Silicon-containing sulfonium salt compound, composition for forming silicon-containing resist underlayer film, and patterning process

Abstract

To provide: a composition for forming a silicon-containing resist underlayer film capable of forming a silicon-containing resist underlayer film that has an appropriate etching rate in a multilayer resist method and can improve LWR and CDU of an ultrafine pattern; a silicon-containing sulfonium salt compound contained in the composition; and a patterning process using the composition.SOLUTION: A silicon-containing sulfonium salt compound is represented by the following general formula (A-1).SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a silicon-containing sulfonium salt compound, a composition for forming a silicon-containing resist underlayer film containing the compound, and a patterning method using the composition.

Background Art

[0002] With the high integration and high speed of large-scale integrated circuits (LSIs), the miniaturization of pattern dimensions has been rapidly progressing. Lithography technology has achieved the formation of fine patterns by shortening the wavelength of the light source and appropriately selecting a resist composition corresponding thereto in accordance with this miniaturization. The core thereof is a positive photoresist composition used as a single layer. This single-layer positive photoresist composition has a skeleton having etching resistance against chlorine-based or fluorine-based gas plasma in the resist resin and a switching mechanism such that the exposed portion is dissolved, thereby dissolving the exposed portion to form a pattern and dry-etching the substrate to be processed using the remaining resist pattern as an etching mask.

[0003] However, when the thickness of the photoresist film used is directly miniaturized, that is, when the pattern width is made smaller, the resolution performance of the photoresist film deteriorates, and when attempting to develop the photoresist film into a pattern with a developer, the so-called aspect ratio becomes too large, resulting in a problem that pattern collapse occurs. For this reason, the photoresist film has been thinned as the pattern is miniaturized.

[0004] On one hand, for processing a substrate to be processed, a method of processing the substrate by dry etching using a photoresist film with a pattern formed thereon as an etching mask is usually used. However, in reality, there is no dry etching method that can achieve complete etching selectivity between the photoresist film and the substrate to be processed. Therefore, during the processing of the substrate, the resist film is also damaged and collapses, resulting in the problem that the resist pattern cannot be accurately transferred to the substrate to be processed. Thus, with the miniaturization of patterns, higher dry etching resistance has been required for photoresist compositions. However, on the other hand, in order to improve the resolution, resins used in photoresist compositions have been required to have low light absorption at the exposure wavelength. Therefore, as the exposure light becomes shorter in wavelength, such as i-line, KrF, and ArF, the resins used in photoresist compositions have also changed from novolak resins, polyhydroxystyrene, to resins with an aliphatic polycyclic skeleton. However, in reality, the etching rate under dry etching conditions during substrate processing has become faster, and recent photoresist compositions with high resolution tend to have weaker etching resistance.

[0005] From this, it becomes necessary to dry-etch the substrate to be processed with a thinner and less etching-resistant photoresist film, and ensuring the materials and processes in this processing step has become an urgent task.

[0006] As one method to solve such problems, there is the multilayer resist method. This method involves interposing a resist lower layer film with different etching selectivity from the photoresist film (i.e., the resist upper layer film) between the resist upper layer film and the substrate to be processed. After obtaining a pattern in the resist upper layer film, the resist upper layer film pattern is used as a dry etching mask to transfer the pattern to the resist lower layer film by dry etching, and further, the resist lower layer film is used as a dry etching mask to transfer the pattern to the substrate to be processed by dry etching.

[0007] One of the multilayer resist methods is a three-layer resist method that can be performed using a general resist composition used in a single-layer resist method. In this three-layer resist method, for example, an organic film made of a novolak resin or the like is formed as a resist underlayer film on a substrate to be processed, a silicon-containing resist intermediate film is formed thereon, and a normal organic photoresist film is formed as a resist upper layer film thereon. When performing dry etching using a fluorine-based gas plasma, the organic resist upper layer film has a good etching selectivity with respect to the silicon-containing resist intermediate film, so the resist upper layer film pattern can be transferred to the silicon-containing resist intermediate film by dry etching using a fluorine-based gas plasma. According to this method, even when using a resist composition that is difficult to form a pattern with a sufficient film thickness for directly processing the substrate to be processed or a resist composition that does not have sufficient dry etching resistance for substrate processing, a pattern can be transferred to the silicon-containing resist intermediate film. Subsequently, if pattern transfer is performed by dry etching using an oxygen-based or hydrogen-based gas plasma, a pattern of an organic film made of a novolak resin or the like having sufficient dry etching resistance for substrate processing can be obtained. The silicon-containing resist intermediate film remaining after forming the organic film pattern is generally removed by dry etching using a fluorine-based gas plasma or wet etching using an etching solution such as an alkali-based or fluorine-based solution so as not to become a residue causing defects. If the etching rate is insufficient, there is a high possibility of problems such as residues derived from the silicon-containing resist intermediate film remaining and becoming defects, or a long etching process being required and damaging the substrate to be processed. Thus, an appropriate etching rate is required for the silicon-containing resist intermediate film for accurate patterning and smooth removal.

[0008] On the one hand, in recent years, with the emergence of ArF immersion lithography, EUV lithography, etc., it has become possible to form finer patterns. Along with this, the thinning of the photoresist film has been progressing further. Such thinning of the photoresist film causes deterioration of edge roughness (LWR) and dimensional uniformity (CDU) of hole patterns in ultra-fine patterns. Therefore, improvement of LWR and CDU has become a serious problem.

[0009] Here, a composition for forming a silicon-containing resist intermediate film for ArF or EUV lithography containing a curing catalyst has been proposed (Patent Documents 1, 2). This curing catalyst has a structure suitable for catalyzing the condensation reaction of silanol and promoting the formation of siloxane bonds that form the main skeleton of the silicon-containing resist intermediate film. Also, it has been gradually understood that the selection of the curing catalyst has various effects on the properties of the silicon-containing resist intermediate film. Examples include acidity / basicity, hydrophilicity / hydrophobicity, hardness, film density, etching rate, etc. Such a curing catalyst has a structure similar to that of a sensitivity regulator in the upper-layer resist. Therefore, when diffusion to the upper-layer resist occurs due to heating or exposure, it has become a problem that it has a great influence on the pattern formation ability of the photoresist. Especially since it affects the performance of LWR and CDU, the development of a curing catalyst with suppressed diffusion to the upper-layer resist is required.

[0010] On the other hand, for improving LWR and CDU, a photosensitive upper-layer resist material to which a compound having a cation and an anion in the molecule is added is known (Patent Document 3). However, in current ultra-fine patterns, higher-precision LWR and CDU are required, and improvement of the performance of the silicon-containing resist intermediate film is also needed.

Prior Art Documents

Patent Documents

[0011]

Patent Document 1

Patent Document 2

[0012] An object of the present invention is to provide a composition for forming a silicon-containing resist underlayer film capable of forming a silicon-containing resist underlayer film having an appropriate etching rate and capable of improving LWR and CDU in an ultrafine pattern in a multilayer resist method, a silicon-containing sulfonium salt compound contained in the composition, and a pattern forming method using the composition. [Means for Solving the Problems]

[0013] In order to solve the above problems, the present invention provides a silicon-containing sulfonium salt compound represented by the following general formula (A-1). [Chemical Formula] (In the formula, Ar 1 , Ar 2 , and Ar 3 are each independently an aromatic group having 6 to 20 carbon atoms which may have a substituent, or a heteroaromatic group having 4 to 20 carbon atoms which may have a substituent. Also, any two or more selected from Ar 1 , Ar 2 , and Ar 3 may be bonded to each other to form a ring together with the sulfur atom in the formula. a, b, and c are each independently an integer of 0 to 3, and 1 ≦ a + b + c ≦ 9. X, Y, and Z are monovalent organic groups having 1 to 14 carbon atoms, and may be the same as or different from each other. A - represents an organic or inorganic anion that becomes a counter ion of the sulfonium cation.)

[0014] Such a silicon-containing sulfonium salt compound can function as a curing catalyst by being added to a composition for forming a silicon-containing resist underlayer film, and can promote its thermal curing. Further, since the silicon-containing sulfonium salt compound of the present invention has a high affinity for a silicon polymer, by adding it to a composition for forming a silicon-containing resist underlayer film, diffusion into the upper-layer resist can be suppressed, and a silicon-containing resist underlayer film having good LWR and CDU characteristics can be formed. Furthermore, due to the effect of the silicon atom, a silicon-containing resist underlayer film having a good etching rate can be formed.

[0015] The present invention also provides a composition for forming a silicon-containing resist underlayer film, which contains the silicon-containing sulfonium salt compound described above and a thermally crosslinkable polysiloxane.

[0016] Such a composition for forming a silicon-containing resist underlayer film can form a silicon-containing resist underlayer film having an appropriate etching rate and capable of improving LWR and CDU in an ultrafine pattern in a multilayer resist method.

[0017] It is preferable that the thermally crosslinkable polysiloxane contains any one or more of a repeating unit represented by the following general formula (Sx-1), a repeating unit represented by the following general formula (Sx-2), and a partial structure represented by the following general formula (Sx-3).

Chemical formula

Chemical formula

Chemical formula

[0018] When the thermosetting polysiloxane contains the specific structure, the effects of the present invention can be more fully exerted.

[0019] The composition for forming a silicon-containing resist lower layer film of the present invention preferably further contains an acid generator.

[0020] By adding an acid generator as needed, the pattern shape, exposure sensitivity, etc. can be finely adjusted.

[0021] Preferably, the acid generator is a photoacid generator that generates an acid upon the action of high-energy rays.

[0022] In this case, while minimizing the deterioration of other performances, the pattern shape, exposure sensitivity, etc. of the resist upper layer film can be appropriately adjusted, and in addition, it may be effective in reducing residues derived from the resist upper layer film.

[0023] Further, in the present invention, a method for forming a pattern on a workpiece, comprising: forming an organic film on the workpiece using a coating-type organic film material; forming a silicon-containing resist lower layer film on the organic film using the composition for forming a silicon-containing resist lower layer film described above; forming a resist upper layer film on the silicon-containing resist lower layer film using a composition for a resist upper layer film composed of a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring the pattern to the silicon-containing resist lower layer film by etching using the resist upper layer film on which the circuit pattern is formed as a mask; transferring the pattern to the organic film by etching using the silicon-containing resist lower layer film on which the pattern is transferred as a mask; transferring the pattern to the workpiece by etching using the organic film on which the pattern is transferred as a mask and providing a pattern forming method including the above steps.

[0024] In addition, the present invention provides a method for forming a pattern on a workpiece, comprising: forming a hard mask on the workpiece by CVD method; forming a silicon-containing resist lower layer film on the hard mask using the composition for forming a silicon-containing resist lower layer film described above; forming a resist upper layer film on the silicon-containing resist lower layer film using a composition for a resist upper layer film comprising a photoresist composition; forming a circuit pattern on the resist upper layer film; transferring the pattern to the silicon-containing resist lower layer film by etching using the resist upper layer film on which the circuit pattern is formed as a mask; transferring the pattern to the hard mask by dry etching using the silicon-containing resist lower layer film on which the pattern is transferred as a mask; transferring the pattern to the workpiece by dry etching using the hard mask on which the pattern is transferred as a mask; and providing a pattern forming method including the above steps.

[0025] In the above pattern forming method, pattern collapse of the resist upper layer film is suppressed, and pattern transfer to the silicon-containing resist lower layer film by dry etching is excellent. In addition, removal of the remaining silicon-containing resist lower layer film after patterning is easy and defects due to residues are less likely to occur. Therefore, it is a practical pattern forming method particularly for forming fine patterns.

[0026] As a method for forming a circuit pattern on the resist upper layer film, it is preferable to use photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof.

[0027] When the method for forming a circuit pattern on the resist upper layer film is the above specific method, the effects of the present invention are more fully exerted.

[0028] As the workpiece, a semiconductor device substrate or a substrate with a metal film, metal carbide film, metal oxide film, metal nitride film, metal oxynitride film, or metal oxycarbide film formed thereon can be used.

[0029] When the above-mentioned specific workpiece is used, the effects of the present invention can be more fully exerted.

[0030] Furthermore, as the metal, it is preferable to use silicon, gallium, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, indium, arsenic, palladium, tantalum, iridium, aluminum, iron, molybdenum, cobalt, or an alloy thereof.

[0031] When the metal constituting the workpiece is the above-mentioned specific metal, the effects of the present invention can be more fully exerted.

Advantages of the Invention

[0032] As described above, in the case of the silicon-containing sulfonium salt compound of the present invention, by adding it to a composition for forming a silicon-containing resist lower layer film containing a thermally crosslinkable polysiloxane as a curing catalyst, not only can an ultrafine upper layer resist pattern having good LWR and CDU be formed, but also excellent dry etching selectivity with respect to the resist upper layer film and the organic film or hard mask is achieved, so that a pattern for a semiconductor device can be formed on a substrate with good yield. In addition, since the formed silicon-containing resist lower layer film has high etching selectivity with respect to the organic material, the formed upper layer resist pattern can be transferred to the silicon-containing resist lower layer film and the organic film or hard mask in sequence using a dry etching process. Furthermore, since the formed silicon-containing resist lower layer film has a sufficient etching rate, it is easy to remove the remaining silicon-containing resist lower layer film after patterning, and defects due to residues are unlikely to occur, so it is particularly useful for forming fine patterns.

Embodiments for Carrying Out the Invention

[0033] As described above, in the multilayer resist method, there has been a demand for the development of a silicon-containing resist underlayer film-forming composition capable of forming a silicon-containing resist underlayer film having an appropriate etching rate and capable of improving LWR and CDU in ultrafine patterns, a silicon-containing sulfonium salt compound contained in the composition, and a patterning method using the composition.

