Naphtholactam polymer and preparation method thereof, hard mask composition and method for forming pattern

Abstract

The invention belongs to the technical field of photoetching, and provides a naphtholactam polymer and a preparation method thereof, a hard mask composition and a method for forming a pattern. The naphtholactam polymer has a structure as shown in a formula 1, and n is an integer from 1 to 500; r1 is hydrogen, 4-10-membered naphthenic base or substituted or unsubstituted aryl with the carbon atom number of 6-30; and L is alkylene with the carbon atom number of 1-10. The hard mask formed by the hard mask composition not only has relatively high heat resistance and etching resistance, but also has good gap filling and planarization capabilities. Formula 1

Description

Technical Field

[0001] This invention belongs to the field of photolithography technology, specifically relating to a naphtholactam polymer and its preparation method, a hard mask composition, and a method for forming patterns. Background Technology

[0002] In photolithography, thinner resist layers are crucial for achieving high-resolution patterns and preventing pattern collapse. However, when the substrate (target material layer) is thick, thin resist layers, due to insufficient etch resistance, struggle to maintain pattern integrity during prolonged etching, hindering the independent and effective transfer of the pattern to the underlying substrate. Therefore, a hard mask (also known as a "hard mask layer") is typically introduced between the resist layer and the substrate as an intermediary for pattern transfer. The core function of this hard mask is to first receive and replicate the pattern on the resist layer, and then, leveraging its high etch selectivity, act as a robust barrier layer to transfer the pattern to the underlying substrate.

[0003] Since hard masks require selective etching to transfer fine photoresist patterns to the material layer, they must possess excellent heat resistance and etching resistance to maintain structural stability and ensure pattern transfer accuracy during multiple etching processes. Currently, related technologies mainly improve etching resistance by using hard mask compositions with high carbon content polymers. However, these materials generally suffer from two major drawbacks: first, poor solubility and insufficient thermal stability, directly affecting the planarization quality and gap-filling ability of the hard mask; second, they easily lead to distortion or even failure of the photolithographic pattern during the transfer process, making it difficult to meet process requirements.

[0004] In summary, there is an urgent need to develop a novel hard mask composition that can simultaneously achieve good etch resistance, solubility, and high stability in order to meet the requirements of advanced photolithography processes for pattern transfer accuracy and reliability. Summary of the Invention

[0005] The present invention aims to provide a naphtholactam polymer and its preparation method, a hard mask composition comprising the naphtholactam polymer, and a method for forming patterns using the hard mask composition. The hard mask formed using the hard mask composition not only has high heat resistance and etching resistance, but also possesses good gap filling and planarization capabilities.

[0006] A first aspect of the present invention provides a naphtholic lactam polymer having the structure shown in Formula 1: Formula 1, In Equation 1, n is an integer from 1 to 500; R1 is hydrogen, a 4-10 membered cycloalkyl group, or a substituted or unsubstituted aryl group with 6-30 carbon atoms, and the substituent is an alkyl group with 1-6 carbon atoms; L is an alkylene group with 1-10 carbon atoms. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms; Ar is an arylene with 6 to 24 carbon atoms.

[0007] In some embodiments of the present invention, the weight-average molecular weight of the naphthyl lactam polymer is 5,000 to 30,000, and the molecular weight distribution index is 1.30 to 3.60.

[0008] A second aspect of the present invention provides a method for preparing the naphthylcarbamate polymer described in the first aspect of the present invention. The method comprises: subjecting a naphthylcarbamate monomer with a structure as shown in Formula 2 to an oxygen-containing organic compound as shown in Formula 3 via a polycondensation reaction to form the naphthylcarbamate polymer. Equation 2, Formula 3, In Formula 2, R1 is hydrogen, a 4-10 membered cycloalkyl group, or a substituted or unsubstituted aryl group with 6-30 carbon atoms, and the substituent is an alkyl group with 1-6 carbon atoms; L is an alkylene group with 1-10 carbon atoms. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms; In Formula 3, Ar is an arylene with 6 to 24 carbon atoms, and R3 is hydrogen or methyl.

[0009] In some embodiments of the present invention, the oxygen-containing organic compound is an aryl diol with the structure shown in Formula 3-1: Equation 3-1.

[0010] Furthermore, the aryl diol is selected from at least one of dihydroxymethylbenzene, dihydroxymethylbiphenyl, dihydroxymethylnaphthalene, and dihydroxymethylanthracene.

[0011] In other embodiments of the present invention, the oxygen-containing organic compound is a dimethoxymethyl aromatic hydrocarbon with the structure shown in Formula 3-2: Equation 3-2.

[0012] Furthermore, the dimethoxymethyl aromatic hydrocarbon is selected from at least one of dimethoxymethylbenzene, dimethoxymethylbiphenyl, dimethoxymethylnaphthalene, and dimethoxymethylanthracene.

[0013] In some embodiments of the present invention, the structure of the naphthyllactam monomer is shown below: .

[0014] A third aspect of the present invention provides a hard mask composition comprising a polymer, a catalyst, a crosslinking agent, a surfactant, a plasticizer, and a solvent, wherein the polymer is a naphtholactam polymer as described in the first aspect of the present invention.

