Resist underlayer composition and method of forming patterns using the same

Abstract

To provide 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: The present invention provides a composition for a resist underlayer film comprising a polymer containing a specific structural unit and a solvent, and a pattern forming method using the composition for a resist underlayer film.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present description 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 been developing from patterns of several hundred nanometers to ultrafine technology with patterns of several to several tens of nanometers. Effective lithography technology is essential to realize such ultrafine technology.

[0003] Lithography is a processing method in which a photoresist film is coated on a semiconductor substrate such as a silicon wafer to form a thin film, which is then irradiated with activating radiation such as ultraviolet light through a mask pattern on which a device pattern is drawn, and the thin film is 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 above pattern.

[0004] As semiconductor patterns become increasingly finer, thinner photoresist layers are required, which in turn requires thinner resist underlayers. The resist underlayer must not collapse the photoresist pattern even when it is thin, and must have high adhesion to the photoresist and be formed with a uniform thickness. In addition, the resist underlayer must have a high refractive index and low absorption coefficient for the light used in photolithography, and a faster etching rate than the photoresist layer. Summary of the Invention [Problem to be solved by the invention]

[0005] The 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, a structural unit represented by the following chemical formula 3, or a combination thereof, and a solvent.

[0006] [ka]

[0007] In chemical formula 1 to chemical formula 3, R 1 and R 2 each independently represents hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 7 each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C3 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof; X 1 ~X 8 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 a C1-C10 alkyl group), or a combination thereof; Y 1 and Y 4 is a group represented by the following chemical formula 4, Y 2 and Y 3are 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 C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a group represented by the following chemical formula 4, or a combination thereof; 2 and Y 3 At least one of the groups is a group represented by the following chemical formula 4: * indicates a connection point.

[0008] [ka]

[0009] In chemical formula 4, R 3 ~R 6 each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, or a combination thereof; * indicates a connection point.

[0010] R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted C1 to C20 alkyl group, A is a moiety represented by the following chemical formula A-1, and L 1 ~L 7 each independently represents a single bond or a substituted or unsubstituted C1 to C10 alkylene group, X 1 ~X 8 each independently represents a single bond, -O-, -C(=O)-, -(CO)O-, -C(=O)NH-, or a combination thereof.

[0011] [ka]

[0012] In chemical formula A-1, * is the linking point.

[0013] R in Chemical Formula 4 3 ~R 6 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a combination thereof.

[0014] The polymer may further include a structural unit represented by the following Chemical Formula 5, a structural unit represented by the following Chemical Formula 6, a structural unit represented by the following Chemical Formula 7, or a combination thereof.

[0015] [ka]

[0016] In chemical formulas 5 to 7, R 7 and R 8 each independently represents hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, L 8 ~L 14 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 9 ~X 16 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 bis hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof; Y 5 ~Y 8 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 a connection point.

[0017] A in Chemical Formula 6 and Chemical Formula 7 can be represented by one or more of the following Chemical Formulae A-1 to A-4.

[0018] [ka]

[0019] In Chemical Formulae A-1 to A-4, * denotes a linking point.

[0020] R 7 and R 8 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, or a combination thereof; L 8 ~L 14 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 9 ~X 16 are each independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, or a combination thereof; Y 5 ~Y 8are 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 C2 to C20 heterocycloalkyl group, or a combination thereof.

[0021] Chemical Formula 1 may be represented by one or more of the following Chemical Formulas 1-1 to 1-5.

[0022] [ka]

[0023] [ka]

[0024] The polymer may contain one or more of the structural units represented by Chemical Formulae 1 to 3 in an amount of 5 mol % to 50 mol % based on the total number of moles of the structural units.

[0025] The weight average molecular weight of the polymer is 1,000 g / mol to 300,000 g / mol.

[0026] The above 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.

[0027] The resist underlayer film composition 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.

[0028] The resist underlayer film composition can further include an additive that is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

[0029] According to another embodiment, there is provided a method for forming a pattern, the method including the steps of forming a film to be etched on a substrate, applying a resist underlayer film composition according to an embodiment onto the film to be etched to form a resist underlayer film, forming a photoresist pattern on the resist underlayer film, and sequentially etching the resist underlayer film and the film to be etched using the photoresist pattern as an etching mask. Effect of the Invention

[0030] The composition for a resist underlayer film according to an embodiment can provide a resist underlayer film that does not cause a resist pattern collapse even in a fine patterning process.

