Fluorine-containing polymer, composition for forming fluorine-containing resin film, fluorine-containing resin film, composition for forming resist pattern, method for forming resist pattern, composition for forming resist upper layer film, method for decomposing fluorine-containing polymer, fluorine-containing polymerizable monomer, and method for producing fluorine-containing polymerizable monomer

Abstract

The present disclosure addresses the problem of providing a fluorine-containing polymer that can be decomposed at a temperature lower than that for conventional fluorine-containing polymers. The present disclosure relates to a fluorine-containing polymer that contains a repeating unit represented by general formula (1) or (1'). (In general formula (1), R1 is a hydrogen atom, a fluorine atom, a chlorine atom, or a C1-10 linear or C3-10 branched alkyl group. Some or all hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (1), R2 is a single bond, an alkylene group which may have a linear, branched, or cyclic structure, an aromatic ring, an ester, a carbonyl, an ether, an amide, an amine, or a composite substituent thereof, and a part thereof may be fluorinated and / or chlorinated. In general formula (1), X is -CH3, -CH2F, -CHF2, -CF2Cl, -CFCl2, or -O-RA (where RA is an alkyl group and some or all of hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms). In general formula (1), n is a natural number of 1-3.) (In general formula (1'), R1 is a hydrogen atom, a fluorine atom, a chlorine atom, or a C1-10 linear or C3-10 branched alkyl group. Some or all hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (1'), R3 is a C1-8 linear or C3-8 branched alkyl group. In general formula (1'), X is -CH3, -CH2F, -CHF2, -CF2Cl, -CFCl2, or -O-RA (where RA is an alkyl group and some or all hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms). In general formula (1'), n is a natural number of 1-3.)

Description

Fluorine-containing polymer, composition for forming fluorine-containing resin film, fluorine-containing resin film, composition for forming resist pattern, method for forming resist pattern, composition for forming resist upper layer film, method for decomposing fluorine-containing polymer, fluorine-containing polymerizable monomer, and method for producing fluorine-containing polymerizable monomer.

[0001] This disclosure relates to fluorine-containing polymers, compositions for forming fluorine-containing resin films, fluorine-containing resin films, compositions for forming resist patterns, methods for forming resist patterns, compositions for forming resist upper layers, methods for decomposing fluorine-containing polymers, fluorine-containing polymerizable monomers, and methods for producing fluorine-containing polymerizable monomers.

[0002] Fluorine-containing polymers (fluorine-containing compounds) are being used or developed in a wide range of application fields, mainly in the field of advanced materials, due to the characteristics of fluorine, such as water repellency, oil repellency, low water absorption, heat resistance, weather resistance, corrosion resistance, transparency, photosensitivity, low refractive index, and low dielectric properties. In particular, regarding coating applications, active research and development is being carried out in fields such as anti-reflective films that utilize low refractive index and transparency in visible light, optical devices that utilize transparency in the high-wavelength band (optical communication wavelength band), and resist materials that utilize transparency in the ultraviolet region (especially the vacuum ultraviolet wavelength range). A common polymer design in these application fields is to achieve transparency at each wavelength of use by introducing as much fluorine as possible, while also achieving adhesion to the substrate and a high glass transition temperature (hardness).

[0003] As a monomer for synthesizing such fluorine-containing polymers, Patent Document 1 describes a polymerizable monomer represented by the following general formula (10).

[0004] (In general formula (10), R １ｐ R represents a group selected from the group consisting of hydrogen atoms, halogen atoms, hydrocarbon groups, and fluorine-containing alkyl groups (the fluorine-containing alkyl group can be linear or branched and may include a cyclic structure). ２ｐR is a divalent or trivalent organic group, which is selected from an aliphatic hydrocarbon group (which may be linear or branched and may include a cyclic structure), an aromatic ring group, or a compound substituent thereof, and some or all of its hydrogen atoms may be substituted with fluorine atoms or hydroxyl groups. ３ｐ m is a hydrogen atom, a hydrocarbon group, a fluorinated alkyl group (the fluorinated alkyl group may be linear or branched and may include a cyclic structure), or an aromatic ring group, and the hydrocarbon group or the fluorinated alkyl group may contain a divalent linking group selected from an ether group (-O-) or a carbonyl group (-(C=O)-). m represents an integer from 1 to 2. When m is 2, two R ３ｐ They can choose either the same thing or different things.

[0005] The polymerizable monomer represented by general formula (10) is derived from hexafluoroacetone (CF ３ ) ２ (OR ３ｐ This monomer compound has a C- moiety and a high fluorine content, while successfully balanced with polar groups within the same molecule. This polymerizable monomer also exhibits excellent polymerizability, and the fluorine-containing polymer obtained by polymerizing this polymerizable monomer is known to possess both the transparency provided by the fluorine atom and the adhesion and processability provided by the polar groups, resulting in excellent physical properties for use as an anti-reflective film material, optical device material, resist material, etc.

[0006] On the other hand, since the resist material becomes a used material after the photolithography process, material design that takes into account the disposal method of the material is also necessary. Patent Document 2 teaches that a polymer containing repeating units made up of monomers represented by the following general formula (11) has the following characteristics: "When treating the resist waste liquid after device fabrication, the (meth)acrylic acid ester portion is subjected to alkaline hydrolysis, so it can be converted into a compound with a lower molecular weight and low accumulation, and when disposed of by combustion, the fluorine substitution rate is low, so it is highly combustible."

[0007]

[0008] Japanese Patent Publication No. 4083399, Japanese Unexamined Patent Publication No. 2012-107151

[0009] In photolithography processes, photosensitive compositions containing fluorine-containing polymers as the main component are widely used as resist films and / or top layers that protect the resist films. The resist films and top layers are removed from the substrate in alkaline development and resist removal processes. The substances that were the resist films and top layers (used materials) are decomposed in a way that does not affect the environment. The fluorine-containing polymer is the main component of the used materials, and therefore, the study of the decomposition of the used materials is essentially the study of the decomposition of the fluorine-containing polymer. Thermal decomposition is a simple and preferred method for decomposing the used materials. Furthermore, it is preferable that the amount of energy required for this thermal decomposition is small.

[0010] According to the teachings in Patent Document 2, it appears that reducing the fluorine substitution rate is key to the thermal decomposition of the compound. On the other hand, multiple fluorine atoms give the compound polarity, making it useful as a resist material and the like. Patent Document 2 suggests that a balance is struck between flammability and usefulness as a resist material and the like by unevenly distributing fluorine to specific groups. Following this teaching, it can be concluded that the compound disclosed in Patent Document 1 strikes a balance between flammability and usefulness as a resist material and the like. Therefore, a breakthrough is needed to design a compound that can reduce the amount of energy required for the thermal decomposition of fluorine-containing polymers that become waste material after the photolithography process.

[0011] The objective of this disclosure is to provide a fluorine-containing polymer that can be decomposed at a lower temperature than conventional fluorine-containing polymers.

[0012] As shown in the examples of this specification, the inventors have newly synthesized fluorine-containing polymers having a skeleton in which chlorodifluoro groups are bonded at specific positions.

[0013] The present disclosure (1) is a fluorine-containing polymer comprising a repeating unit represented by the following general formula (1) or (1').

[0014] (In general formula (1), R １is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the above alkyl group, some or all may be substituted with fluorine atoms. In General Formula (1), R ２ is an alkylene group, an aromatic ring, an ester, a carbonyl, an ether, an amide, an amine, or a composite substituent thereof which may have a single bond, a linear, branched or cyclic structure, and a part thereof may be fluorinated and / or chlorinated. In General Formula (1), X is -CH ３ -, -CH ２ F, -CHF ２ -, -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and among the hydrogen atoms bonded to the carbon atoms in the above alkyl group, some or all may be substituted with fluorine atoms). In General Formula (1), n is a natural number from 1 to 3.)

[0015] (In General Formula (1'), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the above alkyl group, some or all may be substituted with fluorine atoms. In General Formula (1'), R ３ is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In General Formula (1'), X is -CH ３ -, -CH ２ F, -CHF ２ -, -CF ２ Cl, -CFCl ２ or -O-R Ａ [[ID=**36**]] (R Ａ is an alkyl group, and among the hydrogen atoms bonded to the carbon atoms in the above alkyl group, some or all may be substituted with fluorine atoms). In General Formula (1'), n is a natural number from 1 to 3.)

[0016] The present disclosure (2) is a fluorine-containing polymer described in the present disclosure (1) containing a repeating unit represented by the following general formula (2).

[0017] (In general formula (2), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms. In general formula (2), R ４ is a single bond, an alkylene group that may have a linear, branched or cyclic structure, an aromatic ring, and a part thereof may contain an ester bond, a carbonyl bond, an ether bond, an amide bond, an acetal bond, a hydroxyl group, an amino group, a fluorine atom, or a chlorine atom, and these may be complex substituents.)

[0018] The present disclosure (3) is a fluorine-containing polymer described in the present disclosure (1) or (2) and includes a repeating unit represented by the following general formula (3).

