TW202035530A - Film-forming composition and method for producing semiconductor substrate - Google Patents

Abstract

The purpose of the present invention is to provide: a film-forming composition capable of forming a silicon-containing film excellent in terms of filling property, flatness, and resistance to etching with oxygen-containing gases; and a method for producing a semiconductor substrate. The film-forming composition of the present invention comprises a polysilane and a solvent, wherein the polysilane has two or more first structural units, which are represented by formula (1). In formula (1), R1 is a hydrogen atom or a monovalent organic chain group having 1-20 carbon atoms. R2 is a hydrogen atom, a hydroxy group, or a monovalent organic chain group having 1-20 carbon atoms. It is preferable that R2 in formula (1) be -ORA and RA be a hydrogen atom or a monovalent organic chain group having 1-20 carbon atoms. It is preferable that RA be a hydrogen atom or a monovalent hydrocarbon chain group having 1-20 carbon atoms.

Description

Film forming composition and method for manufacturing semiconductor substrate

The present invention relates to a composition for forming a film and a method for manufacturing a semiconductor substrate.

In the pattern formation in the manufacture of semiconductor substrates, for example, a semiconductor lithography process can be used, which exposes and develops a resist film laminated on a substrate through an organic underlayer film, a silicon-containing film, etc. , Etching the resulting resist pattern as a mask, thereby forming a patterned substrate.

A method of forming a pattern on a substrate using a polysilane compound as a composition for forming a silicon-containing film has been studied (refer to Japanese Patent Laid-Open No. 11-256106 and International Publication No. 2009/028511). [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 11-256106 [Patent Document 2] International Publication No. 2009/028511

[The problem to be solved by the invention] Recently, substrates formed with patterns such as trenches and channels are often used, and the film-forming composition is required to be able to fully embed these patterns and be excellent in flatness. In addition, the composition for film formation is also required to be excellent in resistance to oxygen-based gas etching. However, the aforementioned composition for film formation cannot satisfy these requirements.

The present invention is formed based on the above circumstances, and its object is to provide a film-forming composition and a method for manufacturing a semiconductor substrate that can form a silicon-containing film excellent in embedding, flatness, and resistance to oxygen-based gas etching. [Means to solve the problem]

（式（1）中，R¹ 為氫原子或碳數1～20的一價的鏈狀有機基。R² 為氫原子、羥基或碳數1～20的一價的鏈狀有機基）The invention formed to solve the above-mentioned problems is a film-forming composition containing polysilane (hereinafter also referred to as "[A] polysilane") and a solvent (hereinafter also referred to as "[B] solvent"), The [A] polysilane has two or more first structural units represented by the following formula (1) (hereinafter, also referred to as "structural unit I"). [化1]

(In formula (1), R ¹ is a hydrogen atom or a monovalent chain organic group with 1 to 20 carbons. R ² is a hydrogen atom, a hydroxyl group or a monovalent chain organic group with 1 to 20 carbons)

Another invention formed to solve the above-mentioned problem is a method of manufacturing a semiconductor substrate, which includes a step of directly or indirectly applying the film-forming composition on the substrate. [Effects of the invention]

According to the film-forming composition and the method of manufacturing a semiconductor substrate of the present invention, it is possible to form a film with excellent embedding properties, flatness, and resistance to oxygen-based gas etching, and furthermore, resistance to organic solvents, peelability of acidic liquids, and pattern formation. Containing silicon film. Therefore, these inventions can be suitably used for the manufacture of semiconductor elements which are expected to be further miniaturized in the future.

<Composition for film formation> This film-forming composition contains [A] polysiloxane and [B] a solvent. The film forming composition may also contain a silicone compound (hereinafter, also referred to as "[C]silicone compound") and/or an acid generator (hereinafter, also referred to as "[D]acid generator") As a preferable component, other arbitrary components may be contained within the range which does not impair the effect of this invention.

The composition for film formation contains [A] polysilane and [B] solvent, which can form excellent embedding, flatness, and oxygen-based gas etching resistance, and further resistance to organic solvents, acidic liquid peeling, and pattern formation Silicon-containing film with excellent properties (hereinafter, these characteristics are also collectively referred to as "the characteristics of silicon-containing film"). The reason why the above-mentioned effect is exhibited by the composition for film formation having the above-mentioned structure is not necessarily clear, but it can be presumed as follows, for example. That is, [A] polysilane has two or more structural units (I) with a specific structure, so it is resistant to organic solvents. In addition, the Si-Si structure is changed to Si-O-Si structure by heating in the atmosphere. It is considered that thermal shrinkage is suppressed and flatness is improved. In addition, it is considered that [A] polysilane of the specific structure is a structure that is difficult to be decomposed by oxygen plasma, and the resistance to etching with oxygen-based gas is improved. Furthermore, [A] polysilane of the above-mentioned specific structure changes the Si-Si structure to the Si-O-Si structure by heating in the atmosphere, and has excellent acidic liquid peelability. The physical properties of [A] polysilane of the specific structure are changed by electron beam or extreme ultraviolet exposure, and therefore, a pattern of a silicon-containing film can be formed by a development process. Hereinafter, each component will be described.

＜[A]Polysilane＞ The so-called "polysilane" refers to a polymer having Si-Si bonds in the main chain. The "polymer" refers to a compound having two or more structural units. [A] Polysilane has two or more structural units (I). That is, [A] polysilane is a compound having structural unit (I) as a repeating unit.

[A] The lower limit of the number of structural units (I) in polysilane is 2, preferably 5, further preferably 10, and particularly preferably 15. The upper limit of the number is, for example, 50, preferably 40, and more preferably 30.

[A] In addition to the structural unit (I), polysilane may have a second structural unit represented by the formula (2) described later (hereinafter, also referred to as "structural unit (II)"), or may have a structural unit ( I) and other structural units other than structural unit (II). [A] Polysilane may have one or two or more structural units. Hereinafter, each structural unit will be described.

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

[化2]

In the formula (1), R ¹ is a hydrogen atom or a monovalent chain organic group having 1 to 20 carbon atoms. R ² is a hydrogen atom, a hydroxyl group, or a monovalent chain organic group having 1 to 20 carbon atoms.

The so-called "organic group" refers to a group containing at least one carbon atom. The so-called "chain shape" means that it does not contain a ring structure and includes both branched and branched chains.

Examples of the monovalent chain organic group having 1 to 20 carbons represented by R ¹ and R ² include: a monovalent chain hydrocarbon group having 1 to 20 carbons; between carbon and carbon of the chain hydrocarbon group A monovalent group (α1) containing a divalent heteroatom-containing group; a monovalent heteroatom-containing group is used to substitute part or all of the hydrogen atoms of the chain hydrocarbon group and the group (α1) The monovalent group (β1); the monovalent group (γ1) formed by combining the chain hydrocarbon group, the group (α1) or the group (β1) and the divalent heteroatom-containing group.

Examples of monovalent chain hydrocarbon groups having 1 to 20 carbon atoms include alkanes such as methane, ethane, propane, and butane; alkenes such as ethylene, propylene, and butene; and alkynes such as acetylene, propyne, and butyne. The chain hydrocarbon group has one hydrogen atom removed, etc.

Examples of the heteroatom constituting the divalent or monovalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a phosphorus atom, a silicon atom, and a halogen atom.

As a divalent heteroatom-containing group, for example, -O-, -CO-, -S-, -CS-, -NR'-, a group formed by combining two or more of these, and the like can be cited. R'is a hydrogen atom or a monovalent chain hydrocarbon group. Among these, -O- or -S- is preferable, and -O- is more preferable.

Examples of the monovalent heteroatom-containing group include halogen atoms such as a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, a hydroxyl group, a carboxyl group, a cyano group, an amino group, and a mercapto group.

R ^{1 is} preferably a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 20 carbons, more preferably a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 6 carbons, and still more preferably a hydrogen atom or a carbon number The alkyl group of 1 to 6, particularly preferably a methyl group or an ethyl group.

