Resist underlayer composition and method of forming pattern using the same

Abstract

A resist underlayer composition and a method of forming a pattern using the same are disclosed. The resist underlayer composition includes a polymer including a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, or a combination thereof, a photoacid generator, and a solvent, the photoacid generator has a mass reduction rate of about 0% after 3 minutes from a measurement time during thermogravimetric analysis (TGA) in an air atmosphere (air gas) at 205 DEG C. The chemical formula 1 and the chemical formula 2 are defined in the specification. Chemical formula 1 # imgabs0 # and chemical formula 2 # imgabs1 #

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefits of Korean Patent Application No. 10-2023-0105176 filed in the Korean Intellectual Property Office on August 10, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Embodiments of the present disclosure relate to a resist underlayer composition and a method of forming a pattern using the resist underlayer composition. Background Art

[0004] Recently, the semiconductor industry has developed an ultra-fine technology with patterns of a few nanometers to tens of nanometers in size. This ultra-fine technology benefits from efficient photolithography technology.

[0005] Photolithography is a processing method that includes coating a photoresist film on a semiconductor substrate (e.g., a silicon wafer) to form a thin film, irradiating activating radiation (e.g., ultraviolet rays) through a mask pattern on which a device pattern is drawn, developing the pattern to obtain a photoresist pattern, and etching the substrate using the obtained photoresist pattern as a protective film to form a fine pattern corresponding to the pattern on the surface of the substrate.

[0006] As semiconductor patterns become increasingly fine, the thickness of the photoresist layer should be thin, and therefore, the thickness of the resist bottom layer should also be thin. The resist bottom layer should maintain the photoresist pattern, for example, with substantially uniform thickness and excellent and / or suitable close contact properties and adhesion to the photoresist, although the photoresist pattern is thin. The resist bottom layer should have improved sensitivity to the light source used in the photolithography, for example, with a high refractive index and a low extinction coefficient. Summary of the invention

[0007] Some embodiments of the present disclosure provide a resist underlayer composition that prevents or reduces resist pattern collapse even during a fine patterning process and improves patterning performance and energy efficiency by improving sensitivity to an exposure light source.

[0008] Some embodiments provide a method of forming a pattern using a resist underlayer composition.

[0009] The resist underlayer composition according to some embodiments includes a polymer, a photoacid generator, and a solvent, wherein the polymer includes a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, or a combination thereof, and the photoacid generator has a mass reduction rate of about 0% after 3 minutes from the measurement time during thermogravimetric analysis (TGA) at 205° C. in an air atmosphere (air gas),

[0010] Chemical formula 1

[0011]

[0012] Chemical formula 2

[0013]

[0014] In Chemical Formula 1 and Chemical Formula 2,

[0015] A is a heterocyclic group containing a nitrogen atom in the ring,

[0016] L 1 To L 6 each is independently a single bond (e.g., a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C3 to C20 heteroarylene group, or a combination thereof,

[0017] X 1 To X 5 Each is independently a single bond (e.g., a single covalent bond), -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a -(where R a is hydrogen, deuterium or C1 to C10 alkyl) or a combination thereof,

[0018] Y 1 To Y 3each is independently hydroxy, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C1 to C10 heteroalkyl, substituted or unsubstituted C2 to C10 heteroalkenyl, substituted or unsubstituted C2 to C10 heteroalkynyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 heterocycloalkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C3 to C20 heteroaryl, or a combination thereof, and

[0019] * is the connection point.

[0020] A in Chemical Formula 1 and Chemical Formula 2 may be represented by one or more of Chemical Formula A-1 to Chemical Formula A-4,

[0021] Chemical formula A-1

[0022]

[0023] Chemical formula A-2

[0024]

[0025] Chemical formula A-3

[0026]

[0027] Chemical formula A-4

[0028]

[0029] In Chemical Formulae A-1 to A-4, * represents a connection point with another atom or group.

[0030] In some embodiments, L 1 To L 6 are each independently a single bond (eg, a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof, X 1 To X 5 are each independently a single bond (eg, a single covalent bond), -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, and Y 1 To Y 3Each is independently a substituted or unsubstituted C1 to C10 alkyl, a substituted or unsubstituted C2 to C10 alkenyl, a substituted or unsubstituted C1 to C10 heteroalkyl, a substituted or unsubstituted C2 to C10 heteroalkenyl, a substituted or unsubstituted C3 to C20 cycloalkyl, a substituted or unsubstituted C2 to C20 heterocycloalkyl, a substituted or unsubstituted C6 to C20 aryl, or a combination thereof.

[0031] The photoacid generator may be represented by Chemical Formula 3, and / or may include an imide derivative and / or a cyanurate derivative in which a nitrogen atom is substituted with a sulfonate group.

[0032] Chemical formula 3

[0033]

[0034] Wherein, in Chemical Formula 3, R 2 to R 4 are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, and Z - It is a monovalent anion.

[0035] R 2 to R 4 Each is independently a C1 to C20 alkyl group substituted with at least one halogen atom, a C6 to C30 aryl group substituted with at least one halogen atom, or a combination thereof.

[0036] The photoacid generator may be represented by any one selected from Chemical Formula 4 to Chemical Formula 7,

[0037] Chemical formula 4

[0038]

[0039] Among them, in chemical formula 4,

[0040] R 21 , R 31 and R 41 are each independently a halogen atom, and

[0041] n21, n31 and n41 are each independently one of integers selected from 0 to 5, provided that at least one selected from n21, n31 and n41 is 1 or greater than 1;

[0042] Chemical formula 5

[0043]

[0044] Chemical formula 6

[0045]

[0046] Chemical formula 7

[0047]

[0048] Among them, in Chemical Formula 5 to Chemical Formula 7,

[0049] R 51 , R 61 , R 62 and R 71 each independently represents deuterium, a hydroxyl group, a halogen atom, a nitro group, a cyano group, -COOH, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof,

[0050] R 52 , R 63 and R 72 each independently represents a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C5 to C30 bicycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof,

[0051] n51 is one selected from integers from 0 to 2, and

[0052] n71 is one selected from integers from 0 to 6.

[0053] The structural unit represented by Chemical Formula 1 may be represented by Chemical Formula 1-1 or Chemical Formula 1-2, and the structural unit represented by Chemical Formula 2 may be represented by any one selected from Chemical Formula 2-1 to Chemical Formula 2-3,

[0054] Chemical formula 1-1

[0055]

[0056] Chemical formula 1-2

[0057]

[0058] Chemical formula 2-1

[0059]

[0060] Chemical formula 2-2

[0061]

[0062] Chemical formula 2-3

[0063]

[0064] The photoacid generator may be represented by any one selected from Chemical Formula 4-1, Chemical Formula 4-2, and Chemical Formula 5-1 to Chemical Formula 7-1.

[0065] Chemical formula 4-1

[0066]

[0067] Chemical formula 4-2

[0068]

[0069] Chemical formula 5-1

[0070]

[0071] Chemical formula 6-1

[0072]

[0073] Chemical formula 7-1

[0074]

[0075] The weight average molecular weight of the polymer may be about 1,000 g / mol to about 300,000 g / mol.

[0076] The photoacid generator may be included in an amount of about 10 parts by weight to about 100 parts by weight based on 100 parts by weight of the polymer.

[0077] The polymer may be included in an amount of about 0.1 wt % to about 50 wt % based on the total weight of the resist underlayer composition.

