Organic compositions for use in antireflective films and antireflective films comprising the same.

Abstract

This invention relates to an organic composition for an anti-reflective film and an anti-reflective film comprising the same, and more specifically, to an organic composition for an anti-reflective film and an anti-reflective film comprising the same, which, in a lithography process, can achieve fine patterning by minimizing the light source reflectivity of the bottom anti-reflective coating (BARC), has excellent coatability, minimizes the generation of harmful substances and fume by improving thermal decomposition resistance, and exhibits high transparency.

Description

Technical Field

[0001] This invention relates to an organic composition for an anti-reflective film and an anti-reflective film comprising the same, and more specifically, to an organic composition for an anti-reflective film and an anti-reflective film comprising the same, which, in a lithography process, can achieve fine patterning by minimizing the light source reflectivity of the bottom anti-reflective coating (BARC), has excellent coatability, minimizes the generation of harmful substances and fumes by improving thermal decomposition resistance, and exhibits high transparency. Background Technology

[0002] In recent years, due to the high integration of semiconductor devices, the continued development of DRAM and NAND devices requires the realization of micro-patterned circuits. Therefore, hard mask materials used in photolithography processes are also being developed to meet this requirement. With the increasing integration of semiconductor devices, the resulting patterns are ultra-fine patterns below 0.10 micrometers, and the exposure wavelength has shifted from the previously used g-line or i-line regions to require photolithography processes using shorter wavelengths of light. Therefore, in semiconductor device fabrication processes, microlithography processes utilizing KrF excimer lasers and ArF excimer lasers, which are short wavelengths, are currently being used.

[0003] As the pattern size of semiconductor devices continues to shrink, minimizing the reflectivity of the bottom antireflective coating (BARC) on the wafer is crucial during the exposure process. This ensures the uniform presentation of the photoresist used to form the pattern, resulting in uniform, fine patterns and improved process efficiency. From this perspective, antireflective coating materials are continuously being developed among the various materials used in semiconductor processes to reduce the reflectivity of the bottom antireflective coating.

[0004] To date, materials used to minimize the reflectivity of light sources can be categorized into two types: inorganic anti-reflective coatings made from materials such as titanium, chromium oxide, and carbon dioxide, and organic anti-reflective coatings made from substances that absorb light sources.

[0005] Antireflective films are created by coating a light-absorbing material under a photoresist (PR) layer to prevent reflection from the bottom antireflective film. By adjusting the reflectivity, they suppress or eliminate standing waves (waves) that cause textures at the photosensitive interface due to light interference (enhancement and attenuation) during exposure. Maximizing the suppression of standing wave generation allows for optimal exposure during semiconductor device fabrication, facilitating the creation of miniaturized circuit patterns. Therefore, there is a need to develop bottom antireflective film materials and processes that possess excellent antireflective properties and can suppress standing wave generation.

[0006] The anti-reflective film should contain substances capable of absorbing light in the wavelength range of the exposure light source. During the process of laminating the anti-reflective film followed by photoresist, the anti-reflective film should not be dissolved and destroyed by the photoresist solvent. Therefore, the anti-reflective film should be fabricated with a structure that can be cured by heat. Furthermore, the anti-reflective film should not be reactive with the underlying photoresist. Compounds such as amines and acids should not migrate to the photoresist layer, as this can lead to problems such as footing and undercut during exposure. It should also possess optical properties suitable for various exposure processes on various substrates, i.e., appropriate refractive index and absorption coefficient, and should have excellent adhesion and coatability to both the substrate and the photoresist.

[0007] On the other hand, in recent years, there has been a demand to minimize the emission of hazardous substances in industrial processes and to prevent thermal decomposition of materials caused by heat generated during semiconductor fabrication, the generation of fumes from thermal decomposition, and equipment contamination caused by fumes. The resulting fumes are problematic in themselves, but more seriously, they contaminate expensive and contamination-sensitive semiconductor fabrication equipment. Cleaning and rinsing of the equipment used for decontamination removal increases additional process costs. From this perspective, antireflective coating materials used in semiconductor device fabrication processes need to meet the requirements of minimizing the emission of hazardous substances, enhancing the heat resistance of the materials, and minimizing fumes generation. Summary of the Invention

[0008] Technical issues The first objective of this invention is to provide an organic composition for an antireflective film and an antireflective film comprising the same, which uses a novel light absorber material suitable for exposure processes using KrF light and having high light absorption at a wavelength of 248 nm, together with a copolymer (resin) that is highly compatible with photoresist, thereby improving coatability, preventing thermal decomposition of the material during thermal processes to maintain the antireflective film properties of the material, and significantly improving existing problems of decreased antireflective properties, fume generation, color pollution, etc., caused by thermal decomposition.

