Hardmask composition, hardmask layer, and method of forming patterns

Abstract

To provide a hardmask composition suitable for a hardmask layer.SOLUTION: A hardmask composition, a hardmask layer including a cured product of the hardmask composition, and a method of forming patterns using the hardmask composition are provided. The hardmask composition includes a polymer including a structural unit represented by Chemical Formula 1, and a solvent.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a hard mask composition, a hard mask layer containing a cured product of the hard mask composition, and a pattern forming method using the hard mask composition. [Background technology]

[0002] In recent years, the semiconductor industry has evolved from patterns of several hundred nanometers to ultrafine technology with patterns of several nanometers to several tens of nanometers. To realize such ultrafine technology, effective lithographic techniques are essential.

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

[0004] In recent years, as the size of the pattern to be formed becomes smaller, it has become difficult to form a fine pattern with a good profile using only the typical lithographic techniques described above. In response to this, a technique for forming a fine pattern by forming an auxiliary layer, known as a hard mask layer, between the material layer to be etched and the photoresist layer has been developed (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Korean Patent Publication No. 10-2023-0030410 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a hard mask composition suitable for a hard mask layer.

[0007] Another object of the present invention is to provide a hard mask layer comprising a cured product of the hard mask composition.

[0008] It is still another object of the present invention to provide a pattern forming method using the above hard mask composition. [Means for solving the problem]

[0009] A hard mask composition according to one embodiment of the present invention includes a polymer including a structural unit represented by the following Chemical Formula 1, and a solvent:

[0010] [ka]

[0011] In the above chemical formula 1, n1 and n2 each independently represent 0 or 1; n1+n2 are integers equal to or greater than 1, * is a connection point.

[0012] In the above Chemical Formula 1, n1 may be 0 and n2 may be 1.

[0013] The polymer may further include a structural unit represented by the following formula 2:

[0014] [ka]

[0015] In the above chemical formula 2, n3 is an integer from 1 to 6, * is a connection point.

[0016] In the above formula 2, n3 can be 1 or 2.

[0017] The structural unit represented by Chemical Formula 1 may be a structural unit represented by Chemical Formula 1-1 or a structural unit represented by Chemical Formula 1-2:

[0018] [ka]

[0019] [ka]

[0020] The structural unit represented by Chemical Formula 1 may be a structural unit represented by Chemical Formula 1-3 or a structural unit represented by Chemical Formula 1-4:

[0021] [ka]

[0022] [ka]

[0023] The structural unit represented by the above Chemical Formula 2 may be a structural unit represented by the following Chemical Formula 2-1:

[0024] [ka]

[0025] The weight average molecular weight of the polymer may be 1,000 g / mol to 200,000 g / mol.

[0026] The content of the polymer may be 0.1% by mass to 30% by mass based on the total mass of the hard mask composition.

[0027] The solvent may be at least one selected from the group consisting of propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone (methylpyrrolidinone), acetylacetone, and ethyl 3-ethoxypropionate.

[0028] According to another aspect of the present invention, there is provided a hard mask layer comprising a cured product of the hard mask composition described above.

[0029] According to yet another aspect of the present invention, there is provided a pattern formation method including the steps of: forming a material layer on a substrate; applying the above-described hard mask composition on the material layer to form a coating film; heat-treating the coating film to form a hard mask layer; forming a photoresist layer on the hard mask layer; exposing and developing the photoresist layer to form a photoresist pattern; selectively removing the hard mask layer using the photoresist pattern to expose a portion of the material layer; and etching the exposed portion of the material layer.

[0030] The step of forming the hard mask layer may include heat treating the coating film at 100°C to 1,000°C. [Effects of the Invention]

[0031] According to the present invention, a hard mask composition capable of forming a hard mask layer having excellent film density and excellent film strength can be provided.

