JP6565649B2 - Method for removing silicon-containing film - Google Patents

Description

  The present invention relates to a method for removing a silicon-containing film.

  In the field of manufacturing semiconductors and the like, pattern miniaturization using a multilayer resist process is progressing in order to obtain a higher degree of integration. In this multilayer resist process, an inorganic film such as a silicon-containing film is first formed on a substrate, and then a resist film having an etching selectivity different from that of the inorganic film is formed on the inorganic film using a resist composition or the like. Next, the mask pattern is transferred by exposure and developed with a developer to obtain a resist pattern. Subsequently, the resist pattern is transferred to the inorganic film by dry etching, and the pattern of the inorganic film is finally transferred to the substrate to obtain a substrate on which a desired pattern is formed.

  In an actual manufacturing process of a semiconductor or the like, rework may be performed when a defect occurs when the silicon-containing film or the resist film is patterned. In the case of reprocessing, when the inorganic film is a silicon-containing film, in order to peel this silicon-containing film, it is treated with an alkaline stripping solution after the step of treating with an acidic stripping solution containing sulfate ions and / or fluorine ions. Wet stripping method (see JP 2010-139964 A), wet stripping composition containing a fluoride source and an ammonium salt (see JP 2010-515107 A), wet using high concentration hydrogen fluoride water Peeling, dry peeling (refer to JP 2010-85912 A) and the like have been proposed. However, in the conventional dry stripping or wet stripping method using an acidic stripping solution or a solution containing fluorine ions, there is a disadvantage that the substrate is seriously damaged, and the silicon-containing film after dry etching or its residue is There exists a tendency for wet peelability to fall. In view of this, as a method not using an acidic stripping solution or a fluorine compound that causes great damage to the substrate, a silicon-containing film stripping using a basic aqueous solution (see International Publication No. 2015-146524) has been proposed.

JP 2010-139964 A Special table 2010-515107 gazette JP 2010-85912 A International Publication No. 2015-146524

  However, in the manufacturing process of semiconductors and the like, as the miniaturization progresses, if a defect occurs when the silicon-containing film is formed, if a defect occurs when the resist film is patterned, the silicon-containing film The problem that the removability of the silicon-containing film with a basic aqueous solution is not sufficient when reworking such as when a defect occurs when the film is etched, or when etching using the pattern of the silicon-containing film as a mask was there. In particular, after the step of bringing a gas containing a reducing component into contact with the silicon-containing film, there is a problem that the removability of the silicon-containing film with a basic aqueous solution is not sufficient.

  Therefore, the present invention provides a novel method for removing a silicon-containing film that has good silicon-containing film removability when performing wet stripping using a basic liquid, regardless of the type of gas that contacts the silicon-containing film. The main purpose. This silicon-containing film removal method is not limited to the field of manufacturing semiconductors and the like, and can also be applied to fields where a silicon-containing film removal step is required.

  In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive research. As a result, before the step of removing the silicon-containing film using a basic liquid, the oxidizing gas or liquid is removed from the silicon-containing film. It has been found that the silicon-containing film has excellent removal performance when wet-peeling with a basic liquid by bringing it into contact with the substrate, and the present invention has been completed. This silicon-containing film removal method has a problem when a defect occurs when the silicon-containing film is formed, a problem occurs when the resist film is patterned, and a defect occurs when the silicon-containing film is etched. It has been found that the silicon-containing film has excellent removal performance in wet stripping with a basic liquid when reworking in some cases or when etching is performed using the pattern of the silicon-containing film as a mask. In particular, when etching using a gas containing a reducing component, the removability of the silicon-containing film tends to decrease, but before the step of removing the silicon-containing film using a basic liquid, It has been found that the silicon-containing film exhibits remarkable removal performance upon wet peeling with a basic liquid by bringing an oxidizing gas or liquid into contact with the silicon-containing film.

  That is, in the present invention, after a silicon-containing film is formed on a substrate, an oxidizing gas or liquid is brought into contact with the silicon-containing film, and the silicon-containing film is removed using a basic liquid. I will provide a. In particular, after the silicon-containing film is formed, a gas containing a reducing component is brought into contact with the silicon-containing film, and then an oxidizing gas or liquid is brought into contact with the silicon-containing film, and then the basic liquid is used. A silicon-containing film removing method for removing a silicon-containing film is provided.

  According to the present invention, since the silicon-containing film can be removed using a basic liquid, damage to the substrate is small. Therefore, the pattern forming method can be applied to the manufacture of semiconductor devices that are expected to be further miniaturized in the future.

<Silicon-containing film removal method>
The silicon-containing film removal method of this embodiment is
A silicon-containing film forming step (1) for forming a silicon-containing film on the substrate;
Reducing component contacting step (2), wherein the silicon-containing film is brought into contact with a gas containing the reducing component;
An oxidizing component contact step (3) for contacting an oxidizing gas or liquid with the silicon-containing film, and a removing step (4) for removing the silicon-containing film using a basic liquid.
Have

Further, another silicon-containing film removal method of the present embodiment,
Before the silicon-containing film forming step, an organic underlayer film forming step (0) for forming an organic underlayer film, a silicon-containing film forming step (1 ′) for forming a silicon-containing film on the substrate,
A reducing component etching step (2 ′) in which a gas containing a reducing component is brought into contact with the silicon-containing film;
An oxidizing component contact step (3 ′) in which an oxidizing gas or liquid is brought into contact with the silicon-containing film, and a removing step (4 ′) in which the silicon-containing film is removed using a basic liquid.
Have

Furthermore, after the silicon-containing film forming step and before the reducing component etching step (2 ′),
A resist pattern forming step (1′-1) for forming a resist pattern on the silicon-containing film, and an etching step (1′-2) for etching the silicon-containing film using the resist pattern as a mask.
May further be included.

  According to the method for removing a silicon-containing film, an oxidizing gas or liquid is brought into contact with the silicon-containing film before removing the silicon-containing film using a basic liquid. Regardless, the silicon-containing film after etching can be wet peeled using a basic solution. Hereinafter, each step will be described.

<Organic underlayer film forming step (0)>
In this step, an organic underlayer film is formed on the substrate. Examples of the substrate include insulating films such as silicon oxide, silicon nitride, silicon oxynitride, and polysiloxane, and commercially available products such as black diamond (AMAT), silk (Dow Chemical), and LKD5109 (JSR). An interlayer insulating film such as a wafer coated with a dielectric insulating film can be used. Polysilicon, a so-called metal gate film in which a metal component is injected into polysilicon, and the like are also included. As the substrate, a patterned substrate such as a wiring groove (trench) or a plug groove (via) may be used.

  Examples of the organic underlayer film include an organic underlayer film formed using a resist underlayer film composition, and a carbon film formed by a conventionally known CVD (Chemical Vapor Deposition) method. As the resist underlayer film forming composition, conventionally known compositions can be used, and examples thereof include NFC HM8005 (JSR). As a method for forming the resist underlayer film, a coating film of the resist underlayer film forming composition is formed by coating on the substrate, and the coating film is cured by heat treatment, or irradiation with ultraviolet light and heat treatment. Can be formed. Examples of the method for applying the resist underlayer film forming composition include spin coating, roll coating, and dipping. Moreover, as heating temperature, it is 150 to 500 degreeC normally, Preferably it is 180 to 350 degreeC. The heating time is usually 30 seconds to 1,200 seconds, preferably 45 seconds to 600 seconds. The thickness of the resist underlayer film is usually about 50 nm to 500 nm.

Further, another lower layer film different from the organic lower layer film may be formed on the substrate surface or the organic lower layer film. The other lower layer film is a film provided with an antireflection function, coating film flatness, high etching resistance against a fluorine-based gas such as CF _{4, and the} like. As this other lower layer film, for example, a commercially available product such as NFC HM8005 (manufactured by JSR) can be used.

  Note that the organic underlayer film forming step is not an essential step in the silicon-containing film removal method according to the present embodiment, and for example, a substrate on which an organic underlayer film is formed in advance may be used.

<Silicon-containing film forming step (1)>
In this step, a silicon-containing film is formed on the upper side of the substrate. The silicon-containing film is formed, for example, by applying a silicon-containing film forming composition or the like on the organic underlayer film. The silicon-containing film forming composition will be described later. Examples of the method for applying the silicon-containing film forming composition include spin coating, cast coating, roll coating, and the like. Moreover, the heating temperature of the coating film formed is 50-450 degreeC normally. In addition, as a film thickness of the silicon-containing film | membrane formed, it is 10 nm-1,000 nm normally, 10 nm-500 nm are preferable, and 10 nm-300 nm are more preferable.