[0009] The second objective of this invention is to provide an organic composition for an antireflective film and an antireflective film comprising the same, which enables the smooth execution of photoresist (PR) processes, prevents phenomena such as footing and undercut that may occur during micro-patterning processes, enables the creation of ultra-fine patterns that can suppress or eliminate standing waves, and shortens the process time through a single coating process.

[0010] A third objective of the present invention is to provide an organic composition for an antireflective film and an antireflective film comprising the same, which can suppress the generation of harmful substances caused by fume, prevent equipment contamination and malfunction caused by fume, and eliminate the need for additional cleaning or rinsing processes for fume removal, thereby improving process efficiency and cost efficiency.

[0011] The objectives of this invention are not limited to those described above. Other objectives and advantages of this invention not mentioned herein will be understood through the following description and will become clearer through embodiments of the invention. Furthermore, it will be readily recognized that the objectives and advantages of this invention can be achieved by the means and combinations thereof pointed out in the claims.

[0012] Technical solution To achieve the aforementioned objective, according to a first embodiment of the present invention, a light absorber for an antireflective film represented by the following chemical formula 1 can be provided.

[0013] Chemical Formula 1:

[0014] In chemical formula 1, A1 to A4 may be the same as or different from each other, and each independently represents a structure represented by one of chemical formulas a and b, wherein at least one of A1 to A4 is selected from the structure represented by chemical formula a, and at least one of A1 to A4 is selected from the structure represented by chemical formula b. Chemical formula a:

[0015] Chemical formula b:

[0016] In the chemical formulas a and b, Ar is a monocyclic or polycyclic aromatic ring group with 5 to 30 carbon atoms, substituted or unsubstituted by substituent R1, and n is an integer from 1 to 15. Each substituent R1 is independently selected from deuterium, halogen, alkyl with 1 to 10 carbon atoms, and aryl with 5 to 20 carbon atoms.

[0017] At least two of A1 to A4 can be selected from the structure represented by the chemical formula a, and at least three can be selected from the structure represented by the chemical formula a.

[0018] The Ar in the chemical formula a is a polycyclic aromatic ring group with 10 to 20 carbon atoms.

[0019] The polycyclic aromatic ring group with 10 to 20 carbon atoms can be selected from naphthalene group, phenanthrene group, triphenylene group, triphenylene group, anthracene group, benzanthracene group, pyrene group, benzopyrene group, chrysene group, dibenzanthracene group, and perylene group.

[0020] The chemical formula b can be selected from ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, and hexadecanoic acid.

[0021] According to a second embodiment of the present invention, a composition for an antireflective film can be provided, comprising: a light absorber for an antireflective film according to a first embodiment of the present invention; a polymer; a crosslinking agent; a hot acid generator; and a solvent.

[0022] The soluble content is 0.1 to 20 percent by weight relative to 100 percent by weight of the composition for the antireflective film.

[0023] The polymer can be a thermosetting resin with crosslinking sites at the ends of the straight chain or side chain.

[0024] The crosslinking agent may include one or more compounds selected from the group consisting of the following compounds.

[0025] .

[0026] The hot acid generator may include one or more compounds selected from the group consisting of the following compounds.

[0027] .

[0028] The solvent may include one or more selected from the group consisting of propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, propylene glycol n-propyl ether, dimethylformamide (DMF), γ-butyrolactone, ethoxyethanol, methoxyethanol, methyl 3-methoxypropionate (MMP), and ethyl 3-ethoxypropionate (EEP).

[0029] According to a third embodiment of the present invention, an antireflective film formed from a cured product of a composition for an antireflective film according to a second embodiment of the present invention can be provided.

[0030] According to a fourth embodiment of the present invention, a method for patterning a semiconductor device can be provided, comprising the following steps: coating a composition for an antireflective film according to a second embodiment of the present invention onto the upper surface of an etchable layer; curing the coated composition by a baking process and forming crosslinks to form an antireflective film; coating a photoresist on the upper surface of the antireflective film, exposing it and developing it to form a photoresist pattern; and using the photoresist pattern as an etching mask to etch the antireflective film, and then etching the etchable layer to form a pattern of the etched layer.

[0031] The step of forming the photoresist pattern may include a baking process before and after exposure.

[0032] According to a fifth embodiment of the present invention, a semiconductor device can be provided that is fabricated by a patterning method comprising a semiconductor device according to a fourth embodiment of the present invention.

