WO2018155377A1

WO2018155377A1 - Film-forming material for resist process, pattern-forming method, and polysiloxane

Info

Publication number: WO2018155377A1
Application number: PCT/JP2018/005727
Authority: WO
Inventors: 智昭瀬古; 裕介大坪; 真義石川; 博允田中
Original assignee: Jsr株式会社
Priority date: 2017-02-24
Filing date: 2018-02-19
Publication date: 2018-08-30
Also published as: JPWO2018155377A1; TW201835229A

Abstract

The purpose of the present invention is to provide: a film-forming material for a resist process, from which it is possible to form a silicon-containing film that has resistance to oxygen-based etching and exhibits excellent release properties by means of an alkaline hydrogen peroxide solution while maintaining solvent resistance; a pattern-forming method using said film-forming material; and a polysiloxane. The present invention pertains to a film-forming material for a resist process, containing: a polysiloxane having a first structural unit represented by formula (1) or (2); and a solvent. In formula (1), L1 represents a single bond or a divalent organic group having 1-20 carbon atoms; R1 represents an ethynediyl group or a substituted or unsubstituted ethenediyl group; L2 represents a single bond or an (n+1)-valent organic group having 1-20 carbon atoms; n represents an integer of 1-3; and R2 represents a monovalent group including a polar group. In formula (2), L4 represents a single bond or a divalent organic group having 1-20 carbon atoms; and R4 represents a substituted or unsubstituted ethinyl group, or a substituted or unsubstituted ethenyl group.

Description

Film forming material for resist process, pattern forming method, and polysiloxane

The present invention relates to a film forming material for a resist process, a pattern forming method, and polysiloxane.

In the manufacture of semiconductor devices, etc., the resist film laminated on the substrate to be processed through an organic antireflection film is exposed and developed, and then the substrate is microfabricated by etching using the obtained resist pattern as a mask. A pattern forming method is used.

In recent years, in order to perform finer processing on a substrate, there is a demand for miniaturization and thinning of a resist pattern as a mask. However, since the difference in etching rate between the resist film and the organic antireflection film is not so large, it becomes difficult to etch the substrate to be processed as the resist pattern used as a mask is thinned.

Therefore, a silicon-containing film is provided between the resist film and the organic underlayer film, the pattern formed on the resist film is transferred to the silicon-containing film, and the substrate to be processed is then used with the silicon-containing film patterned by transfer as a mask. A multilayer resist process for etching is performed (see International Publication No. 2006-126406). The silicon-containing film is required to have excellent solvent resistance and resistance to etching with an oxygen-based gas or the like (hereinafter also referred to as “oxygen-based gas etching resistance”).

International Publication No. 2006/126406

However, at present, when the miniaturization of the resist pattern has progressed to a level of 45 nm or less, the required level of the performance is further increased, and it is used for forming a silicon-containing film in the conventional multilayer resist process. The resist process film forming material cannot satisfy all of these requirements.

The present invention has been made based on the above circumstances, and can form a silicon-containing film that is excellent in oxygen-based gas etching resistance and peelability by alkaline hydrogen peroxide while maintaining solvent resistance. It is to provide a film forming material for resist process, a pattern forming method using the same, and polysiloxane.

The invention made in order to solve the above problems is a polysiloxane having a first structural unit (hereinafter also referred to as “structural unit (I)”) represented by the following formula (1) or formula (2) (hereinafter referred to as “structural unit (I)”). It is a film forming material for a resist process containing “[A] polysiloxane” and a solvent (hereinafter also referred to as “[B] solvent”).

(In the formula (1), L ¹ is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ¹ is an ethynediyl group or a substituted or unsubstituted ethenediyl group. L ² is a single bond. A bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms, n is an integer of 1 to 3. When L ² is a single bond, n is 1. R ² is a polar group. In the case where n is 2 or more, a plurality of R ² are the same or different, and R ^X is a monovalent group not containing an ethylenic carbon-carbon double bond and carbon-carbon triple bond. I is an integer of 0-2.
In the formula (2), L ³ is an (m + 1) -valent organic group having 1 to 20 carbon atoms. m is an integer of 1 to 3. R ³ is a monovalent group containing a polar group. When m is 2 or more, the plurality of R ³ are the same or different. L ⁴ is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ⁴ is a substituted or unsubstituted ethynyl group or a substituted or unsubstituted ethenyl group. )

Another invention made in order to solve the above problems is a step of forming a silicon-containing film on the upper side of the substrate by coating the film forming material for resist process, a step of patterning the silicon-containing film, And a step of forming a pattern on a substrate using the patterned silicon-containing film as a mask.

