Spin-on carbon hard mask composition having high planarization performance and patterning method using the same

Abstract

The present invention relates to a spin-on carbon hard mask composition having high planarization performance useful for semiconductor lithography processes, and a patterning method using the same. The composition according to the present invention includes a 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one derivative polymer represented by the following formula 1, an organic solvent, and a surfactant, and exhibits excellent effects such as excellent solubility, uniform coating performance, high etch resistance that can withstand a multi-etch process, excellent mechanical properties, and high planarization properties.

Description

[Technical Field]

[0001] The present invention relates to a hard mask composition that maintains high planarization properties useful in semiconductor lithography processes, and more particularly to a spin-on carbon hard mask composition having high planarization performance, characterized by comprising a 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]3-one polymer, an organic solvent, and a surfactant, and having a thickness of 4,010 Å or less and a planarization degree of 20% or less, and a patterning method using the same. [Background technology]

[0002] As devices become smaller and more integrated, there is a demand for finer patterns in semiconductor processes. As a method for forming such fine patterns, research and development is underway on methods such as developing exposure equipment or miniaturizing photoresist patterns by introducing additional processes. Furthermore, photoresists and photolithography process tools with high resolution are being developed to increase the integration density of semiconductor devices and enable the formation of finer structures having dimensions in the nanometer range. In the past, semiconductor manufacturing processes used i-line light sources with a wavelength of 365 nm to form patterns on semiconductor substrates, but to form finer patterns, light sources with even smaller wavelength bands were required. Recent technological trends include the ongoing development of lithography technologies using light sources such as KrF (248 nm), ArF (198 nm), and EUV (extreme ultraviolet, 13.5 nm), and these technologies are either currently in commercial use or are in the process of being commercialized. Current technology requires finer patterns, but photoresists are becoming thinner to achieve these finer patterns, resulting in photoresist pattern collapse. This makes it impossible to etch the layer to be etched using the thinner photoresist pattern. To address this issue, a hard mask with excellent etching properties is inserted between the photoresist layer and the layer to be etched. The hard mask process involves etching and patterning a hard mask using a photoresist pattern, and then etching the layer to be etched using the hard mask pattern. The hard mask film is fabricated using chemical vapor deposition (CVD) or spin-on coating. Hard mask films manufactured by the CVD method have drawbacks such as increased initial costs due to the use of an evaporator, increased process time, and particle issues. To overcome these drawbacks, the spin-on coating method was developed. The spin-on coating method is a technology that reduces costs and process time by using materials that can be spin-coated. Compared to the CVD method, it has the advantages of lower initial investment costs, uniform coating properties, easy control of coating thickness, and reduced process time. In the case of spin-on hard masks, there has been a demand for technology and development related to further miniaturization and pattern stacking in semiconductor processes, and there is a demand for the development of new hard mask films for materials and technology that can uniformly coat hard mask films on wafers with fine patterns. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Korean Patent Registration No. 10-0874655 [Patent Document 2] Korean Patent No. 10-1230529 [Patent Document 3] Korean Patent No. 10-1721979 [Patent Document 4] Korean Patent No. 10-1777687 [Patent Document 5] Korean Patent Registration No. 10-2240213 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides a patterning method and composition using a spin-on carbon hard mask in a semiconductor manufacturing process, which has a low refractive index and extinction coefficient, excellent resistance to dry etching, and is evenly coated to provide good coating performance and high planarization performance, as well as a patterning method using the composition. [Means for solving the problem]

