Materials for forming organic films, substrates for manufacturing semiconductor devices, methods for forming organic films, methods for forming patterns, compounds for forming organic films, and aromatic carboxylic acid anhydrides.

Abstract

The present invention provides an organic film-forming compound, an organic film-forming material, and a substrate for semiconductor device manufacturing, which can form an organic film that hardens even under film formation conditions in an inert gas, exhibits excellent heat resistance, pattern embedding and planarization characteristics on the substrate, and has good film formation properties and adhesion to the substrate. [Solution] (A) A compound represented by formula (1A), and (B) an organic film-forming material containing an organic solvent. TIFF2026066485000114.tif1471 (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in formula (1B)) TIFF2026066485000115.tif2377 (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in formula (1C)) TIFF2026066485000116.tif12128

Description

Technical Field

[0001] The present invention relates to a material for forming an organic film, a substrate for manufacturing a semiconductor device, a method for forming an organic film, a method for forming a pattern, a compound for forming an organic film, and an aromatic carboxylic anhydride.

Background Art

[0002] Conventionally, the high integration and high speed of semiconductor devices have been achieved by miniaturization of pattern dimensions due to shortening of the wavelength of the light source in lithography technology (photo-lithography) using optical exposure as a general-purpose technology. In order to form such a fine circuit pattern on a semiconductor device substrate (substrate to be processed), a method is usually used in which a dry etching process is performed on the substrate to be processed using a photoresist film having a pattern formed thereon as an etching mask. However, in reality, there is no dry etching method that can achieve perfect etching selectivity between the photoresist film and the substrate to be processed. Therefore, in recent years, substrate processing by a multilayer resist method has become common. In this method, a resist lower layer film having a different etching selectivity from the photoresist film (hereinafter, resist upper layer film) is interposed between the resist upper layer film and the substrate to be processed. After obtaining a pattern on the resist upper layer film, the resist upper layer film pattern is used as a dry etching mask, and the pattern is transferred to the resist lower layer film by dry etching. Further, the resist lower layer film is used as a dry etching mask, and the pattern is transferred to the substrate to be processed by dry etching.

[0003] One multilayer resist method is the three-layer resist method, which can be performed using the same resist compositions as those used in the single-layer resist method. In this method, an organic underlayer film (hereinafter referred to as the organic film) is formed on a substrate by coating and firing an organic underlayer film material made from an organic resin-containing composition. A silicon-containing film (hereinafter referred to as the silicon-containing resist interlayer) is then formed on top of the underlayer by coating and firing a resist interlayer material made from a silicon-containing resin-containing composition. Finally, a general organic photoresist film (hereinafter referred to as the resist upper layer) is formed on top of the silicon-containing resist interlayer. After patterning the resist upper layer, dry etching is performed using a fluorine-based gas plasma. Since the organic resist upper layer exhibits a good etching selectivity ratio compared to the silicon-containing resist interlayer, the resist upper layer pattern can be transferred to the silicon-containing resist interlayer. According to this method, even if a resist top layer film does not have sufficient thickness to directly process the substrate, or a resist top layer film does not have sufficient dry etching resistance for processing the substrate, the silicon-containing resist interlayer film usually has a thickness equal to or less than that of the resist top layer film, so the pattern can be easily transferred to the silicon-containing resist interlayer film. Subsequently, the pattern transferred to the silicon-containing resist interlayer film is used as a dry etching mask, and the pattern is transferred to an organic film by dry etching with an oxygen-based or hydrogen-based gas plasma, thereby transferring the pattern to an organic film with sufficient dry etching resistance for processing the substrate. This pattern-transferred organic film can then be used to transfer the pattern to the substrate by dry etching using a fluorine-based gas or a chlorine-based gas.

[0004] On the other hand, miniaturization in the manufacturing process of semiconductor devices is approaching an inherent limit derived from the wavelength of the light source used for photolithography. Therefore, in recent years, the integration of semiconductor devices without relying on miniaturization has been considered, and one method for this is semiconductor devices with complex structures such as multi-gate structures, some of which have already been put into practical use. When such structures are formed using the multilayer resist method, organic film materials that can be planarized can be applied to completely fill minute patterns such as holes, trenches, and fins formed on the substrate, or to fill steps, densely patterned areas, and areas without patterns with a film. By forming a flat organic film surface on a stepped substrate using such organic film materials, variations in the film thickness of the silicon-containing resist interlayer and resist upper layer deposited thereon can be suppressed, thereby reducing the focus margin in photolithography and the margin reduction in subsequent processing steps of the substrate. This makes it possible to manufacture semiconductor devices with a high yield. On the other hand, in the single-layer resist method, the thickness of the upper resist film becomes thicker in order to fill in the steps and patterns on the substrate to be processed. This narrows the margin for pattern formation during exposure, making it difficult to manufacture semiconductor devices with a high yield, as it can lead to pattern collapse after exposure and development, as well as degradation of the pattern shape due to reflection from the substrate during exposure.

[0005] Furthermore, as a method for increasing the speed of next-generation semiconductor devices, the application of new materials with high electron mobility, such as strained silicon and gallium arsenide, and precision materials such as ultrathin polysilicon films controlled in angstroms, is beginning to be considered. However, in substrates to which such new precision materials are applied, under the conditions for planarization film formation using organic film materials as described above, for example, under deposition conditions of 300°C or higher in air, the material of the substrate may corrode due to oxygen in the air. This can prevent the semiconductor device from achieving the performance intended by the material design, and may result in a yield that is not feasible for industrial production. Therefore, organic film materials that can be deposited in an inert gas are expected to avoid the decrease in yield caused by substrate corrosion under such high-temperature conditions.

[0006] Conventionally, condensation resins using carbonyl compounds such as ketones and aldehydes, or aromatic alcohols, as condensing agents for phenolic and naphthol compounds have been known as organic film-forming materials for multilayer resist processes. Examples include the fluorenebisphenol novolac resin described in Patent Document 1, the bisphenol compound and its novolac resin described in Patent Document 2, the adamantanephenol compound novolac resin described in Patent Document 3, and the bisnaphthol compound and its novolac resin described in Patent Document 4. Such materials are formed as films with solvent resistance to coating film materials used in subsequent processes by crosslinking with methylol compounds as crosslinking agents, or by a curing reaction through crosslinking by oxidation at the α-position of the aromatic ring by the action of oxygen in the air and subsequent condensation.

[0007] Furthermore, organic film materials that utilize triple bonds as intermolecular crosslinking groups in curable resins are known. For example, Patent Documents 5 to 16 are known. In these materials, a cured film with solvent resistance is formed not only by the aforementioned methylol-derived crosslinking but also by crosslinking through the polymerization of triple bonds. However, although these organic film-forming materials have excellent heat resistance, their properties such as flatness and adhesion to the substrate are insufficient, leaving room for improvement. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2005-128509 [Patent Document 2] Japanese Patent Publication No. 2006-293298 [Patent Document 3] Japanese Patent Publication No. 2006-285095 [Patent Document 4] Japanese Patent Publication No. 2010-122656 [Patent Document 5] Special Publication No. 11-512430 [Patent Document 6] Japanese Patent Publication No. 2005-041938 [Patent Document 7] Japanese Patent Publication No. 2009-206447 [Patent Document 8] Japanese Patent Publication No. 2010-181605 [Patent Document 9] Japanese Patent Publication No. 2012-215842 [Patent Document 10] International Publication No. 2014 / 208324 [Patent Document 11] Japanese Patent Publication No. 2016-044272 [Patent Document 12] Japanese Patent Publication No. 2016-060886 [Patent Document 13] Japanese Patent Publication No. 2017-014193 [Patent Document 14] Japanese Patent Publication No. 2017-119671 [Patent Document 15] Japanese Patent Publication No. 2018-092170 [Patent Document 16] International Publication No. 2019 / 146378 [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention has been made in view of the above circumstances, and aims to provide an organic film-forming compound that can form an organic film that hardens not only in air but also under inert gas deposition conditions, has excellent heat resistance, and is excellent in embedding and planarization characteristics of patterns formed on a substrate, as well as good film-forming properties and adhesion to the substrate, and an organic film-forming material containing the compound. Furthermore, the present invention also provides a substrate for semiconductor device manufacturing using the material, a method for forming an organic film, and a method for forming a pattern. In addition, it provides an aromatic carboxylic acid anhydride having a crosslinking site that is expected to be an industrially useful raw material for electronic materials, aerospace materials, etc. [Means for solving the problem]

[0010] In order to solve the above problems, the present invention provides a material for forming an organic film, which contains (A) a compound represented by the following general formula (1A) and (B) an organic solvent.

Chemical formula

Chemical formula

Chemical formula

[0011] Such a material for forming an organic film can be cured under film-forming conditions not only in air but also in an inert gas, and can form an organic film having high heat resistance, good film-forming property on a substrate, adhesion, and high embedding / planarization characteristics.

[0012] Further, in the present invention, it is preferable that the component (A) is a compound represented by the following general formula (1D).

Chemical formula

[0013] By combining various W2 structures adjacent to the benzene ring structure, in addition to the curability due to the terminal structure as described above, it becomes possible to tune the physical properties of the compounds contained in organic film-forming materials to match the required performance, such as heat resistance and etching resistance. For example, by introducing substituents that impart flexibility to W2, intermolecular interactions are relaxed and crystallinity is inhibited, thereby improving solubility in organic solvents and film formation properties. By introducing substituents that impart fluidity, embedding / planarization properties can be improved.

[0014] In this case, it is preferable that W2 in the general formula (1D) is either a single bond or one of the groups represented by the following formula (1E). [ka] (The aromatic ring may have substituents.)

[0015] It is preferable, from the viewpoint of heat resistance and solvent solubility, that the compounds contained in the organic film-forming material have the above-described substructure.

[0016] Furthermore, in the present invention, it is preferable that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

[0017] By using compounds that satisfy the above relationship in the organic film-forming material, it becomes possible to form organic films that have excellent not only heat resistance but also embedding / planarization properties.

[0018] Furthermore, in the present invention, it is preferable that the ratio Mw / Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of component (A) as determined by gel permeation chromatography is 1.00 ≤ Mw / Mn ≤ 1.10.

[0019] By controlling the Mw / Mn ratio of compounds contained in organic film-forming materials within this range, it is possible to form organic films with excellent embedding properties and flatness.

[0020] Furthermore, in the present invention, it is preferable that component (B) is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

[0021] With such organic film-forming materials, the addition of a high-boiling-point solvent to the compound imparts thermal fluidity, resulting in an organic film-forming material that possesses even more advanced embedding and planarization properties.

[0022] Furthermore, in the present invention, it is preferable that the organic film-forming material further contains one or more of (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, and (F) a plasticizer.

[0023] The organic film-forming material of the present invention may contain one or more of the above components (C) to (F), depending on its purpose.

[0024] Furthermore, the present invention provides a substrate for manufacturing a semiconductor device, wherein an organic film formed on the substrate is obtained by curing the organic film-forming material described above.

[0025] The organic film forming material of the present invention, possessing both advanced embedding and planarization characteristics, results in an organic film free from micro-voids due to poor embedding and surface irregularities due to insufficient planarization. A semiconductor device manufacturing substrate planarized with the organic film forming material of the present invention offers a wider process margin during patterning, enabling the manufacture of semiconductor devices with a higher yield.

[0026] Furthermore, the present invention provides a method for forming an organic film applicable in the manufacturing process of a semiconductor device, comprising: rotatingly coating a substrate with the above-described organic film forming material; and heat-treating the substrate coated with the organic film forming material in an inert gas atmosphere at a temperature of 50°C to 600°C for a range of 10 to 7200 seconds to obtain an organic film.

[0027] Furthermore, the present invention provides a method for forming an organic film applicable in the manufacturing process of a semiconductor device, comprising: rotatingly coating a substrate with the above-described organic film-forming material; heat-treating the substrate coated with the organic film-forming material in air at a temperature of 50°C to 300°C for 5 to 600 seconds to form a coated film; and subsequently applying heat treatment in an inert gas atmosphere at a temperature of 200°C to 600°C for 10 to 7200 seconds to obtain an organic film.

[0028] The organic film formed by the organic film formation method of the present invention and applied in the manufacturing process of semiconductor devices has high heat resistance and advanced embedding / planarization characteristics, resulting in a good yield of semiconductor devices when used in the manufacturing process.

[0029] In this case, it is preferable to keep the oxygen concentration in the inert gas atmosphere at 1% or less.

[0030] The organic film-forming material of the present invention can be heated in such an inert gas atmosphere, yet it will harden sufficiently without generating sublimation, and it can form an organic film with excellent adhesion to the substrate.

[0031] Furthermore, in the present invention, it is preferable to use a workpiece substrate having a structure or step with a height of 30 nm or more as the workpiece substrate.

[0032] The method for forming an organic film according to the present invention is particularly useful when forming a flat organic film on a workpiece substrate having such irregularities.

[0033] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming a resist upper layer on the silicon-containing resist interlayer using a photoresist composition; forming a circuit pattern on the resist upper layer; transferring the pattern to the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0034] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming an organic anti-reflective film on the silicon-containing resist interlayer; forming a resist upper layer on the organic anti-reflective film using a photoresist composition to form a four-layer structure; forming a circuit pattern on the resist upper layer; transferring the pattern to the organic anti-reflective film and the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0035] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming a resist upper layer film on the inorganic hard mask interlayer film using a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring the pattern to the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0036] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming an organic anti-reflective film on the inorganic hard mask interlayer; forming a resist upper layer film on the organic anti-reflective film using a photoresist composition to form a four-layer film structure; forming a circuit pattern on the resist upper layer film; transferring the pattern to the organic anti-reflective film and the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0037] The organic film forming material 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 interlayer or an inorganic hard mask interlayer, or a four-layer resist process using an organic anti-reflective film in addition to these. By forming circuit patterns using such a pattern formation method of the present invention in the semiconductor device manufacturing process, semiconductor devices can be manufactured with a high yield.

[0038] At this time, it is preferable to form the inorganic hard mask interlayer by CVD or ALD.

[0039] In the pattern formation method of the present invention, an inorganic hard mask interlayer can be formed by, for example, the method described above.

