WO2018159356A1

WO2018159356A1 - Composition for silicon-containing-film formation, silicon-containing film, pattern formation method, and polysiloxane

Info

Publication number: WO2018159356A1
Application number: PCT/JP2018/005724
Authority: WO
Inventors: 裕介大坪; 俊輔栗田
Original assignee: Jsr株式会社
Priority date: 2017-03-02
Filing date: 2018-02-19
Publication date: 2018-09-07
Also published as: TW201841998A

Abstract

The purpose of the present invention is to provide: a composition for silicon-containing-film formation capable of forming a silicon-containing film which retains removability by etching with a fluorine-based gas and is excellent in terms of inhibition of the falling of resist pattern walls; the silicon-containing film; a pattern formation method; and a polysiloxane. The composition for silicon-containing-film formation comprises a polysiloxane having a group represented by formula (1) and a solvent. In formula (1), L is a single bond or a C1-20 (n+1)-valent organic group, E is a group represented by formula (2-1) or (2-2), Y1 is an (un)substituted C6-20 aryl group or a C1-20 monovalent aliphatic hydrocarbon group in which a hydrogen atom has been replaced with an electron-attracting group, and Y2 is an (un)substituted C6-20 arylenediyl group or a C1-20 divalent aliphatic hydrocarbon group in which a hydrogen atom has been replaced with an electron-attracting group.

Description

Silicon-containing film forming composition, silicon-containing film, pattern forming method, and polysiloxane

The present invention relates to a silicon-containing film forming composition, a silicon-containing film, a pattern forming method, and polysiloxane.

For pattern formation of semiconductor elements, etc., a resist film is exposed and developed on a substrate to be processed via an organic antireflection film and a silicon-containing film, and etching is performed using the obtained resist pattern as a mask. The process is heavily used. In recent years, with the miniaturization of resist patterns, there are problems such as collapse of resist patterns and reduction in etching selectivity of mask patterns. Here, studies have been made on silicon-containing film materials that improve the resist pattern collapse and mask pattern etching selectivity, and methods for forming patterns on substrates using such silicon-containing film materials. (See JP 2004-310019 A and International Publication No. 2012/039337).

JP 2004-310019 A International Publication No. 2012/039337

However, when the resist pattern is miniaturized to a line width of 40 nm or less, the above conventional silicon-containing film cannot satisfy these requirements. In addition, there is a problem that the substrate to be processed is damaged when the silicon-containing film is removed by plasma etching with a fluorine-based gas after the silicon-containing film pattern is formed using the resist pattern as a mask. Improvement in the removability of the contained film is also required.

The present invention has been made based on the circumstances as described above, and an object thereof is to form a silicon-containing film that is excellent in resist pattern collapse suppression while maintaining etching removability by a fluorine-based gas. Another object of the present invention is to provide a silicon-containing film forming composition, a silicon-containing film, a pattern forming method, and a polysiloxane.

The invention made to solve the above problems is a silicon-containing film-forming composition containing a polysiloxane having a group represented by the following formula (1) and a solvent.

(In the formula (1), L is a single bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms. E is a group represented by the following formula (2-1) or (2-2). N is an integer of 1 to 3. When n is 2 or more, L is an organic group, and a plurality of E are the same or different, * is a site bonded to a silicon atom in the polysiloxane. Is shown.)

(In Formula (2-1), R ¹ is a single bond or a divalent organic group having 1 to 20 carbon atoms. Y ¹ is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or at least 1 A monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one hydrogen atom is substituted with an electron withdrawing group.
In formula (2-2), R ² is a monovalent organic group having 1 to 20 carbon atoms. Y ² is a substituted or unsubstituted arenediyl group having 6 to 20 carbon atoms or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with an electron withdrawing group. )

Another invention made to solve the above problems is a silicon-containing film formed from the silicon-containing film-forming composition.

Still another invention made in order to solve the above-mentioned problems is a step of forming a silicon-containing film on the upper side of the substrate by coating the silicon-containing film-forming composition, and a step of forming a pattern on the silicon-containing film Is a pattern forming method.

Still another invention made to solve the above problems is a polysiloxane having a group represented by the above formula (1).

According to the composition for forming a silicon-containing film and the pattern forming method of the present invention, it is possible to form a silicon-containing film that is excellent in resist pattern collapse suppression while maintaining the etching removability with a fluorine-based gas. It is possible to form a silicon-containing film that is excellent in resistance to an alkaline developer in the resist pattern forming step and excellent in releasability with alkaline hydrogen peroxide. Furthermore, the silicon-containing film forming composition of the present invention is excellent in storage stability. The silicon-containing film of the present invention is excellent in resist pattern collapse suppression while maintaining etching removability by a fluorine-based gas, and is excellent in resistance to an alkaline developer in the resist pattern forming process, and is also highly alkaline. Excellent peelability with hydrogen oxide water. The polysiloxane of the present invention can be suitably used as a polysiloxane component of the silicon-containing film forming composition. Therefore, these can be used suitably for a multilayer resist process, and can be used suitably for manufacture of a semiconductor device etc. which are expected to be further miniaturized in the future.

Hereinafter, embodiments of the silicon-containing film forming composition, polysiloxane, silicon-containing film, and pattern forming method of the present invention will be described.

<Silicon-containing film forming composition>
The silicon-containing film forming composition includes a polysiloxane having a group represented by the formula (1) (hereinafter also referred to as “[A] polysiloxane”) and a solvent (hereinafter also referred to as “[B] solvent”). ) And. The silicon-containing film-forming composition may contain an optional component as long as the effects of the present invention are not impaired. Hereinafter, each component will be described.

<[A] polysiloxane>
[A] The polysiloxane is a polysiloxane having a group represented by the following formula (1) (hereinafter also referred to as “group (I)”).

In the above formula (1), L is a single bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms. E is a group represented by the following formula (2-1) or (2-2) (hereinafter also referred to as “group (II-1) or (II-2)”). n is an integer of 1 to 3. When n is 2 or more, L is an organic group, and a plurality of E are the same or different. * Shows the site | part couple | bonded with the silicon atom in the said polysiloxane.

In the above formula (2-1), R ¹ is a single bond or a divalent organic group having 1 to 20 carbon atoms. Y ¹ is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with an electron withdrawing group.
In the above formula (2-2), R ² is a monovalent organic group having 1 to 20 carbon atoms. Y ² is a substituted or unsubstituted arenediyl group having 6 to 20 carbon atoms or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with an electron withdrawing group.

The silicon-containing film-forming composition contains [A] polysiloxane and [B] solvent, so that it retains etching removability with a fluorine-based gas and is excellent in resist pattern collapse suppression, A silicon-containing film having excellent resistance to an alkaline developer in the resist pattern forming step and excellent peelability with alkaline hydrogen peroxide can be formed, and storage stability is also excellent. The reason why the composition for forming a silicon-containing film has the above-described configuration and thus achieves the above effect is not necessarily clear, but can be inferred as follows, for example. That is, in the silicon-containing film-forming composition, [A] polysiloxane has a group (I) containing a sulfonate structure to which an electron withdrawing group or the like is bonded. Since this sulfonic acid ester structure has an electron-attracting group or the like bonded thereto, it is difficult to cleave even when heated at room temperature. Therefore, the silicon-containing film-forming composition is excellent in storage stability, and the formed silicon-containing film is excellent in resistance to an alkaline developer. Moreover, since this sulfone ester structure is cleaved by alkaline hydrogen peroxide and a sulfo group is generated, the silicon-containing film is excellent in releasability by alkaline hydrogen peroxide.

[Group (I)]
The (n + 1) -valent organic group having 1 to 20 carbon atoms represented by L in the above formula (1) includes an (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms, and the carbon-carbon of this hydrocarbon group A group (α) containing a divalent heteroatom-containing group in between, a group obtained by substituting part or all of the hydrogen atoms of the hydrocarbon group and the group (α) with a monovalent heteroatom-containing group, and the like It is done.

Examples of the (n + 1) -valent hydrocarbon group having 1 to 20 carbon atoms include an (n + 1) -valent chain hydrocarbon group having 1 to 20 carbon atoms and an (n + 1) -valent alicyclic carbon group having 3 to 20 carbon atoms. Examples thereof include a hydrogen group and an (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms.