[0005] The present invention provides a spin-on hard mask composition having high planarization properties, characterized in that the composition comprises a 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one derivative polymer represented by the following Chemical Formula 1, or a structure containing the same, wherein the weight-average molecular weight of the derivative polymer is 1,000 to 5,000, the thickness is 4,000 Å or less, and the planarization degree is 20% or less. [ka] In the formula, l, m, and n are in the ranges of 1≦l≦20, 1≦m≦40, and 1≦n≦20, respectively; R1 is hydrogen (H), a hydroxy group (OH), a ketone group (CO), an ether group (COC), an aldehyde group (CHO), [ka] [ka] [ka] [ka] and R2 includes any of [ka] [ka] [ka] [ka] [ka] [ka] [ka] R3 is hydrogen (H), a hydroxy group (OH), [ka] [ka] [ka] [ka] [ka] Contains any of the following: In the formula, the ratios of R1, R2, and R3 are mainly used to form polymers with different ratios to improve the high planarization performance of the overall polymer structure, as well as the thermal curing reactivity and etch selectivity. In the formula, R1 is a 3',6'-dihydroxy-3H-spiro[2-benzofuran]-1,9'-xanthen]-3-one derivative, which has the effect of improving high planarization performance. In the formula, R2 is mainly composed of an acid catalyst, and the polymer material formed has a high planarization performance improvement effect and solubility in organic solvents. In the formula, R3 mainly has the effect of enhancing the thermosetting reactivity and etch resistance of the entire polymer structure. If the weight-average molecular weight of the polymer represented by Chemical Formula 1 is less than 1,000, a sufficient amount of polymer structure is not generated, resulting in poor etch resistance, and if it is more than 5,000, the physical properties of the coated surface may be non-uniform. The hard mask composition may include 1 wt % to 50 wt % of the polymer represented by Chemical Formula 1, 50 wt % to 98 wt % of an organic solvent, and more than 0 to 2 wt % of a surfactant. If the polymer component is less than 1 wt % or more than 50 wt %, the coating thickness may be less than or more than the target, making it difficult to achieve an accurate coating thickness. If a coating thickness greater than the target is required, the coating properties may be poor. The organic solvent may be one selected from the group consisting of propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone (CHN), cyclopentanone (CPN), γ-butyrolactone (GBL), ethyl lactate (EL), methyl ethyl ketone (MEK), n-butyl acetate, N-methylpyrrolidone (NMP), methyl 3-methoxypropionate (MMP), and ethyl 3-ethoxypropionate (EEP), or a mixture of two or more thereof. The surfactant may be one selected from the group consisting of ionic and nonionic surfactants such as polyacrylates, polyfluorocarbons, polysiloxanes, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene nonylphenyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene polyoxypropylenes, polyoxyethylene lauryl ethers, and polyoxyethylene sorbitans, or a mixture of two or more thereof. According to another embodiment of the present invention, there is provided a patterning method, which comprises applying the composition onto a layer to be etched by spin coating and then performing a baking process to form a hard mask layer. The spin coating thickness of the composition is not particularly limited, but may be in the range of 100 Å to 20,000 Å. The baking process may be performed at a temperature of 150° C. to 400° C. for 1 minute to 5 minutes to cause a self-crosslinking reaction. [Effects of the Invention]

[0006] The spin-on carbon hard mask composition having high planarization performance and the patterning method using the composition according to the present invention are uniformly coated to a thickness of 4,010 Å or less, providing excellent coating performance. The composition provides a flat coating layer with a planarization degree of 20% or less, achieving high planarization performance. Furthermore, the composition has a low refractive index and extinction coefficient, high etch selectivity, and sufficient resistance to multiple etch processes, thereby providing excellent performance when forming semiconductor fine patterns. [Brief explanation of the drawings]

[0007] [Figure 1] 10 shows FE-SEM data related to the planarization properties of the polymer provided in Experimental Example 5. [Figure 2] FIG. 10 is a diagram relating to a mathematical formula for calculating the degree of flattening in the flattening characteristics. DETAILED DESCRIPTION OF THE INVENTION