As R ² , -OR ^{A is} preferred. R ^A is a hydrogen atom or a monovalent chain organic group having 1 to 20 carbons. Examples of the monovalent chain organic group having 1 to 20 carbons represented by R ^A include the same groups as those exemplified as the monovalent chain organic group having 1 to 20 carbons in R ¹ Wait. R ^{A is} preferably a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 20 carbons, more preferably a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 6 carbons, and still more preferably a hydrogen atom or a carbon number The alkyl group of 1 to 6, particularly preferably a methyl group or an ethyl group.

As the structural unit (I), for example, structural units represented by the following formula (1-1) to formula (1-9) (hereinafter also referred to as "structural unit (I-1) to structural unit (I- 9)”) etc.

[化3]

As structural unit (I), structural unit (I-1), structural unit (I-2) or structural unit (I-6) is preferable.

The lower limit of the content ratio of the structural unit (I) is preferably 1 mol%, more preferably 10 mol%, and still more preferably 30 mol% with respect to all the structural units constituting [A] polysilane. It is preferably 50 mol%, more preferably 70 mol%, and most preferably 90 mol%. The upper limit of the content ratio may also be 100 mol%. By setting the content ratio of the structural unit (I) within the above range, the properties of the silicon-containing film can be further improved.

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

[化4]

In the formula (2), R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbons. R ⁴ is a monovalent organic group having 3 to 20 carbon atoms including a ring structure.

Examples of the monovalent organic group having 1 to 20 carbons represented by R ³ include: a monovalent hydrocarbon group having 1 to 20 carbons; and a divalent heteroatom-containing group between carbon and carbon of the hydrocarbon group A monovalent group (α2) of a group; a monovalent group (β2) obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group and the group (α2) with a monovalent heteroatom-containing group; The hydrocarbyl group, the group (α2) or the group (β2) and the monovalent group (γ2) formed by combining the divalent heteroatom-containing group, and the like. The divalent and monovalent heteroatom-containing groups include the same groups as those exemplified as the divalent and monovalent heteroatom-containing groups in the organic groups of R ¹ and R ² .

Examples of monovalent hydrocarbon groups having 1 to 20 carbons include: monovalent chain hydrocarbon groups having 1 to 20 carbons, monovalent alicyclic hydrocarbon groups having 3 to 20 carbons, and monovalent alicyclic hydrocarbon groups having 6 to 20 carbons. Valence aromatic hydrocarbon groups, etc.

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include the same groups as the monovalent chain hydrocarbon group having 1 to 20 carbon atoms exemplified as R ¹ and R ² .

Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include cycloalkanes such as cyclopentane and cyclohexane; and alicyclic rings such as bridged ring saturated hydrocarbons such as norbornane, adamantane, and tricyclodecane. Cycloolefins such as cyclopentene and cyclohexene; bridged cyclic unsaturated hydrocarbons such as norbornene, tricyclodecene and other alicyclic unsaturated hydrocarbons and other alicyclic hydrocarbons after removing one hydrogen atom The base and so on.

As the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, for example, benzene, toluene, ethylbenzene, xylene, naphthalene, methylnaphthalene, anthracene, methylanthracene and other aromatic hydrocarbons have aromatic rings or alkyl The radical after removing a hydrogen atom from the radical, etc.

R ^{3 is} preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 20 carbons, more preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbons, and still more preferably a hydrogen atom or a monovalent hydrocarbon group having 1 to 6 carbons The alkyl group is particularly preferably methyl or ethyl.

The so-called "ring structure" is a concept including an alicyclic structure, an aromatic carbocyclic structure, an aliphatic heterocyclic structure, and an aromatic heterocyclic structure. Examples of the monovalent organic group having 3 to 20 carbons including a ring structure represented by R ⁴ include: a monovalent alicyclic hydrocarbon group having 3 to 20 carbons; a monovalent aromatic group having 6 to 20 carbons Alicyclic hydrocarbon group; a monovalent group (α3) containing a divalent heteroatom-containing group between the carbon-carbon of the alicyclic hydrocarbon group and the aromatic hydrocarbon group; using the monovalent heteroatom-containing group to convert the aliphatic A cyclic hydrocarbon group, an aromatic hydrocarbon group, and a monovalent group (β3) in which part or all of the hydrogen atoms of the group (α3) are substituted; the alicyclic hydrocarbon group, aromatic hydrocarbon group, group (α3) or A monovalent group (γ3) formed by combining a group (β3) and a divalent heteroatom-containing group. The divalent and monovalent heteroatom-containing groups include the same groups as those exemplified as the divalent and monovalent heteroatom-containing groups in the organic groups of R ¹ and R ² .

R ^{4 is} preferably a monovalent alicyclic hydrocarbon group having 3 to 20 carbons or a monovalent aromatic hydrocarbon group having 6 to 20 carbons, and more preferably a monovalent alicyclic saturated hydrocarbon group having 3 to 20 carbons The hydrocarbon group or the aryl group having 6 to 20 carbons, more preferably the aryl group having 6 to 20 carbons, and particularly preferably a phenyl group or a tolyl group.

As the structural unit (II), for example, structural units represented by the following formulas (2-1) to (2-6) (hereinafter, also referred to as "structural unit (II-1)-structural unit (II- 6)”) etc.

[化5]

As the structural unit (II), the structural unit (II-1) is preferred.

In the case where [A] polysilane has structural unit (II), the lower limit of the content of structural unit (II) is preferably 1 mol% relative to all structural units constituting [A] polysilane, and more It is preferably 2 mol%, further preferably 5 mol%, and particularly preferably 10 mol%. The upper limit of the content ratio is preferably 50 mol%, more preferably 40 mol%, further preferably 30 mol%, particularly preferably 20 mol%. By setting the content ratio of the structural unit (II) within the above range, the properties of the silicon-containing film can be further improved.

[Other structural units] Examples of other structural units include structural units represented by (-Si(R) ₂ -) (R each independently is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbons )Wait.

In the case where [A] polysilane has other structural units, the upper limit of the content of the other structural units is preferably 20 mol%, more preferably 10 mol%. The lower limit of the content ratio is, for example, 0.1 mol%.

[A] The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of polysilane is preferably 300, more preferably 700, still more preferably 1,000, and particularly preferably 1,500. The upper limit of the Mw is preferably 100,000, more preferably 10,000, further preferably 5,000, and particularly preferably 3,000.

Mw in this manual refers to the use of Gel Permeation Chromatography (GPC) columns (Tosoh (stock) "G2000HXL" 2 units, "G3000HXL" 1 unit and "G4000HXL" 1 unit), Measured by gel permeation chromatography (detector: differential refractometer) with monodisperse polystyrene as the standard under the analytical conditions of flow rate: 1.0 mL/min, dissolution solvent: tetrahydrofuran, column temperature: 40°C Value.

The lower limit of the content of [A] polysilane is preferably 30% by mass, more preferably 50% by mass, still more preferably 80% by mass, and particularly preferably 90% by mass relative to all components other than [B] the solvent. The upper limit of the content ratio may be 100% by mass.

The lower limit of the content of [A] polysilane in the film-forming composition is preferably 0.1% by mass, more preferably 0.5% by mass, still more preferably 1% by mass, and particularly preferably 5% by mass. The upper limit of the content ratio is preferably 50% by mass, more preferably 30% by mass, still more preferably 20% by mass, and particularly preferably 15% by mass. [A] One type or two or more types of polysilane can be used.

[[A] Synthesis method of polysilane] [A] Polysilane can be obtained by, for example, the following method: Trichlorosilane, methyldichlorosilane, etc. are provided with a single amount of structural unit (I) as necessary with phenyl The monomer of dichlorosilane, etc. providing structural unit (II) is equivalent to the dehydrohalogenation polycondensation reaction in the presence of a base such as triethylamine in a solvent such as tetrahydrofuran, and then in the presence of a base such as triethylamine in a solvent such as tetrahydrofuran A compound that provides a monovalent chain organic group (R ¹ ) having 1 to 20 carbon atoms, such as methanol and ethanol, is reacted with the obtained polymer.

