Metal oxide film forming composition, pattern forming method, and metal oxide film forming method

Abstract

The present invention relates to a composition for forming a metal oxide film, a pattern forming method, and a metal oxide film forming method. The present invention provides a composition for forming a metal oxide film having excellent coating properties and taking into account high-level filling / flattening characteristics, a pattern forming method using the same, and a metal oxide film forming method. A composition for forming a metal oxide film, comprising (A) an organic-inorganic composite material and (B) a solvent, characterized in that: the aforementioned (A) organic-inorganic composite material is a reaction product of a metal source (I) and an organic source (II), the aforementioned metal source (I) contains a metal compound represented by the following general formula (I-1), a hydrolyzate of a metal compound represented by the general formula (I-1), and one or more compounds of a hydrolysis-condensation product of a metal compound represented by the general formula (I-1), and the aforementioned organic source (II) contains a constituent unit represented by the following general formula (II-1) and a compound of a cardo structure.

Description

Technical Field

[0001] The present invention relates to a metal oxide film forming composition that can be used for fine patterning by a multilayer resist method in a semiconductor device manufacturing process, a pattern forming method using the composition, and a metal oxide film forming method. Background Art

[0002] With the increasing integration and speed of LSIs, pattern sizes are rapidly decreasing. Photolithography technology, along with this miniaturization, has achieved the formation of fine patterns through the shortening of light sources' wavelengths and the appropriate selection of corresponding resist compositions. Central to this development is a single-layer positive photoresist composition. This single-layer positive photoresist composition incorporates a framework within the resist resin that is resistant to dry etching using chlorine- or fluorine-based gas plasmas and incorporates a switching mechanism that dissolves the exposed portion. This dissolution forms a pattern, and the remaining resist pattern serves as an etching mask for dry etching of the substrate being processed.

[0003] However, if the thickness of the photoresist film used is directly reduced, that is, if the pattern width is further reduced, the resolution performance of the photoresist film will be reduced. Moreover, if the photoresist film is developed using a developer, the so-called aspect ratio will become too large, resulting in the problem of pattern collapse. Therefore, as the pattern becomes finer, the photoresist film is becoming thinner and thinner.

[0004] Meanwhile, substrate processing typically involves dry etching using a patterned photoresist film as an etching mask. However, no dry etching method achieves perfect etching selectivity between the photoresist film and the substrate being processed. Consequently, during substrate processing, the photoresist film can be damaged and collapse, preventing the resist pattern from being accurately transferred to the substrate. As patterns become increasingly miniaturized, resist compositions are required to exhibit higher dry etching resistance. However, to improve resolution, the resins used in photoresist compositions are increasingly required to have low absorption at the exposure wavelength. Consequently, as exposure light progresses to shorter wavelengths such as i-rays, KrF, and ArF, resins are shifting to novolac resins, polyhydroxystyrene, and resins with aliphatic polycyclic backbones. However, as the etching speed increases under dry etching conditions during substrate processing, recent photoresist compositions with high resolution tend to exhibit reduced etching resistance.

[0005] Therefore, the substrate to be processed must be dry-etched using a thinner photoresist film with weaker etching resistance, and ensuring the materials and processing in this processing step becomes a top priority.

[0006] One method for solving this problem is the multilayer resist method. In this method, a resist interlayer film having a different etching selectivity from the photoresist film (i.e., the resist upper layer film) is inserted between the resist upper layer film and the substrate being processed. After a pattern is formed on the resist upper layer film, the pattern is transferred to the resist interlayer film by dry etching using the resist upper layer film pattern as a dry etching mask. The pattern is then transferred to the substrate being processed by dry etching using the resist interlayer film as a dry etching mask.

[0007] One type of multilayer resist method is the three-layer resist method, which can be implemented using a common resist composition used in the single-layer resist method. This three-layer resist method involves forming an organic film made from, for example, a novolac resin as a resist lower layer on a substrate to be processed, forming a silicon-containing resist interlayer film thereon, and then forming a conventional organic photoresist film thereon as a resist upper layer. When dry-etched using fluorine-based gas plasma, the organic resist upper layer exhibits a good etching selectivity relative to the silicon-containing resist interlayer film. Therefore, the resist upper layer pattern can be transferred to the silicon-containing resist interlayer film by dry-etching using fluorine-based gas plasma. According to this method, even when using a resist composition that is difficult to form a pattern having a sufficient film thickness for direct processing of a substrate to be processed, or a resist composition that does not have sufficient dry etching resistance for substrate processing, if the pattern can be transferred to a silicon-containing resist interlayer (resist interlayer), and then the pattern transfer is performed by dry etching using oxygen-based or hydrogen-based gas plasma, a pattern of an organic film (resist underlayer film) made of a novolac resin or the like having sufficient dry etching resistance for substrate processing can be obtained. Many such resist underlayer films are already known, such as those described in Patent Document 1.

[0008] Meanwhile, the recent acceleration of DRAM memory miniaturization has led to a growing need for organic films with improved dry etch resistance and superior filling and planarization properties. While coating-type organic underlayer film materials with excellent filling and planarization properties have been reported, such as those described in Patent Document 2, their dry etch resistance is a concern for their anticipated use in advanced generations, reaching the limits of the applicability of existing coating-type organic underlayer film materials.

[0009] To address the issue of dry etching resistance in coating-type organic resist underlayer materials, some have focused on methods using metal oxide films as resist underlayers (Patent Document 3). However, conventional soluble metal compounds used to form metal oxide thin films, such as metal alkoxides, are highly unstable in the presence of atmospheric moisture, leading to concerns about storage stability. Furthermore, metal compounds alone lack fluidity, making high-level filling and planarization difficult. Therefore, compositions incorporating organic materials have been developed to enhance fluidity.

[0010] Such compositions in which an organic material is added to a metal compound are reported in Patent Document 4. The use of an alkynyloxy-functionalized polymer as the organic material allows for a composition with excellent stability even when mixed with the metal compound. While dry etching resistance was not evaluated in the examples of Patent Document 4, the use of a metal compound terminally modified with a Si-containing organic group may result in poor dry etching resistance against fluorocarbon-based gases.

[0011] Patent Document 5 reports a mixed composition of a metal compound and an aromatic compound that generates hydroxyl groups when heated or acidic. While its filling properties have not been evaluated, the metal compound experiences significant volumetric contraction when heated, accompanied by ligand release. Therefore, there is a risk of void formation when high-temperature heating is performed after filling a stepped substrate. Furthermore, insufficient compatibility between the metal compound and the organic polymer can lead to aggregation of the components during coating, potentially causing film formation defects.

[0012] In view of the above, it is desired to develop a method to replace the mixed composition of metal compounds and organic materials.

[0013] Non-Patent Document 1 reports the formation of an organic-inorganic composite material by condensing a metal alkoxide with an organic polymer. In Non-Patent Document 1, a polymer is used as the organic component, and it is speculated that the flowability must be improved to improve the filling properties of patterns with a high aspect ratio.

[0014] Prior art literature

[0015] Patent Literature

[0016] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-205685

[0017] [Patent Document 2] Japanese Patent No. 6714493

[0018] [Patent Document 3] Japanese Patent No. 6189758

[0019] [Patent Document 4] Japanese Patent Publication No. 2022-521531

[0020] [Patent Document 5] Japanese Patent No. 5756134

[0021] Non-patent literature

[0022] [Non-patent document 1] Chem. Commun., 2015, 51, 13523-13526 Summary of the Invention

[0023] [Problems to be solved by the invention]

[0024] In view of the above situation, the present invention aims to provide a metal oxide film forming composition having excellent coating properties compared to known metal oxide film forming materials and having high filling / planarization properties, a pattern forming method using the material, and a metal oxide film forming method.

[0025] [Methods for solving the problem]

[0026] In order to solve the above problems, the present invention provides a metal oxide film forming composition.

[0027] The method comprises (A) an organic-inorganic composite material and (B) a solvent, and is characterized by:

[0028] The aforementioned (A) organic-inorganic composite material is a reaction product of a metal source (I) and an organic source (II).

[0029] The metal source (I) contains one or more compounds selected from the group consisting of metal compounds represented by the following general formula (I-1), hydrolyzates of metal compounds represented by the general formula (I-1), and hydrolysis-condensation products of metal compounds represented by the general formula (I-1).

[0030] The organic source (II) contains a compound having a structural unit represented by the following general formula (II-1) and a cardo structure.

[0031] [Chemistry 1]

[0032]

[0033] [Chemistry 2]

[0034]

[0035] Where M is metal, R A1 is a monovalent organic group having 1 to 30 carbon atoms and having 0 or 1 hydroxyl group, and may be the same group or different groups. A1 They may also be bonded to each other and to form a ring or a spiro ring together with the O and M to which they are bonded. r is an integer from 3 to 6. a It is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms which may be substituted, p is an integer of 0 to 5, q1 is an integer of 1 to 6, p+q1 is an integer of 1 to 6, q2 is 0 or 1, and * is a bonding position.

[0036] Such a metal oxide film-forming composition exhibits excellent coating properties compared to conventional metal oxide film-forming materials while also achieving high levels of fill and planarization properties. In particular, the use of an organic-inorganic composite material, which is a reaction product of a metal source (I) having excellent dry etching resistance and an organic source (II) having a highly reactive structural unit represented by the aforementioned general formula (II-1), enables the formation of a metal oxide film having excellent dry etching resistance.

[0037] The organic source (II) contains a cardo structure, which improves the dry etching resistance and heat resistance of the metal oxide film-forming composition. Furthermore, the cardo structure introduced into the molecule mitigates intermolecular interactions and improves solubility in organic solvents, thereby enhancing the compatibility of the organic-inorganic composite material and improving film-forming properties during coating film formation. Furthermore, despite the introduction of multiple high-carbon-density condensed carbon rings, the composition can achieve a balance between heat resistance and filling / planarization properties, which are mutually exclusive.

[0038] In the present invention, the organic source (II) preferably has, in addition to the structural unit represented by the aforementioned general formula (II-1) and the cardo structure, a structural unit represented by the following general formula (II-2).

[0039] [Chemistry 3]

[0040]

[0041] In the above general formula (II-2), R A is a divalent organic group having 1 to 10 carbon atoms which may be substituted, R B is an optionally substituted hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, R a , p, q1, q2, and * are the same as those in the aforementioned general formula (II-1).

[0042] If such a metal oxide film forming composition has not only the structural unit represented by the above-mentioned general formula (II-1) having excellent reactivity with the metal source (I), but also the structural unit represented by the above-mentioned general formula (II-2) having excellent thermal fluidity, it can further improve the filling / planarization characteristics for the pattern substrate.

[0043] When the proportion of the structural unit represented by the general formula (II-1) is a and the proportion of the structural unit represented by the general formula (II-2) is b, the organic source (II) component as a whole preferably satisfies the relationship of a+b=1 and 0.2≤b≤0.8.

[0044] When the contents of the above-mentioned general formula (II-1) and the above-mentioned general formula (II-2) are within the above-mentioned ranges, the various physical properties required for use in forming metal oxide films, such as filling / planarization characteristics, dry etching resistance, and substrate adhesion, can be adjusted within appropriate ranges. To improve dry etching resistance, the metal content in the organic-inorganic composite material must be increased, so a higher content of the above-mentioned general formula (II-1) is more desirable. To improve filling / planarization characteristics, a higher content of the above-mentioned general formula (II-2), which exhibits excellent thermal fluidity, is more desirable.

[0045] In the aforementioned general formula (II-2), X2 is preferably represented by the following general formula (X-1).

[0046] [Chemistry 4]

[0047]

[0048] In the above formula, * represents the bonding position.

[0049] The general formula (II-2) having the constituent represented by (X-1) provides an organic-inorganic composite material having excellent thermal fluidity and heat resistance, and can further enhance the filling and planarization properties of the metal oxide film-forming composition.

[0050] In the present invention, the organic source (II) preferably contains compounds represented by the following general formulas (1) to (3).

[0051] [Chemistry 5]

[0052]

[0053] [Chemistry 6]

[0054]

[0055] In the formula, W1 and W2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the aforementioned benzene ring and the aforementioned naphthalene ring may be substituted with a hydrocarbon group having 1 to 6 carbon atoms. Y is a group represented by the following general formula (4). Z1 is a group represented by the following general formula (5), and * represents the bonding position to the structural unit represented by the above general formula (II-1).

[0056] [Chemistry 7]

[0057]

[0058] [Chemistry 8]

[0059]

[0060] In the above general formula (5), W1, W2, and Y are the same as described above, and n1 is 0 or 1. * in the above general formulas (4) and (5) represents a bonding position.

[0061] When the organic source (II) is a compound represented by the general formulae (1) to (3), an organic-inorganic composite material having excellent heat resistance can be obtained. Furthermore, since the organic source (II) has superior thermal fluidity compared to high molecular weight compounds, a metal oxide film-forming composition having excellent filling and planarizing properties for patterned substrates can be provided.

[0062] The ratio Mw / Mn (dispersity) of the polystyrene-equivalent weight average molecular weight Mw to the number average molecular weight Mn of the compound contained in the organic source (II) measured by gel permeation chromatography is preferably within the range of 1.00≤Mw / Mn≤1.25.

[0063] If the compound has a dispersion within such a range, the thermal fluidity of the organic-inorganic composite material will be better, so when it is mixed with the composition for forming a metal oxide film, it can well fill the fine structure formed on the substrate. Not only that, it can also form a metal oxide film that is flat across the entire substrate.

[0064] In the present invention, M in the general formula (I-1) preferably contains a metal selected from the group consisting of Zr, Ta, Hf, Ti, Sn, Nb, Mo, Ge, and W.

[0065] By using the metal source (I) having such M, a metal oxide film-forming composition having excellent dry etching resistance can be prepared.

[0066] In the present invention, the composition may further contain (C) a fluidity enhancer having a weight loss rate of less than 30% between 30°C and 190°C and a weight loss rate of 98% or more between 30°C and 350°C.

[0067] Component (C) exhibits a weight loss rate of less than 30% between 30°C and 190°C, and a weight loss rate of 98% or greater between 30°C and 350°C. This contributes to improved fluidity during composition coating. Furthermore, it is removed from the film after baking at 350°C, preventing deterioration in dry etch resistance and improving fill / planarization properties. Furthermore, it suppresses the occurrence of drying-related defects, contributing to improved yield in semiconductor manufacturing.

[0068] In this case, the fluidity-improving agent (C) preferably contains one or more compounds selected from the group consisting of the following general formulae (i) to (iii).

[0069] [General formula (i)]

[0070] [Chemistry 9]

[0071]

[0072] [Chemistry 10]

[0073]

[0074] [Chemistry 11]

[0075]

[0076] Where R 1 Each independently represents a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. 1 W is a phenylene group or a divalent group represented by the general formula (i-1). 2 、W 3 is a single bond or any divalent group represented by the general formula (i-2). m1 is an integer from 1 to 10, n 1 is an integer from 0 to 5. * represents the bonding position, R 10 、R 11 、R 12 、R 13 W is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. 10 、W 11 Each is independently a single bond or a carbonyl group. 10 、m 11 is an integer from 0 to 10, m 10 +m 11 ≥1.

[0077] [General formula (ii)]

[0078] [Chemistry 12]

[0079]

[0080] [Chemistry 13]

[0081]

[0082] [Chemistry 14]

[0083]

[0084] Where R 2 Each independently represents a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. 4 W is a divalent group represented by the general formula (ii-1). 5 is a single bond or any divalent group represented by the general formula (ii-2). 2 is an integer from 2 to 10, and n3 is an integer from 0 to 5. * represents the bonding position, R 20 、R 21 、R 22 、R 23 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms.20 、m 21 is an integer from 0 to 10, m 20 +m 21 ≥1.

[0085] [General formula (iii)]

[0086] [Chemistry 15]

[0087]

[0088] [Chemistry 16]

[0089]

[0090] [Chemistry 17]

[0091]

[0092] Where R 3 、R 4 R is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms which may be substituted, and may be bonded to form a ring structure. 5 、R 6 is an organic group having 1 to 10 carbon atoms, R 5 W is a group containing an aromatic ring or a divalent group represented by the general formula (iii-1). 6 、W 7 is a single bond or any divalent group represented by general formula (iii-2), and at least one of them is a divalent group represented by any one of formula (iii-2). 30 It is an organic group having 1 to 4 carbon atoms. * indicates a bonding position.

[0093] By using the compound having an aromatic ring as a hydrophobic portion and the following structure (C-1) as a hydrophilic portion, the fluidity of the metal oxide film-forming composition can be improved without impairing the stability of the organic-inorganic composite material in the composition.

[0094] [Chemistry 18]

[0095]

[0096] In the formula, * represents a bonding position, and W is an organic group having 1 to 4 carbon atoms.

[0097] In the present invention, the metal oxide film-forming composition may further contain (D) metal oxide nanoparticles having an average primary particle size of 100 nm or less.

[0098] The metal oxide nanoparticles (D) are preferably at least one metal oxide nanoparticle selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and tungsten oxide nanoparticles.

[0099] By using such metal oxide nanoparticles, the metal content in the composition can be easily increased, and the dry etching resistance of the metal oxide film-forming composition can be further improved.

[0100] In the present invention, the composition preferably further contains one or more of a crosslinking agent, a surfactant, an acid generator, and a plasticizer.

[0101] When the metal oxide film-forming composition contains the above-mentioned additives, coating properties, dry etching resistance, and filling / planarization characteristics are further improved.

[0102] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0103] (I-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0104] (I-2) forming a resist upper layer film on the aforementioned metal oxide film using a photoresist material,

[0105] (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,

[0106] (I-4) using the patterned resist upper layer as a mask, transferring the pattern to the metal oxide film by dry etching, and

[0107] (I-5) 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.

[0108] According to the pattern forming method using the above-mentioned two-layer resist process, a fine pattern can be formed on a workpiece (workpiece substrate).

[0109] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0110] (II-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0111] (II-2) forming a resist intermediate film on the aforementioned metal oxide film,

[0112] (II-3) forming a resist upper layer film on the resist intermediate film using a photoresist material,

[0113] (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,

[0114] (II-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film by dry etching,

[0115] (II-6) using the resist intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0116] (II-7) 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.

[0117] According to the pattern forming method using the three-layer resist process described above, a fine pattern can be formed on a substrate to be processed with high precision.

[0118] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0119] (III-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0120] (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,

[0121] (III-3) forming an organic thin film on the aforementioned inorganic hard mask intermediate film,

[0122] (III-4) forming a resist upper layer film on the aforementioned organic thin film using a photoresist material,

[0123] (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,

[0124] (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,

[0125] (III-7) using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0126] (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.

[0127] According to the pattern forming method using the above-mentioned four-layer resist process, a fine pattern can be formed on a substrate to be processed with high precision.

[0128] Furthermore, the present invention provides a pattern forming method, which is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0129] (IV-1) forming a resist underlayer film on a substrate to be processed,

[0130] (IV-2) forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film and an organic thin film on the resist underlayer film,

[0131] (IV-3) forming a resist upper layer film using a photoresist material on the aforementioned resist interlayer film or the combination of the inorganic hard mask interlayer film and the organic thin film,

[0132] (IV-4) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film,

[0133] (IV-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching,

[0134] (IV-6) using the resist intermediate film or inorganic hard mask intermediate film to which the pattern has been transferred as a mask, and transferring the pattern to the resist underlayer film by dry etching,

[0135] (IV-7) applying the metal oxide film-forming composition onto the patterned resist underlayer film, and then covering the metal oxide film by heat treatment to fill the space between the resist underlayer film patterns with the metal oxide film.