[0034] As a result of intensive studies to achieve the above object, the present inventors have found that by blending a silicon-containing sulfonium salt compound having a specific structure into a composition for forming a silicon-containing resist underlayer film, in the multilayer resist method, LWR and CDU of ultrafine patterns can be improved, and a silicon-containing resist underlayer film having an etching rate appropriate for processing can be provided, and thus the present invention has been completed.

[0035] That is, the present invention is a silicon-containing sulfonium salt compound represented by the following general formula (A-1). [Chemical formula] (In the formula, Ar 1 , Ar 2 , and Ar 3 are each independently an aromatic group having 6 to 20 carbon atoms which may have a substituent, or a heteroaromatic group having 4 to 20 carbon atoms which may have a substituent. Also, any two or more selected from Ar 1 , Ar 2 , and Ar 3 may be bonded to each other to form a ring together with the sulfur atom in the formula. a, b, and c are each independently an integer of 0 to 3, and 1 ≦ a + b + c ≦ 9. X, Y, and Z are monovalent organic groups having 1 to 14 carbon atoms, and may be the same as or different from each other. A - represents an organic or inorganic anion that becomes a counter ion of the sulfonium cation.)

[0036] Hereinafter, the present invention will be described in detail, but the present invention is not limited thereto.

[0037] <Composition for Forming Silicon-Containing Resist Underlayer Film> The composition for forming a silicon-containing resist underlayer film of the present invention contains a silicon-containing sulfonium salt compound represented by the following general formula (A-1) and a thermally crosslinkable polysiloxane. In addition, arbitrary components can be included in addition to these. Hereinafter, each component contained in the composition for forming a silicon-containing resist underlayer film of the present invention will be described in detail.

[0038] <Silicon-Containing Sulfonium Salt Compound> The silicon-containing sulfonium salt compound of the present invention is a silicon-containing sulfonium salt compound represented by the following general formula (A-1), and can be used as a curing catalyst. [Chemical formula] (In the formula, Ar 1 , Ar 2 , and Ar 3 are each independently an aromatic group having 6 to 20 carbon atoms which may have a substituent, or a heteroaromatic group having 4 to 20 carbon atoms which may have a substituent. Further, any two or more selected from Ar 1 , Ar 2 , and Ar 3 may be bonded to each other to form a ring together with the sulfur atom in the formula. a, b, and c are each independently an integer of 0 to 3, and 1 ≤ a + b + c ≤ 9. X, Y, and Z are monovalent organic groups having 1 to 14 carbon atoms, and may be the same as or different from each other. A - represents an organic or inorganic anion that becomes a counter ion of the sulfonium cation.)

[0039] By adding the silicon-containing sulfonium salt compound of the present invention to the composition for forming a silicon-containing resist underlayer film, it functions as a curing catalyst and promotes thermal curing. During curing, since this compound has a high affinity with the silicon polymer, diffusion into the upper layer resist is suppressed, contributing to the improvement of LWR and CDU. In addition, since the formed silicon-containing resist underlayer film has an appropriate composition and structure, it is considered to have a sufficient etching rate for processing.

[0040] In the present specification, those formed below the resist upper layer film are referred to as lower layer films, and include those referred to as resist lower layer films and silicon-containing resist intermediate films.

[0041] In the general formula (A-1), Ar 1 , Ar 2 , and Ar 3 each independently represents an aromatic group having 6 to 20 carbon atoms which may have a substituent, or a heteroaromatic group having 4 to 20 carbon atoms which may have a substituent. Specific examples of the aromatic group having 6 to 20 carbon atoms include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, and a pyrenyl group. Specific examples of the heteroaromatic group having 4 to 20 carbon atoms include a furanyl group, a thiophenyl group, a pyrrolyl group, a benzofuranyl group, a pyridinyl group, an indolyl group, an oxazolyl group, an imidazolyl group, and a benzimidazolyl group. Examples of the substituent which may be present include a linear, branched or cyclic saturated or unsaturated hydrocarbon group having 1 to 12 carbon atoms, an aromatic hydrocarbon group, a heteroaromatic group, an alkoxy group, a hydroxyl group, an ester group, a carbonyl group, an amino group, a halogen group, a sulfide group, a carboxy group, a sulfo group, an amide group, an imide group, a cyano group, an aldehyde group, an imino group, a urea group, a carbamate group, a carbonate group, a nitro group, a sulfonyl group, and a group formed by combining these groups. In order to more effectively exhibit the effects of the present invention, a phenyl group, a naphthyl group, a furanyl group, a thiophenyl group, a pyrrolyl group, and a pyridinyl group are preferred, and a phenyl group and a naphthyl group are more preferred. Further, any two or more of Ar 1 , Ar 2 , and Ar 3 selected from may be bonded to each other to form a ring together with the sulfur atom in the formula, but those that do not form a ring are more preferred from the viewpoints of solubility and stability.

[0042] In the general formula (A-1) above, X, Y, and Z are monovalent organic groups having 1 to 14 carbon atoms, and they may be the same as or different from each other. Specific examples of the monovalent organic group having 1 to 14 carbon atoms include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, an adamantyl group, an alkenyl group, an oxoalkyl group, an aryl group, an aralkyl group, an aryloxoalkyl group, etc.

[0043] Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, a cyclohexenyl group, etc. Examples of the oxoalkyl group include a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, etc., and a 2-oxopropyl group, a 2-cyclopentyl-2-oxoethyl group, a 2-cyclohexyl-2-oxoethyl group, a 2-(4-methylcyclohexyl)-2-oxoethyl group, etc. can be mentioned. Examples of the aryl group include a phenyl group, a naphthyl group, etc., and alkoxyphenyl groups such as a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, an m-tert-butoxyphenyl group, etc., alkylphenyl groups such as a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, an ethylphenyl group, a 4-tert-butylphenyl group, a 4-butylphenyl group, a dimethylphenyl group, etc., alkylnaphthyl groups such as a methylnaphthyl group, an ethylnaphthyl group, etc., alkoxynaphthyl groups such as a methoxynaphthyl group, an ethoxynaphthyl group, etc., dialkylnaphthyl groups such as a dimethylnaphthyl group, a diethylnaphthyl group, etc., dialkoxynaphthyl groups such as a dimethoxynaphthyl group, a diethoxynaphthyl group, etc. Examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenethyl group, etc. Examples of the aryloxoalkyl group include 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl group, 2-(1-naphthyl)-2-oxoethyl group, 2-(2-naphthyl)-2-oxoethyl group, and the like.

[0044] In order to more effectively exhibit the effects of the present invention, a methyl group, an ethyl group, and an isopropyl group are preferable, and a methyl group and an ethyl group are more preferable.

[0045] In the above general formula (A-1), A - represents an organic or inorganic anion that serves as a counter ion of the sulfonium cation. Specific examples of the organic anion include formate, acetate, propionate, butyrate, hexanoate, benzoate, t-butylbenzoate, trichloroacetate, trifluoroacetate, 2-hydroxy-2,2-bis(trifluoromethyl)acetate, trimethylacetate, pentafluoropropionate, methanesulfonate, butanesulfonate, benzenesulfonate, toluenesulfonate, trifluoromethanesulfonate, methyl sulfate ion, and the like. Specific examples of the inorganic anion include chloride ion, bromide ion, iodide ion, fluoride ion, cyanide ion, nitrate ion, nitrite ion, hydroxide ion, and the like. Among these anions, chloride ion, iodide ion, fluoride ion, nitrate ion, nitrite ion, and hydroxide ion are preferable, and chloride ion and nitrate ion are more preferable.

[0046] In the present invention, the silicon-containing sulfonium salt compound represented by the above general formula (A-1) may be used alone or in combination of two or more. The compounding amount of the silicon-containing sulfonium salt compound represented by the above general formula (A-1) is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, based on 100 parts by mass of the thermally crosslinkable polysiloxane (Sx) described below.

[0047] As the silicon-containing sulfonium salt compound represented by the above general formula (A-1), more specifically, the following compounds can be exemplified, but are not limited thereto. In the following formulas, Me represents a methyl group, and the same applies hereinafter.

[0048] [Chemical formula]

[0049] [Chemical formula]

[0050] [Chemical formula]

[0051] [Thermally crosslinkable polysiloxane] The composition for forming a silicon-containing resist lower layer film of the present invention contains a thermally crosslinkable polysiloxane in addition to one or more of the silicon-containing sulfonium salt compounds represented by the above general formula (A-1).

[0052] The thermally crosslinkable polysiloxane (Sx) used in the present invention preferably contains any one or more of a repeating unit represented by the following general formula (Sx-1), a repeating unit represented by the following general formula (Sx-2), and a partial structure represented by the following general formula (Sx-3). [Chemical formula] [Chemical formula] [Chemical formula] (In the formula, R 1 , R 2 , and R 3 are each independently a monovalent organic group having 1 to 30 carbon atoms which may be the same or different.)

[0053] The above-mentioned thermally crosslinkable polysiloxane (Sx) can be produced, for example, by hydrolytic condensation of the following hydrolyzable monomer (Sm).

[0054] Specific examples of the hydrolyzable monomer (Sm) include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetraisopropoxysilane, trimethoxysilane, triethoxysilane, tripropoxysilane, triisopropoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopropoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltripropoxysilane, ethyltriisopropoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltripropoxysilane, propyltriisopropoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, isopropyltripropoxysilane, isopropyltriisopropoxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltripropoxysilane, butyltriisopropoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, isobutyltripropoxysilane, isobutyltriisopropoxysilane, sec-butyltrimethoxysilane, sec-butyltriethoxysilane, sec-butyltripropoxysilane, sec-butyltriisopropoxysilane, t-butyltrimethoxysilane, t-butyltriethoxysilane, t-butyltripropoxysilane, t-butyltriisopropoxysilane, allyltrimethoxysilane, allyltriethoxysilane, allyltripropoxysilane, allyltriisopropoxysilane, cyclopropyltrimethoxysilane, cyclopropyltriethoxysilane, cyclopropyltripropoxysilane, cyclopropyltriisopropoxysilane, cyclobutyltrimethoxysilane, cyclobutyltriethoxysilane, cyclobutyltripropoxysilane, cyclobutyltriisopropoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, cyclopentyltripropoxysilane, cyclopentyltriisopropoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, cyclohexyltripropoxysilane,Cyclohexyltriisopropoxysilane, cyclohexenyltrimethoxysilane, cyclohexenyltriethoxysilane, cyclohexenyltripropoxysilane, cyclohexenyltriisopropoxysilane, cyclohexenylethyltrimethoxysilane, cyclohexenylethyltriethoxysilane, cyclohexenylethyltripropoxysilane, cyclohexenylethyltriisopropoxysilane, cyclooctyltrimethoxysilane, cyclooctyltriethoxysilane, cyclooctyltripropoxysilane, cyclooctyltriisopropoxysilane, cyclopentadienylpropyltrimethoxysilane, cyclopentadienylpropyltriethoxysilane, cyclopentadienylpropyltripropoxysilane, cyclopentadienylpropyltriisopropoxysilane, bicycloheptenyltrimethoxysilane, bicycloheptenyltriethoxysilane, bicycloheptenyltripropoxysilane, bicycloheptenyltriisopropoxysilane, bicycloheptyltrimethoxysilane, bicycloheptyltriethoxysilane, bicycloheptyltripropoxysilane, bicycloheptyltriisopropoxysilane, adamantyltrimethoxysilane, adamantyltriethoxysilane, adamantyltripropoxysilane, adamantyltriisopropoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, phenyltriisopropoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, benzyltripropoxysilane, benzyltriisopropoxysilane, anisyltrimethoxysilane, anisyltriethoxysilane, anisyltripropoxysilane, anisyltriisopropoxysilane, tolyltrimethoxysilane, tolyltriethoxysilane, tolyltripropoxysilane, tolyltriisopropoxysilane, phenethyltrimethoxysilane, phenethyltriethoxysilane, phenethyltripropoxysilane, phenethyltriisopropoxysilane, naphthyltrimethoxysilane, naphthyltriethoxysilane, naphthyltripropoxysilane, naphthyltriisopropoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, methylethyldiethoxysilaneDimethyldipropoxysilane, dimethyldiisopropoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldipropoxysilane, diethyldiisopropoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dipropyldipropoxysilane, dipropyldiisopropoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, diisopropyldipropoxysilane, diisopropyldiisopropoxysilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dibutyldipropoxysilane, dibutyldiisopropoxysilane, di-sec-butyldimethoxysilane, di-sec-butyldiethoxysilane, di-sec-butyldipropoxysilane, di-sec-butyldiisopropoxysilane, di-t-butyldimethoxysilane, di-t-butyldiethoxysilane, di-t-butyldipropoxysilane, di-t-butyldiisopropoxysilane, dicyclopropyldimethoxysilane, dicyclopropyldiethoxysilane, dicyclopropyldipropoxysilane, dicyclopropyldiisopropoxysilane, dicyclobutyldimethoxysilane, dicyclobutyldiethoxysilane, dicyclobutyldipropoxysilane, dicyclobutyldiisopropoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, dicyclopentyldipropoxysilane, dicyclopentyldiisopropoxysilane, dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane, dicyclohexyldipropoxysilane, dicyclohexyldiisopropoxysilane, dicyclohexenyldimethoxysilane, dicyclohexenyldiethoxysilane, dicyclohexenyldipropoxysilane, dicyclohexenyldiisopropoxysilane, dicyclohexenylethyldimethoxysilane, dicyclohexenylethyldiethoxysilane, dicyclohexenylethyldipropoxysilane, dicyclohexenylethyldiisopropoxysilane, dicyclooctyldimethoxysilane, dicyclooctyldiethoxysilane, dicyclooctyldipropoxysilane, dicyclooctyldiisopropoxysilane, dicyclopentadienylpropyldimethoxysilane, dicyclopentadienylpropyldiethoxysilane, dicyclopentadienylpropyldipropoxysilane,Examples thereof include dicyclopentadienylpropyl diisopropoxysilane, bis(bicycloheptenyl)dimethoxysilane, bis(bicycloheptenyl)diethoxysilane, bis(bicycloheptenyl)dipropoxysilane, bis(bicycloheptenyl)diisopropoxysilane, bis(bicycloheptyl)dimethoxysilane, bis(bicycloheptyl)diethoxysilane, bis(bicycloheptyl)dipropoxysilane, bis(bicycloheptyl)diisopropoxysilane, diadamantyldimethoxysilane, diadamantyldiethoxysilane, diadamantyldipropoxysilane, diadamantyldiisopropoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, diphenyldipropoxysilane, diphenyldiisopropoxysilane, trimethylmethoxysilane, trimethylethoxysilane, dimethylethylmethoxysilane, dimethylethylethoxysilane, dimethylphenylmethoxysilane, dimethylphenylethoxysilane, dimethylbenzylmethoxysilane, dimethylbenzylethoxysilane, dimethylphenethylmethoxysilane, dimethylphenethylethoxysilane, etc.