[0078] The photoacid generator may be included in an amount of about 0.01 wt % to about 30 wt % based on the total weight of the resist underlayer composition.

[0079] The resist base composition may further include one or more polymers selected from acrylic resin, epoxy resin, novolac-based resin, glycoluril-based resin and melamine-based resin.

[0080] The resist underlayer composition may further include additives such as a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

[0081] According to some embodiments, a method for forming a pattern includes: forming a film to be etched on a substrate; coating an anti-etching base layer composition according to some embodiments on the film to be etched to form an anti-etching base layer; forming a photoresist pattern on the anti-etching base layer; and using the photoresist pattern as an etching mask to sequentially etch the anti-etching base layer and the film to be etched.

[0082] The resist underlayer composition according to some embodiments may provide a resist underlayer that does not cause a resist pattern to collapse even in a fine patterning process and has improved sensitivity to an exposure light source, thereby improving patterning performance and energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0083] The drawings, together with the specification, illustrate embodiments of the presently disclosed subject matter, and, together with the description, serve to explain principles of the embodiments of the presently disclosed subject matter.

[0084] Figures 1 to 7 is a cross-sectional view illustrating a method of forming a pattern using a resist underlayer composition according to some embodiments. DETAILED DESCRIPTION

[0085] The exemplary embodiments of the present disclosure will be described in more detail below, and those skilled in the art can easily implement the exemplary embodiments of the present disclosure after reading the present disclosure. However, the subject matter of the present disclosure can be implemented in many different forms and should not be considered to be limited to the exemplary embodiments described herein.

[0086] In the drawings, the thickness of layers, films, panels, regions, etc. may be exaggerated for clarity, and the same reference numerals represent the same elements throughout the specification. It should be understood that if an element (such as a layer, film, region, or substrate) is said to be "on" another element, the element may be directly on the other element or there may be intervening elements. On the contrary, if an element is said to be "directly" "on" another element, there are no intervening elements.

[0087] When no definition is otherwise provided, "substituted" as used herein refers to a compound in which a hydrogen atom is replaced by a substituent selected from the group consisting of deuterium, a halogen atom (F, Br, Cl or I), a hydroxyl group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazine group, a hydrazo 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 phosphate group or a salt thereof, a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, a C2 to C30 heterocyclyl group, and combinations thereof.

[0088] In some embodiments, adjacent two substituents of a substituted halogen atom (F, Br, Cl, or I), a hydroxyl group, a nitro group, a cyano group, an amino group, an azido group, an amidino group, a hydrazine group, a hydrazone 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 phosphate group or a salt thereof, a C1 to C30 alkyl group, a C2 to C30 alkenyl group, a C2 to C30 alkynyl group, a C6 to C30 aryl group, a C7 to C30 arylalkyl group, a C1 to C30 alkoxy group, a C1 to C20 heteroalkyl group, a C3 to C20 heteroarylalkyl group, a C3 to C30 cycloalkyl group, a C3 to C15 cycloalkenyl group, a C6 to C15 cycloalkynyl group, or a C2 to C30 heterocyclyl group may be fused together to form a ring.

[0089] When no definition is otherwise provided, "hetero" as used herein refers to one containing 1 to 3 heteroatoms selected from N, O, S, Se and P.

[0090] As used herein, "aryl" refers to a group having at least one hydrocarbon aromatic moiety, and broadly refers to hydrocarbon aromatic moieties connected by single bonds (e.g., single covalent bonds) and non-aromatic fused rings, and non-aromatic fused rings include directly or indirectly fused hydrocarbon aromatic moieties. Aryl groups can be monocyclic, polycyclic, or fused polycyclic (e.g., rings that share adjacent pairs of carbon atoms) functional groups.

[0091] As used herein, "heterocyclic group" includes heteroaryl groups and cyclic groups, wherein the cyclic group includes at least one heteroatom selected from N, O, S, P and Si to replace carbon (C) in a cyclic compound (e.g., aryl, cycloalkyl, fused rings thereof or a combination thereof). If the heterocyclic group is a fused ring, each ring or the entire ring of the heterocyclic group may include at least one heteroatom.

[0092] In some embodiments, the substituted or unsubstituted aryl and / or substituted or unsubstituted heterocyclic group may be substituted or unsubstituted phenyl, substituted or unsubstituted naphthyl, substituted or unsubstituted anthracenyl, substituted or unsubstituted phenanthrenyl, substituted or unsubstituted tetraphenyl, substituted or unsubstituted pyrenyl, substituted or unsubstituted biphenyl, substituted or unsubstituted terphenyl, substituted or unsubstituted quaterphenyl, substituted or unsubstituted chrysene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetraphenylene, substituted or unsubstituted chrysene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetraphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted quaternaryl, substituted or unsubstituted chrysene, substituted or unsubstituted triphenylene, substituted or unsubstituted tetraphenylene, substituted or unsubstituted terphenylene, substituted or unsubstituted quaternaryl, substituted or unsubstituted chrysene, substituted or unsubstituted terphenylene, substituted or unsubstituted quaternaryl ... substituted or unsubstituted peryl, substituted or unsubstituted indenyl, substituted or unsubstituted furanyl, substituted or unsubstituted thienyl, substituted or unsubstituted pyrrolyl, substituted or unsubstituted pyrazolyl, substituted or unsubstituted imidazolyl, substituted or unsubstituted triazolyl, substituted or unsubstituted oxazolyl, substituted or unsubstituted thiazolyl, substituted or unsubstituted oxadiazolyl, substituted or unsubstituted thiadiazolyl, substituted or unsubstituted pyridinyl, substituted or unsubstituted pyrimidine substituted or unsubstituted pyrazinyl, substituted or unsubstituted triazinyl, substituted or unsubstituted benzofuranyl, substituted or unsubstituted benzothiophenyl, substituted or unsubstituted benzimidazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted quinolyl, substituted or unsubstituted isoquinolyl, substituted or unsubstituted quinazolinyl, substituted or unsubstituted quinoxalinyl, substituted or unsubstituted naphthyridinyl, substituted or unsubstituted benzoxazinyl, substituted or unsubstituted phenyl The invention may be substituted or unsubstituted thiazinyl, substituted or unsubstituted acridinyl, substituted or unsubstituted phenazinyl, substituted or unsubstituted phenothiazinyl, substituted or unsubstituted phenoxazinyl, substituted or unsubstituted fluorenyl, substituted or unsubstituted dibenzofuranyl, substituted or unsubstituted dibenzothienyl, substituted or unsubstituted carbazolyl, pyridoindolyl, benzopyridooxazinyl, benzopyridothiazinyl, 9,9-dimethyl-9,10-dihydroacridinyl, combinations thereof, or fused rings of the combinations of the foregoing groups, but is not limited thereto.

[0093] When a specific definition is not otherwise provided, the term "combination" used herein means mixing and / or copolymerization.

[0094] In addition, "polymer" used herein may include both oligomers and polymers.

[0095] When no definition is otherwise provided, the "weight average molecular weight" used herein can be measured by dissolving a powder sample (the column is Shodex LF-804, and the standard sample may be Showa polystyrene) in tetrahydrofuran (THF) and using a 1200 series Gel Permeation Chromatography (GPC) of Agilent Technologies.

[0096] When no definition is otherwise provided, "*" as used herein refers to a structural unit of a compound or a point of attachment of a compound moiety.

