Composition for organic film formation, organic film formation method, and pattern formation method

Abstract

To provide a composition for organic film formation which is excellent in film-forming property on a substrate and embedding property, and is excellent in hump suppression property in an EBR step.SOLUTION: A composition for organic film formation contains (A) a polymer having a repeating unit represented by the following general formula (1), (B) a resin for organic film formation, and (C) a solvent. In general formula (1), R1 is a divalent organic group containing C2-30 aliphatic moiety or aromatic moiety, R2 is each independently a hydrogen atom, a C1-6 alkyl group, a hydroxyl group, a C1-6 alkoxy group, a halogen atom other than a fluorine atom, a cyano group, an amino group or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a composition for forming an organic film, a method for forming an organic film using the composition, and a method for forming a pattern using the composition. [Background technology]

[0002] In recent years, with the increasing integration and speed of semiconductor elements, there is a demand for finer pattern rules. In the lithography using light exposure, which is currently used as a general-purpose technology, various technological developments are being carried out to achieve finer and more accurate pattern processing for the light source used.

[0003] As a light source for lithography used in forming resist patterns, light exposure using mercury lamps' g-line (436 nm) or i-line (365 nm) light sources is widely used in areas with low integration. On the other hand, in areas with high integration and requiring finer patterns, lithography using shorter wavelength KrF excimer lasers (248 nm) and ArF excimer lasers (193 nm) has also been put to practical use, and for the most advanced generation requiring even finer patterns, lithography using extreme ultraviolet (EUV, 13.5 nm) is approaching practical use.

[0004] As the resist pattern becomes thinner, the ratio of the pattern height to the pattern line width (aspect ratio) increases in the single-layer resist method used as a typical resist pattern forming method, and it is well known that the surface tension of the developer during development causes the pattern to collapse. Therefore, in order to form a pattern with a high aspect ratio on a stepped substrate, a multi-layer resist method in which films with different dry etching characteristics are laminated to form a pattern is known to be excellent, and a two-layer resist method (Patent Document 1) that combines a photoresist layer (resist upper layer film) made of a silicon-containing photosensitive polymer with a resist lower layer made of an organic polymer mainly composed of carbon, hydrogen, and oxygen, such as a novolac-based polymer, and a three-layer resist method (Patent Document 2) that combines a photoresist layer made of an organic photosensitive polymer used in the single-layer resist method with a resist intermediate film made of a silicon-based polymer or a silicon-based CVD film and a resist lower layer made of an organic polymer have been developed.

[0005] In this three-layer resist method, for example, an organic film made of novolac or the like is uniformly formed on a substrate to be processed as a resist underlayer film, a silicon-containing resist intermediate film is formed on the organic film as a resist intermediate film, and a normal organic photoresist film is formed on the organic film as a resist upper layer film. For dry etching with fluorine-based gas plasma, the organic resist upper layer film has a good etching selectivity to the silicon-containing resist intermediate film, so the resist pattern is transferred to the silicon-containing resist intermediate film by using dry etching with fluorine-based gas plasma. According to this method, even if a resist composition that is difficult to form a pattern with a sufficient thickness for directly processing a substrate to be processed or a resist composition that does not have sufficient dry etching resistance for processing a substrate is used, a pattern can be transferred to the silicon-containing resist intermediate film, and then, by performing pattern transfer using dry etching with oxygen-based gas plasma, a pattern of an organic film (e.g., a resist underlayer film such as a novolac film) that has sufficient dry etching resistance for processing can be obtained.

[0006] Although many technologies for the organic films described above are already known (e.g., Patent Document 3), the recent advances in miniaturization have led to an increased need for excellent filling properties in addition to dry etching properties. There is a demand for organic film materials that can be uniformly formed on the underlying substrate to be processed, even on substrates with complex shapes and materials, and that have filling properties that enable filling the required patterns without gaps.

[0007] The organic film as described above is formed by using a coater / developer capable of performing processes such as spin coating, EBR, and baking when manufacturing a semiconductor substrate. The EBR (Edge Bead Removal) process is a process in which, after a coating is formed on a substrate (wafer) by spin coating, the coating on the edge of the substrate is removed with a remover in order to prevent contamination of the substrate transport arm of the coater / developer. The remover used in the EBR process is, for example, a mixture (30% by mass: 70% by mass) of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether, and such a remover is widely used in the EBR process of resist top layers, silicon-containing resist intermediate films, and organic films.

[0008] The remover used in the EBR process can cause the outer periphery of the organic film to become thick (a hump). Since humps can cause defects in the dry etching process used in substrate processing, there is a demand for organic films that suppress humps. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Application Publication No. 06-118651 [Patent Document 2] JP 2005-128509 A [Patent Document 3] JP 2004-205685 A [Patent Document 4] JP 2000-256550 A [Patent Document 5] JP 2023-87852 A [Non-patent literature]

[0010] [Non-Patent Document 1] Diana J, Gerbi et al., “The effect of water on the formation of polyarylethers via phase-transfer-catalyzed nucleophilic aromatic substitution”, Journal of Polymer Science: Polymer Letters Edition, Vol. 23, 551-556 (1985) Summary of the Invention [Problem to be solved by the invention]

[0011] The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a composition for forming an organic film, which has excellent film-forming properties (in-plane uniformity) and filling properties on a substrate (wafer) and is also excellent in suppressing hump formation during an EBR process, and a method for forming an organic film and a method for forming a pattern using the composition. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention provides a composition for forming an organic film, comprising: (A) a polymer having a repeating unit represented by the following general formula (1): (B) an organic film-forming resin, and (C) Solvent The present invention provides a composition for forming an organic film, which comprises: [ka] (In general formula (1), R1 is a divalent organic group containing an aliphatic moiety or an aromatic moiety having 2 to 30 carbon atoms, and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom, a cyano group, an amino group, or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.)

[0013] Such a composition for forming an organic film makes it possible to form an organic film that is excellent in in-plane uniformity and filling properties, and that can suppress the formation of humps due to the influence of the remover in the EBR process.

[0014] In the present invention, the polymer (A) preferably contains one or more compounds represented by any one of the following general formulas (2) to (4). [ka] (In the formula, R1 and R2 are the same as above, R3 is a monovalent organic group having 1 to 30 carbon atoms, a is 0 or 1. When a is 0, b is 1 to 4, b1 is 1 to 5, c is 0 to 3, and c1 is 0 to 4. When a is 1, b is 1 to 6, b1 is 1 to 7, c is 0 to 5, and c1 is 0 to 6. n represents the average number of repeating units and is 3 to 2,000.)

[0015] A composition for forming an organic film containing such a polymer is preferable because it is possible to form an organic film having superior in-plane uniformity.

[0016] In the present invention, the content of the polymer (A) is preferably 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin (B) for forming an organic film.

[0017] A composition for forming an organic film containing the polymer (A) in such an amount is preferable because it is possible to form an organic film having more excellent in-plane uniformity.

[0018] The present invention also provides a method for forming an organic film used in a manufacturing process of a semiconductor device, comprising the steps of: The composition for forming an organic film of the present invention is spin-coated on a substrate to obtain a coating film; The coating film is heat-treated at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to harden the coating film, thereby forming an organic film.

[0019] The organic film forming method of the present invention can fill a pattern of a complex shape on a substrate to be processed by spin coating, and can form an organic film that exhibits excellent in-plane uniformity. In addition, the organic film formed by the organic film forming method of the present invention is particularly useful when performing an EBR process, since it is possible to remove the edge while suppressing the formation of a hump in the EBR process.

[0020] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming a resist upper layer film on the silicon-containing resist intermediate film using a resist upper layer film material comprising 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, a pattern is transferred to the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0021] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming an organic anti-reflective film or an adhesion film on the silicon-containing resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising 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, a pattern is transferred to the organic anti-reflective film or the adhesion film and the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0022] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming a resist upper layer film on the inorganic hard mask intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film having a circuit pattern formed thereon is used as a mask to transfer the pattern to the inorganic hard mask intermediate film by etching; The pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0023] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film on which the circuit pattern is formed is used as a mask to transfer the pattern to the organic anti-reflective film or the adhesion film and the inorganic hard mask intermediate film by etching; The pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0024] In this way, the organic film-forming composition of the present invention can be suitably used in various pattern formation methods, such as a three-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask intermediate film, and in addition to these, a four-layer resist process using an organic antireflective film or an adhesive film. With such a pattern formation method of the present invention, the circuit pattern of the resist upper layer film can be transferred and formed on the workpiece with high precision.

[0025] In this case, the inorganic hard mask intermediate film is preferably formed by a CVD method or an ALD method.

[0026] In the pattern formation method of the present invention, for example, an inorganic hard mask intermediate film can be formed in this manner.

[0027] In the present invention, the circuit pattern is preferably formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination of these.

[0028] In the present invention, in forming the circuit pattern, it is preferable to develop the circuit pattern with an alkali developer or an organic solvent.

[0029] In the pattern forming method of the present invention, for example, such a circuit pattern forming means and developing means can be suitably used.

[0030] In addition, in the present invention, it is preferable to use, as the workpiece, a semiconductor device substrate, or a semiconductor device substrate having any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film formed thereon.

[0031] In this case, it is preferable to use a metal constituting the workpiece that contains silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0032] According to the pattern forming method of the present invention, a pattern can be formed by processing the above-mentioned workpiece. Effect of the Invention

[0033] As described above, the present invention can provide a composition for forming an organic film that has excellent film-forming properties (in-plane uniformity) and filling properties on a substrate (wafer), and also has excellent hump suppression properties during the EBR process.

[0034] Furthermore, the organic film forming method of the present invention can form an organic film that can suppress the formation of humps, making it possible to efficiently manufacture semiconductor elements and the like.

[0035] In addition, such an organic film-forming composition of the present invention has excellent film-forming properties and filling properties, and is excellent in suppressing humps that occur during the EBR process, and is therefore extremely useful as an organic film-forming material used in multilayer resist processes such as a two-layer resist process, a three-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask intermediate film, or a four-layer resist process using a silicon-containing resist intermediate film or an inorganic hard mask intermediate film and an organic antireflective film or an adhesion film, or as an organic film-forming material for manufacturing semiconductor devices. [Brief description of the drawings]

[0036] [Figure 1] FIG. 2 is an explanatory diagram of an example of a pattern forming method using a three-layer resist process of the present invention. [Diagram 2] 1 is an example of a graph showing the results of measuring the height of a hump using a contact profiler in Example 1 and Comparative Example 1. [Diagram 3] 13 is another example of a graph showing the results of measuring the height of a hump using a contact profiler in Comparative Example 1. [Figure 4] FIG. 2 is an explanatory diagram of a method for evaluating embedding characteristics in an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] As described above, there has been a demand for the development of a composition for forming an organic film capable of forming an organic film that has excellent film-forming properties (in-plane uniformity) and filling properties on a substrate (wafer) and that can suppress the formation of humps during the EBR process, and an organic film forming method and a pattern forming method using this composition.

[0038] Typically, when forming an organic film, a resin for forming the organic film and additives are dissolved in an organic solvent to form a composition, which is then applied to a substrate on which structures, wiring, etc. are formed using a coater and developer. The substrate is rotated to spread the composition, and the composition at the edges is removed in an EBR process. The organic film is then formed by baking.

[0039] If the fluidity of the above composition is insufficient, voids will occur when filling holes or trenches with very high aspect ratios, and it is thought that a hump will occur on the outer periphery of the organic film if the resin or additives used in forming the organic film have poor solubility in the remover used in the EBR process.