[0040] Furthermore, in the present invention, it is preferable to form the circuit pattern using lithography with light having a wavelength of 10 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[0041] Furthermore, in the present invention, it is preferable to develop the circuit pattern using alkaline development or an organic solvent.

[0042] In the pattern formation method of the present invention, such circuit pattern formation means and developing means can be suitably used.

[0043] Furthermore, in the present invention, it is preferable to use a semiconductor device substrate, or a semiconductor device substrate on which any of the following films are formed: a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film.

[0044] In this case, it is preferable to use a workpiece containing silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or alloys thereof.

[0045] With the pattern formation method of the present invention, patterns can be formed by processing the above-described substrate.

[0046] Furthermore, the present invention provides an organic film-forming compound, which is represented by the following general formula (1A). [ka] (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in the general formula (1B) below.) [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1C), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0047] Such organic film-forming compounds harden not only in air but also under inert gas deposition conditions, possess high heat resistance and advanced embedding / planarization properties, and furthermore, due to the action of the dioxin structure, which is a heterocyclic structure containing oxygen, they can form organic films with excellent film-forming properties and adhesion to substrates.

[0048] Furthermore, in the present invention, it is preferable that the organic film-forming compound is represented by the following general formula (1D). [ka] (In the formula, W2 is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, and the organic group in W2 may bond with the substituent on the benzene ring to form a cyclic organic group. X1 is the same as described above.)

[0049] Such organic film-forming compounds can be cured not only in air but also under inert gas conditions, and exhibit excellent heat resistance under any of these film-forming conditions.

[0050] In this case, it is preferable that W2 in the general formula (1D) is either a single bond or one of the groups represented by the following formula (1E). [ka] (The aromatic ring may have substituents.)

[0051] Such organic film-forming compounds can be cured not only in air but also under inert gas conditions, and can exhibit superior heat resistance under any of these film-forming conditions.

[0052] Furthermore, in the present invention, it is preferable that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

[0053] Such organic film-forming compounds suppress film shrinkage during curing, resulting in organic film-forming compounds with excellent embedding / planarization properties.

[0054] Furthermore, the present invention provides an aromatic carboxylic acid anhydride, which is represented by the following general formula (1F). [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1G), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0055] Aromatic carboxylic acid anhydrides as described above contain ether structures and crosslinking groups as terminal structures, and do not contain many polar groups. Such aromatic carboxylic acid anhydrides can impart not only heat resistance and crosslinking properties to imide-based materials, including polyimides, but also seemingly contradictory properties such as high Tg and processability (film formation properties, etc.). Therefore, they can impart not only heat resistance but also properties required for electronic and aerospace materials, such as low dielectric constant and curability, making them industrially very useful candidates as end-capturing agents for polyimides and imide compounds. [Effects of the Invention]

[0056] As described above, the organic film-forming compound of the present invention hardens without generating by-products even when forming films in an inert gas that prevents substrate corrosion, and is a useful compound for forming organic films that combine high embedding and planarization characteristics, heat resistance, etching resistance, film-forming ability, and adhesion. Furthermore, the organic film-forming material containing this compound forms an organic film that has excellent embedding / planarization characteristics and combines various properties such as heat resistance, etching resistance, adhesion to the substrate, and film-forming ability. For this reason, it is extremely useful as an organic film material in multilayer resist methods such as the two-layer resist method, the three-layer resist method using a silicon-containing resist interlayer, and the four-layer resist method using a silicon-containing resist interlayer and an organic anti-reflective film, or as a planarization material for semiconductor device manufacturing. In addition, since the organic film formed from the organic film-forming material of the present invention has excellent heat resistance, there is no change in film thickness due to thermal decomposition even when an inorganic hard mask interlayer is formed on the organic film, making it suitable for pattern formation. Furthermore, aromatic carboxylic acid anhydrides used to introduce terminal structures can be expected to be industrially useful materials as end-capturing agents for polyimides and imide compounds used in electronic and aerospace materials. [Brief explanation of the drawing]

[0057] [Figure 1] This is an explanatory diagram of the planarization characteristics in the present invention. [Figure 2]This is an explanatory diagram of an example of a pattern formation method using the three-layer resist method of the present invention. [Figure 3] This is an explanatory diagram of the embedding characteristics evaluation method in the example. [Figure 4] This is an explanatory diagram of the method for evaluating planarization characteristics in the embodiment. [Modes for carrying out the invention]

[0058] As described above, in order to prevent corrosion of the substrate, there has been a need for the development of organic film forming materials and organic film forming compounds useful for pattern formation methods using such materials. These materials can form organic films that do not generate by-products even under inert gas deposition conditions, for example, at temperatures above 300°C, and that not only have excellent embedding and planarization characteristics for patterns formed on the substrate, but also have good dry etching resistance during substrate processing. Furthermore, even when forming an inorganic hard mask interlayer on the organic film, there has been a need for organic film forming materials and organic film forming compounds useful for pattern formation methods using such materials.

[0059] Normally, when forming an organic film, an organic film-forming compound is dissolved in an organic solvent to form a composition, which is then applied to a substrate on which the structure and wiring of a semiconductor device are formed, and the organic film is formed by firing. Immediately after application of the composition, a coating film is formed that conforms to the shape of the stepped structure on the substrate. However, when the coating film is fired, most of the organic solvent evaporates before it hardens, and the organic film is formed by the organic film-forming compound remaining on the substrate. The inventors of the present invention realized that if the organic film-forming compound remaining on the substrate at this time has sufficient thermal fluidity, it is possible to flatten the stepped shape immediately after application by thermal fluidity and form a flat film.

[0060] The inventors of the present invention have conducted further intensive studies and have found that an organic film-forming compound represented by the following general formula (1A) has thermosetting properties equivalent to conventional resist underlayer materials not only in air but also in inert gases due to the action of the substituent represented by R1, and by incorporating a crosslinked structure linked by an ether linker at the end, it is possible to impart properties that are generally contradictory in general polyimides and imide compounds, such as solvent solubility, adhesion, thermal fluidity, and high embedding / planarization properties, without impairing heat resistance. This provides an organic film-forming material that not only exhibits flatness on a processed substrate but also possesses heat resistance that prevents changes in coating film thickness due to thermal decomposition, even when forming an inorganic hard mask interlayer, thus completing the present invention.

[0061] In other words, the present invention is an organic film-forming material that contains (A) a compound represented by the following general formula (1A), and (B) an organic solvent. [ka] (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in the general formula (1B) below.) [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1C), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0062] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0063] <Compounds for organic film formation> The organic film-forming compound of the present invention is an organic film-forming compound represented by the following general formula (1A). [ka] (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in the general formula (1B) below.) [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1C), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0064] In the above formula (1C), R1 functions as a thermal crosslinking group. Due to its curability, heat resistance, and ease of obtaining raw materials, it is preferably an ethynyl group or an ethynylphenyl group. Substituents on the aromatic ring include halogen atoms such as fluorine, bromine, and iodine, and alkyl groups such as methyl, ethyl, and propyl. Due to the ease of obtaining raw materials, fluorine is preferred as the substituent.

[0065] The terminal structure represented by the above general formula (1B) is a pre-ring-closed imide structure. Polyimide varnishes used as film materials are generally made by coating an intermediate amide acid, then ring-closing it with heat to form a film, and then using it as a polyimide film. However, the compound represented by the above general formula (1A), which is the organic film-forming compound of the present invention, is a pre-ring-closed soluble imide compound. Therefore, elimination reactions such as dehydration that occur when the amide acid, which is the imide compound precursor, is ring-closed by heat are eliminated, so film shrinkage is suppressed and the flatness of the organic film is not impaired. In addition, by having a stable imide compound beforehand, decomposition due to equilibrium reactions of imide compound precursors such as amide acid can be suppressed, which is advantageous in terms of storage stability. Furthermore, by linking the imide structure and the terminal structure having a crosslinking group structure with an ether group, it is possible to impart fluidity without impairing heat resistance, making it possible to impart thermal fluidity during film formation while maintaining high heat resistance. Furthermore, the end structure represented by general formula (1B), which includes an imide structure, in the organic film-forming compound of the present invention is consistent with the design philosophy of polyimide materials, such as low dielectric constant, low moisture absorption, and high processability. Therefore, it can be expected to be applied not only to planarization for semiconductor substrates but also to many other material fields where polyimide and imide compounds are used, such as electronic materials and aerospace materials.

[0066] In general formula (1B), n2 is either 1 or 2, and n2=1 is preferred due to the ease of obtaining raw materials and manufacturing. Examples of substituents on the aromatic ring include halogen atoms such as fluorine, bromine, and iodine, and alkyl groups such as methyl, ethyl, and propyl. When N1 is the number of substituents on the aromatic ring in the imide structure, the relationship 0≦N1≦3 is satisfied. Also, when N2 is the number of substituents on the aromatic ring having R1, the relationships 0≦N2≦3, 1≦n2≦2, and 1≦n2+N2≦4 are satisfied. Fluorine is preferred as a substituent due to the ease of obtaining raw materials.

[0067] Furthermore, the terminal structure represented by R1, which functions as a crosslinking group, does not cause a rapid catalytic curing reaction during heat treatment in film formation, unlike crosslinking catalysts such as epoxy groups and methoxymethyl groups used as common crosslinking agents. This prevents a rapid decrease in thermal fluidity, making it advantageous in terms of imparting thermal fluidity and resulting in an organic film-forming compound with excellent embedding / planarization properties. Moreover, since curing occurs through cyclization reactions between triple bonds and polymerization reactions between double bonds, it is a crosslinking method that does not involve elimination reactions, suppressing film shrinkage during curing and resulting in an organic film-forming compound that can form organic films with excellent planarization properties.

[0068] In the above general formula (1A), n1 is an integer between 2 and 4.

[0069] In the above general formula (1A), W1 is an n1-valent organic group, and the following structural formulas are examples, and substituents may be present on these aromatic rings. Examples of substituents include hydroxyl groups, trifluoromethyl groups, C1-C10 alkyl groups, C3-C10 alkynyl or alkenyl groups, C1-C10 alkyloxy groups, C3-C10 alkynyloxy or alkenyloxy groups, C6-C10 aryl groups, thiol groups, nitro groups, halogen groups, nitrile groups, sulfonic acid groups, C2-C10 alkoxycarbonyl groups, and C2-C10 alkanoyloxy groups.

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] In the present invention, it is preferable that the organic film-forming compound is represented by the following general formula (1D). [ka] (In the formula, W2 is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, and the organic group in W2 may bond with the substituent on the benzene ring to form a cyclic organic group. X1 is the same as described above.)

[0075] Furthermore, in the organic film-forming compound of the present invention, it is preferable that W2 in the above general formula (1D) is a single bond or one of the groups represented by the following formula (1E). Among these, from the viewpoint of solvent solubility and fluidity, those having a single bond, an ether bond, an isopropylidene structure, a hexafluoroisopropylidene structure, a fluorene structure, or those forming an indane structure with an aromatic ring bonded to an imide ring are preferred. [ka] (The aromatic ring may have substituents.)

[0076] Furthermore, in the present invention, it is preferable that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

[0077] By satisfying this relationship between n3 and n4, an organic film-forming compound is obtained that achieves both embedding / planarization properties without impairing thermosetting and heat resistance. In particular, those satisfying 1≦n3≦2, 1≦n4≦2, and 3≦n3+n4≦4 are more preferable from the viewpoint of heat resistance. Among these, those that satisfy the above relationship and in which W2 in the above general formula (1D) is either a single bond, an ether bond, an isopropylidene structure, a hexafluoroisopropylidene structure, or a fluorene structure are preferred, and those having a single bond, an ether bond, or a fluorene structure are even more preferred. In this case, X1 is a substituent on a benzene ring, but when there are two or more X1s on one aromatic ring, that is, when n3=2 and / or n4=2, it is even more preferable that the substituents X1 on the two aromatic rings are adjacent on one aromatic ring, as shown below. When this relationship is satisfied, not only is solubility in the solvent improved due to steric hindrance between the imide groups, but it also becomes possible to satisfy the potentially conflicting properties of heat resistance and thermal fluidity in imide compounds. [ka] (In the formula, W2 and X1 are the same as above.)

[0078] In the present invention, it is preferable that the ratio Mw / Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of the organic film-forming compound, as determined by gel permeation chromatography, is 1.00 ≤ Mw / Mn ≤ 1.10. By controlling the Mw / Mn of the organic film-forming compound within this range, an organic film with excellent embedding properties and planarity can be formed.

[0079] Even if it is a mixture of monomolecular compounds containing multiple terminal structures and main skeleton structures, as long as it is within the Mw / Mn range described above, the thermal fluidity of the organic film-forming compound will be even better. Therefore, when it is incorporated into the organic film-forming material described later, it will not only be able to embed the microstructures formed on the substrate well, but it will also be possible to form an organic film in which the entire substrate is flat.

[0080] <Method for producing compounds for forming organic films> The organic film-forming compound of the present invention can be obtained by first reacting an amine compound with an aromatic carboxylic acid anhydride to obtain an amidic acid compound (STEP 1), followed by thermal or chemical imidation (STEP 2). The amine compound or aromatic carboxylic acid anhydride used in synthesizing the amidic acid compound can be used alone or in combination of two or more types. These can be appropriately selected and combined according to the required properties. W1, R1, n1, and n2 in the following formula are the same as above. It should be noted that, not limited to semiconductor substrate planarization applications, it is also possible to use the amidic acid compound directly as an organic film-forming compound without imidation when forming organic films for electronic materials, etc.

[0081] STEP 1: Synthesis of Amido Acid Compounds [ka]

[0082] STEP 2: Synthesis of imide compounds [ka]

[0083] The synthesis of the amidic acid compounds shown in STEP 1 can usually be carried out in an organic solvent at room temperature or, if necessary, under cooling or heating. Suitable solvents include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; and chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene. Examples of suitable solvents include hydrocarbons such as xane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate, and γ-butyrolactone; and aprotic polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used individually or in combination of two or more. These solvents can be used in an amount of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials. 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 from 0.1 to 100 hours.

[0084] These synthesis processes may utilize base catalysts as needed. Examples of base catalysts include inorganic base compounds such as sodium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, and potassium phosphate, as well as organic bases such as triethylamine, diisopropylethylamine, N,N-dimethylaniline, pyridine, and 4-dimethylaminopyridine. These may be used individually or in combination of two or more. The amount used is in the range of 0.01 to 20 moles, preferably 0.05 to 10 moles, relative to the number of moles of the aromatic carboxylic acid anhydride used as a raw material.