Still another invention made to solve the above problems is a polysiloxane having a structural unit represented by the above formula (1) or (2).

According to the film forming material for resist process and the pattern forming method of the present invention, it is possible to form a silicon-containing film excellent in oxygen gas etching resistance and peelability by alkaline hydrogen peroxide while maintaining solvent resistance, Furthermore, it is possible to form a resist pattern that is excellent in shape and collapse suppression. The polysiloxane of the present invention can be suitably used as a polysiloxane component of the resist process film-forming material. Therefore, these can be used suitably for a multilayer resist process etc., and can be used suitably for manufacture of a semiconductor device etc. in which further miniaturization is expected in the future.

Hereinafter, embodiments of the film forming material for resist process and the pattern forming method of the present invention will be described.

<Film forming material for resist process>
The resist process film-forming material (hereinafter also simply referred to as “film-forming material”) contains [A] polysiloxane and [B] solvent. The film-forming material may contain an optional component as long as the effects of the present invention are not impaired.

According to the film forming material, it is possible to form a silicon-containing film excellent in oxygen-based gas etching resistance and peelability by alkaline hydrogen peroxide while maintaining solvent resistance, and further excellent in shape and collapse suppression A resist pattern can be formed. The reason why the film-forming material has the above-described configuration and exhibits the above-mentioned effects is not necessarily clear, but can be inferred as follows, for example. That is, the structural unit (I) of [A] polysiloxane has a carbon-carbon double bond or a carbon-carbon triple bond as R ¹ or R ⁴ . Since this carbon-carbon double bond or carbon-carbon triple bond has a high cross-linking property, a high-density cross-linked structure is formed by heating. As a result, the silicon-containing film formed from the film-forming material is further improved in oxygen-based gas etching resistance and peelability by alkaline hydrogen peroxide. Moreover, since the structural unit (I) of [A] polysiloxane has a monovalent group containing a polar group as R ² or R ³ , a negative resist pattern formed on the silicon-containing film, etc. Therefore, the shape of the negative resist pattern or the like and the collapse suppression property are further improved. Since the film forming material has such an effect, it can be suitably used for a resist process. Hereinafter, each component will be described.

<[A] polysiloxane>
[A] The polysiloxane is a polysiloxane having the structural unit (I).

[Structural unit (I)]
The structural unit (I) is a structural unit represented by the following formula (1) or the following formula (2).

In the above formula (1), L ¹ is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ¹ is an ethynediyl group or a substituted or unsubstituted ethenediyl group. L ² is a single bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms. n is an integer of 1 to 3. When L ² is a single bond, n is 1. R ² is a monovalent group containing a polar group. When n is 2 or more, the plurality of R ² are the same or different. R ^X is a monovalent group not containing an ethylenic carbon-carbon double bond and carbon-carbon triple bond. i is an integer of 0-2.

In the above formula (2), L ³ is an (m + 1) -valent organic group having 1 to 20 carbon atoms. m is an integer of 1 to 3. R ³ is a monovalent group containing a polar group. When m is 2 or more, the plurality of R ³ are the same or different. L ⁴ is a single bond or a divalent organic group having 1 to 20 carbon atoms. R ⁴ is a substituted or unsubstituted ethynyl group or a substituted or unsubstituted ethenyl group.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by L ¹ and L ⁴ include, for example, a divalent hydrocarbon group having 1 to 20 carbon atoms and a divalent hydrocarbon between carbon-carbon of the hydrocarbon group. Examples include a group (α) having a heteroatom-containing group, 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.

