Organic film forming composition, pattern forming method, and polymer

Abstract

The present invention relates to an organic film-forming composition, a pattern-forming method, and a polymer. The present invention provides an organic film-forming composition containing a high-carbon-content, thermosetting polymer that exhibits high etching resistance and excellent warping resistance, and provides a pattern-forming method using the same and a polymer suitable for the same. The organic film-forming composition comprises a polymer having a partial structure represented by the following general formula (1A) or (1B) and an organic solvent. #imgabs0# In the above general formula (1A), Ar1 and Ar2 represent a benzene ring or a naphthalene ring that may have a substituent, X is a single bond or a methylene group, and L is any of the following; #imgabs1# The dashed line in the above formula represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. #imgabs2# In the above general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring that may have a substituent, and Ar1, Ar2, X, and L are the same as described above.

Description

Technical Field

[0001] The present invention relates to an organic film-forming composition, a pattern-forming method using the composition, and a polymer contained in the composition. Background Art

[0002] In recent years, with the increasing integration and speed of semiconductor devices, there has been a demand for finer patterning rules. Photolithography, which uses light exposure and is currently a widely used technology, has been undergoing various technological developments to achieve finer and higher-precision patterning using the light source used.

[0003] Regarding the light source used for photolithography during resist pattern formation, light exposure using mercury lamp g-rays (436nm) or i-rays (365nm) as the light source is widely used in areas with low density. Meanwhile, in areas with high density and requiring miniaturization, photolithography using shorter wavelengths of KrF excimer lasers (248nm) and ArF excimer lasers (193nm) has become practical. In the most advanced generation, where even greater miniaturization is required, photolithography using extreme ultraviolet (EUV, 13.5nm) light is also approaching practical use.

[0004] As the thinning of resist patterns continues as described above, it is known that in the single-layer resist method, a typical method for forming photoresist patterns, the ratio of pattern height to pattern line width (aspect ratio) increases, and pattern collapse occurs during development due to the surface tension of the developer. However, when forming patterns with high aspect ratios on uneven substrates, multilayer resist methods, which stack films with different dry etching properties, are known to be superior. A two-layer resist method has been developed, combining a photoresist layer made of a silicon-containing photosensitive polymer and a lower layer made of an organic polymer containing carbon, hydrogen, and oxygen as main constituent elements, such as a novolac-based polymer (Patent Document 1, etc.). A three-layer resist method has been developed, combining a photoresist layer made of an organic photosensitive polymer used in the single-layer resist method, an intermediate layer made of a silicon-based polymer or a silicon-based CVD film, and a lower layer made of an organic polymer (Patent Document 2, etc.).

[0005] This three-layer resist method first uses a fluorocarbon-based dry etching gas to transfer the pattern of the photoresist layer to a silicon-containing intermediate layer. This pattern is then used as a mask to dry etch the organic underlayer film, primarily composed of carbon and hydrogen, using an oxygen-containing gas. Using this mask, dry etching is then used to form a pattern on the substrate. However, in semiconductor device manufacturing processes of the 20nm generation and later, when this organic underlayer film pattern is used as a hard mask to dry etch the pattern onto the substrate, the underlayer film pattern may be distorted or warped.

[0006] The carbon hard mask formed directly on the substrate to be processed is generally an amorphous carbon (hereinafter referred to as CVD-C) film made by CVD using methane gas, ethane gas, acetylene gas, etc. as raw materials. This CVD-C film can contain very few hydrogen atoms and is known to be very effective in preventing the distortion and bending of the pattern described above. However, when the underlying substrate to be processed has uneven heights, it is also known that due to the characteristics of the CVD process, it is difficult to fill such uneven heights evenly. Therefore, if a substrate to be processed with uneven heights is filled with CVD-C film and then patterned with photoresist, the uneven heights of the substrate to be processed will cause uneven heights on the surface of the photoresist coating, resulting in uneven film thickness of the resist, which in turn degrades the focus margin and pattern shape during photolithography.

[0007] On the other hand, using spin coating to form an underlayer film, which serves as a carbon hard mask directly above a substrate being processed, is known to offer the advantage of being able to evenly fill in the unevenness of a substrate. Flattening the substrate with this underlayer film material reduces thickness variations in the silicon-containing interlayer and photoresist formed thereon, thereby increasing the focus margin of photolithography and enabling proper pattern formation.

[0008] Therefore, an organic underlayer film material having high etching resistance during dry etching of a substrate to be processed and capable of forming an organic underlayer film having high flatness on the substrate to be processed by spin coating, and a method for forming the organic underlayer film are sought.

[0009] Conventionally, organic film-forming materials for multilayer resist methods have been known to use condensation resins obtained by using carbonyl compounds such as ketones and aldehydes, or aromatic alcohols as condensing agents for phenolic and naphthol compounds in such underlying film materials. Examples include the fluorene bisphenol novolac resins described in Patent Document 2, bisphenol compounds and novolac resins thereof described in Patent Document 3, adamantane phenol compound novolac resins described in Patent Document 4, and bisnaphthol compounds and novolac resins thereof described in Patent Document 5. The resins used in such materials are composed of naphthalene, fluorene, adamantane, and the like as their main skeletons, but are inevitably subject to degradation in etching resistance due to oxygen atoms in the phenolic hydroxyl groups.

[0010] Furthermore, as for resins used as underlayer film materials that do not contain heteroatoms such as oxygen in order to avoid impairing etching resistance, a resin having a fluorene structure as described in Patent Document 6 has been cited. However, since a cured film is formed by using a composition to which a crosslinking agent such as a hydroxymethyl compound is added, even if the carbon content of the resin is increased, there is still the problem of impairing etching resistance due to the presence of a crosslinking agent with a low carbon content.

[0011] Prior art literature

[0012] Patent Literature

[0013] [Patent Document 1] Japanese Patent Application Laid-Open No. 6-118651, etc.

[0014] [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-128509

[0015] [Patent Document 3] Japanese Patent Application Laid-Open No. 2006-293298

[0016] [Patent Document 4] Japanese Patent Application Laid-Open No. 2006-285095

[0017] [Patent Document 5] Japanese Patent Application Laid-Open No. 2010-122656

[0018] [Patent Document 6] International Publication No. 2013 / 047106 Pamphlet Summary of the Invention

[0019] Problems to be solved by the invention

[0020] In view of the above facts, the present invention aims to provide an organic film forming composition that exhibits high etching resistance and excellent distortion resistance without damaging the original carbon content of the resin by using a high-carbon-content, thermosetting polymer in the organic film forming composition, and to provide a pattern forming method using this organic film forming composition and a polymer suitable for such an organic film forming composition.

[0021] Solutions for solving problems

[0022] To achieve the above-mentioned object, the present invention provides an organic film-forming composition comprising a polymer having a partial structure represented by the following general formula (1A) and an organic solvent.

[0023] [Chemistry 1]

[0024]

[0025] In the above general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have a substituent, X is a single bond or a methylene group, and L is any one of the following.

[0026] [Chemistry 2]

[0027]

[0028] In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0029] When an organic film formed from an organic film-forming composition containing a polymer having a partial structure represented by the aforementioned general formula (1A) is heated, a cured film can be formed due to the thermal polymerization of the substituent having an unsaturated bond on the fluorene ring. Therefore, an organic film-forming composition using the polymer of the present invention can form a heat-cured film without a decrease in carbon content due to the addition of a crosslinking agent or the like. Since the polymer of the present invention has a condensed aromatic ring with a high carbon content as its main skeleton, an organic film having high resistance to distortion and dry etching can be formed using an organic film-forming composition using the polymer of the present invention.

[0030] The present invention also provides an organic film-forming composition comprising a polymer having a partial structure represented by the following general formula (1B) and an organic solvent.

[0031] [Chemistry 3]

[0032]

[0033] In the above general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent, and Ar1, Ar2, X, and L are the same as described above.

[0034] When an organic film formed from an organic film-forming composition comprising a polymer having a partial structure represented by the aforementioned general formula (1B) is heated, a cured film can be formed due to the thermal polymerization of the substituent having an unsaturated bond on the fluorene ring. Therefore, an organic film-forming composition using the polymer of the present invention can form a heat-cured film without a decrease in carbon content due to the addition of a crosslinking agent or the like. Since the polymer of the present invention has a condensed aromatic ring with a high carbon content as its main skeleton, an organic film having high resistance to distortion and dry etching can be formed using an organic film-forming composition using the polymer of the present invention.

[0035] The polymer having the partial structure represented by the general formula (1A) preferably further has a partial structure represented by the following general formula (1B).

[0036] [Chemistry 4]

[0037]

[0038] By introducing such a partial structure into the main skeleton, it is possible to more finely adjust the required performance of the organic film-forming composition, such as etching resistance, solvent solubility, and filling / planarization characteristics.

[0039] The polymer having the partial structure represented by the general formula (1A) preferably further has a partial structure represented by the following general formula (1C).

[0040] [Chemistry 5]

[0041]

[0042] In the aforementioned general formula (1C), W2 represents a hydrogen atom or a monovalent organic group having 1 to 50 carbon atoms, and Ar1 and Ar2 are the same as described above.

[0043] By introducing such a partial structure into the main skeleton, it is possible to more finely adjust the required performance of the organic film-forming composition, such as etching resistance, solvent solubility, and filling / planarization characteristics.

[0044] The aforementioned polymer preferably has a weight average molecular weight of 500 to 5000.

[0045] If the organic film-forming composition contains a polymer having a weight average molecular weight within such a range, the solubility in organic solvents can be maintained while suppressing outgassing during baking.

[0046] The organic solvent is preferably a mixture of one or more organic solvents having a boiling point below 180°C and one or more organic solvents having a boiling point of 180°C or higher.

[0047] When the organic solvent is the mixture, the addition of a high-boiling-point solvent to the polymer can impart thermal fluidity to the organic film, thereby enabling the organic film-forming composition to have both high filling and planarizing properties.

[0048] The organic film-forming composition preferably further contains one or more of a surfactant and a plasticizer.

[0049] When the organic film-forming composition contains the aforementioned additives, coating properties and filling / planarization characteristics are further improved.

[0050] The present invention provides a pattern forming method, comprising the following steps: forming an organic film on a workpiece using the aforementioned organic film forming composition; forming a silicon-containing resist underlayer film on the aforementioned organic film using a silicon-containing resist underlayer material; forming a resist upper layer film on the aforementioned silicon-containing resist underlayer film using a photoresist composition; forming a circuit pattern on the aforementioned resist upper layer film; using the aforementioned resist upper layer film on which the circuit pattern is formed as a mask to etch and transfer the pattern to the aforementioned silicon-containing resist underlayer film; using the aforementioned silicon-containing resist underlayer film to which the pattern has been transferred as a mask to etch and transfer the pattern to the aforementioned organic film; using the aforementioned organic film to which the pattern has been transferred as a mask to etch and form a pattern on the aforementioned workpiece.

[0051] The pattern forming method using the three-layer resist process described above can form a fine pattern with high precision on a substrate to be processed.