[0136] (IV-8) chemically stripping or dry etching the metal oxide film covering the patterned resist underlayer film to expose the top surface of the patterned resist underlayer film,

[0137] (IV-9) removing the resist intermediate film or the hard mask intermediate film remaining on the top surface of the resist underlayer film by dry etching,

[0138] (IV-10) removing the patterned resist underlayer film exposed on the surface by dry etching to form a reverse pattern of the original pattern on the metal oxide film,

[0139] (IV-11) The metal oxide film having the reverse pattern formed thereon is used as a mask to process the substrate to form a reverse pattern on the substrate.

[0140] According to the pattern forming method using the above-mentioned inversion process, a fine pattern can be formed on a substrate to be processed with higher precision.

[0141] The substrate to be processed may have a structure with a height of 30 nm or more or a height difference.

[0142] In the present invention, for example, the substrate described above can be used as the substrate to be processed.

[0143] The present invention also provides a method for forming a metal oxide film, which is a method for forming a metal oxide film that serves as a planar film used in the manufacturing steps of semiconductor devices, characterized in that the substrate to be processed, on which the metal oxide film-forming composition is applied, is heat-treated at a temperature of not less than 100°C and not more than 600°C for 10 to 600 seconds to form a cured film.

[0144] The present invention also provides a method for forming a metal oxide film, which is a method for forming a metal oxide film that serves as a planar film used in the manufacturing steps of semiconductor devices, characterized in that a substrate to be processed, on which the metal oxide film-forming composition is applied, is heat-treated in a gas atmosphere having an oxygen concentration of not less than 0.1 volume % and not more than 21 volume %, thereby forming a cured film.

[0145] This method promotes the crosslinking reaction of the metal oxide film-forming composition during metal oxide film formation, further suppressing intermixing with the overlying film. Furthermore, by appropriately adjusting the heat treatment temperature, time, and oxygen concentration within the aforementioned ranges, it is possible to achieve metal oxide film filling / planarization properties and curing properties appropriate for the intended application.

[0146] The present invention also provides a method for forming a metal oxide film, which is a method for forming a metal oxide film that serves as a planar film used in the manufacturing steps of semiconductor devices, characterized in that a substrate to be processed, on which the metal oxide film-forming composition is applied, is heat-treated in a gas atmosphere having an oxygen concentration of less than 0.1% by volume to form a cured film.

[0147] According to this method, even if the processed substrate contains a material that is unstable to heating in an oxygen environment, it will not cause degradation of the processed substrate. It will promote the cross-linking reaction of the above-mentioned metal oxide film forming composition during the formation of the metal oxide film and suppress mixing with the upper film to a higher degree, which is useful.

[0148] [Effects of the Invention]

[0149] As described above, the metal oxide film-forming composition, pattern forming method, and metal oxide film forming method of the present invention are particularly suitable for use in multilayer resist processing, including filling and planarizing steps for substrates with uneven or irregular surfaces, and are extremely useful for fine patterning in semiconductor device manufacturing. Specifically, because the composition comprises a reaction product of a metal compound and a specific compound, it is possible to suppress coating defects caused by poor compatibility between the metal source and the organic source, and the formation of voids in the filled film due to volume shrinkage of the metal compound during heat treatment. Compared to conventional metal oxide film-forming compositions comprising a mixture of a metal compound and a resin, the composition exhibits superior coating properties and filling / planarization characteristics. In particular, in the fine patterning process using the multilayer resist method in the semiconductor device manufacturing step, even on the processed substrate with difficult-to-fill / flatten parts such as dense parts of the high-aspect-ratio fine pattern structure of DRAM memory, which represents the progress of miniaturization, it is possible to fill the area without causing defects such as voids and peeling. Moreover, compared with known coating-type organic lower layer film materials, it has extremely excellent dry etching resistance, so it is possible to form fine patterns on the processed substrate with higher precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0150] Figure 1 (A) to (F) are explanatory diagrams of an example (three-layer resist process) of the pattern forming method of the present invention.

[0151] Figure 2 (G) to (P) are explanatory diagrams of an example of the pattern forming method (tone reversal pattern forming method) of the present invention (reversal of an SOC pattern in a three-layer resist process).

[0152] Figure 3 (Q) to (S) are explanatory diagrams of the landfill characteristic evaluation method.

[0153] Figure 4 (T) and (U) are explanatory diagrams of the planarization characteristic evaluation method. DETAILED DESCRIPTION

[0154] As described above, in the fine patterning process using the multilayer resist method in the semiconductor device manufacturing step, even on the processed substrate with difficult-to-fill / flattened parts such as dense parts of the high-aspect-ratio fine pattern structure of DRAM memory representing the progress of miniaturization, filling / flattening can be achieved without the occurrence of defects such as voids and peeling. Compared with the known coating-type organic lower film materials, it has excellent dry etching resistance and can transfer the resist pattern to the lower film material of the processed substrate with higher precision.

[0155] Regarding this point, Non-Patent Document 1 suggests that since this is a condensation product of a metal compound and an organic substance, unlike a mixture of a metal compound and an organic component, there is no concern about poor compatibility, and it is expected to form a film with excellent coating properties. Furthermore, since the metal compound has already condensed with the organic component, the ligands do not detach from the metal compound during baking, and the effect of volume shrinkage is minimal, resulting in the possibility of forming a film with excellent filling properties for uneven substrates. However, the research focus differs from that in the semiconductor field, and the coating and filling properties are unclear, requiring further improvement.

[0156] As a solution, compositions for forming metal oxide films have received significant attention. However, existing compositions that combine metal compounds with organic polymers are believed to have insufficient compatibility, which can lead to aggregation of the components during coating and poor film formation. Furthermore, metal compounds experience significant volume shrinkage during heating due to ligand detachment, which can cause voids when high-temperature heating is performed after filling uneven substrates. With these considerations in mind, there is a desire to develop alternatives to mixed compositions of metal compounds and organic materials.

[0157] The inventors of this invention have diligently studied the above-mentioned problems and, as a result, have explored various metal oxide film materials and pattern forming methods in order to develop a metal oxide film-forming composition having excellent coating properties, which can achieve both high levels of fill / planarization achieved by forming an underlayer film and excellent dry etching resistance in a multilayer resist method using an underlayer film. As a result, they discovered that a pattern forming method using a metal oxide film-forming composition comprising an organic-inorganic composite material, which is a reaction product of a metal source (I) having excellent dry etching resistance, a highly reactive structural unit represented by the above-mentioned general formula (II-1), and an organic source (II) having a cardo structure, is very effective, leading to the completion of the present invention.

[0158] That is, the present invention is a composition for forming a metal oxide film, comprising (A) an organic-inorganic composite material and (B) a solvent, and is characterized by:

[0159] The aforementioned (A) organic-inorganic composite material is a reaction product of a metal source (I) and an organic source (II).

[0160] The metal source (I) contains one or more compounds selected from the group consisting of metal compounds represented by the following general formula (I-1), hydrolyzates of metal compounds represented by the general formula (I-1), and hydrolysis-condensation products of metal compounds represented by the general formula (I-1).

[0161] The organic source (II) contains a compound having a structural unit represented by the following general formula (II-1) and a cardo structure.

[0162] [Chemistry 19]

[0163]

[0164] [Chemistry 20]

[0165]

[0166] Where M is metal, R A1 is a monovalent organic group having 1 to 30 carbon atoms and having 0 or 1 hydroxyl group, and may be the same group or different groups. A1 They may also be bonded to each other and to form a ring or a spiro ring together with the O and M to which they are bonded. r is an integer from 3 to 6. a It is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms which may be substituted, p is an integer of 0 to 5, q1 is an integer of 1 to 6, p+q1 is an integer of 1 to 6, q2 is 0 or 1, and * is a bonding position.

[0167] The present invention is described in detail below, but the present invention is not limited thereto.

[0168] <Metal Oxide Film Forming Composition>

[0169] The metal oxide film-forming composition of the present invention comprises, as component (A), one or more metal sources (I) selected from the group consisting of metal compounds represented by the following general formula (I-1), hydrolyzates of metal compounds represented by the following general formula (I-1), and hydrolyzed condensates of metal compounds represented by the following general formula (I-1); an organic-inorganic composite material, which is a reaction product of these metal sources with an organic source (II) containing a compound having a structural unit represented by the following general formula (II-1) and a cardo structure; and (B) a solvent. It may also contain additives such as surfactants and crosslinking agents as needed. The components contained in the composition of the present invention are described below.

[0170] <Metal Source (I)>

[0171] The metal oxide film forming composition of the present invention is a composition comprising an organic-inorganic composite material, which is a reaction product of a metal source (I) and an organic source (II), and (B) a solvent, wherein the aforementioned metal source (I) contains one or more selected from the group consisting of a metal compound represented by formula (I-1), a hydrolyzate of a metal compound represented by formula (I-1), and a hydrolysis-condensation product of a metal compound represented by formula (I-1).

[0172] [Chemistry 21]

[0173]

[0174] In the above general formula (I-1), M is a metal, R A1is a monovalent organic group having 1 to 30 carbon atoms and having 0 or 1 hydroxyl group, and may be the same group or different groups. A1 They may also be bonded to each other and form a ring or a spiro ring together with the O and M to which they are bonded. r is an integer of 3-6.

[0175] The monovalent organic group may be straight-chain, branched, or cyclic. Specific examples thereof include monovalent saturated hydrocarbon groups such as methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, n-pentyl, isopentyl, sec-pentyl, tert-pentyl, neopentyl, cyclopentyl, n-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, n-nonyl, cyclononyl, n-decyl, cyclodecyl, adamantyl, and norbornyl; monovalent unsaturated hydrocarbon groups such as cyclohexenyl, cyclohexenylmethyl, cyclohexenylethyl, cycloheptenyl, and cyclopentadienyl; aryl groups such as phenyl, tolyl, xylyl, methoxyphenyl, and naphthyl; aralkyl groups such as benzyl, phenethyl, and methoxybenzyl; and monovalent heterocyclic-containing groups such as tetrahydrofuryl.

[0176] The aforementioned organic group may also have one hydroxyl group. The organic group having a hydroxyl group is preferably one having a tertiary alcohol structure.

[0177] M in the aforementioned formula (I-1) is not particularly limited as long as it is a metal capable of forming a metal oxide film and having a valence of 3 to 6. For example, it may contain a metal selected from elements in Groups 3 to 14 of the periodic table, and more specifically, it may contain a metal selected from elements in Groups 4, 5, 6, and 14 of the periodic table. Among them, M in the aforementioned formula (I-1) preferably contains a metal selected from the group consisting of Zr, Ta, Hf, Ti, Sn, Nb, Mo, Ge, and W, more preferably Zr, Hf, Ti, Sn, and W, and even more preferably Zr, Hf, and Ti.

[0178] By using such a metal source (I), a metal oxide film-forming composition having excellent dry etching resistance can be prepared.

[0179] When M is Zr, the metal compound represented by formula (I-1) includes, for example, dibutoxybis(ethylacetoacetate)zirconium (IV), di-n-butoxybis(2,4-pentanedione)zirconium (IV), tetra-n-butoxyzirconium (IV), tetra-n-propoxyzirconium (IV), tetraisopropoxyzirconium (IV), aminopropyltriethoxyzirconium (IV), 2-(3,4-epoxycyclohexyl)ethyltrimethoxyzirconium (IV), γ-glycidoxypropyltrimethoxyzirconium (IV), 3-isocyanopropyltrimethoxyzirconium (IV), triethoxymono(2,4-pentanedione)zirconium (IV), tri-n-propoxymono(2,4-pentanedione)zirconium (IV), triisopropoxymono(2,4-pentanedione)zirconium (IV), tris(3-methacryloyloxypropyl)methoxyzirconium (IV), and tris(3-acryloyloxypropyl)methoxyzirconium (IV).

[0180] When M is Ta, the metal compound represented by formula (I-1) includes, for example, tetrabutoxytantalum (IV), pentabutoxytantalum (V), pentaethoxytantalum (V), and the like.

[0181] When M is Hf, the metal compound represented by formula (I-1) is, for example, hafnium methoxide, hafnium ethoxide, hafnium propoxide, hafnium butoxide, hafnium pentoxide, hafnium hexoxide, hafnium cyclopentoxide, hafnium cyclohexoxide, hafnium allyloxide, hafnium phenoxide, hafnium methoxyethoxide, hafnium ethoxyethoxide, hafnium dipropoxybisethylacetoacetate, hafnium dibutoxybisethylacetoacetate, hafnium dipropoxybis-2,4-pentanediolate, hafnium dibutoxybis-2,4-pentanediolate, and the like.

[0182] When M is Ti, the metal compound represented by formula (I-1) is, for example, methoxytitanium, ethoxytitanium, propoxytitanium, isopropoxytitanium, butoxytitanium, pentoxytitanium, hexoxytitanium, cyclopentoxytitanium, cyclohexyloxytitanium, allyloxytitanium, phenoxytitanium, methoxyethoxytitanium, ethoxyethoxytitanium, 2-ethyl-1,3-hexanediol alkane titanium, 2-ethylhexyloxytitanium, tetrahydrofurylmethyloxytitanium, bis(triethanolamine)diisopropoxytitanium, dipropoxybisethylacetoacetate titanium, dibutoxybisethylacetoacetate titanium, dipropoxybis-2,4-pentanediol titanium, dibutoxybis-2,4-pentanediol titanium, etc.

[0183] When M is Sn, the metal compound represented by formula (I-1) is, for example, a tetraalkoxide of tin such as tetramethyltin alkoxide (Sn(OCH3)4), tetraethyltin alkoxide, tetraisopropyltin alkoxide, tetrapropyltin alkoxide, tetraisobutyltin alkoxide, tetrabutyltin alkoxide, tetrapentyltin alkoxide, tetraheptyltin alkoxide, tetrahexyltin alkoxide, tetraoctyltin alkoxide, tetranonyltin alkoxide, and tetradecyltin alkoxide.

[0184] When M is Nb, the metal compound represented by formula (I-1) is, for example, pentamethyl alkoxy niobium (Nb(OCH3)5), pentaethyl alkoxy niobium, pentaisopropyl alkoxy niobium, pentapropyl alkoxy niobium, pentaisobutyl alkoxy niobium, pentabutyl alkoxy niobium, pentapentyl alkoxy niobium, pentahexyl alkoxy niobium, pentaheptyl alkoxy niobium, pentaoctyl alkoxy niobium, pentanonyl alkoxy niobium, pentadecyl alkoxy niobium and other pentaalkoxy niobium of niobium.

[0185] When M is Mo, examples of the metal compound represented by formula (I-1) include pentaethoxymolybdenum (V), pentaisopropoxymolybdenum (V), and hexaethoxymolybdenum (VI).

[0186] When M is Ge, the metal compound represented by formula (I-1) includes methoxygermanium, ethoxygermanium, propoxygermanium, butoxygermanium, pentyloxygermanium, hexyloxygermanium, cyclopentyloxygermanium, cyclohexyloxygermanium, allyloxygermanium, phenoxygermanium, methoxyethoxygermanium, ethoxyethoxygermanium, etc.

[0187] When M is W, the metal compound represented by formula (I-1) includes tetrabutoxytungsten (IV), pentabutoxytungsten (V), pentamethoxytungsten (V), hexabutoxytungsten (VI), hexaethoxytungsten (VI), dichlorobis(cyclopentadienyl)tungsten (IV), etc.

[0188] <Organic Source (II)>

[0189] The metal oxide film forming composition of the present invention is a composition comprising an organic-inorganic composite material, which is a reaction product of a metal source (I) and an organic source (II), and (B) a solvent, wherein the aforementioned organic source (II) contains a compound having a constituent unit represented by the following formula (II-1) and a cardo structure.

[0190] [Chemistry 22]

[0191]

[0192] In the above general formula (II-1), R a It is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms which may be substituted, p is an integer of 0 to 5, q1 is an integer of 1 to 6, p+q1 is an integer of 1 to 6, q2 is 0 or 1, and * is a bonding position.

[0193] The structural unit represented by the general formula (II-1) reacts well with the metal source (I), providing a material in which the organic source and the metal source are highly composited. Furthermore, the presence of an aromatic ring allows for the provision of an organic-inorganic composite material with excellent heat resistance and dry etching resistance.

[0194] In the above general formula (II-1), R aIt is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms, for example, a monovalent saturated hydrocarbon group such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, sec-pentyl, and tert-pentyl; a monovalent unsaturated chain hydrocarbon group such as vinyl, propenyl, butenyl, pentenyl, ethynyl, and propynyl; a monocyclic saturated cyclic hydrocarbon group such as cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl; a monovalent monocyclic unsaturated cyclic hydrocarbon group such as cyclobutenyl, cyclopentenyl, and cyclohexenyl; a monovalent polycyclic cyclic hydrocarbon group such as norbornyl and adamantyl; and a monovalent aromatic hydrocarbon group such as phenyl, methylphenyl, naphthyl, methylnaphthyl, anthracenyl, and methylanthracenyl.

[0195] A part or all of the hydrogen atoms possessed by the above-mentioned saturated hydrocarbon groups, unsaturated chain hydrocarbon groups, monocyclic saturated cyclic hydrocarbon groups, monocyclic unsaturated cyclic hydrocarbon groups, polycyclic cyclic hydrocarbon groups, aromatic hydrocarbon groups, alkoxy groups, alkoxycarbonyl groups, etc. may also be substituted, and the substituents include: halogen atoms such as fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, hydroxyl groups, cyano groups, carboxyl groups, nitro groups, amino groups, alkoxy groups, alkoxycarbonyl groups, acyl groups, alkoxycarbonyloxy groups, aryl groups, lactone groups and other aliphatic heterocyclic groups, furyl groups, pyridyl groups and other aromatic heterocyclic groups, etc.

[0196] In the above general formula (II-1), p is preferably 0 or 1, and q1 is preferably 1 or 2.

[0197] In the present invention, the organic source (II) must be a compound containing a cardo structure.

[0198] The organic source (II) containing a cardo structure can improve the dry etching resistance and heat resistance of the metal oxide film-forming composition. Furthermore, the cardo structure introduced into the molecule mitigates intermolecular interactions and improves solubility in organic solvents, thereby enhancing the compatibility of the organic-inorganic composite material and improving film-forming properties during coating film formation. Furthermore, despite the introduction of multiple high-carbon-density condensed carbon rings, the conflicting properties of heat resistance and filling / planarization properties can be achieved.

[0199] The aforementioned organic source (II) preferably has a structural unit represented by formula (II-2) in addition to the structural unit represented by formula (II-1).

[0200] [Chemistry 23]

[0201]

[0202] In the above general formula (II-2), R A is a divalent organic group having 1 to 10 carbon atoms which may be substituted, R B is an optionally substituted hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, R a, p, q1, q2, * are the same as those in (II-1) above.

[0203] By having the structural unit represented by the general formula (II-2), the thermal fluidity of the organic-inorganic composite material can be further improved, and a metal oxide film-forming composition having excellent filling / planarization properties can be provided.

[0204] In the above general formula (II-2), R A Examples of the divalent organic group having 1 to 10 carbon atoms include methylene, alkanediyl, ethanediyl, propanediyl, butanediyl, pentanediyl, hexanediyl, octanediyl, and decanediyl, and arenediyl, such as benzenediyl, methylbenzenediyl, and naphthalenediyl.

