JP6384373B2 - Pattern formation method - Google Patents

Description

  The present invention relates to a pattern forming method.

  The radiation-sensitive composition used for microfabrication by lithography generates an acid in the exposed portion by irradiation with electromagnetic waves such as deep ultraviolet rays such as ArF excimer laser light and KrF excimer laser light, and charged particle beams such as electron beams. A chemical reaction using this acid as a catalyst causes a difference in the dissolution rate in the developer between the exposed area and the unexposed area, thereby forming a resist pattern on the substrate.

  Such a radiation-sensitive composition is required to improve resist performance as processing technology becomes finer. In response to this requirement, the types and molecular structures of polymers, acid generators, and other components used in the composition have been studied, and further their combinations have been studied in detail (Japanese Patent Laid-Open No. 11-125907, special features). (See Kaihei 8-146610 and JP-A 2000-298347).

  At present, miniaturization of resist patterns has progressed to a level of 40 nm or less, but higher resist performance (for example, resolution, sensitivity, nanoedge roughness, and appropriate thickening) is required.

Japanese Patent Laid-Open No. 11-125907 JP-A-8-146610 JP 2000-298347 A

  The present invention has been made based on the circumstances as described above, and can form a pattern with high sensitivity, high resolution, and appropriate thickening, and the storage stability of the composition is also good. The main object is to provide a pattern forming method.

That is, in the present invention,
A film forming step for forming a film;
An exposure step of exposing the film; and a development step of developing the film exposed in the exposure step;
With
A radiation sensitive film in which the film contains a metal compound and a compound represented by the following chemical formula (1) in an organic solvent [I] and an organic solvent [II]. Provided is a pattern forming method formed using an adhesive composition.
(In formula (1), R and R ′ are each independently a hydrogen atom, a chain or cyclic alkyl group having 2 to 20 carbon atoms, a chain or cyclic alkylcarbonyl group having 2 to 20 carbon atoms, carbon, Represents an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, and a part of hydrogen atoms in the cyclic alkyl group, cyclic alkylcarbonyl group, aryl group, or aryloxy group is substituted with a substituent. May be.)
The product that can be used in the pattern forming method according to the present invention can be obtained by further mixing a compound represented by the following chemical formula (2).
(In Formula (2), R ¹ is an n-valent organic group. X is —OH, —COOH, —NCO, or —NR ^a R ^b . R ^a and R ^b are the same or different hydrogen or (It is a monovalent organic group. N is an integer of 2 to 4. A plurality of X may be the same or different.)
In the present invention, a metal compound represented by the following chemical formula (3) can be used as the metal compound.
(In Formula (3), M is a titanium atom, an aluminum atom, a zirconium atom, a tantalum atom, a hafnium atom, a molybdenum atom, or a tungsten atom. L is a polydentate ligand. When a is 2 or more, a plurality of L may be the same or different, and X is a halogen ligand, hydroxo ligand, carboxy ligand, alkoxy ligand, carboxylate coordination A ligand or an amide ligand, b is an integer of 2 to 6. A plurality of X may be the same or different, provided that a + b is 7 or less.)
In the present invention, R and R ′ in the formula (1) can be a hydrogen atom.
In the present invention, a composition containing water and having a weight of the organic solvent [II] equal to or higher than the weight of water can be used as the radiation-sensitive composition.
In the present invention, the same organic solvent can be used as the organic solvent [I] and the organic solvent [II].
The radiation sensitive composition used in the present invention may further contain a radiation sensitive acid generator.
In the pattern forming method according to the present invention, a negative pattern can be formed by developing with an alkaline solution in the developing step.
Moreover, it can develop with an organic solvent in the developing step to form a negative pattern.
In the pattern formation method which concerns on this invention, the said exposure process can be performed by irradiation of an extreme ultraviolet ray or an electron beam.

  ADVANTAGE OF THE INVENTION According to this invention, the pattern formation method which can form the pattern which can be high-sensitivity, high resolution, and moderate thickness increase, and the preservation | save stability of a composition is favorable can be formed. Therefore, the pattern forming method can be suitably used for a semiconductor device processing process and the like that are expected to be further miniaturized in the future. In addition, the effect described here is not necessarily limited, and may be any effect described in the present technology.

  Hereinafter, embodiments for carrying out the present invention will be described in detail. In addition, embodiment described below shows an example of typical embodiment of this invention, and, thereby, this invention is not limited to embodiment described below.

<Pattern formation method>
The pattern forming method includes a film forming process, an exposure process, and a developing process, and the film is mixed with a metal compound and a compound represented by the chemical formula (1) in an organic solvent [I]. It is a method of forming using the radiation sensitive composition containing the obtained product and organic solvent [II]. Hereinafter, each step will be described.

[Film formation process]
In the film forming step, a film is formed using a radiation-sensitive composition described later. The film can be formed, for example, by applying a radiation sensitive composition on a substrate. Although it does not specifically limit as an application | coating method, For example, appropriate application | coating means, such as spin coating, cast coating, roll coating, can be employ | adopted. Examples of the substrate include a silicon wafer and a wafer coated with aluminum. Specifically, after applying the radiation-sensitive composition so that the resulting film has a predetermined thickness, the solvent in the coating film is volatilized by pre-baking (PB) as necessary. As a film thickness of a coating film, 10 nm or more and 500 nm or less are preferable. As a minimum of the temperature of PB, it is 60 degreeC normally and 80 degreeC is preferable. As an upper limit of the temperature of PB, it is 140 degreeC normally and 120 degreeC is preferable. The lower limit of the PB time is usually 5 seconds, and preferably 10 seconds. The upper limit of the PB time is usually 600 seconds, and preferably 300 seconds.

[Radiation sensitive composition]
The radiation-sensitive composition used in the pattern forming method according to the present invention is a product obtained by mixing a metal compound and a compound represented by the chemical formula (1) in an organic solvent [I]. (Hereinafter also referred to as “[A] product”) and organic solvent [II] (hereinafter also referred to as “[B] organic solvent”). Moreover, [C] a radiation sensitive acid generator can also be contained as needed, and in the range which does not impair the effect of this invention, you may contain other arbitrary components.
Hereinafter, each component will be described in detail.

[[A] product]
[A] The product is a product obtained by mixing the metal compound and the compound represented by the chemical formula (1) in the organic solvent [I]. More specifically, the [A] product is a product obtained by reacting a metal compound and hydrogen peroxide in the organic solvent [I]. Moreover, when obtaining the said product as needed, the compound (henceforth "compound (2)") represented by the said Chemical formula (2) can also be mixed.

[Organic solvent [I]]
[A] The organic solvent [I] that can be used for obtaining the product is one or two known organic solvents that can be used for the radiation-sensitive composition as long as the effects of the present invention are not impaired. More than one species can be freely selected and used. For example, alcohol solvents, ketone solvents, amide solvents, ether solvents, ester solvents, hydrocarbon solvents and the like can be mentioned.