[0052] The present invention provides a pattern forming method, comprising the following steps: forming an organic film on a workpiece using the aforementioned organic film forming composition; forming a silicon-containing resist underlayer film on the aforementioned organic film using a silicon-containing resist underlayer material; forming an organic antireflective film (BARC) on the aforementioned silicon-containing resist underlayer film; forming a resist upper layer film on the aforementioned BARC using a photoresist composition; forming a circuit pattern on the aforementioned resist upper layer film; using the aforementioned resist upper layer film on which the circuit pattern is formed as a mask, sequentially transferring the pattern to the aforementioned BARC and the aforementioned silicon-containing resist underlayer film by etching; using the aforementioned silicon-containing resist underlayer film to which the pattern has been transferred as a mask, transferring the pattern to the aforementioned organic film by etching; using the aforementioned organic film to which the pattern has been transferred as a mask, etching the aforementioned workpiece, and forming a pattern on the aforementioned workpiece.

[0053] The pattern forming method using the four-layer resist process described above makes it possible to form a fine pattern with higher precision on a substrate to be processed.

[0054] The present invention provides a pattern forming method, comprising the following steps: forming an organic film on a workpiece using the aforementioned organic film forming composition; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the aforementioned organic film; forming a resist upper layer film on the aforementioned inorganic hard mask using a photoresist composition; forming a circuit pattern on the aforementioned resist upper layer film; using the aforementioned resist upper layer film having formed the circuit pattern as a mask to perform pattern transfer on the aforementioned inorganic hard mask by etching; using the aforementioned inorganic hard mask having formed the pattern as a mask to perform pattern transfer on the aforementioned organic film by etching; using the aforementioned organic film having formed the pattern as a mask to etch the aforementioned workpiece and form a pattern on the aforementioned workpiece.

[0055] By using this pattern forming method using a three-layer resist process, a fine pattern can be formed on a substrate to be processed with high precision.

[0056] Furthermore, the present invention provides a pattern forming method, comprising the following steps: forming an organic film on a workpiece using the aforementioned organic film forming composition; forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the aforementioned organic film; forming a BARC on the aforementioned inorganic hard mask; forming a resist upper layer film on the aforementioned BARC using a photoresist composition; forming a circuit pattern on the aforementioned resist upper layer film; using the aforementioned resist upper layer film having formed the circuit pattern as a mask, sequentially transferring the pattern to the aforementioned BARC and the aforementioned inorganic hard mask by etching; using the aforementioned inorganic hard mask having formed the pattern as a mask, transferring the pattern to the aforementioned organic film by etching; using the aforementioned organic film having formed the pattern as a mask, etching the aforementioned workpiece to form a pattern on the aforementioned workpiece.

[0057] By using this pattern forming method using a four-layer resist process, a fine pattern can be formed on a substrate to be processed with high precision.

[0058] The inorganic hard mask is preferably formed by CVD or ALD.

[0059] If the inorganic hard mask is formed by the CVD method or the ALD method, a fine pattern can be formed on the substrate to be processed with higher precision.

[0060] As the method for forming a circuit pattern on the resist upper layer film, it is preferable to use photolithography with a wavelength of 10 nm to 300 nm, direct writing using an electron beam, nano-stamping, or a combination thereof.

[0061] Regarding the method of forming a circuit pattern on a resist upper layer film, by using the above method, a fine pattern can be formed on a substrate to be processed with high precision.

[0062] As a developing method, alkali development or development using an organic solvent is preferably used.

[0063] As a development method, if alkali development or development using an organic solvent is used, a fine pattern can be formed on a substrate to be processed with higher precision.

[0064] The object to be processed is preferably a semiconductor device substrate, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film or a metal oxide nitride film.

[0065] In the present invention, for example, the aforementioned workpiece can be used.

[0066] The aforementioned metals are preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum or alloys thereof.

[0067] The aforementioned metals can be used as such.

[0068] The present invention provides a polymer having a partial structure represented by the following general formula (1A).

[0069] [Chemistry 6]

[0070]

[0071] In the above general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have a substituent, X is a single bond or a methylene group, and L is any one of the following.

[0072] [Chemistry 7]

[0073]

[0074] In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0075] This polymer is composed of a condensed aromatic ring structure without heteroatoms such as oxygen atoms and a partial structure with a substituent having an unsaturated bond as a thermal crosslinking group, so it can provide a component for forming an organic film composition that can form an organic film with high distortion resistance and high dry etching resistance.

[0076] Furthermore, the present invention provides a polymer having a partial structure represented by the following general formula (1B).

[0077] [Chemistry 8]

[0078]

[0079] In the above general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent, and Ar1, Ar2, X, and L are the same as described above.

[0080] This polymer is composed of a condensed aromatic ring structure without heteroatoms such as oxygen atoms and a partial structure with a substituent having an unsaturated bond as a thermal crosslinking group, so it can provide a component for forming an organic film composition that can form an organic film with high distortion resistance and high dry etching resistance.

[0081] The polymer having the partial structure represented by the general formula (1A) preferably further has a partial structure represented by the following general formula (1B).

[0082] [Chemistry 9]

[0083]

[0084] If the polymer further has the aforementioned partial structure, it can become a component of an organic film-forming composition capable of forming an organic film having high distortion resistance and high dry etching resistance.

[0085] The polymer having the partial structure represented by the general formula (1A) preferably further has a partial structure represented by the following general formula (1C).

[0086] [Chemistry 10]

[0087]

[0088] In the aforementioned general formula (1C), W2 represents a hydrogen atom or a monovalent organic group having 1 to 50 carbon atoms, and Ar1 and Ar2 are the same as described above.

[0089] If the polymer further has the aforementioned partial structure, it can become a component that provides an organic film-forming composition capable of adjusting etching resistance, solvent solubility, filling / planarization characteristics, and other properties according to required performance.

[0090] Effects of the Invention

[0091] As described above, the polymer of the present invention is thermosetting and has a main skeleton composed of condensed aromatic rings that do not contain heteroatoms such as oxygen atoms that would impair etching resistance. Therefore, it becomes a useful polymer for forming organic films with excellent etching resistance and distortion resistance. In addition, the organic film-forming composition of the present invention containing this polymer is a useful material for forming organic films that have excellent etching resistance and distortion resistance and have various properties such as heat resistance, embedding, and planarization. Therefore, it is extremely useful as a resist underlayer film material in multilayer resist processes such as two-layer resist processes, three-layer resist processes using a silicon-containing resist underlayer film, or four-layer resist processes using a silicon-containing resist underlayer film and an organic anti-reflective film. In addition, if it is the pattern forming method of the present invention, in the multilayer resist process, it is possible to form a fine pattern with high precision on the processed substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0092] Figure 1 (A) to (F) are process diagrams showing an example of the pattern forming method of the present invention.

[0093] Figure 2 This is a cross-sectional view showing an example of an organic film formed by applying the organic film-forming composition of the present invention onto a SiO2 wafer substrate having a trench pattern. DETAILED DESCRIPTION

[0094] As described above, the present invention seeks to develop an organic film-forming composition that can exhibit high etching resistance and excellent warping resistance without compromising the original carbon content of the resin by using a high-carbon-content, thermosetting polymer in the organic film-forming composition, a pattern forming method using the composition, and a polymer suitable for such an organic film-forming composition.

[0095] The inventors of the present application have diligently studied the above-mentioned issues and have discovered that a polymer having a condensed aromatic ring structure without heteroatoms such as oxygen atoms and a partial structure having a substituent having an unsaturated bond as a thermal crosslinking group will induce a crosslinking reaction due to heat treatment. Therefore, an organic film-forming composition containing the aforementioned polymer and an organic solvent will form an organic film having excellent etching resistance and distortion resistance while also taking into account various properties such as heat resistance, filling, and planarization properties, thereby completing the present invention.

[0096] That is, the present invention is a composition for forming an organic film comprising a polymer having a partial structure represented by the following general formula (1A) and an organic solvent.

[0097] [Chemistry 11]

[0098]

[0099] In the above general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have a substituent, X is a single bond or a methylene group, and L is any one of the following.

[0100] [Chemistry 12]

[0101]

[0102] In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0103] Furthermore, the present invention provides a composition for forming an organic film, comprising a polymer having a partial structure represented by the following general formula (1B) and an organic solvent.

[0104] [Chemistry 13]

[0105]

[0106] In the above general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent, and Ar1, Ar2, X, and L are the same as described above.

[0107] Furthermore, the present invention is a polymer having a partial structure represented by the aforementioned general formula (1A).

[0108] Furthermore, the present invention is a polymer having a partial structure represented by the aforementioned general formula (1B).

[0109] The following describes in detail embodiments of the present invention, but the present invention is not limited thereto.

[0110] The organic film-forming composition of the present invention contains a polymer having a partial structure represented by the following general formula (1A).

[0111] [Chemistry 14]

[0112]

[0113] In the above general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have a substituent, X is a single bond or a methylene group, and L is any one of the following.

[0114] [Chemistry 15]

[0115]

[0116] In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

[0117] The following are examples of the partial structures composed of Ar1 and Ar2 in the polymer of the general formula (1A). These aromatic rings may also have substituents such as vinyl, ethynyl, ethynylphenyl, allyl, propargyl, aryl, allyloxy, and propargyloxy. Among the following, fluorene and benzofluorene structures are preferred due to the ease of raw material availability.

[0118] [Chemistry 16]

[0119]

[0120] The substituents formed by X and L in the general formula (1A) are listed below. The dashed portion represents a bond to the fluorene ring. Furthermore, when R has an aromatic ring, it may also have an alkyl group, a halogen group, an alkoxy group, a trifluoromethyl group, or the like as a substituent on the aromatic ring. Among the following, ethynyl, propargyl, vinyl, and allyl are preferred from the perspective of ease of polymer production.

[0121] [Chemistry 17]

[0122]

[0123] The organic film-forming composition of the present invention may contain a homopolymer having a partial structure represented by the following general formula (1B), or a copolymer having a partial structure represented by the aforementioned general formula (1A) and a partial structure represented by the following general formula (1B).

[0124] [Chemistry 18]

[0125]

[0126] In the above general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent, and Ar1, Ar2, X, and L are the same as described above.

[0127] Examples of the alkoxy group having 1 to 10 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy, pentyloxy, hexyloxy, cyclohexyloxy, heptyloxy, octyloxy, 2-ethylhexyloxy, nonyloxy, and decyloxy.

[0128] The organic groups having one or more aromatic rings in W1 in the general formula (1B) are exemplified below. These aromatic rings may also have substituents such as vinyl, ethynyl, ethynylphenyl, allyl, propargyl, aryl, allyloxy, and propargyloxy. From the perspective of imparting etching resistance and solvent solubility, the organic groups preferably have a naphthalene ring, a fluorene structure, or a carbazole structure.

[0129] [Chemistry 19]

[0130]

[0131] [Chemistry 20]

[0132]

[0133] [Chemistry 21]

[0134]

[0135] [Chemistry 22]

[0136]

[0137] By changing the type of W1 of the partial structure represented by the aforementioned general formula (1B) of the polymer of the present invention and the polymerization ratio of the partial structure, the physical properties can be adjusted to match the required performance of the polymer of the present invention, and the physical properties of the organic film-forming composition of the present invention containing the polymer of the present invention and the organic film obtained therefrom can also be changed.