[0033] The effects of the invention The organic composition for antireflective films of the present invention and the antireflective film comprising the thereof are used together with a novel light absorber material suitable for exposure processes using KrF light and having high light absorption at a wavelength of 248 nm and a copolymer (resin) with high compatibility with photoresist, thereby improving coatability, preventing thermal decomposition of materials generated during thermal processes to maintain the antireflective film properties of the material, and significantly improving existing problems of decreased antireflective properties, fume generation, color pollution, etc. caused by thermal decomposition.

[0034] Furthermore, the organic composition for antireflective film of the present invention and the antireflective film containing the thereof can facilitate the subsequent photoresist (PR) process, prevent phenomena such as footing and undercut that may occur during the micro-patterning process, realize ultra-fine patterns that can suppress or eliminate standing waves, and shorten the process time through a single coating process.

[0035] Furthermore, the organic composition for antireflective film of the present invention and the antireflective film containing the same can suppress the generation of harmful substances caused by fume generation, prevent equipment pollution and malfunction caused by fume, and eliminate the need for additional cleaning or rinsing processes to remove fume, thereby improving process efficiency and cost efficiency.

[0036] The effects of this invention are not limited to those described above, and other effects not mentioned can be clearly understood by those skilled in the art from the description of the scope of protection of the invention. In addition to the effects described above, the effects of this invention will be described together with the specific embodiments described below. Attached Figure Description

[0037] Figure 1 An image showing the generation of smoke in Embodiment 1 of the present invention.

[0038] Figure 2 An image confirming the generation of smoke in Comparative Example 1 of the present invention is shown.

[0039] Figure 3 An image confirming the generation of smoke in Comparative Example 2 of the present invention is shown.

[0040] Figure 4 The infrared (IR) spectra of Comparative Example 1 and Example 1 of the present invention are shown. Figure 4 The upper end shows the spectrum of Comparative Example 2, and the lower end shows the spectrum of Example 1.

[0041] Figure 5 SEM images showing the results of testing Example 1 with the photoresist pattern according to Experimental Example 4 of the present invention.

[0042] Figure 6 SEM images showing the results of testing Comparative Example 1 with the photoresist pattern of Experimental Example 4 according to the present invention.

[0043] Figure 7 SEM images showing the results of testing Comparative Example 2 with the photoresist pattern of Experimental Example 4 according to the present invention.

[0044] Best practice The aforementioned objectives, features, and advantages will be described in detail below with reference to the specification, thereby enabling those skilled in the art to readily implement the technical concept of this invention. In describing this invention, if it is determined that a detailed description of publicly known techniques related to this invention might unnecessarily obscure the essence of the invention, such detailed description will be omitted.

[0045] In the course of describing this specification, if it is determined that a detailed description of relevant prior art may unnecessarily obscure the essence of this specification, its detailed description will be omitted.

[0046] In this specification, when using terms such as "including," "having," "containing," "setting," or "possessing" to describe structural elements, other parts may be added unless "only" is used. When a structural element is described in the singular, it includes the plural form unless otherwise explicitly stated.

[0047] In this specification, when any element is located "above" or "below" another element, this includes not only the case where any element is in contact with another element, but also the case where there are other elements between the elements.

[0048] The present invention will now be described in more detail.

[0049] The light absorbers contained in organic antireflective films can be categorized into those contained within a compound as light-absorbing chemical species and those separated from a polymer that does not absorb light. Typically, the light absorber is used alone, allowing for adjustment of the amount of light-absorbing chemical species. According to the present invention, a light absorber represented by the following chemical formula 1 can be provided.

[0050] Chemical Formula 1:

[0051] In the chemical formula 1, A1 to A4 may be the same as or different from each other, and each independently represents a structure represented by one of the following chemical formulas a and b.

[0052] Chemical formula a:

[0053] Chemical formula b:

[0054] Chemical formulas a and b are respectively an aryl group containing a carboxyl group and a chain aliphatic group containing a carboxyl group. When observing the reaction with the thermosetting compound of the polymer described later, the carboxyl group reacts with functional groups such as acetal, epoxy, and hemiacetal in the thermosetting compound to form a cross-linked structure.

[0055] In the chemical formula a, Ar can be a monocyclic or polycyclic aromatic ring group with 5 to 30 carbon atoms that is substituted or unsubstituted by substituent R1, and n can be an integer from 1 to 15.

[0056] The light absorber represented by the chemical formula 1 can be synthesized using a tetra-p-phenol derivative represented by the following chemical formula 1-1 as the main skeleton.