[0015] In some embodiments of the present invention, based on the total mass of the hard mask composition, the polymer has a mass content of 5% to 25%, the crosslinking agent has a mass content of 0.5% to 3%, the catalyst has a mass content of 0.005% to 0.1%, the surfactant has a mass content of 0.01% to 0.1%, and the plasticizer has a mass content of 0.2% to 2.5%.

[0016] A fourth aspect of the present invention provides a method for forming a pattern, comprising the following steps: Provide a material layer on the substrate; The hard mask composition according to the third aspect of the present invention is applied to the material layer to form a hard mask; A silicon-containing thin layer is formed on the hard mask; A photoresist resist layer is formed on the silicon-containing thin layer; The photoresist resist layer is exposed and developed to form a photoresist pattern; The silicon-containing thin layer and the hard mask are selectively removed using the photoresist pattern to expose a portion of the material layer; Etch the exposed portion of the material layer.

[0017] The polymer provided by this invention possesses a specific main chain and side group structure, which imparts excellent comprehensive performance to hard mask compositions. The polymer's main chain comprises a benzene ring and a -CH2-Ar-CH2- flexible segment. This structure helps improve the polymer's solubility in spin-coating solvents and provides the film with good flow and spreading capabilities, thereby improving the film's planarization and gap-filling effects. Furthermore, the naphthyl lactam structure introduced into the side groups is a rigid heteroaromatic ring. Its fused-ring backbone significantly enhances the polymer's thermal stability, ensuring morphological stability under the high-temperature conditions of photolithography and effectively preventing pattern deformation. Moreover, the carbon, nitrogen, and oxygen atoms in this fused-ring backbone can promote side group crosslinking under etching conditions, forming a dense protective layer that synergistically works with the main chain aromatic ring to jointly construct the film's excellent etching resistance. In addition, the large steric hindrance and rigid planar structure of the naphthyl lactam side groups can limit excessive stacking and movement of molecular chains during curing, helping to maintain the stability of the film's morphology and ensuring the formation of a dense and flat surface.

[0018] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Detailed Implementation

[0019] The embodiments of the present invention are described in detail below. The embodiments described below are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0020] The "scope" disclosed in this invention is defined in the form of a lower limit and / or an upper limit, whereby a given scope is defined by selecting a lower limit and / or an upper limit. This scope may or may not include endpoints and can be arbitrarily combined; that is, any lower limit can be combined with any upper limit to form an undefined scope, and any lower limit can be combined with other lower limits to form an undefined scope, similarly, any upper limit can be combined with any other upper limit to form an undefined scope. Furthermore, each individually disclosed point or single value can itself serve as a lower or upper limit and can be combined with any other point or single value, or with other lower or upper limits, to form an undefined scope.

[0021] Unless otherwise specified, all embodiments and optional embodiments of the present invention may be combined with each other to form new technical solutions, and such technical solutions should be considered to be included in the disclosure of the present invention.

[0022] In this invention, alkyl groups may include straight-chain alkyl groups and branched-chain alkyl groups. Specific examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, 1,1-dimethyl-n-propyl, 1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-methyl-cyclopropyl, 2-methyl-cyclopropyl, 1-methyl-n-butyl, 2-methyl-n-butyl, 3-methyl-n-butyl, n-hexyl, 1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl, 4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl, 1,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl, n-heptyl, isoheptyl, n-octyl, isooctyl, n-nonyl, and isononyl. An alkylene group is a divalent group formed by the further loss of a hydrogen atom from an alkyl group.

[0023] In this invention, 4-10 membered cycloalkyl refers to monocyclic or polycyclic alkyl with 4-10 carbon atoms on the ring. Specific examples include, but are not limited to, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, adamantyl, and norbornel.

[0024] In this invention, substituted or unsubstituted aryl refers to an aryl group having substituents or an unsubstituted aryl group. A "substituted" aryl group means that the hydrogen atoms on the aryl group can be replaced by one or more substituents. When the number of substituents is greater than one, the substituents can be the same or different. It should be understood that the number of carbon atoms in a substituted aryl group refers to the total number of carbon atoms in the aryl group and its substituents. For example, a substituted aryl group with 18 carbon atoms means that the total number of carbon atoms in the aryl group and its substituents is 18.

[0025] In this invention, specific examples of aryl groups include, but are not limited to, phenyl, naphthyl, biphenyl, anthracene, pyrene, and fluorene. Aromatic groups refer to divalent groups formed by the further loss of a group from an aryl group, and specific examples include, but are not limited to, phenylene, naphthylene, biphenylene, anthracene, pyrene, and fluorene.

[0026] In this invention, " "Indicates a linker bond. A non-positioned linker bond refers to a single bond extending from the ring system." The term "" indicates that one end of the linker can connect to any position in the ring system it traverses, while the other end connects to the rest of the molecule. For example, as shown in formula f below, the naphthyl group represented by formula f is connected to other positions in the molecule via a non-positional linker extending from the middle of one side of the benzene ring. This means that it includes any possible connection method shown in formulas f-1 and f-2. .

[0027] For example, as shown in equation e below, the naphthyl group represented by equation e is connected to other positions in the molecule through two non-positional linkages that span the bicyclic ring. This means that any possible connection configuration can be represented as shown in equations e-1 to e-7.

[0028] .