[0031] In addition, the composition for a resist underlayer film according to one embodiment can provide a resist underlayer film having improved sensitivity to an exposure light source, and improved pattern formability and energy efficiency. [Brief description of the drawings]

[0032] [Figure 1] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. [Diagram 2] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. [Diagram 3] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. [Figure 4] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. [Diagram 5] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. [Figure 6] 1 is a cross-sectional view illustrating a pattern forming method using a resist underlayer film composition according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] 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 will be able to 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.

[0034] In the drawings, the thickness is exaggerated to clearly depict multiple layers and regions. Similar parts are designated by the same reference numerals throughout the specification. When a part, such as a layer, film, region, or plate, is said to be "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 said to be "directly on" another part, it means that there is no other part between them.

[0035] 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 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 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.

[0036] In addition, two adjacent substituents among a substituted 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 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 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, or a C2-C30 heterocyclic group may be fused to form a ring.

[0037] Unless otherwise defined herein, "hetero" means containing 1 to 3 heteroatoms selected from N, O, S, Se, and P.

[0038] As used herein, the term "aryl group" refers to a group having one or more hydrocarbon aromatic moieties, and broadly includes both hydrocarbon aromatic moieties linked by single bonds and non-aromatic fused rings to which hydrocarbon aromatic moieties are directly or indirectly fused. Aryl groups include monocyclic, polycyclic, or fused polycyclic (i.e., rings which share adjacent pairs of carbon atoms) functional groups.

[0039] As used herein, the term "heterocyclic group" refers to a concept that includes heteroaryl groups, and additionally refers to a ring compound, such as an aryl group, a cycloalkyl group, a fused ring thereof, or a combination thereof, that contains at least one heteroatom selected from N, O, S, P, and Si in place of carbon (C). When the heterocyclic group is a fused ring, the entire heterocyclic group or each ring may contain one or more heteroatoms.

[0040] 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 aryl ... An 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 group, a substituted or unsubstituted A pyrazinyl group, a substituted or unsubstituted triazinyl group, a substituted or unsubstituted benzofuranyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted benzimidazolyl group, a substituted or unsubstituted indolyl group, a substituted or unsubstituted quinolinyl group, a substituted or unsubstituted isoquinolinyl group, a substituted or unsubstituted quinazolinyl group, a substituted or unsubstituted quinoxalinyl group, a substituted or unsubstituted naphthyridinyl group, a substituted or unsubstituted benzoxazinyl group, a substituted or unsubstituted benzthiazinyl group, a substituted or unsubstituted acrylo ... The aryl 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.

[0041] Unless otherwise specified herein, "combination" means blending or copolymerization.

[0042] In addition, in this specification, the term "polymer" can include both an oligomer and a polymer.

[0043] Unless otherwise specified in this specification, the "weight average molecular weight" is measured by dissolving a powder sample in tetrahydrofuran (THF) and then using an Agilent Technologies 1200 series gel permeation chromatography (GPC) (the column is a Shodex LF-804 and the standard column is Shodex polystyrene).

[0044] Additionally, unless otherwise defined herein, "*" indicates a structural unit of a compound or a point of attachment of a moiety of a compound.

[0045] In the semiconductor industry, there is a constant demand for reducing the size of chips. To meet this demand, the line width of the resist patterned by lithography technology must be reduced to a few tens of nanometers, and the pattern thus formed is then transferred to the underlying substrate through an etching process. However, as the resist pattern size becomes smaller, the aspect ratio of the resist that can withstand the line width is limited, and therefore the resist may not have sufficient resistance in the etching step. Therefore, when a thin resist is used, when the substrate to be etched is thick, or when a deep pattern is required, a resist underlayer film has been used to compensate for the etching resistance.

[0046] The resist underlayer film is required to be thinner as the resist thickness decreases, and the photoresist pattern must not be destroyed even if 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 resist underlayer film composition must have high coating uniformity and the resist underlayer film produced from the resist underlayer film composition must have high flatness, high sensitivity to the exposure light source, high pattern formability, and high energy efficiency.

[0047] 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, a structural unit represented by the following Chemical Formula 3, or a combination thereof, and a solvent.

[0048] [ka] In chemical formula 1 to chemical formula 3, R 1 and R 2 each independently represents hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, L 1 ~L 7 each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C3 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof; X 1 ~X 8each 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 a C1-C10 alkyl group), or a combination thereof; Y 1 and Y 4 is a group represented by the following chemical formula 4, Y 2 and 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 C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a group represented by the following chemical formula 4, or a combination thereof; 2 and Y 3 At least one of the groups is a group represented by the following chemical formula 4: * indicates a connection point.