[0019] (In general formula (3), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms. In general formula (3), R ５ is a single bond, an alkylene group that may have a linear, branched or cyclic structure, an aromatic ring, and a part thereof may contain an ester bond, a carbonyl bond, an ether bond, an amide bond, an acetal bond, a hydroxyl group, an amino group, a fluorine atom, or a chlorine atom, and these may be complex substituents. L is an acid dissociable group.)

[0020] The present disclosure (4) is a composition for forming a fluorine-containing resin film, characterized by containing the fluorine-containing polymer described in any one of the present disclosures (1) to (3).

[0021] The present disclosure (5) is a fluorine-containing resin film, characterized by containing a coating film of the composition for forming a fluorine-containing resin film described in the present disclosure (4).

[0022] The present disclosure (6) is a composition for forming a resist pattern, containing the fluorine-containing polymer described in any one of the present disclosures (1) to (3), an acid generator, and a solvent.

[0023] The present disclosure (7) is a method for forming a resist pattern, comprising the steps of: preparing the resist pattern forming composition described in the present disclosure (6); a film forming step of applying the resist pattern forming composition onto a substrate to form a film; an exposure step of irradiating the film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less through a photomask to transfer the pattern of the photomask to the film; and a developing step of developing the film using a developer to obtain a pattern.

[0024] Disclosure (8) is a composition for forming a resist upper layer film, comprising a fluorine-containing polymer described in any of Disclosures (1) to (3) and a solvent.

[0025] This disclosure (9) is a method for forming a resist pattern, comprising the steps of: preparing a resist upper layer film forming composition described in this disclosure (8); a film formation step of applying the resist upper layer film forming composition onto a resist film to form a resist upper layer film; an exposure step of irradiating the resist upper layer film and the resist film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less through a photomask to transfer the pattern of the photomask to the resist film; and a developing step of removing the resist upper layer film and developing the resist film to obtain a pattern using a developer.

[0026] Disclosure (10) is a method for decomposing a fluorine-containing polymer, which involves heating the fluorine-containing polymer described in any of Disclosures (1) to (3) at 50°C to 200°C.

[0027] The present disclosure (11) is a fluorine-containing polymerizable monomer represented by the following general formula (4) or (4').

[0028] (In general formula (4), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4), R ２is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a composite substituent thereof, which may have a single bond, linear, branched or cyclic structure, and a part of which may be fluorinated and / or chlorinated. In General Formula (4), X is -CH ３ , -CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms). In General Formula (4), n is a natural number from 1 to 3.)

[0029] (In General Formula (4'), R １ is a hydrogen atom, fluorine atom, chlorine atom or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. In General Formula (4'), R ３ is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In General Formula (4'), X is -CH ３ , -CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms). In General Formula (4'), n is a natural number from 1 to 3.)

[0030] The present disclosure (12) includes a step of preparing a compound represented by the following General Formula (5), and a step of reacting the compound represented by the above General Formula (5) with an acid anhydride represented by General Formula (6), and is a method for producing a fluorine-containing polymerizable monomer represented by the following General Formula (4).

[0031] (In General Formula (5), R １R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (5), R ２ n is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (5), n is a natural number between 1 and 3.

[0032] (In general formula (6), X is -CH) ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (6), Xa is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (This is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.)

[0033] (In general formula (4), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4), R ２X is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (4), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4), n is a natural number between 1 and 3.

[0034] The present disclosure (13) is a method for producing a fluorine-containing polymerizable monomer represented by the following general formula (4'), comprising the steps of: preparing a compound represented by the following general formula (5'); and reacting the compound represented by the above general formula (5') with an acid anhydride represented by the general formula (6).

[0035] (In general formula (5'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (5'), R ３ (This refers to a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (5'), n is a natural number from 1 to 3.)

[0036] (In general formula (6), X is -CH) ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (6), Xa is -CH ３ ien-CH２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.)

[0037] (In general formula (4'), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4'), R ３ is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (4'), X is -CH ３ , -CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms). In general formula (4'), n is a natural number from 1 to 3.)

[0038] The fluorine-containing polymer of the present disclosure has water repellency and photosensitivity equivalent to those of conventional fluorine-containing polymers and can be decomposed at a lower temperature. The fluorine-containing polymer of the present disclosure can be used in resists for photolithography, etc. However, used substances derived from the fluorine-containing polymer of the present disclosure can be treated by precipitation, adsorption, activated sludge method, etc., which are simpler than combustion, so it can contribute to reducing the energy consumption of semiconductor processes.

[0039] Hereinafter, the present disclosure will be described in detail. However, the description of the constituent elements described below is an example of an embodiment of the present disclosure and is not limited to these specific contents. Various modifications can be made and implemented within the scope of the gist.

[0040] In the "Modes for Carrying Out the Invention" section of this specification, the symbols "[" and "]", "<" and ">", etc., are merely symbols and do not have meaning in themselves.

[0041] <Fluorine-containing polymerizable monomers> First, the fluorine-containing polymerizable monomers of this disclosure will be described. The fluorine-containing polymerizable monomers of this disclosure are fluorine-containing polymerizable monomers represented by the following general formula (4) or (4').

[0042] (In general formula (4), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4), R ２ X is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (4), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4), n is a natural number between 1 and 3.

[0043] (In general formula (4'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4'), R ３ X is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (4'), X is -CH ３ ien-CH ２ F, -CHF２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4'), n is a natural number between 1 and 3.

[0044] The above R １ Examples of alkyl groups illustrated include methyl groups, ethyl groups, propyl groups such as 1-propyl groups and 2-propyl groups.

[0045] The above R ２ Examples of alkylene groups exemplified include methylene group, ethylene group, propylene group such as 1,3-propylene group, 1,2-propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1, Examples include saturated chain hydrocarbon groups such as 4-butylene groups, methylidene groups, ethylidene groups, propyridene groups, or 2-propyridene groups; monocyclic hydrocarbon ring groups such as cycloalkylene groups having 3 to 10 carbon atoms, such as cyclobutylene groups such as 1,3-cyclobutylene groups, cyclopentylene groups such as 1,3-cyclopentylene groups, cyclohexylene groups such as 1,4-cyclohexylene groups, and cyclooctylene groups such as 1,5-cyclooctylene groups; and bridged cyclic hydrocarbon ring groups such as norbornylene groups such as 1,4-norbornylene groups or 2,5-norbornylene groups, and adamantylene groups such as 1,5-adamantilene groups and 2,6-adamantilene groups.

[0046] R ２ The amide exemplified is (-C(=O)NB １(B) is a structure represented by -) １ (where represents a hydrogen atom or a monovalent organic group). ２ The ether exemplified here has a structure represented as (-O-). ２ The amines exemplified are (-NB ２ (B) is a structure represented by -) ２ (where represents a hydrogen atom or a monovalent organic group).

[0047] The above R ３ Examples of alkyl groups exemplified in the text include methyl, isopropyl, isobutyl, and isoamyl groups.

[0048] The fluorine-containing polymerizable monomer represented by the above general formula (4) can be produced, for example, by the following method.

[0049] First, a compound represented by the following general formula (7) is reacted with at least one selected from the group consisting of acid halides, acid anhydrides, esters, and carboxylic acids to prepare a compound represented by the following general formula (5).

[0050] (In general formula (7), R ２ n is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. (n is a natural number from 1 to 3.)

[0051] (In general formula (5), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (5), R ２ n is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (5), n is a natural number between 1 and 3.

[0052] The compound shown in general formula (7) is R ２ It is preferable that the bond is a single bond. Compounds represented by general formula (7) can be synthesized by known organic synthesis methods.

[0053] Examples of acid halides include methacrylate chloride, methacrylate bromide, methacrylate fluoride, acrylate chloride, acrylate bromide, and acrylate fluoride. Examples of acid anhydrides include methacrylate anhydride and acrylic acid anhydride. Examples of esters include methyl methacrylate, ethyl methacrylate, methyl acrylate, butyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso-butyl acrylate, sec-butyl acrylate, tert-butyl acrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, sec-butyl methacrylate, and tert-butyl methacrylate. Examples of carboxylic acids include methacrylic acid and acrylic acid.

[0054] The reaction between the compound represented by general formula (7) and these compounds may be carried out with the addition of acids or bases as needed. The reaction conditions are preferably 0 to 130°C for 0.5 to 10 hours.

[0055] Next, by reacting the compound represented by the above general formula (5) with the acid anhydride represented by the following general formula (6), a fluorine-containing polymerizable monomer represented by general formula (4) can be produced.

[0056] (In general formula (6), X is -CH) ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (6), Xa is -CH ３ ien-CH２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (This is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.)

[0057] In the acid anhydride represented by the above general formula (6), X and Xa may be the same or different.

[0058] Furthermore, the reaction conditions are preferably -50 to 150°C for 0.5 to 48 hours.

[0059] The separation and purification of the product after this reaction can be carried out by conventional methods, such as concentration, distillation, extraction, recrystallization, filtration, and column chromatography, and two or more methods may be used in combination.