[0032] Furthermore, according to the present invention, a hard mask composition capable of forming a hard mask layer having excellent etching resistance can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0033] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to exemplary embodiments thereof, so that those skilled in the art will be able to easily practice the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

[0034] In this specification, unless otherwise defined, "substituted" means that a hydrogen atom in a compound is substituted with a halogen atom (F, Br, Cl, or I), a hydroxy group, a nitro group, a cyano group, an amino group, an azide group, an amidino group, a hydrazino group, a hydrazono group, a carbonyl group, a carbamoyl group, a thiol group, an ester group, a carboxyl group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphate group or a salt thereof, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a substituted or unsubstituted alkyl ... the aryl group having from 6 to 30 carbon atoms, the aryl group having from 7 to 30 carbon atoms, the aryl group having from 9 to 30 carbon atoms, the alkynyl group having from 6 to 30 carbon atoms, the aryl group having from 7 to 30 carbon atoms, the arylaryl group having from 9 to 30 carbon atoms, the alkynyl group having from 1 to 30 carbon atoms, the heteroalkyl group having from 1 to 20 carbon atoms, the heteroarylalkyl group having from 3 to 20 carbon atoms, the cycloalkyl group having from 3 to 30 carbon atoms, the cycloalkenyl group having from 3 to 15 carbon atoms, the cycloalkynyl group having from 6 to 15 carbon atoms, the heterocycloalkyl group having from 3 to 30 carbon atoms, and combinations thereof.

[0035] Also, substituted halogen atoms (F, Br, Cl, or I), hydroxy groups, nitro groups, cyano groups, amino groups, azido groups, amidino groups, hydrazino groups, hydrazono groups, carbonyl groups, carbamoyl groups, thiol groups, ester groups, carboxyl groups or salts thereof, sulfonic acid groups or salts thereof, phosphate groups or salts thereof, alkyl groups having 1 to 30 carbon atoms, alkenyl groups having 2 to 30 carbon atoms, and alkynyl groups having 2 to 30 carbon atoms. Two adjacent substituents among the aryl group having 6 to 30 carbon atoms, the arylalkyl group having 7 to 30 carbon atoms, the alkoxy group having 1 to 30 carbon atoms, the heteroalkyl group having 1 to 20 carbon atoms, the heteroarylalkyl group having 3 to 20 carbon atoms, the cycloalkyl group having 3 to 30 carbon atoms, the cycloalkenyl group having 3 to 15 carbon atoms, the cycloalkynyl group having 6 to 15 carbon atoms, and the heterocycloalkyl group having 2 to 30 carbon atoms may be fused (linked) to form a ring.

[0036] In this specification, the term "polymer" can include an oligomer and a polymer.

[0037] Unless otherwise specified in this specification, the "weight average molecular weight" is measured by dissolving a powder sample in tetrahydrofuran (THF) and then using a 1200 series gel permeation chromatography (GPC) manufactured by Agilent Technologies (using a Shodex LF-804 column and Shodex polystyrene as the standard sample).

[0038] The semiconductor industry is constantly demanding smaller chip sizes. To meet this demand, lithography technology requires that the line width of the resist to be patterned be on the order of tens of nanometers. Therefore, the resist may not be sufficiently resistant to the etching step due to the limited height that can be tolerated by the resist pattern line width. To address this issue, an auxiliary layer known as a hard mask layer can be used between the material layer to be etched and the photoresist layer. This hard mask layer serves as an intermediate film that transfers the fine pattern of the photoresist to the material layer through selective etching. Therefore, the hard mask layer must be etch-resistant to withstand the etching process required for pattern transfer.

[0039] Conventional hard mask layers have been formed by chemical vapor deposition or physical vapor deposition, but these methods have drawbacks such as large equipment scale, high process costs, and poor economic viability. Therefore, a technology for forming hard mask layers using a spin coating method has recently been developed. The spin coating method is easier to process than conventional methods, and hard mask layers formed by this method have better gap-filling and planarization properties than hard mask layers formed by conventional methods. However, hard mask layers formed by the spin coating method have a drawback in that the required etching resistance is somewhat reduced. Therefore, a hard mask composition that can be applied to the spin coating method is required, and the hard mask layer formed from the hard mask composition has etching resistance equivalent to that of a hard mask layer formed by a chemical vapor deposition or physical vapor deposition method.

[0040] Therefore, research has been conducted to maximize the carbon content of hard mask compositions in order to improve the etching resistance of hard mask layers. However, as the carbon content of the polymer contained in the hard mask composition increases, the solubility in solvents tends to decrease. Therefore, it is necessary to maximize the carbon content of the polymer contained in the hard mask composition to improve the etching resistance of the hard mask layer formed from the hard mask composition while ensuring that the polymer is highly soluble in solvents.

