Resist underlayer composition and method of forming patterns using the same

Abstract

To provide a composition for the production of a resist underlayer that does not cause resist pattern collapse even in a fine patterning process and has improved sensitivity to an exposure light source, thereby improving patterning performance and energy efficiency.SOLUTION: A composition for a resist underlayer film comprises: a polymer containing a structural unit represented by the following chemical formula, a specific structural unit, or a combination thereof; a radical initiator having a bond dissociation energy of 0 to 60 kcal / mol; and a solvent.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 several hundred nanometers to ultrafine technologies with patterns of several to tens of nanometers. Effective lithographic methods are essential to realize such ultrafine technologies.

[0003] Lithographic techniques are a processing method in which a thin film is formed by coating a photoresist film on a semiconductor substrate such as a silicon wafer, and then the thin film is 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 on the substrate surface that corresponds to the pattern.

[0004] As semiconductor patterns become increasingly finer, the thickness of the photoresist layer is required to be thin, and therefore the thickness of the resist underlayer film is also required to be thin. The resist underlayer film must not collapse the photoresist pattern even at a thin thickness, and must have good adhesion to the photoresist and be formed to a uniform thickness. In addition, the resist underlayer film is required to have improved sensitivity, such as a high refractive index and a low absorption coefficient, for the light source used in photolithography. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2023-0020811 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a composition for producing a resist underlayer film, which 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] An object of the present invention is to provide 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 a structural unit represented by the following chemical formula 1, a structural unit represented by the following chemical formula 2, or a combination thereof, a radical initiator having a bond dissociation energy (BDE) of 0 to 60 kcal / mol, and a solvent.

[0009] [ka] ...chemical formula 1

[0010] [ka] ...Chemical formula 2

[0011] In the above Chemical Formula 1 and Chemical Formula 2, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 6 are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted C2-C20 heterocycloalkylene group, a substituted or unsubstituted C6-C20 arylene group, a substituted or unsubstituted C3-C20 heteroarylene group, or a combination thereof; X1 ~X 5 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 a C1-C10 alkyl group), or a combination thereof; Y 1 ~Y 3 are each independently a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C10 alkynyl group, a substituted or unsubstituted C1-C10 heteroalkyl group, a substituted or unsubstituted C2-C10 heteroalkenyl group, a substituted or unsubstituted C2-C10 heteroalkynyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C3-C20 heteroaryl group, or a combination thereof; * is the attachment point.

[0012] The A is represented by one or more of the following chemical formulae A-1 to A-4.

[0013] [ka] ...Chemical formula A-1

[0014] [ka] ...Chemical formula A-2

[0015] [ka] ...Chemical formula A-3

[0016] [ka] ...Chemical formula A-4

[0017] In the above Chemical Formulae A-1 to A-4, R x is hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, or a substituted or unsubstituted C2 to C10 alkynyl group, and * is the point of attachment.

[0018] Said L 1 ~L 6 are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof; X 1 ~X 5 each independently represents a single bond, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof; Y 1 ~Y 3 are each independently a hydroxy group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C10 heteroalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

[0019] The radical initiator is represented by any one of the following Chemical Formulas 3-1 to 3-4.

[0020] [ka] ...Chemical formula 3-1

[0021] [ka] ...Chemical formula 3-2

[0022] [ka] ...Chemical formula 3-3

[0023] [ka] ...Chemical formula 3-4

[0024] In the above Chemical Formula 3-1 to Chemical Formula 3-4, R 1 ~R 5 are each independently a hydroxy group, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof; R 6 ~R 9 are each independently hydrogen, deuterium, a hydroxyl group, a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof; R a and R b are each independently a deuterium atom, a hydroxyl group, or -SCH 3 , a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof; Each of na and nb is independently an integer of 0 to 5.

[0025] The radical initiator is represented by any one or more of the following Chemical Formula 4 to Chemical Formula 10.

[0026] [ka] ...chemical formula 4

[0027] [ka] ...chemical formula 5

[0028] [ka] ...chemical formula 6

[0029] [ka] ...chemical formula 7

[0030] [ka] ...chemical formula 8

[0031] [ka] ...chemical formula 9

[0032] [ka] ...chemical formula 10

[0033] The chemical formula 1 is represented by the following chemical formula 1-1 or 1-2, and the chemical formula 2 is represented by any one of the following chemical formulas 2-1 to 2-3.

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

[0035] [ka] ...Chemical formula 1-2

[0036] [ka] ...Chemical formula 2-1

[0037] [ka] ...Chemical formula 2-2

[0038] [ka] ...Chemical formula 2-3

[0039] The weight average molecular weight of the polymer is 1,000 g / mol to 300,000 g / mol.

[0040] 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 resist underlayer film.

