JP6741957B2 - Film forming material for resist process and pattern forming method - Google Patents

Description

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

For pattern formation of semiconductor devices, etc., a resist process in which a resist film laminated on a substrate to be processed through an organic antireflection film is exposed and developed and the obtained resist pattern is used as a mask for etching is often used. Has been done. In such a resist process, a phenomenon in which the resist pattern is peeled off during or after development is likely to occur due to higher integration of semiconductor elements and the like, that is, miniaturization of the resist pattern. Further, the difference in etching rate between the resist film and the organic antireflection film is small. For this reason, with the miniaturization and thinning of the resist film, there is a disadvantage that the substrate to be processed coated with the organic antireflection film cannot be finely processed by etching using the resist pattern as a mask.

Therefore, a multilayer resist process technology in which an inorganic resist intermediate film is provided between a resist film and an organic antireflection film is being studied (see International Publication No. 2006/126406). In this multilayer resist process, the resist intermediate film is first etched using the resist pattern as a mask, the resist underlayer film is etched using the obtained resist intermediate film pattern as a mask, and the substrate to be processed is patterned using the resist underlayer film pattern as a mask. This is a method of etching.

On the other hand, as a technique for enhancing the resolution by utilizing the characteristics of the chemically amplified resist material, a technique for forming an exposed portion in a pattern by using an organic solvent having a polarity lower than that of an alkaline aqueous solution as a developing solution has been disclosed (Japanese Patent Laid-Open No. 2000-2000). -199953 gazette). Since the properties of the resist remaining as a pattern are different between the negative development process in which the exposed portion remains as a pattern after development and the positive development process in which the unexposed portion remains as a pattern after development, a multilayer resist process suitable for each process Resist interlayers are generally different.

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

As the pattern becomes finer, higher performance is required for the resist intermediate film.
The present invention has been made based on the above circumstances, and it is possible to form a resist intermediate film (silicon-containing film) which has excellent adhesion to a resist film, has a good resist pattern shape, and is less likely to fall. It is to provide a film forming material for a resist process, a pattern forming method using the same, and a polymer suitable as such a film forming material for a resist process.

MEANS TO SOLVE THE PROBLEM This invention made|formed in order to solve the said subject is the polymer which has the structural unit derived from the silane monomer which has two or more protected alcoholic hydroxyl groups, and the film forming material for resist processes containing an organic solvent. is there.

Another invention made to solve the above-mentioned problems is a film forming material for a resist process, a step of forming a silicon-containing film on at least one surface side of a substrate, and a polymer having an acid dissociable group, With a radiation-sensitive resin composition containing a radiation-sensitive acid generator, on the surface side of the silicon-containing film opposite to the substrate, a step of forming a resist film, a step of exposing the resist film, and the exposure And a step of developing the formed resist film.

（式（１）中、
Ｒ^１は、保護された２つ以上のアルコール性水酸基を含む１価の有機基、又は保護された１つのアルコール性水酸基を含む１価の有機基である。
Ｒ^２は、保護された２つ以上のアルコール性水酸基を含む１価の有機基、保護された１つのアルコール性水酸基を含む１価の有機基、水素原子、ヒドロキシ基、又は保護されたアルコール性水酸基を有さない置換若しくは非置換の炭素数１〜２０の１価の炭化水素基である。ａは、０又は１である。但し、Ｒ^１が保護された１つのアルコール性水酸基を含む１価の有機基である場合は、ａは１である。
Ｒ^３は、保護されたアルコール性水酸基を有さない、光吸収性基を有する１価の有機基である。
Ｒ^４は、水素原子、ヒドロキシ基、保護されたアルコール性水酸基を有さない置換又は非置換の炭素数１〜２０の１価の炭化水素基である。ｂは、０又は１である。
Ｒ^５は、保護されたアルコール性水酸基を有さない、非光吸収性の置換若しくは非置換の１価の脂肪族炭化水素基である。ｃは、０〜２の整数である。ｃが２の場合、複数のＲ^５は、同一でも異なっていてもよい。
ｄは、上記重合体を構成する全構造単位に対する構造単位Ｕ_Ｘのモル比率を表す。
ｅは、上記重合体を構成する全構造単位に対する構造単位Ｕ_Ｙのモル比率を表す。
ｆは、上記重合体を構成する全構造単位に対する構造単位Ｕ_Ｚのモル比率を表す。
ｄ、ｅ及びｆは、それぞれ０＜ｄ＜１、０≦ｅ＜１及び０≦ｆ＜１を満たし、かつｄ＋ｅ＋ｆ≦１である。）Another invention made to solve the above problems is a polymer having a structure represented by the following formula (1).

(In formula (1),
R ¹ is a monovalent organic group containing two or more protected alcoholic hydroxyl groups or a monovalent organic group containing one protected alcoholic hydroxyl group.
R ² is a monovalent organic group containing two or more protected alcoholic hydroxyl groups, a monovalent organic group containing one protected alcoholic hydroxyl group, a hydrogen atom, a hydroxy group, or a protected alcoholic group. It is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms and having no hydroxyl group. a is 0 or 1. However, a is ¹ when R ¹ is a monovalent organic group containing one protected alcoholic hydroxyl group.
R ³ is a monovalent organic group having a light absorbing group, which does not have a protected alcoholic hydroxyl group.
R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which does not have a hydrogen atom, a hydroxy group, or a protected alcoholic hydroxyl group. b is 0 or 1.
R ⁵ is a non-light-absorbing substituted or unsubstituted monovalent aliphatic hydrocarbon group having no protected alcoholic hydroxyl group. c is an integer of 0-2. When c is 2, a plurality of R ⁵ may be the same or different.
d represents the molar ratio of the structural unit U _X to all the structural units constituting the polymer.
e represents the molar ratio of the structural unit U _Y to all structural units constituting the polymer.
f represents the molar ratio of structural units U _Z to the total structural units constituting the polymer.
d, e and f satisfy 0<d<1, 0≦e<1 and 0≦f<1, respectively, and d+e+f≦1. )

According to the film forming material for a resist process of the present invention, it is possible to form a silicon-containing film that is excellent in adhesiveness with a resist film, has a good resist pattern shape, and is less likely to fall.
Moreover, the silicon-containing film obtained from the film forming material for a resist process is excellent in solvent resistance, antireflection property and etching resistance of the resist composition.
According to the pattern forming method of the present invention, an excellent resist pattern can be formed by using the excellent silicon-containing film formed of the above film forming material for resist process.
INDUSTRIAL APPLICABILITY The polymer of the present invention is preferably used as a main component of a film forming material for a resist process capable of forming a silicon-containing film which has excellent adhesiveness to a resist film and has a good resist pattern shape and less tilting. You can
Therefore, these can be suitably used for manufacturing semiconductor devices, which are expected to be further miniaturized in the future.

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

<Film forming material for resist process>
A film forming material for a resist process according to an embodiment of the present invention (hereinafter sometimes simply referred to as “film forming material”) is derived from [A] a silane monomer having two or more protected alcoholic hydroxyl groups. And a polymer having a structural unit of [B] and an organic solvent. The film-forming material may contain an optional component such as a [C] nitrogen-containing compound, a [D] acid generator, and a [E] water as long as the effects of the present invention are not impaired. However, each optional component such as the [C] nitrogen-containing compound, the [D] acid generator, and the [E] water may not be contained. Hereinafter, each component will be described in detail.

<[A] polymer>
The polymer [A] has a structural unit derived from a silane monomer having two or more protected alcoholic hydroxyl groups. When a silicon-containing film is formed from the film-forming material and a resist pattern is formed, it has excellent adhesiveness to the resist pattern due to the following reasons, and it is presumed that pattern collapse during development can be suppressed. It However, the reason why the present invention achieves the above effects is not limited to the following reasons. In the present invention, the protected alcoholic hydroxyl group is preferably an alcoholic hydroxyl group protected by an acid dissociable protective group.

The resist film laminated on the surface of the silicon-containing film is usually formed of a radiation-sensitive composition containing a radiation-sensitive acid generator (hereinafter sometimes simply referred to as “acid generator”). Therefore, acid is generated in the resist film when the resist film is exposed. At this time, also on the surface of the silicon-containing film, the alcoholic hydroxyl group of the structural unit in the [A] polymer is deprotected by the acid, and the silicon-containing film in the exposed portion (hereinafter, “resist intermediate film”, “resist lower layer”). It may also be referred to as a "membrane." The surface is hydrophilized. When performing negative development using an organic solvent as a developing solution, since the silicon-containing film surface of the exposed portion is hydrophilized as described above, a resist film (resist pattern) that is hydrophilized in the exposed portion It is presumed that the adhesion with the silicon-containing film is enhanced and the pattern collapse during development can be suppressed. In particular, since the structural unit of the polymer [A] has two or more protected alcoholic hydroxyl groups, it can be expected that the hydrophilicity can be effectively increased and the pattern collapse suppressing ability is excellent. .. Since substances with low surface energy are unevenly distributed on the gas-phase interface, when a film is formed using a polymer having a hydrophilic group such as an unprotected alcoholic hydroxyl group, this hydrophilic group is unevenly distributed on the surface. do not do. On the other hand, by using the [A] polymer having a structural unit derived from a silane monomer having two or more protected alcoholic hydroxyl groups, it is possible to effectively hydrophilize the film surface after exposure. It is presumed that the adhesiveness with the resist pattern can be improved.