[0041] Specifically, a hard mask composition according to one embodiment of the present invention includes a polymer including a structural unit represented by the following Chemical Formula 1, and a solvent:

[0042] [ka]

[0043] In the above chemical formula 1, n1 and n2 are each independently 0 or 1, n1+n2 is an integer of 1 or more, and * is a connecting point.

[0044] The composition according to the present embodiment includes a polymer containing a structural unit having a carbazole ring containing two benzene rings and a phenyl group substituted with two hydroxy groups, as shown in Chemical Formula 1 above, thereby increasing the carbon content in the composition. Therefore, a hard mask layer formed from the composition according to the present embodiment can ensure excellent etching resistance. Furthermore, because the carbazole ring contains nitrogen containing an unshared electron pair and the phenyl group is substituted with a hydroxy group, the film density and film properties of the hard mask layer formed from the composition can be improved without reducing the solubility of the polymer in a solvent.

[0045] According to one embodiment of the present invention, in the above chemical formula 1, n1 may be 0 and n2 may be 1, and according to another embodiment, n1 may be 1 and n2 may be 0, but is not limited thereto.

[0046] According to one embodiment of the present invention, the polymer may further include a structural unit represented by the following Formula 2:

[0047] [ka]

[0048] In the above chemical formula 2, n3 is an integer of 1 to 6, and * is a connecting point.

[0049] When the polymer contained in the composition according to this embodiment further contains a structural unit represented by Chemical Formula 2, the film density and film strength of the hard mask layer formed from the composition can be further improved.

[0050] According to one embodiment of the present invention, in the above chemical formula 2, n3 is preferably an integer of 1 to 4, more preferably an integer of 1 to 3, and even more preferably 1 or 2, but is not limited thereto.

[0051] According to one embodiment of the present invention, the structural unit represented by Chemical Formula 1 may be a structural unit represented by Chemical Formula 1-1 or a structural unit represented by Chemical Formula 1-2:

[0052] [ka]

[0053] [ka]

[0054] According to one embodiment of the present invention, the structural unit represented by Chemical Formula 1 may be a structural unit represented by Chemical Formula 1-3 or a structural unit represented by Chemical Formula 1-4:

[0055] [ka]

[0056] [ka]

[0057] According to one embodiment of the present invention, the structural unit represented by Chemical Formula 2 may be a structural unit represented by Chemical Formula 2-1 below:

[0058] [ka]

[0059] The polymer can be synthesized by appropriately referring to a conventionally known synthesis method. More specifically, a person skilled in the art can easily synthesize the polymer by referring to the synthesis methods described in the Examples.

[0060] The polymer may have a weight-average molecular weight of 1,000 g / mol to 200,000 g / mol. The weight-average molecular weight of the polymer is preferably 1,000 g / mol to 150,000 g / mol, more preferably 1,000 g / mol to 100,000 g / mol, even more preferably 1,200 g / mol to 50,000 g / mol, and particularly preferably 1,200 g / mol to 10,000 g / mol, but is not limited thereto. By having the polymer have a weight-average molecular weight within the above range, the carbon content and solubility in a solvent of a hard mask composition containing the polymer can be adjusted and optimized.

[0061] The polymer may be contained in an amount of 0.1% by mass to 30% by mass, based on the total mass of the hard mask composition. The content of the polymer is preferably 0.2% by mass to 30% by mass, more preferably 0.5% by mass to 30% by mass, even more preferably 1% by mass to 30% by mass, particularly preferably 1.5% by mass to 25% by mass, and most preferably 2% by mass to 20% by mass, based on the total mass of the hard mask composition, but is not limited thereto. By containing the polymer in the above content range in the hard mask composition, the thickness, surface roughness, degree of planarization, etc. of the hard mask layer can be easily adjusted.

[0062] The hard mask composition according to this embodiment includes a solvent. According to one embodiment of the present invention, the solvent may include, but is not limited to, at least one selected from the group consisting of propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone (methylpyrrolidinone), acetylacetone, and ethyl 3-ethoxypropionate. The type of solvent is not particularly limited as long as it has sufficient solubility and / or dispersibility in the polymer.