[0138] In the present invention, the aforementioned polymer preferably further has a partial structure represented by the following general formula (1C).

[0139] [Chemistry 23]

[0140]

[0141] In the aforementioned general formula (1C), W2 represents a hydrogen atom or a monovalent organic group having 1 to 50 carbon atoms, and Ar1 and Ar2 are the same as described above.

[0142] When W2 in the general formula (1C) is a monovalent organic group other than a hydrogen atom, examples include an alkyl group having 1 to 10 carbon atoms or the following structures. When W2 has an aromatic ring, the aromatic ring may have a substituent, and examples include a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a vinyl group, an ethynyl group, an ethynylphenyl group, an allyl group, a propargyl group, and an aryl group. Among them, when W2 is a hydrogen atom or a naphthyl group, it is preferred from the perspective of imparting etching resistance and solvent solubility.

[0143] [Chemistry 24]

[0144]

[0145] The Mw (weight average molecular weight) of the polymer is preferably 500 to 5000, more preferably 600 to 4000.

[0146] Such a molecular weight ensures solubility in organic solvents, suppressing the generation of sublimates during baking. Furthermore, the thermal fluidity of the organic film-forming composition improves, enabling the fine structures formed on the substrate to be effectively embedded in the organic film-forming composition. Furthermore, an organic film having a flat surface across the entire substrate can be formed. In the present invention, the weight-average molecular weight is a polystyrene-equivalent value determined by GPC (gel permeation chromatography) using THF (tetrahydrofuran) as the developing solvent.

[0147] [Method for producing polymer]

[0148] An example of a method for producing a polymer represented by general formula (1A) of the present invention can be synthesized by, for example, an electrophilic substitution reaction on a fluorene ring accompanied by dehydration using a fluorenol-based monomer having a substituent consisting of X and L as shown below. In the following formula, Ar1, Ar2, X, and L are the same as described above.

[0149] [Chemistry 25]

[0150]

[0151] The polymer can generally be obtained in an organic solvent in the presence of an acid catalyst at room temperature or, if necessary, under cooling or heating. Examples of usable acid catalysts include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acids; organic acids such as oxalic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid; and Lewis acids such as aluminum trichloride, aluminum ethoxide, aluminum isopropoxide, boron trifluoride, boron trichloride, boron tribromide, tin tetrachloride, tin tetrabromide, dibutyltin dichloride, dibutyltin dimethoxide, dibutyltin oxide, titanium tetrachloride, titanium tetrabromide, titanium (IV) methoxide, titanium (IV) ethoxide, titanium (IV) isopropoxide, and titanium (IV) oxide.

[0152] The solvent that can be used is not particularly limited, and examples include alcohols such as methanol, ethanol, isopropanol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as dichloromethane, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, and isobutyl methyl ketone; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; and aprotic polar solvents such as dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used alone or in combination of two or more.

[0153] Reaction methods include adding the fluorenols and the catalyst acid all at once, dispersing or dissolving the fluorenols and then adding the catalyst in batches or in divided doses, diluting the catalyst with a solvent and adding it dropwise, dispersing or dissolving the catalyst and then adding the fluorenols in batches or in divided doses, and diluting the fluorenols with a solvent and adding them dropwise. After the reaction, the catalyst can be removed by diluting the reactants with an organic solvent, separating and washing, and recovering the desired product.

[0154] The organic solvent used here is not particularly limited as long as it can dissolve the target substance and separate into two layers even when mixed with water. Examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, and ethylcyclopentyl methyl ether; chlorinated solvents such as dichloromethane, chloroform, dichloroethane, and trichloroethylene; and mixtures thereof. The rinse water used here can be deionized water or ultrapure water. The number of rinses may be one or more, but since rinsing more than ten times does not produce the desired effect, a number of rinses of approximately one to five is preferred.

[0155] During separation and cleaning, an alkaline aqueous solution may be used to remove acidic components in the system. Specific examples of the base include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium.

[0156] Furthermore, during separation and cleaning, an acidic aqueous solution may be used to remove metallic impurities or alkaline components in the system. Specific examples of the acid include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acids, and organic acids such as oxalic acid, fumaric acid, maleic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0157] The aforementioned separation and cleaning using an alkaline aqueous solution or an acidic aqueous solution may be performed alone or in combination. Separation and cleaning using an alkaline aqueous solution and an acidic aqueous solution in this order is more ideal from the perspective of removing metal impurities.

[0158] After the aforementioned separation and cleaning using an alkaline aqueous solution or an acidic aqueous solution, the product can be subsequently cleaned with neutral water. The number of cleanings can be one or more, but preferably one to five times. Neutral water can be deionized water, ultrapure water, or the like as described above. The number of cleanings can be one or more, but a smaller number may not remove alkaline or acidic components. Even if the product is cleaned 10 or more times, the desired effect may not be achieved, so one to five times is preferred.

[0159] The reaction product after the separation operation can also be recovered as a powder by concentrating the solvent to dryness or crystallizing under reduced pressure or normal pressure. However, to improve workability during the preparation of the organic film-forming composition, it can also be prepared into a solution state with an appropriate concentration. The concentration in this case is preferably 0.1 to 50% by mass, more preferably 0.5 to 30% by mass. This concentration prevents the viscosity from increasing, thus preventing impairment of workability, and also prevents the amount of solvent from becoming excessive, thus being economical.

[0160] The solvent in this case is not particularly limited as long as it can dissolve the polymer. Specific examples include ketones such as cyclohexanone and methyl-2-pentanone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; and esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate. These can be used alone or in combination of two or more.

[0161] The polymer having a partial structure represented by general formula (1B) of the present invention can be produced by copolymerizing fluorenols, which are raw materials for preparing the polymer having a partial structure represented by general formula (1A), with a compound having a partial structure W1, or by adding a compound having a partial structure W1 to the reaction of the polymer having a partial structure represented by general formula (1A) and capping the end portions. When W1 in the following is a hydroxyl group or an alkoxy group, the polymer can be produced by pre-adding water or an alcohol to the reaction system or by adding water or an alcohol during the reaction. Ar1, Ar2, X, L, and W1 in the following formula are the same as described above.

[0162] (Copolymerization method)

[0163] [Chemistry 26]

[0164]

[0165] (End-capping method)

[0166] [Chemistry 27]

[0167]

[0168] When the above reaction is carried out using W1 having at least one aromatic ring, the compound having a partial structure of W1 acts as a terminal terminator for fluorenols in the process of polymerization. During the reaction, as shown below, the aromatic ring of the compound having a partial structure of W1 may react with multiple fluorenol polymers of different chain lengths. However, for simplicity, the present invention describes it as shown in the chemical formula (1B). Ar1, Ar2, X, and R are the same as described above, and n1, n2, and n3 are integers of 1 or greater.

[0169] [Chemistry 28]

[0170]

[0171] The reaction and recovery methods of the aforementioned polymer are the same as those of the polymer having the partial structure represented by the general formula (1A).

[0172] The polymer having a partial structure represented by the general formula (1C) of the present invention can be produced by a method in which a fluorenol, which is a raw material for producing a polymer having a partial structure represented by the general formula (1A), and a fluorenol having a partial structure W2 are fed at once and copolymerized, or a method in which a fluorenol, which is a raw material for producing a polymer having a partial structure represented by the general formula (1A) or a fluorenol having a partial structure W2, is polymerized in a first stage and then a different fluorenol is added in a second stage for polymerization. Furthermore, when the polymerization is carried out in two stages, a plurality of fluorenols may be mixed and used in the first or second stage polymerization, and the same or other fluorenols may be added and polymerized in the third or fourth stage. In these polymerizations, the partial structure W1 may be introduced by copolymerization or end-capping with a compound having the partial structure W1.

[0173] (Copolymerization method)

[0174] [Chemistry 29]

[0175]

[0176] (Multi-stage polymerization method)

[0177] [Chemistry 30]

[0178]

[0179] The aforementioned polymerization and reaction of fluorenols with a compound having an organic group with one or more aromatic rings as W1 is similar. For example, as shown in the following formula, the aromatic rings Ar1 and Ar2 of the fluorenol having W2 as a partial structure may react with various fluorenol polymers produced during the polymerization. For simplicity, the present invention describes the reaction as shown in the chemical formula (1C). Ar1 and Ar2 are the same as described above, and n1, n2, and n3 are integers of 1 or greater.

[0180] [Chemistry 31]

[0181]

[0182] The reaction and recovery methods of the aforementioned polymer are the same as those of the polymer having the partial structure represented by the general formula (1A).

[0183] The polymers contained in the organic film-forming composition of the present invention may be combined with fluorenols having a thermally crosslinked group composed of X and L, and may also be combined with fluorenols having W1 or W2 as partial structures to match the required performance. Specifically, side chain structures that contribute to improved planarization properties and rigid aromatic ring structures that contribute to improved etching resistance and heat resistance may be introduced into structures having W1 and W2 and used, or they may be combined in any proportion to match the required performance. Furthermore, the method for producing the polymer may also be selected according to the required performance. By appropriately selecting copolymerization, multi-stage polymerization, and end-capping methods, the composition of the polymer, such as random or cross-polymerization, may be controlled. An organic film-forming composition using such a polymer can achieve high-dimensional balance between fill / planarization properties, heat resistance, distortion resistance, and etching resistance.

[0184] Another method for obtaining the polymer used in the organic film-forming composition of the present invention involves polymerizing the following fluorenols having hydrogen atoms as substituents to obtain an intermediate (STEP 1), and then converting the hydrogen atoms to substituents having triple bonds (STEP 2). These hydrogen-substituted fluorenols can also react with fluorenols having structures W1 and W2. Ar1, Ar2, and R are the same as described above.

[0185] [Chemistry 32]

[0186]

[0187] There are no particular limitations on the reaction as long as it can introduce a substituent consisting of X and L. Examples include the following substitution reaction using a halide, toluenesulfonate, mesylate, and a base catalyst. In the following formula, Y is a halogen, toluenesulfonyl, or mesylate.

[0188] [Chemistry 33]

[0189]

[0190] Examples of the base catalyst used in the substitution reaction include inorganic base compounds such as sodium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, and potassium phosphate; and organic amine compounds such as triethylamine, pyridine, and N-methylmorpholine. These can be used alone or in combination of two or more.

[0191] The solvent used in this case is not particularly limited as long as it is inactive in the above reaction. Examples include ether solvents such as diethyl ether, tetrahydrofuran, and dioxane, aromatic solvents such as benzene, toluene, and xylene, acetonitrile, dimethyl sulfoxide, N,N-dimethylformamide, N-methylpyrrolidone, and water. These solvents may be used alone or in combination of two or more.

[0192] In the polymerization method of the polymer, the reaction and recovery methods are the same as those of the polymerization method using a fluorenol having a substituent consisting of X and L as a monomer.

[0193] The polymer used in the organic film-forming composition obtained by this method can be prepared by using multiple halides, toluenesulfonates, and mesylates, either singly or in combination, depending on the required performance. For example, polymers with side chains that contribute to improved planarization properties and rigid aromatic ring structures that contribute to etch resistance and heat resistance can be combined in any proportion. Therefore, an organic film-forming composition using such polymers can achieve both high-dimensional fill / planarization properties and etch resistance.