[0029] In a first aspect, the present invention provides a naphthylcarbamate polymer having the structure shown in Formula 1: Formula 1, In Formula 1, n represents the degree of aggregation, which is an integer from 1 to 500, such as 1, 3, 5, 9, 10, 12, 15, 17, 20, 50, 75, 100, 150, 180, 200, 220, 280, 300, 450, 500, etc., and preferably an integer from 2 to 30; R1 is hydrogen, a 4-10 membered cycloalkyl group, or a substituted or unsubstituted aryl group with 6-30 carbon atoms, and the substituent is an alkyl group with 1-6 carbon atoms; L is an alkylene group with 1-10 carbon atoms. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms; Ar is an arylene with 6 to 24 carbon atoms.

[0030] In some embodiments, Ar is selected from any of the following groups:

[0031] Furthermore, Ar is selected from any of the following groups:

[0032] In some embodiments, R1 is hydrogen, a 4- to 10-membered cycloalkyl group, or an aryl group having 6 to 18 carbon atoms. Preferably, R1 is hydrogen or a 4- to 10-membered cycloalkyl group. As some examples, R1 is hydrogen, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, biphenyl, or naphthyl.

[0033] In some embodiments, L is an alkylene group having 2 to 10 carbon atoms. As some preferred examples, L is ethylene (-CH2CH2-), n-propylene (-CH2CH2CH2-), n-butylene (-CH2CH2CH2CH2-), n-pentylene (-CH2CH2CH2CH2CH2-), n-hexylene (-CH2CH2CH2CH2CH2CH2-), n-heptylene (-CH2CH2CH2CH2CH2CH2CH2-), or n-octylene (-CH2CH2CH2CH2CH2CH2CH2-).

[0034] In some embodiments, R2 is hydrogen or an alkyl group having 1 to 4 carbon atoms, preferably hydrogen or methyl.

[0035] In this invention, the weight-average molecular weight (Mw) of the naphthyl lactam polymer can be 5000~30000, for example 5000, 6000, 6500, 7000, 7400, 7700, 8000, 8500, 8800, 9000, 10000, 1070, 11030, 12000, 15000, 20000, 23000, 25000, 30000, etc., preferably 6000~20000; the molecular weight distribution index (PDI) can be 1.30~3.60, for example 1.42, 1.53, 1.66, 1.85, 2.05, 2.24, 2.35, 2.65, 3.15, 3.45, etc. The molecular weight and distribution of the polymer can be determined by gel permeation chromatography (GPC).

[0036] A second aspect of the present invention provides a method for preparing the naphthyl lactam polymer, the method comprising: subjecting a naphthyl lactam monomer with a structure as shown in Formula 2 to an oxygen-containing organic compound with a structure as shown in Formula 3, to form the naphthyl lactam polymer. Equation 2, Formula 3; In Equations 2 and 3, the definitions of R1, L, R2 and Ar are as described in the first aspect of this invention, and will not be repeated here.

[0037] In some embodiments, the structure of the naphtholactam monomer is shown below: .

[0038] In some embodiments, the oxygen-containing organic compound is an aryl diol with the structure shown in Formula 3-1: Equation 3-1.

[0039] Further, the aryl diol is selected from at least one of dihydroxymethylbenzene (e.g., 2,4-dihydroxymethylphenol and / or 2,6-dihydroxymethylphenol), dihydroxymethylbiphenyl (e.g., 4,4'-dihydroxymethylbiphenyl), dihydroxymethylnaphthalene (e.g., 2,6-di(hydroxymethyl)naphthalene), and dihydroxymethylanthracene (e.g., 9,10-di(hydroxymethyl)anthracene).

[0040] In other embodiments, the oxygen-containing organic compound is a dimethoxymethyl aromatic hydrocarbon with the structure shown in Formula 3-2: Equation 3-2.

[0041] Furthermore, the dimethoxymethyl aromatic hydrocarbon is selected from at least one of dimethoxymethylbenzene (e.g., 1,4-bis(methoxymethyl)benzene), dimethoxymethylbiphenyl, dimethoxymethylnaphthalene, and dimethoxymethylanthracene.

[0042] In some embodiments, the molar ratio of the naphthyl lactam monomer to the oxygen-containing organic compound is 1:(1~2.5), for example, 1:1, 1:1.2, 1:1.3, 1:1.5, 1:1.8, 1:2, 1:2.2, etc.

[0043] In some embodiments, the polycondensation reaction is carried out in the presence of an acid catalyst. The acid catalyst can be an organic acid catalyst and / or an inorganic acid catalyst. Specific examples of organic acid catalysts include, but are not limited to, one or more of p-benzenesulfonic acid, formic acid, oxalic acid, benzoic acid, and salicylic acid; specific examples of inorganic acid catalysts include, but are not limited to, one or more of sulfuric acid, phosphoric acid, perchloric acid, nitric acid, and hydrochloric acid.

[0044] In some embodiments, the mass amount of the acid catalyst is 0.1% to 2% of the total mass of the naphthyl lactam monomer and the oxygen-containing organic matter, for example, 0.2%, 0.4%, 0.5%, 0.7%, 1%, 1.2%, 1.5%, 1.8%, 2%, etc.