The polymer [A] has, for example, a structure represented by the following formula (1).

In the above formula (1),
R ¹ is a monovalent organic group containing two or more protected alcoholic hydroxyl groups or a monovalent organic group containing one protected alcoholic hydroxyl group.
R ² is a monovalent organic group containing two or more protected alcoholic hydroxyl groups, a monovalent organic group containing one protected alcoholic hydroxyl group, a hydrogen atom, a hydroxy group, or a protected alcoholic group. It is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms and having no hydroxyl group. a is 0 or 1. However, a is ¹ when R ¹ is a monovalent organic group containing one protected alcoholic hydroxyl group.
R ³ is a monovalent organic group having a light absorbing group, which does not have a protected alcoholic hydroxyl group.
R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which does not have a hydrogen atom, a hydroxy group, or a protected alcoholic hydroxyl group. b is 0 or 1.
R ⁵ is a non-light-absorbing substituted or unsubstituted monovalent aliphatic hydrocarbon group having no protected alcoholic hydroxyl group. c is an integer of 0-2. When c is 2, a plurality of R ⁵ may be the same or different.
d represents the molar ratio of the structural unit U _X to all the structural units constituting the polymer.
e represents the molar ratio of the structural unit U _Y to all structural units constituting the polymer.
f represents the molar ratio of structural units U _Z to the total structural units constituting the polymer.
d, e and f satisfy 0<d<1, 0≦e<1 and 0≦f<1, respectively, and d+e+f≦1.

The structure represented by the above formula (1) may further have a structural unit U _Y in addition to the structural unit U _X. That is, 0<d<1 and 0<e<1 may be satisfied in the above formula (1).

By further including the structural unit U _Y in the formula (1), the substrate reflectance can be lowered by containing the light absorbing group, and a good resist pattern can be obtained.

The structure represented by the above formula (1) may further have a structural unit U _Z in addition to the structural unit U _X and the structural unit U _Y. That is, in the above formula (1), 0<d<1 and 0<f<1 may be satisfied, or 0<d<1, 0<e<1 and 0<f<1 may be satisfied. ..

By further containing the structural unit U _Z in the above formula (1), the silicon content ratio of the polymer is increased, and the oxygen gas etching resistance can be improved.

Hereinafter, each structural unit represented by the above formula (1) will be described.

[Structural unit U _X ]
The structural unit U _X is a structural unit derived from a silane monomer having two or more protected alcoholic hydroxyl groups.

(Monovalent organic group containing two or more protected alcoholic hydroxyl groups)
In the above formula (1), examples of the monovalent organic group containing two or more protected alcoholic hydroxyl groups represented by R ¹ and R ² include a group represented by the following formula (2). You can

In the above formula (2), X ¹ is a trivalent organic group having 1 to 20 carbon atoms. R ^{6 s} are each independently a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms. Y ^1's are each independently a monovalent protecting group, or two Y ^1's may be bonded to each other to form a divalent protecting group. * Indicates a binding site.

The trivalent organic group having 1 to 20 carbon atoms represented by X ¹ is a trivalent hydrocarbon group having 1 to 20 carbon atoms, and a hetero atom-containing group at the carbon-carbon or terminal of the hydrocarbon group. And a group in which a part or all of hydrogen atoms of these groups are substituted with a substituent.

Examples of the trivalent hydrocarbon group having 1 to 20 carbon atoms include a trivalent aliphatic hydrocarbon group having 1 to 20 carbon atoms and a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms. it can. Incidentally, when X ¹ is a trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms, R ⁶ are each independently a divalent hydrocarbon group having a substituted or unsubstituted 1 to 10 carbon atoms can do.

Examples of the trivalent aliphatic hydrocarbon group having 1 to 20 carbon atoms include a trivalent chain hydrocarbon group having 1 to 20 carbon atoms and a trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms. be able to.

Examples of the trivalent chain hydrocarbon group having 1 to 20 carbon atoms include alkanetriyl groups such as methanetriyl group, ethanetriyl group, propanetriyl group, butanetriyl group and pentanetriyl group,
Alkenetriyl groups such as ethenetriyl group, propenetriyl group, butenetriyl group, pentenetriyl group,
Examples thereof include an alkynetriyl group such as a propynetriyl group, a butynetriyl group and a pentintriyl group.

Examples of the trivalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include cycloalkanetriyl groups such as cyclopropanetriyl group, cyclopentanetriyl group and cyclohexanetriyl group,
Cyclopropenetriyl group, cyclopentenetriyl group, cycloalkenetriyl group such as cyclohexenetriyl group,
Examples thereof include trivalent bridged ring hydrocarbon groups such as a norbornanetriyl group, an adamantanetriyl group and a norbornenetriyl group.

Examples of the trivalent aromatic hydrocarbon group having 6 to 20 carbon atoms include a benzenetriyl group, a naphthalenetriyl group, and an anthracentriyl group.

The hetero atom-containing group refers to a group having a divalent or higher valent hetero atom in the structure. The hetero atom-containing group may have one hetero atom or two or more hetero atoms. Moreover, the hetero atom-containing group may be composed of only one hetero atom.

The hetero atom having a valence of 2 or more in the hetero atom-containing group is not particularly limited as long as it is a hetero atom having a valence of 2 or more, and examples thereof include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom and a phosphorus atom. , Boron atom and the like.

As the hetero atom-containing group, for example, a group consisting of only a hetero atom such as —O—, —S—, —SO—, —SO ₂ —, —SO ₂ O—, —SO ₃ —,
A combination of a carbon atom and a hetero atom such as -CO-, -COO-, -COS-, -CONH-, -OCOO-, -OCOS-, -OCONH-, -SCONH-, -SCSNH-, -SCSS-. Groups and the like. The carbon number of the organic group represented by X ¹ includes the carbon number of these hetero atom-containing groups. Hereinafter, the same applies to the carbon number of the organic group.

Examples of the substituent include a halogen atom, a hydroxy group, a carboxy group, a nitro group, a cyano group and the like. The carbon number of the organic group represented by X ¹ includes the carbon number of these substituents. Hereinafter, the same applies to the carbon number of the organic group.

The group represented by X ¹ is preferably a substituted or unsubstituted trivalent hydrocarbon group, more preferably a substituted or unsubstituted trivalent aliphatic hydrocarbon group, or a substituted or unsubstituted trivalent group. A chain hydrocarbon group is more preferable, a substituted or unsubstituted alkanetriyl group is still more preferable, and a linear alkanetriyl group is still more preferable.

A group containing an oxygen atom or a sulfur atom between carbon and carbon of these hydrocarbon groups is also preferable. The lower limit of the number of carbon atoms of the group represented by X ¹ is 1, but is preferably 2 and more preferably 3. On the other hand, the upper limit of the carbon number of the group represented by X ¹ is preferably 20, more preferably 10, and even more preferably 6.

Examples of the substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶ include a divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms and a divalent hydrocarbon group having 6 to 10 carbon atoms. And aromatic hydrocarbon groups, groups obtained by substituting a part or all of hydrogen atoms of these groups with a substituent, and the like.

Examples of the divalent aliphatic hydrocarbon group having 1 to 10 carbon atoms include a divalent chain hydrocarbon group having 1 to 10 carbon atoms and a divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. be able to.

Examples of the divalent chain hydrocarbon group having 1 to 10 carbon atoms include alkanediyl groups such as methanediyl group, ethanediyl group, propanediyl group, butanediyl group and pentanediyl group,
Alkenediyl groups such as ethenediyl group, propenediyl group, butenediyl group, pentenediyl group,
Examples thereof include alkynediyl groups such as ethynediyl group, propynediyl group, butynediyl group and pentindiyl group.

Examples of the divalent alicyclic hydrocarbon group having 3 to 10 carbon atoms include cycloalkanediyl groups such as cyclopropanediyl group, cyclopentanediyl group and cyclohexanediyl group,
Cyclopropenediyl group, cyclopentenediyl group, cycloalkenediyl group such as cyclohexenediyl group,
Examples thereof include a divalent bridged ring hydrocarbon group such as a norbornanediyl group, an adamantanediyl group and a norbornenediyl group.