[0063] The hard mask composition according to this embodiment may further contain additives such as a surfactant, a crosslinking agent, a thermal acid generator, and a plasticizer.

[0064] Examples of surfactants that can be used include, but are not limited to, fluoroalkyl compounds, alkylbenzenesulfonates, alkylpyridinium salts, polyethylene glycols, and quaternary ammonium salts.

[0065] Examples of crosslinking agents include melamine-based agents, substituted urea-based agents, and polymers thereof. Preferably, compounds such as methoxymethylated glycoluril (methoxymethylated glycoluril), butoxymethylated glycoluril (butoxymethylated glycoluril), methoxymethylated melamine, butoxymethylated melamine, methoxymethylated benzoguanamine, butoxymethylated benzoguanamine, methoxymethylated urea, butoxymethylated urea, methoxymethylated thiourea, and butoxymethylated thiourea can be used as crosslinking agents having at least two crosslink-forming substituents.

[0066] In addition, a crosslinking agent having high heat resistance can be used as the crosslinking agent. As the crosslinking agent having high heat resistance, a compound containing a crosslink-forming substituent having an aromatic ring (e.g., a benzene ring or a naphthalene ring) in the molecule can be used.

[0067] Examples of thermal acid generators that can be used include, but are not limited to, acidic compounds such as p-toluenesulfonic acid, trifluoromethanesulfonic acid, pyridinium p-toluenesulfonate, salicylic acid, sulfosalicylic acid, citric acid, benzoic acid, hydroxybenzoic acid, and naphthalenecarboxylic acid, and / or 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, and other organic sulfonic acid alkyl esters.

[0068] According to another aspect of the present invention, there is provided a hard mask layer comprising a cured product of the hard mask composition described above.

[0069] A method for forming a pattern using the above-described hard mask composition will now be described.

[0070] A pattern formation method according to yet another aspect of the present invention includes the steps of forming a material layer on a substrate, applying a hard mask composition containing the above-described polymer and a solvent onto the material layer to form a coating film, heat-treating the coating film to form a hard mask layer, forming a photoresist layer on the hard mask layer, exposing and developing the photoresist layer to form a photoresist pattern, selectively removing the hard mask layer using the photoresist pattern to expose a portion of the material layer, and etching the exposed portion of the material layer.

[0071] The substrate may be, for example, a silicon wafer, a glass substrate, or a polymer substrate. The material layer is the material to be ultimately patterned, and may be, for example, a metal layer such as aluminum or copper, a semiconductor layer such as silicon, or an insulating layer such as silicon oxide or silicon nitride. The material layer may be formed, for example, by chemical vapor deposition.

[0072] The hard mask composition may be prepared in the form of a solution and applied by spin coating to form a coating film, as described above. The coating thickness of the hard mask composition (coating thickness) is not particularly limited, but may be, for example, 50 to 200,000 Å.

[0073] In the step of heat-treating the coating film, the heat treatment may be performed, for example, at 100°C to 1,000°C for 10 seconds to 1 hour. For example, the step of heat-treating the coating film may include multiple heat treatments, for example, a first heat treatment and a second heat treatment.

[0074] The step of heat treating the coating film may include, for example, one heat treatment performed at 100°C to 1000°C for 10 seconds to 1 hour. As an example, the heat treatment may be performed in an air atmosphere or a nitrogen atmosphere, or in an atmosphere with an oxygen concentration of 1% by mass or less.

[0075] The step of heat treating the hard mask composition may include a primary heat treatment that is preferably carried out at 100°C to 1,000°C, more preferably 100°C to 800°C, even more preferably 100°C to 500°C, and particularly preferably 150°C to 400°C, for preferably 30 seconds to 1 hour, more preferably 30 seconds to 30 minutes, even more preferably 30 seconds to 10 minutes, and particularly preferably 30 seconds to 5 minutes.