[0194] As described above, the polymer having the partial structure represented by the general formula (1A) of the present invention can provide an organic film-forming composition exhibiting high etching resistance and excellent warp resistance.

[0195] <Organic Film Forming Composition>

[0196] The present invention also provides an organic film-forming composition comprising a polymer having a partial structure represented by general formula (1A) and an organic solvent. Furthermore, the organic film-forming composition of the present invention may contain multiple polymers having a partial structure represented by general formula (1A) of the present invention, either alone or in combination.

[0197] The organic film forming composition of the present invention may further be blended with a modifier such as a compounding compound or other polymers. The function of the aforementioned modifier is to mix with the organic film forming composition of the present invention and improve the film forming properties of spin coating and the filling properties of substrates with uneven surfaces. Examples of such modifiers include phenol, o-cresol, m-cresol, p-cresol, 2,3-dimethylphenol, 2,5-dimethylphenol, 3,4-dimethylphenol, 3,5-dimethylphenol, 2,4-dimethylphenol, 2,6-dimethylphenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthylphenol, 3-naphthylphenol, 4-naphthylphenol, 4-tritylphenol, Phenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, gallol, thymol, isothymol, 4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-dimethyl-4,4'-(9H-fluoren-9-ylidene)bisphenol , 2,2'-diallyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-difluoro-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-diphenyl-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,2'-dimethoxy-4,4'-(9H-fluorene-9-ylidene)bisphenol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3' ,3',4,4'-hexamethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-5,5'-diol, 5,5'-dimethyl-3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol and 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,Novolac resins such as 6-dihydroxynaphthalene, 3-hydroxynaphthalene-2-carboxylic acid methyl, indene, hydroxyindene, benzofuran, hydroxyanthracene, vinylnaphthalene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornene, 5-vinylnorbornene-2-ene, α-pinene, β-pinene, and limonene, polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyvinylnaphthalene, polynorbornene, polycyclodecene, polytetracyclododecene, polytricyclo[2.2.1.0(2,6)]heptane (poly-nortricyclene), poly(meth)acrylates, and copolymers thereof. Furthermore, naphthol-dicyclopentadiene copolymers described in JP-A-2004-205685, fluorene bisphenol novolac resins described in JP-A-2005-128509, ethylene-naphthalene copolymers described in JP-A-2005-250434, fullerenes having phenol groups described in JP-A-2006-227391, bisphenol compounds and novolac resins thereof described in JP-A-2006-293298, novolac resins of adamantanephenol compounds described in JP-A-2006-285095, bisnaphthol compounds and novolac resins thereof described in JP-A-2010-122656, and fullerene resin compounds described in JP-A-2008-158002 may also be blended. The amount of the modifier is preferably 0 to 1,000 parts by mass, more preferably 0 to 500 parts by mass, relative to 100 parts by mass of the polymer having the partial structure represented by the general formula (1A) of the present invention.

[0198] [Organic solvents]

[0199] The organic solvent that can be used in the organic film-forming composition of the present invention is not particularly limited as long as it dissolves the polymer having the partial structure represented by general formula (1A), the acid generator, the crosslinking agent, and other additives. Specifically, solvents having a boiling point of less than 180°C, such as those described in paragraphs (0091) and (0092) of JP-A-2007-199653, can be used. Among these, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more thereof are preferred.

[0200] Such a composition can be applied by spin coating and contains a polymer having a partial structure represented by the general formula (1A) of the present invention, thereby becoming an organic film-forming composition having good dry etching resistance and heat resistance as well as high filling / planarization properties.

[0201] Furthermore, in the composition for forming an organic film of the present invention, the organic solvent may be a solvent having a boiling point of 180°C or higher (a mixture of a solvent having a boiling point of less than 180°C and a solvent having a boiling point of 180°C or higher) added to the solvent having a boiling point of less than 180°C. The high-boiling-point organic solvent is not particularly limited to hydrocarbons, alcohols, ketones, esters, ethers, chlorine-based solvents, etc., as long as it can dissolve the polymer having the partial structure represented by the general formula (1A). Specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butanediol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethylhexanol, 1-decanol, 1-undecyl alcohol ... 1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerol, n-nonyl acetate, ethylene glycol, monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl Ether, triethylene glycol monomethyl ether, triethylene glycol-n-butyl ether, triethylene glycol butyl methyl ether, triethylene glycol diacetate, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether acetate

[0066] Examples of the present invention include triacetin, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butanediol diacetate, 1,6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate. These may be used alone or in combination.

[0202] The boiling point of the high-boiling-point solvent can be appropriately selected depending on the temperature at which the organic film-forming composition is heat-treated. The boiling point of the added high-boiling-point solvent is preferably between 180°C and 300°C, and more preferably between 200°C and 300°C. When the boiling point is 180°C or higher, there is no risk of excessive volatilization during baking (heat treatment) due to a low boiling point, and sufficient thermal fluidity can be achieved. Furthermore, when the boiling point is 300°C or lower, the boiling point is not too high, and the high-boiling-point solvent does not remain in the organic film after baking due to non-volatilization, thereby preventing adverse effects on the organic film's physical properties, such as etching resistance.

[0203] When using the aforementioned high-boiling-point solvent, the amount of the high-boiling-point solvent blended is preferably 1 to 30 parts by mass per 100 parts by mass of the solvent having a boiling point of less than 180° C. With such a blending amount, there is no risk of the solvent failing to impart sufficient thermal fluidity during baking or remaining in the organic film and deteriorating film properties such as etching resistance.

[0204] Such an organic film-forming composition can achieve both high filling and planarizing properties by adding a high-boiling-point solvent to the polymer having the partial structure represented by general formula (1A) to impart thermal fluidity.

[0205] [Other additives]

[0206] An acid generator may be added to the organic film-forming composition of the present invention to further promote the curing reaction. Acid generators may generate acid by thermal decomposition or by light irradiation. Specifically, the materials described in paragraphs (0061) to (0085) of JP-A-2007-199653 may be added, but the present invention is not limited thereto.

[0207] The acid generator may be used alone or in combination of two or more. The amount of the acid generator added is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polymer having the partial structure represented by formula (1A).

[0208] The organic film-forming composition of the present invention may contain a surfactant to improve the coating properties during spin coating. For example, surfactants described in JP-A-2009-269953 (0142) to (0147) can be used.

[0209] Furthermore, a crosslinking agent may be added to the organic film-forming composition of the present invention to enhance curability and further inhibit cross-mixing with the overlying film. The crosslinking agent is not particularly limited, and various known crosslinking agents can be used. Examples include melamine-based crosslinking agents, glycoluril-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, and epoxy-based crosslinking agents.

[0210] Specific examples of melamine-based crosslinking agents include hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy and / or hydroxyl substitutions thereof, and partial self-condensates thereof. Specific examples of glycoluril-based crosslinking agents include tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, alkoxy and / or hydroxyl substitutions thereof, and partial self-condensates thereof. Specific examples of benzoguanamine-based crosslinking agents include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, alkoxy and / or hydroxyl substitutions thereof, and partial self-condensates thereof. Specific examples of urea-based crosslinking agents include dimethoxymethylated dimethoxyethylene urea, alkoxy and / or hydroxyl substitutions thereof, and partial self-condensates thereof. Specific examples of β-hydroxyalkylamide-based crosslinking agents include N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide. Specific examples of isocyanurate-based crosslinking agents include triglycidyl isocyanurate and triallyl isocyanurate, while specific examples of aziridine-based crosslinking agents include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate]. Specific examples of the oxazoline crosslinking agent include 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis-4,5-diphenyl-2-oxazoline, 2,2'-methylenebis-4-phenyl-2-oxazoline, 2,2'-methylenebis-4-tert-butyl-2-oxazoline, 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymers. Specific examples of the epoxy crosslinking agent include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0211] Furthermore, a plasticizer may be added to the organic film-forming composition of the present invention to improve planarization and filling properties. The plasticizer is not particularly limited, and a wide variety of known plasticizers can be used. For example, low molecular weight compounds such as phthalates, adipates, phosphates, trimellitic acid esters, and citrates, as well as polymers such as polyethers, polyesters, and polyacetal polymers described in Japanese Patent Application Laid-Open No. 2013-253227, can be used.

[0212] Furthermore, in the organic film-forming composition of the present invention, as an additive imparting filling / planarizing properties similar to the plasticizer, it is preferable to use a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a pyrolyzable polymer having a weight loss rate of 40% by mass or greater between 30°C and 250°C and a weight-average molecular weight of 300 to 200,000. This pyrolyzable polymer preferably contains repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a).

[0213] [Chemistry 34]

[0214]

[0215] In the formula, R6 is a hydrogen atom or an optionally substituted saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms. Y1 is a saturated or unsaturated divalent organic group having 2 to 30 carbon atoms.

[0216] [Chemistry 35]

[0217]

[0218] Where R 6a Y is an alkyl group having 1 to 4 carbon atoms. a It is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms, and may have an ether bond. n represents the average number of repeating units and is 3 to 500.

[0219] The organic film-forming composition of the present invention can be used alone or in combination of two or more. The organic film-forming composition can be used as a resist underlayer film material or a planarization material for semiconductor device manufacturing.

[0220] Furthermore, the organic film forming composition of the present invention is extremely useful as a resist underlayer film material for multilayer resist processing such as a two-layer resist processing, a three-layer resist processing using a silicon-containing intermediate film, and a four-layer resist processing using a silicon-containing inorganic hard mask intermediate film and an organic antireflective film.

[0221] <Organic Film Formation Method>

[0222] The present invention provides a method for forming an organic film that functions as a resist underlayer film of a multilayer resist film used in photolithography or a planarizing film for semiconductor manufacturing using the organic film-forming composition.

[0223] The organic film forming method of the present invention is to apply the above-mentioned organic film forming composition to the processed substrate using a spin coating method or the like. By using a spin coating method or the like, good filling characteristics can be obtained. After spin coating, the solvent is evaporated, and baking (heat treatment) is performed to prevent mixing with the resist upper film and the resist intermediate film and to promote the cross-linking reaction. The baking is preferably performed at a temperature of 100°C to 600°C for 10 to 600 seconds, and more preferably at a temperature of 200°C to 500°C for 10 to 300 seconds. Considering the damage to the device and the influence on the deformation of the wafer, the upper limit of the heating temperature in the wafer processing of the photolithography is preferably 600°C or less, and more preferably 500°C or less.

[0224] Furthermore, the organic film forming method of the present invention can be carried out by coating the organic film forming composition of the present invention on the processed substrate according to the same spin coating method as described above, and calcining the organic film forming composition in a gas environment with an oxygen concentration of not less than 0.1% and not more than 21% to harden it to form an organic film.

[0225] The organic film of the present invention is formed by calcining in such an oxygen gas environment to obtain a fully hardened organic film. The gaseous environment during baking can be air, but in order to reduce oxygen, it is preferable to pre-enclose inert gases such as N2, Ar, and He to prevent the organic film from oxidizing. In order to prevent oxidation, it is preferable to control the oxygen concentration, preferably below 1000ppm, more preferably below 100ppm. If the oxidation of the organic film during baking is prevented, there will be no situation in which absorption increases or etching resistance decreases, which is preferable.