[0205] In the above general formula (II-2), R B The monovalent organic group having 1 to 10 carbon atoms represented by , for example, alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, and n-decyl, and aryl groups such as phenyl, tolyl, xylyl, mesityl, and naphthyl.

[0206] Some or all of the hydrogen atoms possessed by the above-mentioned alkanediyl, arenediyl, alkyl, aryl, etc. may be substituted. For example, the substituents may be the same as those in the above-mentioned R a Examples of substituents that the organic groups represented by are also capable of possessing include the same groups.

[0207] When the ratio of the general formula (II-1) is a and the ratio of the general formula (II-2) is b, the organic source (II) components as a whole preferably satisfy the relationship of a + b = 1, preferably 0.2 ≤ b ≤ 0.8, and more preferably 0.3 ≤ b ≤ 0.7. Within this range, the hydroxyl group in formula (II-1) reacts well with the metal compound, thereby suppressing the residual active metal monomers and oligomers. Furthermore, due to the action of X2 in the structural unit represented by formula (II-2), the aggregation of the reaction products due to steric rebound is suppressed, thereby improving stability.

[0208] When the contents of the above-mentioned general formula (II-1) and the above-mentioned general formula (II-2) are within the above-mentioned ranges, various physical properties required for use in forming metal oxide films, such as filling / planarization characteristics, dry etching resistance, and substrate adhesion, can be adjusted within appropriate ranges. To improve dry etching resistance, the metal content in the organic-inorganic composite material must be increased, so a higher content of the above-mentioned general formula (II-1) is preferred. To improve filling / planarization characteristics, a higher content of the above-mentioned general formula (II-2), which exhibits excellent thermal fluidity, is preferred.

[0209] In the above general formula (II-2), the constituent components of X2 are preferably constituted by the following general formula (X-1).

[0210] [Chemistry 24]

[0211]

[0212] In the above formula, * represents a bonding site.

[0213] The general formula (II-2) contains the constituent represented by (X-1) to form an organic-inorganic composite material with excellent thermal fluidity and heat resistance, and can further improve the filling and planarization properties of the metal oxide film-forming composition.

[0214] In the present invention, the organic source (II) having the ratio of the general formula (II-1) to the general formula (II-2) controlled within the above range may be used alone or two or more may be mixed in a desired ratio to prepare an equivalent composition.

[0215] The organic source (II) preferably contains compounds represented by the following general formulas (1) to (3).

[0216] [Chemistry 25]

[0217]

[0218] In the above general formulas (1) and (2), W1 and W2 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 with a hydrocarbon group having 1 to 6 carbon atoms. * represents the bond to the structural unit represented by the above general formulas (II-1) and (II-2), and Y is a group represented by the following general formula (4).

[0219] [Chemistry 26]

[0220]

[0221] In the above general formula (3), Z1 is a group represented by the following general formula (5), and * is a bonding portion with the structural units represented by the above general formula (II-1) and the above general formula (II-2).

[0222] [Chemistry 27]

[0223]

[0224] * indicates atomic bonds.

[0225] [Chemistry 28]

[0226]

[0227] In the above general formula (5), W1, W2, and Y are the same as described above, and n1 is 0 or 1.

[0228] When the organic source (II) is a compound represented by the general formulae (1) to (3), an organic-inorganic composite material having excellent heat resistance can be obtained. Furthermore, since the organic source (II) has superior thermal fluidity compared to high molecular weight compounds, a metal oxide film-forming composition having excellent filling and planarizing properties for patterned substrates can be provided.

[0229] In the general formulae (1) and (2), W1 and W2 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 with a hydrocarbon group having 1 to 6 carbon atoms. From the perspective of fluidity, W1 and W2 are preferably benzene rings.

[0230] In the above general formula (3), Z1 is a group represented by the above general formula (5).

[0231] If it is a compound with such a structure, it has good reactivity with the metal source (I), so an organic-inorganic composite material with a high metal content can be obtained, which can form a metal oxide film with excellent dry etching resistance. In addition, it has a rigid structure containing many aromatic rings, so it can provide a composition for forming a metal oxide film with better heat resistance and etching resistance. Furthermore, due to the effect of the cardo structure introduced into the molecule, the interaction between molecules is relaxed, so the organic-inorganic composite material obtained by the reaction with the metal source (I) has excellent solubility in organic solvents and can form a metal oxide film with excellent film-forming properties. In addition, despite the introduction of multiple condensed carbon rings with high carbon density, it can still take into account the opposite properties of heat resistance and landfill / flattening characteristics.

[0232] Specific examples of the compounds represented by the general formulae (1), (2), and (3) include the following compounds, but are not limited thereto.

[0233] [Chemistry 29]

[0234]

[0235] [Chemistry 30]

[0236]

[0237] The above compounds also include compounds having only the structural unit represented by the general formula (II-2). However, the structural unit of the general formula (II-1) is essential for reaction with the metal source. When the ratio of the general formula (II-1) is a and the ratio of the general formula (II-2) is b, the organic source (II) components as a whole satisfy the relationship of a + b = 1, preferably 0.2 ≤ b ≤ 0.8, and more preferably 0.3 ≤ b ≤ 0.7. In the present invention, the organic source (II) having the ratio of the general formula (II-1) to the general formula (II-2) controlled within the above range can be used alone or two or more can be mixed in the desired ratio to produce an equivalent composition.

[0238] The ratio Mw / Mn (i.e., the degree of dispersion) of the weight average molecular weight Mw and the number average molecular weight Mn in terms of polystyrene of the compound contained in the aforementioned organic source (II) as measured by gel permeation chromatography (GPC) is preferably within the range of 1.00≤Mw / Mn≤1.25 for each compound, and more preferably 1.00≤Mw / Mn≤1.10. By definition, if it is a monomolecular compound, Mw / Mn becomes 1.00, but due to the resolution of GPC, the measured value sometimes exceeds 1.00. Generally, polymers having repeating units are extremely difficult to approach Mw / Mn=1.00 without using a special polymerization method, and will have a distribution of Mw and a value of Mw / Mn exceeding 1. In the present invention, in order to distinguish monomolecular compounds from polymers, an index showing monomolecularity is defined as 1.00≤Mw / Mn≤1.10.

[0239] If the compound has a dispersion within this range, the thermal fluidity of the organic-inorganic composite material will be further improved. When mixed with the metal oxide film forming composition, the fine structure formed on the substrate can be well buried, and a metal oxide film can be formed that is flat across the entire substrate.

[0240] <(A) Synthesis Method of Organic-Inorganic Composite Material>

[0241] The (A) organic-inorganic composite material of the present invention can be manufactured by subjecting a metal source (I) (hereinafter also simply referred to as "metal monomer") containing one or more metal compounds selected from the group consisting of metal compounds represented by the above formula (I-1), hydrolyzates of metal compounds represented by the above formula (I-1), and hydrolysis-condensates of metal compounds represented by the above formula (I-1), and an organic source (II) containing them and a compound having a constituent unit represented by the above formula (II-1) and a cardo structure to a condensation reaction in the absence of a catalyst or in the presence of an acid or base catalyst.

[0242] The acid catalyst may be one or more compounds selected from inorganic acids, aliphatic sulfonic acids, aromatic sulfonic acids, aliphatic carboxylic acids, and aromatic carboxylic acids. Specific examples of the acid catalyst include hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid, formic acid, acetic acid, propionic acid, oxalic acid, malonic acid, maleic acid, fumaric acid, and benzoic acid. The amount of the acid catalyst used is preferably 10 to 10 moles relative to 1 mole of the metal monomer. -6 ~10 mol, more preferably 10 -5 ~7 mol, more preferably 10 -4 ~5 mol.

[0243] The aforementioned base catalysts, for example, methylamine, ethylamine, propylamine, butylamine, ethylenediamine, hexamethylenediamine, dimethylamine, diethylamine, ethylmethylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, cyclohexylamine, dicyclohexylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooctane, diazabicyclocyclononene, diazabicycloundecene, hexamethylenetetramine, aniline, N,N-dimethylaniline, pyridine, N,N-dimethylethanolamine, N,N-diethyl Ethanolamine, N-(β-aminoethyl)ethanolamine, N-methylethanolamine, N-methyldiethanolamine, N-ethylethanolamine, N-n-butylethanolamine, N-tert-butylethanolamine, N-tert-butyldiethanolamine, N,N-dimethylaminopyridine, pyrrole, piperazine, pyrrolidine, piperidine, picoline, tetramethylammonium hydroxide, choline hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, ammonia, lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide, etc. The amount of the base catalyst used is preferably 10 to 1 mol relative to 1 mol of the metal monomer. -6 ~10 mol, more preferably 10 -5 ~7 mol, more preferably 10 -4 ~5 mol.

[0244] When the organic-inorganic composite material is obtained by condensation reaction of the metal source (I) and the organic source (II), the amount of the organic compound is preferably 0.01 to 10 moles, more preferably 0.05 to 7 moles, and even more preferably 0.1 to 5 moles per mole of the metal monomer. An addition amount of 10 moles or less is preferred because it does not impair the stability of the organic-inorganic composite material and a metal oxide film with excellent dry etching resistance can be obtained. Furthermore, an addition amount of 0.01 mole or more is preferred because it provides a metal oxide film with excellent fluidity.

[0245] When the organic-inorganic composite material is obtained by condensation reaction of the metal source (I) and the organic source (II), the amount of organic solvent is preferably 0.01 to 500 moles, more preferably 0.05 to 300 moles, and even more preferably 0.1 to 200 moles per mole of the metal monomer. Adding an amount of 500 moles or less is preferable because the reaction apparatus does not become excessively large, which is economical and does not impair the stability of the organic-inorganic composite material.

[0246] The operation method includes, for example, adding a catalyst and a metal monomer to a solvent containing an organic compound to initiate the condensation reaction. The organic solvent may be added to the catalyst solution, the metal monomer may be pre-diluted with the organic solvent, or both methods may be employed. The reaction temperature is preferably 0-200°C, more preferably 5-150°C. The reaction time is preferably 10 minutes to 24 hours, more preferably 0.5-12 hours. A preferred method is to maintain the temperature at 5-150°C during the dropwise addition of the metal monomer, followed by aging at 20-150°C for 0.5-12 hours.

[0247] Organic solvents capable of dissolving organic compounds are preferably those described in paragraphs

[0091] to

[0092] of Japanese Patent Application Laid-Open No. 2007-199653. Specifically, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and γ-butyrolactone, or mixtures containing one or more of these are preferred.

[0248] The amount of organic solvent capable of dissolving organic compounds added should be adjusted according to the set film thickness of the metal oxide film. It is usually in the range of 100 to 50,000 parts by mass, preferably 500 to 10,000 parts by mass, relative to 100 parts by mass of the organic source (II) containing the compound having the structural unit represented by the above formula (II-1) and a cardo structure.

[0249] The organic solvent that can be added to the catalyst or can dilute the metal monomer is preferably methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, acetonitrile, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, butanediol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, 3-methoxypropane Preferred are methyl acetate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, γ-butyrolactone, acetylacetone, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, methyl pivaloyl acetate, methyl isobutyryl acetate, methyl hexanoyl acetate, methyl lauroyl acetate, 1,2-ethanediol, 1,2-propylene glycol, 1,2-butanediol, 1,2-pentanediol, 2,3-butanediol, 2,3-pentanediol, glycerol, diethylene glycol, hexamethylene glycol, and mixtures thereof.

[0250] Furthermore, the amount of the organic solvent used to dilute the metal monomer, which can be added to the catalyst, is preferably 0.01 to 500 moles, more preferably 0.05 to 300 moles, and even more preferably 0.1 to 200 moles relative to 1 mole of the metal monomer. An amount of 500 moles or less is preferably added because the equipment used for the reaction does not become too large, which is economical and does not impair the stability of the organic-inorganic composite material.

[0251] Afterwards, if necessary, a neutralization reaction of the catalyst is carried out. The amount of acid or base used for neutralization is preferably 0.1 to 2 equivalents relative to the acid or base used as the catalyst. Any substance can be used as long as it can achieve neutrality.

[0252] It is then preferred to remove the alcohol byproduct produced during the condensation reaction from the reaction solution. The temperature at which the reaction solution is heated depends on the organic solvent added and the type of byproduct produced during the reaction, but is preferably 0-200°C, more preferably 10-150°C, and even more preferably 15-150°C. The degree of reduced pressure at this point varies depending on the type of organic solvent and byproduct to be removed, the exhaust system, the condensation system, and the heating temperature, but is preferably below atmospheric pressure, more preferably below 80 kPa absolute, and even more preferably below 50 kPa absolute. While the exact amount of byproduct removed is difficult to determine, it is ideal to remove approximately 80% by mass or more of the byproducts produced.

[0253] If the resulting organic-inorganic composite material is concentrated above a certain concentration, the condensation reaction will proceed further, potentially rendering it insoluble in the organic solvent. Therefore, a solution of moderate concentration is preferred. On the other hand, if the concentration is too dilute, the amount of solvent becomes excessive, so a solution of moderate concentration is economically desirable. The solids concentration in this case is preferably 0.1 to 40% by mass.

[0254] After removing the by-products, the final solvent preferably added to the above reaction solution is butanediol monomethyl ether, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, butanediol monoethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, butanediol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, propylene glycol monobutyl ether, 1-butanol, 2-butanol, 2-methyl-1-propanol , 4-methyl-2-pentanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, diamyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, propylene glycol mono-tert-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, etc.

[0255] By using such an organic-inorganic composite material (A) in the metal oxide film-forming composition of the present invention, a metal oxide film having excellent coating properties compared to conventional metal oxide film-forming compositions and having high filling and planarization properties can be formed.

[0256] <(B) Solvent>

[0257] The (B) organic solvent that can be used in the metal oxide film-forming composition of the present invention is not particularly limited as long as it can dissolve the metal source (I) as the above-mentioned component (A) containing one or more metal compounds selected from the group consisting of metal compounds represented by formula (I-1), hydrolyzates of metal compounds represented by formula (I-1), and hydrolyzed condensates of metal compounds represented by formula (I-1), and the organic source (II) containing these and a compound having a structural unit represented by formula (II-1) and a cardo structure, i.e., an organic-inorganic composite material, and optionally (C) a fluidity promoter, a crosslinking agent, a surfactant, an acid generator, and other additives described later. Specifically, solvents having a boiling point of less than 180°C, such as the solvents described in paragraphs

[0091] to

[0092] of Japanese Patent Application Laid-Open No. 2007-199653, can be used. Among them, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 2-heptanone, cyclopentanone, cyclohexanone, and mixtures of two or more thereof are preferred. The blending amount of the organic solvent is preferably 100 to 50,000 parts, more preferably 150 to 10,000 parts, and even more preferably 200 to 5,000 parts, based on 100 parts of the (A) organic-inorganic composite material.

[0258] Such a metal oxide film-forming composition can well dissolve the (A) organic-inorganic composite material and can be applied by spin coating, thereby forming a metal oxide film having both dry etching resistance and high filling / planarization properties.

[0259] <(C) Flowability Improver>

[0260] The metal oxide film-forming composition of the present invention may contain (C) a fluidity promoter characterized by a weight loss rate of less than 30% between 30°C and 190°C and a weight loss rate of 98% or more between 30°C and 350°C.

[0261] A flowability enhancer with a weight loss rate of less than 30% between 30°C and 190°C and a weight loss rate of 98% or more between 30°C and 350°C is preferred because evaporation during heat treatment is suppressed, thereby maintaining a sufficiently low viscosity, resulting in excellent thermal fluidity and little residual flowability enhancer in the metal oxide film after calcination. In this specification, the weight loss rate is a value determined by TG (thermogravimetric) measurement using a differential thermal balance.

[0262] The upper limit of the temperature range in which the weight loss rate of the fluidity enhancer (C) does not reach 30% is preferably 210° C., and more preferably 230° C. By setting the temperature range in which the weight loss rate of the fluidity enhancer does not reach 30% within this temperature range, the filling and planarization characteristics can be further improved.

[0263] The temperature at which the weight reduction rate of the fluidity promoter (C) reaches 98% or more is preferably 330°C, and particularly preferably 310°C. By setting the temperature at which the weight reduction rate of the fluidity promoter reaches 98% or more within the above temperature range, the residual fluidity promoter in the metal oxide film after calcination can be further reduced.

[0264] By adding the fluidity promoter as described above, the thermal fluidity of the metal oxide film forming composition is improved from the start of heat treatment to the curing due to the cross-linking reaction, so that the filling / planarization characteristics are excellent. On the other hand, the fluidity promoter is reduced due to heat treatment, evaporation, etc., so the etching resistance and optical properties are not damaged.

[0265] In a more preferred embodiment of the fluidity improver, for example, one or more compounds selected from the group consisting of the following general formulae (i) to (iii).

[0266] [Chemistry 31]

[0267]

[0268] Where R 1 Each independently represents a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. 1 W is a phenylene group or a divalent group represented by the following general formula (i-1). 2 、W 3 is a single bond or any divalent group represented by the following general formula (i-2). m1 is an integer from 1 to 10, n 1 An integer from 0 to 5.

[0269] [Chemistry 32]

[0270]

[0271] In the formula, * represents the bonding position, R 10 、R 11 、R 12 、R 13 W is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. 10 、W 11 Each independently represents a single bond or a carbonyl group. 10 、m 11 is an integer from 0 to 10, m 10 +m 11 ≥1.

[0272] [Chemistry 33]

[0273]

[0274] In the formula, * represents the bonding position.

[0275] [Chemistry 34]

[0276]

[0277] Where R 2 Each independently represents a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms. 4 W is a divalent group represented by the following general formula (ii-1). 5 is a single bond or any divalent group represented by the following general formula (ii-2). 2 is an integer from 2 to 10, and n3 is an integer from 0 to 5.

[0278] [Chemistry 35]

[0279]

[0280] In the formula, * represents the bonding position, R 20 、R 21 、R 22 、R 23 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. 20 、m 21 is an integer from 0 to 10, m 20 +m 21 ≥1.

[0281] [Chemistry 36]

[0282]

[0283] In the formula, * represents the bonding position.

[0284] [Chemistry 37]

[0285]

[0286] Where R 3 、R 4 R is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms which may be substituted, and may be bonded to form a ring structure. 5 、R 6 is an organic group having 1 to 10 carbon atoms, R 5 W is a group containing an aromatic ring or a divalent group represented by the following general formula (iii-1). 6 、W 7It is a single bond or any divalent group represented by the following general formula (iii-2), and at least one of them is a divalent group represented by any one of the formulas (iii-2).

[0287] [Chemistry 38]

[0288]

[0289] Where * represents the bonding position, W 30 It is an organic group having 1 to 4 carbon atoms.

[0290] [Chemistry 39]

[0291]

[0292] In the formula, * represents the bonding position.

[0293] In the above general formula (i), R 1 Each is independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms.

[0294] Here, in the present invention, the "organic group" is a group containing at least one carbon atom, further containing hydrogen, and may also contain nitrogen, oxygen, sulfur, silicon, halogen atoms, etc.

[0295] R 1 It can be a single type or a mixture of multiple types. 1 More specifically, examples include a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, a norbornyl group, an adamantyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furyl group, and a 2-tetrahydrofuryl group. Among these, a hydrogen atom is more preferred.

[0296] W 1 W is a phenylene group or a divalent group represented by the above general formula (i-1). 2 、W 3 is a single bond or any divalent group represented by the above general formula (i-2). m1 is an integer from 1 to 10, n 1 Each independently represents an integer from 0 to 5.

