Resist underlayer compositions, and methods of forming patterns using compositions

Abstract

To provide a resist underlayer film in which, even in a fine patterning process, sensitivity to an exposure light source is improved so that patterning performance and energy efficiency are improved, and a pattern is uniformly formed.SOLUTION: Provided are a resist underlayer composition including a polymer including at least one of a structural unit represented by Chemical Formula 1, a structural unit represented by a specific formula, and a structural unit represented by another specific formula different from the above, a protected imidazole compound, and a solvent, and a method of forming a pattern using the resist underlayer composition.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, the semiconductor industry has evolved from patterns of hundreds of nanometers to ultra-fine technology with patterns of several nanometers to tens of nanometers in size. To realize such ultra-fine technology, effective lithographic techniques are essential.

[0003] Lithographic techniques are a processing method in which a thin film of photoresist is coated on a semiconductor substrate such as a silicon wafer to form a thin film, which is then irradiated with activating radiation such as ultraviolet light through a mask pattern on which a device pattern is drawn, and then developed.The resulting photoresist pattern is used as a protective film to etch the substrate, thereby forming a fine pattern corresponding to the pattern on the surface of the substrate.

[0004] As semiconductor patterns become increasingly finer, thinner photoresist layers are required, which in turn requires thinner resist underlayers. The resist underlayer must maintain the photoresist pattern even at a thin thickness, have good adhesion to the photoresist, and be formed with a uniform thickness. Additionally, the resist underlayer must have a high refractive index and low absorption coefficient for the light used in photolithography, and an etching rate faster than the photoresist layer. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2025-0029581 Summary of the Invention [Problem to be solved by the invention]

[0006] The composition for a resist underlayer film according to one embodiment provides a resist underlayer film with improved sensitivity to an exposure light source, improved patterning performance and energy efficiency, and uniformly formed patterns, even in a fine patterning process.

[0007] Another embodiment provides a pattern forming method using a resist underlayer film composition. [Means for solving the problem]

[0008] A composition for a resist underlayer film according to one embodiment includes a polymer including at least one structural unit represented by the following Chemical Formula 1, a structural unit represented by the following Chemical Formula 2, and a structural unit represented by the following Chemical Formula 3, a protected imidazole compound, and a solvent: [Chemical formula 1] [ka] [Chemical formula 2] [ka] [Chemical formula 3] [ka] In chemical formulas 1 to 3, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 8 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 20 carbon atoms, or a combination thereof; X 1 ~X 7 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, or -NR a -(where R a is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y 1 and Y 2 are each independently hydrogen, deuterium, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms; 1 and Y 2 At least one of the groups is an epoxy group, Y 3 and Y 4 is an epoxy group, R 1 ~R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates the linkage site.

[0009] The protected imidazole compound may be represented by Formula 4 below: [Chemical formula 4] [ka] In chemical formula 4, L 9 and L 10each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, X 9 and X 10 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, or -NR b -(where R b is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y 5 and Y 6 each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, R 4 ~R 6 are each independently hydrogen, deuterium, halogen atom, hydroxy group (-OH), cyano group (-CN), nitro group (-NO2), sulfonic acid group (-SO3H), -C(=O)R c (where R c is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), —C(═O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. ) is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0010] A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of the following Chemical Formulas A-1 to A-4. [Chemical formula A-1] [ka] [Chemical formula A-2] [ka] [Chemical formula A-3] [ka] [Chemical formula A-4] [ka] In Chemical Formula A-3 and Chemical Formula A-4, R x and R y each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms; * indicates the linkage site.

[0011] L in Chemical Formula 3 7 and L 8 are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and X 6 and X 7 may each independently be a single bond or —(CO)O—.

[0012] L in Chemical Formula 4 9 and L 10 are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and X 9 and X 10 each independently represents a single bond, —C(═O)—, —(CO)O—, —O(CO)O—, or a combination thereof; Y5 and Y 6 may each independently be a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

[0013] R in Chemical Formula 4 4 ~R 6 are independently hydrogen, deuterium, cyano group (-CN), nitro group (-NO2), -C(=O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.) or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0014] The polymer may contain at least one of structural units represented by the following formula 2-1 and formula 3-1. [Chemical formula 2-1] [ka] [Chemical formula 3-1] [ka] In chemical formula 3-1, R 7 is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, L 11 is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, * indicates the linkage site.

[0015] The protected imidazole compound is represented by any one or more of the following chemical formulas 4-1 to 4-6: [Chemical formula 4-1] [ka] [Chemical formula 4-2] [ka] [Chemical formula 4-3] [ka] [Chemical formula 4-4] [ka] [Chemical formula 4-5] [ka] [Chemical formula 4-6] [ka] In Chemical Formula 4-1 and Chemical Formula 4-2, Ph is a phenyl group.

[0016] The weight average molecular weight (Mw) of the polymer may be from 1,000 g / mol to 300,000 g / mol.