[0008] The carbon hard mask composition according to the present invention will be described in detail below. The present invention provides a spin-on hard mask composition having high planarization properties, characterized in that the composition comprises a 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthen]-3-one derivative polymer represented by the following chemical formula 1, or a structure containing the same, wherein the weight-average molecular weight of the derivative polymer is 1,000 to 5,000, preferably 1,000 to 4,000, and more preferably 1,500 to 3,000, and the thickness is 4,010 Å or less and the planarization degree is 20% or less. [ka] In the formula, l, m, and n are in the ranges of 1≦l≦20, 1≦m≦40, and 1≦n≦20, respectively; R1 is hydrogen (H), a hydroxy group (OH), a ketone group (CO), an ether group (COC), an aldehyde group (CHO), [ka] [ka] [ka] [ka] and R2 includes any of [ka] [ka] [ka] [ka] [ka] [ka] [ka] R3 is hydrogen (H), a hydroxy group (OH), [ka] [ka] [ka] [ka] [ka] Contains any of the following: In the formula, the ratios of R1, R2, and R3 are mainly used to form polymers with different ratios to improve the high planarization performance of the overall polymer structure, as well as the thermal curing reactivity and etch selectivity. In the formula, R1 is a 3',6'-dihydroxy-3H-spiro[2-benzofuran]-1,9'-xanthen]-3-one derivative, which has the effect of improving high planarization performance. In the formula, R2 is mainly composed of an acid catalyst, and the polymer material formed has a high planarization performance improvement effect and solubility in organic solvents. In the formula, R3 mainly has the effect of enhancing the thermosetting reactivity and etch resistance of the entire polymer structure. If the weight-average molecular weight of the polymer represented by Chemical Formula 1 is less than 1,000, a sufficient amount of polymer structure is not generated, resulting in poor etch resistance, and if it is more than 5,000, the physical properties of the coated surface may be non-uniform.

[0009] The hard mask composition may include 1 wt % to 50 wt % of the polymer represented by Formula 1, 50 wt % to 98 wt % of an organic solvent, and more than 0 wt % to 2 wt % of a surfactant. If the polymer component is less than 1 wt % or more than 50 wt %, the coating thickness may be less than or more than the target, making it difficult to achieve an accurate coating thickness. If a coating thickness greater than the target is required, the coating properties may be poor. The organic solvent may be one selected from the group consisting of propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone (CHN), cyclopentanone (CPN), γ-butyrolactone (GBL), ethyl lactate (EL), methyl ethyl ketone (MEK), n-butyl acetate, N-methylpyrrolidone (NMP), methyl 3-methoxypropionate (MMP), and ethyl 3-ethoxypropionate (EEP), or a mixture of two or more thereof. The surfactant may be one selected from the group consisting of ionic and nonionic surfactants such as polyacrylates, polyfluorocarbons, polysiloxanes, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene nonylphenyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene polyoxypropylenes, polyoxyethylene lauryl ethers, and polyoxyethylene sorbitans, or a mixture of two or more thereof. According to another embodiment of the present invention, there is provided a patterning method, which comprises applying the composition onto a layer to be etched by spin coating and then performing a baking process to form a hard mask layer. The spin coating thickness of the composition is not particularly limited, but may be in the range of 100 Å to 20,000 Å. The baking process may be performed at a temperature of 150° C. to 400° C. for 1 minute to 5 minutes to cause a self-crosslinking reaction. Preferred examples of the present invention and comparative examples will be described below. However, the following examples are merely preferred examples of the present invention, and the present invention is not limited to the following examples.

[0010] Example 1 [ka] 15.0 g (0.045 mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]-3-one, 15.0 g (0.090 mol) of 1,4-bismethoxymethylbenzene, 20.3 g (0.045 mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorine, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07 g (0.00045 mol) of diethyl sulfate was added as an initiator to the reactor, and the mixture was refluxed at 140°C for 9 hours. After the reaction was complete, the solution was purified with a 9:1 ethanol / water solution, recrystallized with a 9:1 ethanol / distilled water solution, and then vacuum dried to obtain a polymer with a weight-average molecular weight (Mw) of 1,500 (based on standard polystyrene standards) as determined by GPC. Example 2 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 1. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) calculated in terms of standard polystyrene was 3,000. Example 3 [ka] 15.0 g (0.045 mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]-3-one, 21.7 g (0.090 mol) of 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 20.3 g (0.045 mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorin, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07 g (0.00045 mol) of diethyl sulfate was added as an initiator to the reactor and refluxed at 140°C for 9 hours. After the reaction was completed, the solution was purified with an ethanol / water (9:1) solution, recrystallized using an ethanol / distilled water (9:1) solution, and then vacuum dried to obtain a polymer compound having a weight average molecular weight (Mw) of 1500 in terms of standard polystyrene, as measured by GPC. Example 4 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 3. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 3,000. Example 5 [ka] 15.0 g (0.045 mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]-3-one, 23.1 g (0.090 mol) of 4,4'-bis(methoxymethyl)diphenyl ether, 20.3 g (0.045 mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorin, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07 g (0.00045 mol) of diethyl sulfate was added as an initiator to the reactor and refluxed at 140 °C for 9 hours. After the reaction was completed, the solution was purified with an ethanol / water (9:1) solution, recrystallized using an ethanol / distilled water (9:1) solution, and then vacuum dried to obtain a polymer compound having a weight average molecular weight (Mw) of 1500 in terms of standard polystyrene, as determined by GPC measurement.