＜[B] Solvent＞ [B] The solvent is not particularly limited as long as it is a solvent that can dissolve or disperse [A] polysilane and optional components contained therein.

[B] The solvent includes, for example, alcohol-based solvents, ketone-based solvents, ether-based solvents, ester-based solvents, nitrogen-containing solvents, and water. [B] One type or two or more types of solvents can be used.

Examples of alcohol-based solvents include monoalcohol-based solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol; ethylene glycol, 1,2-propylene glycol, diethylene glycol, and diethylene glycol. Polyol solvents such as propylene glycol, etc.

Examples of ketone-based solvents include acetone, methyl ethyl ketone, methyl n-propyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of ether solvents include diethyl ether, isopropyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, and propylene glycol Monoethyl ether, propylene glycol monopropyl ether, tetrahydrofuran, etc.

Examples of ester-based solvents include ethyl acetate, γ-butyrolactone, n-butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether acetate, diethyl acetate Ethylene glycol monoethyl ether, propylene glycol monomethyl acetate, propylene glycol monoethyl acetate, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl acetate, ethyl propionate, n-butyl propionate, methyl lactate, ethyl lactate, etc.

Examples of nitrogen-containing solvents include N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

Among these solvents, ether-based solvents and/or ester-based solvents are preferred, and ether-based solvents and/or ester-based solvents having a glycol structure are more preferred. The reason for this is that the film-forming properties are excellent.

Examples of ether-based solvents and ester-based solvents having a glycol structure include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl acetate, propylene glycol monoethyl acetate, and propylene glycol monopropyl ether. Among these solvents, propylene glycol monomethyl ether acetate is particularly preferred.

[B] The lower limit of the content ratio 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 quality%.

[B] The lower limit of the content of the solvent is preferably 100 parts by mass, more preferably 200 parts by mass, still more preferably 500 parts by mass, and particularly preferably 1,000 parts by mass relative to 100 parts by mass of [A] polysilane. The upper limit of the content is preferably 100,000 parts by mass, more preferably 50,000 parts by mass, still more preferably 20,000 parts by mass, and particularly preferably 10,000 parts by mass.

The lower limit of the content of the solvent [B] in the film forming composition is preferably 50% by mass, more preferably 70% by mass, and still more preferably 80% by mass. The upper limit of the content ratio is preferably 99.9% by mass, and more preferably 99.5% by mass.

＜[C]Silicone compound＞ [C] Siloxane compounds are compounds having Si-O bonds.

Examples of [C]siloxane compounds include polysiloxane (hereinafter, also referred to as "[C1]polysiloxane"), and siloxane monomers (hereinafter, also referred to as "[C2]silicone Alkane monomer”) and so on. The so-called "polysiloxane" refers to a polymer having Si-O-Si bonds in the main chain. The so-called "silicone monomer" refers to a monomer having a Si-O bond.

Examples of [C1] polysiloxanes include those having a structural unit represented by the following formula (3) (hereinafter, also referred to as "structural unit (A)") and/or represented by the following formula (4) A compound of a structural unit (hereinafter, also referred to as "structural unit (B)"), etc.

[化6]

In the formula (3), R ^A is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. m is an integer of 1-3. In the case where m is 2 or more, R ^A plurality of the same or different.

[化7]

Examples of the monovalent organic group having 1 to 20 carbons represented by R ^A include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbons of R ³ .

R ^{A is} preferably a monovalent hydrocarbon group having 1 to 20 carbons, more preferably a monovalent chain hydrocarbon group having 1 to 20 carbons or a monovalent aromatic hydrocarbon group having 6 to 20 carbons, and still more preferably The alkyl group having 1 to 10 carbons or the aryl group having 6 to 10 carbons is particularly preferably a methyl group or a phenyl group.

As m, 1 or 2 is preferable, and 1 is more preferable.

The lower limit of the content ratio of the structural unit (A) is preferably 1 mol%, more preferably 10 mol%, and still more preferably 20 mol% with respect to all the structural units constituting [C1] polysiloxane , Particularly preferably 30 mol%. The upper limit of the content ratio is preferably 99 mol%, more preferably 90 mol%, further preferably 80 mol%, and particularly preferably 70 mol%.

The lower limit of the content ratio of the structural unit (B) is preferably 1 mol%, more preferably 10 mol%, and still more preferably 20 mol% with respect to all the structural units constituting [C1] polysiloxane , Particularly preferably 30 mol%. The upper limit of the content ratio is preferably 99 mol%, more preferably 90 mol%, further preferably 80 mol%, and particularly preferably 70 mol%.

[C2]Silicone monomers include, for example, alkyltrialkoxysilanes such as dodecyltrimethoxysilane and hexyltriethoxysilane, di-dodecyldimethoxysilane, Dialkyldialkoxysilanes such as dihexyldiethoxysilane, etc.

As the lower limit of the content of the [C] silicone compound, relative to 100 parts by mass of [A] polysiloxane, it is preferably 0.1 part by mass, more preferably 1 part by mass, still more preferably 3 parts by mass, particularly preferably 10 parts by mass Copies. The upper limit of the content is preferably 100 parts by mass, more preferably 30 parts by mass, still more preferably 20 parts by mass, and particularly preferably 10 parts by mass. By setting the content of the [C] siloxane compound in the above range, the properties of the silicon-containing film can be further improved.

＜[D] Acid Generator＞ [D] The acid generator is a component that generates acid by exposure or heating. If the composition for film formation contains an [D] acid generator, the condensation reaction of [A] polysilane can also be promoted at a relatively low temperature (including normal temperature).

Examples of [D] acid generators that generate acid by exposure (hereinafter also referred to as "photoacid generators") include paragraphs [0077] to paragraphs [0081 in Japanese Patent Laid-Open No. 2004-168748 ] Described in the acid generator, etc.

In addition, examples of [D] acid generators that generate acid by heating (hereinafter also referred to as "thermal acid generators") include onium salt-based acid generators exemplified in the patent documents as photoacid generators. Or 2,4,4,6-tetrabromocyclohexadienone, benzoin tosylate, 2-nitrobenzyl tosylate, alkyl sulfonate, etc.

When the film forming composition contains [D] acid generator, the lower limit of the content of [D] acid generator is preferably 0.1 parts by mass, more preferably [A] 100 parts by mass of polysilane It is 0.5 part by mass, more preferably 1 part by mass. The upper limit of the content is preferably 20 parts by mass, more preferably 10 parts by mass, and still more preferably 5 parts by mass.

＜Other optional ingredients＞ Examples of other optional components include basic compounds (including alkali generators), radical generators, surfactants, colloidal silica, colloidal alumina, organic polymers, and the like. The other arbitrary components can be used alone or in combination of two or more.

[Basic compound] The basic compound promotes the curing reaction of the film-forming composition, and as a result, the strength of the formed silicon-containing film is improved. In addition, the alkaline compound improves the releasability of the acidic liquid containing the silicon film. As the basic compound, for example, a compound having a basic amine group, a base generator that generates a compound having a basic amine group by the action of an acid or heat, and the like. As a compound which has a basic amine group, an amine compound etc. are mentioned, for example. Examples of base generators 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, for example, those described in paragraphs [0079] to paragraphs [0082] of JP 2016-27370 A Compound etc.

When the composition for film formation contains a basic compound, the upper limit of the content of the basic compound is preferably 50 parts by mass with respect to 100 parts by mass of [A] polysilane. The lower limit of the content is, for example, 1 part by mass.