[0017] The polymer may be contained in an amount of 0.1% by weight to 50% by weight based on the total weight of the composition for a resist underlayer film.

[0018] The molecular weight of the protected imidazole compound may be from 300 g / mol to 1,000 g / mol.

[0019] The protected imidazole compound may be contained in an amount of 0.01% by weight to 30% by weight based on the total weight of the composition for a resist underlayer film.

[0020] The composition may further include one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluril resins, and melamine resins.

[0021] The composition can further include an additive that is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0022] According to another embodiment, there is provided a pattern forming method including the steps of: forming a film to be etched on a substrate; applying a resist underlayer film composition according to an embodiment onto the film to be etched to form a resist underlayer film; forming a photoresist pattern on the resist underlayer film; and sequentially etching the resist underlayer film and the film to be etched using the photoresist pattern as an etching mask. [Effects of the Invention]

[0023] The composition for a resist underlayer film according to one embodiment can improve sensitivity to an exposure light source even in a fine patterning process, thereby improving patterning performance and energy efficiency, and at the same time, can provide a resist underlayer film that allows a pattern to be formed uniformly. [Brief explanation of the drawings]

[0024] [Figure 1] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0025] Although the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein, the present invention will be described in detail below so that those skilled in the art can easily practice the present invention.

[0026] In the drawings, the thickness of various layers and regions is exaggerated for clarity, and similar parts are designated by the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is said to be "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part between them. Conversely, when a part is said to be "directly on" another part, it means that there is no other part between them.

[0027] Hereinafter, unless otherwise defined in this specification, "substituted" means that a hydrogen atom in a compound is replaced with a deuterium atom, a halogen atom (F, Br, Cl, or I), a hydroxy group, a nitro group, a cyano group, an amino group, an azide group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl 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 group or a salt thereof, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, a carbon It means that the alkyl group is substituted with a substituent selected from an alkynyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, a heteroarylalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a cycloalkenyl group having 3 to 15 carbon atoms, a cycloalkynyl group having 6 to 15 carbon atoms, a heterocyclic group having 2 to 30 carbon atoms, and combinations thereof.

[0028] Furthermore, two adjacent substituents selected from a substituted halogen atom (F, Br, Cl, or I), a hydroxy group, a nitro group, a cyano group, an amino group, an azide group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl 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 group or a salt thereof, an alkyl group having 1 to 30 carbon atoms, an alkenyl group having 2 to 30 carbon atoms, an alkynyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, an alkoxy group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, a heteroarylalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a cycloalkenyl group having 3 to 15 carbon atoms, a cycloalkynyl group having 6 to 15 carbon atoms, or a heterocyclic group having 2 to 30 carbon atoms may be fused to form a ring.

[0029] As used herein, the term "heterocyclic group" encompasses heteroaryl groups and also refers to groups containing at least one heteroatom selected from N, O, S, P, and Si in place of carbon (C) in a ring compound such as an aryl group, a cycloalkyl group, a fused ring thereof, or a combination thereof. When a heterocyclic group is a fused ring, the entire heterocyclic group or each ring may contain one or more heteroatoms.

[0030] More specifically, the substituted or unsubstituted aryl group and / or the substituted or unsubstituted heterocyclic group are 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 biphenylyl group, a substituted or unsubstituted terphenylyl group, a substituted or unsubstituted quaterphenylyl group, a substituted or unsubstituted chrysenyl group, a substituted or unsubstituted a 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, a substituted or unsubstituted oxadiazolyl group, a substituted or unsubstituted thiadiazolyl group, a substituted or unsubstituted pyridinyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted pyrimidinyl group, a substituted or unsubstituted pyrazinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted benzimidazolyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted phenyl ... substituted or unsubstituted benzoxazinyl group, substituted or unsubstituted benzothiazinyl group, substituted or unsubstituted acridinyl group, substituted or unsubstituted phenazinyl group, substituted or unsubstituted phenothiazinyl group, substituted or unsubstituted phenoxazinyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted dibenzofuranyl group, substituted or unsubstituted dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, pyridoindolyl group, benzopyridoxazinyl group, benzopyridothiazinyl group, 9,9-dimethyl-9,10-dihydroacridinyl group, a combination thereof, or a condensed form of a combination thereof, but are not limited to these.

[0031] Unless otherwise specified herein, "combination" means blending or copolymerization.

[0032] In addition, in this specification, the term "polymer" can include both oligomers and polymers.

[0033] Unless otherwise specified in this specification, the "weight average molecular weight" is measured by dissolving a powder sample in tetrahydrofuran (THF) and then using a 1200 series gel permeation chromatography (GPC) manufactured by Agilent Technologies (using a Shodex LF-804 column and Shodex polystyrene as the standard sample).

[0034] Additionally, unless otherwise defined herein, "*" refers to a structural unit of a polymer or a linking site of a moiety of a polymer.