[0041] The radical initiator is contained in an amount of 0.01% by weight to 30% by weight based on the total weight of the composition for resist underlayer film.

[0042] The resist underlayer film composition may further include one or more polymers selected from an acrylic resin, an epoxy resin, a novolac resin, a glucuryl resin, and a melamine resin.

[0043] The resist underlayer film composition may further include an additive such as a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0044] According to another embodiment, there is provided a method for forming a pattern, the method including: 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 gradually etching the resist underlayer film and the film to be etched using the photoresist pattern as an etching mask. Effect of the Invention

[0045] The composition for a resist underlayer film according to one embodiment can provide a resist underlayer film having improved adhesion to a resist even in a fine patterning process, preventing pattern collapse, and having improved sensitivity to an exposure light source, thereby improving patterning performance and energy efficiency. [Brief description of the drawings]

[0046] [Figure 1] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. [Diagram 2] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. [Diagram 3] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. [Figure 4] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. [Diagram 5] FIG. 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to one embodiment. [Figure 6] FIG. 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 PREFERRED EMBODIMENTS

[0047] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to exemplary embodiments thereof, so that those skilled in the art can easily practice the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

[0048] In the drawings, the thickness of the various layers and regions is exaggerated for clarity, and similar parts are designated by the same reference numerals throughout the specification. When a part, such as a layer, film, region, plate, etc. is described as being "on" another part, this includes not only when it is "directly on" the other part, but also when there is another part between them. Conversely, when a part is described as being "directly on" another part, it means that there is no other part between them.

[0049] Hereinafter, unless otherwise defined in the present specification, "substituted" means that a hydrogen atom in a compound is substituted with a substituent selected from deuterium, a halogen atom (F, Br, Cl, or I), a hydroxy group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid or a salt thereof, a C1-C30 alkyl group, a C2-C30 alkenyl group, a C2-C30 alkynyl group, a C6-C30 aryl group, a C7-C30 arylalkyl group, a C1-C30 alkoxy group, a C1-C20 heteroalkyl group, a C3-C20 heteroarylalkyl group, a C3-C30 cycloalkyl group, a C3-C15 cycloalkenyl group, a C6-C15 cycloalkynyl group, a C2-C30 heterocyclic group, and combinations thereof.

[0050] Furthermore, two adjacent substituents among the substituted halogen atoms (F, Br, Cl, or I), hydroxy groups, nitro groups, cyano groups, amino groups, azido groups, amidino groups, hydrazino groups, hydrazono groups, carbonyl groups, carbamyl groups, thiol groups, ester groups, carboxyl groups or salts thereof, sulfonic acid groups or salts thereof, phosphoric acid or salts thereof, C1-C30 alkyl groups, C2-C30 alkenyl groups, C2-C30 alkynyl groups, C6-C30 aryl groups, C7-C30 arylalkyl groups, C1-C30 alkoxy groups, C1-C20 heteroalkyl groups, C3-C20 heteroarylalkyl groups, C3-C30 cycloalkyl groups, C3-C15 cycloalkenyl groups, C6-C15 cycloalkynyl groups, or C2-C30 heterocyclic groups may be bonded to form a ring.

[0051] As used herein, the term "aryl group" refers to a group having one or more aromatic hydrocarbon moieties, and broadly includes both aromatic hydrocarbon moieties bonded by single bonds and non-aromatic fused rings to which aromatic hydrocarbon moieties are directly or indirectly fused. Aryl groups include monocyclic, polycyclic, or fused polycyclic (i.e., rings sharing adjacent pairs of carbon atoms) functional groups.

[0052] More specifically, the substituted or unsubstituted aryl group may be, but is not limited to, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted phenanthryl group, a substituted or unsubstituted naphthacenyl group, a substituted or unsubstituted pyrenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted quaterphenyl group, a substituted or unsubstituted chrysenyl group, a substituted or unsubstituted triphenylenyl group, a substituted or unsubstituted perylenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted indenyl group, a combination thereof, or a condensed form of a combination thereof.

[0053] Unless otherwise defined in this specification, "hetero" means containing 1 to 3 heteroatoms selected from N, O, S, Se and P.

[0054] As used herein, a "heteroalkyl group" refers to a group that contains a heteroatom selected from the group consisting of N, O, S, P and Si in place of one or more of the carbon atoms that form the alkyl group.

[0055] As used herein, a "heterocyclic group" refers to an aryl group containing at least one heteroatom selected from the group consisting of N, O, S, P, and Si. Two or more heterocyclic groups may be directly bonded to each other via a sigma bond, or, if the heterocyclic group contains two or more rings, the two or more rings may be fused to each other. If the heterocyclic group is a fused ring, each ring may contain one or more of the heteroatoms.