Examples of the divalent hydrocarbon group having 1 to 20 carbon atoms include a divalent chain hydrocarbon group having 1 to 20 carbon atoms, a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and 6 carbon atoms. And 20 divalent aromatic hydrocarbon groups.

Examples of the divalent 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 excluding individual hydrogen atoms.

Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include alicyclic saturated carbon such as cycloalkane such as cyclopentane and cyclohexane, bridged saturated hydrocarbon such as norbornane, adamantane and tricyclodecane. Examples thereof include a group in which two hydrogen atoms of a cycloalkene such as hydrogen, cyclopentene and cyclohexene, and an alicyclic unsaturated hydrocarbon such as a bridged ring unsaturated hydrocarbon such as norbornene and tricyclodecene are removed.

Examples of the divalent aromatic hydrocarbon group having 6 to 20 carbon atoms include hydrogen on 2 to 4 aromatic rings possessed by arenes such as benzene, toluene, ethylbenzene, xylene, naphthalene, methylnaphthalene, anthracene, and methylanthracene. Examples include a group in which a hydrogen atom on an atom or two aromatic rings and an alkyl group is 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.

L ¹ is preferably a single bond or a hydrocarbon group, more preferably a single bond or a chain hydrocarbon group, still more preferably a single bond or an alkanediyl group, and particularly preferably a single bond, a methanediyl group or an ethanediyl group.

L ⁴ is preferably a single bond or a hydrocarbon group, and more preferably a single bond.

Examples of the substituent for the ethenediyl group of R ¹ and the ethenyl group of R ⁴ include monovalent organic groups having 1 to 10 carbon atoms. The monovalent organic group having 1 to 10 carbon atoms, among the monovalent organic group plus one hydrogen atom in the divalent organic group of the L ¹ and L ⁴ illustrated having 1 to 20 carbon atoms as a And those having 1 to 10 carbon atoms. The substituent of the ethenediyl group of R ¹ and the ethenyl group of R ⁴ is preferably a hydrocarbon group, more preferably a chain hydrocarbon group, still more preferably an alkyl group, and particularly preferably a methyl group and an ethyl group.

R ¹ is preferably an unsubstituted ethenediyl group. R ⁴ is preferably an unsubstituted ethenyl group.

Examples of the divalent to tetravalent organic group having 1 to 20 carbon atoms represented by L ² and L ³ include those exemplified as the divalent organic group having 1 to 20 carbon atoms of L ¹ and L ⁴ , And a group obtained by removing one or two hydrogen atoms from a divalent organic group.

N and m are preferably 1 and 2, and more preferably 1.

When n is 1, L ² is preferably a single bond or a methanediyl group.
When n is 2 or 3, L ² is preferably a trivalent or tetravalent group obtained by removing 3 or 4 hydrogen atoms from methane.

L ³ is preferably a divalent to tetravalent group obtained by removing 2 to 4 hydrogen atoms from methane.

Examples of the monovalent group not containing the carbon-carbon double bond and carbon-carbon triple bond represented by R ^X are exemplified as the divalent organic groups having 1 to 20 carbon atoms of L ¹ and L ⁴ described above. And monovalent organic groups obtained by adding one hydrogen atom to the group.

I is preferably 0 or 1, more preferably 0.

Examples of the monovalent group containing the polar group represented by R ² and R ³ include a monovalent group containing a hetero atom. R ² and R ³ are preferably groups represented by the following formula (a) or the following formula (b).

In the above formulas (a) and (b), * represents a site that binds to L ² or R ¹ in the above formula (1) or L ³ in the above formula (2).
In the above formula (a), R ^A is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
In the above formula (b), R ^B is either a monovalent hydrocarbon group having 1 to 20 carbon atoms, or R ^B and R ^a and are combined with each other ring members together with the atom chain to which they are attached 5-20 The ring structure is formed. R ^a and R ^b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring composed of these groups combined with each other and the carbon atom to which they are bonded. Represents a ring structure having 3 to 20 members. R ^c and R ^d are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring composed of these groups combined with each other and the carbon atom to which they are bonded. Represents a ring structure having 3 to 20 members.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^A and R ^B and R ^a to R ^d include a divalent carbon group having 1 to 20 carbon atoms exemplified as L ¹ and L ⁴ above. Examples thereof include a monovalent hydrocarbon group obtained by adding one hydrogen atom to a hydrogen group.