[0085] The reaction methods include charging the amine compound and aromatic carboxylic acid anhydride together in the solvent; dispersing or dissolving the amine compound and aromatic carboxylic acid anhydride individually or in combination in the solvent and adding them dropwise; or dispersing or dissolving one of the amine compound or aromatic carboxylic acid anhydride in the solvent and then adding the other, which has also been dispersed or dissolved in the solvent, dropwise. When charging multiple amine compounds or aromatic carboxylic acid anhydrides, they can be mixed beforehand and reacted, or reacted individually and sequentially. When using a catalyst, methods include charging it together with the amine compound or aromatic carboxylic acid anhydride, or dispersing or dissolving the catalyst beforehand and then adding it dropwise. The resulting amide acid solution can proceed to the dehydration imidation reaction in STEP 2. Furthermore, the resulting amide acid solution can be used as is not limited to semiconductor material applications, but can also be used as an organic film-forming compound. To remove unreacted raw materials and catalysts present in the system, it can be diluted in an organic solvent and recovered by liquid-liquid washing.

[0086] The organic solvent used for liquid-liquid washing is not particularly limited as long as it can dissolve the compound and separates into two layers when mixed with water. Examples include hydrocarbons such as hexane, heptane, benzene, toluene, and xylene; esters such as ethyl acetate, n-butyl acetate, and propylene glycol methyl ether acetate; ketones such as methyl ethyl ketone, methyl amyl ketone, cyclohexanone, and methyl isobutyl ketone; ethers such as diethyl ether, diisopropyl ether, methyl tert-butyl ether, and ethyl cyclopentyl methyl ether; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; and mixtures thereof. The washing water used in this process can be what is commonly called deionized water or ultrapure water. One or more washes are sufficient, but washing more than 10 times does not necessarily guarantee the desired washing effect, so 1 to 5 washes are preferable.

[0087] During liquid-liquid washing, washing with a basic aqueous solution may be performed to remove unreacted raw materials and acidic components from the system. Examples of basics include alkali metal hydroxides, alkali metal carbonates, alkaline earth metal hydroxides, alkaline earth metal carbonates, ammonia, and organic ammonium compounds.

[0088] Furthermore, in order to remove unreacted raw materials, metal impurities, and basic components from the system during liquid-liquid washing, washing with an acidic aqueous solution may be performed. Examples of suitable acids include inorganic acids such as hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, and heteropoly acids, and organic acids such as oxalic acid, fumaric acid, maleic acid, trifluoroacetic acid, methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, and trifluoromethanesulfonic acid.

[0089] The above-mentioned separation and washing with basic aqueous solutions and acidic aqueous solutions may be performed individually or in combination. From the viewpoint of removing metal impurities, it is preferable to perform the separation and washing in the order of basic aqueous solution followed by acidic aqueous solution.

[0090] After the separation and washing with the above-mentioned basic and acidic aqueous solutions, further washing with neutral water may be performed. One or more washes are sufficient, but preferably 1 to 5 washes. As neutral water, deionized water or ultrapure water as described above can be used. One or more washes are sufficient, but if the number of washes is insufficient, basic and acidic components may not be removed. Washing more than 10 times does not necessarily guarantee the desired effect, so preferably 1 to 5 washes are performed.

[0091] Furthermore, the reaction product after the liquid-liquid separation can be recovered as a powder by concentrating the solvent to dryness or crystallizing it under reduced pressure or atmospheric pressure. However, to improve the operability when preparing the organic film-forming material of the present invention, which will be described later, it is also possible to keep it in a solution of an appropriate concentration. The concentration at this time is preferably 0.1 to 50% by mass, and more preferably 0.5 to 30% by mass. At such a concentration, the viscosity does not tend to become high, thus preventing impairment of operability, and it is also economical because the amount of solvent does not become excessive.

[0092] The solvent used in this case is not particularly limited as long as it can dissolve the compound, but 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 monotert-butyl ether acetate. These can be used individually or in combination of two or more types.

[0093] The imide compound obtained in the reaction equation of STEP 2 can be synthesized by thermal or chemical imidation. These methods can be appropriately selected depending on the thermal stability of the crosslinking group of the target imide compound and the reactivity of the introduced substituent with the reagent used during chemical imidation.

[0094] When performing thermal imidation, add a solvent that can azeotrope with water to the reaction solution of the amidic acid compound obtained in STEP 1 (or, if recovered as a powder, dissolved in a soluble solvent beforehand), heat to 100°C to 250°C, and perform imidation by a dehydration ring-closing reaction while removing the generated water.

[0095] As solvents that can azeotrope with water, polar solvents such as esters like γ-butyrolactone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, and N,N-dimethylformamide, and nonpolar solvents such as benzene, toluene, xylene, and mesitylene can be used. It is preferable to heat these solvents individually or in combination and dehydrate them while distilling off the water produced by ring closure. These solvents can be used in a range of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials.

[0096] When performing chemical imidation, a base catalyst and an acid anhydride or the like as a dehydrating agent are added to the reaction solution of the amidic acid compound obtained in STEP 1 (or, if recovered as a powder, dissolved in a soluble solvent beforehand), and imidation is carried out at a temperature of 0°C to 120°C.

[0097] Examples of base catalysts used for chemical imidation include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine. Among these, pyridine is preferred because it has a suitable basicity for the reaction to proceed. Examples of dehydrating agents include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, trifluoroacetic anhydride, polyphosphate, phosphorus pentoxide, phosphorus pentachloride, and thionyl chloride. Acetic anhydride is preferred from the viewpoint of purification after the reaction. The amount of these catalysts used is in the range of 0.1 to 20 moles, preferably 0.2 to 10 moles, relative to the number of moles of the acid anhydride raw material. In addition, the base catalyst and dehydrating agent may be used individually or in combination of two or more types. The imidation rate can be appropriately controlled by adjusting the amount of catalyst, amount of dehydrating agent, reaction temperature, and reaction time according to the required performance of the target compound.

[0098] The solvent used at this time is not particularly limited as long as it is inert to the above reaction, but examples include ethers such as diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate, and γ-butyrolactone; and aprotic polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used individually or in mixtures. These solvents can be used in an amount of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials.

[0099] The reaction method and the method for recovering the compound can be the methods described in the section on amidic acid compounds.

[0100] As described above, the organic film-forming compound of the present invention provides an organic film-forming material that possesses both heat resistance of 400°C or higher and advanced embedding / planarization properties.

[0101] In this invention, planarization characteristics refer to the ability to planarize the surface of a substrate. With an organic film-forming material containing the organic film-forming compound of the present invention, for example, as shown in Figure 1, by applying the organic film-forming material 3' to a substrate 1 and heating it to form an organic film 3, it is possible to reduce a 100 nm step on the substrate 1 to 30 nm or less. The step shape shown in Figure 1 is a typical example of a step shape in a substrate for semiconductor device manufacturing, and the step shapes of substrates that can be planarized with the organic film-forming material containing the organic film-forming compound of the present invention are, of course, not limited to this.

[0102] <Aromatic carboxylic acid anhydrides> The aromatic carboxylic acid anhydride of the present invention is represented by the following general formula (1F). [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1G), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0103] In the above formula (1G), R1 functions as a thermal crosslinking group. Due to its curability, heat resistance, and ease of obtaining raw materials, it is preferably an ethynyl group or an ethynylphenyl group. Substituents on the aromatic ring include halogen atoms such as fluorine, bromine, and iodine, and alkyl groups such as methyl, ethyl, and propyl. Due to the ease of obtaining raw materials, fluorine is preferred as the substituent.

[0104] In the above general formula (1F), n2 is 1 or 2, and n2=1 is preferred due to the ease of obtaining raw materials and manufacturing. Examples of substituents on the aromatic ring include halogen atoms such as fluorine, bromine, and iodine, and alkyl groups such as methyl, ethyl, and propyl. When the number of substituents on the aromatic ring on the acid anhydride is N1, the relationship 0≦N1≦3 is satisfied. When the number of substituents on the aromatic ring having R1 is N2, the relationships 0≦N2≦3, 1≦n2≦2, and 1≦n2+N2≦4 are satisfied. Fluorine is preferred as a substituent due to the ease of obtaining raw materials.

[0105] Aromatic carboxylic acid anhydrides as described above contain ether structures and crosslinking groups as terminal structures, and do not contain many polar groups. Such aromatic carboxylic acid anhydrides can impart not only heat resistance and crosslinking properties to imide-based materials, including polyimides, but also seemingly contradictory properties such as high Tg and processability (film formation properties, etc.). Therefore, they can impart not only heat resistance but also properties required for electronic and aerospace materials, such as low dielectric constant and curability, making them industrially very useful candidates as end-capturing agents for polyimides and imide compounds.

[0106] Examples of aromatic carboxylic acid anhydrides as described above include the following: [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] As described above, the aromatic carboxylic acid anhydride of the present invention is not limited to being a raw material for semiconductor planarization film formation compounds, but is also expected to be an industrially useful compound as a raw material for polyimide and imide compounds that can be used in electronic materials, aerospace materials, and the like.

[0112] <Method for producing aromatic carboxylic acid anhydrides> The aromatic carboxylic acid anhydride of the present invention can be synthesized by an etherification reaction (STEP 1) via substitution between phthalonitrile having a fluorine substituent and phenol having R1 as a substituent, followed by conversion to a carboxylic acid by hydrolysis of the nitrile (STEP 2), and then dehydration condensation of adjacent carboxylic acids (STEP 3). R1, n1, and n2 in the following formula are the same as above. In addition to semiconductor substrate planarization applications, it is also possible to use the amide acid compound directly as an organic film-forming compound without imidization when forming organic films for electronic materials, etc.

[0113] STEP 1: Substitution reaction [ka]

[0114] STEP 2: Hydrolysis [ka]

[0115] STEP 3: Dehydration and condensation [ka]

[0116] The substitution reaction shown in STEP 1 can usually be carried out in an organic solvent at room temperature or under cooling or heating as necessary. Suitable organic solvents include alcohols such as methanol, ethanol, isopropyl alcohol, butanol, ethylene glycol, propylene glycol, diethylene glycol, glycerol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ethers such as diethyl ether, dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; and chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene. Examples of suitable solvents include hydrocarbons such as xane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate, and γ-butyrolactone; and aprotic polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used individually or in combination of two or more. These solvents can be used in an amount of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials. The reaction temperature is preferably from -50°C to the boiling point of the solvent, and more preferably from room temperature to 200°C. The reaction time is appropriately selected from 0.1 to 100 hours.

[0117] These synthesis processes may utilize base catalysts as needed. Examples of base catalysts include inorganic base compounds such as sodium bicarbonate, sodium carbonate, potassium carbonate, calcium carbonate, cesium carbonate, sodium hydroxide, potassium hydroxide, sodium hydride, and potassium phosphate, as well as organic bases such as triethylamine, diisopropylethylamine, N,N-dimethylaniline, pyridine, and 4-dimethylaminopyridine. These may be used individually or in combination of two or more. The amount used is in the range of 0.01 to 20 moles, preferably 0.05 to 10 moles, relative to the number of moles of the aromatic carboxylic acid anhydride used as a raw material.

[0118] The reaction method and compound recovery method can be the same as those described in the section on amidic acid compounds. The recovered compound can be purified by recrystallization, crystallization, distillation, etc., according to the physical properties of the reaction product. Alternatively, the reaction can proceed to the next step without a post-reaction purification step.

[0119] The hydrolysis reaction shown in STEP 2 can usually be carried out at room temperature or under cooling or heating as needed, using water such as distilled water, deionized water, or ultrapure water. In addition to the above water, an organic solvent can also be used. Organic solvents that can be mixed with water include one or more of the following: ethanol, methanol, propanol, acetone, methyl ethyl ketone, diethyl ether, diisopropyl ether, tetrahydrofuran, dioxane, benzene, toluene, xylene, chloroform, dichloromethane, trichloroethylene, carbon tetrachloride, etc. The amount of water used is not particularly limited, but it is preferably about 1 to 10 moles, and more preferably about 2 to 5 moles, relative to the raw material ether compound. If the amount of water used is above the lower limit, the hydrolysis reaction will proceed sufficiently. If the amount used is below the upper limit, a large amount of solvent will not be used, and an improvement in yield can be expected. When using an organic solvent, it can be used in the range of 0 to 2,000 parts by mass per 100 parts by mass of water, and the reaction temperature is preferably from -50°C to around the boiling point of the solvent, and more preferably from room temperature to 200°C. The reaction time is selected appropriately from 0.1 to 100 hours.

[0120] These synthesis reactions can be carried out using an acid or base catalyst as needed. Examples of acid catalysts include hydrochloric acid, sulfuric acid, nitric acid, chloric acid, bromate, methanesulfonic acid, and p-toluenesulfonic acid, and one or more of these can be used in combination. Examples of base catalysts include lithium hydroxide, sodium hydroxide, potassium hydroxide, calcium hydroxide, and magnesium hydroxide, and one or more of these can be used in combination. The amount used is in the range of 0.01 to 20 moles, preferably 0.05 to 10 moles, relative to the number of moles of the raw material ether compound. Hydrolysis can be carried out more efficiently within this range of acid or base usage.

[0121] The reaction method and compound recovery method can be the same as those described in the section on amidic acid compounds. The recovered compound can be purified by recrystallization, crystallization, distillation, etc., according to the physical properties of the reaction product. Alternatively, the reaction can proceed to the next step without a post-reaction purification step.

[0122] The dehydration condensation reaction shown in STEP 3 involves adding a solvent that can be azeotropically mixed with water, heating to 100°C to 250°C, and removing the generated water while converting to an acid anhydride through a dehydration ring-closing reaction.

[0123] As solvents that can azeotrope with water, polar solvents such as esters like γ-butyrolactone, N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, and N,N-dimethylformamide, and non-polar solvents such as benzene, toluene, xylene, and mesitylene can be used. It is preferable to heat these solvents individually or in combination and dehydrate them while distilling off the water produced by ring closure. These solvents can be used in a range of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials.