<Silicon-containing film forming step (1 ')>
In this step, a silicon-containing film is formed above the organic underlayer film formed in the organic underlayer film forming step (0). The silicon-containing film is formed, for example, by applying a silicon-containing film forming composition or the like on the organic underlayer film. The silicon-containing film forming composition will be described later. Examples of the method for applying the silicon-containing film forming composition include spin coating, cast coating, roll coating, and the like. Moreover, the heating temperature of the coating film formed is 50-450 degreeC normally. In addition, as a film thickness of the silicon-containing film | membrane formed, it is 10 nm-1,000 nm normally, 10 nm-500 nm are preferable, and 10 nm-300 nm are more preferable.

<Silicon-containing film forming composition>
The silicon-containing film-forming composition contains at least (A) polysiloxane and (B) an organic solvent. Moreover, the other component may be contained. The silicon-containing film-forming composition preferably contains a component having at least one of a sulfur atom and a carbonyl group, and includes a sulfide group (—S—), a sulfoxide group (—SO—), a sulfonyl group (—SO ₂ —). ), A sulfanyl group (—SH) and a carbonyl group. The component having at least one of a sulfur atom and a carbonyl group is not particularly limited, but (A) a polysiloxane having at least one of a sulfur atom and a carbonyl group, at least one of a sulfur atom and a carbonyl group (Excluding the component (A)) and the like. Details will be described below.

<(A) Polysiloxane>
As the (A) polysiloxane, a conventionally known polysiloxane can be used, but in the present embodiment, it is particularly preferable to have at least one of a sulfur atom and a carbonyl group. By using such a polysiloxane (A), hydrophilicity is imparted by oxidizing sulfur atoms and / or carbonyl groups in the step of bringing an oxidizing gas or liquid into contact with the silicon-containing film, thereby providing a base. It exhibits excellent basic liquid peeling performance during wet peeling with an acidic liquid, and can more effectively remove the silicon-containing film.

  (A) The polysiloxane preferably has at least one selected from a sulfide group, a sulfoxide group, a sulfonyl group, a sulfanyl group, and a carbonyl group. (A) When polysiloxane has these groups, the resistance to pattern collapse of the formed resist pattern can be improved. In addition, a sulfoxide group, sulfonyl group, or carbonyl group, which is considered to be reduced in the step of etching the silicon-containing film using a gas containing a reducing component, brings an oxidizing gas or liquid into contact with the silicon-containing film. It is inferred that, by being oxidized in the process, hydrophilicity is imparted again, and excellent basic liquid peeling performance is exhibited in wet peeling with a basic liquid, and the silicon-containing film can be removed more effectively. Is done. The sulfide group or sulfanyl group is oxidized in the step of bringing an oxidizing gas or liquid into contact with the silicon-containing film, thereby imparting hydrophilicity and excellent basicity in wet peeling with a basic liquid. It is presumed that the silicon-containing film can be removed more effectively by showing liquid peeling performance. Among these, it is more preferable to have at least one selected from a sulfonyl group and a carbonyl group, and it is particularly preferable to have a sulfonyl group.

  The polysiloxane having a sulfonyl group is preferably a polysiloxane having at least one selected from a sulfo group and a sulfonate group. Specifically, (A) the polysiloxane is a moiety represented by the following general formula (1): It preferably has a structure.

(In the formula (1), when L, —SO ₂ —O— * and X do not constitute a ring, L is a single bond or a divalent organic group, and X is a hydrogen atom or a monovalent organic group. When L, —SO ₂ —O— * and X form a ring, L is a trivalent organic group, and X is a divalent organic group (where * is a bond between O and X). Indicates position)))

In the present embodiment, the single bond directly binds the substituents to be linked.
Examples of the divalent organic group represented by L include a divalent hydrocarbon group, a divalent hydrocarbon group, and a group formed by combining a linking group containing atoms other than carbon atoms and hydrogen atoms, or these groups. And a group in which a part of the hydrogen atoms is substituted with a halogen atom.
The monovalent organic group of X is a group containing at least one carbon atom. For example, a cyano group, an alkyl group having 1 to 5 carbon atoms, a cyanoalkyl group having 2 to 6 carbon atoms, or an alkylcarbonyloxy group, Examples thereof include an alkenyl group having 2 to 5 carbon atoms, an aryl group having 6 to 10 carbon atoms, and an aralkyl group having 7 to 12 carbon atoms. Note that some or all of the hydrogen atoms contained in these groups may be substituted with fluorine atoms.

Examples of the trivalent organic group include a group formed by combining a trivalent hydrocarbon group, a trivalent hydrocarbon group, and a linking group containing an atom other than a carbon atom and a hydrogen atom, or hydrogen of these groups. Examples thereof include a group in which a part of the atoms is substituted with a halogen atom, and a group constituting a ring together with X and adjacent —SO ₂ —O— *.
The divalent organic group is a group formed by combining a divalent hydrocarbon group, a divalent hydrocarbon group and a linking group containing an atom other than a carbon atom and a hydrogen atom, or a hydrogen atom of these groups. Examples thereof include a group partially substituted with a halogen atom and the like, and a group constituting a ring together with L and adjacent —SO ₂ —O— *.

  More specifically, the polysiloxane (A) is a structural unit derived from at least one compound selected from the group consisting of compounds represented by the following general formulas (2) and (3) ( Polysiloxanes having I) can be used.

[Structural unit (I)]
The structural unit (I) is derived from one or more compounds selected from the group consisting of compounds represented by the following general formulas (2) and (3).

(In Formulas (2) and (3), p is an integer of 1 or more, R ¹ is a single bond or a (p + 1) -valent group. R ² and R ³ are each independently a hydrogen atom or a fluorine atom. Or R ² and R ³ may be the same or different, n is an integer of 1 to 3, m is an integer of 1 to 3, and l is an integer of 0 to 2. And m + 1 + n is 4.
In formula (2), Y is a hydrogen atom or a monovalent organic group.
In formula (3), q and r are each independently an integer of 0 to 3. )
In the general formula (2), Y is not particularly limited, but can be an alkyl group.
Further, the proportion of the structural unit (I) in the (A) polysiloxane is not particularly limited, but may be 1 to 60 mol% based on the raw material monomer.

In general formulas (2) and (3), p is an integer of 1 or more, p is preferably an integer of 1 to 2, and more preferably p = 1.
Moreover, n of general formula (2) and (3) is an integer of 1-3, and it is preferable that n = 1.
Incidentally, sites that are not involved in the main chain bond of R ¹ in the general formula (2) and (3) may be substituted.

In the general formulas (2) and (3), when p = 1, R ¹ is a divalent group, and examples of the divalent group include an oxygen atom, a sulfur atom, and a substituted or unsubstituted carbon number. 1-30 divalent hydrocarbon group, -CO -, - OCO -, - CS -, - SO -, - SO 2 - or -NR- (R; 1 monovalent hydrogen atom or a C1-30 Hydrocarbon group), or a divalent group obtained by combining these.

  Examples of the divalent hydrocarbon group having 1 to 30 carbon atoms include a linear or branched divalent hydrocarbon group having 1 to 30 carbon atoms and a divalent alicyclic group having 3 to 30 carbon atoms. Examples thereof include a hydrocarbon group, a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a group obtained by combining these groups.

  Examples of the linear or branched divalent hydrocarbon group having 1 to 30 carbon atoms include methylene group, ethylene group, 1,2-propylene group, 1,3-propylene group, tetramethylene group, and pentane. Methylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, Linear alkylene groups such as heptacamethylene group, octadecamethylene group, nonadecamethylene group, icosalen group; 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl -1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4-butylene group, methylidene group, Chiriden group, propylidene group, etc. branched alkylene group such as 2-propylidene group.

  Examples of the divalent alicyclic hydrocarbon group having 3 to 30 carbon atoms include 1,3-cyclobutylene group, 1,3-cyclopentylene group, 1,4-cyclohexylene group, 1,5- C3-C30 monocyclic cycloalkylene group such as cyclooctylene group; 1,4-norbornylene group, 2,5-norbornylene group, 1,5-adamantylene group, 2,6-adamantylene group, etc. Examples include a polycyclic cycloalkylene group.

  Examples of the divalent aromatic hydrocarbon group having 6 to 30 carbon atoms include arylene groups such as a phenylene group, a tolylene group, a naphthylene group, a phenanthrylene group, and an anthrylene group.