[0060] The fluorine-containing polymerizable monomer represented by the above general formula (4') can be produced by using the compound represented by the following general formula (8) instead of the compound represented by the above general formula (7) in the method for producing the fluorine-containing polymerizable monomer represented by the above general formula (4).

[0061] (In general formula (8), R ３ (where n is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. n is a natural number from 1 to 3.)

[0062] <Fluorine-containing polymers> Next, we will describe the fluorine-containing polymers of the present disclosure obtained by polymerizing the fluorine-containing polymerizable monomer represented by the above general formula (4) or (4').

[0063] The fluorine-containing polymers of this disclosure are fluorine-containing polymers that include crosslinking units represented by the following general formula (1) or (1').

[0064] (In general formula (1), R １R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (1), R ２ X is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (1), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (1), n ​​is a natural number between 1 and 3.

[0065] (In general formula (1'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (1'), R ３ is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (1'), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (1'), n is a natural number between 1 and 3.

[0066] Fluorine-containing polymers containing repeating units represented by general formulas (1) and (1') can be obtained by a polymerization step of polymerizing polymerizable monomers represented by general formulas (4) and (4'), respectively.

[0067] The fluorine-containing polymers of this disclosure may contain both repeating units represented by general formulas (1) and (1').

[0068] In the following description, polymerizable monomers represented by general formulas (4) and (4') will also be referred to as "first polymerizable monomers," and repeating units represented by general formulas (1) and (1') will also be referred to as "first repeating units."

[0069] The above-mentioned fluorine-containing polymer may contain second repeating units other than the repeating units represented by general formulas (1) and (1'). In this case, the above-mentioned second repeating units may include, for example, at least one repeating unit obtained from the following polymerizable monomers (second polymerizable monomers).

[0070] An example of the above-mentioned second polymerizable monomer is a hexafluoroisopropanol group (-C(CF ３ ) ２ Examples include monomers having an OH group, acrylic acid esters, methacrylic acid esters, fluorinated acrylic acid esters, fluorinated methacrylic acid esters, styrenes, fluorinated styrenes, vinyl ethers, fluorinated vinyl ethers, allyl ethers, fluorinated allyl ethers, unsaturated amides, olefins, fluorinated olefins, norbornene compounds, fluorinated norbornene compounds, vinylsilanes, vinyl sulfonic acid or vinyl sulfonic acid esters, acrylic acid, maleic methacrylic acid, maleic anhydride, fumaric acid, sulfur dioxide, monomers having a lactone structure, etc.

[0071] Furthermore, the fluorine-containing polymers represented by general formulas (1) and (1') may include a repeating unit containing an acid-degradable group as a third repeating unit. When the fluorine-containing polymer containing the above third repeating unit is used as a resist, the acid-degradable group decomposes in the resist film formed on the substrate upon exposure to high-energy beams such as electromagnetic waves or electron beams with a wavelength of 300 nm or less, generating acid in the resist film. This acid can improve the solubility of the resist film in the exposed area in the alkaline developer during development.

[0072] These fluorine-containing polymers may be homopolymers consisting only of the first repeating unit, or they may be heteropolymers containing the second repeating unit or the third repeating unit.

[0073] In the case of a fluorine-containing polymer heteropolymer, when the total amount of repeating units in the fluorine-containing polymer is set to 100 mol%, the proportion of the first repeating unit may be 22 mol% or more and 99 mol% or less, 30 mol% or more and 95 mol% or less, or even 40 mol% or more and 90 mol% or less.

[0074] The above-mentioned fluorine-containing polymers are obtained by polymerization reactions of each polymerizable monomer. The polymerization reaction is not particularly limited and may be a radical polymerization reaction, an ionic polymerization reaction, a coordination anion polymerization reaction, a living anion polymerization reaction, or a cationic polymerization reaction. Among these, a radical polymerization reaction is preferred. When the polymerization reaction is a radical polymerization reaction, the polymerization initiator is not particularly limited as long as it causes the polymerization reaction to occur, but azo compounds, peroxide compounds, and redox compounds can be used.

[0075] Examples of azo compounds include azobisisobutyronitrile. Examples of peroxide compounds include t-butyl peroxypivalate, di-t-butyl peroxide, i-butyryl peroxide, lauroyl peroxide, succinate peroxide, disinnamyl peroxide, di-n-propyl peroxydicarbonate, t-butyl peroxyallyl monocarbonate, benzoyl peroxide, hydrogen peroxide, or ammonium persulfate.

[0076] Examples of redox compounds include those used in combination with an oxidizing agent, such as hydrogen peroxide, persulfates, and cumene hydroperoxide as oxidizing agents, and iron(II) ion salts, copper(I) ion salts, ammonia, and triethylamine as reducing agents.

[0077] Furthermore, a polymerization solvent may be used in the radical polymerization reaction. The polymerization solvent is not particularly limited as long as it does not inhibit the radical polymerization reaction, and may be an organic solvent or water. Examples of organic solvents include hydrocarbon solvents, ester solvents, ketone solvents, alcohol solvents, ether solvents, cyclic ether solvents, fluorocarbon solvents, aromatic solvents, etc. One of these solvents may be used alone, or two or more may be used in combination. Examples of ester solvents include acetic acid and n-butyl acetate. Examples of ketone solvents include acetone and methyl isobutyl ketone. Examples of hydrocarbon solvents include toluene and cyclohexane. Examples of alcohol solvents include methanol, isopropyl alcohol, and ethylene glycol monomethyl ether.

[0078] Furthermore, molecular weight modifiers such as mercaptans may be used in radical polymerization reactions.

[0079] The reaction temperature in the radical polymerization reaction is appropriately changed depending on the radical polymerization initiator or the type of radical polymerization initiator, but it is preferably 20°C or higher and 200°C or lower, and more preferably 30°C or higher and 140°C or lower.

[0080] After the polymerization process, known methods can be used to remove the organic solvent or water, which is the medium, from the solution or dispersion containing the synthesized fluorine-containing polymer. Specifically, examples include reprecipitation, filtration, and heating and distillation under reduced pressure.

[0081] Through the above steps, a fluorine-containing polymer containing repeating units represented by general formulas (1) and (1') can be produced. The mass-average molecular weight of the fluorine-containing polymer of this disclosure may be 5,000 to 20,000, and furthermore, 7,000 to 15,000. In this specification, the mass-average molecular weight of the fluorine-containing polymer refers to the value measured by gel permeation chromatography (GPC) under the following conditions.

[0082] [GPC Conditions] Instrument: Tosoh Corporation, HLC-8320GPC Column for polymerizable monomer analysis: Tosoh Corporation, TSKgel series (G2500HXL, G2000HXL, G1000HXL, G1000HXL connected in series) Column for polymer analysis: Tosoh Corporation, TSKgel series (G2500HXL, G2000HXL, G1000HXL, G1000HXL connected in series) Temperature program: 40°C (held) Flow rate: 1 mL / min Detector: Differential refractive index detector (RI) Eluent: Tetrahydrofuran (THF) Reference material: Polystyrene standard solution

[0083] <Other Repeating Units> The fluorine-containing polymer of this disclosure may contain repeating units represented by the following general formula (2). Since the fluorine-containing polymer of this embodiment may have properties such as alkali solubility, it is suitable for use as a resin included in a resist upper layer film, for example. It is particularly preferable to use it for resist upper layer films used in immersion lithography processes.

[0084] (R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. ４ (This refers to an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated.)

[0085] The fluorine-containing polymer of this disclosure may contain repeating units represented by the following general formula (3). The fluorine-containing polymer of this embodiment may have properties such as water repellency, water resistance, detachment of acid-dissociable groups due to acids generated by exposure, and consequent alkali solubility, and is therefore suitable for use as a resin in additives for resist films, for example.

[0086] (R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. ５ (L is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated.)

[0087] Examples of alkylene groups include methylene group, ethylene group, propylene group such as 1,3-propylene group, 1,2-propylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, nonamethylene group, decamethylene group, undecamethylene group, dodecamethylene group, tridecamethylene group, tetradecamethylene group, pentadecamethylene group, hexadecamethylene group, heptadecamethylene group, octadecamethylene group, nonadecamethylene group, insalen group, 1-methyl-1,3-propylene group, 2-methyl-1,3-propylene group, 2-methyl-1,2-propylene group, 1-methyl-1,4-butylene group, 2-methyl-1,4- Examples include saturated chain hydrocarbon groups such as butylene, methylidene, ethylidene, propyridene, or 2-propyridene; monocyclic hydrocarbon ring groups such as cycloalkylene groups having 3 to 10 carbon atoms, such as cyclobutylene groups such as 1,3-cyclobutylene, cyclopentylene groups such as 1,3-cyclopentylene, cyclohexylene groups such as 1,4-cyclohexylene, and cyclooctylene groups such as 1,5-cyclooctylene; and bridging cyclic hydrocarbon ring groups such as norbornylene groups such as 1,4-norbornylene or 2,5-norbornylene, and adamantylene groups such as 1,5-adamantilene and 2,6-adamantilene.