[0124] Another method for the dehydration condensation reaction involves using a dehydrating agent. Acid anhydrides, for example, can be added as a dehydrating agent, and the conversion to acid anhydrides can be carried out at temperatures between 0°C and 120°C.

[0125] Examples of dehydrating agents include acetic anhydride, trimellitic anhydride, pyromellitic anhydride, trifluoroacetic anhydride, polyphosphate, phosphorus pentoxide, phosphorus pentachloride, and thionyl chloride, with acetic anhydride being preferred from the viewpoint of purification after the reaction. The amount of these dehydrating agents used is preferably about 1 to 10 moles, and more preferably about 2 to 5 moles, relative to the reaction raw materials. If the amount of dehydrating agent used is above the lower limit, the dehydration condensation reaction will proceed sufficiently. If the amount used is below the upper limit, no excess dehydrating agent will remain, and an improvement in yield can be expected. Furthermore, a base catalyst may be used together with the dehydrating agent at this time, and examples of base catalysts include pyridine, triethylamine, trimethylamine, tributylamine, and trioctylamine, among which pyridine is preferred because it has a suitable basicity for the reaction to proceed. The amount of these base catalysts used is in the range of 0.1 to 20 moles, preferably 0.2 to 10 moles, relative to the number of moles of carboxylic acid in the raw materials. Furthermore, the base catalyst and dehydrating agent may be used individually or in combination of two or more types. These can be appropriately controlled by adjusting the amount of catalyst, the amount of dehydrating agent, the reaction temperature, and the reaction time according to the reactivity and heat resistance of the target compound.

[0126] The solvent used at this time is not particularly limited as long as it is inert to the above reaction, but examples include ethers such as diethylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, and 1,4-dioxane; chlorinated solvents such as methylene chloride, chloroform, dichloroethane, and trichloroethylene; hydrocarbons such as hexane, heptane, benzene, toluene, xylene, and cumene; nitriles such as acetonitrile; ketones such as acetone, ethyl methyl ketone, isobutyl methyl ketone, and cyclohexanone; esters such as methyl acetate, ethyl acetate, n-butyl acetate, propylene glycol methyl ether acetate, and γ-butyrolactone; and aprotic polar solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, N,N-dimethylformamide, and hexamethylphosphoric triamide. These can be used individually or in mixtures. These solvents can be used in an amount of 0 to 2,000 parts by mass per 100 parts by mass of the reaction raw materials.

[0127] The reaction method and compound recovery method can be the same as those described in the section on amidic acid compounds. The recovered compound can be purified by recrystallization, crystallization, distillation, etc., according to the physical properties of the reaction product. Alternatively, the reaction can proceed to the next step without a post-reaction purification step.

[0128] <Materials for organic film formation> Furthermore, the present invention provides an organic film-forming material (organic film-forming composition) that contains (A) the organic film-forming compound of the present invention represented by the general formula (1A) above, and (B) an organic solvent. In the organic film-forming material of the present invention, the above-mentioned organic film-forming compound of the present invention can be used individually or in combination of two or more.

[0129] The (B) organic solvent that can be used in the organic film-forming material of the present invention is not particularly limited as long as it dissolves the above-mentioned compound and other components contained in the material such as additives. Specifically, solvents with a boiling point of less than 180°C, such as the solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Application Publication No. 2007-199653, can be used. Among these, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more of these are preferably used. The amount of (B) organic solvent blended is preferably 200 to 10,000 parts by mass, more preferably 300 to 5,000 parts by mass, per 100 parts by mass of the (A) compound.

[0130] Such an organic film-forming material can be applied by rotary coating, and because it contains the organic film-forming compound of the present invention as described above, it is an organic film-forming material that combines heat resistance of 400°C or higher with advanced embedding / planarization characteristics.

[0131] Furthermore, the organic film-forming material of the present invention may also include a high-boiling-point solvent with a boiling point of 180°C or higher as an organic solvent to the above-mentioned solvent with a boiling point of less than 180°C. That is, it is preferable that component (B) is a mixture of one or more organic solvents with a boiling point of less than 180°C and one or more organic solvents with a boiling point of 180°C or higher. As for the high-boiling-point solvent, there are no particular restrictions on hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc., as long as it can dissolve the organic film-forming compound, but specific examples include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-Hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, n-nonyl acetate, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol monoisobutyl ether, diethylene glycol monohexyl ether, diethylene glycol monophenyl ether, diethylene glycol monobenzyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diethylene glycol butyl methyl ether, triethylene glycol dimethyl ether, triethylene glycol monomethyl ether, triethylene glycol n-butyl ether, triethylene glycol butyl methyl ether, triethylene Glycol diacetate, tetraethylene glycol dimethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol dimethyl ether, tripropylene glycol monomethyl ether, tripropylene glycol mono-n-propyl ether, tripropylene glycol mono-n-butyl ether, ethylene glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triacetin, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, dipropylene glycol methyl ether acetate, 1,4-butanediol diacetate, 1,3-butylene glycol diacetate, 1,Examples include 6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, and dibutyl adipate, which may be used individually or in combination.

[0132] The boiling point of the high-boiling point solvent can be appropriately selected according to the temperature at which the organic film-forming material is heat-treated. Preferably, the boiling point of the added high-boiling point solvent is 180°C to 300°C, and more preferably 200°C to 300°C. With such a boiling point, there is no risk of excessive volatilization during baking (heat treatment) due to a boiling point that is too low, thus sufficient thermal fluidity can be obtained. Furthermore, with such a high boiling point, there is no risk of residual solvent remaining in the film after baking without volatilizing, thus avoiding adverse effects on film properties such as etching resistance.

[0133] Furthermore, when using the above-mentioned high-boiling-point solvent, the amount of high-boiling-point solvent added is preferably 1 to 30 parts by mass per 100 parts by mass of solvent with a boiling point of less than 180°C. With such an amount, there is no risk of the amount being too small to provide sufficient thermal fluidity during baking, or of the amount being too large remaining in the film and leading to deterioration of film properties such as etching resistance.

[0134] With such organic film-forming materials, the addition of a high-boiling-point solvent to the above-mentioned organic film-forming compound imparts thermal fluidity, resulting in an organic film-forming material that also possesses advanced embedding / planarization properties.

[0135] Furthermore, it is preferable that the organic film-forming material further contains one or more of the following: (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, and (F) a plasticizer. Each component will be described in detail below.

[0136] In the organic film-forming material of the present invention, an (C) acid generator can be added to further accelerate the curing reaction. The (C) acid generator may be one that generates acid by thermal decomposition or one that generates acid by light irradiation, and either type can be added. Specifically, the materials described in paragraphs

[0061] to

[0085] of Japanese Patent Application Publication No. 2007-199653 can be added, but are not limited to these.

[0137] The above (C) acid generating agent can be used individually or in combination of two or more types. When adding the (C) acid generating agent, the amount to be added is preferably 0.05 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the above (A) compound.

[0138] The organic film-forming material of the present invention may contain a (D) surfactant to improve its coating properties in spin coating. As the (D) surfactant, for example, the one described in paragraphs

[0142] to

[0147] of Japanese Patent Application Publication No. 2009-269953 can be used. When adding the (D) surfactant, the amount to be added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, per 100 parts by mass of the (A) compound.

[0139] Furthermore, the organic film-forming material of the present invention may also contain (E) a crosslinking agent to enhance curability and further suppress intermixing with the upper film. The (E) crosslinking agent is not particularly limited, and various known crosslinking agents of different types can be widely used. Examples include melamine-based crosslinking agents, glycoluryl-based crosslinking agents, benzoguanamine-based crosslinking agents, urea-based crosslinking agents, β-hydroxyalkylamide-based crosslinking agents, isocyanurate-based crosslinking agents, aziridine-based crosslinking agents, oxazoline-based crosslinking agents, and epoxy-based crosslinking agents.

[0140] Examples of melamine-based crosslinking agents include hexamethoxymethylated melamine, hexasubtoxicmethylated melamine, alkoxy and / or hydroxy-substituted derivatives thereof, and partially self-condensed derivatives thereof. Examples of glycoluryl crosslinking agents include tetramethoxymethylated glycoluryl, tetrabutoxymethylated glycoluryl, their alkoxy and / or hydroxy substituted derivatives, and their partial self-condensates. Examples of benzoguanamine-based crosslinking agents include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, their alkoxy and / or hydroxy-substituted derivatives, and their partial self-condensed derivatives. Examples of urea-based crosslinking agents include dimethoxymethylated dimethoxyethyleneurea, its alkoxy and / or hydroxy-substituted derivatives, and partially self-condensed derivatives thereof. A specific example of a β-hydroxyalkylamide crosslinking agent is N,N,N',N'-tetra(2-hydroxyethyl)adipamide. Examples of isocyanurate-based crosslinking agents include triglycidyl isocyanurate and triallyl isocyanurate. Examples of aziridine-based crosslinking agents include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate]. Examples of oxazoline-based crosslinking agents include 2,2'-isopropylidenebis(4-benzyl-2-oxazoline), 2,2'-isopropylidenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis(4,5-diphenyl-2-oxazoline), 2,2'-methylenebis(4-phenyl-2-oxazoline), 2,2'-methylenebis(4-tertbutyl-2-oxazoline), 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyloxazoline copolymers. Examples of epoxy crosslinking agents include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0141] (E) When a crosslinking agent is added, the amount added is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of the compound (A).

[0142] Furthermore, to further improve the planarization / embedding properties, a plasticizer (F) may be added to the organic film-forming material of the present invention. The plasticizer (F) is not particularly limited, and various known types of plasticizers can be widely used. Examples include low molecular weight compounds such as phthalates, adipicates, phosphates, trimelliticates, and citrates, as well as polymers such as polyethers, polyesters, and polyacetal polymers described in Japanese Patent Application Publication No. 2013-253227. When adding the plasticizer (F), the amount to be added is preferably 1 to 100 parts by mass, more preferably 5 to 30 parts by mass, per 100 parts by mass of the above (A) compound.

[0143] Furthermore, the organic film-forming material of the present invention preferably uses, as an additive to impart embedding / planarization properties in the same way as a plasticizer, a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a pyrolytic polymer having a weight loss rate of 40% by mass or more between 30°C and 250°C and a weight-average molecular weight of 300 to 200,000. This pyrolytic polymer preferably contains repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a). When adding these liquid additives, the amount added is preferably 1 to 100 parts by mass, more preferably 5 to 50 parts by mass, per 100 parts by mass of the above (A) compound.

[0144] [ka] (In the formula, X 11 (where Y1 is a hydrogen atom or a saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms, which may be substituted.)

[0145] [ka] (In the formula, X a Y is an alkyl group having 1 to 4 carbon atoms. a (I is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms, and may have an ether bond. l represents the average number of repeating units, which is between 3 and 500.)

[0146] As described above, the organic film forming material of the present invention is an organic film forming material that possesses both heat resistance of 400°C or higher and advanced embedding / planarization characteristics. Therefore, the organic film forming material of the present invention is extremely useful as an organic film forming material for multilayer resist methods such as the two-layer resist method, the three-layer resist method using a silicon-containing resist interlayer or inorganic hard mask interlayer, the four-layer resist method using a silicon-containing resist interlayer or inorganic hard mask interlayer, and an organic anti-reflective film. Furthermore, since the organic film forming material of the present invention does not generate by-products even when forming films in an inert gas and has excellent embedding / planarization characteristics, it can also be suitably used as a planarization material in semiconductor device manufacturing processes other than the multilayer resist method.

[0147] <Substrates for semiconductor device manufacturing> Furthermore, the present invention provides a substrate for semiconductor device manufacturing, wherein an organic film formed on the substrate is obtained by curing the above-mentioned organic film-forming material.

[0148] Organic films formed from the organic film-forming material of the present invention possess advanced embedding and planarization characteristics, resulting in organic films free from micro-voids due to poor embedding and surface irregularities due to insufficient planarization. Semiconductor device substrates planarized with such organic films have a wider process margin during patterning, enabling the manufacture of semiconductor devices with a higher yield.

[0149] <Method for forming organic films> The present invention provides a method for forming an organic film applicable in the manufacturing process of a semiconductor device, comprising: rotating and coating a substrate with the organic film-forming material; and then heat-treating the substrate coated with the organic film-forming material in an inert gas atmosphere at a temperature of 50°C to 600°C for a range of 10 to 7200 seconds to obtain an organic film (single-stage bake).

[0150] Furthermore, the present invention provides a method for forming an organic film that can flatten the surface of a stepped substrate used in the manufacturing process of semiconductor devices, comprising: rotating and coating the above-mentioned organic film forming material onto a substrate to be processed; heat-treating the substrate coated with the organic film forming material in air at a temperature of 50°C to 300°C for 5 to 600 seconds to form a coated film; and subsequently applying heat treatment in an inert gas atmosphere at a temperature of 200°C to 600°C for 10 to 7200 seconds to obtain an organic film (two-stage bake).

[0151] In this organic film formation method, first, the organic film forming material of the present invention described above is applied to the substrate to be processed by spin coating. By using the spin coating method, good embedding characteristics can be obtained. After spin coating, baking (heat treatment) is performed to promote planarization by thermal fluid and crosslinking reaction. Furthermore, since this baking evaporates the organic solvent in the organic film forming material, mixing can be prevented even when forming a resist upper layer film or a silicon-containing resist interlayer film on the organic film.

[0152] The heat deposition process for forming the organic film (organic underlayer film) can be a single-stage bake, a two-stage bake, or a multi-stage bake of three or more stages, but a single-stage bake or a two-stage bake is economically preferable.

[0153] Film deposition by single-stage baking is preferably carried out in an inert gas atmosphere at a temperature of 50°C to 600°C for 10 to 7200 seconds, preferably at a temperature of 150°C to 500°C for 10 to 3600 seconds. Heat treatment under these conditions promotes thermal fluidization, planarization, and crosslinking reactions.

[0154] On the other hand, for film deposition by two-stage baking, considering the effect of corrosion of the substrate by oxygen in the air, the first stage of baking is performed in air at a temperature of 50°C to 300°C, preferably 250°C or lower, for a period of 5 to 600 seconds. The second stage of baking is performed in an inert gas, and the baking temperature is preferably higher than the first stage baking temperature, at a temperature of 200°C to 600°C, preferably 250°C to 500°C, for a period of 10 to 7200 seconds.