[0057] Chemical formula 1-1:

[0058] The structural feature is that chemical formulas a and b are introduced by causing the epoxy groups contained in chemical formula 1-1 to undergo a ring-opening reaction.

[0059] Chemical formula a is an aromatic ring group containing a carboxyl group, which functions as a chromophore. Chemical formula b is a chain-like aliphatic carboxylic acid, which can improve dispersibility and coatability by increasing the solubility in the composition. Therefore, chemical formula 1 should contain one or more chemical formulas a and b respectively.

[0060] Therefore, at least one of A1 to A4 is selected from the structure represented by chemical formula a, and at least one of A1 to A4 is selected from the structure represented by chemical formula b. When there are multiple chemical formulas a, the structures of chemical formulas a selected from A1 to A4 may be the same as or different from each other. Furthermore, when there are multiple chemical formulas b in chemical formula 1, the structures of chemical formulas b selected from A1 to A4 may be the same as or different from each other.

[0061] According to an embodiment of the present invention, at least two of A1 to A4 may be selected from the structure represented by the chemical formula a, and at least three may be selected from the structure represented by the chemical formula a.

[0062] According to an example of the present invention, the Ar of the chemical formula a is a structure used to apply high-carbon compounds to ensure light absorption. Therefore, Ar can be a polycyclic aromatic ring group with 10 to 20 carbon atoms, for example, it can be a polycyclic aromatic ring group with 10 to 15 carbon atoms.

[0063] According to an example of the present invention, Ar may be selected from the following groups: naphthalene group, phenanthrene group, triphenylene group, triphenylene group, anthracene group, benzanthracene group, pyrene group, benzopyrene group, chrysene group, dibenzanthracene group, and perylene group.

[0064] The substituent R1 is a group present when one or more hydrogens of Ar are substituted. When multiple R1s are present, they can be independently selected from deuterium, halogens, alkyl groups having 1 to 10 carbon atoms, and aryl groups having 5 to 20 carbon atoms. However, according to an example of the present invention, chemical formula a can have an unsubstituted aryl group containing a carboxyl group.

[0065] The chemical formula b represents a chain aliphatic carboxylic acid. To ensure solubility, n, which is the number of carbon atoms other than the carboxyl group (-COOH), can be an integer from 1 to 15, for example, n can be an integer from 5 to 10.

[0066] According to one embodiment of the present invention, chemical formula b can be selected from ethanoic acid, propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, and hexadecanoic acid. According to one embodiment of the present invention, n in chemical formula b can be an integer from 5 to 10.

[0067] The light absorber represented by Formula 1 of the present invention can be obtained by the synthetic reaction of four phenol derivatives (Formula 1-1), an aromatic cyclic group containing a carboxyl group capable of introducing the structure of Formula a, and an aliphatic carboxylic acid capable of introducing the structure of Formula b. The synthesis temperature of the compound can be selected according to the solvent, and is 5°C, preferably 20°C.

[0068] The synthetic solvents that can be used in this invention may be selected from one or more of benzene, toluene, xylene, halobenzene, diethyl ether, tetrahydrofuran, esters, ethers, lactones, ketones and amides.

[0069] According to one embodiment of the present invention, a synthetic structure as shown in the following chemical formula 2 can be obtained by synthesizing the main skeleton structure of chemical formula 1-1, 9-anthracarboxylic acid (9-ACA) for introducing chemical formula a, and octanoic acid for introducing chemical formula b.

[0070] Chemical formula 2:

[0071] According to the present invention, a composition for an antireflective film can be provided, comprising: the novel light absorber; a polymer; a crosslinking agent; a thermal acid generator; and a solvent. As described above, the light absorber is represented by chemical formula 1, specifically, by chemical formula 2.

[0072] Preferably, the soluble solids content is 0.1 to 20 percent by weight relative to 100 percent by weight of the composition for the antireflective film. This is because if the solids content exceeds 20 percent by weight and reaches about 25 percent by weight in 100 percent by weight of the composition for the antireflective film, it will fail to cure due to decreased solubility.

[0073] The polymer contained in the composition for antireflective film of the present invention can be obtained by polymerizing acrylate monomers, maleic anhydride monomers, phenolic monomers and / or ester monomers, as long as it is a thermosetting polymer with a straight chain or side chain end containing a crosslinking site capable of crosslinking.

[0074] The antireflective film using the polymer described above is cured by a baking process after being coated onto a substrate, thus exhibiting resistance to solvent dissolution. Therefore, after laminating the antireflective film, the antireflective film will not be dissolved by the solvent of the photosensitizer during the coating process, and stability can be imparted.

