Composition for forming metal oxide film, method for forming pattern, and method for forming metal oxide film

Abstract

The present invention relates to a composition for forming a metal oxide film, a patterning method, and a method for forming a metal oxide film. The object of the present invention is to provide a composition for forming a metal oxide film having excellent dry etching resistance with respect to known organic underlayer film materials and achieving a high level of filling / planarization characteristics, a patterning method using this composition, and a method for forming a metal oxide film (resist underlayer film). A composition for forming a metal oxide film, characterized by containing (A) metal oxide nanoparticles, (B) a fluidity promoter which is one or more compounds represented by the following general formula (I), general formula (II), and general formula (III) and / or a polymer having a molecular weight of 5000 or less, and (C) an organic solvent, and the weight ratio of the (A) metal oxide nanoparticles to the (B) fluidity promoter is 10 / 90 to 90 / 10.

Description

Technical Field

[0001] The present invention relates to a composition for forming a metal oxide film usable for fine patterning by a multi-layer resist method in a semiconductor device manufacturing process, a patterning method using the composition, and a metal oxide film forming method. Background Art

[0002] With the high integration and high speed of LSIs, the miniaturization of pattern sizes has progressed rapidly. In photolithography technology, with this miniaturization, by shortening the wavelength of the light source and appropriately selecting the corresponding resist composition, the formation of fine patterns has been achieved. At the center of this is a positive photoresist composition used in a single layer. This single-layer positive photoresist composition has a skeleton in the resist resin that has etching resistance to dry etching using chlorine-based or fluorine-based gas plasmas and a switching mechanism in which the exposed portion dissolves. By this, the exposed portion is dissolved to form a pattern, and the remaining resist pattern is used as an etching mask to dry-etch the substrate to be processed.

[0003] However, if the film thickness of the photoresist film used is directly miniaturized, that is, if the pattern width is further reduced, the resolution performance of the photoresist film will decrease, and if the photoresist film is to be pattern-developed using a developer, the so-called aspect ratio will become too large, and as a result, there will be a problem of pattern collapse. Therefore, with the miniaturization of the pattern, the photoresist film becomes thinner and thinner.

[0004] On the other hand, in the processing of the substrate to be processed, a method of using the photoresist film having a formed pattern as an etching mask and dry-etching the substrate is usually used, but in reality, there is no dry-etching method that can achieve complete etching selectivity between the photoresist film and the substrate to be processed. Therefore, in substrate processing, there is a problem that the photoresist film is also damaged and collapses, and the resist pattern cannot be correctly transferred to the substrate to be processed. With the miniaturization of the pattern, higher dry-etching resistance is required for the resist composition. However, on the other hand, in order to improve the resolution, the resin used in the photoresist composition increasingly requires a resin with low light absorption at the exposure wavelength. Therefore, as the exposure light progresses to shorter wavelengths such as i-ray, KrF, and ArF, the resin also changes to novolak resin, polyhydroxystyrene, and a resin with an aliphatic polycyclic skeleton. However, in reality, the etching rate under the dry-etching conditions during substrate processing becomes faster, and the latest photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] Therefore, it is necessary to dry-etch the substrate to be processed with a thinner and weaker etching-resistant photoresist film, and the assurance of materials and processes in this processing step has become an urgent matter.

[0006] As one of the methods for solving such problems, there is a multilayer resist method. In this method, an interlayer resist film (i.e., the upper resist film) with different etching selectivity from the upper resist film and the substrate to be processed is inserted between the upper resist film and the substrate to be processed. After a pattern is obtained on the upper resist film, the pattern of the upper resist film is used as a dry etching mask, and the pattern is transferred to the interlayer resist film by dry etching using the upper resist film pattern as a dry etching mask. Then, the pattern is transferred to the substrate to be processed by dry etching using the interlayer resist film as a dry etching mask.

[0007] One of the multilayer resist methods is a three-layer resist method that can be implemented using a general resist composition used in a single-layer resist method. In this three-layer resist method, for example, an organic film obtained by forming a novolak resin or the like on the substrate to be processed is used as the lower resist film, a silicon-containing interlayer resist film is formed thereon as the interlayer resist film, and a normal organic photoresist film is formed thereon as the upper resist film. When dry etching is performed using a fluorine-based gas plasma, the organic upper resist film can obtain a good etching selectivity ratio with respect to the silicon-containing interlayer resist film. Therefore, the pattern of the upper resist film can be transferred to the silicon-containing interlayer resist film by dry etching using the fluorine-based gas plasma. According to this method, even if a resist composition that is difficult to form a pattern with a sufficient film thickness for directly processing the substrate to be processed or a resist composition that does not have sufficient dry etching resistance for substrate processing is used, if the pattern can be transferred to the silicon-containing interlayer resist film (interlayer resist film), and then the pattern is transferred by dry etching using an oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (lower resist film) made of novolak resin or the like that has sufficient dry etching resistance for substrate processing can be obtained. As described above, the lower resist film, for example, those described in Patent Document 1, etc., are already well-known.

[0008] On the other hand, in recent years, the miniaturization of DRAM memories has accelerated, the dry etching resistance has been further improved, and the necessity of a lower resist film having excellent filling characteristics and planarization characteristics has increased. Coating-type organic lower layer film materials with excellent filling characteristics and planarization characteristics, such as those described in Patent Document 2, etc., have been reported, but when expected to be used in an advanced era, there are concerns about dry etching resistance, and the applicable limit of known coating-type organic lower layer film materials has been approached.

[0009] Regarding the problem of dry etching resistance of the lower layer film material of a coating type organic resist, some people have focused on the method of using a metal oxide film for the lower layer film of the resist. However, just using a metal oxide material alone has insufficient fluidity, making it difficult to achieve a high level of filling and planarization. In order to improve the fluidity, a composition containing an organic material added thereto is preferably used. Regarding the composition containing an organic material added to a metal oxide compound, reports have been made in Patent Document 3 and Patent Document 4. Although the filling and planarization characteristics are not mentioned, the metal oxide dicarboxylate used in Patent Document 3 and the metal oxide compound used in Patent Document 4 have a large thermal shrinkage, which will induce a significant deterioration in the filling property. There are concerns that it may not be perfect as a lower layer film material of a resist that requires a high level of planarization characteristics and filling characteristics.

[0010] In response to this, a composition for forming a metal oxide film in which a high-carbon polymer is added to metal oxide nanoparticles has been proposed (Patent Document 5). By using metal oxide nanoparticles with a small thermal shrinkage for the metal oxide compound, it has been reported that the filling property of the metal oxide compound has been improved. Also, a high-carbon polymer has been proposed as a fluidity promoter for metal oxide nanoparticles, but the above-mentioned high-carbon polymer is insufficient in terms of thermal fluidity, and there are concerns about insufficient planarization characteristics in the advanced era that requires a high level of planarization of fine structure patterns.

[0011] Regarding an organic material having excellent dry etching resistance and thermal fluidity, materials having a fluorene skeleton can be cited. In Patent Document 6, a curable composition in which a fluorene compound having an oxirane ring and / or a thiirane ring at the end is added to metal oxide nanoparticles has been reported. Although the dry etching resistance is not mentioned, the fluorene compound having an oxirane ring and a thiirane ring has insufficient curability and heat resistance, and there are concerns that it may significantly deteriorate the excellent dry etching resistance of the metal oxide nanoparticles.

[0012] Prior Art Documents

[0013] Patent Documents

[0014] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-205685

[0015] [Patent Document 2] Japanese Patent No. 6714493

[0016] [Patent Document 3] Japanese Patent No. 6342998

[0017] [Patent Document 4] Japanese Patent No. 5756134

[0018] [Patent Document 5] Japanese Patent No. 7008075

[0019] [Patent Document 6] Japanese Patent Publication No. 6587516 Summary of the Invention

[0020] [Problems to be Solved by the Invention]

[0021] In view of the above circumstances, an object of the present invention is to provide a composition for forming a metal oxide film having excellent dry etching resistance with respect to known organic underlayer film materials and having a high level of filling / planarization characteristics, a pattern forming method using this composition, and a method for forming a metal oxide film (resist underlayer film).

[0022] [Means for Solving the Problems]

[0023] In order to solve the above problems, the present invention provides a composition for forming a metal oxide film, which can be used as a resist underlayer film material used in a multilayer resist method.

[0024] It contains (A) metal oxide nanoparticles, (B) a fluidity promoter which is a compound represented by one or more selected from the following general formula (I), general formula (II) and general formula (III) and / or a polymer having a molecular weight of 5000 or less, and (C) an organic solvent.

[0025] The weight ratio of the aforementioned (A) metal oxide nanoparticles to the aforementioned (B) fluidity promoter is 10 / 90 to 90 / 10.

[0026] [Chemical Formula 1]

[0027]

[0028] In the aforementioned general formula (I) and the aforementioned general formula (II), W 1 and W 2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the aforementioned benzene ring and naphthalene ring may be substituted with a hydrocarbon group having 1 to 6 carbon atoms. R a is a hydrogen atom, or a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, Y is a group represented by the following general formula (1). n1 is 0 or 1, n2 is 1 or 2, and V each independently represents a hydrogen atom or a connecting portion.

[0029] [Chemical Formula 2]

[0030]

[0031] In the aforementioned general formula (III), Z 1 is a group represented by the following general formula (2), R b is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms. n4 is 0 or 1, n5 is 1 or 2, and V each independently represents a hydrogen atom or a connecting portion.

[0032] [Chemical formula 3]

[0033]

[0034] * indicates an atomic bond.

[0035] [Chemical formula 4]

[0036]

[0037] In the above general formula (2), W 1 、W 2 、Y, and n1 are as described above.

[0038] If it is a composition for forming a metal oxide film, because it contains a fluidity promoter that highly balances dry etching resistance and fluidity, it can maximize the excellent dry etching resistance from metal oxide nanoparticles, and furthermore, it can provide a composition for forming a metal oxide film that can be used as an anti-reflective coating material with high flatness characteristics / embedding characteristics that are difficult to achieve solely with metal oxide nanoparticles. Also, if it is a composition for forming a metal oxide film with the ratio of (A) to (B) in such a range, it can adjust various physical properties required when using an anti-reflective coating, such as embedding / flattening characteristics and dry etching resistance, within an appropriate range.

[0039] It is preferable that the aforementioned (A) metal oxide nanoparticles are one or more of metal oxide nanoparticles selected from the group consisting of zirconium, hafnium, aluminum, tungsten, titanium, copper, tin, cerium, indium, zinc, yttrium, lanthanum, chromium, cobalt, platinum, iron, antimony, and germanium.

[0040] By using such metal oxide nanoparticles, a composition for forming a metal oxide film with excellent dispersibility / stability of metal nanoparticles can be prepared.

[0041] It is preferable that the aforementioned (A) metal oxide nanoparticles are one or more of those selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, tungsten oxide nanoparticles, titanium oxide nanoparticles, and tin oxide nanoparticles.

[0042] By using such metal oxide nanoparticles, an anti-reflective coating with excellent etching resistance can be formed.

[0043] It is preferable that the aforementioned (A) metal oxide nanoparticles have an average primary particle size of 100 nm or less.

[0044] By using such metal oxide nanoparticles, a composition for forming a metal oxide film with excellent dispersibility and fluidity of metal nanoparticles can be prepared.

[0045] Preferably, the foregoing (B) fluidity promoter is one or more compounds represented by the following general formulas (3), (4), and (5).

[0046] [Chemical Formula 5]

[0047]

[0048] In the foregoing general formulas (3) and (4), W 1 、W 2 、R a 、Y, n1, and n2 are as described above.

[0049] [Chemical Formula 6]

[0050]

[0051] In the foregoing general formula (5), Z 1 、R b 、n4, and n5 are as described above.

[0052] If the above fluidity promoter is one or more compounds represented by the above general formulas (3), (4), and (5), due to its excellent heat resistance, the compound monomer can be used as a thermal fluidity promoter, and it has more excellent thermal fluidity compared to high molecular weight bodies, and also has excellent filling / planarization characteristics for the pattern substrate.

[0053] Preferably, the foregoing (B) fluidity promoter is a polymer having one or more repeating units represented by the following general formulas (6), (7), and (8).

[0054] [Chemical Formula 7]

[0055]

[0056] In the foregoing general formulas (6) and (7), W 1 、W 2 、R a 、Y, n1, and n2 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

[0057] [Chemical Formula 8]

[0058]

[0059] In the foregoing general formula (8), Z 1 、R b 、n4, and n5 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

[0060] When the above-mentioned fluidity promoter uses a polymer having a repeating unit represented by one or more of the general formulas (6), (7), and (8), the etching resistance is not deteriorated and the curability is improved, whereby a dense metal oxide film can be formed. Furthermore, regardless of the substrate material and shape dependence, it becomes a composition for forming a metal oxide film with excellent film-forming properties.

[0061] It is preferable that the composition for forming a metal oxide film contains at least one of the compounds represented by the following general formulas (3) to (5) and at least one of the polymers having a repeating structural unit represented by the following general formulas (6) to (8) as the aforementioned component (B).

[0062] [Chemical formula 9]

[0063]

[0064] [Chemical formula 10]

[0065]

[0066] [Chemical formula 11]

[0067]

[0068] [Chemical formula 12]

[0069]

[0070] In the above general formula, W 1 , W 2 , R a , Y, n1, n2, Z 1 , R b , n4, n5 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

[0071] When the fluidity promoter is such a mixture, various physical properties required for forming a metal oxide film, such as filling / planarization properties, film-forming properties, and dissipated gas caused by sublimates, can be adjusted within an appropriate range.

[0072] R a in the above general formulas (I) and (II), and R b in the above general formula (III) are preferably a hydrogen atom or any of the structures represented by the following general formula (9).

[0073] [Chemical formula 13]

[0074]

[0075] * indicates the bonding part with an oxygen atom.

[0076] The fluidity promoter has both the crosslinking group and the hydroxyl group of the above general formula (9), and can form a metal oxide film having excellent thermal fluidity and substrate adhesion.

[0077] Let the proportion of hydrogen atoms among the aforementioned R a and R b be a, and the proportion of the structure represented by the above general formula (9) be b. It is preferably that the whole of the component (B) satisfies the relationship of a + b = 1 and 0.2 ≤ b ≤ 0.8.

[0078] If the contents of the crosslinking group and the hydroxyl group of the above general formula (9) are within the above ranges, various physical properties required when forming a metal oxide film, such as filling / planarization characteristics, dry etching resistance, and substrate adhesion, can be adjusted within an appropriate range.

[0079] The ratio Mw / Mn (i.e., the dispersity) of the polystyrene-reduced weight average molecular weight Mw to the number average molecular weight Mn obtained by gel permeation chromatography for a compound represented by one or more selected from the above general formulas (3), (4), and (5) is preferably in the range of 1.00 ≤ Mw / Mn ≤ 1.25 for each compound.

[0080] If it is a composition for forming a metal oxide film containing a compound having a dispersity within such a range, the thermal fluidity of the fluidity promoter is better. Therefore, when incorporated into the composition for forming a metal oxide film, not only can the fine structure formed on the substrate be well filled, but also a resist underlayer film with a flat substrate as a whole can be formed.

[0081] It is preferable that the aforementioned L is a divalent organic group represented by the following general formula (10).

[0082] [Chemical formula 14]

[0083]

[0084] In the above general formula (10), R 1 is a hydrogen atom or an aromatic ring-containing organic group having 6 to 20 carbon atoms, and the dotted line represents an atomic bond.

[0085] By constructing a repeating unit with such a linking group L, properties such as hardening property and etching resistance can be improved.

[0086] The polystyrene-reduced weight average molecular weight obtained by gel permeation chromatography for a polymer represented by one or more selected from the above general formulas (6), (7), and (8) is preferably 1000 to 5000.

[0087] If it is a composition for forming a metal oxide film containing a polymer having a weight average molecular weight within such a range, the solubility in an organic solvent is not impaired, and the evolution of gas during baking can be suppressed.

[0088] It is preferable that the aforementioned organic solvent (C) is a mixture of one or more organic solvents with a boiling point below 180°C and one or more organic solvents with a boiling point of 180°C or higher.

[0089] When the aforementioned organic solvent is such a mixture, by imparting the thermal fluidity obtained by adding a high-boiling solvent to the aforementioned compound and / or polymer, the composition for forming a metal oxide film will have both a high level of filling / planarization characteristics.

[0090] It is more preferable that the aforementioned composition for forming a metal oxide film further contains one or more of a crosslinking agent, a surfactant, an acid generator, a plasticizer, and a polymer for blending.

[0091] When it is a composition for forming a metal oxide film containing the above additives, the coating property, dry etching resistance, and filling / planarization characteristics are more excellent.

[0092] It is preferable that the aforementioned polymer for blending is a polymer containing the following general formula (BP).

[0093] [Chemical formula 15]

[0094]

[0095] In the above general formula (BP), R c is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms, R d is a hydrogen atom, or a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, X is a divalent organic group having 1 to 30 carbon atoms, p is an integer from 0 to 5, q1 is an integer from 1 to 6, p + q1 is an integer of 1 or more and 6 or less, and q2 is 0 or 1.

[0096] By adding the above polymer for blending, the filling / planarization characteristics are more excellent.

