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

Abstract

This invention provides a resist underlayer film in which the resist pattern does not collapse even during fine patterning processes, sensitivity to exposure light sources is improved, and patterning performance and energy efficiency are enhanced. [Solution] A composition for a resist underlayer film comprising a polymer containing a structural unit represented by chemical formula 1 and a structural unit represented by a specific formula, and a solvent. JPEG2026047212000031.jpg5152

Description

[Technical Field]

[0001] This document describes a composition for a resist underlayer film and a pattern formation method using the same. [Background technology]

[0002] In recent years, the semiconductor industry has evolved from patterns of several hundred nanometers in size to ultrafine technology with patterns of several or tens of nanometers in size. Effective lithography techniques are essential to realizing such ultrafine technology.

[0003] Lithography is a processing method that forms a thin film on a semiconductor substrate such as a silicon wafer by coating it with a photoresist film, then irradiates it with an activating irradiation light such as ultraviolet light through a mask pattern on which the device pattern is drawn, develops the film, and then etches the substrate using the resulting photoresist pattern as a protective film to form a fine pattern corresponding to the pattern on the substrate surface.

[0004] As semiconductor patterns become progressively smaller, the thickness of the photoresist layer is required to be smaller, and therefore, the thickness of the resist underlayer film is also required to be smaller. The resist underlayer film must not disrupt the photoresist pattern even if it is thin, and it must have good adhesion to the photoresist and be formed with a uniform thickness. In addition, the resist underlayer film is required to have a high refractive index and a low absorption coefficient with respect to the light rays used in photolithography, and to have a higher etching rate than the photoresist layer. [Overview of the project] [Problems that the invention aims to solve]

[0005] One embodiment is a resist underlayer composition, which provides a resist underlayer that does not experience pattern collapse of the resist even during a fine patterning process, has improved sensitivity to the exposure light source, and offers improved patterning performance and energy efficiency.

[0006] Another embodiment is a pattern formation method using the above-mentioned resist underlayer composition.

[0007] A composition for a resist underlayer according to one embodiment comprises a polymer containing structural units represented by the following chemical formula 1 and structural units represented by the following chemical formula 2, and a solvent.

[0008] [ka]

[0009] In chemical formula 1, m is one of the integers from 1 to 4. n is one of the integers from 1 to 4. m+n is an integer less than or equal to 5, * indicates a connection point;

[0010] [ka]

[0011] In chemical formula 2, L 1 These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C3-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X 1 and X 2 These are, independently, single bonds, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, and -NR. a -(Here, R a (is hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof. Y 1 This is a group represented by the following chemical formula 3, R 1 ~R 3 are each independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group, * is a connection point.

[0012]

Chemical formula

[0013] In Chemical formula 3, M 1 is a single bond, a substituted or unsubstituted C1-C20 alkylene group, a substituted or unsubstituted C2-C20 alkenylene group, -O-, -NH-, or a combination thereof, Z 1 and Z 2 are each independently -C(=O)-, or -CH(OH)-, M 2 is a single bond, a double bond, *-C(R b )=*(where R b is hydrogen, deuterium, or a C1-C5 alkyl group, and * is the connection point to Z 1 or Z 2 ), or a substituted or unsubstituted C1-C3 alkylene group, M 3 is a hydroxy group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, or a substituted or unsubstituted C6-C20 aryl group, M 1 and M 3 or M 2 and M 3 may optionally be linked to each other to form a ring, * is a connection point.

[0014] m and n in Chemical formula 1 may each independently be 1 or 2.

[0015] L in Chemical formula 3 1 is a single bond, or a substituted or unsubstituted C1-C10 alkylene group, X1 and X 2 Each of these can be a single bond or a -(CO)O-, independently of the others.

[0016] Within a polymer, the structural units represented by chemical formula 1 and the structural units represented by chemical formula 2 can exist in a molar ratio of 9:1 to 1:9.

[0017] The polymer may further contain structural units represented by the following chemical formula 4.

[0018] [ka]

[0019] In chemical formula 4, L 2 These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C2-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X 3 and X 4 These are, independently, single bonds, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, and -NR. c -(Here, R c is hydrogen, deuterium, or a C1-C10 alkyl group, or a combination thereof. Y 2 These are a hydroxyl 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 C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group. R 4 ~R 6Each of these is independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group. * indicates a connection point.

[0020] L of chemical formula 4 2 X is a single bond, a substituted or unsubstituted C1-C10 alkylene group, or a substituted or unsubstituted C6-C10 allylene group, 3 and X 4 Each of these is independently a single bond or -(CO)O-, and Y 2 This may be a hydroxyl group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group.

[0021] Chemical formula 2 can be represented by one or more of the following chemical formulas 2-1 to 2-8.

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] The weight-average molecular weight of a polymer can range from 1,000 g / mol to 300,000 g / mol.

[0026] The polymer may be included in an amount of 0.05% to 50% by weight, based on the total weight of the resist underlayer composition.

[0027] The composition may further contain one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluryl resins, and melamine resins.

[0028] The composition may further contain additives such as surfactants, thermoacid generators, photoacid generators, plasticizers, or combinations thereof.

[0029] Another embodiment provides a pattern formation method that includes the steps of forming an etchable film on a substrate, applying a resist underlayer composition according to one embodiment onto the etchable film to form a resist underlayer film, forming a photoresist pattern on the resist underlayer film, and sequentially etching the resist underlayer film and the etchable film using the photoresist pattern as an etching mask.