[0049] [ka]

[0050] In chemical formula 4, R 3 ~R 6 each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, or a combination thereof; * indicates a connection point.

[0051] The polymer contained in the composition according to one embodiment can trap highly reactive radicals by including in its structural unit a group represented by Chemical Formula 4. As a result, the polymer can function as a radical trap, and a composition for a resist underlayer film including the polymer can remove unnecessary radicals in the resist to improve the sensitivity of the resist and improve the formability of a fine pattern.

[0052] R of the structural unit represented by chemical formula 1 1 and R 2 are each independently hydrogen, deuterium, a hydroxy group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a combination thereof, such as hydrogen, a substituted or unsubstituted C1-C20 alkyl group, or a combination thereof, such as hydrogen, or a substituted or unsubstituted C1-C10 alkyl group, such as hydrogen, or a substituted or unsubstituted C1-C5 alkyl group, such as hydrogen, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a combination thereof, but are not limited to these.

[0053] Since the structural unit represented by chemical formula 2 and the structural unit represented by chemical formula 3 contain 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. Therefore, the polymer can have a high electron density, and by including a polymer having a high electron density, the underlayer film composition according to an embodiment can realize a film having a dense structure in the form of an ultra-thin film. In addition, the high electron density of the polymer can have an effect of improving the light absorption efficiency when the resist underlayer film composition is exposed. Furthermore, the polymer containing a heterocyclic skeleton has excellent etching selectivity, and can improve energy efficiency when forming a pattern by exposure using high-energy rays such as EUV (Extreme ultraviolet; wavelength 13.5 nm) and E-Beam (electron beam).

[0054] A in Chemical Formula 2 and Chemical Formula 3 is a heterocyclic group containing two or three nitrogen atoms in the ring, and is represented, for example, by any one of Chemical Formulas A-1 to A-4 below, for example, represented by Chemical Formula A-1 below, but is not limited thereto.

[0055] [ka]

[0056] In Chemical Formulae A-1 to A-4, * denotes a linking point.

[0057] L in Chemical Formula 1 to Chemical Formula 3 1 ~L 7 are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, a substituted or unsubstituted C2-C10 alkynylene group, or a combination thereof, for example, a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, or a combination thereof, for example, a single bond, or a substituted or unsubstituted C1-C10 alkylene group, or a combination thereof, but are not limited to these.

[0058] X 1 ~X 8 are each independently a single bond, -O-, -S-, -S(=O)-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, or a combination thereof, for example, but not limited to, a single bond, -O-, -C(=O)-, -(CO)O-, -C(=O)NH-, or a combination thereof.

[0059] Y in Chemical Formula 2 2 and Y 3are 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 C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 heterocycloalkyl group, a group represented by the following chemical formula 4, or a combination thereof, for example, a hydroxy group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a group represented by the following chemical formula 4, or a combination thereof; Y 2 and Y 3 At least one of the groups may be a group represented by the following formula 4, but is not limited thereto.

[0060] Y in Chemical Formula 1 1 and Y in formula 3 4 is a group represented by the following chemical formula 4.

[0061] [ka]

[0062] R 3 ~R 6 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a combination thereof, for example, hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, or a combination thereof, for example, hydrogen, a substituted or unsubstituted C1-C5 alkyl group, or a combination thereof, for example, hydrogen, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a combination thereof, for example, R 3 ~R 6 are all substituted or unsubstituted methyl groups, but are not limited thereto.

[0063] As an example, Chemical Formula 1 may be represented by any one or more of the following Chemical Formulas 1-1 to 1-5.

[0064] [ka]

[0065] [ka]

[0066] The polymer contained in the resist underlayer film composition according to one embodiment may contain one or more of the structural units represented by Chemical Formulae 1 to 3 in an amount of 5 mol % to 50 mol %, for example, 10 mol % to 50 mol %, or 20 mol % to 40 mol %, based on the total number of moles of the structural units forming the polymer. By containing one or more of the structural units represented by Chemical Formulae 1 to 3 in the above range in the polymer in the composition according to one embodiment, the resist underlayer film composition according to one embodiment can exhibit the effect of removing unnecessary radicals in the resist, improving the sensitivity of the resist, and improving the formability of a fine pattern when forming a resist underlayer film.