[0045] In this invention, the polycondensation reaction is typically carried out in the presence of a solvent. As specific examples, the solvent may be selected from at least one of tetrahydrofuran (THF), propylene glycol monomethyl ether (PGME), propylene glycol dimethyl ether (PGDE), propylene glycol monoethyl ether (PGEE), and propylene glycol monomethyl ether acetate (PGMEA). According to some embodiments, the mass ratio of the solvent to the total amount of the naphthyllactam monomer and the oxygen-containing organic matter may be (4~16):1, for example, 6:1, 7.5:1, 8:1, 9:1, 10:1, 12:1, 15:1, etc.

[0046] In this invention, the temperature of the polycondensation reaction can be 60~200℃, for example 60℃, 80℃, 90℃, 100℃, 110℃, 120℃, 145℃, 150℃, 170℃, 190℃, 200℃, etc. The time of the polycondensation reaction can be selected according to the reaction temperature and the molecular weight of the target product, and is usually 5~40h, for example 5h, 8h, 10h, 12h, 15h, 18h, 20h, 22h, 24h, 25h, 30h, 40h, etc., preferably 8~30h.

[0047] Thirdly, the present invention provides a hard mask composition comprising a polymer, a catalyst, a crosslinking agent, a surfactant, a plasticizer, and a solvent.

[0048] In this invention, the polymer is the naphthanolactam polymer described in the first aspect of this invention. Based on the total mass of the hard mask composition, the mass content of the polymer can be 5% to 25%, for example, 5%, 7%, 8%, 9%, 10%, 12%, 15%, 18%, 20%, 2%, 25%, etc.

[0049] In this invention, the crosslinking agent can react with the polymer to form a dense network backbone, and specific examples include, but are not limited to, at least one of: glycourea compounds (e.g., tetramethoxymethylglycourea), epoxy compounds, melamine, melamine derivatives, and aromatic compounds. Based on the total mass of the hard mask composition, the mass content of the crosslinking agent can be 0.5% to 3%, for example, 0.5%, 0.8%, 1.0%, 1.2%, 1.4%, 1.8%, 2.0%, 2.5%, 2.8%, 3%, etc.

[0050] In this invention, the catalyst is designed to reduce the activation energy required for the reaction between the crosslinking agent and the polymer, thereby improving the crosslinking efficiency. The catalyst can be an acid catalyst, specific examples of which include, but are not limited to, one or more of the following acidic compounds: p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium-p-benzenesulfonate, salicylic acid, camphorsulfonic acid, and benzenedisulfonic acid. Based on the total mass of the hard mask composition, the mass content of the catalyst can be 0.005% to 0.1%, for example, 0.005%, 0.006%, 0.008%, 0.01%, 0.015%, 0.02%, 0.04%, 0.05%, 0.08%, 0.1%, etc.

[0051] In this invention, the surfactant helps improve substrate wettability and film uniformity, and can be selected with reference to existing hard masks. As specific examples, the surfactant can be selected from one or more of polyoxyethylene alkyl ethers, polyoxyethylene alkyl aryl ethers, sorbitol fatty acid esters, and polyoxyethylene sorbitol fatty acid esters. Based on the total mass of the hard mask composition, the mass content of the surfactant can be 0.01% to 0.1%, for example, 0.01%, 0.03%, 0.05%, 0.06%, 0.08%, 0.1%, etc.

[0052] In this invention, the plasticizer can improve the flowability of the hard mask composition and reduce the brittleness of the hard mask by regulating intermolecular forces. The plasticizer is typically selected from one or more of the following: phthalic acid derivatives (e.g., dimethyl phthalate, diethyl phthalate, diisobutyl phthalate), adipic acid derivatives (e.g., di-n-butyl adipate, diisobutyl adipate), maleic acid derivatives (e.g., di-n-butyl maleate, diethyl maleate), and stearic acid derivatives (e.g., n-butyl stearate, glyceryl stearate). Based on the total mass of the hard mask composition, the mass content of the plasticizer can be 0.2% to 2.5%, for example, 0.2%, 0.5%, 0.8%, 1.0%, 1.1%, 1.2%, 1.4%, 1.5%, 1.8%, 2.1%, 2.3%, 2.5%, etc.

[0053] In this invention, the solvent in the hard mask composition can be selected with reference to existing technology, as long as it has good solubility or dispersibility for other components in the composition. Specific examples include, but are not limited to, one or more of propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, propylene glycol monoethyl ether, cyclohexanone, and ethyl lactate. Based on the total mass of the hard mask composition, the solvent content can be 70% to 95%, for example, 70%, 75%, 80%, 85%, 90%, 93%, 95%, etc. As some embodiments, the total mass content of the solvent and other components is 100%.

[0054] The present invention does not particularly limit the preparation method of the hard mask composition. Exemplarily, the polymer, catalyst, crosslinking agent, surfactant and plasticizer can be added to the solvent and thoroughly mixed by mechanical stirring or ultrasonic treatment to form a homogeneous and stable solution. Then, the solution is filtered using a microporous filter with a pore size of 0.1~0.2μm, and the resulting filtrate is the hard mask composition.

[0055] Fourthly, the present invention provides a method for forming a pattern, the method comprising the following steps: (a) Providing a material layer on a substrate; (b) Applying the hard mask composition onto the material layer to form a hard mask; (c) Forming a silicon-containing thin layer on the hard mask; (d) A photoresist layer is formed on the silicon-containing thin layer; the photoresist layer is exposed and developed to form a photoresist pattern; (e) Using the photoresist pattern, selectively remove the silicon-containing thin layer and the hard mask to expose a portion of the material layer; (f) Etching the exposed portion of the material layer.