[0040] The inventors further conducted intensive research and discovered that by incorporating a polymer having a specific repeating unit into a composition for forming an organic film, a composition for forming an organic film having excellent film-forming properties, advanced filling properties, and excellent hump suppression properties during the EBR process can be obtained, and thus completed the present invention.

[0041] That is, the present invention provides a composition for forming an organic film, (A) a polymer having a repeating unit represented by the following general formula (1): (B) an organic film-forming resin, and (C) Solvent The organic film-forming composition is characterized by comprising: [ka] (In general formula (1), R1 is a divalent organic group containing an aliphatic moiety or an aromatic moiety having 2 to 30 carbon atoms, and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom, a cyano group, an amino group, or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.)

[0042] Incidentally, Patent Documents 4 and 5 and Non-Patent Document 1 disclose polymers or resins containing an ether structure in a repeating unit, but these documents do not describe or suggest a composition for forming an organic film containing (A) a polymer having a repeating unit represented by the above general formula (1), (B) a resin for forming an organic film, and (C) a solvent.

[0043] The present invention will be described in detail below, but the present invention is not limited thereto.

[0044] [Composition for organic film formation] The composition for forming an organic film of the present invention contains (A) a polymer having a repeating unit represented by the following general formula (1), (B) a resin for forming an organic film, and (C) a solvent. [ka] (In general formula (1), R1 is a divalent organic group containing an aliphatic moiety or an aromatic moiety having 2 to 30 carbon atoms, and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom, a cyano group, an amino group, or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.)

[0045] In the composition for forming an organic film of the present invention, each of the (A) polymer, the (B) resin for forming an organic film, and the (C) solvent may be used alone or in combination of two or more.

[0046] Here, in the present invention, the term "organic group" means a group containing at least one carbon atom and may further contain a hydrogen atom, and may also contain a nitrogen atom, an oxygen atom, a sulfur atom, a silicon atom, a halogen atom, etc.

[0047] Hereinafter, the essential components of the composition for forming an organic film of the present invention, that is, (A) the polymer, (B) the resin for forming an organic film, and (C) the solvent, will be described in detail.

[0048] [(A) Polymer] The polymer (A) used in the organic film-forming composition of the present invention has a repeating unit represented by the above general formula (1).

[0049] In the above general formula (1), R1 is a divalent organic group containing an aliphatic or aromatic moiety having 2 to 30 carbon atoms. In the polymer (A), R1 may be a single group or a mixture of multiple groups. Examples of R1 include the following.

[0050] [ka] (In the formula, * indicates a bond to an oxygen atom.)

[0051] In the above general formula (1), R2 is each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom (preferably a chlorine atom, a bromine atom, or an iodine atom), a cyano group, an amino group, or a nitro group. In the (A) polymer, R2 may be a single group or a mixture of multiple types.

[0052] In the above general formula (1), a is 0 or 1. That is, the repeating unit of the polymer (A) contains a benzene ring moiety or a naphthalene ring moiety. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5. Thus, regardless of the value of a, b is greater than 1. That is, the repeating unit of the polymer (A) contains fluorine.

[0053] In another aspect, the repeating unit represented by the above general formula (1) can also be said to contain a moiety represented by -O-R1-O- and a fluorine-containing benzene ring moiety or a fluorine-containing naphthalene ring moiety.

[0054] The composition for forming an organic film of the present invention, which contains the polymer (A) containing the repeating unit represented by the general formula (1) together with the resin for forming an organic film (B) and the solvent (C), can adjust the surface tension of the composition for forming an organic film and can increase the compatibility of the polymer (A) with the solvent. As a result, the composition for forming an organic film of the present invention can form an organic film having excellent in-plane uniformity and excellent embedding properties by spin coating. In addition, the composition for forming an organic film of the present invention can suppress the formation of humps during the EBR process.

[0055] Furthermore, the polymer (A) preferably contains at least one compound (polymer) represented by any one of the following general formulas (2) to (4). [ka] (In the formula, R1 and R2 are the same as above, R3 is a monovalent organic group having 1 to 30 carbon atoms, a is 0 or 1. When a is 0, b is 1 to 4, b1 is 1 to 5, c is 0 to 3, and c1 is 0 to 4. When a is 1, b is 1 to 6, b1 is 1 to 7, c is 0 to 5, and c1 is 0 to 6. n represents the average number of repeating units and is 3 to 2,000.)

[0056] R1 in the above general formulas (2) to (4) is a divalent organic group containing an aliphatic or aromatic moiety having 2 to 30 carbon atoms, which may be saturated or unsaturated and may have an ether bond. R1 may be a single group or a mixture of multiple groups, and examples of R1 include the following. Among these, those having a glyme chain are preferred from the viewpoint of surface tension control.

[0057] [ka] (In the formula, * indicates a bond to an oxygen atom.)

[0058] As described above, R2 in the above general formulas (2) to (4) is each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom (preferably a chlorine atom, a bromine atom or an iodine atom), a cyano group, an amino group or a nitro group.

[0059] In the above general formula (4), R3 is a monovalent organic group having 1 to 30 carbon atoms. Specifically, it is a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, a 1-propenyl group, an isopropenyl group, a butyl group, a s-butyl group, a t-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a dodecyl group, an icosanyl group, a norbornyl group, an adamantyl group, a phenyl group, a toluyl group, a xylyl group, a cyclohex ... Examples of the R3 include aryl, naphthyl, phenanthrenyl, anthracenyl, benzyl, fluorenyl, naphthylmethyl, norbornenyl, icosanyl, triacontyl, 2-furanyl, 2-tetrahydrofuranyl, phenyl, toluyl, xylyl, naphthyl, phenanthrenyl, anthracenyl, 2-furanyl, anisyl, acryloyl, methacryloyl, and acetyl groups. When R3 has an aromatic ring, the aromatic ring may have a substituent, and examples of the R3 include halogen groups such as fluorine, chlorine, bromine, and iodine, alkyloxy groups such as methoxy and ethoxy groups, alkynyloxy groups such as allyloxy groups, and alkenyloxy groups such as propargyloxy groups. The hydrogen atom on the methylene constituting these alkylene groups may be substituted with a fluorine atom.

[0060] By making the polymer (A) contain such a structure, the surface tension of the composition for forming an organic film can be more sufficiently adjusted, and the compatibility of the polymer (A) with the solvent (C) can be further increased. As a result, with the composition for forming an organic film of this preferred embodiment, an organic film with more excellent in-plane uniformity can be formed by spin coating. In addition, by appropriately adjusting the structures and terminal structures of multiple R1, it is possible to adjust the desired performance.

[0061] n represents the average number of repeating units and is 3 to 2,000, preferably 3 to 500, and more preferably 5 to 300.

[0062] The polymer (A) may have only a single repeating unit represented by the general formula (1) above, or may have a combination of two or more kinds of repeating units.

[0063] Specific examples of the repeating unit represented by the above general formula (1) include, but are not limited to, those shown below.

[0064] [ka]

[0065] Specific examples of the polymer (A) represented by the above general formula (2) include, but are not limited to, the following: Note that although n is omitted below, each of the following polymers contains the above n number of repeating units in parentheses.

[0066] [ka]

[0067] Specific examples of the polymer (A) represented by the above general formula (3) include, but are not limited to, the following: Note that although n is omitted below, each of the following polymers contains the above n number of repeating units in parentheses.

[0068] [ka]

[0069] Specific examples of the polymer (A) represented by the above general formula (4) include, but are not limited to, the following: Note that although n is omitted below, each of the following polymers contains the above n number of repeating units in parentheses.

[0070] [ka]

[0071] By selecting the structures of R1, R2, and R3, the properties of the polymer (A) can be adjusted as necessary. In particular, the polarity of the polymer (A) can be controlled to adjust the film-forming property and solvent solubility.

[0072] The weight average molecular weight of the (A) polymer is preferably 300 to 200,000, more preferably 300 to 50,000, and even more preferably 500 to 40,000. The average number n of repeating units is preferably 3 to 2,000, and even more preferably 3 to 500. If the weight average molecular weight of the (A) polymer is 300 or more, the decrease in the blending effect due to volatilization or the like can be sufficiently suppressed, and a sufficient blending effect can be obtained. If the weight average molecular weight of the (A) polymer is 200,000 or less, the flowability is not deteriorated, and an organic film-forming composition having excellent filling / flattening properties can be obtained. The weight average molecular weight of the (A) polymer can be determined as a polystyrene-equivalent weight average molecular weight (Mw) by gel permeation chromatography (GPC) using, for example, tetrahydrofuran as an eluent (solvent).

[0073] An example of a method for producing a polymer having a repeating unit represented by the above general formula (1) is a method obtained by an etherification reaction of hexafluorobenzene or octafluoronaphthalene shown below with a diol having R1 as a partial structure using a base catalyst. [ka] (In the formula, R1 is the same as above.)

[0074] Examples of the base catalyst for the etherification reaction described above include inorganic base compounds such as sodium hydrogen carbonate, 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, and one of these may be used alone or two or more may be used in combination. The amount of the catalyst used is preferably 0.1 to 20 mol, more preferably 0.2 to 10 mol, relative to the hydroxyl group that is the substituent of the raw material.

[0075] The solvent used in this case is not particularly limited as long as it is inert to the above reaction, but examples thereof 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, and one of these may be used alone or two or more may be mixed and used. These solvents can be used in the range of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials, and the reaction temperature is preferably from -50°C to the boiling point of the solvent, and more preferably from room temperature to 150°C. The reaction time is appropriately selected, for example, from 0.1 to 100 hours.

[0076] If necessary, the obtained polymer can be purified according to its properties by a conventional method such as separation, crystallization, vacuum concentration, dialysis, ultrafiltration, etc. Furthermore, if necessary, the metal content can be reduced by passing the polymer through a commercially available metal removal filter.

[0077] Examples of reaction methods include a method of charging hexafluorobenzene or octafluoronaphthalene, and a diol all at once in a solvent, a method of dropping hexafluorobenzene or octafluoronaphthalene, and a diol, each or a mixture of them, and dispersing or dissolving them, and a method of dropping one of hexafluorobenzene, octafluoronaphthalene, and a diol dispersed or dissolved in a solvent. In addition, when multiple types of diols are charged, they may be mixed and reacted in advance, or they may be reacted individually and sequentially. In the case of using a catalyst, there are a method of charging hexafluorobenzene or octafluoronaphthalene, and a diol all at once, and a method of dropping the catalyst after dispersing or dissolving it in advance. After the reaction is completed, the reaction mixture is diluted with an organic solvent to remove unreacted raw materials, catalysts, etc. present in the system, and then the mixture is washed with a separation solvent or crystallized with a poor solvent to obtain a powder. In addition, after diluting with an organic solvent, the mixture can be recovered as a solution by solvent replacement with a desired organic solvent. Furthermore, after recovery as a powder by crystallization or the like, it can also be dissolved in a desired organic solvent and recovered as a solution.

[0078] The organic solvent used for the liquid separation washing is not particularly limited as long as it can dissolve the target substance and separate into two layers even when mixed with water, but examples thereof 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-t-butyl ether, and ethylcyclopentyl methyl ether, chlorine-based solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene, and mixtures thereof. The washing water used in this case is usually what is called deionized water or ultrapure water. The number of washings may be one or more times, but since washing 10 or more times does not necessarily provide the effect of washing alone, it is preferably about 1 to 5 times.

[0079] In order to remove acidic components in the system during separation washing, washing may be performed with a basic aqueous solution. Specific examples of the base include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium.

[0080] Furthermore, in order to remove metal impurities or base components in the system during separation washing, washing may be performed with an acidic aqueous solution. Specific examples of the acid include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropolyacids, and organic acids such as oxalic acid, fumaric acid, maleic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0081] The above-mentioned separation washing with a basic aqueous solution and an acidic aqueous solution may be performed either alone or in combination. From the viewpoint of removing metal impurities, the separation washing is preferably performed in the order of a basic aqueous solution and an acidic aqueous solution.