Examples of the divalent aromatic hydrocarbon group having 6 to 10 carbon atoms include benzenediyl group, naphthalenediyl group and anthracenediyl group.

Examples of the substituent of the hydrocarbon group represented by R ⁶ include the same groups as those exemplified as the substituent of the group represented by X ¹ .

As R ⁶ , a single bond and a divalent chain hydrocarbon group having 1 to 10 carbon atoms are preferable. Among the divalent chain hydrocarbon groups having 1 to 10 carbon atoms, the divalent chain hydrocarbon group having 1 to 4 carbon atoms is more preferable, and the divalent chain hydrocarbon group having 1 to 2 carbon atoms is More preferably, the methanediyl group is particularly preferable.

The two R ⁶ are preferably bonded to the same carbon atom in X ¹ . Further, X ¹ is a linear alkanetriyl group or a group containing an oxygen atom or a sulfur atom between the carbon and carbon, and two R ⁶ are bonded to the terminal carbon atom of X ^1. Is more preferable.

The monovalent protecting group represented by Y ¹ is not particularly limited as long as it is a group that can be deprotected by an acid or the like, but is preferably a group that can be deprotected by an acid, for example, R ^a —, R ^The group represented by a-CO-, ^Ra- O-C( ^Rb ) _2- and ^Ra- O-CO- can be mentioned.

In each of the above formulas, ^Ra is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. The two R ^b are each independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^b may combine with R ^a to form a part of a ring structure.

When Y ¹ is ^a group represented by R ^a , an ether type protective structure is formed. When Y ¹ is ^a group represented by R ^a —CO—, it forms an ester type protected structure such as an alkylcarbonyloxy group protected group. When Y ¹ is ^a group represented by ^Ra- OC( ^Rb ) _2- , it forms an acetal-type protective structure.

The substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ^a and R ^b is a monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms, and 6 to 10 carbon atoms. And monovalent aromatic hydrocarbon groups, groups obtained by substituting a part or all of hydrogen atoms of these groups with a substituent, and the like. Examples of the monovalent aliphatic hydrocarbon group having 1 to 10 carbon atoms include a monovalent chain hydrocarbon group having 1 to 10 carbon atoms and a monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms. be able to.

Examples of the monovalent chain hydrocarbon group having 1 to 10 carbon atoms include alkyl groups such as methyl group, ethyl group, propyl group, butyl group and pentyl group, ethenyl group, propenyl group, butenyl group, pentenyl group and the like. Examples thereof include alkynyl groups such as alkenyl groups and ethynyl groups.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 10 carbon atoms include cycloalkyl groups such as cyclopropyl group, cyclopentyl group and cyclohexyl group, cycloalkenyl groups such as cyclopropenyl group, cyclopentenyl group and cyclohexenyl group. And monovalent bridged ring hydrocarbon groups such as norbornyl group and adamantyl group.

Examples of the monovalent aromatic hydrocarbon group having 6 to 10 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group and naphthyl group, and aralkyl groups such as benzyl group and phenethyl group.

Examples of the substituent of the hydrocarbon group represented by R ^a and R ^b include the same groups as those exemplified as the substituent of the group represented by X ¹ .

As R ^a , an alkyl group and a cycloalkyl group are preferable, a secondary and tertiary alkyl group and a cycloalkyl group are more preferable, and a tertiary alkyl group is further preferable, from the standpoint of elimination. , T-butyl groups are particularly preferred. As R ^b , a hydrogen atom and an alkyl group are preferable, and a hydrogen atom and an alkyl group having 1 to 4 carbon atoms are more preferable.

Examples of the divalent protective group formed by the two Y ¹ bonded to each other include a substituted or unsubstituted divalent hydrocarbon group. Examples of the substituted or unsubstituted divalent hydrocarbon group include the groups exemplified as the group represented by R ⁶ . The preferred form of the divalent protecting group is the same as the preferred form of the divalent protecting group represented by Y ^1b described later.

The monovalent organic group containing two or more protected alcoholic hydroxyl groups represented by R ¹ and R ² is preferably a group represented by the following formula (2a) or (2b).

In the above formulas (2a) and (2b), R ⁷ is a divalent organic group having 1 to 10 carbon atoms. p is an integer of 1 to 5. q is an integer of 0-5. Y ^1a's are each independently a monovalent protecting group. Y ^1b is a divalent protecting group.

The divalent organic group having 1 to 10 carbon atoms represented by R ⁷ is a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms represented by R ⁶ , and this hydrocarbon group. And a group containing a hetero atom-containing group at the carbon-carbon or terminal thereof, a group in which a part or all of the hydrogen atoms of these groups are substituted with a substituent, and the like. Examples of the substituent include the same as those exemplified as the substituent of the group represented by X ¹ .

Examples of the divalent organic group having 1 to 10 carbon atoms represented by R ⁷ include a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms and carbon-carbon of the hydrocarbon group. A group containing a hetero atom is preferable, and a substituted or unsubstituted alkanediyl group having 1 to 10 carbon atoms and a group containing a hetero atom at the carbon-carbon or terminal of this alkanediyl group are more preferable, and a substituted or unsubstituted carbon atom. A straight-chain alkanediyl group of formulas 1 to 6 and a group containing an oxygen atom or a sulfur atom at the carbon-carbon or terminal of the alkanediyl group are more preferable.

In addition, in the above-mentioned linear alkanediyl group, it is preferable to have two bonding positions at both ends.

The carbon number of the divalent organic group represented by R ⁷ is more preferably 1 to 3. By setting the carbon number in the above range, it is possible to further improve the oxygen etching resistance of the obtained silicon-containing film.

The above p is an integer of 1 to 5, preferably 1 and 2, and more preferably 1.

The above q is an integer of 0 to 5, but 0 and 1 are preferable, and 0 is more preferable.

Examples of the monovalent protecting group represented by Y ^1a include R ^a −, R ^a —CO—, R ^a —O—C(R ^b ) ₂ — and R ^a described in the description of formula (2). A group represented by -O-CO- is preferable. The details of these groups and more preferable groups among these groups are as described in the description of formula (2).

Examples of the divalent protecting group represented by Y ^1b include a substituted or unsubstituted divalent hydrocarbon group. Examples of the substituted or unsubstituted divalent hydrocarbon group include the groups exemplified as the group represented by R ⁶ . As the substituted or unsubstituted divalent hydrocarbon group, a substituted or unsubstituted methanediyl group and a group represented by the following formula (4) are preferable. When the divalent protecting group represented by Y ^1b is a substituted or unsubstituted methanediyl group or a group represented by the following formula (4), it forms an acetal-type protecting group.

In the above formula (4), n is an integer of 0 to 4. R ^c is each independently a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^d's are each independently a hydrogen atom or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms. Two R ^d's may be bonded to each other to form a carbon ring structure having 4 to 12 carbon atoms (alicyclic structure, aromatic ring structure or ring structure of a combination thereof) with the carbon chain to which they are bonded. .. * Indicates a binding position.

Examples of the substituted or unsubstituted monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R ^c and R ^d include those exemplified as the group represented by R ^a .

As R ^c , an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, and a methyl group is further preferable.

As R ^d , an alkyl group is preferable, an alkyl group having 1 to 4 carbon atoms is more preferable, and a methyl group is further preferable. Although n is an integer of 0 to 4, 0 and 1 are preferable, and 0 is more preferable.

Examples of the substituent that the methanediyl group represented by Y ^1b may have include a hydrocarbon group in addition to the above-mentioned halogen atom and the like, and a hydrocarbon group is preferable, and a hydrocarbon group having 1 to 10 carbon atoms is preferable. Hydrocarbon groups are more preferred. This hydrocarbon group may be an aliphatic hydrocarbon group such as an alkyl group or an aromatic hydrocarbon group such as a phenyl group. Also, two substituents may be bonded to each other to form a ring structure with the carbon atom to which they are bonded. Examples of the ring structure include an alicyclic group having 3 to 20 carbon atoms and an aromatic group. When Y ^1b is a methanediyl group which may have a substituent, a methanediyl group having two hydrocarbon groups as a substituent is preferable. The two hydrocarbon groups may be bonded to each other to form an alicyclic structure.

It is preferable that Y ¹ (Y ^1a and Y ^1b ), which is a protective group for an alcoholic hydroxyl group, forms an acetal-type or ester-type protecting group from the standpoint of elimination by acid and the like.

In the formula (1), a is 0 or 1, but 0 is preferable. By setting a to 0, the oxygen etching resistance of the obtained silicon-containing film can be increased.