When the film-forming composition contains a surfactant, colloidal silica, colloidal alumina, and/or organic polymer, the upper limit of the content of each of these components is relative to [A] poly 100 parts by mass of silane, preferably 2 parts by mass, more preferably 1 part by mass. The lower limit of the content is, for example, 0.1 part by mass.

[Preparation method of film forming composition] As a method of preparing the film-forming composition, for example, it can be prepared by mixing [A] a solution of polysilane and [B] a solvent with optional components in a predetermined ratio, preferably using a pore size of 0.2 Filter the obtained mixed solution with a filter or the like below μm.

<Method of manufacturing semiconductor substrate> The method of manufacturing the semiconductor substrate includes a step of directly or indirectly applying the film-forming composition on the substrate (hereinafter, also referred to as "coating step").

According to the method for manufacturing a semiconductor substrate, since the film forming composition is used, it is possible to form an excellent embedding property, flatness, and resistance to oxygen-based gas etching, and further resistance to organic solvents, acid liquid peeling, and pattern formation. Silicon-containing film with excellent properties.

The manufacturing method of the semiconductor substrate may further include a step of etching at least a part of the silicon-containing film formed by the coating step (hereinafter, also referred to as an “etching step”) after the coating step. In this way, the silicon-containing film can be patterned.

The method for manufacturing a semiconductor substrate may further include, after the coating step, a step of directly or indirectly coating a resist composition on the silicon-containing film formed by the coating step (hereinafter, also referred to as "Resist composition coating step"); a step of exposing the resist film formed by the resist composition coating step (hereinafter, also referred to as "exposure step (I)" ); the step of developing the exposed resist film (hereinafter, also referred to as "development step (I)"); and the resist pattern formed by the development step (I) as Masking and etching the silicon-containing film (hereinafter, also referred to as "silicon-containing film etching step"). In this way, the silicon-containing film can be patterned.

The manufacturing method of the semiconductor substrate may further include after the coating step: a step of exposing the silicon-containing film formed by the coating step with radiation (hereinafter, also referred to as "exposure step (II)" ); and the step of developing the exposed silicon-containing film (hereinafter, also referred to as "development step (II)"). Thereby, excellent pattern forming properties can be exerted to form a pattern of a silicon-containing film.

The manufacturing method of the semiconductor substrate may further include after the coating step: a step of performing oxygen treatment on the silicon-containing film formed by the coating step (hereinafter, also referred to as "oxygen treatment step"); and The step of removing the silicon-containing film after the oxygen treatment step with an acidic liquid (hereinafter, also referred to as "removing step"). Thereby, the excellent acidic liquid removability can be exerted and the silicon-containing film can be easily removed.

The manufacturing method of the semiconductor substrate may further include a step of etching the substrate using the silicon-containing film as a mask after the etching step, the silicon-containing film etching step or the developing step (II) (hereinafter, also referred to as " Substrate etching step"). Thereby, a substrate pattern can be formed.

The method for manufacturing the semiconductor substrate may further include a step of directly or indirectly forming an organic underlayer film on the substrate before the coating step. Hereinafter, each step is explained.

[Organic Underlayer Film Formation Step] In this step, an organic underlayer film is formed directly or indirectly on the substrate.

In this method of manufacturing a semiconductor substrate, when the organic underlayer film formation step is performed, the organic underlayer film formation step is followed by the coating step described later. In this case, the silicon-containing film is formed by coating the film-forming composition on the organic underlayer film in the coating step.

The organic underlayer film is different from the silicon-containing film formed from the film-forming composition. Wherein, the organic underlayer film may also contain silicon atoms. The organic underlayer film is used to further compensate for the functions of the silicon-containing film and/or the resist film in the formation of the resist pattern, or to provide the necessary predetermined functions (such as anti-reflection) in order to obtain functions that these films do not have. The film has high resistance, coating film flatness, and high etching resistance to fluorine-based gas).

As the organic underlayer film, for example, an anti-reflection film or the like can be cited. As the composition for forming an anti-reflection film, for example, "NFC HM8006" of JSR (Stock) etc. can be cited.

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

Examples of the substrate include insulating films such as silicon wafers, silicon oxide, silicon nitride, silicon oxynitride, and polysiloxane, and resin substrates. For example, "Black Diamond" from Applied Materials (AMAT), "Silk" from Dow Chemical, and "Silk" from JSR (stock) can be used. LKD5109", etc., is formed by a low-dielectric insulating film coated with an interlayer insulating film such as a wafer. As the substrate, a substrate having patterns such as wiring grooves (shallow grooves) and plug grooves (channels) formed can also be used.

[Coating Step] In this step, the film-forming composition is applied directly or indirectly on the substrate. In this step, the coating film of the film-forming composition is formed on the substrate directly or through another layer such as an organic underlayer film. When a patterned substrate is used as a substrate and the film-forming composition is directly applied to the pattern side of the substrate, the embedding property and flatness of the patterned substrate can be exhibited. The coating method of this film formation composition is not specifically limited, For example, well-known methods, such as a spin coating method, etc. are mentioned.

Generally, a coating film formed by applying the film-forming composition on a substrate or the like is exposed and/or heated to harden it, thereby forming a silicon-containing film.

Examples of radiation used for the exposure include electromagnetic waves such as visible rays, ultraviolet rays, extreme ultraviolet rays, X-rays, and gamma rays; particle beams such as electron beams, molecular beams, and ion beams.

The lower limit of the temperature when heating the coating film is preferably 90°C, more preferably 150°C, and still more preferably 200°C. The upper limit of the temperature is preferably 550°C, more preferably 450°C, and still more preferably 350°C. The lower limit of the average thickness of the formed silicon-containing film is preferably 1 nm, more preferably 3 nm, and still more preferably 5 nm. The upper limit of the average thickness is preferably 1,000 nm, more preferably 500 nm, and still more preferably 300 nm.

The lower limit of the absorption coefficient (k value) at 193 nm of the formed silicon-containing film is preferably more than 0.2, more preferably 0.25, and still more preferably 0.3. The upper limit of the k value is preferably 1.0, more preferably 0.7, and still more preferably 0.5.

The lower limit of the water contact angle on the surface of the silicon-containing film to be formed is preferably 50°, more preferably 60°, and still more preferably 65°. The upper limit of the water contact angle is preferably 90°, more preferably 88°, and still more preferably 86°.

[Etching step] In this step, at least a part of the silicon-containing film formed by the coating step is etched. In this way, the silicon-containing film can be patterned.

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

Dry etching can be performed using, for example, a known dry etching apparatus. The etching gas used in dry etching can be appropriately selected according to the element composition of the silicon-containing film to be etched. For example, CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF ₆ and other fluorine systems can be used. Gas; Cl ₂ , BCl ₃ and other chlorine-based gases; O ₂ , O ₃ , H ₂ O and other oxygen-based gases; H ₂ , NH ₃ , CO, 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 and other reducing gases; He, N ₂ , Ar and other inert gases. These gases can also be used in combination. For dry etching of a silicon-containing film, a fluorine-based gas is usually used, and a gas in which an oxygen-based gas and an inert gas are mixed can be preferably used.

[Resist composition coating step] In this step, the resist composition is directly or indirectly coated on the silicon-containing film formed by the coating step. Through this step, a resist film is formed directly or via another layer on the silicon-containing film formed in the coating step.

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, and an alkali-soluble resin and A positive resist composition of a quinonediazide-based photosensitive agent, a negative resist composition containing an alkali-soluble resin and a crosslinking agent, and the like. Among these, a radiation-sensitive resin composition is preferable. In the case of using a radiation-sensitive resin composition, by developing with an alkaline developer, a positive pattern can be formed, and by developing with an organic solvent developer, a negative pattern can be formed. When forming a resist pattern, a double patterning method, a double exposure method, etc., which are a method of forming a fine pattern, can also be suitably used.