[0097] In the semiconductor industry, efforts are made to reduce the size of chips. Therefore, the line width of the resist patterned using photolithography should be reduced to a level of tens of nanometers, and the pattern formed in this way is used to transfer the pattern to the lower material by using an etching process on the lower substrate. However, as the pattern size of the resist becomes smaller, the height (e.g., aspect ratio) of the resist that can withstand the line width is limited, and therefore, the resist may not have suitable or sufficient resistance in the etching step. Therefore, if a thin resist material is used, if the substrate to be etched is thick, and / or if a deep pattern is formed, a resist bottom layer has been used to compensate for this.

[0098] As the thickness of the resist becomes thinner, the resist bottom layer should become thinner, and even if the resist bottom layer is thin, the photoresist pattern should not collapse. For this purpose, the resist bottom layer must have excellent adhesion to the photoresist. In certain embodiments, when forming a thin resist bottom layer, the coating uniformity of the resist bottom layer composition and the flatness of the resist bottom layer generated by the resist bottom layer composition should be improved, and the sensitivity to the exposure light source should be improved to improve pattern formation and energy efficiency.

[0099] The resist underlayer composition according to some embodiments includes a polymer, a photoacid generator, and a solvent, wherein the polymer includes a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, or a combination thereof, and the photoacid generator has a mass reduction rate of about 0% after 3 minutes from the measurement time during thermogravimetric analysis (TGA) at 205° C. in an air atmosphere (air gas),

[0100] Chemical formula 1

[0101]

[0102] Chemical formula 2

[0103]

[0104] In Chemical Formula 1 and Chemical Formula 2,

[0105] A is a heterocyclic group containing a nitrogen atom in the ring,

[0106] L 1 To L 6 each is independently a single bond (e.g., a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C3 to C20 heteroarylene group, or a combination thereof,

[0107] X 1 To X 5 Each is independently a single bond (e.g., a single covalent bond), -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a -(where R a is hydrogen, deuterium or C1 to C10 alkyl) or a combination thereof,

[0108] Y 1 To Y 3 each is independently hydroxy, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C1 to C10 heteroalkyl, substituted or unsubstituted C2 to C10 heteroalkenyl, substituted or unsubstituted C2 to C10 heteroalkynyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 heterocycloalkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C3 to C20 heteroaryl, or a combination thereof, and

[0109] * is the connection point.

[0110] In the resist underlayer composition according to some embodiments, the structural unit represented by Chemical Formula 1 and the structural unit represented by Chemical Formula 2 include a heterocyclic ring including a nitrogen atom in the ring, so that the polymer including these structural units can form sp 2 -sp 2bond. Although the present application is not limited by any particular mechanism or theory, it is believed that this enables the polymer to have a high electron density, and by including a polymer having a high electron density, the resist underlying composition according to some embodiments can implement a film with a dense structure in the form of an ultra-thin film, and if the resist underlying composition is exposed to light, the high electron density of the polymer can have the effect of improving light absorption efficiency. In some embodiments, etching sensitivity is improved by including a heterocyclic skeleton, and if a pattern is formed after exposure using high-energy rays (e.g., extreme ultraviolet (EUV); wavelength 13.5nm) and electron beam (electron beam, E-Beam)), energy efficiency can be improved.

[0111] A in Chemical Formula 1 and Chemical Formula 2 may be represented by one or more selected from Chemical Formula A-1 to Chemical Formula A-4,

[0112] Chemical formula A-1

[0113]

[0114] Chemical formula A-2

[0115]

[0116] Chemical formula A-3

[0117]

[0118] Chemical formula A-4

[0119]

[0120] In Chemical Formulae A-1 to A-4, * represents a connection point to another atom or group.

[0121] In some embodiments, L 1 To L 6 Each is independently a single bond (e.g., a single covalent bond), a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof (for example, a single bond, a substituted or unsubstituted C1 to C5 alkylene group, a substituted or unsubstituted C1 to C5 heteroalkylene group, or a combination thereof), but is not limited thereto.

[0122] X 1 To X 5 Each is independently a single bond (eg, a single covalent bond), -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof (for example, -O-, -S-, -(CO)O-, or a combination thereof), but is not limited thereto.

[0123] Y 1 To Y 3 Each is independently a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, a substituted or unsubstituted C1 to C10 heteroalkyl group, a substituted or unsubstituted C2 to C10 heteroalkenyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C2 to C20 heterocycloalkyl group, a substituted or unsubstituted C6 to C20 aryl group, or a combination thereof (for example, a substituted or unsubstituted C1 to C5 alkyl group, a substituted or unsubstituted C2 to C5 alkenyl group, a substituted or unsubstituted C3 to C10 cycloalkyl group, a substituted or unsubstituted C6 to C10 aryl group, or a combination thereof), but is not limited thereto.

[0124] For example, the structural unit represented by Chemical Formula 1 may be represented by Chemical Formula 1-1 or Chemical Formula 1-2, and the structural unit represented by Chemical Formula 2 may be represented by any one selected from Chemical Formula 2-1 to Chemical Formula 2-3.

[0125]

[0126] Chemical formula 1-2

[0127]

[0128] Chemical formula 2-1

[0129]

[0130] Chemical formula 2-2

[0131]

[0132] Chemical formula 2-3

[0133]

[0134] In some embodiments, the composition includes a photoacid generator so that acid can be selectively additionally provided to the exposure area of ​​the photoresist during exposure. Therefore, by improving the deprotection reaction of the photoresist, the sensitivity can be improved, and the line width roughness (LWR) of the pattern can be improved. In some embodiments, if thermogravimetric analysis (TGA) is performed in an air atmosphere at a temperature of 205° C., the photoacid generator has a mass reduction rate of about 0% after 3 minutes from the measurement time, and therefore does not decompose or volatilize at high temperatures, and improves the sensitivity of the photoresist.

[0135] The photoacid generator may be represented by Chemical Formula 3, and / or may include an imide derivative and / or a cyanurate derivative in which a nitrogen atom is substituted with a sulfonate group.

[0136] Chemical formula 3

[0137]

[0138] In chemical formula 3, R 2 to R 4 are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, and for example, R 2 to R 4 Each is independently a C1 to C20 alkyl group substituted with at least one or more halogen atoms, a C6 to C30 aryl group substituted with at least one or more halogen atoms, or a combination thereof (for example, a halogen atom), but is not limited thereto.

[0139] In Chemical Formula 3, Z - is a monovalent anion, for example, a halogen anion, an organic group including a sulfonic acid group (for example, a fluoride anion (F - ), - OS(=O)2CF3 or - OS(=O)2C4F9), but not limited to this.

[0140] In some embodiments, the compound represented by Chemical Formula 3 may be represented by Chemical Formula 4:

[0141] Chemical formula 4

[0142]

[0143] Among them, in chemical formula 4,

[0144] R 21 , R 31 and R 41 are each independently a halogen atom (for example, fluorine (-F) or iodine (-I)), but not limited thereto, and

[0145] n21, n31 and n41 are each independently one of the integers selected from 0 to 5, for example one of the integers selected from 0 to 3, for example one of the integers selected from 0 to 2, but at least one selected from n21, n31 and n41 is an integer greater than 1 or equal to 1.