[0056] More specifically, the substituted or unsubstituted heteroaryl group is 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 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 phenyl ...

[0043] The aryl group may be, but is not limited to, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted naphthyrinidyl group, a substituted or unsubstituted benzoxazinyl group, a substituted or unsubstituted benzthiazinyl group, a substituted or unsubstituted acridinyl group, a substituted or unsubstituted phenazinyl group, a substituted or unsubstituted phenothiazinyl group, a substituted or unsubstituted phenoxazinyl 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 condensed form of a combination thereof.

[0057] In this specification, unless otherwise specified, "combination" means blending or copolymerization.

[0058] In addition, in this specification, the term "polymer" can include both an oligomer and a polymer.

[0059] Unless otherwise specified in this specification, the "weight average molecular weight" is measured by dissolving a powder sample in tetrahydrofuran (THF) and then using Agilent Technologies' 1200 series gel permeation chromatography (GPC) (using a Shodex LF-804 column and Shodex polystyrene as the standard sample).

[0060] Also, unless otherwise defined herein, "*" refers to a structural unit of a compound or a point of attachment of a moiety of a compound.

[0061] In the semiconductor industry, there is a constant demand to reduce the size of chips. To meet this trend, the line width of the resist patterned in lithography technology must be reduced to a few tens of nanometers, and the pattern thus formed is used to transfer the pattern to the underlying material by etching the lower substrate. However, as the resist pattern size becomes smaller, the aspect ratio of the resist that can withstand the line width is limited, and as a result, the resist may not have sufficient resistance in the etching step. Therefore, a resist underlayer film has been used to compensate for this when a thin resist material is used, when the substrate to be etched is thick, or when a deep pattern is required.

[0062] The resist underlayer film is required to be thinner as the resist becomes thinner, and the photoresist pattern must not collapse even when the resist underlayer film is thin. For this reason, the resist underlayer film must have excellent adhesion to the photoresist. In addition, when forming a thin resist underlayer film, the coating uniformity of the resist underlayer film composition and the flatness of the resist underlayer film produced therefrom must be improved, and the sensitivity to the exposure light source must be improved to improve pattern formability and energy efficiency.

[0063] The composition for an underlayer film according to one embodiment includes a polymer including a structural unit represented by the following Chemical Formula 1, a structural unit represented by the following Chemical Formula 2, or a combination thereof, a radical initiator having a bond dissociation energy of 0 to 60 kcal / mol, and a solvent.

[0064] [ka] ...chemical formula 1

[0065] [ka] ...Chemical formula 2

[0066] In the above Chemical Formula 1 and Chemical Formula 2, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 6 each independently represents a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted C2-C20 heterocycloalkylene group, a substituted or unsubstituted C6-C20 arylene group, a substituted or unsubstituted C1-C20 heteroarylene group, or a combination thereof; X 1 ~X 5 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 a C1-C10 alkyl group), or a combination thereof; Y 1 ~Y 3are each independently a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C10 alkynyl group, a substituted or unsubstituted C1-C10 heteroalkyl group, a substituted or unsubstituted C1-C10 heteroalkenyl group, a substituted or unsubstituted C1-C10 heteroalkynyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C3-C20 heteroaryl group, or a combination thereof; * is the attachment point.

[0067] In addition, since the polymer contained in the underlayer film composition according to one embodiment contains a heterocycle containing a nitrogen atom in the ring, the polymer containing these structural units has sp 2 -sp 2 The polymer can be bonded to the resist underlayer film composition according to an embodiment of the present invention. As a result, the polymer can have a high electron density. By including a polymer having a high electron density, the underlayer film composition according to an embodiment of the present invention can realize a film having a dense structure in the form of an ultrathin film. In addition, the high electron density of the polymer can have an effect of improving the light absorption efficiency during exposure of the resist underlayer film composition. Furthermore, the polymer including the heterocyclic skeleton has excellent etching selectivity, and can improve the 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).

[0068] The composition for an underlayer film according to an embodiment includes a radical initiator having a bond dissociation energy in a specific range as described above, and thus can improve adhesion between the photoresist and the resist underlayer film by covalently bonding with radicals generated from the photoresist during exposure. In addition, the composition for an underlayer film according to an embodiment can improve the sensitivity of the resist and improve the pattern formability of fine patterns by quickly removing unnecessary radicals from the photoresist as described above.

[0069] A in the structural unit forming the polymer is represented by one or more of the following chemical formulae A-1 to A-4.

[0070] [ka] ...Chemical formula A-1

[0071] [ka] ...Chemical formula A-2

[0072] [ka] ...Chemical formula A-3

[0073] [ka] ...Chemical formula A-4

[0074] In the above Chemical Formulae A-1 to A-4, R x is hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, or a substituted or unsubstituted C2 to C10 alkynyl group, for example, hydrogen or a substituted or unsubstituted C1 to C5 alkyl group, and * is the point of attachment.