[0082] After the above-mentioned separation washing with the basic aqueous solution or acidic aqueous solution, washing with neutral water may be performed successively. The number of washings may be one or more times, but is preferably about 1 to 5 times. As the neutral water, the above-mentioned deionized water or ultrapure water may be used. The number of washings may be one or more times, but if the number of washings is too few, the basic components and acidic components may not be removed. Even if washing is performed 10 times or more, the effect of washing alone may not be obtained, so it is preferably about 1 to 5 times.

[0083] Furthermore, the reaction product after the liquid separation operation can be recovered as a powder by concentrating the solvent to dryness or crystallizing it under reduced pressure or normal pressure, but it can also be left in a solution state of a moderate concentration in order to improve operability when preparing an organic film-forming composition. The concentration at this time is preferably 0.1 to 50 mass%, more preferably 0.5 to 30 mass%. At such a concentration, the viscosity is unlikely to increase, so operability is not impaired, and the amount of solvent is not excessive, so it is economical.

[0084] The solvent used in this case is not particularly limited as long as it can dissolve the reaction product. Specific examples include ketones such as cyclohexanone and methyl-2-amyl ketone; 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. One of these can be used alone, or two or more can be mixed and used.

[0085] The polymer represented by the general formula (2) or (3) can be easily produced, for example, by adjusting the ratio of the amounts charged of hexafluorobenzene or octafluoronaphthalene and the diol having R1 as a partial structure. Specifically, when the number of moles of hexafluorobenzene or octafluoronaphthalene charged is x and the number of moles of the diol having R1 as a partial structure charged is y, in the case of synthesizing the polymer represented by the general formula (2), the charging ratio of the diol having R1 as a partial structure to hexafluorobenzene or octafluoronaphthalene may be increased, that is, the charging ratio may be set such that x < y. In this case, by making the diol component excessive, unreacted alcohol can be left at the terminal. Similarly, in the case of synthesizing the polymer represented by the general formula (3), the charging ratio of hexafluorobenzene or octafluoronaphthalene to the diol having R1 as a partial structure may be increased, that is, the charging ratio may be set such that x > y. In this case, the terminal has a form in which hexafluorobenzene or octafluoronaphthalene is sealed.

[0086] [Production method of the polymer represented by the general formula (2): When the charging ratio is x < y] [Chemical formula] (In the formula, R1 and n are the same as described above.)

[0087] [Production method of the polymer represented by the general formula (3): When the charging ratio is x > y] [Chemical formula] (In the formula, R1 and n are the same as described above.)

[0088] Furthermore, in the case of synthesis of a compound represented by the above general formula (4), for example, a method of using a polymer represented by the above general formula (2) and further etherifying the terminals with an alcohol or carboxylic acid having R2 as a substituent, or a method of etherifying a diol having R1 as a partial structure and an alcohol or carboxylic acid having R3 as a substituent with hexafluorobenzene or octafluoronaphthalene all at once, is available. When charging all at once, the charge ratio must be strictly controlled, and industrially, a method of producing a polymer represented by the general formula (2) and then capping the terminals with an alcohol or carboxylic acid having R3 as a substituent is preferred.

[0089] [End-capping of the polymer represented by formula (2)] [ka] (In the formula, R1, R3, and n are the same as above.)

[0090] [Bulk input] [ka] (In the formula, R1, R3 and n are the same as above.)

[0091] The polymer represented by the general formula (2) and the polymer represented by the general formula (3) can be produced by the method described in the method for producing a polymer having a repeating unit represented by the above (1) simply by adjusting the ratio of the diol having R1 as a partial structure and hexafluorobenzene or octafluoronaphthalene to be charged in accordance with the structure to be obtained. The reaction method and the polymer recovery method can be performed by the method described in the method for producing a polymer having a repeating unit represented by the above general formula (1).

[0092] In addition, the method for producing the polymer represented by the general formula (4) can be carried out in a lump by simply simultaneously using an alcohol or carboxylic acid having R3 as a substituent in addition to a diol having R1 as a partial structure, and can be carried out according to the method for producing the polymer having a repeating unit represented by the general formula (1), the reaction method, and the method for recovering the polymer. In the case of terminal blocking of the polymer represented by the general formula (2), there is a method in which the polymer represented by the general formula (2) is once recovered, and then reacted with an alcohol or carboxylic acid having R3 as a substituent, similar to the method for producing the polymer having a repeating unit represented by the general formula (1), or a method in which the reaction with the diol having R1 as a partial structure during the reaction for producing the polymer represented by the general formula (2) is completed, and then the alcohol or carboxylic acid having R2 as a substituent used for terminal blocking is added and reacted in one pot. In either case, the reaction method can be carried out according to the method for producing the polymer having a repeating unit represented by the general formula (1), the reaction method, and the method for recovering the polymer, with only the substrate being changed.

[0093] [(B) Resin for organic film formation] The organic film-forming resin (B) used in the organic film-forming composition of the present invention is not particularly limited as long as it is a resin or compound that satisfies the film-forming properties and curing properties of spin coating. From the viewpoints of etching resistance, optical properties, heat resistance, etc., it is more preferable to use a resin or compound that contains an aromatic skeleton.

[0094] Examples of the aromatic skeleton include benzene, naphthalene, anthracene, pyrene, indene, fluorene, furan, pyrrole, thiophene, phosphole, pyrazole, oxazole, isoxazole, thiazole, pyridine, pyrazine, pyrimidine, pyridazine, triazine, carbazole, etc. Among these, benzene, naphthalene, fluorene, and carbazole are particularly preferable.

[0095] Examples of the resin for forming an organic film (B) used in the present invention include resins containing the following structures described in JP-A Nos. 2012-001687 and 2012-077295.

[0096] [ka] (In formula (1B), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. X represents a single bond or an alkylene group having 1 to 20 carbon atoms. m represents 0 or 1. n represents any natural number such that the molecular weight is 100,000 or less. The definitions of the symbols in the formula apply only to this formula.)

[0097] [ka] (In formula (2B), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. n represents any natural number such that the weight average molecular weight as calculated using polystyrene standards by gel permeation chromatography is 100,000 or less. The definitions of the symbols in the formula apply only to this formula.)

[0098] Further examples of the organic film-forming resin (B) used in the present invention include resins having the following structures described in JP-A Nos. 2004-264710, 2005-043471, 2005-250434, 2007-293294, and 2008-065303.

[0099] [ka] (In formula (3B) and formula (4B), R 1 and R 2 each independently represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms, or an aryl group; R 3 represents an alkyl group having 1 to 3 carbon atoms, a vinyl group, an allyl group, or an aryl group which may be substituted, n represents 0 or 1, and m represents 0, 1, or 2. The definitions of the symbols in the formula apply only to this formula.

[0100] [ka] (In formula (5B), R1 is a monovalent atom or group other than a hydrogen atom, and n is an integer of 0 to 4. However, when n is 2 to 4, multiple R1 may be the same or different. R2 and R3 are independently a monovalent atom or group. X is a divalent group. Note that the definitions of the symbols in the formula apply only to this formula.)

[0101] [ka] In formula (6B), R1 is a hydrogen atom or a methyl group. R2 is a single bond, a linear, branched or cyclic alkylene group having 1 to 20 carbon atoms, or an arylene group having 6 to 10 carbon atoms, and may have any of an ether, ester, lactone or amide. R 3 , R 4 are each a hydrogen atom or a glycidyl group. X represents a polymer of any one of a hydrocarbon having an indene skeleton, a cycloolefin having 3 to 10 carbon atoms, and maleimide, and may have any one of an ether, an ester, a lactone, and a carboxylic acid anhydride. R 5 and R 6 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 7 is any one of a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a hydroxyl group, and an alkoxycarbonyl group. p and q are each an integer of 1 to 4. r is an integer of 0 to 4. a, b and c are each within the ranges of 0.5≦a+b+c≦1, 0≦a≦0.8, 0≦b≦0.8, 0.1≦a+b≦0.8, and 0.1≦c≦0.8. The definitions of the symbols in the formula apply only to this formula.)

[0102] [ka] (In formula (7B), R1 represents a hydrogen atom or a monovalent organic group, and R2 and R3 each independently represent a monovalent atom or a monovalent organic group. The definitions of the symbols in the formula apply only to this formula.)

[0103] Specific examples of the organic film-forming resin (B) used in the present invention include resins containing the following structures described in JP-A Nos. 2004-205685, 2007-171895, and 2009-014816.

[0104] [ka] (In formula (8B) and formula (9B), R 1 ~R 8 are each independently a hydrogen atom, a hydroxyl group, a substitutable alkyl group having 1 to 6 carbon atoms, a substitutable alkoxy group having 1 to 6 carbon atoms, a substitutable alkoxycarboxyl group having 2 to 6 carbon atoms, a substitutable aryl group having 6 to 10 carbon atoms, a hydroxyalkyl group having 1 to 6 carbon atoms, an isocyanate group, or a glycidyl group. m and n are positive integers. The definitions of the symbols in the formula apply only to this formula.)

[0105] [ka] (In formula (10B), R 1 and R 6 R is independently a hydrogen atom or a methyl group. 2 , R 3 , and R 4 each independently represents a hydrogen atom, an alkyl group, an alkoxy group, a hydroxy group, an acetoxy group, or an alkoxycarbonyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms; R 5 is a condensed polycyclic hydrocarbon group having 13 to 30 carbon atoms, -OR 7 , -C(=O)-OR 7 , -OC(=O)-R 7 or -C(=O)-NR 8 -R 7 where m is 1 or 2, n is an integer from 0 to 4, and p is an integer from 0 to 6. 7 is an organic group having 7 to 30 carbon atoms, and R 8is a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Z is any one of a methylene group, -O-, -S-, or -NH-. a, b, c, d, and e are respectively in the ranges of 0 < a < 1.0, 0 ≤ b ≤ 0.8, 0 ≤ c ≤ 0.8, 0 ≤ d ≤ 0.8, 0 ≤ e ≤ 0.8, and 0 < b + c + d + e < 1.0. Note that the definitions of the symbols in the formula apply only within this formula.)

[0106] [Chemical formula] (In formula (11B), n represents 0 or 1. R 1 represents an optionally substituted methylene group, an optionally substituted alkylene group having 2 to 20 carbon atoms, or an optionally substituted arylene group having 6 to 20 carbon atoms. R 2 represents a hydrogen atom, an optionally substituted alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group having 6 to 20 carbon atoms. R 3 ~R 7 each independently represents a hydroxyl group, an optionally substituted alkyl group having 1 to 6 carbon atoms, an optionally substituted alkoxy group having 1 to 6 carbon atoms, an optionally substituted alkoxycarbonyl group having 2 to 10 carbon atoms, an optionally substituted aryl group having 6 to 14 carbon atoms, or an optionally substituted glycidyl ether group having 2 to 6 carbon atoms. R 9 represents a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, a linear, branched or cyclic alkyl ether group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. Note that the definitions of the symbols in the formula apply only within this formula.)

[0107] Examples of the resin represented by formula (11B) include the following resins.

[0108] [Chemical formula]

[0109] [Chemical formula]

[0110] Examples of the resin for forming an organic film (B) used in the present invention include resins containing the following structures described in JP-A Nos. 2007-199653, 2008-274250, and 2010-122656.