Examples of alcohol solvents include methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol, tert-butanol, n-pentanol, iso-amyl alcohol, 2-methylbutanol, sec-pentanol, tert-pentanol, n-hexanol, 2-methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, 3-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, 2,6-dimethyl-4-heptanol, n-decanol, sec-undecyl alcohol, trimethylnonyl alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol Monohydric aliphatic alcohols such as
Monovalent alicyclic alcohols such as cyclohexanol, methylcyclohexanol, 3,3,5-trimethylcyclohexanol;
Aromatic alcohols such as benzyl alcohol and phenethyl alcohol;
Monovalent ether group or keto group-containing alcohols such as 3-methoxybutanol, furfuryl alcohol, diacetone alcohol;
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 Polyhydric alcohols such as ethyl-1,3-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, ethylene glycol monophenyl ether, ethylene glycol mono-2-ethylbutyl ether, propylene glycol monomethyl ether, propylene glycol Alkylene glycol monoalkyl ethers such as monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether;
Ether group-containing alkylene glycol mono, such as diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monopropyl ether Examples thereof include alkyl ethers.

Examples of ketone solvents include:
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, diiso-butyl ketone, trimethylnonanone, etc. Chain ketones;
Cyclic ketones such as cyclopentanone, cyclohexanone, cycloheptanone, cyclooctanone, methylcyclohexanone;
Aromatic ketones such as acetophenone and phenyl ethyl ketone;
Γ-diketones such as acetonylacetone are exemplified.

Examples of the amide solvent include
Chain amides such as N-methylformamide, N, N-dimethylformamide, N, N-diethylformamide, acetamide, N-methylacetamide, N, N-dimethylacetamide, N-methylpropionamide;
And cyclic amides such as N-methylpyrrolidone and N, N′-dimethylimidazolidinone.

As an ether solvent, for example,
Dialiphatic ethers such as diethyl ether, dibutyl ether, dipropyl ether;
Aromatic-aliphatic ethers such as anisole and phenylethyl ether;
Diaromatic ethers such as diphenyl ether;
Examples include cyclic ethers such as tetrahydrofuran, tetrahydropyran, and dioxane.

Examples of ester solvents include:
Methyl acetate, ethyl acetate, n-propyl acetate, iso-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methyl pentyl acetate 2-ethylbutyl acetate, 2-ethylhexyl acetate, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, n-nonyl acetate, ethyl propionate, n-butyl propionate, iso-amyl propionate, methyl acetoacetate, ethyl acetoacetate, etc. Monocarboxylic acid esters of
Dicarboxylic acid esters such as diethyl oxalate, di-n-butyl oxalate, diethyl malonate, dimethyl phthalate, diethyl phthalate;
Ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, ethylene glycol monopropyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, propylene glycol monopropyl ether acetate, propylene glycol monobutyl ether acetate, propylene glycol propionate Carboxylic acid esters of alkylene glycol monoalkyl ethers such as monomethyl ether;
Ether-containing alkylene glycol monoalkyl ethers such as diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol mono-n-butyl ether acetate, dipropylene glycol monomethyl ether acetate, dipropylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether propionate Carboxylic acid esters;
Hydroxy acid esters such as methyl glycolate, ethyl glycolate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate;
lactones such as γ-butyrolactone and γ-valerolactone;
Examples thereof include carbonates such as diethyl carbonate and propylene carbonate.

  Among these, as the organic solvent [I], alcohol solvents, ether solvents, ester solvents and hydrocarbon solvents are preferable, monovalent aliphatic alcohols, alkylene glycol monoalkyl ethers, hydroxy acid esters, alkylene glycols. Monoalkyl ether carboxylic acid esters, lactones, cyclic ethers, and aromatic hydrocarbons are more preferable, monovalent aliphatic alcohols having 2 or more carbon atoms, alkylene glycol monoalkyl ethers having 6 or more carbon atoms, and hydroxy acids having 4 or more carbon atoms. Ester, alkylene glycol monoalkyl ether carboxylic acid ester having 6 or more carbon atoms, lactone having 4 or more carbon atoms, cyclic ether having 4 or more carbon atoms, and aromatic hydrocarbon having 7 or more carbon atoms, ethanol, n-butanol, Propylene glycol Monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, ethyl lactate, propylene glycol monomethyl ether acetate, .gamma.-butyrolactone, tetrahydrofuran, toluene is particularly preferred.

  Organic solvent [I] can also be used as [B] organic solvent (organic solvent [II]) of a radiation sensitive composition, without removing after reaction.

[Metal compounds]
[A] As the metal compound that can be used to obtain the product, one or more metal compounds that can be used in the radiation-sensitive composition can be freely selected as long as the effects of the present invention are not impaired. Can be used. For example, a metal compound represented by the chemical formula (3) can be given.

  In the chemical formula (3), the polydentate ligand represented by L can be used to enhance the solubility of the radiation-sensitive composition in the cleaning solvent. The kind of polydentate ligand that can be used in the metal compound is not particularly limited, and one or more polydentate ligands that can be used in the metal compound of the radiation-sensitive composition can be freely used. It can be selected and used.

  In the present invention, the polydentate ligand is a ligand derived from at least one selected from the group consisting of a hydroxy acid ester, a β-diketone, a β-keto ester, a β-dicarboxylic acid ester, and a hydrocarbon having a cage bond. Is preferably selected. By using a multidentate ligand as the ligand, the cleaning solvent removability of the radiation-sensitive composition can be further improved. These compounds usually form a polydentate ligand as an anion obtained by obtaining one electron or as it is.

  The hydroxy acid ester is not particularly limited as long as it is a carboxylic acid ester having a hydroxy group, and examples thereof include a compound represented by the following chemical formula (4).

In the chemical formula (4), R ^A is a divalent organic group having 1 to 20 carbon atoms. R ^B is a monovalent organic group having 1 to 20 carbon atoms.

Examples of the divalent organic group represented by R ^A include a monovalent hydrocarbon group having 1 to 20 carbon atoms, and a divalent hetero group at the carbon-carbon end of the hydrocarbon group or at the end of the bond. Examples include a group (a) containing an atom-containing group, a group obtained by substituting a part or all of the hydrogen atoms of the hydrocarbon group and the group (a) with a monovalent heteroatom-containing group.
Examples of the hetero atom contained in the monovalent or divalent heteroatom-containing group include an oxygen atom, a nitrogen atom, a sulfur atom, a silicon atom, and a phosphorus atom.
Examples of the divalent heteroatom-containing group include —O—, —S—, —CO—, —CS—, —NR′—, and a combination thereof. R ′ is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.
Examples of the monovalent heteroatom-containing group include a hydroxy group, a sulfanyl group (—SH), an amino group, a cyano group, a carboxy group, and a keto group (═O).
Examples of the monovalent organic group represented by R ^B include a group obtained by adding one hydrogen atom to the group exemplified as the divalent organic group of R ^A.

R ^A is preferably a divalent hydrocarbon group, more preferably an alkanediyl group, a cycloalkanediyl group or an arenediyl group, more preferably a methanediyl group, an ethanediyl group, a cyclohexanediyl group or a benzenediyl group, particularly preferably an ethanediyl group. preferable.
Examples of R ^B, preferably a monovalent hydrocarbon group, more preferably an alkyl group, a methyl group, an ethyl group, a propyl group, preferably a butyl group further ethyl group is particularly preferred.