[0035] The semiconductor industry is constantly seeking to reduce chip size. To meet this trend, the linewidth of resists patterned in lithography must be reduced to the order of a few tens of nanometers. This pattern is then used to transfer the pattern to an underlying material through an etching process. However, as the resist pattern size decreases, the resist height (aspect ratio) that can withstand the linewidth becomes limited, which can result in the resist not being sufficiently durable during the etching process. Therefore, when using a thin resist material, when the substrate to be etched is thick, or when a deep pattern is required, a resist underlayer is used to compensate for this.

[0036] The resist underlayer film must become thinner as the resist thickness decreases, and the photoresist pattern must not collapse even at a thin resist underlayer film. To achieve this, 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, resulting in improved pattern formability and energy efficiency.

[0037] A composition for a resist underlayer film according to one embodiment includes a polymer including at least one structural unit represented by the following Chemical Formula 1, a structural unit represented by the following Chemical Formula 2, and a structural unit represented by the following Chemical Formula 3, a protected imidazole compound, and a solvent: [Chemical formula 1] [ka] [Chemical formula 2] [ka] [Chemical formula 3] [ka] In chemical formulas 1 to 3, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 8 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 20 carbon atoms, or a combination thereof; X1 ~X 7 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, or -NR a -(where R a is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y 1 and Y 2 are each independently hydrogen, deuterium, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms; 1 and Y 2 At least one of the groups is an epoxy group, Y 3 and Y 4 is an epoxy group, R 1 ~R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates the linkage site.

[0038] As used herein, the term "protected imidazole compound" refers to an imidazole compound in which at least one hydrogen atom bonded to a nitrogen and / or carbon atom of the imidazole ring has been replaced with a protecting group. Examples of the protecting group include a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, a halogen atom, a hydroxy group (-OH), a cyano group (-CN), a nitro group (-NO), a sulfonic acid group (-SOH), and -C(=O)R. c (where R c is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), —C(═O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof.

[0039] The protected imidazole compound may be represented by Formula 4 below: [Chemical formula 4] [ka] In chemical formula 4, L 9 and L 10 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, X 9 and X 10 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, or -NR b -(where R b is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y5 and Y 6 each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, R 4 ~R 6 are each independently hydrogen, deuterium, halogen atom, hydroxy group (-OH), cyano group (-CN), nitro group (-NO2), sulfonic acid group (-SO3H), -C(=O)R c (where R c is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), —C(═O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. ) is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0040] According to one embodiment, the polymers contained in the composition, which include one or more structural units represented by Formulas 1 to 3, contain terminal epoxy groups. Therefore, when the composition is heat-treated, the imidazole moieties generated as the protecting groups of the compounds are released react with the epoxy groups to form crosslinked structures between the polymers. This allows the polymers to form a network structure, improving the film properties of the resist underlayer film. Furthermore, the resist underlayer film prepared from the composition can form a uniform pattern.

[0041] The compound represented by Chemical Formula 4, which includes the composition, contains imidazole and can absorb or emit secondary electrons when the resist underlayer film composition is exposed to light. The secondary electrons can activate a photoacid generator in the photoresist, thereby improving the sensitivity of the photoresist.

[0042] In addition, the polymer containing the structural unit represented by Chemical Formula 1 and the structural unit represented by Chemical Formula 2 contains a heterocycle containing a nitrogen atom in the ring, and therefore the polymer containing these structural units has interpolymer sp 2 -sp 2 The polymer can bond to the resist underlayer film. This allows the polymer to have a high electron density. By including a polymer with high electron density, an underlayer film composition according to an embodiment can realize a film with a dense structure in the form of an ultrathin film. In addition, the high electron density of the polymer can improve the light absorption efficiency during exposure of the resist underlayer film composition. Furthermore, the inclusion of a heterocyclic skeleton provides excellent etching selectivity and can improve energy efficiency during pattern formation after exposure using high-energy rays such as EUV (Extreme ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam).

[0043] A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of the following Chemical Formulae A-1 to A-4: [Chemical formula A-1] [ka] [Chemical formula A-2] [ka] [Chemical formula A-3] [ka] [Chemical formula A-4] [ka] In Chemical Formula A-3 and Chemical Formula A-4, R x and R yeach independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms; * indicates the linkage site.

[0044] In one embodiment, R x and R y are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, for example, but not limited to, hydrogen, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms.

[0045] In one embodiment, L in Formula 1 1 and L 2 are each independently a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms, or a combination thereof, for example, but not limited to, a single bond, a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, or a combination thereof.

[0046] X in Chemical Formula 1 1 and X 2 are each independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, for example, but not limited to, a single bond, -O-, -S-, -(CO)O-, or a combination thereof.

[0047] Y in Chemical Formula 1 1 and Y2 are each independently a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, or an epoxy group, and examples thereof include, but are not limited to, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 5 carbon atoms, a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, or an epoxy group. 1 and Y 2 One or more of the groups is an epoxy group.