[0011] Example 6 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 5. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 3,000. Example 7 [ka] 18.3 g (0.045 mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]-3-one, 15.0 g (0.090 mol) of 1,4-bismethoxymethylbenzene, 20.3 g (0.045 mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorine, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07 g (0.00045 mol) of diethyl sulfate was added as an initiator to the reactor, and the mixture was refluxed at 140°C for 9 hours. After the reaction was complete, the solution was purified with a 9:1 ethanol / water solution, recrystallized from a 9:1 ethanol / water solution, and then vacuum dried to obtain a polymer with a weight-average molecular weight (Mw) of 1,500 (based on standard polystyrene standards) as determined by GPC analysis. Example 8 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 7. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 3,000. Example 9 [ka] 18.3g (0.045mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran(5-phenyl)-1,9'-xanthene]-3-one, 21.7g (0.090mol) of 4,4'-bis(methoxymethyl)-1,1'-biphenyl, 20.3g (0.045mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorin, and 150g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07g (0.00045mol) of diethyl sulfate was added as an initiator to the reactor and refluxed at 140°C for 9 hours. After the reaction was completed, the solution was purified with an ethanol / water (9:1) solution, recrystallized using an ethanol / water (9:1) solution, and then vacuum dried to obtain a polymer compound having a weight average molecular weight (Mw) of 1,500 in terms of standard polystyrene, as determined by GPC measurement.

[0012] Example 10 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 9. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 3,000. Example 11 [ka] 18.3 g (0.045 mol) of 3',6'-dihydroxy-3H-spiro[2-benzofuran(5-phenyl)-1,9'-xanthene]-3-one, 23.1 g (0.090 mol) of 4,4'-bis(methoxymethyl)diphenyl ether, 20.3 g (0.045 mol) of 9,9-bis(6-hydroxy-2-naphthyl)phlorin, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask and a nitrogen atmosphere was created. 0.07 g (0.00045 mol) of diethyl sulfate was added as an initiator to the reactor and refluxed at 140 °C for 9 hours. After the reaction was completed, the solution was purified with an ethanol / water (9:1) solution, recrystallized using an ethanol / water (9:1) solution, and then vacuum dried to obtain a polymer compound having a weight average molecular weight (Mw) of 1,500 in terms of standard polystyrene, as determined by GPC measurement. Example 12 Except for changing the reaction time to 15 hours, the synthesis was carried out in the same manner as in Example 11. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 3,000.

[0013] Comparative Example 1 [ka] 20 g (1 mol) of 9,9-bis(4-hydroxyphenyl)phlorin, 9.5 g (1 mol) of 1,4-bismethoxymethylbenzene, and 150 g of propylene glycol monomethyl ether acetate were placed in a four-neck flask, and a nitrogen atmosphere was created. 0.07 g (0.01 mol) of diethyl sulfate was added as an initiator to the reactor, and the mixture was refluxed at 140°C for 10 hours. Purification was carried out in the same manner as in Example 1 to obtain a compound with a weight-average molecular weight (Mw) of 1,500, calculated as standard polystyrene. Comparative Example 2 Except for changing the reaction time to 14 hours, synthesis and purification were carried out in the same manner as in Comparative Example 1. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 4,000. Comparative Example 3 Except for changing the reaction time to 16 hours, synthesis and purification were carried out in the same manner as in Comparative Example 1. As a result of GPC measurement of the obtained polymer compound, the weight average molecular weight (Mw) in terms of standard polystyrene was 5,000. Experimental Example 1 3.0 g of the polymer compound obtained in Example 1, 13.6 g of propylene glycol monomethyl ether acetate, and 3.4 g of cyclohexanone were added and stirred for 24 hours to dissolve. The dissolved solution was filtered through a 0.2 μm fine filter to prepare a composition for forming a hard mask film. The prepared solution was coated onto a silicon wafer using a spin coater. The coated wafer was heated on a hot plate at 240°C for 1 minute, followed by 400°C for 1 minute, to form a hard mask film. Experimental Example 2 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 2 was used. Experimental Example 3 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 3 was used. Experimental Example 4 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 4 was used. Experimental Example 5 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 5 was used. Experimental Example 6 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 6 was used. Experimental Example 7 The same procedure as in Experimental Example 1 was carried out, except that 3.0 g of the polymer compound obtained in Example 7 was used. Experimental Example 8 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Example 8 was used. Experimental Example 9 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Example 9 was used. Experimental Example 10 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Example 10 was used. Experimental Example 11 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Example 11 was used. Experimental Example 12 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Example 12 was used.