[0111] [ka] (In formula (12B), R 1 and R 2 are each independently the same or different hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 3 is a single bond, or an alkylene group having a linear, branched or cyclic structure and having 1 to 30 carbon atoms, which may have a bridged cyclic hydrocarbon group, a double bond, a hetero atom or an aromatic group having 6 to 30 carbon atoms; R 4 and R 5 are each independently a hydrogen atom or a glycidyl group, and n is an integer of 1 to 4. The definitions of the symbols in the formula apply only to this formula.

[0112] [ka] (In formula (13B), R 1 and R 2 are each independently the same or different hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms; R 3 is a single bond, or an alkylene group having a linear, branched or cyclic structure and having 1 to 30 carbon atoms, which may have a bridged cyclic hydrocarbon group, a double bond, a hetero atom or an aromatic group having 6 to 30 carbon atoms; R 4 and R 5 are each independently a hydrogen atom or a glycidyl group; R 6 is a single bond, or a linear or branched alkylene group having 1 to 10 carbon atoms. The definitions of the symbols in the formula apply only to this formula.)

[0113]

Chem.

[0114]

Chem.

[0115] Examples of the resin represented by formula (15B) include the following resins.

Chem.

[0116]

Chem.

[0117] [ka]

[0118] [ka]

[0119] Examples of the resin for forming an organic film (B) used in the present invention include resins containing the following structure described in JP-A-2012-214720.

[0120] [ka] (In formula (16B), the ring structures Ar1 and Ar2 each independently represent a benzene ring or a naphthalene ring. Each of x and z independently represents 0 or 1. The definitions of the symbols in the formula apply only to this formula.)

[0121] Examples of the resin for forming an organic film (B) used in the present invention include the resins described in JP-A-2014-29435.

[0122] [ka] (In formula (17B), A represents a structure having carbazole, B represents a structure having an aromatic ring, C represents a hydrogen atom, an alkyl group, or a structure having an aromatic ring, and B and C may form a ring together. The combined structure of A, B, and C has 1 to 4 carboxyl groups or salts thereof, or carboxylate groups. The definitions of the symbols in the formula apply only to this formula.)

[0123] Further, examples of the resin for forming an organic film (B) used in the present invention include a polymer described in WO 2012 / 077640, which contains a unit structure represented by the following formula (18B) and a unit structure represented by the following formula (19B), and in which the ratio of the unit structure represented by formula (18B) to the unit structure represented by formula (19B) is 3 to 97:97 to 3 in molar ratio.

[0124] [ka] In formula (18B), R1 and R2 each independently represent a hydrogen atom, a halogen atom, a nitro group, an amino group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond. R3 represents a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond. R4 represents a hydrogen atom, or an aryl group having 6 to 40 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or a heterocyclic group; R5 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or an aryl group having 6 to 40 carbon atoms, or a heterocyclic group; R4 and R5 may form a ring together; n1 and n2 each independently represent an integer of 1 to 3. The definitions of the symbols in the formula apply only to this formula.

[0125] [ka] In formula (19B), Ar represents an aromatic ring group having 6 to 20 carbon atoms, R6 represents a hydroxy group, R7 represents a hydrogen atom, a halogen atom, a nitro group, an amino group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, or a combination of these groups which may contain an ether bond, a ketone bond, or an ester bond, R8 represents a hydrogen atom, or a carbon atom which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group. R8 represents an aryl group having 6 to 40 carbon atoms, or a heterocyclic group, R9 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms which may be substituted with a halogen atom, a nitro group, an amino group, or a hydroxy group, or an aryl group having 6 to 40 carbon atoms, or a heterocyclic group, R8 and R9 may form a ring together. n6 represents an integer of 1 to p, and n7 represents an integer of p-n6, where p represents the maximum number of substituents that may be substituted on the aromatic ring group Ar. The definitions of the symbols in the formula apply only to this formula.

[0126] Examples of the resin for forming an organic film (B) used in the present invention include a polymer containing a unit structure represented by the following formula (20B) described in WO 2010 / 147155.

[0127] [ka] (In formula (20B), R1 and R2 are each independently selected from the group consisting of a hydrogen atom, a halogen group, a nitro group, an amino group, a hydroxy group, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a combination thereof, and the alkyl group, the alkenyl group, or the aryl group represents a group which may contain an ether bond, a ketone bond, or an ester bond; R3 is selected from the group consisting of a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, an aryl group having 6 to 40 carbon atoms, and a combination thereof, and the alkyl group, the alkenyl group, or the aryl group represents a group which may contain an ether bond, a ketone bond, or an ester bond; The aryl group represents a group which may contain an ether bond, a ketone bond or an ester bond, R4 represents an aryl group or a heterocyclic group having 6 to 40 carbon atoms which may be substituted with a halogen group, a nitro group, an amino group or a hydroxy group, R5 represents a hydrogen atom, or an alkyl group having 1 to 10 carbon atoms, an aryl group or a heterocyclic group having 6 to 40 carbon atoms which may be substituted with a halogen group, a nitro group, an amino group or a hydroxy group, R4 and R5 may form a ring together with the carbon atom to which they are bonded, and n1 and n2 are each independently an integer of 1 to 3. Note that the definitions of the symbols in the formula apply only to this formula.)

[0128] Examples of the resin for forming an organic film (B) used in the present invention include a novolak resin obtained by reacting one or more of phenols such as phenol, cresol, xylenol, catechol, resorcinol, hydroquinone, pyrogallol, hydroxyquinol, and phloroglucinol with one or more of aldehyde sources such as formaldehyde, paraformaldehyde, and trioxane using an acidic catalyst, and a resin containing a repeating unit structure represented by the following formula (21B) described in WO 2012 / 176767.

[0129] [ka] (In formula (21B), A represents a hydroxy-substituted phenylene group derived from polyhydroxybenzene, and B represents a monovalent fused aromatic hydrocarbon ring group in which 2 to 6 benzene rings are fused. The definitions of the symbols in the formula apply only to this formula.)

[0130] Examples of the organic film-forming resin (B) used in the present invention include novolak resins having a fluorene or tetrahydrospirobiindene structure described in JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, and JP-A-2007-316282, as well as resins containing a repeating unit structure represented by the following formula (22B-1) or (22B-2).

[0131] [ka] (In formula (22B-1) and formula (22B-2), R 1 , R 2 , R 6 , and R 7 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an allyl group, or a halogen atom; R 3 , R 4 , R 8 , and R 9 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched or cyclic alkenyl group having 2 to 6 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a glycidyl group; R 5 and R 14 are each independently a hydrogen atom, a linear, branched or cyclic alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms. n, m, p, and q are integers of 1 to 3. R 10 ~R 13are each independently a hydrogen atom, a halogen atom, a hydroxyl group, a linear, branched or cyclic alkyl group having 1 to 6 carbon atoms, or a linear, branched or cyclic alkoxy group having 1 to 6 carbon atoms. The definitions of the symbols in the formula apply only to this formula.)

[0132] The organic film-forming resin (B) used in the present invention may be a reaction product obtained by the method described in JP 2012-145897 A. More specifically, a polymer obtained by condensing one or more compounds represented by the following general formula (23B-1) and / or (23B-2) with one or more compounds represented by the following general formula (24B-1) and / or (24B-2) and / or their equivalents may be exemplified.

[0133] [ka] (In general formula (23B-1) and general formula (23B-2), R 1 ~R 8 are each independently a hydrogen atom, a halogen atom, a hydroxyl group, an isocyanato group, a glycidyloxy group, a carboxyl group, an amino group, an alkoxy group having 1 to 30 carbon atoms, an alkoxycarbonyl group having 1 to 30 carbon atoms, an alkanoyloxy group having 1 to 30 carbon atoms, or an optionally substituted saturated or unsaturated organic group having 1 to 30 carbon atoms. 1 ~R 4 or R 5 ~R 8 Two substituents arbitrarily selected from the following may be bonded to form a cyclic substituent. The definitions of the symbols in the formula apply only to this formula.)

[0134] [ka] (In general formula (24B-1) and general formula (24B-2), Q is an organic group having 1 to 30 carbon atoms which may be substituted, and further, two Qs arbitrarily selected in the molecule may be bonded to form a cyclic substituent. n1 to n6 are the number of each substituent, and n1 to n6 are each independently 0, 1 or 2, and in formula (24B-1), hydroxybenzaldehyde is excluded. In addition, in formula (24B-2), the relationships of 0≦n3+n5≦3, 0≦n4+n6≦4, and 1≦n3+n4≦4 are satisfied. The definitions of the symbols in the formulas apply only to this formula.)

[0135] Further, examples include polymers obtained by condensing one or more compounds represented by the above general formula (23B-1) and / or general formula (23B-2), one or more compounds represented by the above general formula (24B-1) and / or general formula (24B-2) and / or their equivalents, and one or more compounds represented by the following general formula (25B) and / or their equivalents.

[0136] [ka] (In formula (25B), Y is a hydrogen atom or a monovalent organic group having 30 or less carbon atoms which may have a substituent, and the compound represented by formula (25B) is different from the compound represented by general formula (24B-1) and the compound represented by general formula (24B-2). Note that the definitions of the symbols in the formula apply only to this formula.)

[0137] Examples of the resin for forming an organic film (B) used in the present invention include compounds having the following structure described in JP-A-2017-119671.

[0138] [ka] (In formula (26B-1), R is a single bond or an organic group having 1 to 50 carbon atoms, X is a group represented by the following general formula (26B-2), and m1 is an integer satisfying 2≦m1≦10. The definitions of the symbols in the formula apply only to this formula.)

[0139] [ka] (In the formula, X 2 is a divalent organic group having 1 to 10 carbon atoms, n1 is 0 or 1, n2 is 1 or 2, and X 3 is a group represented by the following general formula (26B-3), and n5 is 0, 1 or 2. The definitions of the symbols in the formula apply only to this formula.

[0140] [ka] (In the formula, R 10 is a hydrogen atom or a saturated or unsaturated hydrocarbon group having 1 to 10 carbon atoms, and the hydrogen atom on the benzene ring in the formula may be substituted with a methyl group or a methoxy group. The definitions of the symbols in the formula apply only to this formula.

[0141] Examples of compounds containing the above structure include the following compounds. [ka]

[0142] Examples of the resin for forming an organic film (B) used in the present invention include a polymer having a repeating unit represented by the following general formula (27B-1) described in JP-A-2019-044022.

[0143] [ka] In formula (27B-1), AR1 and AR2 each independently represent a benzene ring or a naphthalene ring which may have a substituent; R 1 and R 2 are each independently a hydrogen atom or an organic group having 1 to 30 carbon atoms, R 1 and R 2 When is an organic group, R 1 and R 2may form a cyclic organic group by bonding intramolecularly. n is 0 or 1, and when n=0, AR1 and AR2 do not form a bridged structure between the aromatic rings of AR1 and AR2 via Z, and when n=1, AR1 and AR2 form a bridged structure between the aromatic rings of AR1 and AR2 via Z, and Z is either a single bond or the following formula (27B-2). Y is a group represented by the following formula (27B-3). Note that the definitions of the symbols in the formula apply only to this formula.)

[0144] [ka]

[0145] [ka] (In the formula, R 3 is a single bond or a divalent organic group having 1 to 20 carbon atoms, and R 4 is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms, and the dashed line indicates a bond. The definitions of the symbols in the formula apply only to this formula.)

[0146] Examples of the polymer having a repeating unit represented by the above general formula (27B-1) include the following polymers.

[0147] [ka]

[0148] [ka]

[0149] The (B) organic film-forming resin may be synthesized by a known method, or a commercially available product may be used.