[0048] In one embodiment, L in Formula 2 3 ~L 6 are each independently a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms, such as a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, such as a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, but are not limited to these. 3 and L 4 are each independently an alkylene group having 1 to 5 carbon atoms substituted with a hydroxy group, but are not limited to these.

[0049] X in Chemical Formula 2 3 ~X 5 are each independently a single bond, —O—, —C(═O)—, —(CO)O—, or —O(CO)O—, for example, a single bond, —O—, or —(CO)O—, for example, —(CO)O—, but are not limited to these.

[0050] In one embodiment, L in Formula 3 7 is a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, for example, but not limited to, a single bond. 8are each independently a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms, for example, a single bond, or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, for example, a single bond, or an unsubstituted alkylene group having 1 to 10 carbon atoms, but are not limited to these.

[0051] X in Chemical Formula 3 6 and X 7 are each independently a single bond, —O—, —C(═O)—, —(CO)O—, or —O(CO)O—, for example, a single bond, —O—, —C(═O)—, or —(CO)O—, for example, a single bond or —(CO)O—, but are not limited to these.

[0052] R in Chemical Formula 3 1 ~R 3 is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, such as, but not limited to, hydrogen, a methyl group, or an ethyl group.

[0053] In one embodiment, L in Formula 4 9 and L 10 are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, for example, a single bond or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, for example, a single bond, a methylene group, or an ethylene group, but are not limited to these.

[0054] X in Chemical Formula 4 9 and X 10 are each independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, for example, a single bond, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, for example, but not limited to, -(CO)O-.

[0055] Y in Chemical Formula 4 5 and Y 6are each independently a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, for example, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, for example, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, but are not limited to these.

[0056] R in Chemical Formula 4 4 ~R 6 are independently hydrogen, deuterium, cyano group (-CN), nitro group (-NO2), sulfonic acid group (-SO3H), -C(=O)R c (where R c is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), —C(═O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.) is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, such as hydrogen, deuterium, a cyano group (-CN), a nitro group (-NO2), -C(=O)OR d (where R d is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms. ) or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, and is hydrogen, a cyano group (-CN), a nitro group (-NO2), -C(=)OR d (where R d is hydrogen, deuterium, a methyl group, an ethyl group, a propyl group, or a butyl group, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, such as, but not limited to, hydrogen, a cyano group (—CN), a nitro group (—NO2), —C(═O)OCH2CH3, or a substituted or unsubstituted phenyl group.

[0057] In one embodiment, the polymer may include at least one structural unit represented by the following formula 2-1 and the following formula 3-1: [Chemical formula 2-1] [ka] [Chemical formula 3-1] [ka] In chemical formula 3-1, R 7 is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms; L 11 is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and * is a linking site.

[0058] In one embodiment, the protected imidazole compound is represented by any one or more of the following formulas 4-1 to 4-6: [Chemical formula 4-1] [ka] [Chemical formula 4-2] [ka] [Chemical formula 4-3] [ka] [Chemical formula 4-4] [ka] [Chemical formula 4-5] [ka] [Chemical formula 4-6] [ka] In Chemical Formula 4-1 and Chemical Formula 4-2, Ph is a phenyl group.

[0059] The polymer may have a weight-average molecular weight of 1,000 g / mol to 300,000 g / mol, for example, about 3,000 g / mol to 200,000 g / mol, for example, 3,000 g / mol to 100,000 g / mol, for example, 3,000 g / mol to 90,000 g / mol, for example, 3,000 g / mol to 70,000 g / mol, for example, 3,000 g / mol to 60,000 g / mol, for example, 3,000 g / mol to 50,000 g / mol, for example, 5,000 g / mol to 50,000 g / mol, for example, 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 resist underlayer film composition containing the polymer can be adjusted and optimized.

[0060] The polymer may be contained 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 contained in an amount of 10 wt % to 50 wt %, for example, 20 wt % to 50 wt %, for example, 20 wt % to 30 wt %, based on the total weight of the composition for a resist underlayer film, but is not limited thereto. By containing the polymer in the composition in the above range, the thickness, surface roughness, and degree of planarization of the resist underlayer film can be adjusted.

[0061] The protected imidazole compound may have a molecular weight of 300 g / mol to 1,000 g / mol, for example, 300 g / mol to 900 g / mol, for example, 300 g / mol to 800 g / mol, for example, 300 g / mol to 700 g / mol, for example, 300 g / mol to 600 g / mol, for example, about 300 g / mol to 500 g / mol, but is not limited thereto. By having the compound have a molecular weight within the above range, the carbon content and solubility in a solvent of a composition for a resist underlayer film containing the protected imidazole compound can be adjusted and optimized.