The polymer contained in the radiation-sensitive resin composition may have, for example, a structural unit including a lactone structure, a cyclic carbonate structure and/or a sultone structure, and an alcohol Structural units of a phenolic hydroxyl group, a structural unit containing a phenolic hydroxyl group, a structural unit containing a fluorine atom, etc. If 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 or electron beams as radiation during exposure can be improved.

The lower limit of the content ratio of all components other than the solvent of the resist composition is preferably 0.1% by mass, and more preferably 1% by mass. The upper limit of the content ratio is preferably 50% by mass, and more preferably 30% by mass. As the resist composition, a resist composition filtered with a filter with a pore diameter of 0.2 μm or the like can be preferably used. In this method of manufacturing a semiconductor substrate, a commercially available resist composition can also be used as the resist composition as it is.

As a coating method of the resist composition, conventional methods, such as spin coating method, etc. are mentioned, for example. When applying the resist composition, the amount of the resist composition applied is adjusted so that the obtained resist film has a predetermined film thickness.

The coating film of the resist composition can be prebaked to volatilize the solvent in the coating film to form a resist film. The temperature of the pre-baking is appropriately adjusted according to the type of the resist composition used, etc., and the lower limit of the temperature of the pre-baking is preferably 30°C, more preferably 50°C. The upper limit of the temperature is preferably 200°C, more preferably 150°C.

[Exposure Step (I)] In this step, the resist film formed by the resist composition coating step is exposed. The exposure is performed by selectively irradiating radiation with a mask, for example. Examples of radiation include electromagnetic waves such as visible rays, ultraviolet rays, extreme ultraviolet rays, extreme ultraviolet rays, X-rays, and gamma rays, and charged particle beams such as electron beams and alpha rays. Among these, extreme ultraviolet rays, extreme ultraviolet rays or electron beams are preferred, and extreme ultraviolet rays or electron beams are more preferred.

[Development step (I)] In this step, the exposed resist film is developed. Through this step, a resist pattern is formed directly or through other layers on the silicon-containing film formed by the coating step. As a developing method, the alkali developing method using an alkaline developing solution may be used, and the organic solvent developing method using an organic solvent developing solution may be sufficient. In this step, after developing with various developing solutions, it is preferable to perform washing and drying, thereby forming a predetermined resist pattern corresponding to the photomask used in the exposure step.

[Silicon-containing film etching step] In this step, after the development step (I), the silicon-containing film is etched using the resist pattern formed by the development step as a mask. More specifically, the silicon-containing film is patterned by one or more etchings using the resist pattern formed by the development step (I) as a mask.

The etching may be dry etching or wet etching, preferably dry etching. As a method of dry etching, for example, the method of dry etching in the etching step is the same.

[Exposure Step (II)] In this step, the silicon-containing film formed by the coating step is exposed with radiation. The exposure is performed by selectively irradiating radiation with a mask, for example. Examples of radiation include electromagnetic waves such as visible rays, ultraviolet rays, extreme ultraviolet rays, extreme ultraviolet rays, X-rays, and gamma rays, and charged particle beams such as electron beams and alpha rays. Among these, extreme ultraviolet rays, extreme ultraviolet rays or electron beams are preferred, and extreme ultraviolet rays or electron beams are more preferred.

[Development step (II)] In this step, the exposed silicon-containing film is developed. Through this step, a pattern containing a silicon film is formed. Examples of the pattern include line and space patterns, hole patterns, and the like. As the development method, an alkali development method using an alkaline developer may be used or an organic solvent development method using an organic solvent developer, and an organic solvent development method is preferred. In this step, after developing with various developing solutions, it is preferable to perform washing and drying, thereby forming a predetermined silicon-containing film pattern corresponding to the photomask used in the exposure step (II). According to the method of manufacturing a semiconductor substrate, since the film-forming composition is used, the silicon-containing film has excellent patterning properties.

[Oxygen treatment steps] In this step, oxygen treatment is performed on the silicon-containing film formed by the coating step. The oxygen treatment can be performed by heating the silicon-containing film in air or the like. The lower limit of the heating temperature is preferably 100°C, more preferably 150°C. The upper limit of the heating temperature is preferably 300°C, more preferably 250°C. The lower limit of the heating time is preferably 50 seconds, more preferably 10 seconds. The upper limit of the heating time is preferably 1 hour, more preferably 5 minutes.

[Removal steps] In this step, an acidic liquid is used to remove the silicon-containing film after the oxygen treatment step. Examples of acidic liquids include liquids containing acid and water; liquids obtained by mixing acid, hydrogen peroxide, and water, and the like. Examples of the acid include sulfuric acid, hydrofluoric acid, and hydrochloric acid. As an acidic liquid, more specifically, for example, a liquid obtained by mixing hydrofluoric acid and water; a liquid obtained by mixing sulfuric acid, hydrogen peroxide, and water; and hydrochloric acid and hydrogen peroxide. The liquid obtained by mixing with water, etc. Among these, a liquid obtained by mixing hydrofluoric acid and water is preferable.

The lower limit of the temperature in the removal step is preferably 20°C, and more preferably 40°C. The upper limit of the temperature is preferably 100°C, more preferably 70°C. The lower limit of the time in the removal step is preferably 10 seconds, more preferably 1 minute. The upper limit of the time is preferably 1 hour, more preferably 10 minutes.

[Substrate etching step] In this step, the pattern of the silicon-containing film is used as a mask and the substrate is etched. More specifically, one or more etchings are performed to obtain a patterned substrate, wherein the etching will be formed in the etching step, the silicon-containing film etching step, or the silicon-containing film obtained in the developing step (II). The pattern on the film serves as a mask.

In the case of forming an organic underlayer film on the substrate, it includes a step of using the pattern of the silicon-containing film as a mask and etching the organic underlayer film. The organic underlayer film pattern formed by the organic underlayer film etching step is used as a mask and the substrate is etched, thereby forming a pattern on the substrate.

The etching may be dry etching or wet etching, preferably dry etching. The dry etching when forming a pattern on the organic underlayer film can be performed using a known dry etching device. The etching gas used in dry etching can be appropriately selected according to the elemental composition of the 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 , SF ₆ fluorine-based gases; Cl ₂ , BCl ₃ and other chlorine-based gases; O ₂ , O ₃ , H ₂ O and other oxygen-based gases; H ₂ , NH ₃ , CO, 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 and other reducing gases; He, N ₂ , Ar and other inert gases Etc., these gases can also be mixed and used. The dry etching of the organic underlayer film using the pattern of the silicon film as a mask generally uses an oxygen-based gas.

The dry etching at the time of etching the substrate with the organic underlayer film pattern as a mask can be performed using a known dry etching device. The etching gas used in dry etching can be appropriately selected according to the element composition of the organic underlayer film and the substrate to be etched. For example, the same etching gas as the one exemplified as the etching gas used in the dry etching of the organic underlayer film can be mentioned. Etching gas, etc. It can also be etched by multiple different etching gases. [Example]

Hereinafter, examples will be described. In addition, the embodiment shown below shows an example of the representative embodiment of this invention, and does not narrowly interpret the scope of the present invention.

The measurement of the weight average molecular weight (Mw), the concentration of [A] polysilane in the solution, and the average thickness of the film in this example were performed by the following method.

[Weight average molecular weight (Mw)] Use GPC columns (Tosoh (stock) 2 "G2000HXL", 1 "G3000HXL", 1 "G4000HXL"), at flow rate: 1.0 mL/min, dissolution solvent: tetrahydrofuran, column temperature: Measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard under analysis conditions of 40°C.

[[A] Concentration of polysilane in solution] Measure the mass of the residue after sintering 0.5 g of [A] polysilane solution at 250°C for 30 minutes, and divide the mass of the residue by the mass of [A] polysilane solution to calculate [A] polysilane The concentration of silane in the solution (mass%).

[Average thickness of silicon-containing film] The average thickness of the silicon-containing film is measured using a spectroscopic ellipsometer (“M2000D” from J.A. WOOLLAM).