  Examples of the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R of —NR— include, for example, a linear or branched monovalent chain hydrocarbon group having 1 to 30 carbon atoms, carbon Examples thereof include a monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a group in which these are combined.

  Examples of the linear or branched monovalent chain hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, 2- Examples include methylpropyl group, 1-methylpropyl group, t-butyl group, pentyl group, hexyl group, octyl group, dodecyl group and the like.

  Examples of the monovalent alicyclic hydrocarbon group having 3 to 30 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a cyclododecyl group, a norbornyl group, an adamantyl group, and the like. Is mentioned.

  Examples of the monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms include phenyl group, tolyl group, naphthyl group, anthryl group, benzyl group, phenethyl group, and naphthylmethyl group.

  Examples of the monovalent oxyhydrocarbon group having 1 to 30 carbon atoms include, for example, an alkoxy group having 1 to 30 carbon atoms such as a methoxy group, an ethoxy group, and a propoxy group; carbon such as a cyclopentyloxy group and a norbornyloxy group. A cycloalkyloxy group having 3 to 30 carbon atoms; an aryloxy group having 6 to 30 carbon atoms such as a phenoxy group, a tolyloxy group and a naphthyloxy group; an aralkyloxy group having 7 to 30 carbon atoms such as a benzyloxy group and a naphthylmethoxy group; Is mentioned.

  Examples of the monovalent sulfanyl hydrocarbon group having 1 to 30 carbon atoms include an alkylsulfanyl group having 1 to 30 carbon atoms such as a methylsulfanyl group and an ethylsulfanyl group; a cyclohexane having 3 to 30 carbon atoms such as a cyclopentylsulfanyl group. Examples thereof include alkylsulfanyl groups; arylsulfanyl groups having 6 to 30 carbon atoms such as phenylsulfanyl groups and naphthylsulfanyl groups; and aralkylsulfanyl groups having 7 to 30 carbon atoms such as benzylsulfanyl groups.

In the general formulas (2) and (3), when p is an integer of 2 to 5, R ¹ is a (p + 1) -valent group. Examples of the (p + 1) -valent group include a substituted or unsubstituted group. C1-30 (p + 1) -valent hydrocarbon radical, or, with these, an oxygen atom, a sulfur atom, -CO -, - OCO -, - CS -, - SO -, - SO 2 - or -NR- (R: a hydrogen atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms), for example, a (p + 1) -valent group containing a sulfur atom in a part of the main chain.

  Examples of the (p + 1) -valent hydrocarbon group having 1 to 30 carbon atoms include, for example, a linear or branched (p + 1) -valent hydrocarbon group having 1 to 30 carbon atoms, and (p + 1) having 3 to 30 carbon atoms. ) -Valent alicyclic hydrocarbon group, (p + 1) -valent aromatic hydrocarbon group having 6 to 30 carbon atoms, or a group obtained by combining these groups.

  Examples of the linear or branched (p + 1) -valent hydrocarbon group having 1 to 30 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, 2- And (p + 1) -valent groups derived from a methylpropyl group, 1-methylpropyl group, t-butyl group, vinyl group, ethynyl group, and the like.

  Examples of the (p + 1) -valent alicyclic hydrocarbon group having 3 to 30 carbon atoms include a (p + 1) -valent group derived from a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a methylcyclohexyl group, and the like. Is mentioned.

  Examples of the (p + 1) -valent aromatic hydrocarbon group having 6 to 30 carbon atoms include a (p + 1) -valent group derived from a phenyl group, a naphthyl group, an anthracenyl group, a pyrene group, a coronene group, and the like. .

  Since the monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R in —NR— is the same as described above, description thereof is omitted here.

Further, as described above, sites that are not involved in the main chain bond of R ¹ in the general formula (1) may be substituted.
But it is not substituents replacing a site that does not participate in the main chain binding specifically limited in R ^1, a halogen atom, a linear or branched alkyl group having 1 to 5 carbon atoms, straight-chain C1-5 or A branched alkoxy group is preferred.

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

Examples of the linear or branched alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a 2-methylpropyl group, 1- Examples thereof include a methylpropyl group and a tert-butyl group.
Examples of the linear or branched alkoxy group having 1 to 5 carbon atoms include methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, 2-methylpropoxy group, Examples thereof include 1-methylpropoxy group and tert-butoxy group.
In addition, these alkyl groups and alkoxy groups may be substituted. Examples of the substituent include trifluoromethyl group, pentafluoroethyl group, hydroxyl group, methoxy group, ethoxy group, phenoxy group, and amino group. And dimethylamino group.

In the present embodiment, R ² in the general formulas (1) and (2) is a hydrogen atom, a fluorine atom, or a monovalent organic group. In the general formulas (1) and (2), m is an integer of 1 to 3, and preferably m = 3.

Examples of the monovalent organic group for R ² include the monovalent organic groups exemplified in the above description of X.

In the present embodiment, R ³ in the general formulas (2) and (3) is a hydrogen atom, a fluorine atom, or a monovalent organic group. In the general formulas (2) and (3), l is an integer of 0 to 2, and preferably 1 = 0.
Examples of the monovalent organic group for R ³ include the monovalent organic groups exemplified in the above description of R ² .

In this embodiment, Y in the general formula (2) is a hydrogen atom or a monovalent organic group.
Examples of the monovalent organic group of Y include the monovalent organic groups exemplified in the above description of X.

  Among these, from the viewpoint of improving storage stability, Y in the general formula (2) is preferably an alkyl group, and more preferably a methyl group, an n-butyl group, or a tert-butyl group. .

  Specific examples of the structural unit (I) represented by the general formula (2) include, for example, structures derived from compounds represented by the following chemical formulas (I-1-1) to (I-1-9) Examples include units.

  Specific examples of the structural unit (I) represented by the general formula (3) include, for example, structures derived from compounds represented by the following chemical formulas (I-2-1) to (I-2-4) Examples include units.

  In addition, (A) polysiloxane may contain only 1 type of structural units (I), and may contain it in combination of 2 or more types.

  On the other hand, the polysiloxane having a carbonyl group is preferably a polysiloxane having a partial structure represented by the following general formula (4).

(In Formula (4), Z is a hydrogen atom or a monovalent organic group.)

  More specifically, as the (A) polysiloxane, polysiloxane having at least a structural unit (II) derived from a compound represented by the following general formula (5) can be used.

(In the formula (5), p is an integer of 1 or more, R ⁴ is a single bond or a (p + 1) valent group. R ⁵ and R ⁶ are each independently a hydrogen atom, a fluorine atom or a monovalent group. R ⁵ and R ⁶ may be the same or different, n is an integer of 1 to 3, m is an integer of 1 to 3, l is an integer of 0 to 2, and m + l + n Is 4. Z is a hydrogen atom or a monovalent organic group.)

In the general formula (5), Z is not particularly limited, but may be an alkyl group.
Z may be a monovalent acid dissociable group.
In addition, the proportion of the structural unit (II) in the (A) polysiloxane is not particularly limited, but may be 5 to 30 mol% based on the raw material monomer.

R ⁴ in the general formula (5) is a single bond or a (p + 1) -valent group, and can be a sulfur atom or a group containing a sulfur atom. In the general formula (5), p is an integer of 1 or more, p is preferably an integer of 1 to 2, and more preferably p = 1.
Moreover, n of General formula (5) is an integer of 1-3, and it is preferable that it is n = 1.
Incidentally, sites that are not involved in the main chain bond R ⁴ in the general formula (5) may be substituted.

In the general formula (5), when p = 1, R ⁴ is a divalent group, and examples of the divalent group include an oxygen atom, a sulfur atom, a substituted or unsubstituted C 1-30 carbon atom. Divalent hydrocarbon group, —CO—, —OCO—, —CS—, —SO—, —SO ₂ — or —NR— (R: hydrogen atom or monovalent hydrocarbon group having 1 to 30 carbon atoms) Or a combination thereof, for example, a divalent group containing a sulfur atom.

Examples of the divalent hydrocarbon group having the from 1 to 30 carbon atoms include a divalent hydrocarbon group exemplified C1-30 in the description for the above-described R ^1.

The monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R of —NR— is the one having 1 to 30 carbon atoms represented by R of —NR— exemplified in the description of R ¹ described above. A monovalent hydrocarbon group can be mentioned.