[0062] The protected imidazole compound may be contained in an amount of 0.01 wt% to 30 wt% based on the total weight of the composition for a resist underlayer film. More specifically, the compound may be contained in an amount of 0.1 wt% to 30.0 wt%, for example, 1.0 wt% to 30.0 wt%, for example, 5.0 wt% to 30.0 wt%, for example, 5.0 wt% to 25.0 wt%, for example, 8.0 wt% to 25.0 wt%, for example, 10.0 wt% to 25.0 wt%, based on the total weight of the composition for a resist underlayer film, but is not limited thereto. By containing the protected imidazole compound in the composition in the above range, the thickness, surface roughness, chemical resistance, and level of planarization of the resist underlayer film can be adjusted.

[0063] The resist underlayer film composition according to an 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 an 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 (PGMEA), cyclohexanone, ethyl lactate, gamma-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, or a combination thereof.

[0064] The composition for a resist underlayer film according to an embodiment may further include, in addition to the polymer, the compound, and the solvent, one or more polymers selected from an acrylic resin, an epoxy resin, a novolac resin, a glycoluril resin, and a melamine resin, but is not limited thereto.

[0065] The resist underlayer film composition according to still another embodiment may further include additives including a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0066] The surfactant can be used to improve coating defects caused by an increase in the solid content during the formation of the resist underlayer film. Examples of surfactants that can be used include, but are not limited to, alkylbenzene sulfonates, alkylpyridinium salts, polyethylene glycols, and quaternary ammonium salts.

[0067] Examples of the thermal acid generator that can be used include, but are 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, and naphthalenecarboxylic acid, and / or benzoin tosylate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters.

[0068] The plasticizer is not particularly limited, and various known plasticizers can be used. Examples of the plasticizer include low molecular weight compounds such as phthalates, adipates, phosphates, trimellitates, and citrates, as well as polyether, polyester, and polyacetal compounds.

[0069] The additive may be contained in an amount of 0.001 to 40 parts by weight relative to 100 parts by weight of the composition for a resist underlayer film. By containing the additive in this range, the solubility of the composition for a resist underlayer film can be improved without changing the optical properties of the composition for a resist underlayer film.

[0070] According to yet another embodiment, there is provided a resist underlayer film prepared using the composition for a resist underlayer film described above. The resist underlayer film may be in a form obtained by, for example, coating the composition for a resist underlayer film on a substrate and then curing it through a heat treatment process.

[0071] Hereinafter, a method for forming a pattern using the above-described composition for a resist underlayer film will be described with reference to FIG.

[0072] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to the present invention.

[0073] Referring to FIG. 1(a), first, a film to be etched is prepared. An example of the film to be etched may be a thin film 102 formed on a semiconductor substrate 100. The following description will be limited to the case where the film to be etched is the thin film 102. The surface of the thin film 102 is 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.

[0074] Next, the above-described resist underlayer film composition is coated on the surface of the washed thin film 102 by spin coating.

[0075] Thereafter, drying and baking steps are performed to form a resist underlayer film 104 on the thin film. The baking process is performed at 100°C to 500°C, for example, 100°C to 300°C. A more specific description of the composition for the resist underlayer film has been given above in detail, so it will be omitted to avoid duplication.

[0076] Referring to FIG. 1(b), a photoresist is coated on the resist underlayer film 104 to form a photoresist film 106.

[0077] Examples of photoresists 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 its 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 that can give a resin that decomposes in the presence of an acid to increase its solubility in an alkaline aqueous solution.

[0078] Next, a first baking step is performed to heat the substrate 100 on which the photoresist film 106 is formed. The first baking step can be performed at a temperature of 90°C to 120°C.

[0079] 1(c), the photoresist film 106 is selectively exposed to light. Explaining the exposure process for exposing the photoresist film 106 as an example, an exposure mask having a predetermined pattern formed thereon is placed on a mask stage of an exposure tool, and an exposure mask 110 is aligned over the photoresist film 106. Next, light is irradiated onto the mask 110, so that predetermined portions of the photoresist film 106 formed on the substrate 100 selectively react with the light transmitted through the exposure mask.

[0080] Examples of light that can be used in the exposure process include short wavelength light such as i-rays, which are activation rays having a wavelength of 365 nm, KrF excimer lasers having a wavelength of 248 nm, and ArF excimer lasers having a wavelength of 193 nm, as well as extreme ultraviolet (EUV) light having a wavelength of 13.5 nm.

[0081] The exposed portion of the photoresist film 106a is relatively hydrophilic compared to the unexposed portion of the photoresist film 106b, and therefore the exposed portion of the photoresist film 106a and the unexposed portion of the photoresist film 106b have different solubilities.

[0082] Next, a second baking step is performed on the substrate 100. The second baking step can be performed at a temperature of 90° C. to 150° C. By performing the second baking step, the photoresist film corresponding to the exposed region becomes easily soluble in a specific solvent.