The hydrocarbon group for ^RA is preferably a chain hydrocarbon group or an alicyclic hydrocarbon group, more preferably an alkyl group or a cycloalkyl group, a methyl group, an i-propyl group, a t-butyl group, or a 1-methyl group. A cyclohexane-1-yl group is more preferred, and a methyl group is preferred. The hydrocarbon group of R ^A, also preferably tertiary hydrocarbon group, t- butyl group is particularly preferable.

Examples of the ring structure having 3 to 20 ring members constituted by the carbon atoms to which R ^a and R ^b and R ^c and R ^d are combined and bonded to each other include, for example, 3 to 3 carbon atoms exemplified as L ¹ and L ⁴ above. Examples thereof include an alicyclic structure contained in 20 divalent alicyclic hydrocarbon groups.

The ring structure of R ^B and ring members 5-20 that the R ^a is formed together with the atom chain to which they are attached are combined to each other, for example 1,3-dioxacyclopentane structure, 1,3-dioxacyclohexane structure 1,3-dioxacycloalkane structures such as Of these, a 1,3-dioxacyclopentane structure is preferable. Examples of the group containing a ring structure having 5 to 20 ring members formed together with an atomic chain in which R ^B and R ^a are combined with each other include 1,3-dioxacyclopentyl group and 2,2-dimethyl-1 , 3-Dioxacyclopentyl group is preferred.

As a minimum of the content rate of structural unit (I), 0.1 mol% is preferred to 1 mol% with respect to all the structural units which constitute [A] polysiloxane, 5 mol% is still more preferred, 10 mol% is particularly preferred, and 20 mol% is even more particularly preferred. As an upper limit of the said content rate, 80 mol% is preferable, 50 mol% is more preferable, 40 mol% is further more preferable, 30 mol% is especially preferable.

Examples of the monomer that gives the structural unit (I) include compounds represented by the following formulas.

In the above formula, R is a monovalent hydrocarbon group having 1 to 20 carbon atoms.

R is preferably a monovalent chain hydrocarbon group, more preferably an alkyl group, and even more preferably a methyl group or an ethyl group.

[Structural unit (II)]
[A] The polysiloxane may have a structural unit (II) represented by the following formula (3).

In the above formula (3), R ^Y is a monovalent hydrocarbon group having 1 to 20 carbon atoms. j is an integer of 1 to 3. When j is 2 or more, the plurality of R ^Y are the same or different.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ^Y include one hydrogen atom in the divalent hydrocarbon group having 1 to 20 carbon atoms exemplified as L ¹ and L ⁴ above. Examples thereof include a monovalent hydrocarbon group. Among these, a chain hydrocarbon group is preferable, an alkyl group is more preferable, and a methyl group is more preferable.

J is preferably 1 or 2, and more preferably 1.

Examples of the monomer giving the structural unit (II) include methyltrimethoxysilane, phenyltriethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, methylphenyldimethoxysilane, cyclohexyltrichlorosilane, and the like.

[A] When the polysiloxane has the structural unit (II), the lower limit of the content ratio of the structural unit (II) is preferably 0.1 mol% with respect to all the structural units constituting the [A] polysiloxane. 1 mol% is more preferable, 10 mol% is further more preferable, 20 mol% is especially preferable, and 30 mol% is further especially preferable. As an upper limit of the said content rate, 80 mol% is preferable, 60 mol% is more preferable, 50 mol% is further more preferable, 40 mol% is further especially preferable.

[Structural unit (III)]
[A] The polysiloxane may have a structural unit (III) represented by the following formula (4).

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

[A] When the polysiloxane has the structural unit (III), the lower limit of the content ratio of the structural unit (III) 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 film-forming material can further enhance the etching resistance by the oxygen-based gas and the peelability by the alkaline hydrogen peroxide solution by setting the content ratio of the structural unit (III) in the above range.

