Resist topcoat compositions and methods of forming patterns using the same

Abstract

To provide a resist topcoat composition capable of reducing pattern distribution by preventing or reducing pattern deterioration.SOLUTION: A resist topcoat composition according to one embodiment includes a copolymer including a first structural unit represented by chemical formula M-1 and a second structural unit represented by chemical formula M-2; a photoacid generator; and a solvent, wherein the photoacid generator is a non-ionic compound or an ionic compound, the non-ionic compound includes an organic sulfonate group, and the ionic compound includes at least one selected from a conjugate base of an inorganic acid and a conjugate base of an organic sulfonic acid as an anion. Details concerning the chemical formulas are as described in the specification.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Recently, the semiconductor industry has been evolving from patterns of hundreds of nanometers to ultra-fine technology with patterns of several nanometers to tens of nanometers. To realize such ultra-fine technology, an effective photolithography process is essential.

[0003] A typical photolithography process includes forming a material layer on a semiconductor substrate, coating a photoresist layer thereon, exposing and developing the material layer to form a photoresist pattern, and then etching the material layer using the photoresist pattern as a mask.

[0004] As photolithography technology advances, the degree of pattern integration increases, and new materials and technologies are required to solve various problems that arise during this process.

[0005] In particular, when EUV is irradiated onto photoresist, it is known that photo shot noise, which occurs when areas are randomly irradiated with more or less light due to the large energy per photon, or the difference in EUV absorption between the top and bottom of the photoresist can cause pattern variation degradation such as pattern roughness (LER: Line Edge Roughness, LWR: Line Width Roughness) or IPU, and there is a demand for technological development to improve this. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Korean Patent Registration No. 0800397 [Patent Document 2] Korean Patent Publication No. 2023-0037368 [Patent Document 3] Korean Patent Publication No. 2012-0074812 Summary of the Invention [Problem to be solved by the invention]

[0007] A composition for a resist upper layer film is provided that can prevent pattern deterioration and reduce pattern variation.

[0008] Another embodiment provides a pattern forming method using a resist top layer film composition. [Means for solving the problem]

[0009] One embodiment provides a composition for a resist top layer film, comprising: a copolymer including a first structural unit represented by the following chemical formula M-1 and a second structural unit represented by the following chemical formula M-2; a photoacid generator; and a solvent, wherein the photoacid generator is a nonionic compound or an ionic compound, the nonionic compound includes an organic sulfonate group, and the ionic compound includes at least one of a conjugate base of an inorganic acid and a conjugate base of an organic sulfonic acid as an anion. [Chemical formula M-1] [ka] [Chemical formula M-2] [ka] In the above chemical formula M-1 and chemical formula M-2, R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, L 1 and L 2 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a combination thereof; X 1 is a single bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO), -O(CO)O-, -NR a -(where R a is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms), or a combination thereof; R 3 is hydrogen, fluorine, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a combination thereof; R 4 is hydrogen, or C(=O)R b and R b is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R 3 , L 1 and L 2 at least one of which contains fluorine and a hydroxy group; R 5 is hydrogen, halogen, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof; m1 is an integer from 1 to 4, * indicates the linkage site.

[0010] Another embodiment provides a pattern formation method including the steps of applying a photoresist composition on a substrate and heating it to form a photoresist film, applying the above-mentioned resist upper layer film composition on the photoresist film and heating it to form an upper layer film, and exposing and developing the upper layer film and the photoresist film to form a resist pattern. [Effects of the Invention]

[0011] When the composition for a resist top layer film according to an embodiment is applied to an EUV photoresist, the amount of acid generated at the exposed area is increased, enabling patterning with less energy, thereby improving the sensitivity of the EUV photoresist. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic diagram illustrating a pattern formation method using a resist upper layer film composition according to one embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0013] Although the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein, the present invention will be described in detail below so that those skilled in the art can easily practice the present invention.

[0014] In the drawings, the thickness of various layers and regions has been exaggerated for clarity, and similar parts have been given the same reference numerals throughout the specification. When a layer, film, region, plate, or other part is said to be "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part between them. Conversely, when a part is said to be "directly on" another part, it means that there is no other part between them.

[0015] Unless otherwise defined in this specification, "substituted" means that a hydrogen atom in a compound has been replaced with a halogen atom (F, Br, Cl, or I), an oxo group, a hydroxy group, a thiol group, a nitro group, a cyano group, an amino group, an azide group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a vinyl group, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkynyl group having 2 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, or an aryl group having 6 to 30 carbon atoms. , an alkoxy group having 1 to 30 carbon atoms, a sulfide group having 1 to 30 carbon atoms, a heteroalkyl group having 1 to 20 carbon atoms, a heteroaryl group having 2 to 20 carbon atoms, a heteroarylalkyl group having 3 to 20 carbon atoms, a cycloalkyl group having 3 to 30 carbon atoms, a cycloalkenyl group having 3 to 15 carbon atoms, a cycloalkynyl group having 6 to 15 carbon atoms, a heterocycloalkyl group having 3 to 30 carbon atoms, and combinations thereof.

[0016] In this description, unless otherwise defined, the term "alkyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group. The alkyl group is a "saturated alkyl group" that does not contain any double or triple bonds.

[0017] The alkyl group may be an alkyl group having 1 to 20 carbon atoms. More specifically, the alkyl group may be an alkyl group having 1 to 10 carbon atoms or an alkyl group having 1 to 6 carbon atoms. For example, an alkyl group having 1 to 5 carbon atoms means that the alkyl chain contains 1 to 5 carbon atoms and is selected from the group consisting of methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups.

[0018] Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, a pentyl group, and a hexyl group.

[0019] In the chemical formulas described herein, t-Bu refers to a tert-butyl group.

[0020] In this description, unless otherwise defined, the term "cycloalkyl group" refers to a monovalent cyclic aliphatic saturated hydrocarbon group.

[0021] The cycloalkyl group means a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and the like.

[0022] The cycloalkyl group may be a cycloalkyl group having 3 to 10 carbon atoms, for example, a cycloalkyl group having 3 to 8 carbon atoms, a cycloalkyl group having 3 to 7 carbon atoms, or a cycloalkyl group having 3 to 6 carbon atoms. For example, the cycloalkyl group may be, but is not limited to, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group.

[0023] In this description, unless otherwise defined, the term "alkenyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group containing one or more double bonds and an aliphatic unsaturated alkenyl group.

