Silicon-containing composition and method for manufacturing semiconductor substrate

Abstract

Provided are a silicon-containing composition with which a resist pattern having an excellent rectangular cross-sectional shape and an easily-removable silicon-containing film can be formed, and a method for manufacturing a semiconductor substrate. Provided is a silicon-containing composition used for forming an underlayer film of a resist film that is developed with an organic solvent, the composition containing a solvent and a polysiloxane compound including an ester bond-containing group and a fluorine atom.

Description

Technical Field

[0001] The present invention relates to a silicon-containing composition and a method for manufacturing a semiconductor substrate.

Background Art

[0002] In pattern formation in the manufacture of semiconductor substrates, for example, a multilayer resist process or the like is used in which a substrate is patterned by performing etching using a resist pattern obtained by exposing and developing a resist film laminated via an organic underlayer film, a silicon-containing film, etc. on the substrate (see International Publication No. 2012 / 039337).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the multilayer resist process, it is required to be able to form a resist pattern excellent in rectangularity of cross-sectional shape and free of defects such as residues on the silicon-containing film.

[0005] In a manufacturing process of a semiconductor substrate or the like, the silicon-containing film is removed using a removal liquid. At this time, it is required to easily remove the silicon-containing film while suppressing damage to the substrate.

[0006] The present invention has been made based on the above circumstances, and an object thereof is to provide a silicon-containing composition capable of forming a silicon-containing film that can form a resist pattern excellent in rectangularity of cross-sectional shape and can be easily removed, and a method for manufacturing a semiconductor substrate.

Means for Solving the Problems

[0007] The invention made to solve the above problems is a silicon-containing composition used for forming an underlying film of a resist film developed with an organic solvent, which contains a polysiloxane compound containing a group having an ester bond and a fluorine atom (hereinafter, also referred to as "[A] compound") and a solvent (hereinafter, also referred to as "[B] solvent").

[0008] Another invention made to solve the above problems is a method for manufacturing a semiconductor substrate, which includes a step of coating the above silicon-containing composition directly or indirectly on a substrate, a step of coating a resist film-forming composition directly or indirectly on the silicon-containing film formed by the above silicon-containing composition coating step, a step of exposing the resist film formed by the above resist film-forming composition coating step to radiation, and a step of developing the exposed resist film with an organic solvent. [Effect of the Invention]

[0009] According to the silicon-containing composition and the method for manufacturing a semiconductor substrate of the present invention, a resist pattern excellent in rectangularity of cross-sectional shape can be formed on the silicon-containing film. Further, according to the silicon-containing composition and the method for manufacturing a semiconductor substrate of the present invention, a silicon-containing film excellent in removability of the silicon-containing film with a removing solution containing a base (hereinafter, also referred to as "film removability") can be formed. Therefore, these can be suitably used for manufacturing a semiconductor substrate and the like. [Embodiments for Carrying Out the Invention]

[0010] Hereinafter, the silicon-containing composition and the method for manufacturing a semiconductor substrate of the present invention will be described in detail.

[0011] [Silicon-Containing Composition] The silicon-containing composition contains an [A] compound and a [B] solvent. The composition may contain other optional components (hereinafter, also simply referred to as "optional components") as long as the effects of the present invention are not impaired.

[0012] When the silicon-containing composition contains an [A] compound and a [B] solvent, a resist pattern excellent in rectangularity of cross-sectional shape can be formed by organic solvent development on the silicon-containing film. Further, the silicon-containing film formed from the silicon-containing composition is excellent in removability (film removability) of the silicon-containing film with a stripping solution containing a base. The reason why the composition exhibits the above effects by having the above configuration is not necessarily clear, but it can be speculated as follows, for example. That is, since the [A] compound has a fluorine atom, when a resist film is formed on the silicon-containing film and the resist film is exposed and then organic solvent development is performed, the exposed portion of the resist film is easily removed with the organic solvent developer, so it is considered that a resist pattern excellent in rectangularity of cross-sectional shape can be formed. Further, since the [A] compound has a group containing an ester bond, the solubility in a stripping solution containing a base is improved, so it is considered that the film removability can be improved.

[0013] Since the silicon-containing composition exhibits the above-described effects, the silicon-containing composition can be suitably used as a composition for forming a silicon-containing film (i.e., a composition for forming a silicon-containing film).

[0014] Generally, the developing method of a resist film is roughly classified into organic solvent development using an organic solvent as a developer and alkali development using an alkaline solution as a developer. The silicon-containing composition is suitably used for forming a lower layer film of a resist film developed with an organic solvent. When the silicon-containing composition is used for forming a lower layer film of a resist film developed with an organic solvent, after the resist film is formed and exposed, when organic solvent development is performed, only the exposed portion of the resist film is dissolved, and the silicon-containing film, which is the lower layer film of the resist film, is not dissolved, and a resist pattern excellent in rectangularity of cross-sectional shape can be formed.

[0015] As the resist film developed with an organic solvent, a negative resist film is particularly preferable, and a negative resist film for exposure with an ArF excimer laser beam (for ArF exposure) described later is more preferable. In other words, the silicon-containing composition is suitably used for forming an underlayer film of a resist film developed with an organic solvent for ArF exposure.

[0016] Hereinafter, each component contained in the silicon-containing composition will be described.

[0017] [Compound [A]] [A] compound is a polysiloxane compound containing a group having an ester bond and a fluorine atom. In the present specification, the "ester bond" means a -C(=O)-O- bond or an -O-C(=O)- bond, and the "group containing an ester bond" includes, for example, an ester group (-C(=O)-O-R), an acyloxy group (-O-C(=O)-R), as well as a group containing a lactone structure, a group containing a carbonate bond (-O-C(=O)-O-), and the like. In the present specification, the "lactone structure" means a structure having at least one ring (lactone ring) containing an ester bond. In the present specification, the "polysiloxane compound" means a compound containing a siloxane bond (-Si-O-Si-).

[0018] Since the [A] compound has a group containing an ester bond, a silicon-containing film excellent in film removability can be formed. Further, since the [A] compound has a fluorine atom, when a resist pattern is formed by organic solvent development on the silicon-containing film, a resist pattern excellent in rectangularity of cross-sectional shape can be formed.

[0019] The silicon-containing composition may contain one or more [A] compounds.

[0020] In the [A] compound, the group containing an ester bond and the fluorine atom may be contained in one functional group, or may be contained in different functional groups, respectively.

[0021] In the [A] compound, a group containing an ester bond may be directly bonded to the silicon atom or may be bonded to the silicon atom via another group.

[0022] The group containing an ester bond is not particularly limited as long as it is a group containing an ester bond, and examples thereof include an ester group, an acyloxy group, a group containing a lactone structure, a group containing a cyclic carbonate structure, and the like. Among these, from the viewpoint of further improving the film removability, an ester group is preferable. The [A] compound can have one or more groups containing an ester bond. In the present specification, the "cyclic carbonate structure" means a structure containing a ring (cyclic carbonate ring) containing a carbonate bond (-O-C(=O)-O-).