[0088] Examples of the aromatic rings mentioned above include o-phenylene groups, m-phenylene groups, and p-phenylene groups.

[0089] Examples of the above acid-dissociable groups include tert-butyl group, tert-amyl group, 1,1-dimethylpropyl group, 1-ethyl-1-methylpropyl group, 1,1-dimethylbutyl group, allyl group, 1-pyrenylmethyl group, 5-dibenzosberyl group, triphenylmethyl group, 1-ethyl-1-methylbutyl group, 1,1-diethylpropyl group, 1,1-dimethyl-1-phenylmethyl group, 1-methyl-1-ethyl-1-phenylmethyl group, 1,1-Diethyl-1-phenylmethyl group, 1-methylcyclohexyl group, 1-ethylcyclohexyl group, 1-methylcyclopentyl group, 1-ethylcyclopentyl group, 1-isobornyl group, 1-methyladamantyl group, 1-ethyladamantyl group, 1-isopropyladamantyl group, 1-isopropylnorbornyl group, 1-isopropyl-(4-methylcyclohexyl) group, tert-butoxycarbonyl group, tert-amyloxycarbonyl group, methoxycarbonyl group, ethoxy Carbonyl group, i-propoxycarbonyl group, methoxymethyl group, ethoxyethyl group, butoxyethyl group, cyclohexyloxyethyl group, benzyloxyethyl group, phenethyloxyethyl group, ethoxypropyl group, benzyloxypropyl group, phenethyloxypropyl group, ethoxybutyl group, ethoxyisobutyl group, trimethylsilyl group, ethyldimethylsilyl group, methyldiethylsilyl group, triethylsilyl group, i-propyldimethylsilyl group, methyldi-i-propylsilyl L group, tri-i-propylsilyl group, tert-butyldimethylsilyl group, methyldi-tert-butylsilyl group, tri-tert-butylsilyl group, phenyldimethylsilyl group, methyldiphenylsilyl group, triphenylsilyl group, acetyl group, propionyl group, butyryl group, heptanol group, hexanoyl group, valeryl group, pivaloyl group, isovaleryl group, lauryl group, myristoyl group, palmitoyl group, stearoyl group, oxalyl group, malonyl group, succinyl group, gluconyl group Examples include tharyl group, adipoyl group, piperoyl group, suberoyl group, azerayl group, sebacoyl group, (meth)acryloyl group, propioloyl group, crotonoyl group, oleoyl group, maleoyl group, fumaroyl group, mesaconoyl group, canholoyl group, benzoyl group, phthaloyl group, isophthaloyl group, terephthaloyl group, naphthoyl group, toluyl group, hydroatropoyl group, atropoyl group, cinnamoyl group, froyl group, tenoyl group, nicotinoyl group, isonicotinoyl group, etc.

[0090] Furthermore, in the fluorine-containing polymer of this disclosure, R in the repeating unit represented by general formula (1) １R may be the same in each repeating unit, or it may be different in each repeating unit. Also, R in the repeating unit represented by general formula (1) ２ Similarly, x may be the same in each repeating unit, or it may be different in each repeating unit. Similarly, x in the repeating unit represented by general formula (1) may be the same in each repeating unit, or it may be different in each repeating unit. Similarly, n in the repeating unit represented by general formula (1) may be the same in each repeating unit, or it may be different in each repeating unit.

[0091] Furthermore, in the fluorine-containing polymer of this disclosure, R in the repeating unit represented by general formula (1') １ R may be the same in each repeating unit, or it may be different in each repeating unit. Also, R in the repeating unit represented by general formula (1') ３ Similarly, x may be the same in each repeating unit, or it may be different in each repeating unit. Similarly, x in the repeating unit represented by general formula (1') may be the same in each repeating unit, or it may be different in each repeating unit. Similarly, n in the repeating unit represented by general formula (1') may be the same in each repeating unit, or it may be different in each repeating unit.

[0092] Furthermore, in the fluorine-containing polymer of this disclosure, R in the repeating unit represented by general formula (2) ４ and R in the repeating unit represented by general formula (3) ５ Similarly, L in the repeating unit represented by general formula (3) may be the same or different in each repeating unit. Furthermore, R in the repeating unit represented by general formula (1) １ , R in the repeating unit represented by general formula (2) １ , and R in the repeating unit represented by general formula (3) １While these are common, if the fluorine-containing polymer of this disclosure contains two or more of these, R １ This may be the same in each repeating unit, or it may be different in each repeating unit.

[0093] Next, a method for using the fluorine-containing polymer of this disclosure will be described.

[0094] <Formation of resist film and top layer film> The fluorine-containing polymer of this disclosure can be used as a component of a resist film and / or a top layer film that protects the resist film.

[0095] The above-mentioned resist film and the above-mentioned upper film are obtained by applying a photosensitive resin composition containing the fluorine-containing polymer of this disclosure to a substrate or the like. The photosensitive resin composition for forming the above-mentioned resist film is the resist pattern forming composition of this disclosure, and comprises the fluorine-containing polymer of this disclosure, an acid generator and a solvent. The photosensitive resin composition for forming the above-mentioned upper film is the resist upper film forming composition of this disclosure, and comprises the fluorine-containing polymer of this disclosure and a solvent.

[0096] The resist film may be either negative or positive. The substrate is not particularly limited and includes silicon wafers, compound semiconductor substrates, insulating substrates, etc. The substrate may have an anti-reflective film formed on it. Furthermore, when forming the upper layer film, the photosensitive resin composition may be applied onto the resist film.

[0097] When using the fluorine-containing polymer of this disclosure to form a resist film, the resist pattern forming composition may be applied to a substrate to form the resist film. Subsequently, the resist film may be exposed to light or subjected to immersion exposure. Alternatively, when using the fluorine-containing polymer of this disclosure to form an upper layer film, the resist upper layer film forming composition may be applied to the resist film and / or resist pattern to form the upper layer film. Subsequently, the upper layer film may be exposed to light or subjected to immersion exposure.

[0098] <<Composition for forming resist patterns>> As described above, when the fluorine-containing polymer of the present disclosure is used to form a resist film, the composition for forming resist patterns may include the fluorine-containing polymer of the present disclosure, an acid generator, and a solvent.

[0099] Examples of the above-mentioned acid generators include onium salt-based acid generators such as iodonium salts and sulfonium salts, oximesulfonate-based acid generators, diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, nitrobenzyl sulfonate-based acid generators, iminosulfonate-based acid generators, and disulfone-based acid generators.

[0100] Specifically, the onium salt-based acid generators include diphenyliodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, bis(4-tert-butylphenyl)iodonium trifluoromethanesulfonate or nonafluorobutanesulfonate, triphenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, tri(4-methylphenyl)sulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, dimethyl(4-hydroxynaphthyl)sulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, monophenyldimethylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or its nonafluorobutanesulfonate, and diphenylmonomethylsulfonium trifluoromethanesulfonate. Examples include nates, their heptafluoropropanesulfonate or nonafluorobutanesulfonate, (4-methylphenyl)diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or nonafluorobutanesulfonate, (4-methoxyphenyl)diphenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or nonafluorobutanesulfonate, tri(4-tert-butyl)phenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or nonafluorobutanesulfonate, diphenyl(1-(4-methoxy)naphthyl)sulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or nonafluorobutanesulfonate, di(1-naphthyl)phenylsulfonium trifluoromethanesulfonate, its heptafluoropropanesulfonate or nonafluorobutanesulfonate, and the like. Furthermore, onium salts in which the anionic portion of these onium salts is replaced with methanesulfonate, n-propanesulfonate, n-butanesulfonate, or n-octanesulfonate can also be used.

[0101] Specifically, the oxime sulfonate acid generators include α-(p-toluenesulfonyl oxyimino)-benzyl cyanide, α-(p-chlorobenzenesulfonyl oxyimino)-benzyl cyanide, α-(4-nitrobenzenesulfonyl oxyimino)-benzyl cyanide, α-(4-nitro-2-trifluoromethylbenzenesulfonyl oxyimino)-benzyl cyanide, α-(benzenesulfonyl oxyimino)-4-chlorobenzyl cyanide, α-(benzenesulfonyl oxyimino)-2,4-dichlorobenzyl cyanide, and α-(benzyl (Benzesulfonyloxyimino)-2,6-dichlorobenzylcyanide, α-(benzenesulfonyloxyimino)-4-methoxybenzylcyanide, α-(2-chlorobenzenesulfonyloxyimino)-4-methoxybenzylcyanide, α-(benzenesulfonyloxyimino)-tiene-2-ylacetonitrile, α-(4-dodecylbenzenesulfonyloxyimino)-benzylcyanide, α-[(p-toluenesulfonyloxyimino)-4-methoxyphenyl]acetonitrile, α-[(dodecylbenzenesulfonyloxyimino)- 4-Methoxyphenyl acetonitrile, α-(tosyloxyimino)-4-thienylcyanide, α-(methylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino)-1-cycloheptenylacetonitrile, α-(methylsulfonyloxyimino)-1-cyclooctenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(trifluoromethylsulfonyl) (Tylsulfonyloxyimino)-cyclohexylacetonitrile, α-(ethylsulfonyloxyimino)-ethylacetonitrile, α-(propylsulfonyloxyimino)-propylacetonitrile, α-(cyclohexylsulfonyloxyimino)-cyclopentylacetonitrile, α-(cyclohexylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclopentenylacetonitrile,α-(isopropylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(n-butylsulfonyloxyimino)-1-cyclopentenylacetonitrile, α-(ethylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(isopropylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(n-butylsulfonyloxyimino)-1-cyclohexenylacetonitrile, α-(methylsulfonyloxyimino)-phenylacetonitrile, α-( Examples include (ethylsulfonyloxyimino)-p-methoxyphenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-phenylacetonitrile, α-(trifluoromethylsulfonyloxyimino)-p-methoxyphenylacetonitrile, α-(ethylsulfonyloxyimino)-p-methoxyphenylacetonitrile, α-(propylsulfonyloxyimino)-p-methylphenylacetonitrile, and α-(methylsulfonyloxyimino)-p-bromophenylacetonitrile.