[0024] In this description, unless otherwise defined, the term "alkynyl group" refers to a straight-chain or branched-chain aliphatic hydrocarbon group, an aliphatic unsaturated alkynyl group containing one or more triple bonds.

[0025] In this description, "aryl group" means a substituent in which all elements of the cyclic substituent have p-orbitals and these p-orbitals form conjugation, including monocyclic or fused-ring polycyclic (i.e., rings that share adjacent pairs of carbon atoms) functional groups.

[0026] Unless otherwise defined in this specification, the term "hetero" means containing 1 to 10 heteroatoms independently selected from N, O, S, and P.

[0027] In this description, unless otherwise defined, the term "heterocycloalkyl group" means that the cycloalkyl group contains at least one heteroatom selected from the group consisting of N, O, S, P, and Si.

[0028] In this description, a "heteroaryl group" refers to an aryl group containing at least one heteroatom selected from the group consisting of N, O, S, P, and Si. Two or more heteroaryl groups can be directly linked through a sigma bond, or if the heteroaryl group contains two or more rings, the two or more rings can be fused together. If the heteroaryl group is a fused ring, each ring can contain 1 to 3 heteroatoms.

[0029] In this specification, the term "acrylic polymer" is a general term for acrylic polymers and methacrylic polymers.

[0030] Unless otherwise specified in this specification, the "weight average molecular weight" is measured by dissolving a powder sample in tetrahydrofuran (THF) and then using Agilent Technologies' 1200 series gel permeation chromatography (GPC) (using a Shodex LF-804 column and Shodex polystyrene as the standard sample).

[0031] Additionally, unless otherwise defined in this specification, "*" indicates a structural unit of a compound or a linking site of a compound moiety.

[0032] A photoresist upper layer film composition according to one embodiment will be described below.

[0033] The present invention relates to a photoresist top layer film composition that can improve photoresist sensitivity by maximizing the amount of acid generated in exposed areas during a fine pattern formation process in photolithography using high-energy rays such as EUV (Extreme ultraviolet; wavelength 13.5 nm), and a method for forming a photoresist pattern using such a top layer film.

[0034] Specifically, a composition for a resist top layer film according to one embodiment includes a copolymer including a first structural unit represented by the following chemical formula M-1 and a second structural unit represented by the following chemical formula M-2; a photoacid generator; and a solvent, wherein the photoacid generator is a nonionic compound or an ionic compound, the nonionic compound includes an organic sulfonate group, and the ionic compound includes at least one of a conjugate base of an inorganic acid and a conjugate base of an organic sulfonic acid as an anion. [Chemical formula M-1] [ka] [Chemical formula M-2] [ka] In the above chemical formula M-1 and chemical formula M-2, R 1 and R 2 are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, L 1 and L 2 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a combination thereof; X 1 is a single bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO), -O(CO)O-, -NR a -(where R a is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms), or a combination thereof; R 3is hydrogen, fluorine, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a combination thereof; R 4 is hydrogen, or C(=O)R b and R b is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R 3 , L 1 and L 2 at least one of which contains fluorine and a hydroxy group; R 5 is hydrogen, halogen, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof; m1 is an integer from 1 to 4, * indicates the linkage site.

[0035] According to an embodiment, the composition for a photoresist upper layer film includes a photoacid generator and is applied to the upper side of a photoresist layer to maximize the amount of acid generated upon exposure, thereby increasing the sensitivity of the photoresist.

[0036] A photoacid generator is a compound that generates an acid compound when irradiated with light, and examples of the acid generated at this time include hydrogen halides, sulfonic acids, antimony derivatives, and halogen peroxides.

[0037] In addition, the use of a photoacid generator can increase the amount of acid generated in the exposed areas at the top of the photoresist layer upon exposure, thereby increasing the EUV absorption rate and enabling patterning with less energy, thereby improving sensitivity.

[0038] The first structural unit contained in the copolymer in the composition is highly soluble in solvents that have little reactivity with photoresists, thereby minimizing the impact on the photoresist and protecting the photoresist, and the second structural unit enhances EUV absorption, thereby improving sensitivity.

[0039] Therefore, the copolymer has excellent solubility in a solvent, allowing it to be uniformly coated on a pattern and minimizing the influence on the resist.

[0040] As an example, the copolymer can include a first structural unit represented by the formula M-1 and a second structural unit represented by the formula M-2.

[0041] In the chemical formula M-2, when m1 is 2 or more, each OR 4 may be the same or different from each other.

[0042] In the chemical formula M-2, when 5-m1 is 2 or more, each R 5 may be the same or different from each other.

[0043] R 3 , L 1 and L 2 At least one of the above contains fluorine and a hydroxy group. R 3 is an alkyl group having 1 to 20 carbon atoms substituted with at least one fluorine atom and at least one hydroxyl group, or L 1 and L 2 at least one of which is an alkylene group having 1 to 10 carbon atoms substituted with one or more fluorine atoms and one or more hydroxy groups, or L 1 and L 2 at least one of the groups is an alkylene group having 1 to 10 carbon atoms substituted with one or more fluorine atoms, and at least one of the remaining groups is an alkylene group having 1 to 10 carbon atoms substituted with one or more hydroxy groups, or R 3 is fluorine and L 1 and L 2 at least one of which is an alkylene group having 1 to 10 carbon atoms substituted with one or more hydroxy groups, or R 3 is a hydroxy group, and L 1 and L 2at least one of which is an alkylene group having 1 to 10 carbon atoms substituted with one or more fluorine atoms, or R 3 is an alkyl group having 1 to 10 carbon atoms substituted with one or more fluorine atoms and one or more hydroxy groups, or R 3 is an alkyl group having 1 to 10 carbon atoms substituted with one or more hydroxy groups and one or more fluoroalkyl groups having 1 to 10 carbon atoms.

[0044] As a specific example, the first structural unit can be represented by the following Chemical Formula 1. [Chemical formula 1] [ka] In the above chemical formula 1, R 1 is hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R k , R l , R m , R n , and R 3 are each independently hydrogen, fluorine, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a combination thereof; m2 and m3 are each independently an integer from 1 to 10; X 1 is a single bond, -O-, -S-, -S(O)-, -S(O)2-, -C(O)-, -(CO)O-, -O(CO), -O(CO)O-, -NR a -(where R a is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms), or a combination thereof; R k , R l , R m , R n , and R 3 At least one of the groups contains fluorine and a hydroxy group.

[0045] When m2 is 2 or more in chemical formula 1, each R k may be the same or different from each other.

[0046] When m2 is 2 or more in chemical formula 1, each R l may be the same or different from each other.

