JP2017068049A - Composition for forming silicon-containing film for multilayer resist process, and method for forming pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition for forming a silicon-containing film for a multilayer resist process, which has excellent durability against a solvent of a resist composition in both processes of positive development with an alkali solution and negative development with an organic solvent, an excellent antireflection property and adhesiveness to a resist film, and a high pattern transfer property by etching, and gives a good shape of a resist pattern with little collapse.SOLUTION: The composition for forming a silicon-containing film for a multilayer resist process comprises polysiloxane and an organic solvent. The polysiloxane comprises a hydrolyzed condensate of a compound comprising a first silane compound having at least one of a group containing a cyclic carbonate structure and a group containing a lactone structure, in which a content percentage of a structural unit derived from the first silane compound to the whole structural units constituting the polysiloxane is 0.1 mol% or more and 30 mol% or less.SELECTED DRAWING: None

Description

  The present invention relates to a silicon-containing film forming composition for a multilayer resist process and a pattern forming method.

  For pattern formation of semiconductor elements and the like, a development process using a resist formed on an antireflection film and an etching of an organic material or an inorganic material using a resist pattern after development as a mask are frequently used. However, with the high integration of semiconductor elements and the like, there is a problem that the resist pattern after development is peeled off. Further, with the miniaturization and thinning of the resist, the etching rate between the resist and the antireflection film is similar, so that there is a problem that the organic material and inorganic material under the antireflection film cannot be processed finely.

  In order to solve the above problems, an inorganic resist underlayer film is provided between the resist and the organic antireflection film, and this resist underlayer film is first etched using the resist pattern as a mask. A multilayer resist process technique for etching a lower layer organic material using a pattern as a mask has been studied (see International Publication No. 2006/126406).

  On the other hand, as a technique for enhancing the resolving power by utilizing the characteristics of a chemically amplified resist material, a technique for forming an exposed portion as a pattern by using an organic solvent having a polarity lower than that of an alkaline aqueous solution as a developing solution is disclosed (Japanese Patent Laid-Open No. 2000). -See 199953). In such a negative development process where the exposed area remains as a pattern after development and a positive development process where the unexposed area remains as a pattern after development, the properties of the resist remaining as a pattern differ. The resist underlayer is generally different.

International Publication No. 2006/126406 JP 2000-199953 A

  As the pattern becomes finer, higher performance is required for the resist underlayer film. The problem of the present invention is that the resist composition is excellent in resistance to a solvent in both the positive development using an alkali solution and the negative development using an organic solvent, has excellent antireflection properties and adhesion to a resist film, and has a high pattern by etching. It is to provide a silicon-containing film forming composition for a multilayer resist process having a transfer property, having a good resist pattern shape and less falling down, and a pattern forming method capable of being miniaturized.

  The invention made to solve the above-mentioned problems contains polysiloxane (hereinafter also referred to as “[A] polysiloxane”) and an organic solvent (hereinafter also referred to as “[B] organic solvent”). A] A compound (hereinafter referred to as “compound (I)”) containing a first silane compound (hereinafter also referred to as “silane compound (I)”) having at least one of a group containing a cyclic carbonate structure and a group containing a lactone structure. A) ”) and the structural unit derived from the silane compound (I) (hereinafter also referred to as“ structural unit (I) ”) constituting the [A] polysiloxane. The silicon-containing film forming composition for a multilayer resist process, wherein the content ratio relative to the unit is 0.1 mol% or more and 30 mol% or less.

  The cyclic carbonate structure and lactone structure are preferably monocyclic structures.

（式（１）中、Ｒ^１は、環員数５〜２０の環状カーボネート構造又は環員数４〜２０のラクトン構造を含む１価の基である。Ｒ^２は、シアノ置換、フッ素置換若しくは非置換の炭素数１〜２０の１価の炭化水素基又はシアノ基である。Ｒ^３は、水素原子、炭素数１〜２０の１価のオキシ炭化水素基、炭素数１〜２０のアシロキシ基又はハロゲン原子である。ａは、１〜３の整数である。ｂは、０〜２の整数である。ｃは、１〜３の整数である。但し、ａ＋ｂ＋ｃは４である。ａが２以上の場合、複数のＲ^１は同一でも異なっていてもよい。ｂが２の場合、２つのＲ^２は同一でも異なっていてもよい。ｃが２以上の場合、複数のＲ^３は同一でも異なっていてもよい。） The silane compound (I) is preferably represented by the following formula (1).

(In Formula (1), R ¹ is a monovalent group containing a cyclic carbonate structure having 5 to 20 ring members or a lactone structure having 4 to 20 ring members. R ² is cyano-substituted, fluorine-substituted or unsubstituted. R ³ is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. A is an integer of 1 to 3. b is an integer of 0 to 2. c is an integer of 1 to 3. However, a + b + c is 4. a is 2 or more. A plurality of R ¹ groups may be the same or different, and when b is 2, two R ² groups may be the same or different, and when c is 2 or more, a plurality of R ³ groups are the same or different. May be.)

（式（２）中、Ｘは、水素原子、炭素数１〜２０の１価のオキシ炭化水素基、炭素数１〜２０のアシロキシ基又はハロゲン原子である。４つのＸは同一でも異なっていてもよい。） The compound (A) preferably further contains a second silane compound represented by the following formula (2) (hereinafter also referred to as “silane compound (II)”).

(In the formula (2), X is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. May be good.)

  The content ratio of the structural unit derived from the silane compound (II) (hereinafter also referred to as “structural unit (II)”) to the total structural units constituting the [A] polysiloxane is 20 mol% or more and 95 mol%. The following is preferred.

（式（３）中、Ｒ^４は、炭素数２〜１０のアルケニル基、又は環員数６〜２０の芳香族炭素環若しくは環員数４〜２０の芳香族複素環を含む１価の基である。Ｒ^５は、シアノ置換、フッ素置換若しくは非置換の炭素数１〜２０のアルキル基若しくは炭素数３〜２０の１価の脂環式炭化水素基又はシアノ基である。Ｒ^６は、水素原子、炭素数１〜２０の１価のオキシ炭化水素基、炭素数１〜２０のアシロキシ基又はハロゲン原子である。ｄは、１〜３の整数である。ｅは、０〜２の整数である。ｆは、１〜３の整数である。但し、ｄ＋ｅ＋ｆは４である。ｄが２以上の場合、複数のＲ^４は同一でも異なっていてもよい。ｅが２の場合、２つのＲ^５は同一でも異なっていてもよい。ｆが２以上の場合、複数のＲ^６は同一でも異なっていてもよい。） The compound (A) preferably further contains a third silane compound represented by the following formula (3) (hereinafter also referred to as “silane compound (III)”).

(In Formula (3), R ⁴ is a monovalent group containing an alkenyl group having 2 to 10 carbon atoms, an aromatic carbocyclic ring having 6 to 20 ring members, or an aromatic heterocyclic ring having 4 to 20 ring members. R ⁵ is a cyano-substituted, fluorine-substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a cyano group, and R ⁶ is a hydrogen atom , A monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom, d is an integer of 1 to 3. e is an integer of 0 to 2. F is an integer of 1 to 3. However, d + e + f is 4. When d is 2 or more, a plurality of R ⁴ may be the same or different, and when e is 2, two R ⁵ in the case of two or more is also good .f be the same or different, a plurality of R ⁶ is be the same or different from each other .)

  The content ratio of the structural unit derived from the silane compound (III) (hereinafter also referred to as “structural unit (III)”) to the total structural units constituting the [A] polysiloxane is 0.1 mol% or more and 30 Mole% or less is preferable.

  Another invention made in order to solve the above-mentioned problems is a step of forming a silicon-containing film on at least one surface side of a substrate with the silicon-containing film forming composition for a multilayer resist process (hereinafter referred to as “silicon-containing film”). Forming step), a step of forming a resist film on the opposite side of the silicon-containing film from the substrate (hereinafter also referred to as a “resist film forming step”), and selecting by passing through a photomask A step of exposing the resist film by irradiation with radiation (hereinafter also referred to as “exposure process”) and a step of forming a resist pattern by developing the exposed resist film (hereinafter referred to as “development process”). And the step of dry etching the silicon-containing film and the substrate (hereinafter referred to as “etching step”) using the resist pattern as a mask. ) And a pattern forming method comprising a.

  Before the silicon-containing film forming step, the method further comprises a step of forming an organic underlayer film on the surface side of the substrate on which the silicon-containing film is formed (hereinafter also referred to as “organic underlayer film forming step”), In the step, it is preferable to further etch the organic underlayer film.