[0102] Regarding diazomethane-based acid generators such as bisalkyl or bisarylsulfonyl diazomethanes and poly(bissulfonyl) diazomethanes, specific examples of bisalkyl or bisarylsulfonyl diazomethanes include bis(isopropylsulfonyl) diazomethane, bis(p-toluenesulfonyl) diazomethane, bis(1,1-dimethylethylsulfonyl) diazomethane, bis(cyclohexylsulfonyl) diazomethane, and bis(2,4-dimethylphenylsulfonyl) diazomethane.

[0103] Examples of the above solvents include methanol, ethanol, 1-propanol, isopropanol, n-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, n-hexanol, cyclohexanol, 2-methyl-2-butanol, 3-methyl-2-butanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-Methyl-1-pentanol, 3-Methyl-2-pentanol, 3-Methyl-3-pentanol, 4-Methyl-1-pentanol, 4-Methyl-2-pentanol, Ethylene glycol, Propylene glycol, Tetrahydrofuran, Dioxane, Ethylene glycol monomethyl ether, Ethylene glycol monoethyl ether, Ethylene glycol dimethyl ether, Ethylene glycol diethyl ether, Diethylene glycol monomethyl ether, Diethylene glycol monoethyl ether, Diethyl Examples include ethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol ethyl methyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol ethyl ether acetate, diethylene glycol ethyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol monomethyl ether acetate, toluene, xylene, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, diacetone alcohol, ethyl acetate, butyl acetate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate, ethyl ethoxyethyl acetate, ethyl hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutanoate, methyl 3-methoxypropionate, ethyl 3-methoxypropionate, ethyl 3-ethoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, water, etc.

[0104] The resist pattern forming composition of this disclosure may also contain basic compounds. Examples of basic compounds include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-hexylamine, tri-n-pentylamine, tri-n-heptylamine, tri-n-octylamine, and tri-n-nonylamine. Examples include trialkylamines such as sylamine, tri-n-decanylamine, and tri-n-dodecylamine; alkyl alcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine; and piperidine, piperazine, 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

[0105] Furthermore, the resist pattern forming composition of this disclosure may also contain a base resin other than the fluorine-containing polymer of this disclosure, or a weakly acidic photoacid generator (weakly acidic PAG).

[0106] Examples of base resins include resins containing the structure shown in the following chemical formula.

[0107] (In general formulas (a) and (b), R Ｂ This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Ｂ This is a single bond, a phenylene group, a naphthylene group, or (main chain)-C(=O)-O-Z'-, where Z' is a hydroxyl group, an ether bond, an ester bond, or a C1-C10 alkanediyl group which may contain a lactone ring, or a phenylene group or a naphthylene group. Ｂ Y is an acid-unstable group. ＢThis is a polar group comprising a hydrogen atom or at least one structure selected from a hydroxyl group, cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, lactone ring, sultone ring, and carboxylic acid anhydride (-C(=O)-O-C(=O)-).

[0108] Alkanediyl groups can be linear, branched, or cyclic. Specific examples include methylene group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, propane-1,3-diyl group, 2-methylpropane-1,3-diyl group, butane-1,3-diyl group, butane-2,3-diyl group, butane-1,4-diyl group, pentane-1,3-diyl group, pentane-1,4-diyl group, 2,2-dimethylpropane-1,3-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, cyclopentane-1,2-diyl group, cyclopentane-1,3-diyl group, and cyclohexane-1,6-diyl group.

[0109] Z in equation (a) Ｂ Examples of structures that have been modified include, but are not limited to, those listed below. Note that in the following formula, R Ｂ and X Ｂ This is the same as above.

[0110]

[0111] X Ｂ The acid-unstable group represented by is not particularly limited, but examples include tertiary alkyl groups having 4 to 20 carbon atoms, trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, and oxoalkyl groups having 4 to 20 carbon atoms.

[0112] As for acid-unstable groups, those represented by the following general formulas (xa), (xb), or (xc) are particularly preferred.

[0113] (In general formulas (xa), (xb), and (xc), R ＸThis is a monovalent hydrocarbon group having 1 to 10 carbon atoms, which may contain heteroatoms. k is 1 or 2. Dashed lines indicate bonds.

[0114] When a tertiary alicyclic hydrocarbon group represented by the general formula (xa), (xb), or (xc) is bonded to an ester oxygen, it exhibits higher acid decomposition capabilities compared to other tertiary alkyl groups, such as tert-butyl or tert-pentyl groups, due to steric repulsion.

[0115] The repeating units represented by general formula (a) include, but are not limited to, the following. Note that in the general formula below, R Ｂ These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0116]

[0117]

[0118]

[0119] Note that the above specific example is Z Ｂ This is the case for a single bond, but Z Ｂ Even when the bond is not a single bond, it can be combined with similar acid-unstable groups.

[0120] The repeating units represented by general formula (b) include, but are not limited to, the following. Note that in the following formula, R Ｂ These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0121]

[0122]

[0123]

[0124] The base resin in the resist pattern forming composition of this disclosure may contain one of the above structures, or it may contain two or more of the above structures. When the base resin contains two or more of the above structures, in each structure, R Ｂ , X Ｂ , Y Ｂ Z Ｂ , RＸ They may be the same or they may be different.

[0125] As a weak acid PAG, a photo-disintegrating base that is sensitive to light and generates a weak acid upon exposure can also be used. Examples of photo-disintegrating bases include onium salt compounds that decompose upon exposure. Examples of onium salt compounds include sulfonium salt compounds represented by the following formula (9-1) and iodonium salt compounds represented by the following formula (9-2).

[0126] (In the above equations (9-1) and (9-2), R ６ ~R １０ Each of these is independently a hydrogen atom, an alkyl group, an alkoxy group, a hydroxyl group, or a halogen atom. － and Q － Each of them is independent of OH － , R Ｃ - COO － , R Ｃ -SO ３ － Or it is an anion represented by the following formula (9-3). However, R Ｃ (This is an alkyl group, an aryl group, or an aralkyl group.)

[0127] (In the above formula (9-3), R １１ (u is a linear or branched alkyl group having 1 to 12 carbon atoms, or a linear or branched alkoxyl group having 1 to 12 carbon atoms, in which some or all of the hydrogen atoms may be substituted with fluorine atoms. u is an integer from 0 to 2.)

[0128] Specific examples of weak acid PAGs include the following compounds:

[0129]

[0130] The above-mentioned resist pattern can be obtained through the steps of: preparing the resist pattern forming composition; coating the composition onto a substrate to form a film; irradiating the film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less via a photomask to transfer the pattern of the photomask to the film; and developing the film using a developer to obtain the pattern.

[0131] <<Composition for forming a resist upper layer film>> As described above, the resist upper layer film formation composition of the present disclosure preferably comprises the fluorine-containing polymer of the present disclosure and a solvent. Examples of the solvent are the same as the examples of preferred solvents in the resist pattern formation composition of the present disclosure.

[0132] A method for forming a resist pattern using such a resist upper film forming composition includes the steps of: preparing the resist upper film forming composition; coating the resist upper film forming composition onto a resist film to form a resist upper film; irradiating the resist upper film and the resist film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less via a photomask to transfer the pattern of the photomask to the resist film; and developing the resist upper film using a developer solution and developing the resist film to obtain a pattern.

[0133] <Formation of the resist film or upper layer material (used material)> After the exposed substrate is baked, it is developed using a developer. Development is the process of forming a resist pattern using an alkaline solution (positive pattern formation) or an organic solvent (negative pattern formation) as the developer.

[0134] [Positive Pattern Formation] Positive pattern formation is a method of forming a pattern by using an alkaline solution as a developer to dissolve and wash away only the exposed areas. Typically, an alkaline aqueous solution of tetramethylammonium hydroxide with a concentration of 0.1% to 10% by mass can be used as the developer.

[0135] Other alkaline developers include alkaline aqueous solutions containing sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide, tetraethylammonium hydroxide, pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, 1,5-diazabicyclo-[4.3.0]-5-nonane, etc.