[0150] The amount of the (B) organic film-forming resin is not particularly limited as long as the film-forming properties of the organic film-forming composition are satisfied, but the content of the (B) organic film-forming resin is preferably 10 to 40 parts by mass, more preferably 10 to 30 parts by mass, and even more preferably 10 to 25 parts by mass, based on 100 parts by mass of the organic film-forming composition. For example, when filling holes or trenches with a very high aspect ratio of a 3D NAND memory architecture with an organic film-forming composition, it is necessary to increase the amount of the organic film-forming resin, but on the other hand, such an organic film-forming composition has a high viscosity, and the in-plane uniformity and filling properties after spin coating are deteriorated. Even with the above-mentioned (B) organic film-forming resin blending ratio, the organic film-forming composition of the present invention can be suitably applied because it is possible to form an organic film with excellent in-plane uniformity and filling properties.

[0151] The content of the polymer (A) is preferably 0.01 to 5 parts by mass relative to 100 parts by mass of the resin (B) for forming an organic film. When the composition for forming an organic film contains the polymer in such a content, an organic film having better in-plane uniformity can be formed.

[0152] [(C) Solvent] The (C) solvent that can be used in the composition for forming an organic film of the present invention is not particularly limited as long as it can dissolve the (B) resin for forming an organic film and the (A) polymer, and it is preferable that the solvent can also dissolve the acid generator, crosslinking agent, surfactant, etc. described below. Specific examples of the ketones include 2-heptanone, cyclopentanone, and cyclohexanone; 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, γ-butyrolactone, and propylene glycol mono tert-butyl ether acetate. These may be used alone or in combination of two or more, but are not limited thereto.

[0153] Among these, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, γ-butyrolactone, and mixtures of two or more of these are preferably used.

[0154] The content of the (C) solvent is preferably 200 to 10,000 parts by mass, and more preferably 300 to 5,000 parts by mass, relative to 100 parts by mass of the (B) organic film-forming resin. By setting the content within such a range, the concentration can be adjusted according to the desired film thickness.

[0155] [Other ingredients] Moreover, an acid generator and a crosslinking agent for further accelerating the crosslinking reaction can be further added as optional components to the organic film-forming composition of the present invention.

[0156] The acid generator may be one that generates an acid by thermal decomposition or one that generates an acid by light irradiation, and either one may be added. Specific examples of the acid generator include those described in paragraphs

[0061] to

[0085] of JP-A-2007-199653. The acid generators may be used alone or in combination of two or more. When an acid generator is added, the amount of the acid generator is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 100 parts by mass of (B) the resin for forming an organic film. Such an amount promotes the crosslinking reaction and enables the formation of a dense film.

[0157] Specific examples of the crosslinking agent include those described in paragraphs

[0055] to

[0060] of JP 2007-199653 A. The above crosslinking agents can be used alone or in combination of two or more. The amount of the crosslinking agent added is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of (B) the resin for forming an organic film. Such an amount can enhance the curability and further suppress intermixing with the upper layer film.

[0158] In addition, a surfactant may be added as an optional component to the organic film-forming composition of the present invention in order to further improve the in-plane uniformity in spin coating. Specific examples of the surfactant include those described in paragraphs

[0142] to

[0147] of JP 2009-269953 A. The above surfactants may be used alone or in combination of two or more. When a surfactant is added, the amount of the surfactant is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the organic film-forming composition. With such an amount, an organic film with excellent in-plane uniformity can be formed.

[0159] Furthermore, a basic compound for improving storage stability can be added as an optional component to the organic film-forming composition of the present invention. The basic compound plays the role of a quencher for the acid to prevent a small amount of acid generated from the acid generator from proceeding with the crosslinking reaction. Specific examples of such basic compounds include those described in paragraphs

[0086] to

[0090] of JP-A-2007-199653. The above basic compounds can be used alone or in combination of two or more. When the acid generator is added, the amount of the acid generator is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, based on 100 parts by mass of the (B) organic film-forming resin. Such an amount makes it possible to improve the storage stability of the organic film-forming composition.

[0160] As described above, the organic film-forming composition of the present invention is excellent in film-forming properties (in-plane uniformity) and filling properties on the substrate, and is excellent in hump suppression during the EBR process. Therefore, the organic film-forming composition of the present invention is extremely useful as a resist underlayer film material (organic film material) for multilayer resist processes such as a two-layer resist process, a three-layer resist process using a silicon-containing resist intermediate film or a silicon-containing inorganic hard mask intermediate film, and a four-layer resist process using a silicon-containing resist intermediate film or a silicon-containing inorganic hard mask intermediate film and an organic anti-reflective film or adhesive film.

[0161] [Organic film formation method] The present invention provides a method for forming an organic film used in the manufacturing process of a semiconductor device, which comprises spin-coating the above-mentioned composition for forming an organic film of the present invention on a substrate to be processed to obtain a coating film, and then heat-treating the coating film at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to harden the coating film, thereby forming an organic film.

[0162] In this method for forming an organic film, the composition for forming an organic film of the present invention is first spin-coated onto a substrate to be processed. By using the spin-coating method, good filling properties can be obtained.

[0163] Then, the edge of the coating film can be removed in the EBR process. As described above, the organic film-forming composition of the present invention is an organic film-forming composition that is excellent in suppressing humps during the EBR process. Therefore, in the organic film-forming method of the present invention, even if the EBR process is performed, the occurrence of humps can be suppressed.

[0164] Next, the coating is baked (heat-treated) to promote the crosslinking reaction. This baking process can evaporate the solvent in the composition, so that mixing can be prevented even when a resist top layer or a silicon-containing resist intermediate layer is formed on the organic film.

[0165] Baking is performed at a temperature of 100° C. to 600° C. for 10 to 600 seconds, preferably at a temperature of 200° C. to 500° C. for 10 to 300 seconds. Considering the effect on device damage and wafer deformation, the upper limit of the heating temperature in the lithography wafer process is 600° C. or less, preferably 500° C. or less. By carrying out heat treatment under such conditions, the crosslinking reaction is promoted, and an organic film that does not mix with the film formed on the upper layer can be formed.

[0166] [Pattern formation method] A pattern forming method using the composition for forming an organic film of the present invention will be described below.

[0167] [Three-layer resist process using silicon-containing resist intermediate film] The present invention provides a pattern forming method, comprising the steps of: An organic film is formed on a workpiece using the composition for forming an organic film of the present invention described above, forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming a resist upper layer film on the silicon-containing resist intermediate film using a resist upper layer film material comprising 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, a pattern is transferred to the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0168] As the workpiece, for example, it is preferable to use a semiconductor device substrate, or the semiconductor device substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film is formed. More specifically, although not limited to, a substrate such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, or the like, or a substrate on which the above-mentioned metal film or the like is formed as a workpiece layer, may be used.

[0169] As the processed layer, for example, various low-k films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, and their stopper films are used, and can be formed to a thickness of usually 50 to 10,000 nm, particularly 100 to 5,000 nm. When forming the processed layer, the substrate and the processed layer are made of different materials.

[0170] It is preferable to use a metal constituting the workpiece that contains silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0171] When forming an organic film on a workpiece using the organic film-forming composition of the present invention, the above-mentioned organic film-forming method of the present invention may be applied, although there is no limitation thereto.

[0172] Next, a resist intermediate film (silicon-containing resist intermediate film) is formed on the organic film using a resist intermediate film material containing silicon atoms. As the resist intermediate film material containing silicon atoms, a polysiloxane-based intermediate film material is preferable. By imparting an anti-reflection effect to the silicon-containing resist intermediate film, reflection can be suppressed. In particular, for 193 nm exposure, if a material containing many aromatic groups and having high etching selectivity with the substrate is used as the organic film forming composition, the k value becomes high and the substrate reflection becomes high, but by imparting absorption to an appropriate k value as the silicon-containing resist intermediate film, it becomes possible to suppress reflection, and the substrate reflection can be reduced to 0.5% or less. As the silicon-containing resist intermediate film having an anti-reflection effect, anthracene is preferably used for 248 nm or 157 nm exposure, and polysiloxane having a pendant structure with a light-absorbing group having a phenyl group or a silicon-silicon bond for 193 nm exposure, which is crosslinked by acid or heat.

[0173] Next, a resist upper layer film is formed on the silicon-containing resist intermediate film using a resist upper layer film material consisting of a photoresist composition. The resist upper layer film material may be either positive or negative, and the same as a commonly used photoresist composition can be used. After spin-coating the resist upper layer film material, it is preferable to perform pre-baking at 60 to 180°C for 10 to 300 seconds. Thereafter, exposure is performed according to a conventional method, and further post-exposure baking (PEB) and development are performed to obtain a resist upper layer film pattern. The thickness of the resist upper layer film is not particularly limited, but is preferably 30 to 500 nm, and particularly preferably 50 to 400 nm.

[0174] Next, a circuit pattern (resist upper layer film pattern) is formed on the resist upper layer film. In forming the circuit pattern, it is preferable to form the circuit pattern by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination of these.

[0175] Examples of the exposure light include high-energy rays with a wavelength of 300 nm or less, specifically far ultraviolet rays, KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F2 laser light (157 nm), Kr2 laser light (146 nm), Ar2 laser light (126 nm), soft X-rays (EUV) of 3 to 20 nm, electron beams (EB), ion beams, and X-rays.

[0176] In forming the circuit pattern, it is preferable to develop the circuit pattern using an alkali developer or an organic solvent.

[0177] Next, the resist top layer film on which the circuit pattern is formed is used as a mask to transfer the pattern to the silicon-containing resist intermediate film by etching. The etching of the silicon-containing resist intermediate film using the resist top layer film pattern as a mask is preferably performed using a fluorocarbon gas. This allows the pattern (silicon-containing resist intermediate film pattern) to be transferred to the silicon-containing resist intermediate film.

[0178] Next, the pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film (silicon-containing resist intermediate film pattern) as a mask. Since the silicon-containing resist intermediate film exhibits resistance to etching by oxygen gas or hydrogen gas, it is preferable to use an etching gas mainly composed of oxygen gas or hydrogen gas to etch the organic film using the silicon-containing resist intermediate film pattern as a mask. This allows the pattern (organic film pattern) to be transferred to the organic film.

[0179] Next, the pattern is transferred (formed) onto the workpiece by etching using the organic film (organic film pattern) with the transferred pattern as a mask. The next etching of the workpiece (layer to be processed) can be performed by a standard method. For example, if the workpiece is SiO2, SiN, or a silica-based low dielectric constant insulating film, etching is performed mainly with fluorocarbon gas, and if it is p-Si, Al, or W, etching is performed mainly with chlorine- or bromine-based gas. If the substrate is processed by etching with fluorocarbon gas, the organic film pattern is peeled off at the same time as the substrate is processed. On the other hand, if the substrate is processed by etching with chlorine- or bromine-based gas, a separate dry etching stripping with fluorocarbon gas must be performed after the substrate is processed in order to strip the organic film pattern.

[0180] An organic film obtained by using the organic film-forming composition of the present invention can have excellent etching resistance when etching the workpiece as described above.

[0181] [Four-layer resist process using silicon-containing resist intermediate film and organic anti-reflective or adhesive film] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming an organic anti-reflective film or an adhesion film on the silicon-containing resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising 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, a pattern is transferred to the organic anti-reflective film or the adhesion film and the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0182] This method can be carried out in the same manner as the three-layer resist process using the silicon-containing resist intermediate film described above, except that an organic antireflective coating (BARC) or an adhesion film is formed between the silicon-containing resist intermediate film and the resist top layer film.

[0183] The organic anti-reflective film and the adhesion film can be formed by spin coating using known organic anti-reflective film materials.