  Examples of the hydroxy acid ester include glycolic acid ester, lactic acid ester, 2-hydroxycyclohexane-1-carboxylic acid ester, and salicylic acid ester. Of these, lactic acid esters are preferred, and ethyl lactate is more preferred.

  Although it will not specifically limit if it is a compound which has a 1, 3- diketo structure as said beta-diketone, For example, the compound etc. which are represented by following Chemical formula (5) are mentioned.

In the chemical formula (5), R ^C and R ^D are each independently a monovalent organic group having 1 to 20 carbon atoms. R ^E is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ^C , R ^D and R ^E are the same as those exemplified as the monovalent organic group of R ^{B in} the formula (3). Groups and the like.

As R ^C and R ^D , a monovalent hydrocarbon group is preferable, an alkyl group is more preferable, a methyl group, an ethyl group, a propyl group, and a butyl group are further preferable, and a methyl group is particularly preferable.
R ^E is preferably a hydrogen atom or a monovalent hydrocarbon group, more preferably a hydrogen atom or an alkyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

  Examples of β-diketone include acetylacetone, methylacetylacetone, and ethylacetylacetone. Of these, acetylacetone is preferred.

  The β-ketoester is not particularly limited as long as it is a compound having a ketonic carbonyl group at the β-position of the carboxylic acid ester, and examples thereof include compounds represented by the following chemical formula (6).

In the chemical formula (6), R ^F and R ^G are each independently a monovalent organic group having 1 to 20 carbon atoms. ^RH is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

Examples of the monovalent organic group having 1 to 20 carbon atoms represented by R ^F , R ^G and R ^H are the same as those exemplified as the monovalent organic group of R ^{B in} the formula (4). Groups and the like.

R ^F is preferably a monovalent hydrocarbon group or a carbonyloxy hydrocarbon group-substituted hydrocarbon group, more preferably an alkyl group, an aryl group, or an alkoxycarbonylalkyl group, and a methyl group, a phenyl group, or a methoxycarbonylmethyl group. More preferred is a methyl group.
R ^G is preferably a monovalent hydrocarbon group, more preferably an alkyl group, further preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably an ethyl group.
The ^RH is preferably a hydrogen atom or a monovalent hydrocarbon group, more preferably a hydrogen atom or an alkyl group, still more preferably a hydrogen atom or a methyl group, and particularly preferably a hydrogen atom.

  Examples of the β-ketoester include acetoacetate ester, α-alkyl substituted acetoacetate ester, β-ketopentanoate ester, benzoyl acetate ester, 1,3-acetone dicarboxylate ester and the like. Of these, acetoacetate is preferable, and ethyl acetoacetate is more preferable.

  Examples of the β-dicarboxylic acid ester include compounds represented by the following chemical formula (7).

In the chemical formula (7), R ^I and R ^J are each independently a monovalent organic group having 1 to 20 carbon atoms. ^RK is a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms.

Wherein ^R I, as the monovalent organic group having 1 to 20 carbon atoms represented by ^{R J} and ^{R K,} for example, the formula similar to those exemplified as the monovalent organic group ^{R B} (4) Groups and the like.

R ^I and R ^J are preferably a monovalent hydrocarbon group, more preferably an alkyl group, still more preferably a methyl group, an ethyl group, a propyl group, or a butyl group, and particularly preferably an ethyl group.
Examples of R ^K, a hydrogen atom, preferably a monovalent hydrocarbon group, a hydrogen atom, an alkyl group, a cycloalkyl group, more preferably an aryl group, a hydrogen atom, more preferably an alkyl group, a hydrogen atom is particularly preferred.

  Examples of the β-dicarboxylic acid ester include malonic acid diester, α-alkyl substituted malonic acid diester, α-cycloalkyl substituted malonic acid diester, α-aryl substituted malonic acid diester, and the like. Among these, malonic acid diester is preferable, and diethyl malonate is more preferable.

Examples of the hydrocarbon having a saddle bond include
Chain olefins such as ethylene and propylene;
Cyclic olefins such as cyclopentene, cyclohexene, norbornene;
Chain dienes such as butadiene and isoprene;
Cyclic dienes such as cyclopentadiene, methylcyclopentadiene, pentamethylcyclopentadiene, cyclohexadiene, norbornadiene;
Examples thereof include aromatic hydrocarbons such as benzene, toluene, xylene, hexamethylbenzene, naphthalene, and indene.
Among these, cyclic dienes are preferable, and cyclopentadiene is more preferable. Cyclopentadiene usually obtains one electron and forms a cyclopentadienyl anion, which is a multidentate ligand.

  The number of polydentate ligands coordinated to the metal atom (“a” in the chemical formula (3)) is 1 to 3 with respect to one metal atom. One is preferable, and one is more preferable. In addition, the number of this multidentate ligand shows the average number per metal atom.

  In the chemical formula (3), examples of the halogen ligand represented by X include a fluorine ligand, a chlorine ligand, a bromine ligand, and an iodine ligand. Among these, a chlorine ligand is preferable.

  Examples of the alkoxy ligand represented by X include a methoxy ligand (OMe), an ethoxy ligand (OEt), an n-propoxy ligand (nOPr), and an i-propoxy ligand (iOPr). , N-butoxy ligand (nOBu) and the like. Among these, an ethoxy ligand, i-propoxy ligand, and n-butoxy ligand are preferable.

  Examples of the carboxylate ligand represented by X include formate ligand (OOCH), acetate ligand (OOCMe), propionate ligand (OOCEt), butyrate ligand (OOCPr), and the like. It is done. Of these, acetate ligands are preferred.

Examples of the amide ligand represented by X include unsubstituted amide ligand (NH ₂ ), methylamide ligand (NHMe), dimethylamide ligand (NMe ₂ ), and diethylamide ligand (NEt ₂ ). , Dipropylamide ligand (NPr ₂ ) and the like. Among these, a dimethylamide ligand and a diethylamide ligand are preferable.

  In said chemical formula (3), as said b, it is an integer of 2-6, the integer of 2-4 is preferable, 2 or 3 is more preferable, and 2 is more preferable. By setting b to 2, the formed [A] product can have a more linear structure, and as a result, the cleaning solvent stability of the radiation-sensitive composition can be improved.

[Organic peroxide]
[A] The organic peroxide that can be used to obtain the product is one or two organic peroxides that can be used in the radiation-sensitive composition as long as the effects of the present invention are not impaired. These can be freely selected and used. The organic peroxide can be represented by a compound represented by the chemical formula (1).

R and R ′ in the above formula (1) are each independently a hydrogen atom, a chain or cyclic alkyl group having 2 to 20 carbon atoms, a chain or cyclic alkylcarbonyl group having 2 to 20 carbon atoms, carbon Represents an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, and a part of hydrogen atoms in the cyclic alkyl group, cyclic alkylcarbonyl group, aryl group, or aryloxy group is substituted with a substituent. May be.
Examples of the substituent include a hydroxyl group, a cyano group, a chain alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or a group in which these groups are combined. Can be mentioned.