[0030] A resist underlayer composition according to one embodiment can provide a resist underlayer that prevents pattern collapse of the resist even in a fine patterning process, improves sensitivity to the exposure light source, and enables improved patterning performance and energy efficiency. [Brief explanation of the drawing]

[0031] [Figure 1] This is a cross-sectional view illustrating a pattern formation method using a resist underlayer composition according to one embodiment. [Modes for carrying out the invention]

[0032] The following describes embodiments of the present invention in detail so that those with ordinary skill in the art to which the present invention pertains can easily implement it. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein.

[0033] In the drawings, thicknesses are enlarged to clearly represent multiple layers and regions, and similar parts throughout the specification are denoted by the same reference numerals. When a layer, film, region, plate, or other part is said to be "on top of" another part, this includes not only when it is "directly above" the other part, but also when there is another part in between. Conversely, when one part is said to be "directly above" another part, it means that there is no other part between them.

[0034] In this specification, unless otherwise defined, "substituted" means that a hydrogen atom in a compound is substituted with a substituent selected from deuterium, halogen atoms (F, Br, Cl, or I), hydroxyl groups, nitro groups, cyano groups, amino groups, azide groups, amidino groups, hydrazino groups, hydrazono groups, carbonyl groups, carbamyl groups, thiol groups, ester groups, carboxyl groups or their salts, sulfonic acid groups or their salts, phosphoric acid or its salts, 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, C2-C30 heterocyclic groups, and combinations thereof.

[0035] Furthermore, two adjacent substituents from among substituted halogen atoms (F, Br, Cl, or I), hydroxyl groups, nitro groups, cyano groups, amino groups, azide groups, amidino groups, hydrazino groups, hydrazono groups, carbonyl groups, carbamyl groups, thiol groups, ester groups, carboxyl groups or their salts, sulfonic acid groups or their salts, phosphoric acid or its salts, 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 heterocycles may fuse to form a ring.

[0036] In this specification, the term "heterocyclic group" includes the concept of a heteroaryl group, and in addition, means a cyclic compound that contains at least one heteroatom selected from N, O, S, P, and Si in place of carbon (C), such as an aryl group, a cycloalkyl group, a fusion ring thereof, or a combination thereof. If the heterocyclic group is a fusion ring, it may contain one or more heteroatoms in the entire heterocyclic group or in each ring.

[0037] More specifically, substituted or unsubstituted aryl groups and / or substituted or unsubstituted heterocyclic groups include substituted or unsubstituted phenyl groups, substituted or unsubstituted naphthyl groups, substituted or unsubstituted anthracenyl groups, substituted or unsubstituted phenanthryl groups, substituted or unsubstituted naphthacenyl groups, substituted or unsubstituted pyrenyl groups, substituted or unsubstituted biphenyl groups, substituted or unsubstituted terphenyl groups, substituted or unsubstituted quarterphenyl groups, substituted or unsubstituted chrysenyl groups, and substituted or unsubstituted triphenyl groups. 114 group, substituted or unsubstituted perilenyl group, substituted or unsubstituted indenyl group, substituted or unsubstituted furanyl group, substituted or unsubstituted thiophenyl group, substituted or unsubstituted pyrrolyl group, substituted or unsubstituted pyrazolyl group, substituted or unsubstituted imidazoleyl group, substituted or unsubstituted triazoleyl group, substituted or unsubstituted oxazoleyl group, substituted or unsubstituted thiazoyl group, substituted or unsubstituted oxadiazoleyl group, substituted or unsubstituted thiadiazoleyl group, substituted or unsubstituted pyridinyl group Group, substituted or unsubstituted pyrimidinyl group, substituted or unsubstituted pyrazinyl group, substituted or unsubstituted triazinyl group, substituted or unsubstituted benzofuranyl group, substituted or unsubstituted benzothiophenyl group, substituted or unsubstituted benzimidazoleyl group, substituted or unsubstituted indoleyl group, substituted or unsubstituted quinolinyl group, substituted or unsubstituted isoquinolinyl group, substituted or unsubstituted quinazolinyl group, substituted or unsubstituted quinoxalinyl group, substituted or unsubstituted naphthilidinyl group, substituted or unsubstituted ben Zooxazineyl group, substituted or unsubstituted benzothiadinyl group, substituted or unsubstituted acridinyl group, substituted or unsubstituted phenazineyl group, substituted or unsubstituted phenothiazineyl group, substituted or unsubstituted phenoxazineyl group, substituted or unsubstituted fluorenyl group, substituted or unsubstituted dibenzofuran group, substituted or unsubstituted dibenzothiophenyl group, substituted or unsubstituted carbazolyl group, pyridoindoleyl group, benzopyridoxazineyl group, benzopyridhiazineyl group, 9,9-dimethyl-9,The 10-dihydroacridine group, combinations thereof, or fused forms thereof may be, but are not limited to, these.

[0038] In this specification, unless otherwise specified, “combination” means mixing or copolymerization.

[0039] Furthermore, in this specification, "polymer" may include both oligomers and polymers.

[0040] Unless otherwise specified herein, "weight-average molecular weight" is measured by dissolving the 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).