[0076] Furthermore, the step of heat-treating the hard mask composition may include, after the first heat treatment, a consecutive second heat treatment, which is preferably carried out at 100°C to 1,000°C, more preferably 300°C to 1,000°C, even more preferably 500°C to 1,000°C, and particularly preferably 500°C to 600°C, for preferably 30 seconds to 1 hour, more preferably 30 seconds to 30 minutes, even more preferably 30 seconds to 10 minutes, and particularly preferably 30 seconds to 5 minutes. As an example, the first and second heat treatments may be carried out in an air atmosphere or a nitrogen atmosphere, or in an atmosphere with an oxygen concentration of 1% by mass or less.

[0077] In the step of heat treating the coating film, at least one heat treatment is performed at a high temperature of 200°C or higher, thereby obtaining a hard mask layer that exhibits high etching resistance that can withstand etching gases and chemical solutions to which the coating film is exposed in subsequent steps, including an etching step.

[0078] Forming the hard mask layer may include curing with ultraviolet-visible light and / or curing with near-infrared light.

[0079] The step of forming the hard mask layer may include at least one of a first heat treatment, a second heat treatment, curing using ultraviolet-visible light, and curing using near-infrared light, or may include two or more of these sequentially.

[0080] According to an embodiment of the present invention, the patterning method may further include forming a silicon-containing thin film layer on the hard mask layer. The silicon-containing thin film layer may be formed of a material such as SiCN, SiOC, SiON, SiOCN, SiC, SiO, and / or SiN.

[0081] Before the step of forming the photoresist layer, a bottom anti-reflective coating (BARC) may be further formed on the silicon-containing thin film layer or on the hard mask layer.

[0082] The step of exposing the photoresist layer can be carried out using, for example, ArF, KrF, or EUV (extreme ultraviolet), etc. After exposure, a heat treatment at 100°C to 700°C may be carried out.

[0083] Etching the exposed portions of the material layer may be performed by dry etching using an etching gas, such as N2 / O2, CHF3, CF4, Cl2, BCl3, and mixtures thereof.

[0084] The etched material layer can be formed in a variety of patterns, such as metal patterns, semiconductor patterns, and insulating patterns, and can be applied to a variety of patterns within a semiconductor integrated circuit device, for example. [Example]

[0085] The above-described embodiments of the present invention will be described in more detail below through examples, which are provided for illustrative purposes only and are not intended to limit the scope of the present invention.

[0086] <Polymer synthesis> [Synthesis Example 1] A 250ml flask was charged with 2-hydroxycarbazole (4.27g, 0.02mol) and 3,4-dihydroxybenzaldehyde (3.22g, 0.02mol). Next, p-toluenesulfonic acid monohydrate (0.89g, 0.005mol) was dissolved in 11g of propylene glycol monomethyl ether acetate (PGMEA), and the resulting solution was added to the flask and stirred at 100°C. Samples were taken from the polymerization reaction mixture at hourly intervals, and the reaction was completed when the weight-average molecular weight of the sample reached 1,800g / mol-2,000g / mol. After the polymerization reaction was completed, the mixture was cooled to room temperature. The intermediate product was then added to 300g of distilled water and 30g of methanol, stirred vigorously, and allowed to stand (first step). The supernatant was removed, and the precipitate was dissolved in 100 g of propylene glycol monomethyl ether acetate (PGMEA). Then, 30 g of methanol and 300 g of distilled water were added, and the mixture was stirred vigorously and allowed to stand (second step). The resulting supernatant was removed again, and the precipitate was dissolved in 80 g of propylene glycol monomethyl ether acetate (PGMEA). The first and second steps constituted one purification step, and this purification step was repeated a total of 10 times. After the purification, the polymer was dissolved in 80 g of propylene glycol monomethyl ether acetate (PGMEA), and the remaining methanol and distilled water were removed under reduced pressure to obtain polymer 1, which consists of a structural unit represented by the following chemical formula 1-3.

[0087] [ka]

[0088] [Synthesis Example 2] In Synthesis Example 1, 0.02 mol of 1,5-dihydroxynaphthalene was further added to the reactant, and polymer 2 consisting of structural units represented by the following chemical formula 1-3 and structural units represented by the following chemical formula 2-2 was obtained in the same manner as in Synthesis Example 1.