[0067] In another embodiment, the polymer may further include a structural unit represented by the following Formula 5, a structural unit represented by the following Formula 6, a structural unit represented by the following Formula 7, or a combination thereof.

[0068] [ka]

[0069] In chemical formulas 5 to 7, R 7 and R 8 each independently represents hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, L 8 ~L 14are 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 9 ~X 16 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 a C1-C10 alkyl group), or a combination thereof; Y 5 ~Y 8 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 a connection point.

[0070] The structural units represented by Chemical Formulae 5 to 7 differ from the structural units represented by Chemical Formulae 1 to 3 in that they do not contain the substituent represented by Chemical Formula 4. The rest have the same definitions as those in Chemical Formulae 1 to 3, and polymers containing these structural units can satisfy various requirements for forming a resist underlayer film.

[0071] R in Chemical Formula 5 7 and R 8are each independently hydrogen, deuterium, a hydroxy group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a combination thereof, such as hydrogen, a substituted or unsubstituted C1-C20 alkyl group, or a combination thereof, such as hydrogen, or a substituted or unsubstituted C1-C10 alkyl group, such as hydrogen, or a substituted or unsubstituted C1-C5 alkyl group, such as hydrogen, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, or a combination thereof, but are not limited to these.

[0072] A in Chemical Formula 6 and Chemical Formula 7 can be represented by one or more of Chemical Formulas A-1 to A-4.

[0073] L 8 ~L 14 are each independently a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C1-C10 heteroalkylene group, or a combination thereof, for example, 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, a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C1-C5 heteroalkylene group containing a sulfur atom, or a combination thereof, but are not limited to these.

[0074] X 9 ~X 16 are each independently a single bond, -O-, -S-, -S(=O)-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, or a combination thereof, for example, but not limited to, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof.

[0075] Y 5 ~Y 8are 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 C2 to C10 alkynyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 heteroaryl group, or a combination thereof, for example, a hydroxy group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkynyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C3 to C20 heteroaryl group, or a combination thereof. and combinations thereof, such as, but not limited to, a hydroxy group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or combinations thereof, such as, but not limited to, a hydroxy group, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, or combinations thereof.

[0076] As an example, Chemical Formula 5 may be represented by any one of Chemical Formulas 5-1 to 5-3 below, Chemical Formula 6 may be represented by any one of Chemical Formulas 6-1 to 6-3 below, and Chemical Formula 7 may be represented by any one of Chemical Formulas 7-1 to 7-3 below.

[0077] [ka]

[0078] [ka]

[0079] The weight average molecular weight (Mw) of the polymer contained in the composition for forming a resist underlayer film according to an embodiment may be in the range of about 1,000 g / mol to about 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 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 the weight average molecular weight in the above range, the carbon content and solubility in a solvent of the composition for a resist underlayer film containing the polymer can be adjusted and optimized.

[0080] 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 resist underlayer film. More specifically, the polymer may be 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 for resist underlayer film in the above range, the thickness, surface roughness and flatness of the resist underlayer film can be adjusted.

[0081] 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 in the polymer according to an embodiment. The solvent may include, but is not limited to, for example, propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate, or a combination thereof.

[0082] The composition for a resist underlayer film according to an embodiment may further include, in addition to the polymer and the solvent, one or more additional polymers selected from an acrylic-based resin, an epoxy-based resin, a novolac-based resin, a glycoluril-based resin, and a melamine-based resin, but the additional polymers are not limited thereto.

[0083] 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.

[0084] The surfactant may 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, alkylbenzenesulfonate, alkylpyridinium salt, polyethylene glycol, and quaternary ammonium salt.

[0085] 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.

[0086] 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 acids, phosphates, trimellitic acids, and citrates, polyethers, polyesters, and polyacetals.

[0087] According to another embodiment, there is provided a resist underlayer film prepared using the composition for a resist underlayer film. The resist underlayer film may be in a form obtained by, for example, coating the composition for a resist underlayer film on a substrate and then curing the composition through a heat treatment process.

[0088] Hereinafter, a method for forming a pattern using the above-mentioned composition for a resist underlayer film will be described with reference to Figures 1 to 6. Figures 1 to 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.

[0089] Referring to FIG. 1, first, an object to be etched is prepared. 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. 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.

[0090] Next, the above-mentioned composition for a resist underlayer film is coated on the surface of the cleaned thin film 102 by spin coating.