[0055] As the above compound, preferably, tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, butyltrimethoxysilane, butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, allyltrimethoxysilane, allyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, cyclohexenyltrimethoxysilane, cyclohexenyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, benzyltrimethoxysilane, benzyltriethoxysilane, phenethyltrimethoxysilane, phenethyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, methylethyldimethoxysilane, methylethyldiethoxysilane, dipropyldimethoxysilane, dibutyldimethoxysilane, methylphenyldimethoxysilane, methylphenyldiethoxysilane, trimethylmethoxysilane, dimethylethylmethoxysilane, dimethylphenylmethoxysilane, dimethylbenzylmethoxysilane, dimethylphenethylmethoxysilane, etc. can be exemplified.

[0056] The above R 1 , R 2 , and R 3 As another example of the organic group represented by, an organic group having one or more carbon-oxygen single bonds or carbon-oxygen double bonds can be mentioned. Specifically, it is an organic group having one or more groups selected from the group consisting of an ether bond, an ester bond, an alkoxy group, a hydroxy group, etc. As this example, those represented by the following general formula (Sm-R) can be mentioned.

[0057] (P-Q1-(S1) v1 -Q2-) u -(T)v2 -Q3-(S2) v3 -Q4- (Sm-R) (In the general formula (Sm-R), P is a hydrogen atom, a cyclic ether group, a hydroxy group, an alkoxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 6 carbon atoms, or an alkylcarbonyl group having 2 to 6 carbon atoms, and Q1, Q2, Q3, and Q4 are each independently -C q H (2q-p) P p -(wherein P is the same as above, p is an integer of 0 to 3, q is an integer of 0 to 10 (provided that q = 0 indicates a single bond), u is an integer of 0 to 3, and S1 and S2 each independently represent -O-, -CO-, -OCO-, -COO-, or -OCOO-. v1, v2, and v3 each independently represent 0 or 1. T is a divalent group consisting of a divalent atom other than carbon, an alicyclic ring, an aromatic ring, or a heterocyclic ring.)

[0058] Examples of the alicyclic ring, aromatic ring, or heterocyclic ring that may contain a hetero atom such as an oxygen atom as T are shown below. The position where Q2 and Q3 are bonded in T is not particularly limited, but it can be appropriately selected in consideration of factors such as reactivity due to steric factors and availability of commercially available reagents used in the reaction.)

[0059]

Chemical formula

[0060] Preferred examples of the organic group having one or more carbon-oxygen single bonds or carbon-oxygen double bonds in the general formula (Sm-R) include the following. In the following formulas, (Si) is described to indicate the bonding position with Si.)

[0061]

Chemical formula

[0062]

Chemical formula

[0063] Also, as examples of the organic groups of R 1 , R 2 , and R 3 , organic groups containing a silicon-silicon bond can also be used. Specifically, the following can be mentioned. [Chemical formula]

[0064] Also, as examples of the organic groups of R 1 , R 2 , and R 3 , organic groups having a protecting group that decomposes with an acid can also be used. Specifically, the organic groups listed in paragraphs

[0043] to

[0048] of JP-A No. 2013-167669 and the organic groups obtained from the silicon compounds shown in paragraph

[0056] of JP-A No. 2013-224279 can be mentioned.

[0065] Furthermore, as examples of the organic groups of R 1 , R 2 , and R 3 , organic groups having a fluorine atom can also be used. Specifically, the organic groups obtained from the silicon compounds shown in paragraphs

[0059] to

[0065] of JP-A No. 2012-053253 can be mentioned.

[0066] In the above hydrolyzable monomer (Sm), one, two, or three chlorine, bromine, iodine, acetoxy group, methoxy group, ethoxy group, propoxy group, or butoxy group, etc. are bonded as hydrolyzable groups to the silicon shown in the above partial structure (Si).

[0067] [Synthesis method of thermally crosslinkable polysiloxane (Sx)] (Synthesis method 1: Acid catalyst) The thermally crosslinkable polysiloxane (Sx) used in the present invention can be produced by subjecting a mixture of one or more hydrolyzable monomers (Sm) to hydrolysis and condensation in the presence of an acid catalyst.

[0068] The acid catalysts used at this time include organic acids such as formic acid, acetic acid, oxalic acid, maleic acid, methanesulfonic acid, benzenesulfonic acid, and toluenesulfonic acid, and inorganic acids such as hydrofluoric acid, hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, perchloric acid, and phosphoric acid. The amount of the catalyst used is preferably 1×10 -6 ~10 moles, more preferably 1×10 -5 ~5 moles, still more preferably 1×10 -4 ~1 mole per mole of the monomer.

[0069] When obtaining the thermally crosslinkable polysiloxane (Sx) by hydrolysis condensation from these monomers, the amount of water added is preferably 0.01 to 100 moles, more preferably 0.05 to 50 moles, still more preferably 0.1 to 30 moles per mole of the hydrolyzable substituent bonded to the monomer. If it is 100 moles or less, the apparatus used for the reaction becomes smaller and more economical. If it is 0.01 mole or more, the reaction proceeds sufficiently.

[0070] As an operation method, the monomer is added to the aqueous catalyst solution to initiate the hydrolysis condensation reaction. At this time, an organic solvent may be added to the aqueous catalyst solution, the monomer may be diluted with an organic solvent, or both may be done. The reaction temperature is preferably 0 to 100 °C, more preferably 5 to 80 °C. A method of maintaining the temperature at 5 to 80 °C during the dropping of the monomer and then aging at 20 to 80 °C is preferred.

[0071] Examples of the organic solvent that can be added to the catalyst aqueous solution or dilute the monomer include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, ethylene glycol, propylene glycol, acetone, acetonitrile, tetrahydrofuran, toluene, hexane, ethyl acetate, acetone, methyl ethyl ketone, methyl isobutyl ketone, 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, ethylene glycol monopropyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, t-butyl propionate, propylene glycol mono-t-butyl ether acetate, γ-butyrolactone, acetonitrile, tetrahydrofuran, and mixtures thereof, etc. are preferred.

[0072] Among these organic solvents, preferred ones are water-soluble ones. For example, alcohols such as methanol, ethanol, 1-propanol, 2-propanol, polyhydric alcohols such as ethylene glycol, propylene glycol, polyhydric alcohol condensate derivatives such as 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, acetone, acetonitrile, tetrahydrofuran, etc. can be mentioned. Among them, particularly preferred are those having a boiling point of 100 °C or lower.

[0073] Incidentally, the amount of the organic solvent used is preferably 0 to 1,000 ml, particularly preferably 0 to 500 ml, per 1 mol of the monomer. When the amount of the organic solvent used is reduced, the reaction vessel becomes smaller, which is economical.

[0074] Thereafter, if necessary, a neutralization reaction of the catalyst is carried out to obtain an aqueous solution of the reaction mixture. At this time, the amount of the alkaline substance that can be used for neutralization is preferably 0.1 to 2 equivalents with respect to the acid used in the catalyst. Any substance may be used as long as it shows alkalinity in water.

[0075] Subsequently, it is preferable to remove by-products such as alcohol produced by the hydrolysis condensation reaction from the aqueous solution of the reaction mixture by means of reduced pressure removal or the like. The temperature at which the aqueous solution of the reaction mixture is heated depends on the types of the added organic solvent and the alcohol generated by the reaction, etc., but is preferably 0 to 100°C, more preferably 10 to 90°C, and still more preferably 15 to 80°C. Also, the degree of reduced pressure at this time varies depending on the types of the organic solvent and alcohol to be removed, the exhaust device, the condensation device, and the heating temperature, but is preferably below atmospheric pressure, more preferably 80 kPa or less in absolute pressure, and still more preferably 50 kPa or less in absolute pressure. Although it is difficult to accurately know the amount of alcohol removed at this time, it is desirable that approximately 80 mass% or more of the generated alcohol or the like is removed.

[0076] Next, the acid catalyst used for hydrolysis condensation may be removed from the aqueous solution of the reaction mixture. As a method for removing the acid catalyst, water and a thermally crosslinkable polysiloxane solution are mixed, and the thermally crosslinkable polysiloxane is extracted with an organic solvent. The organic solvent used at this time is preferably one that can dissolve the thermally crosslinkable polysiloxane and separates into two layers when mixed with water. For example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, acetone, 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, butanediol monopropyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono-t-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, tetrahydrofuran, and mixtures thereof, etc. can be mentioned.

[0077] Furthermore, it is also possible to use a mixture of a water-soluble organic solvent and a water-insoluble organic solvent. For example, methanol-ethyl acetate mixture, ethanol-ethyl acetate mixture, 1-propanol-ethyl acetate mixture, 2-propanol-ethyl acetate mixture, butanediol monomethyl ether-ethyl acetate mixture, propylene glycol monomethyl ether-ethyl acetate mixture, ethylene glycol monomethyl ether-ethyl acetate mixture, butanediol monoethyl ether-ethyl acetate mixture, propylene glycol monoethyl ether-ethyl acetate mixture, ethylene glycol monoethyl ether-ethyl acetate mixture, butanediol monopropyl ether-ethyl acetate mixture, propylene glycol monopropyl ether-ethyl acetate mixture, ethylene glycol monopropyl ether-ethyl acetate mixture, methanol-methyl isobutyl ketone mixture, ethanol-methyl isobutyl ketone mixture, 1-propanol-methyl isobutyl ketone mixture, 2-propanol-methyl isobutyl ketone mixture, propylene glycol monomethyl ether-methyl isobutyl ketone mixture, ethylene glycol monomethyl ether-methyl isobutyl ketone mixture, propylene glycol monoethyl ether-methyl isobutyl ketone mixture, ethylene glycol monoethyl ether-methyl isobutyl ketone mixture, propylene glycol monopropyl ether-methyl isobutyl ketone mixture, ethylene glycol monopropyl ether-methyl isobutyl ketone mixture, methanol-cyclopentyl methyl ether mixture, ethanol-cyclopentyl methyl ether mixture, 1-propanol-cyclopentyl methyl ether mixture, 2-propanol-cyclopentyl methyl ether mixture, propylene glycol monomethyl ether-cyclopentyl methyl ether mixture, ethylene glycol monomethyl ether-cyclopentyl methyl ether mixture, propylene glycol monoethyl ether-cyclopentyl methyl ether mixture, ethylene glycol monoethyl ether-cyclopentyl methyl ether mixture, propylene glycol monopropyl ether-cyclopentyl methyl ether mixture, ethylene glycol monopropyl ether-cyclopentyl methyl ether mixture,Methanol-propylene glycol methyl ether acetate mixture, ethanol-propylene glycol methyl ether acetate mixture, 1-propanol-propylene glycol methyl ether acetate mixture, 2-propanol-propylene glycol methyl ether acetate mixture, propylene glycol monomethyl ether-propylene glycol methyl ether acetate mixture, ethylene glycol monomethyl ether-propylene glycol methyl ether acetate mixture, propylene glycol monoethyl ether-propylene glycol methyl ether acetate mixture, ethylene glycol monoethyl ether-propylene glycol methyl ether acetate mixture, propylene glycol monopropyl ether-propylene glycol methyl ether acetate mixture, ethylene glycol monopropyl ether-propylene glycol methyl ether acetate mixture, etc. are preferred, but the combination is not limited thereto.

[0078] In addition, the mixing ratio of the water-soluble organic solvent and the water-insoluble organic solvent is appropriately selected. However, with respect to 100 parts by mass of the water-insoluble organic solvent, 0.1 to 1,000 parts by mass of the water-soluble organic solvent is preferred, more preferably 1 to 500 parts by mass, and still more preferably 2 to 100 parts by mass.

[0079] Subsequently, it may be washed with neutral water. As this water, what is usually called deionized water or ultrapure water may be used. The amount of this water is preferably 0.01 to 100 L, more preferably 0.05 to 50 L, and still more preferably 0.1 to 5 L with respect to 1 L of the thermally crosslinkable polysiloxane solution. For this washing method, both may be put in the same container, stirred, and then left to stand to separate the aqueous layer. The number of washing times may be 1 or more, but washing 10 times or more does not provide any additional washing effect, so it is preferably about 1 to 5 times.

[0080] As other methods for removing the acid catalyst, methods using an ion exchange resin and methods of neutralizing with an epoxy compound such as ethylene oxide or propylene oxide and then removing can be mentioned. These methods can be appropriately selected according to the acid catalyst used in the reaction.

[0081] In the water washing operation at this time, a part of the thermally crosslinkable polysiloxane may escape into the aqueous layer, and an effect equivalent to a fractionation operation may be obtained. Therefore, the number of water washing times and the amount of washing water may be appropriately selected in view of the catalyst removal effect and the fractionation effect.