[0097] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0098] (I-1) After coating the above composition for forming a metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment,

[0099] (I-2) A resist upper layer film is formed on the aforementioned metal oxide film using a photoresist material,

[0100] (I-3) After pattern exposure of the aforementioned resist upper layer film, development is performed with a developer to form a pattern on the aforementioned resist upper layer film,

[0101] (I-4) Using the aforementioned resist upper layer film on which the pattern has been formed as a mask, the pattern is transferred to the aforementioned metal oxide film by dry etching, and

[0102] (I-5) Using the formed patterned metal oxide film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0103] With the pattern formation method using the above two-layer resist treatment, a fine pattern can be formed on the object to be processed (substrate to be processed).

[0104] Further, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0105] (II-1) After coating the above composition for forming a metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment.

[0106] (II-2) A silicon-containing resist intermediate film is formed on the above metal oxide film using a silicon-containing resist intermediate film material.

[0107] (II-3) A resist upper layer film is formed on the above resist intermediate film using a photoresist material.

[0108] (II-4) After pattern exposure of the above resist upper layer film, it is developed with a developer to form a pattern on the above resist upper layer film.

[0109] (II-5) Using the formed patterned resist upper layer film as a mask, the pattern is transferred to the above resist intermediate film by dry etching.

[0110] (II-6) Using the resist intermediate film with the transferred pattern as a mask, the pattern is transferred to the above metal oxide film by dry etching, and

[0111] (II-7) Using the formed patterned metal oxide film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0112] With the pattern formation method using the above three-layer resist treatment, a fine pattern can be formed on the object to be processed with high precision.

[0113] Further, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0114] (III-1) After coating the above composition for forming a metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment.

[0115] (III-2) An inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the above metal oxide film.

[0116] (III-3) Form an organic thin film on the aforementioned inorganic hard mask intermediate film.

[0117] (III-4) Form an upper resist film on the aforementioned organic thin film using a photoresist material.

[0118] (III-5) After pattern exposure of the aforementioned upper resist film, develop it with a developer to form a pattern on the aforementioned upper resist film.

[0119] (III-6) Use the aforementioned patterned upper resist film as a mask and transfer the pattern to the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0120] (III-7) Use the aforementioned inorganic hard mask intermediate film with the transferred pattern as a mask and transfer the pattern to the aforementioned metal oxide film by dry etching, and

[0121] (III-8) Use the aforementioned patterned metal oxide film as a mask and process the aforementioned substrate to be processed to form a pattern on the aforementioned substrate to be processed.

[0122] The pattern formation method using the above four-layer resist treatment can form fine patterns on the object to be processed with high precision.

[0123] Further, the present invention provides a pattern formation method, which is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0124] (IV-1) Form a lower resist film on the substrate to be processed.

[0125] (IV-2) Form an intermediate resist film on the aforementioned lower resist film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film and an organic thin film.

[0126] (IV-3) On the aforementioned intermediate resist film, or the combination of the inorganic hard mask intermediate film and the organic thin film, form an upper resist film using a photoresist material.

[0127] (IV-4) After pattern exposure of the aforementioned upper resist film, develop it with a developer to form a pattern on the aforementioned upper resist film.

[0128] (IV-5) Use the aforementioned patterned upper resist film as a mask and transfer the pattern to the aforementioned intermediate resist film, or the aforementioned organic thin film and the aforementioned inorganic hard mask intermediate film by dry etching.

[0129] (IV-6) Use the aforementioned intermediate resist film with the transferred pattern, or the inorganic hard mask intermediate film as a mask and transfer the pattern to the aforementioned lower resist film by dry etching.

[0130] (IV-7) After coating the above-described metal oxide film-forming composition on the above-described resist underlayer film having the previously formed pattern, the metal oxide film is coated by heat treatment, and the space between the patterns of the above-described resist underlayer film is filled with the above-described metal oxide film.

[0131] (IV-8) The above-described metal oxide film coated on the above-described resist underlayer film having the previously formed pattern is etched back by chemical stripping or dry etching to expose the upper surface of the above-described resist underlayer film having the formed pattern.

[0132] (IV-9) The resist intermediate film or the hard mask intermediate film remaining on the upper surface of the above-described resist underlayer film is removed by dry etching.

[0133] (IV-10) The above-described resist underlayer film having the formed pattern with the exposed surface is removed by dry etching to form an inverted pattern of the original pattern on the metal oxide film.

[0134] (IV-11) Using the above-described metal oxide film having the formed inverted pattern as a mask, the above-described substrate to be processed is processed to form a tone-inverted pattern on the above-described substrate to be processed.

[0135] With the pattern formation method by the above-described inversion process, a fine pattern can be formed on the object to be processed with higher precision.

[0136] It is preferable that the above-described substrate to be processed is a substrate having a structure or a height difference with a height of 30 nm or more.

[0137] In the present invention, for example, the above-described can be used as the above-described object to be processed.

[0138] Further, the present invention provides a method for forming a metal oxide film, which is a method for forming a metal oxide film serving as a planarizing film used in the manufacturing process of a semiconductor device. A hardened film is formed by heat treatment on a substrate coated with the above-described metal oxide film-forming composition on a substrate to be processed at a temperature in the range of 100 °C or more and 600 °C or less for 10 to 600 seconds.

[0139] Further, the present invention provides a method for forming a metal oxide film, which is a method for forming a metal oxide film serving as a planarizing film used in the manufacturing process of a semiconductor device. A hardened film is formed by heat treatment on a substrate coated with the above-described metal oxide film-forming composition on a substrate to be processed in a gas environment with an oxygen concentration of 1% by volume or more and 21% by volume or less.

[0140] By such a method, the crosslinking reaction of the composition for forming the metal oxide film during the formation of the underlayer film of the resist can be promoted, and the mixing with the upper layer film can be suppressed to a greater extent. Further, by appropriately adjusting the heat treatment temperature, time, and oxygen concentration within the above ranges, the filling / planarization characteristics and hardening characteristics of the underlayer film of the resist suitable for the intended use can be obtained.

[0141] Further, the present invention provides a method for forming a metal oxide film, which is a method for forming a metal oxide film that functions as a planar film used in the manufacturing process of a semiconductor device. A hardened film is formed by heat treatment of a substrate coated with the above composition for forming a metal oxide film in a gas environment where the oxygen concentration is less than 1% by volume.

[0142] By such a method, even when the substrate to be processed contains a material that is unstable to heating in an oxygen environment, the substrate to be processed is not deteriorated, but the crosslinking reaction of the composition for forming the metal oxide film during the formation of the underlayer film of the resist is promoted, and the mixing with the upper layer film is suppressed to a greater extent, which is useful.

[0143] (Effects of the Invention)

[0144] As described above, the composition for forming a metal oxide film, the pattern forming method, and the method for forming an underlayer film of a resist of the present invention are particularly suitable for multi-layer resist processing including filling / planarization of a substrate to be processed having height differences and unevenness, and are extremely useful for fine patterning in the manufacture of semiconductor devices. Specifically, since it contains a flow promoter that highly balances dry etching resistance and fluidity, the excellent dry etching resistance from metal oxide nanoparticles can be maximally exerted, and further, an underlayer film material of a resist that balances high-level planarization characteristics / filling characteristics, which is difficult to achieve with metal oxide nanoparticles alone, can be provided. Especially in the fine patterning process using a multi-layer resist method in the manufacturing process of semiconductor devices, even on a substrate to be processed in a portion where filling / planarization is difficult, such as a dense portion having a fine pattern structure with a high aspect ratio represented by a DRAM memory with progress in miniaturization, it can be filled without defects such as pores and peeling, and further, it has extremely excellent dry etching resistance compared to known coating-type organic underlayer film materials of a resist, so that a fine pattern can be formed on the object to be processed with higher precision. Description of the Drawings

[0145] Figure 1 (A) to (F) are explanatory diagrams of an example (three-layer resist process) of the pattern forming method of the present invention.

[0146] Figure 2 (G) to (P) are explanatory diagrams of an example (inversion of an SOC pattern in a three-layer resist process) of the tone inversion type pattern forming method of the present invention.

[0147] Figure 3 Figures (Q) to (S) are explanatory diagrams of the landfill characteristic evaluation method.

[0148] Figure 4 Figures (T) and (U) are explanatory diagrams of the planarization characteristic evaluation method. Detailed Description of the Invention

[0149] As described above, in the fine patterning process using a multilayer resist method in the semiconductor device manufacturing process, even on a substrate to be processed such as a dense portion of a fine pattern structure with a high aspect ratio represented by a DRAM memory with progress in miniaturization, which is difficult to fill / planarize such as a landfill / planarization difficult portion, it is possible to fill / planarize without defects such as voids and peeling, and has excellent dry etching resistance compared to known coating-type organic resist underlayer film materials and can transfer the resist pattern to the substrate to be processed with higher accuracy.

[0150] The inventors of the present case diligently studied the above problems. In order to achieve a high level of landfill / planarization and excellent dry etching resistance due to the formation of the underlayer film in the multilayer resist method using an underlayer film, various underlayer film materials and pattern formation methods were explored. As a result, it was found that a pattern formation method using a metal oxide film-forming composition containing metal oxide nanoparticles with excellent dry etching resistance, a fluidity promoter containing a compound / polymer with a specific structure, and an organic solvent is very effective, and thus the present invention was completed.

[0151] That is, the present invention is a metal oxide film-forming composition containing

[0152] (A) metal oxide nanoparticles, (B) a fluidity promoter which is one or more compounds represented by the following general formula (I), general formula (II), and general formula (III) and / or a polymer having a molecular weight of 5000 or less, and (C) an organic solvent,

[0153] The weight ratio of the aforementioned (A) metal oxide nanoparticles to the aforementioned (B) fluidity promoter is 10 / 90 to 90 / 10.

[0154] [Chemical Formula 16]

[0155]

[0156] In the aforementioned general formula (I) and the aforementioned general formula (II), W 1 and W 2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the aforementioned benzene ring and naphthalene ring may be substituted with a hydrocarbon group having 1 to 6 carbon atoms. R ais a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, Y is a group represented by the following general formula (1). n1 is 0 or 1, n2 is 1 or 2, and each V independently represents a hydrogen atom or a connecting portion.

[0157] [Chemical formula 17]

[0158]

[0159] In the aforementioned general formula (III), Z 1 is a group represented by the following general formula (2), R b is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms. n4 is 0 or 1, n5 is 1 or 2, and each V independently represents a hydrogen atom or a connecting portion.

[0160] [Chemical formula 18]

[0161]

[0162] * represents an atomic bond.

[0163] [Chemical formula 19]

[0164]

[0165] In the aforementioned general formula (2), W 1 , W 2 , Y, n1 are as described above.

[0166] The following is a detailed description of the present invention, but the present invention is not limited thereto.

[0167] <Composition for forming metal oxide film>

[0168] The composition for forming a metal oxide film of the present invention contains (A) metal oxide nanoparticles described below, (B) a fluidity promoter represented by a specific general formula, and (C) an organic solvent. The weight ratio of the above (A) metal oxide nanoparticles to the above (B) fluidity promoter is 10 / 90 to 90 / 10. If necessary, additives such as a surfactant and a crosslinking agent may also be contained. The components contained in the composition of the present invention are described below.

[0169] <(A) Metal oxide nanoparticles>

[0170] The aforementioned (A) metal oxide nanoparticles contained in the composition for forming a metal oxide film of the present invention are preferably one or more metal oxide nanoparticles selected from the group consisting of zirconium, hafnium, aluminum, tungsten, titanium, copper, tin, cerium, indium, zinc, yttrium, lanthanum, chromium, cobalt, platinum, iron, antimony, and germanium. Among them, zirconia nanoparticles, hafnia nanoparticles, tungsten oxide nanoparticles, titanium oxide nanoparticles, and tin oxide nanoparticles are more ideal from the viewpoints of dispersibility and dry etching resistance.

[0171] By selecting the above metal oxides, a metal oxide film with excellent dispersibility and dry etching resistance can be formed.

[0172] The aforementioned (A) metal oxide nanoparticles preferably have an average primary particle diameter of 100 nm or less, more preferably 50 nm or less, still more preferably 30 nm or less, and particularly preferably 15 nm or less. There is no particular limitation on the lower limit value of the average primary particle diameter, and for example, it can be 0.1 nm or more. The average primary particle diameter of the aforementioned metal oxide nanoparticles before dispersion in an organic solvent can be determined by a method of directly measuring the size of primary particles from an electron microscope photograph. Specifically, the minor axis diameter and major axis diameter of each primary particle are measured, and their average is taken as the particle diameter of this particle. Then, for 100 or more particles, approximating the obtained particle diameter to a rectangular parallelepiped, the volume (mass) of the particles is determined respectively, and the volume average particle diameter is determined as the average particle diameter. Also, the same result can be obtained using a transmission type (TEM), scanning type (SEM), or scanning transmission type (STEM) electron microscope.

[0173] If it is within such a particle diameter range, good dispersibility can be exhibited in the composition for forming a metal oxide film, and a metal oxide film with excellent filling / planarization characteristics for a dense portion of a fine pattern structure can be formed.

[0174] The (A) metal oxide nanoparticles contained in the composition for forming a metal oxide film of the present invention can use commercially available metal oxide nanoparticles.

[0175] Titanium oxide nanoparticles, for example, TTO series (TTO-51(A), TTO-51(C), etc.), TTO-S, V series (TTO-S-1, TTO-S-2, TTO-V-3, etc.) manufactured by Ishihara Sangyo Co., Ltd., MT series (MT-01, MT-05, MT-100SA, MT-500SA, NS405, etc.) manufactured by TAYCA Corporation, STR-100A-LP manufactured by Sakai Chemical Industry Co., Ltd., etc.

[0176] Zirconia nanoparticles, such as: PCS (manufactured by Nippon Denko Corporation), JS-01, JS-03, JS-04 (manufactured by Nippon Denko Corporation), UEP, UEP-50, UEP-100 (manufactured by Daiichi Rare Element Chemical Industry Co., Ltd.), PCPB-2-50-PGA and PCPA-2-502-PGA (manufactured by Pixelligent Technologies), ZrO 2 nanoparticles 915505 (manufactured by Sigma-Aldrich) and the like.

[0177] The aforementioned (A) metal oxide nanoparticles contained in the composition for forming a metal oxide film of the present invention may be used alone or in combination of two or more, and any combination can be selected according to the required performance. The (A) component can be 11 to 900 parts by mass with respect to 100 parts by mass of the fluidity promoter in the composition.

[0178] <(B) Fluidity promoter>

[0179] The composition for forming a metal oxide film of the present invention is characterized by containing a fluidity promoter which is a compound represented by one or more of the following general formulas (I), (II) and (III) and / or a polymer having a molecular weight of 5000 or less.

[0180] [Chemical formula 20]

[0181]

[0182] In the above general formula (I) and the above general formula (II), W 1 and W 2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and the naphthalene ring may be substituted by a hydrocarbon group having 1 to 6 carbon atoms. R a is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, Y is a group represented by the following general formula (1). n1 is 0 or 1, n2 is 1 or 2, and V each independently represents a hydrogen atom or a connecting portion.

[0183] [Chemical formula 21]

[0184]

[0185] In the above general formula (III), Z 1 is a group represented by the following general formula (2), R b is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms. n4 is 0 or 1, n5 is 1 or 2, and V each independently represents a hydrogen atom or a connecting portion.

[0186] [Chemical formula 22]

[0187]

[0188] * represents an atomic bond.

[0189] [Chemical formula 23]

[0190]

[0191] In the above general formula (2), W 1 , W 2 , Y, and n1 are as described above.

[0192] In the above general formulas (I) and (II), W 1 and W 2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and the naphthalene ring may also be substituted by hydrocarbon groups having 1 to 6 carbon atoms. From the viewpoint of fluidity, it is preferable that W 1 and W 2 are benzene rings. From the viewpoints of dry etching resistance and reduction of outgassing caused by sublimates, it is more ideal that n1 is 1, and it is preferable that n2 is 1. R a is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms, or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, and does not contain heteroatoms. From the viewpoints of thermosetting property and fluidity, a hydrogen atom or a structure represented by the following formula (R a -1) is preferable. Moreover, a hydrogen atom, an allyl group, or a propargyl group is more ideal.

[0193] [Chemical formula 24]

[0194]

[0195] In the formula (R a -1), p is 1 to 10, and this formula is only applicable here.

[0196] In the above general formula (III), Z 1 is a group represented by the above general formula (2), and R b is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms, or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, and does not contain heteroatoms. It is more ideal that n4 is 1, and it is preferable that n5 is 1.

[0197] In the above general formula (III), R b From the viewpoints of thermosetting property and fluidity, it is preferably a hydrogen atom or a structure represented by the following formula (R b -1). Among them, a hydrogen atom, an allyl group, or a propargyl group is more ideal.

[0198] [Chemical formula 25]

[0199]

[0200] In the formula (R b-1), p is from 1 to 10, and this formula is applicable only here.

[0201] In the general formulas (I), (II), and (III) above, each V independently represents a hydrogen atom or a linking moiety. When all of the Vs are hydrogen atoms (without a linking moiety), the flowability promoter represented by the above general formula is a monomolecular compound and corresponds to the compounds represented by the following general formulas (3), (4), and (5). When V is a linking moiety, the aforementioned flowability promoter is a polymer. The linking moiety is a part that connects the structures represented by the above general formula to each other, and for example, it can be a single bond or those listed for the following linking group L. That is, the aforementioned polymer includes polymers having repeating units represented by the following general formulas (6), (7), and (8).