[0136] The developer used is not particularly limited as long as it can remove the desired resist and resist upper film using a predetermined development method. Generally, examples include alkaline aqueous solutions using inorganic alkalis, primary amines, secondary amines, tertiary amines, quaternary ammonium salts, and mixtures thereof. In addition, appropriate amounts of water-soluble organic solvents, such as methanol and ethanol, or surfactants may be added to these developers.

[0137] When developing using the above alkaline aqueous solution, the desired pattern can be formed by washing, rinsing, drying, etc., as necessary. Known development methods such as immersion, paddle, and spray methods can be used, and the development time may be 0.1 minutes or more and 3 minutes or less. Preferably, it is 0.5 minutes or more and 2 minutes or less. During development, the upper layer film dissolves, and only the exposed areas of the lower resist film dissolve.

[0138] During the alkaline development process and the resist removal process, the fluorine-containing polymer is removed from the substrate. The resist film and the upper layer film removed from the substrate become spent materials. These spent materials include the fluorine-containing polymer of this disclosure.

[0139] [Negative Pattern Formation] Negative pattern formation is a method of forming a pattern by using an organic solvent as a developer to dissolve and wash away only the unexposed areas. Typically, butyl acetate can be used as the organic solvent in the developer.

[0140] Other organic solvents include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutylketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonic acid, ethyl crotonic acid, propiopropyl acetate Examples include methyl benzoate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenyl acetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, and 2-phenylethyl acetate.

[0141] The developer used is not particularly limited as long as it can remove the desired resist and resist upper film using a predetermined development method. These developers may also contain appropriate amounts of water-soluble organic solvents, such as methanol, ethanol, or other alcohols, or surfactants.

[0142] When developing using the above organic solvent, washing, rinsing, drying, etc., can be performed as needed to form the desired negative pattern. Known development methods such as immersion, paddle, and spray methods can be used, and the development time may be 0.1 minutes or more and 3 minutes or less. Preferably, it is 0.5 minutes or more and 2 minutes or less. During development, the upper layer film dissolves, and only the exposed areas of the lower resist film dissolve.

[0143] During the development process and the resist removal process, the fluorine-containing polymer is removed from the substrate. The resist film and the upper layer film removed from the substrate become spent materials. These spent materials include the fluorine-containing polymer of this disclosure.

[0144] Wastewater containing the fluorine-containing polymer of this disclosure, generated during the developing process and subsequent rinsing process, is treated by heating through total combustion. Alternatively, it is treated by heating during distillation to recover water from the wastewater. These heating processes decompose the monochloro-difluoroalkyl groups in the fluorine-containing polymer, leading to the decomposition of the polymer. It has been confirmed that fluoride ions and chloride ions are generated by the heating process, so it is predicted that the monochloro-difluoroalkyl groups are decomposed and converted into carboxyl groups. The heating temperature is preferably 50 to 200°C, more preferably 55 to 160°C, and even more preferably 60 to 120°C. The upper limit of the temperature may be set lower, such as 100°C or less, or even 95°C or less. Methods for treatment at such low heating temperatures include precipitation, adsorption, and activated sludge methods. These methods are simpler than combustion, and the treatment of spent materials derived from the fluorine-containing polymer of this disclosure is easy. Therefore, using the fluorine-containing polymer of this disclosure can contribute to reducing the energy consumption of semiconductor processes.

[0145] The present disclosure will be described in detail below with reference to examples. However, the present disclosure is not limited to the following examples.

[0146] In the examples, unless otherwise specified, some compounds are denoted as follows:

[0147] Methyl ethyl ketone: MEK Diisopropyl ether: IPE Tetrahydrofuran: THF Tetramethylammonium hydroxide: TMAH Propylene glycol monomethyl ether acetate: PGMEA

[0148] i-4FHK-OH: Compound represented by the following chemical formula

[0149]

[0150] MA-4FHB-OH: A compound represented by the following chemical formula.

[0151]

[0152] MA-BTHB-OH: A compound represented by the following chemical formula.

[0153]

[0154] Acetic anhydride: A compound represented by the following chemical formula.

[0155] Difluoroacetic anhydride: A compound represented by the following chemical formula.

[0156] MA-4FHB-OAc: A compound represented by the following chemical formula.

[0157]

[0158] MA-4FHB-ODFAc: A compound represented by the following chemical formula.

[0159]

[0160] MA-BTHB-OAc: A compound represented by the following chemical formula.

[0161]

[0162] MA-BTHB-ODFAc: A compound represented by the following chemical formula.

[0163] This section explains the equipment and measurement conditions used for various measurements.

[0164] [Analysis of fluorine-containing polymerizable monomers] Using a nuclear magnetic resonance spectrometer (NMR, manufactured by JEOL Ltd., instrument name JNM-ECA400) with a resonance frequency of 400 MHz, １９ F-NMR, １ H-NMR was measured.

[0165] [Analysis of Polymers] The composition of repeating compositions in polymers is determined by NMR. １ H-NMR and １９ The determination was made based on F-NMR measurements.

[0166] [Analysis of Mass-Average Molecular Weight] The mass-average molecular weight (Mw) of the resin composition described below was measured as follows. The number-average molecular weight Mn and molecular weight dispersion (ratio of number-average molecular weight Mn to mass-average molecular weight Mw = Mw / Mn) of the polymer were measured using high-speed gel permeation chromatography (hereinafter sometimes referred to as GPC; manufactured by Tosoh Corporation, model HLC-8320GPC), with one ALPHA-M column and one ALPHA-2500 column from Tosoh Corporation connected in series, and tetrahydrofuran used as the developing solvent. A refractive index difference detector was used as the detector.

[0167] The synthesis of fluorine-containing polymerizable monomers and intermediates for fluorine-containing polymerizable monomers will be described.

[0168] [Synthesis Example 1: Synthesis of MA-4FHB-OAc] In a 1 L three-necked round-bottom flask, concentrated sulfuric acid (0.31 g, 3.16 mmol), acetone (307 g, 5.28 mol), and 1,3-dichlorotetrafluoroacetone (Synquest Laboratories, 210 g, 1.06 mol) were added and stirred overnight at 30°C. The reaction mixture was concentrated in an evaporator under conditions of a bath temperature of 30°C and 100 hPa, and the resulting concentrate was washed with deionized water. Then, it was concentrated again in an evaporator to obtain concentrate 1 (245 g). In a 1 L three-necked round-bottom flask, tetrahydrofuran (super-dehydrated grade, 551 g) and sodium borohydride (32.5 g, 857 mmol) were added and dispersed, and the mixture was cooled by immersion in an ice bath. Subsequently, the above-mentioned concentrated solution 1 was added dropwise over 30 minutes, and the reaction was stopped with hydrochloric acid water after 1.5 hours. The reaction solution was extracted with IPE (551 g) and washed once with deionized water. The washed IPE solution was concentrated in an evaporator under conditions of a bath temperature of 42°C and 20 hPa while replacing the solvent with toluene to obtain concentrated solution 2 (215 g) containing i-4FHK-OH. In a 1 L three-necked round-bottom flask, the above-mentioned concentrated solution 2, methanesulfonic acid (5.97 g, 62.1 mmol), and Nonflex MBP (Seiko Chemicals, 0.96 g) were added and mixed, and methacrylic anhydride (hereinafter referred to as MAAH, Tokyo Chemical Reagents, 105 g, 683 mmol) was added dropwise under conditions of a bath temperature of 38°C. Subsequently, the mixture was stirred at a bath temperature of 47°C for 1.5 hours and at a bath temperature of 57°C for 3 hours to stop the reaction. The reaction mixture was extracted with IPE (322 g), followed by one wash each with sodium hydroxide solution and deionized water. Then, a small amount of 2-methoxyphenothiazine was added, and the mixture was concentrated in an evaporator under conditions of a bath temperature of 42°C and a pressure of 20 hPa. The resulting concentrate was distilled at 0.2 kPa and an internal temperature of 125–136°C to obtain MA-4FHB-OH (123 g, yield 36% (3-step yield), GC purity > 99%). The reaction is described below.

[0169]

[0170] In a 250 mL three-necked round-bottom flask, MA-4FHB-OH (40 g, 122 mmol), pyridine (40 g, 500 mmol, manufactured by Kanto Chemical Co., Ltd.), 4-dimethylaminopyridine (0.3 g, 2.4 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), and topanol A (0.03 g, manufactured by Tokyo Chemical Industry Co., Ltd.) were added. After cooling in an ice bath, acetic anhydride (18.8 g, 183 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was slowly added dropwise, and the mixture was stirred at 23°C for 5 hours. Then, the reaction mixture was added dropwise to hydrochloric acid water, 120 g of heptane was added, and after liquid-liquid extraction, the mixture was washed twice with water and once with hydrochloric acid. The mixture was then concentrated using an evaporator under conditions of a bath temperature of 50°C and 20 hPa. The resulting concentrate was distilled at 1 kPa and an internal temperature of 100-110°C to obtain MA-4FHB-OAc (38 g, yield 84%, GC purity > 99%). The reaction is shown below.