[0297] R 10 、R 11 、R 12 、R 13It is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms. More specifically, it includes a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, a norbornyl group, an adamantyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furyl group, and a 2-tetrahydrofuryl group. Among these, a hydrogen atom and a methyl group are preferred, and a hydrogen atom is even more desirable.

[0298] W 10 、W 11 Each independently represents a single bond or a carbonyl group. 10 、m 11 is an integer from 0 to 10, m 10 +m 11 ≥1.

[0299] R 2 It can be a single type or a mixture of multiple types. 2 More specifically, examples include a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, a norbornyl group, an adamantyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furyl group, and a 2-tetrahydrofuryl group. Among these, a hydrogen atom is more preferred.

[0300] W 4 W is a divalent group represented by the above general formula (ii-1). 5 is a single bond or any divalent group represented by the above general formula (ii-2). 2 is an integer from 2 to 10, and n3 is an integer from 0 to 5.

[0301] R 20 、R 21 、R 22 、R 23 , more specifically, for example, a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, a n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, a norbornyl group, an adamantyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furyl group, and a 2-tetrahydrofuryl group. Among them, a hydrogen atom and a methyl group are more preferred, and a hydrogen atom is even more desirable.

[0302] m 20 、m 21 is an integer from 0 to 10, m 20 +m 21 ≥1.

[0303] R 3 、R 4 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms which may be substituted, and may also be bonded to form a cyclic structure. More specifically, examples include a hydrogen atom, a hydroxyl group, a methyl group, an ethyl group, a vinyl group, a 2,2,2-trifluoroethyl group, a propyl group, an isopropyl group, an allyl group, a n-butyl group, a sec-butyl group, a tert-butyl group, an isobutyl group, a pentyl group, a cyclopentyl group, a hexyl group, a cyclohexyl group, a cyclohexenyl group, a decyl group, a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, a tert-butoxy group, an isobutoxy group, a norbornyl group, an adamantyl group, a phenyl group, a tolyl group, a xylyl group, a naphthyl group, a benzyl group, a 2-furyl group, and a 2-tetrahydrofuryl group. Among these, a hydrogen atom is more desirable.

[0304] R 6 is an organic group having 1 to 10 carbon atoms. 5 is an organic group having 1 to 10 carbon atoms and is a group containing an aromatic ring or one of the divalent groups represented by the general formula (iii-1). Examples of the organic group having 1 to 10 carbon atoms include the above R 3 、R 4 Exemplary groups.

[0305] W 6 、W 7 It is a single bond or any divalent group represented by the above general formula (iii-2), and at least one of them is a divalent group represented by any one of the above general formula (iii-2).

[0306] W 30 It is an organic group having 1 to 4 carbon atoms. More specifically, it includes methylene, ethylene, propylene, butylene, trimethylene, and tetramethylene. Among them, ethylene is more preferred.

[0307] More specific examples of the compound represented by the general formula (i) include the following, but are not limited thereto.

[0308] [Chemistry 40]

[0309]

[0310] More specific examples of the compound represented by the general formula (ii) include the following, but are not limited thereto.

[0311] [Chemistry 41]

[0312]

[0313] More specific examples of the compound represented by the general formula (iii) include, but are not limited to, the following.

[0314] [Chemistry 42]

[0315]

[0316] If the improvement in the stability of the organic-inorganic composite material in the metal oxide film forming composition, the film forming properties, the filling / planarization performance of the substrate, etc. are comprehensively considered, it is ideal that the (C) fluidity promoter used in the metal oxide film forming composition of the present invention is an aromatic compound having a benzyl group or a benzoyl group, especially the aromatic compound as follows.

[0317] (i) (Poly)ethylene glycol dibenzoate

[0318] (ii) (Poly)ethylene glycol dibenzyl ether

[0319] (iii) (Poly)propylene glycol dibenzyl ether

[0320] (iv) (Poly)butylene glycol dibenzyl ether

[0321] (v) linear aliphatic dicarboxylic acid dibenzyl ester

[0322] (vi) (Poly)ethylene glycol monobenzyl ether

[0323] (vii) (Poly)phenylene ether

[0324] [Chemistry 43]

[0325]

[0326] In the above formula, n is an integer within the range of molecular weight of 500 or less, and is applicable only to this formula.

[0327] The (C) fluidity promoter used in the metal oxide film forming composition of the present invention has a structure having both a hydrophobic portion composed of an aromatic ring and a hydrophilic portion composed of a (C-1) structure. Therefore, it has excellent compatibility with organic-inorganic composite materials and can improve the fluidity of the composition without impairing film forming properties and storage stability.

[0328] [Chemistry 44]

[0329]

[0330] In the formula, * represents a bonding position, and W is an organic group having 1 to 4 carbon atoms.

[0331] (C) The amount of the fluidity enhancer added is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 30 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the organic-inorganic composite material. When the amount of the fluidity enhancer added is 0.1% by mass or greater, the fluidity and stability of the metal oxide film-forming composition can be sufficiently improved. When the content of the fluidity enhancer is 0.1 to 50 parts by mass relative to the organic-inorganic composite material, the stabilization effect and the effect of improving the thermal fluidity of the metal oxide film are sufficient, and the resulting coating film has good film-forming properties and dry etching resistance.

[0332] The (C) fluidity improver may be one of the aromatic compounds described above, or two or more of them may be used in combination.

[0333] <(D) Metal Oxide Nanoparticles>

[0334] The metal oxide film-forming composition of the present invention may further contain (D) metal oxide nanoparticles having an average primary particle size of 100 nm or less.

[0335] The type of metal oxide nanoparticles is not particularly limited, and known metal oxide nanoparticles can be used. In addition, the metal of the metal oxide nanoparticles also includes semimetals such as B, Si, Ge, As, Sb, and Te.

[0336] The average primary particle size of the metal oxide nanoparticles is preferably less than 100 nm, more preferably less than 50 nm, and more preferably less than 20 nm, taking into account the properties imparted by the metal oxide film forming composition described later. The lower limit of the average primary particle size is not particularly limited and may be, for example, 1 nm. The average primary particle size of the metal oxide nanoparticles is a value obtained by measuring the diameter of any 100 particles using a transmission electron microscope (TEM) and calculating the arithmetic mean of the 100 diameters. In addition, when the shape of the particle is not spherical, the longest side is used as the diameter.

[0337] Metal oxide nanoparticles are preferably oxide particles containing atoms such as Be, Mg, Ca, Sr, Ba, Sc, Y, La, Ce, Gd, Tb, Dy, Yb, Lu, Ti, Zr, Hf, Nb, Ta, Mo, W, Zn, B, Al, In, Ga, Si, Ge, Sn, Pb, Sb, Bi, and Te. They can also be composite oxides composed of any combination of metals. Specifically, examples include titanium oxide, titanium composite oxide, zinc oxide, zirconium oxide, hafnium oxide, tin oxide, indium / tin oxide, antimony / tin oxide, and tungsten oxide. They can be crystalline, and there are no particular restrictions on crystallization. For example, titanium dioxide can be rutile, anatase, or brookite. These metal oxide nanoparticles can also be surface-treated with organic materials to impart dispersion stability.

[0338] (D) The metal oxide nanoparticles are preferably at least one selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and tungsten oxide nanoparticles.

[0339] Commercially available metal oxide nanoparticles can be used, for example, ZrO 2 nanoparticles (5 nm core, 915505, Sigma-Aldrich Corp).

[0340] The metal oxide nanoparticles may be used alone or in combination of two or more.

[0341] The content of the metal oxide particles in the metal oxide film-forming composition is preferably 0 to 50 parts by mass, more preferably 5 to 30 parts by mass, relative to 100 parts by mass of component (A).

[0342] By using such metal oxide nanoparticles, the metal content in the composition can be easily increased, further improving the dry etching resistance of the metal oxide film-forming composition. Furthermore, by incorporating metal oxide nanoparticles at any ratio into the metal oxide film-forming composition, the refractive index and light transmittance of the resulting metal oxide film can be adjusted.

[0343] <Other ingredients>

[0344] [Crosslinking agent]

[0345] Furthermore, in the metal oxide film forming composition of the present invention, a crosslinking agent may be added in order to improve the curability and to further suppress cross-mixing with the upper film. There are no special restrictions on the crosslinking agent, and various well-known crosslinking agents can be widely used. For example, there are hydroxymethyl or alkoxymethyl type crosslinking agents of polynuclear phenols (polynuclear phenol crosslinking agents), 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. The amount of the crosslinking agent added is preferably 1 to 100 parts, more preferably 5 to 50 parts, relative to the aforementioned (A) organic-inorganic composite material.

[0346] Specific examples of the melamine-based crosslinking agent include hexamethoxymethylated melamine, hexabutoxymethylated melamine, alkoxy and / or hydroxyl-substituted melamines thereof, and partially self-condensed melamines thereof.

[0347] Specific examples of the glycoluril-based crosslinking agent include tetramethoxymethylated glycoluril, tetrabutoxymethylated glycoluril, alkoxy and / or hydroxyl-substituted products thereof, and partially self-condensed products thereof.

[0348] Specific examples of the benzoguanamine-based crosslinking agent include tetramethoxymethylated benzoguanamine, tetrabutoxymethylated benzoguanamine, alkoxy and / or hydroxyl-substituted products thereof, and partially self-condensed products thereof.

[0349] Specific examples of the urea crosslinking agent include dimethoxymethylated dimethoxyethylene urea, alkoxy and / or hydroxyl substituted products thereof, and partial self-condensation products thereof.

[0350] Specific examples of β-hydroxyalkylamide crosslinking agents include N,N,N',N'-tetrakis(2-hydroxyethyl)adipamide. Specific examples of isocyanurate crosslinking agents include triglycidyl isocyanurate and triallyl isocyanurate.

[0351] Specific examples of the aziridine-based crosslinking agent include 4,4′-bis(ethyleneiminocarbonylamino)diphenylmethane and 2,2-bishydroxymethylbutanol-tris[3-(1-aziridinyl)propionate].

[0352] Oxazoline crosslinking agents include, for example, 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-isopropenyloxazoline copolymers.

[0353] Specific examples of the epoxy crosslinking agent include diglycidyl ether, ethylene glycol diglycidyl ether, 1,4-butanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, poly(glycidyl methacrylate), trimethylolethane triglycidyl ether, trimethylolpropane triglycidyl ether, and pentaerythritol tetraglycidyl ether.

[0354] The polynuclear phenol-based crosslinking agent is specifically, for example, a compound represented by the following general formula (XL-1): Here, the following R3 applies only to the following general formula (XL-1).

[0355] [Chemistry 45]

[0356]

[0357] In the formula, Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. R3 is a hydrogen atom or an alkyl group having 1 to 20 carbon atoms. q is an integer of 1 to 5.

[0358] Q is a single bond or a q-valent hydrocarbon group having 1 to 20 carbon atoms. q is an integer from 1 to 5, preferably 2 or 3. Specifically, Q is a group 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, or eicosane. R3 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, preferably a hydrogen atom or a methyl group.

[0359] Specific examples of compounds represented by the general formula (XL-1) include the following compounds. Among these, trisphenolmethane, trisphenolethane, 1,1,1-tris(4-hydroxyphenyl)ethane, and hexamethoxymethylated tris(4-hydroxyphenyl)-1-ethyl-4-isopropylbenzene are preferred from the perspective of improving the curability and thickness uniformity of the organic film. R3 is the same as described above.

[0360] [Chemistry 46]

[0361]

[0362] [Chemistry 47]

[0363]

[0364] [Surfactant]

[0365] The metal oxide film-forming composition of the present invention may contain a surfactant to improve the coating properties during spin coating. Examples of the surfactant include those described in

[0142] to

[0147] of JP-A-2009-269953. The amount of the surfactant added is preferably 0.01 to 10 parts by mass, more preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the organic-inorganic composite material (A).

[0366] [Acid generator]

[0367] An acid generator may be added to the metal oxide film-forming composition of the present invention to further promote the curing reaction. Acid generators include those that generate acid by thermal decomposition and those that generate acid by light irradiation; both can be added. Specifically, the materials described in paragraphs

[0061] to

[0085] of JP-A-2007-199653 may be added, but are not limited thereto.

[0368] The acid generators may be used alone or in combination. The amount of the acid generator added is preferably 0.05 to 50 parts, more preferably 0.1 to 10 parts, relative to 100 parts by mass of the organic-inorganic composite material (A).

[0369] [Plasticizer]

[0370] Furthermore, in order to further enhance the planarization / landfilling characteristics, a plasticizer may be added to the metal oxide film-forming composition of the present invention. There are no particular restrictions on the plasticizer, and plasticizers of various well-known systems can be widely used. For example, low molecular weight compounds such as phthalates, adipic acid esters, phosphates, trimellitic acid esters, and citrates, polyethers, polyesters, and polymers such as polyacetal polymers described in Japanese Patent Application Laid-Open No. 2013-253227 are included. The amount of the plasticizer added is preferably 1 to 100 parts, more preferably 5 to 30 parts, relative to 100 parts by mass of the aforementioned (A) organic-inorganic composite material. Furthermore, the plasticizer is different from the aforementioned (C) component.

[0371] Furthermore, in the metal oxide film-forming composition of the present invention, an additive that imparts filling / planarizing properties similar to a plasticizer is preferably used, such as a liquid additive having a polyethylene glycol or polypropylene glycol structure, or a pyrolyzable polymer having a weight loss rate of 40% or more between 30°C and 250°C and a weight-average molecular weight of 300 to 200,000. This pyrolyzable polymer preferably contains repeating units having an acetal structure represented by the following general formulas (DP1) and (DP1a). Here, R6 is applicable only to the following general formula (DP1).

[0372] [Chemistry 48]

[0373]

[0374] In the formula, R6 is a hydrogen atom or an optionally substituted saturated or unsaturated monovalent organic group having 1 to 30 carbon atoms. Y is a saturated or unsaturated divalent organic group having 2 to 30 carbon atoms.

[0375] [Chemistry 49]

[0376]

[0377] Where R 6a Y is an alkyl group having 1 to 4 carbon atoms. a It is a saturated or unsaturated divalent hydrocarbon group having 4 to 10 carbon atoms, and may have an ether bond. n represents the average number of repeating units and is 3 to 500.

[0378] [Dispersant]

[0379] The metal oxide film forming composition of the present invention can be added with a general dispersant. There is no particular limitation on the type of dispersant used, and known dispersants can be used. For example: low molecular dispersants such as alkylamines, alkylthiols, alkyl glycols, and phosphates, polymer dispersants with various functional groups, silane coupling agents, etc. In addition, polymer dispersants, for example: styrene resins (styrene-(meth) acrylic acid copolymers, styrene-maleic anhydride copolymers, etc.), acrylic resins ((meth) acrylate-(meth) acrylic acid copolymers, poly(meth) acrylic acid, etc. (meth) acrylic resins, etc.), water-soluble carbamate resins, water-soluble acrylic carbamate 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, hydroxyethyl cellulose, etc. The dispersant may be a cellulose ether such as hydroxyalkyl cellulose (e.g., hydroxypropyl cellulose, carboxyalkyl cellulose such as carboxymethyl cellulose), polyvinyl alcohol, polyalkylene glycol (e.g., liquid polyethylene glycol, polypropylene glycol), natural polymers (e.g., polysaccharides such as gelatin, casein, dextrin, and gum arabic), polyethylene sulfonic acid or its salts, polystyrene sulfonic acid or its salts, formalin condensates of naphthalenesulfonic acid, and nitrogen-containing polymers [e.g., polymers having amino groups such as polyalkyleneimines (e.g., polyethyleneimine), polyvinyl pyrrolidone, polyallylamine, and polyether polyamines (e.g., polyoxyethylene polyamine)]. The amount of the dispersant to be added is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 30 parts by mass, and even more preferably 1 to 10 parts by mass, relative to 100 parts by mass of the organic-inorganic composite material (A).

[0380] By adding the above-mentioned dispersant, the stability of the above-mentioned (A) organic-inorganic composite material can be further improved.

[0381] The metal oxide film-forming composition of the present invention can be used alone or in combination of two or more. The metal oxide film-forming composition can be used as a metal oxide film material or a planarizing material for semiconductor device manufacturing.

[0382] As described above, if the metal oxide film forming composition of the present invention is a composition having a reaction product of a metal compound and a specific compound, it can suppress the occurrence of poor coating due to poor compatibility between the metal source and the organic source, and poor porosity in the filling film caused by thermal shrinkage of the metal compound during heat treatment. Compared with the known metal oxide film forming composition that is a mixture of a metal compound and a resin, it can exhibit excellent coating properties and filling / planarization characteristics.

[0383] (Pattern Formation Method)

[0384] Furthermore, the present invention provides a pattern forming method using such a metal oxide film-forming composition and utilizing a two-layer resist process, wherein a pattern forming method is provided, wherein the method is a method for forming a pattern on a processed substrate, comprising the following steps:

[0385] (I-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0386] (I-2) forming a resist upper layer film on the aforementioned metal oxide film using a photoresist material,

[0387] (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,

[0388] (I-4) using the patterned resist upper layer film as a mask to transfer the pattern to the metal oxide film by dry etching, and

[0389] (I-5) 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.

[0390] The resist upper layer film in the above-mentioned two-layer resist treatment shows resistance to etching by chlorine-based gas. Therefore, in the above-mentioned two-layer resist treatment, the dry etching of the metal oxide film performed using the resist upper layer film as a mask is preferably performed using an etching gas mainly composed of chlorine-based gas.

[0391] Furthermore, in the present invention, as a pattern forming method using such a metal oxide film-forming composition and utilizing a three-layer resist process,

[0392] A method for forming a pattern on a processed substrate is provided, comprising the following steps:

[0393] (II-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0394] (II-2) forming a resist interlayer film on the metal oxide film using a resist interlayer film material,

[0395] (II-3) forming a resist upper layer film on the resist intermediate film using a photoresist material,

[0396] (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,

[0397] (II-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film by dry etching,

[0398] (II-6) using the resist intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0399] (II-7) 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.

[0400] For an example of 3-layer resist processing, if using Figure 1 Specifically disclosed is as follows. 3 layers of resist processing, such as Figure 1 As shown in (A), a metal oxide film (metal-containing anti-etching lower layer film) 3 is formed on a processed layer 2 stacked on a processed substrate 1 using the metal oxide film forming material of the present invention, and then an anti-etching intermediate film 4 containing silicon atoms is formed, and an anti-etching upper layer film 5 is formed thereon.

[0401] Secondly, if Figure 1 As shown in (B), the portion (exposed portion) 6 of the resist upper film 5 is exposed, and PEB and development are performed to form a resist upper film pattern 5a ( Figure 1 (C)). The obtained resist upper film pattern 5a is used as a mask, and the resist intermediate film 4 containing silicon atoms is etched using CF series gas to form a resist intermediate film pattern 4a containing silicon atoms ( Figure 1 (D)). After removing the resist upper film pattern 5a, the obtained silicon-containing resist intermediate film pattern 4a is used as a mask to perform plasma etching on the metal oxide film 3 with a chlorine-based gas to form a metal oxide film pattern (metal-containing resist lower film pattern) 3a ( Figure 1 (E)). After removing the silicon-containing resist intermediate film pattern 4a, the metal oxide film pattern 3a is used as a mask to etch the processed layer 2 to form a pattern 2a ( Figure 1 (F)).

[0402] The silicon-containing resist intermediate film in the above-mentioned three-layer resist treatment shows resistance to etching with chlorine-based gas or oxygen-based gas. Therefore, in the above-mentioned three-layer resist treatment, the dry etching of the metal oxide film performed using the silicon-containing resist intermediate film as a mask is preferably carried out using an etching gas mainly composed of chlorine-based gas or oxygen-based gas.