[0047] When m3 is 2 or more in chemical formula 1, each R m may be the same or different from each other.

[0048] When m3 is 2 or more in chemical formula 1, each R n may be the same or different from each other.

[0049] R k , R l , R m , R n , and R 3 wherein at least one of the groups contains fluorine and a hydroxy group, R k , R l , R m , R n , and R 3 at least one of which is independently a fluorine atom and a hydroxy group; or R k , R l , R m , R n , and R 3 at least one of which independently contains an alkyl group having 1 to 10 carbon atoms substituted with one or more fluorine atoms and an alkyl group having 1 to 10 carbon atoms substituted with one or more hydroxy groups, or R k , R l , R m , R n , and R 3 at least one of which independently contains one or more hydroxy groups and one or more fluorine-substituted alkyl groups having 1 to 10 carbon atoms; or R k , R l , Rm , R n , and R 3 at least one of which independently contains an alkyl group having 1 to 5 carbon atoms substituted with one or more hydroxy groups and one or more fluoroalkyl groups having 1 to 5 carbon atoms; or R k , R l , R m , R n , and R 3 at least one of the groups is fluorine and at least one of the remaining groups is a hydroxy group; or R k , R l , R m , R n , and R 3 at least one of the groups is fluorine, and at least one of the remaining groups contains an alkyl group having 1 to 10 carbon atoms substituted with one or more hydroxy groups, or R k , R l , R m , R n , and R 3 at least one of the groups is a hydroxy group, and at least one of the remaining groups contains an alkyl group having 1 to 10 carbon atoms substituted with one or more fluorine atoms, or R k , R l , R m , R n , and R 3 This means that the present invention includes cases where at least one of the above is an alkyl group having 1 to 20 carbon atoms substituted with one or more fluorine groups, and at least one of the remaining is an alkyl group having 1 to 20 carbon atoms substituted with one or more hydroxy groups.

[0050] For example, R 1 is hydrogen or a methyl group, X 1 is a single bond, -O- or -NR a -(where R a is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms; R 3may be a fluorine atom, a hydroxy group, an alkyl group having 1 to 10 carbon atoms substituted with at least one fluorine atom, or an alkyl group having 1 to 10 carbon atoms substituted with at least one hydroxy group.

[0051] As an example, R in Formula 1 m , R n , and R 3 At least one of the groups may contain fluorine and a hydroxy group.

[0052] As a specific example, R in Chemical Formula 1 m and R n At least one of R is fluorine or an alkyl group having 1 to 10 carbon atoms substituted with at least one fluorine atom, 5 may be a hydroxy group or an alkyl group having 1 to 10 carbon atoms substituted with at least one hydroxy group.

[0053] As a specific example, R in Chemical Formula 1 m and R n at least one of R is a hydroxy group or an alkyl group having 1 to 10 carbon atoms substituted with at least one hydroxy group; 3 may be fluorine or an alkyl group having 1 to 10 carbon atoms substituted with at least one fluorine atom.

[0054] As a specific example, R in Chemical Formula 1 m is a hydroxy group or an alkyl group having 1 to 10 carbon atoms substituted with at least one hydroxy group, and R n is a fluorine atom or an alkyl group having 1 to 10 carbon atoms and substituted with at least one fluorine atom, and R 3 may be a hydroxy group, fluorine, or an alkyl group having 1 to 10 carbon atoms substituted with at least one of a fluorine group and a hydroxy group.

[0055] As a specific example, R in Chemical Formula 1 m and R nAt least one of R is fluorine or an alkyl group having 1 to 10 carbon atoms substituted with at least one fluorine atom, 3 may be a hydroxy group, or an alkyl group having 1 to 5 carbon atoms substituted with at least one of a hydroxy group and a fluoroalkyl group having 1 to 5 carbon atoms.

[0056] For example, the first structural unit can be selected from Group I below. [Group I] [ka]

[0057] In Group I above, R 1 are each independently hydrogen or a methyl group, and * is a linking site.

[0058] As a specific example, the second structural unit can be represented by any one of the following Chemical Formulas 2-1 to 2-4. [Formula 2-1] [Formula 2-2] [Formula 2-3] [Formula 2-4] [ka]

[0059] In the above chemical formulas 2-1 to 2-4, R 2 is hydrogen or a methyl group, R 4 , R 4a , and R 4b are each independently hydrogen or C(=O)R b and R b is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R 5a , R 5b , R 5c , and R 5d are each independently a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof; * indicates the linkage site.

[0060] As an example, R 5 At least one of them may be a halogen.

[0061] As a specific example, R 5 At least one of the groups may be an iodo group.

[0062] When the second structural unit contains an iodine group, the sensitivity can be further improved.

[0063] For example, the second structural unit can be selected from Group II below. [Group II] [ka] [ka]

[0064] In Group II above, R 2 are each independently hydrogen or a methyl group, and * is a linking site.

[0065] The copolymer can contain 50 to 99 mol % of the first structural unit and 1 to 50 mol % of the second structural unit.

[0066] For example, the copolymer may contain 70 to 99 mol% of the first structural unit and 1 to 30 mol% of the second structural unit, and most specifically, may contain 80 to 95 mol% of the first structural unit and 5 to 20 mol% of the second structural unit.

[0067] When the molar ratio of each structural unit contained in the copolymer is within the range, the copolymer has excellent solubility in organic solvents, and can coat a pattern uniformly.

[0068] The copolymer may have a weight-average molecular weight (Mw) of 1,000 g / mol to 50,000 g / mol. For example, the copolymer may have a weight-average molecular weight of about 2,000 g / mol to 30,000 g / mol, such as about 3,000 g / mol to 20,000 g / mol, or about 4,000 g / mol to 10,000 g / mol, but is not limited thereto. When the weight-average molecular weight of the copolymer is within this range, the carbon content and solubility in a solvent of a composition for a resist top layer film containing the copolymer can be adjusted and optimized.

[0069] The copolymer may be contained in an amount of 0.1 to 10% by weight based on the total weight of the composition for a resist top layer film, which makes it easier to remove the resist top layer film.

[0070] In a most specific embodiment, the copolymer can be selected from those listed in Group III below. [Group III] [ka]

[0071] In the above Group III, x:y may be 99:1 to 90:10, specifically 90:10, 91:9, 95:5, or 96:4.