[0171]

[0172] <NMR Analysis Results> The results of the nuclear magnetic resonance analysis (hereinafter sometimes referred to as NMR) are shown below. １ H-NMR (CDCl3, reference material: TMS): 6.07-6.05ppm (m, 1H), 5.57-5.55ppm (m, 1H), 5.31-5.24ppm (m, 1H), 3 .14-3.04ppm (m, 1H), 2.80-2.76ppm (m, 1H), 2.15ppm (s, 3H), 1.92-1.91ppm (m, 3H), 1.31 (d, 3H) １９ F-NMR (CDCl3, reference material: C6F6): -53.8 to -55.2ppm (m, 2F), -56.8 to -57.5ppm (m, 2F)

[0173] [Synthesis Example 2: Synthesis of MA-4FHB-ODFAc] MA-4FHB-OH (50 g, 153 mmol), triethylamine (25 g, 244 mmol, manufactured by Kanto Chemical Co., Ltd.), IPE (100 g, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and topanol A (0.04 g, manufactured by Tokyo Chemical Industries, Ltd.) were added to a 250 mL three-necked round-bottom flask. After cooling in an ice bath, difluoroacetic anhydride (39.8 g, 229 mmol, manufactured by Tokyo Chemical Industries, Ltd.) was slowly added dropwise, and the mixture was stirred at 23°C for 3 hours. The reaction mixture was then added dropwise to hydrochloric acid water, 200 g of IPE was added, and after liquid-liquid extraction, the mixture was washed twice with water and once with hydrochloric acid. The mixture was then concentrated in an evaporator under conditions of a bath temperature of 50°C and 20 hPa. The resulting concentrate was distilled at 0.3 kPa and an internal temperature of 95–115°C to obtain MA-4FHB-ODFAc (50 g, yield 81%, GC purity > 99%). The reaction is shown below.

[0174]

[0175] <NMR Analysis Results> The NMR results are shown below. １ H-NMR (CDCl3, reference material: TMS): 6.02-6.01ppm (m, 1H), 5.92-5.92ppm (m, 1H), 5.58-5.56ppm (m, 1H), 5.3 9-5.31ppm (m, 1H), 3.28-3.20ppm (m, 1H), 2.74-2.69ppm (m, 1H), 1.92-1.90ppm (m, 3H), 1.34 (d, 3H) １９ F-NMR (CDCl3, reference material: C6F6): -53.8 to -62.9ppm (m, 4F), -126.4 to -126.7ppm (m, 2F)

[0176] [Synthesis Example 3: Synthesis of MA-BTHB-OAc] MA-BTHB-OAc was obtained in the same manner as in Synthesis Example 1, except that MA-BTHB-OH was reacted with acetic anhydride. The reaction is shown below.

[0177]

[0178] <NMR Analysis Results> The NMR results are shown below. １H-NMR (CDCl3, reference material: TMS): 6.16-6.14ppm (m, 1H), 5.66-5.63ppm (m, 1H), 5.13-5.20p pm (m, 1H), 2.39-2.30ppm (m, 2H), 2.23ppm (s, 3H), 1.92-1.91ppm (m, 3H), 1.41 (d, 3H) １９ F-NMR (CDCl3, reference material: C6F6): -76.3 to -76.0ppm (m, 3F), -79.8 to -79.5ppm (m, 3F)

[0179] [Synthesis Example 4: Synthesis of MA-BTHB-ODFAc] MA-BTHB-ODFAc was obtained in the same manner as in Synthesis Example 2 for the synthesis of MA-4FHB-ODFAc, except that MA-BTHB-OH was reacted with difluoroacetic anhydride. The reaction is shown below.

[0180]

[0181] <NMR Analysis Results> The NMR results are shown below. １ H-NMR (CDCl3, reference material: TMS): 6.12-6.12ppm (m, 1H), 6.05-5.80ppm (m, 1H) 5.68-5.65ppm (m, 1H), 5.15-5.11ppm (m, 1H), 2.38-2.31ppm (m, 2H), 1.92-1.91ppm (m, 3H), 1.42 (d, 3H) １９ F-NMR (CDCl3, reference material: C6F6): -76.7 to -76.3ppm (m, 3F), -79.9 to -79.7ppm (m, 3F), -125.3 to -125.7ppm (m, 2F)

[0182] [Synthesis Example 5: Synthesis of Fluorine-Containing Polymer 1] In a 100 mL glass flask at 23°C, 4.0 g (10 mmol) of MA-4FHB-OAc and 16 g of PGMEA were added, and then 0.1 g of 2,2'-Azobis(isobutyrate)dimethyl (hereinafter referred to as V-601) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2.4 mmol) was added. The flask was then degassed while stirring. After that, the flask was replaced with nitrogen gas, the internal temperature was raised to 78°C, and the reaction was carried out for 18 hours. The reaction solution was added dropwise to 40 g of heptane to reprecipitation, then decanted, and the resulting polymer was dried in a vacuum dryer to obtain 3.4 g of fluorine-containing polymer 1 having the following repeating units, in a yield of 85%.

[0183]

[0184] [Synthesis Example 6: Synthesis of Fluorine-Containing Polymer 2] The same procedure as in Synthesis Example 5 was followed, except that MA-4FHB-OAc was replaced with MA-4FHB-ODFAc, to obtain fluorine-containing polymer 2 (3.3 g, yield 83%).

[0185]

[0186] [Synthesis Example 7: Synthesis of Fluorine-Containing Polymer 3] In a 100 mL glass flask, 8.0 g (24 mmol) of MA-BTHB-OH and 32 g of MEK were added at 23°C. Furthermore, 0.6 g of 2,2'-Azobis(isobutyrate)dimethyl (hereinafter referred to as V-601) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., 2.4 mmol) was added. The flask was then degassed while stirring. Afterward, the flask was purged with nitrogen gas, the internal temperature was raised to 78°C, and the reaction was carried out for 18 hours. The reaction solution was added dropwise to 80 g of heptane to reprecipitate, then decanted. The resulting polymer was dried in a vacuum dryer to obtain fluorine-containing polymer 3 having the following repeating units. Note that fluorine-containing polymer 3 is a conventionally used fluorine-containing polymer.

[0187]

[0188] [Synthesis Example 8: Synthesis of Fluorine-Containing Polymer 4] The procedure was carried out in the same manner as in Synthesis Example 5, except that MA-4FHB-OAc was replaced with MA-BTHB-OAc, to obtain fluorine-containing polymer 4 (3.4 g, yield 85%).

[0189]

[0190] [Synthesis Example 9: Synthesis of Fluorine-Containing Polymer 5] The procedure was carried out in the same manner as in Synthesis Example 6, except that MA-4FHB-ODFAc was replaced with MA-BTHB-ODFAc, to obtain fluorine-containing polymer 5 (3.3 g, yield 83%).

[0191] [Synthesis Example 10: Synthesis of Fluorine-Containing Polymer 6] In a 100 mL glass flask at 23°C, 8.0 g (24 mmol) of MA-4FHB-OH and 32 g of MEK were added, and then 0.6 g (2.4 mmol) of 2,2'-azobis(isobutyrate)dimethyl (hereinafter referred to as V-601) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added. The flask was then degassed while stirring. After that, the flask was replaced with nitrogen gas, the internal temperature was raised to 78°C, and the reaction was carried out for 18 hours. The reaction solution was added dropwise to 80 g of heptane to reprecipitation, and then decanted. The resulting polymer was dried in a vacuum dryer to obtain fluorine-containing polymer 6 having the following repeating units.

[0192] Table 1 shows the yield, Mw, and molecular weight distribution (Mw / Mn) of fluorine-containing polymers 1 to 6.

[0193]

[0194] <Degradability Evaluation 1> The degradability of fluorine-containing polymers 1 to 6 was confirmed using NMR by the following method. 20 g of 2.38% by mass TMAH aqueous solution was added to 1 g of each fluorine-containing polymer. １９ F-NMR was measured. After stirring at 23°C for 24 hours, or after stirring at 90°C for 24 hours, the measurement was repeated. １９ F-NMR was measured before stirring. １９ Decomposition of the chlorodifluoro group was determined when more than 50% of the F-NMR peak area was replaced by new peaks with different chemical shift values. The results are shown in Table 2.

[0195]

[0196] As shown in Table 2, fluorine-containing polymers 3-5 (Comparative Examples 1-3) did not decompose at 23°C and 90°C, but it was confirmed that the chlorodifluoro group of fluorine-containing polymers 1-2 (Examples 1-2) decomposed at 90°C. From these results, it is possible to provide fluorine-containing polymers that can be decomposed at lower temperatures, and in the photolithography process, the fluorine-containing polymer after development can be decomposed at lower temperatures, which is thought to contribute to the reduction of energy in semiconductor processes.