[0082] In both the thermally crosslinkable polysiloxane solution in which the acid catalyst remains and the thermally crosslinkable polysiloxane solution from which the acid catalyst has been removed, the final solvent is added and the solvent is exchanged under reduced pressure to obtain a desired thermally crosslinkable polysiloxane solution. The temperature of the solvent exchange at this time depends on the type of reaction solvent or extraction solvent to be removed, but is preferably 0 to 100°C, more preferably 10 to 90°C, and still more preferably 15 to 80°C. Also, the degree of reduced pressure at this time varies depending on the type of extraction solvent to be removed, the exhaust device, the condensation device, and the heating temperature, but is preferably below atmospheric pressure, more preferably 80 kPa or less in absolute pressure, and still more preferably 50 kPa or less in absolute pressure.

[0083] At this time, the thermally crosslinkable polysiloxane may become unstable due to the change of the solvent. This is caused by the compatibility between the final solvent and the thermally crosslinkable polysiloxane. To prevent this, as a stabilizer, a monohydric or polyhydric alcohol having a cyclic ether described in paragraphs

[0181] to

[0182] of JP-A-2009-126940 as a substituent may be added. The amount to be added is preferably 0 to 25 parts by mass, more preferably 0 to 15 parts by mass, and still more preferably 0 to 5 parts by mass with respect to 100 parts by mass of the thermally crosslinkable polysiloxane in the solution before the solvent exchange. However, when adding, 0.5 part by mass or more is preferable. If necessary, a monohydric or polyhydric alcohol having a cyclic ether as a substituent may be added to the solution before the solvent exchange to perform the solvent exchange operation.

[0084] The thermally crosslinkable polysiloxane is preferably kept in a solution state at an appropriate concentration. The concentration at this time is preferably 0.1 to 20% by mass. At such a concentration, since further condensation reaction does not proceed, it does not change to a state where it cannot be redissolved in the organic solvent. Also, since the amount of the solvent is reduced, it is economical and preferable.

[0085] The preferable final solvent to be added to the thermally crosslinkable polysiloxane solution is an alcohol-based solvent, and particularly preferable are monoalkyl ether derivatives such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, and butanediol. Specifically, 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, diacetone alcohol, etc. are preferable.

[0086] If these solvents are the main components, it is also possible to add a non-alcohol-based solvent as an auxiliary solvent. Examples of this auxiliary solvent include acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono-t-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, etc.

[0087] As another reaction operation using an acid catalyst, water or a water-containing organic solvent is added to a monomer or an organic solution of the monomer to initiate a hydrolysis reaction. At this time, the catalyst may be added to the monomer or the organic solution of the monomer, or may be added to water or the water-containing organic solvent. The reaction temperature is preferably 0 to 100°C, more preferably 10 to 80°C. A method of heating to 10 to 50°C during the dropwise addition of water and then raising the temperature to 20 to 80°C for aging is preferred.

[0088] When using an organic solvent, a water-soluble one is preferred, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran, acetonitrile, 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, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether, and polyhydric alcohol condensate derivatives such as these and mixtures thereof.

[0089] The amount of the organic solvent used is preferably 0 to 1,000 ml, particularly 0 to 500 ml, per 1 mol of the monomer. When the amount of the organic solvent used is small, the reaction vessel becomes smaller and it is economical. The post-treatment of the obtained aqueous reaction mixture can be carried out in the same manner as described above to obtain a thermally crosslinkable polysiloxane.

[0090] (Synthesis Method 2: Alkali Catalyst) In addition, the thermally crosslinkable polysiloxane (Sx) can be produced by subjecting one or more hydrolyzable monomers (Sm) to hydrolysis and condensation in the presence of an alkali catalyst. The alkali catalysts used at this time include methylamine, ethylamine, propylamine, butylamine, ethylenediamine, hexamethylenediamine, dimethylamine, diethylamine, ethylmethylamine, trimethylamine, triethylamine, tripropylamine, tributylamine, cyclohexylamine, dicyclohexylamine, monoethanolamine, diethanolamine, dimethylmonoethanolamine, monomethyldiethanolamine, triethanolamine, diazabicyclooctane, diazabicyclononene, diazabicycloundecene, hexamethylenetetramine, aniline, N,N-dimethylaniline, pyridine, 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 catalyst used is preferably 1×10 -6 mol to 10 mol, more preferably 1×10 -5 mol to 5 mol, still more preferably 1×10 -4 mol to 1 mol.

[0091] When obtaining the thermally crosslinkable polysiloxane by hydrolysis and condensation from the above monomers, it is preferable to add 0.1 to 50 mol of water per 1 mol of the hydrolyzable substituent bonded to the monomer. If it is 50 mol or less, the apparatus used for the reaction becomes smaller and more economical. If it is 0.1 mol or more, the reaction proceeds sufficiently.

[0092] As an operation method, a monomer is added to an aqueous catalyst solution to initiate a hydrolysis-condensation reaction. At this time, an organic solvent may be added to the aqueous catalyst solution, the monomer may be diluted with an organic solvent, or both may be carried out. The reaction temperature is preferably 0 to 100°C, more preferably 5 to 80°C. A method of maintaining the temperature at 5 to 80°C during the dropping of the monomer and then aging at 20 to 80°C is preferred.

[0093] As the organic solvent that can be added to the alkaline aqueous catalyst solution or can dilute the monomer, the same organic solvents as those exemplified as the ones that can be added to the acidic aqueous catalyst solution are preferably used. In addition, for the economic conduct of the reaction, the amount of the organic solvent used is preferably 0 to 1,000 ml per mole of the monomer.

[0094] Thereafter, if necessary, a neutralization reaction of the catalyst is carried out to obtain an aqueous reaction mixture solution. At this time, the amount of the acidic substance that can be used for neutralization is preferably 0.1 to 2 equivalents with respect to the alkaline substance used as the catalyst. Any substance may be used as long as it shows acidity in water.

[0095] Subsequently, it is preferable to remove by-products such as alcohol generated by the hydrolysis-condensation reaction from the aqueous reaction mixture solution by means of reduced pressure removal or the like. At this time, the temperature for heating the aqueous reaction mixture solution depends on the type of the added organic solvent and the alcohol generated by the reaction, but is preferably 0 to 100°C, more preferably 10 to 90°C, and still more preferably 15 to 80°C. Also, the degree of reduced pressure at this time varies depending on the types of the organic solvent and alcohol to be removed, the exhaust device, the condensation device, and the heating temperature, but is preferably below atmospheric pressure, more preferably 80 kPa or less in absolute pressure, and still more preferably 50 kPa or less in absolute pressure. Although it is difficult to accurately know the amount of alcohol removed at this time, it is desirable that approximately 80 mass% or more of the generated alcohol is removed.

[0096] Next, in order to remove the catalyst used in the hydrolysis condensation, the thermally crosslinkable polysiloxane is extracted with an organic solvent. As the organic solvent to be used at this time, those that can dissolve the thermally crosslinkable polysiloxane and separate into two layers when mixed with water are preferable. For example, methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran, toluene, hexane, ethyl acetate, cyclohexanone, methyl amyl ketone, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, t-butyl acetate, t-butyl propionate, propylene glycol mono-t-butyl ether acetate, γ-butyrolactone, methyl isobutyl ketone, cyclopentyl methyl ether, and mixtures thereof, etc. can be mentioned.

[0097] Furthermore, it is also possible to use a mixture of a water-soluble organic solvent and a water-insoluble organic solvent.

[0098] Specific examples of the organic solvent used when removing the alkali catalyst can be the same as those specifically exemplified above for the organic solvents used when removing the acid catalyst and the mixture of a water-soluble organic solvent and a water-insoluble organic solvent.

[0099] In addition, the mixing ratio of the water-soluble organic solvent and the water-insoluble organic solvent is appropriately selected, but for 100 parts by mass of the water-insoluble organic solvent, preferably 0.1 to 1,000 parts by mass of the water-soluble organic solvent, more preferably 1 to 500 parts by mass, and still more preferably 2 to 100 parts by mass.

[0100] Subsequently, wash with neutral water. As this water, what is usually called deionized water or ultrapure water may be used. The amount of this water is preferably 0.01 to 100 L, more preferably 0.05 to 50 L, and preferably 0.1 to 5 L with respect to 1 L of the thermally crosslinkable polysiloxane solution. As for the method of this washing, both may be put in the same container, stirred, and then left to stand to separate the aqueous layer. The number of washing times may be one or more, but even if washed 10 times or more, only the effect of washing is not obtained, so it is preferably about 1 to 5 times.

[0101] Add the final solvent to the washed thermally crosslinkable polysiloxane solution and perform solvent exchange under reduced pressure to obtain the desired thermally crosslinkable polysiloxane solution. The temperature of the solvent exchange at this time depends on the type of extraction solvent to be removed, but is preferably 0 to 100 °C, more preferably 10 to 90 °C, and still more preferably 15 to 80 °C. Also, the degree of reduced pressure at this time varies depending on the type of extraction solvent to be removed, the exhaust device, the condensation device, and the heating temperature, but is preferably below atmospheric pressure, more preferably 80 kPa or less in absolute pressure, and still more preferably 50 kPa or less in absolute pressure.

[0102] A preferable final solvent to be added to the thermally crosslinkable polysiloxane solution is an alcohol-based solvent, and particularly preferable ones are monoalkyl ether derivatives such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol. Specifically, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, diacetone alcohol, etc. are preferable.

[0103] As another reaction operation using an alkali catalyst, water or a water-containing organic solvent is added to a monomer or an organic solution of the monomer to initiate a hydrolysis reaction. At this time, the catalyst may be added to the monomer or the organic solution of the monomer, or may be added to the water or the water-containing organic solvent. The reaction temperature is preferably 0 to 100°C, more preferably 10 to 80°C. A method of heating to 10 to 50°C during the dropping of water and then raising the temperature to 20 to 80°C for aging is preferred.

[0104] As the organic solvent that can be used as the organic solution of the monomer or the water-containing organic solvent, water-soluble ones are preferred, such as methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-1-propanol, acetone, tetrahydrofuran, acetonitrile, propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol monopropyl ether, ethylene glycol monopropyl ether, propylene glycol dimethyl ether, diethylene glycol dimethyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether, and polyhydric alcohol condensate derivatives such as these, and mixtures thereof.

[0105] The molecular weight of the thermally crosslinkable polysiloxane obtained by the above synthesis method 1 or 2 can be adjusted by controlling the reaction conditions during polymerization as well as by the selection of the monomer. However, if the weight average molecular weight is 100,000 or less, no foreign matter generation or coating spots will occur. Therefore, it is preferable to use those with a weight average molecular weight of 100,000 or less, more preferably 200 to 50,000, and still more preferably 300 to 30,000. The data regarding the above weight average molecular weight is represented by the molecular weight in terms of polystyrene using gel permeation chromatography (GPC) with RI as the detector and tetrahydrofuran as the eluent solvent, and using polystyrene as the standard substance.

[0106] The physical properties of the thermosetting polysiloxane used in the present invention vary depending on the type of acid or alkali catalyst used during hydrolysis and condensation and the reaction conditions. Therefore, it can be appropriately selected according to the performance of the target resist underlayer film.

[0107] Furthermore, a mixture of one or more hydrolyzable monomers (Sm) and a hydrolyzable metal compound represented by the following general formula (Mm) can be used as a component of the resist underlayer film-forming composition, which is produced under conditions using the above-mentioned acid or alkali catalyst.

Chemical formula

[0108] Examples of the hydrolyzable metal compound represented by the general formula (Mm) used at this time include the following. When U is boron, examples of the hydrolyzable metal compound represented by the general formula (Mm) include boron methoxide, boron ethoxide, boron propoxide, boron butoxide, boron amyloxide, boron hexyloxide, boron cyclopentoxide, boron cyclohexyloxide, boron allyloxide, boron phenoxide, boron methoxyethoxide, boric acid, boron oxide, etc.

[0109] When U is aluminum, examples of the hydrolyzable metal compound represented by the general formula (Mm) include aluminum methoxide, aluminum ethoxide, aluminum propoxide, aluminum butoxide, aluminum amyloxide, aluminum hexyloxide, aluminum cyclopentoxide, aluminum cyclohexyloxide, aluminum allyloxide, aluminum phenoxide, aluminum methoxyethoxide, aluminum ethoxyethoxide, aluminum dipropoxyethyl acetoacetate, aluminum dibutoxyethyl acetoacetate, aluminum propoxybisethyl acetoacetate, aluminum butoxybisethyl acetoacetate, aluminum 2,4-pentanedionate, aluminum 2,2,6,6-tetramethyl-3,5-heptanedionate, and the like.

[0110] When U is gallium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include gallium methoxide, gallium ethoxide, gallium propoxide, gallium butoxide, gallium amyloxide, gallium hexyloxide, gallium cyclopentoxide, gallium cyclohexyloxide, gallium allyloxide, gallium phenoxide, gallium methoxyethoxide, gallium ethoxyethoxide, gallium dipropoxyethyl acetoacetate, gallium dibutoxyethyl acetoacetate, gallium propoxybisethyl acetoacetate, gallium butoxybisethyl acetoacetate, gallium 2,4-pentanedionate, gallium 2,2,6,6-tetramethyl-3,5-heptanedionate, and the like.

[0111] When U is yttrium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include yttrium methoxide, yttrium ethoxide, yttrium propoxide, yttrium butoxide, yttrium amyloxide, yttrium hexyloxide, yttrium cyclopentoxide, yttrium cyclohexyloxide, yttrium allyloxide, yttrium phenoxide, yttrium methoxyethoxide, yttrium ethoxyethoxide, yttrium dipropoxyethyl acetoacetate, yttrium dibutoxyethyl acetoacetate, yttrium propoxybisethyl acetoacetate, yttrium butoxybisethyl acetoacetate, yttrium 2,4-pentanedionate, yttrium 2,2,6,6-tetramethyl-3,5-heptanedionate, and the like.