[0023] In the [A] compound, a fluorine atom may be directly bonded to the silicon atom or may be bonded to the silicon atom via another group. From the viewpoint of more effectively exerting the effects of the present invention, it is preferable that the fluorine atom is bonded to the silicon atom via another group. In other words, in the [A] compound, it is preferable that the fluorine atom is bonded to the silicon atom as a group containing a fluorine atom.

[0024] Examples of the group containing a fluorine atom include a group in which at least one hydrogen atom of an organic group is substituted with a fluorine atom. Among these, from the viewpoint of forming a resist pattern with excellent rectangularity in cross-sectional shape when forming a resist pattern by organic solvent development on a silicon-containing film, an aromatic hydrocarbon group having a substituent containing a fluorine atom is preferable.

[0025] The [A] compound is preferably a compound having a first structural unit (hereinafter also referred to as "structural unit (I)") represented by the following formula (1) described later and a second structural unit (hereinafter also referred to as "structural unit (II)") represented by the following formula (2) described later. The [A] compound may have other structural units (hereinafter simply also referred to as "other structural units") other than the above structural unit (I) and structural unit (II) as long as the effects of the present invention are not impaired.

[0026] The following describes each structural unit of the [A] compound.

[0027] (Structural unit (I)) Structural unit (I) is a structural unit represented by the following formula (1). The [A] compound can have one or more structural units (I). Structural unit (I) has a monovalent organic group having 1 to 20 carbon atoms containing a fluorine atom represented by X in the following formula (1) (hereinafter also referred to as "fluorine atom-containing group (X)"), so that when forming a resist pattern by organic solvent development on a silicon-containing film, a resist pattern excellent in rectangularity of cross-sectional shape can be formed.

[0028]

Chemical formula

[0029] In the above formula (1), X is a monovalent organic group having 1 to 20 carbon atoms containing a fluorine atom. a is an integer of 1 to 3. When a is 2 or more, the plurality of Xs are the same as or different from each other. R 1 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group or a halogen atom. b is an integer of 0 to 2. When b is 2, the two Rs 1 are the same as or different from each other. However, a + b is 3 or less.

[0030] In this specification, "organic group" means a group containing at least one carbon atom, and "number of carbon atoms" means the number of carbon atoms constituting the group.

[0031] Examples of the monovalent organic group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) include a monovalent hydrocarbon group having 1 to 20 carbon atoms, a group containing a divalent heteroatom-containing group between carbon-carbon bonds of this hydrocarbon group (hereinafter also referred to as "group (α)"), a group in which part or all of the hydrogen atoms of the above hydrocarbon group or the above group (α) are substituted with a monovalent heteroatom-containing group (hereinafter also referred to as "group (β)"), a group obtained by combining the above hydrocarbon group, the above group (α) or the above group (β) with a divalent heteroatom-containing group (hereinafter also referred to as "group (γ)"), and the like.

[0032] In this specification, the "hydrocarbon group" includes a chain hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group. This "hydrocarbon group" may be a saturated hydrocarbon group or an unsaturated hydrocarbon group. The "chain hydrocarbon group" refers to a hydrocarbon group that does not contain a cyclic structure and is composed only of a chain structure, including both a linear hydrocarbon group and a branched hydrocarbon group. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure as the ring structure and does not contain an aromatic ring structure, including both a monocyclic alicyclic hydrocarbon group and a polycyclic alicyclic hydrocarbon group. However, it is not necessary to be composed only of an alicyclic structure, and a part thereof may contain a chain structure. The "aromatic hydrocarbon group" refers to a hydrocarbon group that contains an aromatic ring structure as the ring structure. However, it is not necessary to be composed only of an aromatic ring structure, and a part thereof may contain a chain structure or an alicyclic structure.

[0033] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms include a monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

[0034] Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, sec-butyl group, iso-butyl group, tert-butyl group, alkenyl groups such as ethenyl group, propenyl group, butenyl group, and alkynyl groups such as ethynyl group, propynyl group, butynyl group.

[0035] Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include monocyclic alicyclic saturated hydrocarbon groups such as cyclopentyl group, cyclohexyl group, polycyclic alicyclic saturated hydrocarbon groups such as norbornyl group, adamantyl group, tricyclodecyl group, tetracyclododecyl group, monocyclic alicyclic unsaturated hydrocarbon groups such as cyclopentenyl group, cyclohexenyl group, and polycyclic alicyclic unsaturated hydrocarbon groups such as norbornenyl group, tricyclodecenyl group, tetracyclododecenyl group.

[0036] Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, anthryl group, etc., and aralkyl groups such as benzyl group, phenethyl group, naphthylmethyl group, anthrylmethyl group, etc.

[0037] Examples of the heteroatom constituting the divalent and monovalent heteroatom-containing groups include oxygen atom, nitrogen atom, sulfur atom, phosphorus atom, silicon atom, halogen atom, etc. Examples of the halogen atom include fluorine atom, chlorine atom, bromine atom, iodine atom.

[0038] Examples of the divalent heteroatom-containing group include -O-, -C(=O)-, -S-, -C(=S)-, -NR’-, and groups formed by combining two or more of these. R’ is a hydrogen atom or a monovalent hydrocarbon group.

[0039] Examples of the monovalent heteroatom-containing group include halogen atom, hydroxy group, carboxy group, cyano group, amino group, sulfanyl group, etc.

[0040] Examples of the fluorine-containing group (X) include organic groups having a substituent containing a fluorine atom. Among these, hydrocarbon groups having a substituent containing a fluorine atom are preferred, aromatic hydrocarbon groups having a substituent containing a fluorine atom are more preferred, and aromatic hydrocarbon groups having a fluorine atom as a substituent are even more preferred. Examples of the substituent containing a fluorine atom include a fluorine atom, and groups in which at least one hydrogen atom of a hydrocarbon group having 1 to 10 carbon atoms is substituted with a fluorine atom. As the aromatic hydrocarbon group having a substituent containing a fluorine atom, a fluorophenyl group or a pentafluorophenyl group is preferred.

[0041] As a, 1 or 2 is preferred, and 1 is more preferred.

[0042] R 1Examples of the monovalent organic group having 1 to 20 carbon atoms represented by [0] include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbon atoms in the above-described fluorine atom-containing group (X).

[0043] R 1 Examples of the halogen atom represented by [6] include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0044] R 1 Preferably,

[12] is a monovalent chain hydrocarbon group, a monovalent aromatic hydrocarbon group, or a monovalent group in which some or all of the hydrogen atoms of a monovalent hydrocarbon group are substituted with a monovalent heteroatom-containing group, more preferably an alkyl group or an aryl group, and even more preferably a methyl group, an ethyl group, or a phenyl group.