[0184] [Three-layer resist process using inorganic hard mask intermediate film] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film of the present invention; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming a resist upper layer film on the inorganic hard mask intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film having a circuit pattern formed thereon is used as a mask to transfer the pattern to the inorganic hard mask intermediate film by etching; The pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; Furthermore, there is provided a pattern forming method, characterized in that a pattern is formed on the workpiece by etching using the organic film onto which the pattern has been transferred as a mask.

[0185] This method can be carried out in the same manner as the three-layer resist process using the silicon-containing resist intermediate film described above, except that an inorganic hard mask intermediate film is formed on the organic film instead of the silicon-containing resist intermediate film.

[0186] The inorganic hard mask intermediate film selected from silicon oxide film, silicon nitride film, and silicon oxynitride film (SiON film) can be formed by, for example, CVD method or ALD method. Examples of the method for forming the silicon nitride film are described in JP 2002-334869 A and WO 2004 / 066377 A. The thickness of the inorganic hard mask intermediate film is preferably 5 to 200 nm, more preferably 10 to 100 nm. As the inorganic hard mask intermediate film, a SiON film, which has a high effect as an anti-reflection film, is most preferably used.

[0187] [4-layer resist process using inorganic hard mask intermediate film and organic anti-reflective or adhesive film] The present invention also provides a pattern forming method, comprising the steps of: forming an organic film on a workpiece using the composition for forming an organic film described above; forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film on which the circuit pattern is formed is used as a mask to transfer the pattern to the organic anti-reflective film or the adhesion film and the inorganic hard mask intermediate film by etching; the pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; Furthermore, the present invention provides a pattern forming method in which the pattern is transferred to the workpiece by etching using the organic film to which the pattern has been transferred as a mask.

[0188] This method can be performed in the same manner as the three-layer resist process using the inorganic hard mask intermediate film described above, except that an organic antireflective coating (BARC) or an adhesion film is formed between the inorganic hard mask intermediate film and the resist top layer film.

[0189] In particular, when a SiON film is used as the inorganic hard mask intermediate film, the two-layer anti-reflection film of the SiON film and the BARC makes it possible to suppress reflections even in immersion lithography with a high NA exceeding 1.0. Another advantage of forming the BARC is that it has the effect of reducing the tailing of the resist top layer film pattern directly above the SiON film.

[0190] Here, an example of a pattern forming method by the three-layer resist process of the present invention is shown in Figures 1(A) to (F). In the case of the three-layer resist process, as shown in Figure 1(A), an organic film 3 is formed on a workpiece layer (workpiece) 2 formed on a substrate 1 using the organic film-forming composition of the present invention, then a silicon-containing resist intermediate film 4 is formed on the organic film 3, and a resist upper layer film 5 is formed thereon. Next, as shown in Figure 1(B), the exposed portion 6 of the resist upper layer film 5 is exposed, and then PEB (post exposure bake) is performed. Next, as shown in Figure 1(C), development is performed to form a resist upper layer film pattern 5a. Next, as shown in Figure 1(D), the silicon-containing resist intermediate film 4 is dry-etched using a fluorocarbon gas with the resist upper layer film pattern 5a as a mask to form a silicon-containing resist intermediate film pattern 4a. Next, the resist upper layer film pattern 5a is removed, and then, as shown in Fig. 1(E), the organic film 3 is oxygen plasma etched using the silicon-containing resist intermediate film pattern 4a as a mask to form an organic film pattern 3a. Furthermore, as shown in Fig. 1(F), the silicon-containing resist intermediate film pattern 4a is removed, and then, as shown in Fig. 1(F), the processed layer 2 is etched using the organic film pattern 3a as a mask to form a pattern 2a.

[0191] In the pattern formation method of this example, humps are suppressed during the formation of the organic film 3, making it possible to reduce defects caused by the humps in the organic film during the dry etching processing of Figures 1(D), (E), and (F).

[0192] When an inorganic hard mask intermediate film is formed, the silicon-containing resist intermediate film 4 may be changed to an inorganic hard mask intermediate film, and when a BARC or an adhesion film is formed, the BARC or adhesion film may be formed between the silicon-containing resist intermediate film 4 and the resist upper layer film 5. The etching of the BARC or adhesion film may be performed consecutively prior to the etching of the silicon-containing resist intermediate film 4, or the etching of the silicon-containing resist intermediate film 4 may be performed by changing the etching device after etching only the BARC or adhesion film.

[0193] As described above, the pattern formation method of the present invention makes it possible to form a fine pattern on a workpiece with high precision by a multilayer resist process, and also to reduce defects resulting from humps in the organic film by suppressing the formation of humps in the organic film. EXAMPLES

[0194] The present invention will be described in more detail below with reference to synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited thereto. Specifically, the molecular weight was measured by the following method. The weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene were determined by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent (solvent), and the polydispersity (Mw / Mn) was determined.

[0195] [Synthesis of polymers (A1) to (A8)] The polymers (A1) to (A8) used in the preparation of the organic film-forming composition (UDL) were synthesized using hexafluorobenzene or octafluoronaphthalene, an alcohol, and any one of the following compounds (a1) to (a11) as a carboxylic acid component.

[0196] [ka]

[0197] [Synthesis Example 1] Synthesis of polymer (A1) [ka]

[0198] Under a nitrogen atmosphere, 4.96 g of compound (a1) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, 9.30 g of hexafluorobenzene was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 24 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK (methyl isobutyl ketone) was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous nitric acid solution and five times with 50 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50g of THF was added again to make a homogeneous solution, 200g of hexane was added to precipitate a mochi-like precipitate, and the mixture was left to stand, after which the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A1) was obtained as a PGMEA solution with a polymer concentration of 30wt%.

[0199] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A1) were determined by GPC, and the results were as follows. (A1): Mw = 3,300, Mw / Mn = 3.32

[0200] [Synthesis Example 2] Synthesis of polymer (A2) [ka] Under a nitrogen atmosphere, 5.32 g of compound (a2) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, 9.30 g of hexafluorobenzene was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 16 hours, after which 1.08 g of compound (a3) ​​was dropped and the reaction was carried out for another 8 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed once with 50 g of 3.0% aqueous sodium hydrogen carbonate solution, three times with 50 g of 3.0% aqueous nitric acid solution, and five times with 100 g of pure water, in that order, and the organic layer was dried under reduced pressure. 50g of THF was added to the residue, and 200g of hexane was added dropwise while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50g of THF was added again to make a homogenous solution, and 200g of hexane was added to precipitate a mochi-like precipitate. After standing, the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A2) was obtained as a PGMEA solution with a polymer concentration of 30wt%.

[0201] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A2) were determined by GPC, and the results were as follows. (A2): Mw = 5,200, Mw / Mn = 3.76

[0202] [Synthesis Example 3] Synthesis of polymer (A3) [ka]

[0203] Under a nitrogen atmosphere, 11.79 g of compound (a4) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, 9.30 g of hexafluorobenzene was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 24 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous nitric acid solution and five times with 50 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50g of THF was added again to make a homogeneous solution, 200g of hexane was added to precipitate a mochi-like precipitate, and the mixture was left to stand, after which the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A3) was obtained as a PGMEA solution with a polymer concentration of 30wt%.

[0204] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A3) were determined by GPC, and the results were as follows. (A3): Mw = 11,100, Mw / Mn = 3.81

[0205] [Synthesis Example 4] Synthesis of polymer (A4) [ka]

[0206] Under a nitrogen atmosphere, 19.27 g of compound (a5) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, 9.30 g of hexafluorobenzene was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 24 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous nitric acid solution and five times with 50 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50g of THF was added again to make a homogeneous solution, 200g of hexane was added to precipitate a mochi-like precipitate, and the mixture was left to stand, after which the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A4) was obtained as a PGMEA solution with a polymer concentration of 30wt%.

[0207] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A4) were determined by GPC, and the results were as follows. (A4): Mw=4,500, Mw / Mn=2.29

[0208] [Synthesis Example 5] Synthesis of polymer (A5) [ka] Under a nitrogen atmosphere, 4.78 g of compound (a6) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, 9.30 g of hexafluorobenzene was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 16 hours, after which 7.08 g of compound (a7) was dropped and the reaction was carried out for another 8 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous nitric acid solution and five times with 50 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50 g of THF was added again to make a homogeneous solution, and 200 g of hexane was added to precipitate a mochi-like precipitate. After standing, the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A5) was obtained as a PGMEA solution with a polymer concentration of 30 wt%.

[0209] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A5) were determined by GPC, and the results were as follows. (A5): Mw=7,700, Mw / Mn=2.94

[0210] [Synthesis Example 6] Synthesis of polymer (A6) [ka]

[0211] Under a nitrogen atmosphere, 8.26 g of compound (a8) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, a mixed solution of 13.60 g of octafluoronaphthalene and 10.0 g of THF was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 24 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous sodium hydroxide solution, three times with 50 g of 3.0% aqueous nitric acid solution, and five times with 100 g of pure water, in that order, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50 g of THF was added again to make a homogeneous solution, and 200 g of hexane was added to precipitate a mochi-like precipitate. After standing, the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A6) was obtained as a PGMEA solution with a polymer concentration of 30 wt%.

[0212] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A6) were determined by GPC, and the results were as follows. (A6): Mw=6,300, Mw / Mn=3.19

[0213] [Synthesis Example 7] Synthesis of polymer (A7) [ka]

[0214] Under a nitrogen atmosphere, 2.79 g of compound (a9) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, a mixed solution of 13.60 g of octafluoronaphthalene and 10.0 g of THF was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 24 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed twice with 50 g of 3.0% aqueous nitric acid solution and five times with 50 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant liquid was decanted. 50g of THF was added again to make a homogeneous solution, 200g of hexane was added to precipitate a mochi-like precipitate, and the mixture was left to stand, after which the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A7) was obtained as a PGMEA solution with a polymer concentration of 30wt%.

[0215] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A7) were determined by GPC, and the results were as follows. (A7): Mw=12,800, Mw / Mn=3.31

[0216] [Synthesis Example 8] Synthesis of polymer (A8) [ka]

[0217] Under a nitrogen atmosphere, 6.22 g of compound (a10) and 50.0 g of THF (tetrahydrofuran) were stirred in an ice bath to obtain a homogeneous solution. Then, 2.88 g of sodium hydride was added to the homogeneous solution and stirred for 1 hour. Then, a mixed solution of 13.60 g of octafluoronaphthalene and 10.0 g of THF was dropped into the mixture over 20 minutes, and the reaction was carried out at room temperature for 16 hours, after which 1.80 g of compound (a11) was dropped and the reaction was carried out for another 8 hours. After the reaction, 50 g of pure water was dropped into the reaction product to quench the reaction. Next, 100 ml of MIBK was added to the reaction product to perform layer separation. Next, the separated lower layer was removed. The remaining organic layer was washed three times with 50 g of 2.0% aqueous nitric acid solution and five times with 100 g of pure water, and the organic layer was dried under reduced pressure. 50 g of THF was added to the residue, and 200 g of hexane was dropped while stirring to precipitate a mochi-like precipitate. After standing for a while, the clear supernatant was decanted. 50 g of THF was added again to make a homogeneous solution, and 200 g of hexane was added to precipitate a mochi-like precipitate. After standing, the supernatant was decanted. PGMEA (propylene glycol monomethyl ether acetate) was added to the residue, and the mixture was distilled under reduced pressure and the concentration was adjusted. Thus, polymer (A8) was obtained as a PGMEA solution with a polymer concentration of 30 wt%.

[0218] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the polymer (A8) were determined by GPC, and the results were as follows. (A8): Mw=14,300, Mw / Mn=4.04

[0219] [Synthesis of Comparative Polymers (R1) to (R5)] For the synthesis of the comparative polymers (R1) to (R5) used in the preparation of the comparative organic film-forming composition (comparative UDL), any one of the following monomers (r1) to (r6) was used.