[0075] Furthermore, the antireflective film composition of the present invention may contain additives to improve the curing and performance of the light absorber and polymer, and the additives may include crosslinking agents and thermal acid generators (TAG).

[0076] The cross-linker is preferably a compound having two or more cross-linking functional groups, and imidazole cross-linkers can be used. According to an example of the present invention, the cross-linker may include one or more compounds selected from the group of compounds listed in Table 1 below.

[0077] Table 1

[0078] The hot acid generator can generate an acid with a pKa of less than 2.0 during subsequent heat treatment of the photoresist composition coating (i.e., after application or exposure). For example, the hot acid generator can generate the acid at a temperature of about 250°C, or in a temperature range of 150–100°C, and can also help increase the film density. The hot acid generator can be, for example, toluenesulfonic acid, amine or pyridinium salts of toluenesulfonic acid, alkylsulfonic acid, amine or pyridinium salts of alkylsulfonic acid, etc. According to an embodiment of the invention, the hot acid generator may include one or more compounds selected from the group of compounds listed in Table 2 below.

[0079] Table 2

[0080] The organic solvents that can be used in the antireflective film composition of the present invention may include one or more selected from propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), cyclohexanone, ethyl lactate, propylene glycol n-propyl ether, dimethylformamide (DMF), γ-butyrolactone, ethoxyethanol, methoxyethanol, methyl 3-methoxypropionate (MMP), ethyl 3-ethoxypropionate (EEP), etc.

[0081] The content of the light absorber represented by chemical formula 1 may be 1 to 70% by weight, for example, 10 to 55% by weight, for example, 20 to 50% by weight, for example, 30 to 50% by weight, for example, 40 to 50% by weight, based on 100% by weight of the total amount of the antireflective film composition of the present invention.

[0082] The polymer content can be 0.1 to 50% by weight, for example, 1 to 40% by weight, for example, 5 to 30% by weight, or for example, 20 to 30% by weight, based on 100% by weight of the total amount of the antireflective film composition of the present invention.

[0083] The crosslinking agent content can be 1 to 50% by weight, for example, 5 to 40% by weight, for example, 10 to 30% by weight, for example, 20 to 30% by weight, based on 100% by weight of the total amount of the antireflective film composition of the present invention.

[0084] The content of the hot acid generator may be 0.1 to 20% by weight, for example, 0.5 to 10% by weight, for example, 1 to 5% by weight, or for example, 2 to 4% by weight, based on 100% by weight of the total amount of the antireflective film composition of the present invention.

[0085] If an antireflective film composition satisfying the composition and content described above is coated onto a wafer, and then subjected to thermal processes such as baking, acid is generated from the aforementioned thermal acid generator. In the presence of the generated acid, a cross-linking reaction is promoted between the light absorber represented by Chemical Formula 1, the polymer, and the cross-linking agent used as an additive, thereby forming an antireflective film insoluble in organic solvents. The antireflective film thus formed can prevent diffuse reflection from the underlying photoresist film by absorbing far-ultraviolet light that passes through the photoresist.

[0086] According to a third embodiment of the present invention, a method for patterning a semiconductor device using the antireflective film may include the following steps: coating a composition for the antireflective film onto the upper surface of an etchable layer; curing the coated composition by a baking process and forming crosslinks to form an antireflective film; coating a photoresist onto the upper surface of the antireflective film, exposing it, and developing it to form a photoresist pattern; and using the photoresist pattern as an etching mask to etch the antireflective film, and then etching the etchable layer to form a pattern of the etchable layer.

[0087] The process of forming an antireflective film by coating and curing the antireflective film composition of the present invention is carried out by a baking process, in which the baking process can be carried out in a temperature range of 150 to 250°C, for example, for 0.5 to 5 minutes.

[0088] Furthermore, in the pattern forming method according to the present invention, the step of forming the photoresist pattern may include a baking process before and after exposure, which may be performed at a temperature of 70 to 200°C.

[0089] As described above, the antireflective film composition of the present invention exhibits excellent coatability and transparency, and can maintain the antireflective film properties of the material by preventing thermal decomposition during the thermal process, thereby exhibiting excellent resolution in ultra-fine patterns. Furthermore, it can significantly improve existing problems such as decreased antireflective properties, fume generation, and color contamination caused by thermal decomposition, and improves process efficiency because it does not generate pollutants such as fume.

[0090] Furthermore, by using an organic antireflective film composition to form patterns, the antireflective film can be rapidly etched in an ultra-fine patterning process using a 248nm light source, which also facilitates the fabrication of highly integrated semiconductors. Detailed Implementation

[0091] The present invention will now be described in more detail through embodiments. However, the following embodiments are merely examples of the present invention, and the scope of the present invention is not limited to the following embodiments.

