Resist underlayer compositions and methods of forming patterns using the compositions

Abstract

To provide a resist underlayer film in which pattern collapse of a resist does not occur even in a fine patterning process, sensitivity to an exposure light source is improved, and patterning performance and energy efficiency are improved.SOLUTION: A resist underlayer composition includes a polymer including a group represented by the following formula, and a solvent. Z1 and Z2 are -C(=O)- or -C(OH)-, and M3 is a hydroxy group, an alkyl group, or the like.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 on the order of hundreds of nanometers to ultrafine technologies with patterns on the order of a few to tens of nanometers. To realize such ultrafine technologies, effective lithography methods are essential.

[0003] Lithography is a processing method in which a photoresist film is applied to a semiconductor substrate such as a silicon wafer to form a thin film, which is then irradiated with i-line rays 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 photoresist pattern on the surface of the substrate.

[0004] As semiconductor patterns become finer, thinner photoresist layers are required, which in turn requires thinner resist underlayers. A resist underlayer must be thin enough to maintain the photoresist pattern, have good adhesion to the photoresist, and be formed with a uniform thickness. Additionally, a 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. 10-2023-0029363 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 that does not cause resist pattern collapse even in a fine patterning process, has improved sensitivity to an exposure light source, and has improved patterning performance and energy efficiency.

[0007] Another embodiment provides a pattern forming method using the above-mentioned composition for a resist underlayer film. [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, and a solvent.

[0009] [Chemical formula 1] [ka]

[0010] [Chemical formula 2] [ka]

[0011] [Chemical formula 3] [ka]

[0012] In chemical formulas 1 to 3, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 8each independently represents 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, a substituted or unsubstituted alkynylene group having 2 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, 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-, -C(=O)NH-, 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 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 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, a group represented by the following chemical formula 4, or a combination thereof; Y 1 and Y 2 At least one of the groups is a group represented by the following chemical formula 4: Y 3 and Y 4 are each independently a group represented by the following chemical formula 4: R 1 ~R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.

[0013] [Chemical formula 4] [ka]

[0014] In chemical formula 4, M 1 represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, -O-, -NH-, or a combination thereof, Z 1 and Z 2 are each independently —C(═O)— or —C(OH)—; M 2 is a single bond, a double bond, *-C(R c )=*(where R c represents hydrogen, deuterium, or an alkyl group having 1 to 5 carbon atoms, and * represents the Z 1 or Z 2 ) or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M 3 is a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, M 1 and M 3 or M 2 and M 3 are optionally linked to each other to form a ring, * indicates a connection point.

[0015] A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of Chemical Formulas A-1 to A-5 below.

[0016] [Chemical formula A-1] [ka]

[0017] [Chemical formula A-2] [ka]

[0018] [Chemical formula A-3] [ka]

[0019] [Chemical formula A-4] [ka]

[0020] [Chemical formula A-5] [ka]

[0021] In Chemical Formula A-3 and Chemical Formula A-4, R x and R y each independently represents a hydrogen atom, 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 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 1 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, a substituted or unsubstituted heteroaryl group having 1 to 20 carbon atoms, or a combination thereof; * indicates a connection point.

[0022] A in Chemical Formula 1 is the following Chemical Formula A-1, and L 1 and L 2 are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and X 1 and X 2 may each independently be a single bond.

[0023] [Chemical formula A-1] [ka]

[0024] 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 are each independently a single bond or -(CO)O-, and R 1 ~R 3 may each independently be hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms.

[0025] The polymer may further include a structural unit represented by the following Chemical Formula 5 or a structural unit represented by the following Chemical Formula 6:

[0026] [Chemical formula 5] [ka]

[0027] [Chemical formula 6] [ka]

[0028] In Chemical Formula 5 and Chemical Formula 6, L 9 ~L 11 each independently represents 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, a substituted or unsubstituted alkynylene group having 2 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, or a combination thereof; X 8 ~X 11 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, or -NR b -(where Rb is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms, or a combination thereof; Y 5 ~Y 7 each independently represents 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 cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; R 4 and R 5 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.

[0029] L in Chemical Formula 5 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 8 and X 9 are each independently a single bond, and Y 5 and Y 6 may each independently be a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms.

[0030] L in Chemical Formula 6 11 is a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, and X 10 and X 11 are each independently a single bond or -(CO)O-, and Y 7 may be a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0031] The polymer may contain at least one of structural units represented by the following Chemical Formula 1-1, the following Chemical Formula 2-1, and the following Chemical Formulas 3-1 to 3-8.