[0075] L of the above Chemical Formula 1 and Chemical Formula 2 1 ~L 6 are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, or a combination thereof, for example, but not limited to, a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C1-C5 heteroalkylene group, or a combination thereof.

[0076] X in the above Chemical Formula 1 and Chemical Formula 2 1 ~X 5 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, -C(=O)O-, -OC(=O)-, or -S-.

[0077] Y in the above Chemical Formula 1 and Chemical Formula 2 1 ~Y 3 are each independently a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C1-C10 heteroalkyl group, a substituted or unsubstituted C2-C10 heteroalkenyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof, for example, a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a combination thereof, for example, a hydroxy group, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, or a combination thereof, but are not limited to these.

[0078] As an example, the formula 1 is represented by the following formula 1-1 or 1-2, and the formula 2 is represented by any one of the following formulas 2-1 to 2-3.

[0079] [ka] ...Chemical formula 1-1

[0080] [ka] ...Chemical formula 1-2

[0081] [ka] ...Chemical formula 2-1

[0082] [ka] ...Chemical formula 2-2

[0083] [ka] ...Chemical formula 2-3

[0084] In the above Chemical Formula 1-1, Chemical Formula 1-2, and Chemical Formula 2-1 to Chemical Formula 2-3, * represents a bonding point.

[0085] The bond dissociation energy of the radical initiator contained in the composition is 0 to 60 kcal / mol, for example, 0 to 55 kcal / mol, for example, 0 to 50 kcal / mol, for example, 0 to 45 kcal / mol, for example, 0 to 40 kcal / mol, but is not limited thereto. When the bond dissociation energy of the radical initiator is within the above range, the bond in the radical initiator can be decomposed to form a radical when exposed to short wavelength light such as an activation irradiation line i-line having a wavelength of 365 nm, a KrF excimer laser having a wavelength of 248 nm, an ArF excimer laser having a wavelength of 193 nm, and an EUV (Extreme ultraviolet) having a wavelength of 13.5 nm. The radical thus formed is covalently bonded to the radical in the photoresist, thereby improving the adhesion between the photoresist and the resist underlayer film.

[0086] The radical initiator is not limited to a specific compound, and any radical initiator known in the art can be used as long as it can be decomposed by light having energy equivalent to the bond dissociation energy to form a radical.

[0087] Bond dissociation energy (BDE) is the energy required for one chemical bond to break in equilibrium, and refers to the energy required for the equilibrium breakage of the most fragile bond in a compound. In this specification, bond dissociation energy is calculated using Jaguar software ([DFT(b3lyp-d3)6-31g++**Jaguar software]) using a function that adds a dispersion term to a B3LYP hybrid that includes an effective core potential, and a 6-31g++** basis set.

[0088] The radical initiator is represented by any one of the following Chemical Formulas 3-1 to 3-4.

[0089] [ka] ...Chemical formula 3-1

[0090] [ka] ...Chemical formula 3-2

[0091] [ka] ...Chemical formula 3-3

[0092] [ka] ...Chemical formula 3-4

[0093] In the above Chemical Formula 3-1 to Chemical Formula 3-4, R 1 ~R 5are each independently a hydroxy group, a substituted or unsubstituted C1-C30 alkyl group, a substituted or unsubstituted C1-C30 alkoxy group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof, for example, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C1-C20 alkoxy group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, or a combination thereof, for example, a C1-C10 alkyl group substituted with a heterocyclic group, a substituted or unsubstituted C1-C10 alkoxy group, a C3-C10 cycloalkyl group substituted with a hydroxy group, a substituted or unsubstituted C6-C10 aryl group, or a combination thereof, but are not limited to these.

[0094] R 6 ~R 9 are each independently hydrogen, deuterium, a hydroxyl group, a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof, for example, hydrogen, or a substituted or unsubstituted C1 to C10 alkyl group, for example, a substituted or unsubstituted C1 to C5 alkyl group, but are not limited to these.

[0095] R a and R b are each independently a deuterium atom, a hydroxyl group, or -SCH 3 , a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof, for example, -SCH 3 , a substituted or unsubstituted C1 to C10 alkyl group, or a combination thereof, for example, -SCH 3 , a substituted or unsubstituted C1 to C5 alkyl group, or a combination thereof, but are not limited to these.

[0096] The na and nb are each independently an integer of 0 to 5, for example, an integer of 0 to 4, for example, an integer of 0 to 3, but are not limited thereto.

[0097] As an example, the radical initiator is represented by any one or more of the following formulas 4 to 10.

