight of the polymer is 1,500 g / mol, and the electron affinity is -0.42 eV.

[0211] [Chemical Formula 5]

[0212]

[0213]

[0214] Preparation of a composition for resist underlayer film

[0215] Examples and Comparative Examples

[0216] Each of 3.032 g of the polymers obtained from Synthetic Examples 1 to 6 and Comparative Synthetic Examples 1 to 3 and 1.766 g of PL1174 (crosslinking agent) was mixed with 0.471 g of pyridinium para-toluenesulfonate (PPTS) to completely dissolve them, and diluted with an additional solvent to prepare a composition for a resist underlayer film according to Examples 1 to 6 and Comparative Examples 1 to 3, each having 10 wt% of the polymer based on the total weight.

[0217]

[0218] Evaluation 1: Line Edge Roughness (LER)

[0219] The films according to Examples 1 to 6 and Comparative Examples 1 to 3 manufactured on a circular silicon wafer are exposed to extreme ultraviolet light with different energies and focuses to form line / space patterns of 12 to 100 nm. After exposure, they are baked at 180°C for 120 seconds, then immersed in a petri dish containing 2-heptanone for 60 seconds, taken out, and washed with the same solvent for 10 seconds. Finally, after baking at 150°C for 5 minutes, pattern images are obtained by scanning electron microscopy (SEM). The line edge roughness (LER) confirmed from the SEM images is converted into a ratio compared to Ref. (Comparative Example 2) and is shown in Table 1 below.

[0220] LER(%)Example 192Example 293Example 391Example 489Example 593Example 685Comparative Example 1102Comparative Example 2100Comparative Example 3105

[0221] Referring to Table 1 above, it was confirmed that the line edge roughness (LER) of the resist underlayer pattern manufactured according to the example was smaller than the line edge roughness of the resist underlayer pattern manufactured according to the comparative example, and it can be seen that the resist underlayer pattern according to the example was formed more uniformly and clearly.

[0222]

[0223] Evaluation 2: Exposure Characteristics Evaluation

[0224] The compositions prepared from Examples 1 to 6 and Comparative Examples 1 to 3 were applied by a spin-on coating method, and then heat-treated on a hot plate at 205°C for 60 seconds to form a 50Å thick resist underlayer film. Thereafter, a photoresist solution was applied on the underlayer film by a spin-on coating method, and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The photoresist layer was exposed using an e-beam exposure device (manufactured by Elionix) in the range of 200 μC / cm2 to 2000 μC / cm2, and then heat-treated at 150°C for 60 seconds. Next, the photoresist layer was developed with a 2.38 mass% aqueous solution of TMAH and then rinsed in pure water for 15 seconds to form a 50 nm line and space (L / S) photoresist pattern. Next, the optimal exposure dose of the photoresist pattern was evaluated, and the minimum size at which the pattern is well formed without the lines of the pattern being connected or collapsing is referred to as the minimum CD, and a smaller value means a better resolution.

[0225] Minimum CD (nm) Example 147 Example 248 Example 347 Example 445 Example 549 Example 644 Comparative Example 155 Comparative Example 258 Comparative Example 356

[0226] Referring to Table 2 above, it can be confirmed that the resist underlayer film according to the example has excellent exposure characteristics compared to the comparative example, and thus has excellent pattern formation ability of a fine pattern (50 nm L / S).

[0227] While specific embodiments of the present invention have been described and illustrated above, it will be apparent to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Accordingly, such modifications or variations should not be understood individually from the technical spirit or perspective of the present invention, and such modified embodiments should fall within the scope of the claims of the present invention.

Claims

1. A composition for a resist underlayer film comprising a polymer having a structural unit represented by the following chemical formula 1 and an electron affinity of 1.0 eV to 3.0 eV, and a solvent: [Chemical Formula 1] In the above chemical formula 1, R 1 Inland R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, L 1 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C2 to C10 heteroalkenylene group, or a combination thereof, X 1 is a single bond, -O-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a - (Here, R a is hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group), or a combination thereof, L 2 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof, Y 1 is a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group, a substituted or unsubstituted C6 to C30 aryl group, a substituted or unsubstituted C2 to C30 heteroaryl group, a nitro group, a cyano group, -S(=O)2OH, -C(=O)OR x (Here, R x is a substituted or unsubstituted C1 to C10 alkyl group), or -NR b R c (Here, R b and R c are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a substituted or unsubstituted C6 to C20 aryl group, and R b and R c are optionally interconnected to form a ring.) * is a connection point.