Examples of the (n + 1) -valent chain hydrocarbon group having 1 to 20 carbon atoms include alkanes such as methane, ethane, propane, and butane, alkenes such as ethene, propene, and butene, and alkynes such as ethyne, propyne, and butyne. And a group in which 2 to 4 hydrogen atoms are removed.

Examples of the (n + 1) valent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkanes such as cyclopentane and cyclohexane, alicyclic rings such as bridged ring saturated hydrocarbons such as norbornane, adamantane, and tricyclodecane. Groups in which alicyclic unsaturated hydrocarbons such as cycloalkenes such as saturated hydrocarbons, cyclopentenes, cyclohexenes and the like, bridged ring unsaturated hydrocarbons such as norbornene and tricyclodecene, etc., are removed from 2 to 4 hydrogen atoms Etc.

Examples of the (n + 1) -valent aromatic hydrocarbon group having 6 to 20 carbon atoms include 2 to 4 aromatic rings contained in an arene such as benzene, toluene, ethylbenzene, xylene, naphthalene, methylnaphthalene, anthracene, and methylanthracene. Examples include a hydrogen atom on the above or a group on which 2 to 4 aromatic rings and an alkyl group are removed.

Examples of the hetero atom constituting the divalent and monovalent hetero atom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the divalent heteroatom-containing group include —O—, —CO—, —S—, —CS—, —NR′—, a group in which two or more of these are combined, and the like. R 'is a hydrogen atom or a monovalent hydrocarbon group. Of these, —O— and —S— are preferred.

Examples of the monovalent heteroatom-containing group include halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom, hydroxy group, carboxy group, cyano group, amino group and sulfanyl group. Among these, a halogen atom is preferable, and a fluorine atom is more preferable.

As n in the above formula (1), 1 and 2 are preferable, and 1 is more preferable.

L is preferably an (n + 1) -valent hydrocarbon group and a group containing a divalent heteroatom-containing group between carbon-carbons of this hydrocarbon group, and is an (n + 1) -valent chain hydrocarbon group or aromatic carbon group. A hydrogen group and a group containing a divalent heteroatom-containing group between carbon-carbons of these hydrocarbon groups are more preferable. When n is 1, L is more preferably an alkanediyl group, a group containing —O— or —S— between the carbon-carbon of the alkanediyl group, and an arenediyl group. A methanediyl group, an ethanediyl group, a propanediyl group Methanediylsulfanylmethanediyl group, methanediylsulfanylethanediyl group, ethanediylsulfanylethanediyl group, propanediylsulfanylmethanediyl group, propanediylsulfanylethanediyl group, methanediyloxymethanediyl group, methanediyloxyethanediyl group, Ethanediyloxymethanediyl group, ethanediyloxyethanediyl group, propanediyloxymethanediyl group, propanediyloxyethanediyl group, and benzenediyl group are particularly preferred.

If L is a group containing a divalent heteroatom-containing group between carbon-carbon of the hydrocarbon group, the etching removability of the silicon-containing film with a fluorine-based gas can be further enhanced.

[Group (II-1)]
Examples of the divalent organic group having 1 to 20 carbon atoms represented by R ¹ in the formula (2-1) include those in which n is 1 among those exemplified as the (n + 1) valent organic group of L above. Etc.

R ¹ is preferably a single bond.

Examples of the aryl group in the substituted or unsubstituted aryl group having 6 to 20 carbon atoms represented by Y ¹ in the above formula (2-1) include, for example, a phenyl group, a benzyl group, a tolyl group, a xylyl group, a naphthyl group, an anthryl group. Groups and the like.

Examples of the substituent for the aryl group of Y ¹ include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxy group, a cyano group, a nitro group, an acyl group, an acyloxy group, a hydrocarbon group, and an oxycarbonization. A hydrogen group etc. are mentioned. Among these, a halogen atom, a cyano group, a nitro group, an acyl group, and an acyloxy group are preferable from the viewpoint of electron withdrawing property, a halogen atom is more preferable, and a fluorine atom is more preferable.

Examples of the substituted or unsubstituted aryl group having 6 to 20 carbon atoms of Y ¹ include a phenyl group, a naphthyl group, an anthryl group, a fluorophenyl group, a chlorophenyl group, a trifluorophenyl group, a pentafluorophenyl group, a fluorobenzyl group, and A difluorobenzyl group is preferred, a phenyl group, a fluorophenyl group and a fluorobenzyl group are more preferred, and a phenyl group and a fluorophenyl group are more preferred.

A monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom represented by Y ¹ in the formula (2-1) is substituted with an electron withdrawing group (hereinafter referred to as “electron withdrawing”). Examples of the aliphatic hydrocarbon group in (also referred to as “substituent group-substituted aliphatic hydrocarbon group”) include, for example, the above-mentioned (1 + 1) -valent chain hydrocarbon group having 1 to 20 carbon atoms and (n + 1) carbon atoms having 3 to 20 carbon atoms. ) Among those exemplified as the valent alicyclic hydrocarbon group, a group in which one hydrogen atom is added to a divalent group in which n is 1 can be mentioned.

Examples of the electron withdrawing group in the Y ¹ electron withdrawing group-substituted aliphatic hydrocarbon group include a halogen atom, a cyano group, a nitro group, a halogenated hydrocarbon group having 1 to 10 carbon atoms, and a carbon number of 1 to 10 A group having —O—, a group having —SO— having 1 to 10 carbon atoms, a group having —SO ₂ — having 1 to 10 carbon atoms, a group having —CO— having 1 to 10 carbon atoms, And groups having 1 to 10 —COO—.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

Examples of the halogenated hydrocarbon group having 1 to 10 carbon atoms include monovalent groups such as a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a trichloromethyl group, a trifluoroethyl group, a hexafluoro i-propyl group, And halogenated chain hydrocarbon groups such as pentafluoro n-propyl group and nonafluoro n-butyl group.

Examples of the group having —O— having 1 to 10 carbon atoms include monovalent groups such as oxy hydrocarbon groups such as methoxy group, cyclohexyloxy group, and phenoxy group, hydroxy aromatic hydrocarbon groups such as hydroxyphenyl group, Examples thereof include cyclic ether groups such as a tetrahydrofuranyl group and a tetrahydropyranyl group.

Examples of the group having —SO— having 1 to 10 carbon atoms include monovalent groups such as a sulfoxy hydrocarbon group such as a methylsulfoxy group and a phenylsulfoxy group, and a cyclic sulfoxy group such as an S-oxotetrahydrothiophenyl group. Etc.

Examples of the group having 1 to 10 carbon atoms —SO ₂ — include monovalent groups such as sulfonyl hydrocarbon groups such as methylsulfonyl group and phenylsulfonyl group, and cyclic sulfonyl groups such as S-dioxotetrahydrothiophenyl group. Etc.

Examples of the group having -CO- having 1 to 10 carbon atoms include monovalent groups such as acyl groups such as formyl group, acetyl group and benzoyl group, cyclic ketone groups such as oxocyclohexyl group and oxoadamantyl group. It is done.

Examples of the group having 1 to 10 carbon atoms —COO— include monovalent groups such as acyloxy groups such as formyloxy group, acetoxy group and benzoyloxy group, and carbonyloxy hydrocarbons such as methoxycarbonyl group and phenoxycarbonyl group. And a group having a lactone structure such as a butyrolactone-yl group and a norbornanelactone-yl group.

Examples of the electron withdrawing group include a monovalent group such as a halogen atom, a cyano group, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a group having —O— having 1 to 10 carbon atoms, and 1 to 10 carbon atoms. A group having —SO—, a group having 1 to 10 carbon atoms —SO ₂ —, a group having 1 to 10 carbon atoms —CO—, and a group having 1 to 10 carbon atoms —COO— are preferred, More preferred are a fluorine atom, a chlorine atom, a cyano group, a fluorinated hydrocarbon group, an oxyhydrocarbon group, an acyl group, a carbonyloxy hydrocarbon group and a sulfonyl hydrocarbon group, a fluorine atom, a chlorine atom, a cyano group, a fluorinated alkyl group. More preferably an alkoxy group, an alkylcarbonyl group, an alkoxycarbonyl group and an alkylsulfonyl group, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a methoxy group, an acetyl group, Group, methoxycarbonyl group and methylsulfonyl group is particularly preferred.