[0112] When U is germanium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include germanium methoxide, germanium ethoxide, germanium propoxide, germanium butoxide, germanium amyloxide, germanium hexyloxide, germanium cyclopentoxide, germanium cyclohexyloxide, germanium allyloxide, germanium phenoxide, germanium methoxyethoxide, germanium ethoxyethoxide, and the like.

[0113] When U is titanium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include titanium methoxide, titanium ethoxide, titanium propoxide, titanium butoxide, titanium amyloxide, titanium hexyloxide, titanium cyclopentoxide, titanium cyclohexyloxide, titanium allyloxide, titanium phenoxide, titanium methoxyethoxide, titanium ethoxyethoxide, titanium dipropoxybisethyl acetoacetate, titanium dibutoxybisethyl acetoacetate, titanium dipropoxybis2,4-pentanedionate, titanium dibutoxybis2,4-pentanedionate, and the like.

[0114] When U is hafnium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include hafnium methoxide, hafnium ethoxide, hafnium propoxide, hafnium butoxide, hafnium amyloxide, hafnium hexyloxide, hafnium cyclopentoxide, hafnium cyclohexyloxide, hafnium allyloxide, hafnium phenoxide, hafnium methoxyethoxide, hafnium ethoxyethoxide, hafnium dipropoxybisethylacetoacetate, hafnium dibutoxybisethylacetoacetate, hafnium dipropoxybis 2,4-pentanedionate, hafnium dibutoxybis 2,4-pentanedionate, and the like.

[0115] When U is tin, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxytin, ethoxytin, propoxytin, butoxytin, phenoxytin, methoxyethoxytin, ethoxyethoxytin, tin 2,4-pentanedionate, tin 2,2,6,6-tetramethyl-3,5-heptanedionate, and the like.

[0116] When U is arsenic, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxyarsenic, ethoxyarsenic, propoxyarsenic, butoxyarsenic, phenoxyarsenic, and the like.

[0117] When U is antimony, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxyantimony, ethoxyantimony, propoxyantimony, butoxyantimony, phenoxyantimony, antimony acetate, antimony propionate, and the like.

[0118] When U is niobium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxyniobium, ethoxyniobium, propoxyniobium, butoxyniobium, phenoxyniobium, and the like.

[0119] When U is tantalum, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxytantalum, ethoxytantalum, propoxytantalum, butoxytantalum, phenoxytantalum, and the like.

[0120] When U is bismuth, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxybismuth, ethoxybismuth, propoxybismuth, butoxybismuth, phenoxybismuth, and the like.

[0121] When U is phosphorus, examples of the hydrolyzable metal compound represented by the general formula (Mm) include trimethyl phosphate, triethyl phosphate, tripropyl phosphate, trimethyl phosphite, triethyl phosphite, tripropyl phosphite, diphosphorus pentoxide, and the like.

[0122] When U is vanadium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include vanadium oxide bis(2,4-pentanedionate), vanadium 2,4-pentanedionate, vanadium tributoxide oxide, vanadium tripropoxide oxide, and the like.

[0123] When U is zirconium, examples of the hydrolyzable metal compound represented by the general formula (Mm) include methoxyzirconium, ethoxyzirconium, propoxyzirconium, butoxyzirconium, phenoxyzirconium, zirconium dibutoxide bis(2,4-pentanedionate), zirconium dipropoxide bis(2,2,6,6-tetramethyl-3,5-heptanedionate), and the like.

[0124] In the composition for forming a silicon-containing resist underlayer film of the present invention, the blending amount of the thermally crosslinkable polysiloxane (Sx) is preferably, for example, 0.1 to 10% by mass based on the solvent.

[0125] [Acid generator] The composition for forming a silicon-containing resist underlayer film of the present invention preferably further contains an acid generator. One or more acid generators can be blended. As the acid generator, any substance that acts as an acid precursor, such as a thermal acid generator, a photoacid generator, or an acid proliferator, can be used. However, in the present invention, it is preferable that the acid generator is a photoacid generator that generates an acid by the action of high-energy rays, and the acid generator to be blended is a sulfonium salt and is more preferably a photoacid generator that generates an acid by the action of high-energy rays. More specifically, the materials described in paragraphs

[0160] to

[0179] of JP-A-2009-126940 can be exemplified, but are not limited thereto. The blending amount of the acid generator is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the thermally crosslinkable polysiloxane (Sx).

[0126] [Other components] (Crosslinking catalyst) In the composition for forming a silicon-containing resist underlayer film of the present invention, in addition to the silicon-containing sulfonium salt compound represented by the general formula (A-1), another crosslinking catalyst (Xc) may be blended. Examples of the crosslinking catalyst (Xc) that can be blended include compounds represented by the following general formula (Xc0). L a H b A (Xc0) (In the general formula (Xc0), L is lithium, sodium, potassium, rubidium, cesium, sulfonium, iodonium, phosphonium, or ammonium, A is a non-nucleophilic counter ion, a is an integer of 1 or more, b is 0 or an integer of 1 or more, and a + b is the valence of the non-nucleophilic counter ion.)

[0127] Examples of the crosslinking catalyst (Xc) used in the present invention as a compound represented by the specific general formula (Xc0) include a sulfonium salt of the following general formula (Xc-1), an iodonium salt of (Xc-2), a phosphonium salt of (Xc-3), an ammonium salt of (Xc-4), an alkali metal salt, and the like.

[0128] Examples of the sulfonium salt (Xc-1), iodonium salt (Xc-2), phosphonium salt (Xc-3), and ammonium salt (Xc-4) are as follows.

[0129] [Chemical formula] [Chemical formula] (In the formula, R 204 , R 205 , R 206 , and R 207 each represent a linear, branched, or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 12 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted by an alkoxy group or the like. Further, R 205 and R 206 may form a ring, and when forming a ring, R 205 , R 206 each represent an alkylene group having 1 to 6 carbon atoms. A - represents a non-nucleophilic counter ion. R 208 , R 209 , R 210 , and R 211 are the same as R 204 , R 205 , R 206 , and R 207 , but may be a hydrogen atom. R 208 and R 209 , or R 208 and R 209 and R 210 may form a ring, and when forming a ring, R 208 and R 209 , and R 208 and R 209 and R 210 represent an alkylene group having 3 to 10 carbon atoms.)

[0130] The above R 204 , R 205 , R206 , R 207 , R 208 , R 209 , R 210 , and R 211They may be the same as or different from each other. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopropylmethyl group, a 4-methylcyclohexyl group, a cyclohexylmethyl group, a norbornyl group, an adamantyl group, and the like. Specific examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a hexenyl group, a cyclohexenyl group, and the like. Specific examples of the oxoalkyl group include a 2-oxocyclopentyl group, a 2-oxocyclohexyl group, a 2-oxopropyl group, a 2-cyclopentyl-2-oxoethyl group, a 2-cyclohexyl-2-oxoethyl group, a 2-(4-methylcyclohexyl)-2-oxoethyl group, and the like. Specific examples of the oxoalkenyl group include a 2-oxopropenyl group, a 2-oxobutenyl group, a 2-oxohexenyl group, a 2-oxocyclopentenyl group, a 2-oxocyclohexenyl group, and the like. Specific examples of the aryl group include a phenyl group, a naphthyl group, and alkoxyphenyl groups such as a p-methoxyphenyl group, an m-methoxyphenyl group, an o-methoxyphenyl group, an ethoxyphenyl group, a p-tert-butoxyphenyl group, an m-tert-butoxyphenyl group; alkylphenyl groups such as a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, an ethylphenyl group, a 4-tert-butylphenyl group, a 4-butylphenyl group, a dimethylphenyl group; alkylnaphthyl groups such as a methylnaphthyl group, an ethylnaphthyl group; alkoxynaphthyl groups such as a methoxynaphthyl group, an ethoxynaphthyl group; dialkylnaphthyl groups such as a dimethylnaphthyl group, a diethylnaphthyl group; dialkoxynaphthyl groups such as a dimethoxynaphthyl group, a diethoxynaphthyl group, and the like. Specific examples of the aralkyl group include a benzyl group, a phenylethyl group, a phenethyl group, and the like. Specific examples of the aryloxoalkyl group include 2-aryl-2-oxoethyl groups such as a 2-phenyl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, a 2-(2-naphthyl)-2-oxoethyl group, and the like.

[0131] A- Examples of non-nucleophilic counterions include hydroxide ion, formate ion, acetate ion, propionate ion, butyrate ion, pentanoate ion, hexanoate ion, heptanoate ion, octanoate ion, nonanoate ion, decanoate ion, oleate ion, stearate ion, linoleate ion, linolenate ion, benzoate ion, phthalate ion, isophthalate ion, terephthalate ion, salicylate ion, trifluoroacetate ion, monochloroacetate ion, dichloroacetate ion, trichloroacetate ion, fluoride ion, chloride ion, bromide ion, iodide ion, nitrate ion, nitrite ion, chlorate ion, bromate ion, methanesulfonate ion, paratoluenesulfonate ion, monomethyl sulfate ion and other monovalent ions, as well as monovalent or divalent oxalate ion, malonate ion, methylmalonate ion, ethylmalonate ion, propylmalonate ion, butylmalonate ion, dimethylmalonate ion, diethylmalonate ion, succinate ion, methylsuccinate ion, glutarate ion, adipate ion, itaconate ion, maleate ion, fumarate ion, citraconate ion, citrate ion, carbonate ion, sulfate ion, etc.

[0132] Examples of alkali metal salts include hydroxides, formates, acetates, propionates, butyrates, pentanoates, hexanoates, heptanoates, octanoates, nonanoates, decanoates, oleates, stearates, linoleates, linolenates, benzoates, phthalates, isophthalates, terephthalates, salicylates, trifluoroacetates, monochloroacetates, dichloroacetates, trichloroacetates of lithium, sodium, potassium, cesium, magnesium, calcium and other monovalent salts, as well as monovalent or divalent oxalates, malonates, methylmalonates, ethylmalonates, propylmalonates, butylmalonates, dimethylmalonates, diethylmalonates, succinates, methylsuccinates, glutarates, adipates, itaconates, maleates, fumarates, citraconates, citrates, carbonates, etc.

[0133] Specifically, examples of the sulfonium salt (Xc-1) include triphenylsulfonium formate, triphenylsulfonium acetate, triphenylsulfonium propionate, triphenylsulfonium butyrate, triphenylsulfonium benzoate, triphenylsulfonium phthalate, triphenylsulfonium isophthalate, triphenylsulfonium terephthalate, triphenylsulfonium salicylate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium monochloroacetate, triphenylsulfonium dichloroacetate, triphenylsulfonium trichloroacetate, triphenylsulfonium hydroxide, triphenylsulfonium nitrate, triphenylsulfonium chloride, triphenylsulfonium bromide, triphenylsulfonium oxalate, triphenylsulfonium malonate, triphenylsulfonium methylmalonate, triphenylsulfonium ethylmalonate, triphenylsulfonium propylmalonate, triphenylsulfonium butylmalonate, triphenylsulfonium dimethylmalonate, triphenylsulfonium diethylmalonate, triphenylsulfonium succinate, triphenylsulfonium methylsuccinate, triphenylsulfonium glutarate, triphenylsulfonium adipate, triphenylsulfonium itaconate, triphenylsulfonium maleate, triphenylsulfonium fumarate, triphenylsulfonium citraconate, triphenylsulfonium citrate, triphenylsulfonium carbonate, bis(triphenylsulfonium) oxalate, bis(triphenylsulfonium) maleate, bis(triphenylsulfonium) fumarate, bis(triphenylsulfonium) citraconate, bis(triphenylsulfonium) citrate, bis(triphenylsulfonium) carbonate, and the like.

[0134] Specific examples of the iodonium salt (Xc-2) include diphenyliodonium formate, diphenyliodonium acetate, diphenyliodonium propionate, diphenyliodonium butyrate, diphenyliodonium benzoate, diphenyliodonium phthalate, diphenyliodonium isophthalate, diphenyliodonium terephthalate, diphenyliodonium salicylate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium monochloroacetate, diphenyliodonium dichloroacetate, diphenyliodonium trichloroacetate, diphenyliodonium hydroxide, diphenyliodonium nitrate, diphenyliodonium chloride, diphenyliodonium bromide, diphenyliodonium iodide, diphenyliodonium oxalate, diphenyliodonium maleate, diphenyliodonium fumarate, diphenyliodonium citraconate, diphenyliodonium citrate, diphenyliodonium carbonate, bis(diphenyliodonium) oxalate, bis(diphenyliodonium) maleate, bis(diphenyliodonium) fumarate, bis(diphenyliodonium) citraconate, bis(diphenyliodonium) citrate, bis(diphenyliodonium) carbonate, and the like.