[0226] The organic film forming method of the present invention can obtain a flat organic film regardless of the unevenness of the processed substrate due to its excellent filling / flattening properties. Therefore, it is very useful for forming a flat organic film on a processed substrate with a structure having a height of more than 30nm or a height difference.

[0227] The thickness of the organic film such as the resist underlayer film or the planarization film for semiconductor device manufacturing can be appropriately selected, and is preferably 30 to 20,000 nm, more preferably 50 to 15,000 nm.

[0228] (Pattern Formation Method)

[0229] The present invention provides a pattern forming method, which is a pattern forming method using such an organic film forming composition and utilizing a three-layer resist process. The method is a method for forming a pattern on a processed substrate, comprising at least the following steps: forming an organic film on the processed substrate using the organic film forming composition of the present invention; forming a silicon-containing resist underlayer film using a silicon-containing resist underlayer material on the aforementioned organic film; forming a resist upper layer film using a photoresist composition on the aforementioned silicon-containing resist underlayer film; forming a circuit pattern on the aforementioned resist upper layer film; using the aforementioned resist upper layer film having the circuit pattern formed thereon as a mask to transfer the pattern to the aforementioned silicon-containing resist underlayer film by etching; using the aforementioned silicon-containing resist underlayer film having the pattern transferred thereon as a mask to transfer the pattern to the aforementioned organic film by etching; using the aforementioned organic film having the pattern transferred thereon as a mask to form a pattern on the aforementioned processed object by etching.

[0230] The silicon-containing resist underlayer film in the above-mentioned three-layer resist treatment shows etching resistance to oxygen or hydrogen. In the above-mentioned three-layer resist treatment, dry etching of the organic film using the silicon-containing resist underlayer film as a mask is preferably carried out using an etching gas mainly composed of oxygen or hydrogen.

[0231] A polysiloxane-based underlayer film is preferably used as the silicon-containing resist underlayer film for the three-layer resist treatment. Imparting an antireflective effect to the silicon-containing resist underlayer film can suppress reflection. In particular, for 193nm exposure, using materials containing a high number of aromatic groups and exhibiting high substrate etch selectivity increases the k value, which in turn increases substrate reflection. However, imparting an absorbent with an appropriate k value to the silicon-containing resist underlayer film can suppress reflection and reduce substrate reflection to less than 0.5%. For silicon-containing resist underlayer films with an antireflective effect, anthracene is preferably used for 248nm and 157nm exposure applications, while polysiloxanes with pendant phenyl groups or silicon-silicon bonded light-absorbing groups and crosslinked with acid or heat are preferred for 193nm exposure.

[0232] An organic antireflective film (BARC) may also be formed on the silicon-containing resist underlayer film. In this case, a pattern may be formed on the workpiece by using the organic film-forming composition of the present invention to form an organic film on the workpiece, forming a silicon-containing resist underlayer film on the organic film using a silicon-containing resist underlayer material, forming a BARC on the silicon-containing resist underlayer film, forming a resist upper layer film on the BARC using a photoresist composition, forming a circuit pattern on the resist upper layer film, using the resist upper layer film on which the circuit pattern is formed as a mask and sequentially etching the BARC and the silicon-containing resist underlayer film to transfer the pattern, using the silicon-containing resist underlayer film to which the pattern has been transferred as a mask and etching the pattern to transfer the pattern to the organic film, and using the organic film to which the pattern has been transferred as a mask and etching the workpiece to form a pattern on the workpiece.

[0233] Furthermore, an inorganic hard mask can also be formed as an anti-etching lower layer film. In this case, a pattern can be formed on the aforementioned object by using the organic film forming composition of the present invention to form an organic film on the processed substrate, forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the aforementioned organic film, forming an anti-etching upper layer film using a photoresist composition on the aforementioned inorganic hard mask, forming a circuit pattern on the aforementioned anti-etching upper layer film, using the aforementioned anti-etching upper layer film with the circuit pattern formed as a mask and transferring the pattern to the aforementioned inorganic hard mask by etching, using the aforementioned patterned inorganic hard mask as a mask and transferring the pattern to the aforementioned organic film by etching, and using the aforementioned patterned organic film as a mask and etching the aforementioned object to form a pattern on the aforementioned object.

[0234] As described above, when forming an inorganic hard mask on an organic film, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiON film) can be formed using CVD, ALD, or the like. For example, methods for forming a silicon nitride film are described in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The inorganic hard mask preferably has a thickness of 5 to 200 nm, more preferably 10 to 100 nm. Furthermore, the inorganic hard mask is preferably a SiON film, which is highly effective as an antireflective film. To maintain a substrate temperature of 300 to 500°C during SiON film formation, the underlying film must be able to withstand temperatures of 300 to 500°C. The organic film-forming composition used in the present invention has high heat resistance and can withstand temperatures of 300 to 500°C. Therefore, a combination of an inorganic hard mask formed by CVD or ALD and an organic film formed by spin coating is possible.

[0235] Furthermore, it is also suitable for a four-layer resist process using BARC. In this case, a pattern can be formed on the workpiece by forming an organic film on the workpiece using the organic film-forming composition of the present invention, forming an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the organic film, forming a BARC on the inorganic hard mask, forming a resist upper layer on the BARC using a photoresist composition, forming a circuit pattern on the resist upper layer, using the resist upper layer with the circuit pattern formed as a mask to sequentially etch the BARC and the inorganic hard mask to transfer a pattern, using the patterned inorganic hard mask as a mask to etch the organic film to transfer the pattern, and using the patterned organic film as a mask to etch the workpiece to form a pattern on the workpiece.

[0236] As described above, a photoresist film can be formed on an inorganic hard mask as a resist upper layer. Alternatively, a BARC can be formed on the inorganic hard mask by spin coating, and a photoresist film formed thereon. In particular, when using a SiON film as the inorganic hard mask, the dual antireflection coating of the SiON film and the BARC can suppress reflections even during immersion exposure at high NA exceeding 1.0. Another benefit of forming a BARC is that it reduces smearing of the photoresist pattern directly above the SiON film.

[0237] The resist top layer in the three-layer resist process can be either positive or negative, and can be made of the same conventional photoresist composition. After spin coating, the photoresist composition is pre-baked, preferably at 60-180°C for 10-300 seconds. Exposure, post-exposure baking (PEB), and development are then performed according to conventional methods to obtain a resist pattern. The thickness of the resist top layer is not particularly limited, but is preferably 30-500 nm, and more preferably 50-400 nm.

[0238] Examples of the exposure light include high-energy rays having a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, and X-rays.

[0239] In the pattern forming method of the present invention, for forming a circuit pattern on the resist upper layer film, preferably, photolithography with a wavelength of 10 nm to 300 nm, direct writing using an electron beam, nano-stamping, or a combination thereof is used.

[0240] In the pattern forming method of the present invention, it is preferable that alkali development or development using an organic solvent be used as the development method.

[0241] Etching is then performed using the resulting resist pattern as a mask. Etching of the silicon-containing resist underlayer film and the inorganic hard mask in the three-layer resist process is performed using a fluorocarbon-based gas, using the upper resist pattern as a mask. This forms a silicon-containing resist underlayer film pattern and an inorganic hard mask pattern.

[0242] Next, the organic film is etched using the obtained silicon-containing resist underlayer film pattern and inorganic hard mask pattern as masks.

[0243] Subsequent etching of the substrate or other workpiece can be performed using conventional methods. For example, if the substrate is a SiO2, SiN, or silicon dioxide-based low-k dielectric film, etching is performed primarily with a fluorine-based gas, while etching of p-Si, Al, or W is performed primarily with a chlorine- or bromine-based gas. When etching with a fluorine-based gas during substrate processing, the silicon-containing resist underlayer pattern during the three-layer resist process is stripped simultaneously with the substrate processing. When etching with a chlorine- or bromine-based gas, stripping of the silicon-containing resist underlayer pattern requires a separate dry etching stripping process using a fluorine-based gas after substrate processing.

[0244] The organic film obtained using the organic film-forming composition of the present invention is characterized by excellent etching resistance when etching these substrates to be processed.

[0245] In the pattern forming method of the present invention, the object to be processed is preferably a semiconductor device substrate, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film.

[0246] Furthermore, the aforementioned metal is preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum or an alloy thereof.

[0247] Furthermore, the substrate to be processed is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, as well as substrates having a processed layer formed thereon, can be used. The processed layer can be made of various low-k films and barrier films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, and can typically be formed to a thickness of preferably 50 to 10,000 nm, more preferably 100 to 5,000 nm. Furthermore, when forming the processed layer, the substrate and the processed layer can be made of different materials.

[0248] Furthermore, it is preferable to use a substrate to be processed that has a structure with a height of 30 nm or more or a height difference.

[0249] For an example of 3-layer resist processing, use Figure 1 The details are as follows.

[0250] When 3-layer resist is processed, as Figure 1 (A) An organic film 3 is formed on a processing layer 2 stacked on a substrate 1 using the organic film-forming composition of the present invention, and then a silicon-containing resist underlayer film 4 is formed, and a resist upperlayer film 5 is formed thereon.

[0251] Secondly, Figure 1 (B) A specific portion 6 of the resist upper layer film is exposed, PEB and development are performed to form a resist pattern 5a ( Figure 1 (C)). Using the obtained resist pattern 5a as a mask, the silicon-containing resist underlayer film 4 is etched using CF-based gas to form a silicon-containing resist underlayer film pattern 4a ( Figure 1 (D)). After the resist pattern 5a is removed, the obtained silicon-containing resist lower film pattern 4a is used as a mask to perform oxygen plasma etching on the organic film 3 to form an organic film pattern 3a ( Figure 1 (E)). After removing the silicon-containing resist lower film pattern 4a, the processed layer 2 is etched using the organic film pattern 3a as a mask to form a pattern 2a ( Figure 1 (F)).

[0252] When an inorganic hard mask is used, the silicon-containing resist underlayer film 4 serves as the inorganic hard mask. When applying BARC, a BARC layer is provided between the silicon-containing resist underlayer film 4 or the inorganic hard mask and the resist upper layer film 5. BARC etching may be performed continuously before etching the silicon-containing resist underlayer film 4. Alternatively, etching of the silicon-containing resist underlayer film 4 may be performed after performing only BARC etching and then changing the etching equipment.

[0253] As described above, according to the pattern forming method of the present invention, a fine pattern can be formed on a substrate to be processed with high precision in a multilayer resist process.

[0254] [Example]

[0255] The present invention is described in detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

[0256] The following fluorenols (B1) to (B10) and aromatic compounds (C1) to (C3) are used to synthesize the polymers (A1) to (A17) contained in the organic film-forming composition.

[0257] Fluorenols:

[0258] [Chemistry 36]

[0259]

[0260] Aromatic compounds:

[0261] [Chemistry 37]

[0262]

[0263] When a plurality of fluorenols are used to synthesize a polymer, the feed ratio of the fluorenols is as follows, expressed using m and l.