[0403] A polysiloxane-based interlayer is also preferred for the silicon-containing resist interlayer used in the three-layer resist treatment. Imparting an antireflection effect to the silicon-containing resist interlayer can suppress reflection. In particular, for 193nm exposure, using an organic film containing a material with a high number of aromatic groups and high substrate etch selectivity increases the k value and substrate reflection. However, by imparting an absorber with an appropriate k value for the silicon-containing resist interlayer, reflection can be suppressed, reducing substrate reflection to less than 0.5%. For 248nm and 157nm exposure, polysiloxanes with pendant anthracene groups that are crosslinked by acid or heat are preferred. For 193nm exposure, polysiloxanes with pendant phenyl groups or light-absorbing groups with silicon-silicon bonds that are crosslinked by acid or heat are preferred.

[0404] Furthermore, the present invention provides a pattern forming method using a four-layer resist process using such a metal oxide film-forming composition, which is characterized by comprising the following steps: forming a metal oxide film on a substrate to be processed using the metal oxide film-forming composition; forming a silicon-containing resist interlayer film using a silicon-containing resist interlayer material on the metal oxide film; forming an organic antireflective film (BARC) or a bonding film on the silicon-containing resist interlayer film; and forming a photoresist on the BARC. The material forms a resist upper film, the resist upper film is pattern-exposed, and then developed with a developer to form a pattern on the resist upper film, the patterned resist upper film is used as a mask, and the pattern is transferred to the BARC or the adhesion film and the silicon-containing resist intermediate film by dry etching, the silicon-containing resist intermediate film with the transferred pattern 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 processed substrate is processed to form a pattern on the processed substrate.

[0405] Furthermore, an inorganic hard mask may be formed instead of forming a silicon-containing resist intermediate film. In this case, a metal oxide film is formed at least on the workpiece using the metal oxide film forming composition of the present invention, an inorganic hard mask selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film is formed on the metal oxide film, a photoresist composition is formed on the inorganic hard mask, a circuit pattern is formed on the resist upper film, the inorganic hard mask is etched using the patterned resist upper film as a mask, the metal oxide film is etched using the patterned inorganic hard mask as a mask, and the workpiece is etched using the patterned metal oxide film as a mask to form a pattern on the workpiece, thereby forming a circuit pattern of a semiconductor device on the substrate.

[0406] Furthermore, the present invention provides a method for forming a pattern on a processed substrate, comprising the following steps:

[0407] (III-1) After applying the metal oxide film-forming composition on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0408] (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,

[0409] (III-3) forming an organic thin film on the aforementioned inorganic hard mask intermediate film,

[0410] (III-4) forming a resist upper layer film on the aforementioned organic thin film using a photoresist material,

[0411] (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,

[0412] (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,

[0413] (III-7) using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0414] (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.

[0415] In this case, the inorganic hard mask is preferably formed by CVD or ALD.

[0416] If the inorganic hard mask is formed by the CVD method or the ALD method, a fine pattern can be formed on the workpiece with higher precision.

[0417] As described above, when forming an inorganic hard mask on a metal oxide film, a silicon oxide film, a silicon nitride film, or a silicon oxynitride film (SiON film) can be formed using CVD, ALD, or the like. For example, methods for forming a silicon nitride film are described in Japanese Patent Application Publication No. 2002-334869 and International Publication No. 2004 / 066377. The inorganic hard mask preferably has a thickness of 5 to 200 nm, more preferably 10 to 100 nm. Furthermore, it is most desirable to use a SiON film, which is highly effective as an antireflective film, as the inorganic hard mask. The substrate temperature during SiON film formation is 300 to 500°C, so the metal oxide film must be able to withstand temperatures of 300 to 500°C. The metal oxide film-forming composition used in the present invention has high heat resistance and can withstand temperatures of 300 to 500°C. Therefore, a combination of an inorganic hard mask formed using CVD or ALD and a metal oxide film formed using spin coating is possible.

[0418] As mentioned above, a photoresist film can be formed on an inorganic hard mask as the resist upper layer. Alternatively, an organic antireflective film (BARC) or a bonding film can be formed on the inorganic hard mask by spin coating, and the photoresist film formed thereon. In particular, when using a SiON film as the inorganic hard mask, the dual antireflective film of the SiON film and the BARC can suppress reflections even during immersion exposure at a high NA exceeding 1.0. Another benefit of forming a BARC is that it reduces the tailing of the photoresist pattern directly on the SiON film.

[0419] The resist top layer of the multilayer resist treatment can be either positive or negative-working, and can be made of the same conventional photoresist composition. After spin coating, the photoresist composition is prebaked, preferably at 60-180°C for 10-300 seconds. Exposure, post-exposure baking (PEB), and development are then performed according to conventional methods to obtain a resist pattern. The thickness of the resist top layer is not particularly limited, but is preferably 30-500 nm, more preferably 50-400 nm.

[0420] Examples of the exposure light include high-energy rays having a wavelength of 300 nm or less, specifically, excimer lasers of 248 nm, 193 nm, and 157 nm, soft X-rays of 3 to 20 nm, electron beams, and X-rays.

[0421] When the above method is used as a method for forming a circuit pattern on the resist upper layer film, a fine pattern can be formed on a workpiece with higher precision.

[0422] The patterning method of the resist upper layer film is preferably to form the pattern by optical lithography with a wavelength of 5 nm to 300 nm, direct writing using an electron beam, nano-stamping, or a combination thereof.

[0423] Furthermore, the development method of the above-mentioned pattern forming method is preferably alkali development or development using an organic solvent. Specifically, in the above-mentioned pattern forming method, exposure and development are performed to form a circuit pattern on the resist upper layer film, and the above-mentioned development is preferably alkali development or development using an organic solvent.

[0424] When alkali development or development using an organic solvent is used as the development method, a fine pattern can be formed on the workpiece with higher precision.

[0425] The resulting resist pattern is then used as a mask for etching. Etching of the silicon-containing resist interlayer and inorganic hard mask in the three-layer resist process is performed using a fluorocarbon-based gas, with the upper resist pattern serving as a mask. This forms a silicon-containing resist interlayer pattern and an inorganic hard mask pattern.

[0426] Next, the obtained silicon-containing resist interlayer pattern and inorganic hard mask pattern are used as masks to perform etching of the metal oxide film. Chlorine-based gas or oxygen-based gas is preferably used for etching of the metal oxide film.

[0427] The workpiece can then be etched using conventional methods. For example, if the workpiece is a SiO2, SiN, or silicon dioxide-based low-k dielectric film, etching can be performed primarily using a Teflon-based gas. When etching a substrate with a Teflon-based gas, the silicon-containing resist interlayer pattern in the three-layer resist process is stripped away simultaneously with the substrate processing.

[0428] The metal oxide film obtained using the metal oxide film-forming composition of the present invention has a characteristic of being excellent in etching resistance when etching these workpieces.

[0429] Furthermore, the workpiece (substrate to be processed) is not particularly limited, and substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al, as well as substrates on which a workpiece layer has been formed, can be used. The workpiece layer can be made of various low-k films and barrier films such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, typically with a thickness of 50 to 10,000 nm, particularly 100 to 5,000 nm. Furthermore, when forming the workpiece layer, the substrate and the workpiece layer are made of different materials.

[0430] The object to be processed is preferably a semiconductor device substrate, or a semiconductor device substrate on which a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxide carbide film, and a metal oxide nitride film are formed. More specifically, without particular limitation, substrates such as Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, Al, etc., and a substrate on which the above-mentioned metal films have been formed as a processed layer, etc. can be used.

[0431] The processed layer can be made of various low-k films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, as well as barrier films. Typically, thicknesses of 50 to 10,000 nm, particularly 100 to 5,000 nm, can be achieved. Furthermore, when forming the processed layer, the substrate and the processed layer must be made of different materials.

[0432] In addition, the metal constituting the workpiece is preferably silicon, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, aluminum, indium, gallium, arsenic, palladium, iron, tantalum, iridium, cobalt, manganese, molybdenum, ruthenium, or an alloy thereof.

[0433] As the metal mentioned above, the following metals can be used. Thus, when the organic film-forming composition of the present invention is used to form a pattern, the pattern of the upper photoresist layer can be transferred and formed on the workpiece with high precision.

[0434] The pattern forming method of the present invention preferably uses a substrate to be processed having a structure or height difference of 30 nm or more. As mentioned above, the metal oxide film forming composition of the present invention has excellent filling / flattening properties, so even if the substrate to be processed has a structure or height difference (concave and convex) of 30 nm or more, a flat hardened film can still be formed. The height of the structure or height difference of the above-mentioned substrate to be processed is preferably 30 nm or more, more preferably 50 nm or more, and even more preferably 100 nm or more. In the processing method of a substrate with a height difference pattern having the above-mentioned height, by forming the metal oxide film forming composition of the present invention into a film and performing filling / flattening, the film thickness of the resist intermediate film and the resist upper film formed thereafter can be uniform, so it is easy to ensure the exposure depth tolerance (DOF) during optical lithography, which is very ideal.

[0435] Furthermore, the present invention provides a method for forming a pattern on a substrate using a tone reversal pattern forming method using such a metal oxide film-forming composition, comprising the following steps:

[0436] (IV-1) forming a resist underlayer film on a substrate to be processed,

[0437] (IV-2) forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film and an organic thin film on the resist underlayer film,

[0438] (IV-3) forming a resist upper layer film using a photoresist material on the aforementioned resist interlayer film or the combination of the inorganic hard mask interlayer film and the organic thin film,

[0439] (IV-4) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film,

[0440] (IV-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching,

[0441] (IV-6) using the resist intermediate film or inorganic hard mask intermediate film to which the pattern has been transferred as a mask, and transferring the pattern to the resist underlayer film by dry etching,

[0442] (IV-7) applying the metal oxide film-forming composition onto the patterned resist underlayer film, and then covering the metal oxide film by heat treatment to fill the space between the resist underlayer film patterns with the metal oxide film.

[0443] (IV-8) chemically stripping or dry etching the metal oxide film covering the patterned resist underlayer film to expose the top surface of the patterned resist underlayer film,

[0444] (IV-9) The resist intermediate film or hard mask intermediate film remaining on the top surface of the resist underlayer film is removed by dry etching.

[0445] (IV-10) removing the patterned resist underlayer film exposed on the surface by dry etching to form a reverse pattern of the original pattern on the metal oxide film,

[0446] (IV-11) The substrate to be processed is processed using the metal oxide film on which the reverse pattern has been formed as a mask to form a reversed pattern (tone reversed pattern) on the substrate to be processed.

[0447] For an example of forming a tone reversal pattern, use Figure 2 The details are as follows. Figure 2 As shown in (G), after forming a resist lower layer film 7 composed of a coating type organic lower layer film material on the processed layer 2 stacked on the processed substrate 1, a resist intermediate film 4 containing silicon atoms is formed, and a resist upper layer film 5 is formed thereon.

[0448] Secondly, if Figure 2 As shown in (H), the portion (exposed portion) 6 of the resist upper film 5 is exposed, and PEB and development are performed to form a resist upper film pattern 5a ( Figure 2 (I)). The obtained resist upper film pattern 5a is used as a mask, and the resist intermediate film 4 containing silicon atoms is etched using CF series gas to form a resist intermediate film pattern 4a containing silicon atoms ( Figure 2 (J)). After the resist upper film pattern 5a is removed, the obtained silicon-containing resist intermediate film pattern 4a is used as a mask to perform oxygen plasma etching on the resist lower film 7 composed of the coating type organic lower film material to form a resist lower film pattern 7a composed of the coating type organic lower film material ( Figure 2 (K)).

[0449] After coating the metal oxide film-forming composition of the present invention on the resist underlayer film pattern 7a composed of the coating type organic underlayer film material, a metal oxide film 8 is formed by heat treatment, and the space between the resist underlayer film patterns 7a composed of the coating type organic underlayer film material is filled with the metal oxide film ( Figure 2 Then, the metal oxide film 8 covering the resist lower film pattern 7a composed of the coating type organic lower film material is etched back by chemical stripping or dry etching to expose the top surface of the resist lower film pattern 7a composed of the coating type organic lower film material ( Figure 2 Then, the silicon-atom-containing resist intermediate film pattern 4a remaining on the top surface of the resist lower film pattern 7a composed of the coating type organic lower film material is removed by dry etching ( Figure 2 Then, the resist lower film pattern 7a composed of the coating type organic lower film material is removed by dry etching, and a reverse pattern of the original pattern is formed on the metal oxide film (forming a metal oxide film pattern 8a formed by reversing the resist lower film pattern) step ( Figure 2 After that, the metal oxide film pattern 8a formed by reversing the resist lower film pattern is used as a mask to process the aforementioned substrate to form a tone-reversed pattern ( Figure 2 (P)).

[0450] As described above, when forming an organic resist underlayer film on a substrate to be processed, the organic resist underlayer film can be formed by a method using a coating type organic underlayer film material, a CVD method, an ALD method, or the like. Coating type organic underlayer film materials are disclosed in, for example, Japanese Patent Application Laid-Open No. 2012-1687, Japanese Patent Application Laid-Open No. 2012-77295, Japanese Patent Application Laid-Open No. 2004-264710, Japanese Patent Application Laid-Open No. 2005-043471, Japanese Patent Application Laid-Open No. 2005-250434, Japanese Patent Application Laid-Open No. 2007-293294, Japanese Patent Application Laid-Open No. 2008-65303. Japanese Patent Application Publication No. 2004-205685, Japanese Patent Application Publication No. 2007-171895, Japanese Patent Application Publication No. 2009-14816, Japanese Patent Application Publication No. 2007-199653, Japanese Patent Application Publication No. 2008-274250, Japanese Patent Application Publication No. 2010-122656, Japanese Patent Application Publication No. 2012-214720, Japanese Patent Application Publication No. 2 014-29435, International Publication No. WO2012 / 077640, International Publication No. WO2010 / 147155, International Publication No. WO2012 / 077640, International Publication No. WO2010 / 147155, International Publication No. WO2012 / 176767, Japanese Patent Application Laid-Open No. 2005-128509, Japanese Patent Application Laid-Open No. Resins and compositions disclosed in 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-2019-44022, and the like.

[0451] In the tone-reversal patterning method, after the metal oxide film-forming composition is coated on the obtained resist underlayer film pattern, the metal oxide film is preferably removed by dry etching using a chlorine-based gas or an oxygen-based gas to expose the top surface of the resist underlayer film pattern. Subsequently, the resist interlayer film or hard mask interlayer film remaining on the resist underlayer film is removed by dry etching using a fluorocarbon-based gas, and the exposed surface of the resist underlayer film pattern is removed by dry etching using an oxygen-based gas, thereby forming a metal oxide film pattern.

[0452] In the above-mentioned tone reversal pattern forming method, the resist lower film pattern preferably has a structure or height difference of 30nm or more. As mentioned above, the metal oxide film forming composition of the present invention has excellent filling / flattening properties, so even if the processed film has a structure or height difference (concave and convex) of 30nm or more, a flat hardened film can still be formed. The height of the structure or height difference of the above-mentioned resist lower film pattern is preferably 30nm or more, more preferably 50nm or more, and more preferably 100nm or more. In the method of reversing the resist lower film pattern having the above-mentioned height pattern, by forming the metal oxide film forming composition of the present invention into a film and performing filling / flattening, the pattern can be reversed / transferred with high precision, which is very ideal. Compared with the resist underlayer film using the known coating type organic underlayer material, the dry etching resistance using fluorocarbon gas is excellent. Therefore, by reversing the resist underlayer film pattern with the above-mentioned metal oxide film forming composition, the desired resist pattern can be formed on the processed film with high precision.

[0453] (Metal Oxide Film Formation Method)

[0454] The present invention provides a method for forming a metal oxide film serving as a filler film, such as a resist underlayer film of a multilayer resist film used for photolithography or a planarizing film (organic planarizing film) for semiconductor manufacturing, using the metal oxide film-forming composition.

[0455] Specifically, a method for forming a metal oxide film is provided, which is a method for forming a metal oxide film that serves as a flat film used in the manufacturing steps of a semiconductor device. A substrate to be processed, on which the above-mentioned metal oxide film-forming composition is coated, is heat-treated at a temperature of not less than 100°C and not more than 600°C for 10 to 600 seconds to form a cured film.

[0456] A method for forming a metal oxide film that serves as a planar film used in the manufacturing steps of semiconductor devices is also provided. The method comprises: applying the metal oxide film-forming composition to a substrate to be processed, and then heat-treating the substrate in a gas atmosphere having an oxygen concentration of not less than 0.1 volume % and not more than 21 volume % to form a cured film.

[0457] A method for forming a metal oxide film that serves as a planar film used in the manufacturing steps of semiconductor devices is also provided. The method comprises applying the metal oxide film-forming composition to a substrate to be processed and heat-treating the substrate in an atmosphere having an oxygen concentration of less than 0.1% by volume to form a cured film.

[0458] The method for forming a metal oxide film using the metal oxide film forming composition of the present invention is to apply the metal oxide film forming composition to the substrate to be processed by spin coating or the like. By using the spin coating method or the like, good filling characteristics can be obtained. After spin coating, baking (heat treatment) is performed to evaporate the solvent and prevent mixing with the resist upper film and the resist intermediate film in order to promote the cross-linking reaction. The baking is preferably performed at a temperature of 100°C to 600°C for 10 to 600 seconds, more preferably at a temperature of 200°C to 500°C for 10 to 300 seconds. Considering the effects of device damage and wafer deformation, the upper limit of the heating temperature for wafer processing in photolithography is preferably set to 600°C or less, more preferably 500°C or less.

[0459] In addition, in the method for forming a metal oxide film using the metal oxide film forming composition of the present invention, the metal oxide film forming composition of the present invention and the above-mentioned composition can be coated on the processed substrate by spin coating, etc., and the above-mentioned metal oxide film forming composition can be calcined in a gas environment with an oxygen concentration of not less than 0.1 volume % and not more than 21 volume % to harden it to form a metal oxide film.

[0460] By forming the metal oxide film of the present invention with a composition and calcining it in such an oxygen environment, a fully hardened film can be obtained. It is also acceptable for the gaseous environment during baking to be air. In order to reduce oxygen, it is desirable to seal in advance with inert gases such as N2, Ar, and He to prevent oxidation of the metal oxide film. In order to prevent oxidation, the oxygen concentration needs to be controlled, preferably below 1000ppm, more preferably below 100ppm (volume basis). If oxidation of the metal oxide film during baking is prevented, there is no absorption increase or reduction in etching resistance, so it is desirable.

[0461] [Example]

[0462] The following preparation examples, comparative preparation examples, synthesis examples, comparative synthesis examples, examples, and comparative examples further illustrate the present invention, but the present invention is not limited thereto. Furthermore, molecular weight and dispersity were determined by measuring the polystyrene-equivalent weight average molecular weight (Mw) and number average molecular weight (Mn) by gel permeation chromatography (GPC) using tetrahydrofuran as the eluent, and dispersity (Mw / Mn) was determined. The weight loss rate between 30°C and 350°C was determined by TG (thermogravimetric) measurement using a differential thermobalance in an air-like atmosphere (20% oxygen by volume: 80% nitrogen by volume) with a temperature increase of 10°C / min.

[0463] [Synthesis Example of Organic Source (II)]

[0464] In the synthesis example of the organic source (II), the following raw material group G: (G1) to (G10) and the modifying agents H: (H1) to (H3) were used.