[0098] [ka] ...chemical formula 4

[0099] [ka] ...chemical formula 5

[0100] [ka] ...chemical formula 6

[0101] [ka] ...chemical formula 7

[0102] [ka] ...chemical formula 8

[0103] [ka] ...chemical formula 9

[0104] [ka] ...chemical formula 10

[0105] The polymer may have a weight average molecular weight of 1,000g / mol to 300,000g / mol, for example, about 3,000g / mol to 200,000g / mol, for example, 3,000g / mol to 100,000g / mol, for example, 3,000g / mol to 90,000g / mol, for example, 3,000g / mol to 70,000g / mol, for example, 3,000g / mol to 70,000g / mol, for example, 3,000g / mol to 50,000g / mol, for example, 5,000g / mol to 50,000g / mol, for example, 5,000g / mol to 30,000g / mol, but is not limited thereto. By having a weight average molecular weight in the above range, the carbon content and solubility in a solvent of the composition for resist underlayer film containing the polymer can be adjusted and optimized.

[0106] 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 resist underlayer film. More specifically, the polymer is contained in an amount of 10% by weight to 50% by weight, for example, 20% by weight to 50% by weight, for example, 20% by weight to 30% by weight based on the total weight of the composition for resist underlayer film, but is not limited thereto. By containing the polymer in the composition in the above range, the thickness, surface roughness and flatness of the resist underlayer film can be adjusted.

[0107] The radical initiator is included in an amount of 0.01% by weight to 30% by weight based on the total weight of the composition for resist underlayer film. More specifically, the radical initiator is included in an amount of 0.1% by weight to 30.0% by weight based on the total weight of the composition for resist underlayer film, for example, 1.0% by weight to 30.0% by weight, for example, 5.0% by weight to 30.0% by weight, for example, 5.0% by weight to 25.0% by weight, for example, 8.0% by weight to 25.0% by weight, for example, 10.0% by weight to 25.0% by weight, but is not limited thereto. By including the radical initiator in the composition in the above range, the thickness, surface roughness, chemical resistance, and flattening degree of the resist underlayer film can be adjusted.

[0108] 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 according to an embodiment and the radical initiator, and may include, for example, propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, gamma-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, or a combination thereof, but is not limited thereto.

[0109] The composition for a resist underlayer film according to an embodiment may further include, in addition to the polymer, the radical initiator, 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.

[0110] The resist underlayer film composition according to another embodiment may further include additives including a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0111] The surfactant may be used to improve coating defects caused by an increase in solid content during the formation of a resist underlayer film, and examples of the surfactant include, but are not limited to, alkylbenzenesulfonate, alkylpyridinium salt, polyethylene glycol, and quaternary ammonium salt.

[0112] The thermal acid generator may be, for example, an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid, or / and an organic sulfonic acid alkyl ester such as benzoin tosylate, 2-nitrobenzyl tosylate, or the like, but is not limited thereto.

[0113] 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, adipic esters, phosphates, trimellitates, and citrates, polyether-based, polyester-based, and polyacetal-based compounds.

[0114] The additive may be, for example, a compound containing tin (Sn), and the addition of the compound containing tin can provide a resist underlayer film having improved adhesion to the resist. The additive may be represented by any one of the following chemical formulas X-1 to X-4.

[0115] [ka] ...Chemical formula X-1

[0116] [ka] ...Chemical formula X-2

[0117] [ka] ...Chemical formula X-3

[0118] [ka] ...Chemical formula X-4

[0119] The additive is contained in an amount of 0.001 to 40 parts by weight based on 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.

[0120] According to yet another embodiment, there is provided a resist underlayer film produced using the above-mentioned composition for a resist underlayer film. The resist underlayer film may be in a form obtained by, for example, coating the above-mentioned composition for a resist underlayer film on a substrate and then curing the composition through a heat treatment process.

[0121] Hereinafter, a method for forming a pattern using the above-mentioned composition for a resist underlayer film will be described with reference to Fig. 1 to Fig. 6. Fig. 1 to Fig. 6 are cross-sectional views for explaining the method for forming a pattern using the composition for a resist underlayer film according to the present invention.

[0122] Referring to FIG. 1, first, an object to be etched is provided. An example of the object to be etched may be a thin film 102 formed on a semiconductor substrate 100. Hereinafter, only the case where the object to be etched is the thin film 102 will be described. In order to remove contaminants remaining on the thin film 102, the surface of the thin film 102 is cleaned. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0123] Next, the above-mentioned composition for a resist underlayer film is coated on the surface of the cleaned thin film 102 by applying a spin coating method.

[0124] Thereafter, drying and baking processes 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, at 100° C. to 300° C. A more specific description of the composition for resist underlayer film has been given above in detail, so it will be omitted to avoid duplication.