[0045] Preferably, b is 0 or 1, and more preferably 0.

[0046] Examples of the structural unit (I) include structural units derived from compounds represented by the following formulas (1-1) to (1-3) (hereinafter, also referred to as "structural units (I-1) to (I-3)").

[0047]

Chemical formula

[0048] From the viewpoint of forming a resist pattern excellent in rectangularity of a cross-sectional shape when forming a resist pattern by organic solvent development on a silicon-containing film, the structural unit (I-1) or (I-2) is preferable as the structural unit (I).

[0049] [A] As the lower limit of the content ratio of structural unit (I) in the [A] compound, 1 mol% is preferable, 5 mol% is more preferable, 10 mol% is further preferable, and 15 mol% is particularly preferable with respect to all the structural units constituting the [A] compound. Also, as the upper limit of the content ratio of structural unit (I), 50 mol% is preferable, 40 mol% is more preferable, 35 mol% is further preferable, and 30 mol% is particularly preferable. When the content ratio of structural unit (I) is within the above range, when forming a resist pattern by organic solvent development on a silicon-containing film, a resist pattern excellent in the rectangularity of the cross-sectional shape can be formed.

[0050] (Structural unit (II)) Structural unit (II) is a structural unit represented by the following formula (2). The [A] compound can have one or more structural units (II). Structural unit (II) has a monovalent organic group having 1 to 20 carbon atoms containing an ester bond represented by Y in the following formula (2) (hereinafter, also referred to as "ester bond-containing group (Y)"), whereby a silicon-containing film excellent in film removability can be formed.

[0051] [Chemical formula]

[0052] In the above formula (2), Y is a monovalent organic group having 1 to 20 carbon atoms containing an ester bond. c is an integer of 1 to 3. When c is 2 or more, a plurality of Ys are the same as or different from each other. R 2 is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, or a halogen atom. d is an integer of 0 to 2. When d is 2, two Rs 2 are the same as or different from each other. However, c + d is 3 or less.

[0053] Examples of the monovalent organic group having 1 to 20 carbon atoms in the ester bond-containing group (Y) include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) of the above formula (1).

[0054] Examples of the ester bond-containing group (Y) include a group containing an ester group, a group containing an acyloxy group, a group containing a lactone structure, a group containing a cyclic carbonate structure, and the like.

[0055] Examples of the group containing an ester group include a group represented by the following formula (3-1) (hereinafter, also referred to as "ester bond-containing group (Y-1)") and the like.

[0056]

Chemical formula

[0057] In the above formula (3-1), L 1 is a single bond or a divalent linking group. R 3 is a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates the bonding site with the silicon atom in the above formula (2).

[0058] Examples of the divalent linking group represented by L 1 include, for example, a divalent organic group having 1 to 10 carbon atoms. Examples of the divalent organic group having 1 to 10 carbon atoms include a group obtained by removing one hydrogen atom from a monovalent organic group having 1 to 10 carbon atoms among the groups exemplified as the monovalent organic group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) of the above formula (1).

[0059] Examples of L 1 include a single bond, a divalent hydrocarbon group having 1 to 10 carbon atoms, or a group containing a divalent heteroatom-containing group between the carbon-carbon bonds of a divalent hydrocarbon group having 1 to 10 carbon atoms. A single bond, an alkylene group, an alkenylene group, or a group containing -S- between the carbon-carbon bonds of an alkylene group is more preferable.

[0060] Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by R 3 include, for example, a monovalent hydrocarbon group having 1 to 10 carbon atoms among the groups exemplified as the monovalent hydrocarbon group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) of the above formula (1).

[0061] Examples of R 3As for this, a monovalent chain hydrocarbon group or a monovalent alicyclic hydrocarbon group is preferable. Also, R 3 As for this, a group that bonds with the ether oxygen atom of the carbonyloxy group at a tertiary carbon atom is preferable. Examples of such a group include a tert-butyl group, a 1-methylcyclopentan-1-yl group, and the like.

[0062] Examples of the group containing an acyloxy group include a group represented by the following formula (3-2) (hereinafter, also referred to as "ester bond-containing group (Y-2)") and the like.

Chemical formula

[0063] In the above formula (3-2), L 2 is a single bond or a divalent linking group. R 4 is a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates the bonding site with the silicon atom in the above formula (2).

[0064] L 2 Examples of the divalent linking group represented by include the same groups as those exemplified for L 1 in the above formula (3-1). As for L 2 a single bond, a methylene group, or a divalent alkylene group having 2 to 10 carbon atoms is preferable, and a methylene group is more preferable.

[0065] R 4 Examples of the monovalent hydrocarbon group having 1 to 10 carbon atoms represented by include the same groups as those exemplified for R 3 in the above formula (3-1). As for R 4 a monovalent chain hydrocarbon group is preferable.

[0066] Examples of the group containing a lactone structure include a group represented by the following formula (3-3) (hereinafter, also referred to as "ester bond-containing group (Y-3)") and the like.

[0067]

Chemical formula

[0068] In the above formula (3-3), L 3 is a single bond or a divalent linking group. R 5 is a monovalent group having a lactone structure. * indicates the bonding site with the silicon atom in the above formula (2).

[0069] L 3 Examples of the divalent linking group represented by include the same groups as those exemplified for L 1 in the above formula (3-1). L 3 is preferably a single bond.

[0070] R 5 Examples of the lactone structure in include monocyclic lactone structures such as a propiolactone structure, a butyrolactone structure, a valerolactone structure, a caprolactone structure, etc., and polycyclic lactone structures such as a cyclopentanelactone structure, a cyclohexanelactone structure, a norbornanelactone structure, a benzobutyrolactone structure, a benzovalerolactone structure, etc. Among these, a monocyclic lactone structure is preferable, and a butyrolactone structure is more preferable.

[0071] Examples of the group containing a cyclic carbonate structure include a group represented by the following formula (3-4) (hereinafter, also referred to as "ester bond-containing group (Y-4)") and the like.

[0072]

Chemical formula

[0073] In the above formula (3-4), L 4 is a single bond or a divalent linking group. R 6 is a monovalent group having a cyclic carbonate structure. * indicates the bonding site with the silicon atom in the above formula (2).

[0074] L 4 Examples of the divalent linking group represented by include the same groups as those exemplified for L 1 in the above formula (3-1). L4 Preferably, it is a divalent alkylene group having 2 to 10 carbon atoms.