(Monovalent organic group containing one protected alcoholic hydroxyl group)
In the above formula (1), the monovalent organic group containing one protected alcoholic hydroxyl group represented by R ¹ and R ² is not particularly limited, but a group represented by the following formula (3) may be used. Can be mentioned.

In the above formula (3), X ² is a single bond or a divalent organic group having 1 to 20 carbon atoms. Y ² is a monovalent protecting group. * Indicates a binding site.

Examples of the divalent organic group having 1 to 20 carbon atoms represented by X ² include those exemplified as the divalent organic group represented by R ⁷ . As the group represented by X ² , a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, and a group containing a hetero atom at the carbon-carbon end of this hydrocarbon group are preferable, and substituted. Or, an unsubstituted alkanediyl group having 1 to 10 carbon atoms and a group containing a hetero atom between carbon and carbon of the alkanediyl group are more preferable, and a substituted or unsubstituted linear alkanediyl group having 1 to 6 carbon atoms. A group and a group containing an oxygen atom or a sulfur atom between the carbon and the carbon of the alkanediyl group are more preferable.

In addition, in the above-mentioned linear alkanediyl group, it is preferable to have two bonding positions at both ends.

Examples of the monovalent protecting group represented by Y ² include those described as the monovalent protecting group represented by Y ¹ and Y ^1a . The preferable group of the monovalent protecting group represented by Y ² is also the same as those of Y ¹ and Y ^1a . That, ^R a and described in the description of formula ^{(2) -, R a -CO-} , R a -O-C (R b) 2 - and groups represented by ^R a -O-CO- preferred. Specific structures of these groups, and more preferable structures are also as described above.

It is preferable that Y ² which is a protective group for an alcoholic hydroxyl group forms an acetal-type or ester-type protecting group from the viewpoint of acid releasability and the like.

The substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which does not have a protected alcoholic hydroxyl group and is represented by R ² , is the substituted or non-substituted one represented by R ^a and R ^b. Examples thereof include the same groups as those exemplified as the substituted monovalent hydrocarbon group having 1 to 10 carbon atoms.

R ¹ in the above formula (1) is preferably a monovalent organic group containing two or more protected alcoholic hydroxyl groups.

The structural unit U _X , in which R ¹ is a monovalent organic group containing two or more protected alcoholic hydroxyl groups, includes two or more protected alcoholic hydroxyl groups and a hydrolyzable group bonded to a silicon atom. It is obtained by hydrolysis condensation of the silane monomer (I) having Examples of the hydrolyzable group include an alkoxy group such as a methoxy group and an ethoxy group, an acyloxy group such as an acetoxy group, and a halogen atom such as a chlorine atom. The silane monomer (I) preferably has 2 or 3 hydrolyzable groups, and more preferably 3 hydrolyzable groups.

Specific examples of the silane monomer (I) include compounds represented by the following formulas (i-1) to (i-27). The silane monomer (I) may be used alone or in combination of two or more.

[A] The lower limit of the content ratio (molar ratio d) of the structural unit derived from the silane monomer having two or more protected alcoholic hydroxyl groups in the polymer, specifically the structural unit U _X is [A] 0.1 mol% is preferable, 1 mol% is more preferable, 3 mol% is still more preferable with respect to all the structural units which comprise a polymer. On the other hand, the upper limit is preferably 40 mol%, more preferably 30 mol%, further preferably 25 mol%, particularly preferably 20 mol%. By setting the content ratio of the structural unit U _X to the above lower limit or more, the hydrophilicity of the surface of the silicon-containing film after exposure is further enhanced, and the adhesiveness of the resist pattern can be further enhanced. On the other hand, when the content ratio of the structural unit U _X is not more than the above upper limit, other structural units can be sufficiently contained, and antireflection property, etching resistance and the like can be exhibited in a well-balanced manner.

The content ratio of the structural unit in the [A] polymer can be regarded as the same as the ratio of the charged amount of the corresponding silane monomer when the [A] polymer is synthesized by hydrolytic condensation of the silane monomer.

[Structural unit U _Y ]
The monovalent organic group having a light-absorbing group, which does not have a protected alcoholic hydroxyl group and is represented by R ³ , is an alkenyl group having 2 to 10 carbon atoms or an aromatic group having 6 to 20 ring members. A monovalent group containing a carbon ring or an aromatic heterocycle having 4 to 20 ring members can be mentioned. Some or all of the hydrogen atoms contained in these groups may be substituted with a substituent.

Examples of the alkenyl group having 2 to 10 carbon atoms include ethenyl group, 1-propen-1-yl group, 1-propen-2-yl group, 1-propen-3-yl group, 1-buten-1-yl group. Group, 1-buten-2-yl group, 1-buten-3-yl group, 1-buten-4-yl group, 2-buten-1-yl group, 2-buten-2-yl group, 1-pentene -5-yl group, 2-penten-1-yl group, 2-penten-2-yl group, 1-hexen-6-yl group, 2-hexen-1-yl group, 2-hexen-2-yl group Etc. can be mentioned.

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

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

As R ³ , a group containing an aromatic carbocycle is preferable, an aryl group is more preferable, and a phenyl group and a methylphenyl group are further preferable.

The substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms and having no protected alcoholic hydroxyl group represented by R ⁴ is the substituted or unsubstituted 1 represented by R ^a. The same groups as those exemplified as the valent hydrocarbon group can be mentioned.

As b above, 0 is preferable.

Examples of the silane monomer that gives the structural unit U _Y include phenyltrimethoxysilane, phenyltriethoxysilane, methylphenyltrimethoxysilane, and vinyltrimethoxysilane.

The lower limit of the content ratio (molar ratio e) of the structural unit U _{Y in} the [A] polymer is preferably 0.1 mol% and more preferably 1 mol% with respect to all the structural units constituting the [A] polymer. Preferably, 3 mol% is more preferable, and 5 mol% is particularly preferable. On the other hand, the upper limit is preferably 40 mol%, more preferably 30 mol%, further preferably 20 mol%, particularly preferably 15 mol%. By setting the content ratio of the structural unit U _{Y in} the above range, it is possible to enhance the adhesion of the resist pattern and the like, and to exert the antireflection property and the like in a better and balanced manner.

[Structural unit U _Z ]
As the non-light-absorbing substituted or unsubstituted monovalent aliphatic hydrocarbon group having no protected alcoholic hydroxyl group represented by R ⁵ , the substituted or unsubstituted represented by R ^{a can} be used. Examples of the monovalent hydrocarbon group include a monovalent chain hydrocarbon group and a monovalent alicyclic hydrocarbon group. Some or all of the hydrogen atoms contained in these chain hydrocarbon groups and alicyclic hydrocarbon groups may be substituted with a substituent. The carbon number of the group represented by R ⁵ can be, for example, 1 to 10, and in the case of an alicyclic hydrocarbon group, the carbon number can be 3 to 10.

As R ⁵ , a chain hydrocarbon group is preferable, a chain hydrocarbon group having 1 to 4 carbon atoms is more preferable, and a methyl group is further preferable.

In the above formula (1), in the structural unit U _Z , c is preferably 0 or 1, and more preferably 0.

Examples of the silane monomer that gives the structural unit U _Z include tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and dimethyldimethoxysilane.

The lower limit of the content ratio (molar ratio f) of the structural unit U _{Z in} the polymer [A] is preferably 20 mol%, more preferably 40 mol%, based on all the structural units constituting the polymer [A]. 60 mol% is more preferable, and 70 mol% is particularly preferable. On the other hand, the upper limit is preferably 95 mol%, more preferably 90 mol%, and further preferably 85 mol%. By setting the content ratio of the structural unit U _{Z in} the above range, it is possible to further improve solvent resistance, etching resistance and the like while improving the adhesiveness of the resist pattern and the like.

The polymer [A] may have a structural unit other than the structural unit U _X , the structural unit U _Y, and the structural unit U _Z. Other structural units include structural units derived from silane monomers containing a plurality of silicon atoms such as hexamethoxydisilane, bis(trimethoxysilyl)methane, and polydimethoxymethylcarbosilane. When the polymer [A] has other structural units, the upper limit of the content of the other structural units is preferably 20 mol% with respect to all structural units constituting the polymer [A], and 10 mol% Is more preferable, 3 mol is further preferable, and 1 mol% is particularly preferable. That is, the lower limit of the sum (d+e+f) of d, e and f in the formula (1) is preferably 0.8, more preferably 0.9, further preferably 0.97, and particularly preferably 0.99.