[0072] According to an embodiment, the amide-based quencher may be a cyclic amide or a derivative thereof. More specifically, the amide-based quencher may be one selected from a cyclic amine protected by a protecting group, a derivative thereof, a cyclic amide, and a derivative thereof. The amide-based quencher is exposed as an amino group during exposure, thereby selectively quenching acid generated on the photoresist in the region where the amino group is exposed, thereby improving the pattern profile and IPU or LWR.

[0073] According to an embodiment, the photoacid generator may be a nonionic compound, and the nonionic compound may be represented by any one of the following Formulas 3 to 6. [Chemical formula 3] [Chemical formula 4] [ka] [Chemical formula 5] [Chemical formula 6] [ka]

[0074] In the above chemical formulas 3 to 6, R 6 ~R 15 each independently represents a halogen, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms, or a combination thereof; L 3 ~L 8 each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms, or a combination thereof; Q is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms; A is a cyclic organic group, n1 is an integer of 0 or 1.

[0075] The cyclic organic group may be a monocyclic compound or a polycyclic compound.

[0076] Examples of monocyclic compounds include cycloalkyl groups and cycloalkenyl groups, and specific examples include substituted or unsubstituted cycloalkyl groups having 1 to 20 carbon atoms and substituted or unsubstituted cycloalkenyl groups having 2 to 20 carbon atoms.

[0077] More specific examples of the monocyclic compound may be a substituted or unsubstituted cycloalkyl group having 1 to 10 carbon atoms, or a substituted or unsubstituted cycloalkenyl group having 2 to 10 carbon atoms, such as cyclopentyl, substituted or unsubstituted cyclohexyl, substituted or unsubstituted cycloheptyl, and substituted or unsubstituted cyclooctyl.

[0078] An example of a polycyclic compound is a bicyclic compound.

[0079] The bicyclic compound may be a fused bicyclic compound (e.g., a structure in which only two atoms are shared between the rings, such as decalin), a bridged bicyclic compound (e.g., a structure in which two atoms are shared between the rings and an additional atom is bridged, such as bicyclo[3,2,1]octane), or a spirocyclic compound (e.g., a structure in which one carbon is shared without a bridge).

[0080] As an example, A can be substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, substituted or unsubstituted cycloheptyl, substituted or unsubstituted cyclooctyl, substituted or unsubstituted norbornane, substituted or unsubstituted norbornene, substituted or unsubstituted tricyclodecane, substituted or unsubstituted tetracyclodecane, substituted or unsubstituted tetracyclododecane, substituted or unsubstituted adamantane, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted anthracene, substituted or unsubstituted furan, substituted or unsubstituted thiophene, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, or substituted or unsubstituted pyridine.

[0081] As a specific example, A may be substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, substituted or unsubstituted norbornane, substituted or unsubstituted norbornene, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted phenanthrene, or substituted or unsubstituted anthracene.

[0082] As an example, R 6 ~R 15 may each independently represent a halogen, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 10 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms, or a combination thereof.

[0083] As a specific example, R 6 , R 7 , R 9 , and R 10are each independently a halogen, a hydroxy group, an ester group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted butyl group, a substituted or unsubstituted pentyl group, or a substituted or unsubstituted hexyl group; R 8 , R 11 ~R 15 may each independently be a halogen, a hydroxy group, an ester group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted butyl group, a substituted or unsubstituted pentyl group, a substituted or unsubstituted hexyl group, a substituted or unsubstituted cyclopentyl group, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted cycloheptyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted adamantyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted furanyl group, a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted pyridinyl group.

[0084] The non-ionic compound may be a compound listed in Group IV below. [Group IV] [ka] .

[0085] According to another embodiment, the photoacid generator may be an ionic compound, and the ionic compound may be represented by the following Formula 7 or 8. [Chemical formula 7] [ka] [Chemical formula 8] [ka]

[0086] In the above chemical formula 7 and chemical formula 8, M 1 is F, Cl, Br, or I, M 2 is O, S, Se, or Te, R 16 ~R 20 are each independently a halogen, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; Z - is the anion derived from the conjugate base of an inorganic acid and the conjugate base of an organic sulfonic acid.

[0087] As an example, M 1 may be I.

[0088] As an example, M 2 may be S.

[0089] As an example, R 16 ~R 20 may each independently be a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0090] For example, Chemical Formula 7 can be represented by Chemical Formula 7-1 below, and Chemical Formula 8 can be represented by Chemical Formula 8-1 below. [Chemical formula 7-1] [ka] [Chemical formula 8-1] [ka]

[0091] In the above chemical formula 7-1 and chemical formula 8-1, R 26 ~R 50 each independently represents a hydrogen atom, a halogen atom, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; Z - is the anion derived from the conjugate base of an inorganic acid and the conjugate base of an organic sulfonic acid.

[0092] As an example, Z - PF6 - , BF4 - , SbF6 - and organic sulfonate anions.

[0093] The organic sulfonate anion can include both aliphatic sulfonate anions and aromatic sulfonate anions.

[0094] In the aliphatic sulfonate anion, the aliphatic group is selected from substituted or unsubstituted linear or branched alkyl groups having 1 to 30 carbon atoms and substituted or unsubstituted cycloalkyl groups having 3 to 30 carbon atoms.

[0095] Examples of the substituted or unsubstituted linear or branched alkyl group having 1 to 30 carbon atoms and the substituted or unsubstituted cycloalkyl group having 3 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, a neo-pentyl group, an iso-pentyl group, a sec-pentyl group, a substituted or unsubstituted cyclobutyl group, a substituted or unsubstituted cyclopentyl group, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted norbornenyl group, and a substituted or unsubstituted adamantyl group.

[0096] In the aromatic sulfonate anion, the aromatic may be a substituted or unsubstituted aryl group having 6 to 20 carbon atoms.

[0097] The substituted or unsubstituted aryl group having 6 to 20 carbon atoms may be, for example, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted tolyl group, a substituted or unsubstituted anthracenyl group, or a substituted or unsubstituted phenanthrenyl group.

[0098] As a specific example, the organic sulfonate anion can be represented by the following chemical formula 9. [Chemical formula 9] [ka]

[0099] In the above chemical formula 9, R 21 is hydrogen, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a cyclic organic group, or a combination thereof; L 9 represents a single bond, O, S, OC(═O), a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a combination thereof; R 22 ~R 25 each independently represents a hydrogen atom, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; n2 is an integer between 0 and 10.

[0100] As a specific example, R 22 ~R 25 At least one of them may be a fluoro group or an alkyl group having 1 to 10 carbon atoms substituted with one or more fluoro groups.