[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 of other structural units is preferably 10 mol%, more preferably 5 mol%, still more preferably 2 mol%, and more preferably 5 mol%. Particularly preferred.

The lower limit of the content of [A] polysiloxane in the film forming material is preferably 0.01% by mass, more preferably 0.1% by mass, further preferably 0.5% by mass, and particularly preferably 1% by mass. . As an upper limit of the said content, 20 mass% is preferable, 10 mass% is more preferable, 5 mass% is further more preferable, 3 mass% is especially preferable. [A] By making content of polysiloxane into the said range, the applicability | paintability of the said film formation material can be improved. [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.

<[B] Solvent>
The film forming material contains a [B] solvent. [B] Examples of the solvent include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, 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 film forming material 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 film forming material may contain optional components such as a basic compound and an acid generator.

[Basic compounds]
The basic compound promotes the curing reaction of the film forming material, and as a result, improves the strength and the like of the formed silicon-containing film. Further, the basic compound improves the peelability of the silicon-containing film with an acidic solution. Examples of the basic compound include a compound having a basic amino group and a base generator that generates a compound having a basic amino group by the action of an acid or the action of heat. Examples of the compound having a basic amino group include amine compounds. Examples of the base generator include amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. Specific examples of the amine compound, amide group-containing compound, urea compound and nitrogen-containing heterocyclic compound include compounds described in paragraphs [0079] to [0082] of JP-A-2016-27370, for example. .

When the film forming material contains the basic compound, the content of the basic compound with respect to 100 parts by mass of [A] polysiloxane is, for example, 1 part by mass or more and 50 parts by mass or less.

[Acid generator]
The acid generator is a component that generates an acid upon exposure or heating. When the film forming material contains an acid generator, the condensation reaction of the [A] polysiloxane compound can be promoted even at a relatively low temperature (including room temperature).

Examples of the acid generator that generates an acid upon exposure (hereinafter, also referred to as “photoacid generator”) include the acid generators described in paragraphs [0077] to [0081] of JP-A No. 2004-168748. It is done.

Examples of the acid generator that generates an acid upon heating (hereinafter also referred to as “thermal acid generator”) include onium salt acid generators exemplified as photoacid generators in the above-mentioned patent documents, , 4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, alkylsulfonates and the like.

When the film-forming material contains an acid generator, the lower limit of the content of the acid generator with respect to 100 parts by mass of [A] polysiloxane is preferably 0.01 parts by mass, more preferably 0.1 parts by mass. 0.5 parts by mass is more 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 film forming material 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 said film forming material 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 film forming material for resist process>
The method for preparing the film-forming material is not particularly limited. For example, [A] polysiloxane, [B] solvent and, if necessary, optional components are mixed in a predetermined ratio. Preferably, the obtained mixed solution is mixed with a pore size of 0. It can be prepared by filtering with a 2 μm filter.

The lower limit of the solid content concentration of the film forming material is preferably 0.01% by mass, more preferably 0.1% by mass, further preferably 0.5% by mass, and particularly preferably 1% by mass. 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 film forming material means that the mass of the solid content in the film forming material is measured by baking the film forming material at 250 ° C. for 30 minutes, and the mass of the solid content is the mass of the film forming material. It is a value (mass%) calculated by dividing.

<Silicon-containing film>
The silicon-containing film obtained from the film-forming material forms a resist pattern that is excellent in oxygen gas etching resistance and alkaline hydrogen peroxide solution while maintaining solvent resistance, and is excellent in shape and collapse suppression. be able to. Therefore, the film forming material 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 the coating film by applying the film-forming material described above to the surface of another lower layer film such as a substrate or an organic lower layer film, and heat-treats and cures the coating film. Can be formed.

Examples of the method for applying the film forming material 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 the substrate by applying the film-forming material (hereinafter also referred to as “silicon-containing film forming step”), and a step of patterning the silicon-containing film ( Hereinafter, it is also referred to as a “silicon-containing film patterning step” and a step of forming a pattern on the substrate using the patterned silicon-containing film as a mask (hereinafter also referred to as “substrate pattern forming step”).