[0092] Example 1 Synthesis example 1 In a flask, 12 g (1 eq) of tetraglycidyl ether 1,1,2,2-tetraphenylethane, 12.42 g (2.9 eq) of 9-anthracarboxylic acid, 2.78 g (1 eq) of n-octanoic acid, 0.4 g of benzyltriethylammonium chloride, and 82.78 g (PGME) of propylene glycol monomethyl ether were added. The flask was heated to 1130 °C and stirred for 24 hours to allow the reaction to proceed. The reactants were neutralized with pyridine, purified with 1 wt% hydrochloric acid aqueous solution and distilled water, and then distilled to obtain light-absorbing compound A of formula 2.

[0093] Synthesis example 2 29.4 g of maleic anhydride, 30 g of methyl methacrylate, and 2.97 g of AIBN were dissolved in 120 g of 1,4-dioxane, and then polymerized at 70 °C for 12 hours. After the reaction, the reaction solution was added dropwise to methanol, and the resulting precipitate was filtered. The solution was then washed repeatedly with methanol and dried under vacuum (Mw = 47100, PDI = 2.17, yield = 58%). 72 g of the vacuum-dried polymer and 0.55 g of toluenesulfonic acid monohydrate were mixed into 725 g of methanol, and then reacted at 70 °C for 48 hours. After the reaction, the reaction solution was added dropwise to distilled water, and the resulting precipitate was filtered. The solution was then washed repeatedly with distilled water and dried under vacuum to obtain "Polymer 1 (yield 58%)".

[0094] Preparation Example 1 The antireflective film composition of Example 1 was prepared by dissolving 2.45 g of the light absorber prepared in Synthesis Example 1, 1.05 g of the polymer prepared in Synthesis Example 2, 1.375 g of 1,3,4,6-tetrakis(butoxymethyl)glycoluril as a curing agent, and 0.125 g of pyridinium p-toluenesulfonic acid as a hot acid generator in 95 g of propylene glycol monomethyl ether acetate, and then filtering the solution through a membrane filter with a diameter of 0.1 μm. The proportions (by weight) of the mixed light absorber, polymer, curing agent, and hot acid generator are shown in Table 3 below.

[0095] Comparative Example 1 Synthesis example 3 109 g of benzophenone tetracarboxylic acid dianhydride, 140 g of anthracene methanol, and 7.3 g of isopropyl ethylamine were dissolved in 540 g of 1,4-dioxane, and then reacted at 50 °C for 16 hours. After the reaction was completed, formic acid was added dropwise to the reaction solution for neutralization. The reactants were added dropwise to water, and the resulting precipitate was filtered. After washing several times with distilled water and drying, the light absorber compound B of the following chemical formula 3 was obtained.

[0096] Chemical formula 3:

[0097] Comparative Preparation Example 2 The same polymer, crosslinking agent, and hot acid generator as those used in Preparation Example 1 were used, but the light absorber compound used was compound B from Synthesis Example 3 instead of the compound from Synthesis Example 1, and the antireflective film composition of Comparative Example 1 was prepared in the proportions shown in Table 3 below.

[0098] Comparative Example 2 Synthesis example 4 75 g of 4,4'-oxophthalic anhydride, 100 g of anthracene methanol, and 7.3 g of diisopropylethylamine were dissolved in 540 g of 1,4-dioxane, and the mixture was reacted at 50 °C for 16 hours. After the reaction was complete, formic acid was added dropwise to the reaction solution for neutralization. The reactants were then added dropwise to water, and the resulting precipitate was filtered. After washing several times with distilled water and drying, the light absorber compound C with the following chemical formula 4 was obtained.

[0099] Chemical formula 4:

[0100] Comparative Preparation Example 2 The same polymer, crosslinking agent, and hot acid generator as those used in Preparation Example 1 were used, but the light absorber compound used was compound C from Synthesis Example 4 instead of the compound from Synthesis Example 1, and the antireflective film composition of Comparative Example 1 was prepared in the proportions shown in Table 3 below.

[0101] Table 3

[0102] Experimental Example Experimental Example 1 - Measurement of thickness, refractive index (n), and extinction coefficient (k) The composition sample for the antireflective film was brought into the clean room and coated onto an 8-inch silicon wafer using a track device (TEL-MARK 8, Tokyo Electron). The curing temperature was then set to 230°C, and the composition was baked on a hot plate for 1 minute to cure the antireflective film, thus preparing an antireflective film experimental sample, which was then taken out of the clean room.