[0101] For example, R 22 ~R 25 At least one of them may be a fluoro group or an alkyl group having 1 to 5 carbon atoms substituted with one or more fluoro groups.

[0102] For example, alkyl groups having 1 to 5 carbon atoms substituted with one or more fluoro groups include CF3, C2F5, C3F7, C4F9, CH2CF3, CH2CH2CF3, CH2C2F5, CH2CH2C2F5, CH2C3F7, CH2CH2C3F7, CH2C4F9, and CH2CH2C4F9.

[0103] The ionic compound may be at least one of the compounds listed in Group V below. [Group V] [ka] [ka] .

[0104] The photoacid generator may be included in an amount of 0.1 to 40 parts by weight, for example, 0.1 to 30 parts by weight, for example, 0.5 to 30 parts by weight, based on 100 parts by weight of the copolymer. By including the photoacid generator in this range, the solubility can be optimized and the pattern LWR improvement effect can be ensured.

[0105] In addition, the composition for the resist top layer film may further include one or more different polymers selected from the group consisting of an acrylic resin, an epoxy resin, a novolac resin, a glycoluril resin, and a melamine resin, but is not limited thereto.

[0106] The resist top layer film composition may further include additives including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

[0107] The surfactant may be, for example, alkylbenzenesulfonate, alkylpyridinium salt, polyethylene glycol, quaternary ammonium salt, or the like, but is not limited to these.

[0108] 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.

[0109] The amount of these additives used can be easily adjusted depending on the desired physical properties, and they can also be omitted.

[0110] The solvent may be an ether solvent, for example, represented by the following chemical formula 10. [Chemical formula 10] [ka]

[0111] In the above chemical formula 10, R 51 and R 52 are each independently a substituted or unsubstituted alkyl group having 3 to 20 carbon atoms.

[0112] For example, the ether solvent may be selected from diisopropyl ether, dipropyl ether, diisoamyl ether, diamyl ether, dibutyl ether, diisobutyl ether, di-sec-butyl ether, dihexyl ether, bis(2-ethylhexyl) ether, didecyl ether, diundecyl ether, didodecyl ether, ditetradecyl ether, hexadecyl ether, butyl methyl ether, butyl ethyl ether, butyl propyl ether, tert-butyl methyl ether, tert-butyl ethyl ether, tert-butyl propyl ether, di-tert-butyl ether, cyclopentyl methyl ether, cyclohexyl methyl ether, cyclopentyl ethyl ether, cyclohexyl ethyl ether, cyclopentyl propyl ether, cyclopentyl-2-propyl ether, cyclohexyl propyl ether, cyclohexyl-2-propyl ether, cyclopentyl butyl ether, cyclopentyl-tert-butyl ether, cyclohexyl butyl ether, cyclohexyl-tert-butyl ether, 2-octanone, 4-heptanone, and combinations thereof.

[0113] The ether solvent may have sufficient solubility or dispersibility for the aforementioned composition.

[0114] According to another embodiment, there is provided a method for forming a pattern using the composition for a resist top layer film. For example, the pattern formed may be a photoresist pattern.

[0115] A pattern formation method according to one embodiment includes the steps of applying a photoresist composition on a substrate and heating it to form a photoresist film, applying the above-described photoresist upper layer film composition on the photoresist film and heating it to form an upper layer film, and exposing and developing the upper layer film and the photoresist film to form a resist pattern.

[0116] A method for forming a pattern using the above-described composition for a photoresist upper layer film will now be described with reference to Fig. 1. Fig. 1 is a schematic diagram for explaining the method for forming a pattern using the composition for a photoresist upper layer film according to the present invention.

[0117] Referring to FIG. 1, first, an etching target 100 is provided. An example of the etching target may be a thin film formed on a semiconductor substrate. The following description will be limited to the case where the etching target is a thin film. The surface of the thin film is cleaned to remove contaminants remaining on the thin film. The thin film may be, for example, a silicon nitride film, a polysilicon film, or a silicon oxide film.

[0118] A photoresist composition is applied onto the thin film and heated to form a photoresist film 101 (1). Next, the above-described photoresist upper layer film composition is applied onto the photoresist film and heated to form a photoresist upper layer film 30 (2).

[0119] Heating can be carried out at a temperature of 80°C to 500°C.

[0120] The photoresist top layer and the photoresist film are then exposed to high energy radiation.

[0121] For example, high-energy radiation that can be used in the exposure step includes light having a high-energy wavelength such as EUV (Extreme Ultra Violet; wavelength 13.5 nm) and E-Beam (electron beam).

[0122] Next, a post-exposure bake (PEB) step is performed. The post-exposure bake step can be performed at a temperature of about 80° C. to about 200° C. By performing the post-exposure bake step, the exposed regions of the photoresist film, i.e., the regions not covered by the patterned mask, are changed to have a property of being soluble in a developer, and thus have a different solubility from the unexposed regions of the photoresist film.

[0123] The photoresist film and the photoresist upper layer film corresponding to the exposed area are dissolved and removed using a developer, thereby forming a photoresist pattern 102b (3).

[0124] Specifically, the developer may be an alkaline developer or a developer containing an organic solvent (hereinafter referred to as an organic developer).

[0125] As the alkaline developer, a quaternary ammonium salt, typically tetramethylammonium hydroxide, is usually used, but other alkaline aqueous solutions such as inorganic alkalis, primary to tertiary amines, alcohol amines, and cyclic amines can also be used.

[0126] The alkaline developer may contain an appropriate amount of alcohols and / or surfactants. The alkaline developer may have an alkali concentration of, for example, 0.1 to 20% by mass, and a pH of, for example, 10 to 15.

[0127] The organic developer may be a developer containing at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents.

[0128] Examples of ketone solvents include 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone (methyl amyl ketone), 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, cyclohexanone, methylcyclohexanone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, isophorone, and propylene carbonate.

[0129] Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

[0130] As the alcohol solvent, amide solvent, ether solvent, and hydrocarbon solvent, known solvents can be used.

[0131] The developer may be mixed with a plurality of solvents, or may be mixed with other solvents or water. The water content of the developer as a whole is preferably less than 50% by weight, more preferably less than 20% by weight, even more preferably less than 10% by weight, and particularly preferably substantially free of water.

[0132] The content of the organic solvent in the organic developer is preferably 50 to 100% by weight, more preferably 80 to 100% by weight, further preferably 90 to 100% by weight, and particularly preferably 95 to 100% by weight, based on the total amount of the developer.

[0133] The organic developer may contain an appropriate amount of a known surfactant, if necessary.