[0202] If it is a flowability promoter with such a structure, it has a rigid structure containing many aromatic rings and can form a metal oxide film-forming composition with better heat resistance and etching resistance. Furthermore, due to the action of the cardo structure introduced into the molecule, the intermolecular interaction is alleviated and solubility in organic solvents is imparted, so metal oxide nanoparticles can be well dispersed in the metal oxide film-forming composition, and the film-forming property during coating film formation can be better. Also, even if multiple condensed carbon rings with a high carbon density are introduced, opposite properties such as heat resistance and filling / planarization properties can be balanced.

[0203] R in the above general formulas (I) and (II) a The structural component is a hydrogen atom or any of the structures represented by the above general formula (R a -1). The constituent component of R in the above general formula (III) b is a hydrogen atom or any of the structures represented by the above general formula (R b -1). Among the structures constituting the above R a and R b , when the proportion of hydrogen atoms is a and the proportion of the structures represented by the above general formulas (R a -1) and (R b -1) is b, it is preferably the case that for the whole of component (B), a + b = 1 and 0.2 ≤ b ≤ 0.8, more preferably 0.3 ≤ b ≤ 0.7, and even more preferably 0.4 ≤ b ≤ 0.6.

[0204] By combining a hydrogen atom with the above general formulas (R a -1) and (R bIf the ratio of (1) is controlled within the above range, the fluidity and the substrate adhesion performance can be highly exhibited, and a resist underlayer film material with improved landfill / planarization characteristics can be provided. When it is desired to improve the film-forming property and the adhesion of the film to the substrate, the ratio a of hydrogen atoms is increased, that is, a > b. Also, when it is desired to improve the curability, heat resistance, and planarization characteristics, a < b can be set, and they can be adjusted to any ratio according to the required performance.

[0205] The above general formula (R a -1) and (R b -1) are more preferably the structures of the following general formula (9).

[0206] [Chemical formula 26]

[0207]

[0208] * indicates the bonding part with an oxygen atom.

[0209] By having such a crosslinking group, the fluidity can be better, and a cured film with excellent film-forming property and less outgassing can be formed.

[0210] In the present invention, the fluidity promoter represented by the above general formula (I) to (III) in which the ratio of hydrogen atoms to the above general formula (R a -1) and (R b -1) is controlled within the above range can be used alone, or two or more kinds can be mixed in a desired ratio to form an equivalent composition.

[0211] The above fluidity promoter can be a compound represented by the following general formula (3), (4), or (5) (hereinafter, these compounds will also be referred to as "compounds for fluidity promoter"), or a polymer having a repeating unit represented by the following general formula (6), (7), or (8) (hereinafter, such a polymer will also be referred to as "polymer for fluidity promoter"). Also, the above fluidity promoter may contain one or more of each of the compounds represented by the general formula (3) to (5) and the polymer having a repeating unit represented by the general formula (6) to (8). The fluidity promoter (compound and polymer) will be further described below.

[0212] [Compounds for fluidity promoter]

[0213] The compound for fluidity promoter contained in the composition for forming a metal oxide film of the present invention can be one or more compounds selected from the following general formula (3), (4), and (5).

[0214] [Chemical formula 27]

[0215]

[0216] In the above general formulas (3) and (4), W 1 , W 2 , R a , Y, n1, and n2 are as described above.

[0217] [Chemical formula 28]

[0218]

[0219] In the above general formula (5), Z 1 , R b , n4, and n5 are as described above.

[0220] W in the above general formulas (3) and (4) 1 , W 2 , R a , Y, n1, and n2 are as described in the explanation for the above general formulas (I) and (II).

[0221] Z in the above general formula (5) 1 , R b , n4, and n5 are as described in the explanation for the above general formula (III).

[0222] Examples of the compound for the fluidity promoter represented by the above general formulas (3), (4), and (5) include, but are not limited to, the following compounds.

[0223] [Chemical formula 29]

[0224]

[0225] [Chemical formula 30]

[0226]

[0227] The ratio Mw / Mn (i.e., the dispersity) of the polystyrene-reduced weight-average molecular weight Mw to the number-average molecular weight Mn obtained by gel permeation chromatography for a compound represented by one or more selected from the above general formulas (3), (4), and (5) is preferably in the range of 1.00 ≤ Mw / Mn ≤ 1.25 for each compound. With such a dispersity, the thermal fluidity of the compound for the fluidity promoter is better. When incorporated into the composition, it can not only well fill the fine structures formed on the substrate but also form a flat underlayer film for the resist over the entire substrate.

[0228] [Polymer for fluidity promoter]

[0229] The polymer for the fluidity promoter contained in the composition for forming a metal oxide film of the present invention, and the above fluidity promoter can be a polymer having repeating units represented by one or more selected from the following general formulas (6), (7), and (8).

[0230] [Chemical Formula 31]

[0231]

[0232] In the above general formulas (6) and (7), W 1 、W 2 、R a 、Y, n1, and n2 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

[0233] [Chemical Formula 32]

[0234]

[0235] In the above general formula (8), Z 1 、R b 、n4, and n5 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

[0236] W 1 、W 2 、R a 、Y, n1, and n2 in the above general formulas (6) and (7) are as described for the above general formulas (I) and (II).

[0237] Z 1 、R b 、n4, and n5 in the above general formula (8) are as described for the above general formula (III).

[0238] They are polymers obtained using the compounds represented by the above general formulas (3), (4), and (5). Because the compound for the above flowability promoter is used, they have excellent heat resistance, planarization characteristics, and thermosetting properties. Also, since they are polymers having repeating units instead of monomers, the amount of off-gas components is small. Further, since they are polymers having a molecular weight distribution, the crystallinity is alleviated, and an improvement in film-forming properties can also be expected.

[0239] The linking group L constituting the repeating units of the above general formulas (6), (7), and (8) is a divalent organic group having 1 to 40 carbon atoms, and specific examples thereof include the following.

[0240] [Chemical Formula 33]

[0241]

[0242] Furthermore, it is preferable that the linking group L of the polymer described above is represented by the following general formula (10).

[0243] [Chemical Formula 34]

[0244]

[0245] In the above general formula (10), R1 is a hydrogen atom or an aromatic ring-containing organic group having 6 to 20 carbon atoms, and the dotted line represents an atomic bond.

[0246] Specifically, the above general formula (10) can be exemplified as follows. Among the following, considering the ease of obtaining raw materials, methylene, that is, R 1 is preferably a hydrogen atom.

[0247] [Chemical formula 35]

[0248]

[0249] Furthermore, the polystyrene-converted weight-average molecular weight measured by gel permeation chromatography of the polymer having one or more repeating structural units represented by the above general formulas (6), (7), and (8) is 5000 or less, preferably 1000 to 5000, and more preferably Mw of 1000 to 4000.

[0250] In such a molecular weight range, solubility in an organic solvent can be ensured, and sublimates generated during baking can also be suppressed. Also, the thermal fluidity of the polymer for the fluidity promoter becomes good. Therefore, when blended into a material, not only can the fine structure formed on the substrate be well filled, but also a flat metal oxide film can be formed over the entire substrate.

[0251] [Compound and / or polymer for fluidity promoter]

[0252] In the metal oxide film-forming composition of the present invention containing metal oxide nanoparticles, the above compound and / or polymer for fluidity promoter, and an organic solvent, the above compound or polymer for fluidity promoter can be used alone or in combination of multiple kinds.

[0253] Furthermore, the present invention contains one or more of each of the above compounds for fluidity promoter and polymers. Specifically, it is preferable that the metal oxide film-forming composition contains any one or more of the compounds represented by the above general formulas (3) to (5) and any one or more of the polymers having the repeating structural units represented by the above general formulas (6) to (8) as the above component (B).

[0254] In the case of the above mixture, various physical properties required when using a composition for forming a metal oxide film, such as landfill / planarization characteristics and dissipated gas caused by sublimates, can be adjusted within an appropriate range. That is, the fluidity promoter contained in the composition for forming a metal oxide film can be (i) composed of one or more compounds for a fluidity promoter, (ii) composed of one or more polymers for a fluidity promoter, or (iii) a mixture composed of one or more of each selected from the compound and polymer for a fluidity promoter, and can be freely combined, whereby a metal oxide film with desired characteristics can be provided. If the fluidity promoter is a single blending of a compound or a polymer, it is easy to prepare. If it is a blending of a mixture of a compound and a polymer, the degree of freedom in controlling the workability of the composition and the physical properties of the metal oxide film is increased.

[0255] When the fluidity promoter is a mixture of a compound and a polymer, the weight ratio of compound x to polymer y is preferably x / y = 20 / 80 to 80 / 20. By controlling within the above range, fluidity and the denseness of the cured film can be highly exhibited, and a resist underlayer film material with improved landfill / planarization characteristics and dry etching resistance can be provided. When it is desired to improve the landfill / planarization characteristics, the proportion of compound x is increased, that is, x > y is sufficient. When it is desired to improve the curability, heat resistance, and film-forming property, x < y is sufficient, and they can be adjusted to any ratio according to the required performance.

[0256] In the composition for forming a metal oxide film of the present invention, the weight ratio of the aforementioned (A) metal oxide nanoparticles to the aforementioned (B) fluidity promoter is 10 / 90 to 90 / 10, more preferably 20 / 80 to 80 / 20, and even more preferably 30 / 70 to 70 / 30.

[0257] By controlling the ratio of (A) metal oxide nanoparticles to (B) fluidity promoter within the above range, dry etching resistance and landfill / planarization characteristics can be highly exhibited. If it is outside the range of 10 / 90 to 90 / 10, heat resistance and dry etching resistance are reduced. When it is desired to improve dry etching resistance, the proportion of (A) metal oxide nanoparticles is increased. When it is desired to improve landfill / planarization characteristics, the proportion of (B) fluidity promoter is increased, and they can be adjusted to any ratio according to the required performance. The amount of component (B) can be 11 to 900 parts by mass relative to 100 parts by mass of the metal oxide nanoparticles in the composition.

[0258] <(C) organic solvent>

[0259] The (C) organic solvent that can be used in the composition for forming a metal oxide film of the present invention is not particularly limited as long as it can disperse the above-mentioned (A) metal oxide nanoparticles and can dissolve the crosslinking agent, surfactant, acid generator, plasticizer, other additives, etc. described later when containing a compound and / or polymer (flowability promoter) for promoting flowability. Specifically, solvents with a boiling point of less than 180°C such as those described in paragraphs

[0091] to

[0092] of Japanese Patent Laid-Open No. 2007-199653 can be used. Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and a mixture of two or more thereof are preferably used. The blending amount of the organic solvent is preferably 200 to 10,000 parts, more preferably 300 to 5,000 parts, relative to 100 parts of the (A) metal oxide nanoparticles.

[0260] For such a composition for forming a metal oxide film, the (A) metal oxide nanoparticles can be well dispersed and can be coated by spin coating, so a metal oxide film having both dry etching resistance and a high level of filling / planarization characteristics can be formed.

[0261] Furthermore, in the composition for forming a metal oxide film of the present invention, a high-boiling solvent having a boiling point of 180 °C or higher may also be added to the solvent having a boiling point of less than 180 °C as an organic solvent (a mixture of a solvent having a boiling point of less than 180 °C and a solvent having a boiling point of 180 °C or higher). The high-boiling organic solvent only needs to be able to dissolve the compound and / or polymer for promoting fluidity, and is not particularly limited to hydrocarbons, alcohols, ketones, esters, ethers, chlorinated solvents, etc. Specific examples may include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, 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, glycerol, n-nonyl acetate, ethylene glycol monohexyl ether, ethylene glycol mono-2-ethylhexyl ether, ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, diethylene glycol monoethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol mono-isobutyl 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-butanediol diacetate, 1,6-hexanediol diacetate, triethylene glycol diacetate, γ-butyrolactone, dihexyl malonate, diethyl succinate, dipropyl succinate, dibutyl succinate, dihexyl succinate, dimethyl adipate, diethyl adipate, dibutyl adipate, etc. They can be used alone or in combination.

[0262] The boiling point of the above high-boiling solvent can be appropriately selected in accordance with the temperature for heat-treating the composition for forming a metal oxide film. The boiling point of the added high-boiling solvent is preferably 180 °C to 300 °C, more preferably 200 °C to 300 °C. If the boiling point is such, there is no fear of excessive volatilization during baking (heat treatment) due to too low a boiling point, and sufficient thermal fluidity can be obtained. Also, if the boiling point is such, the boiling point is not too high, and it will not remain non-volatile in the film after baking, so there is no fear of adversely affecting film physical properties such as etching resistance.

[0263] When the high boiling point solvent is used, the amount of the high boiling point solvent is preferably 1 to 30 parts by mass based on 100 parts by mass of the solvent having a boiling point of less than 180° C. Such an amount can provide sufficient thermal fluidity, does not remain in the film, and improves film properties such as etching resistance.

[0264] According to such a metal oxide film forming composition, by adding a high boiling point solvent to the metal oxide film forming composition, thermal fluidity can be imparted to the metal oxide film forming composition to achieve both higher filling and planarizing properties.

[0265] <Other ingredients>

[0266] [Crosslinking agent]

[0267] In addition, in the metal oxide film forming composition of the present invention, a crosslinking agent may be added in order to improve the hardening property and inhibit cross-mixing with the upper film of the resist. There is no particular limitation on the crosslinking agent, and various known systems of crosslinking agents can be widely used. As an example, hydroxymethyl or alkoxymethyl type crosslinking agents (multinuclear phenol crosslinking agents) of polynuclear phenols, melamine crosslinking agents, glycoluril crosslinking agents, benzoguanamine crosslinking agents, urea crosslinking agents, β-hydroxyalkylamide crosslinking agents, isocyanurate crosslinking agents, aziridine crosslinking agents, oxazoline crosslinking agents, and epoxy crosslinking agents can be listed. The amount of the crosslinking agent added is preferably 1 to 100 parts relative to 100 parts of the aforementioned metal oxide nanoparticles, and more preferably 5 to 50 parts.

[0268] Specific examples of the melamine-based crosslinking agent include hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy and / or hydroxyl-substituted melamines thereof, and partial self-condensates thereof.

[0269] Specific examples of the glycoluril-based crosslinking agent include tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, alkoxy and / or hydroxyl-substituted products thereof, and partial self-condensation products thereof.

[0270] Specific examples of the benzoguanamine-based crosslinking agent include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, alkoxy and / or hydroxyl-substituted products thereof, and partial self-condensation products thereof.

[0271] Specific examples of the urea crosslinking agent include dimethoxymethylated dimethoxyethylene urea, alkoxy and / or hydroxyl-substituted products thereof, and partial self-condensates thereof.

[0272] Specific examples of the β-hydroxyalkylamide crosslinking agent include N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide. Specific examples of the isocyanurate crosslinking agent include triglycidyl isocyanurate and triallyl isocyanurate.

[0273] Examples of aziridine crosslinking agents include 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bis(hydroxymethyl)butanol-tris[3-(1-aziridinyl)propionate].

[0274] Examples of oxazoline 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-tert-butyl-2-oxazoline), 2,2'-bis(2-oxazoline), 1,3-phenylenebis(2-oxazoline), 1,4-phenylenebis(2-oxazoline), and 2-isopropenyl oxazoline copolymer.

[0275] 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.

[0276] Examples of polynuclear phenol crosslinking agents include compounds represented by the following general formula (11).

[0277] [Chemical formula 36]

[0278]

[0279] In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R 2 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. s is an integer of 1 to 5.

[0280] Q is a single bond or an s-valent hydrocarbon group having 1 to 20 carbon atoms. s is an integer of 1 to 5, preferably 2 or 3. Specific examples of Q include groups obtained by removing q hydrogen atoms from methane, ethane, propane, butane, isobutane, pentane, cyclopentane, hexane, cyclohexane, methylpentane, methylcyclohexane, dimethylcyclohexane, trimethylcyclohexane, benzene, toluene, xylene, ethylbenzene, ethylisopropylbenzene, diisopropylbenzene, methylnaphthalene, ethylnaphthalene, and eicosane. R 2 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, pentyl, isopentyl, hexyl, octyl, ethylhexyl, decyl, and eicosyl. A hydrogen atom or a methyl group is preferred.

[0281] Examples of the compound represented by the above general formula (11) specifically include the following compounds. Among them, from the viewpoint of improving the hardening property and film thickness uniformity of the organic film, hexamethoxymethylated products of triphenylmethane, triphenylethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred. R 2 As described above.

[0282] [Chemical formula 37]

[0283]

[0284] [Chemical formula 38]

[0285]

[0286] [Surfactant]

[0287] In the composition for forming a metal oxide film of the present invention, in order to improve the coatability of spin coating, a surfactant can be added. As the surfactant, for example, those described in paragraphs

[0142] to

[0147] of Japanese Patent Application Laid-Open No. 2009-269953 can be used. When adding a surfactant, the addition amount is preferably 0.01 to 10 parts, more preferably 0.05 to 5 parts, relative to 100 parts of the aforementioned compound and / or polymer.

[0288] [Acid generator]

[0289] In the composition for forming a metal oxide film of the present invention, in order to further promote the hardening reaction, an acid generator can be added. As the acid generator, those that generate acid by thermal decomposition or those that generate acid by light irradiation can be added. Specifically, the materials described in paragraphs

[0061] to

[0085] of Japanese Patent Application Laid-Open No. 2007-199653 can be added, but are not limited thereto.