[0155] In the multilayer resist method, a silicon-containing resist interlayer or an inorganic hard mask interlayer may be formed on the obtained organic film. When a silicon-containing resist interlayer is applied, it is preferable to form the organic film at a temperature higher than the temperature at which the silicon-containing resist interlayer is formed. Typically, the silicon-containing resist interlayer is formed at a temperature of 100°C to 400°C, preferably 150°C to 350°C. Forming the organic film at a temperature higher than this prevents the dissolution of the organic film by the silicon-containing resist interlayer forming composition, and allows for the formation of an organic film that does not mix with the composition. When an inorganic hard mask interlayer is applied, it is preferable to form the organic film at a temperature higher than the temperature at which the inorganic hard mask interlayer is formed. An example of a temperature for forming the inorganic hard mask interlayer is 150°C to 500°C.

[0156] Furthermore, the present invention provides a method for forming an organic film used in the manufacturing process of semiconductor devices, wherein the organic film is formed by heat-treating the substrate in an atmosphere with an oxygen concentration of 1% or less in order to prevent corrosion of the substrate. Specifically, it is preferable that the oxygen concentration in the inert gas atmosphere be 1% or less.

[0157] In this organic film formation method, first, the organic film forming material of the present invention described above is applied to the substrate to be processed by spin coating. After spin coating, in the case of a two-stage bake, the first stage of baking is performed in air at 300°C or below, and then the second stage of baking is performed in an atmosphere with an oxygen concentration of 1% or less. In the case of a one-stage bake, the first stage of baking in air can be skipped. Examples of atmospheres during baking include inert gases such as nitrogen, argon, and helium. With the organic film forming material of the present invention, even when fired in such an inert gas atmosphere, a sufficiently hardened organic film can be formed without the generation of sublimation.

[0158] Furthermore, in the method for forming an organic film of the present invention, a substrate having a structure or step with a height of 30 nm or more can be used as the substrate to be processed. As described above, the organic film forming material of the present invention has excellent embedding / planarization properties, so a flat organic film can be formed even if the substrate to be processed has a structure or step (unevenness) with a height of 30 nm or more. In other words, the method for forming an organic film of the present invention is particularly useful when forming a flat organic film on such a substrate to be processed.

[0159] The thickness of the formed organic film is selected as appropriate, but is preferably 30 to 20,000 nm, and particularly preferably 50 to 15,000 nm.

[0160] Furthermore, the above method for forming an organic film is applicable to both cases: when forming an organic film for an organic underlayer using the organic film forming material of the present invention, and when forming an organic film for a planarization film.

[0161] <Pattern Formation Method> [Three-layer resist method using silicon-containing resist interlayer] The present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming a resist upper layer on the silicon-containing resist interlayer using a photoresist composition; forming a circuit pattern on the resist upper layer; transferring the pattern to the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0162] Preferably, the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which any of the following films are deposited: a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film. More specifically, although not particularly limited, substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, etc., or a substrate on which the above-mentioned metal films, etc., are deposited as the workpiece layer, can be used.

[0163] Various low-k films and their stopper films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, can be used as the workpiece layer, and can typically be formed to a thickness of 50 to 10,000 nm, and especially 100 to 5,000 nm. When forming the workpiece layer, the substrate and the workpiece layer are made of different materials.

[0164] Furthermore, it is preferable to use a workpiece containing silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or alloys thereof.

[0165] Furthermore, it is preferable to use a workpiece that has a structure or step with a height of 30 nm or more as the workpiece.

[0166] When forming an organic film on a workpiece using the organic film-forming material of the present invention, the organic film-forming method of the present invention described above may be applied.

[0167] Next, a resist interlayer (silicon-containing resist interlayer) is formed on the organic film using a resist interlayer material containing silicon atoms. A polysiloxane-based interlayer material is preferred as the silicon-containing resist interlayer material. By giving the silicon-containing resist interlayer an anti-reflective effect, reflection can be suppressed. In particular, for 193nm exposure, if a material containing many aromatic groups and having high etching selectivity with the substrate is used as the organic film formation material, the k value will be high and substrate reflection will be high. However, by giving the silicon-containing resist interlayer an absorption that results in an appropriate k value, reflection can be suppressed, and substrate reflection can be reduced to 0.5% or less. As silicon-containing resist interlayers with an anti-reflective effect, anthracene is preferred for 248nm and 157nm exposure, and for 193nm exposure, a polysiloxane with a structure pendanting a phenyl group or an absorbent group having a silicon-silicon bond, or a polysiloxane structure that is crosslinked by acid or heat, is preferred.

[0168] Next, a resist upper film is formed on the silicon-containing resist interlayer using a resist upper film material consisting of a photoresist composition. The resist upper film material can be either positive or negative type, and the same photoresist compositions commonly used can be used. After spin-coating the resist upper film material, it is preferable to perform a pre-bake at 60-180°C for 10-300 seconds. Then, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain the resist upper film pattern. The thickness of the resist upper film is not particularly limited, but 30-500 nm is preferred, and 50-400 nm is particularly preferred.

[0169] Next, a circuit pattern (resist upper layer pattern) is formed on the resist upper layer. In forming the circuit pattern, it is preferable to form the circuit pattern by lithography using light with a wavelength of 10 nm to 300 nm, direct writing with an electron beam, nanoimprinting, or a combination thereof.

[0170] Examples of exposure light include high-energy rays with wavelengths of 300 nm or less, specifically far ultraviolet light, 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) in the 3-20 nm range, electron beams (EB), ion beams, and X-rays.

[0171] Furthermore, in forming the circuit pattern, it is preferable to develop the circuit pattern using alkaline development or an organic solvent.

[0172] Next, the resist upper layer film on which the circuit pattern has been formed is used as a mask to transfer the pattern to the silicon-containing resist interlayer film by etching. It is preferable to use a fluorocarbon-based gas for etching the silicon-containing resist interlayer film using the resist upper layer film pattern as a mask. This forms the silicon-containing resist interlayer film pattern.

[0173] Next, the silicon-containing resist interlayer, onto which the pattern has been transferred, is used as a mask to transfer the pattern to the organic film by etching. Since the silicon-containing resist interlayer exhibits higher etching resistance to oxygen or hydrogen gas compared to the organic film, it is preferable to use an etching gas mainly composed of oxygen or hydrogen gas when etching the organic film using the silicon-containing resist interlayer pattern as a mask. This allows for the formation of the organic film pattern.

[0174] Next, the pattern is transferred to the substrate by etching, using the organic film on which the pattern has been transferred as a mask. Etching of the substrate (workpiece layer) can be performed by conventional methods. For example, if the substrate is made of SiO2, SiN, or silica-based low dielectric constant insulating film, etching is performed mainly with fluorocarbon gases; if it is made of p-Si, Al, or W, etching is performed mainly with chlorine-based or bromine-based gases. When substrate processing is performed by etching with fluorocarbon gases, the silicon-containing resist interlayer pattern is removed simultaneously with the substrate processing. On the other hand, when substrate processing is performed by etching with chlorine-based or bromine-based gases, dry etching with fluorocarbon gases is required separately after substrate processing to remove the silicon-containing resist interlayer pattern.

[0175] The organic film obtained using the organic film forming material of the present invention can have excellent etching resistance when the substrate to be processed is etched, as described above.

[0176] [Four-layer resist method using silicon-containing resist interlayer and organic anti-reflective coating] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming an organic anti-reflective film on the silicon-containing resist interlayer; forming a resist upper layer on the organic anti-reflective film using a photoresist composition to form a four-layer structure; forming a circuit pattern on the resist upper layer; transferring the pattern to the organic anti-reflective film and the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0177] This method can be carried out in the same manner as the three-layer resist method using the silicon-containing resist interlayer described above, except that an organic anti-reflective coating (BARC) is formed between the silicon-containing resist interlayer and the resist upper layer.

[0178] Organic anti-reflective coatings can be formed by spin coating using known organic anti-reflective coating materials.

[0179] [Three-layer resist method using inorganic hard mask interlayer] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming a resist upper layer film on the inorganic hard mask interlayer film using a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring the pattern to the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0180] This method can be carried out in the same manner as the three-layer resist method using the silicon-containing resist interlayer described above, except that an inorganic hard mask interlayer is formed on top of the organic film instead of a silicon-containing resist interlayer.

[0181] Inorganic hard mask interlayers selected from silicon oxide films, silicon nitride films, silicon oxynitride films (SiON films), titanium oxide films, and titanium nitride films can be formed by CVD or ALD methods. Specifically, it is preferable to form the inorganic hard mask interlayer by CVD or ALD. Methods for forming silicon nitride films are described, for example, in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The thickness of the inorganic hard mask interlayer is preferably 5 to 200 nm, more preferably 10 to 100 nm. Among inorganic hard mask interlayers, the SiON film, which has a high anti-reflective effect, is most preferably used. Since the substrate temperature when forming the SiON film is 300 to 500°C, the organic film needs to withstand temperatures of 300 to 500°C. The organic film formed using the organic film-forming material of the present invention has high heat resistance and can withstand high temperatures of 300°C to 500°C, making it possible to combine an inorganic hard mask interlayer formed by CVD or ALD with an organic film formed by rotary coating.

[0182] [Four-layer resist method using inorganic hard mask interlayer and organic anti-reflective coating] Furthermore, the present invention provides a pattern formation method comprising: forming an organic film on a workpiece using the organic film forming material described above; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming an organic anti-reflective film on the inorganic hard mask interlayer; forming a resist upper layer film on the organic anti-reflective film using a photoresist composition to form a four-layer film structure; forming a circuit pattern on the resist upper layer film; transferring the pattern to the organic anti-reflective film and the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[0183] This method can be carried out in the same manner as the three-layer resist method using the inorganic hard mask interlayer described above, except that an organic anti-reflective coating (BARC) is formed between the inorganic hard mask interlayer and the resist upper layer.

[0184] In particular, when a SiON film is used as an inorganic hard mask interlayer, the two-layer anti-reflective coating of the SiON film and BARC makes it possible to suppress reflection even in immersion lithography with high NA values ​​exceeding 1.0. Another advantage of forming BARC is that it reduces the trailing of the resist upper layer pattern directly on top of the SiON film.

[0185] Here, an example of the pattern formation method using the three-layer resist method of the present invention is shown in Figures 2(A) to (F). In the three-layer resist method, as shown in Figure 2(A), an organic film 3 is formed on a workpiece layer 2 formed on a substrate 1 using the organic film forming material of the present invention, then a silicon-containing resist interlayer 4 is formed, and a resist upper layer 5 is formed on top of it. Next, as shown in Figure 2(B), the exposed portion 6 of the resist upper layer 5 is exposed and PEB (post-exposure bake) is performed. Next, as shown in Figure 2(C), development is performed to form a resist upper layer pattern 5a. Next, as shown in Figure 2(D), the silicon-containing resist interlayer is dry-etched using a fluorocarbon gas with the resist upper layer pattern 5a as a mask to form a silicon-containing resist interlayer pattern 4a. Next, as shown in Figure 2(E), after removing the resist upper layer pattern, the organic film is oxygen-plasma-etched using the silicon-containing resist interlayer pattern 4a as a mask to form an organic film pattern 3a. Furthermore, as shown in Figure 2(F), after removing the silicon-containing resist interlayer pattern, the workpiece layer is etched using the organic film pattern 3a as a mask to form pattern 2a.

[0186] When forming an inorganic hard mask interlayer, the silicon-containing resist interlayer 4 can be replaced with an inorganic hard mask interlayer. When forming a BARC, the BARC can be formed between the silicon-containing resist interlayer 4 and the resist upper layer 5. Etching of the BARC may be performed consecutively prior to etching of the silicon-containing resist interlayer 4, or etching of only the BARC may be performed first, and then the etching equipment may be changed to etch the silicon-containing resist interlayer 4.

[0187] As described above, with the pattern formation method of the present invention, fine patterns can be formed on a workpiece substrate with high precision using a multilayer resist method. [Examples]

[0188] The present invention will be further described below with reference to synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited thereto. The molecular weight and dispersion were determined by calculating the weight-average molecular weight (Mw) and number-average molecular weight (Mn) in polystyrene terms using gel permeation chromatography (GPC) with tetrahydrofuran as the eluent, and then determining the dispersion (Mw / Mn).

[0189] Synthesis Example: Synthesis of Aromatic Carboxylic Acid Anhydrides The following phenol compounds (a1) to (a5) and phthalonitrile compounds (b1) to (b2) were used to synthesize aromatic carboxylic acid anhydrides (B1) to (B5).

[0190] [Phenols] [ka]

[0191] [Phthalonitriles] [ka]

[0192] [Synthesis Example 1] Synthesis of Aromatic Carboxylic Acid Anhydride (B1)

[0193] Synthesis of aromatic carboxylic acid anhydride (B1): Synthesis of intermediate (B1-1) [ka] 20.0 g (166 mmol) of compound (a1) and 25.3 g (183 mmol) of potassium carbonate were mixed with 100 g of N-methylpyrrolidone (NMP). Under a nitrogen atmosphere, the mixture was dispersed at an internal temperature of 70°C. Then, 92.4 g of a 25% by mass NMP solution of compound (b1) (equivalent to 158 mmol of b1) was slowly added dropwise. The reaction was then carried out at an internal temperature of 80°C for 5 hours. After the resulting reaction solution was cooled to room temperature, 300 ml of diisopropyl ether and 200 g of pure water were added to dissolve the precipitated salt. After standing, the separated aqueous layer was removed and the organic layer was recovered. The organic layer was washed once with 100 g of 1% sodium hydroxide aqueous solution and four times with 100 ml of pure water, and the organic layer was dried under reduced pressure to obtain 33.5 g of (B1-1).

[0194] Synthesis of aromatic carboxylic acid anhydride (B1): Synthesis of intermediate (B1-2) [ka] 33.0 g (134 mmol) of (B1-1) and 26.5 g (equivalent to 402 mmol of KOH) of KOH (15% hydrated) were added to 100 g of ultrapure water and 100 g of ethanol. The reaction was carried out under a nitrogen atmosphere at an internal temperature of 80°C for 30 hours. After the resulting reaction solution was cooled to room temperature, it was added dropwise to 176 g of 10% hydrochloric acid aqueous solution and extracted with 500 ml of ethyl acetate. The organic layer was recovered and washed four times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to make a homogeneous solution, and crystallization was performed with 500 g of hexane. The precipitated crystals were separated by filtration and recovered after washing twice with 100 ml of hexane. The recovered crystals were vacuum dried at 70°C to obtain 29.2 g of (B1-2).