[0041] Furthermore, unless otherwise defined herein, "*" indicates a linkage point between structural units or moieties of a polymer.

[0042] The semiconductor industry continues to demand smaller chip sizes. To meet this trend, it is necessary to reduce the line width of resists patterned using lithography technology to the tens of nanometers level. The patterns formed in this way are then used to transfer the patterns onto the underlying substrate using an etching process. However, as the resist pattern size decreases, the height (aspect ratio) of the resist that can withstand that line width is limited, which can result in the resist not having sufficient resistance during the etching step. Therefore, when using a thin resist material, when the substrate to be etched is thick, or when deep patterns are required, a resist underlayer film has been used to compensate for this.

[0043] The resist underlayer must become thinner as the resist thickness decreases, and even with a small thickness of the resist underlayer, the photoresist pattern must not be disrupted. Therefore, the resist underlayer needs to have excellent adhesion to the photoresist. Furthermore, in forming a thin resist underlayer, it is required that the coating uniformity of the resist underlayer composition and the flatness of the resist underlayer produced therefrom be improved, as well as improved sensitivity to the exposure light source, pattern formation performance, and energy efficiency.

[0044] One embodiment of the resist underlayer composition comprises a polymer containing structural units represented by the following chemical formula 1 and structural units represented by the following chemical formula 2, and a solvent.

[0045] [ka]

[0046] In chemical formula 1, m is one of the integers from 1 to 4. n is one of the integers from 1 to 4. m+n is an integer less than or equal to 5, * indicates a connection point.

[0047] [ka]

[0048] In chemical formula 2, L 1 These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C3-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X 1 and X 2These are, independently, single bonds, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, and -NR. a -(Here, R a (is hydrogen, deuterium, or a C1-C10 alkyl group), or a combination thereof. Y 1 This is a group represented by the following chemical formula 3, R 1 ~R 3 Each of these is independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group. * indicates a connection point.

[0049] [ka]

[0050] In chemical formula 3, M 1 These are single bonds, substituted or unsubstituted C1-C20 alkylene groups, substituted or unsubstituted C2-C20 alkenylene groups, -O-, -NH-, or combinations thereof. Z 1 and Z 2 These are, independently, -C(=O)- or -CH(OH)-, M 2 These are single bonds, double bonds, and *-C(R b )=*(where R b is hydrogen, deuterium, or a C1-C5 alkyl group, and * is Z 1 or Z 2 It is a linking point to, or a substituted or unsubstituted C1-C3 alkylene group. M 3 These are a hydroxyl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, or a substituted or unsubstituted C6-C20 aryl group. M 1 and M 3 or M 2 and M 3They selectively connect with each other to form a ring, * indicates a connection point.

[0051] The polymer contained in the resist underlayer composition according to one embodiment includes a structural unit represented by chemical formula 1 and a structural unit represented by chemical formula 2. The structural unit represented by chemical formula 1 contains a benzene ring and an iodine(I) atom, has high absorbance efficiency, and can improve the sensitivity of the polymer during exposure. The structural unit represented by chemical formula 2 contains a group represented by chemical formula 3 at its terminal end, and the group represented by chemical formula 3 can coordinate bond with inorganic substances in the photoresist by containing two or more (C=O)- or -C(OH)- groups in close proximity. Therefore, the adhesion between the resist underlayer formed from the polymer-containing composition and the photoresist film can be improved.

[0052] In chemical formula 1, m may be, for example, one integer from 1 to 4, for example, one integer from 1 to 3, 1 or 2, or 1. Also, n may be, for example, one integer from 1 to 4, for example, one integer from 1 to 3, 2 or 3, or 2. In this case, m+n is less than or equal to 5, and may be, for example, one integer from 2 to 4, for example, 3.

[0053] In chemical formula 2, X 1 and X 2 These may, for example, be a single bond, -O-, -C(=O)-, or -(CO)O-, independently of each other, for example, a single bond or -(CO)O-, but are not limited to these.

[0054] In chemical formula 2, L 1 This may include, for example, a single-bonded, substituted or unsubstituted C1-C10 alkylene group, or a substituted or unsubstituted C2-C10 alkenylene group, for example, a single-bonded, substituted or unsubstituted C1-C10 alkylene group, for example, a single-bonded or unsubstituted C1-C10 alkylene group, for example, a single-bonded or unsubstituted C1-C10 alkylene group, or for example, a single-bonded or unsubstituted C1-C5 alkylene group with a hydroxyl group, but is not limited to these.

[0055] In chemical formula 2, R 1 ~R 3 This may be, for example, hydrogen, deuterium, or a substituted or unsubstituted C1-C5 alkyl group, such as a hydrogen, methyl group, or ethyl group, but is not limited to these.

[0056] In chemical formula 3, M 1 This may be, for example, a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, -O-, -NH-, or a combination thereof; for example, a single bond, a substituted or unsubstituted C1-C5 alkylene group, a substituted or unsubstituted C2-C5 alkenylene group, -O-, -NH-, or a combination thereof; for example, a substituted or unsubstituted C1-C5 alkylene group; for example, -N-; for example, a combination of -O- and a C1-C5 alkylene group; for example, a combination of -O- and a C2-C5 alkenylene, but is not limited to these.