[0134] The content of the surfactant is usually 0.001 to 5% by weight, preferably 0.005 to 2% by weight, and more preferably 0.01 to 0.5% by weight, based on the total amount of the developer.

[0135] The organic developer may contain the inhibitors described above.

[0136] The photoresist pattern is then applied as an etching mask to etch the exposed thin film, resulting in the thin film being formed into a thin film pattern.

[0137] The thin film can be etched by dry etching using an etching gas, such as CHF3, CF4, Cl2, BCl3, or a mixture thereof.

[0138] The thin film pattern formed using the photoresist pattern formed by the previous exposure process using an EUV light source may have a width corresponding to the photoresist pattern. For example, it may have a width of 5 nm to 100 nm, the same as the photoresist pattern. For example, the thin film pattern formed by the exposure process using an EUV light source may have 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, or 5 nm to 20 nm, similar to the photoresist pattern, and more specifically, may have a width of 20 nm or less. [Example]

[0139] The present invention will be described in more detail below through examples of the synthesis of the above polymer and the preparation of a photoresist upper layer film composition containing the same, but the present invention is not technically limited by the following examples.

[0140] Synthesis Example Synthesis Example 1: Synthesis of Compound 1a Under a nitrogen atmosphere, 20 g (59.86 mmol) of hexafluoro-2,3-bis(trifluoromethyl)-2,3-butanediol (perfluoropinacol), 7.79 g (59.86 mmol) of 2-(hydroxyethyl)methacrylate, and 18.84 g (71.84 mmol) of triphenylphosphine (PH3P) were mixed with 110 mL of diethyl ether and stirred. After stirring for 30 minutes, the mixture was cooled to 0°C and a mixture of 14.52 g (71.84 mmol) of diisopropyl azodicarboxylate (DIAD) and 35 mL of diethyl ether was added dropwise over 2 hours. After stirring at room temperature (23°C) for 24 hours, the mixture was concentrated. The concentrated mixture was dissolved in dichloromethane and purified by silica gel column chromatography to isolate the synthesized product. This was again distilled under reduced pressure to synthesize 2-[3,3,3-Trifluoro-2-hydroxy-1,1,2-tris(trifluoromethyl)propoxy]ethyl 2-methyl-2-propenoate, represented by the following chemical formula 1a.

[0141] * 1 H-NMR (Acetone-d6): δ1.90 (3H, t), 4.36 (4H, m), 5.63 (1H, t), 6.091H, t), 8.34 (1H, s) * 19 F-NMR (Acetone-d6): δ -70.12 (6F, m), -65.38 (6F, m)

[0142] [Chemical formula 1a] [ka]

[0143] Synthesis Example 2: Preparation of Copolymer R1 A 250 mL two-neck round bottom flask was charged with the compound represented by Formula 1a (16.1 g, 36 mmol), the compound represented by Formula 1b (DIVPA, Songwon Co., Ltd.) (1.7 g, 4 mmol), and 110 g of diisoamyl ether (DIAE) under a nitrogen atmosphere and heated to an internal temperature of 85°C. When the internal temperature reached 85°C, 14.7 g of a 25 wt% V-601 / DIAE solution (3.7 g, 16 mmol of V-601) was gradually added. After 6 hours, the reaction mixture was cooled to room temperature and concentrated to a solids content of 50%. 270 g of heptane was added to the concentrated solution, and the resulting polymer was filtered. The filtered polymer was completely dissolved in 34 g of DIAE, and then 270 g of heptane was added to precipitate it twice. After that, it was completely dried to finally prepare copolymer R1 (Mw = 4,000).

[0144] [Formula 1b] [ka] [ka] (x:y=90:10)

[0145] Synthesis Example 3: Preparation of Copolymer R2 Copolymer R2 (Mw=9,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Formula 1b was replaced with the compound represented by Formula 2b (2,4-diiodo-6-vinylphenol, Accela Chembio) (1.5 g, 16 mmol).

[0146] [Chemical formula 2b] [ka] [ka] (x:y=96:4)

[0147] Synthesis Example 4: Preparation of Copolymer R3 Copolymer R3 (Mw=5,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by the following Formula 2a (10.6 g, 36 mmol) was used instead of the compound represented by Formula 1a.

[0148] [Chemical formula 2a] [ka] [ka] (x:y=90:10)

[0149] Synthesis Example 5: Preparation of Copolymer R4 Copolymer R4 (Mw=6,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Formula 2a (16.1 g, 36 mmol) was used instead of the compound represented by Formula 1a, and the compound represented by Formula 2b (1.5 g, 4 mmol) was used instead of the compound represented by Formula 1b.

[0150] [ka] (x:y=91:9)

[0151] Synthesis Example 6: Preparation of Copolymer R5 Copolymer R5 (Mw=5,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Formula 1a was replaced with the compound represented by Formula 3a (MA-TTBD, HALOCARBON) (10.1 g, 36 mmol).

[0152] [Chemical formula 3a] [ka] [ka] (x:y=90:10)

[0153] Synthesis Example 7: Preparation of Copolymer R6 Copolymer R6 (Mw=5,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Formula 3a (10.1 g, 36 mmol) was used instead of the compound represented by Formula 1a, and the compound represented by Formula 2b (1.5 g, 4 mmol) was used instead of the compound represented by Formula 1b.

[0154] [ka] (x:y=90:10)

[0155] Synthesis Example 8: Preparation of Copolymer R7 Copolymer R7 (Mw=5,000) was prepared in the same manner as in Synthesis Example 2, except that the compound represented by Formula 1b was not used.

[0156] [ka] (x=100)

[0157] Production of composition for resist top layer film Example 1 0.98 g (0.5 wt %) of the copolymer R1 prepared in Synthesis Example 2 and 1.47 mg (0.15 wt %) of a photoacid generator represented by P1 below were dissolved in 199 g (w / w=97 / 3) of a DIAE / PGME mixed solvent, and the resulting mixture was stirred at room temperature (23° C.) for 24 hours. The mixture was then filtered through a Teflon filter with a 0.45 μm pore size to prepare a composition for a resist top layer film.

[0158] P1: [ka]

[0159] Examples 2 to 34 Each composition for a resist upper layer film was prepared in the same manner as in Example 1, except that the types of copolymer and photoacid generator were changed as shown in Table 1 below.

[0160] P2: [ka] P3: [ka] P4: [ka] P5: [ka] P6: [ka] P7: [ka] P8: [ka]

[0161] Comparative Example 1 Each composition for a resist upper layer film was prepared in the same manner as in Example 1, except that no photoacid generator was used.