[0075] R 6 Examples of the cyclic carbonate structure in R include monocyclic cyclic carbonate structures such as ethylene carbonate structure, trimethylene carbonate structure, and tetramethylene carbonate structure, and polycyclic carbonate structures such as cyclopentylene carbonate structure, cyclohexylene carbonate structure, norbornylene carbonate structure, phenylene carbonate structure, and naphthylene carbonate structure. Among these, a monocyclic cyclic carbonate structure is preferable, and an ethylene carbonate structure is more preferable.

[0076] As the ester bond-containing group (Y), from the viewpoint of further improving the film removability, the ester bond-containing group (Y-1) is preferable.

[0077] Preferably, c is 1 or 2, and more preferably 1.

[0078] R 2 Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) of the above formula (1).

[0079] R 2 Examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0080] R 2 Preferably, R is a monovalent chain hydrocarbon group, a monovalent aromatic hydrocarbon group, or a monovalent group in which some or all of the hydrogen atoms of a monovalent hydrocarbon group are substituted with a monovalent heteroatom-containing group, more preferably an alkyl group or an aryl group, and even more preferably a methyl group, an ethyl group, or a phenyl group.

[0081] Preferably, d is 0 or 1, and more preferably 0.

[0082] Examples of the structural unit (II) include structural units derived from compounds represented by the following formulas (2-1) to (2-8) (hereinafter also referred to as "structural units (II-1) to (II-8)") and the like.

[0083]

Chemical formula

[0084] From the viewpoint of further improving the film removability, the structural units (II-1) to (II-4) or (II-6) are preferable as the structural unit (II), and the structural units (II-1) to (II-4) are more preferable.

[0085] The lower limit of the content ratio of the structural unit (II) in the [A] compound is preferably 0.5 mol%, more preferably 1 mol%, and still more preferably 2 mol% with respect to all the structural units constituting the [A] compound. The upper limit of the content ratio of the structural unit (II) is preferably 30 mol%, more preferably 25 mol%, and still more preferably 20 mol%. When the content ratio of the structural unit (II) is within the above range, a silicon-containing film with more excellent film removability can be formed.

[0086] (Other structural units) Examples of other structural units include a structural unit represented by the following formula (4) (hereinafter also referred to as "structural unit (III)"), a structural unit represented by the following formula (5) described later (hereinafter also referred to as "structural unit (IV)"), and the like. When the [A] compound has the structural unit (III), the storage stability and coatability of the silicon-containing composition can be improved. When the [A] compound has the structural unit (IV), the oxygen gas etching resistance of the silicon-containing film formed by the silicon-containing composition can be improved.

[0087]

Chemical formula

[0088] In the above formula (4), R 7is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, or a halogen atom. e is an integer of 1 to 3. When e is 2 or more, a plurality of R 7 are the same as or different from each other.

[0089] R 7 Examples of the monovalent organic group having 1 to 20 carbon atoms represented by include the same groups as those exemplified as the monovalent organic group having 1 to 20 carbon atoms in the fluorine atom-containing group (X) of the above formula (1).

[0090] R 7 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0091] R 7 is preferably a monovalent aromatic hydrocarbon group, more preferably an aryl group, and even more preferably a phenyl group.

[0092] e is preferably 1.

[0093] When the [A] compound has the structural unit (III) as another structural unit, the lower limit of the content ratio of the structural unit (III) is preferably 1 mol%, more preferably 5 mol%, and even more preferably 10 mol% with respect to all the structural units constituting the [A] compound. The upper limit of the above content ratio is preferably 40 mol%, more preferably 30 mol%, and even more preferably 25 mol%.

[0094]

Chemical formula

[0095] When the [A] compound has the structural unit (IV) as another structural unit, the lower limit of the content ratio of the structural unit (IV) is preferably 30 mol%, more preferably 40 mol%, and even more preferably 50 mol% with respect to all the structural units constituting the [A] compound. The upper limit of the above content ratio is preferably 95 mol%, more preferably 90 mol%, and even more preferably 85 mol%.

[0096] As the lower limit of the content ratio of the [A] compound in the silicon-containing composition, 0.1% by mass is preferable, 0.5% by mass is more preferable, and 1% by mass is even more preferable with respect to all components contained in the silicon-containing composition. As the upper limit of the above content ratio, 10% by mass is preferable, 7.5% by mass is more preferable, and 5% by mass is even more preferable.

[0097] The [A] compound is preferably in the form of a polymer. In the present specification, the "polymer" refers to a compound having two or more structural units, and when two or more identical structural units are continuous in the polymer, this structural unit is also referred to as a "repeating unit". When the [A] compound is in the form of a polymer, the lower limit of the polystyrene-reduced weight average molecular weight (Mw) of the [A] compound by gel permeation chromatography (GPC) is preferably 1,000, more preferably 1,200, even more preferably 1,500, and particularly preferably 1,600. As the upper limit of the above Mw, 10,000 is preferable, 5,000 is more preferable, 3,000 is even more preferable, and 2,500 is particularly preferable.

[0098] In the present specification, the Mw of the [A] compound is a value measured by gel permeation chromatography (GPC) under the following conditions using GPC columns of Tosoh Corporation ("G2000HXL" two, "G3000HXL" one, and "G4000HXL" one). Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Column temperature: 40 °C Detector: Differential refractometer Standard substance: Monodisperse polystyrene

[0099] [A] compound can be synthesized by a conventional method using monomers that provide each structural unit. For example, monomers that provide structural unit (I), monomers that provide structural unit (II), and, if necessary, monomers that provide other structural units are subjected to hydrolysis condensation in a solvent in the presence of a catalyst such as oxalic acid and water, and preferably the resulting solution containing the hydrolysis condensate is purified by performing solvent substitution or the like in the presence of a dehydrating agent such as trimethyl orthoformate. It can be synthesized by. By hydrolysis condensation reaction or the like, each monomer is considered to be incorporated into the [A] compound regardless of its type. Therefore, the content ratios of structural unit (I), structural unit (II), and other structural units in the synthesized [A] compound usually become equivalent to the ratio of the charged amounts of the respective monomers used in the synthesis reaction.

[0100] [[B] Solvent] [B] The solvent is not particularly limited, and examples thereof include alcohol solvents, ketone solvents, ether solvents, ester solvents, nitrogen-containing solvents, water, and the like. The silicon-containing composition can contain one or more [B] solvents.

[0101] Examples of the alcohol solvent include monoalcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, and iso-butanol, and polyhydric alcohol solvents such as ethylene glycol, 1,2-propylene glycol, diethylene glycol, and dipropylene glycol.

[0102] Examples of the ketone solvent include acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl-iso-butyl ketone, and cyclohexanone.

[0103] Examples of ether solvents include ethyl ether, iso-propyl ether, ethylene glycol dibutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, tetrahydrofuran, and the like.

[0104] Examples of ester solvents 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, propylene glycol monoethyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, ethyl propionate, n-butyl propionate, methyl lactate, ethyl lactate, and the like.