Examples of the compound represented by the formula (1) include hydrogen peroxide, peracetic acid, diisobutyryl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, and dilauroyl. Peroxide, di (3,5,5-trimethylhexanoyl) peroxide, t-butyl peroxypivalate, t-hexyl peroxypivalate, t-butyl peroxyneoheptanoate, t-butyl peroxyneo Decanoate, t-hexylperoxyneodecanoate, di (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, 1,1,3,3-tetramethylbutyl Peroxyneodecanoate, di-sec-butyl peroxydicarbonate, di-n-propiate Peroxydicarbonate, cumyl peroxyneodecanoate, methyl ethyl ketone peroxide, benzoyl peroxide, metachloroperbenzoic acid, and the like.
Of these, hydrogen peroxide is preferred.

[Compound represented by chemical formula (2)]
[A] In order to obtain a product, it is preferable to mix a compound represented by the chemical formula (2) (hereinafter also referred to as “compound (2)”).
Although the exact action and effect of the compound (2) is not clear, the organic solvent [I] reacts with the complex obtained by mixing the metal compound and the organic peroxide to dissolve in the organic solvent. It is thought that it has a function to increase Moreover, it is thought that it functions also as a bridge | crosslinking ligand which coordinates so that the metal atom in the said metal compound may be bridge | crosslinked. Therefore, when the metal compound and hydrogen peroxide are mixed in the organic solvent [I], the presence of the compound (2) suppresses complex precipitation, and reaction with the metal compound. The binuclear complex derived from the said metal compound can be formed while improving property. In addition, the compound (2) can function as a bridging ligand by itself, or can function as a bridging ligand in the state of an anion from which a proton is eliminated from the compound (2).

In the chemical formula (2), examples of the n-valent organic group represented by R ¹ include an n-valent hydrocarbon group and an n-valent group including a group having a hetero atom between carbon-carbon of the hydrocarbon group. And a n-valent group obtained by substituting some or all of the hydrogen atoms of the hydrocarbon group and heteroatom-containing group with a substituent.

Examples of the n-valent hydrocarbon group include:
Alkanes such as methane, ethane, propane and butane; alkenes such as ethene, propene, butene and pentene; chain hydrocarbons having 1 to 30 carbon atoms such as alkyne such as ethyne, propyne, butyne and pentyne, cyclopropane, cyclobutane, C3-C30 alicyclic hydrocarbons such as cycloalkanes such as cyclopentane, cyclohexane, norbornane and adamantane, cycloalpenes such as cyclopropene, cyclobutene, cyclopentene, cyclohexene and norbornene, benzene, toluene, xylene, mesitylene and naphthalene And groups obtained by removing n hydrogen atoms from hydrocarbons such as aromatic hydrocarbons having 6 to 30 carbon atoms such as arenes such as methylnaphthalene, dimethylnaphthalene and anthracene.

  Examples of the group having a hetero atom include a group having at least one selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a phosphorus atom, and a sulfur atom, and the like, -O-, -NH-, -CO-, -S-, group which combined these, etc. are mentioned. Of these, -O- is preferred.

Examples of the substituent include:
Halogen atoms such as fluorine atom, chlorine atom, bromine atom and iodine atom;
Alkoxy groups such as methoxy group, ethoxy group, propoxy group;
Alkoxycarbonyl groups such as methoxycarbonyl group and ethoxycarbonyl group;
Alkoxycarbonyloxy groups such as methoxycarbonyloxy group and ethoxycarbonyloxy group;
Examples include acyl groups such as formyl group, acetyl group, propionyl group, butyryl group and benzoyl group; cyano group and nitro group.

  As said n, 2-4 are preferable and 2 or 3 is more preferable.

Examples of the monovalent organic group represented by R ^a and R ^b of —NR ^a R ^{b in} X in the formula (2) include, for example, a hydrogen atom, a monovalent hydrocarbon group having 1 to 20 carbon atoms, Examples include a heteroatom-containing group containing a group having a heteroatom between carbon-carbon of this hydrocarbon group, a group in which part or all of the hydrogen atoms of the hydrocarbon group and heteroatom-containing group are substituted with a substituent, and the like It is done. R ^a and R ^b are preferably a monovalent hydrocarbon group, more preferably a monovalent chain hydrocarbon group, still more preferably an alkyl group, and particularly preferably a methyl group.

As R ¹ ,
As n is 2, a divalent chain hydrocarbon group, a divalent aromatic hydrocarbon group, or a divalent heteroatom-containing group is preferable, an alkanediyl group, an alkenediyl group, an arenediyl group, an alkanediyloxyalkanediyl Group is more preferable, 1,1-ethanediyl group, 1,2-ethanediyl group, 1,2-propanediyl group, butanediyl group, hexanediyl group, ethenediyl group, xylenediyl group, ethanediyloxyethanediyl group are more preferable. .
When n is 3, a trivalent chain hydrocarbon group is preferable, an alkanetriyl group is more preferable, and a 1,2,3-propanetriyl group is more preferable.
When n is 4, a tetravalent chain hydrocarbon group is preferable, an alkanetetrayl group is more preferable, 1,2,2,3-propanetetrayl group, 1,2,3,4-butanetetrayl More preferred are groups.

  Examples of the compound (2) include a compound represented by the following chemical formula (8) (hereinafter also referred to as “compound (8)”).

(In formula (8), X ′ is —COOH, —NCO or —NR ^a R ^b . R ^a and R ^b are the same or different hydrogen or a monovalent organic group. N is 0 to 4) (Several Xs may be the same or different. R1 is an n-valent organic group.)

In said formula (8), R < ¹ >, ^Ra and ^Rb are synonymous with the said Chemical formula (2).

As the compound (8), for example,
Assuming that n is 2,
Alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol;
Dialkylene glycols such as diethylene glycol, dipropylene glycol, dibutylene glycol, triethylene glycol, tripropylene glycol;
Cycloalkylene glycols such as cyclohexanediol, cyclohexanedimethanol, norbornanediol, norbornanedimethanol, adamantanediol;
Aromatic ring-containing glycols such as 1,4-benzenedimethanol and 2,6-naphthalenediethanol;
And dihydric phenols such as catechol, resorcinol, hydroquinone, etc.
Assuming that n is 3,
Alkanetriols such as glycerin and 1,2,4-butanetriol;
Cycloalkanetriols such as 1,2,4-cyclohexanetriol, 1,2,4-cyclohexanetrimethanol;
Aromatic ring-containing glycols such as 1,2,4-benzenetrimethanol and 2,3,6-naphthalenetrimethanol;
Examples include trivalent phenols such as pyrogallol and 2,3,6-naphthalenetriol,
Assuming that n is 4,
Alkanetetraols such as erythritol and pentaerythritol;
Cycloalkanetetraols such as 1,2,4,5-cyclohexanetetraol;
Aromatic ring-containing tetraols such as 1,2,4,5-benzenetetramethanol;
And tetrahydric phenols such as 1,2,4,5-benzenetetraol.
Among these, n is preferably 2 or 3, more preferably alkylene glycol, dialkylene glycol and alkanetriol, and further preferably propylene glycol, diethylene glycol and glycerin.