[0290] The above acid generator can be used alone or in combination of two or more. When adding an acid generator, the addition amount is preferably 0.05 to 50 parts, more preferably 0.1 to 10 parts, relative to 100 parts of the aforementioned (A) metal oxide nanoparticles.

[0291] [Plasticizer]

[0292] Further, in the composition for forming a metal oxide film of the present invention, a plasticizer may be added in order to improve the planarization / embedding properties. The plasticizer is not particularly limited, and various known plasticizers of various systems can be widely used. For example, low molecular compounds such as phthalates, adipates, phosphates, trimellitates, and citrates, polymers such as polyether-based, polyester-based, and polyacetal-based polymers described in JP-A-2013-253227 can be cited. When adding a plasticizer, the addition amount is preferably 1 to 100 parts, more preferably 5 to 30 parts, relative to 100 parts of the aforementioned (A) metal oxide nanoparticles.

[0293] Further, in the composition for forming a metal oxide film of the present invention, as an additive that imparts embedding / planarization properties similar to those of the plasticizer, for example, a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a thermally decomposable polymer having a weight reduction rate of 40% by mass or more between 30°C and 250°C and a weight average molecular weight of 300 to 200,000 is preferably used. It is preferable that this thermally decomposable polymer contains repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a).

[0294] [Chemical formula 39]

[0295]

[0296] In the formula, R 5 is a hydrogen atom or a saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms which may be substituted. Y is a saturated or unsaturated divalent organic group having 2 to 30 carbon atoms. Each symbol is only applicable in this formula.

[0297] [Chemical formula 40]

[0298]

[0299] In the formula, R 5a is an alkyl group having 1 to 4 carbon atoms. Y a is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms, and may have an ether bond. n represents the average number of repeating units and is 3 to 500.

[0300] [Polymer or compound for blending]

[0301] Other polymers and compounds may be further blended in the composition for forming a metal oxide film of the present invention. The polymer or compound for blending is mixed with the (A) metal oxide nanoparticles and (B) fluidity promoter of the present invention, and has the effect of improving the film-forming property by spin coating and the embedding property on a substrate having height differences.

[0302] Such materials may include phenol, o-cresol, m-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,4-xylenol, 2,6-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, 2-tert-butylphenol, 3-tert-butylphenol, 4-tert-butylphenol, 2-phenylphenol, 3-phenylphenol, 4-phenylphenol, 3,5-diphenylphenol, 2-naphthol, 3-naphthol, 4-naphthol, 4-tritylphenol, resorcinol, 2-methylresorcinol, 4-methylresorcinol, 5-methylresorcinol, catechol, 4-tert-butylcatechol, 2-methoxyphenol, 3-methoxyphenol, 2-propylphenol, 3-propylphenol, 4-propylphenol, 2-isopropylphenol, 3-isopropylphenol, 4-isopropylphenol, 2-methoxy-5-methylphenol, 2-tert-butyl-5-methylphenol, pyrogallol, thymol, isothymol, 4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-dimethyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-diallyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-difluoro-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-diphenyl-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,2'-dimethoxy-4,4'-(9H-fluoren-9-ylidene)bisphenol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 3,3,3',3',4,4'-hexamethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 2,3,2',3'-tetrahydro-(1,1')-spirobiindene-5,5'-diol, 5,5'-dimethyl-3,3,3',3'-tetramethyl-2,3,2',3'-tetrahydro-(1,1')-spirobiindene-6,6'-diol, 1-naphthol, 2-naphthol, 2-methyl-1-naphthol, 4-methoxy-1-naphthol, 7-methoxy-2-naphthol and dihydroxynaphthalenes such as 1,5-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, methyl 3-hydroxynaphthalene-2-carboxylate, indene, hydroxyindene, benzofuran, hydroxyanthracene, vinylnaphthalene, biphenyl, bisphenol, triphenol, dicyclopentadiene, indane, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene and other novolac resins, polyhydroxystyrene, polystyrene, polyvinylnaphthalene, polyvinylanthracene, polyvinylcarbazole, polyindene, polyvinylnaphthalene, polynorbornene, polycyclodecene, poly(tetracyclododecene), polytricyclo[2.2.1.0(2,6)]heptane (poly-nortricyclene), poly(meth)acrylate and their copolymers.Alternatively, it is also possible to blend a naphthol dicyclopentadiene copolymer described in Japanese Patent Application Laid-Open No. 2004-205685, a fluorene bisphenol novolak resin described in Japanese Patent Application Laid-Open No. 2005-128509, an ethylene naphthalene copolymer described in Japanese Patent Application Laid-Open No. 2005-250434, a fullerene having a phenol group described in Japanese Patent Application Laid-Open No. 2006-227391, a bisphenol compound and its novolak resin described in Japanese Patent Application Laid-Open No. 2006-293298, a novolak resin of an adamantane phenol compound described in Japanese Patent Application Laid-Open No. 2006-285095, a binaphthol compound and its novolak resin described in Japanese Patent Application Laid-Open No. 2010-122656, a fullerene resin compound described in Japanese Patent Application Laid-Open No. 2008-158002, etc. Alternatively, it is also possible to blend a polymer containing the following general formula (BP). Among them, from the viewpoint of fluidity, it is preferable to use a polymer containing (BP) as the polymer for blending.

[0303] [Polymer for blending (BP)]

[0304] The above-mentioned compound or polymer for blending is preferably a polymer for blending having a structure represented by the following general formula (BP).

[0305] [Chemical formula 41]

[0306]

[0307] In the above general formula (BP), R c is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms, R d is a hydrogen atom, or a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, X is a divalent organic group having 1 to 30 carbon atoms, p is an integer of 0 to 5, q1 is an integer of 1 to 6, p + q1 is an integer of 1 or more and 6 or less, and q2 is 0 or 1.

[0308] In the above general formula (BP), from the viewpoint of raw material acquisition, X is preferably a methylene group, p is preferably 0 or 1, q1 is preferably 1 or 2, and q2 is preferably 0.

[0309] In the above general formula (BP), R d A particularly ideal example of the structure is a hydrogen atom or a structure represented by the following general formula (12). By adding a polymer for blending having such a structure, the fluidity of the composition for forming a metal oxide film can be made better. Moreover, the heat resistance and film-forming property become good, the generation of sublimates during heat hardening is suppressed, the contamination of the device caused by sublimates is suppressed, and the occurrence of coating defects can be suppressed.

[0310] [Chemical formula 42]

[0311]

[0312] In the above formula, * represents the bonding site to the oxygen atom.

[0313] R in the above general formula (BP) d The constituent is a hydrogen atom or any one of the structures represented by the above general formula (12). When the proportion of the hydrogen atom is Ba and the proportion of the structure represented by the above general formula (12) is Bb, a polymer in which the whole (BP) component satisfies the relationship of Ba + Bb = 1 and 0.2 ≤ Bb ≤ 0.8 is more preferable. By adding the blending polymer within such a range, the thermal fluidity can be better.

[0314] The blending amount of the above blending compound or blending polymer is preferably 0 to 1,000 parts by mass, more preferably 0 to 500 parts by mass, based on 100 parts by mass of the aforementioned (A) metal oxide nanoparticles.

[0315] [Dispersant]

[0316] A dispersant can be further added to the composition for forming a metal oxide film of the present invention. The type of the dispersant used is not particularly limited, and known dispersants can be used. For example: low molecular weight dispersants such as alkylamines, alkylthiols, alkyl diols, phosphate esters, etc., high molecular weight dispersants having various functional groups, silane coupling agents, etc. Further, high molecular weight dispersants, for example: styrene resins (styrene-(meth)acrylic acid copolymers, styrene-maleic anhydride copolymers, etc.), acrylic resins ((meth)acrylic acid methyl ester-(meth)acrylic acid copolymers, poly((meth)acrylic acid) and other (meth)acrylic acid resins, etc.), water-soluble urethane resins, water-soluble acrylic urethane resins, water-soluble epoxy resins, water-soluble polyester resins, cellulose derivatives (nitrocellulose; alkyl celluloses such as ethyl cellulose, alkyl-hydroxyalkyl celluloses such as ethyl hydroxyethyl cellulose, hydroxyalkyl celluloses such as hydroxyethyl cellulose, hydroxypropyl cellulose, etc., carboxyalkyl celluloses such as carboxymethyl cellulose, etc. cellulose ethers, etc.), polyvinyl alcohol, polyalkylene glycols (liquid polyethylene glycol, polypropylene glycol, etc.), natural polymers (polysaccharides such as gelatin, dextrin, gum arabic, casein, etc.), polyvinyl sulfonic acid or its salts, polystyrene sulfonic acid or its salts, formalin condensates of naphthalenesulfonic acid, nitrogen atom-containing high molecular compounds [for example: polyalkyleneimines (polyethyleneimine, etc.), polyvinylpyrrolidone, polyallylamine, polyether polyamines (polyoxyethylene polyamines, etc.) and other high molecular compounds having amino groups], etc.

[0317] Generally, metal nanoparticles are coated with an organic protective film to prevent aggregation, but by adding a dispersant, the aggregation prevention property of the metal nanoparticles can be better.

[0318] Further, the composition for forming a metal oxide film of the present invention can be used alone or in combination of two or more. The composition for forming a metal oxide film can be used for metal oxide film materials or planarization materials for semiconductor device manufacturing.

[0319] As described above, in the case of the composition for forming a metal oxide film of the present invention, by combining (A) metal oxide nanoparticles having excellent dry etching resistance and the fluidity promoters represented by the above general formulas (I) to (III), a resist underlayer film having extremely excellent dry etching resistance with respect to known spin-on carbon can be formed, which is useful for fine patterning in semiconductor device manufacturing. Also, even in the filling / planarization of a dense portion of a fine pattern structure with a high aspect ratio that is difficult to achieve with known metal oxide nanoparticles, in the case of the composition for forming a metal oxide film of the present invention, since it contains the fluidity promoters represented by the above general formulas (I) to (III), it is useful as a planarization film for semiconductor manufacturing. That is, it is extremely useful as a resist underlayer film of a multilayer resist film used in lithography such as two-layer resist processing, three-layer resist processing using a silicon-containing resist intermediate film, four-layer resist processing using an inorganic hard mask intermediate film, or a silicon-containing resist intermediate film and an organic antireflection film, or a pattern inversion process, or as a filling film acting as a planarization film for semiconductor manufacturing.

[0320] (Pattern formation method)

[0321] Further, the present invention provides a pattern formation method, which is a pattern formation method by two-layer resist processing using such a composition for forming a metal oxide film.

[0322] It is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0323] (I-1) After coating the composition for forming a metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment.

[0324] (I-2) A resist upper layer film is formed on the aforementioned metal oxide film using a photoresist material.

[0325] (I-3) After pattern exposure of the aforementioned resist upper layer film, it is developed with a developer to form a pattern on the aforementioned resist upper layer film.

[0326] (I-4) Using the aforementioned patterned resist upper layer film as a mask, the pattern is transferred to the aforementioned metal oxide film by dry etching, and

[0327] (I-5) Using the aforementioned patterned metal oxide film as a mask, the aforementioned substrate to be processed is processed to form a pattern on the aforementioned substrate to be processed.

[0328] The upper resist film of the two-layer resist treatment shows resistance to etching by chlorine-based gases. Therefore, in the two-layer resist treatment, for the dry etching of the metal oxide film using the upper resist film as a mask, it is preferably carried out using an etching gas mainly composed of a chlorine-based gas.

[0329] Furthermore, the present invention provides a patterning method, which is a patterning method using a three-layer resist treatment with a composition for forming such a metal oxide film.

[0330] It is a method for forming a pattern on a substrate to be processed, having the following steps:

[0331] (II-1) After coating the composition for forming the metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment.

[0332] (II-2) A silicon-containing resist intermediate film is formed on the aforementioned metal oxide film using a silicon-containing resist intermediate film material.

[0333] (II-3) A resist upper film is formed on the aforementioned resist intermediate film using a photoresist material.

[0334] (II-4) After pattern exposure of the aforementioned resist upper film, it is developed with a developer to form a pattern on the aforementioned resist upper film.

[0335] (II-5) Using the aforementioned patterned resist upper film as a mask, the pattern is transferred to the aforementioned resist intermediate film by dry etching.

[0336] (II-6) Using the aforementioned resist intermediate film with the transferred pattern as a mask, the pattern is transferred to the aforementioned metal oxide film by dry etching, and

[0337] (II-7) Using the aforementioned metal oxide film with the formed pattern as a mask, the aforementioned substrate to be processed is processed to form a pattern on the aforementioned substrate to be processed.

[0338] Regarding an example of the three-layer resist treatment, use Figure 1 Specifically shown as follows. During the three-layer resist treatment, as shown in (A) of Figure 1 , after forming a metal oxide film (metal-containing resist lower film) 3 on the processed layer 2 laminated on the substrate to be processed 1 using the metal oxide film forming material of the present invention, a resist intermediate film 4 containing silicon atoms is formed, and a resist upper film 5 is formed thereon.

[0339] Next, as shown in (B) of Figure 1 , the important part (exposed part) 6 of the resist upper film 5 is exposed, PEB and development are carried out to form a resist upper film pattern 5a ( Figure 1(C). Using the obtained resist upper layer film pattern 5a as a mask, the resist intermediate film 4 containing silicon atoms is etched using a CF-based gas to form a resist intermediate film pattern 4a containing silicon atoms ( Figure 1 (D). After removing the resist upper layer film pattern 5a, using the obtained resist intermediate film pattern 4a containing silicon atoms as a mask, the metal oxide film 3 is subjected to oxygen plasma etching to form a metal oxide film pattern (resist lower layer film pattern containing metal) 3a ( Figure 1 (E). After removing the resist intermediate film pattern 4a containing silicon atoms, using the metal oxide film pattern 3a as a mask, the layer to be processed 2 is etched to form a pattern 2a formed on the layer to be processed ( Figure 1 (F).

[0340] The above three-layer resist-treated silicon-containing resist intermediate film shows resistance to etching with chlorine-based and oxygen-based gases. In the above three-layer resist treatment, for the dry etching of the metal oxide film using the silicon-containing resist intermediate film as a mask, it is preferably carried out using an etching gas mainly composed of a chlorine-based or oxygen-based gas.

[0341] The above three-layer resist-treated silicon-containing resist intermediate film is also preferably a polysiloxane-based intermediate film. By making the silicon-containing resist intermediate film have an antireflection effect, reflection can be suppressed. Especially for 193 nm exposure applications, if a material containing a large amount of aromatic groups and having a high substrate etching selectivity is used, the k value will increase and the substrate reflection will increase. However, by making the silicon-containing resist intermediate film have an absorption that results in an appropriate k value to suppress reflection, the substrate reflection can be made 0.5% or less. For the silicon-containing resist intermediate film having an antireflection effect, for 248 nm and 157 nm exposure applications, it is preferably a polysilsesquioxane with anthracene as a pendant group, and for 193 nm exposure applications, it is preferably a polysilsesquioxane with a phenyl group or a light-absorbing group having a silicon-silicon bond as a pendant group and crosslinked by acid or heat.

[0342] In addition, the present invention provides a pattern forming method. As a pattern forming method using such a composition for forming a metal oxide film and carried out by a four-layer resist treatment, it is characterized by having the following steps:

[0343] A metal oxide film is formed on a substrate to be processed using the above-described composition for forming a metal oxide film. A silicon-containing resist intermediate film is formed on the resist underlayer film using a silicon-containing resist intermediate film material. An organic antireflective film (BARC) or a conformal film is formed on the silicon-containing resist intermediate film, and a resist upper layer film is formed on the BARC using a photoresist material. After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film. The patterned resist upper layer film is used as a mask, and the pattern is transferred to the BARC or the conformal film and the silicon-containing resist intermediate film by dry etching. The patterned silicon-containing resist intermediate film is used as a mask, and the pattern is transferred to the metal oxide film by dry etching. The patterned metal oxide film is used as a mask, and the substrate to be processed is processed to form a pattern on the substrate to be processed.

[0344] Alternatively, an inorganic hard mask may be formed instead of the silicon-containing resist intermediate film. In this case, at least a metal oxide film is formed on the object to be processed using the composition for forming a metal oxide film of the present invention, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the metal oxide film, a resist upper layer film is formed on the inorganic hard mask using a photoresist composition, a circuit pattern is formed on the resist upper layer film, the patterned resist upper layer film is used as a mask, the inorganic hard mask is etched, the patterned inorganic hard mask is used as a mask, the metal oxide film is etched, and then the patterned metal oxide film is used as a mask to etch the object to be processed, and a pattern is formed on the object to be processed, and a semiconductor device circuit pattern can be formed on the substrate.

[0345] Furthermore, the present invention provides a pattern forming method.

[0346] It is a method for forming a pattern on a substrate to be processed, and has the following steps:

[0347] (III-1) After coating the above-described composition for forming a metal oxide film on the substrate to be processed, a metal oxide film is formed by heat treatment.

[0348] (III-2) An inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film is formed on the metal oxide film.

[0349] (III-3) An organic thin film is formed on the inorganic hard mask intermediate film.

[0350] (III-4) A resist upper layer film is formed on the organic thin film using a photoresist material.

[0351] (III-5) After pattern exposure of the resist upper layer film, it is developed with a developer to form a pattern on the resist upper layer film.

[0352] (III-6) Using the previously formed patterned upper resist film as a mask, transfer the pattern to the intermediate film between the organic thin film and the inorganic hard mask by dry etching.