＜Synthesis of [A] polysiloxane and [C] siloxane compound＞ The monomers used in the synthesis of [A] polysilane and [C] siloxane compounds are shown below.

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[Synthesis Example 1] (Synthesis of Polysilane (A-1)) In a reaction vessel that was filled and replaced with nitrogen, 27.09 g of the compound represented by the formula (H-1) and 44 g of tetrahydrofuran were added, and the mixture was cooled to 5° C. or lower with ice cooling. Next, 20.24 g of triethylamine was dissolved in 44 g of tetrahydrofuran to prepare a solution for dropping. The solution for dropping was added dropwise over 1 hour while stirring. The end of the dropping was set as the start time of the reaction, and the polymerization reaction was carried out at 40°C for 1 hour, and then at 60°C for 1 hour. After the reaction was completed, 267 g of tetrahydrofuran was added, and the polymerization reaction liquid was ice-cooled and cooled to 10°C or lower. After adding 60.71 g of triethylamine to the cooled polymerization reaction solution, 19.22 g of methanol was dropped from the dropping funnel over 10 minutes while stirring. The end of the dropping was set as the start time of the reaction, and the reaction was carried out at 20°C for 1 hour. The salt precipitated in the reaction liquid was separated by filtration. Second, use an evaporator to remove tetrahydrofuran, remaining triethylamine and remaining methanol in the filtrate. To the obtained residue, 84 g of propylene glycol monomethyl ether acetate and 2.7 g of trimethyl orthoformate were added to obtain a propylene glycol monomethyl ether acetate solution of polysiloxane represented by the following formula (A-1). The concentration of polysilane (A-1) in the propylene glycol monomethyl ether acetate solution was 4% by mass. The Mw of polysilane (A-1) is 2,500.

[Synthesis Example 2] (Synthesis of Polysiloxane (A-2)) Except for using ethanol instead of methanol, in the same manner as in Synthesis Example 1, a propylene glycol monomethyl ether acetate solution of polysilane represented by the following formula (A-2) was obtained. The concentration of polysilane (A-2) in the propylene glycol monomethyl ether acetate solution was 4% by mass. The Mw of polysiloxane (A-2) is 2,600.

[Synthesis Example 3-Synthesis Example 5] (Synthesis of Polysilane (A-3)-Polysilane (A-5)) Except for using the monomers of the type and usage amount shown in Table 1 below, in the same manner as in Synthesis Example 1, the following formula (A-3) to formula (A-5) represented by polysiloxane propylene glycol was obtained Monomethyl ether solution. The "-" in Table 1 indicates that the corresponding single body is not used. The Mw of the obtained [A] polysilane and the concentration (% by mass) of the [A] polysilane in the solution are shown in Table 1.

[Synthesis Example 6] (Synthesis of polysilane (a-1)) In a reaction vessel that was filled and replaced with nitrogen, 11.95 g of metallic sodium was added to 88 g of xylene and heated while stirring, thereby preparing a metallic sodium xylene dispersion. While stirring, 55.00 g of the compound represented by the formula (M-1) was added dropwise under reflux over 3 hours. The end of the dropping was set as the start time of the reaction, and the polymerization reaction was carried out under reflux for 1 hour. After the reaction was completed, 352 g of xylene was added, and the polymerization reaction liquid was ice-cooled and cooled to 10°C or lower. After adding 52.62 g of triethylamine to the cooled polymerization reaction solution, 16.66 g of methanol was dropped from the dropping funnel over 10 minutes while stirring. The end of the dropping was set as the start time of the reaction, and the reaction was carried out at 20°C for 1 hour. The salt precipitated in the reaction liquid was separated by filtration. Secondly, use an evaporator to remove xylene, remaining triethylamine and remaining methanol in the filtrate. To the obtained residue, 177 g of propylene glycol monomethyl ether acetate and 5.3 g of trimethyl orthoformate were added to obtain a propylene glycol monomethyl ether acetate solution of polysiloxane represented by the following formula (a-1). The concentration of polysilane (a-1) in the propylene glycol monomethyl ether acetate solution was 10% by mass. The Mw of polysiloxane (a-1) is 2,000.

[Synthesis Example 7] (Synthesis of Siloxane Compound (C-1)) In the reaction vessel, 14.74 g of the compound represented by the formula (S-1) and 9.64 g of the compound represented by the formula (S-2) were dissolved in 64 g of propylene glycol monoethyl ether to prepare a monomer Measure the body solution. The inside of the reaction vessel was set to 35°C, and 12 g of a 7.7% by mass oxalic acid aqueous solution was added dropwise over 20 minutes while stirring. The end of the dropwise addition was set as the start time of the reaction, and the reaction was performed for 4 hours and then cooled to 30°C or lower. An evaporator is used to remove water, alcohols produced by the reaction, and remaining propylene glycol monoethyl ether to obtain a propylene glycol monoethyl ether solution of a silicone compound represented by the following formula (C-1). The concentration of the silicone compound (C-1) in the propylene glycol monoethyl ether solution was 11% by mass. The Mw of the siloxane compound (C-1) is 1,900.

[Synthesis Example 8] (Synthesis of Silicone Compound (C-2)) Except having used each monomer of the type and usage amount shown in Table 1 below, in the same manner as in Synthesis Example 7, a propylene glycol monoethyl ether solution of a silicone compound represented by the following formula (C-2) was obtained. The "-" in Table 1 indicates that the corresponding single body is not used. The Mw of the obtained [C]siloxane compound and the concentration (mass %) of the [C]siloxane compound in the solution are shown in Table 1 together.

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[Table 1] [A] Polysiloxane/[C] Silicone compound The amount of each single body (mol%) Concentration in solution (mass%) Mw H-1 H-2 H-3 M-1 S-1 S-2 S-3 Synthesis example 1 A-1 100 - - - - - - 4 2,500 Synthesis Example 2 A-2 100 - - - - - - 4 2,600 Synthesis Example 3 A-3 70 30 - - - - - 4 2,100 Synthesis Example 4 A-4 90 - 10 - - - - 4 2,200 Synthesis Example 5 A-5 - 100 - - - - - 4 1,500 Synthesis Example 6 a-1 - - - 100 - - - 10 2,000 Synthesis Example 7 C-1 - - - - 50 50 - 11 1,900 Synthesis Example 8 C-2 - - - - 60 30 10 11 2,100

<Preparation of composition for film formation> The [B] solvent, [C] siloxane compound, and [D] acid generator used in the preparation of the film forming composition are shown below.

[[B]Solvent] B-1: Acetic acid propylene glycol monomethyl ether B-2: Propylene glycol monoethyl ether

[[C]Silicone compounds] C-1: The synthesized silicone compound (C-1) C-2: The synthesized silicone compound (C-2) C-3: n-dodecyltrimethoxysilane (compound represented by the following formula (C-3))

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[[D] Acid Generator] D-1: 1-(4-n-butoxynaphthalene-1-yl)tetrahydrothiophenium nonafluoro-n-butane-1-sulfonate (a compound represented by the following formula (D-1))

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[Example 1] Combine 1.00 parts by mass of (A-1) as [A] polysilane (excluding the solvent) and 99.00 parts by mass of (B-1) as [B] solvent (also included in the solution as [A] polysilane) (B-1)) of the contained solvents were mixed, and the resulting solution was filtered with a filter with a pore size of 0.2 μm to prepare a membrane forming composition (J-1).

[Example 2 to Example 14 and Comparative Example 1 to Comparative Example 6] Except for using the types and blending amounts of each component shown in Table 2 below, the same operations as in Example 1 were carried out to prepare the film formation composition (J-2) to the film formation composition (J-14) and Film formation composition (j-1)-film formation composition (j-6).