According to the pattern forming method, since the film forming material is used, it is possible to form a silicon-containing film that is excellent in oxygen-based gas etching resistance and peelability with alkaline hydrogen peroxide while maintaining solvent resistance. It is possible to form a resist pattern that is excellent in shape and collapse suppression.

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. 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 in the silicon-containing film forming step, silicon is formed using the film forming material on the organic underlayer film. A containing film is formed.

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 this 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 film forming material. 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 antireflection film forming material 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 coating the film forming material. 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, but for example, by exposing and / or heating a coating film formed by coating the film-forming material on a substrate or the like by a known method such as a spin coating method. For example, a method of forming by curing.

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] organic 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 pattern formation process>
In this step, a pattern is formed on the substrate using the patterned silicon-containing film as a mask. This step is usually performed by etching the substrate 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 dry etching can be appropriately selected depending on the elemental composition of the silicon-containing film and the organic underlayer film to be etched, and 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 Reducing gases such as 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 , An inert gas such as He, N ₂ , Ar, or the like is used, and these gases can be mixed and used. 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 organic underlayer film pattern, etc. after the substrate pattern forming step, the silicon-containing film can be removed by performing a silicon-containing film removing step described later. it can.

<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.

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% aqueous ammonia solution / 30% aqueous hydrogen peroxide solution / water = 1/2/40 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 of the [A] polysiloxane solution and the measurement of the weight average molecular weight (Mw) of [A] polysiloxane in this example were carried out 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.

[Measurement of 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.
Compounds (M-1) to (M-15): Compounds represented by the following formulas (M-1) to (M-15)

[Synthesis Example 1] (Synthesis of polysiloxane (A-1))
In the reaction vessel, the compound represented by the above formula (M-1), the compound represented by the above formula (M-2) and the compound represented by the above formula (M-3) have a molar ratio of 50/25 / It melt | dissolved in 142 mass parts of methanol so that it might become 25 (mol%), and the monomer solution was prepared. The inside of the reaction vessel was set to 60 ° C., and 47.9 parts by mass of a 6.25 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 adding 379 parts by mass of propylene glycol monomethyl ether acetate to the cooled reaction solution, using an evaporator, the alcohol produced by the reaction and excess propylene glycol monomethyl ether acetate were removed to remove the propylene acetate of polysiloxane (A-1). A glycol monomethyl ether solution was obtained. The Mw of the polysiloxane (A-1) was 1,820. The solid content concentration of this polysiloxane (A-1) solution in propylene glycol monomethyl ether acetate was 11.1% by mass.

[Synthesis Examples 2 to 14] (Synthesis of polysiloxanes (A-2) to (A-11) and (a-1) to (a-3))
Polysiloxanes (A-2) to (A-11) and (a-1) to (a-1) are prepared in the same manner as in Synthesis Example 1 except that the monomers shown in Table 1 below are used in the amounts and charged amounts. -3) was obtained as a propylene glycol monomethyl ether solution. “-” In Table 1 indicates that the corresponding monomer was not used. Table 1 shows the Mw and solid content concentration (% by mass) of [A] polysiloxane in the obtained [A] polysiloxane solution.

[Preparation of film forming material for resist process]
Components other than [A] polysiloxane used for the preparation of a film forming material for a resist process are shown below.

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

[Example 1]
[A] 1.8 parts by mass of (A-1) as a polysiloxane (solid content) and 98.2 parts by mass of (B-1) as a [B] solvent (included in the solution of [A] polysiloxane Solvent (including B-1)), and the obtained solution was filtered through a filter having a pore size of 0.2 μm to prepare a film forming material (J-1) for resist process.

[Examples 2 to 11 and Comparative Examples 1 to 3]
Resist process film-forming materials (J-2) to (J-11) and (j-1) to (j-1) in the same manner as in Example 1 except that the components of the types and blending amounts shown in Table 2 below were used. (J-3) was prepared.

<Formation of silicon-containing film>
Each of the prepared resist process film-forming materials was applied 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 1 minute, and then cooled at 23 ° C. for 60 seconds to obtain an average thickness of 30 nm shown in Examples 1 to 11 and Comparative Examples 1 to 3 in Table 2. A substrate on which a silicon-containing film was formed was obtained.