[0032] [Chemical formula 1-1] [ka]

[0033] [Chemical formula 2-1] [ka]

[0034] [Chemical formula 3-1] [ka]

[0035] [Chemical formula 3-2] [ka]

[0036] [Chemical formula 3-3] [ka]

[0037] [Chemical formula 3-4] [ka]

[0038] [Chemical formula 3-5] [ka]

[0039] [Chemical formula 3-6] [ka]

[0040] [Chemical formula 3-7] [ka]

[0041] [Chemical formula 3-8] [ka]

[0042] The weight average molecular weight of the polymer may be from 1,000 g / mol to 300,000 g / mol.

[0043] 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.

[0044] The composition may further include one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluril resins, and melamine resins.

[0045] The composition can further include an additive that is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0046] 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 on 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]

[0047] The composition for a resist underlayer film according to one embodiment can provide a resist underlayer film that does not cause resist pattern collapse even in a fine patterning process, has improved sensitivity to an exposure light source, and can improve patterning performance and energy efficiency. [Brief explanation of the drawings]

[0048] [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

[0049] Although the present invention may be embodied in many different forms, it is not intended to be limited to the embodiments set forth herein, and the present invention is not limited to the embodiments set forth herein.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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 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 phenyl ... 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 pyrimidinyl ... A radinyl 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 benzoxazinyl group, a substituted or unsubstituted benzothiazinyl group, a substituted or unsubstituted acridinyl group, The alkyl group may be, but is not limited to, a substituted or unsubstituted phenyl group, a substituted or unsubstituted phenazinyl group, a substituted or unsubstituted phenothiazinyl group, a substituted or 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.

[0055] Unless otherwise specified herein, "combination" means blending or copolymerization.

[0056] In addition, in this specification, the term "polymer" can include both oligomers and polymers.

[0057] 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).

[0058] Also, unless otherwise defined herein, "*" refers to a structural unit of a polymer or a linking point of a moiety of a polymer.

[0059] The semiconductor industry is constantly seeking to reduce chip size. To meet this demand, resist linewidths patterned using lithography must be reduced to the order of several tens of nanometers. These patterns must then be used to form patterns in the underlying material through etching of the underlying substrate. However, as resist pattern sizes become smaller, 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 thin resist materials, when the substrate to be etched is thick, or when deep patterns are required, resist underlayers are used to compensate for this.

[0060] As the thickness of the resist decreases, the resist underlayer film must also become thinner, and even a thin resist underlayer film must be able to maintain the photoresist pattern. Therefore, 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 using the same must be improved. Furthermore, the sensitivity to the exposure light source must be improved, resulting in improved pattern formability and energy efficiency.

[0061] The composition for an 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, and a solvent.

[0062] [Chemical formula 1] [ka]

[0063] [Chemical formula 2] [ka]

[0064] [Chemical formula 3] [ka]

[0065] In chemical formulas 1 to 3, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 8each independently represents 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, a substituted or unsubstituted alkynylene group having 2 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, 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-, -C(=O)NH-, 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 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 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, a group represented by the following chemical formula 4, or a combination thereof; Y 1 and Y 2 At least one of the groups is a group represented by the following chemical formula 4: Y 3 and Y 4 are each independently a group represented by the following chemical formula 4: R 1 ~R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.

[0066] [Chemical formula 4] [ka]

[0067] In chemical formula 4, M 1 represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, -O-, -NH-, or a combination thereof, Z 1 and Z 2 are each independently —C(═O)— or —C(OH)—; M 2 is a single bond, a double bond, *-C(R c )=*(where R c represents hydrogen, deuterium, or an alkyl group having 1 to 5 carbon atoms, and * represents the Z 1 or Z 2 ) or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M 3 is a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or a combination thereof; M 1 and M 3 or M 2 and M 3 are optionally linked to each other to form a ring, * indicates a connection point.

[0068] In the composition for an underlayer film according to one embodiment, the structural unit represented by Chemical Formula 1 and the structural unit represented by Chemical Formula 2 contain a heterocycle containing a nitrogen atom in the ring, and thus the polymer containing these structural units has inter-polymer sp 2 -sp 2Bonding is possible. This allows the polymer to have 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).

[0069] The polymer containing the composition contains a structural unit having a terminal group represented by Chemical Formula 4. Chemical Formula 4 contains two or more -(C=O)- or -C(OH)- groups in close proximity to each other and can form coordinate bonds with inorganic substances in the photoresist, thereby improving adhesion between the photoresist film and a resist underlayer film formed from the composition.

[0070] A in Chemical Formula 1 and Chemical Formula 2 is represented by any one of Chemical Formulas A-1 to A-5 below.