[0465] Raw material group G: (G1) to (G10) are as follows.

[0466] [Chemistry 50]

[0467]

[0468] Modifying agent group H: (H1) to (H3) are shown below.

[0469] [Chemistry 51]

[0470]

[0471] [Synthesis Example 1] Synthesis of organic source (B-4)

[0472] 100 g of N-methylpyrrolidone was added to 30.00 g of tetracarboxylic anhydride (G4), and after the internal temperature was 40°C under a nitrogen environment to prepare a uniform solution, 10.20 g of an amine compound (H3) was added, and the reaction was carried out at an internal temperature of 40°C for 3 hours to obtain an amide acid solution. 200 g of o-xylene was added to the obtained amide acid solution, and the reaction was carried out for 9 hours at an internal temperature of 150°C while removing the generated low-boiling substances and the generated water from the system to carry out dehydration imidization. After the reaction was completed, it was cooled to room temperature and crystallized in 1000 g of methanol. The precipitated crystals were separated by filtration, washed twice with 500 g of methanol and recovered. The recovered crystals were vacuum dried at 70°C to obtain an organic source (B-4).

[0473] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0474] (B-4): Mw=901, Mw / Mn=1.01

[0475] [Chemistry 52]

[0476]

[0477] [Synthesis Example 2] Synthesis of Organic Source (B-5)

[0478] Under a nitrogen atmosphere, 46.9 g of compound (G2), 10.1 g of potassium carbonate, and 150 g of DMF were added to form a uniform dispersion at an internal temperature of 50°C. 9.0 g of the modifying agent (H1) was slowly added, and the reaction was allowed to proceed 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 the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of a 3% aqueous nitric acid solution and 100 g of pure water, and then dried under reduced pressure to obtain an organic source (B-5).

[0479] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0480] (B-5): Mw=903, Mw / Mn=1.08

[0481] [Chemistry 53]

[0482]

[0483] [Synthesis Example 3] Synthesis of Organic Source (B-6)

[0484] Under a nitrogen atmosphere, 45.7 g of compound (G5) of the raw material group, 9.3 g of potassium carbonate, and 150 g of DMF were added to form a uniform dispersion at an internal temperature of 50°C. 13.4 g of the modifying agent (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 the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of a 3% nitric acid aqueous solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain an organic source (B-6).

[0485] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0486] (B-6): Mw=1050, Mw / Mn=1.02

[0487] [Chemistry 54]

[0488]

[0489] [Synthesis Example 4] Synthesis of Organic Source (B-7)

[0490] Under a nitrogen atmosphere, 44.7 g of compound (G1), 16.5 g of potassium carbonate, and 150 g of DMF were added to form a uniform dispersion at an internal temperature of 50°C. 16.5 g of the modifying agent (H2) 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 the separated aqueous layer was removed. The organic layer was further washed 6 times with 100 g of a 3% nitric acid aqueous solution and 100 g of pure water, and then the organic layer was dried under reduced pressure to obtain an organic source (B-7).

[0491] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0492] (B-7): Mw=540, Mw / Mn=1.03

[0493] [Chemistry 55]

[0494]

[0495] [Comparative Synthesis Example 1] Synthesis of Comparative Organic Source (R-1)

[0496] Under a nitrogen atmosphere, 45.5 g of compound (G2), 9.8 g of potassium carbonate, and 150 g of DMF were added to form a uniform dispersion at an internal temperature of 50°C. 17.6 g of the modifying agent (H1) was slowly added, and the reaction was allowed to proceed 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 the separated aqueous layer was removed. The organic layer was then washed six times with 100 g of a 3% aqueous nitric acid solution and 100 g of pure water, and then dried under reduced pressure to obtain a comparative organic source (R-1).

[0497] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0498] (R-1): Mw=965, Mw / Mn=1.08

[0499] [Chemistry 56]

[0500]

[0501] [Comparative Synthesis Example 2] Synthesis of Comparative Organic Source (R-2)

[0502] To a 300 ml flask were added 200 g of compound (G6) from the raw material group, 75 g of a 37% formalin aqueous solution (G8), and 5 g of oxalic acid, and the mixture was stirred at 100°C for 24 hours. After the reaction, the mixture was dissolved in 500 ml of methyl isobutyl ketone and washed thoroughly with water to remove the catalyst and metallic impurities. The solvent was then removed under reduced pressure, and the pressure was reduced to 2 mmHg at 150°C to remove water and unreacted monomers, thereby obtaining a comparative organic source (R-2).

[0503] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0504] (R-2): Mw=6,500, Mw / Mn=5.20.

[0505] [Chemistry 57]

[0506]

[0507] [Comparative Synthesis Example 3] Synthesis of Comparative Organic Source (R-3)

[0508] Under a nitrogen atmosphere, 160.2 g of resin raw material (G7), 56.8 g of resin raw material (G8), and 300 g of PGME (propylene glycol monomethyl ether) were added and homogenized at an internal temperature of 100°C. After that, a pre-mixed and homogenized mixture of 8.0 g of p-toluenesulfonic acid monohydrate and 8.0 g of PGME was slowly added dropwise, and the mixture was reacted at an internal temperature of 80°C for 8 hours. After the reaction was completed, it was cooled to room temperature, 2,000 ml of MIBK was added, and the mixture was washed 6 times with 500 ml of pure water, and the organic layer was dried under reduced pressure. 300 g of THF was added to the residue to make a uniform solution, and then crystallized in 2,000 g of hexane. The precipitated crystals were separated by filtration, washed twice with 500 g of hexane, and recovered. The recovered crystals were vacuum dried at 70°C to obtain a comparative organic source (R-3) for the resin.

[0509] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0510] (R-3): Mw=3,300, Mw / Mn=2.54

[0511] [Chemistry 58]

[0512]

[0513] [Comparative Synthesis Example 4] Synthesis of Comparative Organic Source (R-4)

[0514] 57.2 g of the epoxy compound (G9), 42.8 g of the carboxylic acid compound (G10), and 300 g of 2-methoxy-1-propanol were prepared into a homogeneous solution at 100°C under a nitrogen atmosphere. 10.0 g of benzyltriethylammonium chloride was then added, and the solution was stirred at 120°C for 12 hours. After cooling to room temperature, 1,000 g of methyl isobutyl ketone was added, and the organic layer was washed five times with 200 g of pure water. The organic layer was dried under reduced pressure to obtain a comparative organic source (R-4).

[0515] The weight average molecular weight (Mw) and the degree of dispersion (Mw / Mn) were determined by GPC, and the results were as follows.

[0516] (R-4): Mw=780, Mw / Mn=1.04

[0517] [Chemistry 59]

[0518]

[0519] The structure, weight average molecular weight (Mw), and dispersity (Mw / Mn) of the obtained organic source (II) are shown in Tables 1 and 2. As the organic source (B-1), (G1) of the raw material group G used as the raw material in the above-mentioned synthesis example was used; as the organic source (B-2), (G2) of the raw material group G was used; and as the organic source (B-3), (G3) of the raw material group G was used.

[0520] [Table 1]

[0521]

[0522] [Table 2]

[0523]

[0524] [Manufacturing of organic-inorganic composite materials]

[0525] [Manufacturing Example 1] Manufacture of an organic-inorganic composite material (M-1)

[0526] In a reaction vessel, 1.4 g of an organic source (B-1) was dissolved in 23 g of PGMEA, and 3.2 g of acetic acid was slowly added dropwise to the solution, and the mixture was stirred at 25°C for 30 minutes. A solution of 6 g of tetrabutoxytitanium (IV) diluted with 24 g of 1-butanol as a metal source was then slowly added dropwise, and the mixture was stirred at 25°C for 30 minutes. After the condensation reaction was completed, the reaction solution was concentrated and removed under reduced pressure at 30°C, and then filtered with a 0.45 μm PTFE filter to obtain a PGMEA solution of an organic-inorganic composite material (M-1). The concentration of the components other than the solvent in the solution was 5.2% by mass.

[0527] [Manufacturing Examples 2 to 11, Comparative Manufacturing Examples 1 to 4] Manufacture of Organic-Inorganic Composite Materials (M-2 to M-11) and Comparative Organic-Inorganic Composite Materials (Comparative Examples M-1 to M-4)

[0528] The organic source and metal source were used in the feed amounts shown in Table 3, and the same reaction conditions as in Preparation Example 1 were followed to obtain the organic-inorganic composite materials (M-2 to M-11) and comparative organic-inorganic composite materials (Comparative Examples M-1 to M-4) shown in Table 3.

[0529] The following metal compounds were used as the inorganic sources in Table 3. In addition, (OBu) is n-butoxy.

[0530] Ti(OBu)4: Tetrabutyl orthotitanate (Tokyo Chemical Industry Co., Ltd., B0742)

[0531] Zr(OBu)4:tetrabutoxyzirconium(IV) (80 wt% 1-butanol solution) (Tokyo Chemical Industry Co., Ltd., Z0016)

[0532] Hf(OBu)4: n-butoxide hafnium(IV) (Sigma-Aldrich Corp, 667943)

[0533] [Table 3]

[0534]

[0535] [Synthesis of Comparative Metal Compound (Comparative Example MA-1)]

[0536] The comparative metal compound (Comparative Example MA-1) was synthesized according to the following procedure with reference to [Synthesis Example A-II] in Patent Document 5.

[0537] A mixture of 2.7 g of pure water and 50 g of isopropyl alcohol was added dropwise to a mixture of 32.7 g of tetraisopropoxyzirconium, 50 g of isopropyl alcohol, and 50 g of acetylacetone. After the addition, the mixture was stirred for 2 hours to allow hydrolysis and condensation to proceed, followed by reflux for another 2 hours. 200 g of PGMEA was added, and the mixture was concentrated under reduced pressure to obtain 250 g of a PGMEA solution containing a zirconium compound (Comparative Example MA-1).

[0538] [Synthesis of Comparative Metal Compound (Comparative Example MA-2)]

[0539] The comparative metal compound (Comparative Example MA-2) was synthesized according to the following procedure with reference to [Metal Complex Synthesis Example 3] in Patent Document 4.

[0540] 16.7 g of tetrabutoxyzirconium (IV) (80% in n-butanol) was dissolved in 20.6 g of 70 / 30 PGMEA / PGME and then injected into a reaction vessel under N2. The temperature was raised to 50°C while stirring, and 6.5 g of trimethylsilanol was added dropwise. After the addition was complete, the mixture was stirred at 60°C for 2 hours. 8.6 g of 1,2-cyclohexanedicarboxylic anhydride and 8.6 g of 70 / 30 PGMEA / PGME were then mixed with the reaction mixture, and the reaction was continued at 60°C for approximately 1 hour. After cooling to room temperature, a PGMEA / PGME solution containing the zirconium compound (Comparative Example MA-2) was obtained.

[0541] [Metal Compound for Comparison (Comparative Example MA-3)]

[0542] Tetrabutyl orthotitanate was used as the comparative metal compound (Comparative Example MA-3).

[0543] [Metal oxide nanoparticles (m1)]

[0544] As the metal oxide nanoparticles (m1) used in the metal oxide film-forming composition, ZrO2 nanoparticles (5 nm core, 915505, Sigma-Aldrich Corp) were used.

[0545] [Flowability enhancer]

[0546] C-1: Compound represented by the following formula (C-1)

[0547] C-2: Compound represented by the following formula (C-2)

[0548] C-3: Compound represented by the following formula (C-3)

[0549] [Table 4]

[0550]

[0551] [Crosslinking agent]

[0552] The cross-linking agent (XL-1) used in the metal oxide film-forming composition is shown below.

[0553] [Chemistry 60]

[0554]

[0555] [Acid generator]

[0556] As the acid generator (TAG), a compound represented by the following formula (F-1) was used.

[0557] [Chemistry 61]

[0558]

[0559] [Metal Oxide Film Forming Composition UL-1]

[0560] The above-mentioned organic-inorganic composite material (M-1) and propylene glycol monomethyl ether acetate (PGMEA) containing 0.5% by mass of the surfactant FC-4430 (produced by Sumitomo 3M Co., Ltd.) are mixed according to the composition shown in Table 5, and filtered with a 0.02 μm membrane filter to prepare a composition for forming a metal oxide film (UL-1).

[0561] [Metal Oxide Film-Forming Compositions UL-2 to 14 and Comparative Examples UL-1 to 9]

[0562] Each chemical solution was prepared in the same manner as UL-1 except that the types and contents of each component are shown in Table 5. In Table 5, "-" indicates that the component was not used.

[0563] [Table 5]

[0564]

[0565]

[0566] (Examples 1-1 to 1-14, Comparative Examples 1-1 to 1-8)

[0567] [Film-forming property evaluation]

[0568] The above-described metal oxide film-forming compositions (UL-1 to 14 and Comparative Examples UL-1 to 8) were each coated onto a SiO2 wafer substrate and heated in air at 350°C for 60 seconds using a hot plate to form a 100 nm thick metal oxide film. The resulting metal oxide film was observed under an optical microscope to confirm film-forming properties. A mirror-finished film with no defects was rated "good," while a film with defects such as cracks, wrinkles, pinholes, or streaks was rated "poor." The results are shown in Table 6.

[0569] [Table 6]

[0570]

[0571] As shown in Table 6, the metal oxide film-forming compositions of the present invention (UL-1 to 14) exhibited excellent film-forming properties. Among them, the composition (UL-11) containing the organic-inorganic composite material mixed with metal oxide nanoparticles (m1) exhibited excellent film-forming properties. Since the morphology of the organic-inorganic composite material is controlled by the reactivity of the metal compound, it is inferred that the metal oxide nanoparticles were well dispersed in the composition, and film formation defects due to aggregation of the components were not observed.

[0572] On the other hand, in Comparative Example UL-1, which used a reaction product with an organic source (R-1) without a hydroxyl group (Comparative Example M-1), poor film formation with wrinkles across the entire membrane was observed. It is speculated that this is due to insufficient condensation between the organic source and the metal source, which easily caused the components to aggregate during coating, resulting in poor coating. Furthermore, unlike the organic-inorganic composite material of the present invention, compositions in which metal compounds and organic compounds are simply mixed (Comparative Examples UL-6 to UL-8) showed wrinkles across the entire membrane. Because the metal compound and the organic compound did not react but existed independently in the composition, it is speculated that poor film formation due to aggregation occurred in the same way as in Comparative Example UL-1.

[0573] (Examples 2-1 to 2-14, Comparative Examples 2-1 to 2-5)

[0574] [Evaluation of Etching Resistance Using CF4 Gas]

[0575] The metal oxide film-forming compositions (UL-1 to 14, Comparative Examples UL-2 to 5) that showed good film-forming properties in the above film-forming property evaluation, as well as Comparative Example UL-9 composed solely of an organic compound, were coated on a silicon substrate and baked in air at 350°C for 60 seconds to form a 100 nm coating film. The film thickness a was then measured. Then, using a Tokyo Electron etching system (Telius), etching was performed with CF4 gas for 1 minute under the following conditions, and the film thickness b was measured. The film thickness after 1 minute of etching with CF4 gas was calculated (film thickness b - film thickness a), which was defined as the etching resistance to CF4 gas. An "A" (very good) rating was given when the difference between film thickness b and film thickness a (film loss) was less than 60 nm; a "B" (good) rating was given when the thickness was 60 nm or more and less than 70 nm; and a "C" (poor) rating was given when the thickness was 70 nm or more.

[0576] Dry etching conditions using CF4 gas

[0577] Chamber pressure: 100mTorr

[0578] RF power (upper): 500W

[0579] RF power (lower): 400W

[0580] CF4 gas flow rate: 300 sccm

[0581] Time: 60 seconds

[0582] [Table 7]

[0583]

[0584] The metal oxide film-forming compositions (UL-1 to 14) of the present invention are reaction products of an organic compound having a cardo structure and a metal compound, exhibiting excellent dry etching resistance to CF₄ gas. Therefore, they exhibit superior dry etching resistance compared to Comparative Example 2-5, which does not contain an inorganic source. On the other hand, deterioration in dry etching resistance was observed in Comparative Examples 2-2 and 2-3. This is presumably due to the poor dry etching resistance of the compound used as the organic source in the organic-inorganic composite material to CF₄ gas.

[0585] (Examples 3-1 to 3-14, Comparative Examples 3-1 to 3-8)

[0586] [Landfill characteristics evaluation]

[0587] The above-mentioned metal oxide film forming composition (UL-1 to 14 and comparative examples UL-1 to 8) is coated on a SiO2 wafer substrate having a dense line & space pattern (line width 40nm, line depth 120nm, distance between the centers of two adjacent lines 80nm), and heated at 350°C for 60 seconds in the atmosphere using a hot plate to form a metal oxide film with a film thickness of 100nm. Similarly, the organic film is formed by heating at 350°C for 60 seconds in the atmosphere and then baking at 500°C for 60 seconds under a nitrogen flow with an oxygen concentration of 0.1% by volume or more and 0.2% by volume or less. The substrate used is as follows. Figure 3 (Q) (bird's eye view) and Figure 3 The base substrate 9 (SiO2 wafer substrate) with a dense line & space pattern shown in (R) (cross-sectional view). The cross-sectional shape of each wafer substrate obtained was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd., and it was confirmed whether there were pores (voids) inside the metal oxide film between the filling lines. The results are shown in Table 8. When a metal oxide film-forming composition with poor filling characteristics was used, pores appeared inside the metal oxide film between the filling lines in this evaluation. When a metal oxide film-forming composition with good filling characteristics was used, in this evaluation, as Figure 3 As shown in (S), a metal oxide film 10 having no voids inside the metal oxide film is formed to fill the spaces between the lines of the base substrate 9 having a dense line & space pattern.

[0588] [Table 8]

[0589]

[0590]

[0591] As shown in Table 8, Examples 3-1 to 3-14 using the metal oxide film forming composition of the present invention (UL-1 to 14) can fill dense line & space patterns without generating voids, and it is confirmed that both 350°C baking and 500°C baking have good filling characteristics. On the other hand, in Comparative Example 3-5 composed solely of the metal compound (Comparative Example MA-1), voids were observed. It is speculated that volume shrinkage occurred due to the detachment of the ligands of the metal compound, resulting in the formation of voids. Similarly, in Comparative Example 3-1, it is speculated that volume shrinkage occurred due to the detachment of the ligands of the unreacted metal compound and the metal compound that formed the oligomer, resulting in the formation of voids. In addition, in the mixed composition of the organic source and the metal source of Comparative Examples 3-6 to 3-8, the organic source and the metal source exist independently in the composition, so it is speculated that volume shrinkage occurred due to the detachment of the ligands of the metal compound during baking, resulting in the formation of voids.

[0592] In Comparative Example 3-4, no pores were observed when baked at 350°C, but pores were confirmed when baked at 500°C. It is speculated that the organic compound (R-4) used in the synthesis of the organic-inorganic composite material has low heat resistance, so pores were generated by thermal decomposition when baked at 500°C. In Comparative Examples 3-2 and 3-3, pores were observed after baking at 350°C. It is speculated that the organic source used in the synthesis of the organic-inorganic composite material (Comparative Example UL-2, Comparative Example UL-3) is a polymer, and the lack of fluidity is the cause of the pores.

[0593] In order to suppress the volume shrinkage caused by the detachment of the ligands of the metal compound that affects the generation of pores, it is better to use the reaction product of the condensation reaction of the organic source and the metal source as in the present invention. It is better to choose a compound with a cardo structure that has excellent heat resistance and fluidity as the organic source.