The lower limit of the content of the polymer [A] is preferably 50% by mass, more preferably 70% by mass, further preferably 80% by mass, particularly preferably 90% by mass, based on the total solid content of the film-forming material. preferable. As a maximum of the above-mentioned content, 99 mass% is preferred and 97 mass% is more preferred. The total solid content of the film-forming material means the sum of components other than [B] organic solvent and [E] water. The polymer [A] may be contained alone or in combination of two or more.

The lower limit of the polystyrene-equivalent weight average molecular weight (Mw) of the polymer [A] by size exclusion chromatography is preferably 1,000, more preferably 1,300, and even more preferably 1,500. As the upper limit of the Mw, 100,000 is preferable, 30,000 is more preferable, 10,000 is further preferable, and 4,000 is particularly preferable.

The Mw of the [A] polymer in the present specification uses, for example, a GPC column of Tosoh Corporation (two "G2000HXL", one "G3000HXL" and one "G4000HXL"), and a flow rate of 1.0 mL/min. It is a value measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard under analysis conditions of eluting solvent: tetrahydrofuran and column temperature: 40°C.

The polymer [A] can be produced by a method of hydrolyzing and condensing the hydrolyzable silane monomer corresponding to each structural unit described above. The hydrolysis condensation of the silane monomer can be performed by a conventionally known method.

When synthesizing the polymer [A], the upper limit of the content of the alcohol solvent having a boiling point of 100° C. or less in the solvent in the reaction liquid is preferably 20% by mass, and more preferably 5% by mass. An alcoholic solvent having a boiling point of 100° C. or less may be generated during the hydrolytic condensation of each of the above silane monomers, and the content of the solvent in the reaction solution is 20% by mass or less, preferably 5% by mass or less. Therefore, it is preferable to remove it by distillation or the like.

<[B] organic solvent>
As the organic solvent [B], any solvent that can dissolve or disperse the [A] polymer (polysiloxane) and optional components can be used.

Examples of the organic solvent [B] include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents and the like. The organic solvent [B] may be used alone or in combination of two or more.

Examples of alcohol solvents 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 the ketone-based solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-iso-butyl ketone, cyclohexanone, and the like.

As the ether solvent, for example, 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, and acetic acid. Propylene glycol monoethyl ether, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethyl propionate, n-butyl propionate, methyl lactate, ethyl lactate and the like can be mentioned.

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

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

Examples of the ether solvent and ester solvent 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, and propylene glycol monopropyl acetate. Examples include ether and the like. Of these, propylene glycol monomethyl ether acetate is particularly preferable.

As the organic solvent [B], one type may be used alone, or two or more types may be used in combination.

As a minimum of content of [B] organic solvent in the film formation material, 80 mass% is preferred, 90 mass% is more preferred, and 95 mass% is still more preferred. As a maximum of the above-mentioned content, 99 mass% is preferred and 98 mass% is more preferred.

<[C] nitrogen-containing compound>
[C] Nitrogen-containing compound is a compound having a nitrogen atom. When the film forming material contains the [C] nitrogen-containing compound, the shape of the resist pattern formed in the resist process can be further improved while maintaining the above effect. Further, curing can be accelerated, and as a result, the strength of the obtained silicon-containing film can be further increased. The nitrogen-containing compound [C] may be used alone or in combination of two or more.

As the nitrogen-containing compound [C], a compound having a basic amino group and a compound which produces a basic amino group by the action of an acid or the action of heat are preferable.

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

Examples of the amine compound include mono(cyclo)alkylamines, di(cyclo)alkylamines, tri(cyclo)alkylamines, substituted alkylaniline or a derivative thereof, ethylenediamine, N,N,N′,N′- Tetramethylethylenediamine, tetramethylenediamine, hexamethylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminobenzophenone, 4,4'-diaminodiphenylamine, 2,2-bis( 4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2-(4-aminophenyl)-2-(3-hydroxyphenyl)propane, 2-(4- Aminophenyl)-2-(4-hydroxyphenyl)propane, 1,4-bis(1-(4-aminophenyl)-1-methylethyl)benzene, 1,3-bis(1-(4-aminophenyl) -1-Methylethyl)benzene, bis(2-dimethylaminoethyl)ether, bis(2-diethylaminoethyl)ether, 1-(2-hydroxyethyl)-2-imidazolidinone, 2-quinoxalinol, N, Examples thereof include N,N′,N′-tetrakis(2-hydroxypropyl)ethylenediamine, N,N,N′,N″N″-pentamethyldiethylenetriamine and the like.

Examples of the amide group-containing compound include Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, Nt-butoxycarbonyl-2-carboxypyrrolidine and the like. Nt-butoxycarbonyl group-containing amino compounds, Nt-amyloxycarbonyl-4-hydroxypiperidine and other Nt-amyloxycarbonyl group-containing amino compounds, N-(9-anthrylmethyloxycarbonyl)piperidine and the like N-(9-anthrylmethyloxycarbonyl) group-containing amino compound, formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, Pyrrolidone, N-methylpyrrolidone, N-acetyl-1-adamantylamine and the like can be mentioned.

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

Examples of the nitrogen-containing heterocyclic compound include imidazoles; pyridines; piperazines; pyrazine, pyrazole, pyridazine, quinazoline, purine, pyrrolidine, piperidine, piperidine ethanol, 3-(N-piperidino)-1,2-propanediol, Morpholine, 4-methylmorpholine, 1-(4-morpholinyl)ethanol, 4-acetylmorpholine, 3-(N-morpholino)-1,2-propanediol, 1,4-dimethylpiperazine, 1,4-diazabicyclo[2 2.2.2] Octane and the like can be mentioned.

Among these, amide group-containing compounds and nitrogen-containing heterocyclic compounds are preferable, and amide group-containing compounds are more preferable. As the amide group-containing compound, Nt-butoxycarbonyl group-containing amino compounds, Nt-amyloxycarbonyl group-containing amino compounds and N-(9-anthrylmethyloxycarbonyl) group-containing amino compounds are preferable, and N- t-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-2-carboxy-4-hydroxypyrrolidine, Nt-butoxycarbonyl-2-carboxy-pyrrolidine, Nt-amyloxycarbonyl-4-hydroxy More preferred are piperidine and N-(9-anthrylmethyloxycarbonyl)piperidine.

When the film forming material contains a [C] nitrogen-containing compound, the lower limit of the content of the [C] nitrogen-containing compound is preferably 0.1 part by mass relative to 100 parts by mass of the [A] polymer, 1 part by mass is more preferable, and 3 parts by mass is further preferable. The upper limit of the content is preferably 30 parts by mass, more preferably 15 parts by mass, and even more preferably 10 parts by mass.

However, as described above, the film forming material may not substantially contain the [C] nitrogen-containing compound, and the upper limit of the content of the [C] nitrogen-containing compound is 100 mass of the [A] polymer. The amount may be 5 parts by mass, 1 part by mass, or 0.1 part by mass.

<[D] acid generator>
The acid generator [D] is a compound that generates an acid upon irradiation with radiation such as ultraviolet rays and/or heating. When the film-forming material contains the acid generator [D], the surface of the obtained silicon-containing film can be further hydrophilized. Examples of the acid generator [D] include onium salts such as sulfonium salts, tetrahydrothiophenium salts and iodonium salts, N-sulfonyloxyimide compounds, organic halogen compounds, sulfone compounds such as disulfones and diazomethanesulfones. To be

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

Examples of the tetrahydrothiophenium salt include the tetrahydrothiophenium salt described in paragraph [0111] of JP-A-2014-037386, and more specifically, 1-(4-n-butoxynaphthalene-1- 1-(4-n-butoxynaphthalen-1-yl)tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1-(4-n-butoxynaphthalen-1-yl) Tetrahydrothiophenium 2-bicyclo[2.2.1]hept-2-yl-1,1,2,2-tetrafluoroethane sulfonate etc. are mentioned.

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

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

Moreover, as the [D] acid generator, compounds represented by the following formulas (4-1) to (4-7) which are sulfonium salts (hereinafter, referred to as “compounds (4-1) to (4-7)”). (Also referred to as) and the like.

These [D] acid generators may be used alone or in combination of two or more.

As the acid generator [D], onium salts are preferable, sulfonium salts are more preferable, compounds (4-1) to (4-7) are further preferable, and compound (4-1) is particularly preferable.

When the film-forming material contains the [D] acid generator, the lower limit of the content of the [D] acid generator is preferably 0.1 part by mass relative to 100 parts by mass of the [A] polymer, 0.5 parts by mass is more preferable, 1 part by mass is further preferable, and 3 parts by mass is further preferable. The upper limit of the content is preferably 30 parts by mass, more preferably 20 parts by mass, even more preferably 15 parts by mass, still more preferably 10 parts by mass.