[0146] In some embodiments, the compound represented by Chemical Formula 4 may be represented by Chemical Formula 4-1 or Chemical Formula 4-2:

[0147] Chemical formula 4-1

[0148]

[0149] Chemical formula 4-2

[0150]

[0151] In the imide derivatives and / or cyanurate derivatives in which the nitrogen atom is substituted with a sulfonate group, the imide derivatives may include a linear compound comprising an imide structure, a five-membered ring compound comprising an imide structure, a six-membered ring compound comprising an imide structure, and / or derivatives thereof, and the five-membered ring compound and the six-membered ring compound may have more than one ring fused to one side. The nitrogen atom in the imide structure is substituted with a sulfonate group.

[0152] In the cyanurate derivatives, at least one nitrogen atom of the cyanurate is substituted with a sulfonate group.

[0153] The sulfonate group substituted with the nitrogen atom can be represented by -OS(=O)2R 1 Indicates that R 1 It may be a monovalent organic group.

[0154] The imide derivative and / or cyanurate derivative in which the nitrogen atom is substituted with a sulfonate group may be represented by one or more selected from Chemical Formula 5 to Chemical Formula 7,

[0155] Chemical formula 5

[0156]

[0157] Chemical formula 6

[0158]

[0159] Chemical formula 7

[0160]

[0161] In Chemical Formulae 5 to 7,

[0162] R 51 , R 61 , R 62 and R 71Each is independently deuterium, a hydroxyl group, a halogen atom, a nitro group, a cyano group, -COOH, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, and may each be, for example, independently deuterium, a hydroxyl group, a halogen atom, a substituted or unsubstituted C1 to C10 alkoxy group, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C2 to C10 alkenyl group, or a combination thereof (for example, a substituted or unsubstituted C2 to C10 alkenyl group).

[0163] In some embodiments, n51 is one of integers selected from 0 to 2, and may be, for example, 0 or 1, or, for example, 0, but is not limited thereto.

[0164] In some embodiments, n71 is one of integers selected from 0 to 6, such as one of integers selected from 0 to 3, such as 0 or 1 or such as 0, but is not limited thereto.

[0165] R 52 , R 63 and R 72 Each is independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C5 to C30 bicycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof.

[0166] For example, R 52 and R 72 Each is independently an unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C5 to C30 bicycloalkyl group, an alkyl group substituted by a substituted or unsubstituted C5 to C30 bicycloalkyl group, or a combination thereof. 52 and R 72 Each is independently a C1 to C20 alkyl group substituted with a substituted C5 to C20 bicycloalkyl group, but is not limited thereto.

[0167] In some embodiments, R 62 For example, it is a substituted or unsubstituted C1 to C10 alkyl group, for example, a C1 to C10 alkyl group substituted by a halogen atom, for example, a C1 to C5 alkyl group substituted by fluorine, but is not limited thereto.

[0168] As an example, the photoacid generator represented by Chemical Formula 5 may be represented by Chemical Formula 5-1, the photoacid generator represented by Chemical Formula 6 may be represented by Chemical Formula 6-1, and the photoacid generator represented by Chemical Formula 7 may be represented by Chemical Formula 7-1,

[0169] Chemical formula 5-1

[0170]

[0171] Chemical formula 6-1

[0172]

[0173] Chemical formula 7-1

[0174]

[0175] The polymer may have a weight average molecular weight of about 1,000 g / mol to about 300,000 g / mol, such as about 3,000 g / mol to about 200,000 g / mol, such as about 3,000 g / mol to about 100,000 g / mol, such as about 3,000 g / mol to about 90,000 g / mol, such as about 3,000 g / mol to about 70,000 g / mol, such as about 3,000 g / mol to about 50,000 g / mol, but is not limited thereto. By making the weight average molecular weight within the above range, the carbon content of the resist bottom layer composition comprising the polymer and its solubility in the solvent can be adjusted and / or optimized or improved.

[0176] The photoacid generator may be included in an amount of about 10 to about 100 parts by weight, such as about 10 to about 80 parts by weight, such as about 10 to about 70 parts by weight, such as about 10 to about 60 parts by weight, such as about 20 to about 60 parts by weight, such as about 30 to about 100 parts by weight, or such as about 30 to about 70 parts by weight, based on 100 parts by weight of the polymer, but is not limited thereto. By including the photoacid generator within the above range based on the polymer content, the amount of acid provided to the resist can be optimized or improved by a film formed from a resist base layer composition including the photoacid generator, and the sensitivity to an exposure light source can be improved, thereby improving patterning performance and energy efficiency.

[0177] The polymer may be included in an amount of about 0.1 wt % to about 50 wt % based on the total weight of the resist bottom layer composition. In some embodiments, the polymer may be included in an amount of about 10 wt % to about 50 wt %, such as about 20 wt % to about 50 wt %, or such as about 20 wt % to about 30 wt %, based on the total weight of the resist bottom layer composition, but is not limited thereto. By including a polymer within the above range in the composition, the thickness, surface roughness and flatness of the resist bottom layer may be adjusted.

[0178] The photoacid generator may be included in an amount of about 0.01 wt % to about 30 wt % based on the total weight of the resist bottom layer composition. In some embodiments, the photoacid generator may be included in an amount of about 0.1 wt % to about 30.0 wt %, such as about 1.0 wt % to about 30.0 wt %, such as about 5.0 wt % to about 30.0 wt %, such as about 5.0 wt % to about 25.0 wt %, such as about 8.0 wt % to about 25.0 wt %, or such as about 10.0 wt % to about 25.0 wt %, based on the total weight of the resist bottom layer composition, but is not limited thereto. By including the photoacid generator in the above range, the thickness, surface roughness, chemical resistance and flatness of the resist bottom layer can be adjusted.

[0179] The resist bottom layer composition according to some embodiments may include a solvent. The solvent is not particularly limited as long as the solvent has suitable or sufficient solubility and / or dispersibility for the polymer and compound according to some embodiments, but may be, for example, propylene glycol, propylene glycol diacetate, methoxypropylene glycol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methyl pyrrolidone, methyl pyrrolidone, methyl 2-hydroxyisobutyrate, acetylacetone, ethyl 3-ethoxypropionate or a combination thereof.

[0180] In addition to the polymer, the compound and the solvent, the resist base composition according to some embodiments may further include one or more additional polymers selected from acrylic resins, epoxy resins, phenolic resins, glycoluril resins and melamine resins, but is not limited thereto.

[0181] The resist underlayer composition according to some embodiments may further include an additive including a surfactant, a thermal acid generator, a plasticizer, or a combination thereof.

[0182] If a resist bottom layer is formed, a surfactant may be used to improve coating defects that occur as the solid content increases. For example, the surfactant may be alkylbenzene sulfonate, alkylpyridinium salt, polyethylene glycol, quaternary ammonium salt, etc., but is not limited thereto.

[0183] The thermal acid generator may be, for example, an acidic compound such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, naphthalenecarboxylic acid and / or benzoin toluenesulfonate, 2-nitrobenzyl toluenesulfonate and other organic alkyl sulfonates, but is not limited thereto.

[0184] There is no particular limitation on the plasticizer, and various suitable types (or kinds) of plasticizers commonly used in the art can be used. Examples of plasticizers may include low molecular weight compounds (e.g., phthalates, adipates, phosphates, trimellitates and citrates, as well as polyether compounds, polyester compounds and polyacetal compounds).

[0185] The additive may be included in an amount of about 0.001 to about 40 parts by weight based on 100 parts by weight of the resist underlying composition. By including the additive within the above range, solubility may be improved without (or substantially without) changing the optical properties of the resist underlying composition.