When a fluorine atom is contained in the group (I) as an electron-attracting group or the like, the silicon-containing film formed from [A] polysiloxane is a resist pattern formed on the upper side thereof, particularly a positive electrode formed by alkali development. It is considered that the adhesion between the mold and the resist pattern is further improved, and the resist pattern collapse prevention property is further improved. [A] When the polysiloxane contains a fluorine atom, the etching removability by the fluorine-based gas is further improved. Moreover, when [A] polysiloxane contains a fluorine atom, the sensitivity of the radiation sensitive resin composition in the case of using extreme ultraviolet rays (EUV) can be increased.

Examples of the electron-withdrawing group-substituted aliphatic hydrocarbon group for Y ¹ include a group represented by the following formula (4-1).

In the above formula (4-1), R ⁴ to R ⁸ are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 18 carbon atoms, or a monovalent electron withdrawing group. p is 0 or 1. However, when p is 0, at least one of R ⁶ to R ⁸ is an electron withdrawing group. When p is 1, at least one of R ⁴ to R ⁸ is an electron withdrawing group.

R ⁴ to R ⁸ are preferably a hydrogen atom, a methyl group, a fluorine atom, a chlorine atom, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a methylsulfonyl group, and an acetoxy group.

Y ¹ is preferably an electron-withdrawing group-substituted aliphatic hydrocarbon group.

[Group (II-2)]
As the monovalent organic group having 1 to 20 carbon atoms represented by R ² in the above formula (2-2), for example, among those exemplified as the (n + 1) valent organic group of L, n is 1. And a group obtained by adding one hydrogen atom to a divalent organic group. Among these, a monovalent hydrocarbon group is preferable, a monovalent chain hydrocarbon group is more preferable, an alkyl group is further preferable, and a methyl group and an ethyl group are particularly preferable.

Examples of the arenediyl group in the substituted or unsubstituted arenediyl group represented by Y ² in the above formula (2-2) include benzenediyl group, toluenediyl group, xylenediyl group, naphthalene A diyl group, an anthracene diyl group, etc. are mentioned. Of these, a benzenediyl group is preferred.

Examples of the substituent of the above arenediyl group of Y ² include those exemplified as the substituent of the aryl group of Y ¹ . Among these, a halogen atom is preferable and a fluorine atom is more preferable.

Examples of the electron-withdrawing group-substituted aliphatic hydrocarbon group for Y ² include a group represented by the following formula (4-2).

In the above formula (4-2), R ⁹ to R ¹² are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 18 carbon atoms, or a monovalent electron withdrawing group. R ¹³ is a single bond, a divalent hydrocarbon group having 1 to 18 carbon atoms, or a divalent electron withdrawing group. q is 0 or 1. However, when q is 0, at least one of R ¹¹ to R ¹³ is an electron withdrawing group. When q is 1, at least one of R ⁹ to R ¹³ is an electron withdrawing group. ** represents a site bonded to —O— in the above formula (2-2).

R ⁹ to R ¹² are preferably a hydrogen atom, a methyl group, a fluorine atom, a chlorine atom, a trifluoromethyl group, a cyano group, a methoxy group, a methoxycarbonyl group, a methylsulfonyl group, and an acetoxy group.

R ¹³ is preferably a single bond.

Q is preferably 1.

Y ² is preferably a substituted or unsubstituted arenediyl group, more preferably a substituted or unsubstituted benzenediyl group, and even more preferably a benzenediyl group and a fluorobenzenediyl group.

[A] The polysiloxane has a first structural unit represented by the formula (3) containing the group (I) (hereinafter also referred to as “structural unit (I)”). [A] In addition to the structural unit (I), the polysiloxane includes a second structural unit represented by the formula (5) described later (hereinafter also referred to as “structural unit (II)”) and / or a formula (6) described later. 3) (hereinafter also referred to as “structural unit (III)”), and other than the structural units (I) to (III), as long as the effects of the present invention are not impaired. Other structural units may be included. Hereinafter, each structural unit will be described.

[Structural unit (I)]
The structural unit (I) is a structural unit represented by the following formula (3). The composition for forming a silicon-containing film has the [A] polysiloxane having the structural unit (I), so that it is resistant to an alkaline developer, resist pattern is prevented from being collapsed, peelable by alkaline hydrogen peroxide, and stored. Stability can be further improved.

In said formula (3), Z is said group (I). R ³ is a monovalent organic group having 1 to 20 carbon atoms, a hydrogen atom or a hydroxy group that does not contain —SO ₂ O—. m is an integer of 0-2. When m is 2, two R ³ are the same or different.

Examples of the monovalent organic group having 1 to 20 carbon atoms that does not include —SO ₂ O— represented by R ³ include, for example, a monovalent organic group having 1 to 20 carbon atoms in R ² of the above formula (2-2). Examples thereof include those similar to the organic group.

R ³ is preferably an alkoxy group or a hydroxy group.

M is preferably 0 or 1, more preferably 0.

Examples of the monomer that gives the structural unit (I) include compounds represented by the following formulas (i-1-1) to (i-1-18) having the group (II-1) (hereinafter, It is assumed that “compounds (i-1-1) to (i-1-18)” have a group represented by the group (II-2) and the following formulas (i-2-1) to ( i-2-3) (hereinafter also referred to as “compounds (i-2-1) to (i-2-3)”) and the like.

In the above formulas (i-1-1) to (i-1-18) and (i-2-1) to (i-2-3), R represents a monovalent hydrocarbon group having 1 to 20 carbon atoms. It is.

The hydrocarbon group for R is preferably an alkyl group, more preferably a methyl group or an ethyl group.

The lower limit of the content ratio of the structural unit (I) is preferably 0.1 mol%, more preferably 1 mol%, still more preferably 2 mol%, based on all structural units constituting the [A] polysiloxane. 5 mol% is particularly preferred, and 8 mol% is even more particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 50 mol% is more preferable, 30 mol% is further more preferable, 20 mol% is especially preferable. The composition for forming a silicon-containing film makes the content ratio of the structural unit (I) within the above range, so that it is resistant to an alkali developer, resist pattern collapse prevention, peelability by alkaline hydrogen peroxide, and storage stability. The property can be further improved.

[Structural unit (II)]
The structural unit (II) is a structural unit represented by the following formula (5). In the composition for forming a silicon-containing film, the etching resistance of the silicon-containing film with an oxygen-based gas can be further improved because [A] polysiloxane has the structural unit (II).

Examples of the monomer that gives the structural unit (II) include tetraalkoxysilanes such as tetramethoxysilane and tetraethoxysilane, and tetrahalosilanes such as tetrachlorosilane and tetrabromosilane.

[A] When the polysiloxane has the structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 1 mol% with respect to all the structural units constituting the [A] polysiloxane. More preferably, mol% is more preferable, 30 mol% is further more preferable, and 60 mol% is especially preferable. As an upper limit of the said content rate, 95 mol% is preferable, 90 mol% is more preferable, 85 mol% is further more preferable, 80 mol% is especially preferable. The composition for forming a silicon-containing film can further enhance the resistance of the silicon-containing film to an alkali developer and the etching resistance with an oxygen-based gas by setting the content ratio of the structural unit (II) in the above range.

[Structural unit (III)]
The structural unit (III) is a structural unit represented by the following formula (6). The said silicon-containing film formation composition can adjust the various characteristics of a silicon-containing film because [A] polysiloxane has structural unit (III).

In the above formula (6), R ^A is a monovalent organic group having 1 to 20 carbon atoms that does not contain —SO ₂ O—. a is 1 or 2. When a is 2, two ^RA are the same or different.

Examples of the monovalent organic group having 1 to 20 carbon atoms that does not include —SO ₂ O— represented by R ^A include monovalent organic groups having 1 to 20 carbon atoms of R ^{2 in} the above formula (2-2). Examples are the same as those described above. Among these, a hydrocarbon group is preferable, a chain hydrocarbon group and an aromatic hydrocarbon group are more preferable, an alkyl group and an aryl group are further preferable, and a methyl group, an ethyl group, a phenyl group, and a naphthyl group are particularly preferable.

A is preferably 1.

Examples of the monomer that gives the structural unit (III) include methyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, cyclohexyltrichlorosilane, and the like.

[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, 8 mol% is further more preferable, and 12 mol% is especially preferable. As an upper limit of the said content rate, 80 mol% is preferable, 50 mol% is more preferable, 40 mol% is further more preferable, 25 mol% is further especially preferable.