Examples of the divalent group containing a sulfur atom include divalent groups derived from structures represented by the following chemical formulas (R ⁴ -1) to (R ⁴ -11). * Indicates a bonding site with a carbonyl carbon or Si atom in the general formula (2).

In the general formula (5), when p is an integer of 2 to 5, R ⁴ is a (p + 1) -valent group, and the (p + 1) -valent group includes, for example, a substituted or unsubstituted carbon number of 1 to 30 (p + 1) -valent hydrocarbon groups, or an oxygen atom, a sulfur atom, —CO—, —OCO—, —CS—, —SO—, —SO ₂ — or —NR— (R; hydrogen) For example, a (p + 1) -valent group containing a sulfur atom, or the like, in combination with an atom or a monovalent hydrocarbon group having 1 to 30 carbon atoms.

Examples of the (p + 1) -valent hydrocarbon group having 1 to 30 carbon atoms include the (p + 1) -valent hydrocarbon group having 1 to 30 carbon atoms exemplified in the description of R ¹ described above.

The monovalent hydrocarbon group having 1 to 30 carbon atoms represented by R of —NR— is the one having 1 to 30 carbon atoms represented by R of —NR— exemplified in the description of R ¹ described above. A monovalent hydrocarbon group can be mentioned.

Further, as described above, sites that are not involved in the main chain bond R ⁴ in the general formula (5) may be substituted.
Examples of the substituent that substitutes a site that does not participate in the main chain bond of R ⁴ include the substituent that substitutes a site that does not participate in the main chain bond exemplified in the above description of R ¹ .

In the present embodiment, from the viewpoint of enhancing the adhesion to the resist, R ⁴ in the general formula (5) is preferably a single bond, a sulfur atom or a group containing a sulfur atom, Among these, a divalent group derived from the structure represented by the chemical formula (R ⁴ -1) or (R ⁴ -2) is more preferable.

In the present embodiment, R ⁵ in the general formula (5) is a hydrogen atom, a fluorine atom, or a monovalent organic group. M in the general formula (5) is an integer of 1 to 3, and preferably m = 3.

The monovalent organic group for R ⁵ is a group containing at least one carbon atom, and includes, for example, a cyano group, an alkyl group, a cyanoalkyl group having 2 to 6 carbon atoms or an alkylcarbonyloxy group, and 2 to 5 carbon atoms. Alkenyl group, an aryl group having 6 to 10 carbon atoms or an aralkyl group having 7 to 12 carbon atoms.
In addition, some or all of the hydrogen atoms contained in these groups may be substituted with fluorine atoms.

Among these, R ⁵ in the general formula (5) is preferably an alkyl group from the viewpoint of reactivity and ease of handling of the substance.

In the present embodiment, R ⁶ in the general formula (5) is a hydrogen atom, a fluorine atom, or a monovalent organic group. In the general formula (5), l is an integer of 0 to 2, and it is preferable that l = 0.
Examples of the monovalent organic group for R ⁶ include the monovalent organic groups exemplified in the above description of R ⁵ .

In the present embodiment, Z is a hydrogen atom or a monovalent organic group.
Examples of the monovalent organic group of X include the monovalent organic groups exemplified in the above description of R ⁵ .

  In the present embodiment, from the viewpoint of easy handling of the substance, the Z is preferably an alkyl group.

In the present embodiment, from the viewpoint of reactivity, the Z is particularly preferably a monovalent acid dissociable group. In the present embodiment, the “acid-dissociable group” refers to a group that substitutes a hydrogen atom of a carboxy group and dissociates by the action of an acid.
Examples of the acid dissociable group for Z include a group represented by the following general formula (Z-1).

(In formula (Z-1), each R ⁷ independently represents a linear or branched alkyl group having 1 to 5 carbon atoms or a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms. Or a substituted derivative thereof, or any two R ⁷ 's bonded to each other, and a divalent alicyclic hydrocarbon group having 4 to 20 carbon atoms and a substituted derivative thereof together with the carbon atoms to which they are bonded. The remaining R ⁷ is a linear or branched alkyl group having 1 to 5 carbon atoms, a monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms, or a substituted derivative thereof.

  Examples of the linear or branched alkyl group having 1 to 5 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a 2-methylpropyl group, 1- Examples thereof include a methylpropyl group and a tert-butyl group.

Monovalent alicyclic hydrocarbon group having 4 to 20 carbon atoms R ^7, and any two of R ⁷ is 2 having 4 to 20 carbon atoms formed together with the carbon atom bonded respectively bonded to each other Examples of the valent alicyclic hydrocarbon group include groups derived from cycloalkanes such as cyclobutane, cyclopentane, cyclopentene, cyclohexane, cyclohexene, cycloheptane, cyclooctane, or cycloalkenes; ] Alicyclic rings such as heptane, bicyclo [2.2.2] octane, tricyclo [5.2.1.02,6] decane, tetracyclo [6.2.13,6.02,7] dodecane, adamantane, etc. And groups derived from formula hydrocarbons.

Examples of the substituent in the substituted derivative of the monovalent or divalent alicyclic hydrocarbon group include a substituent that substitutes a site not involved in the main chain bond exemplified in the description of R ¹ described above.
One or more or one or more of these substituents may be present in each substituted derivative.

  Examples of the group represented by the general formula (Z-1) include tert-butyl group, tert-amyl group, 2-ethyl-2-butyl group, 3-methyl-3-pentyl group, 1,1- Alkyl groups such as diethylpropyl group; 1 such as 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-n-propylcyclopentyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-n-propylcyclohexyl group An alkylcycloalkyl group;

  Among these, from the viewpoint of improving peelability, Z is preferably an alkyl group having 1 to 5 carbon atoms, and particularly preferably a tert-butyl group.

  Specific examples of the structural unit (II) include structural units derived from compounds represented by the following chemical formulas (II-1) to (II-5).

  In addition, (A) polysiloxane may contain 1 type of structural units (II), and may contain 2 or more types.

[Structural unit (III)]
Moreover, (A) polysiloxane may contain the structural unit (III) derived from tetraalkoxysilane in addition to the structural units (I) and (II) from the viewpoint of oxygen ashing resistance.

  In the tetraalkoxysilane that gives the structural unit (III), all of the four alkoxy groups bonded to the Si atom may be the same, or all or part of them may be different.

The alkoxy group is preferably an alkoxy group having 1 to 8 carbon atoms.
The alkoxy group is not limited to a straight chain, and may be branched or cyclic.

  Specific examples of the tetraalkoxysilane that gives the structural unit (III) include, for example, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-iso-propoxysilane, tetra-n-butoxysilane, and tetra-sec. -Butoxysilane, tetra-tert-butoxysilane, tetrakis (2-ethylbutoxy) silane and the like.

  Of these, tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, and tetra-iso-propoxysilane are particularly preferred as tetraalkoxysilanes that give structural unit (III) from the viewpoint of reactivity and ease of handling of substances. Tetra-n-butoxysilane and tetra-sec-butoxysilane are preferable, and tetraethoxysilane is more preferable.

  In addition, (A) polysiloxane may contain 1 type of structural units (III), and may contain 2 or more types.

[Structural unit (IV)]
Moreover, (A) polysiloxane may contain the structural unit (IV) derived from the compound represented by the following general formula (6).

(In Formula (6), R ⁸ is a light-absorbing group, R ⁹ and R ¹⁰ are monovalent organic groups, a is an integer of 1 to 3, and b is an integer of 1 to 3. Yes, c is an integer from 0 to 2, and a + b + c is 4.)

Examples of the light absorbing group of R ^{8 in} the general formula (6) include a group having an aromatic ring and a carbonyl group.
In general formula (6), when b is 2 or 3, two or three R ^{8 s} may all be the same, or all or part of them may be different.

R ⁹ and R ¹⁰ in the general formula (6) are monovalent organic groups.
Examples of the monovalent organic group for R ⁹ and R ¹⁰ include the monovalent organic groups exemplified in the above description of X.

Among these, R ^{9 in the} general formula (6) is preferably a methyl group or an ethyl group, and more preferably a methyl group.
Incidentally, in the general formula (6), when a is 2 or 3, two or three R ⁹ bonded to the oxygen atom may all be the same, may be different for all or part.
In the general formula (6), when c is 2, two R ¹⁰ may be the same or different.