[0125] 2, a photoresist is coated on the resist underlayer film 104 to form a photoresist film 106. In one embodiment, the photoresist composition that forms the photoresist film 106 may include, but is not limited to, an organometallic compound containing Sn, a solvent, etc.

[0126] 3, the photoresist film 106 is selectively exposed to light. To explain an exposure process for exposing the photoresist film 106 as an example, an exposure mask having a predetermined pattern formed thereon is positioned on a mask stage of an exposure tool, and an exposure mask 110 is aligned on 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.

[0127] As an example, examples of light that can be used in the exposure process include short wavelength light such as an activation irradiation line i-line having a wavelength of 365 nm, a KrF excimer laser having a wavelength of 248 nm, and an ArF excimer laser having a wavelength of 193 nm, as well as EUV (Extreme ultraviolet) having a wavelength of 13.5 nm, which corresponds to extreme ultraviolet light.

[0128] The exposed regions 106b of the photoresist film 106 have a different solubility from the unexposed regions 106a of the photoresist film 106 by forming a polymer through a crosslinking reaction such as condensation between organometallic compounds.

[0129] Next, a second baking step is performed on the substrate 100. The second baking step can be performed at a temperature of about 90° C. to about 200° C. By performing the second baking step, the exposed region 106b of the photoresist film 106 becomes less soluble in a developer.

[0130] Referring to FIG. 4, the photoresist film 106a corresponding to the non-exposed region is dissolved and removed using an organic solvent developer such as 2-heptanone, and the photoresist film 106b remaining after development forms a photoresist pattern 108.

[0131] As described above, the developer used in the pattern formation method according to an embodiment may be an organic solvent. Examples of the organic solvent used in the pattern formation method according to an embodiment include ketones such as methyl ethyl ketone, acetone, cyclohexanone, and 2-heptanone, alcohols such as 4-methyl-2-propanol, 1-butanol, isopropanol, 1-propanol, and methanol, esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, and butyrolactone, aromatic compounds such as benzene, xylene, and toluene, or combinations thereof.

[0132] However, the photoresist pattern according to an embodiment is not necessarily limited to being formed with a negative tone image, and may be formed with a positive tone image. In this case, a developer that can be used to form a positive tone image includes a quaternary ammonium hydroxide composition such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof.

[0133] As described above, the photoresist pattern 108 formed by exposure to light having a wavelength such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), ArF excimer laser (wavelength 193 nm), as well as high-energy light such as EUV (Extreme UltraViolet; wavelength 13.5 nm) and E-Beam (electron beam) may have a thickness width of 5 nm to 100 nm. As an example, the photoresist pattern 108 is formed with a width of 5 nm to 90 nm, 5 nm to 80 nm, 5 nm to 70 nm, 5 nm to 60 nm, 5 nm to 50 nm, 5 nm to 40 nm, 5 nm to 30 nm, 5 nm to 20 nm, or 5 nm to 10 nm.

[0134] On the other hand, the photoresist pattern 108 may have a half-pitch of about 50 nm or less, e.g., 40 nm or less, e.g., 30 nm or less, e.g., 20 nm or less, e.g., 10 nm or less, and a pitch with a line width roughness of about 5 nm or less, about 3 nm or less, about 2 nm or less, about 1 nm or less.

[0135] Next, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. By such an etching process, an organic film pattern 112 as shown in FIG.

[0136] The formed organic layer pattern 112 may also have a width corresponding to that of the photoresist pattern 108. The etching may be performed by dry etching using an etching gas, for example, CHF 3 , C.F. 4 , Cl 2 , O 2 As described above, the resist underlayer film formed using the resist underlayer film composition according to an embodiment has a high etching rate, so that a smooth etching process can be performed within a short time.

[0137] 6, 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.

[0138] The thin film pattern 114 formed by the previous exposure process using a short wavelength light source such as an activation irradiation i-line (wavelength 365 nm), a KrF excimer laser (wavelength 248 nm), or an ArF excimer laser (wavelength 193 nm) can have a width of several tens of nm to several hundreds of nm, and the thin film pattern 114 formed by the exposure process using an EUV light source can have a width of 20 nm or less.