[0071] [Chemical formula A-1] [ka]

[0072] [Chemical formula A-2] [ka]

[0073] [Chemical formula A-3] [ka]

[0074] [Chemical formula A-4] [ka]

[0075] [Chemical formula A-5] [ka]

[0076] In Chemical Formula A-3 and Chemical Formula A-4, R x and R y each independently represents a hydrogen atom, 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 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 1 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, a substituted or unsubstituted heteroaryl group having 1 to 20 carbon atoms, or a combination thereof; * indicates a connection point.

[0077] In one embodiment, A in Chemical Formula 1 is, for example, but not limited to, Chemical Formula A-1.

[0078] L in Chemical Formula 1 1 and L 2 are each independently, for example, a single bond, a substituted or unsubstituted heteroalkylene group having 1 to 10 carbon atoms, 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 10 carbon atoms, for example, a single bond, or a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, but are not limited to these.

[0079] X in Chemical Formula 1 1 and X 2 are each independently a single bond, -O-, -C(=O)-, or -(CO)O-, for example, but not limited to, a single bond.

[0080] Y in Chemical Formula 1 1 and Y 2 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 20 carbon atoms, or a group represented by the above chemical formula 4, for example, 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, or a group represented by the above chemical formula 4, for example, a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, but are not limited to these. 1 and Y 2 At least one of the groups is a group represented by Chemical Formula 4.

[0081] In one embodiment, A in Chemical Formula 2 is, for example, but not limited to, Chemical Formula A-1 or Chemical Formula A-5. 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 heteroalkylene group having 1 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 a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, but are not limited to these. 3 ~X 5 are each independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, or -O(CO)O-, for example, a single bond, -O-, -C(=O)-, or -(CO)O-, for example, but not limited to, a single bond. Y 3 is a group represented by chemical formula 4.

[0082] 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 a substituted alkylene group having 1 to 10 carbon atoms, for example, a single bond or an alkylene group having 1 to 5 carbon atoms substituted with a hydroxy group, but are not limited to these.

[0083] X in Chemical Formula 3 6 and X 7 are each independently a single bond, —O—, —C(═O)—, or —(CO)O—, for example, but not limited to, a single bond or —(CO)O—.

[0084] 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.

[0085] In one embodiment, M in Formula 4 1 represents 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, -O-, -NH-, or a combination thereof, for example, a single bond, a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 5 carbon atoms, -O-, -NH-, or a combination thereof, for example, may be a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, for example, -N-, or may be a combination of -O- and an alkylene group having 1 to 5 carbon atoms, for example, may be a combination of -O- and an alkenylene group having 2 to 5 carbon atoms, but is not limited to these.

[0086] Z in Chemical Formula 4 1 and Z 2 are each independently -C(=O)- or -C(OH)-, for example, Z 1 and Z 2are each -C(=O)-, for example, Z 1 and Z 2 are each -C(OH)-, for example, Z 1 and Z 2 One of them is -C(=O)- and the other is -C(OH)-.

[0087] M in Chemical Formula 4 2 is a single bond, a double bond, *-C(R c )=*(where R c is hydrogen, deuterium, or an alkyl group having 1 to 5 carbon atoms. ) or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, such as a single bond, a double bond, *-CH=*, *-C(CH3)=*, or a substituted or unsubstituted methylene group, such as, but not limited to, a single bond, a double bond, *-CH=*, or a substituted or unsubstituted methylene group. *-C(R c )=*Medium, * is Z 1 or Z 2 It is the connecting point with

[0088] M 2 If Z has more carbon atoms than the above options, 1 and Z 2 The distance between the photoresist and the inorganic substance is far, making it difficult to effectively form coordinate bonds with the inorganic substance in the photoresist, and the adhesion to the photoresist film is poor. 2 is a single bond, double bond, *-C(R c )=*, or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, the adhesion between the resist underlayer film produced from the polymer and the photoresist film can be effectively improved.

[0089] M in Chemical Formula 4 3is a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, for example, 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, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, for example, 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, or a phenyl group, but is not limited to these.

[0090] M in Chemical Formula 4 1 and M 3 , or M 2 and M 3 can be independently linked to each other to form a ring. 1 and M 3 can optionally be linked together to form a ring, or M 2 and M 3 can optionally be linked together to form a ring. For example, M 1 and M 3 can exist independently, and M 1 and M 3 can be linked together to form a ring, and M 2 and M 3 can exist independently, and M 2 and M 3 can be linked to each other to form a ring.