[Other structural units]
[A] The polysiloxane may have structural units other than the structural units (I) to (III) as other structural units as long as the effects of the present invention are not impaired. Examples of other structural units include structural units derived from silane monomers containing a plurality of silicon atoms, such as hexamethoxydisilane, bis (trimethoxysilyl) methane, polydimethoxymethylcarbosilane, and the like. [A] When the polysiloxane has other structural units, the upper limit of the content ratio of the other structural units is preferably 10 mol%, preferably 5 mol% with respect to all structural units constituting the [A] polysiloxane. Is more preferable, 2 mol% is more preferable, and 5 mol% is particularly preferable.

[A] The lower limit of the content of polysiloxane is preferably 50% by mass, more preferably 80% by mass, still more preferably 90% by mass, based on the total solid content of the silicon-containing film-forming composition. Mass% is particularly preferred. As an upper limit of the said content, 100 mass% is preferable, 99 mass% is preferable, and 97 mass% is more preferable. The total solid content of the silicon-containing film forming composition refers to the sum of components other than [B] solvent. [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) of the polysiloxane is preferably 1,000, more preferably 1,300, still more preferably 1,500, and particularly preferably 1,700. The upper limit of Mw is preferably 100,000, more preferably 20,000, still more preferably 7,000, and particularly preferably 3,000.

The Mw of [A] polysiloxane in this specification uses Tosoh's GPC columns (two "G2000HXL", one "G3000HXL" and one "G4000HXL"), flow rate: 1.0 mL / min, elution It is a value measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene under the analysis conditions of solvent: tetrahydrofuran, column temperature: 40 ° C.

[A] Polysiloxane can be obtained by a method of hydrolyzing and condensing a hydrolyzable silane monomer corresponding to each structural unit described above. It is considered that each hydrolyzable silane monomer is incorporated into the polysiloxane regardless of the type by the hydrolytic condensation reaction, and the structural units (I) to (III) and other structural units in the synthesized [A] polysiloxane The content ratio of is usually equivalent to the ratio of the amount of each monomer compound used in the synthesis reaction.

<[B] Solvent>
The silicon-containing film-forming composition contains a [B] solvent. [B] Examples of the solvent include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, water, and the like. [B] A solvent can be used individually by 1 type or in combination of 2 or more types.

Examples of the alcohol solvent include monoalcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol and iso-butanol, ethylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol and the like. Examples thereof include polyhydric alcohol solvents.

Examples of ketone solvents include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-iso-butyl ketone, and cyclohexanone.

Examples of ether solvents include ethyl ether, iso-propyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, Tetrahydrofuran etc. are mentioned.

Examples of the ester solvent include ethyl acetate, γ-butyrolactone, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, acetic acid Examples include propylene glycol monoethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethyl propionate, n-butyl propionate, methyl lactate, and ethyl lactate.

Examples of the nitrogen-containing solvent include N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone and the like.

Among these, ether solvents and ester solvents are preferable, and ether solvents and ester solvents having a glycol structure are more preferable because of excellent film-forming properties.

Examples of ether solvents and ester solvents having a glycol structure 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 acetate Examples include ether. Among these, propylene glycol monomethyl ether acetate is particularly preferable.

[B] The lower limit of the content of the ether solvent and the ester solvent having a glycol structure in the solvent is preferably 20% by mass, more preferably 60% by mass, still more preferably 90% by mass, and particularly preferably 100% by mass. preferable.

The lower limit of the content of the [B] solvent in the silicon-containing film-forming composition is preferably 80% by mass, more preferably 90% by mass, and still more preferably 95% by mass. As an upper limit of the said content, 99 mass% is preferable and 98 mass% is more preferable.

<Optional component>
The silicon-containing film-forming composition may contain optional components such as a basic compound and an acid generator.

[Basic compounds]
Examples of the basic compound (including a base generator) include a compound having a basic amino group and a compound (base generator) that becomes a compound having a basic amino group by the action of an acid or the action of heat. More specifically, an amine compound, an amide group-containing compound as a base generator, a urea compound, a nitrogen-containing heterocyclic compound, and the like can be given. When the silicon-containing film-forming composition contains a base compound, curing of the silicon-containing film-forming composition can be promoted, and the resulting silicon-containing film can be more peelable from an acidic liquid. Can be increased.

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-dimethylamino) Ethyl) 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, and Nt-butoxycarbonyl-2-carboxypyrrolidine. Nt-butoxycarbonyl group-containing amino compounds, Nt-amyloxycarbonyl group-containing amino compounds such as Nt-amyloxycarbonyl-4-hydroxypiperidine, N- (9-anthrylmethyloxycarbonyl) piperidine, etc. N- (9-anthrylmethyloxycarbonyl) group-containing amino compounds, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, propionamide, benzamide, Piro Don, N- methylpyrrolidone, N- acetyl-1-adamantyl amine, and the like.

Examples of the urea compound include urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tri-n-butylthiourea. Etc.

Examples of the nitrogen-containing heterocyclic compound include imidazoles, pyridines, piperazines, pyrazines, pyrazoles, pyridazines, quinosalines, purines, pyrrolidines, piperidines, 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.

In this embodiment, among these, an amide group-containing compound and a nitrogen-containing heterocyclic compound are particularly 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 more preferable. Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, Nt-butoxycarbonyl-2-carboxy-pyrrolidine, Nt-amyloxycarbonyl-4 More preferred are -hydroxypiperidine and N- (9-anthrylmethyloxycarbonyl) piperidine. As the nitrogen-containing heterocyclic compound, 3- (N-piperidino) -1,2-propanediol is preferable.

When the silicon-containing film forming composition contains a basic compound, the content of the basic compound with respect to 100 parts by mass of [A] polysiloxane is preferably 0.01 parts by mass, and 0.1% by mass. More preferably, 0.5 part by mass is further preferable, and 1 part by mass is particularly 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.

[Acid generator]
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 an acid generator, curing can be promoted, and as a result, the strength of the silicon-containing film can be further increased, and solvent resistance and oxygen gas etching resistance can be increased. it can. An acid generator can be used individually by 1 type or in combination of 2 or more types.

Examples of the acid generator include onium salt compounds and N-sulfonyloxyimide compounds.

Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, ammonium salts, and the like.

Examples of the sulfonium salt include the sulfonium salts described in paragraph [0110] of JP-A-2014-037386, and more specifically, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, Examples include triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonate, 4-cyclohexylphenyl diphenylsulfonium trifluoromethane sulfonate, and the like.

Examples of the tetrahydrothiophenium salt include tetrahydrothiophenium salts described in paragraph [0111] of JP 2014-037386 A, and more specifically, 1- (4-n-butoxynaphthalene-1- Yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) And tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate.

Examples of the iodonium salt include iodonium salts described in paragraph [0112] of JP 2014-037386 A, and more specifically, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium. Examples include 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethane sulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butane sulfonate, and the like. .

Examples of the ammonium salt include trimethylammonium nonafluoro-n-butanesulfonate, triethylammonium nonafluoro-n-butanesulfonate, and the like.

Examples of the N-sulfonyloxyimide compound include N-sulfonyloxyimide compounds described in paragraph [0113] of JP-A No. 2014-037386, and more specifically, 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-di Carboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene- 2,3-dicarboximide and the like can be mentioned.

When the silicon-containing film-forming composition contains an acid generator, the content of the acid generator with respect to 100 parts by mass of [A] polysiloxane is preferably 0.01 parts by mass, and 0.1% by mass. More preferably, 0.5 part by mass is further preferable, and 1 part by mass is particularly 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.

The silicon-containing film-forming composition may contain other optional components in addition to the basic compound and the acid generator. Examples of other optional components include surfactants, radical generators, colloidal silica, colloidal alumina, and organic polymers. When the composition for forming a silicon-containing film contains other optional components, the upper limit of the content is preferably 2 parts by mass and more preferably 1 part by mass with respect to 100 parts by mass of [A] polysiloxane. .

<Method for Preparing Silicon-Containing Film-Forming Composition>
The method for preparing the composition for forming a silicon-containing film is not particularly limited, and for example, [A] polysiloxane, [B] solvent and optional components are mixed at a predetermined ratio, preferably, the obtained mixture The solution can be prepared by filtering with a filter having a pore size of 0.2 μm.