Examples of the compound in which X ′ of the compound (8) is —COOH include:
Chain saturated dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid;
Chain unsaturated dicarboxylic acids such as maleic acid and fumaric acid;
Alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, norbornane dicarboxylic acid, adamantane dicarboxylic acid;
Aromatic dicarboxylic acids such as phthalic acid, terephthalic acid, 2,6-naphthalenedicarboxylic acid, and 2,7-naphthalenedicarboxylic acid; chain saturated tricarboxylic acids such as 1,2,3-propanetricarboxylic acid;
Chain unsaturated tricarboxylic acids such as 1,2,3-propenetricarboxylic acid;
Alicyclic tricarboxylic acids such as 1,2,4-cyclohexanetricarboxylic acid;
Aromatic tricarboxylic acids such as trimellitic acid and 2,3,7-naphthalenetricarboxylic acid; chain saturated tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid;
Chain unsaturated tetracarboxylic acids such as 1,2,3,4-butadienetetracarboxylic acid;
Alicyclic tetracarboxylic acids such as 1,2,5,6-cyclohexanetetracarboxylic acid, 2,3,5,6-norbornanetetracarboxylic acid;
Examples include pyromellitic acid and aromatic tetracarboxylic acids such as 2,3,6,7-naphthalenetetracarboxylic acid.
Among these, chain saturated dicarboxylic acid, chain unsaturated dicarboxylic acid, alicyclic dicarboxylic acid, and aromatic dicarboxylic acid are preferable, chain saturated dicarboxylic acid and chain unsaturated dicarboxylic acid are more preferable, maleic acid, More preferred is succinic acid.

As the compound wherein X ′ of the compound (8) is —NCO, for example,
Chain diisocyanates such as ethylene diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate;
Alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate;
Aromatic diisocyanates such as tolylene diisocyanate, 1,4-benzene diisocyanate, 4,4′-diphenylmethane diisocyanate; chain triisocyanates such as trimethylene triisocyanate;
Alicyclic triisocyanates such as 1,2,4-cyclohexane triisocyanate;
Aromatic triisocyanates such as 1,2,4-benzene triisocyanate; chain tetraisocyanates such as tetramethylene tetraisocyanate;
Alicyclic tetraisocyanates such as 1,2,4,5-cyclohexanetetraisocyanate;
And aromatic tetraisocyanates such as 1,2,4,5-benzenetetraisocyanate.
Among these, chain diisocyanate, alicyclic diisocyanate, and aromatic diisocyanate are preferable, chain diisocyanate is more preferable, and hexamethylene diisocyanate is further preferable.

Examples of the compound in which X ′ of the compound (8) is —NR ^a R ^b include:
Chain diamines such as ethylenediamine, N-methylethylenediamine, N, N′-dimethylethylenediamine, trimethylenediamine, N, N′-dimethyltrimethylenediamine, tetramethylenediamine, N, N′-dimethyltetramethylenediamine;
Alicyclic diamines such as 1,4-cyclohexanediamine and 1,4-di (aminomethyl) cyclohexane;
Aromatic diamines such as 1,4-diaminobenzene and 4,4′-diaminodiphenylmethane; chain triamines such as triaminopropane and N, N ′, N ″ -trimethyltriaminopropane;
Alicyclic triamines such as 1,2,4-triaminocyclohexane;
Aromatic triamines such as 1,2,4-triaminobenzene; chain tetraamines such as tetraaminobutane;
Alicyclic tetraamines such as 1,2,4,5-tetraaminocyclohexane, 2,3,5,6-tetraaminonorbornane;
Examples include aromatic tetraamines such as 1,2,4,5-tetraaminobenzene.
Among these, chain diamines, alicyclic diamines, and aromatic diamines are preferable, chain diamines are more preferable, and N, N′-dimethylethylenediamine is more preferable.

  Moreover, it is also possible to use the compound which has multiple types of each functional group of a compound (8) as a compound (2). Examples of the compound having a plurality of functional groups include citric acid, glycolic acid, lactic acid, amino acid, triethanolamine, and ethylenediaminediacetic acid.

[[A] Product Synthesis Method]
[A] The product can be obtained by reacting the metal compound with the organic peroxide in the organic solvent [I]. At this time, it is preferable to mix the compound represented by the chemical formula (2). When mixing the compound (2), the order of mixing is not particularly limited, and the metal compound, the organic peroxide, and the compound (2) can be mixed in any order.

  As temperature of the said reaction, 0 to 150 degreeC is preferable and 10 to 120 degreeC is more preferable. The reaction time is preferably 30 minutes to 24 hours, more preferably 1 hour to 20 hours, and even more preferably 2 hours to 15 hours.

[[B] Organic solvent (organic solvent [II])]
[B] As the organic solvent, as long as it can dissolve or disperse the product [A], one or more known organic solvents that can be used for the radiation-sensitive composition are freely used. Can be selected and used. For example, alcohol solvents, ketone solvents, amide solvents, ether solvents, ester solvents, hydrocarbon solvents and the like can be mentioned. [B] The organic solvent can be used as it is without removing the organic solvent used in the reaction in the synthesis of the [A] product. In addition, since the specific example of each organic solvent is the same as the above-mentioned organic solvent [I], description is omitted here.

  [B] The content of the organic solvent is such that the content of the [A] product in the radiation-sensitive composition is usually 0.1% by mass to 50% by mass, and 0.5% by mass. The content of% to 30% by mass is preferable, the content of 1% to 15% by mass is more preferable, and the content of 2% to 10% by mass is more preferable. The radiation-sensitive composition can further improve storage stability and coatability by setting the content of the [A] product in the composition in the above range.

  The radiation sensitive composition can contain water. When water is contained in the composition, it is preferable to adjust the content of [B] organic solvent so that the weight of [B] organic solvent is equal to or more than the weight of water. [B] By making the weight of the organic solvent equal to or more than the weight of water, it is possible to maintain good coatability on the substrate.

[[C] Radiation sensitive acid generator]
The radiation sensitive composition may further contain a [C] radiation sensitive acid generator. [C] The radiation-sensitive acid generator is a compound that generates an acid by light or heat. A radiation sensitive composition can improve resist pattern formation property and etching selectivity by further containing a [C] radiation sensitive acid generator. [C] Examples of the radiation sensitive acid generator include onium salt compounds and N-sulfonyloxyimide compounds, among which onium salt compounds are preferred.

  Examples of the onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, ammonium salts, and the like.

  Examples of the sulfonium salt include triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium perfluoro-n-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept. 2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro N-octane sulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept 2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium Perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 1,1 2,2-tetrafluoro-6- (1-adamantanecarbonyloxy) -hexane-1-sulfonate and the like.

  Examples of the tetrahydrothiophenium salt include 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium. Nonafluoro-n-butanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (4-n-butoxynaphthalen-1-yl) tetrahydrothio Phenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium trifluoro L-methanesulfonate, 1- (6-n-butoxynaphthalene- -Yl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (6-n-butoxynaphthalen-2-yl) tetrahydrothiophenium perfluoro-n-octanesulfonate, 1- (6-n-butoxynaphthalene) -2-yl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 1- (3,5-dimethyl-4-hydroxy Phenyl) tetrahydrothiophenium trifluoromethanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium nonafluoro-n-butanesulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) Tetrahydrothiophenium perfluoro-n-octane Sulfonate, 1- (3,5-dimethyl-4-hydroxyphenyl) tetrahydrothiophenium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, and the like. Can be mentioned.