[Table 2] Composition for film formation [A] Polysiloxane [B] Solvent [C] Siloxane compound [D] Acid generator species Blending (parts by mass) species Blending (parts by mass) species Blending (parts by mass) species Blending (parts by mass) Example 1 J-1 A-1 1.00 B-1 99.00 - - - - Example 2 J-2 A-2 1.00 B-1 99.00 - - - - Example 3 J-3 A-3 1.00 B-1 99.00 - - - - Example 4 J-4 A-4 1.00 B-1 99.00 - - - - Example 5 J-5 A-5 1.00 B-1 99.00 - - - - Example 6 J-6 A-1 0.95 B-1 99.00 C-1 0.05 - - Example 7 J-7 A-1 0.95 B-1 99.00 C-2 0.05 - - Example 8 J-8 A-1 0.95 B-1 99.00 C-3 0.05 - - Example 9 J-9 A-1 0.95 B-1 98.98 C-1 0.05 D-1 0.02 Example 10 J-10 A-1 10.00 B-1 90.00 - - - - Example 11 J-11 A-2 10.00 B-1 90.00 - - - - Example 12 J-12 A-3 10.00 B-1 90.00 - - - - Example 13 J-13 A-4 10.00 B-1 90.00 - - - - Example 14 J-14 A-5 10.00 B-1 90.00 - - - - Comparative example 1 j-1 a-1 1.00 B-1 99.00 - - - - Comparative example 2 j-2 - - B-2 99.00 C-1 1.00 - - Comparative example 3 j-3 - - B-2 99.00 C-2 1.00 - - Comparative example 4 j-4 a-1 10.00 B-1 90.00 - - - - Comparative example 5 j-5 - - B-2 90.00 C-1 10.00 - - Comparative example 6 j-6 - - B-2 90.00 C-2 10.00 - -

＜Evaluation＞ Using the film-forming composition prepared as described above, a silicon-containing film was formed by the following method. Regarding the formed silicon-containing film, the embedding property, flatness, resistance to oxygen-based gas etching, resistance to organic solvents, light absorption coefficient (k value), water contact angle, acidic liquid peelability, and pattern were evaluated by the following methods Formative. The evaluation results are shown in Tables 3 to 5 below. "-" in Table 3 to Table 5 means that the corresponding evaluation is not performed.

[Buried] The film-forming composition prepared as described above was applied to the formation by the spin coating method using a spin coater ("CLEAN TRACK ACT8" of Tokyo Electron (Stock)) On a silicon nitride substrate with a groove pattern of 300 nm depth and 30 nm width. The rotation speed of the spin coating was set to be the same as the following: the film-forming composition prepared was coated on a silicon wafer by a spin coating method using the spin coater, under a nitrogen atmosphere After heating at 300°C for 60 seconds, cooling at 23°C for 30 seconds, thereby forming a silicon-containing film with an average thickness of 200 nm. Then, after heating at 300° C. for 60 seconds in a nitrogen atmosphere, it was cooled at 23° C. for 30 seconds, thereby obtaining a substrate on which a silicon-containing film was formed. The cross-section of the obtained substrate was observed using a scanning electron microscope (“S-4800” of Hitachi High-technologies (Stock)), and the embedding properties were confirmed. Regarding the embedding property, it was evaluated as "A" (good) when no embedding defects (pores) were observed, and it was evaluated as "B" (bad) when embedding defects were observed.

[Flatness] The film forming composition prepared as described above was prepared by the spin coating method using a spin coater ("CLEAN TRACK ACT8" of Tokyo Electron (Stock)") It is shown coated on a silicon substrate 1 formed with a groove pattern with a depth of 100 nm and a width of 10 μm. The rotation speed of the spin coating is set to be the same as the following: the prepared film-forming composition is coated on the silicon wafer by the spin coating method using the spin coater, in an atmospheric environment After heating at 300°C for 60 seconds, cooling at 23°C for 30 seconds, thereby forming a silicon-containing film with an average thickness of 200 nm. Then, after heating at 300°C for 60 seconds in an atmospheric environment, it was cooled at 23°C for 30 seconds, thereby forming a silicon-containing film 2 with an average thickness of 200 nm in the non-groove pattern portion, and obtaining a silicon-containing film Of the substrate. A scanning electron microscope (Hitachi High-technologies (stock) "S-4800") was used to observe the cross-sectional shape of the obtained substrate, and the central part of the groove pattern of the silicon-containing film 2 The difference (ΔFT) between the height of b and the height of the portion a of the non-groove pattern at a position 5 μm from the end of the groove pattern (ΔFT) is used as an index of flatness. Regarding the flatness, when the ΔFT is less than 40 nm, it is evaluated as "A" (good), when the ΔFT is greater than 40 nm and less than 60 nm, it is evaluated as "B" (slightly good). In this case, the evaluation is "C" (bad). Furthermore, the height difference shown in FIG. 1 is described in an exaggerated manner compared to the actual situation.

＜Formation of silicon-containing film＞ [Example 1 to Example 9 and Comparative Example 1 to Comparative Example 3] The film-forming composition prepared as described above was applied to silicon by a spin coating method using a spin coater ("CLEAN TRACK ACT8" of Tokyo Electron (Stock)) On the wafer, heated at 300°C for 60 seconds in a nitrogen atmosphere, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 15 nm, thereby obtaining a silicon-containing film with an average thickness of 15 nm Of the substrate.

[Etching resistance to oxygen-based gases] Using an etching device ("Tactras-Vigus" of Tokyo Electronics Co., Ltd.), at O ₂ =400 sccm, PRESS.=25 mT, HF RF ( High-frequency power for plasma generation) = 200 W, LF RF (high-frequency power for bias) = 0 W, DCS = 0 V, RDC (gas sensor flow rate ratio) = 50%, 60 sec. The substrate with a silicon-containing film with an average thickness of 15 nm was subjected to an etching process, and the etching rate (nm/min) was calculated from the average thickness before and after the process, and the oxygen-based gas etching resistance was evaluated. Regarding the oxygen-based gas etching resistance, when the etching rate was less than 5.0 nm/min, it was evaluated as "A" (good), and when the etching rate was 5.0 nm/min or more, it was evaluated as "B" (bad).

[Organic solvent resistance] The substrate with a silicon-containing film with an average thickness of 15 nm was immersed in cyclohexanone (20°C to 25°C) for 10 seconds and then dried. The average thickness of the silicon-containing film before and after immersion was measured. The film thickness change rate (%) when the average thickness of the silicon-containing film before immersion is T ₀ and the average thickness of the silicon-containing film after immersion is T ₁ is obtained by the following equation. Regarding the resistance to organic solvents, when the film thickness change rate is less than 1%, it is evaluated as "A" (good), and when it is 1% or more, it is evaluated as "B" (bad). Film thickness change rate (%)=│T ₁ -T ₀ │×100/T ₀

[Absorbance coefficient (k value, 193 nm)] Regarding the substrate with a silicon-containing film with an average thickness of 15 nm, a spectroscopic ellipsometer ("M2000D" of J.A. WOOLLAM) was used to measure the k value (193 nm).

[Water contact angle] Regarding the substrate with a silicon-containing film with an average thickness of 15 nm, a contact angle meter ("DSA-10" of KRUSS) was used to measure the water contact angle at a temperature of 23°C and a humidity of 45%. The water contact angle is the contact angle of water just after 10 μL of water droplets are contacted on the silicon-containing film.