[0105] Examples of nitrogen-containing solvents include N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, and the like.

[0106] Among these, ether solvents or ester solvents are preferred, and ether solvents or ester solvents having a glycol structure are more preferred because of their excellent film-forming properties.

[0107] Examples of ether solvents and ester solvents having a glycol structure include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, and the like. Among these, propylene glycol monomethyl ether acetate or propylene glycol monoethyl ether is preferred, and propylene glycol monomethyl ether is more preferred.

[0108] As the lower limit of the content ratio of the [B] solvent in the silicon-containing composition, 90% by mass is preferable, 92.5% by mass is more preferable, and 95% by mass is even more preferable, based on all the components contained in the silicon-containing composition. As the upper limit of the above content ratio, 99.9% by mass is preferable, 99.5% by mass is more preferable, and 99% by mass is even more preferable.

[0109] (Optional component) Examples of the optional component include an acid generator, a basic compound (including a base generator), a radical generator, a surfactant, colloidal silica, colloidal alumina, an organic polymer, etc. The silicon-containing composition can contain one or more optional components.

[0110] When the silicon-containing composition contains an optional component, the content ratio of the optional component in the silicon-containing composition can be appropriately determined according to the type of the optional component used and within a range that does not impair the effects of the present invention.

[0111] <Method for preparing a silicon-containing composition> The method for preparing the silicon-containing composition is not particularly limited and can be prepared according to a conventional method. For example, a solution of the [A] compound, the [B] solvent, and, if necessary, an optional component are mixed at a predetermined ratio, and preferably the obtained mixed solution is filtered through a filter with a pore size of 0.2 μm or less, etc.

[0112] <Method for manufacturing a semiconductor substrate> The method for manufacturing the semiconductor substrate includes a step of applying a silicon-containing composition directly or indirectly to the substrate (hereinafter, also referred to as the "silicon-containing composition application step"), a step of applying a resist film-forming composition directly or indirectly to the silicon-containing film formed by the silicon-containing composition application step (hereinafter, also referred to as the "resist film-forming composition application step"), a step of exposing the resist film formed by the resist film-forming composition application step to radiation (hereinafter, also referred to as the "exposure step"), and a step of developing the exposed resist film with an organic solvent (hereinafter, also referred to as the "organic solvent development step"). In the silicon-containing composition application step in the method for manufacturing the semiconductor substrate, the above-described silicon-containing composition is used as the silicon-containing composition.

[0113] The method for manufacturing the semiconductor substrate may further include a step of forming an organic underlayer film directly or indirectly on the substrate (hereinafter, also referred to as the "organic underlayer film formation step") before the silicon-containing composition application step, if necessary.

[0114] Further, the method for manufacturing the semiconductor substrate may further include a step of removing the silicon-containing film with a removal liquid containing a base (hereinafter, also referred to as the "removal step") after the silicon-containing composition application step, if necessary.

[0115] According to the method for manufacturing the semiconductor substrate, by using the above-described silicon-containing composition as the silicon-containing composition in the silicon-containing composition application step, a resist pattern excellent in rectangularity of cross-sectional shape can be formed on the silicon-containing film. Further, since the silicon-containing film formed in the silicon-containing composition application step is excellent in film removability, it can be removed with a removal liquid containing a base.

[0116] Hereinafter, each step included in the method for manufacturing the semiconductor substrate will be described.

[0117] [Silicon-containing composition application step] In this step, a silicon-containing composition is applied directly or indirectly to a substrate. By this step, a coating film of the silicon-containing composition is formed directly or indirectly on the substrate, and this coating film is usually heated and cured or the like to form a silicon-containing film.

[0118] In this step, the above-described silicon-containing composition is used as the silicon-containing composition.

[0119] Examples of the substrate include insulating films such as silicon oxide, silicon nitride, silicon oxynitride, polysiloxane, and resin substrates. Further, the substrate may be a substrate having patterning such as wiring grooves (trenches) and plug grooves (vias).

[0120] The coating method of the composition for forming a silicon-containing film is not particularly limited, and examples thereof include a spin coating method.

[0121] When the composition for forming a silicon-containing film is applied indirectly to the substrate, examples thereof include a case where the silicon-containing composition is applied on another film formed on the substrate. Examples of the other film formed on the substrate include an organic underlayer film formed by the organic underlayer film forming step described later, an antireflection film, and a low dielectric constant insulating film.

[0122] When heating the coating film, the atmosphere is not particularly limited, and examples thereof include under the atmosphere and under a nitrogen atmosphere. Usually, the heating of the coating film is performed under the atmosphere. Various conditions such as the heating temperature and heating time when heating the coating film can be appropriately determined. The lower limit of the heating temperature is preferably 90°C, more preferably 150°C, and even more preferably 200°C. The upper limit of the heating temperature is preferably 550°C, more preferably 450°C, and even more preferably 300°C. The lower limit of the heating time is preferably 15 seconds, and more preferably 30 seconds. The upper limit of the heating time is preferably 1,200 seconds, and more preferably 600 seconds.

[0123] When the composition for forming a silicon-containing film contains an acid generator and this acid generator is a radiation-sensitive acid generator, the formation of the silicon-containing film can be promoted by combining heating and exposure. Examples of the radiation used for exposure include the same types of radiation as those exemplified in the exposure process described later.

[0124] As the lower limit of the average thickness of the silicon-containing film formed by this step, 1 nm is preferable, 3 nm is more preferable, and 5 nm is even more preferable. As the upper limit of the above average thickness, 500 nm is preferable, 300 nm is more preferable, and 200 nm is even more preferable. The average thickness of the silicon-containing film is a value measured using a spectroscopic ellipsometer ("M2000D" manufactured by J.A. WOLLAM).

[0125] [Resist Film Forming Composition Coating Step] In this step, the resist film forming composition is coated directly or indirectly on the silicon-containing film formed by the above silicon-containing composition coating step. By this step, a resist film is formed directly or indirectly on the silicon-containing film.

[0126] The coating method of the resist film forming composition is not particularly limited, and examples thereof include a spin coating method.

[0127] Explaining this step in more detail, for example, after coating the resist composition so that the formed resist film has a predetermined thickness, pre-baking (hereinafter also referred to as "PB") is performed to volatilize the solvent in the coated film, thereby forming a resist film.

[0128] The PB temperature and PB time can be appropriately determined according to the type of the resist film forming composition used, etc. As the lower limit of the PB temperature, 30 °C is preferable, and 50 °C is more preferable. As the upper limit of the PB temperature, 200 °C is preferable, and 150 °C is more preferable. As the lower limit of the PB time, 10 seconds is preferable, and 30 seconds is more preferable. As the upper limit of the PB time, 600 seconds is preferable, and 300 seconds is more preferable.