[0186] According to some embodiments, a resist underlayer manufactured using the resist underlayer composition is provided. The resist underlayer can be obtained, for example, by coating the resist underlayer composition on a substrate and then curing it through a heat treatment process.

[0187] In the following, reference will be made to Figures 1 to 7 A method for forming a pattern using the resist underlying composition is described. Figures 1 to 7 is a cross-sectional view illustrating a method of forming a pattern using a resist underlayer composition according to an embodiment of the present disclosure.

[0188] Reference Figure 1 First, an object to be etched is prepared. An example of the object to be etched may be a thin film 102 located on a semiconductor substrate 100. Hereinafter, only an embodiment in which the object to be etched is the thin film 102 will be described, but the present disclosure is not limited thereto. The surface of the thin film 102 is cleaned to remove contaminants remaining on the thin film 102. The thin film 102 may be, for example, a silicon nitride film, a polysilicon film, and / or a silicon oxide film.

[0189] Subsequently, the above-mentioned resist underlayer composition is applied on the surface of the cleaned thin film 102 by spin coating.

[0190] Then, a drying and baking process is performed to form a resist bottom layer 104 on the thin film. The baking process may be performed at about 100° C. to about 500° C., for example, about 100° C. to about 300° C. A more detailed description of the resist bottom layer composition will not be repeated here to avoid repetition, because the resist bottom layer composition has been described in more detail above.

[0191] Reference Figure 2 , a photoresist is coated on the resist bottom layer 104 to form a photoresist film 106. Subsequently, a first baking process is performed to heat the substrate 100 on which the photoresist film 106 is formed. The first baking process may be performed at a temperature of about 90°C to about 120°C.

[0192] Reference Figure 3 , the photoresist film 106 is selectively exposed. In order to explain the exposure process for exposing the photoresist film 106 as an example, an exposure mask having a set or predetermined pattern is placed on a mask stage of an exposure device, and the exposure mask 110 is placed on the photoresist film 106. Subsequently, by irradiating light to the mask 110, a set or predetermined portion of the photoresist film 106 formed on the substrate 100 selectively reacts with the light passing through the exposure mask.

[0193] For example, examples of light that can be used in the exposure process may include short-wavelength light such as i-line activating radiation having a wavelength of 365 nm, KrF excimer laser having a wavelength of 248 nm, and ArF excimer laser having a wavelength of 193 nm. In some embodiments, extreme ultraviolet (EUV) corresponding to extreme ultraviolet light having a wavelength of 13.5 nm may be used.

[0194] The exposed region 106 b of the photoresist film 106 has a different solubility from the unexposed region 106 a of the photoresist film 106 because the polymer is formed by a cross-linking reaction (eg, condensation between organic metal compounds).

[0195] Subsequently, a second baking process is performed on the substrate 100. The second baking process may be performed at a temperature of about 90° C. to about 200° C. By performing the second baking process, the exposed region 106 b of the photoresist film 106 becomes difficult to dissolve in a developer.

[0196] like Figure 4 As shown, in the resist bottom layer 104 formed of the bottom layer composition according to some embodiments, by providing an acid (H + ) 107, so that the solubility difference in the developer between the unexposed area 106a and the exposed area 106b of the photoresist film 106 is larger, thereby improving the line width roughness of the photoresist pattern and ensuring excellent pattern formability.

[0197] Reference Figure 5 The photoresist film 106 corresponding to the unexposed area 106 a is dissolved and removed using an organic solvent developer (eg, 2-heptanone), and thus the photoresist film 106 corresponding to the exposed area 106 b remaining after development forms a photoresist pattern 108 .

[0198] As described above, the developer used in the method of forming a pattern according to some embodiments may be an organic solvent. Examples of the organic solvent used in the method of forming a pattern according to some embodiments may include: ketones such as methyl ethyl ketone, acetone, cyclohexanone, and 2-heptanone; alcohols such as 4-methyl-2-propanol, 1-butanol, isopropanol, 1-propanol, methanol; esters such as propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate, n-butyl acetate, and butyrolactone; aromatic compounds such as benzene, xylene, and toluene; or combinations thereof.

[0199] However, the photoresist pattern according to some embodiments is not necessarily limited to being formed as a negative image, but can be formed to have a positive image. In some embodiments, the developer that can be used to form a positive image can be a quaternary ammonium hydroxide composition (e.g., tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, or a combination thereof).

[0200] As explained above, the photoresist pattern 108 formed by exposure to high-energy light may have a width of about 5 nm to about 100 nm thick. The high-energy light is, for example, not only light having a wavelength such as i-line (wavelength: 365 nm), KrF excimer laser (wavelength: 248 nm) and / or ArF excimer laser (wavelength: 193 nm), but also, for example, EUV (extreme ultraviolet; wavelength: 13.5 nm) and / or electron beam. For example, the photoresist pattern 108 may be formed to have a width of about 5 nm to about 90 nm, about 5 nm to about 80 nm, about 5 nm to about 70 nm, about 5 nm to about 60 nm, about 5 nm to about 50 nm, about 5 nm to about 40 nm, about 5 nm to about 30 nm, about 5 nm to about 20 nm, or about 5 nm to about 10 nm.

[0201] In some embodiments, the photoresist pattern 108 may have a half-pitch pitch of less than or equal to about 50 nm, for example, less than or equal to about 40 nm, for example, less than or equal to about 30 nm, for example, less than or equal to about 20 nm, or for example, less than or equal to about 10 nm, and a line width roughness of less than or equal to about 5 nm, less than or equal to about 3 nm, less than or equal to about 2 nm, or less than or equal to about 1 nm.

[0202] Subsequently, the resist bottom layer 104 is etched using the photoresist pattern 108 as an etching mask. Figure 5 The organic film pattern 112 shown is formed by the above etching process.

[0203] The formed organic film pattern 112 may also have a width corresponding to the photoresist pattern 108. For example, etching may be performed by dry etching using an etching gas, and the etching gas may be, for example, CHF3, CF4, Cl2, O2, or a mixture thereof. As described above, since the resist underlayer formed of the resist underlayer composition according to some embodiments has a fast etching rate, a smooth etching process may be performed in a short time.

[0204] Reference Figure 7 The exposed thin film 102 is etched by using the photoresist pattern 108 as an etching mask. Thus, the thin film is formed into a thin film pattern 114.

[0205] In the exposure process performed as described above, the thin film pattern formed by the exposure process performed using a short wavelength light source (e.g., activating radiation i-line (wavelength: 365 nm), KrF excimer laser (wavelength: 248 nm) and / or ArF excimer laser (wavelength: 193 nm) may have a width of tens to hundreds of nanometers, and the thin film pattern 114 formed by the exposure process performed using an EUV light source may have a width less than or equal to about 20 nm.

[0206] Hereinafter, embodiments of the present disclosure will be described in more detail through examples related to the synthesis of the above polymer and the preparation of a resist underlayer composition comprising the polymer. However, the present disclosure is not technically limited to the following examples.