  Specific examples of the silane monomer that gives the structural unit (IV) include phenyltrimethoxysilane, 4-methylphenyltrimethoxysilane, 4-ethylphenyltrimethoxysilane, 4- (n-propyl) phenyltrimethoxysilane, 4- (Iso-propyl) phenyltrimethoxysilane, 4- (n-butyl) phenyltrimethoxysilane, 4- (2-methylpropyl) phenyltrimethoxysilane, 4- (1-methylpropyl) phenyltrimethoxysilane, 4- (Tert-butyl) phenyltrimethoxysilane, 4-methoxyphenyltrimethoxysilane, 4-methylbenzyltrimethoxysilane and the like can be mentioned. Phenyltrimethoxysilane and 4-methylphenyltrimethoxysilane are preferable, and phenyltrimethoxysilane is more preferable.

  In addition, (A) polysiloxane may contain 1 type of structural units (IV), and may contain 2 or more types.

  (A) In the polysiloxane, the proportion of each structural unit is preferably from 1 to 60 mol%, and preferably from 2 to 25 mol%, based on the raw material monomers, the total content of the structural units (I) and (II). It is more preferable, and it is still more preferable that it is 5-20 mol%. This is because if the content is less than 1 mol%, the effects of the present invention may not be sufficiently exhibited, and if it exceeds 30 mol%, storage stability may be deteriorated. In addition, in (A) polysiloxane, structural unit (I) and (II) may contain either one or both.

  Moreover, it is preferable that the content rate of structural unit (III) is 55-85 mol% on the basis of a raw material monomer, and it is more preferable that it is 60-80 mol%. This is because when the content ratio is 55 to 85 mol%, a silicon-containing film excellent in oxygen ashing resistance can be formed, and a composition excellent in oxygen ashing resistance can be obtained.

  Furthermore, the content ratio of the structural unit (IV) is preferably 1 to 40 mol%, more preferably 5 to 30 mol%, and still more preferably 10 to 20 mol%, based on the raw material monomer. This is because when the content ratio is 10 to 40 mol%, a composition having an excellent antireflection function can be obtained.

The “raw material monomer standard” in the present specification refers to the ratio of the raw material monomer for obtaining the corresponding structural unit with respect to the total amount of the raw material monomer used in the production of the copolymer.
Such a content rate of each structural unit can be estimated from the analysis result of a 29Si-NMR spectrum, for example.

  The weight average molecular weight in terms of polystyrene (hereinafter also referred to as “Mw”) measured by (A) polysiloxane gel permeation chromatography (GPC) is preferably 1000 to 15000, and preferably 1000 to 10,000. More preferably, it is 1500-6000. This is because when the Mw is 1000 to 15000, coating properties and storage stability are good.

  In this embodiment, (A) polysiloxane can be manufactured by a well-known method.

  In addition, (A) polysiloxane may be contained in the silicon-containing film-forming composition according to the present embodiment, or may be contained in two or more kinds.

<(B) Organic solvent>
In order to obtain the silicon-containing film-forming composition according to this embodiment in addition to (A) polysiloxane, the silicon-containing film-forming composition according to this embodiment is used for the purpose of dissolving or dispersing (A) polysiloxane. (B) An organic solvent may be contained.

  (B) Examples of the organic solvent include n-pentane, iso-pentane, n-hexane, i-hexane, n-heptane, iso-heptane, 2,2,4-trimethylpentane, n-octane and iso-octane. Aliphatic hydrocarbon solvents such as cyclohexane and methylcyclohexane; benzene, toluene, xylene, ethylbenzene, trimethylbenzene, methylethylbenzene, n-propyl benzene, iso-propyl benzene, diethylbenzene, iso-butylbenzene, triethylbenzene, di- Aromatic hydrocarbon solvents such as iso-propyl benzene, n-amyl naphthalene, trimethylbenzene; methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, t rt-butanol, n-pentanol, iso-pentanol, 2-methylbutanol, sec-pentanol, tert-pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2- Ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethylheptanol-4, n-decanol, sec-undecyl alcohol, trimethyl Nonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, phenol, cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol, benzyl alcohol, phenyl Monoalcohol solvents such as lucarbinol, diacetone alcohol, cresol; ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, 2,4-pentanediol, 2-methyl-2,4-pentanediol, 2 , 5-hexanediol, 2,4-heptanediol, 2-ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, glycerin and other polyhydric alcohol solvents;

  Acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, diethyl ketone, methyl-iso-butyl ketone, methyl-n-pentyl ketone, ethyl-n-butyl ketone, methyl-n-hexyl ketone, di-iso- Ketone solvents such as butyl ketone, trimethylnonanone, cyclohexanone, methylcyclohexanone, 2,4-pentanedione, acetonylacetone, diacetone alcohol, acetophenone, fenchon; ethyl ether, iso-propyl ether, n-butyl ether, n- Hexyl ether, 2-ethylhexyl ether, ethylene oxide, 1,2-propylene oxide, dioxolane, 4-methyldioxolane, dioxane, dimethyldioxane, 2-methoxyethanol, 2 Ethoxyethanol, ethylene glycol diethyl ether, 2-n-butoxyethanol, 2-n-hexoxyethanol, 2-phenoxyethanol, 2- (2-ethylbutoxy) ethanol, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether Diethylene glycol diethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol di-n-butyl ether, diethylene glycol mono-n-hexyl ether, ethoxytriglycol, tetraethylene glycol di-n-butyl ether, 1-n-butoxy-2-propanol, 1-phenoxy-2-propanol, propylene glycol monomethyl ether, propylene glycol Monoethyl ether, propylene glycol monopropyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether, tripropylene glycol monomethyl ether, tetrahydrofuran, ether solvents such as 2-methyltetrahydrofuran;

  Diethyl carbonate, methyl acetate, ethyl acetate, γ-butyrolactone, γ-valerolactone, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec -Pentyl, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, methyl acetoacetate, ethyl acetoacetate, ethylene glycol monomethyl acetate Ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, propylene glycol acetate Monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, glycol diacetate, methoxytriglycol acetate, propionic acid Ethyl, n-butyl propionate, iso-amyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, diethyl malonate, dimethyl phthalate, Ester solvents such as diethyl phthalate; N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N- Nitrogen-containing solvents such as methylacetamide, N-methylpropionamide, N-methylpyrrolidone; sulfur-containing solvents such as dimethyl sulfide, diethyl sulfide, thiophene, tetrahydrothiophene, dimethyl sulfoxide, sulfolane, 1,3-propane sultone, etc. Can be mentioned.

Among these, as the organic solvent (B), ether solvents and ester solvents are preferable, and among ether solvents and ester solvents, glycol solvents are more preferable because they are excellent in film formability.
Examples of the glycol solvent include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate and the like.
In addition, these (B) organic solvents may be used individually by 1 type, and may be used in combination of 2 or more type.

  As a minimum of content of (B) organic solvent in a silicon-containing film formation material, 80 mass% is preferred and 90 mass% is more preferred. As an upper limit of the said content, 99.8 mass% is preferable and 99 mass% is more preferable.

<Other ingredients>
The composition for forming a silicon-containing film according to this embodiment may contain other components in addition to (A) polysiloxane as long as the effects of this embodiment are not impaired. Examples of other components include a compound having at least one of a sulfur atom and a carbonyl group, a surfactant, and water.

[Compound having at least one of sulfur atom and carbonyl group]
The silicon-containing film-forming composition preferably contains a compound having at least one of a sulfur atom and a carbonyl group. When the silicon-containing film-forming composition contains a compound having at least one of a sulfur atom and a carbonyl group, a sulfur atom and / or a carbonyl group in the step of bringing an oxidizing gas or liquid into contact with the silicon-containing film. It is surmised that, by being oxidized, hydrophilicity is imparted, and excellent basic liquid peeling performance is exhibited during wet peeling with a basic liquid, and the silicon-containing film can be removed more effectively.
More preferably, the compound having a sulfur atom has at least one selected from a sulfide group, a sulfoxide group, a sulfonyl group, a sulfanyl group, and a carbonyl group. The group having a sulfonyl group is preferably a sulfo group or a sulfonate group. By having these groups, the resistance to pattern collapse of the formed resist pattern can be improved.
Further, the sulfoxide group, sulfonyl group or carbonyl group, which is considered to be reduced in the step of bringing a gas containing a reducing component into contact with the silicon-containing film, is a step of bringing an oxidizing gas or liquid into contact with the silicon-containing film. It is inferred that, by being oxidized in the step, hydrophilicity is imparted again, and excellent basic liquid peeling performance is exhibited during wet peeling with a basic liquid, and the silicon-containing film can be removed more effectively. . In addition, the sulfide group or sulfanyl group has an excellent basic property in wet peeling with a basic liquid because sulfur atoms are oxidized and hydrophilicity is imparted in the step of contacting an oxidizing gas or liquid with the silicon-containing film. It is presumed that the silicon-containing film can be removed more effectively by showing liquid peeling performance. Among these, a sulfonyl group is more preferable. As the group having a sulfonyl group, a sulfonic acid group and a sulfonic acid ester group are particularly preferable.