[table 3] Composition for film formation Embeddedness Flatness Oxygen gas etching resistance Resistance to organic solvents k value (193 nm) Water contact angle (°) Example 1 J-1 - - A A 0.3 65 Example 2 J-2 - - A A 0.3 67 Example 3 J-3 - - A A 0.3 73 Example 4 J-4 - - A A 0.5 70 Example 5 J-5 - - A A 0.3 86 Example 6 J-6 - - A A 0.3 82 Example 7 J-7 - - A A 0.4 67 Example 8 J-8 - - A A 0.3 81 Example 9 J-9 - - A A 0.3 80 Example 10 J-10 A A - - - - Example 11 J-11 A A - - - - Example 12 J-12 A A - - - - Example 13 J-13 A A - - - - Example 14 J-14 A A - - - - Comparative example 1 j-1 - - B B 1.3 76 Comparative example 2 j-2 - - B A 0.0 83 Comparative example 3 j-3 - - B A 0.2 68 Comparative example 4 j-4 A B - - - - Comparative example 5 j-5 A B - - - - Comparative example 6 j-6 A B - - - -

From the results of Table 3, it can be seen that the silicon-containing film formed from the film-forming composition in the example has good burying properties, flatness, resistance to etching with oxygen-based gases, and resistance to organic solvents. In contrast, the silicon-containing film formed from the film-forming composition in the comparative example has poor flatness and oxygen-based gas etching resistance, and some have poor organic solvent resistance.

[Acid liquid peelability] Regarding the silicon-containing film with an average thickness of 15 nm, the acidic liquid peelability in each case with or without oxygen treatment was evaluated by the following method.

(Oxygen treatment) The substrate with the silicon-containing film is heated in clean air at 200° C. for 60 seconds.

(Removal of silicon-containing film) The obtained substrate without oxygen treatment and the substrate with oxygen treatment are immersed in a removal solution (50% by mass hydrofluoric acid/water=1/5 (volume ratio) mixed aqueous solution) heated to 50° C. for 5 minutes. A spectroscopic ellipsometer ("M2000D" from J.A. WOOLLAM) was used to measure the average thickness of the silicon-containing film after immersion.

[Table 4] Composition for film formation Acidic liquid peelability Film thickness without oxygen treatment (nm) Film thickness with oxygen treatment (nm) Example 1 J-1 14.4 0 Example 2 J-2 14.7 0 Example 3 J-3 15.0 0 Example 4 J-4 15.0 0 Example 5 J-5 15.0 2.7 Example 6 J-6 15.0 0 Example 7 J-7 14.1 0 Example 8 J-8 15.0 0 Example 9 J-9 15.0 0 Example 10 J-10 - - Example 11 J-11 - - Example 12 J-12 - - Example 13 J-13 - - Example 14 J-14 - - Comparative example 1 j-1 15.0 14.4 Comparative example 2 j-2 1.5 1.2 Comparative example 3 j-3 3.0 3.0 Comparative example 4 j-4 - - Comparative example 5 j-5 - - Comparative example 6 j-6 - -

From the results of Table 4, it can be seen that the silicon-containing film formed from the film-forming composition in the example is excellent in acidic liquid peelability by being treated with oxygen. On the other hand, it can be seen that the acidic liquid peelability of the silicon-containing film formed from the film-forming composition in the comparative example does not change depending on the presence or absence of oxygen treatment.

[Pattern formability] (Electron beam exposure) Under the conditions of 100 μC/cm ² (output power: 50 KeV, current density: 5.0 Ampere/cm ² ), the substrate with a silicon-containing film with an average thickness of 15 nm Expose the electron beam. The device uses "HL800D" from Hitachi Manufacturing Co., Ltd. After exposure, development was performed with isopropanol for 60 seconds. Observe the cross-sectional shape of the obtained substrate with a scanning electron microscope (Hitachi High-technologies ("S-4800")), and form a 1:1 line and space pattern with a line width of 200 nm It was evaluated as "A" (good), and when the pattern was not formed, it was evaluated as "B" (bad).

(Extreme ultraviolet exposure) Expose extreme ultraviolet light to the substrate with a silicon-containing film with an average thickness of 15 nm under the condition of 200 mJ/cm ² . The device uses the extreme ultraviolet lithography beam line of the NewSUBARU radiation facility of the Institute of Advanced Industrial Science and Technology, Hyogo Prefectural University. After exposure, development was performed with isopropanol for 60 seconds. Observing the cross-sectional shape of the obtained substrate with a scanning electron microscope (Hitachi High-technologies (stock) "S-4800"), and forming a 1:1 line and space pattern with a line width of about 8 mm The next evaluation is "A" (good), and when the pattern is not formed, the evaluation is "B" (bad).

[table 5] Composition for film formation Pattern formation Electron beam exposure Extreme ultraviolet exposure Example 1 J-1 A A Example 2 J-2 A A Example 3 J-3 A A Example 4 J-4 A A Example 5 J-5 A A Example 6 J-6 A A Example 7 J-7 A A Example 8 J-8 A A Example 9 J-9 A A Example 10 J-10 - - Example 11 J-11 - - Example 12 J-12 - - Example 13 J-13 - - Example 14 J-14 - - Comparative example 1 j-1 B B Comparative example 2 j-2 B B Comparative example 3 j-3 B B Comparative example 4 j-4 - - Comparative example 5 j-5 - - Comparative example 6 j-6 - -

According to the results of Table 5, the silicon-containing film formed from the film-forming composition in the example has good pattern formation even in the case of electron beam exposure and extreme ultraviolet exposure. In contrast, the silicon-containing film formed from the film-forming composition in the comparative example had poor pattern formation. [Industrial availability]

According to the film-forming composition and the method of manufacturing a semiconductor substrate of the present invention, it is possible to form a film with excellent embedding properties, flatness, and resistance to oxygen-based gas etching, and furthermore, resistance to organic solvents, peelability of acidic liquids, and pattern formation. Containing silicon film. Therefore, these inventions can be suitably used for the manufacture of semiconductor elements which are expected to be further miniaturized in the future.

1: Silicon substrate 2: Silicon film a: Non-groove pattern part b: The central part of the groove pattern

Fig. 1 is a schematic cross-sectional view for explaining the flatness evaluation method.

1: Silicon substrate

2: Silicon film

a: Non-groove pattern part

b: The central part of the groove pattern

Claims (10)

A composition for forming a film, comprising polysilane and a solvent, the polysilane having two or more first structural units represented by the following formula (1);

In the formula (1), R ¹ is a hydrogen atom or a monovalent chain organic group having 1 to 20 carbons; R ² is a hydrogen atom, a hydroxyl group, or a monovalent chain organic group having 1 to 20 carbons. The film formation composition according to claim 1, wherein R ^{2 in} the formula (1) is -OR ^A , and R ^A is a hydrogen atom or a monovalent chain organic group having 1 to 20 carbon atoms. The film of the composition for two requests, wherein R ^A is a divalent chain hydrocarbon group or a hydrogen atom having 1 to 20 carbon atoms is formed. The film formation composition according to any one of claims 1 to 3, wherein R ^{1 in} the formula (1) is a hydrogen atom or a monovalent chain hydrocarbon group having 1 to 20 carbon atoms. The film formation composition according to any one of claims 1 to 3, wherein the polysilane further has a second structural unit represented by the following formula (2);

In the formula (2), R ³ is a hydrogen atom or a monovalent organic group having 1 to 20 carbons; R ⁴ is a monovalent organic group having 3 to 20 carbons including a ring structure. A method for manufacturing a semiconductor substrate includes the step of directly or indirectly applying the film formation composition according to any one of claims 1 to 3 on the substrate. The method of manufacturing a semiconductor substrate according to claim 6, wherein the substrate is a substrate with a pattern formed, and in the coating step, the film forming composition is directly applied to the pattern side of the substrate . The method for manufacturing a semiconductor substrate according to claim 6 or 7, which further comprises after the coating step The step of etching at least a part of the silicon-containing film formed by the coating step. The method for manufacturing a semiconductor substrate according to claim 6 or 7, further comprising after the coating step: A step of directly or indirectly coating a resist composition on the silicon-containing film formed by the coating step; A step of exposing the resist film formed by the step of applying the resist composition; The step of developing the exposed resist film; and The step of etching the silicon-containing film using the resist pattern formed by the development step as a mask. The method for manufacturing a semiconductor substrate according to claim 6 or 7, further comprising after the coating step: A step of exposing the silicon-containing film formed by the coating step with radiation; and The step of developing the exposed silicon-containing film.

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