However, as described above, the film forming material may not substantially contain the [D] acid generator, and the upper limit of the content of the [D] acid generator is 100 mass of the [A] polymer. The amount may be 5 parts by mass, 1 part by mass, or 0.1 part by mass.

<[E] water>
The film forming material may contain [E] water, if necessary. When the film-forming material further contains [E] water, the [A] polymer and the like are hydrated, so that the storage stability is improved. Further, by containing [E] water, curing during film formation is promoted, and a dense silicon-containing film can be obtained.

When the film forming material contains [E] water, the lower limit of the content of [E] water is preferably 0.01% by mass, more preferably 0.1% by mass, and further preferably 0.3% by mass. preferable. The upper limit of the content is preferably 10% by mass, more preferably 5% by mass, further preferably 2% by mass, and particularly preferably 1% by mass. If the water content exceeds the above upper limit, the storage stability may be deteriorated or the uniformity of the coating film may be deteriorated.

<Other optional ingredients>
The film forming material may contain other optional components in addition to the components [A] to [E]. Other optional components include, for example, surfactants, colloidal silica, colloidal alumina, organic polymers and the like. When the film-forming material contains other optional components, the upper limit of the content is preferably 2 parts by mass and more preferably 1 part by mass with respect to 100 parts by mass of the [A] polymer.

<Preparation Method of Film Forming Material for Resist Process>
The method for preparing the film-forming material is not particularly limited, and includes, for example, [A] polymer, [B] organic solvent and, if necessary, [C] nitrogen-containing compound, [D] acid generator, [E] water and the like. It can be prepared by mixing at a predetermined ratio and preferably filtering the obtained mixed solution with a filter having a pore size of 0.2 μm.

As a minimum of solid content concentration of the film formation material, 0.01 mass% is preferred, 0.1 mass% is more preferred, 0.5 mass% is more preferred, and 1 mass% is especially preferred. As a maximum of the above-mentioned solid content concentration, 20 mass% is preferred, 10 mass% is more preferred, 5 mass% is still more preferred, and 3 mass% is especially preferred. 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 firing the film forming material at 250° C. for 30 minutes, and the mass of the solid content is defined as the mass of the film forming material. It is a value (mass %) calculated by dividing.

<Applications and silicon-containing film>
The silicon-containing film obtained from the film forming material has high adhesiveness with a resist film (resist pattern) and the like, and when used as a resist intermediate film, a resist pattern having a good shape can be formed on this surface. Therefore, the film-shaped material can be preferably used as a resist intermediate film forming material in a resist process, particularly a multilayer resist process. Among the multi-layer resist processes, it is particularly preferably used in pattern formation using the multi-layer resist process in a region finer than 90 nm (ArF, ArF in liquid immersion exposure, F ₂ , EUV, nanoimprint, etc.). it can.

The above-mentioned silicon-containing film is formed by applying the above-mentioned film forming material to the surface of a substrate, another underlayer film such as an organic underlayer film to form a coating film, and subjecting this coating film to heat treatment and curing. Can be formed.

Examples of the method of applying the film forming material include a spin coating method, a roll coating method, and a dipping method. The temperature of the heat treatment is usually 50° C. or higher and 450° C. or lower. The average thickness of the formed silicon-containing film is usually 10 nm or more and 200 nm or less.

The film forming material can be used for resist process applications other than the formation of a resist intermediate film in the resist process, such as a pattern (reversal pattern) forming material obtained through an inversion process.

<Pattern forming method>
The pattern forming method includes a silicon-containing film forming step, a resist film forming step, an exposing step, and a developing step. The pattern forming method may include an organic underlayer film forming step before the silicon-containing film forming step, and may include an etching step after the developing step. Each step will be described below.

<Organic underlayer film forming step>
In this step, the organic underlayer film is formed on the surface side of the substrate on which the silicon-containing film is formed.

Examples of the substrate include an insulating film made of silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, or the like, or a resin substrate. Further, as a commercially available product, an interlayer insulating film such as a wafer covered with a low dielectric insulating film such as “Black Diamond” manufactured by AMAT, “Silk” manufactured by Dow Chemical, “LKD5109” manufactured by JSR can be used. .. As this substrate, a wiring substrate (trench), a patterned substrate such as 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, an antireflection function) required in order to further supplement the function of the silicon-containing film and/or the resist film in the formation of the resist pattern or to obtain the function that these do not have. , Coating film flatness, and high etching resistance to a fluorine-based gas such as CF ₄ ).

Examples of the organic lower layer film include an antireflection film and the like. As a composition for forming the antireflection film, as a commercially available product, for example, "NFC HM8006" by JSR Co. and the like can be mentioned.

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

<Silicon-containing film forming step>
In this step, a silicon-containing film is formed on at least one surface side of the substrate by the above film forming material. When the organic underlayer film is formed on the substrate, it is formed on the surface of the organic underlayer film opposite to the substrate. This makes it possible to obtain a substrate with a silicon-containing film in which the silicon-containing film is formed on the substrate.

The method for forming the silicon-containing film is not particularly limited, but for example, a coating film formed by applying the film forming material on a substrate by a known method such as a spin coating method is cured by exposing and/or heating. Can be formed.

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

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

The resist composition used for forming the resist film is a radiation-sensitive resin composition containing a polymer having an acid dissociable group and a radiation-sensitive acid generator (radiation-sensitive acid generator) (chemically amplified resist Composition) and a positive resist composition comprising an alkali-soluble resin and a quinonediazide-based photosensitizer, and a negative resist composition containing an alkali-soluble resin, a crosslinking agent, and a photosensitizer such as a photopolymerization initiator or a photoacid generator. Examples of the chemically amplified resist composition include the above-mentioned chemically amplified resist compositions. When the chemically amplified resist composition is used, a positive type pattern can be formed by developing with an alkali developing solution, and a negative type pattern can be formed by developing with an organic solvent. A double patterning method, a double exposure method or the like, which is a method of forming a fine pattern, may be appropriately used for forming the resist pattern.

The solid content concentration of the resist composition is not particularly limited, but is preferably 5% by mass or more and 50% by mass or more. Further, as the resist composition, one obtained by filtering with a filter having a pore size of about 0.2 μm can be preferably used. In the pattern forming method of the present invention, as such a resist composition, a commercially available resist composition can be used as it is.

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

The resist film can be formed by prebaking the coating film formed by applying the resist composition to volatilize the solvent in the coating film. The pre-baking temperature is appropriately adjusted depending on the type of resist composition used and the like, but the lower limit of the pre-baking temperature is preferably 30°C, and more preferably 50°C. The upper limit of the temperature is preferably 200°C, more preferably 150°C.

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

The radiation used for the exposure includes visible light, ultraviolet rays, far ultraviolet rays, X-rays, electron beams, γ rays, and molecular beams, depending on the type of radiation-sensitive acid generator used in the resist composition. , An ion beam, or the like, but far ultraviolet rays are preferable among them, and KrF excimer laser (248 nm), ArF excimer laser (193 nm), F ₂ excimer laser (wavelength 157 nm), Kr ₂ excimer laser ( A wavelength of 147 nm), an ArKr excimer laser (wavelength of 134 nm), and extreme ultraviolet rays (wavelength of 13 nm) are more preferable. The exposure method is also not particularly limited, and it can be performed according to a conventionally known method for pattern formation.

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

The above-mentioned development may be either alkali development or organic solvent development. In the case of organic solvent development, particularly excellent adhesiveness of the resist pattern can be exhibited.

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

The developing solution used for organic solvent development is an organic solvent-containing solution. Examples of this developing solution include ketone solvents, alcohol solvents, amide solvents, ether solvents, ester solvents and the like. Examples of these solvents include those similar to the respective solvents exemplified as the [B] organic solvent. These solvents may be used alone or as a mixture of two or more, or may be used as a mixture with water.

When a resist film formed from the above chemically amplified resist composition is developed with an organic solvent, the polarity of the exposed portion increases, so that the exposed portion becomes a resist pattern. On the other hand, the exposed portion on the surface of the silicon-containing film formed from the film-forming material has increased hydrophilicity due to the acid generated by the acid generator. Therefore, the adhesiveness between the resist film (resist pattern) and the silicon-containing film is high with respect to the organic solvent that is the developing solution, and it is possible to suppress pattern collapse and the like.