<Evaluation>
The film-forming material prepared above was evaluated by the following method for the following items. The evaluation results are shown in Table 2 below. “-” In Table 2 indicates that evaluation was not performed.

[Solvent resistance]
The obtained substrate on which the silicon-containing film was formed was immersed in cyclohexane (20 to 25 ° C.) for 10 seconds and dried. The average thickness of the film before and after immersion was measured. The film thickness change rate (%) when the average thickness of the film before immersion was T ₀ and the average thickness of the film after immersion was T ₁ was obtained by the following formula.
Film thickness change rate (%) = | T ₁ −T ₀ | × 100 / T ₀
The solvent resistance 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%.

[Resist pattern shape and resist pattern collapse suppression]
The resist pattern shape and resist pattern collapse-inhibiting property were evaluated by performing the following lithography evaluation.

(Lithography evaluation, organic solvent development)
A composition for forming an organic underlayer film (“NFC HM8006” from JSR) is applied on a 12-inch silicon wafer by the above spin coater and then heated at 250 ° C. for 60 seconds to form an organic underlayer film having an average thickness of 100 nm. did. On the organic underlayer film, the obtained film forming material is applied by the spin coater, heated at 220 ° C. for 60 seconds, and cooled at 23 ° C. for 60 seconds to form a silicon-containing film having an average thickness of 30 nm. did. Next, a radiation-sensitive resin composition (“ARF AR2772JN” manufactured by JSR) was coated on the silicon-containing film by the spin coater, heated at 90 ° C. for 60 seconds, and cooled at 23 ° C. for 30 seconds. A resist film having a thickness of 100 nm was formed.

Next, using an ArF immersion exposure apparatus (“S610C” manufactured by NIKON) under an optical condition of NA: 1.30 and Dipole, exposure is performed through a mask having a mask size for pattern formation of 40 nm line / 80 nm pitch. did. After heating at 100 ° C for 60 seconds and cooling at 23 ° C for 30 seconds, paddle development with butyl acetate as a developer for 30 seconds, washing with methyl isobutyl carbinol (MIBC) and drying, a resist pattern is formed. A substrate for evaluation was obtained.

(Evaluation of resist pattern shape and collapse inhibition)
The shape of the resist pattern and the collapse inhibition property 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.

In the formation of the resist pattern, the exposure amount is gradually decreased and the exposure is sequentially performed, and the line width corresponding to the minimum exposure amount at which the collapse of the resist pattern is not confirmed is defined as the minimum dimension before collapse (nm). It was used as an index of pattern collapse inhibition. The resist pattern collapse inhibition property was evaluated as “A” (good) when the minimum dimension before collapse was 32 nm or less, and “B” (bad) when it exceeded 32 nm.

The shape of the resist pattern was evaluated as “A” (good) when there was no tailing in the resist pattern, and “B” (bad) when there was pattern collapse or tailing.

[Oxygen-based gas etching resistance]
The substrate on which the obtained silicon-containing film is formed by using an etching apparatus (Tokyo Electron Co. _{"Tactras-Vigus"), O 2 = 400sccm, PRESS} . = 25 mT, HF RF = 200 W, LF RF = 0 W, DCS = 0 V, RDC = 50%, 60 sec. Etching is performed, and the etching rate (nm / min) is calculated from the average film thickness before and after the treatment. System gas etching resistance was evaluated. When the etching rate was less than 5 nm / min, “A” (good), and when the etching rate was 5 nm / min or more, “B” (bad).

From the results of Table 2, according to the film forming material of the example, a resist pattern excellent in shape and collapse-inhibiting property can be formed, and while maintaining solvent resistance, oxygen-based gas etching resistance and alkaline hydrogen peroxide water It can be seen that a silicon-containing film having excellent peelability can be formed.

Claims

A polysiloxane having a first structural unit represented by the following formula (1) or formula (2);
A film forming material for a resist process containing a solvent.