[0195] Synthesis of aromatic carboxylic acid anhydride (B1) [ka] (B1-2) 27.0 g (94.5 mmol) was added with 100 g of acetic anhydride, and the reaction was carried out at an internal temperature of 100 °C for 4 hours under a nitrogen atmosphere. After the obtained reaction solution was cooled to room temperature, 300 g of xylene was added, and acetic acid and acetic anhydride generated in the reaction were distilled off. After adding 50 g of THF to the residue obtained by distillation to make a homogeneous solution, 300 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration and washed 3 times with 200 ml of hexane, and the crystals were recovered. The recovered crystals were dried under vacuum at 70 °C to obtain 23.6 g of (B1).

[0196] [Synthesis Example 2] Synthesis of Aromatic Carboxylic Anhydride (B2)

[0197] Synthesis of Aromatic Carboxylic Anhydride (B2): Synthesis of Intermediate (B2-1)

Chemical formula

[0198] Synthesis of Aromatic Carboxylic Anhydride (B2): Synthesis of Intermediate (B2-2)

Chemical formula

[0199] Synthesis of Aromatic Carboxylic Anhydride (B2)

Chemical formula

[0202] Synthesis of aromatic carboxylic acid anhydride (B3): Synthesis of intermediate (B3-2) [ka] 34.0 g (139 mmol) of (B3-1) and 27.6 g (equivalent to 418 mmol of KOH) of KOH (15% water content) were mixed with 100 g of ultrapure water and 100 g of ethanol. The reaction was carried out under a nitrogen atmosphere at an internal temperature of 80°C for 24 hours. After the resulting reaction solution was cooled to room temperature, it was added dropwise to 183 g of 10% hydrochloric acid aqueous solution and extracted with 400 ml of ethyl acetate. The organic layer was recovered and washed four times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to make a homogeneous solution, and then 400 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration and recovered after washing twice with 100 ml of hexane. The recovered crystals were vacuum dried at 70°C to obtain 29.3 g of (B3-2).

[0203] Synthesis of aromatic carboxylic acid anhydrides (B3) [ka] 29.0 g (103 mmol) of (B3-2) was mixed with 105 g of acetic anhydride, and the reaction was carried out under a nitrogen atmosphere at an internal temperature of 100°C for 4 hours. After the resulting reaction solution was cooled to room temperature, 250 g of xylene was added, and the acetic acid and acetic anhydride produced in the reaction were removed by distillation. 50 g of THF was added to the residue to make a homogeneous solution, and then 300 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed three times with 100 ml of hexane, and the crystals were recovered. The recovered crystals were vacuum-dried at 70°C to obtain 26.7 g of (B3).

[0204] [Synthesis Example 4] Synthesis of Aromatic Carboxylic Acid Anhydride (B4)

[0205] Synthesis of aromatic carboxylic acid anhydride (B4): Synthesis of intermediate (B4-1) [ka] 20.0 g (151 mmol) of compound (a4) and 23.0 g (167 mmol) of potassium carbonate were mixed with 100 g of N-methylpyrrolidone (NMP). Under a nitrogen atmosphere, the mixture was dispersed at an internal temperature of 70°C. Then, 84.0 g of a 25% by mass NMP solution of compound (b1) (equivalent to 143.8 mmol of b1) was slowly added dropwise. The reaction was then carried out at an internal temperature of 80°C for 5 hours. After the resulting reaction solution was cooled to room temperature, 400 ml of diisopropyl ether and 200 g of pure water were added to dissolve the precipitated salt. After standing, the separated aqueous layer was removed and the organic layer was recovered. The organic layer was washed once with 100 g of 1% sodium hydroxide aqueous solution and four times with 100 ml of pure water, and the organic layer was dried under reduced pressure to obtain 34.5 g of (B4-1).

[0206] Synthesis of aromatic carboxylic acid anhydride (B4): Synthesis of intermediate (B4-2) [ka] (B4-1) 34.0 g (132 mmol), 26.1 g of KOH (equivalent to 395 mmol in terms of KOH) containing 15% water, 100 g of ultrapure water, and 100 g of ethanol were added, and the reaction was carried out at an internal temperature of 80 °C for 31 hours under a nitrogen atmosphere. After cooling the obtained reaction solution to room temperature, it was dropped into 183 g of 10% hydrochloric acid aqueous solution, and then extracted with 400 ml of ethyl acetate. The organic layer was recovered, further washed 4 times with 100 ml of pure water, and then the organic layer was dried to dryness under reduced pressure. After adding 100 g of THF to the residue to form a homogeneous solution, 400 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed twice with 100 ml of hexane, and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain 27.3 g of (B4-2).

[0207] Synthesis of Aromatic Carboxylic Anhydride (B4)

Chemical Formula

[0208] [Synthesis Example 5] Synthesis of Aromatic Carboxylic Anhydride (B5)

[0209] Synthesis of Aromatic Carboxylic Anhydride (B5): Synthesis of Intermediate (B5-1)

Chemical Formula

[0210] Synthesis of aromatic carboxylic acid anhydride (B5): Synthesis of intermediate (B5-2) [ka] 28.0 g (82.7 mmol) of (B5-1) and 16.4 g (equivalent to 248 mmol of KOH) of KOH (15% water content) were mixed with 100 g of ultrapure water and 100 g of ethanol. The reaction was carried out under a nitrogen atmosphere at an internal temperature of 80°C for 31 hours. After the resulting reaction solution was cooled to room temperature, it was added dropwise to 183 g of 10% hydrochloric acid aqueous solution and extracted with 300 ml of ethyl acetate. The organic layer was recovered and washed four times with 100 ml of pure water, and the organic layer was dried under reduced pressure. 80 g of THF was added to the residue to make a homogeneous solution, and then 400 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration and recovered after washing twice with 100 ml of hexane. The recovered crystals were vacuum dried at 70°C to obtain 25.3 g of (B5-2).

[0211] Synthesis of aromatic carboxylic acid anhydrides (B5) [ka] 25.0 g (66.4 mmol) of (B5-2) was mixed with 70 g of acetic anhydride, and the reaction was carried out under a nitrogen atmosphere at an internal temperature of 100°C for 4 hours. After the resulting reaction solution was cooled to room temperature, 250 g of xylene was added, and the acetic acid and acetic anhydride produced in the reaction were removed by distillation. 50 g of THF was added to the residue to make a homogeneous solution, and then 300 g of hexane was added while stirring to precipitate crystals. The precipitated crystals were separated by filtration, washed three times with 100 ml of hexane, and the crystals were recovered. The recovered crystals were vacuum-dried at 70°C to obtain 22.1 g of (B5).

[0212] Synthesis Example: Synthesis of Compounds for Organic Film Formation For the synthesis of the organic film-forming compounds (A1) to (A22), the aromatic carboxylic acid anhydrides (B1) to (B5) and the amine compound group (C1) to (C13) shown in the above synthesis example were used. For (C8), a 60:40 isomer mixture was used.

[0213] Aromatic carboxylic acid anhydrides: [ka]

[0214] Amine compound group: [ka]

[0215] [ka]

[0216] [Synthesis Example 6] Synthesis of Organic Film Forming Compound (A1) 5.33 g (20.0 mmol) of aromatic carboxylic acid anhydride (B1) and 2.00 g (10.0 mmol) of amine compound (C1) were mixed with 50 g of NMP (N-methyl-2-pyrrolidone). The reaction was carried out under a nitrogen atmosphere at an internal temperature of 40°C for 3 hours to obtain an amide acid solution. 0.79 g (10.0 mmol) of pyridine was added to the obtained amide acid solution, and then 3.07 g (30.0 mmol) of acetic anhydride was slowly added dropwise. The reaction was carried out at an internal temperature of 60°C for 4 hours to perform imidization. After the reaction was complete, the mixture was cooled to room temperature, and 100 g of methyl isobutyl ketone was added. The organic layer was washed with 100 g of 3% aqueous nitric acid solution, then washed five times with 100 g of pure water, and the organic layer was dried under reduced pressure. 30 g of THF (tetrahydrofuran) was added to the residue to make a homogeneous solution, and then crystallized with 150 g of methanol. The precipitated crystals were separated by filtration, washed twice with 100 g of methanol, and recovered. (A1) was obtained by vacuum drying the recovered crystals at 70°C. The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (A1): Mw=700, Mw / Mn=1.01

[0217] [Synthesis Examples 7-27] Synthesis of organic film-forming compounds (A2)-(A22) Except for using the aromatic carboxylic acid anhydrides and amine compounds shown in Tables 1 and 2, the same reaction conditions as in Synthesis Example 1 were used to obtain the organic film-forming compounds (A2) to (A22) shown in Tables 1 and 2 as products. Organic film-forming compound (A1) is also shown.

[0218] [Table 1]

[0219] [Table 2]

[0220] For the synthesis of organic film-forming compounds (R1) to (R5), compounds (D1) to (D8), which are synthetic starting materials for the comparative synthesis example shown below, were used.

[0221] Synthetic raw materials for comparative synthesis examples: [ka]

[0222] [Comparative Synthesis Example 1] Synthesis of Organic Film Forming Compound (R1) 10.00 g of compound (D1), 4.76 g of potassium carbonate, and 50 g of N-methyl-2-pyrrolidone were dispersed under a nitrogen atmosphere at an internal temperature of 50°C to form a homogeneous dispersion. 3.72 g of propargyl bromide was slowly added dropwise, and the reaction was carried out at an internal temperature of 50°C for 16 hours. After cooling to room temperature, 100 g of methyl isobutyl ketone and 50 g of pure water were added to form a homogeneous solution, and the aqueous layer was removed. The organic layer was then washed twice with 30 g of 3.0% aqueous nitric acid solution and five times with 30 g of pure water, and the organic layer was dried under reduced pressure. 30 g of THF was added to the residue, and crystals were allowed to form with 100 g of methanol. The crystals were separated by filtration, washed twice with 60 g of methanol, and recovered. The recovered crystals were vacuum-dried at 70°C to obtain (R1). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (R1): Mw=960, Mw / Mn=1.07

[0223] [Comparative Synthesis Example 2] Synthesis of Organic Film Forming Compound (R2) 10.65 g of compound (D5) and 9.93 g of compound (D2) were mixed with 120 g of NMP and reacted under a nitrogen atmosphere at an internal temperature of 40°C for 3 hours to obtain an amide acid solution. After cooling to room temperature, 200 g of methyl isobutyl ketone and 100 g of pure water were added and homogenized, and the aqueous layer was removed. The organic layer was then washed five times with 100 g of 3.0% aqueous nitric acid solution and 100 g of pure water, and the organic layer was dried under reduced pressure. 60 g of THF was added to the residue, and crystals were induced with 300 g of hexane. The crystals were separated by filtration and recovered after washing twice with 200 g of hexane. The recovered crystals were vacuum dried at 70°C to obtain (R2). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (R2): Mw=1,100, Mw / Mn=1.03

[0224] [Comparative Synthesis Example 3] Synthesis of Organic Film-Forming Compound (R3) 6.89 g of compound (D3) and 8.21 g of compound (D6) were mixed with 100 g of NMP (N-methyl-2-pyrrolidone), and the reaction was carried out under a nitrogen atmosphere at an internal temperature of 40°C for 3 hours to obtain an amide acid solution. 1.58 g of pyridine was added to the obtained amide acid solution, and then 6.14 g of acetic anhydride was slowly added dropwise. The reaction was carried out at an internal temperature of 60°C for 4 hours to perform imidation. After the reaction was complete, the mixture was cooled to room temperature, and 200 g of methyl isobutyl ketone was added. The organic layer was washed with 100 g of 3% aqueous nitric acid solution, then washed five times with 100 g of pure water, and the organic layer was dried under reduced pressure. 60 g of THF (tetrahydrofuran) was added to the residue to make a homogeneous solution, and then crystallized with 300 g of methanol. The precipitated crystals were separated by filtration, washed twice with 100 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain (R3). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (R3): Mw=760, Mw / Mn=1.02

[0225] [Comparative Synthesis Example 4] Synthesis of Organic Film Forming Compound (R4) 5.88 g of compound (D4) and 15.98 g of compound (D5) were added to 100 g of acetone, and the reaction was carried out under a nitrogen atmosphere at an internal temperature of 40°C for 3 hours. 2.46 g of sodium acetate and 15.33 g of acetic anhydride were slowly added dropwise to the resulting reaction solution, and the reaction was carried out at an internal temperature of 50°C for 4 hours. After the reaction was complete, the mixture was cooled to room temperature, 300 g of methyl isobutyl ketone was added, and the organic layer was washed with 100 g of 3% aqueous nitric acid solution, followed by six washes with 100 g of pure water. The organic layer was then dried under reduced pressure. 100 g of THF was added to the residue to make a homogeneous solution, and crystallization was carried out with 300 g of diisopropyl ether. The precipitated crystals were separated by filtration, washed twice with 200 g of diisopropyl ether, and recovered. The recovered crystals were vacuum-dried at 70°C to obtain (R4). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (R4): Mw=680, Mw / Mn=1.03

[0226] [Comparative Synthesis Example 5] Synthesis of Organic Film-Forming Compound (R5) Under a nitrogen atmosphere, 13.98 g of compound (D7) was dissolved in 192 g of NMP, then 11.46 g of compound (D8) was added, and the reaction was carried out at an internal temperature of 40°C for 2 hours. Furthermore, 5.16 g of compound (D3) was added, and the reaction was carried out for another 2 hours. To the resulting amide acid solution, 3.16 g of pyridine was added, and then 10.22 g of acetic anhydride was slowly added dropwise, and the reaction was carried out at an internal temperature of 60°C for 4 hours to carry out imidation. The mixture was cooled to room temperature and crystallized in 600 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol, and recovered. The recovered crystals were vacuum dried at 70°C to obtain (R5). The weight-average molecular weight (Mw) and dispersion (Mw / Mn) were determined using GPC, and the following results were obtained. [ka] (R5): Mw=4,900, Mw / Mn=1.33

[0227] Tables 3 to 6 list the structural formulas, weight-average molecular weight (Mw), and dispersion (Mw / Mn) of the organic film-forming compounds (A1) to (A22) obtained above. Table 7 also shows the Mw and Mw / Mn values ​​for the organic film-forming compounds (R1) to (R5) used in the comparative examples.