[0056] In this invention, the substrate can be a silicon wafer, a glass substrate, or a polymer substrate. The material layer is the material to be finally patterned, and can be a metal layer such as an aluminum layer or a copper layer, a semiconductor layer such as a silicon layer, or an insulating layer such as silicon dioxide or silicon nitride.

[0057] In step (b), the method for forming the hard mask may be: spin-coating the hard mask composition onto the material layer, and heat-treating it at 200~500°C to form a hard mask. The heat treatment time may be 10s~10min, and the thickness of the spin coating is preferably 100~1000nm.

[0058] In this invention, the silicon-containing thin layer may be selected from at least one of silicon nitride, silicon oxide, and silicon oxynitride. The photoresist resist layer can be exposed using any one of ArF, KrF, or EUV light sources. Alternatively, a gas such as CHF3 / CF4 can be used to dry etch the material layer.

[0059] The following describes embodiments of the present invention. These embodiments are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0060] The following synthesis examples illustrate the preparation method of the naphthyl lactam monomers used in the examples.

[0061] Synthesis Example 1: Synthesis of Monomer C1 (1) Dissolve 5-bromo-8-naphthylcarboxamide (4.96 g, 20 mmol) in 200 mL of acetonitrile, add potassium carbonate (8.29 g, 60 mmol) with stirring, then add bromobutane (4.11 g, 30 mmol), and finally add solid potassium iodide catalyst (0.17 g, 1 mmol). Heat to reflux and react. After the starting material disappears as monitored by TLC, concentrate the resulting reaction solution under reduced pressure to obtain concentrated product. Add DCM (dichloromethane, 100 mL) to dilute the mixture, and wash twice with 10 wt% sodium carbonate aqueous solution. Combine the organic phases, dry the organic phase with anhydrous sodium sulfate, filter, concentrate under reduced pressure, and purify the crude product by silica gel (200~300 mesh) column chromatography to obtain intermediate IM-1 (5.07 g, yield 83.4%).

[0062]

[0063] (2) Intermediate IM-1 (3.04 g, 10 mmol), p-methoxyphenylboronic acid (1.52 g, 10 mmol), tetrakis(triphenylphosphine)palladium (0.35 g, 0.3 mmol), potassium carbonate (2.76 g, 20 mmol), 20 mL of toluene and 10 mL of water were placed in a three-necked flask. The mixture was heated to reflux under nitrogen protection and reacted. The reaction was monitored by HPLC until the p-methoxyphenylboronic acid had completely reacted. The reaction was then terminated, cooled, allowed to stand, and separated. The resulting organic phase was washed twice with water, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and the crude product was purified by silica gel (200-300 mesh) column chromatography to obtain monomer C1 (2.83 g, yield 85.5%).

[0064]

[0065] NMR characterization results of monomer C1, 1 H-NMR (400 MHz, CDCl3) δ (ppm): 8.92 (d, 1H, ArH), 8.16 (d, 1H, ArH), 7.85 (d, 2H, PhH), 7.81 (d, 1H, ArH), 7.61 (d, 1H, ArH), 7.28 (t, 1H, ArH), 7.13 (d, 2H, ArH), 3.91 (t, 2H, -NCH2), 3.83 (s, 3H, -OCH3), 1.66 (m, 2H, -NCH2CH2), 1.38 (m, 2H, -CH2CH3), 0.92 (t, 3H, -CH2CH3).

[0066] Synthesis Example 2: Synthesis of Monomer C2 (1) Dissolve 5-bromo-8-naphthylcarboxamide (4.96 g, 20 mmol) in 200 mL of acetonitrile, add potassium carbonate (8.29 g, 60 mmol) with stirring, then add 2-cyclohexylbromoethane (5.73 g, 30 mmol), and finally add solid potassium iodide catalyst (0.17 g, 1 mmol). Heat to reflux and react. After the starting material disappears as monitored by TLC, concentrate the resulting reaction solution under reduced pressure to obtain concentrated product. Add 100 mL of DCM to dilute the mixture, and wash twice with 10 wt% sodium carbonate aqueous solution. Combine the organic phases, dry the organic phase with anhydrous sodium sulfate, filter, concentrate under reduced pressure, and purify the crude product by silica gel (200~300 mesh) column chromatography to obtain intermediate IM-2 (5.92 g, yield 82.6%).

[0067]

[0068] (2) The intermediate IM-2 (3.58 g, 10 mmol), p-methoxyphenylboronic acid (1.52 g, 10 mmol), tetrakis(triphenylphosphine)palladium (0.35 g, 0.3 mmol), potassium carbonate (2.76 g, 20 mmol), 20 mL of toluene and 10 mL of water were placed in a three-necked flask and heated to reflux under nitrogen protection. The reaction was monitored by HPLC until the p-methoxyphenylboronic acid had completely reacted. The reaction was then terminated, cooled, allowed to stand, and separated. The resulting organic phase was washed twice with water, dried with anhydrous sodium sulfate, filtered, concentrated under reduced pressure, and the crude product was purified by silica gel (200-300 mesh) column chromatography to obtain monomer C2 (3.33 g, yield 86.4%).