[0129] Generally, the development method of a resist film is roughly classified into organic solvent development using an organic solvent as a developer and alkali development using an alkaline solution as a developer. However, the composition for forming a resist film used in this step is limited to a composition for forming a resist film that can form a resist film developed with an organic solvent. This is because when a composition for forming a resist film that can form a resist film developed with an alkali is used, in the step of alkali development, not only the exposed portion of the resist film but also the silicon-containing film formed by the above-described silicon-containing composition coating step under the resist film will be dissolved in the alkali developer.

[0130] The composition for forming a resist film used in this step is not particularly limited as long as it is a composition for forming a resist film that can form a resist film developed with an organic solvent, and a known composition for forming a resist film can be used. For example, a negative-type composition for forming a resist film containing a radiation-sensitive acid generator can be mentioned. Among them, a negative-type composition for forming a resist film for exposure with ArF excimer laser light (for ArF exposure) described later is preferable.

[0131] [Exposure step] In this step, the resist film formed by the above-described resist film forming composition coating step is exposed to radiation. By this step, a difference in solubility in the organic solvent, which is the developer, occurs between the exposed portion and the unexposed portion in the resist film. More specifically, the solubility of the exposed portion in the resist film in the organic solvent decreases.

[0132] The radiation used for exposure can be appropriately selected according to the type of the composition for forming a resist film used, etc. For example, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, X-rays, γ-rays, and particle beams such as electron beams, molecular beams, and ion beams can be mentioned. Among these, far ultraviolet light is preferable, such as KrF excimer laser light (wavelength 248 nm), ArF excimer laser light (wavelength 193 nm), F 2 excimer laser light (wavelength 157 nm), Kr 2Excimer laser light (wavelength 147 nm), ArKr excimer laser light (wavelength 134 nm), or extreme ultraviolet light (wavelength 13.5 nm etc., also referred to as "EUV") is more preferable, and ArF excimer laser light is even more preferable. Also, the exposure conditions can be appropriately determined according to the type of the resist film-forming composition used etc.

[0133] Also, in this step, after the above exposure, in order to improve the performance of the resist film such as resolution, pattern profile, developability, etc., post-exposure bake (hereinafter also referred to as "PEB") can be performed. The PEB temperature and PEB time can be appropriately determined according to the type of the resist film-forming composition used etc. As the lower limit of the PEB temperature, 50 °C is preferable, and 70 °C is more preferable. As the upper limit of the PEB temperature, 200 °C is preferable, and 150 °C is more preferable. As the lower limit of the PEB time, 10 seconds is preferable, and 30 seconds is more preferable. As the upper limit of the PEB time, 600 seconds is preferable, and 300 seconds is more preferable.

[0134] [Organic solvent development step] In this step, the above-exposed resist film is developed with an organic solvent. Due to the difference in solubility in the organic solvent which is the developer between the exposed part and the unexposed part in the resist film by the above exposure step, by performing organic solvent development, the part with relatively high solubility in the organic solvent is removed, and thus a resist pattern is formed. More specifically, due to the decrease in solubility in the organic solvent of the exposed part in the resist film by the above exposure step, by performing organic solvent development, the unexposed part with relatively high solubility in the organic solvent is removed, and thus a resist pattern is formed.

[0135] The developer used in organic solvent development is not particularly limited as long as it is a developer used in organic solvent development, and a known developer can be used. For example, those similar to those exemplified as the [B] solvent in the above silicon-containing composition etc. can be mentioned.

[0136] In this process, after the above-mentioned organic solvent development, washing and / or drying may be performed.

[0137] [Organic Lower Layer Film Formation Process] In this process, an organic lower layer film is formed directly or indirectly on the above-mentioned substrate before the above-mentioned silicon-containing composition coating process. This process is an optional process. By this process, an organic lower layer film is formed directly or indirectly on the substrate. Note that "before the above-mentioned silicon-containing composition coating process" does not mean only immediately before the silicon-containing composition coating process, but means a point upstream from the silicon-containing composition coating process. Therefore, any other optional process may be provided between this process and the silicon-containing composition coating process.

[0138] The organic lower layer film can be formed by coating an organic lower layer film-forming composition or the like. As a method of forming the organic lower layer film by coating an organic lower layer film-forming composition, for example, a method of curing a coating film formed by directly or indirectly coating an organic lower layer film-forming composition on a substrate by heating, exposure, or the like can be mentioned. As the above-mentioned organic lower layer film-forming composition, for example, "HM8006" of JSR Corporation can be used. The various conditions of heating and exposure can be appropriately determined according to the type of the organic lower layer film-forming composition used and the like.

[0139] As a case of forming an organic lower layer film indirectly on the substrate, for example, a case of forming an organic lower layer film on a low dielectric insulating film formed on the substrate can be mentioned.

[0140] [Removal Process] In this process, after the step of applying the silicon-containing composition, the silicon-containing film is removed with a stripping solution containing a base (hereinafter also referred to as "base-containing stripping solution"). This step is an optional step. By this step, the silicon-containing film is removed from the substrate. Note that "after the step of applying the silicon-containing composition" does not mean only immediately after the step of applying the silicon-containing composition, but means a downstream point in time from the step of applying the silicon-containing composition. Therefore, "after the step of applying the silicon-containing composition" includes not only after the step of applying the silicon-containing composition and before the step of applying the composition for forming a resist film, but also, for example, after an organic solvent development step.

[0141] When this step is performed after the step of applying the silicon-containing composition and before the step of applying the composition for forming a resist film, for example, when defects or the like are detected in the silicon-containing film before the step of applying the composition for forming a resist film, the silicon-containing film can be easily removed as a rework step.

[0142] In addition, the residual silicon-containing film after etching can be removed.

[0143] The base-containing stripping solution is not particularly limited as long as it is a basic solution containing a base. Examples of the base include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (hereinafter also referred to as "TMAH"), tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo[5.4.0]-7-undecene, 1,5-diazabicyclo[4.3.0]-5-nonene, and the like. Among these, ammonia is preferable from the viewpoint of avoiding damage to the substrate.

[0144] As the base-containing stripping solution, from the viewpoint of further improving the removability of the silicon-containing film, a solution containing a base and water, or a solution containing a base, hydrogen peroxide, and water is preferable.

[0145] The method for removing the silicon-containing film is not particularly limited as long as it can bring the silicon-containing film into contact with a base-containing removal liquid. For example, methods include immersing the substrate in the base-containing removal liquid, spraying the base-containing removal liquid, applying the base-containing removal liquid, and the like.

[0146] Various conditions such as the temperature and time during the removal of the silicon-containing film are not particularly limited and can be appropriately determined according to the film thickness of the silicon-containing film, the type of the base-containing removal liquid used, and the like. As the lower limit of the temperature, 20°C is preferable, 40°C is more preferable, and 50°C is even more preferable. As the upper limit of the above temperature, 300°C is preferable, and 100°C is more preferable. As the lower limit of the time, 5 seconds is preferable, and 30 seconds is more preferable. As the upper limit of the above time, 10 minutes is preferable, and 180 seconds is more preferable.