[0057] In chemical formula 3, Z 1 and Z 2 These can each be independently -C(=O)- or -CH(OH)-, for example, Z 1 and Z 2 These are -C(=O)- respectively, for example, Z 1 and Z 2 These are each -CH(OH)-, for example, Z 1 and Z 2 One of them may be -C(=O)-, and the other may be -CH(OH)-.

[0058] In chemical formula 3, M 2 These are single bonds, double bonds, and *-C(R b )=*(where R b*-C(R b In )=*, * is Z 1 or Z 2 This is the point of connection.

[0059] M 2 If it has more carbon atoms than the options, Z 1 and Z 2 The distance between them increases, making it difficult to effectively form coordination bonds with inorganic materials in the photoresist, which can result in poor adhesion between the photoresist film and the resist underlayer film. In other words, M 2 However, single bonds, double bonds, *-C(R b )=*, or in the case of substituted or unsubstituted C1-C3 alkylene groups, the adhesion between the resist underlayer film produced from the polymer and the photoresist film can be effectively improved.

[0060] In chemical formula 3, M 3 This includes, but is not limited to, a hydroxyl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, or a substituted or unsubstituted C6-C20 aryl group, for example, a hydroxyl group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C10 alkenyl group, or a substituted or unsubstituted C6-C10 aryl group, for example, a hydroxyl group, a substituted or unsubstituted C1-C5 alkyl group, a substituted or unsubstituted C2-C5 alkenyl group, or a phenyl group.

[0061] M in chemical formula 3 1 and M 3 , or M 2 and M 3 These can be linked together independently to form a ring. In other words, M of chemical formula 31 and M 3 can be selectively connected to each other to form a ring, or M 2 and M 3 can be selectively connected to each other to form a ring. For example, M 1 and M 3 can each independently exist, and M 1 and M 3 can be connected to each other to form a ring, and M 2 and M 3 can each independently exist, and M 2 and M 3 can be connected to each other to form a ring.

[0062] In the polymer, the molar ratio of the structural unit represented by Chemical Formula 1 to the structural unit represented by Chemical Formula 2 may be 9:1 to 1:9, for example, 8:2 to 2:8, 7:3 to 2:8, 6:4 to 2:8, 5:5 to 2:8, 8:2 to 3:7, 8:2 to 4:6, or 8:2 to 5:5, but is not limited thereto. By including the structural units in the polymer in the above ratios, it becomes possible to easily adjust the light absorption efficiency and / or sensitivity of the resist underlayer film composition according to one embodiment, and the surface roughness and flattening degree of the resist underlayer film produced therefrom can be optimized.

[0063] The resist underlayer film composition according to another embodiment may further include a structural unit represented by the following Chemical Formula 4.

[0064]

Chemical formula

[0065] [[ID=^2]] In Chemical Formula 4, L 2These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C2-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X 3 and X 4 These are, independently, single bonds, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, and -NR. c -(Here, R c is hydrogen, deuterium, or a C1-C10 alkyl group, or a combination thereof. Y 2 These are a hydroxyl 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 C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group. R 4 ~R 6 Each of these is independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group. * indicates a connection point.

[0066] In chemical formula 4, L 2 For example, this could be a single bond, a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkenylene group, or a substituted or unsubstituted C6-C10 allylene group. For example, it could be a single bond, a substituted or unsubstituted C1-C10 alkylene group, or a substituted or unsubstituted C6-C10 allylene group. For example, it could be a single bond, or a substituted or unsubstituted C1-C5 alkylene group, but is not limited to these.

[0067] In chemical formula 4, X 3 and X 4These are, for example, independently a single bond, -O-, -C(=O)-, -S-, -S(=O)-, -S(=O)2-, or -(CO)O-, and may, for example, be a single bond or -(CO)O-, but are not limited to these.

[0068] In chemical formula 4, Y 2 For example, this could be a hydroxyl 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 a substituted or unsubstituted C6-C20 aryl group. For example, it could be a hydroxyl group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group. For example, it could be a hydroxyl group, a substituted or unsubstituted C1-C5 alkyl group, or a substituted or unsubstituted C2-C10 heterocycloalkyl group, but is not limited to these.

[0069] In chemical formula 4, R 4 ~R 6 Each of these is independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group, which may, for example, be hydrogen, deuterium, or a substituted or unsubstituted C1-C5 alkyl group, but is not limited to these.

[0070] For example, chemical formula 2 can be represented by one or more of the following chemical formulas 2-1 to 2-8.

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] The polymer can have a weight-average molecular weight of 1,000 g / mol to 300,000 g / mol, for example, about 3,000 g / mol to 200,000 g / mol, for example, 3,000 g / mol to 100,000 g / mol, for example, 3,000 g / mol to 90,000 g / mol, for example, 3,000 g / mol to 70,000 g / mol, for example, 3,000 g / mol to 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, or for example, 5,000 g / mol to 30,000 g / mol, but is not limited to these ranges. By having a weight-average molecular weight within the above range, the carbon content and solubility in the solvent of the resist underlayer composition containing the polymer can be adjusted and optimized.

[0075] The polymer may be included in an amount of 0.05% to 50% by weight based on the total weight of the resist underlayer composition. More specifically, the polymer may be included in amounts of 0.05% to 40% by weight, 0.05% to 30% by weight, 0.05% to 20% by weight, 0.1% to 40% by weight, for example, 0.1% to 30% by weight, for example, 0.1% to 20% by weight, for example, 0.2% to 20% by weight, based on the total weight of the resist underlayer composition, but is not limited to these. By including the polymer in the composition within the above ranges, the thickness, surface roughness, and degree of planarization of the resist underlayer can be adjusted.