[0089] [ka]

[0090] [ka]

[0091] [Comparative Synthesis Example 1] Comparative polymer 1 containing a structural unit represented by the following chemical formula 3 was obtained in the same manner as in Synthesis Example 1, except that 2.34 g (0.02 mol) of indole was used instead of 2-hydroxycarbazole.

[0092] [ka]

[0093] <Preparation of Hard Mask Composition> [Example 1] 1 g of Polymer 1 obtained in Synthesis Example 1 was dissolved in 10 g of a mixed solvent of propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) (PGMEA:PGME = 7:3 (volume ratio)), and the solution was filtered through a 0.1 μm Teflon filter to prepare a hard mask composition.

[0094] [Example 2] A hard mask composition was prepared in the same manner as in Example 1, except that Polymer 2 was used instead of Polymer 1.

[0095] [Comparative Example] A hard mask composition was prepared in the same manner as in Example 1, except that Comparative Polymer 1 was used instead of Polymer 1.

[0096] <Evaluation 1: Film density evaluation> The hard mask compositions of Examples 1 and 2 and the Comparative Example were spin-coated onto a silicon wafer and then heat-treated on a hot plate at 400°C for 2 minutes to form a thin film with a thickness of 4,000 Å. The film density of the thin film was measured using an X-ray diffraction device manufactured by PANalytical. The results are shown in Table 1 below.

[0097] [Table 1]

[0098] As shown in Table 1 above, it can be seen that the film density of the hard mask layers manufactured from the hard mask compositions of Examples 1 and 2 is superior to the film density of the hard mask layers manufactured from the hard mask compositions of Comparative Examples.

[0099] <Evaluation 2: Film strength evaluation> The hard mask compositions of Examples 1 and 2 and the Comparative Example were spin-coated onto a silicon wafer to a thickness of 5,000 Å and then heat-treated on a hot plate at 400°C for 2 minutes to form thin films. The hardness (H) of the thin films was then measured using a nanoindenter (cube corner tip, Pmax = 300 μN). The measurement results are shown in Table 2 below.

[0100] [Table 2]

[0101] As shown in Table 2, the hard mask layers formed using the hard mask compositions of Examples 1 and 2 exhibit higher hardness than the hard mask layer formed using the hard mask composition of Comparative Example. That is, it can be seen that the hard mask layers formed using the hard mask compositions of Examples 1 and 2 have better film strength than the hard mask layers formed using the hard mask compositions of Comparative Example.

[0102] <Evaluation 3: Solubility evaluation> Five grams of the polymers obtained in Synthesis Examples 1 and 2 and Comparative Synthesis Example were uniformly dissolved in 45 g of PGMEA to prepare a 10% by mass polymer solution, which was then filtered through a 0.1 μm Teflon filter. After filtration, the mass of the solids in the filtrate was measured by the loss on drying method. If there was a difference between the mass of the polymer (5 g) before dissolution and the mass of the solids in the filtrate, it was evaluated as "×", and if there was no difference, it was evaluated as "◯".

[0103] [Table 3]

[0104] As shown in Table 3 above, it was confirmed that the solubility in solvent of the polymers obtained in Synthesis Examples 1 and 2 was not lower than the solubility of the polymer obtained in Comparative Synthesis Example.

[0105] <Evaluation 4: Heat resistance evaluation> The hard mask compositions obtained in Examples 1 and 2 and the Comparative Example were spin-coated onto a silicon wafer. The formed films were baked (heat-treated) on a hot plate at 240°C for 1 minute, and their thicknesses were measured. They were then baked (heat-treated) at 400°C for 2 minutes, and their thicknesses were measured again. The thin film thickness reduction rate was calculated from the film thicknesses measured after baking at the two temperatures according to Equation 1 below, and the relative heat resistance of the hard mask layer was quantified. The results are shown in Table 4 below.

[0106]

number

[0107] [Table 4]

[0108] As shown in Table 4 above, it was confirmed that the hard mask layers formed from the hard mask compositions of Examples 1 and 2 had a lower thin film thickness reduction rate than the hard mask layer formed from the hard mask composition of Comparative Example. This indicates that the hard mask layers formed from the compositions of Examples 1 and 2 have better heat resistance than the hard mask layer formed from the composition of Comparative Example.