[0147] In this step, after removing the silicon-containing film, washing and / or drying may be performed.

Examples

[0148] Hereinafter, examples will be described. Note that the examples shown below are examples of typical examples of the present invention and the scope of the present invention should not be construed narrowly thereby.

[0149] In this example, the measurement of the weight average molecular weight (Mw) of the [A] compound, the measurement of the concentration of the [A] compound in the solution, and the measurement of the average thickness of the film were each performed by the following methods.

[0150] [Measurement of weight average molecular weight (Mw)] The weight average molecular weight (Mw) of the [A] compound was measured by gel permeation chromatography (GPC) using GPC columns of Tosoh Corporation (two "G2000HXL", one "G3000HXL", and one "G4000HXL") under the following conditions. Eluent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0 mass% Sample injection volume: 100 μL Column temperature: 40 °C Detector: Differential refractometer Standard substance: Monodisperse polystyrene

[0151] [Concentration of compound [A] in solution] [A] The mass of the residue obtained by calcining 0.5 g of the solution of compound [A] at 250 °C for 30 minutes was measured, and the concentration (unit: mass%) of the solution of compound [A] was calculated by dividing the mass of this residue by the mass of the solution of compound [A].

[0152] [Average thickness of the film] The average thickness of the film was measured using a spectroscopic ellipsometer ("M2000D" manufactured by J.A. WOLLAM).

[0153] <Synthesis of compound [A]>[[]] In Examples 1-1 to 1-21 and Comparative Examples 1-1 and 1-2, the monomers used in the synthesis (hereinafter also referred to as "monomers (M-1) to (M-13)") are shown below. Also, in Examples 1-1 to 1-21 and Comparative Examples 1-1 and 1-2 below, mol% means the value when the total number of moles of the monomers (M-1) to (M-13) used is 100 mol%.

[0154] [Chemical formula][[]]

[0155] [Example 1-1] Synthesis of compound (A-1)[[]] In a reaction vessel, the above compound (M-1), compound (M-3) and compound (M-6) were dissolved in 62 parts by mass of propylene glycol monoethyl ether so that the molar ratio was 84 / 15 / 1 (mol %), and a monomer solution was prepared. The inside of the reaction vessel was set at 60° C., and while stirring, 40 parts by mass of a 9.1 mass % oxalic acid aqueous solution was added dropwise over 20 minutes. The start of the addition was taken as the start time of the reaction, and the reaction was carried out for 4 hours. After completion of the reaction, the inside of the reaction vessel was cooled to 30° C. or lower. After adding 550 parts by mass of propylene glycol monoethyl ether to the cooled reaction solution, water, alcohols produced by the reaction and excess propylene glycol monoethyl ether were removed using an evaporator to obtain a propylene glycol monoethyl ether solution of compound (A-1). The Mw of compound (A-1) was 1,700. The concentration of compound (A-1) in the above propylene glycol monoethyl ether solution was 7.2 mass %.

[0156] [Examples 1-2 to 1-21 and Comparative Examples 1-1 and 1-2] Synthesis of Compounds (A-2) to (A-21), (AJ-1) and (AJ-2) Propylene glycol monoethyl ether solutions of compounds (A-2) to (A-21), (AJ-1) and (AJ-2) were obtained in the same manner as in Example 1-1, except that each monomer of the types and amounts shown in Table 1 below was used. In the monomers in Table 1 below, “-” indicates that the corresponding monomer was not used. The concentration (mass %) of the obtained [A] compound in the solution and the Mw of the [A] compound are shown in accordance with Table 1 below.

[0157] [Table 1]

[0158] [Preparation of Silicon-Containing Composition] The [B] solvent used for the preparation of the silicon-containing composition is shown below. In Examples 2-1 to 2-21 and Comparative Examples 2-1 and 2-2 below, unless otherwise specified, the parts by mass indicate the values when the total mass of the components used is 100 parts by mass.

[0159] [[B] Solvent] B-1: Propylene glycol monoethyl ether

[0160] [Example 2-1] Preparation of Silicon-containing Composition (J-1) [A] 1 part by mass of (A-1) as a compound (excluding the solvent) and [B] 99 parts by mass of (B-1) as a solvent (including the solvent contained in the solution of [A] compound) were mixed, and the resulting solution was filtered through a polytetrafluoroethylene filter with a pore size of 0.2 μm to prepare a silicon-containing composition (J-1).

[0161] [Examples 2-2 to 2-21 and Comparative Examples 2-1 and 2-2] Preparation of Silicon-containing Compositions (J-2) to (J-21), (j-1) and (j-2) Except for using the components of the types and blending amounts shown in Table 2 below, in the same manner as in Example 2-1, silicon-containing compositions (J-2) to (J-17) of Examples 2-2 to 2-21, and silicon-containing compositions (j-1) and (j-2) of Comparative Examples 2-1 and 2-2 were prepared.

[0162] [Evaluation] Using the above-prepared compositions, the resist pattern shape and alkali solution peelability were evaluated by the following method. The evaluation results are shown in Table 2 below.

[0163] [Resist Pattern Shape] On a 12-inch silicon wafer, a material for forming an organic underlayer film (JSR Corporation's "HM8006") was applied by spin coating using a spin coater (Tokyo Electron Limited's "CLEAN TRACK ACT12"), and then heated at 250°C for 60 seconds to form an organic underlayer film with an average thickness of 100 nm. The silicon-containing composition prepared above was applied on this organic underlayer film, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 20 nm. A radiation-sensitive resin composition (JSR Corporation's "ARF AR2772JN") was applied on the formed silicon-containing film, heated at 90°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a resist film with an average thickness of 100 nm. Subsequently, using an ArF immersion exposure apparatus (Nikon Corporation's "S610C"), after exposure through a mask with a mask size for forming a 40 nm line / 80 nm pitch under the optical conditions of NA: 1.30 and Dipole, the substrate was heated at 100°C for 60 seconds and then cooled at 23°C for 60 seconds. Thereafter, using n-butyl acetate (20°C to 25°C), after developing by the paddle method and drying, an evaluation substrate with a resist pattern formed thereon was obtained. For measuring the length of the resist pattern and observing the cross-sectional shape of the above evaluation substrate, a scanning electron microscope (Hitachi High-Technologies Corporation's "CG-4000") was used. In the above evaluation substrate, the exposure amount at which a 1:1 line and space with a line width of 40 nm was formed was defined as the optimum exposure amount. The resist pattern shape was evaluated as "A" (good) when the cross-sectional shape of the pattern was rectangular, "B" (slightly good) when there was a trailing edge in the cross-section of the pattern, and "C" (bad) when there were residues (defects) in the pattern.