[0076] A composition for a resist underlayer according to one embodiment may contain a solvent. The solvent is not particularly limited as long as it has sufficient solubility and / or dispersibility with the polymer and compound according to one embodiment. For example, the solvent may include, but is not limited to, propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, de-friction-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone, methylpyrrolidinone, methyl 2-hydroxyisobutyrate methyl, acetylacetone, ethyl 3-ethoxypropionate, or combinations thereof.

[0077] A composition for a resist underlayer film according to one embodiment may further include, but is not limited to, one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluryl resins, and melamine resins, in addition to the polymer and solvent.

[0078] Furthermore, compositions for resist underlayers according to other embodiments may further include additives comprising surfactants, thermal acid generators, plasticizers, or combinations thereof.

[0079] Surfactants can be used to suppress coating defects that occur due to an increase in solid content during the formation of the resist underlayer film. Examples of surfactants that can be used include, but are not limited to, alkylbenzene sulfonates, alkylpyridinium salts, polyethylene glycol, and quaternary ammonium salts.

[0080] Examples of acidic compounds and / or benzoin tosylate, 2-nitrobenzyl tosylate, and other organic alkyl sulfonates can be used as the thermal acid generator, but are not limited to these. Examples include p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonic acid, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid, and / or benzoin tosylate, 2-nitrobenzyl tosylate, and other organic alkyl sulfonates.

[0081] The plasticizer is not particularly limited, and various known types of plasticizers can be used. Examples of plasticizers include low molecular weight compounds such as phthalates, adipicates, phosphates, trimelliticates, and citrates, as well as compounds such as polyethers, polyesters, and polyacetals.

[0082] The additive can be included in an amount of 0.001 to 40 parts by weight per 100 parts by weight of the resist underlayer composition. By including the additive within this range, the solubility can be improved without changing the optical properties of the resist underlayer composition.

[0083] In another embodiment, a resist underlayer film is provided which is manufactured using the resist underlayer film composition described above. The resist underlayer film may be obtained by coating the resist underlayer film composition described above onto a substrate, for example, and then curing it through a heat treatment process.

[0084] The following describes a method for forming a pattern using the resist underlayer composition described above, with reference to Figure 1. Figure 1 is a cross-sectional view illustrating a pattern formation method using the resist underlayer composition according to the present invention.

[0085] Referring to Figure 1(a), a priority etching target is prepared. An example of an etching target may be a thin film 102 formed on a semiconductor substrate 100. The following explanation will only describe the case where the etching target is a thin film 102. To remove contaminants and other materials remaining on the thin film 102, the surface of the thin film is cleaned. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0086] Next, the aforementioned resist underlayer composition is coated onto the surface of the cleaned thin film 102 using a spin coating method.

[0087] Subsequently, drying and baking steps are performed to form a resist underlayer film 104 on the thin film. The baking process is carried out at 100°C to 500°C, for example, at 100°C to 300°C. A more specific description of the resist underlayer film composition has already been explained in detail, so it will be omitted to avoid repetition.

[0088] Referring to Figure 1(b), a photoresist is coated onto the resist underlayer film 104 to form a photoresist film 106.

[0089] Examples of photoresists include positive-type photoresists containing a naphthoquinone diazide compound and a novolac resin; chemically amplified positive-type photoresists containing an acid generator that can dissociate acid upon exposure, a compound and an alkali-soluble resin that decompose in the presence of acid to increase solubility in alkaline aqueous solutions; and chemically amplified positive-type photoresists containing an acid generator and an alkali-soluble resin having a group that can impart a resin that decomposes in the presence of acid to increase solubility in alkaline aqueous solutions.

[0090] 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.

[0091] Referring to Figure 1(c), the photoresist film 106 is selectively exposed. As an example of the exposure process for exposing the photoresist film 106, an exposure mask with a predetermined pattern is placed on the mask stage of the exposure apparatus, and the exposure mask 110 is placed on the photoresist film 106. Subsequently, by irradiating the exposure mask 110 with light, a predetermined portion of the photoresist film 106 formed on the substrate 100 reacts selectively with the light transmitted through the exposure mask.

[0092] Examples of light that can be used in the exposure process include short-wavelength light such as the i-line activation irradiation line with a wavelength of 365 nm, the KrF excimer laser with a wavelength of 248 nm, and the ArF excimer laser with a wavelength of 193 nm. In addition, there is also EUV (Extreme Ultra Violet) with a wavelength of 13.5 nm, which corresponds to extreme ultraviolet light.

[0093] The photoresist film 106a in the exposed area is relatively more hydrophilic than the photoresist film 106b in the unexposed area. Therefore, the photoresist films in the exposed area 106a and the unexposed area 106b have different solubility levels.

[0094] Next, a second baking process is performed on the substrate 100. The second baking process can be carried out at a temperature of 90°C to 150°C. By performing the second baking process, the photoresist film corresponding to the exposed area becomes easily soluble in a specific solvent.

[0095] Referring to Figure 1(d), specifically, by using tetramethylammonium hydroxide (TMAH) or the like to dissolve and remove the photoresist film 106a corresponding to the exposed area, the photoresist film 106b remaining after development forms the photoresist pattern 108.