[0220] [ka]

[0221] [Comparative Synthesis Example 1] Synthesis of Comparative Polymer (R1) [ka] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. A mixture of 3.44 g (0.011 mol) of monomer (r1), 7.46 g (0.034 mol) of monomer (r3), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA was added dropwise to the mixture for 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R1) was obtained.

[0222] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the comparative polymer (R1) were determined by GPC, and the results were as follows. (R1): Mw = 9,500, Mw / Mn = 1.20

[0223] [Comparative Synthesis Example 2] Synthesis of Comparative Polymer (R2) [ka]

[0224] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. A mixture of 1.43 g (0.005 mol) of monomer (r1), 5.76 g (0.041 mol) of monomer (r4), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA was added dropwise to the mixture for 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R2) was obtained.

[0225] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the comparative polymer (R2) were determined by GPC, and the results were as follows. (R2): Mw = 5,800, Mw / Mn = 1.42

[0226] [Comparative Synthesis Example 3] Synthesis of Comparative Polymer (R3) [ka]

[0227] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. A mixture of 7.00 g (0.032 mol) of monomer (r2), 1.92 g (0.014 mol) of monomer (r4), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA was added dropwise to the mixture for 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R3) was obtained.

[0228] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the comparative polymer (R3) were determined by GPC, and the results were as follows. (R3): Mw = 6,200, Mw / Mn = 1.33

[0229] [Comparative Synthesis Example 4] Synthesis of Comparative Polymer (R4) [ka]

[0230] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. A mixture of 5.00 g (0.023 mol) of monomer (r2), 3.20 g (0.023 mol) of monomer (r5), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA was added dropwise to the mixture for 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R4) was obtained.

[0231] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the comparative polymer (R4) were determined by GPC, and the results were as follows. (R4): Mw = 8,300, Mw / Mn = 1.33

[0232] [Comparative Synthesis Example 5] Synthesis of Comparative Polymer (R5) [ka]

[0233] Under a nitrogen atmosphere, 6.0 g of propylene glycol monomethyl ether acetate (PGMEA) was heated and stirred at 80°C. A mixture of 2.00 g (0.009 mol) of monomer (r2), 5.41 g (0.036 mol) of monomer (r6), 0.473 g of dimethyl 2,2-azobis(2-methylpropionate), and 34 g of PGMEA was added dropwise to the mixture for 4 hours. After further heating and stirring for 16 hours, the mixture was cooled to room temperature. Thus, a PGMEA solution of the target comparative polymer (R5) was obtained.

[0234] The weight average molecular weight (Mw) and dispersity (Mw / Mn) of the comparative polymer (R5) were determined by GPC, and the results were as follows. (R5): Mw = 3,800, Mw / Mn = 1.44

[0235] [Organic film forming resin] B1: Resin represented by the following formula (B1) B2: Resin represented by the following formula (B2) B3: A compound represented by the following formula (B3): B4: A compound represented by the following formula (B4): B5: Resin represented by the following formula (B5): B6: Resin represented by the following formula (B6)

[0236] [ka]

[0237] [solvent] (C1): Propylene glycol monomethyl ether acetate (C2): Propylene glycol monoethyl ether

[0238] [Preparation of organic film-forming compositions (UDL-1 to 59, Comparative UDL-1 to 11)] Any of the above polymers (A1) to (A8), any of the comparative polymers (R1) to (R5), or any of the organic film-forming resins (B1) to (B6) were dissolved in a solvent (C1) or a mixed solvent of the solvent (C1) and the solvent (C2) in the ratios shown in Tables 1 to 3, and the resulting mixture was filtered through a 0.1 μm fluororesin filter to prepare compositions for forming organic films (resist underlayer film materials: UDL-1 to 59, comparative UDL-1 to 11).

[0239] [Table 1]

[0240] [Table 2]

[0241] [Table 3]

[0242] [Preparation of silicon wafers with organic films formed using compositions for forming organic films (UDL-1 to 59, Comparative UDL-1 to 11)] Using a coater / developer "CLEAN TRACK LITHIUS Pro AP" manufactured by Tokyo Electron Ltd., 2 ml of each of the compositions for forming organic films (UDL-1 to 59, comparative UDL-1 to 11) prepared above was discharged onto the center of a silicon wafer, and after baking, the wafer was rotated at a rotation speed that gave the average film thickness shown in Tables 4 to 6, and spread to obtain a coating film. While rotating the silicon wafer at a speed of 1,000 rpm, the removal solution discharge nozzle was moved at a speed of 5 mm / s from the outer periphery of the silicon wafer to a position 3 mm from the center while discharging the removal solution (a mixture of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether (30:70, mass ratio)) at a discharge rate of 2 mL / s, and the removal solution was discharged at that position for 5 seconds at a discharge rate of 2 mL / s (EBR process). After that, the discharge of the discharge solution was stopped, and the wafer was rotated at a speed of 1,000 rpm for another 30 seconds. Next, the silicon wafer on which the coating film was formed was heated at 350° C. for 60 seconds to harden the coating film, thereby obtaining a silicon wafer on which an organic film was formed.

[0243] [Solvent resistance evaluation: Examples 1-1 to 1-59, Comparative Examples 1-1 to 1-11] The thickness of each organic film formed on a silicon wafer using each of the organic film-forming compositions (UDL-1 to 59, Comparative UDL-1 to 11) was measured by the above method. Next, PGMEA solvent was dispensed on the organic film, left for 30 seconds, spin-dried, and baked at 100°C for 60 seconds to evaporate PGMEA, and then the thickness of the organic film was measured. The film thickness before dispensing the PGMEA solvent was X, the film thickness after dispensing the PGMEA solvent was X1, and the absolute value of the value obtained by [(X1-X) / X]×100 was taken as the film thickness change rate (%). A film thickness change rate of less than 0.5% was considered good, and a film thickness change rate of 0.5% or more was considered bad. The results are shown in Tables 4 to 6.

[0244] [In-plane uniformity evaluation: Examples 1-1 to 1-59, Comparative Examples 1-1 to 1-11] The thickness of each organic film formed on a silicon wafer using each of the organic film-forming compositions (UDL-1 to 59, Comparative UDL-1 to 11) was measured within a radius of 145 mm from the center of the organic film. The maximum measured thickness was X max , the minimum film thickness is X min , the average film thickness is X average As, (X max -X min ) / X average The value obtained by the above was taken as the in-plane uniformity (%). When the in-plane uniformity was less than 2%, it was rated as A (very good), when it was 2% or more but less than 3%, it was rated as B (good), and when it was 3% or more, it was rated as C (poor). The results are shown in Tables 4 to 6.

[0245] [Table 4]

[0246] [Table 5]

[0247] [Table 6]

[0248] [Hump suppression evaluation: Examples 2-1 to 2-59, Comparative Examples 2-1 to 2-5] The height change associated with the change in position from the outer peripheral edge of the organic film formed on the silicon wafer using the organic film-forming composition (UDL-1 to 59, Comparative UDL-1 to 5) toward the center of the silicon wafer was measured using Alpha-Step D-600 (contact profiler) manufactured by KLA-TENCOR. When the height of the silicon wafer is set to 0, the maximum height was evaluated as A (very good) when it was less than 110% of the film thickness as shown in FIG. 2, B (good) when it was 110% or more but less than 150%, and C (poor) when an area with a height of 150% or more was generated as shown in FIG. 3. The results are shown in Tables 7 to 9.

[0249] [Embedding evaluation: Examples 2-1 to 2-59, Comparative Examples 2-1 to 2-5] As shown in FIG. 4, an organic film 8 was formed on a SiO2 wafer substrate having a dense hole pattern (hole diameter 0.2 μm, hole depth 1.0 μm, distance between the centers of two adjacent holes 0.4 μm) using each of the organic film-forming compositions (UDL-1 to 59, comparative UDL-1 to 5) in the same manner as described above. The substrate used was a base substrate (SiO2 wafer substrate) 7 having a dense hole pattern as shown in FIG. 4(G) (overhead view) and (H) (cross-sectional view). The cross-sectional shape of each of the obtained wafer substrates was observed using a scanning electron microscope (SEM) to confirm whether the holes were filled with an organic film without any voids. When a composition for forming an organic film with poor filling properties was used, voids were generated inside the holes. When a composition for forming an organic film with good filling properties was used, in this evaluation, the organic film 8 was filled without any voids inside the holes as shown in FIG. 4(I). When no voids were generated, it was evaluated as good, and when voids were generated, it was evaluated as bad. The results are shown in Tables 7 to 9.

[0250] [Table 7]

[0251] [Table 8]

[0252] [Table 9]

[0253] As shown in Tables 4, 5, 7 and 8, it was confirmed that the organic film-forming compositions of the present invention (UDL-1 to 59) are excellent in all of solvent resistance, in-plane uniformity, hump suppression and filling properties.

[0254] On the other hand, as shown in Tables 6 and 9, it was confirmed that Comparative UDL-1 to 11, which do not use the organic film-forming composition of the present invention, showed poor results in one or more of the in-plane uniformity, hump suppression, and filling characteristics.

[0255] [Pattern formation test: Examples 3-1 to 3-59] An organic film was formed on a SiO2 wafer substrate using each of the organic film-forming compositions (UDL-1 to 59) in the same manner as described above. Then, the following silicon-containing resist intermediate film material (SOG1) was applied thereon and baked at 200°C for 60 seconds to form a silicon-containing resist intermediate film with a thickness of 35 nm. Then, the following ArF single layer resist was applied thereon as a resist upper layer film material and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. Then, the following liquid immersion protective film material (TC-1) was applied on the photoresist film and baked at 90°C for 60 seconds to form a protective film with a thickness of 50 nm.

[0256] As a silicon-containing resist intermediate film material (SOG1), a 2% solution of the following polymer in propylene glycol ethyl ether was prepared.

[0257] [ka]

[0258] The resist top layer film material (ArF single layer resist) was prepared as follows. The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) were dissolved in a solvent containing 0.1 mass% of FC-430 (Sumitomo 3M Limited) in the ratios shown in Table 10. Next, the resulting mixture was filtered through a 0.1 μm fluororesin filter. In this way, the resist top layer film material (ArF single layer resist) was prepared.

[0259] [Table 10]

[0260] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) are shown below.

[0261] [ka]

[0262] The liquid immersion protective film material (TC-1) was prepared as follows. First, the polymer (PP1) was dissolved in an organic solvent in the ratio shown in Table 11. The resulting mixture was filtered through a 0.1 μm fluororesin filter. In this way, a liquid immersion protective film material was obtained.

[0263] [Table 11]

[0264] The polymer (PP1) is shown below. [ka]

[0265] Next, the resist upper layer film was subjected to pattern exposure using an ArF immersion exposure apparatus (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35 degree dipole s-polarized illumination, 6% halftone phase shift mask). After that, it was baked (PEB) at 100°C for 60 seconds, and then developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds. This resulted in a 55 nm 1:1 positive type line and space pattern (resist upper layer film pattern).

[0266] Next, using the resist upper layer film pattern as a mask, the silicon-containing resist intermediate film was dry etched (pattern transferred) using a Telius etching device manufactured by Tokyo Electron, to obtain a silicon-containing resist intermediate film pattern.

[0267] Next, the organic film was dry etched (pattern transfer) using the obtained silicon-containing resist intermediate film pattern as a mask to obtain an organic film pattern.

[0268] Next, the obtained organic film pattern was used as a mask to dry etch (pattern transfer) the SiO2 wafer substrate (SiO2 film).