[0083] Referring to FIG. 1(d), specifically, the photoresist film 106a corresponding to the exposed portion is dissolved and removed using tetramethyl ammonium hydroxide (TMAH) or the like, and after development, the remaining photoresist film 106b forms the photoresist pattern 108.

[0084] Next, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. This etching process forms an organic film pattern 112 as shown in FIG. 1(e). The etching can be performed, for example, by dry etching using an etching gas, such as CHF, CF, Cl, O, or a mixture thereof. As described above, the resist underlayer film formed using the resist underlayer film composition according to one embodiment has a high etching rate, allowing for a smooth etching process to be performed within a short period of time.

[0085] 1(f), the photoresist pattern 108 is used 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. The thin film pattern 114 formed by the previous exposure process using a short wavelength light source such as i-rays (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), or ArF excimer laser (wavelength 193 nm) may have a width of tens to hundreds of nm, and the thin film pattern 114 formed by the exposure process using an EUV light source may have a width of 20 nm or less. [Example]

[0086] The present invention will be described in more detail below through examples of the synthesis of the above-mentioned polymer and the preparation of a composition for a resist underlayer film containing the same, but the present invention is not limited to these examples.

[0087] Synthesis Example Synthesis Example 1 Under a nitrogen atmosphere, 33.17 g of PGMEA was placed in a 500 ml two-necked round flask, connected to a condenser, and heated to 90°C. A solution of 71.08 g of glycidyl methacrylate (SAMCHUN Pure Chemical Industries, Ltd.) and 17.27 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601, Wako Co., Ltd.) dissolved in 132.67 g of PGMEA was added dropwise over 1 hour, reacted for 3 hours, and then cooled to room temperature. The reaction solution was then transferred to a 1 L wide-mouth bottle, and 450 g of heptane was added with stirring to form a gum, which was then dissolved in 150 g of tetrahydrofuran (THF). The solution was then used to remove monomolecular and small molecules using heptane, dried, and finally yielded a polymer consisting of the structural unit represented by the following chemical formula 3-2 (Mw = 3,900 g / mol).

[0088] [Chemical formula 3-2] [ka]

[0089] Synthesis Example 2 Under a nitrogen atmosphere, 42.61 g of PGMEA was placed in a 500 ml two-necked flask, connected to a condenser, and heated to 80°C. A solution of 51.25 g of glycidyl acrylate (TCI) and 27.63 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601) dissolved in 170.43 g of PGMEA was added dropwise over 1 hour, reacted for 3 hours, and then cooled to room temperature. The reaction solution was then transferred to a 1 L wide-mouth bottle, and 450 g of heptane was added with stirring to form a gum, which was then dissolved in 150 g of tetrahydrofuran (THF). The solution was then dried after removing monomolecular and small molecules using heptane to obtain a copolymer consisting of structural units represented by the following formulas: 3-3 and 5 (Mw = 8,800 g / mol).

[0090] [Chemical formula 3-3] [ka] [Chemical formula 5] [ka]

[0091] Synthesis Example 3 Under a nitrogen atmosphere, 38.12 g of PGMEA was placed in a 500 ml two-necked round flask, connected to a condenser, and heated to 80 °C. A solution of 28.43 g of glycidyl methacrylate (SAMCHUN Pure Chemical Industries, Ltd.), 53.26 g of 4-benzoylphenyl methacrylate (TCI Corporation), and 152.49 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601, 13.82 g, 60 mmol; Wako Co., Ltd.) dissolved in 152.49 g of PGMEA was added dropwise over 1 hour, reacted for 3 hours, and then cooled to room temperature. The reaction solution was then transferred to a 1 L wide-mouth bottle, and 450 g of heptane was added with stirring to form a gum, which was then dissolved in 150 g of tetrahydrofuran (THF). The solution was then dried using heptane to remove monomolecules and small molecules, and finally a copolymer consisting of structural units represented by the following formula 3-2 and formula 6 was obtained (Mw=7,000g / mol).

[0092] [Chemical formula 3-2] [ka] [Chemical formula 6] [ka]

[0093] Synthesis Example 4 A 1L two-necked flask was charged with 148.6g of 1,3,5-triglycidyl isocyanurate, 60.0g of butanedioic acid, 9.1g of benzyl triethyl ammonium chloride, and 350g of N,N-dimethylformamide, and a condenser was connected. The temperature was raised to 100°C and the reaction was allowed to proceed for 8 hours. The reaction solution was then cooled to room temperature (23°C). The reaction solution was then transferred to a 1L wide-mouth bottle and washed three times with hexane, followed by subsequent washing with purified water. The resulting gum-like resin was completely dissolved in 80g of THF and slowly added dropwise to 700g of toluene while stirring. The solvent was then removed. Finally, a polymer consisting of the structural unit represented by the following chemical formula 1-3 was obtained. (Mw=7,500g / mol)

[0094] [Chemical formula 1-3] [ka]