The lower limit of the solid content concentration of the silicon-containing film forming composition is preferably 0.01% by mass, more preferably 0.05% by mass, still more preferably 0.1% by mass, and particularly preferably 0.2% by mass. preferable. The upper limit of the solid content concentration is preferably 20% by mass, more preferably 10% by mass, further preferably 5% by mass, and particularly preferably 3% by mass. The solid content concentration of the silicon-containing film-forming composition means that the mass of the solid content in the silicon-containing film-forming composition is measured by baking the silicon-containing film-forming composition at 250 ° C. for 30 minutes, It is a value (mass%) calculated by dividing the mass of this solid content by the mass of the composition for forming a silicon-containing film.

The silicon-containing film-forming composition can be suitably used as a film-forming material in a resist process such as a silicon-containing film as an intermediate film in a multilayer resist process, and a pattern (inverted pattern) obtained through an inversion process It can also be used for applications other than the film forming material in the resist process, such as the forming material.

<Silicon-containing film>
The silicon-containing film obtained from the silicon-containing film-forming composition is excellent in resist pattern collapse suppression while maintaining etching removability with a fluorine-based gas, and is resistant to an alkaline developer in the resist pattern forming step. Excellent resistance and exfoliation with alkaline hydrogen peroxide. Therefore, the composition for forming a silicon-containing film can be suitably used as a material for forming a silicon-containing film as an intermediate film in a resist process, particularly a multilayer resist process. In addition, 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 a coating film by applying the above-mentioned composition for forming a silicon-containing film to the surface of another lower layer film such as a substrate or an organic lower layer film, and heat-treats the coating film. Then, it can be formed by curing.

Examples of the method for applying the silicon-containing film forming composition include a spin coating method, a roll coating method, and a dip method. As a minimum of the temperature of heat processing, 50 ° C is preferred and 70 ° C is more preferred. As an upper limit of the said temperature, 450 degreeC is preferable and 300 degreeC is more preferable. The lower limit of the average thickness of the formed silicon-containing film is preferably 10 nm, more preferably 20 nm. The upper limit of the average thickness is preferably 200 nm, and more preferably 150 nm.

<Pattern formation method>
The pattern forming method includes a step of forming a silicon-containing film on the upper side of a substrate by applying the silicon-containing film-forming composition (hereinafter also referred to as “silicon-containing film forming step”), and patterning the silicon-containing film. (Hereinafter, also referred to as “silicon-containing film patterning step”).

According to the pattern forming method, since the silicon-containing film-forming composition described above is used, it is possible to form a silicon-containing film that is excellent in resist pattern collapse suppression while maintaining etching removability with a fluorine-based gas. In addition, it is possible to form a silicon-containing film that is excellent in resistance to an alkaline developer in the resist pattern forming step and excellent in releasability with alkaline hydrogen peroxide.

The silicon-containing film patterning step includes a step of forming a resist pattern on the upper side of the silicon-containing film (hereinafter also referred to as “resist pattern forming step”), and a step of etching the silicon-containing film using the resist pattern as a mask. (Hereinafter also referred to as “silicon-containing film etching step”).

The pattern forming method may further include a step of forming an organic underlayer film on the upper side of the substrate (hereinafter, also referred to as “organic underlayer film forming step”) before the silicon-containing film forming step, if necessary. Good. The pattern forming method may further include a step of removing the silicon-containing film (hereinafter, also referred to as “silicon-containing film removing step”) after the silicon-containing film forming step. The pattern forming method usually includes a step of etching a substrate (hereinafter also referred to as “substrate etching step”) using the patterned silicon-containing film as a mask after the silicon-containing film patterning step. Hereinafter, each step will be described.

<Organic underlayer formation process>
In this step, an organic underlayer film is formed on the upper side of the substrate. In the pattern forming method, an organic underlayer film forming step can be performed as necessary.

In the pattern forming method, when the organic underlayer film forming step is performed, the silicon-containing film forming step is performed after the organic underlayer film forming step, and the silicon-containing film forming composition is formed on the organic underlayer film in the silicon-containing film forming step. Is used to form a silicon-containing film.

Examples of the substrate include an insulating film such as silicon oxide, silicon nitride, silicon oxynitride, and polysiloxane, a resin substrate, and the like. For example, an interlayer insulating film such as a wafer covered with a low dielectric insulating film formed by “Black Diamond” from AMAT, “Silk” from Dow Chemical, “LKD5109” from JSR, or the like can be used. As the substrate, a patterned substrate such as a wiring groove (trench) or a plug groove (via) may be used.

The 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, antireflection) that is necessary for further supplementing the function of the silicon-containing film and / or the resist film in the formation of the resist pattern, or to obtain a function that these do not have. Film, coating film flatness, and high etching resistance against fluorine-based gas).

Examples of the organic underlayer film include an antireflection film. Examples of the composition for forming an antireflection film include “NFC HM8006” manufactured by JSR Corporation.

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, followed by heating.

<Silicon-containing film formation process>
In this step, a silicon-containing film is formed on the upper side of the substrate by applying the silicon-containing film-forming composition. By this step, a silicon-containing film is formed on the substrate directly or via another layer such as an organic underlayer film.

The method for forming the silicon-containing film is not particularly limited. For example, the coating film formed by applying the silicon-containing film-forming composition onto a substrate or the like by a known method such as a spin coating method may be exposed and / or Examples of the method include a method of curing by heating.

Examples of the radiation used for this exposure include electromagnetic waves such as visible light, ultraviolet rays, far ultraviolet rays, X-rays and γ rays, particle beams such as electron beams, molecular beams and ion beams.

As a minimum of the temperature at the time of heating a coating film, 90 ° C is preferred, 150 ° C is more preferred, and 200 ° C is still more preferred. As an upper limit of the said temperature, 550 degreeC is preferable, 450 degreeC is more preferable, and 300 degreeC is further more preferable. As a minimum of average thickness of a silicon content film formed, 1 nm is preferred, 10 nm is more preferred, and 20 nm is still more preferred. The upper limit of the average thickness is preferably 20,000 nm, more preferably 1,000 nm, and even more preferably 100 nm.

<Silicon-containing film patterning process>
In this step, the silicon-containing film is patterned. By this step, the silicon-containing film formed in the silicon-containing film forming step is patterned. Examples of the method for patterning the silicon-containing film include a method including a resist pattern forming step and a silicon-containing film etching step.

[Resist pattern formation process]
In this step, a resist pattern is formed on the upper side of the silicon-containing film. By this step, a resist pattern is formed on the upper side of the silicon-containing film formed in the silicon-containing film forming step. Examples of the method for forming a resist pattern include conventionally known methods such as a method using a resist composition and a method using a nanoimprint lithography method. This resist pattern is usually formed from an organic material.

As a method of using the resist composition, for example, a step of forming a resist film on the upper side of the silicon-containing film with the resist composition (hereinafter also referred to as “resist film forming step”), and a step of exposing the resist film ( Hereinafter, a method including an “exposure step” and a step of developing the exposed resist film (hereinafter also referred to as “development step”) may be used.

(Resist film formation process)
In this step, a resist film is formed on the upper side of the silicon-containing film with a resist composition. By this step, a resist film is formed on the upper side of the silicon-containing film.

Examples of the resist composition include a radiation-sensitive resin composition (chemically amplified resist composition) containing a polymer having an acid-dissociable group and a radiation-sensitive acid generator, an alkali-soluble resin, and a quinonediazide-based photosensitizer. And a negative resist composition containing an alkali-soluble resin and a crosslinking agent. Among these, a radiation sensitive resin composition is preferable. When a radiation sensitive resin composition is used, a positive pattern can be formed by developing with an alkali developer, and a negative pattern can be formed by developing with an organic solvent developer. For the formation of the resist pattern, a double patterning method, a double exposure method, or the like, which is a method for forming a fine pattern, may be used as appropriate.

The polymer contained in the radiation-sensitive resin composition includes, in addition to the structural unit containing an acid dissociable group, for example, a structural unit containing a lactone structure, a cyclic carbonate structure and / or a sultone structure, or a structural unit containing an alcoholic hydroxyl group. Further, it may have a structural unit containing a phenolic hydroxyl group, a structural unit containing a fluorine atom, or the like. When the polymer has a structural unit containing a phenolic hydroxyl group and / or a structural unit containing a fluorine atom, the sensitivity when using extreme ultraviolet rays (EUV), electron beams or the like as radiation in exposure can be improved.