  The silicon-containing film forming composition for a multilayer resist process according to the present invention is excellent in resistance to a solvent of a resist composition in both positive development with an alkaline solution and negative development with an organic solvent, and antireflection properties for a resist film. It is characterized in that it has excellent adhesiveness, has high pattern transferability by etching, has a good resist pattern shape, and has little collapse.

Hereinafter, preferred embodiments for carrying out the present invention will be described. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<Silicon-containing film forming composition for multilayer resist process>
The silicon-containing film-forming composition for multilayer resist process of the present invention (hereinafter simply referred to as “silicon-containing film-forming composition”) contains [A] polysiloxane and [B] an organic solvent. The silicon-containing film-forming composition may contain an optional component such as [C] nitrogen-containing compound, [D] acid generator, [E] water, etc., as long as the effects of the present invention are not impaired. Hereinafter, each component will be described in detail.

<[A] polysiloxane>
[A] The polysiloxane includes a hydrolysis condensate of a compound containing the silane compound (I) having at least one of a group containing a cyclic carbonate structure and a group containing a lactone structure. Moreover, the content rate with respect to all the structural units which comprise the said polysiloxane of the structural unit (I) derived from the said silane compound (I) is 0.1 mol% or more and 30 mol% or less.

  The silicon-containing film-forming composition contains the above [A] polysiloxane and [B] organic solvent, and by making the content ratio of the structural unit (I) in the specific range, positive development with an alkaline solution, organic In both processes of negative development with a solvent, the resist composition has excellent resistance to solvents, has excellent antireflection properties and adhesion to the resist film, has high pattern transferability by etching, and has a good resist pattern shape. There is little fall. Although the reason why the silicon-containing film-forming composition has the above-described configuration has the above-mentioned effects is not necessarily clear, for example, [A] a cyclic carbonate structure having a relatively high polarity due to a ring structure containing polyoxygen. In addition, by having the lactone structure at the specific ratio, it is possible to particularly improve the adhesion with the resist film while maintaining the resistance to oxygen etching.

  [A] In addition to the structural unit (I), the polysiloxane further has a structural unit (II) derived from a silane compound (II) described later and a structural unit (III) derived from a silane compound (III) described later. It may have other structural units other than the structural units (I) to (III). Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit derived from the silane compound (I). Silane compound (I) is a silane compound having at least one of a group containing a cyclic carbonate structure and a group containing a lactone structure. The structural unit (I) is formed by hydrolytic condensation of a compound containing the silane compound (I).

  The “cyclic carbonate structure” refers to a structure including one ring (cyclic carbonate ring) including a bond represented by —O—C (O) —O—. A cyclic carbonate ring is counted as the first ring, and when it is only a cyclic carbonate ring, it is called a monocyclic cyclic carbonate structure, and when it has another ring structure, it is called a polycyclic cyclic carbonate structure regardless of the structure.

Examples of the cyclic carbonate structure include monocyclic cyclic carbonate structures such as an ethylene carbonate structure, a trimethylene carbonate structure, and a tetramethylene carbonate structure;
Examples thereof include polycyclic carbonate structures such as a cyclopentylene carbonate structure, a cyclohexylene carbonate structure, a norbornylene carbonate structure, a phenylene carbonate structure, and a naphthylene carbonate structure. Among these, an ethylene carbonate structure, a trimethylene carbonate structure, and a phenylene carbonate structure are preferable, and an ethylene carbonate structure is more preferable.

  “Lactone structure” refers to a structure containing one ring (lactone ring) containing a bond represented by —O—C (O) —. The lactone ring is counted as the first ring. When only the lactone ring is present, it is called a monocyclic lactone structure, and when it has another ring structure, it is called a polycyclic lactone structure regardless of the structure.

Examples of the lactone structure include monocyclic lactone structures such as a propiolactone structure, a butyrolactone structure, a valerolactone structure, and a caprolactone structure;
Examples thereof include polycyclic lactone structures such as a cyclopentane lactone structure, a cyclohexane lactone structure, a norbornane lactone structure, a benzobutyrolactone structure, and a benzovalerolactone structure. Among these, a propiolactone structure, a butyrolactone structure, a valerolactone structure and a benzobutyrolactone structure are preferable, and a butyrolactone structure is more preferable.

  As the cyclic carbonate structure and the lactone structure, a monocyclic structure is preferable from the viewpoint of further improving the adhesion between the silicon-containing film and the resist film.

  As the silane compound (I), a compound represented by the following formula (1) (hereinafter also referred to as “compound (1)”) is preferable. The silane compound (I) may be used alone or in combination of two or more.

In the above formula (1), R ¹ is a monovalent group containing a cyclic carbonate structure having 5 to 20 ring members or a lactone structure having 4 to 20 ring members. R ² is a cyano-substituted, fluorine-substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms or a cyano group. R ³ is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. a is an integer of 1 to 3. b is an integer of 0-2. c is an integer of 1 to 3. However, a + b + c is 4. When a is 2 or more, the plurality of R ¹ may be the same or different. When b is 2, two R ² may be the same or different. When c is 2 or more, the plurality of R ³ may be the same or different.

The monovalent group containing a cyclic carbonate structure having 5 to 20 ring members represented by R ¹ is preferably a group represented by the following formula (i).

In said formula (i), R ^<A1> is a single bond or a C1-C10 alkanediyl group. Y ¹ is a single bond, an oxygen atom, a sulfur atom, a carbonyl group or a phenylene group. R ^B1 is a single bond or an alkanediyl group having 1 to 5 carbon atoms. R ^C is a monovalent cyclic carbonate ring group having 5 to 20 ring members.

The monovalent group containing a lactone structure having 4 to 20 ring members represented by R ¹ is preferably a group represented by the following formula (ii).

In the above formula (ii), R ^A2 is a single bond or an alkanediyl group having 1 to 5 carbon atoms. Y ² is a single bond, an oxygen atom, a sulfur atom, a carbonyl group or a phenylene group. R ^B2 is a single bond or an alkanediyl group having 1 to 10 carbon atoms. R ^L is a monovalent lactone ring group having 5 to 20 ring members.

The monovalent cyclic carbonate ring group having 5 to 20 ring members represented by R ^C is a group in which one hydrogen atom bonded to the cyclic carbonate ring of a compound having a cyclic carbonate ring having 5 to 20 ring members is removed. Etc.

Examples of the monovalent lactone ring group having 4 to 20 ring members represented by R ^L include groups in which one hydrogen atom bonded to the lactone ring of a compound having a lactone ring having 4 to 20 ring members is removed. .

  For example, a monovalent hydrocarbon group such as an alkyl group, a hydroxyl group, a cyano group, a halogen atom, or the like may be bonded to the cyclic carbonate ring and the lactone ring.

Examples of the alkanediyl group having 1 to 10 carbon atoms represented by R ^A1 , R ^A2 , R ^B1 and R ^B2 include a methanediyl group, an ethanediyl group, a linear or branched propanediyl group, a butanediyl group, and a pentanediyl group. And hexanediyl group.

As R ^A1 and R ^A2 , a single bond and an alkanediyl group having 1 to 6 carbon atoms are preferable, and a single bond, a methanediyl group, an ethanediyl group, a 1,3-propanediyl group, a 1,4-butanediyl group, and 1,5 -A pentanediyl group is more preferred.

As R ^B1 and R ^B2 , a single bond and an alkanediyl group having 1 to 3 carbon atoms are preferable, and a single bond and a methanediyl group are more preferable.

Y ¹ and Y ² are preferably a single bond, an oxygen atom, a sulfur atom and a carbonyl group, and more preferably a single bond, an oxygen atom and a sulfur atom.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ² include alkyl groups such as a methyl group, an ethyl group, a propyl group, and a butyl group;
A cycloalkyl group such as a cyclopentyl group, a cyclohexyl group or a norbornyl group;
Aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group;
Examples thereof include aralkyl groups such as benzyl group, phenethyl group, and naphthylmethyl group.

Examples of the monovalent cyano-substituted hydrocarbon group having 2 to 20 carbon atoms represented by R ² include a cyanoalkyl group having 2 to 6 carbon atoms, and specifically include a cyanomethyl group, a cyanoethyl group, and a cyano group. A propyl group etc. are mentioned.

Examples of the monovalent fluorine-substituted hydrocarbon group having 2 to 20 carbon atoms represented by R ² include a fluorinated alkyl group having 2 to 6 carbon atoms, specifically, a fluoromethyl group, trifluoro A methyl group, a perfluoroethyl group, a perfluoropropyl group, etc. are mentioned.