[0228] [Table 3]

[0229] [Table 4]

[0230] [Table 5]

[0231] [Table 6]

[0232] [Table 7]

[0233] Preparation of materials for forming organic films (UDL-1 to 25, comparative UDL-1 to 5) Organic film-forming materials (UDL-1 to 25, comparative UDL-1 to 5) were prepared by dissolving the above organic film-forming compounds (A1) to (A22) and (R1) to (R5), along with (S1) 1,6-diacetoxyhexane (boiling point 260°C) and (S2) tripropylene glycol monomethyl ether (boiling point 242°C) as high-boiling point solvents in the proportions shown in Tables 8 and 9 in a solvent containing 0.1% by mass of propylene glycol monomethyl ether acetate (PGMEA), FC-4430 (manufactured by Sumitomo 3M Co., Ltd.), and filtering the mixture through a 0.1 μm fluororesin filter.

[0234] [Table 8]

[0235] [Table 9]

[0236] Example 1 Solvent resistance measurement (Examples 1-1 to 1-25, Comparative Examples 1-1 to 1-5) The organic film-forming materials (UDL-1 to 25, comparative UDL-1 to 5) prepared above were coated onto a silicon substrate, baked at 450°C for 60 seconds under a nitrogen stream with an oxygen concentration controlled to 0.2% or less, and the film thickness was measured. Then, PGMEA solvent was dispensed onto the film, left for 30 seconds to allow to stand, and spin-dried. The film was then baked at 100°C for 60 seconds to evaporate the PGMEA, and the film thickness was measured again to determine the difference in film thickness before and after PGMEA treatment. These results are shown in Tables 10 and 11.

[0237] [Table 10]

[0238] [Table 11]

[0239] As shown in Table 10, the organic film-forming materials of the present invention (Examples 1-1 to 1-25) exhibited a residual film rate of 99.8% or more after PGMEA treatment, indicating that crosslinking reactions occurred even under a nitrogen atmosphere, resulting in sufficient solvent resistance. In contrast, as shown in Table 11, Comparative Examples 1-1, 1-2, and 1-4 exhibited insufficient heat resistance, resulting in a residual film rate of less than 99.5% after PGMEA treatment. In particular, Comparative Example 1-4 had a residual film rate of less than 90%. Comparative Examples 1-3 and 1-5 exhibited solvent resistance, resulting in a residual film rate of 99.8% or more. This is thought to be due to the excellent heat resistance caused by the ethynylbenzene terminus containing an imide ring.

[0240] Example 2: Evaluation of heat resistance properties (Examples 2-1 to 2-25, Comparative Examples 2-1 to 2-5) The above organic film-forming materials (UDL-1 to 25, comparative UDL-1 to 5) were each coated onto a silicon substrate and baked in air at 180°C to form a 200 nm coated film, and the film thickness was measured. This substrate was then baked for 10 minutes at 450°C under a nitrogen atmosphere with an oxygen concentration controlled to 0.2% or less, and the film thickness was measured again. These results are shown in Tables 12 and 13.

[0241] [Table 12]

[0242] [Table 13]

[0243] As shown in Table 12, the organic film-forming materials of the present invention (Examples 2-1 to 2-25) show a film thickness reduction of 3% or less even after baking at 450°C for 10 minutes, indicating that the organic film-forming materials of the present invention can form organic films with high heat resistance even under high temperature conditions of 450°C. In particular, Examples 2-2, 2-5, 2-10, 2-13, 2-16, 2-18, and 2-20 to 25, which have an ethynyl group in R1, show particularly excellent heat resistance, with film thickness reduction kept to less than 2% even after baking at 450°C for 10 minutes. In contrast, as shown in Table 13, Comparative Examples 2-1, 2-2, and 2-4 show a large film thickness reduction of more than 20%, indicating that the imide structure has high heat resistance.

[0244] Example 3: Evaluation of Embedding Characteristics (Examples 3-1 to 3-25, Comparative Examples 3-1 to 3-5) As shown in Figure 3, the above-mentioned organic film-forming materials (UDL-1 to 25, comparative UDL-1 to 5) were applied to SiO2 wafer substrates having a dense hole pattern (hole diameter 0.16 μm, hole depth 0.50 μm, distance between the centers of two adjacent holes 0.32 μm), and baked for 600 seconds at 450°C using a hot plate under a nitrogen atmosphere controlled to an oxygen concentration of 0.2% or less to form an organic film. The substrate used was the base substrate 7 (SiO2 wafer substrate) having a dense hole pattern as shown in Figure 3(G) (overhead view) and (H) (cross-sectional view). The cross-sectional shape of each obtained wafer substrate was observed using a scanning electron microscope (SEM) to confirm whether the holes were filled with organic film without any voids (gaps). The results are shown in Tables 14 and 15. When an organic film material with poor filling characteristics was used, voids were generated inside the holes in this evaluation. When an organic film-forming material with good embedding properties is used, the organic film 8 fills the inside of the holes without voids, as shown in Figure 3(I) in this evaluation.

[0245] [Table 14]

[0246] [Table 15]

[0247] As shown in Table 14, the organic film-forming materials of the present invention (Examples 3-1 to 3-25) were able to fill hole patterns without generating voids, and were confirmed to have good embedding properties. On the other hand, as shown in Table 15, in Comparative Examples 3-1, 3-2, and 3-4, voids were generated due to insufficient heat resistance, as was the case with Comparative Example 2. In addition, in Comparative Example 3-5, although the heat resistance was sufficient, the embedding performance was insufficient due to the rigid polymer structure and high molecular weight, and voids were observed. From these results, it was confirmed that the organic film-forming materials of the present invention have good embedding properties.

[0248] Example 4: Evaluation of Planarization Characteristics (Examples 4-1 to 4-25, Comparative Examples 4-1 to 4-5) Organic film-forming materials (UDL-1 to 25, comparative UDL-1 to 5) were applied to a substrate 9 (SiO2 wafer substrate) having a large isolated trench pattern (trench width 10 μm, trench depth 0.10 μm) as shown in Figure 4(J). The materials were then baked at 450°C for 240 seconds under a nitrogen atmosphere controlled to an oxygen concentration of 0.2% or less to form an organic film 10 as shown in Figure 4(K). The step difference delta 10 between the trenched and non-trenched portions of the organic film was then observed using a Park Systems NX10 atomic force microscope (AFM). The results are shown in Tables 16 and 17. In this evaluation, a smaller step difference indicates better planarization characteristics. Note that in this evaluation, a trench pattern with a depth of 0.10 μm was planarized using an organic film-forming material with a typical film thickness of approximately 0.2 μm, making the evaluation conditions strict in order to assess the superiority of the planarization characteristics.

[0249] [Table 16]

[0250] [Table 17]

[0251] As shown in Table 16, the organic film-forming materials of the present invention (Examples 4-1 to 4-25) were found to have a smaller step difference between the trenched and non-trenched portions of the organic film and superior planarization characteristics compared to Comparative Examples 4-1 to 4-5 shown in Table 17. In Comparative Examples 4-2 and 4-4, although fluidity was provided by ether bonding, the heat resistance was insufficient as shown in the heat resistance evaluation results for Comparative Example 2, resulting in significant film shrinkage and deterioration of flatness after baking at 450°C. In Comparative Example 4-3, the ethynyl group was used as a crosslinking group, and although it had excellent heat resistance, the phenyl ether structure, as in the present invention, was located far from the crosslinking group, so the fluidity did not improve, resulting in poor flatness compared to UDL-10, which has a similar structure. In Comparative Example 4-5, although it had high heat resistance due to the imide structure, the large molecular weight and lack of a phenyl ether structure resulted in poor fluidity and poor flatness. Furthermore, comparing Examples 4-23 to 4-25, which included the addition of a high-boiling-point solvent, with Examples 4-10, 4-16, and 4-20, which did not, it can be seen that the flatness was further improved by the addition of the high-boiling-point solvent. From these results, it can be seen that the organic film-forming material of the present invention has excellent heat resistance, which suppresses film shrinkage during high-temperature baking and exhibits excellent planarization characteristics.

[0252] Example 5: Pattern Formation Test (Examples 5-1 to 5-25, Comparative Examples 5-1 to 5-2) The above organic film-forming materials (UDL-1 to 25, comparative UDL-3 and 5) were applied to a base substrate 9 (SiO2 wafer substrate) having a large isolated trench pattern (trench width 10 μm, trench depth 0.10 μm) formed of SiO2, as shown in Figure 4(J). They were then baked at 450°C for 60 seconds under a nitrogen atmosphere with an oxygen concentration controlled to 0.2% or less to form an organic film (resist underlayer film). A CVD-SiON hard mask was then formed on top of this, and an organic anti-reflective film material (ARC-29A: manufactured by Nissan Chemical Corporation) was applied and baked at 210°C for 60 seconds to form an organic anti-reflective film with a thickness of 80 nm. An ArF single-layer resist, a resist toplayer film material, was then applied on top of this and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. A protective film material (TC-1) was applied to the photoresist film and baked at 90°C for 60 seconds to form a protective film with a thickness of 50 nm. However, as shown in the results of Comparative Example 2, comparative UDL-1, 2, and 4 exhibited poor heat resistance, making it impossible to form CVD-SiON hard masks, and therefore they could not proceed to the subsequent pattern formation tests.

[0253] The resist top layer material (single-layer resist for ArF) was prepared by dissolving a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) in the proportions shown in Table 18 in a solvent containing 0.1% by mass of FC-430 (manufactured by Sumitomo 3M Co., Ltd.), and filtering the mixture through a 0.1 μm fluororesin filter.

[0254] [Table 18]

[0255] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used are shown below. [ka]

[0256] The immersion protective film material (TC-1) was prepared by dissolving the protective film polymer (PP1) in an organic solvent in the proportions shown in Table 19 and filtering it through a 0.1 μm fluororesin filter.

[0257] [Table 19]

[0258] The polymer used (PP1) is shown below. [ka]

[0259] Next, the material was exposed using an ArF immersion lithography system (Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35° dipole s polarized illumination, 6% halftone phase shift mask), baked (PEB) at 100°C for 60 seconds, and developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 55 nm 1:1 positive type line and space pattern (resist pattern).

[0260] Next, using a Tokyo Electron Telius etching system, the resist pattern was used as a mask to etch the organic anti-reflective film and the CVD-SiON hard mask by dry etching to form a hard mask pattern. The resulting hard mask pattern was then used as a mask to etch the organic film to form an organic film pattern, and the resulting organic film pattern was used as a mask to etch the SiO2 film. The etching conditions are as follows.

[0261] Conditions for transferring the resist pattern to a SiON hard mask Chamber pressure 10.0 Pa RF Power 1,500W CF4 gas flow rate: 75 sccm O2 gas flow rate: 15 sccm Time 15sec

[0262] Conditions for transferring hard mask patterns to organic films Chamber pressure 2.0 Pa RF Power 500W Ar gas flow rate: 75 sccm O2 gas flow rate: 45 sccm Time 120sec

[0263] Conditions for transferring organic film patterns to SiO2 films Chamber pressure 2.0 Pa RF Power 2,200W C5F 12 Gas flow rate: 20 sccm C2F6 gas flow rate: 10 sccm Ar gas flow rate: 300 sccm O2 gas flow rate: 60 sccm Time 90sec

[0264] Table 20 shows the results of observing the pattern cross-section using an electron microscope (S-4700) manufactured by Hitachi, Ltd.

[0265] [Table 20]

[0266] As shown in Table 20, the results for the organic film forming material of the present invention (Examples 5-1 to 5-25) show that in all cases the resist upper layer film pattern (resist pattern) was successfully transferred to the substrate, confirming that the organic film forming material of the present invention is suitable for use in microfabrication by the multilayer resist method. In Comparative Examples 5-1 and 5-2, defocusing occurred during resist exposure due to insufficient flatness, resulting in a poor pattern and thus a poor pattern during transfer.

[0267] Example 6: Glass transition temperature (Example 6-1, Comparative Examples 6-1 to 6-2) The organic film-forming compound (A5) synthesized in the above synthesis example, and the organic film-forming compounds (R4) and (R5) synthesized in the above comparative synthesis example, were each diluted with N-methyl-2-pyrrolidone to a solid content concentration of 50% by mass. Then, 2% by mass of dicumyl peroxide was added and dissolved to obtain a varnish in which the organic film-forming compound was dissolved. Subsequently, the mixture was microfiltration using a 1.0 μm Teflon® filter.

[0268] <Preparation of film-like samples> The varnishes of each organic film-forming compound prepared above were spin-coated onto an aluminum substrate to a cured finish thickness of 10 μm. Next, a pre-bake was performed on a hot plate at 100°C for 4 minutes to obtain a photosensitive resin film. Then, curing was performed in an oven at 180°C for 2 hours while purging with nitrogen to obtain a cured resin film. Next, the wafer with the cured film was cut into strips 10 mm wide and 60 mm long, and the cured film was peeled off the substrate by immersion in 20% by mass hydrochloric acid to obtain a film-like sample.

[0269] <Glass transition temperature (Tg)> The glass transition temperature of the film-like samples prepared as described above was measured using a Hitachi High-Tech TMA7100. The measurement results are shown in Table 21.

[0270] [Table 21]

[0271] The cured varnish film using the organic film-forming compound of the present invention in Example 6-1 exhibited a high glass transition temperature. Furthermore, compared to the organic film-forming compounds of Comparative Examples 6-1 and 6-2, it exhibits superior film processability, making it suitable not only as a resist underlayer material but also for applications such as multilayer printed circuit boards used in high-frequency electronic equipment that require insulating materials with excellent dielectric properties. As described in the specification, it can be applied as a raw material for a variety of imide compounds and polyimide compounds in electronic materials, aerospace materials, and other applications.