[0091] Thereafter, drying and baking steps are performed to form a resist underlayer film 104 on the thin film. The baking step is performed at 100° C. to 500° C., for example, 100° C. to 300° C. A more specific explanation of the composition for the resist underlayer film has already been given in detail, so it will be omitted to avoid duplication.

[0092] 2, a photoresist is coated on the resist underlayer film 104 to form a photoresist film 106. In one embodiment, the photoresist composition for forming the photoresist film 106 may include, but is not limited to, an organometallic compound containing Sn, a solvent, etc.

[0093] 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.

[0094] 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 placed on a mask stage of an exposure tool, and an exposure mask 110 is placed 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.

[0095] Examples of light that can be used in the exposure process include short wavelength light such as activation radiation i-line having a wavelength of 365 nm, KrF excimer laser having a wavelength of 248 nm, and 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.

[0096] The exposed regions 106b of the photoresist film 106 form polymers through cross-linking reactions such as condensation between organometallic compounds, and therefore have different solubilities from the unexposed regions 106a of the photoresist film 106.

[0097] 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.

[0098] Referring to FIG. 4, the photoresist film 106a corresponding to the unexposed area 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.

[0099] 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, and combinations thereof.

[0100] However, the photoresist pattern according to an embodiment is not necessarily limited to being formed as a negative tone image, but may be formed to have a positive tone image. In this case, examples of developers that can be used to form a positive tone image include quaternary ammonium hydroxide compositions such as tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or combinations thereof.

[0101] As described above, the photoresist pattern 108 formed by exposure to high-energy light such as EUV (Extreme ultraViolet; wavelength 13.5 nm) and E-Beam (electron beam) as well as light such as i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), and ArF excimer laser (wavelength 193 nm) can have a width of 5 nm to 100 nm. As an example, the photoresist pattern 108 can be 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.

[0102] Meanwhile, 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 of linewidth roughness of about 5 nm or less, about 3 nm or less, about 2 nm or less, about 1 nm or less.

[0103] Next, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. By the above-mentioned etching process, an organic film pattern 112 as shown in FIG.

[0104] The formed organic film pattern 112 may also have a width corresponding to the photoresist pattern 108. The etching may be performed by dry etching using an etching gas, such as CHF3, CF4, Cl2, O2, or a mixture thereof. As described above, the resist underlayer film formed using the resist underlayer film composition according to an embodiment has a high etching rate, and therefore, a smooth etching process can be performed within a short time.

[0105] 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 as a thin film pattern 114.

[0106] The thin film pattern 114 formed by the previous exposure process using a short wavelength light source such as activating radiation i-line (wavelength 365 nm), KrF excimer laser (wavelength 248 nm), or 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. EXAMPLES

[0107] The present invention will be described in more detail below through examples of the synthesis of the above-mentioned polymer and the preparation of a composition for a resist underlayer film containing the same. However, the technical features of the present invention are not limited to the following examples.

[0108] Polymer Synthesis Synthesis Example 1 9g of 2,2,6,6-tetramethylpiperidine methacrylate, 24.9g of 1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione, 3.7g of mercaptoethanol, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) were added to a 500mL three-neck round-bottom flask, and a condenser was connected to the flask. The temperature was raised to 80°C in a nitrogen atmosphere, and the reaction was carried out for 12 hours, after which the reaction solution was cooled to room temperature (25±2°C). The reaction solution was then washed three times with 200mL of ethyl ether, filtered, and the solvent was removed to obtain compound (A).

[0109] 23.7g of compound (A) and 170mL of dichloromethane were placed in a 500mL two-neck round-bottom flask, and the flask was filled with argon. 15.75g of m-chloroperbenzoic acid was dissolved in 105mL of dichloromethane, and then slowly added dropwise to the flask containing intermediate (A), and then reacted at room temperature for 3 hours. After the reaction was completed, the organic layer was washed with 250mL of water using a separatory funnel, and the organic layer was dried to obtain a polymer represented by the following chemical formula 1A (weight average molecular weight (Mw) = 18,000g / mol). (x: 28.5mol%, y: 71.5mol%)

[0110] [ka]

[0111] Synthesis Example 2 In a 500mL three-neck round-bottom flask, 9g of N-(2,2,6,6-Tetramethyl-4-piperidyl)methacrylamide, 24.9g of 1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione, 3.7g of mercaptoethanol, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) were placed, and a condenser was connected to the flask. The temperature was raised to 80°C in a nitrogen atmosphere, and the reaction was carried out for 12 hours, after which the reaction solution was cooled to room temperature. Thereafter, the reaction solution was dissolved in 200 mL of ethyl ether and washed three times with water, after which the organic layer was filtered and the solvent was removed to obtain compound (B).