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

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

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

The dry etching can be performed using a known dry etching device. The source gas for dry etching depends on the elemental composition of the film to be etched, but may be fluorine-based gas such as CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ or SF ₆ , Cl ₂ , BCl ₃ or the like chlorine based _gas, an oxygen-containing gas such as _{O 2, O 3, H 2} , NH 3, CO, CO 2, CH 4, C 2 H 2, C 2 H 4, C 2 H 6, C 3 A reducing gas such as H ₄ , C ₃ H ₆ , C ₃ H ₈ , HF, HI, HBr, HCl, NO, NH ₃ , BCl ₃ or an inert gas such as He, N ₂ or Ar is used, These gases may be mixed and used. A fluorine-based gas is usually used for dry etching of the silicon-containing film, and a mixture of this with an oxygen-based gas and an inert gas is preferably used.

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

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

<Polymer>
The polymer according to one embodiment of the present invention is a polymer having a structure represented by the above formula (1). The details of the polymer are as described above for the [A] polymer which is a component of the “film forming material for resist process”, and the description thereof is omitted here. The polymer has excellent adhesiveness to a resist film and can be suitably used as a main component of a film forming material for a resist process capable of forming a pattern having a good shape.

Hereinafter, the present invention will be specifically described based on Examples, but the present invention is not limited to these Examples. The solid content concentration and the weight average molecular weight (Mw) of the polymer solution in this example were measured by the following methods.

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

[Weight average molecular weight (Mw)]
Tosoh GPC columns (two "G2000HXL", one "G3000HXL" and one "G4000HXL") were used, and flow rate: 1.0 mL/min, elution solvent: tetrahydrofuran, column temperature: 40°C under analysis conditions. , Was measured by gel permeation chromatography (detector: differential refractometer) using monodisperse polystyrene as a standard.

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

<Synthesis of [A] Polymer>
The silane monomers used to synthesize the polymer (A) (polysiloxane) are shown below.
Compounds (M-1) to (M-16): Compounds represented by the following formulas (M-1) to (M-16) The compounds (M-1) and (M-2) are structural units U _Z. The compound (M-3) is a silane monomer that gives the structural unit U _Y , and the compounds (M-4) to (M-15) are silane monomers that give the structural unit U _X.

[Example 1] (Synthesis of Polymer A-1)
7.22 g of tetramethylammonium hydroxide was dissolved in 21.67 g of water by heating to prepare an aqueous solution of tetraammonium hydroxide. Then, a cooling tube and a dropping funnel charged with a silane monomer were set in a reaction vessel containing the prepared tetraammonium hydroxide aqueous solution and 40.89 g of methanol. As the silane monomer, the compound represented by the chemical formula (M-1), the compound represented by the chemical formula (M-2), the compound represented by the chemical formula (M-3), and the compound represented by the chemical formula (M-4) are used in a molar ratio of 50. It was used at /25/10/15 (mol %), and the total mass of silane monomers was 30.21 g. Next, the reaction vessel was heated to 60° C. in an oil bath, and then the mixed solution of the silane monomer prepared above was added dropwise over 10 minutes. The reaction was carried out at 60° C. for 4 hours with the start of dropping being the start time of the reaction. After completion of the reaction, the reaction vessel was cooled to 10°C or lower.

Then, 9.33 g of maleic anhydride was dissolved in 34.25 g of water to prepare a maleic acid aqueous solution at 10° C. or lower, and the reaction solution in the reaction vessel was dropped, and the mixture was stirred at 10° C. or lower for 30 minutes. Then, 143.58 g of 1-butyl alcohol and water were added, and liquid-liquid extraction was performed with a separating funnel water to obtain a 1-butanol solution of the polysiloxane polymer (A-1). 143.58 g of propylene glycol monoethyl ether acetate was added, and 1-butanol was removed using an evaporator to obtain a propylene glycol monoethyl ether acetate solution of the polymer (A-1). The solid content concentration of the propylene glycol monoethyl ether acetate solution of the polymer (A-1) was 9.8 mass %. The weight average molecular weight (Mw) of the polymer (A-1) was 1,780.

[Example 13] (Synthesis of polymer (A-13))
0.75 g of oxalic acid was dissolved in 11.23 g of water by heating to prepare an aqueous oxalic acid solution. A silane monomer and 14.09 g of methanol were added to the reaction vessel. As the silane monomer, compound (M-1), compound (M-2), compound (M-3) and compound (M-10) are used at a molar ratio of 30/50/10/10 (mol %), The total mass of silane monomers was 23.93 g. A cooling tube and a dropping funnel containing the prepared oxalic acid aqueous solution were set in the reaction vessel. Next, after heating the flask to 60° C. in an oil bath, the oxalic acid aqueous solution was added dropwise over 10 minutes. The reaction was carried out at 60° C. for 4 hours, with the start of dropping being the start time of the reaction. After completion of the reaction, the inside of the reaction vessel was cooled to 30°C or lower. After 200.0 g of propylene glycol monomethyl ether acetate acetate was added to the above reaction vessel, water and generated alcohols were removed using an evaporator to obtain a propylene glycol monoethyl ether acetate solution of the polymer (A-13). It was The solid content concentration of the propylene glycol monoethyl ether acetate solution of the polymer (A-13) was 12.1% by mass. The Mw of the polymer (A-13) was 1,850.

[Examples 2 to 12, Comparative Example 1] (Synthesis of Polymers (A-2) to (A-12) and Polymer (a-1))
Polymers (A-2) to (A-12) and polymer (a-1) were prepared in the same manner as in Example 1 except that the types and amounts of the silane monomers shown in Table 1 below were used. Was synthesized. The solid content concentration (mass %) of the obtained polymer solution and the Mw of the [A] polymer are also shown in Table 1.

[Example 14, Comparative Example 2] (Synthesis of Polymer (A-14) and Polymer (a-2))
The polymer (A-14) and the polymer (a-2) were synthesized by the same method as in Example 13 except that the types and amounts of the silane monomers shown in Table 1 below were used. The solid content concentration (mass %) of the obtained polymer solution and the Mw of the [A] polymer are also shown in Table 1.

[Preparation of film forming material for resist process]
The components other than the [A] polymer used for the preparation of the film forming material for the resist process are shown below.

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

[[C] Nitrogen-containing compound]
C-1: Nt-butoxycarbonyl-4-hydroxypiperidine Structural formula is shown below.

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

[Example 15]
2.0 parts by mass of (A-1) as [A] polymer (solid content), 97.4 parts by mass of (B-1) as [B] organic solvent (contained in a solution of the [A] polymer) The solvent (including B-1)), 0.1 part by mass of (D-1) as a [D] acid generator, and 0.5 part by mass of [E] water are mixed, and the resulting mixed solution has a pore size. It was filtered with a 0.2 μm filter to obtain a film forming material for resist process (J-1).

[Examples 16 to 28 and Comparative Examples 3 to 4]
Film forming materials for resist process (J-2) to (J-14) and (j-1) were prepared in the same manner as in Example 15, except that the components shown in Table 2 below were used. ~ (J-2) were prepared.

<Formation of silicon-containing film>
The obtained film forming material for a process was applied onto a silicon wafer by a spin coating method using a spin coater (“CLEAN TRACK ACT12” manufactured by Tokyo Electron Ltd.). The obtained coating film was heat-treated for 60 seconds on a hot plate at 220° C. and then cooled at 23° C. for 60 seconds to give an average thickness of 30 nm shown in Examples 15 to 28 and Comparative Examples 3 and 4 in Table 2. A substrate on which the above-mentioned silicon-containing film was formed was obtained.

<Evaluation>
The silicon-containing film formed above was evaluated for the following items by the methods described below. The evaluation results are shown in Table 3 below.

[Substrate reflectance]
The silicon-containing film, the composition for forming a lower layer film (“NFC HM8006” by JSR Co.) and the resist material (“ARF AR2772JN” by JSR Co.) each having the above refractive index parameter (n) and extinction coefficient (k). ) Is measured by a high-speed spectroscopic ellipsometer (“M-2000D” manufactured by JA Woollam Co.), and NA1.3, using simulation software (“Prolith” manufactured by KLA-Tencor) based on the measured values. The substrate reflectance of the film obtained by laminating the resist material/silicon-containing film/underlayer film-forming composition under Dipole conditions was determined. The substrate reflectance was evaluated as "A" when it was 1% or less, and "B" when it was more than 1%.

[Solvent resistance]
The substrate having the silicon-containing film obtained above was immersed in cyclohexanone at room temperature for 10 seconds. The average thickness of the silicon-containing film before and after immersion was measured using a spectroscopic ellipsometer. When the average thickness before immersion was T ₀ and the average thickness after immersion was T ₁ , the rate of change in film thickness (%) due to solvent immersion was determined by the following formula.
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" (poor) when the film thickness change rate was 1% or more.

[Minimum collapse dimension and pattern shape]
The minimum pre-collapse dimension and the pattern shape were evaluated by performing the following lithography evaluation.