[0264] [Chemistry 38]

[0265]

[0266] (Synthesis example 1)

[0267] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B1) to prepare a uniform solution at an internal temperature of 50°C. 14.0 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF (tetrahydrofuran) was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A1) represented by the following formula. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A1) obtained by polystyrene conversion were determined by GPC measurement using THF as the developing solvent. The results were Mw = 2200 and Mw / Mn = 1.38.

[0268] [Chemistry 39]

[0269]

[0270] (Synthesis example 2)

[0271] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B2) to prepare a uniform solution at an internal temperature of 50°C. 13.8 g of methanesulfonic acid was slowly added and reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water, and the organic layer was dried under reduced pressure. 100 g of THF (tetrahydrofuran) was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were filtered and separated, washed twice with 200 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A2) represented by the following formula. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A2) obtained by GPC measurement using THF as the developing solvent were Mw = 2190 and Mw / Mn = 1.43, respectively, as calculated using polystyrene conversion.

[0272] [Chemistry 40]

[0273]

[0274] (Synthesis example 3)

[0275] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B3) to prepare a uniform solution at an internal temperature of 50°C. 13.1 g of methanesulfonic acid was slowly added and reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were filtered and separated, washed twice with 200 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A3) represented by the following formula. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A3) obtained by GPC measurement using THF as the developing solvent were Mw = 2450 and Mw / Mn = 1.68, respectively, as calculated using polystyrene conversion.

[0276] [Chemistry 41]

[0277]

[0278] (Synthesis Example 4)

[0279] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B4) and a uniform solution was prepared at an internal temperature of 50°C. 13.0 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A4). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A4) obtained by GPC measurement using THF as the developing solvent were Mw = 2370 and Mw / Mn = 1.59, respectively, as determined by polystyrene conversion.

[0280] [Chemistry 42]

[0281]

[0282] (Synthesis Example 5)

[0283] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B5) and a uniform solution was prepared at an internal temperature of 50°C. 10.7 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (A5) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A5) obtained by GPC measurement using THF as the developing solvent were Mw = 2720 and Mw / Mn = 1.69, respectively, as calculated using polystyrene conversion.

[0284] [Chemistry 43]

[0285]

[0286] (Synthesis Example 6)

[0287] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B6) to prepare a uniform solution at an internal temperature of 50°C. 10.1 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (A6) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A6) obtained by GPC measurement using THF as the developing solvent were Mw = 2840 and Mw / Mn = 1.75, respectively, in terms of polystyrene conversion.

[0288] [Chemistry 44]

[0289]

[0290] (Synthesis Example 7)

[0291] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B7) and a uniform solution was prepared at an internal temperature of 50°C. 10.6 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (A7) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A7) obtained by GPC measurement using THF as the developing solvent were Mw = 2760 and Mw / Mn = 1.65, respectively, as calculated using polystyrene conversion.

[0292] [Chemistry 45]

[0293]

[0294] (Synthesis Example 8)

[0295] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B8) to prepare a uniform solution at an internal temperature of 50°C. 10.2 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution and then precipitated into 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (A8) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A8) obtained by GPC measurement using THF as the developing solvent were Mw = 2820 and Mw / Mn = 1.58, respectively, as calculated using polystyrene conversion.

[0296] [Chemistry 46]

[0297]

[0298] (Synthesis Example 9)

[0299] Under nitrogen, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B3) and 0.49 g of water, and a uniform solution was prepared at an internal temperature of 50°C. 13.1 g of methanesulfonic acid was slowly added, and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (A9) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A9) obtained by GPC measurement using THF as the developing solvent were Mw = 1820 and Mw / Mn = 1.45, respectively, as calculated using polystyrene conversion.

[0300] [Chemistry 47]

[0301]

[0302] (Synthesis Example 10)

[0303] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B1) and 3.44 g of an aromatic compound (C1), and the mixture was stirred at an internal temperature of 50°C to form a homogeneous solution. 14.0 g of methanesulfonic acid was slowly added, and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed six times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to form a homogeneous solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A10). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A10) were determined in terms of polystyrene by GPC measurement using THF as the developing solvent, and the results were Mw = 1620 and Mw / Mn = 1.52.

[0304] [Chemistry 48]

[0305]

[0306] (Synthesis Example 11)

[0307] Under nitrogen, 30.0 g of fluorenol (B3) and 2.28 g of aromatic compound (C2) were added to 200 g of 1,2-dichloroethane, and a uniform solution was prepared at an internal temperature of 50°C. 13.1 g of methanesulfonic acid was slowly added, and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A11). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A11) obtained by GPC measurement using THF as the developing solvent were Mw = 1670 and Mw / Mn = 1.58, respectively, in terms of polystyrene conversion.

[0308] [Chemistry 49]

[0309]

[0310] (Synthesis Example 12)

[0311] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 30.0 g of fluorenol (B7) and 4.96 g of an aromatic compound (C3), and a uniform solution was prepared at an internal temperature of 50°C. 10.6 g of methanesulfonic acid was slowly added, and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed six times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum-dried at 70°C to obtain a polymer (A12). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A12) were determined in terms of polystyrene by GPC measurement using THF as the developing solvent, and the results were Mw = 1830 and Mw / Mn = 1.33.

[0312] [Chemistry 50]

[0313]

[0314] (Synthesis Example 13)

[0315] Under a nitrogen atmosphere, 200 g of 1,2-dichloroethane was added to 15.0 g of fluorenol (B1) and 13.3 g of fluorenol (B9), and a uniform solution was prepared at an internal temperature of 50°C. 14.0 g of methanesulfonic acid was slowly added, and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed 6 times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to prepare a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A13). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A13) obtained by GPC measurement using THF as the developing solvent were Mw = 2550 and Mw / Mn = 1.72, respectively, as calculated using polystyrene conversion.

[0316] [Chemistry 51]

[0317]

[0318] (Synthesis Example 14)

[0319] Under a nitrogen atmosphere, 100 g of 1,2-dichloroethane was added to 13.1 g of fluorenol (B10) at an internal temperature of 50°C to form a homogeneous solution. 13.1 g of methanesulfonic acid was slowly added, and the mixture was allowed to react at an internal temperature of 70°C for 4 hours. After cooling to an internal temperature of 50°C, a pre-homogenized mixture of 21.0 g of fluorenol (B3) and 100 g of 1,2-dichloroethane was slowly added dropwise, and the temperature was raised to 70°C again, and the mixture was allowed to react for 8 hours. After cooling to room temperature, 500 g of toluene was added, and the mixture was washed six times with 100 g of pure water. The organic layer was dried under reduced pressure. 100 g of THF was added to the residue to form a homogeneous solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum-dried at 70°C to obtain polymer (A14). The weight average molecular weight (Mw) and the dispersion degree (Mw / Mn) of the polymer (A14) were determined in terms of polystyrene conversion by GPC measurement using THF as a developing solvent. The results were Mw = 2890 and Mw / Mn = 1.64.

[0320] [Chemistry 52]

[0321]

[0322] (Synthesis Example 15)

[0323] Under nitrogen, 400 g of 1,2-dichloroethane was added to 60.0 g of fluorenol (B9) to prepare a homogeneous solution at an internal temperature of 50°C. 31.6 g of methanesulfonic acid was slowly added and the mixture was reacted at an internal temperature of 70°C for 8 hours. After cooling to room temperature, 1000 g of toluene was added, and the mixture was washed 6 times with 200 g of pure water. The organic layer was dried under reduced pressure. 200 g of THF (tetrahydrofuran) was added to the residue to prepare a homogeneous solution, which was then precipitated in 600 g of methanol. The precipitated crystals were separated by filtration, washed twice with 400 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a polymer (A15). The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A15) obtained by GPC measurement using THF as the developing solvent were Mw = 2630 and Mw / Mn = 1.67, respectively, in terms of polystyrene conversion.

[0324] [Chemistry 53]

[0325]

[0326] (Synthesis Example 16)

[0327] 20.0 g of the polymer (A15) synthesized in Synthesis Example 15, 1.4 g of tetrabutylammonium iodide, 25.3 g of a 25% aqueous sodium hydroxide solution, and 120 g of toluene were prepared into a uniform dispersion at an internal temperature of 50°C under a nitrogen atmosphere. A mixture of 4.0 g of n-butyl bromide and 13.9 g of propargyl bromide was slowly added dropwise, and the mixture was reacted at an internal temperature of 50°C for 12 hours. After cooling to room temperature, 200 g of toluene was added and the aqueous layer was removed. The organic layer was further washed twice with 60 g of a 3.0% aqueous nitric acid solution and five times with 60 g of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue, and the polymer was reprecipitated with 300 g of methanol. The precipitated polymer was separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered polymer was vacuum dried at 70°C to obtain polymer (A16). The weight average molecular weight (Mw) and the dispersion degree (Mw / Mn) of the polymer (A16) were determined in terms of polystyrene conversion by GPC measurement using THF as a developing solvent. The results were Mw = 3280 and Mw / Mn = 1.75.

[0328] [Chemistry 54]

[0329]

[0330] (Synthesis Example 17)

[0331] 20.0 g of the polymer (A15) synthesized in Synthesis Example 15, 1.4 g of tetrabutylammonium iodide, 25.3 g of a 25% aqueous sodium hydroxide solution, and 120 g of toluene were prepared into a uniform dispersion at an internal temperature of 50°C under a nitrogen environment. A mixture of 8.8 g of allyl bromide and 8.7 g of propargyl bromide was slowly added, and the mixture was reacted at an internal temperature of 50°C for 12 hours. After cooling to room temperature, 200 g of toluene was added and the aqueous layer was removed. The organic layer was further washed twice with 60 g of a 3.0% aqueous nitric acid solution and five times with 60 g of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue, and the polymer was reprecipitated with 300 g of methanol. The precipitated polymer was separated by filtration, washed twice with 200 g of methanol and recovered. The recovered polymer was vacuum dried at 70°C to obtain polymer (A17). The weight average molecular weight (Mw) and the dispersion degree (Mw / Mn) of the polymer (A17) were determined in terms of polystyrene conversion by GPC measurement using THF as a developing solvent. The results were Mw = 2980 and Mw / Mn = 1.68.

[0332] [Chemistry 55]

[0333]

[0334] [Comparative Synthesis Example]

[0335] Under a nitrogen atmosphere, 12.8 g of naphthalene and 18.0 g of 9-fluorenone were added, the temperature was raised to 230°C, and the reaction was allowed to proceed for 8 hours. From the beginning of the reaction, 0.25 ml of methanesulfonic acid was added to the reaction solution every hour for a total of 8 times. After cooling to room temperature, 40 g of toluene was added to the reaction solution, which was washed with pure water 6 times. The organic layer was dried under reduced pressure. 100 g of THF (tetrahydrofuran) was added to the residue to make a uniform solution, which was then precipitated in 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain the polymer (R1) shown below. The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (R1) obtained by GPC measurement using THF as the developing solvent were Mw = 2130 and Mw / Mn = 2.61, which were obtained by polystyrene conversion.

[0336] [Chemistry 56]

[0337]

[0338] Table 1 shows the structural formulas and Mw and Mw / Mn results of polymers (A1) to (A14), (A-16), and (A-17) used in Examples and polymer (R1) used in Comparative Examples.