[0112] 27g of compound (B) and 170mL of dichloromethane were placed in a 500mL two-neck round-bottom flask, and the flask was filled with argon. 15.75g of m-chloroperbenzoic acid was dissolved in 105mL of dichloromethane, and then slowly added dropwise to the flask containing intermediate (B), and then reacted at room temperature for 3 hours. After the reaction was completed, the organic layer was washed with 250mL of water using a separatory funnel, and the organic layer was separated and dried to obtain a polymer (Mw=15,000g / mol) containing a structural unit represented by the following chemical formula 1B. (x: 28.5mol%, y: 71.5mol%)

[0113] [ka]

[0114] Synthesis Example 3 11.4g of 2-[(2,2,6,6-Tetramethyl-4-piperidinyl)oxy]ethyl 2-methyl-2-propenoate, 24.9g of 1,3,5-triallyl-1,3,5-triazinane-2,4,6-trione, 3.7g of mercaptoethanol, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) were placed in a 500mL three-neck round-bottom flask, and a condenser was connected to the flask. The temperature was raised to 80°C in a nitrogen atmosphere, and the reaction was carried out for 12 hours, after which the reaction solution was cooled to room temperature. Thereafter, the reaction solution was dissolved in 200 mL of ethyl ether and washed three times with water, and then the organic layer was filtered and the solvent was removed to obtain compound (C).

[0115] 20g of compound (C) and 170mL of dichloromethane were placed in a 500mL two-neck round-bottom flask, and the flask was filled with argon. 15.75g of m-chloroperbenzoic acid was dissolved in 105mL of dichloromethane, and then slowly added dropwise to the flask containing intermediate (C), and reacted at room temperature for 3 hours. After the reaction was completed, the organic layer was washed with 250mL of water using a separatory funnel, dried, and the solvent was removed to obtain 13g of a polymer (Mw=17,000g / mol) containing a structural unit represented by the following chemical formula 1C. (x: 30mol%, y: 70mol%)

[0116] [ka]

[0117] Synthesis Example 4 24.9g of 1,3-diallyl-5-(2-hydroxyethyl) isocyanurate, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) were placed in a 500mL three-neck round-bottom flask, and a condenser was connected to the flask. After the reaction was carried out at a temperature of 80°C for 16 hours, the reaction solution was cooled to room temperature. The reaction solution was dropped into a 1L wide-mouth bottle containing 800g of water while stirring to generate gum, which was then dissolved in 80g of tetrahydrofuran (THF). A precipitate was formed from the dissolved resin solution using toluene, and the monomolecules and small molecules were removed to obtain compound (D).

[0118] In a 500mL two-neck round-bottom flask, 10g of compound (D), 2.2g of 4-carboxy-2,2,6,6-tetramethyl-1-piperidinyloxy, 1.36g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, 134mg of 4-dimethylaminopyridine, and 140mL of dichloromethane were added. The reaction mixture was reacted for 24 hours at room temperature under an argon atmosphere. After the reaction was completed, the mixture was diluted with 300mL of dichloromethane using a separatory funnel, and the organic layer was washed with 300mL of hydrochloric acid aqueous solution (2M concentration) and 300mL of brine. The organic layer was then washed with 300 mL of water, separated, and dried to obtain 8 g of a polymer (Mw=11,000 g / mol) containing a structural unit represented by the following chemical formula 1D (x: 34 mol%, y: 66 mol%).

[0119] [ka]

[0120] Synthesis Example 5 24.9g of 1,3-diallyl-5-(2-hydroxyethyl) isocyanurate, 0.7g of AIBN (azobisisobutyronitrile), and 48g of N,N-dimethylformamide (DMF) were placed in a 500mL three-neck round-bottom flask, and a condenser was connected to the flask. After the reaction was allowed to proceed at 80°C for 16 hours, the reaction solution was cooled to room temperature. The reaction solution was dropped into a 1L wide-mouth bottle containing 800g of water while stirring to produce gum, which was then dissolved in 80g of tetrahydrofuran (THF). A precipitate was formed from the dissolved resin solution using toluene, and monomolecules and low molecules were removed to obtain a polymer (Mw=10,500g / mol) consisting of a structural unit represented by the following chemical formula 6-1.