[0162] Comparative Example 2 Each composition for a resist top layer film was prepared in the same manner as in Example 1, except that copolymer R7 prepared in Synthesis Example 8 was used instead of copolymer R1.

[0163] Evaluation 1: Solubility evaluation The compositions of Examples 1 to 34 and Comparative Examples 1 and 2 were stirred for 24 hours, and then visually observed for the presence or absence of precipitates. The results are shown in Table 1 below. (No precipitate - Solubility ○, Precipitation - Solubility X)

[0164] Evaluation 2: Developability evaluation The photoresist top layer compositions prepared in the Examples and Comparative Examples were applied to silicon substrates by spin-on coating and then heat-treated on a hot plate at 110°C for 1 minute to form photoresist top layers with a thickness of approximately 5 nm. The substrates were then rinsed with a 2.38% tetramethylammonium hydroxide solution and heat-treated on a hot plate at 110°C for 1 minute. The thickness change of the top layer was measured, and the results are shown in Table 1 below. *Remaining film after development (%) = [Thickness of upper layer film before development (nm) - Thickness of upper layer film after development (nm)] x 100 / Thickness of upper layer film before development (nm) (Remaining film after development ≦ 20% - Developability OK, Remaining film after development > 20% - Developability X)

[0165] Evaluation 3: Sensitivity evaluation A resist underlayer film (50 Å thick) and an EUV photoresist thin film (700 Å thick) were formed on a 12-inch silicon substrate, and then the photoresist upper layer film compositions prepared in the Examples and Comparative Examples were applied by spin-on coating and then heat-treated on a hot plate at 110°C for 1 minute to form a photoresist upper layer film with a thickness of approximately 5 nm.

[0166] A line and space pattern is formed in the Focus-Energy Matrix (FEM) format on a wafer with a photoresist top layer using the NXE3400B EUV equipment. The optimum sensitivity for forming a critical dimension (CD) of 26.0 nm is confirmed using the interpolation method, and the results are shown in Table 1 below.

[0167] [Table 1]

[0168] Referring to Table 1, it can be seen that when the composition for a resist top layer film according to the embodiment of the present invention is applied, not only is the solubility and developability excellent, but also the acid generation in the exposed area is promoted, resulting in excellent sensitivity.

[0169] On the other hand, in the case of the resist top layer film composition according to the comparative example, the sensitivity improvement effect was not observed or the sensitivity was decreased.

[0170] Although specific embodiments of the present invention have been described and illustrated above, it will be apparent to those skilled in the art that the present invention is not limited to the described embodiments, and that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, such modifications and variations should not be understood separately from the technical spirit and perspective of the present invention, and the modified embodiments should be considered to fall within the scope of the claims of the present invention. [Explanation of symbols]

[0171] 1: Step of forming a photoresist film 2: Step of forming a photoresist upper layer film 3: Step of exposing and developing the photoresist film and the photoresist top layer film to form a resist pattern 30: Photoresist upper layer film 100: Substrate 101: Photoresist film 102b: Photoresist pattern

Claims

1. A copolymer including a first structural unit represented by the following chemical formula M-1 and a second structural unit represented by the following chemical formula M-2: a photoacid generator; and Contains a solvent, the photoacid generator is a nonionic compound or an ionic compound; the nonionic compound comprises an organic sulfonate group; a composition for a resist upper layer film, wherein the ionic compound contains at least one of a conjugate base of an inorganic acid and a conjugate base of an organic sulfonic acid as an anion; [Chemical formula M-1] 【Chemical 1】 [Chemical formula M-2] 【Chemistry 2】 In the above chemical formula M-1 and chemical formula M-2, R １ and R ２ are each independently hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, L １ and L ２ each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms, or a combination thereof; X １ is a single bond, -O-, -S-, -S(O)-, -S(O) ２ -, -C(O)-, -(CO)O-, -O(CO), -O(CO)O-, -NR ａ - (where R ａ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms), or a combination thereof; R ３ is hydrogen, fluorine, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a combination thereof; R ４ is hydrogen, or C(=O)R ｂ and R ｂ is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R ３ , L １ and L ２ at least one of which contains fluorine and a hydroxy group; R ５ is hydrogen, halogen, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof; m1 is an integer from 1 to 4; * indicates the linkage site.

2. 2. The composition for a resist upper layer film according to claim 1, wherein the first structural unit is represented by the following chemical formula 1: [Chemical formula 1] 【Chemistry 3】 In the above chemical formula 1, R １ is hydrogen or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R ｋ , R ｌ , R ｍ , R ｎ , and R ３ are each independently hydrogen, fluorine, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, or a combination thereof; m2 and m3 are each independently an integer from 1 to 10; X １ is a single bond, -O-, -S-, -S(O)-, -S(O) ２ -, -C(O)-, -(CO)O-, -O(CO), -O(CO)O-, -NR ａ - (where R ａ is hydrogen, deuterium, or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms), or a combination thereof; R ｋ , R ｌ , R ｍ , R ｎ , and R ３ At least one of the groups contains fluorine and a hydroxy group.

3. 2. The composition for a resist upper layer film according to claim 1, wherein the first structural unit is at least one selected from the following Group I: [Group I] 【Chemistry 4】 In the above Group I, R １ are each independently hydrogen or a methyl group, and * is a linking site.

4. The composition for a resist upper layer film according to claim 1, wherein the second structural unit is represented by any one of the following chemical formulas 2-1 to 2-4: [Chemical formula 2-1] [Chemical formula 2-2] [Chemical formula 2-3] [Chemical formula 2-4] 【Chemistry 5】 In the above chemical formulas 2-1 to 2-4, R ２ is hydrogen or a methyl group, R ４ , R ４ａ , and R ４ｂ are each independently hydrogen or C(=O)R ｂ and R ｂ is a substituted or unsubstituted alkyl group having 1 to 5 carbon atoms, R ５ａ , R ５ｂ , R ５ｃ , and R ５ｄ are each independently a hydrogen atom, a halogen atom, a hydroxy group, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, or a combination thereof; * indicates the linkage site.

5. The R ５ａ , R ５ｂ , R ５ｃ , and R ５ｄ The composition for a resist upper layer film according to claim 4 , wherein at least one of the groups is an iodo group.

6. 2. The composition for a resist upper layer film according to claim 1, wherein the second structural unit is at least one selected from the following Group II: [Group II] 【Chemistry 6】 【Chemistry 7】 In the above Group II, R ２ are each independently hydrogen or a methyl group, and * is a linking site.