[0091] In another embodiment, the polymer may further include a structural unit represented by the following Chemical Formula 5 or a structural unit represented by the following Chemical Formula 6:

[0092] [Chemical formula 5] [ka]

[0093] [Chemical formula 6] [ka]

[0094] In Chemical Formula 5 and Chemical Formula 6, L 9 ~L 11 each independently represents 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, a substituted or unsubstituted alkynylene group having 2 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, or a combination thereof; X 8 ~X 11 each independently represents a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, 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 ~Y 7 each independently represents 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 cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; R 4 and R 5 are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.

[0095] In one embodiment, L in Formula 5 9 and L 10are 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 substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, but are not limited to these.

[0096] X in Chemical Formula 5 8 and X 9 are each independently a single bond, —O—, —C(═O)—, —(CO)O—, —O(CO)O—, or a combination thereof, for example, but not limited to, a single bond, —O—, —C(═O)—, —(CO)O—, or a combination thereof, for example, a single bond.

[0097] Y in Chemical Formula 5 5 and Y 6 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, or a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, for example, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms, for example, a hydroxy group, or a substituted or unsubstituted alkenyl group having 2 to 5 carbon atoms, but are not limited to these.

[0098] In one embodiment, L in Formula 6 11 represents 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 substituted or unsubstituted arylene group having 6 to 14 carbon atoms, for example, a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 10 carbon atoms, for example, a single bond, a substituted or unsubstituted alkylene group having 1 to 5 carbon atoms, or a substituted or unsubstituted phenylene group, but is not limited to these.

[0099] X in Chemical Formula 6 10 and X11 are each independently a single bond, —O—, —C(═O)—, —(CO)O—, —O(CO)O—, or a combination thereof, for example, but not limited to, a single bond or —(CO)O—.

[0100] Y in Chemical Formula 6 7 is 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 heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, for example, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 10 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 10 carbon atoms, for example, a hydroxy group, an epoxy group, or a substituted or unsubstituted phenyl group, but is not limited to these.

[0101] In one embodiment, the polymer includes at least one structural unit represented by the following Chemical Formula 1-1, the following Chemical Formula 2-1, and the following Chemical Formulas 3-1 to 3-8.

[0102] [Chemical formula 1-1] [ka]

[0103] [Chemical formula 2-1] [ka]

[0104] [Chemical formula 3-1] [ka]

[0105] [Chemical formula 3-2] [ka]

[0106] [Chemical Formula 3-3]

change

[0107] [Chemical Formula 3-4]

change

[0108] [Chemical Formula 3-5]

change

[0109] [Chemical Formula 3-6]

change

[0110] [Chemical Formula 3-7]

change

[0111] [Chemical Formula 3-8]

change

[0112] 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 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.

[0113] 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 0.1 wt % to 40 wt %, for example, 0.1 wt % to 30 wt %, for example, 0.1 wt % to 20 wt %, for example, 0.2 wt % to 20 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 level of planarization of the resist underlayer film can be adjusted.

[0114] The resist underlayer film composition according to one embodiment may contain a solvent. The solvent is not particularly limited as long as it has sufficient solubility and / or dispersibility for the polymer and the compound. Examples of the solvent include, but are not limited to, 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, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, and combinations thereof.

[0115] In addition to the polymer and solvent, the composition for a resist underlayer film according to an embodiment may further include 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.

[0116] The resist underlayer film composition according to still another embodiment may further include additives including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

[0117] The surfactant can be used to improve coating defects caused by an increase in solid content during the formation of the resist underlayer film, and examples of the surfactant include, but are not limited to, alkylbenzene sulfonate, alkylpyridinium salt, polyethylene glycol, and quaternary ammonium salt.

[0118] 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.

[0119] 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.

[0120] 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 the above 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.

[0121] According to yet another embodiment, there is provided a resist underlayer film prepared using the above-described resist underlayer film composition. The resist underlayer film may be in a form obtained by, for example, applying the resist underlayer film composition onto a substrate and then curing the composition through a heat treatment process.

[0122] A method for forming a pattern using a composition for a resist underlayer film will be described below with reference to Fig. 1. Fig. 1 is a cross-sectional view illustrating the method for forming a pattern using a composition for a resist underlayer film according to the present invention.

[0123] 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 substrate 100. In the following description, the etching target 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.

[0124] Next, a resist underlayer film composition is applied onto the surface of the washed thin film 102 by spin coating.

[0125] Thereafter, drying and baking steps are performed to form a resist underlayer film 104 on the thin film 102. The baking process is performed at 100°C to 500°C, and can be performed at, for example, 100°C to 300°C. A more specific description of the composition for a resist underlayer film has been given above, and will be omitted here to avoid duplication.