  Examples of the iodonium salt include diphenyliodonium trifluoromethanesulfonate, diphenyliodonium nonafluoro-n-butanesulfonate, diphenyliodonium perfluoro-n-octanesulfonate, diphenyliodonium 2-bicyclo [2.2.1] hept-2-yl. -1,1,2,2-tetrafluoroethanesulfonate, bis (4-t-butylphenyl) iodonium trifluoromethanesulfonate, bis (4-t-butylphenyl) iodonium nonafluoro-n-butanesulfonate, bis (4- t-butylphenyl) iodonium perfluoro-n-octanesulfonate, bis (4-t-butylphenyl) iodonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-teto Fluoro ethanesulfonate.

  Examples of ammonium salts include ammonium formate, ammonium maleate, ammonium fumarate, ammonium phthalate, ammonium malonate, ammonium succinate, ammonium tartrate, ammonium malate, ammonium lactate, ammonium citrate, ammonium acetate, and ammonium propionate. , Ammonium butanoate, ammonium pentanoate, ammonium hexanoate, ammonium heptanoate, ammonium octanoate, ammonium nonanoate, ammonium decanoate, ammonium oxalate, ammonium adipate, ammonium sebacate, ammonium butyrate, ammonium oleate, stearic acid Ammonium, ammonium linoleate, ammonium linoleate, ammonium salicylate, ben Ammonium Nsuruhon acid, ammonium benzoate, ammonium p- aminobenzoic acid, ammonium p- toluenesulfonic acid, ammonium methanesulfonate, ammonium trifluoromethanesulfonate, ammonium trifluoroethane sulfonic acid and the like. The ammonium ions of the ammonium salt are methylammonium ion, dimethylammonium ion, trimethylammonium ion, tetramethylammonium ion, ethylammonium ion, diethylammonium ion, triethylammonium ion, tetraethylammonium ion, propylammonium ion, dipropylammonium ion. Ion, tripropylammonium ion, tetrapropylammonium ion, butylammonium ion, dibutylammonium ion, tributylammonium ion, tetrabutylammonium ion, trimethylethylammonium ion, dimethyldiethylammonium ion, dimethylethylpropylammonium ion, methylethylpropylbutylammonium Ammonium salt substituted with urium ion, ethanolammonium ion, diethanolammonium ion, triethanolammonium ion, 1,8-diazabicyclo [5.4.0] undec-7-eneformate, 1,8-diazabicyclo [5. 4.0] undec-7-ene p-toluenesulfonate 1,8-diazabicyclo [5.4.0] undec-7-ene salt, 1,5-diazabicyclo [4.3.0] -5 -Nonene formate, 1,5-diazabicyclo [4.3.0] -5-nonene salt such as 1,5-diazabicyclo [4.3.0] -5-nonene p-toluenesulfonate, etc. .

  Examples of the N-sulfonyloxyimide compound include N- (trifluoromethanesulfonyloxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (nonafluoro-n-butanesulfonyl). Oxy) bicyclo [2.2.1] hept-5-ene-2,3-dicarboximide, N- (perfluoro-n-octanesulfonyloxy) bicyclo [2.2.1] hept-5-ene- 2,3-dicarboximide, N- (2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonyloxy) bicyclo [2.2.1] hept -5-ene-2,3-dicarboximide and the like.

  Among these [C] radiation-sensitive acid generators, onium salt compounds are preferred, sulfonium salts are more preferred, triphenylsulfonium nonafluoro-n-butanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium perfluoro N-octanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, triphenylsulfonium 2-bicyclo [2.2.1 ] Hept-2-yl-1,1-difluoroethanesulfonate, triphenylsulfonium camphorsulfonate, 4-cyclohexylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-cyclohexylphenyldipheny Sulfonium nonafluoro-n-butanesulfonate, 4-cyclohexylphenyldiphenylsulfonium perfluoro-n-octanesulfonate, 4-cyclohexylphenyldiphenylsulfonium 2-bicyclo [2.2.1] hept-2-yl-1,1,2 , 2-tetrafluoroethanesulfonate, 4-cyclohexylphenyldiphenylsulfonium camphorsulfonate, 4-methanesulfonylphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium nonafluoro-n-butanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium Perfluoro-n-octanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium 2 Bicyclo [2.2.1] hept-2-yl-1,1,2,2-tetrafluoroethanesulfonate, 4-methanesulfonylphenyldiphenylsulfonium camphorsulfonate, triphenylsulfonium 1,1,2,2-tetrafluoro -6- (1-adamantane carbonyloxy) -hexane-1-sulfonate and the like. More preferred sulfonium salts include triphenylsulfonium nonafluoro-n-butanesulfonate.

  These [C] radiation sensitive acid generators may be used alone or in combination of two or more. [C] The content of the radiation-sensitive acid generator is preferably 0 to 10 parts by mass, more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the product [A]. preferable. [C] By making content of a radiation sensitive acid generator into the said range, the resist pattern formation property and etching selectivity of a radiation sensitive composition can be improved more.

[Other optional ingredients]
The radiation-sensitive composition may contain other optional components such as a surfactant as long as the effects of the present invention are not impaired.

  A surfactant is a component that exhibits an effect of improving coating properties, 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 glycol In addition to nonionic surfactants such as 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.), MegaFuck F171, F173 (above, manufactured by Dainippon Ink & Chemicals, Inc.), Fluorard FC430, FC431 (above, manufactured by Sumitomo 3M Limited), Asahi Guard AG710, Surflon S-382, SC-101, SC-102, SC-103, SC-104, SC-105, SC-106 (manufactured by Asahi Glass Co., Ltd.) and the like.

  Surfactants may be used alone or in combination of two or more. Moreover, the compounding quantity of surfactant can be suitably determined according to the objective.

[Method for preparing radiation-sensitive composition]
The radiation-sensitive composition is, for example, a mixture of [A] product and [B] organic solvent, and, if necessary, water, [C] radiation-sensitive acid generator and other optional components at a predetermined ratio. Can be prepared. As described above, the radiation-sensitive composition may be prepared using the organic solvent [I] used in the synthesis of the product [A] as it is as the organic solvent [B]. The radiation-sensitive composition is usually prepared by dissolving in a solvent at the time of use and then filtering with a filter having a pore size of about 0.2 μm, for example.

The radiation-sensitive composition described above is soluble in both alkali solutions and organic solvents. Therefore, in the development step described later, development with an organic solvent in addition to the alkaline solution is possible.
In addition, since the radiation-sensitive composition described above is used in the pattern forming method according to the present invention, the storage stability of the composition is high, and high sensitivity, high resolution, and appropriate thickening are possible. is there.

[Exposure process]
In the exposure step, the film formed in the film formation step is exposed. In some cases, this exposure is performed by irradiating radiation through a mask having a predetermined pattern through an immersion medium such as water. The radiation is appropriately selected from, for example, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV; wavelength 13.5 nm), electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as electron beams and α-rays. . Among these, radiation in which secondary electrons are emitted from the metal by exposure is preferable, and EUV and electron beam are more preferable.