[0103] The thickness of the antireflective coating on the experimental samples was measured using a VM-120 instrument from DNS Corporation, and the refractive index (n) and extinction coefficient (k) were determined at 248 nm using an elliptic polarization spectrometer (Eliipsometer JA woolams / V-Vase). The results are shown in Table 4 below.

[0104] Table 4

[0105] As shown in Table 4, in order to confirm that for the same source of fume pollution, the samples prepared in Example 1, Comparative Example 1 and Comparative Example 2 exhibited almost the same levels of thickness, refractive index (n) and extinction coefficient (k).

[0106] Experiment Example 2 - Stripping Experiment In Experiment 1, the thickness, refractive index (n), and extinction coefficient (k) were measured. The curing temperature was then changed, and it was confirmed that 100% curing was achieved. Furthermore, the wafer with the antireflective film was reworked using a Thinner (OK7030) machine, and the thickness, refractive index (n), and extinction coefficient (k) were measured again. The differences were expressed as ΔT (thickness difference), Δn (refractive index difference), and Δk (extinction coefficient difference), and the results are shown in Table 5 below.

[0107] Table 5

[0108] Referring to Table 5, even when the curing temperature is changed to 180°C to 260°C, the curing rate of the antireflective film composition of the present invention reaches 100%, thus confirming its applicability under various process conditions and temperatures. Furthermore, even after a rework process used for peel testing, the thickness, refractive index, and extinction coefficient remain unchanged, thus confirming its excellent physical properties.

[0109] Experiment Example 3 - Generation and Color Evaluation of Hazardous Substances and Fume Take 1g of the antireflective film composition as a sample and place it in an aluminum dish. Bake at 120°C for 90 seconds to remove the solvent from the sample. Then, at 230°C, use an air particle counter to measure the air particles five times according to their particle size, and the results are shown in Table 6 below.

[0110] After measurement, the collected substances were observed with the naked eye to confirm the color. Images of the collected substances from Example 1, Comparative Example 1, and Comparative Example 2 are shown respectively. Figures 1 to 3 middle.

[0111] Table 6

[0112] As shown in Table 6, compared with Comparative Examples 1 and 2, the amount of air particles measured in Example 1 was significantly reduced. Figure 1 The collected material is transparent, so no fume was generated. In contrast, the collected materials of Comparative Example 1 and Comparative Example 2 are yellow, indicating that fume was generated and that the transparency was significantly reduced when coating was performed.

[0113] Furthermore, the infrared (IR) spectra of Comparative Example 2 and Example 1 were confirmed respectively, and are shown in [the figures]. Figure 4 and Figure 5 middle. Figure 4 The dashed line represents the yellow substance detected in the sample of Comparative Example 2, while Figure 5 Unlike Figure 4 No yellow substance peak was detected.

[0114] The inventors have confirmed that, as with the prior art of Comparative Examples 1 and 2, when phthalic anhydride is used to introduce high-carbon compounds through a ring-opening reaction, harmful substances that cause fumes or yellowing of antireflective films are emitted. Therefore, in this invention, a light absorber that does not use phthalic anhydride for a ring-opening reaction is derived.

[0115] Experiment Example 4 - Photoresist Pattern Experiment The composition sample for the antireflective film was brought into the clean room and then coated onto an 8-inch silicon wafer using a track device (TEL-MARK 8, Tokyo Electron). The composition was then baked on a hot plate at 230°C for 1 minute to cure the antireflective film, thus preparing an antireflective film experimental sample, which was then taken out of the clean room.

[0116] Then, krF photoresist was coated onto the surface of the prepared antireflective film, and then baked at 100°C (soft bake) for 60 seconds. Next, it was exposed using a scanner (Nikon S-203B, NA=0.68 Conv. (Sigma: 0.75)) and baked at 100°C (post-treatment bake) for 60 seconds. The exposed wafer was developed with 2.38 wt% tetramethylammonium hydroxide (TMAH) developer to obtain the final photoresist pattern. A pattern size of 180 nm linewidth (1:1 pitch) was confirmed. The CD-SEM and V-SEM images of Experiment 4 are shown below. Figure 6 The measured EOP, EL, and DOF values ​​are shown in Table 7 below.

[0117] Table 7

[0118] In Table 7, Eop represents the energy required to achieve the target pattern, measured using an exposure device (Nikon NSR-204B), EL represents the rate of change of pattern size per 1 mJ, measured using the CD-SEM method, and DoF represents the vertical distance of the lens (focus), measured using (Nikon NSR-204B).