[0339] [Table 1]

[0340]

[0341] Preparation of organic film-forming compositions (UDL-1 to 19, comparative UDL-1 to 2)

[0342] The polymers (A1) to (A14), (A16), (A17), and (R1) were dissolved in propylene glycol monomethyl ether acetate (PGMEA) or cyclohexanone (CyHO) containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) at the ratios shown in Table 2, along with (S1) 1,6-diacetoxyhexane (boiling point 260°C) and (S2) tripropylene glycol monomethyl ether (boiling point 242°C) as high-boiling-point solvents. The mixture was then filtered through a 0.1 μm fluororesin filter to prepare organic film-forming compositions (UDL-1 to 19, Comparative UDL-1 to 2). Comparative UDL-2 used an acid generator (AG) and a crosslinking agent (XL) represented by the following formulas.

[0343] [Table 2]

[0344]

[0345] [Chemistry 57]

[0346]

[0347] Examples 1-1 to 1-19, Comparative Examples 1-1 to 1-2 (Solvent Resistance Measurement)

[0348] The aforementioned UDLs 1 to 19 and comparative UDLs 1 to 2 were coated on a silicon substrate and baked in air at 350°C for 60 seconds. The film thickness was then measured. PGMEA solvent was then dispensed onto the substrate, left to stand for 30 seconds, and then spin-dried. The films were then baked at 100°C for 60 seconds to evaporate the PGMEA. The film thickness before and after the PGMEA treatment was measured. The residual film rate was calculated using the film thickness after deposition and the film thickness after the PGMEA treatment. The results are shown in Table 3.

[0349] [Table 3]

[0350]

[0351] As shown in Table 3, the organic membranes using the polymers of the present invention (Examples 1-1 to 1-19) exhibited a residual film rate of 99% or higher after PGMEA treatment, demonstrating sufficient solvent resistance through crosslinking reactions induced by heat treatment. In contrast, comparative UDL-1 using polymer (R1) lacked crosslinking sites and, as a result, exhibited no solvent resistance on its own. Therefore, the addition of an acid generator and a crosslinking agent was required to achieve solvent resistance (Comparative UDL-2). These results demonstrate that partial structures of the polymers of the present invention effectively function as thermally crosslinkable groups.

[0352] Examples 2-1 to 2-19, Comparative Examples 2-1 to 2-2 (Hardness Measurement)

[0353] The aforementioned UDLs 1 to 19 and comparative UDLs 1 and 2 were applied to a silicon substrate and baked in air at 350°C for 60 seconds to form organic films with a thickness of 200 nm. These organic films were subjected to nanoindentation testing using a TOYO SA2 nanoindenter to measure their hardness. The results are shown in Table 4.

[0354] [Table 4]

[0355] Organic film materials Hardness (GPa) Example 2-1 UDL-1 0.73 Example 2-2 UDL-2 0.68 Example 2-3 UDL-3 0.69 Examples 2-4 UDL-4 0.67 Examples 2-5 UDL-5 0.68 Examples 2-6 UDL-6 0.63 Examples 2-7 UDL-7 0.63 Examples 2-8 UDL-8 0.67 Examples 2-9 UDL-9 0.69 Example 2-10 UDL-10 0.71 Example 2-11 UDL-11 0.65 Example 2-12 UDL-12 0.62 Example 2-13 UDL-13 0.71 Examples 2-14 UDL-14 0.70 Example 2-15 UDL-15 0.61 Example 2-16 UDL-16 0.68 Example 2-17 UDL-17 0.68 Example 2-18 UDL-18 0.69 Example 2-19 UDL-19 0.67 Comparative Example 2-1 Compare UDL-1 0.45 Comparative Example 2-2 Compare UDL-2 0.48

[0356] As can be confirmed in Table 4: Examples 2-1 to 2-19 have greater hardness than Comparative Examples 2-1 to 2-2. The polymer of the present invention can form a denser and stronger organic film than the polymer (R1) used in Comparative Examples UDL-1 and -2. The reason is that the polymer of the present invention has thermosetting properties, so the organic film after curing can form a dense organic film composed only of condensed aromatic rings with a high carbon density, so the hardness is high. In contrast, the polymer (R1) used in the comparative example has a high carbon density, but the polymer itself does not have thermosetting properties, so the hardness of the organic film will not be high. In addition, the polymer (R1) can exhibit solvent resistance by using a crosslinking agent, but because the crosslinking agent will cause damage to the carbon density of the polymer, after forming a cured organic film, a significant increase in hardness is still not achieved.

[0357] Examples 3-1 to 3-19, Comparative Examples 3-1 to 3-2 (etching test)

[0358] [Etching test using CF4 / CHF3 gas]

[0359] The aforementioned UDLs 1 to 19 and comparative UDLs 1 to 2 were coated on a silicon substrate and baked in air at 350°C for 60 seconds to form an organic film with a thickness of 200 nm. Etching tests were then conducted using a CF4 / CHF3 gas system under the following conditions. A Tokyo Electron TE-8500 dry etching system was used to measure the difference in organic film thickness before and after etching. The results are shown in Table 5.

[0360] The etching conditions are as follows.

[0361]

[0362] [Table 5]

[0363]

[0364] In Table 5, the film thickness reduction of each of Examples and Comparative Examples is expressed as a ratio, with the film thickness reduction of Comparative UDL-1 by etching with CF4 / CHF3 gas being 100. The smaller the ratio, the better the etching resistance.

[0365] [Etching test using O2-based gas]

[0366] The aforementioned UDLs 1 to 19 and comparative UDLs 1 to 2 were coated on a silicon substrate and baked in air at 350°C for 60 seconds to form an organic film with a thickness of 200 nm. Etching tests were then conducted using an O2-based gas under the following conditions. A Tokyo Electron TE-8500 dry etching system was used to measure the difference in polymer film thickness before and after etching. The results are shown in Table 5.

[0367] The etching conditions are as follows.

[0368]

[0369] Similar to the etching test using CF4 / CH3-based gases, Table 5 shows the film reduction of each Example and Comparative Example as a ratio, with the film thickness reduction of Comparative UDL-1 by etching using O2-based gases being set to 100. The smaller the ratio, the better the etching resistance.

[0370] As shown in Table 5, when comparing Examples 3-1 to 3-19 with Comparative Examples 3-1 to 3-2, in both the CF4 / CH3-based gas and O2-based gas etching tests, the organic film reduction after etching in Examples 3-1 to 3-19 was smaller than that in Comparative Examples UDL-1 and UDL-2, demonstrating that the organic films formed exhibited excellent etching resistance. Furthermore, when comparing Comparative Examples 3-1 and 3-2, Comparative Example 3-2, which used a crosslinking agent to form the organic film, exhibited a decrease in carbon content in the organic film due to the addition of the crosslinking agent, resulting in a loss of approximately 10% in etching resistance. Furthermore, when Examples 3-1 to 3-19 using the polymers of the present invention are compared with Comparative Example 3-1 using the comparative polymer (R1), as indicated by the results of the hardness measurement, Examples 3-1 to 3-19 using the polymers of the present invention form dense organic films due to thermal crosslinking. Therefore, the reduction in thickness of the organic film after etching is suppressed by more than 5% compared to Comparative Example 3-1, and the etching resistance of the organic film formed using the organic film forming composition of the present invention is superior.

[0371] Examples 4-1 to 4-19, Comparative Examples 4-1 to 4-2 (Pattern Etching Test)

[0372] The aforementioned UDLs 1 to 19 and comparative UDLs 1 and 2 were applied to a 300 mm diameter Si wafer substrate with a 200 nm thick SiO2 film formed thereon. A resist underlayer film was formed in air at 350°C and baked for 60 seconds to a thickness of 200 nm. A silicon-containing resist interlayer material (SOG-1) was applied thereto and baked at 220°C for 60 seconds to form a 35 nm thick resist interlayer film. A resist upper layer material (SL resist for ArF) was applied thereto and baked at 105°C for 60 seconds to form a 100 nm thick resist upper layer film. A wet resist film (TC-1) was applied to the resist upper layer film and baked at 90°C for 60 seconds to form a 50 nm thick protective film.

[0373] As for the resist upper film material (SL resist for ArF), it is prepared by dissolving 100 parts by mass of a polymer (RP1) represented by the following formula, 6.6 parts by mass of an acid generator (PAG1) represented by the following formula, and 0.8 parts by mass of a basic compound (Amine1) represented by the following formula in 2500 parts by mass of PGMEA containing 0.1% by mass of FC-430 (produced by Sumitomo 3M Co., Ltd.), and filtering with a 0.1 μm fluororesin filter.

[0374] [Chemistry 58]

[0375]

[0376] The wet protective film material (TC-1) was prepared by dissolving 100 parts by mass of a protective film polymer (PP1) represented by the following formula in an organic solvent consisting of 2700 parts by mass of diisoamyl ether and 270 parts by mass of 2-methyl-1-butanol, and filtering the solution through a 0.1 μm fluororesin filter.

[0377] [Chemistry 59]

[0378]

[0379] The silicon-containing anti-etching intermediate layer material (SOG-1) is prepared by dissolving 100 parts by mass of an ArF silicon-containing intermediate film polymer (SiP1) represented by the following formula and 1 part by mass of a cross-linking catalyst (CAT1) represented by the following formula in 4000 parts by mass of PGMEA containing 0.1% by mass of FC-4430 (produced by Sumitomo 3M Co., Ltd.), and filtering through a fluororesin filter with a pore size of 0.1 μm.

[0380] [Chemistry 60]

[0381]

[0382] Next, exposure was performed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% half-step phase shift mask) while varying the exposure dose, followed by baking at 100°C for 60 seconds (PEB), and development with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a positive line and space pattern with a pitch of 100 nm and a resist line width of 50 nm to 30 nm.

[0383] Then, using the Tokyo Electron etching device Telius, the silicon-containing intermediate layer was processed using the resist pattern as a mask by dry etching, the lower film was processed using the silicon-containing intermediate layer as a mask, and the SiO2 film was processed using the lower film as a mask.

[0384] The etching conditions are as follows.

[0385] Resist pattern transfer conditions for SOG film:

[0386]

[0387] The conditions for SOG film transfer to the lower film are:

[0388]

[0389] Transfer conditions for SiO2 film:

[0390]

[0391] The cross sections of the patterns were observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd., and the shapes were compared and summarized in Table 6.

[0392] [Table 6]

[0393]

[0394] As shown in Table 6, the results of Examples 4-1 to 4-19 show that when UDL-1 to 4-19 were used as the resist underlayer film for a three-layer resist for immersion lithography, the resist shape after development was good in the pattern shape evaluation, demonstrating its usefulness as an antireflective film. In contrast, Comparative Example 4-1, which used Comparative UDL-1, lacked thermosetting properties and solvent resistance. Therefore, the film dissolved when the silicon-containing resist interlayer material (SOG-1) was applied, preventing pattern formation. Comparative Example 4-2, which used Comparative UDL-2, was able to form a resist pattern, so a comparison of the pattern shape after etching was performed.