[0353] (III-7) Using the previously pattern-transferred inorganic hard mask intermediate film as a mask, transfer the pattern to the metal oxide film by dry etching, and

[0354] (III-8) Using the previously formed patterned metal oxide film as a mask, process the substrate to be processed to form a pattern on the substrate to be processed.

[0355] In this case, it is preferable to form the above-mentioned inorganic hard mask intermediate film by CVD method or ALD method.

[0356] If the above-mentioned inorganic hard mask intermediate film is formed by CVD method or ALD method, fine patterns can be formed on the workpiece with higher precision.

[0357] As described above, when an inorganic hard mask intermediate film is formed on a metal oxide film, a silicon oxide film, a silicon nitride film, and a silicon oxynitride film (SiON film) can be formed by CVD method, ALD method, etc. For example, the formation method of a silicon nitride film is described in Japanese Patent Laid-Open No. 2002-334869 and International Publication No. 2004 / 066377. The film thickness of the inorganic hard mask intermediate film is preferably 5 to 200 nm, more preferably 10 to 100 nm. Also, it is most ideal to use a SiON film with a high anti-reflection effect as the inorganic hard mask intermediate film. Since the substrate temperature when forming the SiON film becomes 300 to 500 °C, the metal oxide film needs to be able to withstand the temperature of 300 to 500 °C. The composition for forming the metal oxide film used in the present invention has high heat resistance and can withstand high temperatures of 300 °C to 500 °C, so a combination of an inorganic hard mask intermediate film formed by CVD method or ALD method and a metal oxide film formed by spin coating is possible.

[0358] As described above, a photoresist film as an upper resist film can also be formed on the inorganic hard mask intermediate film, but an organic anti-reflection film (BARC) or a conformal film can also be spin-coated on the inorganic hard mask intermediate film, and a photoresist film can be formed thereon. In particular, when using a SiON film as the inorganic hard mask intermediate film, even in immersion exposure with a high NA exceeding 1.0, reflection can be suppressed by using a SiON film and a BARC two-layer anti-reflection film. Another advantage of forming a BARC is the effect of reducing the tailing of the photoresist pattern directly above the SiON film.

[0359] In the above multi-layer resist process, the upper resist film can be either positive or negative, and the same photosensitive resist composition as the commonly used one can be used. After spin-coating the photosensitive resist composition, pre-baking is carried out, preferably in the range of 60 to 180 °C for 10 to 300 seconds. Then, exposure is carried out in the usual manner, and post-exposure baking (PEB) and development are carried out to obtain a resist pattern. Also, the thickness of the upper resist film is not particularly limited, and 30 to 500 nm is preferable, especially 50 to 400 nm is more preferable.

[0360] Also, the exposure light is high-energy radiation with a wavelength of 300 nm or less. Specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, X-rays, etc. can be cited.

[0361] If the above method is used as the circuit pattern formation method for the above upper resist film, a fine pattern can be formed on the workpiece with higher precision.

[0362] The pattern formation method of the above upper resist film is preferably carried out by optical lithography with a wavelength of 5 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof.

[0363] Also, the development method in the above pattern formation method is preferably alkali development or development using an organic solvent. Specifically, in the above pattern formation method, in order to form a circuit pattern on the upper resist film, exposure and development are carried out, and the above development is preferably alkali development or development using an organic solvent.

[0364] If the development method uses alkali development or development using an organic solvent, a fine pattern can be formed on the workpiece with higher precision.

[0365] Then, the obtained resist pattern is used as a mask for etching. For the etching of the silicon-containing resist intermediate film and the inorganic hard mask intermediate film in the three-layer resist process, a fluorocarbon-based gas is used with the upper resist pattern as a mask. Thereby, a silicon-containing resist intermediate film pattern and an inorganic hard mask intermediate film pattern are formed.

[0366] Next, the obtained silicon-containing resist intermediate film pattern and inorganic hard mask intermediate film pattern are used as masks for etching the metal oxide film. For the etching of the metal oxide film, it is preferably to use a chlorine-based or oxygen-based gas.

[0367] The etching of the next workpiece can also be carried out in the usual manner. For example, if the workpiece is SiO 2 , SiN, or a silicon dioxide-based low dielectric constant insulating film, etching mainly using a fluorocarbon-based gas is carried out. When the substrate is etched with a fluorocarbon-based gas, the silicon-containing resist intermediate film pattern in the three-layer resist process will be peeled off simultaneously during the substrate processing.

[0368] The metal oxide film obtained from the composition for forming a metal oxide film according to the present invention has the characteristic that the etching resistance during etching of the workpiece is excellent.

[0369] Furthermore, the workpiece (workpiece substrate) is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO 2 , SiN, SiON, W, TiN, Al, etc., and substrates on which a processed layer has been formed on the substrate can be used. As the processed layer, various Low-k films such as Si, SiO 2 , SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, Al-Si, and their barrier films can be used, and a thickness of usually 50 to 10,000 nm, particularly 100 to 5,000 nm can be formed. Furthermore, when forming the processed layer, different materials are used for the substrate and the processed layer.

[0370] In the pattern formation method of the present invention, it is preferably to use a workpiece substrate having a structure or height difference with a height of 30 nm or more. As described above, since the filling / planarization characteristics of the composition for forming a metal oxide film of the present invention are excellent, even if the workpiece substrate has a structure or height difference (concavity and convexity) with a height of 30 nm or more, a flat hardened film can still be formed. It is more desirable that the height of the structure or height difference of the workpiece substrate is 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the method of processing a substrate with a height difference of a pattern having the above height, by forming the composition for forming a metal oxide film of the present invention and performing filling / planarization, the film thicknesses of the resist intermediate film and the resist upper layer film formed later can be made uniform, so it is easy to ensure the exposure depth tolerance (DOF) during optical lithography, which is very desirable.

[0371] Furthermore, the present invention provides a pattern formation method, which is a tone inversion type pattern formation method using such a composition for forming a metal oxide film,

[0372] which is a method of forming a pattern on a workpiece substrate, and is characterized by having the following steps:

[0373] (IV-1) Forming a resist lower layer film on the workpiece substrate,

[0374] (IV-2) Forming a resist intermediate film on the aforementioned resist lower layer film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film and an organic thin film,

[0375] (IV-3) Using a photoresist material to form a resist upper layer film on the aforementioned resist intermediate film, or a combination of an inorganic hard mask intermediate film and an organic thin film,

[0376] (IV-4) After subjecting the aforementioned upper resist film to pattern exposure, develop it with a developer to form a pattern in the aforementioned upper resist film.

[0377] (IV-5) Use the aforementioned patterned upper resist film as a mask and transfer the pattern to the aforementioned intermediate resist film, or the aforementioned organic thin film and the intermediate inorganic hard mask film by dry etching.

[0378] (IV-6) Use the aforementioned intermediate resist film with the transferred pattern, or the intermediate inorganic hard mask film as a mask and transfer the pattern to the aforementioned lower resist film by dry etching.

[0379] (IV-7) After coating the aforementioned composition for forming a metal oxide film on the aforementioned patterned lower resist film, coat the metal oxide film by heat treatment and fill the spaces between the patterns of the aforementioned lower resist film with the aforementioned metal oxide film.

[0380] (IV-8) Etch back the aforementioned metal oxide film coated on the aforementioned patterned lower resist film by chemical stripping or dry etching to expose the upper surface of the aforementioned patterned lower resist film.

[0381] (IV-9) Remove the remaining intermediate resist film or hard mask film on the upper surface of the aforementioned lower resist film by dry etching.

[0382] (IV-10) Remove the aforementioned patterned lower resist film with the exposed surface by dry etching to form an inverted pattern of the original pattern on the metal oxide film.

[0383] (IV-11) Use the aforementioned metal oxide film with the formed inverted pattern as a mask and process the aforementioned substrate to be processed to form a tone-inverted pattern on the aforementioned substrate to be processed.

[0384] For an example of the formation of a tone-inverted pattern, if Figure 2 Specifically shown, it is as follows. As Figure 2 Shown in (G), after forming a lower resist film 7 composed of a coating-type organic lower film material on a processed layer 2 laminated on a substrate to be processed 1, form a resist intermediate film 4 containing silicon atoms and form an upper resist film 5 thereon.

[0385] Next, as Figure 2 Shown in (H), expose the important part (exposed part) 6 of the upper resist film 5, perform PEB and development, and form an upper resist film pattern 5a ( Figure 2(I). Using the obtained resist upper layer film pattern 5a as a mask, the resist intermediate film 4 containing silicon atoms is etched using a CF-based gas to form a resist intermediate film pattern 4a containing silicon atoms. Figure 2 (J). After removing the resist upper layer film pattern 5a, using the obtained resist intermediate film pattern 4a containing silicon atoms as a mask, the resist lower layer film 7 made of a coating-type organic lower layer film material is subjected to oxygen plasma etching to form a resist lower layer film pattern 7a made of a coating-type organic lower layer film material. Figure 2 (K).

[0386] After coating the composition for forming a metal oxide film of the present invention on the resist lower layer film pattern 7a made of a coating-type organic lower layer film material, the metal oxide film 8 is formed by heat treatment to fill the space between the resist lower layer film patterns 7a made of a coating-type organic lower layer film material. Figure 2 (L). Then, the metal oxide film 8 covering the resist lower layer film pattern 7a made of a coating-type organic lower layer film material is etched back by chemical stripping or dry etching to expose the upper surface of the resist lower layer film pattern 7a made of a coating-type organic lower layer film material. Figure 2 (M). Next, the resist intermediate film pattern 4a containing silicon atoms remaining on the upper surface of the resist lower layer film pattern 7a made of a coating-type organic lower layer film material is removed by dry etching. Figure 2 (N). Then, the resist lower layer film pattern 7a made of a coating-type organic lower layer film material is removed by dry etching to form an inverted pattern of the original pattern on the metal oxide film (forming a metal oxide film pattern 8a obtained by inverting the resist lower layer film pattern). Figure 2 (O). After that, using the metal oxide film pattern 8a obtained by inverting the resist lower layer film pattern as a mask, the substrate to be processed is processed to form a tone-inverted pattern 2b on the substrate to be processed. Figure 2 (P).

[0387] As described above, when forming the lower resist film on the substrate to be processed, the lower resist film can be formed by a method using a coating-type organic lower film material, CVD method, ALD method, etc. Examples of the coating-type organic lower film material include those disclosed in JP-A-2012-001687, JP-A-2012-077295, JP-A-2004-264710, JP-A-2005-043471, JP-A-2005-250434, JP-A-2007-293294, JP-A-2008-065303, JP-A-2004-205685, JP-A-2007-171895, JP-A-2009-014816, JP-A-2007-199653, JP-A-2008-274250, JP-A-2010-122656, JP-A-2012-214720, JP-A-2014-029435, WO2012 / 077640, WO2010 / 147155, WO2012 / 176767, JP-A-2005-128509, JP-A-2006-259249, JP-A-2006-259482, JP-A-2006-293298, JP-A-2007-316282, JP-A-2012-145897, JP-A-2017-119671, JP-A-2019-044022, etc., such as resins and compositions.

[0388] In the above-described tone inversion type pattern forming method, after coating the composition for forming a metal oxide film on the obtained lower resist film pattern, in order to expose the upper surface of the lower resist film pattern, it is preferably to remove the metal oxide film by dry etching using a chlorine-based or oxygen-based gas. Thereafter, the resist intermediate film or the inorganic hard mask intermediate film remaining on the above-described lower resist film is removed by dry etching using a fluorocarbon-based gas, and the lower resist film pattern with the exposed surface is removed by dry etching using an oxygen-based gas to form a metal oxide film pattern.

[0389] In the above-described tone-inversion type pattern formation method, it is preferable that the resist underlayer film pattern has a structure or height difference of 30 nm or more. As described above, the composition for forming a metal oxide film of the present invention has excellent filling / planarization characteristics. Therefore, even if the film to be processed has a structure or height difference (concavo-convex) of 30 nm or more, a flat hardened film can still be formed. It is more preferable that the height of the structure or height difference of the above-described resist underlayer film pattern is 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the method of inverting the resist underlayer film pattern having a pattern of the above-described height, by forming the composition for forming a metal oxide film of the present invention and performing filling / planarization, pattern inversion / transfer can be performed with high precision, which is very preferable. The dry etching resistance of the resist underlayer film using a fluorine-based gas is excellent compared to the resist underlayer film using a known coating-type organic underlayer film material. By inverting the resist underlayer film pattern with the above-described composition for forming a metal oxide film, the advantage is that a desired resist pattern can be formed with high precision on the film to be processed.

[0390] (Method for forming metal oxide film)

[0391] The present invention provides a method for forming a resist underlayer film or a filling film of a planarization film (organic planar film) for semiconductor manufacturing, which uses the above-described composition for forming a metal oxide film to form a multilayer resist film for lithography.

[0392] Specifically, a method for forming a metal oxide film is provided. It is a method for forming a metal oxide film that functions as a planarization film in the manufacturing process of a semiconductor device. After coating the above-described composition for forming a metal oxide film on a substrate to be processed, the substrate is heat-treated at a temperature of 100 °C or more and 600 °C or less for 10 to 600 seconds to form a hardened film.

[0393] Furthermore, a method for forming a metal oxide film is provided. It is a method for forming a metal oxide film that functions as a planarization film in the manufacturing process of a semiconductor device. After coating the above-described composition for forming a metal oxide film on a substrate to be processed, the substrate is heat-treated in a gas environment with an oxygen concentration of 1 vol% or more and 21 vol% or less to form a hardened film.

[0394] Furthermore, a method for forming a metal oxide film is provided. It is a method for forming a metal oxide film that functions as a planarization film in the manufacturing process of a semiconductor device. After coating the above-described composition for forming a metal oxide film on a substrate to be processed, the substrate is heat-treated in a gas environment with an oxygen concentration of less than 1 vol% to form a hardened film.

[0395] The method for forming a metal oxide film using the composition for forming a metal oxide film of the present invention is to coat the composition for forming a metal oxide film on a substrate to be processed by a spin coating method (rotary coating) or the like. By using a spin coating method or the like, good filling characteristics can be obtained. After spin coating, the solvent is evaporated, and in order to prevent mixing with the upper resist film and the intermediate resist film and to promote the crosslinking reaction, baking (heat treatment) is performed. The baking is preferably carried out in the range of 100 °C or higher and 600 °C or lower for 10 to 600 seconds, more preferably in the range of 200 °C or higher and 500 °C or lower for 10 to 300 seconds. Considering the influence on device damage and wafer deformation, it is preferable that the upper limit of the heating temperature in the wafer processing of lithography is 600 °C or lower, more preferably 500 °C or lower.

[0396] Furthermore, in the method for forming a metal oxide film using the composition for forming a metal oxide film of the present invention, the composition for forming a metal oxide film of the present invention can also be coated on a substrate to be processed by a spin coating method or the like in the same manner as above, and the composition for forming a metal oxide film is calcined in a gas environment with an oxygen concentration of 0.1 vol% or more and 21 vol% or less to be hardened, thereby forming a metal oxide film.

[0397] By calcining the composition for forming a metal oxide film of the present invention in such an oxygen gas environment, a sufficiently hardened film can be obtained. The gas environment during baking may be air, but in order to reduce oxygen, it is ideal to previously enclose an inert gas such as N 2 , Ar, or He in advance, which can prevent the oxidation of the metal oxide film. In order to prevent oxidation, it is necessary to control the oxygen concentration, preferably 1000 ppm or less, more preferably 100 ppm or less (volume basis). If the oxidation of the metal oxide film during baking is prevented, there will be no increase in absorption or decrease in etching resistance, so it is ideal.

[0398] [Examples]

[0399] The following synthesis examples, comparative synthesis examples, examples, and comparative examples will illustrate the present invention more specifically, but the present invention is not limited thereto. Also, as the molecular weight and dispersity, the weight average molecular weight (Mw), number average molecular weight (Mn) in terms of polystyrene are obtained by gel permeation chromatography (GPC) using tetrahydrofuran as an eluent, and then the dispersity (Mw / Mn) is obtained.

[0400] [Synthesis Example]

[0401] In the following synthesis examples, the following raw material groups G: (G1) to (G8) and modifier groups H: (H1) to (H4) are used.

[0402] Raw material groups G: (G1) to (G8) are as follows.

[0403] [Chemical 43]

[0404]

[0405] The modifier group H: (H1) to (H4) is as follows.

[0406] [Chemical formula 44]

[0407]

[0408] [Synthesis Example 1] Synthesis of the compound (B2) for the fluidity promoter

[0409] Under a nitrogen atmosphere, 42.8 g of the compound (G1) in the raw material group, 15.7 g of potassium carbonate, and 150 g of DMF were added, and a homogeneous dispersion was prepared at an internal temperature of 50°C. 28.2 g of the modifier (H1) was slowly added, and the reaction was carried out at an internal temperature of 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and then the separated aqueous layer was removed. The organic layer was washed 6 times with 100 g of a 3% aqueous nitric acid solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain the compound (B2) for the fluidity promoter.

[0410] The weight-average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, and the results were as follows.