The lower limit of the solid content concentration of the resist composition is preferably 0.1% by mass, and more preferably 1% by mass. As an upper limit of the said solid content concentration, 50 mass% is preferable and 30 mass% is more preferable. As the resist composition, a resist composition filtered with a filter having a pore diameter of about 0.2 μm can be suitably used. In the pattern forming method, a commercially available resist composition can be used as it is as the resist composition.

Examples of the resist film forming method include a method of coating a resist composition on a silicon-containing film. Examples of the resist composition coating method include conventional methods 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 of 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. This exposure is performed by selectively irradiating radiation, for example, through a photomask.

The radiation used for the exposure includes electromagnetic waves such as visible rays, ultraviolet rays, far ultraviolet rays, X-rays, γ rays, electron beams, molecular rays, ions, depending on the type of acid generator used in the resist composition. Among these, a particle beam such as a beam is appropriately selected, and among these, deep ultraviolet rays and electron beams are preferable, and KrF excimer laser light (248 nm), ArF excimer laser light (193 nm), F ₂ excimer laser light (wavelength 157 nm). ), Kr ₂ excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), EUV (wavelength 13 nm, etc.) and electron beam are more preferred, and ArF excimer laser light, EUV and electron beam 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, the exposed resist film is developed. Thereby, a resist pattern is formed.

The development may be alkali development or organic solvent development.

Examples of the alkali developer include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanol. Amine, 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 an alkaline aqueous solution in which at least one of the alkaline compounds is dissolved. In addition, these alkaline aqueous solutions may be those obtained by adding appropriate amounts of water-soluble organic solvents such as alcohols such as methanol and ethanol, surfactants and the like.

Examples of the organic solvent developer include liquids mainly composed of organic solvents such as 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 above [B] solvent. These solvents may be used alone or in combination.

After developing with a developing solution, preferably, a predetermined resist pattern corresponding to the photomask can be formed by washing and drying.

[Silicon-containing film etching process]
In this step, the silicon-containing film is etched using the resist pattern as a mask. More specifically, a silicon-containing film on which a pattern is formed is obtained by one or more etchings using the resist pattern formed in the resist pattern forming step as a mask.

The etching may be dry etching or wet etching, but is preferably dry etching.

Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used for dry etching can be selected as appropriate depending on the elemental composition of the silicon-containing film to be etched, such as CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF _6, etc. Fluorine gas, chlorine gas such as Cl ₂ , BCl ₃ , oxygen gas such as O ₂ , O ₃ , H ₂ O, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , C ₂ H ₂ , C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , HF, HI, HBr, HCl, NO, NH ₃ , reducing gases such as BCl ₃ , He, N ₂ , An inert gas such as Ar is used. These gases can also be mixed and used. For dry etching of a silicon-containing film, a fluorine-based gas is usually used, and a mixture of an oxygen-based gas and an inert gas is preferably used.

<Substrate etching process>
In this step, the substrate is etched using the patterned silicon-containing film as a mask. More specifically, the patterned substrate is obtained by performing etching one or more times using the pattern formed on the silicon-containing film obtained in the silicon-containing film etching step as a mask.

When an organic underlayer film is formed on a substrate, the organic underlayer film is formed by etching the organic underlayer film using the silicon-containing film pattern as a mask, and then the substrate is etched using the organic underlayer film pattern as a mask. Thus, a pattern is formed on the substrate.

The etching may be dry etching or wet etching, but is preferably dry etching.

Dry etching for forming a pattern on the organic underlayer film can be performed using a known dry etching apparatus. The etching gas used for the dry etching can be appropriately selected depending on the elemental composition of the gas silicon-containing film and the organic underlayer film to be etched. For example, CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , fluorine gas such as SF ₆ , chlorine gas such as Cl ₂ and BCl ₃ , oxygen gas such as O ₂ , O ₃ and H ₂ O, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , _{_{_{_{C 2 H 2, C 2 H}}}} 4, C 2 H 6, C 3 H 4, C 3 H 6, C 3 H 8, HF, HI, HBr, HCl, NO, NH 3, BCl 3 or the like of a reducing gas An inert gas such as He, N ₂ , or Ar is used, and these gases may be used in combination. For dry etching of an organic underlayer film using a silicon-containing film pattern as a mask, an oxygen-based gas is usually used.

Dry etching for forming a pattern on a substrate using an organic underlayer film pattern as a mask can be performed using a known dry etching apparatus. The etching gas used for the dry etching can be appropriately selected depending on the elemental composition of the organic underlayer film and the substrate to be etched, and is similar to those exemplified as the etching gas used for the dry etching of the organic underlayer film. Etching gas or the like. Etching may be performed by a plurality of different etching gases. If the silicon-containing film remains on the substrate, the resist underlayer pattern, etc. after the substrate pattern forming process, the silicon-containing film can be removed by performing a silicon-containing film removing process described later. .

<Silicon-containing film removal process>
In this step, the silicon-containing film is removed after the silicon-containing film forming step. When this step is performed after the substrate etching step, the silicon-containing film remaining on the upper side of the substrate is removed. This step can also be performed on a patterned or non-patterned silicon-containing film before the substrate etching step. That is, for example, when a defect occurs in the formation of a silicon-containing film, or when a defect occurs in the patterned silicon-containing film before the substrate etching process, this step is performed without discarding the substrate. It is possible to start again from the silicon-containing film forming step.

Examples of the method for removing the silicon-containing film include a method of dry etching the silicon-containing film, and a method of bringing a liquid such as a basic liquid or an acidic liquid into contact with the silicon-containing film. As the liquid, a basic liquid is preferable.

The dry etching can be performed using a known dry etching apparatus. Further, as a source gas at the time of dry etching, for example, a fluorine gas such as CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF ₆ , a chlorine gas such as Cl ₂ , BCl _3, or the like is used. These gases can be mixed and used.

Examples of the basic liquid include alkaline hydrogen peroxide. More specifically, a mixed aqueous solution of ammonia and hydrogen peroxide (25% by mass ammonia aqueous solution / 30% by mass hydrogen peroxide aqueous solution / water = 1/2/40 (mass ratio) mixed aqueous solution (SC1)) is particularly preferable. When the alkaline hydrogen peroxide solution is used, the wet stripping method is not particularly limited as long as the silicon-containing film and the alkaline hydrogen peroxide solution can be in contact with each other for a certain period of time under heating conditions, for example, a silicon-containing film. The method of immersing the board | substrate which has this in the heated alkaline hydrogen peroxide solution, the method of spraying alkaline hydrogen peroxide solution in a heating environment, the method of coating the heated alkaline hydrogen peroxide solution, etc. are mentioned. After each of these methods, the substrate may be washed with water and dried.

The lower limit of the temperature when the silicon-containing film removing step is performed using alkaline hydrogen peroxide is preferably 40 ° C., more preferably 50 ° C. As an upper limit of the said temperature, 90 degreeC is preferable and 80 degreeC is more preferable.

The lower limit of the dipping time in the dipping method is preferably 0.2 minutes, and more preferably 0.5 minutes. The upper limit of the immersion time is preferably 30 minutes, more preferably 20 minutes, further preferably 10 minutes, and particularly preferably 5 minutes from the viewpoint of suppressing the influence on the substrate.

Hereinafter, examples will be described. In addition, the Example shown below shows an example of the typical Example of this invention, and, thereby, the range of this invention is not interpreted narrowly.

The measurement of the solid content concentration in the [A] polysiloxane solution and the measurement of the weight average molecular weight (Mw) of [A] polysiloxane in this example were performed by the following methods.

[[A] Solid content concentration of polysiloxane solution]
[A] 0.5 g of the polysiloxane solution was baked at 250 ° C. for 30 minutes to measure the mass of the solid content in 0.5 g of the solution, and [A] the solid content concentration of the polysiloxane solution (mass%) ) Was calculated.

[Weight average molecular weight (Mw)]
Using GPC columns (two "G2000HXL", one "G3000HXL", one "G4000HXL" from Tosoh Corporation), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column temperature: 40 ° C. Measurement was performed by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard.