[0272] From the above, it has become clear that the organic film-forming material of the present invention, which contains the organic film-forming compound of the present invention, possesses both heat resistance of 400°C or higher and advanced embedding / planarization characteristics even under an oxygen-free inert gas, making it extremely useful as an organic film material for use in the multilayer resist method. Furthermore, it has become clear that the pattern formation method of the present invention using this material can form fine patterns with high precision even on substrates with steps. In addition, the organic film-forming compound synthesized using the aromatic carboxylic acid anhydride of the present invention can be used not only as an organic film material for the multilayer resist method described above, but also for applications such as multilayer printed circuit boards used in high-frequency electronic equipment that require insulating materials with excellent dielectric properties. As described in the specification, it can be applied as a raw material for various imide compounds and polyimide compounds in electronic materials, aerospace materials, etc.

[0273] This specification includes the following embodiments: [1]: An organic film-forming material characterized by containing (A) a compound represented by the following general formula (1A), and (B) an organic solvent. [ka] (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in the general formula (1B) below.) [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1C), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka] [2]: The organic film-forming material according to [1], characterized in that the component (A) is a compound represented by the following general formula (1D). [ka] (In the formula, W2 is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, and the organic group in W2 may bond with the substituent on the benzene ring to form a cyclic organic group. X1 is the same as described above.) [3]: The organic film-forming material according to [2] above, characterized in that W2 in the general formula (1D) is either a single bond or one of the groups represented by the following formula (1E). [ka] (The aromatic ring may have substituents.) [4]: The organic film-forming material according to [2] or [3] above, characterized in that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4. [5]: Any one of the organic film-forming materials described in [1] to [4] above, characterized in that the ratio Mw / Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of component (A) as determined by gel permeation chromatography is 1.00 ≤ Mw / Mn ≤ 1.10. [6]: An organic film-forming material according to any one of [1] to [5] above, characterized in that component (B) is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher. [7]: The organic film-forming material according to any one of the above [1] to [6], characterized in that the organic film-forming material further contains one or more of (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, and (F) a plasticizer. [8]: A substrate for manufacturing a semiconductor device, characterized in that an organic film is formed on the substrate by curing any one of the organic film-forming materials described in [1] to [7] above. [9]: A method for forming an organic film applied in the manufacturing process of a semiconductor device, characterized by rotating coating one of the organic film forming materials from [1] to [7] onto a workpiece substrate, and then heat-treating the workpiece substrate coated with the organic film forming material in an inert gas atmosphere at a temperature of 50°C to 600°C for a range of 10 seconds to 7200 seconds to obtain an organic film.

[10] : A method for forming an organic film applied in the manufacturing process of a semiconductor device, characterized by rotating coating one of the organic film forming materials from [1] to [7] onto a workpiece substrate, heat-treating the workpiece substrate coated with the organic film forming material in air at a temperature of 50°C to 300°C for 5 to 600 seconds to form a coated film, and then applying heat treatment in an inert gas atmosphere at a temperature of 200°C to 600°C for 10 to 7200 seconds to obtain an organic film.

[11] : The method for forming an organic film according to [9] or

[10] above, characterized in that the oxygen concentration in the inert gas atmosphere is 1% or less.

[12] : A method for forming an organic film according to any one of the above [9] to

[11] , characterized in that the substrate to be processed is a substrate to be processed having a structure or step with a height of 30 nm or more.

[13] : A pattern formation method characterized by forming an organic film on a workpiece using any one of the organic film forming materials from [1] to [7] above, forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material, forming a resist upper layer on the silicon-containing resist interlayer using a photoresist composition, forming a circuit pattern on the resist upper layer, transferring the pattern to the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask, transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[14] : A pattern formation method characterized by forming an organic film on a workpiece using any one of the organic film forming materials from [1] to [7] above, forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material, forming an organic anti-reflective film on the silicon-containing resist interlayer, forming a resist upper layer on the organic anti-reflective film using a photoresist composition to form a four-layer structure, forming a circuit pattern on the resist upper layer, transferring the pattern to the organic anti-reflective film and the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask, transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[15] : A pattern formation method characterized by forming an organic film on a workpiece using any one of the organic film forming materials from [1] to [7] above; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming a resist upper layer film on the inorganic hard mask interlayer film using a photoresist composition to form a circuit pattern on the resist upper layer film; transferring the pattern to the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[16] : A pattern formation method characterized by forming an organic film on a workpiece using any one of the organic film forming materials from [1] to [7] above, forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film, forming an organic anti-reflective film on the inorganic hard mask interlayer, forming a resist upper layer film on the organic anti-reflective film using a photoresist composition to form a four-layer film structure, forming a circuit pattern on the resist upper layer film, transferring the pattern to the organic anti-reflective film and the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask, transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask, and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

[17] : The pattern formation method according to

[15] or

[16] , characterized in that the inorganic hard mask interlayer is formed by a CVD method or an ALD method.

[18] : A pattern formation method according to any one of the above

[13] to

[17] , characterized in that the circuit pattern is formed by lithography using light with a wavelength of 10 nm to 300 nm, direct drawing with an electron beam, nanoimprinting, or a combination thereof.

[19] : A pattern formation method of any one of the above

[13] to

[18] , characterized in that the circuit pattern is developed by alkaline development or an organic solvent.

[20] : A pattern formation method according to any one of the above

[13] to

[19] , characterized in that the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film is formed.

[21] : The pattern forming method of

[20] above, characterized in that the workpiece contains silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or alloys thereof.

[22] : A compound for forming an organic film, characterized in that it is represented by the following general formula (1A). [ka] (In the formula, W1 is an n1-valent organic group, n1 is an integer from 2 to 4, and X1 is the group shown in the general formula (1B) below.) [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1C), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[23] : The organic film-forming compound according to

[22] , characterized in that the organic film-forming compound is represented by the following general formula (1D). [ka] (In the formula, W2 is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, and the organic group in W2 may bond with the substituent on the benzene ring to form a cyclic organic group. X1 is the same as described above.)

[24] : The organic film-forming compound according to

[23] , characterized in that W2 in the general formula (1D) is either a single bond or one of the groups represented by the following formula (1E). [ka] (The aromatic ring may have substituents.)

[25] : The organic film-forming compound according to

[23] or

[24] above, characterized in that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

[26] : An aromatic carboxylic acid anhydride characterized by being represented by the following general formula (1F). [ka] (In the formula, n2 is 1 or 2, and R1 is any of the groups shown in the following formula (1G), which may have substituents on the aromatic ring, and two or more terminal structures of R1 may be used in combination.) [ka]

[0274] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention. [Explanation of symbols]

[0275] 1...Substrate, 2...Workpiece layer, 2a...Pattern (pattern formed on the workpiece layer) 3...Organic film, 3'...Material for forming organic film, 3a...Organic film pattern 4...Silicon-containing resist interlayer, 4a...Silicon-containing resist interlayer pattern, 5...Resist upper layer film, 5a...Resist upper layer film pattern, 6...Exposed area, 7…Substrate with a densely packed hole pattern, 8…Organic film, 9…Substrate with a large isolated trench pattern, 10…Organic film, delta10…The difference in height between the trenched and non-trenched areas of the organic film.

Claims

1. An organic film-forming material characterized by containing (A) a compound represented by the following general formula (1A), and (B) an organic solvent. 【Chemistry 1】 (In the formula, W １ is an n1-valent organic group, where n1 represents an integer from 2 to 4, and X １ This is the group represented by the following general formula (1B). 【Chemistry 2】 (In the formula, n2 is 1 or 2, R １ R is one of the groups shown in the following formula (1C), and may have substituents on the aromatic ring, and may have two or more terminal structures. １ (These may be used in combination.) 【Transformation 3】

2. The organic film-forming material according to claim 1, characterized in that the aforementioned component (A) is a compound represented by the following general formula (1D). 【Chemistry 4】 (In the formula, W ２ is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, W ２ The organic group inside may bond with a substituent on the benzene ring to form a cyclic organic group. １ (This is the same as above.)

3. In the above general formula (1D) W ２ The organic film-forming material according to claim 2, characterized in that the group is either a single bond or one of the groups represented by the following formula (1E). 【Transformation 5】 (The aromatic ring may have substituents.)

4. The organic film-forming material according to claim 2, characterized in that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

5. The organic film-forming material according to claim 1, characterized in that the ratio Mw / Mn of the weight-average molecular weight Mw to the number-average molecular weight Mn of component (A) as determined by gel permeation chromatography is 1.00 ≤ Mw / Mn ≤ 1.

10.

6. The organic film-forming material according to claim 1, characterized in that the (B) component is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

7. The organic film-forming material according to claim 1, characterized in that the organic film-forming material further contains one or more of (C) an acid generator, (D) a surfactant, (E) a crosslinking agent, and (F) a plasticizer.

8. A substrate for manufacturing a semiconductor device, characterized in that an organic film formed on the substrate is obtained by curing an organic film-forming material according to any one of claims 1 to 7.

9. A method for forming an organic film to be applied in the manufacturing process of a semiconductor device, characterized by rotatingly coating a workpiece substrate with an organic film-forming material described in any one of claims 1 to 7, and then heat-treating the workpiece substrate coated with the organic film-forming material in an inert gas atmosphere at a temperature of 50°C to 600°C for a range of 10 seconds to 7200 seconds to obtain an organic film.

10. A method for forming an organic film applicable in the manufacturing process of a semiconductor device, characterized by: rotatingly coating a workpiece substrate with an organic film-forming material described in any one of claims 1 to 7; heat-treating the workpiece substrate coated with the organic film-forming material in air at a temperature of 50°C to 300°C for 5 to 600 seconds to form a coated film; and subsequently applying heat treatment in an inert gas atmosphere at a temperature of 200°C to 600°C for 10 to 7200 seconds to obtain an organic film.

11. The method for forming an organic film according to claim 9, characterized in that the oxygen concentration in the inert gas atmosphere is 1% or less.

12. The method for forming an organic film according to claim 9, characterized in that the substrate to be processed is a substrate having a structure or step with a height of 30 nm or more.

13. A pattern formation method characterized by forming an organic film on a workpiece using an organic film forming material according to any one of claims 1 to 7; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming a resist upper layer on the silicon-containing resist interlayer using a photoresist composition; forming a circuit pattern on the resist upper layer; transferring the pattern to the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

14. A pattern formation method characterized by forming an organic film on a workpiece using an organic film forming material according to any one of claims 1 to 7; forming a silicon-containing resist interlayer on the organic film using a silicon-containing resist interlayer material; forming an organic anti-reflective film on the silicon-containing resist interlayer; forming a resist upper layer on the organic anti-reflective film using a photoresist composition to form a four-layer structure; forming a circuit pattern on the resist upper layer; transferring the pattern to the organic anti-reflective film and the silicon-containing resist interlayer by etching using the resist upper layer on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist interlayer on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

15. A pattern formation method characterized by forming an organic film on a workpiece using an organic film forming material according to any one of claims 1 to 7; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming a resist upper layer film on the inorganic hard mask interlayer film using a photoresist composition to form a circuit pattern on the resist upper layer film; transferring the pattern to the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

16. A pattern formation method characterized by forming an organic film on a workpiece using an organic film forming material according to any one of claims 1 to 7; forming an inorganic hard mask interlayer selected from silicon oxide film, silicon nitride film, silicon oxynitride film, titanium oxide film, and titanium nitride film on the organic film; forming an organic anti-reflective film on the inorganic hard mask interlayer; forming a resist upper layer film on the organic anti-reflective film using a photoresist composition to form a four-layer film structure; forming a circuit pattern on the resist upper layer film; transferring the pattern to the organic anti-reflective film and the inorganic hard mask interlayer film by etching using the resist upper layer film on which the pattern is formed as a mask; transferring the pattern to the organic film by etching using the inorganic hard mask interlayer film on which the pattern has been transferred as a mask; and further transferring the pattern to the workpiece by etching using the organic film on which the pattern has been transferred as a mask.

17. The pattern forming method according to claim 15, characterized in that the inorganic hard mask interlayer is formed by a CVD method or an ALD method.

18. The pattern formation method according to claim 13, characterized in that the circuit pattern is formed by lithography using light with a wavelength of 10 nm to 300 nm, direct drawing with an electron beam, nanoimprinting, or a combination thereof.

19. The pattern forming method according to claim 13, characterized in that the circuit pattern is developed using alkaline development or an organic solvent in the formation of the circuit pattern.

20. The pattern forming method according to claim 13, characterized in that the workpiece is a semiconductor device substrate, or a semiconductor device substrate on which any of the following films is formed: a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, or a metal oxide nitride film.

21. The pattern forming method according to claim 20, characterized in that the workpiece contains silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, or alloys thereof.

22. An organic film-forming compound characterized by being represented by the following general formula (1A). 【Transformation 6】 (where W １ is an n1-valent organic group, n1 represents an integer of 2 to 4, and X １ is a group represented by the following general formula (1B).) 【Transformation 7】 (In the formula, n2 is 1 or 2, R １ R is one of the groups shown in the following formula (1C), and may have substituents on the aromatic ring, and may have two or more terminal structures. １ (These may be used in combination.) 【Transformation 8】

23. The organic film-forming compound according to claim 22, characterized in that the organic film-forming compound is represented by the following general formula (1D). 【Chemistry 9】 (In the formula, W ２ is a single bond or a divalent organic group, an integer satisfying 2 ≤ n3 + n4 ≤ 4, and may have substituents on the benzene ring in the formula, W ２ The organic group inside may bond with a substituent on the benzene ring to form a cyclic organic group. １ (This is the same as above.)

24. In the above general formula (1D) W ２ The organic film-forming compound according to claim 23, characterized in that it is either a single bond or one of the groups represented by the following formula (1E). 【Chemistry 10】 (The aromatic ring may have substituents.)

25. The organic film-forming compound according to claim 23, characterized in that n3 and n4 in the general formula (1D) satisfy the relationships 1 ≤ n3 ≤ 2, 1 ≤ n4 ≤ 2, and 2 ≤ n3 + n4 ≤ 4.

26. An aromatic carboxylic acid anhydride characterized by being represented by the following general formula (1F). 【Chemistry 11】 (In the formula, n2 is 1 or 2, R １ R is one of the groups shown in the following formula (1G), and may have substituents on the aromatic ring, and may have two or more terminal structures. １ (These may be used in combination.) 【Chemistry 12】

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