[0164] [Film removability] The prepared silicon-containing composition was coated on a 12-inch silicon wafer, heated at 220°C for 60 seconds, and then cooled at 23°C for 30 seconds to form a silicon-containing film with an average thickness of 20 nm. Each substrate with the obtained silicon-containing film was immersed in a removal solution (mixed aqueous solution of 25% by mass ammonia aqueous solution / 30% by mass hydrogen peroxide aqueous solution / water = 1 / 1 / 5 (volume ratio)) heated to 65°C for 5 minutes, then washed with water and dried to obtain a substrate for evaluation. Also, each substrate with the obtained silicon-containing film was immersed in a removal solution (mixed aqueous solution of 25% by mass ammonia aqueous solution / 30% by mass hydrogen peroxide aqueous solution / water = 1 / 1 / 5 (volume ratio)) heated to 65°C for 10 minutes, then washed with water and dried to obtain a substrate for evaluation. Regarding the cross-section of each of the obtained substrates for evaluation, it was observed using a field emission scanning electron microscope ("SU8220" of Hitachi High-Tech Corporation). When the silicon-containing film did not remain after immersion in the removal solution for 5 minutes, it was evaluated as "A" (good). When the silicon-containing film remained after immersion in the removal solution for 5 minutes but did not remain after immersion in the removal solution for 10 minutes, it was evaluated as "B" (slightly good). When the silicon-containing film remained after immersion in the removal solution for 5 minutes and 10 minutes, it was evaluated as "C" (bad).

[0165]

Table 2

[0166] As is clear from the results in Table 2 above, the silicon-containing film formed from the silicon-containing composition of the example was able to form a resist pattern with excellent rectangularity in cross-sectional shape on the film as compared with the silicon-containing film formed from the silicon-containing composition of the comparative example. Furthermore, the silicon-containing film formed from the silicon-containing composition of the example had good film removability as compared with the silicon-containing film formed from the silicon-containing composition of the comparative example.

Industrial Applicability

[0167] According to the silicon-containing composition of the present invention and the method for manufacturing a semiconductor substrate, it is possible to form a resist pattern excellent in rectangularity of the cross-sectional shape and to form a silicon-containing film that can be easily removed. Therefore, these can be suitably used for manufacturing a semiconductor substrate and the like.

Claims

1. A silicon-containing composition used for forming an underlayer film of a resist film developed with an organic solvent, a polysiloxane compound containing a group having an ester bond and a fluorine atom, a solvent and containing, the polysiloxane compound having a first structural unit represented by the following formula (1) and a second structural unit represented by the following formula (2), a silicon-containing composition. 【Chemical 1】 (In formula (1), X is an aromatic hydrocarbon group having a fluorine atom as a substituent. a is an integer of 1 to 3. When a is 2 or more, a plurality of Xs may be the same as or different from each other. R １ is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group or a halogen atom. b is an integer of 0 to 2. When b is 2, the two Rs １ may be the same as or different from each other. However, a + b is 3 or less.) [Chemical Formula 2] (In formula (2), Y is a monovalent organic group having 1 to 20 carbon atoms including an ester bond. c is an integer of 1 to 3. When c is 2 or more, a plurality of Ys are the same as or different from each other. R ２ is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group, or a halogen atom. d is an integer of 0 to 2. When d is 2, two Rs ２ are the same as or different from each other. However, c + d is 3 or less.)

2. The silicon-containing composition according to claim 1, wherein Y in the above formula (2) is a monovalent organic group having 1 to 20 carbon atoms containing an ester group, a monovalent organic group having 1 to 20 carbon atoms containing an acyloxy group, a monovalent organic group having 1 to 20 carbon atoms containing a lactone structure, or a monovalent organic group having 1 to 20 carbon atoms containing a cyclic carbonate.

3. The silicon-containing composition according to claim 1, wherein Y in the above formula (2) is a group represented by the following formulas (3-1) to (3-4). 【Chemical Formula 3】 (In formula (3-1), L １ is a single bond or a divalent linking group. R ３ is a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates the bonding site with the silicon atom in the above formula (2).) 【Chemical 4】 (In formula (3-2), L ２ is a single bond or a divalent linking group. R ４ is a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates the bonding site with the silicon atom in the above formula (2).) [Chemical Formula 5] (In formula (3-3), L ３ is a single bond or a divalent linking group. R ５ is a monovalent group having a lactone structure. * indicates the bonding site with the silicon atom in the above formula (2).) 【Chemical Formula 6】 (In formula (3-4), L ４ is a single bond or a divalent linking group. R ６ is a monovalent group having a cyclic carbonate structure. * indicates the bonding site with the silicon atom in the above formula (2).)

4. The silicon-containing composition according to any one of claims 1 to 3, wherein the polysiloxane compound further has a third structural unit represented by the following formula (4). 【Chemical Formula 7】 (In formula (4), R ７ is a monovalent organic group having 1 to 20 carbon atoms, a hydroxy group or a halogen atom. e is an integer of 1 to 3. When e is 2 or more, a plurality of R ７ are the same as or different from each other.)

5. The silicon-containing composition according to any one of claims 1 to 4, wherein the polysiloxane compound further has a fourth structural unit represented by the following formula (5). 【Chemical Formula 8】

6. The silicon-containing composition according to any one of claims 1 to 5, wherein the content ratio of the first structural unit to all the structural units constituting the polysiloxane compound is 1 mol% or more and 40 mol% or less.

7. The silicon-containing composition according to any one of claims 1 to 6, wherein the content ratio of the second structural unit to all the structural units constituting the polysiloxane is 1 mol% or more and 20 mol% or less.

8. The silicon-containing composition according to any one of claims 1 to 7, which is used for forming an underlayer film of a negative resist film developed with an organic solvent for ArF exposure.

9. A step of coating the silicon-containing composition according to any one of claims 1 to 8 directly or indirectly on a substrate, a step of coating a resist film-forming composition directly or indirectly on the silicon-containing film formed by the silicon-containing composition coating step, a step of exposing the resist film formed by the resist film-forming composition coating step to radiation, a step of developing the exposed resist film with an organic solvent and a method for manufacturing a semiconductor substrate.

10. Before the silicon-containing composition coating step, a step of forming an organic underlayer film directly or indirectly on the substrate The method for manufacturing a semiconductor substrate according to claim 9, further comprising

11. After the step of applying the silicon-containing composition, The method for manufacturing a semiconductor substrate according to claim 9 or claim 10, further comprising a step of removing the silicon-containing film with a removing solution containing a base.

12. The method for manufacturing a semiconductor substrate according to claim 11, wherein the removing solution containing a base is a solution containing a base and water, or a solution containing a base, hydrogen peroxide and water. ​

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