[0119] The present invention has been described in more detail above with reference to embodiments of this specification. However, this specification is not necessarily limited to these embodiments, and various modifications can be made without departing from the technical spirit of this specification. Therefore, the embodiments disclosed in this specification are not intended to limit the technical spirit of this specification, but are intended to illustrate that the scope of the technical spirit of this specification is not limited to these embodiments. Therefore, the above embodiments should be understood as exemplary in all respects and not restrictive. The scope of protection of the invention as claimed in this specification should be interpreted by the claims, and all technical ideas within the equivalent scope should be interpreted as being included within the scope of protection of the invention as claimed in this specification.

Claims

1. A light absorber for use in antireflective films, characterized in that, Represented by the following chemical formula 1: Chemical Formula 1: In chemical formula 1, A1 to A4 may be the same as or different from each other, and each independently represents a structure represented by one of chemical formulas a and b, wherein at least one of A1 to A4 is selected from the structure represented by chemical formula a, and at least one of A1 to A4 is selected from the structure represented by chemical formula b. Chemical formula a: Chemical formula b: In the chemical formulas a and b, Ar is a monocyclic or polycyclic aromatic ring group with 5 to 30 carbon atoms, substituted or unsubstituted by substituent R1, and n is an integer from 1 to 15. Each substituent R1 is independently selected from deuterium, halogen, alkyl with 1 to 10 carbon atoms, and aryl with 5 to 20 carbon atoms.

2. The light absorber for antireflective films according to claim 1, characterized in that, At least two of A1 to A4 are selected from the structures represented by the chemical formula a.

3. The light absorber for antireflective films according to claim 1, characterized in that, At least three of A1 to A4 are selected from the structures represented by the chemical formula a.

4. The light absorber for antireflective films according to claim 1, characterized in that, The Ar in the chemical formula a is a polycyclic aromatic ring group with 10 to 20 carbon atoms.

5. The light absorber for antireflective films according to claim 4, characterized in that, The polycyclic aromatic ring group with 10 to 20 carbon atoms is selected from naphthyl, phenanthryl, triphenylene, fluorenyl, anthracene, benzo[a]anthryl, pyrene, benzo[a]pyrene, alkyl, dibenzo[a]anthryl, and peryl.

6. The light absorber for antireflective films according to claim 1, characterized in that, The chemical formula b is selected from acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tetradecanoic acid, pentadecanoic acid, and hexadecanoic acid.

7. A composition for use in an antireflective film, characterized in that, Contains: a light absorber for the antireflective film; a polymer; a crosslinking agent; a hot acid generator; and a solvent. The light absorber used in the antireflective film is the light absorber used in the antireflective film according to any one of claims 1 to 6.

8. The composition for an antireflective film according to claim 7, characterized in that, The content of soluble solids is 0.1 to 20 percent by weight relative to 100 percent by weight of the composition for the antireflective film.

9. The composition for an antireflective film according to claim 7, characterized in that, The polymer is a thermosetting resin with crosslinking sites at the ends of the straight chain or side chain.

10. The composition for an antireflective film according to claim 7, characterized in that, The crosslinking agent comprises one or more compounds selected from the group consisting of: 。 11. The composition for an antireflective film according to claim 7, characterized in that, The hot acid generator comprises one or more compounds selected from the group consisting of: 。 12. The composition for an antireflective film according to claim 7, characterized in that, The solvent comprises one or more selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, cyclohexanone, ethyl lactate, propylene glycol n-propyl ether, dimethylformamide, γ-butyrolactone, ethoxyethanol, methoxyethanol, methyl 3-methoxypropionate, and ethyl 3-ethoxypropionate.

13. An antireflective film, characterized in that, It is formed from the cured product of the composition for antireflective film according to any one of claims 7 to 12.

14. A method for patterning a semiconductor device, characterized in that, Includes the following steps: The composition for an antireflective film according to any one of claims 7 to 12 is applied to the upper surface of the etched layer; The coated composition is cured by a baking process and cross-linked to form an anti-reflective film; Photoresist is coated on the upper surface of the antireflective film, and after exposure, it is developed to form a photoresist pattern; as well as The antireflective film is etched using the photoresist pattern as an etching mask, and then the etched layer is etched to form the pattern of the etched layer.

15. The method for patterning a semiconductor device according to claim 14, characterized in that, The step of forming the photoresist pattern includes a baking process before and after exposure.

16. A semiconductor device, characterized in that, Prepared by a patterning method comprising a semiconductor device according to any one of claims 14 to 15.

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