Examples of the monovalent cyano having 2 to 20 carbon atoms and the fluorine-substituted hydrocarbon group represented by R ² include a cyanofluorinated alkyl group having 2 to 6 carbon atoms, specifically, fluorocyanomethyl. Group, fluorocyanoethyl group and the like.

R ² is preferably a hydrocarbon group, more preferably an alkyl group, and still more preferably a methyl group.

Examples of the monovalent oxyhydrocarbon group having 1 to 20 carbon atoms represented by R ³ include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, an n-butoxy group, and a 2-methylpropoxy group. 1-methylpropoxy group, t-butoxy group, n-pentyloxy group, neopentyloxy group, n-hexyloxy group, n-heptyloxy group, n-octyloxy group, 2-ethylhexyloxy group, n-nonyloxy group Group, n-decyloxy group and the like.

Examples of the monovalent acyloxy group having 1 to 20 carbon atoms represented by R ³ include an acetoxy group and a benzoyloxy group.

Examples of the halogen atom represented by R ³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

R ³ is preferably an oxyhydrocarbon group, more preferably an alkoxy group, and further preferably a methoxy group and an ethoxy group.

  As a, 1 and 2 are preferable and 1 is more preferable. As b, 0 and 1 are preferable, and 0 is more preferable. c is preferably 2 or 3, and more preferably 3.

  Specific examples of the compound (1) having a cyclic carbonate structure (hereinafter also referred to as “compound (1-1)”) are represented by the following formulas (1-1-1) to (1-1-34), for example. (Hereinafter also referred to as “compounds (1-1-1) to (1-1-34)”) and the like.

  Among these, the compound (1-1-3) and the compound (1-1-12) are preferable.

  Specific examples of the compound (1) having a lactone structure (hereinafter also referred to as “compound (1-2)”) are represented by the following formulas (1-2-1) to (1-237), for example. Compounds (hereinafter also referred to as “compounds (1-2-1) to (1-237)”) and the like.

  Among these, the compound (1-2-1) and the compound (1-2-2) are preferable.

  As a minimum of the content rate of structural unit (I), it is 0.1 mol% with respect to all the structural units which comprise [A] polysiloxane, 1 mol% is more preferable, 5 mol% is more preferable, 10 mol% is particularly preferred. As an upper limit of the said content rate, it is 30 mol%, 25 mol% is more preferable, 22 mol% is further more preferable, and 20 mol% is especially preferable. By making the content rate of structural unit (I) into the said range, the said various performance can be improved more. When the content ratio of the structural unit (I) is less than the above lower limit, the adhesion between the silicon-containing film and the resist film is lowered, and the performance of the minimum dimensions before collapse and the good pattern shape is lowered. When the content rate of structural unit (I) exceeds the said upper limit, the carbon atom content rate in a silicon-containing film will fall, and oxygen etching tolerance will fall.

  In addition, the content rate of the structural unit in [A] polysiloxane can be considered equivalent to the ratio of the preparation amount of each silane compound at the time of synthesizing [A] polysiloxane in the hydrolysis condensation of a silane compound.

[Structural unit (II)]
The structural unit (II) is a structural unit derived from the silane compound (II). [A] Since the polysiloxane has the structural unit (II), the strength of the silicon-containing film can be increased. Further, the solvent resistance of the silicon-containing film can be further increased. The silane compound (II) is a compound represented by the following formula (2) (hereinafter also referred to as “compound (2)”). Silane compound (II) may be used alone or in combination of two or more.

  In said formula (2), X is a hydrogen atom, a C1-C20 monovalent oxyhydrocarbon group, a C1-C20 acyloxy group, or a halogen atom. The four Xs may be the same or different.

Examples of the oxyhydrocarbon group, acyloxy group and halogen atom represented by X include the same groups as those exemplified as the respective groups in R ³ of the above formula (1).

  X is preferably an oxyhydrocarbon group, more preferably an alkoxy group, further preferably a methoxy group and an ethoxy group, and particularly preferably an ethoxy group.

  Specific examples of the compound (2) include, for example, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, tetra-sec-butoxysilane, tetra-tert- Examples include butoxysilane, tetraphenoxysilane, tetraacetoxysilane, tetrabenzoyloxysilane, and tetrachlorosilane. Among these, tetramethoxysilane and tetraethoxysilane are preferable from the viewpoints of reactivity and easy handling of substances.

  [A] When the polysiloxane has the structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 20 mol% with respect to all the structural units constituting the [A] polysiloxane, More preferably, mol% is more preferable, 40 mol% is further more preferable and 50 mol% is especially preferable. As an upper limit of the said content rate, 95 mol% is preferable, 80 mol% is more preferable, 70 mol% is further more preferable, 65 mol% is especially preferable. By making the content rate of structural unit (II) into the said range, the intensity | strength of a silicon-containing film | membrane can be raised more.

[Structural unit (III)]
The structural unit (III) is a structural unit derived from the silane compound (III). [A] When the polysiloxane has the structural unit (III), the absorption coefficient of the silicon-containing film can be increased, and the substrate reflectivity performance of the silicon-containing film can be further improved. Silane compound (III) is a compound represented by the following formula (3) (hereinafter also referred to as “compound (3)”). The silane compound (III) may be used alone or in combination of two or more.

In the above formula (3), R ⁴ is a monovalent group containing an alkenyl group having 2 to 10 carbon atoms, an aromatic carbocyclic ring having 6 to 20 ring members, or an aromatic heterocyclic ring having 4 to 20 ring members. . R ⁵ is a cyano-substituted, fluorine-substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a cyano group. R ⁶ is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. d is an integer of 1 to 3. e is an integer of 0-2. f is an integer of 1 to 3. However, d + e + f is 4. When d is 2 or more, the plurality of R ⁴ may be the same or different. When e is 2, two R ⁵ may be the same or different. When f is 2 or more, the plurality of R ⁶ may be the same or different.

Examples of the alkenyl group having 2 to 10 carbon atoms represented by R ⁴ include ethenyl group, 1-propen-1-yl group, 1-propen-2-yl group, 1-propen-3-yl group, 1- Buten-1-yl group, 1-buten-2-yl group, 1-buten-3-yl group, 1-buten-4-yl group, 2-buten-1-yl group, 2-buten-2-yl Group, 1-penten-5-yl group, 2-penten-1-yl group, 2-penten-2-yl group, 1-hexen-6-yl group, 2-hexen-1-yl group, 2-hexene And 2-yl group.

Examples of the monovalent group containing an aromatic carbon ring having 6 to 20 ring members represented by R ⁴ include a phenyl group, a naphthyl group, a methylphenyl group, a benzyl group, a phenethyl group, an ethylphenyl group, a chlorophenyl group, and a bromo group. Examples thereof include aryl groups such as a phenyl group and a fluorophenyl group. Among these, a phenyl group and a methylphenyl group are preferable.

Examples of the monovalent group containing an aromatic heterocyclic ring having 4 to 20 ring members represented by R ⁴ include a pyridyl group, a furyl group, and a thienyl group.

R ⁴ is preferably a group containing an aromatic carbocycle, more preferably an aryl group, and still more preferably a phenyl group and a methylphenyl group.

Examples of the alkyl group having 1 to 20 carbon atoms represented by R ⁵ , a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a cyano substituent and a fluorine substituent of these groups include, for example, the above formula (1 ), The same groups as those exemplified as the respective groups in R ² .

R ⁵ is preferably an alkyl group or an alicyclic hydrocarbon group, more preferably an alkyl group, and still more preferably a methyl group.

Examples of the oxyhydrocarbon group, acyloxy group and halogen atom represented by R ⁶ include the same groups as those exemplified as the respective groups in R ³ of the above formula (1).

R ⁶ is preferably an oxyhydrocarbon group, more preferably an alkoxy group, further preferably a methoxy group and an ethoxy group, and particularly preferably a methoxy group.