  The compound having a sulfonyl group is preferably a compound having at least one selected from a sulfo group and a sulfonic acid ester group, and specifically has a partial structure represented by the following general formula (1).

(In the formula (1), when L, —SO ₂ —O— * and X do not constitute a ring, L is a single bond or a divalent organic group, and X is a hydrogen atom or a monovalent organic group. When L, —SO ₂ —O— * and X form a ring, L is a trivalent organic group, and X is a divalent organic group (where * is a bond between O and X). Indicates position)))

  Specific examples of the compound having at least one of a sulfur atom and a carbonyl group include compounds represented by the following chemical formulas (1a) to (1h).

In the present embodiment, the content of the compound having at least one of a sulfur atom and a carbonyl group in the silicon-containing film forming composition is preferably 0.01% by mass to 30% by mass, more preferably 0.1% by mass to 20 mass% is more preferable, 0.2 mass%-15 mass% is further more preferable.
In addition, the compound which has at least any one of these sulfur atoms and carbonyl groups may be used individually by 1 type, and may be used in combination of 2 or more type.

[Surfactant]
The silicon-containing film-forming composition according to this embodiment may contain a surfactant for the purpose of improving applicability, striation, and the like.
Examples of the surfactant include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene n-octylphenyl ether, polyoxyethylene n-nonylphenyl ether, polyethylene glycol dilaurate, polyethylene In addition to nonionic surfactants such as glycol distearate, the following trade names are KP341 (manufactured by Shin-Etsu Chemical Co., Ltd.), Polyflow No. 75, no. 95 [above, manufactured by Kyoeisha Chemical Co., Ltd.], Ftop EF301, EF303, EF352 [above, manufactured by Tochem Products Co., Ltd.], MegaFac F171, F173 [above, manufactured by Dainippon Ink & Chemicals, Inc.], Fluorad FC430, FC431 (above, manufactured by Sumitomo 3M), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 [ As described above, manufactured by Asahi Glass Co., Ltd.).
In addition, these surfactants may be used individually by 1 type, and may be used in combination of 2 or more type. Moreover, the compounding quantity of surfactant can be suitably determined according to the objective.

[water]
The silicon-containing film forming composition according to this embodiment may contain water. When water is contained, since (A) polysiloxane is hydrated, the storage stability of the silicon-containing film-forming composition is improved. Further, when water is contained, curing during the formation of the silicon-containing film is promoted, and a dense film can be obtained. The water content in the silicon-containing film-forming composition is preferably 0.01% by mass to 30% by mass, more preferably 0.1% by mass to 20% by mass, and 0.2% by mass to 15% by mass. Is more preferable. If the water content exceeds the above upper limit, the storage stability of the polysiloxane composition may be reduced, and the uniformity of the coating film may be reduced.

<Method for Preparing Silicon-Containing Film-Forming Composition>
The method for preparing the composition for forming a silicon-containing film according to this embodiment is not particularly limited. For example, by mixing (A) polysiloxane, (B) solvent, and other components at a predetermined ratio. Can be prepared. As solid content concentration of the said silicon-containing film formation composition, it is 0.5 mass%-20 mass% normally, 1 mass%-15 mass% are preferable, and 1 mass%-10 mass% are more preferable.

  The lower limit of the contact angle of the silicon-containing film with respect to pure water is preferably 40 °, particularly preferably 45 °. The upper limit is preferably 80 °, and particularly preferably 75 °. In the present specification, unless otherwise specified, the contact angle indicates a measured value at 25 ° C. By making the contact angle of the silicon-containing film within the above range, the wettability of the basic liquid in the silicon-containing film removal step described later and the adhesion of the resist pattern usually formed on the silicon-containing film are improved. be able to.

  After apply | coating the said silicon-containing film formation composition, you may volatilize the solvent in a coating film by prebaking (PB) as needed. The PB temperature is appropriately selected depending on the composition of the composition, but is usually about 50 ° C to 450 ° C. Further, the PB time is usually about 5 seconds to 600 seconds.

<Resist pattern formation process (1'-1)>
In this step, a resist pattern is formed on the silicon-containing film formed in [Silicon-containing film forming step]. In this step, the resist pattern can be formed by a conventionally known method such as a method using a resist composition or a method using a nanoimprint lithography method.

<Etching step (1'-2)>
In this step, the silicon-containing film is etched using the resist pattern as a mask to form a pattern on the silicon-containing film.
This etching can be performed using, for example, a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the elemental composition of the silicon-containing film to be etched, and examples thereof include CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF _{6, and the} like. Fluorine gas, chlorine gas such as Cl ₂ and BCl ₃ , oxygen gas such as O ₂ , O ₃ and H ₂ O, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , C ₂ H ₂ , Reducing gases such as 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 , He, N ₂ An inert gas such as Ar is used, and these gases may be used in combination. For dry etching of a silicon-containing film, a fluorine-based gas is usually used, and a mixture of an oxygen-based gas and an inert gas is preferably used.

<Reducing component contact step (2)>
In this step, a gas containing a reducing component is brought into contact with the silicon-containing film. For example, in the etching step (1′-2), if a silicon-containing film is dry-etched using a gas containing a reducing component, the gas containing the reducing component comes into contact with the silicon-containing film. Examples of the gas containing the reducing component include H ₂ , CH ₄ , C ₂ H ₂ , C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , HF, HI, HBr, HCl, CO, NO, NH ₃ , BCl _{3 and the} like can be mentioned. Among these, a gas containing H ₂ is preferably used. In addition, these gases can also be mixed and used. More specifically, an N ₂ / H ₂ mixed gas can be used.
In addition, you may perform a reducing component contact process by multiple different gas.

<Reducing component etching step (2 ')>
Using the silicon-containing film pattern obtained in the etching step (1′-2) as a mask, the organic underlayer film is dry-etched using a gas containing a reducing component to form a pattern in the organic underlayer film. At this time, the gas containing the reducing component comes into contact with the silicon-containing film pattern. Thereafter, since the silicon-containing film is removed in a silicon-containing film removal step described later, a substrate having a patterned organic underlayer film can be obtained, and a pattern can be formed on the substrate using this. This dry etching can be performed using a known dry etching apparatus. Etching gas containing a reducing component used for dry etching includes H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , C ₂ H ₂ , C ₂ H ₄ , C ₂ H ₆ , C ₃ H ₄ , C ₃ H ₆ , C ₃ H ₈ , HF, HI, HBr, HCl, NO, NH ₃ , BCl _{3 and the} like can be mentioned. Among these, a gas containing H ₂ is preferably used. In addition, these gases can also be mixed and used. More specifically, an N ₂ / H ₂ mixed gas can be used. Etching may be performed by a plurality of different etching gases.

This step may include a step of further dry etching the substrate using the organic underlayer film pattern as a mask. This dry etching can be performed using a known dry etching apparatus. The etching gas used for dry etching can be appropriately selected depending on the organic underlayer film to be etched and the elemental composition of the substrate. For example, CHF ₃ , CF ₄ , C ₂ F ₆ , C ₃ F ₈ , SF ₆ fluorine gas, chlorine gas such as Cl ₂ and BCl ₃ , oxygen gas such as O ₂ , O ₃ , and H ₂ O, H ₂ , NH ₃ , CO, CO ₂ , CH ₄ , C ₂ H ₂ , reducing gas such as 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 , He, An inert gas such as N ₂ or Ar is used. Etching may be performed by a plurality of different etching gases. In addition, when the silicon-containing film remains on the upper side of the organic lower layer pattern, the silicon-containing film can be removed in a silicon-containing film removing step described later.