[0095] Synthesis Example 5 A 500 mL two-necked flask was charged with 43.25 g of 4-phenylimidoazole, 40.04 g of diisopropyl fumarate, and 192.40 g of PGMEA. While stirring, 3.05 g of 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) was added dropwise, and the mixture was allowed to react at room temperature for 24 hours. The reaction mixture was washed with distilled water, then dehydrated using MgSO4. The mixture was then purified by silica gel column chromatography to finally obtain the compound represented by the following chemical formula 4-2. (Molecular weight: 345.41 g / mol)

[0096] [Chemical formula 4-2] [ka]

[0097] Synthesis Example 6 A 500 mL two-necked flask was charged with 42.04 g of ethyl 4-imidazolecarboxylate, 68.11 g of bis(2-ethylhexyl)fumarate, and 192.4 g of PGMEA. While stirring, 3.05 g (20 mmol) of 1,8-Diazabicyclo(5.4.0)undec-7-ene (DBU) was added dropwise, and the mixture was allowed to react at room temperature for 24 hours. The reaction mixture was washed with distilled water, then dehydrated using MgSO4. The mixture was then purified by silica gel column chromatography to finally obtain the compound represented by the following chemical formula 4-4. (Molecular weight: 480.65 g / mol)

[0098] [Chemical formula 4-4] [ka]

[0099] Production of a composition for a resist underlayer film Examples 1 to 8 and Comparative Examples 1 to 4 Resist underlayer film compositions were prepared by dissolving the polymer, compound, and thermal acid generator in PGMEA in the amounts shown in Table 1. In Table 1, PPTS is pyridinium p-toluenesulfonate, and PD1174 is a glycoluril-based crosslinker from TCI (Tokyo Chemical Industry).

[0100] [Table 1]

[0101] Evaluation 1: Exposure characteristics evaluation 2 ml of each composition obtained in the Examples and Comparative Examples was applied to an 8-inch wafer and spin-coated at a main spin speed of 1,500 rpm for 20 seconds using an auto track (TEL, ACT-8). The wafer was then cured at 205°C for 60 seconds to form a 50 Å thick resist underlayer film. A photoresist solution was then applied to the underlayer film using a spin-on coating method and 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 system (Elionix) and then heat-treated at 150°C for 60 seconds. The photoresist layer was then developed in a 2.38 wt% TMAH aqueous solution and rinsed with pure water for 15 seconds to form a line and space (L / S) photoresist pattern. The optimal exposure dose for the photoresist pattern was then evaluated.

[0102] Evaluation 2: Line width roughness (LWR) evaluation The compositions prepared in Examples 1 to 8 and Comparative Examples 1 to 4 were each coated by spin-on coating and then heat-treated on a hot plate at 205°C for 60 seconds to form a 50 Å thick resist underlayer film. A photoresist solution was then coated on the underlayer film by spin-on coating 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 e-beam exposure system (Elionix, accelerating voltage 100 keV). The resist layer was then heat-treated at 95°C for 60 seconds, developed in a 2.38 wt% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, and rinsed with pure water for 15 seconds to form a resist pattern.

[0103] The line width roughness (LWR) was measured by observing the formed pattern with a scanning electron microscope (SEM) S-9260 (Hitachi Corporation) and measuring the distance from the reference line where the edge should be within a 2 μm range from the edge in the longitudinal direction of the pattern.

[0104] The evaluation values ​​of the exposure dose and LWR measured in the examples and comparative examples were converted into ratios using the exposure dose or LWR value of Comparative Example 1 as a reference, as shown in the following formula. The results are shown in Table 2 below. The smaller the exposure dose and line width roughness (LWR) values, the better the pattern formability and sensitivity. *Exposure (or LWR) (%) = (Exposure (or LWR) in each Experimental Example - Exposure (or LWR) in Comparative Example 1) / Exposure (or LWR) in Comparative Example 1 x 100

[0105] [Table 2]

[0106] Referring to Table 2 above, it can be seen that the resist underlayer films according to the examples have superior fine pattern (L / S) formability and sensitivity compared to the comparative examples. In addition, it can be seen that the resist underlayer films according to the examples have smaller LWR values ​​compared to the comparative examples, resulting in more uniform patterns.

[0107] Although specific embodiments of the present invention have been described and illustrated above, the present invention is not limited to the described embodiments, and it will be apparent to those skilled in the art that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications and variations should not be understood separately from the technical spirit and perspective of the present invention, and the modified embodiments should be considered to fall within the scope of the claims of the present invention. [Explanation of symbols]

[0108] 100 boards 102 Thin Film 104 Resist underlayer film 106 Photoresist film 106a Exposed area 106b Non-exposed area 108 Photoresist pattern 110 Mask 112 Organic film pattern 114 Thin Film Pattern