  Specific examples of the compound (3) include phenyltrimethoxysilane, 4-methylphenyltrimethoxysilane, 4-ethylphenyltrimethoxysilane, 4- (n-propyl) phenyltrimethoxysilane, and 4- (iso-propyl). ) Phenyltrimethoxysilane, 4- (n-butyl) phenyltrimethoxysilane, 4- (2-methylpropyl) phenyltrimethoxysilane, 4- (1-methylpropyl) phenyltrimethoxysilane, 4- (tert-butyl) ) Phenyltrimethoxysilane, 4-methoxyphenyltrimethoxysilane, 4-phenoxyphenyltrimethoxysilane, 4-hydroxyphenyltrimethoxysilane, 4-aminophenyltrimethoxysilane, 4-dimethylaminophenyltrimethoxysilane, 4-acetyl Minophenyltrimethoxysilane, 3-methylphenyltrimethoxysilane, 3-ethylphenyltrimethoxysilane, 3-methoxyphenyltrimethoxysilane, 3-phenoxyphenyltrimethoxysilane, 3-hydroxyphenyltrimethoxysilane, 3-aminophenyl Trimethoxysilane, 3-dimethylaminophenyltrimethoxysilane, 3-acetylaminophenyltrimethoxysilane, 2-methylphenyltrimethoxysilane, 2-ethylphenyltrimethoxysilane, 2-methoxyphenyltrimethoxysilane, 2-phenoxyphenyl Trimethoxysilane, 2-hydroxyphenyltrimethoxysilane, 2-aminophenyltrimethoxysilane, 2-dimethylaminophenyltrimethoxysilane, 2-acetylamino Phenyltrimethoxysilane, 2,4,6-trimethylphenyltrimethoxysilane, 4-methylbenzyltrimethoxysilane, 4-ethylbenzyltrimethoxysilane, 4-methoxybenzyltrimethoxysilane, 4-phenoxybenzyltrimethoxysilane, 4 -Hydroxybenzyltrimethoxysilane, 4-aminobenzyltrimethoxysilane, 4-dimethylaminobenzyltrimethoxysilane, 4-acetylaminobenzyltrimethoxysilane, N-3- (triethoxysilyl) propylbenzylsulfonamide, N-3 -(Triethoxysilyl) propylbenzoylsulfonamide, N-3- (triethoxysilyl) propylbenzylsulfonamide, N-3- (triethoxysilyl) propyl-2-oxo-2-phenylethyls Ruhonamide, N-3- (triethoxysilyl) propyl-C-benzoxazol-2-ylsulfonamide, N-3- (triethoxysilyl) propyl-C-benzoxazol-2-ylsulfonamide, N-2- (Triethoxysilyl) ethylbenzylsulfonamide, N-2- (triethoxysilyl) ethylbenzoylsulfonamide, N-2- (triethoxysilyl) ethyl-2-phenylethylsulfonamide, N-2- (triethoxysilyl) ) Ethyl-3-nitrophenylsulfonamide, N-3- (trimethoxysilyl) propylbenzylsulfonamide, N-3- (trimethoxysilyl) propylbenzoylsulfonamide, N-3- (trimethoxysilyl) propylbenzylsulfone Amide, N-3- (trimethoxy Ryl) propyl-2-oxo-2-phenylethylsulfonamide, N-3- (trimethoxysilyl) propyl-C-benzoxazol-2-ylsulfonamide, N-3- (trimethoxysilyl) propyl-C- Benzoxazol-2-ylsulfonamide, N-2- (trimethoxysilyl) ethylbenzylsulfonamide, N-2- (trimethoxysilyl) ethylbenzoylsulfonamide, N-2- (trimethoxysilyl) ethyl-2- Phenylethylsulfonamide, N-2- (trimethoxysilyl) ethyl-3-nitrophenylsulfonamide, N-2- (trimethoxysilyl) ethyl-4-nitrophenylsulfonamide, diphenyldimethoxysilane, allylphenyldimethoxysilane, Diphenyldiethoxysilane, Phenyl dichlorosilane, tert- butylphenyl dichlorosilane, phenyl methyl dichlorosilane, phenethylmethyldichlorosilane, di (p- tolyl) dichlorosilane, and the like.

  Among these, from the viewpoint of reactivity and ease of handling of substances, phenyltrimethoxysilane, 4-methylphenyltrimethoxysilane, 4-ethylphenyltrimethoxysilane, 4- (n-propyl) phenyltrimethoxysilane, 4- (iso-propyl) phenyltrimethoxysilane, 4- (n-butyl) phenyltrimethoxysilane, 4- (2-methylpropyl) phenyltrimethoxysilane, 4- (1-methylpropyl) phenyltrimethoxysilane, 4- (tert-butyl) phenyltrimethoxysilane, 4-methoxyphenyltrimethoxysilane and 4-methylbenzyltrimethoxysilane are preferred, and phenyltrimethoxysilane and 4-methylphenyltrimethoxysilane are more preferred.

  [A] When the polysiloxane has the structural unit (III), the lower limit of the content ratio of the structural unit (III) is preferably 0.1 mol% with respect to all the structural units constituting the [A] polysiloxane. 1 mol% is more preferable, 4 mol% is further more preferable, and 9 mol% is especially preferable. As an upper limit of the said content rate, 30 mol% is preferable, 25 mol% is more preferable, 20 mol% is more preferable, 18 mol% is especially preferable.

[Other structural units]
[A] The polysiloxane may have other structural units other than the structural units (I) to (III). Examples of other silane compounds that give structural units include alkyltrialkoxysilanes such as methyltrimethoxysilane, 1,2-bis (trimethoxysilyl) benzene, 1,2-bis (triethoxysilyl) benzene, and the like. Examples include 2-bis (trialkoxysilyl) benzene.

  [A] When the polysiloxane has other structural units, the upper limit of the content ratio of the other structural units is preferably 30 mol%, and 20 mol% with respect to all the structural units constituting the [A] polysiloxane. Is more preferable, 15 mol% is further more preferable, and 5 mol% is especially preferable.

  [A] The lower limit of the content of polysiloxane is preferably 50% by mass, more preferably 70% by mass, further preferably 80% by mass, and 90% by mass with respect to the total solid content of the silicon-containing film-forming composition. % Is particularly preferred. As an upper limit of the said content, 100 mass% is preferable and 90 mass% is more preferable. The total solid content of the silicon-containing film-forming composition refers to the sum of components other than [B] organic solvent and [E] water. [A] Only 1 type of polysiloxane may be contained and 2 or more types may be contained.

  [A] The lower limit of the weight average molecular weight (Mw) in terms of polystyrene by polysiloxane size exclusion chromatography is preferably 1,000, more preferably 1,300, and even more preferably 1,500. The upper limit of Mw is preferably 100,000, more preferably 50,000, still more preferably 30,000, and particularly preferably 10,000.

  Mw of [A] polysiloxane in this specification uses, for example, Tosoh's GPC columns ("G2000HXL", "G3000HXL" and "G4000HXL"), flow rate: 1.0 mL / min, Elution solvent: Tetrahydrofuran, column temperature: A value measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C.

  As a method of hydrolyzing and / or hydrolyzing and condensing compound (1), compound (2), compound (3) and other hydrolyzable silane compounds, known hydrolysis and / or hydrolytic condensation methods are used. be able to.

  [A] In the synthesis of polysiloxane, the upper limit of the content of the alcohol solvent having a boiling point of 100 ° C. or lower in the solvent in the reaction solution is preferably 20% by mass, and more preferably 5% by mass. Alcohol solvents having a boiling point of 100 ° C. or lower may be generated during hydrolysis and / or hydrolysis condensation of the above compound (1), compound (2), compound (3), etc., and contained in the solvent in the reaction solution It is preferable to remove by a distillation column so that the rate is 20% by mass or less, preferably 5% by mass or less.

<[B] Organic solvent>
[B] Any organic solvent can be used as long as it can dissolve or disperse [A] polysiloxane and optional components.

  [B] Examples of the organic solvent include hydrocarbon solvents, alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, sulfur-containing solvents, and the like.

Examples of hydrocarbon solvents include n-pentane, iso-pentane, n-hexane, i-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane, iso-octane, and cyclohexane. , Aliphatic hydrocarbon solvents such as methylcyclohexane;
Benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propylbenzene, iso-propylbenzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di-iso-propylbenzene, n-amylnaphthalene, trimethylbenzene, etc. Aromatic hydrocarbon solvents are exemplified.

Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol , Sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec- Monoalcohol solvents such as heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenylmethylcarbinol, diacetone alcohol, cresol;
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 Examples thereof include polyhydric alcohol solvents such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and glycerin.

  Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n- Examples include hexyl ketone, di-iso-butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, and fencheon.

  Examples of ether solvents include ethyl ether, iso-propyl ether, n-butyl ether, n-hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol diethyl ether, 2-n-butoxyethanol, 2-n-hexoxyethanol, 2-phenoxyethanol, 2- (2-ethylbutoxy) ethanol, ethylene glycol dibutyl ether, diethylene glycol Monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, di Tylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, 1-n-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monomethyl Examples include ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, and 2-methyltetrahydrofuran. .