[0069]

[0070] NMR characterization results of monomer C2, 1 H-NMR (400 MHz, CDCl3) δ (ppm): 8.91 (d, 1H, ArH), 8.17 (d, 1H, ArH), 7.84 (d, 2H, PhH), 7.79 (d, 1H, ArH), 7.60 (d, 1H, ArH), 7.28 (t, 1H, ArH), 7.12 (d, 2H, ArH), 3.91 (t, 2H, -NCH2), 3.84 (s, 3H, -OCH3),1.59-1.25(m, 13H, -CH2C6H 11 ).

[0071] Synthesis Example 3: Synthesis of Monomer C3 Monomer C1 (3.31 g, 0.01 mol) and 50 mL of dichloromethane were placed in a three-necked flask and stirred thoroughly. Then, a solution of boron tribromide (12.53 g, 0.05 mol) in dichloromethane (50 mL) was slowly added dropwise under ice bath conditions (0 °C) for 30 min. After the addition was completed, the reaction was continued for 24 h. The resulting reaction solution was then slowly poured into ice water, and the pH was adjusted to neutral with a 10 wt% NaHCO3 aqueous solution. The solid precipitated out and was filtered to obtain monomer C3 (2.71 g, yield 85.5%).

[0072]

[0073] NMR characterization results of monomer C3, 1 H-NMR (400 MHz, CDCl3) δ (ppm): 9.65 (s, 1H, -OH), 8.92 (d, 1H, ArH), 8.17 (d, 1H, ArH), 7.86 (d, 2H, PhH), 7.81 (d, 1H, ArH), 7.62 (d, 1H, ArH), 7.27(t, 1H, ArH), 7.13 (d, 2H, ArH), 3.91 (t, 2H, -NCH2), 1.65 (m, 2H, -NCH2CH2), 1.38 (m, 2H, -CH2CH3), 0.91 (t, 3H, -CH2CH3).

[0074] Synthesis Example 4: Synthesis of Monomer C4 Monomer C2 (3.86 g, 0.01 mol) and 50 mL of dichloromethane were placed in a three-necked flask and stirred thoroughly. Then, a solution of boron tribromide (12.53 g, 0.05 mol) in dichloromethane (50 mL) was slowly added dropwise under ice bath conditions (0 °C) for 30 min. After the addition was completed, the reaction was continued for 24 h. The resulting reaction solution was then slowly poured into ice water, and the pH was adjusted to neutral with a 10 wt% NaHCO3 aqueous solution. The solid precipitated out and was filtered to obtain monomer C4 (2.98 g, yield 80.4%).

[0075]

[0076] NMR results of single C4, 1H-NMR (400 MHz, CDCl3) δ (ppm): 9.68 (s, 1H, -OH), 8.91 (d, 1H, ArH), 8.16 (d, 1H, ArH), 7.85 (d, 2H, PhH), 7.80 (d, 1H, ArH), 7.61 (d, 1H, ArH), 7.28 (t, 1H, ArH), 7.13 (d, 2H, ArH), 3.91 (t, 2H, -NCH2),1.59-1.25(m, 13H, -CH2C6H 11 ).

[0077] The following preparation examples illustrate the naphthylcarbamate polymers and their preparation methods of the present invention.

[0078] Preparation Example 1 At room temperature, monomer C1 (3.98 g, 0.012 mol), 1,4-bis(methoxymethyl)benzene (1.99 g, 0.012 mol), 0.119 g of p-toluenesulfonic acid, and 53.75 g of propylene glycol monomethyl ether acetate (PGMEA) were added to a four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 100 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 12 h. After the reaction was complete, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarboxylactam polymer with the structure shown in Formula 2-1, denoted as P1. P1 has Mw = 8750 and PDI = 2.04.

[0079] Preparation Example 2 At room temperature, monomer C3 (3.81 g, 0.012 mol), 1,4-bis(methoxymethyl)benzene (1.99 g, 0.012 mol), 0.116 g p-toluenesulfonic acid, and 52.23 g PGMEA were added to a four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 100 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 12 h. After the reaction was completed, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarbamate polymer with the structure shown in Formula 2-2, denoted as P2. P2 has Mw = 9820 and PDI = 2.15.

[0080] Preparation Example 3 At room temperature, monomer C3 (3.81 g, 0.012 mol), 4,4'-dihydroxymethylbiphenyl (2.57 g, 0.012 mol), 0.116 g p-toluenesulfonic acid, and 57.55 g PGMEA were added to a four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 110 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 18 h. After the reaction was completed, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarboxylactam polymer with the structure shown in Formula 2-3, denoted as P3. P3 has Mw = 7630 and PDI = 1.91.

[0081] Preparation Example 4 The naphthylcarbamate polymer was prepared according to the method of Preparation Example 3, except that equimolar amounts of 2,6-bis(hydroxymethyl)naphthalene were used instead of 4,4'-dihydroxymethylbiphenyl, and all other conditions were the same as in Preparation Example 3, thereby obtaining a naphthylcarbamate polymer with the structure shown in Formula 2-4, denoted as P4, with Mw=13540 and PDI=2.28.