[0207] Polymer synthesis

[0208] Synthesis example 1

[0209] 24.9g of 1,3-diallyl-5-(2-hydroxyethyl)isocyanurate, 7.4g of mercaptoethanol, 0.7g of azobisisobutyronitrile (AIBN) and 48g of N,N-dimethylformamide (DMF) were added to a 500ml three-necked round-bottom flask and a condenser was connected to it. After the reaction was carried out at 80°C for 16 hours, the resulting reaction solution was cooled to room temperature. While stirring, the reaction solution was added dropwise to a 1L wide-mouth bottle containing 800g of water to generate a gum, which was dissolved in 80g of tetrahydrofuran (THF). The dissolved resin solution was treated with toluene to form a precipitate while removing single molecules and low molecular weight molecules. Finally, a polymer A represented by chemical formula 1-1 was obtained. (Weight average molecular weight (Mw) = 10,500g / mol)

[0210] Chemical formula 1-1

[0211]

[0212] Synthesis example 2

[0213] 24.9g of 1,3,5-triallyl-1,3,5-triazine-2,4,6-trione), 7.4g of mercaptoethanol, 0.7g of azobisisobutyronitrile (AIBN) and 48g of N,N-dimethylformamide (DMF) were placed in a 500ml three-necked round-bottom flask and a condenser was connected to it. After the reaction was carried out at 80°C for 16 hours, the resulting reaction solution was cooled to room temperature. While stirring, the reaction solution was added dropwise to a 1L wide-mouth bottle containing 800g of water to generate a gum, which was dissolved in 80g of THF. The dissolved resin solution was treated with toluene to form a precipitate while removing single molecules and low molecular weight molecules. Finally, a polymer B represented by chemical formula 1-2 was obtained. (Weight average molecular weight (Mw) = 8,000g / mol)

[0214] Chemical formula 1-2

[0215]

[0216] Synthesis example 3

[0217] 20 g of 1,3-diallyl-5,5-dimethyl-1,3-diazinane-2,4,6(1H,3H,5H)-trione, 8.4 g of 2,3-dimercapto-1-propanol, 0.5 g of azobisisobutyronitrile (AIBN) and 50 g of N,N-dimethylformamide were added to a 250 mL four-necked flask to prepare a reaction solution, and a condenser was connected thereto. The resulting reaction solution was reacted by heating at 60° C. for 5 hours, and then cooled to room temperature. Subsequently, the reaction solution was added dropwise to a beaker containing 300 g of distilled water while stirring to generate a gum, which was dissolved in 30 g of THF. The dissolved resin solution was treated with toluene to form a precipitate, while removing single molecules and low molecular weight molecules, to finally obtain a polymer C composed of the structural unit represented by Chemical Formula 2-1. (Weight average molecular weight (Mw) = 3,700 g / mol)

[0218] Chemical formula 2-1

[0219]

[0220] Synthesis example 4

[0221] 148.6g (0.5mol) of 1,3,5-triglycidyl isocyanurate, 60.0g (0.4mol) of 2,2'-thiodiacetic acid, 9.1g of benzyltriethylammonium chloride and 350g of N,N-dimethylformamide were added to a 1L double-necked round-bottom flask, and a condenser was connected to it. After the temperature was raised to 100°C and the reaction was carried out for 8 hours, the resulting reaction solution was cooled to room temperature (23°C). Subsequently, the reaction solution was moved to a 1L wide-mouth bottle, and then washed three times with hexane, and then washed with pure water. The obtained gum-like resin was completely dissolved in 80g of THF, and then slowly added dropwise to 700g of toluene while stirring. After removing the solvent, a polymer D including a structural unit represented by chemical formula 2-2 was finally obtained. (Weight average molecular weight (Mw) = 9,100g / mol)

[0222] Chemical formula 2-2

[0223]

[0224] Synthesis example 5

[0225] 20g of 1,3-diallyl-5-(2,2-dimethyl)-isocyanurate, 6.0g of 1,2-dithiol (ethane-1,2-dithiol), 1g of azobisisobutyronitrile (AIBN) and 50g of N,N-dimethylformamide were added to a 250mL four-necked flask to prepare a reaction solution, and a condenser was connected to it. The resulting reaction solution was reacted by heating at 50°C for 5 hours, and after adding 10g of 3,4-difluorobenzyl mercaptan and 1g of azobisisobutyronitrile (AIBN), it was reacted for another 2 hours and then cooled to room temperature. Subsequently, while stirring, the reaction solution was added dropwise to a beaker containing 300g of distilled water to generate a gum, which was dissolved in 30g of THF. The dissolved resin solution was treated with toluene to form a precipitate, while removing single molecules and low molecular weight molecules to finally obtain a polymer E represented by chemical formula 2-3. (Weight average molecular weight (Mw) = 5,500 g / mol)

[0226] Chemical formula 2-3

[0227]

[0228] Synthesis of compounds

[0229] Synthesis example 6

[0230] 6g of diphenyl sulfoxide, 6.7g of iodobenzene and 200g of dichloromethane were added to a 500mL single-necked flask. Subsequently, 9.3g of trifluoromethanesulfonic anhydride was slowly added dropwise, and the reaction was allowed to proceed at -78°C for 30 minutes, followed by further reaction at room temperature for 4 hours. The resulting reaction solution was then washed with distilled water, the organic solution portion was taken out, and the solvent was removed. The organic material from which the solvent had been removed was dissolved in dichloromethane, diethyl ether was slowly added dropwise, and the precipitated solid was filtered and dried to obtain a compound represented by chemical formula 4-1.

[0231] Chemical formula 4-1

[0232]

[0233] Synthesis Example 7

[0234] A compound represented by Chemical Formula 4-2 was obtained in the same manner as in Synthesis Example 6, except that 3.2 g of fluorobenzene was used instead of iodobenzene.

[0235] Chemical formula 4-2

[0236]

[0237] Synthesis example 8

[0238] In a 100 mL single-necked flask, 1.6 g of 5-norbornene-2,3-dicarboximide, 4.8 g of di-tert-butyl dicarbonate, and 0.12 g of 4-dimethylaminopyridine were added to 5 ml of acetonitrile and reacted at room temperature. Then, 0.61 ml of hydroxylamine (50 wt % aqueous solution) was added dropwise, and the reaction was allowed to proceed for 24 hours at room temperature. Then, 10 ml of diethyl ether was added, and the resulting solid was filtered, washed with diethyl ether, and dried. The dried solid was added to 15 ml of distilled water, and diluted HCl was added until the pH reached 1. The insoluble hydroxy-5-norbornene-2,3-dicarboxylic acid imide (N-Hydroxy-5-norbornene-2,3-dicarboxylic acid imide) solid was filtered, washed with distilled water, and dried.

[0239] Then, under a nitrogen atmosphere, 1.4 g of hydroxy-5-norbornene-2,3-dicarboxylic acid imide and 1.7 g of tosyl chloride were added to 30 mL of THF in a 100 mL three-necked flask, and cooled to -5 ° C, and then 1.6 g of trimethylamine was slowly added dropwise. After reacting for 24 hours, the product was filtered and dried at room temperature to obtain a solid. The solid was dissolved in ethyl acetate, mixed with 1% sodium bicarbonate solution, and then the ethyl acetate layer was separated. Then, the ethyl acetate solvent was completely removed to obtain a compound represented by chemical formula 5-1.

[0240] Chemical formula 5-1

[0241]

[0242] Synthesis example 9

[0243] A compound represented by Chemical Formula 6-1 was obtained in the same manner as in Synthesis Example 8 except that 2.1 g of 1,3-diallyl-1,3,5-triazinane-2,4,6-trione was used instead of 5-norbornene-2,3-dicarboximide.