[0411] (B2): Mw = 560, Mw / Mn = 1.01

[0412] [Chemical formula 45]

[0413]

[0414] [Synthesis Example 2] Synthesis of the compound (B4) for the fluidity promoter

[0415] Under a nitrogen atmosphere, 45.5 g of the compound (G2) in the raw material group, 9.8 g of potassium carbonate, and 150 g of DMF were added, and a homogeneous dispersion was prepared at an internal temperature of 50°C. 17.6 g of the modifier (H1) was slowly added, and the reaction was carried out at an internal temperature of 50°C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and then the separated aqueous layer was removed. The organic layer was washed 6 times with 100 g of a 3% aqueous nitric acid solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain the compound (B4) for the fluidity promoter.

[0416] The weight-average molecular weight (Mw) and the dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0417] (B4): Mw = 965, Mw / Mn = 1.08

[0418] [Chemical 46]

[0419]

[0420] [Synthesis Example 3] Synthesis of Compound (B5) for Flow Promoter

[0421] Under a nitrogen atmosphere, 200 g of N-methylpyrrolidone was added to 20.0 g of compound (G3) in the raw material group, 16.4 g of modifier (H2), and 23.3 g of potassium carbonate, and the reaction was carried out at an internal temperature of 140 °C for 24 hours. After cooling to room temperature, 300 ml of methyl isobutyl ketone and 300 ml of pure water were added to the reaction solution. After homogenization, the separated aqueous layer was removed. The organic layer was then washed twice with 100 ml of 3% aqueous nitric acid solution and five times with 100 ml of pure water, and then the organic layer was dried under reduced pressure. 100 g of THF was added to the residue to form a homogeneous solution, and then crystallization was carried out with 350 g of methanol. The precipitated crystals were separated by filtration, washed twice with 200 g of methanol and recovered. The recovered crystals were dried in vacuo at 70 °C to obtain compound (B5) for flow promoter.

[0422] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0423] (B5): Mw = 580, Mw / Mn = 1.03

[0424] [Chemical 47]

[0425]

[0426] [Synthesis Example 4] Synthesis of Compound (B6) for Flow Promoter

[0427] Under a nitrogen atmosphere, 45.7 g of compound (G4) in the raw material group, 9.3 g of potassium carbonate, and 150 g of DMF were added to form a homogeneous dispersion at an internal temperature of 50 °C. 13.4 g of modifier (H1) was slowly added, and the reaction was carried out at an internal temperature of 50 °C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and then the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of 3% aqueous nitric acid solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain compound (B6) for flow promoter.

[0428] The weight average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0429] (B6): Mw = 1,050, Mw / Mn = 1.02

[0430] [Chemical 48]

[0431]

[0432] [Synthesis Example 5] Synthesis of Compound (B7) for Flow Promoter

[0433] Under a nitrogen atmosphere, 100 g of N-methylpyrrolidone was added to 30.00 g of compound (G5) in the raw material group. After forming a homogeneous solution at an internal temperature of 40 °C under a nitrogen atmosphere, 13.7 g of modifier (H3) was added, and the reaction was carried out at an internal temperature of 40 °C for 3 hours to obtain an amic acid solution. 200 g of o-xylene was added to the obtained amic acid solution, and the reaction was carried out for 9 hours while removing the generated low-boiling substances and the generated water from the system at an internal temperature of 150 °C, and dehydration imidization was carried out. After the reaction was completed, it was cooled to room temperature, and crystallization was carried out in 1,000 g of methanol. The precipitated crystals were separated by filtration, washed twice with 500 g of methanol and recovered. The recovered crystals were dried under vacuum at 70 °C to obtain compound (B7) for flow promoter.

[0434] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0435] (B7): Mw = 930, Mw / Mn = 1.01

[0436] [Chemical Formula 49]

[0437]

[0438] [Synthesis Example 6] Synthesis of Polymer (B9) for Flow Promoter

[0439] Under a nitrogen atmosphere, 44.7 g of compound (G6) in the raw material group, 16.5 g of potassium carbonate, and 150 g of DMF were added, and a homogeneous dispersion was formed at an internal temperature of 50 °C. 16.5 g of modifier (H1) was slowly added, and the reaction was carried out at an internal temperature of 50 °C for 24 hours. 300 ml of methyl isobutyl ketone and 300 g of pure water were added to the reaction solution to dissolve the precipitated salt, and then the separated aqueous layer was removed. The organic layer was then washed 6 times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain polymer (B9) for flow promoter.

[0440] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0441] (B9): Mw = 2,500, Mw / Mn = 3.10

[0442] [Chemical Formula 50]

[0443]

[0444] [Synthesis Example 7] Synthesis of Polymer (B10) for Flow Promoter

[0445] Weigh 10.0 g of compound (G2) from the raw material group and 30 ml of 1-methoxy-2-propanol into a 200-ml three-necked flask. Stir in a nitrogen atmosphere in an oil bath at 75 °C to dissolve it. Add 0.25 g of paraformaldehyde and dropwise add 2.5 g of a 1-methoxy-2-propanol solution of 20 wt% p-toluenesulfonic acid monohydrate. After the dropping is complete, raise the temperature of the oil bath to 85 °C and carry out the reaction for 4 hours. After cooling to room temperature, dilute with 100 ml of methyl isobutyl ketone, filter off the insoluble components, transfer to a separatory funnel, and repeat liquid separation and water washing 8 times with 30 ml of ultrapure water. Concentrate the organic layer under reduced pressure, recover the polymer, and dry it under reduced pressure to obtain the polymer (B10) for flow promoter.

[0446] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0447] (B10): Mw = 4,920, Mw / Mn = 1.75

[0448] [Chemical Formula 51]

[0449]

[0450] [Synthesis Example 8] Synthesis of Polymer (B11) for Flow Promoter

[0451] Under a nitrogen atmosphere, add 40 g of N-methyl-2-pyrrolidone to 8.00 g of polymer (G7) and 4.72 g of potassium carbonate from the raw material group, and make a homogeneous dispersion at an internal temperature of 50 °C under a nitrogen atmosphere. Slowly dropwise add 4.04 g of modifier (H1), and carry out the reaction at an internal temperature of 50 °C for 24 hours. Add 150 g of methyl isobutyl ketone and 50 g of pure water to the reaction solution, homogenize it, and then remove the separated water layer. Then wash the organic layer 6 times with 50 g of 3% nitric acid aqueous solution and 50 g of pure water, and then dry the organic layer under reduced pressure to dryness. Add 40 g of THF to the residue to make a homogeneous solution, and then crystallize with 150 g of methanol. Separate the precipitated crystals by filtration, wash them twice with 60 g of methanol, and recover them. Dry the recovered crystals under vacuum at 70 °C to obtain the polymer (B11) for flow promoter.

[0452] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0453] (B11): Mw = 3,740, Mw / Mn = 1.55

[0454] [Chemical Formula 52]

[0455]

[0456] [Comparative Synthesis Example 1] Synthesis of Polymer (R1) for Comparative Flow Promoter

[0457] 23.3 g of PGMEA was heated and stirred at 80 °C under a nitrogen atmosphere. A mixture of 25.8 g of glycidyl methacrylate, 12.0 g of (2-phenoxyethyl) acrylate, 12.9 g of tricyclodecanyl acrylate, 46.7 g of PGMEA, and a mixture of 4.45 g of dimethyl 2,2-azobis(2-methylpropionate) and 46.7 g of PGMEA were added thereto simultaneously and individually over 2 hours. After further heating and stirring for 16 hours, the mixture was cooled to 60 °C, 200 g of heptane was added, and then the mixture was cooled to room temperature and allowed to stand for 2 hours. The upper layer was separated off, 100 g of PGMEA was added, and then heptane was distilled off under reduced pressure to obtain a PGMEA solution of the target polymer (R1).

[0458] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0459] (R1): Mw = 7,700, Mw / Mn = 1.90

[0460] [Chemical Formula 53]

[0461]

[0462] [Comparative Synthesis Example 2] Synthesis of Compound (R3) for Comparative Flow Promoter

[0463] 77.5 g of compound (G8) of the raw material group, 47.0 g of modifier (H4), and 600 g of 2-methoxy-1-propanol were made into a homogeneous solution at an internal temperature of 100 °C under a nitrogen atmosphere, 5.7 g of benzyltriethylammonium chloride was added, and the mixture was stirred at an internal temperature of 120 °C for 12 hours. After cooling to room temperature, 1,500 g of methyl isobutyl ketone was added, and the organic layer was washed 5 times with 300 g of pure water. The organic layer was solidified under reduced pressure to obtain compound (R3).

[0464] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0465] (R3): Mw = 960, Mw / Mn = 1.03.

[0466] [Chemical Formula 54]

[0467]

[0468] [Comparative Synthesis Example 3] Synthesis of Compound (R4) for Comparative Flow Promoter

[0469] In a 300 ml flask, 200 g of the compound (G3) in the raw material group, 75 g of a 37% aqueous formalin solution, and 5 g of oxalic acid were added, and the mixture was stirred at 100 °C for 24 hours while stirring. After the reaction, it was dissolved in 500 ml of methyl isobutyl ketone, and the catalyst and metal impurities were removed by thorough washing with water, and then the solvent was removed under reduced pressure. The pressure was reduced to 150 °C and 2 mmHg to remove water and unreacted monomers, and the compound (R4) was obtained.

[0470] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0471] (R4): Mw = 6,500, Mw / Mn = 5.20.

[0472] [Chemical Formula 55]

[0473]

[0474] [Comparative Synthesis Example 4] Synthesis of the compound (R5) for a comparative flowability promoter

[0475] Under a nitrogen atmosphere, 15.6 g of 2-phenylphenol, 19.1 g of 9-anthracenemethanol, 12.3 g of divinylbenzene, 30 g of cyclopentyl methyl ether (CPME), and 110 g of diethylene glycol dimethyl ether were added, and the mixture was stirred at room temperature to disperse it uniformly. Then, 1.14 g of trifluoromethanesulfonic acid was slowly added, and stirring was continued for 5 minutes. After it became a uniform solution, the reaction was carried out for 4 hours in an oil bath at 140 °C while removing the water generated from the reaction system. After cooling to room temperature, it was diluted with 250 g of CPME, transferred to a separatory funnel, washed 4 times with ultrapure water, and then the organic layer was dried under reduced pressure. 120 g of CPME was added to the residue, and the polymer was crystallized with 500 g of hexane. The crystallized crystals were separated by filtration, washed twice with 200 g of hexane, and recovered. The recovered crystals were dried in vacuo at 70 °C to obtain (R5).

[0476] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0477] (R5): Mw = 1,960, Mw / Mn = 1.57.

[0478] [Chemical Formula 56]

[0479]

[0480] [Blending Polymer Synthesis Example 1] Synthesis of the blending polymer (BP1)

[0481] Dissolve 78.8 g of 2,7-dipropargyloxynaphthalene, 21.6 g of 37% formalin solution, and 250 g of 1,2-dichloroethane in a nitrogen atmosphere at a liquid temperature of 70 °C to form a homogeneous solution. Then, slowly add 5 g of methanesulfonic acid and stir at a liquid temperature of 80 °C for 12 hours. After cooling to room temperature, add 500 g of methyl isobutyl ketone, wash the organic layer 5 times with 200 g of pure water, and then dry the organic layer under reduced pressure. Add 300 mL of THF to the residue and reprecipitate the polymer with 2,000 mL of hexane. Separate the precipitated polymer by filtration and dry it under reduced pressure to obtain polymer (BP1).

[0482] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0483] (BP1): Mw = 2,720, Mw / Mn = 1.55.

[0484] [Chemical Formula 57]

[0485]

[0486] [Synthesis Example 2 of Polymer for Blending] Synthesis of Polymer for Blending (BP2)

[0487] Add 20.0 g of cresol novolac, 27.6 g of potassium carbonate, and 100 g of DMF in a nitrogen atmosphere and form a homogeneous dispersion at an internal temperature of 50 °C. Slowly add 11.9 g of modifier (H-1) and react at an internal temperature of 50 °C for 24 hours. Add 300 ml of methyl isobutyl ketone and 300 g of pure water to the reaction solution to dissolve the precipitated salt, and then remove the separated aqueous layer. Wash the organic layer 6 times with 100 g of 3% nitric acid aqueous solution and 100 g of pure water, and then dry the organic layer under reduced pressure to obtain resin (BP2).

[0488] The weight-average molecular weight (Mw) and dispersity (Mw / Mn) were determined by GPC, and the following results were obtained.

[0489] (BP2): Mw = 8,500, Mw / Mn = 3.46

[0490] [Chemical Formula 58]

[0491]

[0492] The structures of the compounds, polymers, and blending polymers for the obtained fluidity promoters, as well as the weight-average molecular weight (Mw) and dispersity (Mw / Mn), are shown in Tables 1 to 3. As the compound (B1) for the fluidity promoter, (G1) of the raw material group G used as the raw material in the synthesis example is used; as the compound (B3) for the fluidity promoter, (G2) of the raw material group G is used; as the polymer (B8) for the fluidity promoter, (G6) of the raw material group G is used; and as the comparative compound (R2) for the fluidity promoter, (G8) of the raw material group G is used. Further, in the general formulas (I) to (III) representing the compounds and polymers for the fluidity promoter of the present invention, R a and R b are hydrocarbon groups and do not contain heteroatoms. Therefore, R2 and R3 of the comparative compound for the fluidity promoter are used as comparative examples.

[0493] [Table 1]

[0494]

[0495] [Table 2]

[0496]

[0497] [Table 3]

[0498]

[0499] [(A) Metal oxide nanoparticles]

[0500] As the (A) metal oxide nanoparticles (A1) used as the composition for forming a metal oxide film, ZrO 2 nanoparticles (5 nm core, 915505, Sigma-Aldrich Corp) are used.

[0501] [(A) Comparative metal oxide compound]

[0502] To a 10 g solution of 40 g of tetrabutoxytitanium tetramer (manufactured by Tokyo Chemical Industry Co., Ltd.) in 1-butanol (BuOH), 24 g of 2,4-dimethyl-2,4-hexanediol was added, and the mixture was stirred at room temperature for 30 minutes. After concentrating this solution under reduced pressure at 50 °C, it was further heated to 60 °C, and heating was continued under reduced pressure until no distillate appeared. At the point when no more distillate was seen, 200 g of propylene glycol monomethyl ether acetate (PGMEA) was added, and the mixture was heated at 50 °C under reduced pressure until no more BuOH was distilled off, obtaining 160 g of a PGMEA solution containing titanium compound A2 (compound concentration: 25% by mass). The polystyrene-equivalent molecular weight thereof was measured to be Mw = 1,000.

[0503] (A2) is not a metal oxide nanoparticle, so it is used in the comparative example.

[0504] [(D) Crosslinking agent]

[0505] The (D) crosslinking agent used in the composition for forming a metal oxide film is as follows.

[0506] [Chemical formula 59]

[0507]

[0508] [(E) Thermal acid generator]

[0509] The (E) thermal acid generator used in the composition for forming a metal oxide film is as follows.

[0510] [Chemical formula 60]

[0511]

[0512] [Composition UDL-1 for forming a metal oxide film]

[0513] Dissolve the metal oxide nanoparticles (A1) and the compound (B1) for promoting fluidity in 1350 parts by mass of propylene glycol monomethyl ether acetate (PGMEA) containing 0.5% by mass of the surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 4, and filter through a 0.02 μm membrane filter to prepare the composition (UDL-1) for forming a metal oxide film.

[0514] [Compositions UDL-2 to 18 for forming a metal oxide film and comparative examples UDL-1 to 11]

[0515] Set the types and contents of each component as shown in Table 4, and perform the same operations as UDL-1 for the rest to prepare each liquid medicine. Also, in Table 4, "-" indicates that the corresponding component is not used. The acid generator (TAG) uses the above formula (E1), and the high-boiling solvent (F1) uses 1,6-diacetoxyhexane: boiling point 260 °C.

[0516] [Table 4]

[0517]

[0518]

[0519] [Evaluation of landfill characteristics (Examples 1-1 to 1-18, Comparative Examples 1-1 to 1-11)]

[0520] The above-described compositions for forming a metal oxide film (UDL-1 to 18 and Comparative Examples UDL-1 to 11) were respectively coated on a SiO wafer substrate having a dense line & space pattern (line width: 40 nm, line depth: 120 nm, distance between the centers of adjacent two lines: 80 nm), heated on a hot plate at 350 °C for 60 seconds to form a metal oxide film with a thickness of 100 nm. Similarly, it was heated at 350 °C for 60 seconds in the atmosphere, and then baked at 450 °C for 60 seconds under a nitrogen gas flow with an oxygen concentration controlled to be 0.2% or less to form a metal oxide film. The substrate used was a base substrate 9 (SiO wafer substrate) having a dense line & space pattern as shown in (Q) (bird's-eye view) and (R) (cross-sectional view). The cross-sectional shape of each wafer substrate obtained was observed using a scanning electron microscope (S-4700) manufactured by Hitachi, Ltd., and it was confirmed whether there were pores (voids) inside the metal oxide film filled between the lines. The results are shown in Table 5. When using a composition for forming a metal oxide film with poor filling properties, pores appeared inside the metal oxide film filled between the lines in this evaluation. When using a composition for forming a metal oxide film with good filling properties, as shown in (S), inside the metal oxide film filled between the lines of the base substrate 9 having a dense line & space pattern, a metal oxide film 10 without pores was filled. 2 On a wafer substrate, it was heated at 350 °C for 60 seconds using a hot plate to form a metal oxide film with a thickness of 100 nm. Similarly, it was heated at 350 °C for 60 seconds in the atmosphere, and then baked at 450 °C for 60 seconds under a nitrogen gas flow with an oxygen concentration controlled to be 0.2% or less to form a metal oxide film. The substrate used was a base substrate 9 (SiO wafer substrate) having a dense line & space pattern as shown in (Q) (bird's-eye view) and (R) (cross-sectional view). Figure 3 The base substrate 9 (SiO wafer substrate) having a dense line & space pattern as shown in (Q) (bird's-eye view) and (R) (cross-sectional view). 2 The cross-sectional shape of each wafer substrate obtained was observed using a scanning electron microscope (S-4700) manufactured by Hitachi, Ltd., and it was confirmed whether there were pores (voids) inside the metal oxide film filled between the lines. The results are shown in Table 5. When using a composition for forming a metal oxide film with poor filling properties, pores appeared inside the metal oxide film filled between the lines in this evaluation. When using a composition for forming a metal oxide film with good filling properties, as shown in (S), inside the metal oxide film filled between the lines of the base substrate 9 having a dense line & space pattern, a metal oxide film 10 without pores was filled. Figure 3 As shown in (S), inside the metal oxide film filled between the lines of the base substrate 9 having a dense line & space pattern, a metal oxide film 10 without pores was filled.