[0096] Next, the resist underlayer film 104 is etched using the photoresist pattern 108 as an etching mask. This etching process forms an organic film pattern 112 as shown in Figure 1(e). Etching can be performed, for example, by dry etching using an etching gas. Examples of etching gases that can be used include CHF3, CF4, Cl2, O2, and mixtures thereof. As described above, the resist underlayer film formed by the resist underlayer film composition according to one embodiment has a high etching rate, so the etching process can be carried out smoothly in a short time.

[0097] Referring to Figure 1(f), the photoresist pattern 108 is applied as an etching mask to etch the exposed thin film 102. As a result, the thin film is formed into a thin film pattern 114. In the exposure process performed earlier, the thin film pattern 114 formed by exposure using a short-wavelength light source such as the activation irradiation line 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 to several hundred nm, while the thin film pattern 114 formed by exposure using an EUV light source can have a width of 20 nm or less. [Examples]

[0098] The present invention will be described in more detail below through examples relating to the synthesis of the polymer described above and the formation of a resist underlayer film composition containing the polymer. However, the present invention is not technically limited by the following examples.

[0099] Polymer synthesis Synthesis Example 1 A reaction solution was prepared by adding 42.77 g of 2,6-diiodo-4-vinylphenol, 24.64 g of (2-acetoacetoxy)ethyl methacrylate (TCI), 1.9 g of dimethyl-2,2'-azobis(2-methylpropionate) (V-601; TCI), and 70 g of propylene glycol methyl ether acetate (PGMEA) to a 500 mL three-necked round-bottom flask. A condenser was then connected to the three-necked round-bottom flask. The reaction solution was heated at 100 °C for 5 hours to allow the reaction to proceed, and then the reaction solution was cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum, and the gum was dissolved in 70 g of PGMEA. Finally, a polymer consisting of structural units represented by chemical formulas 1-1 and 2-1 below was obtained (Mw: 4,400 g / mol).

[0100] [ka]

[0101] Synthesis Example 2 A reaction solution was prepared by adding 42.77 g of 2,6-diiodo-4-vinylphenol, 27.17 g of 2-(1-oxo-2-propenyl)oxyethyl ester of 2-hydroxybenzoic acid (Angene), 1.9 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI), and 70 g of propylene glycol methyl ether acetate (PGMEA) to a 100 mL two-necked round-bottom flask. A condenser was then connected to the two-necked round-bottom flask. The reaction solution was heated at 100 °C for 5 hours to allow the reaction to proceed, and then the reaction solution was cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum, and the gum was dissolved in 70 g of PGMEA. Ultimately, a polymer consisting of structural units represented by the following chemical formulas 1-1 and 2-2 was obtained (Mw: 6,100 g / mol).

[0102] [ka]

[0103] Synthesis Example 3 A reaction solution was prepared by adding 19.65 g of 3-chloro-2-hydroxypropyl methacrylate, 16.1 g of 5-methyl isatin, 0.02 g of dibutylated hydroxytoluene (BHT), and 50 g of DMF to a 250 mL two-necked round-bottom flask, and the reaction was carried out at 90°C. After stirring the reaction solution for 5 hours, the reaction solution was quenched with NH4Cl. The reaction solution was washed with water, and the organic layer was concentrated to obtain a compound consisting of structural units represented by the following chemical formulas 2-5.

[0104] Subsequently, 57.5 g of monomer represented by chemical formula 2-5, along with 43 g of 2,6-diiodo-4-vinylphenol, 2 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI), and 100 g of propylene glycol methyl ether acetate (PGMEA) were added to a 500 mL two-necked round-bottom flask to prepare the reaction solution, and a condenser was connected to the two-necked round-bottom flask. The reaction solution was heated at 90°C for 2 hours, and the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum. The gum was then dissolved in 100 g of PGMEA to finally obtain a polymer consisting of structural units represented by chemical formulas 1-1 and 2-5 below (Mw: 7,600 g / mol).

[0105] [ka]

[0106] Synthesis Example 4 A reaction solution was prepared by adding 42.8g of 2,6-diiodo-4-vinylphenol, 24.6g of (2-acetoacetoxy)ethyl methacrylate (TCI), 16.4g of glycidyl methacrylate (TCI), 2g of dimethyl 2,2'azobis(methylpropionate) (V-601; TCI), and 85g of propylene glycol methyl ether acetate (PGMEA) to a 500mL three-necked round-bottom flask. A condenser was then connected to the three-necked round-bottom flask. The reaction solution was heated at 90°C for 1 hour to allow the reaction to proceed, and then cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450g of heptane in a beaker with stirring to produce gum, and the gum was then dissolved in 90g of PGMEA. Ultimately, a polymer consisting of structural units represented by the following chemical formulas 1-1, 2-1, and 4-1 was obtained (Mw: 8,800 g / mol).

[0107] [ka]

[0108] Comparative Synthesis Example 1 A reaction solution was prepared by adding 20 g of methyl methacrylate, 3.5 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI) and 75 g of propylene glycol methyl ether acetate (PGMEA) to a 250 mL three-necked round-bottom flask, and a condenser was connected to the three-necked round-bottom flask. The reaction solution was heated at 75°C for 3 hours to allow the reaction to proceed, and then the reaction solution was cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum, and the gum was dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following chemical formula 5 was obtained (Mw: 3,000 g / mol).