[0139] The present invention will be described in more detail below with reference to examples of the synthesis of the above-mentioned polymer and the preparation of a composition for a resist underlayer film containing the same. However, the present invention is not technically limited to the following examples. EXAMPLES

[0140] Polymer Synthesis Synthesis Example 1 In a 500ml three-necked round-bottom flask, 24.9g of 1,3-diallyl-5-(2-hydroxyethyl)isocyanurate, 7.4g of mercaptoethanol, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) are added and a condenser is connected. After the reaction is carried out at a temperature of 80°C for 16 hours, the reaction solution is cooled to room temperature. The reaction solution is stirred in a 1L wide-mouth bottle containing 800g of water, and the water is dropped to form a gum, which is then dissolved in 80g of tetrahydrofuran (THF). The dissolved resin solution is precipitated using toluene to remove monomolecules and low molecules. Finally, a polymer consisting of structural units represented by the following chemical formula 1-1 is obtained. (Weight average molecular weight (Mw)=10,500g / mol)

[0141] [ka] ...Chemical formula 1-1

[0142] Synthesis Example 2 In a 500ml three-necked round-bottom flask, 24.9g of 1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione, 7.4g of mercaptoethanol, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) are placed and a condenser is connected. After the reaction is carried out at a temperature of 80°C for 16 hours, the reaction solution is cooled to room temperature. The reaction solution is stirred in a 1L wide-mouth bottle containing 800g of water, dropped to form a gum, and then dissolved in 80g of THF. The dissolved resin solution is precipitated using toluene to remove monomolecules and small molecules. Finally, a polymer consisting of structural units represented by the following chemical formula 1-2 is obtained. (Weight average molecular weight (Mw)=8,000g / mol)

[0143] [ka] ...Chemical formula 1-2

[0144] Production of composition for resist underlayer film Examples 1 to 5 and Comparative Example 1 As shown in the composition in Table 1 below, the polymer obtained in the synthesis example and the radical initiators represented by the following formulas 4 to 9 and X were mixed in a ratio of 100:40 (1.2 g), PD1174 (crosslinking agent) 0.4 g, and pyridinium para-toluenesulfonate (PPTS) 0.02 g were mixed and completely dissolved in propylene glycol monomethyl ether to a solid content of 3%, and then diluted with an additional solvent to prepare a resist underlayer film composition according to each example.

[0145] [Table 1]

[0146]

change

[0147]

change

[0148]

change

[0149]

change

[0150]

change

[0151] Comparative Example 2 1.2 g of the polymer represented by Chemical Formula 1-2 obtained in Synthesis Example 2, 0.4 g of PD1174 (crosslinking agent), and 0.02 g of pyridinium para-toluenesulfonate (PPTS) were mixed and completely dissolved in propylene glycol monomethyl ether to a solid content of 3%, and then diluted with an additional solvent to prepare a composition for a resist underlayer film.

[0152] Evaluation 1: Coating uniformity evaluation 2 ml of each of the compositions obtained in the Examples and Comparative Examples was applied onto an 8-inch wafer, and spin-coated at a main spin speed of 1,500 rpm for 20 seconds using an auto track (TEL's ACT-8), and then cured at 205° C. for 60 seconds to form a thin film with a thickness of 50 Å.

[0153] The thickness was measured at 51 points on the horizontal axis, and the difference between the maximum and minimum thickness values ​​was compared to evaluate the coating uniformity using the following formula 1. The smaller the coating uniformity value, the better the coating uniformity; specifically, coating uniformity of less than 2 Å is evaluated as "excellent," between 2 Å and 5 Å as "average," and 5 Å or more as "poor." The results are shown in Table 2 below.

[0154] [Formula 1] Coating uniformity (Å) = Maximum-minimum thickness measured at 51 points across the wafer

[0155] [Table 2]

[0156] Referring to Table 2, it can be seen that the coating uniformity of the resist underlayer film formed from the composition according to the embodiment is smaller than that of the film formed from the composition according to the comparative example, and the composition according to the embodiment has a better coating uniformity of the resist underlayer film formed therefrom than the composition according to the comparative example.

[0157] Evaluation 2: Chemical resistance evaluation 2 ml of each of the resist underlayer film compositions prepared in the examples and comparative examples was applied onto a 4-inch wafer, and spin-coated at 1,500 rpm for 20 seconds using a spin coater (Mikasa). After curing at 210°C for 90 seconds, the thickness of the thin film formed was measured using a K-MAC thin film thickness meter. The thin film was then placed in a mixed solvent (70% by weight propylene glycol monomethyl ether + 30% by weight propylene glycol monomethyl ether acetate) for 1 minute, removed, and the thickness of the thin film was measured. The chemical resistance of the underlayer film was evaluated from the thickness reduction rate measured before and after loading according to the following calculation formula 2. The smaller the thickness reduction rate, the better the chemical resistance, and the results are shown in Table 3 below.

[0158] [Formula 2] Lower layer film thickness reduction rate (%) = {(thickness of thin film before support - thickness of thin film after support) / thickness of thin film before support} x 100

[0159] [Table 3]

[0160] Referring to Table 2, it can be seen that the chemical resistance of the resist underlayer film formed from the composition according to the embodiment is superior to that of the comparative example.