[0594] (Examples 4-1 to 4-14, Comparative Examples 4-1 to 4-9)

[0595] [Planarization Characteristics Evaluation]

[0596] The above-mentioned metal oxide film forming compositions (UL-1 to 14 and comparative examples UL-1 to 8) and comparative example UL-9 consisting only of an organic compound were coated on a SiO2 wafer substrate having a dense line & space pattern (line width 40nm, line depth 120nm, and distance between the centers of two adjacent lines 80nm). The metal oxide film having a thickness of 100nm was formed by heating the substrate at 350°C for 60 seconds in the atmosphere using a hot plate. Figure 4 The base substrate 11 (SiO2 wafer substrate) with a dense line & space pattern shown in (T) (cross-sectional view). The cross-sectional shape of each wafer substrate obtained was observed using a scanning electron microscope (SEM), and the height difference of the filling film between the dense line pattern portion and the non-line pattern forming portion was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. Figure 4 The results are shown in Table 9. In this evaluation, the smaller the height difference, the better the flattening characteristics.

[0597] [Table 9]

[0598]

[0599]

[0600] Examples 4-1 to 4-14, using the metal oxide film-forming compositions of the present invention (UL-1 to 14), demonstrated superior planarization properties, demonstrating a smaller height difference between the filled film in areas with dense line patterns and areas with non-line pattern formations, compared to Comparative Examples 4-2 and 4-3, which used organic-inorganic composite materials using polymers as organic sources (Comparative Examples UL-2 and UL-3). Furthermore, comparable planarization properties were achieved compared to a material composed solely of an organic compound (Comparative Example UL-9).

[0601] When comparing Examples 4-1 and 4-7, which have the same skeletal structure as the organic source compound, and Example 4-2 and Example 4-5, the organic-inorganic composite material's organic source contains a structural unit represented by the general formula (II-2) in addition to the structural unit of the general formula (II-1), Examples 4-7 and 4-5 achieve superior planarization properties. It is speculated that this improvement in planarization properties is due to the inclusion of the general formula (II-2) having excellent fluidity in the organic-inorganic composite material. Furthermore, it is speculated that Examples 4-12 to 4-14, to which fluidity promoters (C-1 to C-3) are added, exhibit improved fluidity and thermal fluidity during coating, and exhibit superior planarization properties compared to Examples 4-2, 4-7, and 4-8 to which no fluidity promoters (C-1 to C-3) are added.

[0602] On the other hand, in Comparative Examples UL-1 and UL-5 to 8, in which voids were observed in the evaluation of the filling property after baking at 350° C., it was confirmed that the planarization characteristics were insufficient.

[0603] (Examples 5-1 to 5-14, Comparative Examples 5-1 to 5-5)

[0604] [Pattern transferability evaluation]

[0605] The metal oxide film-forming compositions (UL-1 to 14, comparative examples UL-2 to 5) with good film-forming properties in the above film-forming property evaluation and comparative example UL-9 composed only of an organic compound were coated on a silicon wafer substrate having a SiO2 film with a trench pattern (trench width 10 μm, trench depth 0.10 μm) formed thereon, and calcined at 350°C for 60 seconds in air to form an organic film with a thickness of 100 nm. A silicon-atom-containing resist intermediate film material (SOG-1) was coated thereon and baked at 220°C for 60 seconds to form a resist intermediate film with a thickness of 35 nm. A single-layer ArF resist, which was a resist upper film material, was coated thereon and baked at 105°C for 60 seconds to form a photoresist film with a thickness of 100 nm. A wet resist material (TC-1) was applied on the photoresist film and baked at 90° C. for 60 seconds to form a resist film with a thickness of 50 nm.

[0606] As for the silicon-containing anti-etching intermediate film material (SOG-1), a polymer represented by an ArF silicon-containing intermediate film polymer (SiP1) and a cross-linking catalyst (CAT1) are dissolved in an organic solvent containing 0.1% by mass of FC-4430 (produced by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 10, and filtered with a fluororesin filter with a pore size of 0.1 μm to prepare a silicon-containing anti-etching intermediate film material (SOG-1).

[0607] [Table 10]

[0608]

[0609] The structural formulas of the ArF silicon-containing interlayer polymer (SiP1) and the crosslinking catalyst (CAT1) used are shown below.

[0610] [Chemistry 62]

[0611]

[0612] As for the resist upper film material (single-layer resist for ArF), a polymer (RP1), an acid generator (PAG1), and an alkaline compound (Amine1) are dissolved in a solvent containing 0.1% by mass of a surfactant FC-4430 (manufactured by Sumitomo 3M Co., Ltd.) according to the proportions shown in Table 11, and the mixture is filtered through a 0.1 μm fluororesin filter for preparation.

[0613] [Table 11]

[0614]

[0615] The polymer (RP1), the acid generator (PAG1), and the basic compound (Amine1) used in the resist upper layer film material (single-layer resist for ArF) are shown below.

[0616] [Chemistry 63]

[0617]

[0618] The wet protective film material (TC-1) was prepared by dissolving the protective film polymer (PP1) in an organic solvent according to the ratio shown in Table 12 and filtering the solution through a 0.1 μm fluororesin filter.

[0619] [Table 12]

[0620]

[0621] The polymer (PP1) used in the wet protection film material (TC-1) is shown below.

[0622] [Chemistry 64]

[0623]

[0624] Next, exposure was performed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% half-step phase shift mask), followed by baking (PEB) at 100°C for 60 seconds and development with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 55nm 1:1 positive line and space pattern (resist pattern).

[0625] Next, using a Tokyo Electron Telius etching system, dry etching was performed on the organic antireflective film and the silicon-containing resist interlayer material (SOG-1) using the resist pattern as a mask to form a hard mask pattern. The metal oxide film was then etched using the resulting SOG-1 pattern as a mask to form a metal oxide film pattern. The SiO2 film was then etched using the resulting metal oxide film pattern as a mask. The etching conditions are shown below.

[0626] Transfer conditions of the resist pattern to the resist interlayer material containing silicon atoms (SOG-1).

[0627] Chamber pressure: 50mTorr

[0628] RF power (upper): 500W

[0629] RF power (lower): 300W

[0630] CF4 gas flow rate: 150sccm

[0631] CHF3 gas flow rate: 50sccm

[0632] Time: 20 seconds

[0633] Transfer conditions of the resist interlayer material (SOG-1) pattern containing silicon atoms onto the metal oxide film.

[0634] Chamber pressure: 15mTorr

[0635] RF power (upper): 300W

[0636] RF power (lower): 50W

[0637] O2 gas flow rate: 30sccm

[0638] N2 gas flow rate: 270sccm

[0639] Time: 90 seconds

[0640] Transfer conditions of metal oxide film pattern to SiO2 film.

[0641] Chamber pressure: 10mTorr

[0642] RF power (upper): 100W

[0643] RF power (lower): 800W

[0644] CF4 gas flow rate: 25sccm

[0645] CHF3 gas flow rate: 15sccm

[0646] O2 gas flow rate: 5sccm

[0647] Time: 100 seconds

[0648] The pattern cross section was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. The results are shown in Table 13.

[0649] [Table 13]

[0650]

[0651] As shown in Table 13, in Examples 5-1 to 5-14 using the metal oxide film-forming compositions (UL-1 to 14) of the present invention, the resist upper layer pattern was ultimately successfully transferred to the substrate, forming a vertical line and space pattern. This confirms that the metal oxide film-forming compositions of the present invention are suitable for microfabrication using the multilayer resist method.

[0652] On the other hand, Comparative Examples 5-1 to 5-2 and 5-4, which showed voids in the filling property evaluation, experienced pattern collapse during pattern processing, ultimately failing to obtain a good pattern. Furthermore, Comparative Examples 5-3 and 5-5, which showed insufficient performance in the dry etching resistance evaluation, experienced distortion of the pattern shape during pattern processing, ultimately failing to obtain a good pattern.

[0653] (Examples 6-1 to 6-14, Comparative Examples 6-1 to 6-5)

[0654] [SOC pattern reversal shape evaluation]

[0655] A coating-type organic underlayer film material (SOC-1) was applied to a silicon wafer substrate on which a 300nm SiO2 film had been formed as a resist underlayer. The film was then baked at 350°C for 60 seconds in air to form an 80nm thick resist underlayer film. A silicon-containing resist interlayer material (SOG-1) was then applied to the film and baked at 220°C for 60 seconds to form a 35nm thick resist interlayer film. An ArF single-layer resist, which served as a resist upper layer material, was then applied to the film and baked at 105°C for 60 seconds to form a 100nm thick photoresist film. A wet-protective film material (TC-1) was then applied to the photoresist film and baked at 90°C for 60 seconds to form a 50nm thick protective film.

[0656] The resist upper layer film material (single-layer resist for ArF) and the photoresist film wetting protection film material (TC-1) were the same materials as those used in the above-mentioned pattern transferability evaluation (Example 5).

[0657] As for the coating type organic lower layer membrane material (SOC-1), the polymer represented by the organic lower layer membrane polymer (SOP1) is dissolved in an organic solvent containing 0.1 mass% FC-4430 (produced by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 14, and filtered with a fluororesin filter with a pore size of 0.2 μm to prepare an organic lower layer membrane material (SOC-1) containing silicon atoms.

[0658] [Table 14]

[0659]

[0660] The structural formula of the organic underlayer film polymer (SOP1) used is shown in Table 15.

[0661] [Table 15]

[0662]

[0663] As for the silicon-containing resist intermediate film material (SOG-1), a polymer represented by an ArF silicon-containing intermediate film polymer (SiP1) and a cross-linking catalyst (CAT1) are dissolved in an organic solvent containing 0.1% by mass of FC-4430 (produced by Sumitomo 3M Co., Ltd.) in the proportions shown in Table 16, and filtered with a fluororesin filter with a pore size of 0.1 μm to prepare a silicon-containing resist intermediate film material (SOG-1).

[0664] [Table 16]

[0665]

[0666] The structural formulas of the ArF silicon-containing interlayer polymer (SiP1) and the crosslinking catalyst (CAT1) used are shown below.

[0667] [Chemistry 65]

[0668]

[0669] Then, the film was exposed using an ArF immersion exposure apparatus (manufactured by Nikon Corporation; NSR-S610C, NA1.30, σ0.98 / 0.65, 35-degree dipole s-polarized illumination, 6% half-step phase shift mask), baked (PEB) at 100°C for 60 seconds, and developed with a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution for 30 seconds to obtain a 55nm 1:1 positive line and space pattern.

[0670] Next, using a Tokyo Electron Telius etching system, dry etching was performed using the resist pattern as a mask to etch the silicon-containing resist interlayer material (SOG-1) to form a hard mask pattern. Using the resulting hard mask pattern as a mask, the organic underlayer film (SOC-1) was etched to form a SOC-1 film pattern. The etching conditions are as follows.

[0671] Transfer conditions of the resist pattern to the resist interlayer material containing silicon atoms (SOG-1).

[0672] Chamber pressure: 50mTorr

[0673] RF power (upper): 500W

[0674] RF power (lower): 300W

[0675] CF4 gas flow rate: 150sccm

[0676] CHF3 gas flow rate: 50sccm

[0677] Time: 20 seconds

[0678] Transfer conditions of the pattern of the silicon-containing resist interlayer material (SOG-1) to the organic underlayer film (SOC-1).

[0679] Chamber pressure: 10mTorr

[0680] RF power (upper): 1,000W

[0681] RF power (lower): 300W

[0682] CO2 gas flow rate: 150sccm

[0683] CO gas flow rate: 50 sccm

[0684] N2 gas flow rate: 50sccm

[0685] H2 gas flow rate: 150sccm

[0686] Time: 60 seconds

[0687] Then, the metal oxide film forming composition (UL-1 to 14, comparative examples UL-2 to 5) with good film forming properties in the above-mentioned film forming property evaluation and comparative example UL-9 composed only of organic compounds are coated on the obtained SOC-1 film pattern, and calcined at 350°C for 60 seconds in the atmosphere to form a metal oxide film with a film thickness of 100 nm. Afterwards, the metal oxide film covering the SOC-1 film pattern is etched to expose the top surface of the SOC-1 film pattern. The SOG-1 film remaining on the surface of the SOC-1 film pattern exposed on the top surface is removed by etching, and then the exposed SOC-1 is removed by etching, and the above-mentioned pattern is reversed on the metal oxide film, and the obtained metal oxide film pattern is used as a mask to perform etching of the SiO2 film. The etching conditions are shown below. As a comparative example, the SiO2 film is also etched using the SOC-1 film pattern as a mask without using the metal oxide film forming composition (Comparative Example 6-6). The etching conditions are shown below.

[0688] Conditions for etching back the metal oxide film (exposure of the SOC-1 film pattern).

[0689] Chamber pressure: 15mTorr

[0690] RF power (upper): 300W

[0691] RF power (lower): 50W

[0692] O2 gas flow rate: 30sccm

[0693] N2 gas flow rate: 270sccm

[0694] Time: 60 seconds

[0695] Removal of the residual SOG-1 film on the SOC-1 film pattern.

[0696] Chamber pressure: 50mTorr

[0697] RF power (upper): 500W

[0698] RF power (lower): 300W

[0699] CF4 gas flow rate: 150sccm

[0700] CHF3 gas flow rate: 50sccm

[0701] Time: 15 seconds

[0702] Removal of SOC-1 film pattern.

[0703] Chamber pressure: 10mTorr

[0704] RF power (upper): 1,000W

[0705] RF power (lower): 300W

[0706] CO2 gas flow rate: 150sccm

[0707] CO gas flow rate: 50 sccm

[0708] N2 gas flow rate: 50sccm

[0709] H2 gas flow rate: 150sccm

[0710] Time: 60 seconds

[0711] Transfer conditions of metal oxide film pattern to SiO2 film.

[0712] Chamber pressure: 10mTorr

[0713] RF power (upper): 100W

[0714] RF power (lower): 800W

[0715] CF4 gas flow rate: 25sccm

[0716] CHF3 gas flow rate: 15sccm

[0717] O2 gas flow rate: 5sccm

[0718] Time: 200 seconds

[0719] Comparative Example 6-6: Transfer conditions of the SOC-1 film pattern to the SiO2 film.

[0720] Chamber pressure: 10mTorr

[0721] RF power (upper): 100W

[0722] RF power (lower): 800W

[0723] CF4 gas flow rate: 25sccm

[0724] CHF3 gas flow rate: 15sccm

[0725] O2 gas flow rate: 5sccm

[0726] Time: 200 seconds

[0727] The pattern cross section was observed using an electron microscope (S-4700) manufactured by Hitachi, Ltd. The results are shown in Table 17.

[0728] [Table 17]

[0729]

[0730]

[0731] As shown in Table 17, in Examples 6-1 to 6-14 using the metal oxide film-forming composition (UDL-1 to 14) of the present invention, the SOC-1 film pattern was reversed with good precision, the pattern did not collapse, and the reversed pattern was ultimately well transferred to the substrate. This confirms that the metal oxide film-forming composition of the present invention is suitable for use in microfabrication using a tone reversal etching method in a multilayer resist processing method. On the other hand, in Comparative Example 6-6, in which the SOC-1 film pattern was directly transferred to a SiO2 film, the etching resistance of the SOC-1 film was insufficient, and thus the pattern shape was twisted. Furthermore, in Comparative Example 6-5, the etching resistance of Comparative Example UL-9, which is composed solely of an organic compound, was insufficient, so the selectivity with the SOC-1 film pattern could not be achieved, and a good reversed pattern could not be obtained. Similarly, although there were no problems in the evaluation of the filling characteristics and the flattening characteristics, Comparative Example 6-3 was confirmed to have insufficient performance in the dry etching resistance evaluation. It is speculated that the pattern shape was twisted during the pattern reversal processing, and ultimately a good reversed pattern could not be obtained. Furthermore, in Comparative Examples 6-1, 6-2, and 6-4, which were found to have insufficient performance in the evaluation of the filling property and the evaluation of the planarization property, it is presumed that pattern collapse occurred during pattern processing, and ultimately a good reverse pattern could not be obtained.

[0732] As described above, the metal oxide film-forming composition of the present invention, being a condensation reaction product of an organic compound and a metal compound, can suppress coating defects caused by poor compatibility between the metal source and the organic source, as well as defects such as the formation of voids in the filled film due to thermal shrinkage of the metal compound during heat treatment. Compared to conventional metal oxide film-forming compositions comprising a mixture of a metal compound and a resin, it exhibits superior coating properties and filling / planarization characteristics. Furthermore, it is understood that, due to its excellent dry etching resistance, it is extremely useful as a resist underlayer film material used in multilayer resist processes and as a reversing agent used in tone reversal etching processes. The pattern forming method of the present invention using this composition enables the formation of fine patterns with high precision, even on substrates with uneven surfaces.

[0733] This specification includes the following aspects.

[0734] [1]: A composition for forming a metal oxide film, comprising (A) an organic-inorganic composite material and (B) a solvent,

[0735] The characteristics are as follows: the aforementioned (A) organic-inorganic composite material is the reaction product of a metal source (I) and an organic source (II),

[0736] The metal source (I) contains one or more compounds selected from the group consisting of metal compounds represented by the following general formula (I-1), hydrolyzates of metal compounds represented by the general formula (I-1), and hydrolysis-condensation products of metal compounds represented by the general formula (I-1).

[0737] The organic source (II) contains a compound having a structural unit represented by the following general formula (II-1) and a cardo structure,

[0738] [Chemistry 66]

[0739]

[0740] [Chemistry 67]

[0741]

[0742] Where M is metal, R A1 is a monovalent organic group having 1 to 30 carbon atoms and having 0 or 1 hydroxyl group, which may be the same group or different groups. A1 They can also be bonded to each other and form a ring or spiro ring together with the O and M to which they are bonded, r is an integer from 3 to 6, R a It is a saturated or unsaturated monovalent organic group having 1 to 10 carbon atoms which may be substituted, p is an integer of 0 to 5, q1 is an integer of 1 to 6, p+q1 is an integer of 1 to 6, q2 is 0 or 1, and * is a bonding position.

[0743] [2]: The metal oxide film-forming composition according to [1], wherein the organic source (II) has a structural unit represented by the general formula (II-1) and a cardo structure and further has a structural unit represented by the following general formula (II-2),

[0744] [Chemistry 68]

[0745]

[0746] In the above general formula (II-2), R A is a divalent organic group having 1 to 10 carbon atoms which may be substituted, R B is an optionally substituted hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, R a , p, q1, q2, and * are the same as those in the aforementioned general formula (II-1).

[0747] [3]: A composition for forming a metal oxide film as described in [2], wherein when the ratio of the constituent units represented by the general formula (II-1) is set to a and the ratio of the constituent units represented by the general formula (II-2) is set to b, the organic source (II) components as a whole satisfy the relationship of a+b=1 and 0.2≤b≤0.8.

[0748] [4]: The metal oxide film-forming composition according to [2] or [3], wherein in the general formula (II-2), X2 is represented by the following general formula (X-1):

[0749] [Chemistry 69]

[0750]

[0751] In the above formula, * represents the bonding position.

[0752] [5]: The metal oxide film-forming composition according to any one of [1] to [4], wherein the organic source (II) contains a compound represented by the following general formulas (1) to (3):

[0753] [Chemistry 70]

[0754]

[0755] [Chemistry 71]

[0756]

[0757] In the formula, W1 and W2 are each independently a benzene ring or a naphthalene ring, and the hydrogen atoms in the aforementioned benzene ring and the aforementioned naphthalene ring may be substituted by a hydrocarbon group having 1 to 6 carbon atoms, Y is a group represented by the following general formula (4), Z1 is a group represented by the following general formula (5), and * is the bonding position with the structural unit represented by the above general formula (II-1).