  Examples of the ester solvents include diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, N-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, aceto Ethyl acetate, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether Ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriacetate Glycol, ethyl propionate, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, Examples thereof include dimethyl phthalate and diethyl phthalate.

  Examples of the nitrogen-containing solvent include N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide, N-methyl. Examples include pyrrolidone and the like.

  Examples of the sulfur-containing solvent include dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, 1,3-propane sultone, and the like.

  Among these, ether solvents and ester solvents are preferable, and glycol solvents are more preferable from the viewpoint of excellent film formability.

  Examples of the glycol solvent include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate and the like.

  [B] An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

  [B] As a minimum of content of an organic solvent, 80 mass% is preferred, 90 mass% is more preferred, and 95 mass% is still more preferred. As an upper limit of the said content, 99.8 mass% is preferable, 99 mass% is more preferable, 98 mass% is further more preferable.

<Optional component>
<[C] Nitrogen-containing compound>
[C] The nitrogen-containing compound is a compound having a nitrogen atom. When the silicon-containing film-forming composition contains a [C] nitrogen-containing compound, the shape of the resist pattern formed in the multilayer resist process can be further improved while maintaining the above effects. [C] The nitrogen-containing compounds may be used alone or in combination of two or more.

  [C] The nitrogen-containing compound is preferably a compound having a basic amino group and a compound that generates a basic amino group by the action of an acid or the action of heat.

  Examples of the compound having a basic amino group and the compound that generates a basic amino group by the action of an acid or the action of heat include amine compounds, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

Examples of the amine compound include mono (cyclo) alkylamines;
Di (cyclo) alkylamines;
Tri (cyclo) alkylamines;
Substituted alkylanilines or derivatives thereof;
Ethylenediamine, N, N, N ′, N′-tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl ether, 4,4′-diaminobenzophenone, 4, 4'-diaminodiphenylamine, 2,2-bis (4-aminophenyl) propane, 2- (3-aminophenyl) -2- (4-aminophenyl) propane, 2- (4-aminophenyl) -2- ( 3-hydroxyphenyl) propane, 2- (4-aminophenyl) -2- (4-hydroxyphenyl) propane, 1,4-bis (1- (4-aminophenyl) -1-methylethyl) benzene, 1, 3-bis (1- (4-aminophenyl) -1-methylethyl) benzene, bis (2-dimethylaminoethyl) Ether, bis (2-diethylaminoethyl) ether, 1- (2-hydroxyethyl) -2-imidazolidinone, 2-quinoxalinol, N, N, N ′, N′-tetrakis (2-hydroxypropyl) ethylenediamine N, N, N ′, N ″ N ″ -pentamethyldiethylenetriamine and the like.

Examples of the amide group-containing compound include Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, Nt-butoxycarbonyl-2-carboxypyrrolidine and the like. A t-butoxycarbonyl group-containing amino compound;
Nt-amyloxycarbonyl group-containing amino compounds such as Nt-amyloxycarbonyl-4-hydroxypiperidine;
N- (9-anthrylmethyloxycarbonyl) group-containing amino compounds such as N- (9-anthrylmethyloxycarbonyl) piperidine;
Formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine and the like Can be mentioned.

  Examples of urea compounds include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea and the like. Is mentioned.

  Examples of the nitrogen-containing heterocyclic compound include imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinosaline, purine, pyrrolidine, piperidine, piperidine ethanol, 3- (N-piperidino) -1,2-propanediol, Morpholine, 4-methylmorpholine, 1- (4-morpholinyl) ethanol, 4-acetylmorpholine, 3- (N-morpholino) -1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo [2 2.2] octane and the like.

  Among these, an amide group-containing compound and a nitrogen-containing heterocyclic compound are preferable. As the amide group-containing compound, an Nt-butoxycarbonyl group-containing amino compound, an Nt-amyloxycarbonyl group-containing amino compound, and an N- (9-anthrylmethyloxycarbonyl) group-containing amino compound are preferable. t-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, Nt-butoxycarbonyl-2-carboxy-pyrrolidine, Nt-amyloxycarbonyl-4-hydroxy Piperidine and N- (9-anthrylmethyloxycarbonyl) piperidine are more preferred. As the nitrogen-containing heterocyclic compound, 3- (N-piperidino) -1,2-propanediol is preferable.

  When the silicon-containing film-forming composition contains a [C] nitrogen-containing compound, the lower limit of the content of the [C] nitrogen-containing compound is 0.01 parts by mass with respect to 100 parts by mass of [A] polysiloxane. Is preferable, 0.1 mass part is more preferable, and 0.5 mass part is further more preferable. As an upper limit of the said content, 10 mass parts is preferable, 5 mass parts is more preferable, and 3 mass parts is further more preferable.

<[D] Acid generator>
[D] The acid generator is a compound that generates an acid upon irradiation with ultraviolet light and / or heating. When the silicon-containing film-forming composition contains a [D] acid generator, curing can be promoted, and as a result, the strength of the silicon-containing film can be further increased. [D] Examples of the acid generator include onium salts such as sulfonium salts, tetrahydrothiophenium salts, and iodonium salts, sulfone compounds such as N-sulfonyloxyimide compounds, organic halogen compounds, disulfones, and diazomethane sulfones. It is done.

Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclohexane, and the like. [2.2.1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2- (3-tetracyclo [4.4.0.1 ^2,5 .1 ^{7, 10]} dodecanyl) -1,1-difluoroethanesulfonate, triphenylsulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate, triphenylsulfonium salicylate, triphenylsulfonium Ca Fur sulfonate, triphenylsulfonium salts such as triphenylsulfonium tricyclo [3.3.1.1 ^{3, 7]} decanyl difluoromethane sulfonate;
4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2. 2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexyl-phenyl diphenyl sulfonium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7, 10]} dodecanyl) -1,1-difluoroethanesulfonate, 4-cyclohexyl-phenyl diphenyl sulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate And 4-cyclohexyl-phenyl camphorsulfonate 4-cyclohexyl-phenyl diphenyl sulfonium salts;
4-t-butylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-t-butylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-t-butylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-t-butylphenyl Diphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-t-butylphenyldiphenylsulfonium 2- (3-tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10] dodecanyl) -1,1-difluoroethanesulfonate, 4-t-butylphenyl diphenyl sulfonium N, N'-bis (nonafluoro -n- butanesulfonyl) imidate, 4-t- Butylphenyl 4-t-butylphenyl diphenyl sulfonium salts such as triphenylsulfonium camphorsulfonate;
Tri (4-t-butylphenyl) sulfonium trifluoromethanesulfonate, tri (4-t-butylphenyl) sulfonium nonafluoro-n-butanesulfonate, tri (4-t-butylphenyl) sulfonium perfluoro-n-octanesulfonate, Tri (4-t-butylphenyl) sulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, tri (4-t-butylphenyl) sulfonium 2 - (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, tri (4-t- butylphenyl) sulfonium N, N'-bis (nonafluoro -N-butanesulfonyl) imidate, tri (4-t-butylphenyl) sulfur And tri (4-t- butylphenyl) sulfonium salts such as triphenylsulfonium camphorsulfonate and the like.

Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydro thiophenium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, 1- (4-n- butoxy-1-yl) 1- (4-n-butoxy) such as tetrahydrothiophenium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium camphorsulfonate Naphthalen-1-yl) tetrahydrothiophenium salt;
1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, (3,5-Dimethyl-4-hydroxyphenyl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2. 1] Hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2- (3-tetracyclo [4.4. 0.1 ^2,5 .1 ^7,10 ] dodecanyl) -1,1-difluoro Ethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, 1- (3,5-dimethyl-4-hydroxyphenyl) ) 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium salt such as tetrahydrothiophenium camphorsulfonate.

Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl- 1,1,2,2-tetrafluoroethane sulfonate, diphenyliodonium 2- (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, diphenyliodonium Diphenyliodonium salts such as N, N′-bis (nonafluoro-n-butanesulfonyl) imidate, diphenyliodonium camphorsulfonate;
Bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4-t-butylphenyl) iodonium perfluoro-n-octanesulfonate, Bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium 2 - (3-tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethanesulfonate, bis (4-t- butylphenyl) iodonium N, N'-bis (nonafluoro -N-butanesulfonyl) imidate, bis (4-t-butylphenyl) io Bis (4-t- butylphenyl) iodonium salts such as iodonium camphorsulfonate and the like.

Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) succinimide, N- (nonafluoro-n-butanesulfonyloxy) succinimide, N- (perfluoro-n-octanesulfonyloxy) succinimide, N- ( 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) succinimide, N- (2- (3-tetracyclo [4.4.0.1 ^{2] ,} 5.1 ^7,10 ] dodecanyl) -1,1-difluoroethanesulfonyloxy) succinimide, N- (camphorsulfonyloxy) succinimide and the like;
N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- ( 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboxy imide, N- (2- (3- tetracyclo ^[4.4.0.1 2,5 ^{.1 7,10]} dodecanyl) -1,1-difluoroethane-sulfonyloxy) bicyclo [2.2.1] hept Bicyclo [2.2.1] such as -5-ene-2,3-dicarboximide, N- (camphorsulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide. And hept-5-ene-2,3-dicarboximide compound.

  [D] Acid generators include compounds represented by the following formulas (4-1) to (4-7) (hereinafter also referred to as “compounds (4-1) to (4-7)”), and the like. Also mentioned.

  These [D] acid generators may be used individually by 1 type, and may be used in combination of 2 or more type.

  [D] The acid generator is preferably an onium salt, more preferably a sulfonium salt, still more preferably compounds (4-1) to (4-7), and particularly preferably compound (4-1).

  When the silicon-containing film-forming composition contains a [D] acid generator, the lower limit of the content of the [D] acid generator is 0.1 part by mass with respect to 100 parts by mass of [A] polysiloxane. Is preferable, 0.5 mass part is more preferable, 1 mass part is further more preferable, and 2 mass parts is further more preferable. As an upper limit of the said content, 20 mass parts is preferable, 10 mass parts is more preferable, and 5 mass parts is further more preferable.

<[E] water>
The silicon-containing film forming composition may contain [E] water as necessary. Since the silicon-containing film-forming composition further contains [E] water, [A] polysiloxane and the like are hydrated, so that the storage stability is improved. [E] By containing water, curing during film formation is promoted, and a dense silicon-containing film can be obtained.

  When the said silicon-containing film formation composition contains [E] water, as a minimum of content of [E] water, 0.01 mass% is preferable, 0.1 mass% is more preferable, 0.3 mass % Is more preferable. As an upper limit of the said content, 20 mass% is preferable, 10 mass% is more preferable, and 3 mass% is further more preferable. When the water content exceeds the above upper limit, the storage stability may be deteriorated or the uniformity of the coating film may be deteriorated.

<Other optional components>
The silicon-containing film-forming composition may contain other optional components in addition to the [A] to [E] components. Examples of other optional components include surfactants, colloidal silica, colloidal alumina, and organic polymers. When the said silicon-containing film formation composition contains another arbitrary component, as an upper limit of the content, 2 mass parts is preferable with respect to 100 mass parts of [A] polysiloxane, and 1 mass part is more preferable.

<Method for preparing silicon-containing film forming composition for multilayer resist process>
The method for preparing the silicon-containing film-forming composition is not particularly limited. For example, [A] polysiloxane, [B] an organic solvent, and if necessary, [C] nitrogen-containing compound, [D] acid generator, [E] It can be prepared by mixing water or the like at a predetermined ratio, and preferably filtering the obtained mixed solution with a filter having a pore size of 0.2 μm.

  As a minimum of solid content concentration of the silicon content film formation constituent, 0.01 mass% is preferred, 0.1 mass% is more preferred, 0.5 mass% is more preferred, and 1 mass part is especially preferred. As an upper limit of the said solid content concentration, 20 mass% is preferable, 10 mass% is more preferable, 5 mass% is further more preferable, and 3 mass parts is especially preferable.

<Silicon-containing film>
The silicon-containing film obtained from the silicon-containing film-forming composition has a feature that a resist pattern having high adhesion to a resist film, an antireflection film, and the like and having an excellent bottom shape without tailing or the like is obtained. Therefore, it can be suitably used in a multilayer resist process. Further, among the multilayer resist processes, it is particularly preferably used in pattern formation using a multilayer resist process in a region finer than 90 nm (ArF, ArF in immersion exposure, F ₂ , EUV, nanoimprint, etc.). it can.

  The silicon-containing film forms the coating film of the silicon-containing film-forming composition by applying the silicon-containing film-forming composition described above to the surface of another lower layer film such as a substrate or an organic underlayer film, The coating film can be formed by heat treatment and curing.

  Examples of the method for applying the silicon-containing film forming composition include spin coating, roll coating, and dipping. As temperature of heat processing, it is 50 to 450 degreeC normally. The average thickness of the formed silicon-containing film is usually from 10 nm to 200 nm.

<Pattern formation method>
The pattern forming method includes a silicon-containing film forming process, a resist film forming process, an exposure process, a developing process, and an etching process. The pattern forming method may include an organic underlayer film forming step before the silicon-containing film forming step. Hereinafter, each step will be described.

<Organic underlayer formation process>
In this step, an organic underlayer film is formed on the side of the substrate on which the silicon-containing film is formed. This organic underlayer film is different from the silicon-containing film formed from the silicon-containing film-forming composition. The organic underlayer film has a predetermined function (for example, an antireflection function) required to further supplement the function of the silicon-containing film and / or the resist film in forming the resist pattern, or to obtain a function that these do not have. , Coating film flatness, high etching resistance against fluorine-based gas such as CF ₄ ).

  Examples of the organic underlayer film include a resist underlayer film and an antireflection film.

  The organic underlayer film can be formed by applying a composition for forming an organic underlayer film by a spin coating method or the like to form a coating film, and then heating.

<Silicon-containing film formation process>
In this step, a silicon-containing film is formed on at least one surface side of the substrate with the above-described silicon-containing film forming composition. When the organic underlayer film is formed on the substrate, it is formed on the surface opposite to the substrate of the organic underlayer film. Thereby, the substrate with a silicon-containing film in which the silicon-containing film is formed on the substrate can be obtained.

  Examples of the substrate include insulating films such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, and the like. Further, as a commercially available product, an interlayer insulating film such as a wafer coated with a low dielectric insulating film such as “Black Diamond” from AMAT, “Silk” from Dow Chemical, or “LKD5109” from JSR can be used. . As this substrate, a patterned substrate such as a wiring course (trench) or a plug groove (via) may be used.

  The silicon-containing film can also be formed on the antireflection film. As an antireflection film, as a commercial product, for example, “NFC HM8006” manufactured by JSR Corporation may be mentioned.

  The method for forming the silicon-containing film is not particularly limited. For example, a coating film formed by applying the silicon-containing film forming composition on a substrate by a known method such as a spin coating method is exposed and / or heated. Can be formed by curing.

  Examples of radiation used for exposure include visible light, ultraviolet light, far ultraviolet light, X-rays, electron beams, γ-rays, molecular beams, and ion beams. As a minimum of the temperature at the time of heating a coating film, 90 degreeC is preferable, 150 degreeC is more preferable, and 200 degreeC is further more preferable. As an upper limit of the said temperature, 550 degreeC is preferable, 450 degreeC is more preferable, and 300 degreeC is further more preferable. The lower limit of the average thickness of the formed silicon-containing film is preferably 1 nm, more preferably 10 nm, and even more preferably 20 nm. The upper limit of the average thickness is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm.

  In order to further improve the adhesion between the silicon-containing film and the resist film, the silicon-containing film surface may be methylsilylated with a silylation treatment agent.

  Examples of the silylation treatment agent include allyloxytrimethylsilane, N, O-bis (trimethylsilyl) acetamide, bis (trimethylsilyl) trifluoroacetamide, bis (trimethylsilyl) urea, trimethylchlorosilane, N- (trimethylsilyl) acetamide, trimethylsilylazide, Trimethylsilyl cyananide, N- (trimethylsilyl) imidazole, 3-trimethylsilyl-2-oxazolidinone, trimethylsilyltrifluoromethanesulfonate, hexamethyldisilazane, heptamethyldisilazane, hexamethyldisiloxane, N-methyl-N-trimethylsilyltrifluoro Acetamide, (N, N-dimethylamino) trimethylsilane, nonamethyltrisilazane, 1,1,3,3-tetramethyldisilazaza , Trimethyl iodo silane, and the like.

  The methylsilylation of the silicon-containing film can be performed by dip coating, spin coating, or the like with the silylation treatment agent on the silicon-containing film, or by exposing the silicon-containing film to the vapor atmosphere of the silylation treatment agent. Moreover, you may heat a coating film to 50 to 300 degreeC after methylsilylation.

<Resist film formation process>
In this step, a resist film is formed on the surface of the silicon-containing film opposite to the substrate.