[Average thickness of film]
The average thickness of the film was measured using a spectroscopic ellipsometer (“M2000D” from JA WOOLLAM).

<[A] Synthesis of polysiloxane>
[A] Monomers used for the synthesis of polysiloxane are shown below.
In the following synthesis examples, unless otherwise specified, parts by mass means a value when the total mass of the monomers used is 100 parts by mass.

[Synthesis Example 1] (Synthesis of polysiloxane (A-1))
In the reaction vessel, the molar ratio of the compound represented by the above formula (M-1), the compound represented by the above formula (M-A1) and the compound represented by the above formula (MA2) is 10/75 / A monomer solution was prepared by dissolving in 62 parts by mass of propylene glycol monoethyl ether so as to be 15 (mol%). The inside of the reaction vessel was set to 60 ° C., and 40 parts by mass of a 9.1% by mass oxalic acid aqueous solution was added dropwise over 20 minutes while stirring. The start of dropping was taken as the start time of the reaction, and the reaction was carried out for 4 hours. After completion of the reaction, the inside of the reaction vessel was cooled to 30 ° C. or lower. After 52 parts by mass of propylene glycol monoethyl ether was added to the cooled reaction solution, the alcohol produced by the reaction and excess propylene glycol monoethyl ether were removed using an evaporator, and the propylene of polysiloxane (A-1) was removed. A glycol monoethyl ether solution was obtained. The Mw of the polysiloxane (A-1) was 1,800. The solid content concentration of this polysiloxane (A-1) in propylene glycol monoethyl ether solution was 10.7% by mass.

[Synthesis Examples 2 to 22] (Synthesis of polysiloxanes (A-2) to (A-20) and (a-1) to (a-2))
Polysiloxanes (A-2) to (A-20), (a-1) and (a-1) and (a) were prepared in the same manner as in Synthesis Example 1 except that the respective types and amounts of monomers shown in Table 1 were used. -2) was obtained as a propylene glycol monoethyl ether solution. Table 1 shows the Mw and solid content concentration (% by mass) of [A] polysiloxane in the obtained [A] polysiloxane solution.

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

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

[Example 1]
[A] 2.2 parts by mass of (A-1) as a polysiloxane (solid content), 10 parts by mass of (B-1) and (B-2) 90 parts by mass of (B) as a solvent ([A] And a solvent (B-2) contained in a polysiloxane solution), and the resulting solution is filtered through a filter having a pore size of 0.2 μm to obtain a silicon-containing film-forming composition (J-1). Prepared.

[Examples 2 to 20 and Comparative Examples 1 and 2]
The silicon-containing film-forming compositions (J-2) to (J-20) and (j-1) were obtained in the same manner as in Example 1 except that the components of the types and blending amounts shown in Table 2 were used. And (j-2) were prepared.

<Formation of silicon-containing film>
Each of the silicon-containing film-forming compositions prepared above was coated on a silicon wafer (substrate) by a spin coating method using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron Ltd.). The obtained coating film was heated on a hot plate at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 60 seconds, whereby the average thickness of 35 nm shown in Examples 1 to 20 and Comparative Examples 1 and 2 in Table 2 was obtained. A substrate on which a silicon-containing film was formed was obtained.

<Evaluation>
The following methods of the silicon-containing film forming composition prepared above and the silicon-containing film formed above were evaluated by the following methods. The evaluation results are shown in Table 2 below. “-” In Table 2 indicates that the corresponding evaluation was not performed.

[Resistance to alkaline developer]
The substrate on which the silicon-containing film was formed was immersed in an aqueous 2.38 mass% tetramethylammonium hydroxide (TMAH) solution (20 to 25 ° C.) for 60 seconds and washed with water. The average thickness of the film before and after immersion was measured.
When the average thickness before immersion was T ₀ and the average thickness after immersion was T ₁ , the film thickness change rate (%) by immersion in the TMAH aqueous solution was obtained by the following formula.
Film thickness change rate (%) = | T ₁ −T ₀ | × 100 / T ₀
The resistance to alkaline developer was evaluated as “A” (good) when the film thickness change rate was less than 1%, and “B” (bad) when the film thickness change rate was 1% or more.

[Peelability with alkaline hydrogen peroxide]
The substrate on which the silicon-containing film was formed was mixed with alkaline hydrogen peroxide (mixed liquid (SC1) of 25 mass% aqueous ammonia solution / 30 mass% aqueous hydrogen peroxide solution / water = 1/2/40 (mass ratio), 60 (~ 65 ° C) for 5 minutes and washed with water. The average thickness of the film before and after immersion was measured.
When the average thickness before immersion was S ₀ and the average thickness after immersion was S ₁ , the film thickness change rate (%) due to SC1 immersion was determined by the following formula.
Film thickness change rate (%) = (S ₀ −S ₁ ) × 100 / S ₀
The peelability by the alkaline hydrogen peroxide solution was evaluated as “A” (good) when the rate of change in film thickness was 99% or more, and “B” (bad) when it was less than 99%.

[Collapse Inhibition (1)] (Inhibition of resist pattern collapse in ArF exposure)
An organic underlayer film forming composition (“NFC HM8006” from JSR) was applied on a 12-inch silicon wafer by the spin coating method using the above spin coater, and then heat-treated at 250 ° C. for 60 seconds to obtain an average. An organic underlayer film having a thickness of 100 nm was formed. On this organic underlayer film, the obtained composition for forming a silicon-containing film was applied by the spin coating method using the spin coater, heat-treated at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 60 seconds. As a result, a silicon-containing film having an average thickness of 35 nm was formed. Next, a radiation sensitive resin composition (“ARF AR2772JN” manufactured by JSR) is coated on the silicon-containing film by the spin coater, heat-treated at 90 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds. Thus, a resist film having an average thickness of 100 nm was formed.
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. Heat treatment is performed at 100 ° C. for 60 seconds on a “Lithius Pro-i” hot plate, cooled at 23 ° C. for 30 seconds, then paddle-developed with a 2.38 mass% TMAH aqueous solution as a developer for 30 seconds, and then washed with water. Washed. By rotating and drying at 2,000 rpm for 15 seconds, an evaluation substrate on which a resist pattern with 40 nm line / 80 nm pitch was formed was obtained.
A scanning electron microscope (“CG-4000” manufactured by Hitachi High-Technologies Corporation) was used for measuring and observing the resist pattern on the evaluation substrate.
In the formation of the resist pattern, the exposure amount is increased in stages, and the exposure is sequentially performed. The line width corresponding to the maximum exposure amount at which the resist pattern is not confirmed to be collapsed is defined as the minimum collapse dimension (nm). It was used as an index of pattern collapse inhibition. The collapse inhibition property (1) is “A” (good) when the minimum pre-collapse dimension is 32 nm or less, “B” (slightly good) when it exceeds 32 nm and 38 nm or less, and “C” when it exceeds 38 nm. "(Poor).

[Collapse inhibition property (2)] (Restoration inhibition of resist pattern in electron beam exposure)
An antireflection film-forming material (“HM8006” from JSR) is applied on an 8-inch silicon wafer by the spin coating method using the spin coater, and then heated at 250 ° C. for 60 seconds to prevent reflection with an average thickness of 100 nm. A film was formed. On this antireflection film, a silicon-containing film-forming composition was applied, heated at 220 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds to form a silicon-containing film having an average thickness of 35 nm.
Next, a radiation-sensitive resin composition to be described later was applied on the silicon-containing film, heat-treated at 130 ° C. for 60 seconds, and then cooled at 23 ° C. for 30 seconds to form a resist film having an average thickness of 50 nm. .
The radiation-sensitive resin composition comprises a structural unit (1) derived from 4-hydroxystyrene, a structural unit (2) derived from styrene, and a structural unit (3) derived from 4-t-butoxystyrene (each structural unit The content ratio of (1) / (2) / (3) = 65/5/30 (mol%)) is 100 parts by mass of a polymer, and triphenylsulfonium salicylate as a radiation-sensitive acid generator. It was obtained by mixing 2.5 parts by mass with 1,500 parts by mass of ethyl lactate as a solvent and 700 parts by mass of propylene glycol monomethyl ether and filtering the obtained solution through a filter having a pore size of 0.2 μm.
Subsequently, the resist film was irradiated with an electron beam using an electron beam drawing apparatus (“HL800D” manufactured by Hitachi, Ltd., output: 50 KeV, current density: 5.0 amperes / cm ² ). After irradiation with the electron beam, the substrate was heated at 110 ° C. for 60 seconds, then cooled at 23 ° C. for 60 seconds, and then developed using a 2.38 mass% TMAH aqueous solution (20 to 25 ° C.) by the paddle method. The substrate for evaluation on which a resist pattern was formed was obtained by washing with water and drying.
When forming the resist pattern, the exposure amount formed in a one-to-one line and space with a line width of 150 nm was determined as the optimum exposure amount.
A scanning electron microscope (“CG-4000” manufactured by Hitachi High-Technologies Corporation) was used for measuring and observing the resist pattern on the evaluation substrate.
The collapse inhibition property (2) was evaluated as “A” (good) when pattern collapse was not confirmed and “B” (bad) when pattern collapse was confirmed at the optimum exposure amount.