[0014] Comparative Experiment Example 1 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Comparative Example 1 was used. Comparative Experiment Example 2 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Comparative Example 2 was used. Comparative Experiment Example 3 The experiment was conducted in the same manner as in Experimental Example 1, except that 3.0 g of the polymer compound obtained in Comparative Example 3 was used. <Gap-Fill Property Evaluation> The solutions prepared in Experimental Examples 1 to 12 and Comparative Experimental Examples 1 to 3 were coated on a pattern wafer using a spin coater. The cross-section of the wafer was measured to check for the presence of voids. The experiment was repeated 5 times using each sample. The cross-section was confirmed using a scanning electron microscope (FE-SEM, manufactured by Hitachi, Ltd.) as the measurement equipment, and the measurement results are shown in Table 1.

Table 1

number

[0015] [Table 2] The results of the evaluation of the planarization characteristics of the hard mask film are shown in Table 2. The evaluation results confirmed that Experimental Examples 1, 3 to 7, and 9 to 12 exhibited better planarization performance than Comparative Experimental Example 1. In contrast, Experimental Examples 2, 8, Comparative Experimental Example 2, and Comparative Experimental Example 3 did not undergo planarization evaluation due to the presence of voids. The planarization degree of a hard mask film can be defined as excellent if the degree of planarization is 20% or less compared to the coating thickness. Experimental Examples 1, 3 to 7, and 9 to 12 exhibited excellent planarization performance, and Experimental Example 5 was evaluated as having the best planarization degree at 9.2%. <Coating thickness characteristic test> The thickness of the hard mask films formed in Experimental Examples 1 to 12 and Comparative Experimental Examples 1 to 3 was measured, and the results are shown in Table 3. The equipment used was an Ellipsometer (manufactured by Horiba, Ltd.).

[0016] [Table 3] As a result of coating using the materials of the experimental examples and comparative experimental examples, the coating performance of Comparative Experimental Example 3 was evaluated as poor because the coating was not uniform on the wafer surface and the physical properties of the coating surface were uneven. <Measurement of weight average molecular weight> The weight average molecular weights obtained in the examples were analyzed using gel permeation chromatography (GPC). The column used for the analysis was a product of Shodex Corporation, and the measurement conditions were as follows: The column temperature was 40°C, the mobile phase was tetrahydrofuran (THF), the flow rate was 1 mL / 1 min, and the GPC column was KF-801, 802, 803 (Shodex, 8 x 300 mm). The results are shown in Table 4. [Table 4] <Optical property testing> The refractive index n and extinction coefficient k of the hard mask films formed in Experimental Examples 1 to 12 and Comparative Experimental Examples 1 to 3 were measured, and the results are shown in Table 5. The equipment used was an Ellipsometer (manufactured by Horiba, Ltd.).

[0017] [Table 5] The refractive index (n@193nm) and absorption coefficient (k@193nm) of the hard mask film were measured as shown in Table 5, except for Comparative Example 3, which was not evaluated due to poor coating properties. The refractive index (n@193nm) of the hard mask film can be evaluated as excellent if it is 1.41 or less, and the absorption coefficient (k@193nm) of the hard mask film can be evaluated as excellent if it is 0.50 or less. In Experimental Examples 1 to 12, it was confirmed that the refractive index was 1.41 or less and the extinction coefficient was 0.50 or less, which were superior compared to Comparative Experimental Examples 1 and 2. Among these, Experimental Example 3 showed the most excellent results, with a refractive index of 1.36 and an extinction coefficient of 0.46.