  The resist composition used for forming the resist film includes, for example, a chemically amplified resist composition having a resin whose solubility in an alkaline developer is increased by the action of an acid, a positive composition comprising an alkali-soluble resin and a quinonediazide photosensitizer. Preferable examples include a type resist composition, a negative type resist composition containing an alkali-soluble resin and a crosslinking agent. In addition, a resist pattern may be formed by appropriately using a double patterning method, a double exposure method, or the like, which is a technique for forming a fine pattern. A method of forming a negative pattern by developing a resist composition having a resin whose solubility in an alkali developer increases by the action of an acid as described in JP-A-2008-292975 with an organic solvent. May be used, and this method and the double exposure method may be used in combination.

  The solid content concentration of the resist composition is not particularly limited, but is preferably 5% by mass or more and 50% by mass. Moreover, as a resist composition, what was filtered using the filter with a hole diameter of about 0.2 micrometer can be used conveniently. In the pattern forming method of the present invention, a commercially available resist composition can be used as it is as such a resist composition.

  The method for applying the resist composition is not particularly limited, and can be applied by a conventional method such as a spin coating method. When applying the resist composition, the amount of the resist composition to be applied is adjusted so that the resulting resist film has a predetermined thickness.

  The resist film can be formed by volatilizing the solvent in the coating film by pre-baking the coating film formed by applying the resist composition. The pre-baking temperature is appropriately adjusted according to the type of resist composition to be used, and the like. The lower limit of the pre-baking temperature is preferably 30 ° C., more preferably 50 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable.

<Exposure process>
In this step, the resist film is exposed by selectively irradiating radiation through a photomask.

The radiation used for the exposure is from visible light, ultraviolet light, deep ultraviolet light, X-rays, electron beams, gamma rays, molecular beams, ion beams, etc., depending on the type of acid generator used in the resist composition. Among these, far ultraviolet rays are preferable, and KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (wavelength 157 nm), Kr ₂ excimer laser (wavelength 147 nm), ArKr Excimer laser (wavelength 134 nm) and extreme ultraviolet light (wavelength 13 nm, etc.) are more preferred. Further, the exposure method is not particularly limited, and can be performed in accordance with a conventionally known pattern formation method.

<Development process>
In this step, a resist pattern is formed by developing the exposed resist film.

  The development may be alkali development or organic solvent development.

  Examples of the developer used for alkali development include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, and methyl. Diethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo [5.4.0] -7-undecene, 1,5-diazabicyclo [ 4.3.0] -5-nonene and other alkaline aqueous solutions. These alkaline aqueous solutions may be those obtained by adding an appropriate amount of a water-soluble organic solvent, for example, alcohols such as methanol and ethanol, surfactants and the like.

  Examples of the developer used for organic solvent development include ketone solvents, alcohol solvents, amide solvents, ether solvents, ester solvents, and the like. Examples of these solvents include those similar to the respective solvents exemplified as the [B] organic solvent. These solvents may be used singly or in combination, or may be used by mixing with water.

  A predetermined resist pattern corresponding to a photomask can be formed by performing development with a developer, washing, and drying.

  In this step, post-baking is preferably performed before development in order to improve resolution, pattern profile, developability, and the like. The post-baking temperature is appropriately adjusted according to the type of resist composition used, but the lower limit of the post-baking temperature is preferably 50 ° C., more preferably 80 ° C. As an upper limit of the said temperature, 200 degreeC is preferable and 150 degreeC is more preferable.

<Etching process>
In this step, the silicon-containing film and the substrate are dry-etched using the resist pattern as a mask.

The dry etching can be performed using a known dry etching apparatus. The source gas during dry etching depends on the elemental composition of the film to be etched, but includes oxygen atoms such as O ₂ , CO, and CO ₂ , inert gases such as He, N ₂ , and Ar, Cl ₂ , chlorine gas such as BCl ₄ , H ₂ , NH ₃ gas, or the like can be used. These gases can also be mixed and used.

  When a substrate on which another resist underlayer film is formed is used, this resist underlayer film is also dry etched together with the silicon-containing film and the substrate.

  According to the pattern forming method, a predetermined substrate pattern can be formed by appropriately performing the above steps.

  EXAMPLES Hereinafter, although this invention is demonstrated concretely based on an Example, this invention is not limited to these Examples. The solid content concentration and the weight average molecular weight (Mw) of the polysiloxane solution in this example were measured by the following methods.

[Solid content concentration of polysiloxane solution]
By baking 0.5 g of the polysiloxane solution at 250 ° C. for 30 minutes, the mass of the solid content relative to 0.5 g of the polysiloxane solution was measured, and the solid content concentration (% by mass) of the polysiloxane solution was calculated.

[Weight average molecular weight (Mw)]
Using Tosoh's GPC columns (“G2000HXL”, “G3000HXL” and “G4000HXL”), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C. Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard.

<[A] Synthesis of polysiloxane>
[A] Silane compounds used for the synthesis of polysiloxane are shown below.
Compound (M-1): Tetraethoxysilane Compound (M-2): Phenyltrimethoxysilane Compound (M-3): Methyltrimethoxysilane Compound (M-4): 4-Methylphenyltrimethoxysilane Compound (M- 5) to (M-10): compounds represented by the following formulas (M-5) to (M-10)

[Synthesis Example 1] (Synthesis of polysiloxane (A-1))
1.28 g of oxalic acid was dissolved in 12.85 g of water by heating to prepare an aqueous oxalic acid solution. Next, in a flask containing 25.05 g (90 mol%) of the compound (M-1), 3.63 g (10 mol%) of the compound (M-2) and 43.21 g of methanol, a condenser tube and the above prepared Shu A dropping funnel containing an acid aqueous solution was set. Subsequently, after heating the said flask to 60 degreeC with an oil bath, the said oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution is allowed to cool, and after adding 129.00 g of propylene glycol monomethyl ether acetate to the above reaction solution, it is set in an evaporator to remove the remaining water and generated methanol, As a result, 86.0 g of a solution containing polysiloxane (A-1) was obtained. The solid content concentration of the polysiloxane (A-1) in the solution was 18.0% by mass, and the Mw of the polysiloxane (A-1) was 2,000.

[Synthesis Examples 2 to 16] (Synthesis of polysiloxanes (A-2) to (A-16))
Polysiloxanes (A-2) to (A-16) were synthesized in the same manner as in Synthesis Example 1 except that each type and amount of monomers shown in Table 1 were used. Table 1 shows the solid content concentration (% by mass) of the obtained polysiloxane solution and Mw of [A] polysiloxane.

[Preparation of silicon-containing film forming composition for multilayer resist process]
Components other than [A] polysiloxane used for the preparation of the silicon-containing film forming composition for the multilayer resist process are shown below.

[[B] Organic solvent]
B-1: Propylene glycol monoethyl ether B-2: Propylene glycol monomethyl ether acetate

[[C] Nitrogen-containing compound]
The structural formula is shown below.
C-1; Nt-butoxycarbonyl-4-hydroxypiperidine C-2: Nt-amyloxycarbonyl-4-hydroxypiperidine C-3: N- (2,3-dihydroxypropyl) piperidine

[[D] acid generator]
The structural formula is shown below.
D-1: 4-cyclohexylphenyldiphenylsulfonium 2,4-difluorobenzene-1-sulfonate

[Example 1]
[A] 2.00 parts by mass of (A-3) as a polysiloxane (solid content), 97.5 parts by mass of (B-1) as an organic solvent, and 0.05 parts by mass of [E] water. The resulting mixed solution was filtered through a filter having a pore size of 0.2 μm to obtain a silicon-containing film forming composition (J-1) for a multilayer resist process.

[Examples 2 to 15 and Comparative Examples 1 to 4]
Except having used each component of the kind and compounding quantity which are shown in following Table 2, in the same way as Example 1, the silicon-containing film formation composition for multilayer resist processes (J-2)-(J-15) and ( CJ-1) to (CJ-4) were prepared.

<Formation of silicon-containing film>
On the silicon wafer, the obtained silicon-containing film forming composition for a multilayer process was applied by a spin coat method using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron Ltd.). The resulting coating film was subjected to PB for 1 minute on a hot plate at 220 ° C. to form a silicon-containing film, thereby obtaining a substrate on which the silicon-containing film was formed. It was 30 nm when the average thickness of the formed silicon-containing film was measured with a film thickness measuring device (“M-2000D” manufactured by JA Woollam).

<Evaluation>
About the formed silicon-containing film | membrane, the following item was evaluated by the method shown below. The evaluation results are shown in Table 3 below.