[0135] Specific examples of the phosphonium salt (Xc-3) include tetraethylphosphonium formate, tetraethylphosphonium acetate, tetraethylphosphonium propionate, tetraethylphosphonium butyrate, tetraethylphosphonium benzoate, tetraethylphosphonium phthalate, tetraethylphosphonium isophthalate, tetraethylphosphonium terephthalate, tetraethylphosphonium salicylate, tetraethylphosphonium trifluoromethanesulfonate, tetraethylphosphonium trifluoroacetate, tetraethylphosphonium monochloroacetate, tetraethylphosphonium dichloroacetate, tetraethylphosphonium trichloroacetate, tetraethylphosphonium hydroxide, tetraethylphosphonium nitrate, tetraethylphosphonium chloride, tetraethylphosphonium bromide, tetraethylphosphonium iodide, tetraethylphosphonium oxalate, tetraethylphosphonium maleate, tetraethylphosphonium fumarate, tetraethylphosphonium citraconate, tetraethylphosphonium citrate, tetraethylphosphonium carbonate, bis(tetraethylphosphonium) oxalate, bis(tetraethylphosphonium) maleate, bis(tetraethylphosphonium) fumarate, bis(tetraethylphosphonium) citraconate, bis(tetraethylphosphonium) citrate, bis(tetraethylphosphonium) carbonate, tetraphenylphosphonium formate, tetraphenylphosphonium acetate, tetraphenylphosphonium propionate, tetraphenylphosphonium butyrate, tetraphenylphosphonium benzoate, tetraphenylphosphonium phthalate, tetraphenylphosphonium isophthalate, tetraphenylphosphonium terephthalate, tetraphenylphosphonium salicylate, tetraphenylphosphonium trifluoromethanesulfonate, tetraphenylphosphonium trifluoroacetate, tetraphenylphosphonium monochloroacetate, tetraphenylphosphonium dichloroacetate, tetraphenylphosphonium trichloroacetate, tetraphenylphosphonium hydroxide, tetraphenylphosphonium nitrate, tetraphenylphosphonium chloride, tetraphenylphosphonium bromide, tetraphenylphosphonium iodide, tetraphenylphosphonium oxalate, tetraphenylphosphonium maleate, tetraphenylphosphonium fumarate,Examples include tetraphenylphosphonium citrate, tetraphenylphosphonium citrate, tetraphenylphosphonium carbonate, bistetraphenylphosphonium oxalate, bistetraphenylphosphonium maleate, bistetraphenylphosphonium fumarate, bistetraphenylphosphonium citraconate, bistetraphenylphosphonium citrate, bistetraphenylphosphonium carbonate, etc.

[0136] On the one hand, as the ammonium salt (Xc-4), specifically, tetramethylammonium formate, tetramethylammonium acetate, tetramethylammonium propionate, tetramethylammonium butyrate, tetramethylammonium benzoate, tetramethylammonium phthalate, tetramethylammonium isophthalate, tetramethylammonium terephthalate, tetramethylammonium salicylate, tetramethylammonium trifluoromethanesulfonate, tetramethylammonium trifluoroacetate, tetramethylammonium monochloroacetate, tetramethylammonium dichloroacetate, tetramethylammonium trichloroacetate, tetramethylammonium hydroxide, tetramethylammonium nitrate, tetramethylammonium chloride, tetramethylammonium bromide, tetramethylammonium iodide, tetramethylammonium monomethyl sulfate, tetramethylammonium oxalate, tetramethylammonium malonate, tetramethylammonium maleate, tetramethylammonium fumarate, tetramethylammonium citraconate, tetramethylammonium citrate, tetramethylammonium carbonate, bis(tetramethylammonium) oxalate, bis(tetramethylammonium) malonate, bis(tetramethylammonium) maleate, bis(tetramethylammonium) fumarate, bis(tetramethylammonium) citraconate, bis(tetramethylammonium) citrate, bis(tetramethylammonium) carbonate, tetraethylammonium formate, tetraethylammonium acetate, tetraethylammonium propionate, tetraethylammonium butyrate, tetraethylammonium benzoate, tetraethylammonium phthalate, tetraethylammonium isophthalate, tetraethylammonium terephthalate, tetraethylammonium salicylate, tetraethylammonium trifluoromethanesulfonate, tetraethylammonium trifluoroacetate, tetraethylammonium monochloroacetate, tetraethylammonium dichloroacetate, tetraethylammonium trichloroacetate, tetraethylammonium hydroxide, tetraethylammonium nitrate, tetraethylammonium chloride, tetraethylammonium bromide, tetraethylammonium iodide, tetraethylammonium monomethyl sulfate,Tetraethylammonium oxalate, tetraethylammonium malonate, tetraethylammonium maleate, tetraethylammonium fumarate, tetraethylammonium citraconate, tetraethylammonium citrate, tetraethylammonium carbonate, bis(tetraethylammonium) oxalate, bis(tetraethylammonium) malonate, bis(tetraethylammonium) maleate, bis(tetraethylammonium) fumarate, bis(tetraethylammonium) citraconate, bis(tetraethylammonium) citrate, bis(tetraethylammonium) carbonate, tetrapropylammonium formate, tetrapropylammonium acetate, tetrapropylammonium propionate, tetrapropylammonium butyrate, tetrapropylammonium benzoate, tetrapropylammonium phthalate, tetrapropylammonium isophthalate, tetrapropylammonium terephthalate, tetrapropylammonium salicylate, tetrapropylammonium trifluoromethanesulfonate, tetrapropylammonium trifluoroacetate, tetrapropylammonium monochloroacetate, tetrapropylammonium dichloroacetate, tetrapropylammonium trichloroacetate, tetrapropylammonium hydroxide, tetrapropylammonium nitrate, tetrapropylammonium chloride, tetrapropylammonium bromide, tetrapropylammonium iodide, tetrapropylammonium monomethyl sulfate, tetrapropylammonium oxalate, tetrapropylammonium malonate, tetrapropylammonium maleate, tetrapropylammonium fumarate, tetrapropylammonium citraconate, tetrapropylammonium citrate, tetrapropylammonium carbonate, bis(tetrapropylammonium) oxalate, bis(tetrapropylammonium) malonate, bis(tetrapropylammonium) maleate, bis(tetrapropylammonium) fumarate, bis(tetrapropylammonium) citraconate, bis(tetrapropylammonium) citrate, bis(tetrapropylammonium) carbonate, tetrabutylammonium formate, tetrabutylammonium acetate, tetrabutylammonium propionate, tetrabutylammonium butyrate, tetrabutylammonium benzoateTetrabutylammonium phthalate, tetrabutylammonium isophthalate, tetrabutylammonium terephthalate, tetrabutylammonium salicylate, tetrabutylammonium trifluoromethanesulfonate, tetrabutylammonium trifluoroacetate, tetrabutylammonium monochloroacetate, tetrabutylammonium dichloroacetate, tetrabutylammonium trichloroacetate, tetrabutylammonium hydroxide, tetrabutylammonium nitrate, tetrabutylammonium chloride, tetrabutylammonium bromide, tetrabutylammonium iodide, tetrabutylammonium methanesulfonate, tetrabutylammonium monomethyl sulfate, tetrabutylammonium oxalate, tetrabutylammonium malonate, tetrabutylammonium maleate, tetrabutylammonium fumarate, tetrabutylammonium citraconate, tetrabutylammonium citrate, tetrabutylammonium carbonate, bis(tetrabutylammonium) oxalate, bis(tetrabutylammonium) malonate, bis(tetrabutylammonium) maleate, bis(tetrabutylammonium) fumarate, bis(tetrabutylammonium) citraconate, bis(tetrabutylammonium) citrate, bis(tetrabutylammonium) carbonate, etc. can be exemplified.

[0137] Examples of alkali metal salts include lithium formate, lithium acetate, lithium propionate, lithium butyrate, lithium benzoate, lithium phthalate, lithium isophthalate, lithium terephthalate, lithium salicylate, lithium trifluoromethanesulfonate, lithium trifluoroacetate, lithium monochloroacetate, lithium dichloroacetate, lithium trichloroacetate, lithium hydroxide, lithium nitrate, lithium chloride, lithium bromide, lithium iodide, lithium methanesulfonate, lithium hydrogen oxalate, lithium hydrogen malonate, lithium hydrogen maleate, lithium hydrogen fumarate, lithium hydrogen citraconate, lithium hydrogen citrate, lithium hydrogen carbonate, lithium oxalate, lithium malonate, lithium maleate, lithium fumarate, lithium citraconate, lithium citrate, lithium carbonate, sodium formate, sodium acetate, sodium propionate, sodium butyrate, sodium benzoate, sodium phthalate, sodium isophthalate, sodium terephthalate, sodium salicylate, sodium trifluoromethanesulfonate, sodium trifluoroacetate, sodium monochloroacetate, sodium dichloroacetate, sodium trichloroacetate, sodium hydroxide, sodium nitrate, sodium chloride, sodium bromide, sodium iodide, sodium methanesulfonate, sodium hydrogen oxalate, sodium hydrogen malonate, sodium hydrogen maleate, sodium hydrogen fumarate, sodium hydrogen citraconate, sodium hydrogen citrate, sodium hydrogen carbonate, sodium oxalate, sodium malonate, sodium maleate, sodium fumarate, sodium citraconate, sodium citrate, sodium carbonate, potassium formate, potassium acetate, potassium propionate, potassium butyrate, potassium benzoate, potassium phthalate, potassium isophthalate, potassium terephthalate, potassium salicylate, potassium trifluoromethanesulfonate, potassium trifluoroacetate, potassium monochloroacetate, potassium dichloroacetate, potassium trichloroacetate, potassium hydroxide, potassium nitrate, potassium chloride, potassium bromide, potassium iodide, potassium methanesulfonate, potassium hydrogen oxalate, potassium hydrogen malonate, potassium hydrogen maleate, potassium hydrogen fumarate, potassium hydrogen citraconate,Potassium hydrogen citrate, potassium bicarbonate, potassium oxalate, potassium malonate, potassium maleate, potassium fumarate, potassium citraconate, potassium citrate, potassium carbonate, etc. can be exemplified.

[0138] In the present invention, as the crosslinking catalyst (Xc), a polysiloxane (Xc-10) having an ammonium salt, a sulfonium salt, a phosphonium salt, or an iodonium salt as a part of the structure may be blended in the composition for forming a resist underlayer film.

[0139] As a raw material used for producing (Xc-10) used herein, a compound represented by the following general formula (Xm) can be used. R 1A A1 R 2A A2 R 3A A3 Si(OR 0A ) (4-A1-A2-A3) (Xm) (In the general formula (Xm), R 0A is a hydrocarbon group having 1 to 6 carbon atoms, and among R 1A , R 2A , and R 3A , at least one is an organic group having an ammonium salt, a sulfonium salt, a phosphonium salt, or an iodonium salt, and the other is a hydrogen atom or a monovalent organic group having 1 to 30 carbon atoms. A1, A2, and A3 are 0 or 1, and 1 ≦ A1 + A2 + A3 ≦ 3.)

[0140] Here, examples of OR 0A include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a cyclopentyl group, an n-hexyl group, a cyclohexyl group, and a phenyl group.

[0141] Examples of Xm include a compound represented by the following general formula (Xm-1), which is a hydrolyzable silicon compound having a sulfonium salt as a part of the structure. [Chemistry] (In the general formula (Xm-1), R SA1 , and R SA2 each represent a linear, branched, or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxyalkyl group having 7 to 20 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted by an alkoxy group, amino group, alkylamino group, halogen atom, etc. Also, R SA1 and R SA2 may together form a ring with the sulfur atom to which they are attached. When forming a ring, R SA1 , and R SA2 each represent an alkylene group having 1 to 6 carbon atoms. R SA3 represents a linear, branched, or cyclic alkylene group or alkenylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted by an alkoxy group, amino group, alkylamino group, etc.).

[0142] Note that in the above general formula (Xm-1), (Si) is described to indicate the bonding position with Si.

[0143] X -Examples include hydroxide ions, fluoride ions, chloride ions, bromide ions, iodide ions, formate ions, acetate ions, propionate ions, butyrate ions, pentanoate ions, hexanoate ions, heptanoate ions, octanoate ions, nonanoate ions, decanoate ions, oleate ions, stearate ions, linoleate ions, linolenate ions, benzoate ions, p-methylbenzoate ions, p-t-butylbenzoate ions, phthalate ions, isophthalate ions, terephthalate ions, salicylate ions, trifluoroacetate ions, monochloroacetate ions, dichloroacetate ions, trichloroacetate ions, nitrate ions, chlorate ions, perchlorate ions, bromate ions, iodate ions, methanesulfonate ions, benzenesulfonate ions, toluenesulfonate ions, monomethyl sulfate ions, hydrogen sulfate ions, oxalate ions, malonate ions, methylmalonate ions, ethylmalonate ions, propylmalonate ions, butylmalonate ions, dimethylmalonate ions, diethylmalonate ions, succinate ions, methylsuccinate ions, glutarate ions, adipate ions, itaconate ions, maleate ions, fumarate ions, citraconate ions, citrate ions, carbonate ions, etc.

[0144] Specific examples of the cation moiety of the compound represented by the general formula (Xm-1) include the following ions.

Chemical formula

[0145] Examples of Xm include compounds represented by the following general formula (Xm-2) as hydrolyzable silicon compounds having an iodonium salt as part of the structure.

Chemical formula

[0146] In the general formula (Xm-2), (Si) is described to indicate the bonding position to Si. X - is as described above.

[0147] Specific examples of the cationic moiety of the compound represented by the general formula (Xm-2) include the following ions.

[0148] [Chemical formula]

[0149] As Xm, for example, a compound represented by the following general formula (Xm-3) can be exemplified as a hydrolyzable silicon compound having a phosphonium salt as a part of its structure. [Chemical formula] (In the general formula (Xm-3), R PA1 , R PA2 , and R PA3is each a linear, branched, or cyclic alkyl group, alkenyl group, oxoalkyl group, or oxoalkenyl group having 1 to 20 carbon atoms, a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, or an aralkyl group or aryloxoalkyl group having 7 to 20 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted by an alkoxy group, an amino group, an alkylamino group, a halogen atom, or the like. Further, R PA1 and R PA2 may form a ring together with the phosphorus atom to which they are bonded. When forming a ring, R PA1 , and R PA2 each represent an alkylene group having 1 to 6 carbon atoms. R PA4 is a linear, branched, or cyclic alkylene group or alkenylene group having 1 to 20 carbon atoms, or a substituted or unsubstituted arylene group having 6 to 20 carbon atoms, and some or all of the hydrogen atoms of these groups may be substituted by an alkoxy group, an amino group, an alkylamino group, or the like.)

[0150] In the general formula (Xm-3) above, (Si) is described to indicate the bonding position with Si. X - is as described above.)