[0758] [Chemistry 72]

[0759]

[0760] [Chemistry 73]

[0761]

[0762] In the above general formula (5), W1, W2, and Y are the same as described above, n1 is 0 or 1, and * in the above general formulas (4) and (5) represents a bonding position.

[0763] [6]: A composition for forming a metal oxide film as described in any one of [1] to [5], wherein the ratio Mw / Mn (dispersity) of the weight average molecular weight Mw and number average molecular weight Mn of the compound contained in the aforementioned organic source (II) in terms of polystyrene, as measured by gel permeation chromatography, is in the range of 1.00≤Mw / Mn≤1.25.

[0764] [7]: A composition for forming a metal oxide film as described in any one of [1] to [6], wherein M in the general formula (I-1) contains a metal selected from the group consisting of Zr, Ta, Hf, Ti, Sn, Nb, Mo, Ge and W.

[0765] [8]: A composition for forming a metal oxide film as described in any one of [1] to [7], wherein the composition further contains a fluidity promoter (C) having a weight reduction rate of less than 30% between 30°C and 190°C and a weight reduction rate of 98% or more between 30°C and 350°C.

[0766] [9]: The metal oxide film-forming composition according to [8], wherein the fluidity promoter (C) contains one or more compounds selected from the group consisting of the following general formulae (i) to (iii):

[0767] [General formula (i)]

[0768] [Chemistry 74]

[0769]

[0770] [Chemistry 75]

[0771]

[0772] [Chemistry 76]

[0773]

[0774] Where R 1 are each independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, W 1 is a phenylene group or a divalent group represented by the general formula (i-1), W 2 、W 3 is a single bond or any divalent group represented by the general formula (i-2), m 1 is an integer from 1 to 10, n 1 is an integer from 0 to 5, * represents the bonding position, R 10 、R 11 、R 12 、R 13 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms, W 10 、W 11Each independently represents a single bond or a carbonyl group, m 10 、m 11 is an integer from 0 to 10, m 10 +m 11 ≥1,

[0775] [General formula (ii)]

[0776] [Chemistry 77]

[0777]

[0778] [Chemistry 78]

[0779]

[0780] [Chemistry 79]

[0781]

[0782] Where R 2 are each independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, W 4 is a divalent group represented by the general formula (ii-1), W 5 is a single bond or any divalent group represented by the general formula (ii-2), m 2 is an integer from 2 to 10, n3 is an integer from 0 to 5, * represents the bonding position, R 20 、R 21 、R 22 、R 23 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms, m 20 、m 21 is an integer from 0 to 10, m 20 +m 21 ≥1,

[0783] [General formula (iii)]

[0784] [Chemistry 80]

[0785]

[0786] [Chemistry 81]

[0787]

[0788] [Chemistry 82]

[0789]

[0790] Where R 3 、R 4is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms which may be substituted, and may be bonded to form a ring structure, R 5 、R 6 is an organic group having 1 to 10 carbon atoms, R 5 is a group containing an aromatic ring or one of the divalent groups represented by the general formula (iii-1), W 6 、W 7 is a single bond or any divalent group represented by general formula (iii-2), at least one of which is a divalent group represented by any one of formula (iii-2), W 30 It is an organic group with 1 to 4 carbon atoms, and * indicates the bonding position.

[0791]

[10] : The metal oxide film-forming composition according to any one of [1] to [9], further comprising (D) metal oxide nanoparticles having an average primary particle size of 100 nm or less.

[0792]

[11] : The metal oxide film forming composition of

[10] , wherein the aforementioned (D) metal oxide nanoparticles are one or more selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and tungsten oxide nanoparticles.

[0793]

[12] : The metal oxide film-forming composition according to any one of [1] to

[11] , wherein the composition further contains one or more of a crosslinking agent, a surfactant, an acid generator, and a plasticizer.

[0794]

[13] : A pattern forming method is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0795] (I-1) After applying the metal oxide film-forming composition according to any one of [1] to

[12] on a substrate to be processed, heat treatment is performed to form a metal oxide film,

[0796] (I-2) forming a resist upper layer film on the aforementioned metal oxide film using a photoresist material,

[0797] (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,

[0798] (I-4) using the patterned resist upper layer film as a mask to transfer the pattern to the metal oxide film by dry etching, and

[0799] (I-5) 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.

[0800]

[14] : A pattern forming method is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0801] (II-1) After applying the metal oxide film-forming composition described in any one of [1] to

[12] on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0802] (II-2) forming a resist intermediate film on the aforementioned metal oxide film,

[0803] (II-3) forming a resist upper layer film on the resist intermediate film using a photoresist material,

[0804] (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,

[0805] (II-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film by dry etching,

[0806] (II-6) using the resist intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0807] (II-7) 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.

[0808]

[15] : A pattern forming method is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0809] (III-1) After applying the metal oxide film-forming composition described in any one of [1] to

[12] on a substrate to be processed, heat treatment is performed to form a metal oxide film.

[0810] (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,

[0811] (III-3) forming an organic thin film on the aforementioned inorganic hard mask intermediate film,

[0812] (III-4) forming a resist upper layer film on the aforementioned organic thin film using a photoresist material,

[0813] (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,

[0814] (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,

[0815] (III-7) using the inorganic hard mask intermediate film to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and

[0816] (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.

[0817]

[16] : A pattern forming method is a method for forming a pattern on a processed substrate, characterized by comprising the following steps:

[0818] (IV-1) forming a resist underlayer film on a substrate to be processed,

[0819] (IV-2) forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film and an organic thin film on the resist underlayer film,

[0820] (IV-3) forming a resist upper layer film using a photoresist material on the aforementioned resist interlayer film or the combination of the inorganic hard mask interlayer film and the organic thin film,

[0821] (IV-4) after pattern exposure of the resist upper layer film, developing with a developer to form a pattern on the resist upper layer film,

[0822] (IV-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching,

[0823] (IV-6) using the resist intermediate film or inorganic hard mask intermediate film to which the pattern has been transferred as a mask, and transferring the pattern to the resist underlayer film by dry etching,

[0824] (IV-7) After applying the metal oxide film-forming composition as described in any one of [1] to

[12] on the patterned resist underlayer film, the metal oxide film is coated by heat treatment to fill the space between the resist underlayer film patterns with the metal oxide film.

[0825] (IV-8) chemically stripping or dry etching the metal oxide film covering the patterned resist underlayer film to expose the top surface of the patterned resist underlayer film,

[0826] (IV-9) removing the resist intermediate film or the hard mask intermediate film remaining on the top surface of the resist underlayer film by dry etching,

[0827] (IV-10) removing the patterned resist underlayer film exposed on the surface by dry etching to form a reverse pattern of the original pattern on the metal oxide film,

[0828] (IV-11) The metal oxide film having the reverse pattern formed thereon is used as a mask to process the substrate to form a reverse pattern on the substrate.

[0829]

[17] : The pattern forming method according to any one of

[13] to

[16] , wherein a substrate having a structure with a height of 30 nm or more or a height difference is used as the substrate to be processed.

[0830]

[18] : A method for forming a metal oxide film, which is a method for forming a metal oxide film that acts as a flat film used in the manufacturing steps of a semiconductor device, characterized in that a substrate to be processed, on which a metal oxide film forming composition as described in any one of [1] to

[12] is coated, is heat-treated at a temperature in the range of 100°C to 600°C for 10 to 600 seconds to form a hardened film.

[0831]

[19] : A method for forming a metal oxide film, which is a method for forming a metal oxide film that acts as a flat film used in the manufacturing steps of a semiconductor device, characterized in that a substrate to be processed, on which a metal oxide film forming composition as described in any one of [1] to

[12] is coated, is heat-treated in a gas environment having an oxygen concentration of not less than 0.1 volume % and not more than 21 volume %, to form a hardened film.

[0832]

[20] : A method for forming a metal oxide film, which is a method for forming a metal oxide film that acts as a flat film used in the manufacturing steps of a semiconductor device, characterized in that a substrate to be processed, on which a metal oxide film forming composition as described in any one of [1] to

[12] is coated, is heat-treated in a gas environment having an oxygen concentration of less than 0.1% by volume to form a hardened film.

[0833] Furthermore, the present invention is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely illustrative, and any other embodiment having substantially the same structure and exhibiting the same functions and effects as the technical concept described in the scope of the present invention is within the technical scope of the present invention.

[0834] Description of Reference Numerals

[0835] 1: Processed substrate

[0836] 2: Processed layer

[0837] 2a: Pattern (pattern formed on the processed layer)

[0838] 3: Metal oxide film

[0839] 3a: Metal oxide film pattern

[0840] 4: Resist interlayer containing silicon atoms

[0841] 4a: Resist interlayer pattern containing silicon atoms

[0842] 5: Resist upper film

[0843] 5a: Resist upper film pattern

[0844] 6: Exposure part

[0845] 7: Resist underlayer film composed of coating type organic underlayer film material

[0846] 7a: Resist lower layer film pattern composed of coating type organic lower layer film material

[0847] 8:Metal oxide film

[0848] 8a: Metal oxide film pattern formed by inverting the resist lower film pattern

[0849] 9: Base substrate with dense line & space pattern

[0850] 10:Metal oxide film

[0851] 11: Base substrate with dense line & space pattern

[0852] 12:Metal oxide film

[0853] Delta12: The height difference between the metal oxide film 12 in the patterned part and the non-patterned part

Claims

1. A composition for forming a metal oxide film, comprising (A) an organic-inorganic composite material and (B) a solvent, Its characteristics are: The (A) organic-inorganic composite material is a reaction product of a metal source (I) and an organic source (II). The metal source (I) contains one or more compounds selected from the group consisting of metal compounds represented by the following general formula (I-1), hydrolyzates of metal compounds represented by the general formula (I-1), and hydrolysis-condensation products of metal compounds represented by the general formula (I-1). The organic source (II) contains a compound having a constituent unit represented by the following general formula (II-1) and a cardo structure, Where M is metal, R A1 is a monovalent organic group having 1 to 30 carbon atoms and having 0 or 1 hydroxyl group, and may be the same group or different groups, and adjacent R A1 They are optionally bonded to each other and form a ring or spiro ring together with the O and M to which they are bonded, r is an integer from 3 to 6, R a is an optionally substituted saturated or unsaturated monovalent organic group having 1 to 10 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 to 6, q2 is 0 or 1, and * is a bonding position; M in the general formula (I-1) contains a metal selected from the group consisting of Zr, Ta, Hf, Ti, Sn, Nb, Mo, Ge, and W.

2. The metal oxide film-forming composition according to claim 1, wherein The organic source (II) has a constituent unit represented by the general formula (II-1) and a cardo structure and a constituent unit represented by the following general formula (II-2), In the above general formula (II-2), R A is an optionally substituted divalent organic group having 1 to 10 carbon atoms, R B is an optionally substituted hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, R a , p, q1, q2, and * are the same as those in the general formula (II-1).

3. The metal oxide film-forming composition according to claim 2, wherein When the ratio of the structural unit represented by the general formula (II-1) is a and the ratio of the structural unit represented by the general formula (II-2) is b, the organic source (II) component as a whole satisfies the relationship of a+b=1 and 0.2≤b≤0.

8.

4. The metal oxide film-forming composition according to claim 2, wherein In the general formula (II-2), X2 is represented by the following general formula (X-1): In the above formula, * represents the bonding position.

5. The metal oxide film-forming composition according to claim 1, wherein The organic source (II) contains compounds represented by the following general formulas (1) to (3): In the formula, W1 and W2 are each independently a benzene ring or a naphthalene ring, the hydrogen atoms in the benzene ring and the naphthalene ring are optionally substituted by a hydrocarbon group having 1 to 6 carbon atoms, Y is a group represented by the following general formula (4), Z1 is a group represented by the following general formula (5), * is the bonding position with the structural unit represented by the above general formula (II-1), In the above general formula (5), W1, W2, and Y are the same as described above, n1 is 0 or 1, and * in the above general formulas (4) and (5) represents a bonding position.

6. The metal oxide film-forming composition according to claim 1, wherein The ratio Mw / Mn (dispersity) of the polystyrene-equivalent weight average molecular weight Mw to the number average molecular weight Mn of the compound contained in the organic source (II) measured by gel permeation chromatography is within the range of 1.00≤Mw / Mn≤1.

25.

7. The metal oxide film-forming composition according to claim 1, wherein The metal oxide film-forming composition contains (C) a fluidity promoter having a weight loss rate of less than 30% from 30° C. to 190° C. and a weight loss rate of 98% or more from 30° C. to 350° C.

8. The metal oxide film-forming composition according to claim 7, wherein The fluidity-enhancing agent (C) contains one or more compounds selected from the group consisting of the following general formulae (i) to (iii): [General formula (i)] Where R 1 are each independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, W 1 is a phenylene group or a divalent group represented by the general formula (i-1), W 2 、W 3 is a single bond or any divalent group represented by the general formula (i-2), m1 is an integer from 1 to 10, n 1 is an integer from 0 to 5, * represents the bonding position, R 10 、R 11 、R 12 、R 13 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms, W 10 、W 11 Each independently represents a single bond or a carbonyl group, m 10 、m 11 is an integer from 0 to 10, m 10 +m 11 ≥1, [General formula (ii)] Where R 2 are each independently a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, W 4 is a divalent group represented by the general formula (ii-1), W 5 is a single bond or any divalent group represented by the general formula (ii-2), m 2 is an integer from 2 to 10, n3 is an integer from 0 to 5, * represents the bonding position, R 20 、R 21 、R 22 、R 23 is a hydrogen atom, a hydroxyl group, or an organic group having 1 to 10 carbon atoms, m 20 、m 21 is an integer from 0 to 10, m 20 +m 21 ≥1, [General formula (iii)] Where R 3 、R 4 is a hydrogen atom, a hydroxyl group, or an optionally substituted organic group having 1 to 10 carbon atoms, optionally bonded to form a cyclic structure, R 5 、R 6 is an organic group having 1 to 10 carbon atoms, R 5 is a group containing an aromatic ring or one of the divalent groups represented by the general formula (iii-1), W 6 、W 7 is a single bond or any divalent group represented by general formula (iii-2), at least one of which is a divalent group represented by any one of formula (iii-2), W 30 It is an organic group with 1 to 4 carbon atoms, and * indicates the bonding position.

9. The metal oxide film-forming composition according to claim 1, wherein The metal oxide film-forming composition contains (D) metal oxide nanoparticles having an average primary particle size of 100 nm or less.

10. The metal oxide film-forming composition according to claim 9, wherein The (D) metal oxide nanoparticles are at least one selected from the group consisting of zirconium oxide nanoparticles, hafnium oxide nanoparticles, titanium oxide nanoparticles, tin oxide nanoparticles, and tungsten oxide nanoparticles.

11. The metal oxide film-forming composition according to claim 1, wherein The metal oxide film-forming composition contains one or more of a crosslinking agent, a surfactant, an acid generator, and a plasticizer.

12. A method for forming a pattern on a substrate to be processed. It is characterized by having the following steps: (I-1) Coating on the substrate to be processed After the metal oxide film-forming composition according to any one of claims 1 to 11 is subjected to heat treatment to form a metal oxide film, (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 to transfer the pattern to the metal oxide film by dry etching, and (I-5) The substrate to be processed is processed using the patterned metal oxide film as a mask to form a pattern on the substrate to be processed.

13. A method for forming a pattern on a processed substrate. It is characterized by having the following steps: (II-1) Coating on the substrate to be processed After the metal oxide film-forming composition according to any one of claims 1 to 11 is subjected to heat treatment to form a metal oxide film, (II-2) forming a resist intermediate film on the metal oxide film, (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 to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and (II-7) The substrate to be processed is processed using the patterned metal oxide film as a mask to form a pattern on the substrate to be processed.

14. A method for forming a pattern on a substrate to be processed. It is characterized by having the following steps: (III-1) Coating on the substrate to be processed After the metal oxide film-forming composition according to any one of claims 1 to 11 is subjected to heat treatment to form a metal oxide film, (III-2) forming an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride 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 to which the pattern has been transferred as a mask, dry etching is performed to transfer the pattern to the metal oxide film, and (III-8) The substrate to be processed is processed using the patterned metal oxide film as a mask to form a pattern on the substrate to be processed.

15. A method for forming a pattern on a substrate to be processed. It is characterized by having the following steps: (IV-1) forming a resist underlayer film on a substrate to be processed, (IV-2) forming a resist intermediate film, or a combination of an inorganic hard mask intermediate film selected from a silicon oxide film, a silicon nitride film, and a silicon oxide nitride film and an organic thin film on the resist underlayer film, (IV-3) forming a resist upper layer film using a photoresist material on the resist intermediate film or the combination of the inorganic hard mask intermediate film and the organic thin film, (IV-4) After pattern exposure of the resist upper layer film, the resist upper layer film is developed with a developer to form a pattern on the resist upper layer film, (IV-5) using the patterned resist upper layer film as a mask, transferring the pattern to the resist intermediate film, or the organic thin film and the inorganic hard mask intermediate film by dry etching, (IV-6) using the resist intermediate film or inorganic hard mask intermediate film to which the pattern has been transferred as a mask, and transferring the pattern to the resist underlayer film by dry etching, (IV-7) coating the patterned resist underlayer film After preparing the metal oxide film-forming composition according to any one of claims 1 to 11, the metal oxide film is coated by heat treatment, and the space between the resist underlayer film patterns is filled with the metal oxide film. (IV-8) chemically stripping or dry etching the metal oxide film covering the patterned resist underlayer film to expose the top surface of the patterned resist underlayer film, (IV-9) removing the resist intermediate film or the hard mask intermediate film remaining on the top surface of the resist underlayer film by dry etching, (IV-10) removing the patterned resist underlayer film exposed on the surface by dry etching to form a reverse pattern of the original pattern on the metal oxide film, (IV-11) The metal oxide film having the reverse pattern formed thereon is used as a mask to process the substrate to form a reverse pattern on the substrate. 16 . The pattern forming method according to claim 12 , wherein a substrate having a structure or a height difference of 30 nm or more is used as the substrate to be processed.

17. The pattern forming method according to claim 13, wherein a substrate having a structure or a height difference of 30 nm or more is used as the substrate to be processed.

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

19. The pattern forming method according to claim 15, wherein a substrate having a structure or a height difference of 30 nm or more is used as the substrate to be processed.

20. A method for forming a metal oxide film that functions as a planar film used in a semiconductor device manufacturing step, characterized by: The substrate coated with the metal oxide film-forming composition according to any one of claims 1 to 11 is heat-treated at a temperature of 100° C. to 600° C. for 10 to 600 seconds to form a cured film.

21. A method for forming a metal oxide film that functions as a planar film used in a semiconductor device manufacturing step, characterized by: A substrate coated with the metal oxide film-forming composition according to any one of claims 1 to 11 is heat-treated in a gas atmosphere having an oxygen concentration of 0.1% by volume to 21% by volume to form a cured film.

22. A method for forming a metal oxide film that functions as a planar film used in a semiconductor device manufacturing step, characterized by: A substrate coated with the metal oxide film-forming composition according to any one of claims 1 to 11 is heat-treated in a gas atmosphere having an oxygen concentration of less than 0.1% by volume to form a cured film.

Images