7. 2. The resist upper layer film composition according to claim 1, wherein the copolymer contains the first structural unit in an amount of 50 to 99 mol % and the second structural unit in an amount of 1 to 50 mol %.

8. 2. The composition for a resist upper layer film according to claim 1, wherein the weight average molecular weight of the copolymer is 1,000 g / mol to 50,000 g / mol.

9. The composition for a resist upper layer film according to claim 1, wherein the nonionic compound is represented by any one of the following chemical formulas 3 to 6: [Chemical formula 3] [Chemical formula 4] 【Chemistry 8】 [Chemical formula 5] [Chemical formula 6] 【Chemistry 9】 In the above chemical formulas 3 to 6, R ６ ~R １５ each independently represents a halogen, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted cycloalkenyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroaryl group having 2 to 20 carbon atoms, or a combination thereof; L ３ ~L ８ each independently represents a single bond, a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted alkenylene group having 2 to 20 carbon atoms, a substituted or unsubstituted alkynylene group having 2 to 20 carbon atoms, a substituted or unsubstituted cycloalkylene group having 3 to 20 carbon atoms, a substituted or unsubstituted cycloalkenylene group having 3 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, a substituted or unsubstituted heteroarylene group having 2 to 20 carbon atoms, or a combination thereof; Q is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted alkenylene group having 2 to 10 carbon atoms; A is a cyclic organic group, n1 is an integer of 0 or 1.

10. 10. The resist upper layer film composition according to claim 9, wherein A is substituted or unsubstituted cyclopentyl, substituted or unsubstituted cyclohexyl, substituted or unsubstituted cycloheptyl, substituted or unsubstituted cyclooctyl, substituted or unsubstituted norbornane, substituted or unsubstituted norbornene, substituted or unsubstituted tricyclodecane, substituted or unsubstituted tetracyclodecane, substituted or unsubstituted tetracyclododecane, substituted or unsubstituted adamantane, substituted or unsubstituted benzene, substituted or unsubstituted naphthalene, substituted or unsubstituted phenanthrene, substituted or unsubstituted anthracene, substituted or unsubstituted furan, substituted or unsubstituted thiophene, substituted or unsubstituted benzothiophene, substituted or unsubstituted dibenzofuran, substituted or unsubstituted dibenzothiophene, or substituted or unsubstituted pyridine.

11. The R ６ , R ７ , R ９ , and R １０ are each independently a halogen, a hydroxy group, an ester group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted butyl group, a substituted or unsubstituted pentyl group, or a substituted or unsubstituted hexyl group; R ８ , R １１ ~R １５ are each independently a halogen, a hydroxy group, an ester group, a substituted or unsubstituted methyl group, a substituted or unsubstituted ethyl group, a substituted or unsubstituted propyl group, a substituted or unsubstituted butyl group, a substituted or unsubstituted pentyl group, a substituted or unsubstituted hexyl group, a substituted or unsubstituted cyclopentyl group, a substituted or unsubstituted cyclohexyl group, a substituted or unsubstituted cycloheptyl group, a substituted or unsubstituted norbornyl group, a substituted or unsubstituted adamantyl group, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, a substituted or unsubstituted anthracenyl group, a substituted or unsubstituted furanyl group, a substituted or unsubstituted thiophenyl group, a substituted or unsubstituted benzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted dibenzothiophenyl group, or a substituted or unsubstituted pyridinyl group.

12. 2. The composition for a resist upper layer film according to claim 1, wherein the nonionic compound is a compound listed in Group IV below: [Group IV] 【Chemistry 10】 。

13. The composition for a resist upper layer film according to claim 1 , wherein the ionic compound is represented by the following chemical formula 7 or 8: [Chemical formula 7] 【Chemistry 11】 [Chemical formula 8] 【Chemistry 12】 In the above Chemical Formula 7 and Chemical Formula 8, M １ is F, Cl, Br, or I, M ２ is O, S, Se, or Te, R １６ ~R ２０ are each independently a halogen, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; Z － is the anion derived from the conjugate base of an inorganic acid and the conjugate base of an organic sulfonic acid.

14. The composition for a resist upper layer film according to claim 13, wherein the ionic compound is represented by the following chemical formula 7-1, and the chemical formula 8 is represented by the following chemical formula 8-1: [Chemical formula 7-1] 【Chemistry 13】 [Chemical formula 8-1] 【Chemistry 14】 In the above chemical formula 7-1 and chemical formula 8-1, R ２６ ~R ５０ each independently represents a hydrogen atom, a halogen atom, a hydroxy group, an ester group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; Z － is the anion derived from the conjugate base of an inorganic acid and the conjugate base of an organic sulfonic acid.

15. Said Z － is PF ６ － , B.F. ４ － , SbF ６ － 14. The resist upper layer film composition according to claim 13, wherein the anion is one selected from the group consisting of:

16. The composition for a resist upper layer film according to claim 15, wherein the organic sulfonic acid anion is represented by the following chemical formula 9: [Chemical formula 9] 【Chemistry 15】 In the above chemical formula 9, R ２１ is hydrogen, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double or triple bonds, a cyclic organic group, or a combination thereof; L ９ represents a single bond, O, S, OC(═O), a substituted or unsubstituted alkylene group having 1 to 20 carbon atoms, a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, or a combination thereof; R ２２ ~R ２３ each independently represents a hydrogen atom, a fluoro group, a substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 20 carbon atoms, a substituted or unsubstituted aliphatic unsaturated organic group having 2 to 20 carbon atoms and containing one or more double bonds or triple bonds, a substituted or unsubstituted aryl group having 6 to 30 carbon atoms, or a combination thereof; n2 is an integer from 0 to 10.

17. 2. The composition for a resist upper layer film according to claim 1, wherein the ionic compound is at least one of the compounds listed in Group V below: [Group V] 【Chemistry 16】 【Chemistry 17】 。

18. 2. The resist upper layer film composition according to claim 1, wherein the photoacid generator is contained in an amount of 0.1 to 50 parts by weight based on 100 parts by weight of the copolymer.

19. 2. The composition for a resist upper layer film according to claim 1, wherein the solvent is an ether-based solvent.

20. applying a photoresist composition onto a substrate and heating to form a photoresist film; A step of applying a composition for a resist upper layer film according to any one of claims 1 to 19 onto the photoresist film and heating the composition to form an upper layer film; and forming a resist pattern by exposing and developing the upper layer film and the photoresist film; A pattern forming method comprising:

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