(In the formula (1), L 1 is a single bond or a divalent organic group having 1 to 20 carbon atoms. R 1 is an ethynediyl group or a substituted or unsubstituted ethenediyl group. L 2 is a single bond. A bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms, n is an integer of 1 to 3. When L 2 is a single bond, n is 1. R 2 is a polar group. In the case where n is 2 or more, a plurality of R 2 are the same or different, and R X is a monovalent group not containing an ethylenic carbon-carbon double bond and carbon-carbon triple bond. I is an integer of 0-2.
In the formula (2), L 3 is an (m + 1) -valent organic group having 1 to 20 carbon atoms. m is an integer of 1 to 3. R 3 is a monovalent group containing a polar group. When m is 2 or more, the plurality of R 3 are the same or different. L 4 is a single bond or a divalent organic group having 1 to 20 carbon atoms. R 4 is a substituted or unsubstituted ethynyl group or a substituted or unsubstituted ethenyl group. )
The film forming material for a resist process according to claim 1, wherein R 2 in the formula (1) and R 3 in the formula (2) are represented by the following formula (a) or the following formula (b).

(In the formulas (a) and (b), * represents a site that binds to L 2 or R 1 in the above formula (1) or L 3 in the above formula (2).
In the formula (a), R A is a monovalent hydrocarbon group having 1 to 20 carbon atoms.
In the formula (b), R B is a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a group having 5 to 20 ring members together with an atomic chain in which R B and R a are combined with each other. Form a ring structure. R a and R b are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring composed of these groups combined with each other and the carbon atom to which they are bonded. Represents a ring structure having 3 to 20 members. R c and R d are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbon atoms, or a ring composed of these groups combined with each other and the carbon atom to which they are bonded. Represents a ring structure having 3 to 20 members. )
The film forming material for a resist process according to claim 2, wherein the hydrocarbon group of RA in the formula (a) is a chain hydrocarbon group or an alicyclic hydrocarbon group.
4. The film forming material for a resist process according to claim 2, wherein R B and R a in the formula (b) are combined with each other to form a ring structure having 5 to 20 ring members together with an atomic chain to which they are bonded. .
The film forming material for a resist process according to any one of claims 1 to 4, wherein L 2 in the formula (1) is a single bond or a methanediyl group.
The film forming material for a resist process according to any one of claims 1 to 5, wherein the polysiloxane further has a second structural unit represented by the following formula (3).

(In Formula (3), R Y is a monovalent hydrocarbon group having 1 to 20 carbon atoms. J is an integer of 1 to 3. When j is 2 or more, a plurality of R Y are the same. Or different.)
The film forming material for a resist process according to any one of claims 1 to 6, wherein the polysiloxane further has a third structural unit represented by the following formula (4).
The resist process according to any one of claims 1 to 7, 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. Film forming material.
The film forming material for a resist process according to any one of claims 1 to 8, which is used in a multilayer resist process.
A step of forming a silicon-containing film on the upper side of the substrate by coating the film forming material for a resist process according to any one of claims 1 to 9,
Patterning the silicon-containing film;
Forming a pattern on a substrate using the patterned silicon-containing film as a mask.
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, 11 or 12, comprising: 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.
Polysiloxane having a structural unit represented by the following formula (1) or formula (2).

(In the formula (1), L 1 is a single bond or a divalent organic group having 1 to 20 carbon atoms. R 1 is an ethynediyl group or a substituted or unsubstituted ethenediyl group. L 2 is a single bond. A bond or an (n + 1) -valent organic group having 1 to 20 carbon atoms, n is an integer of 1 to 3. When L 2 is a single bond, n is 1. R 2 is a polar group. In the case where n is 2 or more, a plurality of R 2 are the same or different, and R X is a monovalent group not containing an ethylenic carbon-carbon double bond and carbon-carbon triple bond. I is an integer of 0-2.
In the formula (2), L 3 is an (m + 1) -valent organic group having 1 to 20 carbon atoms. m is an integer of 1 to 3. R 3 is a monovalent group containing a polar group. When m is 2 or more, the plurality of R 3 are the same or different. L 4 represents a divalent organic group single bond or a C 1-20. R 4 is a substituted or unsubstituted ethynyl group or a substituted or unsubstituted ethenyl group. )