[0126] Referring to FIG. 1(b), a photoresist is applied onto the resist underlayer film 104 to form a photoresist film 106.

[0127] 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.

[0128] 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.

[0129] 1(c), the photoresist film 106 is selectively exposed to light. To explain 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 device, and the exposure mask 110 is aligned on the photoresist film 106. Next, by irradiating the exposure mask 110 with light, predetermined portions of the photoresist film 106 formed on the substrate 100 selectively react with the light transmitted through the exposure mask 110.

[0130] Examples of light that can be used in the exposure process include short wavelength light such as i-line with a wavelength of 365 nm, KrF excimer laser with a wavelength of 248 nm, and ArF excimer laser with a wavelength of 193 nm, as well as extreme ultraviolet (EUV) with a wavelength of 13.5 nm.

[0131] The exposed portion of the photoresist film 106a (hereinafter referred to as "exposed region 106a") is relatively hydrophilic compared to the unexposed portion of the photoresist film 106b (hereinafter referred to as "unexposed region 106b"). Therefore, the exposed region 106a and the unexposed region 106b have different solubilities.

[0132] 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 exposed region 106a becomes more soluble in a specific solvent.

[0133] Referring to FIG. 1(d), specifically, the exposed regions 106a are dissolved and then removed using tetramethyl ammonium hydroxide (TMAH) or the like, and the remaining unexposed regions 106b form a photoresist pattern 108 after development.

[0134] 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 smooth etching to be performed in a short time.

[0135] 1(f), the exposed thin film 102 is etched using the photoresist pattern 108 as an etching mask. As a result, the thin film 102 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-line (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.

[0136] 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 resist underlayer film composition containing the same, but the following examples are not intended to limit the present invention. [Example]

[0137] <Polymer synthesis> <Synthesis Example 1> A 500 ml three-necked flask was charged with 7.5 g of 2-acetoacetoxyethyl methacrylate (TCI), 4.9 g of glycidyl methacrylate (TCI), 4.8 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI), and propylene glycol methyl ether acetate. A reaction solution was prepared by adding 64 g of methylcellulose acetate (PGMEA) and connecting a capacitor. The reaction solution was heated to 90°C for 1 hour and then cooled to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 3-1 and 6-2 was obtained (Mw: 4,000 g / mol).

[0138] [Chemical formula 3-1] [ka]

[0139] [Chemical formula 6-2] [ka]

[0140] <Synthesis Example 2> A 100 ml two-necked flask was charged with 1.46 g of glycidyl methacrylate, 1.81 g of 4-vinylphenyl acetate (TCI), 2.43 g of benzoic acid, 2-hydroxy-, 2-[(1-oxo-2-propenyl)oxy]ethyl ester (Angene), 1.06 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI), and 22 g of PGMEA to prepare a reaction solution, which was then connected to a condenser. The reaction solution was heated at 90 °C for 3 hours and then cooled to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g of toluene while stirring to form a gum, which was then dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 3-2, 6-2, and 6-3 was obtained (Mw: 5,000 g / mol).

[0141] [Chemical formula 3-2] [ka]

[0142] [Chemical formula 6-2] [ka]

[0143] [Chemical formula 6-3] [ka]

[0144] <Synthesis Example 3> Add 2-hydroxyethyl methacrylate to a 500 ml three-necked round flask. A reaction solution was prepared by adding 5.86 g of 1-[2-[(1-oxo-2-propen-1-yl)oxo]ethyl]propanedioate (manufactured by Hong Kong Chem Co., Ltd.)), 9.1 g of dimethyl 2,2'-azobis(2-methylpropionate), 3.1 g of dimethyl 2,2'-azobis(2-methylpropionate), and 35 g of PGMEA, and a condenser was connected. The reaction solution was heated at 90°C for 2.5 hours and then cooled to room temperature. The reaction solution was then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following chemical formulas 3-3 and 6-4 was obtained (Mw: 6,500 g / mol).

[0145] [Chemical formula 3-3] [ka]

[0146] [Chemical formula 6-4] [ka]

[0147] <Synthesis Example 4> A reaction solution was prepared by adding 6.49 g of 2-hydroxy-5-(2-propen-1-yl)-2,4,6-cycloheptatrien-1-one (Aurora)), 4.9 g of glycidyl methacrylate, 4.8 g of dimethyl 2,2'-azobis(2-methylpropionate), and 64 g of PGMEA to a 200 ml two-necked round flask and connecting a condenser. The reaction solution was heated at 80°C for 2 hours, then added dropwise to a beaker containing 450 g of heptane with stirring to form a gum, which was then dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 3-4 and 6-2 was obtained (MW: 5,000 g / mol).