[0151] As the cation part of the compound represented by the general formula (Xm-3), specifically, the following ions are exemplified.)

[0152]

Chemical formula

[0153]

Chemical formula

[0154] As Xm, for example, a compound represented by the following general formula (Xm-4) can be exemplified as a hydrolyzable silicon compound having an ammonium salt as part of its structure.)

Chemical formula

[0155] Note that in the above general formula (Xm-4), (Si) is described to indicate the bonding position with Si. X - is as described above.

[0156] Specifically, the following ions are exemplified as the cation moiety of the compound represented by the above general formula (Xm-4).

[0157]

Chemical formula

[0158] [Chemistry]

[0159] [Chemistry]

[0160] [Chemistry]

[0161] [Chemistry]

[0162] [Chemistry]

[0163] [Chemistry]

[0164] [Chemistry]

[0165] [Chemistry]

[0166] [Chemistry]

[0167] [Chemistry]

[0168] [Chemistry]

[0169] [Chemical]

[0170] As the hydrolyzable silicon compound used simultaneously with the above (Xm-1), (Xm-2), (Xm-3), and (Xm-4) for producing (Xc-10), the above hydrolyzable monomer (Sm) can be exemplified. Further, a hydrolyzable metal compound (Mm) represented by the above general formula (Mm) may be added.

[0171] One or more of the monomers (Xm-1), (Xm-2), (Xm-3), and (Xm-4) and one or more of (Sm) shown in this way, and if necessary, one or more of (Mm) can be selected and mixed before or during the reaction to be used as a reaction raw material for forming (Xc-10). The reaction conditions may be the same as those for the synthesis method of the thermally crosslinkable polysiloxane (Sx).

[0172] The molecular weight of the obtained crosslinking catalyst (Xc-10) can be adjusted not only by the selection of the monomer but also by controlling the reaction conditions during polymerization. However, if the weight average molecular weight is 100,000 or less, no foreign matter generation or coating spots will occur. Therefore, those with a weight average molecular weight of 100,000 or less, more preferably 200 to 50,000, and still more preferably 300 to 30,000 are preferably used. The data regarding the above weight average molecular weight is represented by the molecular weight in terms of polystyrene using gel permeation chromatography (GPC) with RI as the detector and tetrahydrofuran as the elution solvent, and using polystyrene as the standard substance.

[0173] In addition, the above crosslinking catalysts (Xc-1), (Xc-2), (Xc-3), (Xc-4), and (Xc-10) can be used alone or in combination of two or more. The addition amount of the crosslinking catalyst is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, based on 100 parts by mass of the base polymer (the thermally crosslinkable polysiloxane (Sx) obtained by the above method).

[0174] (Organic acid) In order to improve the stability of the composition for forming a silicon-containing resist underlayer film of the present invention, it is preferable to add a monovalent or divalent or higher organic acid having 1 to 30 carbon atoms. Examples of the acid to be added at this time include formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oleic acid, stearic acid, linoleic acid, linolenic acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, trifluoroacetic acid, monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, oxalic acid, malonic acid, methylmalonic acid, ethylmalonic acid, propylmalonic acid, butylmalonic acid, dimethylmalonic acid, diethylmalonic acid, succinic acid, methylsuccinic acid, glutaric acid, adipic acid, itaconic acid, maleic acid, fumaric acid, citraconic acid, citric acid, etc. Particularly, oxalic acid, maleic acid, formic acid, acetic acid, propionic acid, citric acid, etc. are preferable. Further, in order to maintain the stability, two or more kinds of acids may be mixed and used. The addition amount of the organic acid is preferably 0.001 to 25 parts by mass, more preferably 0.01 to 15 parts by mass, and still more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of silicon contained in the composition for forming a silicon-containing resist underlayer film of the present invention.

[0175] Alternatively, when the above organic acid is converted to the pH of the composition for forming a silicon-containing resist underlayer film of the present invention, it is preferably formulated so that 0 ≦ pH ≦ 7, more preferably 0.3 ≦ pH ≦ 6.5, and still more preferably 0.5 ≦ pH ≦ 6.

[0176] (Water) In the present invention, water may be added to the composition for forming a silicon-containing resist underlayer film. When water is added, the polysiloxane compound in the composition for forming a silicon-containing resist underlayer film of the present invention is hydrated, so that the lithography performance is improved. The water content in the solvent component of the composition for forming a silicon-containing resist underlayer film of the present invention is preferably more than 0% by mass and less than 50% by mass, particularly preferably 0.3 to 30% by mass, and still more preferably 0.5 to 20% by mass. If the added amount of water is less than 50% by mass, the uniformity of the silicon-containing resist underlayer film becomes good and repelling does not occur. On the other hand, when the added amount of water exceeds 0% by mass, the lithography performance becomes good.

[0177] The amount of the total solvent containing water is preferably 100 to 100,000 parts by mass, particularly preferably 200 to 50,000 parts by mass, based on 100 parts by mass of the thermally crosslinkable polysiloxane which is the base polymer.

[0178] (Stabilizer) Furthermore, in the present invention, a stabilizer can be added to the composition for forming a silicon-containing resist underlayer film. As the stabilizer, a monohydric or polyhydric alcohol having a cyclic ether as a substituent can be added. In particular, adding the stabilizer described in paragraphs

[0181] to

[0182] of JP-A-2009-126940 can improve the stability of the composition for forming a silicon-containing resist underlayer film. The compounding amount of the stabilizer is preferably 0 to 50 parts by mass, more preferably 0 to 40 parts by mass, based on 100 parts by mass of the thermally crosslinkable polysiloxane (Sx) which is the base polymer.

[0179] (Surfactant) Furthermore, in the present invention, a surfactant can be blended into the composition for forming a silicon-containing resist underlayer film as needed. Specifically, the materials described in paragraph

[0185] of JP-A-2009-126940 can be added. The compounding amount of the surfactant is preferably 0 to 10 parts by mass, more preferably 0 to 5 parts by mass, based on 100 parts by mass of the thermally crosslinkable polysiloxane (Sx) which is the base polymer.

[0180] (High-boiling solvent) Furthermore, in the present invention, it is also possible to add a high-boiling solvent having a boiling point of 180 °C or higher to the composition as needed. Examples of such high-boiling solvents include 1-octanol, 2-ethylhexanol, 1-nonanol, 1-decanol, 1-undecanol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin, gamma-butyrolactone, tripropylene glycol monomethyl ether, diacetone alcohol, n-nonyl acetate, ethylene glycol monoethyl ether acetate, 1,2-diacetoxyethane, 1-acetoxy-2-methoxyethane, 1,2-diacetoxypropane, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, etc. The blending amount of the high-boiling solvent is preferably 0 to 20% by mass, more preferably 0 to 10% by mass, based on the solvent component.

[0181] [Pattern formation method] One of the pattern formation methods of the present invention is a method of forming a pattern on a workpiece, comprising: a step of forming an organic film on the workpiece using a coating-type organic film material; a step of forming a silicon-containing resist underlayer film on the organic film using the composition for forming a silicon-containing resist underlayer film described above; a step of forming a resist upper layer film on the silicon-containing resist underlayer film using a composition for a resist upper layer film comprising a photoresist composition; a step of forming a circuit pattern on the resist upper layer film; A step of transferring a pattern by etching onto the silicon-containing resist lower layer film using the resist upper layer film on which the circuit pattern is formed as a mask; A step of transferring a pattern by etching onto the organic film using the silicon-containing resist lower layer film onto which the pattern has been transferred as a mask; A step of transferring a pattern by etching onto the workpiece using the organic film onto which the pattern has been transferred as a mask and a pattern forming method (so-called "multi-layer resist method") including the above steps.

[0182] One of the pattern forming methods of the present invention is a method of forming a pattern on a workpiece, a step of forming a hard mask on the workpiece by CVD method; a step of forming a silicon-containing resist lower layer film on the hard mask using the composition for forming a silicon-containing resist lower layer film described above; a step of forming a resist upper layer film on the silicon-containing resist lower layer film using a composition for a resist upper layer film composed of a photoresist composition; a step of forming a circuit pattern on the resist upper layer film; a step of transferring a pattern by etching onto the silicon-containing resist lower layer film using the resist upper layer film on which the circuit pattern is formed as a mask; a step of transferring a pattern by dry etching onto the hard mask using the silicon-containing resist lower layer film onto which the pattern has been transferred as a mask; a step of transferring a pattern by dry etching onto the workpiece using the hard mask onto which the pattern has been transferred as a mask and a pattern forming method (so-called "multi-layer resist method") including the above steps.

[0183] One of the pattern forming methods of the present invention is a method of forming a pattern on a workpiece, a step of forming a silicon-containing resist lower layer film on the workpiece using the composition for forming a silicon-containing resist lower layer film described above; A step of forming a resist upper layer film using a composition for a resist upper layer film composed of a photoresist composition on the silicon-containing resist lower layer film; A step of forming a circuit pattern on the resist upper layer film; A step of transferring a pattern by etching to the silicon-containing resist lower layer film using the resist upper layer film on which the circuit pattern is formed as a mask; A step of transferring a pattern by dry etching to the workpiece using the silicon-containing resist lower layer film on which the pattern is transferred as a mask It is a pattern forming method (so-called "multi-layer resist method") including.

[0184] As described above, the pattern obtained by blending the silicon-containing sulfonium salt compound of the present invention into the composition for forming a silicon-containing resist lower layer film can form a fine pattern excellent in LWR and CDU on the substrate by optimizing the combination of a hard mask and an organic film. Further, since it is easy to remove the silicon-containing resist lower layer film remaining after pattern formation by etching or the like, residues that cause defects can be suppressed, and substrate damage due to excessive etching conditions can also be prevented.

[0185] In the positive pattern forming method, after forming a photoresist film (resist upper layer film) and performing heat treatment, exposure is performed, and alkali development is usually performed using an alkali developer to obtain a positive resist pattern. Further, it is preferable to perform post-exposure bake (PEB) after exposure.

[0186] As the alkali developer, an aqueous solution of tetramethylammonium hydroxide (TMAH) or the like can be used.

[0187] As a method of forming a circuit pattern on the resist upper layer film, it is preferable to use a pattern forming method using photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing by an electron beam, nanoimprinting, or a combination thereof.

[0188] As the workpiece, it is preferable to use a semiconductor device substrate or a substrate on which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, and a metal oxynitride film is formed.

[0189] As the metal, it is preferable to use silicon, gallium, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, indium, arsenic, palladium, tantalum, iridium, aluminum, iron, molybdenum, cobalt, or an alloy thereof.

Examples

[0190] Hereinafter, the present invention will be specifically described by showing synthesis examples, comparative synthesis examples, examples, and comparative examples, but the present invention is not limited by these descriptions. In the following examples, % represents mass %, and the molecular weight Mw is the weight average molecular weight in terms of polystyrene measured by GPC measurement.

[0191] [Synthesis Example 1-1] To a mixture of 120 g of methanol, 0.1 g of 10% nitric acid, and 60 g of deionized water, a mixture of 30.6 g of compound (101), 38.1 g of compound (102), and 5.9 g of compound (110) was added (molar ratio: 40 / 50 / 10), and the mixture was maintained at 40 °C for 12 hours for hydrolysis and condensation. After completion of the reaction, 600 g of propylene glycol monoethyl ether (PGEE) was added, and the water and by-produced alcohol used for hydrolysis and condensation were distilled off under reduced pressure to obtain 440 g of a PGEE solution of polysiloxane compound 1 (compound concentration 10%). When the polystyrene-equivalent molecular weight of polysiloxane compound 1 was measured, Mw = 2,900.

[0192] [Synthesis Examples 1-2] to [Synthesis Example 1-18] were carried out using the monomers shown in Table 1 under the same conditions as in [Synthesis Example 1-1], and the target products were obtained as polysiloxane compounds 2 to 18, respectively.

[0193]

Table 1

[0194] PhSi(OCH3)3 ··· Compound (100) CH3Si(OCH3)3 ··· Compound (101) Si(OCH3)4 ··· Compound (102)

[0195] [Chemically]

[0196] [Synthesis Example of Crosslinking Catalyst] [Synthesis Example 2-1] Synthesis of Compound A (Intermediate 1) [Chemically] 55 g of trimethylsilylmagnesium bromide was dissolved in 190 g of tetrahydrofuran. To this solution, 14 g of thionyl chloride dissolved in 35 g of tetrahydrofuran was added dropwise at 0 °C. After aging at room temperature for 6 hours, 10% hydrochloric acid was added for quenching. The reaction solution was diluted with dichloromethane, washed with water, and then water was added to the organic layer three more times for liquid separation. Subsequently, the obtained organic layer was concentrated under reduced pressure. The resulting oily substance was decanted with hexane, filtered, and the obtained solid was dried under reduced pressure to obtain 52 g of the target compound A as white crystals (yield 69%).

[0197] [Synthesis Example 2-2] Synthesis of Compound B [Chemically] 10 g of Compound A prepared in Synthesis Example 2-1 was dissolved in 50 g of dichloromethane, and 9 g of chlorotrimethylsilane was added dropwise thereto under ice cooling. Subsequently, a separately prepared Grignard reagent was added dropwise under ice cooling. After aging at room temperature for 1.5 hours, an aqueous ammonium chloride solution was added under ice cooling, then dichloromethane was added to separate the organic layer, and water was added to the organic layer five more times for liquid separation. Subsequently, the obtained organic layer was concentrated under reduced pressure. The resulting oily substance was decanted with diisopropyl ether, filtered, and the obtained solid was dried under reduced pressure to obtain 12 g of the target compound B as white crystals (yield 92%).

[0198] [Synthesis Example 2-3] Synthesis of Compound B'

Chem.