[0521] [Table 5]

[0522]

[0523]

[0524] As shown in Table 5, in Examples 1-1 to 1-18 using the composition for forming a metal oxide film of the present invention (UDL-1 to 18), no pores occurred, and the dense line & space pattern could be filled, confirming good filling properties. In Comparative Examples 1-1 and 1-9 where the weight ratio of the metal oxide nanoparticles to the fluidity promoter was outside the scope of the present invention, pores were observed during baking at 350 °C due to low thermal fluidity. On the other hand, in the composition for forming a metal oxide film of the present invention, since it contains an appropriate amount of a compound or polymer for a fluidity promoter with excellent thermal fluidity, a metal oxide film with excellent filling properties was successfully formed. In Comparative Example 1-3, since the heat resistance of the fluidity-promoting polymer (R1) without a cardo structure was insufficient, it was speculated that pores appeared at the time of baking at 350 °C. Also, in Comparative Examples 1-4 to 1-5, the fluidity of the compound for the fluidity promoter was not a problem, but the R2 and R3 used had a structure corresponding to the compound for the fluidity promoter of the present invention in the R acontains heteroatoms at the [specific location], so it has insufficient heat resistance. It is speculated that pores appeared due to baking at 450 °C. In Comparative Examples 1-8 where metal oxide nanoparticles and the polymer for blending (BP1) were combined without the fluidity promoter (thermal fluidity promoter) of the present invention, pores were also speculated to have appeared during baking at 450 °C for the same reason. When comparing compositions with a weight ratio of metal oxide nanoparticles to the fluidity promoter of 90 / 10, pores were observed at the time of baking at 350 °C in Comparative Examples 1-7, but Examples 1-13 of the present invention showed good filling characteristics at the time of baking at 350 °C and 450 °C. It is speculated that this is because the structure of the compound or polymer used as the fluidity promoter in the metal oxide film-forming composition of the present invention has a cardo structure, showing the effect of good thermal fluidity. On the other hand, in Comparative Examples 1-6, the polymer R4 having a cardo structure was used, but the molecular weight was large and the thermal fluidity was insufficient, and pores were speculated to have appeared at the time of baking at 350 °C. In Comparative Example 1-11 where metal oxide compounds (A2) were used instead of metal oxide nanoparticles, pores and peeling from the substrate were observed. It is speculated that this is because the heat resistance of the metal oxide compound is lacking and the thermal shrinkage at 350 °C is large.

[0525] [Planarization property evaluation (Examples 2-1 to 2-18, Comparative Examples 2-1 to 2-11)]

[0526] The above metal oxide film-forming compositions (UDL-1 to 18 and Comparative Example UDL-1 to 11) were respectively coated on a SiO 2 wafer substrate having a dense line & space pattern (line width 40 nm, line depth 120 nm, distance between the centers of adjacent two lines 80 nm), and heated on a hot plate at 350 °C for 60 seconds to form a metal oxide film with a thickness of 100 nm. The substrate used was a Figure 4 (T) (cross-sectional view) shown basal substrate 11 (SiO 2 wafer substrate) having a dense line & space pattern. The cross-sectional shape of each wafer substrate obtained by forming the metal oxide film 12 as a filling film was observed using a scanning electron microscope (SEM), and the height difference ([Delta 12 in Figure 4 (U)) between the filled film in the dense line pattern part and the non-line pattern formed part was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. The results are shown in Table 6. In this evaluation, the smaller the height difference, the better the planarization property can be considered.

[0527] [Table 6]

[0528]

[0529] As shown in Table 6, when comparing the compositions with a weight ratio of metal oxide nanoparticles to flow improver of 50 / 50, in Examples 2-1 to 2-12 using the composition for forming a metal oxide film of the present invention, compared with Comparative Example 2-3 using a flow improver polymer without a cardo structure, it was confirmed that the height difference between the filled films in the dense line pattern portion and the non-line pattern forming portion was smaller and the planarization property was excellent. Similarly, when comparing the compositions with a weight ratio of metal oxide nanoparticles to flow improver of 90 / 10, Example 2-13 compared with Comparative Example 2-7 using a flow improver polymer without a cardo structure, it was confirmed that the height difference between the filled films in the dense line pattern portion and the non-line pattern forming portion was small and the planarization property was excellent. It is speculated that because the structure of the flow improver compound or polymer used in the composition for forming a metal oxide film of the present invention has an excellent heat-resistant cardo structure, exhibits good thermal fluidity, and contains a most appropriate amount of highly reactive hydroxyl groups or propargyloxy groups, etc., it can form a cured film with small thermal shrinkage during baking. Comparative Examples 2-4 and 2-5 also contain a flow improver compound having a cardo structure, so the flatness is good. On the other hand, in Comparative Example 2-6, a polymer R4 having a cardo structure was used, but the molecular weight was large and the thermal fluidity was insufficient, so it is speculated that the flatness was insufficient. In Examples 2-17 to 2-18 to which a high-boiling solvent and / or a blending polymer was added, it was found that the planarization property was further improved by adding a high-boiling solvent and / or a blending polymer. Also, it was found that in Example 2-9 using a flow improver having both hydroxyl groups and propargyloxy groups in a more ideal range, the planarization property was improved compared to Example 2-8 using a flow improver having only hydroxyl groups. The reason is speculated to be that the balance of propargyloxy groups that contribute to fluidity and hydroxyl groups that contribute to adhesion and heat resistance is optimal, and a film with excellent thermal fluidity and thermal shrinkage resistance can be formed. In Comparative Example 2-9 with a weight ratio of metal oxide nanoparticles to flow improver of 95 / 5, the improvement in the planarization property from the metal oxide nanoparticles alone (Comparative Example 2-1) was small, and it can be said that in order to exert the thermal fluidity effect of the flow improver, a weight ratio of the flow improver of 10 or more is necessary.

[0530] [Etching resistance evaluation of CF 4 gas (Examples 3-1 to 3-18, Comparative Examples 3-1 to 3-11)]

[0531] The above-prepared compositions for forming a metal oxide film (UDL-1 to 18, Comparative UDL-1 to 11) were coated on a silicon substrate, baked in the atmosphere at 350 °C for 60 seconds to form a 100-nm coating film, and the film thickness a was measured. Then, using an etching apparatus Telius manufactured by Tokyo Electron Limited, for 1 minute under the following conditions with CF 4Etching of the gas, measuring the film thickness b. Calculate the film thickness etched in 1 minute (film thickness b - film thickness a), which is defined as the etching resistance. When the film thickness difference between B and A is less than 60 nm, it is rated as "A" (extremely good); when it is 60 nm or more but less than 70 nm, it is rated as "B" (good); when it is 70 nm or more, it is rated as "C" (bad). The results are shown in Table 7.

[0532] Using CF 4 Dry etching conditions of the gas

[0533] Chamber pressure: 100 mT

[0534] RF power (upper part): 500 W

[0535] RF power (lower part): 400 W

[0536] CF 4 Gas flow rate: 300 sccm

[0537] Time: 60 sec

[0538] [Table 7]

[0539]

[0540]

[0541] As shown in Table 7, when comparing the compositions with a weight ratio of metal oxide nanoparticles to flowability promoter of 50 / 50, Examples 3-1 to 3-12 using the composition for forming a metal oxide film of the present invention, compared with Comparative Examples 3-3 to 3-5, it was confirmed that for CF 4The etching resistance of the system gas is relatively excellent. On the other hand, in Comparative Examples 3-8 which combined metal oxide nanoparticles and the polymer for blending (BP1), the thermal fluidity promoter of the present invention with excellent dry etching resistance was not contained, so insufficient etching resistance was observed. Also, compared with Comparative Example 3-10 where the weight ratio of metal oxide nanoparticles to the fluidity promoter was 5 / 95, a clear improvement in etching resistance was seen in Example 3-14 with a weight ratio of 10 / 90. It is speculated that in order to derive the characteristics of dry etching resistance, it is preferable that the weight ratio of metal oxide nanoparticles is 10 or more. The above results are presumably due to the fact that the structure of the compound or polymer for the fluidity promoter used in the metal oxide film-forming composition of the present invention has a rigid cardo structure and has excellent reactivity such as hydroxyl groups or propargyloxy groups, so that a dense hardened film can be formed. According to the evaluation results of the above-mentioned burying characteristics and planarization characteristics, it can be seen that the metal oxide film-forming composition of the present invention has burying characteristics / planarization characteristics close to those of known coating-type organic underlayer film materials, and is a material that shows extremely excellent dry etching resistance with respect to known coating-type organic underlayer film materials. That is, in the metal oxide film-forming composition of the present invention, by adjusting the weight ratio of metal oxide nanoparticles to the fluidity promoter within the range of 10 / 90 to 90 / 10, a metal oxide film-forming composition that takes into account excellent burying characteristics / planarization characteristics and etching resistance can be provided. When it is desired to derive the characteristics of burying characteristics / planarization characteristics, the weight ratio of the fluidity promoter to metal oxide nanoparticles can be set as "fluidity promoter > metal oxide nanoparticles", and when it is desired to derive the characteristics of etching resistance, it can be set as "fluidity promoter < metal oxide nanoparticles". Also, when it is desired to more highly exhibit the burying / planarization characteristics and dry etching resistance, it is preferably to adjust the weight ratio of metal oxide nanoparticles to the fluidity promoter within the range of 30 / 70 to 70 / 30.

[0542] [Pattern formation method (Examples 4-1 to 4-18, Comparative Examples 4-1 to 4-11)]

[0543] The above metal oxide film-forming compositions (UDL-1 to 18, Comparative UDL-1 to 11) were respectively coated on SiO having a trench pattern (trench width 10 μm, trench depth 0.10 μm) 2On a wafer substrate, calcination is carried out at 350 °C for 60 seconds in the atmosphere to form an organic film with a film thickness of 100 nm. A CVD-SiON hard mask is formed thereon, and then an organic anti-reflection film material (ARC-29A: manufactured by Nissan Chemical Industries, Ltd.) is coated, baked at 210 °C for 60 seconds to form an organic anti-reflection film with a film thickness of 80 nm. A single-layer resist for ArF, which is a resist upper-layer film material, is coated thereon and baked at 105 °C for 60 seconds to form a photoresist film with a film thickness of 100 nm. An immersion protection film material (TC-1) is coated on the photoresist film and baked at 90 °C for 60 seconds to form a protection film with a film thickness of 50 nm.

[0544] Regarding the resist upper-layer film material (single-layer resist for ArF), a polymer (RP1), an acid generator (PAG1), and a basic compound (Amine1) are dissolved in a solvent containing 0.1 mass% of a surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) in the ratio shown in Table 8, and filtered through a 0.1-μm fluororesin filter to prepare.

[0545] [Table 8]

[0546]

[0547] The polymer (RP1), acid generator (PAG1), and basic compound (Amine1) used for the resist upper-layer film material (single-layer resist for ArF) are as follows.

[0548] [Chemical formula 61]

[0549]

[0550] The immersion protection film material (TC-1) is prepared by dissolving a protection film polymer (PP1) in an organic solvent in the ratio shown in Table 9 and filtering through a 0.1-μm fluororesin filter.

[0551] [Table 9]

[0552]

[0553] The polymer (PP1) used for the immersion protection film material (TC-1) is as follows.

[0554] [Chemical formula 62]

[0555]

[0556] Then, exposure was performed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% halftone phase shift mask), followed by baking at 100 °C for 60 seconds (PEB), and development for 30 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) to obtain a 55-nm 1:1 positive line-and-space pattern (resist pattern).

[0557] Then, using the etching apparatus Telius manufactured by Tokyo Electron Limited, dry etching was performed with the resist pattern as a mask to etch the organic antireflection film and the CVD-SiON hard mask to form a hard mask pattern. Using the obtained hard mask pattern as a mask, the metal oxide film was etched to form a metal oxide film pattern. Using the obtained metal oxide film pattern as a mask, etching of the SiO 2 film was performed. The etching conditions are as follows.

[0558] Conditions for transferring the resist pattern to the SiON hard mask.

[0559] Chamber pressure: 50 mT

[0560] RF power (upper): 500 W

[0561] RF power (lower): 300 W

[0562] CF 4 Gas flow rate: 150 sccm

[0563] CHF 3 Gas flow rate: 50 sccm

[0564] Time: 20 sec Conditions for transferring the SiON hard mask pattern to the metal oxide film.

[0565] Chamber pressure: 15 mT

[0566] RF power (upper): 300 W

[0567] RF power (lower): 50 W

[0568] O 2 Gas flow rate: 30 sccm

[0569] N 2 Gas flow rate: 270 sccm

[0570] Time: 300 sec

[0571] Conditions for transferring the metal oxide film pattern to the SiO 2 film.

[0572] Chamber pressure: 10 mT

[0573] RF power (upper): 100 W

[0574] RF power (lower): 800 W

[0575] CF 4 Gas flow rate: 25 sccm

[0576] CHF 3 Gas flow rate: 15 sccm

[0577] O 2 Gas flow rate: 5 sccm

[0578] Time: 200 sec

[0579] The pattern cross-section was observed with a Hitachi, Ltd. electron microscope (S-4700), and the results are shown in Table 10.

[0580] [Table 10]

[0581]

[0582]

[0583] As shown in Table 10, in Examples 4-1 to 4-18 using the composition for forming a metal oxide film (UDL-1 to 18) of the present invention, the upper resist film patterns were all finally transferred well onto the substrate, and it was confirmed that the composition for forming a metal oxide film of the present invention is suitable for use in fine processing by the multilayer resist method. On the other hand, in Comparative Examples 4-1, 4-3, 4-6, 4-7, 4-9, and 4-11 where the filling property evaluation and the planarization property evaluation confirmed insufficient performance, pattern collapse occurred during pattern processing, and finally, good patterns could not be obtained. Also, in Comparative Examples 4-2, 4-4, 4-5, 4-8, and 4-10 where there were no problems in the filling property and planarization property evaluations but the dry etching resistance evaluation confirmed insufficient performance, twisting of the pattern shape occurred during pattern processing, and finally, good patterns could not be obtained.

[0584] [SOC Pattern Inversion Method (Examples 5-1 to 5-18, Comparative Examples 5-1 to 5-12)]

[0585] On a substrate where 300 nm of SiO has been formed 2A coating-type organic underlayer film material (SOC-1) as an underlayer film for a resist is coated on a silicon wafer substrate of a film, baked at 350 °C for 60 seconds to form an underlayer film for a resist with a film thickness of 80 nm. A resist intermediate layer material (SOG-1) containing a silicon atom is coated thereon, baked at 220 °C for 60 seconds to form a resist intermediate layer film with a film thickness of 35 nm, and a single-layer resist for ArF as a resist upper layer film material is coated thereon, baked at 105 °C for 60 seconds to form a photoresist film with a film thickness of 100 nm. An immersion protective film material (TC-1) is coated on the photoresist film and baked at 90 °C for 60 seconds to form a protective film with a film thickness of 50 nm.

[0586] As the resist upper layer film material (single-layer resist for ArF) and the immersion protective film material (TC-1) on the photoresist film, the same materials as those used in the above pattern formation method (Example 4) are used.

[0587] As the coating-type organic underlayer film material (SOC-1), a polymer represented by a resist underlayer film polymer (SOP1) is dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Limited) in the ratio shown in Table 11, and filtered through a fluororesin filter with a pore size of 0.2 μm to prepare a coating-type organic underlayer film material (SOC-1).

[0588] [Table 11]

[0589]

[0590] The structural formula of the resist underlayer film polymer (SOP1) used is shown in Table 12.

[0591] [Table 12]

[0592]

[0593] As the resist intermediate layer material (SOG-1) containing a silicon atom, a polymer represented by an ArF silicon-containing intermediate film polymer (SiP1) and a crosslinking catalyst (CAT1) are dissolved in an organic solvent containing 0.1% by mass of FC-4430 (manufactured by Sumitomo 3M Limited) in the ratio shown in Table 13, and filtered through a fluororesin filter with a pore size of 0.1 μm to prepare a resist intermediate layer material (SOG-1) containing a silicon atom.

[0594] [Table 13]

[0595]

[0596] The structural formulas of the ArF silicon-containing intermediate film polymer (SiP1) and the crosslinking catalyst (CAT1) used are shown below.