Claims

1. A composition for a resist underlayer film, comprising: a polymer including at least one structural unit represented by the following chemical formula 1, a structural unit represented by the following chemical formula 2, and a structural unit represented by the following chemical formula 3; a protected imidazole compound; and a solvent: [Chemical formula 1] 【Chemistry 1】 [Chemical formula 2] 【Chemistry 2】 [Chemical formula 3] 【Transformation 3】 In the chemical formulas 1 to 3, A is a heterocyclic group containing a nitrogen atom in the ring, L １ ~L ８ each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkylene group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkylene group having 2 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 1 to 20 carbon atoms, or a combination thereof; X １ ~X ７ are each independently a single bond, —O—, —S—, —S(═O)—, or —S(═O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -NR ａ - (where R ａ is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y １ and Y ２ are each independently hydrogen, deuterium, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms; Y １ and Y ２ At least one of the groups is an epoxy group, Y ３ and Y ４ is an epoxy group, R １ ~R ３ are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates the linkage site.

2. The protected imidazole compound is a composition for a resist underlayer film represented by the following chemical formula 4: [Chemical formula 4] 【Chemistry 4】 In the above Chemical Formula 4, L ９ and L １０ each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, X ９ and X １０ are each independently a single bond, —O—, —S—, —S(═O)—, or —S(═O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -NR ｂ - (where R ｂ is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms), or a combination thereof; Y ５ and Y ６ each independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, R ４ ~R ６ are each independently hydrogen, deuterium, a halogen atom, a hydroxy group (—OH), a cyano group (—CN), a nitro group (—NO ２ ), sulfonic acid group (—SO ３ H), -C(=O)R ｃ (where R ｃ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), —C(═O)OR ｄ (where R ｄ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.), a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

3. The composition for a resist underlayer film according to claim 1, wherein A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of the following Chemical Formulas A-1 to A-4: [Chemical formula A-1] 【Transformation 5】 [Chemical formula A-2] 【Transformation 6】 [Chemical formula A-3] 【Transformation 7】 [Chemical formula A-4] 【Transformation 8】 In the chemical formula A-3 and the chemical formula A-4, R ｘ and R ｙ each independently represents hydrogen, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkenyl group having 2 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 2 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms; * indicates the linkage site.

4. L in Formula 3 ７ and L ８ are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; ６ and X ７ The resist underlayer film composition according to claim 1, wherein each of the groups independently represents a single bond or —(CO)O—.

5. L in Formula 4 ９ and L １０ are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; ９ and X １０ each independently represents a single bond, —C(═O)—, —(CO)O—, —O(CO)O—, or a combination thereof; Y ５ and Y ６ The resist underlayer film composition according to claim 2, wherein each of the groups independently represents a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms.

6. R in Formula 4 ４ ~R ６ are each independently hydrogen, deuterium, a cyano group (-CN), a nitro group (-NO ２ ), -C(=O)OR ｄ (where R ｄ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

7. The composition for a resist underlayer film according to claim 1, wherein the polymer contains at least one structural unit represented by the following chemical formula 2-1 and the following chemical formula 3-1: [Chemical formula 2-1] 【Chemistry 9】 [Chemical formula 3-1] 【Chemistry 10】 In the above chemical formula 3-1, R ７ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms; L １１ is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, * indicates the linkage site.

8. The composition for a resist underlayer film according to claim 1, wherein the protected imidazole compound is represented by any one or more of the following Chemical Formulas 4-1 to 4-6: [Chemical formula 4-1] 【Chemistry 11】 [Chemical formula 4-2] 【Chemistry 12】 [Chemical formula 4-3] 【Chemistry 13】 [Chemical formula 4-4] 【Chemistry 14】 [Chemical formula 4-5] 【Chemistry 15】 [Chemical formula 4-6] 【Chemistry 16】 In the chemical formulas 4-1 and 4-2, Ph is a phenyl group.

9. 2. The resist underlayer film composition according to claim 1, wherein the polymer has a weight average molecular weight of 1,000 g / mol to 300,000 g / mol.

10. 2. The composition for a resist underlayer film according to claim 1, wherein the polymer is contained in an amount of 0.1% by weight to 50% by weight based on the total weight of the composition for a resist underlayer film.

11. 2. The resist underlayer film composition according to claim 1, wherein the molecular weight of the protected imidazole compound is 300 g / mol to 1,000 g / mol.

12. 2. The composition for a resist underlayer film according to claim 1, wherein the protected imidazole compound is contained in an amount of 0.01% by weight to 30% by weight based on the total weight of the composition for a resist underlayer film.

13. 2. The composition for a resist underlayer film according to claim 1, further comprising one or more polymers selected from an acrylic resin, an epoxy resin, a novolac resin, a glycoluril resin, and a melamine resin.

14. 2. The resist underlayer film composition according to claim 1, further comprising an additive selected from the group consisting of a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, and a combination thereof.

15. forming a film to be etched on a substrate; A step of applying the resist underlayer film composition according to any one of claims 1 to 13 onto the etching target film to form a resist underlayer 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.

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