[0269] The etching conditions are as follows.

[0270] (Transfer conditions of resist top layer film pattern to silicon-containing resist intermediate film) Chamber pressure 10.0Pa RF power 1,500W CF4 gas flow rate: 75mL / min O2 gas flow rate: 15mL / min Time 15sec

[0271] (Conditions for transferring silicon-containing resist intermediate film pattern to organic film) Chamber pressure 2.0Pa RF power 500W Ar gas flow rate: 75mL / min O2 gas flow rate: 45mL / min Time 120sec

[0272] (Transfer conditions for organic film pattern onto SiO2 wafer substrate) Chamber pressure 2.0Pa RF power: 2,200W C5F 12 Gas flow rate: 20mL / min C2F6 gas flow rate: 10mL / min Ar gas flow rate: 300mL / min O2 gas flow rate: 60mL / min Time 90sec

[0273] The cross section of the obtained pattern was observed with an electron microscope (S-4700) manufactured by Hitachi, Ltd. The results are shown in Tables 12 and 13.

[0274] [Table 12]

[0275] [Table 13]

[0276] As shown in Tables 12 and 13, in Examples 3-1 to 3-59 in which the organic film-forming composition of the present invention (UDL-1 to 59) was used, the resist top layer film pattern was successfully transferred to the SiO2 wafer substrate, and it was confirmed that the organic film-forming composition of the present invention is suitable for use in microfabrication using the multilayer resist method.

[0277] From the above, the organic film-forming composition of the present invention has excellent film-forming properties, advanced filling properties, and excellent hump suppression properties, and is therefore extremely useful as an organic film material for use in multilayer resist processes. Furthermore, the pattern formation method of the present invention using this composition is capable of filling holes and trenches with extremely high aspect ratios without voids, and is capable of forming fine patterns with high precision. In addition, it is possible to form an organic film in which humps are suppressed, making it possible to efficiently manufacture semiconductor elements, etc.

[0278] The present specification includes the following aspects. [1] A composition for forming an organic film, comprising: (A) a polymer having a repeating unit represented by the following general formula (1); (B) a resin for forming an organic film; and (C) a solvent. A composition for forming an organic film, comprising: [ka] (In general formula (1), R1 is a divalent organic group containing an aliphatic moiety or an aromatic moiety having 2 to 30 carbon atoms, and R2 are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom, a cyano group, an amino group, or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.) [2] The composition for forming an organic film according to [1], wherein the polymer (A) contains one or more compounds represented by any one of the following general formulas (2) to (4): [ka] (In the formula, R1 and R2 are the same as above, R3 is a monovalent organic group having 1 to 30 carbon atoms, a is 0 or 1. When a is 0, b is 1 to 4, b1 is 1 to 5, c is 0 to 3, and c1 is 0 to 4. When a is 1, b is 1 to 6, b1 is 1 to 7, c is 0 to 5, and c1 is 0 to 6. n represents the average number of repeating units and is 3 to 2,000.) [3] The composition for forming an organic film according to [1] or [2], characterized in that the content of the (A) polymer is 0.01 parts by mass to 5 parts by mass per 100 parts by mass of the (B) resin for forming an organic film. [4] A method for forming an organic film used in a manufacturing process of a semiconductor device, comprising the steps of: A method for forming an organic film, comprising spin-coating a composition for forming an organic film according to any one of [1] to [3] on a substrate to be processed to obtain a coating film, and then heat-treating the coating film at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to harden the coating film, thereby forming an organic film. [5] A pattern formation method comprising the steps of: forming an organic film on a workpiece using the organic film-forming composition according to any one of [1] to [3]; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming a resist upper layer film on the silicon-containing resist intermediate film using a resist upper layer film material consisting of a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring a pattern to the silicon-containing resist intermediate film by etching using the resist upper layer film on which the circuit pattern has been formed as a mask; transferring a pattern to the organic film by etching using the silicon-containing resist intermediate film on which the pattern has been transferred as a mask; and further forming a pattern on the workpiece by etching using the organic film on which the pattern has been transferred as a mask. [6] A pattern forming method, comprising: forming an organic film on a workpiece using the organic film-forming composition according to any one of [1] to [3]; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming an organic antireflective film or an adhesive film on the silicon-containing resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesive film using a resist upper layer film material consisting of a photoresist composition; forming a circuit pattern on the resist upper layer film; using the resist upper layer film on which the circuit pattern has been formed as a mask, transferring a pattern to the organic antireflective film or the adhesive film, and the silicon-containing resist intermediate film by etching; using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask, transferring a pattern to the organic film by etching; and further using the organic film to which the pattern has been transferred as a mask, forming a pattern on the workpiece by etching. [7] A pattern forming method, comprising: forming an organic film on a workpiece using the composition for forming an organic film according to any one of [1] to [3]; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming a resist upper layer film on the inorganic hard mask intermediate film using a resist upper layer film material consisting of a photoresist composition; and forming a circuit pattern on the resist upper layer film; a resist top layer film having a circuit pattern formed thereon is used as a mask to transfer the pattern to the inorganic hard mask intermediate film by etching, the inorganic hard mask intermediate film having the pattern transferred thereto is used as a mask to transfer the pattern to the organic film by etching, and the organic film having the pattern transferred thereto is used as a mask to form a pattern on the workpiece by etching. [8] A pattern formation method, comprising: forming an organic film on a workpiece using the composition for forming an organic film according to any one of [1] to [3]; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming an organic antireflective film or an adhesion film on the inorganic hard mask intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material consisting of a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring a pattern to the organic antireflective film or the adhesion film, and the inorganic hard mask intermediate film by etching using the resist upper layer film on which the circuit pattern has been formed as a mask; transferring a pattern to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; and further forming a pattern on the workpiece by etching using the organic film to which the pattern has been transferred as a mask. [9] The pattern forming method according to [7] or [8], wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method.

[10] The method for forming a pattern according to any one of [5] to [9], wherein the circuit pattern is formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[11] The method for forming a pattern according to any one of [5] to

[10] , wherein in forming the circuit pattern, the circuit pattern is developed using an alkali developer or an organic solvent.

[12] The pattern forming method according to any one of [5] to

[11] , wherein the workpiece is a semiconductor device substrate, or the semiconductor device substrate having any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film formed thereon.

[13] The pattern formation method according to

[12] , characterized in that the metal constituting the workpiece is silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, or an alloy thereof.

[0279] The present invention is not limited to the above-described embodiment. The above-described embodiment is merely an example, and anything that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits similar effects is included in the technical scope of the present invention. [Explanation of symbols]

[0280] 1...substrate, 2...processed layer, 2a...pattern (pattern formed on processed layer), 3...organic film, 3a...organic film pattern, 4...silicon-containing resist intermediate film, 4a...silicon-containing resist intermediate film pattern, 5...resist upper layer film, 5a...resist upper layer film pattern, 6...exposed portion, 7...underlying substrate, 8...organic film.

Claims

1. A composition for forming an organic film, (A) a polymer having a repeating unit represented by the following general formula (1): (B) an organic film-forming resin, and (C) Solvent A composition for forming an organic film, comprising: 【Chemistry 1】 (In general formula (1), R １ is a divalent organic group containing an aliphatic or aromatic moiety having 2 to 30 carbon atoms; R ２ are each independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a halogen atom other than a fluorine atom, a cyano group, an amino group, or a nitro group. a is 0 or 1. When a is 0, b is 1 to 4, and c is 0 to 3. When a is 1, b is 1 to 6, and c is 0 to 5.

2. The composition for forming an organic film according to claim 1, wherein the polymer (A) contains one or more compounds represented by any one of the following general formulas (2) to (4): 【Chemistry 2】 (In the formula, R １ and R ２ is the same as above, and R ３ is a monovalent organic group having 1 to 30 carbon atoms. a is 0 or 1. When a is 0, b is 1 to 4, b1 is 1 to 5, c is 0 to 3, and c1 is 0 to 4. When a is 1, b is 1 to 6, b1 is 1 to 7, c is 0 to 5, and c1 is 0 to 6. n represents the average number of repeating units and is 3 to 2,000.

3. 2. The composition for forming an organic film according to claim 1, wherein the content of the polymer (A) is 0.01 to 5 parts by mass with respect to 100 parts by mass of the resin (B) for forming an organic film.

4. A method for forming an organic film used in a manufacturing process of a semiconductor device, comprising the steps of: A composition for forming an organic film according to any one of claims 1 to 3 is spin-coated on a substrate to be processed to obtain a coating film, The method for forming an organic film is characterized in that the coating film is cured by heat treating it at a temperature of 100° C. or higher and 600° C. or lower for 10 to 600 seconds to form an organic film.

5. A pattern formation method comprising the steps of: forming an organic film on a workpiece by using the composition for forming an organic film according to any one of claims 1 to 3; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming a resist upper layer film on the silicon-containing resist intermediate film using a resist upper layer film material comprising 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, a pattern is transferred to the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; The pattern forming method further comprises forming a pattern on the workpiece by etching using the organic film to which the pattern has been transferred as a mask.

6. A pattern formation method comprising the steps of: forming an organic film on a workpiece by using the composition for forming an organic film according to any one of claims 1 to 3; forming a silicon-containing resist intermediate film on the organic film using a silicon-containing resist intermediate film material; forming an organic anti-reflective film or an adhesion film on the silicon-containing resist intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising 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, a pattern is transferred to the organic anti-reflective film or the adhesion film and the silicon-containing resist intermediate film by etching; a pattern is transferred to the organic film by etching using the silicon-containing resist intermediate film to which the pattern has been transferred as a mask; The pattern forming method further comprises forming a pattern on the workpiece by etching using the organic film to which the pattern has been transferred as a mask.

7. A pattern formation method comprising the steps of: forming an organic film on a workpiece by using the composition for forming an organic film according to any one of claims 1 to 3; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming a resist upper layer film on the inorganic hard mask intermediate film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film having a circuit pattern formed thereon is used as a mask to transfer the pattern to the inorganic hard mask intermediate film by etching; The pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; The pattern forming method further comprises forming a pattern on the workpiece by etching using the organic film to which the pattern has been transferred as a mask.

8. A pattern formation method comprising the steps of: forming an organic film on a workpiece by using the composition for forming an organic film according to any one of claims 1 to 3; forming an inorganic hard mask intermediate film selected from the group consisting of a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the organic film; forming an organic anti-reflective film or an adhesion film on the inorganic hard mask intermediate film; forming a resist upper layer film on the organic antireflective film or the adhesion film using a resist upper layer film material comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; a resist upper layer film on which the circuit pattern is formed is used as a mask to transfer the pattern to the organic anti-reflective film or the adhesion film and the inorganic hard mask intermediate film by etching; The pattern is transferred to the organic film by etching using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask; The pattern forming method further comprises forming a pattern on the workpiece by etching using the organic film to which the pattern has been transferred as a mask.

9. 8. The pattern forming method according to claim 7, wherein the inorganic hard mask intermediate film is formed by a CVD method or an ALD method.

10. 6. The pattern forming method according to claim 5, wherein the circuit pattern is formed by lithography using light having a wavelength of 10 nm or more and 300 nm or less, direct writing with an electron beam, nanoimprinting, or a combination thereof.

11. 6. The method for forming a pattern according to claim 5, wherein in forming the circuit pattern, the circuit pattern is developed with an alkali developer or an organic solvent.

12. 6. The pattern forming method according to claim 5, wherein the workpiece is a semiconductor device substrate, or a semiconductor device substrate having any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film formed thereon.

13. 13. The pattern formation method according to claim 12, wherein the metal constituting the workpiece is selected from the group consisting of silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, molybdenum, and alloys thereof.

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