[0395] Regarding the pattern shape after etching, Examples 4-1 to 4-19 all showed good resist shapes after development, and the shapes of the underlying films after oxygen etching and substrate processing etching. The pattern dimensions after substrate transfer also vary depending on the resist line width produced by exposure. Comparative Example 4-2 exhibited pattern distortion at line widths of approximately 40 nm, but Examples 4-1 to 4-19, which used the polymer of the present invention, exhibited no distortion up to a pattern size of 35 nm or less. This demonstrates that organic films formed from organic film-forming compositions containing the polymer of the present invention have high distortion resistance. Using a dense, high-strength organic film with a hardness exceeding 0.60 GPa, such as the polymer of the present invention, as a resist underlayer film can achieve high distortion resistance.

[0396] Examples 5-1 to 5-19 (Landfill Characteristics)

[0397] UDL-1 to UDL-19 were applied to a 500 nm thick SiO2 substrate with a dense pore pattern of 160 nm in diameter. After baking at 350°C for 60 seconds, a film thickness of 80 nm was formed on the flat substrate to form a resist underlayer film. The substrate with the resist underlayer film formed was cut and examined using a scanning electron microscope (SEM) to confirm that the resist underlayer film had filled the bottom of the pores. The results are shown in Table 7.

[0398] [Table 7]

[0399] Resist underlayer film material Landfill characteristics Example 5-1 UDL-1 Fill well to the bottom of the hole Example 5-2 UDL-2 Fill well to the bottom of the hole Example 5-3 UDL-3 Fill well to the bottom of the hole Example 5-4 UDL-4 Fill well to the bottom of the hole Example 5-5 UDL-5 Fill well to the bottom of the hole Examples 5-6 UDL-6 Fill well to the bottom of the hole Examples 5-7 UDL-7 Fill well to the bottom of the hole Examples 5-8 UDL-8 Fill well to the bottom of the hole Examples 5-9 UDL-9 Fill well to the bottom of the hole Examples 5-10 UDL-10 Fill well to the bottom of the hole Examples 5-11 UDL-11 Fill well to the bottom of the hole Examples 5-12 UDL-12 Fill well to the bottom of the hole Examples 5-13 UDL-13 Fill well to the bottom of the hole Examples 5-14 UDL-14 Fill well to the bottom of the hole Examples 5-15 UDL-15 Fill well to the bottom of the hole Examples 5-16 UDL-16 Fill well to the bottom of the hole Example 5-17 UDL-17 Fill well to the bottom of the hole Examples 5-18 UDL-18 Fill well to the bottom of the hole Example 5-19 UDL-19 Fill well to the bottom of the hole

[0400] As shown in Table 7, Examples 5-1 to 5-19, which use UDL-1 to UDL-19 of the present invention to form an anti-etching lower layer film, can all be well filled to the bottom of the hole. Even if there are height differences in the processed substrate, sufficient filling characteristics can be expected. It can be seen that they have useful characteristics for anti-etching lower layer film materials for multi-layer processing.

[0401] Examples 6-1 to 6-4, Comparative Examples 6-1 to 6-2 (Planarization Characteristics)

[0402] The organic film forming compositions (UDL-3, 4, 18, 19, and comparative UDL-1 and 2) were coated on SiO2 wafer substrates with large isolated trench patterns (trench width 10 μm, trench depth 0.10 μm), and after calcination at 350°C for 60 seconds in the atmosphere, the height difference of the organic film between the trench portion and the non-trench portion was observed using an NX10 atomic force microscope (AFM) manufactured by Park Systems. Figure 2 The results are shown in Table 8. In this evaluation, smaller height differences indicate better planarization characteristics. Furthermore, this evaluation employed strict evaluation conditions to assess the quality of the planarization characteristics, as a trench pattern with a depth of 0.10 μm was typically planarized using an organic film-forming composition with a film thickness of approximately 0.2 μm.

[0403] [Table 8]

[0404] Resist underlayer film material Height difference (nm) Example 6-1 UDL-3 65 Example 6-2 UDL-4 60 Example 6-3 UDL-18 55 Example 6-4 UDL-19 55 Comparative Example 6-1 Compare UDL-1 90 Comparative Example 6-2 Compare UDL-2 90

[0405] As shown in Table 8, the organic film-forming composition of the present invention exhibits a smaller height difference between the trench and non-trench areas of the organic film than Comparative Examples 6-1 and 6-2, confirming excellent planarization properties. The films of Comparative Examples 6-1 and 6-2 exhibited poor density, resulting in increased film loss during baking. This resulted in a more pronounced difference in film thickness between the upper and lower portions of the height difference after baking, resulting in poor planarization. Furthermore, a comparison of Examples 6-3 and 6-4, which added a high-boiling-point solvent, with Examples 6-1 and 6-2, which did not, reveals that the addition of the high-boiling-point solvent improved planarization.

[0406] As described above, the organic film-forming composition of the present invention has high etching resistance and excellent distortion resistance during etching, and is an extremely useful organic film for multilayer resist processing for ultrafine and high-precision pattern processing, especially for three-layer resist processing underlayer film.

[0407] Furthermore, the present invention is not limited to the above-described embodiments. The above-described embodiments are merely illustrative, and any technology having substantially the same structure and having the same functions and effects as those described in the claims of the present invention is included within the technical scope of the present invention.

[0408] Explanation of symbols

[0409] 1:Substrate

[0410] 2: Processed layer

[0411] 2a: Pattern of processed layer

[0412] 3: Organic film

[0413] 3a: Organic film pattern

[0414] 4: Silicon-containing resist underlayer film

[0415] 4a: Silicon-containing resist lower film pattern

[0416] 5: Resist upper film

[0417] 5a: Resist pattern

[0418] 6: Specific parts

Claims

1. A composition for forming an organic film, characterized by comprising a polymer having a partial structure represented by the following general formula (1A) and an organic solvent; In the general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have substituents, X is a single bond or a methylene group, and L is any one of the following: In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

2. A composition for forming an organic film, characterized by containing a polymer having a partial structure represented by the following general formula (1B) and an organic solvent; In the general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may be substituted, Ar1 and Ar2 are a benzene ring or a naphthalene ring which may be substituted, X is a single bond or a methylene group, and L is any one of the following: In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

3. The organic film-forming composition according to claim 1, wherein The polymer further has a partial structure represented by the following general formula (1B); In the general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent.

4. The organic film-forming composition according to claim 1 or 3, wherein The polymer further has a partial structure represented by the following general formula (1C); In the general formula (1C), W2 represents a hydrogen atom or a monovalent organic group having 1 to 50 carbon atoms, and Ar1 and Ar2 represent a benzene ring or a naphthalene ring which may have a substituent.

5. The organic film-forming composition according to any one of claims 1 to 3, wherein The weight average molecular weight of the polymer is 500 to 5000.

6. The organic film-forming composition according to any one of claims 1 to 3, wherein The organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180° C. and one or more organic solvents having a boiling point of 180° C. or higher.

7. The organic film-forming composition according to any one of claims 1 to 3, wherein The organic film-forming composition further contains one or more of a surfactant and a plasticizer.

8. A pattern forming method comprising the following steps: forming an organic film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming a resist underlayer film containing silicon on the organic film using a resist underlayer film material containing silicon; forming a resist upper film on the silicon-containing resist lower film using a photoresist composition; forming a circuit pattern on the resist upper film; Using the resist upper layer film on which the circuit pattern has been formed as a mask, the pattern is transferred to the resist lower layer film containing silicon by etching; Using the silicon-containing resist underlayer film to which the pattern has been transferred as a mask, the pattern is transferred to the organic film by etching; The organic film to which the pattern has been transferred is used as a mask to form a pattern on the workpiece by etching.

9. A pattern forming method comprising the following steps: forming an organic film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming a resist underlayer film containing silicon on the organic film using a resist underlayer film material containing silicon; forming an organic anti-reflective film (BARC) on the silicon-containing resist underlayer film; forming a resist upper layer film on the BARC using a photoresist composition; forming a circuit pattern on the upper layer of the resist; Using the resist upper layer film on which the circuit pattern has been formed as a mask, the pattern is transferred to the BARC and the silicon-containing resist lower layer film by etching in sequence; Using the silicon-containing resist underlayer film to which the pattern has been transferred as a mask, the pattern is transferred to the organic film by etching; The object to be processed is etched using the organic film to which the pattern has been transferred as a mask to form a pattern on the object to be processed.

10. A pattern forming method, comprising the following steps: forming an organic film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming an inorganic hard mask film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the organic film; forming a resist upper layer film on the inorganic hard mask using a photoresist composition; forming a circuit pattern on the upper layer of the resist; Using the resist upper layer film on which the circuit pattern has been formed as a mask, pattern transfer is performed on the inorganic hard mask by etching; Using the patterned inorganic hard mask as a mask, pattern transfer is performed on the organic film by etching; The object to be processed is etched using the patterned organic film as a mask to form a pattern on the object to be processed.

11. A pattern forming method comprising the following steps: forming an organic film on a workpiece using the organic film-forming composition according to any one of claims 1 to 7; forming an inorganic hard mask film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film on the organic film; forming a BARC on the inorganic hard mask; forming a resist upper layer film on the BARC using a photoresist composition; forming a circuit pattern on the upper layer of the resist; Using the resist upper layer film having the circuit pattern formed thereon as a mask, the pattern is sequentially transferred to the BARC and the inorganic hard mask by etching; Using the patterned inorganic hard mask as a mask, the pattern is transferred to the organic film by etching; The object to be processed is etched using the patterned organic film as a mask to form a pattern on the object to be processed.

12. The pattern forming method according to claim 10 or 11, wherein The inorganic hard mask is formed by a CVD method or an ALD method.

13. The pattern forming method according to any one of claims 8 to 11, wherein The method for forming a circuit pattern on the resist upper layer film includes photolithography with a wavelength of 10 nm to 300 nm, direct writing using an electron beam, nano-stamper, or a combination thereof.

14. The pattern forming method according to any one of claims 8 to 11, wherein As a developing method, alkali development or development using an organic solvent is used.

15. The pattern forming method according to any one of claims 8 to 11, wherein As the workpiece, a semiconductor device substrate, a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film is used.

16. The pattern forming method according to claim 15, wherein As the metal, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof is used.

17. A polymer characterized by having a partial structure represented by the following general formula (1A); In the general formula (1A), Ar1 and Ar2 are benzene rings or naphthalene rings which may have substituents, X is a single bond or a methylene group, and L is any one of the following: In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

18. A polymer characterized by having a partial structure represented by the following general formula (1B); In the general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent, Ar1 and Ar2 are a benzene ring or a naphthalene ring which may have a substituent, X is a single bond or a methylene group, and L is any one of the following: In the above formula, the dashed line represents a valence bond, and R is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

19. The polymer according to claim 17, wherein The polymer further has a partial structure represented by the following general formula (1B); In the general formula (1B), W1 is a hydroxyl group, an alkoxy group having 1 to 10 carbon atoms, or an organic group having at least one aromatic ring which may have a substituent.

20. The polymer according to claim 17 or 19, wherein The polymer further has a partial structure represented by the following general formula (1C); In the general formula (1C), W2 represents a hydrogen atom or a monovalent organic group having 1 to 50 carbon atoms, and Ar1 and Ar2 represent a benzene ring or a naphthalene ring which may have a substituent.

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