[0161] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications or variations should not be understood individually 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]

[0162] 100: substrate, 102: thin film 104: resist underlayer film, 106: photoresist film 106a: non-exposed area, 106b: 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 a structural unit represented by the following Chemical Formula 1, a structural unit represented by the following Chemical Formula 2, or a combination thereof; a radical initiator having a bond dissociation energy (BDE) of 0 to 60 kcal / mol; and a solvent: 【Chemistry 1】 ...Chemical formula 1 【Chemistry 2】 ...Chemical formula 2 In the above Chemical Formula 1 and Chemical Formula 2, A is a heterocyclic group containing a nitrogen atom in the ring, L １ ~L ６ are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, a substituted or unsubstituted C3-C20 cycloalkylene group, a substituted or unsubstituted C2-C20 heterocycloalkylene group, a substituted or unsubstituted C6-C20 arylene group, a substituted or unsubstituted C3-C20 heteroarylene group, or a combination thereof; X １ ~X ５ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -NR ａ - (where R ａ is hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof; Y １ ~Y ３ are each independently a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C10 alkynyl group, a substituted or unsubstituted C1-C10 heteroalkyl group, a substituted or unsubstituted C2-C10 heteroalkenyl group, a substituted or unsubstituted C2-C10 heteroalkynyl group, a substituted or unsubstituted C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C3-C20 heteroaryl group, or a combination thereof; * indicates the binding site.

2. The composition for a resist underlayer film according to claim 1, wherein A is represented by one or more of the following chemical formulas A-1 to A-4: 【Chemistry 3】 ...Chemical formula A-1 【Chemistry 4】 ...Chemical formula A-2 【Chemistry 5】 ...Chemical formula A-2 【Chemistry 6】 ...Chemical formula A-4 In the above Chemical Formula A-1 to Chemical Formula A-4, The R ｘ is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a substituted or unsubstituted C2-C10 alkynyl group; * indicates the binding site.

3. Said L １ ~L ６ are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, or a combination thereof; X １ ~X ５ each independently represents a single bond, —O—, —S—, —C(═O)—, —(CO)O—, —O(CO)O—, or a combination thereof, Y １ ~Y ３ are each independently a hydroxy group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C10 heteroalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof.

4. The composition for a resist underlayer film according to claim 1, wherein the radical initiator is represented by any one of the following formulas 3-1 to 3-4: 【Chemistry 7】 ...Chemical formula 3-1 【Chemistry 8】 ...Chemical formula 3-2 【Chemistry 9】 ...Chemical formula 3-3 【Chemistry 10】 ...Chemical formula 3-4 In the above Chemical Formula 3-1 to Chemical Formula 3-4, R １ ~R ５ are each independently a hydroxy group, a substituted or unsubstituted C1 to C30 alkyl group, a substituted or unsubstituted C1 to C30 alkoxy group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof; R ６ ~R ９ are each independently hydrogen, deuterium, a hydroxyl group, a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof; R ａ and R ｂ are each independently a deuterium atom, a hydroxyl group, or -SCH ３ , a substituted or unsubstituted C1 to C20 alkyl group, or a combination thereof; Each of na and nb is independently an integer of 0 to 5.

5. The composition for a resist underlayer film according to claim 1, wherein the radical initiator is represented by any one or more of the following formulas 4 to 10: 【Chemistry 11】 ...Chemical formula 4 【Chemistry 12】 ...Chemical formula 5 【Chemistry 13】 ...Chemical formula 6 【Chemistry 14】 ...Chemical formula 7 【Chemistry 15】 ...Chemical formula 8 【Chemistry 16】 ...Chemical formula 9 【Chemistry 17】 ...Chemical formula 10

6. The composition for a resist underlayer film according to claim 1, wherein the chemical formula 1 is represented by the following chemical formula 1-1 or 1-2, and the chemical formula 2 is represented by any one of the following chemical formulas 2-1 to 2-3. 【Chemistry 18】 ...Chemical formula 1-1 【Chemistry 19】 ...Chemical formula 1-2 【Chemistry 20】 ...Chemical formula 2-1 【Chemistry 21】 ...Chemical formula 2-2 【Chemical 22】 ...Chemical formula 2-3

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

8. 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.

9. 2. The composition for a resist underlayer film according to claim 1, wherein the radical initiator 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.

10. 2. The resist underlayer film composition 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.

11. 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 combinations thereof.

12. forming a film to be etched on a substrate; A step of forming a resist underlayer film by applying the resist underlayer film composition according to any one of claims 1 to 11 onto the film to be etched; forming a photoresist pattern on the resist underlayer film; gradually etching the resist underlayer film and the film to be etched using the photoresist pattern as an etching mask; A pattern forming method comprising the steps of:

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