[0121] [ka]

[0122] Synthesis Example 6 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) were placed in a 500mL three-neck round-bottom flask, and a condenser was connected to the flask. After the reaction was allowed to proceed at a temperature of 80°C for 16 hours, the reaction solution was cooled to room temperature. The reaction solution was dropped into a 1L wide-mouth bottle containing 800g of water while stirring to produce gum, and the gum was then dissolved in 80g of tetrahydrofuran (THF). A precipitate was formed from the dissolved resin solution using toluene, and monomolecules and low molecular weight molecules were removed to obtain a polymer (Mw = 8,000 g / mol) consisting of structural units represented by the following chemical formula 6-2.

[0123] [ka]

[0124] Preparation of Resist Underlayer Film Composition Example 1 1.2 g of the polymer obtained in Synthesis Example 1, 0.4 g of PD1174 (crosslinking agent), and 0.02 g of pyridinium p-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.

[0125] Example 2 A composition for a resist underlayer film was prepared in the same manner as in Example 1, except that the polymer obtained in Synthesis Example 2 was used instead of the polymer obtained in Synthesis Example 1.

[0126] Example 3 A composition for a resist underlayer film was prepared in the same manner as in Example 1, except that the polymer obtained in Synthesis Example 3 was used instead of the polymer obtained in Synthesis Example 1.

[0127] Example 4 A composition for a resist underlayer film was prepared in the same manner as in Example 1, except that the polymer obtained in Synthesis Example 4 was used instead of the polymer obtained in Synthesis Example 1.

[0128] Example 5 A composition for resist underlayer film was prepared in the same manner as in Example 1, except that 1 g of the polymer obtained in Synthesis Example 5 was further added.

[0129] Example 6 A composition for resist underlayer film was prepared in the same manner as in Example 2, except that 1 g of the polymer obtained in Synthesis Example 5 was further added.

[0130] Example 7 A composition for resist underlayer film was prepared in the same manner as in Example 3, except that 1 g of the polymer obtained in Synthesis Example 5 was further added.

[0131] Example 8 A composition for resist underlayer film was prepared in the same manner as in Example 4, except that 1 g of the polymer obtained in Synthesis Example 5 was further added.

[0132] Example 9 A composition for resist underlayer film was prepared in the same manner as in Example 1, except that 1 g of the polymer obtained in Synthesis Example 6 was further added.

[0133] Comparative Example 1 1.2 g of the polymer obtained in Synthesis Example 5, 0.4 g of PD1174 (crosslinking agent), and 0.02 g of pyridinium p-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.

[0134] Comparative Example 2 1.2 g of the polymer obtained in Synthesis Example 6, 0.4 g of PD1174 (crosslinking agent), and 0.02 g of pyridinium p-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.

[0135] Evaluation 1: Coating uniformity evaluation 2 mL of each of the compositions obtained in the examples and comparative examples was dropped 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 5 nm.

[0136] The thickness was measured at 51 points along the horizontal axis, and the difference between the maximum and minimum thickness values ​​was compared according to the following calculation formula 1 to evaluate the coating uniformity. The smaller the coating uniformity value, the better the coating uniformity. The results are shown in Table 1 below. [Formula 1] Coating uniformity (%) = (maximum thickness measured at 51 points on the wafer - minimum thickness) / average thickness x 100

[0137] [Table 1]

[0138] Referring to Table 1, it can be seen that the coating uniformity of the resist underlayer film formed from the composition for resist underlayer film according to the embodiment is superior to that of the resist underlayer film formed from the composition for resist underlayer film according to the comparative example.

[0139] Evaluation 2: Chemical resistance evaluation 2 mL of each of the resist underlayer film compositions prepared in the examples and comparative examples was dropped onto a 4-inch wafer, and spin-coated at 1,500 rpm for 20 seconds using a spin coater (Mikasa). The film was then cured at 210°C for 90 seconds, and the thickness of the thin film formed was measured using a K-MAC thin film thickness meter. Next, the thin film was immersed in a mixed solvent (70% by weight of propylene glycol monomethyl ether + 30% by weight of propylene glycol monomethyl ether acetate) for 1 minute, then removed, and the thickness of the thin film was measured. The chemical resistance of the underlayer film was evaluated from the reduction rate of the thickness measured before and after immersion 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 2 below. [Formula 2] Lower layer film thickness reduction rate (%) = {(thin film thickness before immersion - thin film thickness after immersion) / thin film thickness before immersion} × 100

[0140] [Table 2]

[0141] Referring to Table 2, it can be seen that the chemical resistance of the resist underlayer film formed from the resist underlayer film composition according to the Examples is equal to or better than that of the Comparative Examples.