(Lithography evaluation, organic solvent development)
A 12-inch silicon wafer was spin-coated with an antireflection film-forming material (“HM8006” manufactured by JSR Corporation), and then heat-treated at 250° C. for 60 seconds to form an antireflection film having an average thickness of 100 nm. The obtained film forming material for a resist process was spin-coated on the antireflection film using the spin coater, heat-treated at 220° C. for 60 seconds, and then cooled at 23° C. for 60 seconds to obtain an average. A silicon-containing film having a thickness of 30 nm was formed. Then, a resist material (“ARF AR2772JN” manufactured by JSR) is spin-coated on the silicon-containing film, heated at 90° C. for 60 seconds, and then cooled at 23° C. for 30 seconds to form a resist film having an average thickness of 100 nm. Formed.

Then, using an ArF immersion exposure apparatus (“S610C” manufactured by NIKON), exposure was performed through a mask having a mask size for forming a 40 nm line/80 nm pitch under NA: 1.30 and optical conditions of Dipole. PEB was performed at 100° C. for 60 seconds on a “Lithius Pro-i” hot plate, and after cooling at 23° C. for 30 seconds, paddle development was performed for 30 seconds using butyl acetate as a developing solution, and then methyl isobutyl carbinol (MIBC) was used. I rinsed. By spin-drying at 2,000 rpm for 15 seconds by spin-off, an evaluation substrate having a resist pattern of 40 nm line/80 nm pitch was obtained.

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

Exposure amount for forming a resist pattern having a line width of 42 nm and a distance (space) between adjacent lines of 84 nm (line and space is 1:2) when the above-described evaluation substrate was obtained. (MJ/cm ² ) was set as the optimum exposure amount, and the exposure amount was increased stepwise from this optimum exposure amount to perform sequential exposure. At this time, since the line width of the obtained pattern is gradually narrowed, the collapse of the resist pattern is finally observed at the line width corresponding to a certain exposure amount. The line width corresponding to the maximum exposure amount at which collapse of the resist pattern was not confirmed was defined as the minimum pre-collapse dimension (nm) and used as an index of pattern collapse resistance. The minimum pre-collapse dimension is "A" (good) if it is 30 nm or less, "B" (somewhat good) if it exceeds 30 nm and 40 nm or less, or if it cannot be evaluated due to pattern collapse due to pattern collapse. It was evaluated as "C" (poor). The pattern shape was evaluated as "A" when the bottom of the resist pattern has no skirt, "B" when the pattern collapse or hem can be confirmed, and "C" when the pattern collapse or hem can be confirmed in multiple places. ..

[Oxygen etching resistance]
The formed silicon-containing film was subjected to O ₂ treatment at 100 W for 120 seconds using a dry etching device (“Telius SCCM” manufactured by Tokyo Electron Ltd.), and the difference in film thickness before and after the treatment was measured. The oxygen etching resistance is “A” (good) when the difference in film thickness before and after the treatment is less than 10 nm, “B” (somewhat good) when the difference is 10 nm or more and 15 nm or less, and “C” when it exceeds 15 nm. It was evaluated as (poor).

From the results of Table 3, according to the film forming materials of Examples, the resist composition has excellent resistance to a solvent, excellent antireflection property, etching resistance, a good resist pattern shape and less collapse. It can be seen that a film can be formed.

The film forming material for a resist process according to the present invention can be suitably used as a forming material for various silicon-containing films such as a resist intermediate film and a resist underlayer film in a resist process.

Claims (4)

A resist film formed directly on the surface of a silicon-containing film as a resist intermediate film by a radiation-sensitive resin composition containing a polymer having an acid-dissociable group and a radiation-sensitive acid generator is developed with an organic solvent-containing solution. A film forming material for a resist process used for forming the above-mentioned silicon-containing film in a negative resist process including a step,
Containing a polymer having a structural unit derived from a silane monomer having two or more protected alcoholic hydroxyl groups, and an organic solvent ,
A film forming material for a resist process, wherein the polymer has a structure represented by the following formula (1) .

(In formula (1),
R ¹ represents a monovalent organic group containing two or more protected alcoholic hydroxyl groups represented by the following formula (2) or one protected alcoholic hydroxyl group represented by the following formula (3). It is a monovalent organic group containing.
R ² includes a monovalent organic group having two or more protected alcoholic hydroxyl groups represented by the following formula (2) and one protected alcoholic hydroxyl group represented by the following formula (3). A monovalent organic group, a hydrogen atom, a hydroxy group, or a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which does not have a protected alcoholic hydroxyl group. a is 0 or 1. However, when R ¹ is a monovalent organic group containing one protected alcoholic hydroxyl group represented by the following formula (3), a is 1 and R ² is represented by the following formula (3). Is a monovalent organic group containing one protected alcoholic hydroxyl group.
R ³ is a monovalent organic group having a light absorbing group, which does not have a protected alcoholic hydroxyl group.
R ⁴ is a substituted or unsubstituted monovalent hydrocarbon group having 1 to 20 carbon atoms, which does not have a hydrogen atom, a hydroxy group, or a protected alcoholic hydroxyl group. b is 0 or 1.
R ⁵ is a non-light-absorbing substituted or unsubstituted monovalent aliphatic hydrocarbon group having no protected alcoholic hydroxyl group. c is an integer of 0-2. When c is 2, a plurality of R ⁵ may be the same or different.
d represents the molar ratio of the structural unit U _X to all the structural units constituting the polymer .
e represents the molar ratio of the structural unit U _Y to all structural units constituting the polymer .
f represents the molar ratio of structural units U _Z to the total structural units constituting the polymer.
d, e, and f satisfy 0<d<1, 0<e<1, and 0≦f<1, respectively, and d+e+f≦1. )

(In formula (2),
X ¹ is a trivalent organic group having 1 to 20 carbon atoms. The trivalent organic group is a substituted or unsubstituted trivalent hydrocarbon group having 1 to 20 carbon atoms, or a group containing a hetero atom-containing group between carbon and carbon of this hydrocarbon group.
R ^{6 s} are each independently a single bond or a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms.
Y ^{1 s} are each independently a monovalent protecting group α, or two Y ^{1 s} may be bonded to each other to form a divalent protecting group. The monovalent protecting group α is represented by R ^a1 −, R ^a1 —CO—, R ^a1 —O—C(R ^b1 ) ₂ — or R ^a1 —O—CO— (R ^a1 has 3 to 10 carbon atoms. secondary or .2 one R ^b1 is a tertiary alkyl group or a cycloalkyl group independently, .R ^b1 is a monovalent hydrocarbon group having a hydrogen atom or 1 to 10 carbon atoms, It may be bonded to R ^a1 to form part of a ring structure). The divalent protecting group is a divalent hydrocarbon group or a group represented by the following formula (4).
* Indicates a binding site. )

(In formula (3),
X ² is a divalent organic group having 1 to 20 carbon atoms. The divalent organic group is a substituted or unsubstituted divalent hydrocarbon group having 1 to 10 carbon atoms, or a group containing a hetero atom-containing group between carbon and carbon of this hydrocarbon group.
Y ² is a monovalent protecting group β. The above monovalent are protecting groups ^{β, R a2 -, R a2} -CO-, R a2 -O-C (R b2) 2 - or ^{R a2} -O-CO- ^(R a2 is from 3 to 10 carbon atoms secondary or .2 one R ^b2 is a tertiary alkyl group or a cycloalkyl group independently, .R ^b2 is a monovalent hydrocarbon group having a hydrogen atom or 1 to 10 carbon atoms, R ^a2 may combine to form a part of the ring structure).
* Indicates a binding site. )

(In the formula (4), n is an integer of 0 to 4. R ^c is each independently a monovalent hydrocarbon group having 1 to 10 carbon atoms. R ^d is each independently. , A hydrogen atom, or a monovalent hydrocarbon group having 1 to 10 carbon atoms, two R ^d's are bonded to each other to form a carbon ring structure having 4 to 12 carbon atoms together with the carbon chain to which they are bonded. (* indicates a binding position.) F in the above formula (1) is, 0 <resist process for film-forming material of claim 1 that satisfies f <1. The film forming material for a resist process according to claim 1 or 2 , wherein the X ¹ is a substituted or unsubstituted trivalent aliphatic hydrocarbon group having 1 to 20 carbon atoms. A step of forming a silicon-containing film on at least one surface side of a substrate using the film forming material for resist process according to any one of claims 1 to 3 ;
A radiation-sensitive resin composition containing a polymer having an acid dissociable group and a radiation-sensitive acid generator, on the side of the silicon-containing film opposite to the substrate, a step of forming a resist film,
Exposing the resist film,
And a step of developing the exposed resist film ,
A pattern forming method, wherein the resist film is developed with an organic solvent-containing liquid .