[0109] [ka]

[0110] Comparative Synthesis Example 2 A reaction solution was prepared by adding 28 g of glycidyl methacrylate (TCI), 3.2 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI), and 30 g of propylene glycol methyl ether acetate (PGMEA) to a 250 mL three-necked round-bottom flask. A condenser was then connected to the three-necked round-bottom flask. The reaction solution was heated at 85°C for 2 hours to allow the reaction to proceed, and then the reaction solution was cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum, and the gum was dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units represented by the following chemical formula 4-1 was obtained (Mw: 3,500 g / mol).

[0111] [ka]

[0112] Comparative Synthesis Example 3 A reaction solution was prepared by adding 75 g of 2,6-diiodo-4-vinylphenol, 3.3 g of dimethyl 2,2'-azobis(2-methylpropionate) (V-601; TCI) and 75 g of propylene glycol methyl ether acetate (PGMEA) to a 250 mL three-necked round-bottom flask. A condenser was then connected to the three-necked round-bottom flask. The reaction solution was heated at 90°C for 3 hours to allow the reaction to proceed, and then the reaction solution was cooled to room temperature. Subsequently, the reaction solution was added dropwise to 450 g of heptane in a beaker with stirring to produce gum, and the gum was dissolved in 90 g of PGMEA. Finally, a polymer consisting of structural units shown in the following chemical formula 1-1 was obtained (Mw: 3,400 g / mol).

[0113] [ka]

[0114] Preparation of compositions for resist underlayer films Examples 1-4 and Comparative Examples 1-3 1.2 g of each polymer obtained in Synthesis Examples 1-4 and Comparative Synthesis Examples 1-3, 0.4 g of PL1174 (crosslinking agent), and 0.04 g of ammonium triflate (AOTf) were mixed in 15 g of propylene glycol monomethyl ether and completely dissolved. Further dilution with a solvent prepared the resist underlayer compositions of Examples 1-4 and Comparative Examples 1-3, each containing 0.45% by weight of polymer based on total weight.

[0115] Evaluation 1: Exposure characteristics evaluation The compositions prepared in Examples 1-4 and Comparative Examples 1-3 were each coated by spin coating, and then heat-treated on a hot plate at 205°C for 60 seconds to form a 5 nm thick resist underlayer film. Subsequently, a photoresist solution was coated onto the resist underlayer film by spin coating, and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The photoresist layer was exposed to 200 μC / cm using an e-beam exposure unit (manufactured by Elionix). 2 ~2000 μC / cm 2 After exposure at the specified intensity, the material was heat-treated at 150°C for 60 seconds. Subsequently, the photoresist layer was developed with a 2.38 mass% aqueous solution of TMAH, washed with pure water for 15 seconds, and a 50 nm line-and-space (L / S) photoresist pattern was formed. The optimal exposure amount for the photoresist pattern was then evaluated.

[0116] Evaluation 2: Line Width Roughness (LWR) Evaluation The compositions prepared in Examples 1-4 and Comparative Examples 1-3 were each coated by spin coating, and then heat-treated on a hot plate at 205°C for 60 seconds to form a 5 nm thick resist underlayer film. Subsequently, a photoresist solution was coated onto the resist underlayer film by spin coating, and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist layer. The resist layer was exposed using an e-beam exposure unit (manufactured by Elionix, accelerating voltage 100 keV) under conditions of a line width of 30 nm and a space width between lines of 30 nm. Next, after heat treatment at 95°C for 60 seconds, the resist pattern was formed by developing with a 2.38 wt% aqueous solution of tetramethylammonium hydroxide (TMAH) for 60 seconds and washing with pure water for 15 seconds.

[0117] Pattern collapse was evaluated by observing the formed pattern with an electron scanning microscope (SEM) S-9260 (manufactured by Hitachi). In Table 1 below, cases where pattern collapse was observed are indicated by O, and cases where it was not observed are indicated by X.

[0118] Line width roughness (LWR) was determined by observing a pattern formed with a width of 30 nm using an electron scanning microscope (SEM) S-9260 (manufactured by Hitachi). The distance from the reference line to the edge was measured for a 2 μm range in the longitudinal direction of the pattern. The results are shown in Table 1, and a smaller LWR value is considered better.

[0119] The exposure evaluation values ​​for the measured examples and comparative examples were converted based on the exposure of Comparative Example 3 (100%), and the LWR evaluation values ​​were converted based on the LWR value of Comparative Example 2 (100%). The results are shown in Table 1 below. For exposure and line width roughness (LWR), smaller values ​​indicate better pattern formation and sensitivity.

[0120] [Table 1]

[0121] Referring to Table 1, it can be confirmed that the resist underlayer films produced in Examples 1-4 exhibit superior fine pattern formation (L / S: 50 nm) and sensitivity compared to the comparative example. Furthermore, the resist underlayer films produced in Examples 1-4 have a lower LWR value compared to the comparative example, indicating even greater pattern uniformity.