[Substrate reflectivity]
Refractive index parameter (n) and extinction coefficient (k) of the silicon-containing film, the underlayer film forming composition (“NFC HM8006” from JSR) and the resist material (“ARF AR2772JN” from JSR) formed above. ) With a high-speed spectroscopic ellipsometer (“M-2000” from JA Woollam), and based on this measurement value, using simulation software (“Prolith” from KLA-Tencor), NA 1.3, The substrate reflectance of the film obtained by laminating the resist material / silicon-containing film / underlayer film forming composition under Dipole conditions was determined. The substrate reflectivity was evaluated as “◯” when it was 1% or less, and “x” when it exceeded 1%.

[Solvent resistance]
The obtained substrate on which the silicon-containing film was formed was immersed in cyclohexanone for 10 seconds at room temperature. The average thickness before and after immersion of the silicon-containing film was measured using a spectroscopic ellipsometer (“UV1280E” manufactured by KLA-TENCOR). Assuming that the average thickness before immersion is T0 and the average thickness after immersion is T1, the rate of change in film thickness (%) due to solvent immersion was determined by the formula | T1-T0 | × 100 / T0. The solvent resistance was evaluated as “◯” (good) when the film thickness change rate was less than 1%, and “x” (bad) when the film thickness change rate was 1% or more.

[Minimum dimensions before collapse and pattern shape]
The minimum dimensions before collapse and the pattern shape were evaluated by performing the lithography evaluation shown below.

(Lithography evaluation, organic solvent development)
An antireflection film-forming material (“HM8006” from JSR) was spin-coated on a 12-inch silicon wafer, and PB was performed at 250 ° C. for 60 seconds to form an antireflection film having an average thickness of 100 nm. On the antireflection film, the obtained silicon-containing film-forming composition for a multilayer process is spin-coated using the spin coater, PB at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 60 seconds. Thus, a silicon-containing film having an average thickness of 30 nm was formed. Next, a resist material (“ARF AR2772JN” from JSR) is spin-coated on the resist underlayer film, PB is applied at 90 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds to form a resist film having an average thickness of 100 nm. did.

  Next, using an ArF immersion exposure apparatus (“S610C” manufactured by NIKON), exposure was performed through a mask having a mask size for forming a 40 nm line / 80 nm pitch under the optical conditions of NA: 1.30 and Dipole. PEB is applied at 100 ° C. for 60 seconds on a “Lithius Pro-i” hot plate, cooled at 23 ° C. for 30 seconds, then paddle developed with butyl acetate as a developer for 30 seconds, and methyl isobutyl carbinol (MIBC). Rinse. An evaluation substrate on which a resist pattern of 40 nm line / 80 nm pitch was formed was obtained by spin-drying by shaking off at 2,000 rpm for 15 seconds.

(Evaluation of minimum collapse dimensions and pattern shape)
The minimum dimensions before collapse and the pattern shape were measured as follows. A scanning electron microscope (“CG-4000” manufactured by Hitachi High-Technologies Corporation) was used for length measurement and observation of the resist pattern on the evaluation substrate.

When the substrate for evaluation was obtained, the exposure amount formed a resist pattern having a line width of 42 nm and a distance (space) between adjacent lines of 84 nm (line and space is 1 to 2). (MJ / cm ² ) was set as the optimum exposure amount, and the exposure amount was increased stepwise from the optimum exposure amount, and the exposure was sequentially performed. At this time, since the line width of the obtained pattern is gradually narrowed, the collapse of the resist pattern is finally observed at the line width corresponding to a certain exposure amount. The line width corresponding to the maximum exposure amount at which the resist pattern collapse was not confirmed was defined as the minimum pre-collapse dimension (nm) and used as an index for pattern collapse resistance. The minimum dimension before collapse is “◯” (good) when it is 30 nm or less, “△” (useable) when it is over 30 nm and 40 nm or less, and when it is over 40 nm or cannot be evaluated due to pattern collapse Evaluated as “x” (bad). The pattern shape was evaluated as “◯” when the bottom of the resist pattern had no bottom, and “×” when the pattern collapsed or bottomed.

[Oxygen etching resistance]
The silicon-containing film thus formed was O ₂ treated at 100 W for 120 seconds using a dry etching apparatus (“Telius SCCM” manufactured by Tokyo Electron Ltd.), and the difference in film thickness before and after the treatment was measured. The oxygen etching resistance is “◯” (good) when the difference in film thickness before and after the treatment is less than 10 nm, “△” (available) when it is 10 nm or more and 15 nm or less, and “×” when it exceeds 15 nm. (Poor).

  From the results of Table 3, according to the silicon-containing film forming compositions of the examples, the resist composition has excellent resistance to solvents, excellent anti-reflective properties for resist films, and has high pattern transferability by etching. It can be seen that a silicon-containing film having a good shape and less collapse can be formed.

  The silicon-containing film forming composition for a multilayer resist process according to the present invention is excellent in resistance to a solvent of a resist composition in both positive development with an alkaline solution and negative development with an organic solvent, and antireflection properties for a resist film. It is characterized in that it has excellent adhesiveness, has high pattern transferability by etching, has a good resist pattern shape, and has little collapse.

Claims (9)

Containing polysiloxane and an organic solvent,
The polysiloxane includes a hydrolysis condensate of a compound containing a first silane compound having at least one of a group containing a cyclic carbonate structure and a group containing a lactone structure,
A silicon-containing film forming composition for a multilayer resist process, wherein a content ratio of a structural unit derived from the first silane compound to all structural units constituting the polysiloxane is 0.1 mol% or more and 30 mol% or less.   The silicon-containing film forming composition for a multilayer resist process according to claim 1, wherein the cyclic carbonate structure and the lactone structure are monocyclic structures. The silicon-containing film forming composition for a multilayer resist process according to claim 1 or 2, wherein the first silane compound is represented by the following formula (1).

(In Formula (1), R ¹ is a monovalent group containing a cyclic carbonate structure having 5 to 20 ring members or a lactone structure having 4 to 20 ring members. R ² is cyano-substituted, fluorine-substituted or unsubstituted. R ³ is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. A is an integer of 1 to 3. b is an integer of 0 to 2. c is an integer of 1 to 3. However, a + b + c is 4. a is 2 or more. A plurality of R ¹ groups may be the same or different, and when b is 2, two R ² groups may be the same or different, and when c is 2 or more, a plurality of R ³ groups are the same or different. May be.) The silicon-containing film forming composition for a multilayer resist process according to claim 1, wherein the compound further contains a second silane compound represented by the following formula (2).

(In the formula (2), X is a hydrogen atom, a monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom. May be good.)   5. The silicon-containing film forming composition for a multilayer resist process according to claim 4, wherein the content ratio of the structural unit derived from the second silane compound to all structural units constituting the polysiloxane is 20 mol% or more and 95 mol% or less. object. The silicon-containing film forming composition for a multilayer resist process according to any one of claims 1 to 5, wherein the compound further contains a third silane compound represented by the following formula (3).

(In Formula (3), R ⁴ is a monovalent group containing an alkenyl group having 2 to 10 carbon atoms, an aromatic carbocyclic ring having 6 to 20 ring members, or an aromatic heterocyclic ring having 4 to 20 ring members. R ⁵ is a cyano-substituted, fluorine-substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a cyano group, and R ⁶ is a hydrogen atom , A monovalent oxyhydrocarbon group having 1 to 20 carbon atoms, an acyloxy group having 1 to 20 carbon atoms, or a halogen atom, d is an integer of 1 to 3. e is an integer of 0 to 2. F is an integer of 1 to 3. However, d + e + f is 4. When d is 2 or more, a plurality of R ⁴ may be the same or different, and when e is 2, two R ⁵ in the case of two or more is also good .f be the same or different, a plurality of R ⁶ is be the same or different from each other .)   The silicon-containing film for a multilayer resist process according to claim 6, wherein the content ratio of the structural unit derived from the third silane compound to all structural units constituting the polysiloxane is 0.1 mol% or more and 30 mol% or less. Forming composition. A step of forming a silicon-containing film on at least one surface side of the substrate by the silicon-containing film forming composition for a multilayer resist process according to any one of claims 1 to 7,
Forming a resist film on the opposite side of the silicon-containing film from the substrate;
Exposing the resist film by selectively irradiating radiation through a photomask; and
A step of forming a resist pattern by developing the exposed resist film;
And a step of dry etching the silicon-containing film and the substrate using the resist pattern as a mask. Before the silicon-containing film forming step,
Further comprising the step of forming an organic underlayer film on the surface side of the substrate on which the silicon-containing film is formed,
The pattern forming method according to claim 8, wherein the organic underlayer film is further etched in the etching step.