<Oxidizing component contact step (3) and (3 ')>
In this step, an oxidizing gas or liquid is brought into contact with the silicon-containing film. An example of the oxidizing gas is O ₂ .
Examples of the method for contacting the oxidizing liquid include a method in which the substrate is immersed in a bath filled with the oxidizing liquid for a certain time (dip method), and the oxidizing liquid is raised on the surface of the substrate by surface tension for a certain time. Method of stationary (paddle method), method of spraying oxidizing liquid on the substrate surface (spraying method), oxidizing while scanning the oxidizing liquid application nozzle at a constant speed on the substrate rotating at a constant speed And a method of continuously applying the liquid (dynamic dispensing method).
As immersion time, it is 1 second-1 hour normally, and 10 second-30 minutes are preferable. Thereafter, rinsing with pure water or the like is performed to remove the used oxidizing liquid. An appropriate amount of a surfactant can be added to the oxidizing liquid as necessary. As the surfactant, for example, an ionic or nonionic fluorine-based surfactant and / or a silicon-based surfactant can be used.
Examples of the oxidizing liquid include a liquid containing hydrogen peroxide and water. In the case of hydrogen peroxide water, the lower limit of the content ratio of hydrogen peroxide to water is preferably 1% or more, more preferably 3% or more, and further preferably 5% or more. The upper limit of the content ratio of hydrogen peroxide to water is preferably 40% or less, more preferably 30% or less, from the viewpoint of safety. This step is preferably performed at less than 100 ° C. The lower limit of the temperature of the oxidizing gas or liquid is preferably 20 ° C. or higher, more preferably 50 ° C. or higher, and particularly preferably 60 ° C. or higher. The upper limit is preferably 100 ° C. or lower, more preferably 90 ° C. or lower, and particularly preferably 80 ° C. or lower.

<Removal step (4) and (4 ′)>
In this step, the silicon-containing film is removed using a basic liquid. It is preferable that the said removal process is performed at less than 100 degreeC. The removal of the silicon-containing film in this step can be performed, for example, by immersing the substrate on which the silicon-containing film is formed in a heated basic liquid. As temperature of a basic liquid, it is 30 to 100 degreeC normally, 40 to 95 degreeC is preferable and 50 to 90 degreeC is more preferable. As immersion time, it is 1 second-1 hour normally, and 10 second-30 minutes are preferable. Then, pure water rinse etc. are performed and the used basic liquid is removed.

The basic liquid is preferably a liquid containing at least one nitrogen compound selected from the group consisting of ammonia, organic amines, and tetraalkylammonium salts.
As the organic amine, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, and triethylamine are preferable.
As the tetraalkylammonium salt, tetramethylammonium hydroxide and tetraethylammonium hydroxide are preferable. The basic liquid is preferably an aqueous solution of the nitrogen compound.
An aqueous ammonia solution and an aqueous tetramethylammonium hydroxide solution are particularly preferred.

  Here, the content of water in the basic liquid is usually 40% by mass or more, preferably 60% by mass or more, and more preferably 80% by mass or more.

  As a density | concentration of these basic liquids, it is 0.1 mass%-40 mass% normally, and 0.5 mass%-30 mass% are preferable.

Further, the basic liquid preferably further contains hydrogen peroxide because the removability of the silicon-containing film is further improved. More specifically, a mixed aqueous solution (SC1) of ammonia and hydrogen peroxide is particularly preferable.
The content ratio of hydrogen peroxide is preferably nitrogen compound: hydrogen peroxide = 1/1/500 to 1: 500 in terms of mass ratio to the nitrogen compound in the basic liquid.

  By performing this step after step (1 '), the silicon-containing film that has not been properly applied can be peeled off, and reworking such as forming the silicon-containing film again becomes possible. By performing after the step (1′-1), the resist film that has not been properly patterned can be removed together with the silicon-containing film by removing the silicon-containing film, and the silicon-containing film and the resist film can be separated again. Reworking such as forming becomes possible. Moreover, this process can also be performed after forming a pattern in a silicon-containing film | membrane by process (1'-2). Thereby, since the silicon-containing film or the like that has not been properly patterned can be peeled off by the above-described silicon-containing film removal step, reworking such as forming the silicon-containing film and the resist film again becomes possible. Furthermore, this step can be performed after the pattern is formed on the resist underlayer film in the step (2 '), or can be performed after the pattern is formed on the substrate.

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

  The determination of the solid content and the measurement of the weight average molecular weight (Mw) in this example were carried out by the following methods.

[Determination of solid content]
By baking 0.5 g of the resin solution for 30 minutes at 250 ° C., the weight of the solid content relative to 0.5 g of the resin solution was measured, and the content ratio of the solid content was determined.

[Measurement of weight average molecular weight (Mw)]
GPC column [manufactured by Tosoh Corporation] (2 product names “G2000HXL”, 1 product name “G3000HXL”, 1 product name “G4000HXL”), flow rate: 1.0 mL / min, elution solvent: tetrahydrofuran, column Temperature: Measured by gel permeation chromatography (GPC) using monodisperse polystyrene as a standard under analysis conditions of 40 ° C.

1. (A) Synthesis of Polysiloxane In each of the synthesis examples described below, (A) polysiloxane was synthesized using compounds represented by the following chemical formulas (M-1) to (M-7) as monomers.

<Synthesis Example 1: (A-1) Polysiloxane>
An aqueous oxalic acid solution was prepared by dissolving 0.45 g of oxalic acid in 21.6 g of water by heating. Then, compound 10.65 g represented by chemical formula (M-1), compound 0.99 g represented by chemical formula (M-2), compound 4.74 g represented by chemical formula (M-4), and propylene glycol monoethyl ether 53.5 g. A dropping tube containing the cooling tube and the prepared aqueous oxalic acid solution was set in the flask containing the. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 45.4 g of a resin solution. The solid content in this resin solution was (A-1) polysiloxane.
The content ratio of the solid content in the obtained resin solution was 7.0% as a result of measurement by a firing method. Moreover, the weight average molecular weight (Mw) of solid content was 2,000.

<Synthesis Example 2: (A-2) Polysiloxane>
An aqueous oxalic acid solution was prepared by dissolving 0.45 g of oxalic acid in 21.6 g of water by heating. Then, compound 10.80 g shown in chemical formula (M-1), compound 0.50 g shown in chemical formula (M-2), compound 2.03 g shown in chemical formula (M-3), compound shown in chemical formula (M-4) A cooling tube and a dropping funnel containing the prepared aqueous oxalic acid solution were set in a flask containing 2.37 g and 53.5 g of propylene glycol monoethyl ether. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 45.4 g of a resin solution. The solid content in this resin solution was (A-2) polysiloxane.
The content ratio of the solid content in the obtained resin solution was 7.5% as a result of measurement by a firing method. Moreover, the weight average molecular weight (Mw) of solid content was 2,000.

<Synthesis Example 3: (A-3) Polysiloxane>
An aqueous oxalic acid solution was prepared by dissolving 0.45 g of oxalic acid in 21.6 g of water by heating. Thereafter, 10.65 g of the compound represented by the chemical formula (M-1), 1.35 g of the compound represented by the chemical formula (M-3), 3.44 g of the compound represented by the chemical formula (M-5), and 53.5 g of propylene glycol monoethyl ether. A dropping tube containing the cooling tube and the prepared aqueous oxalic acid solution was set in the flask containing the. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 45.4 g of a resin solution. The solid content in this resin solution was (A-3) polysiloxane.
The content ratio of the solid content in the obtained resin solution was 7.0% as a result of measurement by a firing method. Moreover, the weight average molecular weight (Mw) of solid content was 2,000.

<Synthesis Example 4: (A-4) Polysiloxane>
An aqueous oxalic acid solution was prepared by dissolving 0.45 g of oxalic acid in 21.6 g of water by heating. Then, compound 10.65 g represented by chemical formula (M-1), compound 1.35 represented by chemical formula (M-3), compound 3.33 g represented by chemical formula (M-6), and propylene glycol monoethyl ether 53.5 g. A dropping tube containing the cooling tube and the prepared aqueous oxalic acid solution was set in the flask containing the. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 45.4 g of a resin solution. The solid content in this resin solution was (A-4) polysiloxane.
The content ratio of the solid content in the obtained resin solution was 7.0% as a result of measurement by a firing method. Moreover, the weight average molecular weight (Mw) of solid content was 2,000.