[Etching removability by fluorine gas]
The substrate on which the silicon-containing film obtained above was formed was subjected to CF ₄ = 200 sccm, PRESS. Using an etching apparatus (“TACTRAS” manufactured by Tokyo Electron Ltd.). = 75 mT, HF RF = 250 W, LF RF = 0 W, DCS = -150 V, RDC = 50%, RDC = 50%, etching for 5 seconds, and the etching rate (nm / min) is calculated from the average film thickness before and after the treatment. The etching removability with a fluorine-based gas was evaluated. The etching removability by the fluorine-based gas is “A” (good) when the etching rate is 60 (nm / min) or more, and “B” when the etching rate is 55 (nm / min) or more and less than 60 (nm / min). (Slightly good) and less than 55 (nm / min) were evaluated as “C” (bad).

[Storage stability]
Each silicon-containing film-forming composition prepared above was stored at −15 ° C. and 40 ° C. for 7 days, and then the weight average molecular weight (Mw) of [A] polysiloxane in the composition was measured. The storage stability is “A” (good) when the difference between Mw after storage at −15 ° C. and Mw after storage at 40 ° C. is less than 100, and “B” when the difference is 100 or more and less than 1,000. When (slightly good) and 1,000 or more, it was evaluated as “C” (bad).

As can be seen from the results in Table 2, the silicon-containing film forming compositions of the examples are excellent in storage stability, excellent in resistance to an alkaline developer, and excellent in peelability with alkaline hydrogen peroxide, and etched with a fluorine-based gas. It is possible to form a silicon-containing film that is excellent in removability and excellent in resist pattern collapse suppression.
In general, it is known that electron beam exposure shows the same tendency as in EUV exposure. Therefore, according to the composition for forming a silicon-containing film of Examples, even in the case of EUV exposure. It is presumed that the resist pattern collapse resistance is excellent.

According to the composition for forming a silicon-containing film and the pattern forming method of the present invention, it is possible to form a silicon-containing film that is excellent in resist pattern collapse suppression while maintaining the etching removability with a fluorine-based gas. It is possible to form a silicon-containing film that is excellent in resistance to an alkaline developer in the resist pattern forming step and excellent in releasability with alkaline hydrogen peroxide. Furthermore, the silicon-containing film forming composition of the present invention is excellent in storage stability. The silicon-containing film of the present invention is excellent in resistance to an alkali developer while maintaining etching removability by a fluorine-based gas and excellent in peelability by an alkaline hydrogen peroxide solution. The polysiloxane of the present invention can be suitably used as a polysiloxane component of the silicon-containing film forming composition. Therefore, these can be used suitably for a multilayer resist process, and can be used suitably for manufacture of a semiconductor device etc. which are expected to be further miniaturized in the future.

Claims

A polysiloxane having a group represented by the following formula (1);
A silicon-containing film-forming composition containing a solvent.

(In the formula (1), L is a single bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms. E is a group represented by the following formula (2-1) or (2-2). N is an integer of 1 to 3. When n is 2 or more, L is an organic group, and a plurality of E are the same or different, * is a site bonded to a silicon atom in the polysiloxane. Is shown.)

(In Formula (2-1), R 1 is a single bond or a divalent organic group having 1 to 20 carbon atoms. Y 1 is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or at least 1 A monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one hydrogen atom is substituted with an electron withdrawing group.
In formula (2-2), R 2 is a monovalent organic group having 1 to 20 carbon atoms. Y 2 is a substituted or unsubstituted arenediyl group having 6 to 20 carbon atoms or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with an electron withdrawing group. )
The composition for forming a silicon-containing film according to claim 1, wherein the polysiloxane has a first structural unit represented by the following formula (3).

(In the formula (3), Z is a group represented by the above formula (1). R 3 is a monovalent organic group having 1 to 20 carbon atoms not containing —SO 2 O—, a hydrogen atom or A hydroxy group, m is an integer of 0 to 2. When m is 2, two R 3 are the same or different.
The electron-withdrawing group has a halogen atom, a cyano group, a halogenated hydrocarbon group having 1 to 10 carbon atoms, a group having —O— having 1 to 10 carbon atoms, or —SO— having 1 to 10 carbon atoms. 3. A group having 1 to 10 carbon atoms —SO 2 —, a group having 1 to 10 carbon atoms —CO—, or a group having 1 to 10 carbon atoms —COO—. 2. A composition for forming a silicon-containing film according to 1.
Y 1 in the above formula (2-1) is a substituted or unsubstituted aryl group or a group represented by the following formula (4-1), and Y 2 in the above formula (2-2) is substituted or unsubstituted. The composition for forming a silicon-containing film according to claim 1, wherein the composition is an arenediyl group.

(In Formula (4-1), R 4 to R 8 are each independently a hydrogen atom, a monovalent hydrocarbon group having 1 to 18 carbon atoms, or a monovalent electron-withdrawing group. , 0 or 1. However, when p is 0, at least one of R 6 to R 8 is an electron withdrawing group, and when p is 1, at least one of R 4 to R 8 One is an electron withdrawing group.)
The composition for forming a silicon-containing film according to claim 2, wherein the polysiloxane further has a second structural unit represented by the following formula (5).
The composition for forming a silicon-containing film according to any one of claims 2 to 5, wherein the polysiloxane further has a third structural unit represented by the following formula (6).

(In Formula (6), R A is a monovalent organic group having 1 to 20 carbon atoms that does not contain —SO 2 O—. A is 1 or 2. When a is 2, R A is the same or different.
The silicon-containing film according to any one of claims 2 to 6, wherein a content ratio of the first structural unit with respect to all structural units constituting the polysiloxane is 0.1 mol% or more and 50 mol% or less. Forming composition.
The composition for forming a silicon-containing film according to any one of claims 1 to 7, which is used in a resist process.
A silicon-containing film formed from the silicon-containing film-forming composition according to any one of claims 1 to 8.
Forming a silicon-containing film on the upper side of the substrate by coating the composition for forming a silicon-containing film according to any one of claims 1 to 8,
Patterning the silicon-containing film.
After the silicon-containing film forming step,
The pattern forming method according to claim 10, further comprising: removing the silicon-containing film.
The pattern forming method according to claim 11, wherein the step of removing the silicon-containing film removes the silicon-containing film by bringing a basic liquid into contact with the silicon-containing film.
The silicon-containing film patterning step is
Forming a resist pattern on the upper side of the silicon-containing film;
The pattern forming method according to claim 10, comprising the step of etching the silicon-containing film using the resist pattern as a mask.
Before the silicon-containing film forming step,
The pattern forming method according to claim 10, further comprising: forming an organic underlayer film on the upper side of the substrate.
A polysiloxane having a group represented by the following formula (1).

(In the formula (1), L is a single bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms. E is a group represented by the following formula (2-1) or (2-2). N is an integer of 1 to 3. When n is 2 or more, L is an organic group, and a plurality of E are the same or different, * is a site bonded to a silicon atom in the polysiloxane. Is shown.)

(In Formula (2-1), R 1 is a single bond or a divalent organic group having 1 to 20 carbon atoms. Y 1 is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or at least 1 A monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which one hydrogen atom is substituted with an electron withdrawing group.
In formula (2-2), R 2 is a monovalent organic group having 1 to 20 carbon atoms. Y 2 is a substituted or unsubstituted arenediyl group having 6 to 20 carbon atoms or a divalent aliphatic hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with an electron withdrawing group. )