[0018] <Dry etch characteristic evaluation> The hard mask films formed in Experimental Examples 1 to 12 and Comparative Experimental Examples 1 and 2 were dry-etched for 20 seconds using CF4 gas on dry etching equipment. The dry etching rate was quantified using the following Equations 2 and 3. The dry etching characteristics indicate the dry etching rate of the hard mask film when the ACL (amorphous carbon layer) is taken as 100%. When measuring the film thickness, a scanning electron microscope (FE-SEM, manufactured by Hitachi) was used to observe the cross section, and the measurement results, excluding Comparative Experimental Example 3, which was not evaluated due to poor coating properties, are shown in Table 6.

number

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[0019] Although certain parts of the present invention have been described in detail above, it will be apparent to those skilled in the art that such specific descriptions are merely preferred embodiments and are not intended to limit the scope of the present invention. Therefore, the true scope of the present invention should be defined by the claims and their equivalents.

Claims

1. A spin-on hard mask composition having high planarization properties includes a 3',6'-dihydroxy-3H-spiro[2-benzofuran-1,9'-xanthene]-3-one derivative polymer represented by the following formula 1, an organic solvent, and a surfactant. 【Chemistry 1】 (In the formula, l, m, and n are in the ranges of 1≦l≦20, 1≦m≦40, and 1≦n≦20, respectively; R １ represents hydrogen (H), hydroxyl group (OH), ketone group (CO), ether group (COC), aldehyde group (CHO), 【Chemistry 2】 【Transformation 3】 【Chemistry 4】 【Transformation 5】 and R ２ teeth, 【Transformation 6】 【Transformation 7】 【Transformation 8】 【Chemistry 9】 【Chemistry 10】 【Chemistry 11】 【Chemistry 12】 and R ３ teeth, 【Chemistry 13】 【Chemistry 14】 【Chemistry 15】 【Chemistry 16】 【Chemistry 17】 (including any of the following.)

2. 10. The spin-on hard mask composition having high planarization properties according to claim 1, wherein the hard mask composition includes a polymer having a weight-average molecular weight of 1,000 to 5,000, and has a planarization degree of 20% or less at a thickness of 4,000 Å or less.

3. 3. The spin-on hard mask composition having high planarization properties according to claim 2, wherein the polymer has a weight average molecular weight of 1,000 to 4,000.

4. 4. The spin-on hard mask composition having high planarization properties according to claim 3, wherein the polymer has a weight average molecular weight of 1,500 to 3,000.

5. 2. The spin-on hard mask composition having high planarization properties according to claim 1, comprising, based on the total composition, 1 to 50 wt % of a polymer, more than 0 to 2 wt % of a surfactant, and 50 to 99 wt % of an organic solvent.

6. 10. The spin-on hard mask composition having high planarization properties according to claim 1, wherein the organic solvent is selected from the group consisting of propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone (CHN), cyclopentanone (CPN), γ-butyrolactone (GBL), ethyl lactate (EL), methyl ethyl ketone (MEK), n-butyl acetate, N-methylpyrrolidone (NMP), methyl 3-methoxypropionate (MMP), and ethyl 3-ethoxypropionate (EEP), or a mixture of two or more thereof.

7. 2. The spin-on hard mask composition having high planarization properties according to claim 1, wherein the surfactant is selected from the group consisting of polyacrylates, polyfluorocarbons, polysiloxanes, polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene nonylphenyl ethers, polyoxyethylene octylphenyl ethers, polyoxyethylene polyoxypropylenes, polyoxyethylene lauryl ethers, and polyoxyethylene sorbitans, or a mixture of two or more thereof.

8. A patterning method comprising the steps of applying the spin-on hard mask composition having high planarization properties according to any one of claims 1 to 7 onto a layer to be etched by spin coating, and then performing a baking step to form a hard mask layer.

9. 9. The patterning method of claim 8, wherein the baking process is performed at a temperature of 150 to 400° C. for 1 to 5 minutes to form a hard mask layer.

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