[0142] As described above, specific embodiments of the present invention have been described and illustrated, but the present invention is not limited to the described embodiments, and it is obvious 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 individually from the technical spirit and perspective of the present invention, and the modified embodiments are considered to belong to the scope of the claims of the present invention. [Explanation of symbols]

[0143] 100: Substrate 102: Thin film 104: Resist underlayer film 106: Photoresist film 106a: Unexposed area 106b: Exposed area 108: Photoresist pattern 110: Mask 112: Organic film pattern 114: Thin film pattern

Claims

1. A polymer including a structural unit represented by the following chemical formula 1, a structural unit represented by the following chemical formula 2, a structural unit represented by the following chemical formula 3, or a combination thereof, and a solvent, 【Chemistry 1】 In the above Chemical Formula 1 to Chemical Formula 3, R １ and R ２ are each independently hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, L １ ~L ７ each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkenylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C3 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, or a combination thereof; X １ ~X ８ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR ａ - (where R ａ is hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof; Y １ and Y ４ is a group represented by the following chemical formula 4: Y ２ and 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 C2 to C10 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C3 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, a group represented by the above chemical formula 4, or a combination thereof; ２ and Y ３ At least one of the groups represented by Formula 4 is a group represented by Formula 4, * indicates a connection point. 【Chemistry 2】 In the above Chemical Formula 4, R ３ ~R ６ are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C2 to C10 alkynyl group, or a combination thereof; * indicates a linking point. Composition for resist underlayer film.

2. The R １ and R ２ are each independently hydrogen or a substituted or unsubstituted C1 to C20 alkyl group; A is a moiety represented by the following chemical formula A-1: L １ ~L ７ each independently represents a single bond or a substituted or unsubstituted C1-C10 alkylene group; X １ ~X ８ each independently represents a single bond, —O—, —C(═O)—, —(CO)O—, —C(═O)NH—, or a combination thereof; 【Chemistry 3】 The composition for a resist underlayer film according to claim 1, wherein in said chemical formula A-1, * is a linking point.

3. R of Formula 4 ３ ~R ６ wherein each independently is hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, or a combination thereof.

4. The polymer further includes a structural unit represented by the following formula 5, a structural unit represented by the following formula 6, a structural unit represented by the following formula 7, or a combination thereof: 【Chemistry 4】 In the above Chemical Formula 5 to Chemical Formula 7, R ７ and R ８ are each independently hydrogen, deuterium, a hydroxy group, a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, or a combination thereof; A is a heterocyclic group containing a nitrogen atom in the ring, 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 ９ ~X １６ are each independently a single bond, -O-, -S-, -S(=O)-, -S(=O) ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR ｂ - (where R ｂ is hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof; Y ５ ~Y ８ 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; The resist underlayer film composition according to claim 1 , wherein * represents a linking point.

5. A in the above Chemical Formula 6 and Chemical Formula 7 is represented by one or more of the following Chemical Formulas A-1 to A-4: 【Chemistry 5】 The composition for a resist underlayer film according to claim 4, wherein in the chemical formulas A-1 to A-4, * represents a linking point.

6. The R ７ and R ８ are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, or a combination thereof; L ８ ~L １４ 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 ９ ~X １６ each independently represents a single bond, —O—, —S—, —C(═O)—, —(CO)O—, or a combination thereof, Y ５ ~Y ８ 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 C2 to C20 heterocycloalkyl group, or a combination thereof.

7. The composition for a resist underlayer film according to claim 1, wherein the formula 1 is represented by any one or more of the following formulas 1-1 to 1-5. 【Chemistry 6】 【Chemistry 7】

8. The composition for a resist underlayer film according to claim 1, wherein the polymer contains one or more of the structural units represented by Chemical Formula 1 to Chemical Formula 3 in an amount of 5 mol % to 50 mol % based on the number of moles of all structural units.

9. 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.

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

11. 2. The resist underlayer film composition according to claim 1, 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 combinations 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; and sequentially 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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