[0597] [Chemical formula 63]

[0598]

[0599] Then, it was exposed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA 1.30, σ 0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% halftone phase shift mask), baked at 100 °C for 60 seconds (PEB), and developed for 30 seconds with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) to obtain a 55 nm 1:1 positive line-and-space pattern.

[0600] Then, using the etching apparatus Telius manufactured by Tokyo Electron Limited, dry etching was performed with the resist pattern as a mask to etch the resist intermediate layer material containing silicon atoms (SOG-1) to form a hard mask pattern. Using the obtained hard mask pattern as a mask, the resist underlayer film (SOC-1) was etched to form an SOC-1 film pattern. The etching conditions are shown below.

[0601] Conditions for transferring the upper resist film pattern to the SOG-1 film.

[0602] Chamber pressure: 50 mT

[0603] RF power (upper): 500 W

[0604] RF power (lower): 300 W

[0605] CF 4 Gas flow rate: 150 sccm

[0606] CHF 3 Gas flow rate: 50 sccm

[0607] Time: 20 sec

[0608] Conditions for transferring the SOG-1 film pattern to the SOC-1 film.

[0609] Chamber pressure: 10 mT

[0610] RF power (upper): 1,000 W

[0611] RF power (lower): 300 W

[0612] CO 2 Gas flow rate: 150 sccm

[0613] CO gas flow rate: 50 sccm

[0614] N 2 Gas flow rate: 50 sccm

[0615] H 2 Gas flow rate: 150 sccm

[0616] Time: 60 sec

[0617] Then, the above composition for forming a metal oxide film (UDL-1 to 18, Comparative UDL-1 to 11) was coated on the obtained SOC-1 film pattern, and calcined in the atmosphere at 350 °C for 60 seconds to form a metal oxide film with a thickness of 100 nm. After that, the metal oxide film covering the SOC-1 film pattern was etched to expose the upper surface of the SOC-1 film pattern. The remaining SOG-1 film on the surface of the SOC-1 film pattern with the upper surface exposed was etched away, and then the exposed SOC-1 was etched away. The pattern was inverted on the metal oxide film, and the obtained metal oxide film pattern was used as a mask to perform SiO 2 etching of the film. In the comparative example, the composition for forming a metal oxide film was not used, and the SOC-1 film pattern was used as a mask to perform etching on the SiO 2 film as well (Comparative Examples 5-12). The etching conditions are as follows.

[0618] Etching conditions for the metal oxide film (exposing the SOC-1 film pattern).

[0619] Chamber pressure: 15 mT

[0620] RF power (upper): 300 W

[0621] RF power (lower): 50 W

[0622] O 2 Gas flow rate: 30 sccm

[0623] N 2 Gas flow rate: 270 sccm

[0624] Time: 60 sec

[0625] Removal of the remaining SOG-1 film on the SOC-1 film pattern.

[0626] Chamber pressure: 50 mT

[0627] RF power (upper): 500 W

[0628] RF power (lower): 300 W

[0629] CF 4 Gas flow rate: 150 sccm

[0630] CHF 3 Gas flow rate: 50 sccm

[0631] Time: 15 sec, removal of the SOC-1 film pattern.

[0632] Chamber pressure: 10 mT

[0633] RF power (upper): 1,000 W

[0634] RF power (lower): 300 W

[0635] CO 2 Gas flow rate: 150 sccm

[0636] CO gas flow rate: 50 sccm

[0637] N 2 Gas flow rate: 50 sccm

[0638] H 2 Gas flow rate: 150 sccm

[0639] Time: 60 sec

[0640] Transfer conditions of the metal oxide film pattern to the SiO 2 film.

[0641] Chamber pressure: 10 mT

[0642] RF power (upper): 100 W

[0643] RF power (lower): 800 W

[0644] CF 4 Gas flow rate: 25 sccm

[0645] CHF 3 Gas flow rate: 15 sccm

[0646] O 2 Gas flow rate: 5 sccm

[0647] Time: 200 sec

[0648] Comparative Example 5 - 12: Transfer conditions of the SOC-1 film pattern to the SiO 2 film.

[0649] Chamber pressure: 10 mT

[0650] RF power (upper): 100 W

[0651] RF power (lower): 800 W

[0652] CF 4 Gas flow rate: 25 sccm

[0653] CHF3 Gas flow rate: 15 sccm

[0654] O 2 Gas flow rate: 5 sccm

[0655] Time: 200 sec

[0656] The results of observing the pattern cross-section with the electron microscope (S-4700) manufactured by Hitachi, Ltd. are shown in Table 14.

[0657] [Table 14]

[0658]

[0659] As shown in Table 14, in Examples 5-1 to 5-18 using the composition for forming a metal oxide film (UDL-1 to 18) of the present invention, the SOC-1 film patterns can all be inverted with good accuracy, the patterns do not collapse, and the inverted patterns can be finally well transferred to the substrate. Thus, it can be confirmed that the composition for forming a metal oxide film of the present invention is suitable for microfabrication using a tone inversion etching method in a multilayer resist process. On the other hand, in Comparative Example 5-12 where the SOC-1 film pattern was directly transferred to the SiO 2 film, the etching resistance of the SOC-1 film was insufficient, so the twisting of the pattern shape was confirmed. Also, in Comparative Examples 5-1, 5-3, 5-6, 5-7, 5-9, 5-11 where insufficient performance was confirmed in the filling property evaluation and the planarization property evaluation, pattern collapse occurred during pattern processing, and finally a good inverted pattern could not be obtained. On the other hand, in Comparative Examples 5-4, 5-5, 5-8, 5-10 where there were no problems in the filling property and the planarization property evaluation but insufficient performance was confirmed in the dry etching resistance evaluation, the pattern shape was twisted during pattern inversion processing, and finally a good inverted pattern could not be obtained. Also, for Comparative Example 5-2 where the etching selectivity of the SOC-1 film was insufficient, the formation of the pattern could not be confirmed.

[0660] From the above, it can be seen that if it is the composition for forming a metal oxide film of the present invention, it has both a high level of filling / planarization properties and dry etching resistance. Therefore, it is extremely useful as a resist underlayer film material used in a multilayer resist method and a reversing agent used in a tone inversion etching method. And if it is the pattern forming method of the present invention using this composition, even if the object to be processed is a substrate with height differences, fine patterns can be formed with high precision.

[0661] Also, the present invention is not limited to the above-described embodiments. The above-described embodiments are illustrative, and all those having substantially the same configuration as the technical idea described in the claims of the present invention and exhibiting the same effects are included in the technical scope of the present invention.

[0662] Description of the Reference Numerals

[0663] 1: Substrate to be processed

[0664] 2: Layer to be processed

[0665] 2a: Pattern (pattern formed on the layer to be processed)

[0666] 2b: Tone-inverted pattern

[0667] 3: Metal-containing anti-resist underlayer film

[0668] 3a: Metal-containing anti-resist underlayer film pattern

[0669] 4: Silicon atom-containing anti-resist intermediate film

[0670] 4a: Silicon atom-containing anti-resist intermediate film pattern

[0671] 5: Anti-resist upper layer film

[0672] 5a: Anti-resist upper layer film pattern

[0673] 6: Exposed part

[0674] 7: Anti-resist underlayer film composed of a coating-type organic underlayer film material

[0675] 7a: Anti-resist underlayer film pattern composed of a coating-type organic underlayer film material

[0676] 8: Metal oxide film

[0677] 8a: Metal oxide film pattern obtained by inverting the anti-resist underlayer film pattern

[0678] 9: Substrate with dense lines & spaces

[0679] 10: Metal oxide film

[0680] 11: Substrate with dense lines & spaces

[0681] 12: Metal oxide film

[0682] Delta 12: Height difference between the filling film in the dense line pattern part and the non-line pattern forming part

Claims

1. A composition for forming a metal oxide film, characterized in that it contains (A) metal oxide nanoparticles, (B) a fluidity promoter which is one or more compounds represented by the following general formulae (3), (4) and (5) and / or a polymer having a molecular weight of 5000 or less and having one or more repeating units represented by the following general formulae (6), (7) and (8), and (C) an organic solvent, the weight ratio of the (A) metal oxide nanoparticles to the (B) fluidity promoter is 10 / 90 to 90 / 10, In the general formula (3) and the general formula (4), W 1 and W 2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the benzene ring and the naphthalene ring may also be substituted by a hydrocarbon group having 1 to 6 carbon atoms. R a is a hydrogen atom or a structure represented by the following formula (R a -1), Y is a group represented by the following general formula (1), n1 is 0 or 1, and n2 is 1 or 2. In the formula (R a -1), p is from 1 to 10; In the general formula (5), Z 1 is a group represented by the following general formula (2), R b is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, n4 is 0 or 1, and n5 is 1 or 2. * represents an atomic bond, In the general formula (2), W 1 and W 2 are the same as described above; Y and n1 are the same as described above. In the general formulas (6) and (7), W 1 , W 2 , R a , Y, n1, and n2 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms. In the general formula (8), Z 1 , R b , n4, and n5 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

2. The composition for forming a metal oxide film according to claim 1, wherein the (A) metal oxide nanoparticles are one or more of metal oxide nanoparticles selected from the group consisting of zirconium, hafnium, aluminum, tungsten, titanium, copper, tin, cerium, indium, zinc, yttrium, lanthanum, chromium, cobalt, platinum, iron, antimony and germanium.

3. The composition for forming a metal oxide film according to claim 1 or 2, wherein the (A) metal oxide nanoparticles are one or more of the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, tungsten oxide nanoparticles, titanium oxide nanoparticles and tin oxide nanoparticles.

4. The composition for forming a metal oxide film according to claim 1 or 2, wherein the (A) metal oxide nanoparticles have an average primary particle size of 100 nm or less.

5. The composition for forming a metal oxide film according to claim 1 or 2, wherein the composition for forming a metal oxide film contains any one or more of the compounds represented by the following general formulae (3) to (5) and any one or more of the polymers having the repeating structural units represented by the following general formulae (6) to (8) as the (B) component, In this general formula, W 1 , W 2 , R a , Y, n1, n2, Z 1 , R b , n4, n5 are as described above, and L is a divalent organic group having 1 to 40 carbon atoms.

6. The composition for forming a metal oxide film according to claim 1 or 2, wherein R in the general formulas (3) and (4) a and R in the general formula (5) b is a hydrogen atom or any of the structures represented by the following general formula (9). * represents the bonding part with an oxygen atom.

7. The composition for forming a metal oxide film according to claim 6, wherein Let R a and R b When the proportion of hydrogen atoms is a and the proportion of the structure represented by the general formula (9) is b among them, the whole of the component (B) satisfies the relationship of a + b = 1 and 0.2 ≤ b ≤ 0.

8.

8. The composition for forming a metal oxide film according to claim 1, wherein the ratio Mw / Mn of the polystyrene-equivalent weight-average molecular weight Mw to the number-average molecular weight Mn obtained by gel permeation chromatography of one or more compounds represented by the general formulae (3), (4) and (5) is in the range of 1.00 ≤ Mw / Mn ≤ 1.25 for each compound.

9. The composition for forming a metal oxide film according to claim 1, wherein the L is a divalent organic group represented by the following general formula (10), In the general formula (10), R 1 is a hydrogen atom or an aromatic ring-containing organic group having 6 to 20 carbon atoms, and the dashed line represents an atomic bond.

10. The composition for forming a metal oxide film according to claim 1, wherein the polystyrene-equivalent weight-average molecular weight obtained by gel permeation chromatography of one or more polymers represented by the general formulae (6), (7) and (8) is 1000 to 5000.

11. The composition for forming a metal oxide film according to claim 1 or 2, wherein the (C) organic solvent is a mixture of one or more organic solvents having a boiling point of less than 180°C and one or more organic solvents having a boiling point of 180°C or higher.

12. The composition for forming a metal oxide film according to claim 1 or 2, wherein The composition for forming a metal oxide film further contains one or more of a crosslinking agent, a surfactant, an acid generator, a plasticizer, and a polymer for blending.

13. The composition for forming a metal oxide film according to claim 12, wherein, the polymer for blending is a polymer containing the following general formula (BP), In the general formula (BP), R c is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms, R d is a hydrogen atom, a saturated hydrocarbon group having 1 to 10 carbon atoms or an unsaturated hydrocarbon group having 2 to 10 carbon atoms, X is a divalent organic group having 1 to 30 carbon atoms, p is an integer from 0 to 5, q1 is an integer from 1 to 6, p + q1 is an integer of 1 or more and 6 or less, and q2 is 0 or 1.

14. A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (I-1) After coating the composition for forming a metal oxide film according to any one of claims 1 to 13 on the substrate to be processed, forming a metal oxide film by heat treatment, (I-2) Forming a resist upper layer film on the metal oxide film using a photoresist material, (I-3) After pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (I-4) Using the patterned resist upper layer film as a mask, transferring the pattern to the metal oxide film by dry etching, and (I-5) Using the patterned metal oxide film as a mask, processing the substrate to be processed to form a pattern on the substrate to be processed.

15. A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (II-1) After coating the composition for forming a metal oxide film according to any one of claims 1 to 13 on the substrate to be processed, forming a metal oxide film by heat treatment, (II-2) Forming a silicon-containing resist intermediate film on the metal oxide film using a silicon-containing resist intermediate film material, (II-3) Forming a resist upper layer film on the resist intermediate film using a photoresist material, (II-4) After pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (II-5) Using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film by dry etching, (II-6) Using the resist intermediate film with the transferred pattern as a mask, transferring the pattern to the metal oxide film by dry etching, and (II-7) Using the patterned metal oxide film as a mask, processing the substrate to be processed to form a pattern on the substrate to be processed.

16. A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (III-1) After coating the composition for forming a metal oxide film according to any one of claims 1 to 13 on the substrate to be processed, forming a metal oxide film by heat treatment, (III-2) Forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxynitride film on the metal oxide film, (III-3) Forming an organic thin film on the inorganic hard mask intermediate film, (III-4) Forming a resist upper layer film on the organic thin film using a photoresist material, (III-5) After pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film, (III-6) Using the patterned resist upper layer film as a mask, transferring the pattern to the organic thin film and the inorganic hard mask intermediate film by dry etching, (III-7) Using the inorganic hard mask intermediate film of the transferred pattern as a mask, the pattern is transferred onto the metal oxide film by dry etching, and (III-8) Using the patterned metal oxide film as a mask, the substrate to be processed is processed to form a pattern on the substrate to be processed.

17. A pattern forming method, which is a method for forming a pattern on a substrate to be processed, characterized by comprising the following steps: (IV-1) Forming an underlayer resist film on the substrate to be processed, (IV-2) Forming an intermediate resist film on the underlayer resist film, or a combination of an inorganic hard mask intermediate film selected from silicon oxide films, silicon nitride films, and silicon oxynitride films and an organic thin film, (IV-3) Using a photoresist material to form an upper layer resist film on the intermediate resist film, or the combination of the inorganic hard mask intermediate film and the organic thin film, (IV-4) After pattern exposure of the upper layer resist film, developing with a developer to form a pattern on the upper layer resist film, (IV-5) Using the patterned upper layer resist film as a mask, transferring the pattern onto the intermediate resist film, or the organic thin film and the inorganic hard mask intermediate film by dry etching, (IV-6) Using the intermediate resist film with the transferred pattern, or the inorganic hard mask intermediate film as a mask, transferring the pattern onto the underlayer resist film by dry etching, (IV-7) Coating the patterned underlayer resist film with the composition for forming a metal oxide film according to any one of claims 1 to 13, and then covering the metal oxide film by heat treatment and filling the spaces between the patterns of the underlayer resist film with the metal oxide film, (IV-8) Etching back the metal oxide film covered on the patterned underlayer resist film by chemical stripping or dry etching to expose the upper surface of the patterned underlayer resist film, (IV-9) Removing the remaining intermediate resist film or hard mask intermediate film on the upper surface of the underlayer resist film by dry etching, (IV-10) Removing the patterned underlayer resist film with the exposed surface by dry etching to form an inverted pattern of the original pattern on the metal oxide film, (IV-11) Using the metal oxide film with the formed inverted pattern as a mask, processing the substrate to be processed to form a tone-inverted pattern on the substrate to be processed.

18. The pattern forming method according to any one of claims 14 to 17, wherein, A substrate having a structure or height difference with a height of 30 nm or more is used as the substrate to be processed.

19. A method for forming a metal oxide film, which is a method for forming a metal oxide film serving as a planar film used in the manufacturing process of a semiconductor device, characterized in that: A substrate coated with the composition for forming a metal oxide film according to any one of claims 1 to 13 on the substrate to be processed is heat-treated at a temperature of 100 °C or more and 600 °C or less for 10 to 600 seconds to form a hardened film.

20. A method for forming a metal oxide film, which is a method for forming a metal oxide film serving as a planar film used in the manufacturing process of a semiconductor device, characterized in that: A substrate coated with the composition for forming a metal oxide film according to any one of claims 1 to 13 on a substrate to be processed is heat-treated in a gas environment with an oxygen concentration of 1% by volume or more and 21% by volume or less to form a hardened film.

21. A method for forming a metal oxide film, which is a method for forming a metal oxide film acting as a planar film used in a manufacturing step of a semiconductor device, characterized in that: A substrate coated with the composition for forming a metal oxide film according to any one of claims 1 to 13 on a substrate to be processed is heat-treated in a gas environment with an oxygen concentration of less than 1% by volume to form a hardened film.

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