  Moreover, you may perform post-exposure baking (PEB) after exposure. As a minimum of the temperature of PEB, it is 50 degreeC normally and 80 degreeC is preferable. The upper limit of the PEB temperature is usually 180 ° C, preferably 130 ° C. The lower limit of the PEB time is usually 5 seconds, and preferably 10 seconds. The upper limit of the PEB time is usually 600 seconds, and preferably 300 seconds.

  In the present invention, in order to maximize the potential of the radiation-sensitive composition, for example, an organic or inorganic antireflection film can be formed on the substrate to be used. Moreover, in order to prevent the influence of the basic impurity etc. which are contained in environmental atmosphere, a protective film can also be provided on a coating film, for example. When immersion exposure is performed, an immersion protective film may be provided on the film, for example, in order to avoid direct contact between the immersion medium and the film.

[Development process]
In this step, the film exposed in the exposure step is developed. Examples of the developer used for the development include an alkaline solution and an organic solvent. Therefore, in this step, a negative pattern can be formed by developing with an alkaline solution. It is also possible to develop with an organic solvent to form a negative pattern.

  Examples of the alkaline solution include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, and methyldiethylamine. , Ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo- [5.4.0] -7-undecene, 1,5-diazabicyclo- [4 .3.0] -5 aqueous solution in which at least one of alkaline compounds such as 5-nonene is dissolved.

  As said organic solvent, the thing similar to the solvent illustrated as organic solvent [I] of the said radiation sensitive composition is mentioned, for example. Of these, ester solvents are preferred, and butyl acetate is more preferred.

  These developers may be used alone or in combination of two or more. In general, after development, the substrate is washed with water or the like and dried.

  Hereinafter, the present invention will be described in more detail based on examples. In addition, the Example demonstrated below shows an example of the typical Example of this invention, and, thereby, the range of this invention is not interpreted narrowly.

<[A] Synthesis of product>
[A] The metal compounds used in the synthesis of the product are as follows.
M-1: Titanium (IV) diisopropoxybis (2,4-pentanedionate) (75% strength by weight 2-propanol solution)
M-2: Aluminum (III) diisopropoxyethyl acetoacetate M-3: Zirconium (IV) di-n-butoxide bis (2,4-pentanedionate) (60% strength by weight butanol solution)
M-4: Tantalum (V) tetraethoxy (2,4-pentanedionate)
M-5: Bis (cyclopentadienyl) tungsten (IV) dichloride M-6: Hafnium (IV) tetra t-butoxide M-7: Hafnium (IV) monooxide dichloride (HfOCl ₂ ) · 8 hydrate

[Synthesis Example 1]
10.0 g of the above compound (M-1) (complex mass: 7.5 g, 20.6 mmol) was dissolved in 65.0 g of propylene glycol monoethyl ether, stirred well, and 30% hydrogen peroxide was added to this solution at room temperature. 0.75 g of water (0.23 g, 6.6 mmol as hydrogen peroxide) was added dropwise over 10 minutes. Subsequently, after reacting at room temperature for 1 hour, 7.9 g (41.2 mmol) of citric acid was added, followed by stirring at room temperature for 2 hours to obtain a solution (S-1).

[Synthesis Example 2]
4.9 g (18 mmol) of the compound (M-2) was dissolved in 40.2 g of 2-propanol, stirred well, and then mixed with 1.8 g (18 mmol) of maleic anhydride and 7.2 g of water at room temperature. The solution was added and stirred for 30 minutes. Next, 1.02 g of 30% aqueous hydrogen peroxide (0.31 g, 9.0 mmol as hydrogen peroxide) was added dropwise at room temperature over 10 minutes. After reacting at room temperature for 3 hours, 42.2 g of propylene glycol monomethyl ether acetate was added to this solution to obtain a solution (S-2).

[Synthesis Example 3]
16.7 g (complex mass: 10.0 g, 23 mmol) of the above compound (M-3) was dissolved in 99.6 g of 1-butanol and stirred well. Hydrogen oxide (0.39 g, 11.5 mmol) was added dropwise at room temperature over 10 minutes. Subsequently, after reacting at 60 degreeC for 1 hour, it cooled at room temperature, Furthermore, after adding 1.2 g (11.5 mmol) of diethylene glycol, it stirred at room temperature for 2 hours, and obtained solution (S-3).

[Synthesis Example 4]
After 4.6 g (10 mmol) of the compound (M-4) was dissolved in 44.32 g of dibutyl ether and stirred well, 1.1 g of 30% aqueous hydrogen peroxide (0.34 g, 10 mmol as hydrogen peroxide) was added to this solution. ) Was added dropwise at room temperature over 10 minutes. Subsequently, after reacting at 60 degreeC for 1 hour, it cooled at room temperature, and also after adding 0.30 g (5.0 mmol) of ethylenediamine, it stirred at room temperature for 1 hour, and obtained solution (S-4).

[Synthesis Example 5]
3.8 g (10 mmol) of the compound (M-5) was dissolved in 44.42 g of ethyl lactate and stirred well, and then 0.57 g of 30% aqueous hydrogen peroxide (0.17 g as hydrogen peroxide, 5 0.0 mmol) was added dropwise at room temperature over 10 minutes. Next, after reacting at room temperature for 2 hours, 0.90 g (10 mmol) of lactic acid was further added, and the mixture was stirred at room temperature for 1 hour to obtain a solution (S-5).

[Synthesis Example 6]
In Synthesis Example 1, except that citric acid was not added, the same operation as in Synthesis Example 1 was performed to obtain a solution (S-6).

[Synthesis Example 7]
10.0 g of the compound (M-6) was dissolved in 20 ml of tetrahydrofuran, and a solution of 6.0 g of 2,2-dimethyl-3,5-hexanedione and 50 ml of tetrahydrofuran was added thereto at room temperature. . After refluxing for 1 hour, the solvent was removed under reduced pressure to obtain a compound represented by the following chemical formula (M-8). This compound (M-8) (complex mass: 7.5 g, 20.6 mmol) was dissolved in 65.0 g of propylene glycol monoethyl ether, stirred well, and 30% hydrogen peroxide solution was added to this solution at room temperature. 75 g (0.23 g, 6.6 mmol as hydrogen peroxide) was added dropwise over 10 minutes. Next, after reacting at room temperature for 1 hour, 7.9 g (41.2 mmol) of citric acid was added, followed by stirring at room temperature for 2 hours to obtain a solution (S-7).

[Comparative Synthesis Example 1]
The same operation as in Synthesis Example 1 was performed except that 0.75 g of 30% hydrogen peroxide solution was added to 0.52 g of pure water in Synthesis Example 1 to obtain a solution (CS-1).

[Comparative Synthesis Example 2]
To 10 ml (10.0 mmol) of a 1.0 M aqueous solution of the compound (M-7), 3.42 g of 30% hydrogen peroxide (1.05 g, 30.0 mmol as hydrogen peroxide) was added dropwise over 10 minutes. 7 ml (7.0 mmol) of 1.0 M sulfuric acid aqueous solution was added thereto, and ultrapure water was added thereto to add a total of 66 ml of solution (CS-2: equivalent to 0.15 M) and a total of 20 ml of solution (CS-3). : Equivalent to 0.5M).