2. In paragraph 1, X of the chemical formula 1 1 A composition for a resist underlayer film having this single bond, -(CO)O-, or -NH-.

3. In paragraph 1, L of the chemical formula 1 1 is a C1 to C10 alkylene group substituted with a hydroxy group, and L 2 A composition for a resist underlayer film, which is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof.

4. A composition for a resist underlayer film, wherein the electron affinity of the polymer in the first paragraph is 1.2 eV to 2.5 eV.

5. In paragraph 1, the polymer further comprises a structural unit represented by the following chemical formula 2, a composition for a resist underlayer film: [Chemical Formula 2] In the above chemical formula 2, R 4 Inland R 6 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group, X 2 and X 3 are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR d - (Here, R d is hydrogen, deuterium, or a C1 to C10 alkyl group), or a combination thereof, L 3 is a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene 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, a substituted or unsubstituted C2 to C20 heteroarylene group, or a combination thereof, Y 2 is hydrogen, deuterium, halogen atom, hydroxyl group, nitro group, cyano group, -COOH, -NR e R f (Here, R e and R f are each independently hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl 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 C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C10 heteroalkenyl group, a substituted or unsubstituted C2 to C10 heteroalkynyl 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, or a substituted or unsubstituted C2 to C20 heteroaryl group, * is a connection point.

6. In paragraph 1, the polymer is a composition for a resist underlayer film comprising at least one structural unit represented by the following chemical formula 1-1 or the following chemical formula 1-2: [Chemical Formula 1-1] In the above chemical formula 1-1, R 7 is hydrogen, deuterium, methyl group, or -CF3, L 4 is a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C2 to C5 alkenylene group, a substituted or unsubstituted C6 to C10 arylene group, or a combination thereof, Y 3 is a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a nitro group, a cyano group, -S(=O)2OH, -C(=O)OR x (Here, R x is a substituted or unsubstituted C1 to C5 alkyl group), or -NR g R h (Here, R g and R h are each independently hydrogen, deuterium, or a C1 to C5 alkyl group, * is a connection point: [Chemical Formula 1-2] In the above chemical formula 1-2, R 8 is hydrogen, deuterium, methyl group, or -CF3, Y 4 is -NR i R j and the above R i and R j are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group containing nitrogen in the ring, a substituted or unsubstituted C2 to C20 heterocycloalkenyl group containing nitrogen in the ring, a substituted or unsubstituted C6 to C20 aryl group, or a substituted or unsubstituted C2 to C30 heteroaryl group containing nitrogen in the ring, and R i and R j are optionally interconnected to form a ring, * is a connection point.

7. In paragraph 1, the polymer comprises at least one structural unit represented by the following chemical formulas 1-3 to 1-13: a composition for a resist underlayer film: [Chemical Formula 1-3] [Chemical Formula 1-4] [Chemical Formula 1-5] [Chemical Formula 1-6] [Chemical Formula 1-7] [Chemical Formula 1-8] [Chemical Formula 1-9] [Chemical Formula 1-10] [Chemical Formula 1-11] [Chemical Formula 1-12] [Chemical Formula 1-13] 8. A composition for a resist underlayer film, wherein the structural unit represented by the chemical formula 1 in the first paragraph is 40% to 100% by weight based on the total weight of the polymer.

9. A composition for a resist underlayer film in the first paragraph, wherein the weight average molecular weight of the polymer is 1,000 g / mol to 300,000 g / mol.

10. A composition for a resist underlayer film, wherein the polymer in paragraph 1 is included in an amount of 0.1 wt% to 50 wt% based on the total weight of the composition for a resist underlayer film.

11. In paragraph 1, the composition further comprises at least one polymer selected from an acrylic resin, an epoxy resin, a novolak resin, a glucouryl resin, and a melamine resin.

12. A composition for a resist underlayer film, wherein the composition further comprises an additive that is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

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

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