[0109] <Evaluation 5: Etching resistance evaluation> The hard mask compositions of Examples 1 and 2 and the Comparative Example were spin-coated onto a silicon wafer with a pattern formed thereon and then heat-treated at 400°C for 120 seconds to form a hard mask layer. The thickness of the thin film (hard mask layer) was measured using a K-MAC ST5000 thin film thickness gauge. Next, the thin film was dry-etched for 60 seconds and 120 seconds using a N2 / O2 mixed gas (50mT / 300W / 10O2 / 50N2) and CFx gas (100mT / 600W / 42CF4 / 600Ar / 15O2), respectively, and the thickness of the thin film after each dry etching was measured again. The etching rate was calculated using Equation 2 below from the thin film thickness before and after dry etching and the etching time. The results are shown in Table 5 below.

[0110]

number

[0111] [Table 5]

[0112] As shown in Table 5 above, it was confirmed that the hard mask layers formed from the hard mask compositions of Examples 1 and 2 had lower etching rates when etched with an N2 / O2 mixed gas and an CFx gas than the hard mask layers formed from the hard mask compositions of Comparative Examples. This result shows that the hard mask layers formed from the compositions of Examples 1 and 2 have better etching resistance than the hard mask layers formed from the compositions of Comparative Examples.

[0113] Although the preferred embodiments of the present invention have been described in detail above, the scope of the invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the invention defined in the claims below also fall within the scope of the invention.

Claims

1. A hard mask composition comprising a polymer having a structural unit represented by the following chemical formula 1, and a solvent: 【Chemical 1】 In the above Chemical Formula 1, n1 and n2 each independently represent 0 or 1; n1+n2 is an integer equal to or greater than 1, * denotes a connection point.

2. 2. The hard mask composition of claim 1, wherein n1 is 0 and n2 is 1 in Formula 1.

3. 10. The hard mask composition of claim 1, wherein the polymer further comprises a structural unit represented by the following Formula 2: 【Chemistry 2】 In the above Chemical Formula 2, n3 is an integer from 1 to 6, * denotes a connection point.

4. The hard mask composition of claim 3 , wherein n3 in Formula 2 is 1 or 2.

5. 2. The hard mask composition of claim 1, wherein the structural unit represented by Chemical Formula 1 is a structural unit represented by the following Chemical Formula 1-1 or a structural unit represented by the following Chemical Formula 1-2: 【Chemistry 3】 【Chemistry 4】

6. 2. The hard mask composition of claim 1, wherein the structural unit represented by Chemical Formula 1 is a structural unit represented by Chemical Formula 1-3 or a structural unit represented by Chemical Formula 1-4: 【Chemistry 5】 【Chemistry 6】

7. 4. The hard mask composition according to claim 3, wherein the structural unit represented by Chemical Formula 2 is a structural unit represented by Chemical Formula 2-1: 【Chemistry 7】

8. 2. The hard mask composition of claim 1, wherein the weight average molecular weight of the polymer is 1,000 g / mol to 200,000 g / mol.

9. 2. The hard mask composition of claim 1, wherein the content of the polymer is 0.1% by mass to 30% by mass based on the total mass of the hard mask composition.

10. 2. The hard mask composition of claim 1, wherein the solvent is at least one selected from the group consisting of propylene glycol, propylene glycol diacetate, methoxypropanediol, diethylene glycol, diethylene glycol butyl ether, tri(ethylene glycol) monomethyl ether, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, methylpyrrolidone (methylpyrrolidinone), acetylacetone, and ethyl 3-ethoxypropionate.

11. A hard mask layer comprising a cured product of the hard mask composition according to any one of claims 1 to 10.

12. forming a layer of material on a substrate; Applying the hard mask composition according to any one of claims 1 to 10 onto the material layer to form a coating film; heat-treating the coating to form a hard mask layer; forming a photoresist layer over the hard mask layer; exposing and developing the photoresist layer to form a photoresist pattern; selectively removing the hard mask layer utilizing the photoresist pattern to expose portions of the material layer; and A method of patterning comprising etching exposed portions of the material layer.

13. 13. The pattern formation method according to claim 12, wherein the step of forming the hard mask layer includes heat treatment at 100° C. to 1,000° C.

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