[0082] Preparation Example 5 At room temperature, monomer C3 (3.81 g, 0.012 mol), 9,10-bis(hydroxymethyl)anthracene (2.86 g, 0.012 mol), 0.115 g p-toluenesulfonic acid, and 60.05 g PGMEA were added to a four-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 130 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 22 h. After the reaction was completed, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarboxamide polymer with the structure shown in Formula 2-5, denoted as P5. P5 has Mw = 11070 and PDI = 2.39.

[0083] Preparation Example 6 At room temperature, monomer C2 (4.63 g, 0.012 mol), 1,4-bis(methoxymethyl)benzene (1.99 g, 0.012 mol), 0.119 g of p-toluenesulfonic acid, and 59.75 g of propylene glycol monomethyl ether acetate (PGMEA) were added to a 100 mL three-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 105 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 17 h. After the reaction was completed, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarboxylactam polymer with the structure shown in Formula 2-6, denoted as P6. P6 has Mw = 6920 and PDI = 1.75.

[0084] Preparation Example 7 Naphtholactam polymers were prepared according to the method of Preparation Example 6, except that monomer C4 was used instead of monomer C2 in equimolar amounts, and all other conditions were the same as in Preparation Example 6, thereby obtaining a naphtholactam polymer with the structure shown in Formula 2-7, denoted as P7, with Mw=7860 and PDI=1.83.

[0085] Preparation Example 8 At room temperature, monomer C4 (4.46 g, 0.012 mol), 2,6-di(hydroxymethyl)naphthalene (2.26 g, 0.012 mol), 0.114 g of p-toluenesulfonic acid, and 60.50 g of PGMEA were added to a 100 mL three-necked flask equipped with a thermometer, mechanical stirrer, reflux condenser, and water separator. Under nitrogen protection, the mixture was heated to 135 °C until the reactants were completely dissolved. The reaction system was then refluxed and reacted for 21 h. After the reaction was complete, the system was cooled to room temperature, and the resulting reaction solution was slowly added to methanol and stirred for 0.5 h. The precipitate was filtered, and the resulting filter cake was further washed twice with methanol and then dried under vacuum at 60 °C for 10 h to obtain a naphthylcarboxylactam polymer with the structure shown in Formula 2-8, denoted as P8. P8 has Mw = 10370 and PDI = 2.18.

[0086] Comparative Preparation Example 1 The polymer was prepared according to the method of Preparation Example 1, except that the same molar amount of 1-naphthol was used instead of monomer C1, and all other conditions were the same as in Preparation Example 1. Thus, a reference polymer with the formula shown in Formula 2-9 was prepared, denoted as D1, with Mw=9150 and PDI=2.04.

[0087] The polymers of Preparation Examples 1-8 and Comparative Preparation Example 1 have the following structures:

[0088] The following examples illustrate the hard mask composition and its preparation method of the present invention.

[0089] Examples 1-8 The naphthylcarbamate polymers P1 to P8 prepared in Preparation Examples 1 to 8 were added to clean bottles with catalyst, crosslinking agent, solvent, surfactant and plasticizer in the proportions shown in Table 1. The mixture was shaken until all components were completely dissolved. Then, each sample was filtered through a 0.2 μm PTFE membrane filter to obtain spin coating solution (i.e. hard mask composition).

[0090] The catalyst is p-toluenesulfonic acid, the crosslinking agent is tetramethoxymethyl urea, the solvent is propylene glycol monomethyl ether acetate (PGMEA), the surfactant is polyoxyethylene lauryl ether (purchased from Tianjin Xiens Biochemical Technology Co., Ltd., product number 1327009), and the plasticizer is dimethyl phthalate.

[0091] Comparative Example 1 The hard mask composition was prepared according to the method of Example 1, except that the naphthyl lactam polymer P1 was replaced with the reference polymer D1 of Comparative Preparation Example 1.

[0092] Table 1

[0093] Note: All percentages in Table 1 refer to mass percentages.

[0094] Test case This test example aims to illustrate the application performance of the hard mask compositions prepared in the above embodiments and comparative examples.

[0095] 1. Sample Preparation Hard mask spin coating solution was applied to silicon wafers using a spin coater to form a wet film with a thickness of approximately 3500 Å. The film was then heat-treated at 350°C for 180 s to form a hard mask. Three sets of hard masks were obtained using the same spin coating solution and this method, which were then used as test samples for the following tests 2 through 4.

[0096] 2. Heat resistance test Hard mask powder is obtained by scraping hard mask from silicon wafer. The mass loss rate of the powder is tested using a thermogravimetric analyzer (TGA). The test conditions are: in a nitrogen atmosphere, the temperature is increased from 30℃ to 450℃. The mass loss rate is tested according to the following formula: mass loss rate (%) = [(initial mass - mass at 400℃)] / initial mass × 100%.

[0097] 3. Etching resistance test The initial thickness of the hard mask formed was measured; then, CHF3 / CF4 gas was used as the etching gas (volume flow ratio of 1:1) for 80s of dry etching. After etching, the film thickness was measured again, and finally the etching rate (Å / s) was determined according to the following formula.