<Preparation of radiation-sensitive composition>
The [C] radiation sensitive acid generator used for the preparation of the radiation sensitive composition is as follows.
C-1: Triphenylsulfonium nonafluoro-n-butanesulfonate

[Preparation Example 1]
The solution (S-1) of the product [A] obtained above was filtered with a filter having a pore size of 0.2 μm to prepare a radiation sensitive composition (R-1). When it was necessary to reduce the film thickness, it was appropriately diluted with the solvent used in the synthesis example (in the case where there were a plurality of solvents having a high boiling point), and then filtered through a filter having a pore diameter of 0.2 μm.

[Preparation Examples 2 to 7 and Comparative Preparation Example 1]
As in Preparation Example 1, a solution of the product [A] shown in Table 1 below was used, and if necessary, the type and amount of the [C] radiation-sensitive acid generator shown in Table 1 were used. By operation, radiation sensitive compositions (R-2) to (R-7) and (CR-1) were prepared. “-” Indicates that the corresponding component was not used. Moreover, the usage-amount of a [C] radiation sensitive acid generator is the usage-amount (mass part) with respect to 100 mass parts of the solution of [A] product.

[Comparative Preparation Examples 2 and 3]
CS-2 and CS-3 mentioned in the above comparative synthesis example were directly filtered through a filter having a pore diameter of 0.2 μm to obtain radiation-sensitive compositions (CR-2) and (CR-3).

<Formation of resist pattern>
[Example 1]
After spin-coating the radiation-sensitive composition (R-1) prepared in Example 1 on a silicon wafer in “Clean Track ACT-8” of Tokyo Electron, PB was used at 80 ° C. for 60 seconds. Then, a resist film having a thickness of 50 nm was formed. Subsequently, patterning was performed using a vacuum ultraviolet light exposure apparatus (NA: 0.3, dipole illumination). Thereafter, in the clean track ACT-8, using butyl acetate (AcOBu), development was performed at 23 ° C. for 1 minute by the paddle method, followed by drying to form a negative resist pattern. The resist pattern thus formed was evaluated for the sensitivity and resolution shown below. The evaluation results are shown in Table 2.

[Examples 2-7, Comparative Examples 1-4]
Each resist pattern was formed in the same manner as in Example 1 except that the radiation-sensitive composition and developer described in Table 2 were changed. The film thickness after PB obtained at this time is also shown in Table 2. The negative resist pattern thus formed was evaluated for the sensitivity and resolution described below. The evaluation results are shown in Table 2.

[Sensitivity (mJ / cm ² )]
By patterning using vacuum ultraviolet rays, a line-and-space pattern (1L1S) composed of a line portion having a line width of 30 nm and a space portion having an interval of 30 nm formed by adjacent line portions is formed in a one-to-one line width. The exposure amount was the optimum exposure amount, and this optimum exposure amount was the sensitivity (mJ / cm ² ).

[Limit resolution (nm)]
By patterning with vacuum ultraviolet rays, the lower limit resolution was determined when the SEM image was observed by changing the line width every 1 nm in a line-and-space pattern (1L1S) composed of a line part and a space part.

[Storage stability evaluation]
The radiation-sensitive composition obtained in the above example was stored at room temperature for 1 week, and then subjected to a resist pattern formation test by patterning with vacuum ultraviolet rays, and a line-and-space pattern (1L1S) having a line width of 30 nm was 1: 1. “AA (very good)” when the change in the amount of exposure formed in the line width is less than 5% compared to before the start of storage, and “AA (very good)” before the start of storage. “A (good)” and “B (defect)” exceeding 10%, and a 30 nm line-and-space pattern (1L1S) could not be resolved (line width was larger than 30 nm) ) Was designated as “C (unresolvable)”.

  From the results of patterning by the vacuum ultraviolet light exposure apparatus shown in Table 2, by applying the patterning method using the radiation-sensitive composition of the present invention, high-resolution patterning is possible, and the storage stability of the composition Was also found to be good. It was also confirmed that the patterning method according to the present invention can be developed with an organic solvent effective for increasing the sensitivity of the resist.

  On the other hand, the composition in which hydrogen peroxide was not allowed to act (Comparative Example 1) required a considerable ultraviolet light exposure amount to realize LS of 30 nm, and the storage stability of the chemical solution was also poor. In addition, in the case of using a radiation-sensitive composition composed of only an inorganic component (Comparative Examples 2 to 4), (1) development with an organic solvent is not possible (2) storage stability is very high Poor (3) It turned out that it was difficult to increase the thickness effective when etching using a resist as a mask, and the effectiveness of the present invention was confirmed.

  The present invention can form a pattern with high sensitivity, high resolution, and appropriate thickness, regardless of the type of developer. The storage stability of the composition is also good. Therefore, the pattern forming method can be suitably used for a semiconductor device processing process and the like that are expected to be further miniaturized in the future.

Claims (9)

A film forming step for forming a film;
An exposure step of exposing the film; and a development step of developing the film exposed in the exposure step;
With
A radiation sensitive film in which the film contains a metal compound and a compound represented by the following chemical formula (1) in an organic solvent [I] and an organic solvent [II]. Formed using a sex composition ,
The pattern forming method , wherein the metal compound is a metal compound represented by the following chemical formula (3) .
(In formula (1), R and R ′ are each independently a hydrogen atom, a chain or cyclic alkyl group having 2 to 20 carbon atoms, a chain or cyclic alkylcarbonyl group having 2 to 20 carbon atoms, carbon, Represents an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, and a part of hydrogen atoms in the cyclic alkyl group, cyclic alkylcarbonyl group, aryl group, or aryloxy group is substituted with a substituent. May be.)
(In Formula (3), M is a titanium atom, an aluminum atom, a zirconium atom, a tantalum atom, a hafnium atom, a molybdenum atom, or a tungsten atom. L is a polydentate ligand. When a is 2 or more, a plurality of L may be the same or different, and X is a halogen ligand, hydroxo ligand, carboxy ligand, alkoxy ligand, carboxylate coordination A ligand or an amide ligand, b is an integer of 2 to 6. A plurality of X may be the same or different, provided that a + b is 7 or less.) The pattern formation method according to claim 1, wherein the product is obtained by further mixing a compound represented by the following chemical formula (2).
(In Formula (2), R ¹ is an n-valent organic group. X is —OH, —COOH, —NCO, or —NR ^a R ^b . R ^a and R ^b are the same or different hydrogen or (It is a monovalent organic group. N is an integer of 2 to 4. A plurality of X may be the same or different.) The pattern forming method according to claim 1 or 2 R and R 'is a hydrogen atom in the formula (1). The radiation sensitive composition comprises water,
The weight of the organic solvent [II] The pattern forming method according to any one of claims 1 to 3 wherein a weight or more water. The pattern formation method according to any one of claims 1 to 4 , wherein the organic solvent [I] and the organic solvent [II] are the same. The pattern formation method according to any one of claims 1 to 5, wherein the radiation-sensitive composition further contains a radiation-sensitive acid generator. The development was developed with an alkaline solution in step, the pattern forming method according to any one of claims 1 to 6, to form a negative pattern. The developing and developed with an organic solvent in the process, the pattern forming method according to any one of claims 1 to 6, to form a negative pattern. The pattern formation method as described in any one of Claim 1 to 8 which performs the said exposure process by irradiation of an extreme ultraviolet ray or an electron beam.