[0199] Under the same conditions as in Synthesis Examples 2-2 and 3, using the raw materials and acids shown in Table 2, [Synthesis Example 2-4] to [Synthesis Example 2-13] were carried out to obtain the target products respectively.

[0200]

Table 2

[0201] [Reaction Raw Materials]

Chem.

[0202] [Target Products]

Chem.

[0203] [Comparative Synthesis Example 1-1] Synthesis of Sulfonium Salt-Containing Polysiloxane Compound R To a mixture of 120 g of methanol, 0.1 g of 10% nitric acid, and 60 g of deionized water, a mixture of 61.3 g of compound (101) and 24.4 g of compound (120) was added, and the mixture was maintained at 40 °C for 12 hours for hydrolysis and condensation. After completion of the reaction, 300 g of propylene glycol monoethyl ether (PGEE) was added, and the water and by-product alcohol used for hydrolysis and condensation were distilled off under reduced pressure to obtain 250 g of a PGEE solution of a sulfonium salt-containing polysiloxane compound R (compound concentration: 20%). When the polystyrene-reduced molecular weight of the polysiloxane compound R was measured, Mw = 2,000.

[0204] [Examples 1-1 to 1-55 and Comparative Examples 1-1 to 1-4] Polysiloxane compounds 1 to 18 obtained in the above Synthesis Example, a silicon-containing sulfonium salt compound represented by the above general formula (A-1) as a crosslinking catalyst or a comparative crosslinking catalyst, an acid, a photoacid generator (PAG-1 to 7 shown in Table 6), a solvent, and water were mixed at the ratios shown in Tables 3 to 5, and filtered through a 0.1-μm fluororesin filter to prepare composition solutions for forming silicon-containing lower layer films, which were designated as Sol.1 to 59, respectively.

[0205] [Table 3]

[0206] [Table 4]

[0207] [Table 5]

[0208] The crosslinking catalysts used are as follows. XL-1... Compound (B) XL-2... Compound (B') XL-3... Compound (C) XL-4... Compound (D) XL-5... Compound (E) XL-6... Compound (F) XL-7... Compound (G) XL-8... Compound (I) XL-9... Compound (K) XL-10... Compound (M) XL-11... Compound (O) XL-12... Compound (Q) XL-13... Triphenylsulfonium nitrate XL-14... Tetramethylammonium nitrate XL-15... Tetraoctylammonium nitrate XL-16... Sulfonium salt-containing polysiloxane compound (R)

[0209] The solvents used are as follows. PGEE... Propylene glycol monoethyl ether PGME... Propylene glycol monomethyl ether GBL... Gamma-butyrolactone DAA... Diacetone alcohol

[0210]

Table 6

[0211] (EUV patterning test) On a silicon wafer, Sol.1 to 59, which are compositions for forming a silicon-containing resist underlayer film, were spin-coated on a Si substrate and heated at 220°C for 60 seconds to prepare Film1 to 59, which are silicon-containing resist underlayer films with a film thickness of 25 nm.

[0212] Subsequently, a resist material prepared by dissolving the following components at the ratios shown in Table 7 was spin-coated onto Films 1 to 59, and pre-baked at 105 °C for 60 seconds using a hot plate to form a resist upper layer film with a thickness of 60 nm. This was then exposed using an EUV scanner NXE3300 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a hole pattern having a wafer-level dimension of pitch 46 nm and +20% bias) manufactured by ASML, PEB was performed on a hot plate at 100 °C for 60 seconds, and development was carried out for 30 seconds using a 2.38 mass% TMAH aqueous solution to obtain a hole pattern with a dimension of 23 nm. Using a length measurement SEM (CG5000) manufactured by Hitachi High-Technologies Corporation, the exposure dose when a hole dimension of 23 nm was formed was measured and regarded as the sensitivity. Also, the dimensions of 50 holes at this time were measured to determine the dimension variation (CDU, 3σ). The results are shown in Tables 8 and 9.

[0213] The polymer, quencher, sensitizer, surfactant, and organic solvent used as the resist material are as follows.

[0214]

Chemical formula

[0215]

Chemical formula

[0216]

Chemical formula

[0217] Surfactant: FC-4430 manufactured by 3M PGMEA: Propylene glycol monomethyl ether acetate CyHO: Cyclohexanone PGME: Propylene glycol monomethyl ether

[0218]

Table 7

[0219] (Silicon-containing resist lower layer film etching test) On a silicon wafer, Sol.1 to 59, which are compositions for forming a silicon-containing resist lower layer film, were spin-coated on a Si substrate and heated at 220 °C for 60 seconds to prepare Film1 to 59, which are silicon-containing resist lower layer films with a film thickness of 25 nm. An etching test was carried out on these silicon-containing resist lower layer films under the following etching conditions.

[0220] Etching test with CHF3 / CF4-based gas Equipment: Dry etching equipment Telius SP manufactured by Tokyo Electron Limited Etching test: Chamber pressure 10 Pa Upper / Lower RF power 200 W / 100 W CHF3 gas flow rate 50 ml / min CF4 gas flow rate 50 ml / min N2 gas flow rate 100 ml / min Processing time 20 sec

[0221]

Table 8

[0222]

Table 9

[0223] As shown in Comparative Examples 1-1 to 1-4 of Tables 8 and 9, in Films 56 to 59 where the silicon-containing sulfonium salt compound represented by the general formula (A-1) of the present invention was not used as a crosslinking catalyst, it was confirmed that there was deterioration of CDU or insufficient etching rate. On the other hand, as shown in Examples 1-1 to 1-55, in Films 1 to 55 where the silicon-containing sulfonium salt compound represented by the general formula (A-1) of the present invention was used as a crosslinking catalyst, since the affinity with the silicon polymer was high, diffusion into the upper resist was suppressed, it was found to have a CDU improvement effect and a sufficient etching rate.

[0224] [Examples 2-1 to 2-14 and Comparative Examples 2-1 to 2-4] (ArF patterning test) On a silicon wafer, a spin-on carbon film ODL-102 (carbon content 89% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was formed to a film thickness of 200 nm. On top of that, Sols. 1 to 4, 10 to 12, 26 to 29, 50 to 52, 56 to 59, which are compositions for forming a silicon-containing resist lower layer film, were applied on the spin-on carbon film and heated at 220 °C for 60 seconds to produce Films 1 to 4, 10 to 12, 26 to 29, 50 to 52, 56 to 59, which are silicon-containing resist lower layer films with a film thickness of 20 nm.

[0225] Subsequently, the ArF resist solution for positive development (PR-1) described in Table 10 was applied on the silicon-containing resist lower layer film and baked at 110 °C for 60 seconds to form a photoresist film with a film thickness of 100 nm. Further, the immersion protective film material (TC-1) described in Table 11 was applied on the photoresist film and baked at 90 °C for 60 seconds to form a protective film with a film thickness of 50 nm. Next, these were exposed using an ArF immersion exposure apparatus (manufactured by ASML; XT-1900i, NA 1.35, σ 0.97 / 0.77, 35-degree dipole polarization illumination), baked at 100 °C for 60 seconds (PEB), developed with a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (TMAH) for 30 seconds, and a 40 nm 1:1 positive line-and-space pattern was obtained. For this dimension, the LWR was observed using an electron microscope (CG5000) manufactured by Hitachi High-Technologies Corporation. The results are shown in Table 12.

[0226]

Table 10

[0227] ArF resist polymer 1 [molecular weight (Mw) = 7,800, dispersity (Mw / Mn) = 1.78]:

Chem.

[0228] Acid generator: PAG-A

Chem.

[0229] Base: Quencher

Chem.

[0230] Surfactant: FC-4430 manufactured by 3M

[0231]

Table 11

[0232] Protective film polymer [molecular weight (Mw) = 8,800, dispersity (Mw / Mn) = 1.69]

Chem.

[0233]

Table 12

[0234] As shown in Examples 2-1 to 2-14 of Table 12, Films 1 to 4, 10 to 12, 26 to 29, and 50 to 52 using the silicon-containing sulfonium salt compound represented by the above general formula (A-1) of the present invention as a crosslinking catalyst were confirmed to have a high affinity with the silicon polymer, so that diffusion into the upper resist was suppressed and an LWR improvement effect was observed.

[0235] On the other hand, as shown in Comparative Examples 2-1 to 2-4, in Films 56 to 59 that did not use the silicon-containing sulfonium salt compound represented by the above general formula (A-1) of the present invention as a crosslinking catalyst, the LWR deteriorated.

[0236] This specification includes the following aspects. [1]: A silicon-containing sulfonium salt compound, characterized in that it is represented by the following general formula (A-1).

Chemical formula

Chemical formula

Chemical formula

Chemical formula

[10] : The pattern formation method according to [9] above, characterized in that as the metal, silicon, gallium, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, indium, arsenic, palladium, tantalum, iridium, aluminum, iron, molybdenum, cobalt, or an alloy thereof is used.

[0237] Note that the present invention is not limited to the above embodiments. The above embodiments are illustrative, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and exhibits the same operational effects is included in the technical scope of the present invention.

Claims

1. A silicon-containing sulfonium salt compound, which is represented by the following general formula (A-1). A silicon-containing sulfonium salt compound characterized by this. 【Chemical 1】 (wherein, Ar １ , Ar ２ , and Ar ３ are each independently an aromatic group having 6 to 20 carbon atoms which may have a substituent, or a heteroaromatic group having 4 to 20 carbon atoms which may have a substituent. Also, any two or more selected from Ar １ , Ar ２ , and Ar ３ may be bonded to each other to form a ring together with the sulfur atom in the formula. a, b, and c are each independently an integer of 0 to 3, and 1 ≦ a + b + c ≦ 9. X, Y, and Z are monovalent organic groups having 1 to 14 carbon atoms, and may be the same as or different from each other. A － represents an organic or inorganic anion that serves as a counter ion of the sulfonium cation.)

2. A composition for forming a silicon-containing resist underlayer film, which contains the silicon-containing sulfonium salt compound according to Claim 1 and a thermally crosslinkable polysiloxane. A composition for forming a silicon-containing resist underlayer film characterized by this.

3. The thermally crosslinkable polysiloxane contains any one or more of a repeating unit represented by the following general formula (Sx-1), a repeating unit represented by the following general formula (Sx-2), and a partial structure represented by the following general formula (Sx-3). The composition for forming a silicon-containing resist underlayer film according to Claim 2, characterized by this. [Chemical Formula 2] 【Chemical Formula 3】 【Chemical Formula 4】 (wherein R １ , R ２ , and R ３ are each independently a monovalent organic group having 1 to 30 carbon atoms which may be the same or different.)

4. The composition for forming a silicon-containing resist underlayer film according to Claim 2, further characterized by containing an acid generator.

5. The acid generator is a photoacid generator that generates an acid upon the action of high-energy rays. The composition for forming a silicon-containing resist underlayer film according to Claim 4, characterized by this.

6. A method for forming a pattern on a workpiece, including the step of forming an organic film on the workpiece using a coating-type organic film material, the step of forming a silicon-containing resist underlayer film on the organic film using the composition for forming a silicon-containing resist underlayer film according to any one of Claims 2 to 5, the step of forming a resist upper layer film on the silicon-containing resist underlayer film using a composition for a resist upper layer film composed of a photoresist composition, the step of forming a circuit pattern on the resist upper layer film, the step of transferring the pattern to the silicon-containing resist underlayer film by etching using the resist upper layer film on which the circuit pattern is formed as a mask, the step of transferring the pattern to the organic film by etching using the silicon-containing resist underlayer film on which the pattern is transferred as a mask, and the step of transferring the pattern to the workpiece by etching using the organic film on which the pattern is transferred as a mask A pattern formation method characterized by including these steps.

7. A method for forming a pattern on a workpiece, including the step of forming a hard mask on the workpiece by CVD method, the step of forming a silicon-containing resist underlayer film on the hard mask using the composition for forming a silicon-containing resist underlayer film according to any one of Claims 2 to 5, A step of forming a resist upper layer film using a composition for a resist upper layer film composed of a photoresist composition on the silicon-containing resist lower layer film; A step of forming a circuit pattern on the resist upper layer film; A step of transferring a pattern by etching to the silicon-containing resist lower layer film using the resist upper layer film on which the circuit pattern is formed as a mask; A step of transferring a pattern by dry etching to the hard mask using the silicon-containing resist lower layer film on which the pattern is transferred as a mask; A step of transferring a pattern by dry etching to the workpiece using the hard mask on which the pattern is transferred as a mask A pattern forming method characterized by including the above steps.

8. As a method of forming a circuit pattern on the resist upper layer film, the pattern forming method according to claim 6, characterized in that photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination thereof is used.

9. As a method of forming a circuit pattern on the resist upper layer film, the pattern forming method according to claim 7, characterized in that photolithography with a wavelength of 10 nm or more and 300 nm or less, direct drawing with an electron beam, nanoimprinting, or a combination thereof is used.

10. As the workpiece, a semiconductor device substrate or a substrate in which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, and a metal oxynitride film is formed on the semiconductor device substrate is used. The pattern forming method according to claim 6, characterized by the above.

11. As the workpiece, a semiconductor device substrate or a substrate in which any one of a metal film, a metal carbide film, a metal oxide film, a metal nitride film, a metal oxynitride film, and a metal oxynitride film is formed on the semiconductor device substrate is used. The pattern forming method according to claim 7, characterized by the above.

12. As the metal, silicon, gallium, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, indium, arsenic, palladium, tantalum, iridium, aluminum, iron, molybdenum, cobalt, or an alloy thereof is used. The pattern forming method according to claim 10, characterized by the above.

13. The pattern forming method according to claim 11, characterized in that as the metal, silicon, gallium, titanium, tungsten, hafnium, zirconium, chromium, germanium, copper, silver, gold, indium, arsenic, palladium, tantalum, iridium, aluminum, iron, molybdenum, cobalt, or an alloy thereof is used.

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