[0148] [Chemical formula 3-4] [ka]

[0149] [Chemical formula 6-2] [ka]

[0150] <Synthesis Example 5> A reaction solution was prepared by adding 21.3 g of glycidyl methacrylate, 5.1 g of dimethyl 2,2'-azobis(2-methylpropionate), and 50 g of PGMEA to a 250 ml two-necked flask and connecting a condenser. The reaction solution was heated at 90°C for 1 hour and then added dropwise to a beaker containing 450 g of heptane with stirring to form a gum, which was then dissolved in 100 g of PGMEA to obtain a polymer consisting of the structural unit represented by the following chemical formula 6-2.

[0151] A reaction solution was prepared by adding 5.4 g of the above polymer, 0.7 g of isatin (TCI), 0.04 g of pyridine, 0.011 g of butylated hydroxytoluene (BHT), and 7.55 g of DMF to a 100 ml two-necked round flask, and then connecting a capacitor. The reaction solution was heated at 100°C for 1 hour, then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 100 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 6-2 and 3-5 was obtained (Mw: 8,000 g / mol).

[0152] [Chemical formula 6-2] [ka]

[0153] [Chemical formula 3-5] [ka]

[0154] <Synthesis Example 6> A reaction solution was prepared by adding 21.3 g of glycidyl methacrylate, 5.1 g of dimethyl 2,2'-azobis(2-methylpropionate), and 50 g of PGMEA to a 250 ml two-necked flask and connecting a condenser. The reaction solution was heated at 90°C for 1 hour and then added dropwise to a beaker containing 450 g of heptane with stirring to form a gum, which was then dissolved in 100 g of PGMEA to obtain a polymer consisting of the structural unit represented by the following chemical formula 6-2.

[0155] A reaction solution was prepared by adding 5.4 g of the above polymer, 0.62 g of 1H-indole-2,3-diol (Aurora), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF to a 100 ml two-necked flask, and then connecting a condenser. The reaction solution was heated at 100°C for 1 hour, then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 100 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 6-2 and 3-6 was obtained (Mw: 8,000 g / mol).

[0156] [Chemical formula 6-2] [ka]

[0157] [Chemical formula 3-6] [ka]

[0158] <Synthesis Example 7> A reaction solution was prepared by adding 21.3 g of glycidyl methacrylate, 5.1 g of dimethyl 2,2'-azobis(2-methylpropionate), and 50 g of PGMEA to a 250 ml two-necked flask and connecting a condenser. The reaction solution was heated at 90°C for 1 hour and then added dropwise to a beaker containing 450 g of heptane with stirring to form a gum, which was then dissolved in 100 g of PGMEA to obtain a polymer consisting of the structural unit represented by the following chemical formula 6-2.

[0159] A reaction solution was prepared by adding 5.4 g of the above polymer, 0.68 g of 3-hydroxy-4(1H)-quinolinone (Aurora), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF to a 100 ml two-necked round flask, and then connecting a condenser. The reaction solution was heated at 100°C for 1 hour, then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 100 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 6-2 and 3-7 was obtained (MW: 8,000 g / mol).

[0160] [Chemical formula 6-2] [ka]

[0161] [Chemical formula 3-7] [ka]

[0162] <Synthesis Example 8> A reaction solution was prepared by adding 21.3 g of glycidyl methacrylate, 5.1 g of dimethyl 2,2'-azobis(2-methylpropionate), and 50 g of PGMEA to a 250 ml two-necked flask and connecting a condenser. The reaction solution was heated at 90°C for 1 hour and then added dropwise to a beaker containing 450 g of heptane with stirring to form a gum, which was then dissolved in 100 g of PGMEA to obtain a polymer consisting of the structural unit represented by the following chemical formula 6-2.

[0163] A reaction solution was prepared by adding 5.4 g of the above polymer, 0.7 g of 1,2-dihydro-2-hydroxy-3H-indol-3-one (ACCEL), 0.04 g of pyridine, 0.011 g of BHT, and 7.55 g of DMF to a 100 ml two-necked round flask, and then connecting a condenser. The reaction solution was heated at 100°C for 1 hour, then added dropwise to a beaker containing 450 g of heptane while stirring to form a gum, which was then dissolved in 100 g of PGMEA. Finally, a polymer consisting of structural units represented by the following formulas 6-2 and 3-8 was obtained (Mw: 8,000 g / mol).