[0244] Chemical formula 6-1

[0245]

[0246] Synthesis example 10

[0247] In a 100 mL single-necked flask, 2 g of 1,8-naphthalene dicarboximide, 4.8 g of di-tert-butyl dicarbonate and 0.12 g of dimethylaminopyridine were added to 5 ml of acetonitrile and reacted at room temperature. Then, 0.61 ml of hydroxylamine (50 wt % aqueous solution) was added dropwise and reacted at room temperature for 24 hours. Then, 10 ml of diethyl ether was added, and the resulting solid was filtered, washed with diethyl ether and dried. The dried solid was added to 15 ml of distilled water, and diluted HCl was added until the pH reached 1. The insoluble hydroxynaphthalene dicarboximide solid was filtered, washed with distilled water and dried.

[0248] Then, under a nitrogen atmosphere, 1.7 g of hydroxynaphthalene dicarboximide and 2.2 g of (7,7-dimethyl-2-oxobicyclo[2.2.1]hept-1-yl) methanesulfonyl chloride were added to 30 mL of THF in a 100 mL three-necked flask, and cooled to -5 ° C, and then 1.6 g of trimethylamine was slowly added dropwise. After reacting for 24 hours, the product was filtered and dried at room temperature to obtain a solid. The solid was dissolved in ethyl acetate, mixed with 1% sodium bicarbonate solution, and then the ethyl acetate layer was separated. Then, the ethyl acetate solvent was completely removed to obtain a compound represented by chemical formula 7-1.

[0249] Chemical formula 7-1

[0250]

[0251] Preparation of resist base composition

[0252] Example 1

[0253] The polymer A according to Synthesis Example 1 and the compound of Chemical Formula 4-1 according to Synthesis Example 6 as a photoacid generator were mixed together in a ratio of 100:50, and 1.2 g of the mixture, 0.4 g of PD 1174 (cross-linking agent) and 0.02 g of pyridinium para-toluenesulfonate (PPTS) were completely dissolved in propylene glycol monomethyl ether to a solid content of 3%, and then diluted by further adding a solvent thereto to prepare a resist underlayer composition according to Example 1.

[0254] Example 2

[0255] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 4-2 obtained in Synthesis Example 7 was used instead of the compound represented by Chemical Formula 4-1.

[0256] Example 3

[0257] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 5-1 obtained in Synthesis Example 8 was used instead of the compound represented by Chemical Formula 4-1.

[0258] Example 4

[0259] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 6-1 obtained in Synthesis Example 9 was used instead of the compound represented by Chemical Formula 4-1.

[0260] Example 5

[0261] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 7-1 obtained in Synthesis Example 10 was used instead of the compound represented by Chemical Formula 4-1.

[0262] Example 6

[0263] A resist underlayer composition was prepared in the same manner as in Example 1, except that the polymer B obtained in Synthesis Example 2 was used instead of the polymer A.

[0264] Comparative Example 1

[0265] A resist underlayer composition was prepared by mixing 1.2 g of polymer A according to Synthesis Example 1, 0.4 g of PD 1174 (crosslinking agent) and 0.02 g of pyridinium p-toluenesulfonate (PPTS), and completely dissolving them in propylene glycol monomethyl ether to a solid content of 3%, and then diluting with an additional solvent.

[0266] Comparative Example 2

[0267] A resist underlayer composition was prepared in the same manner as in Comparative Example 1, except that the polymer B was used instead of the polymer A.

[0268] Comparative Example 3

[0269] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 8 (NDI-105, Midori Kagaku) ​​was used instead of the compound represented by Chemical Formula 4-1.

[0270] Chemical formula 8

[0271]

[0272] Comparative Example 4

[0273] A resist underlayer composition was prepared in the same manner as in Example 1, except that the compound represented by Chemical Formula 9 (NDI-109, Green Chem) was used instead of the compound represented by Chemical Formula 4-1.

[0274] Chemical formula 9

[0275]

[0276] Evaluation: Thermogravimetric analysis (TGA) of photoacid generators

[0277] The mass reduction rate (%) of each of the compounds represented by Chemical Formula 4-1, Chemical Formula 4-2, Chemical Formula 5-1, Chemical Formula 6-1, Chemical Formula 7-1, Chemical Formula 8, and Chemical Formula 9 was measured by maintaining an isothermal temperature of 205° C. for 10 minutes under air gas conditions using a TGA / differential scanning calorimetry (DSC) 3 instrument (Mettler Toledo). At this time, the mass at 3 minutes was compared with the initial mass, and the mass reduction rate (%) values ​​are shown in Table 1.

[0278] Table 1

[0279] Photoacid generator Mass reduction rate after three minutes (%) Chemical formula 4-1 0 Chemical formula 4-2 0 Chemical formula 5-1 0 Chemical formula 6-1 0 Chemical formula 7-1 0 Chemical formula 8 5 Chemical formula 9 2

[0280] Evaluation: Evaluation of exposure characteristics

[0281] Each of the compositions according to Examples 1 to 6 and Comparative Examples 1 to 4 was coated by spin coating and heat treated on a hot plate at 205° C. for 60 seconds to form A photoresist solution was applied on the bottom layer 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 light at 200 μC / cm by using an electron beam lithography machine (Elionix Inc.). 2 To 2000μC / cm 2 The photoresist layer was exposed within the range of , and heat treated at 150°C for 60 seconds. Subsequently, the photoresist layer was developed in a 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution and rinsed with pure water for 15 seconds to form a photoresist pattern with a line and space (L / S) of 50nm. Then, the photoresist pattern was evaluated with respect to the optimal exposure dose, and the results are shown in Table 2. In this article, the optimal exposure dose (optimal energy) (Eop, μC / cm 2 ) represents the exposure dose for developing a 50 nm thread and space pattern at 1:1. In addition, the minimum critical dimension (CD) represents the minimum dimension that can form a pattern well without line connection or collapse, where the lower the resolution, the better.

[0282] Table 2

[0283]

[0284] Referring to Table 2, the resist underlayer according to the example has excellent fine pattern (50 nm L / S) formability and sensitivity compared with the comparative example.

[0285] Evaluation: Evaluation of Line Width Roughness (LWR)

[0286] Each of the compositions of Examples 1 to 6 and Comparative Examples 1 to 4 was coated by spin coating and heat treated on a hot plate at 205° C. for 60 seconds to form The photoresist layer was formed by a 30 nm thick resist bottom layer. Subsequently, a photoresist solution was applied on the bottom layer by spin coating, and heat treated on a hot plate at 110° C. for 1 minute to form a photoresist layer. By using an electron beam exposure machine (acceleration voltage: 100 keV, Elionix Inc.), the resist layer was exposed to have a line width of 30 nm and a line spacing of 30 nm. Subsequently, the exposed resist layer was heat treated at 95° C. for 60 seconds, and developed in a 2.38 wt % tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds, and rinsed with pure water for 60 seconds to form a resist pattern.

[0287] The line width roughness (LWR) was obtained by examining a pattern having a width of 30 nm using a scanning electron microscope (SEM) S-9260 (Hitachi, Ltd.), and measuring the distance from a reference line in the length direction of the pattern where the edge should be within an edge range of 2 μm. The results are shown in Table 2, where the smaller the line width roughness (LWR), the better.