[0122] Although specific embodiments of the present invention have been described and illustrated above, it is obvious to those ordinary skill in the art that the present invention is not limited to the described embodiments, and that various modifications and variations are possible without departing from the spirit and scope of the invention. Therefore, such modifications or variations should not be understood individually from the technical spirit or viewpoint of the present invention, and the modified embodiments should be considered to fall within the scope of the claims of the present invention. [Explanation of symbols]

[0123] 100 circuit boards 102 Thin film 104 Resist underlayer 106 Photoresist film 106a Exposed region 106b Unexposed area 108 Photoresist Patterns 110 masks 112 Organic film patterns 114 Thin Film Patterns

Claims

1. A polymer comprising a structural unit represented by the following chemical formula 1 and a structural unit represented by the following chemical formula 2, and a solvent, 【Chemistry 1】 In the aforementioned chemical formula 1, m is one of the integers from 1 to 4. n is one of the integers from 1 to 4. m+n is an integer less than or equal to 5, * indicates a connecting point. 【Chemistry 2】 In the aforementioned chemical formula 2, L １ These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C3-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X １ and X ２ These are, independently, single bonds, -O-, -S-, -S(=O)-, and -S(=O). ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR ａ - (Here, R ａ is hydrogen, deuterium, or a C1-C10 alkyl group, or a combination thereof. Y １ This is a group represented by the following chemical formula 3, R １ ~R ３ each independently represents hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group, * indicates a connection point. 【Transformation 3】 In the aforementioned chemical formula 3, M １ These are single bonds, substituted or unsubstituted C1-C20 alkylene groups, substituted or unsubstituted C2-C20 alkenylene groups, -O-, -NH-, or combinations thereof. Z １ and Z ２ These are, independently, -C(=O)- or -CH(OH)-, M ２ This includes single bonds, double bonds, and *-C(R) ｂ ) = * (where R ｂ is hydrogen, deuterium, or a C1-C5 alkyl group, and * is the same as Z. １ or Z ２ It is a linking point with, or a substituted or unsubstituted C1-C3 alkylene group. M ３ These are a hydroxyl group, a substituted or unsubstituted C1-C20 alkyl group, a substituted or unsubstituted C2-C20 alkenyl group, or a substituted or unsubstituted C6-C20 aryl group. Said M １ and M ３ or M ２ and M ３ They selectively connect with each other to form a ring, * indicates a linking point; composition for resist underlayer film.

2. The resist underlayer composition according to claim 1, wherein m and n in the chemical formula 1 are independently 1 or 2.

3. L of the aforementioned chemical formula 3 １ is a single bond, or a substituted or unsubstituted C1-C10 alkylene group, X １ and X ２ The resist underlayer composition according to claim 1, wherein each of them is independently a single bond or -(CO)O-.

4. The resist underlayer composition according to claim 1, wherein the structural unit represented by chemical formula 1 and the structural unit represented by chemical formula 2 are present in the polymer in a molar ratio of 9:1 to 1:

9.

5. The polymer further comprises a structural unit represented by the following chemical formula 4, 【Chemistry 4】 In the aforementioned chemical formula 4, L ２ These are single bonds, substituted or unsubstituted C1-C10 alkylene groups, substituted or unsubstituted C2-C10 alkenylene groups, substituted or unsubstituted C2-C10 alkylylene groups, substituted or unsubstituted C3-C20 cycloalkylene groups, substituted or unsubstituted C2-C20 heterocycloalkylene groups, substituted or unsubstituted C6-C20 allylene groups, or combinations thereof. X ３ and X ４ These are, independently, single bonds, -O-, -S-, -S(=O)-, and -S(=O). ２ -, -C(=O)-, -(CO)O-, -O(CO)O-, -C(=O)NH-, -NR ｃ - (Here, R ｃ is hydrogen, deuterium, or a C1-C10 alkyl group, or a combination thereof. Y ２ These are a hydroxyl 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 C3-C20 cycloalkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group. R ４ ~R ６ Each of these is independently hydrogen, deuterium, or a substituted or unsubstituted C1-C10 alkyl group. * indicates a linking point, the resist underlayer composition according to claim 1.

6. L of the aforementioned chemical formula 4 ２ X is a single bond, a substituted or unsubstituted C1-C10 alkylene group, or a substituted or unsubstituted C6-C10 allylene group, ３ and X ４ Each of these is independently a single bond or -(CO)O-, and Y ２ The resist underlayer composition according to claim 5, wherein is a hydroxyl group, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C2-C20 heterocycloalkyl group, or a substituted or unsubstituted C6-C20 aryl group.

7. The resist underlayer film composition according to claim 1, wherein the chemical formula 2 is represented by one or more of the following chemical formulas 2-1 to 2-8. 【Transformation 5】 【Transformation 6】 【Transformation 7】

8. 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.

9. The resist underlayer composition according to claim 1, wherein the polymer is contained in an amount of 0.05% to 50% by weight, based on the total weight of the resist underlayer composition.

10. The composition for a resist underlayer film according to claim 1, further comprising one or more polymers selected from acrylic resins, epoxy resins, novolac resins, glycoluryl resins, and melamine resins.

11. The composition for a resist underlayer film according to claim 1, further comprising an additive which is a surfactant, a thermal acid generator, a photoacid generator, a plasticizer, or a combination thereof.

12. Steps include forming an etching target film 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, The steps of forming a photoresist pattern on the resist underlayer film, and The step involves using the aforementioned photoresist pattern as an etching mask to sequentially etch the resist underlayer and the film to be etched. A pattern formation method including the following.

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