[0164] [Chemical formula 6-2] [ka]

[0165] [Chemical formula 3-8] [ka]

[0166] <Comparative Synthesis Example 1> A reaction solution was prepared by adding 2.8 g of glycidyl methacrylate, 2.1 g of methyl 2,2'-azobis(2-methylpropionate), and 7 g of PGMEA to a 500 ml three-necked flask and connecting a capacitor. The reaction solution was heated to 85°C for 2 hours and then cooled to room temperature. The reaction solution was then stirred and added dropwise to a beaker containing 450 g of heptane to form a gum, which was then dissolved in 90 g of PGMEA. Finally, a polymer consisting of the structural unit represented by the following chemical formula 6-2 was obtained (Mw: 3,000 g / mol).

[0167] [Chemical formula 6-2] [ka]

[0168] <Production of Resist Underlayer Film Composition> <Examples 1 to 8 and Comparative Example 1> 1.2 g of each of the polymers obtained in Synthesis Examples 1 to 8 and Comparative Synthesis Example 1, 0.4 g of PL1174 (crosslinking agent), and 0.04 g of ammonium triflate (AOTf) were mixed and completely dissolved in 15 g of propylene glycol monomethyl ether, and the mixture was diluted with an additional solvent to prepare resist underlayer film compositions of Examples 1 to 8 and Comparative Example 1, each containing 0.45 wt % of the polymer based on the total weight.

[0169] <Evaluation 1: Exposure characteristics evaluation> The compositions prepared in Examples 1 to 8 and Comparative Example 1 were each applied by spin 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 applied on the underlayer film by spin coating and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The photoresist layer was then exposed to light at 200 μC / cm using an e-beam exposure device (Elionix). 2 ~2000μC / cm 2 After exposure to a range of 1000 nm, the photoresist layer was heat-treated at 150°C for 60 seconds. The photoresist layer was then developed with a 2.38 wt% aqueous solution of TMAH and rinsed in pure water for 15 seconds to form a 50 nm line and space (L / S) photoresist pattern. The optimal exposure dose for the photoresist pattern was then evaluated.

[0170] <Evaluation 2: Line width roughness (LWR) evaluation> The compositions prepared in Examples 1 to 8 and Comparative Example 1 were each spin-coated 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 spin-coated onto the underlayer film and heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The resist layer was exposed to light using an e-beam exposure system (Elionix, accelerating voltage 100 keV) with a line width of 30 nm and a space width between lines of 30 nm. The resist was then heat-treated at 95°C for 60 seconds, developed in a 2.38 wt% TMAH aqueous solution for 60 seconds, and rinsed with pure water for 15 seconds to form a resist pattern.

[0171] Pattern collapse was evaluated by observing the formed patterns with a scanning electron microscope (SEM) (S-9260 (manufactured by Hitachi)). In Table 1 below, cases where pattern collapse was observed were indicated by "O" and cases where it was not observed were indicated by "X".

[0172] Line width roughness (LWR) was measured by observing a pattern formed with a width of 30 nm using an SEM and measuring the distance from the reference line where the edge was located within a 2 μm range from the edge in the longitudinal direction of the pattern. The results are shown in Table 1 below, and the smaller the value of LWR, the better.

[0173] The evaluation values ​​of the exposure dose and LWR measured as described above for the Examples and Comparative Examples were converted into ratios based on the exposure dose or LWR value of Comparative Example 1 using the following formula, and the results are shown in Table 1. The smaller the exposure dose and LWR values, the better the pattern formability and sensitivity.

[0174] *Exposure (or LWR) (%) = (Exposure (or LWR) in each Example - Exposure (or LWR) in Comparative Example 1) / Exposure (or LWR) in Comparative Example 1 x 100

[0175] [Table 1]

[0176] Referring to Table 1, it can be seen that the resist underlayer films of Examples 1 to 8 are superior in fine pattern (50 nm L / S) formability and sensitivity compared to Comparative Example 1. Furthermore, it can be seen that the resist underlayer films of Examples 1 to 8 have smaller LWR values ​​compared to Comparative Example 1, resulting in more uniform patterns.