<Synthesis Example 5: (A-5) Polysiloxane>
An aqueous oxalic acid solution was prepared by dissolving 0.45 g of oxalic acid in 21.6 g of water by heating. Then, compound 10.65 g represented by chemical formula (M-1), compound 1.35 represented by chemical formula (M-3), compound 2.05 g represented by chemical formula (M-7), and propylene glycol monoethyl ether 53.5 g. A dropping tube containing the cooling tube and the prepared aqueous oxalic acid solution was set in the flask containing the. Subsequently, after heating to 60 degreeC with an oil bath, the oxalic acid aqueous solution was dripped slowly, and it was made to react at 60 degreeC for 4 hours. After completion of the reaction, the flask containing the reaction solution was allowed to cool and then set in an evaporator, and methanol produced by the reaction was removed to obtain 45.4 g of a resin solution. The solid content in this resin solution was (A-5) polysiloxane.
The content ratio of the solid content in the obtained resin solution was 7.0% as a result of measurement by a firing method. Moreover, the weight average molecular weight (Mw) of solid content was 2,000.

<Result>
It shows in Table 1 about the usage-amount of the monomer in the resin solution obtained in the synthesis examples 1-5, solid content concentration, and the weight average molecular weight (Mw) of solid content.
In Table 1, the resin composition (theoretical value, unit: mol%) determined by the amount of each monomer used is also shown.

2. Preparation of composition for forming silicon-containing film Using the polysiloxanes (A-1) to (A-5) obtained in each of the synthesis examples described above and the (B) solvent, Synthesis Example 1 was performed as shown below. ~ 5 silicon-containing film forming compositions were prepared.
In this example, “parts” means all parts by mass. In this example, propylene glycol monoethyl ether (B-1) was used as an example of the solvent.

<Preparation Example 1>
As shown in Table 2, after 1.2 parts of (A-1) polysiloxane obtained in Synthesis Example 1 was dissolved in 98.8 parts of (B) solvent, this solution was filtered with a filter having a pore diameter of 0.2 μm. The silicon-containing film forming composition of Preparation Example 1 was obtained by filtration.

<Preparation Examples 2-5>
Except having used each component in the ratio shown in Table 2, the composition (J-1)-(J-5) for silicon-containing film formation of the preparation examples 2-5 was prepared by the method similar to the preparation example 1. FIG.

3. Evaluation A silicon-containing film-coated substrate was formed using the silicon-containing film-forming compositions (J-1) to (J-5) of Preparation Examples 1 to 5 obtained as described above, and the following various evaluations were made. went.

The method for forming the substrate will be described below.
Each of the silicon-containing film forming compositions (J-1) to (J-5) obtained as described above was applied onto a silicon wafer (substrate) by a spin coating method.
Thereafter, baking is performed in an air atmosphere under baking conditions of a temperature of 220 ° C. and a time of 60 seconds to form a silicon-containing film having a thickness of 30 nm, and a “substrate with silicon-containing film” in which a silicon-containing film is formed on the substrate. Obtained.

[Solvent resistance]
The substrate obtained above was immersed in cyclohexanone (room temperature) for 10 seconds.
The film thickness before and after immersion was measured using a spectroscopic ellipsometer UV1280E (manufactured by KLA-TENCOR), and the film thickness change rate was calculated from the measured value. The solvent resistance was evaluated as “◯” (good) when the film thickness change rate was less than 1%, and “x” (bad) when the film thickness change rate was 1% or more.

[TMAH developer resistance]
The substrate obtained above was immersed in a 2.38% TMAH developer (room temperature) for 60 seconds.
The film thickness before and after the immersion was measured using a spectroscopic ellipsometer UV1280E (manufactured by KLA-TENCOR), and the film thickness change rate was calculated from the measured value. The solvent resistance was evaluated as “◯” (good) when the film thickness change rate was less than 1%, and “x” (bad) when the film thickness change rate was 1% or more.

[Etching resistance]
An N ₂ / H ₂ mixed gas is used as an example of a gas containing a reducing component for the substrate obtained above using an etching apparatus (“TACTRAS” manufactured by Tokyo Electron Ltd.), and N ₂ / H ₂ = 250. / 150 sccm, PRESS. = 30 mT, HF RF = 350 W, LF RF = 50 W, DCS = -10 V, RDC = 70%, and processed for 60 sec. The etching rate (nm / min) was calculated from the average film thickness before and after the treatment. The etching resistance was evaluated as “◯” (good) when the etching rate (nm / min) was less than 10, and “x” (bad) when the etching rate was 10 or more.

[Oxidizing substance resistance]
The substrate after etching was immersed in 9% hydrogen peroxide (65 ° C.) for 10 minutes as an example of an oxidizing substance.
The film thickness before and after immersion was measured using a spectroscopic ellipsometer UV1280E, and the film thickness change rate was calculated from the measured value. Oxidizing substance resistance was evaluated as “◯” (good) when the rate of change in film thickness was less than 1%, and “x” (poor) when it was 1% or more.

  The results of solvent resistance, TMAH developer resistance, etching resistance and oxidizing substance resistance are shown in Table 3 below.

  As shown in Table 3, solvent resistance, TMAH developer resistance, etching resistance, and oxidizing substance resistance of silicon-containing films formed using the respective silicon-containing film-forming compositions (J-1) to (J-5) are All were good.

[Basic liquid peelability]
The substrates before evaluation of the oxidizing substance resistance (without hydrogen peroxide solution treatment) are referred to as Comparative Examples 1 to 5, and the substrates after evaluation of the oxidizing substance resistance (with hydrogen peroxide solution treatment) are Examples 1 to 5. As a result, it was immersed in a basic liquid (25% aqueous ammonia solution / 30% aqueous hydrogen peroxide solution / water = 1/1/5 mixed aqueous solution) heated to 65 ° C. for 5 minutes. The film thickness after immersion is measured using a spectroscopic ellipsometer UV1280E (manufactured by KLA-TENCOR). When peelable within 2 minutes, “◯”, when peelable within 2-3 minutes, “△”, over 3 minutes When peelable, it was evaluated as “x”.

  The results of basic liquid peelability are shown in Table 4 below.

  Even when the gas containing the reducing component is brought into contact with the silicon-containing film as shown in Table 4, the oxidizing component contacting step is performed immediately before the silicon-containing film removing step using the basic liquid. Thus, it can be seen that the silicon-containing film removability using a basic liquid is good.

Claims (9)

A silicon-containing film forming step (1) for forming a silicon-containing film on the substrate;
A reducing component contact step (2) in which a gas containing a reducing component is brought into contact with the silicon-containing film.
An oxidizing component contact step (3) for contacting an oxidizing gas or liquid with the silicon-containing film, and a removing step (4) for removing the silicon-containing film using a basic liquid.
I have a,
The silicon-containing film is formed by a composition for forming a silicon-containing film containing polysiloxane and an organic solvent,
The silicon-containing film forming method, wherein the silicon-containing film-forming composition contains a component having a sulfur atom . An organic underlayer film forming step (0) for forming an organic underlayer film on the substrate;
A silicon-containing film forming step (1 ′) for forming a silicon-containing film on the organic underlayer film,
A reducing component etching step (2 ′) for etching the organic underlayer using a gas containing a reducing component,
An oxidizing component contact step (3 ′) in which an oxidizing gas or liquid is brought into contact with the silicon-containing film, and a removing step (4 ′) in which the silicon-containing film is removed using a basic liquid.
I have a,
The silicon-containing film is formed by a composition for forming a silicon-containing film containing polysiloxane and an organic solvent,
The silicon-containing film forming method, wherein the silicon-containing film-forming composition contains a component having a sulfur atom . After the silicon-containing film forming step (1 ′) and before the reducing component etching step (2 ′),
A resist pattern forming step (1′-1) for forming a resist pattern on the silicon-containing film, and an etching step (1′-2) for etching the silicon-containing film using the resist pattern as a mask.
The method for removing a silicon-containing film according to claim 2, further comprising: The silicon-containing film removal method according to any one of claims 1 to 3, wherein the basic liquid is a liquid containing at least one nitrogen compound selected from the group consisting of ammonia, organic amines, and tetraalkylammonium. . The silicon-containing film removing method according to any one of claims 1 to 4 , wherein the oxidizing gas or liquid is a liquid containing hydrogen peroxide. The silicon-containing film removal method according to any one of claims 1 to 5 , wherein the oxidizing component contact step is performed at less than 100 ° C. The method for removing a silicon-containing film according to any one of claims 1 to 6 , wherein the removing step is performed at less than 100 ° C. Characterized in that it contains hydrogen as the reducing component, the silicon-containing film removal method according to any one of claims 1 to 7. Characterized in that it contains a component having at least one of the silicon-containing film-forming composition is a sulfide group, selected sulfoxide groups, et al or sulfonyl group and sulfanyl group, according to any one of claims 1 to 8 The silicon-containing film removing method.