[0288] Referring to Table 2, the resist underlayer of the example had a smaller LWR than the resist underlayer of the comparative example and exhibited a more uniform pattern.

[0289] In the above, exemplary embodiments of the present disclosure have been described and illustrated, however, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described, and various modifications and changes can be made without departing from the spirit and scope of the present disclosure. Therefore, the modified or changed embodiments themselves may not be understood separately from the technical ideas and aspects of the present disclosure, and the modified embodiments are within the scope of the claims of the present disclosure and their equivalents.

Claims

1. A resist bottom layer composition, comprising: A polymer, a photoacid generator, and a solvent, wherein the polymer includes a structural unit represented by Chemical Formula 1, a structural unit represented by Chemical Formula 2, or a combination thereof, and the photoacid generator has a mass reduction rate of 0% after 3 minutes from the measurement time during thermogravimetric analysis at 205° C. in an air atmosphere containing air gas, Chemical formula 1 Chemical formula 2 In Chemical Formula 1 and Chemical Formula 2, A is a heterocyclic group containing a nitrogen atom in the ring, L 1 To L 6 each independently represents a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, a substituted or unsubstituted C3 to C20 cycloalkylene group, a substituted or unsubstituted C2 to C20 heterocycloalkylene group, a substituted or unsubstituted C6 to C20 arylene group, a substituted or unsubstituted C3 to C20 heteroarylene group, or a combination thereof, X 1 To X 5 Each is independently a single bond, -O-, -S-, -S(=O)-, -S(=O)2-, -C(=O)-, -(CO)O-, -O(CO)O-, -NR a - or a combination thereof, wherein R a is hydrogen, deuterium or C1 to C10 alkyl, Y 1 To Y 3 each is independently hydroxy, substituted or unsubstituted C1 to C10 alkyl, substituted or unsubstituted C2 to C10 alkenyl, substituted or unsubstituted C2 to C10 alkynyl, substituted or unsubstituted C1 to C10 heteroalkyl, substituted or unsubstituted C2 to C10 heteroalkenyl, substituted or unsubstituted C2 to C10 heteroalkynyl, substituted or unsubstituted C3 to C20 cycloalkyl, substituted or unsubstituted C2 to C20 heterocycloalkyl, substituted or unsubstituted C6 to C20 aryl, substituted or unsubstituted C3 to C20 heteroaryl, or a combination thereof, and * is the connection point.

2. The resist underlayer composition according to claim 1, wherein A in Chemical Formula 1 and Chemical Formula 2 is represented by one or more selected from Chemical Formula A-1 to Chemical Formula A-4, Chemical formula A-1 Chemical formula A-2 Chemical formula A-3 Chemical formula A-4 in, In Chemical Formula A-1 to Chemical Formula A-4, * represents a connection point to another atom or group.

3. The resist base composition according to claim 1, wherein L 1 To L 6 are each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C1 to C10 heteroalkylene group, or a combination thereof, X 1 To X 5 are each independently a single bond, -O-, -S-, -C(=O)-, -(CO)O-, -O(CO)O-, or a combination thereof, and Y 1 To Y 3 Each is independently a substituted or unsubstituted C1 to C10 alkyl, a substituted or unsubstituted C2 to C10 alkenyl, a substituted or unsubstituted C1 to C10 heteroalkyl, a substituted or unsubstituted C2 to C10 heteroalkenyl, a substituted or unsubstituted C3 to C20 cycloalkyl, a substituted or unsubstituted C2 to C20 heterocycloalkyl, a substituted or unsubstituted C6 to C20 aryl, or a combination thereof.

4. The resist underlayer composition according to claim 1, wherein the photoacid generator is represented by Chemical Formula 3 or comprises an imide derivative or a cyanurate derivative in which a nitrogen atom is substituted by a sulfonate group, Chemical formula 3 in, In chemical formula 3, R 2 to R 4 are each independently a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, and Z - It is a monovalent anion.

5. The resist underlayer composition according to claim 4, wherein R 2 to R 4 Each is independently a C1 to C20 alkyl group substituted by at least one or more halogen atoms, a C6 to C30 aryl group substituted by at least one or more halogen atoms, or a combination thereof.

6. The resist underlayer composition according to claim 1, wherein the photoacid generator is represented by any one or more selected from Chemical Formula 4 to Chemical Formula 7, Chemical formula 4 in, In chemical formula 4, R 21 , R 31 and R 41 are each independently a halogen atom, and n21, n31 and n41 are each independently one of integers selected from 0 to 5, provided that at least one of n21, n31 and n41 is 1 or greater than 1; Chemical formula 5 Chemical formula 6 Chemical formula 7 Among them, in Chemical Formula 5 to Chemical Formula 7, R 51 , R 61 , R 62 and R 71 each independently represents deuterium, a hydroxyl group, a halogen atom, a nitro group, a cyano group, -COOH, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, R 52 , R 63 and R 72 each independently represents a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C2 to C20 alkenyl group, a substituted or unsubstituted C2 to C20 alkynyl group, a substituted or unsubstituted C3 to C20 cycloalkyl group, a substituted or unsubstituted C5 to C30 bicycloalkyl group, a substituted or unsubstituted C6 to C30 aryl group, or a combination thereof, n51 is one selected from integers from 0 to 2, and n71 is one selected from integers from 0 to 6.

7. The resist underlayer composition according to claim 1, wherein the structural unit represented by Chemical Formula 1 is represented by Chemical Formula 1-1 or Chemical Formula 1-2, and the structural unit represented by Chemical Formula 2 is represented by any one selected from Chemical Formula 2-1 to Chemical Formula 2-3, Chemical formula 1-1 Chemical formula 1-2 Chemical formula 2-1 Chemical formula 2-2 Chemical formula 2-3 8. The resist underlayer composition according to claim 1, wherein the photoacid generator is represented by any one selected from Chemical Formula 4-1, Chemical Formula 4-2, and Chemical Formula 5-1 to Chemical Formula 7-1, Chemical formula 4-1 Chemical formula 4-2 Chemical formula 5-1 Chemical formula 6-1 Chemical formula 7-1 9 . The resist underlayer composition according to claim 1 , wherein the weight average molecular weight of the polymer is 1,000 g / mol to 300,000 g / mol. 10 . The resist underlayer composition according to claim 1 , wherein the photoacid generator is included in an amount of 10 parts by weight to 100 parts by weight based on 100 parts by weight of the polymer.

11. The resist underlayer composition according to claim 1, wherein the polymer is included in an amount of 0.1 wt% to 50 wt% based on the total weight of the resist underlayer composition. 12 . The resist underlayer composition according to claim 1 , wherein the photoacid generator is included in an amount of 0.01 wt % to 30 wt % based on the total weight of the resist underlayer composition.

13. The resist base layer composition according to claim 1, wherein the resist base layer composition further comprises an additional polymer selected from one or more of acrylic resin, epoxy resin, phenolic resin, glycoluril resin and melamine resin. 14 . The resist underlayer composition according to claim 1 , wherein the resist underlayer composition further comprises an additive, and the additive comprises a surfactant, a thermal acid generator, a plasticizer or a combination thereof.

15. A method for forming a pattern, comprising: forming a film to be etched on a substrate; applying the resist base layer composition according to claim 1 on the film to be etched to form a resist base layer; forming a photoresist pattern on the resist bottom layer; as well as The resist base layer and the film to be etched are sequentially etched using the photoresist pattern as an etching mask.

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