[0177] 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 or variations should not be understood separately from the technical spirit and perspective of the present invention, and the modified embodiments belong to the scope of the claims of the present invention. [Explanation of symbols]

[0178] 100: Substrate 102: Thin film 104: Resist underlayer film 106: Photoresist film 106a: exposure area 106b: Non-exposed area 108: Photoresist pattern 110: Exposure mask 112: Organic film pattern 114: Thin film pattern

Claims

1. A composition for a resist underlayer film, comprising: a polymer containing 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; and a solvent. [Chemical formula 1] 【Chemistry 1】 [Chemical formula 2] 【Chemistry 2】 [Chemical formula 3] 【Transformation 3】 (In the above 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 alkenylene group having 2 to 10 carbon atoms, a substituted or unsubstituted alkynylene group having 2 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, 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-, -C(=O)NH-, -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 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 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, a group represented by the following chemical formula 4, or a combination thereof; Y １ and Y ２ At least one of the groups is a group represented by the following chemical formula 4: Y ３ and Y ４ are each independently a group represented by the following chemical formula 4: R １ ~R ３ are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.) [Chemical formula 4] 【Chemistry 4】 (In the above chemical formula 4, M １ represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, —O—, —NH—, or a combination thereof, Z １ and Z ２ are each independently —C(═O)— or —C(OH)—, M ２ is a single bond, a double bond, *-C(R ｃ ) = * (where R ｃ is hydrogen, deuterium, or an alkyl group having 1 to 5 carbon atoms, and * is the same as Z １ or Z ２ ) or a substituted or unsubstituted alkylene group having 1 to 3 carbon atoms, M ３ is a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, M １ and M ３ or M ２ and M ３ are optionally linked to each other to form a ring, * indicates a connection point.)

2. 2. 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 Chemical Formulas A-1 to A-5 below. [Chemical formula A-1] 【Transformation 5】 [Chemical formula A-2] 【Transformation 6】 [Chemical formula A-3] 【Transformation 7】 [Chemical formula A-4] 【Transformation 8】 [Chemical formula A-5] 【Chemistry 9】 (In the chemical formula A-3 and the chemical formula A-4, R ｘ and R ｙ are each independently a hydrogen atom, 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 1 to 10 carbon atoms, a substituted or unsubstituted heteroalkynyl group having 1 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, a substituted or unsubstituted heteroaryl group having 1 to 20 carbon atoms, or a combination thereof; * indicates a connection point.)

3. A in the above formula 1 is the following formula A-1, and L １ and L ２ are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; １ and X ２ The resist underlayer film composition according to claim 1 , wherein each independently represents a single bond. [Chemical formula A-1] 【Chemistry 10】

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 are each independently a single bond or —(CO)O—, and R １ ~R ３ 2. The resist underlayer film composition according to claim 1, wherein each independently represents hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms.

5. The composition for a resist underlayer film according to claim 1 , wherein the polymer further comprises a structural unit represented by the following chemical formula 5 or a structural unit represented by the following chemical formula 6: [Chemical formula 5] 【Chemistry 11】 [Chemical formula 6] 【Chemistry 12】 (In the chemical formula 5 and the chemical formula 6, L ９ ~L １１ each independently represents 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, a substituted or unsubstituted alkynylene group having 2 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, or a combination thereof; X ８ ~X １１ are each independently a single bond, —O—, —S—, —S(═O)—, or —S(═O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR ｂ - (where R ｂ is hydrogen, deuterium, or an alkyl group having 1 to 10 carbon atoms; or a combination thereof; Y ５ ~Y ７ each independently represents 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 cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms; R ４ and R ５ are each independently hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; * indicates a connection point.)

6. L in Chemical Formula 5 ９ and L １０ are each independently a single bond or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms; ８ and X ９ are each independently a single bond, and Y ５ and Y ６ are each independently a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted alkenyl group having 2 to 10 carbon atoms.

7. L in Formula 6 １１ represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 10 carbon atoms; X １０ and X １１ are each independently a single bond or —(CO)O—, and Y ７ is a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted heterocycloalkyl group having 2 to 20 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

8. The composition for a resist underlayer film according to claim 1, wherein the polymer comprises at least one structural unit represented by the following Chemical Formula 1-1, the following Chemical Formula 2-1, and the following Chemical Formulas 3-1 to 3-8: [Chemical formula 1-1] 【Chemistry 13】 [Chemical formula 2-1] 【Chemistry 14】 [Chemical formula 3-1] 【Chemistry 15】 [Chemical formula 3-2] 【Chemistry 16】 [Chemical formula 3-3] 【Chemistry 17】 [Chemical formula 3-4] [Chemistry 18] [Chemical formula 3-5] 【Chemistry 19】 [Chemical formula 3-6] 【Chemistry 20】 [Chemical formula 3-7] 【Chemistry 21】 [Chemical formula 3-8] 【Chemistry 22】

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 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.

12. 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.

13. forming a film to be etched on a substrate; A step of forming a resist underlayer film by applying the composition for a resist underlayer film according to any one of claims 1 to 12 onto the film to be etched; forming a photoresist pattern on the resist underlayer film; sequentially etching the resist underlayer film and the etching target film using the photoresist pattern as an etching mask.

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