[0098] Etching rate = (Initial thickness of hard mask - Film thickness after etching) / Etching time 4. Tests on void filling and flattening properties The cross-section of the hard mask formed is observed using field emission scanning electron microscopy to determine whether there are gaps, thus evaluating the gap-filling characteristics (if there are no gaps, it indicates that the hard mask composition can effectively fill the gaps in the microstructure and avoid the generation of defects). The planarization characteristics are then determined by the difference between the thicker part (line part) and the thinner part (spacer part) of the hard mask. The smaller the thickness difference, the stronger the planarization ability of the hard mask composition, and the more uniform the surface can be formed. The specific evaluation criteria are: if the difference is less than 5 nm, the planarization characteristics are judged as "very good"; if it is between 5 and 10 nm, it is judged as "good"; and if it is greater than 10 nm, it is judged as "poor".

[0099] The results of the above tests are shown in Table 2.

[0100] Table 2

[0101] As shown in Table 2, compared with Comparative Example 1, the hard masks formed using naphtholactam polymers P1 to P8 from Examples 1 to 8 have lower mass loss rate and dry etching rate at 450°C than those in Comparative Example 1, indicating that P1 to P8 can improve the heat resistance and etching resistance of the hard mask; furthermore, the hard masks formed using polymers P1 to P8 also have good gap filling and planarization capabilities.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered within the scope of the claims and specification of the present invention. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A naphthylcarbamate polymer, characterized in that, It has the structure shown in Equation 1: Formula 1, In Equation 1, n is an integer from 1 to 500; R1 is hydrogen, a 4-10 membered cycloalkyl group, or a substituted or unsubstituted aryl group with 6-30 carbon atoms, and the substituent is an alkyl group with 1-6 carbon atoms; L is an alkylene group with 1-10 carbon atoms. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms; Ar is an arylene with 6 to 24 carbon atoms.

2. The naphthylcarbamate polymer according to claim 1, characterized in that, Ar is selected from any of the following groups: Preferably, R1 is hydrogen, a 4-10 membered cycloalkyl group, or an aryl group with 6-18 carbon atoms, and L is an alkylene group with 2-10 carbon atoms.

3. The naphthylcarbamate polymer according to claim 1 or 2, characterized in that, The weight-average molecular weight of the naphthyl lactam polymer is 5,000 to 30,000, and the molecular weight distribution index is 1.30 to 3.

60.

4. A method for preparing the naphthylcarbamate polymer according to any one of claims 1-3, characterized in that, The preparation method includes: performing a polycondensation reaction between a naphthyl lactam monomer with the structure shown in Formula 2 and an oxygen-containing organic compound with the structure shown in Formula 3 to form the naphthyl lactam polymer. Equation 2, Formula 3, In Formula 2, R1 is hydrogen, a 4-10 membered cycloalkyl group, or a substituted or unsubstituted aryl group with 6-30 carbon atoms, and the substituent is an alkyl group with 1-6 carbon atoms; L is an alkylene group with 1-10 carbon atoms. R2 is hydrogen or an alkyl group having 1 to 6 carbon atoms; In Formula 3, Ar is an aryl group with 6 to 24 carbon atoms, and R3 is hydrogen or methyl.

5. The preparation method according to claim 4, characterized in that, The oxygen-containing organic compound is an aryl diol with the structure shown in Formula 3-1: Equation 3-1, Preferably, the aryl diol is selected from at least one of dimethylolbenzene, dimethylolbiphenyl, dimethylolnaphthalene, and dimethylolanthracene; or The oxygen-containing organic compound is a dimethoxymethyl aromatic hydrocarbon with the structure shown in Formula 3-2: Equation 3-2, Preferably, the dimethoxy aromatic hydrocarbon is selected from at least one of dimethoxymethylbenzene, dimethoxymethylbiphenyl, dimethoxymethylnaphthalene, and dimethoxymethylanthracene; Preferably, the structure of the naphthyllactam monomer is as follows: 。 6. The preparation method according to claim 4 or 5, characterized in that, The molar ratio of the naphthyl lactam monomer to the oxygen-containing organic compound is 1:(1~2.5).

7. The preparation method according to any one of claims 4-6, characterized in that, The polycondensation reaction is carried out in the presence of an acid catalyst; Preferably, the mass amount of the acid catalyst is 0.1% to 2% of the total mass of the naphthyl lactam monomer and the oxygen-containing organic matter; Preferably, the polycondensation reaction is carried out at a temperature of 60~200℃ and for a reaction time of 5~40h.

8. A hard mask composition, characterized in that, It comprises a polymer, a catalyst, a crosslinking agent, a surfactant, a plasticizer, and a solvent, wherein the polymer is a naphtholic lactam polymer as described in any one of claims 1-3.

9. The hard mask composition according to claim 8, characterized in that, Based on the total mass of the hard mask composition, the polymer has a mass content of 5% to 25%, the crosslinking agent has a mass content of 0.5% to 3%, the catalyst has a mass content of 0.005% to 0.1%, the surfactant has a mass content of 0.01% to 0.1%, and the plasticizer has a mass content of 0.2% to 2.5%.

10. A method for forming a pattern, characterized in that, Includes the following steps: Provide a material layer on the substrate; The hard mask composition of claim 8 or 9 is applied to the material layer to form a hard mask; A silicon-containing thin layer is formed on the hard mask; A photoresist resist layer is formed on the silicon-containing thin layer; The photoresist resist layer is exposed and developed to form a photoresist pattern; The silicon-containing thin layer and the hard mask are selectively removed using the photoresist pattern to expose a portion of the material layer; Etch the exposed portion of the material layer.

Images