[0197] <Degradability Evaluation 2> The degradability of each fluorine-containing polymer was evaluated by treating fluorine-containing polymers 1 to 6 under the following conditions and measuring the concentrations of fluoride ions and chloride ions generated. 20 g of a 2.38% by mass TMAH aqueous solution was added to 1 g of each fluorine-containing polymer and stirred at 90°C for 24 hours to obtain a solution. 20 g of diisopropyl ether (IPE) was added to 21 g of each solution and stirred for 5 minutes. After standing and separation, organic matter was removed, and the fluoride ions and chloride ions contained in the aqueous layer were measured by ion chromatography. A Thermo Fisher Scientific ICS-2100 ion chromatography system was used, along with a Thermo Fisher Scientific IonPac CS16 RFIC (5 x 250 mm) column, a KOH aqueous solution as the eluent, and an electrical conductivity detector (under these conditions, fluoride ions were detected at 8.8 min and chloride ions at 13.3 min). The concentrations of fluoride and chloride ions were measured using a calibration curve based on the measurement results. The results are shown in Table 3.

[0198]

[0199] As shown in Table 3, it was confirmed that fluorine-containing polymers 1-2 (Examples 1-2) containing MA-4FHB-OAc or MA-4FHB-ODFAAc as repeating units decompose into fluoride ions and chloride ions at basic conditions and 90°C.

[0200] From the above results, it was found that the fluorine-containing polymers in each example of this disclosure are fluorine-containing polymers that can be decomposed at a lower temperature than conventional fluorine-containing polymers.

[0201] <Evaluation of liquid repellency> Compositions were prepared by adding 1 g of each fluorine-containing polymer to PGMEA (3 g). The prepared compositions were then coated onto a 4-inch silicon substrate using a spinner and dried on a hot plate heated to 80°C for 3 minutes to form a film with a thickness of 2 to 3 μm.

[0202] [Measurement of Hysteresis (Dynamic Advance Angle - Dynamic Receding Angle)] A water droplet was placed on a film on a silicon substrate, and hysteresis (dynamic advance angle - dynamic receding angle) was measured using the expansion-contraction method with a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.). In this disclosure, the dynamic receding angle refers to the contact angle when the water droplet is contracted after being drawn in with a needle or the like, the dynamic advance angle refers to the contact angle when the water droplet is expanded after being discharged with a needle or the like, and hysteresis refers to the difference between the dynamic contact angle and the dynamic receding angle. The results are shown in Table 4.

[0203] [Measurement of Static Contact Angle] A water droplet was placed on a film on a silicon substrate, and the static contact angle was measured using a contact angle meter (manufactured by Kyowa Interface Science Co., Ltd.) with the droplet method. In this disclosure, the static contact angle refers to the angle made between the droplet and the film surface when the droplet is placed on the film surface and deposited. The results are shown in Table 4.

[0204]

[0205] As shown in Table 4, it was confirmed that fluorine-containing polymers 1 and 2 (Examples 1 and 2) have liquid-repellent properties comparable to those of conventional fluorine-containing polymers, such as fluorine-containing polymer 3 (Comparative Example 1).

[0206] <Evaluation of Alkali Developability> Compositions were prepared by adding each fluorine-containing polymer (1 g) to PGMEA (3 g). The prepared compositions were then coated onto a 4-inch silicon substrate using a spinner and dried on a hot plate heated to 80°C for 3 minutes to form a film with a thickness of 3 μm. The films were then immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH), and the dissolution rate (nm / s) was measured. The results are shown in Table 5.

[0207]

[0208] As shown in Table 5, it was confirmed that fluorine-containing polymers 1 and 2 (Examples 1 and 2) have alkali developability comparable to that of conventional fluorine-containing polymer 3 (Comparative Example 1).

[0209] Based on the above results, it has been found that the fluorine-containing polymer of this disclosure can be suitably used in photolithography resist films, top layers, and the like.

[0210] In summary, the above results show that this disclosure provides a fluorine-containing polymer that can be decomposed at a lower temperature than conventional fluorine-containing polymers. Furthermore, while the fluorine-containing polymer of this disclosure can be suitably used in photolithography resist films and upper layers, the spent material derived from the fluorine-containing polymer of this disclosure can be treated by simpler methods such as precipitation, adsorption, and activated sludge processes, rather than combustion, thus contributing to the reduction of energy consumption in semiconductor processes.

Claims

1. A fluorine-containing polymer comprising a repeating unit represented by the following general formula (1) or (1'). (In general formula (1), R Ａ , ２ , Ａ , ２ , ２ , ２ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms. In general formula (1), R ２ is a single bond, an alkylene group which may have a linear, branched or cyclic structure, an aromatic ring, an ester, a carbonyl, an ether, an amide, an amine, or a composite substituent thereof, and a part thereof may be fluorinated and / or chlorinated. In general formula (1), X is -CH ３ , -CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms). In general formula (1), n is a natural number from 1 to 3.). (In general formula (1'), R １ is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms. In general formula (1'), R ３ is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (1'), X is -CH ３ , -CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and among the hydrogen atoms bonded to the carbon atoms in the alkyl group, some or all may be substituted with fluorine atoms). In general formula (1'), n is a natural number from 1 to 3.).

2. The fluorine-containing polymer according to claim 1, comprising a repeating unit represented by the following general formula (2). (In general formula (2), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (2), R ４ This refers to an alkylene group or aromatic ring that may have a single bond, linear, branched, or cyclic structure, and which may contain ester bonds, carbonyl bonds, ether bonds, amide bonds, acetal bonds, hydroxyl groups, amino groups, fluorine atoms, or chlorine atoms, or a combination thereof.

3. The fluorine-containing polymer according to claim 1, comprising a repeating unit represented by the following general formula (3). (In general formula (3), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (3), R ５ L is an alkylene group or aromatic ring that may have a single bond, linear, branched, or cyclic structure, and may contain ester bonds, carbonyl bonds, ether bonds, amide bonds, acetal bonds, hydroxyl groups, amino groups, fluorine atoms, or chlorine atoms, or may be a complex substituent thereof. (L is an acid-dissociable group.) 4. A composition for forming a fluorine-containing resin film, characterized by comprising the fluorine-containing polymer described in any one of claims 1 to 3.

5. A fluororesin film characterized by comprising a coating film of the fluororesin film-forming composition described in claim 4.

6. A resist pattern forming composition comprising a fluorine-containing polymer according to any one of claims 1 to 3, an acid generator, and a solvent.

7. A method for forming a resist pattern, comprising the steps of: preparing a resist pattern forming composition according to claim 6; a film forming step of applying the resist pattern forming composition onto a substrate to form a film; an exposure step of irradiating the film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less through a photomask to transfer the pattern of the photomask to the film; and a developing step of developing the film using a developer to obtain a pattern.

8. A composition for forming a resist upper layer film, comprising a fluorine-containing polymer according to any one of claims 1 to 3 and a solvent.

9. A method for forming a resist pattern, comprising the steps of: preparing a resist upper layer film forming composition according to claim 8; a film formation step of applying the resist upper layer film forming composition onto a resist film to form a resist upper layer film; an exposure step of irradiating the resist upper layer film and the resist film with electromagnetic waves or high-energy rays with a wavelength of 300 nm or less through a photomask to transfer the pattern of the photomask to the resist film; and a developing step of removing the resist upper layer film and developing the resist film using a developer to obtain a pattern.

10. A method for decomposing a fluorine-containing polymer, comprising heating the fluorine-containing polymer according to any one of claims 1 to 3 at 50°C to 200°C.

11. A fluorine-containing polymerizable monomer represented by the following general formula (4) or (4'). (In general formula (4), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4), R ２ X is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (4), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4), n is a natural number between 1 and 3. (In general formula (4'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4'), R ３ X is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (4'), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4'), n is a natural number between 1 and 3.

12. A method for producing a fluorine-containing polymerizable monomer represented by the following general formula (4), comprising the steps of: preparing a compound represented by the following general formula (5); and reacting the compound represented by the following general formula (5) with an acid anhydride represented by the following general formula (6). (In general formula (5), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (5), R ２ n is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (5), n is a natural number between 1 and 3. (In general formula (6), X is -CH) ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (6), Xa is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (This is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) (In general formula (4), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4), R ２ X is an alkylene group, aromatic ring, ester, carbonyl, ether, amide, amine, or a compound substituent thereof, which may have a single bond, linear, branched, or cyclic structure, and which may be partially fluorinated and / or chlorinated. In general formula (4), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein n is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (4), n is a natural number between 1 and 3.

13. A method for producing a fluorine-containing polymerizable monomer represented by the following general formula (4'), comprising the steps of: preparing a compound represented by the following general formula (5'); and reacting the compound represented by the following general formula (5') with an acid anhydride represented by the following general formula (6). (In general formula (5'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (5'), R ３ (This refers to a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (5'), n is a natural number from 1 to 3.) (In general formula (6), X is -CH) ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) In general formula (6), Xa is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ OR OR Ａ (R Ａ (wherein it is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms.) (In general formula (4'), R １ R is a hydrogen atom, a fluorine atom, a chlorine atom, or a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms. Some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms. In general formula (4'), R ３ X is a linear alkyl group having 1 to 8 carbon atoms or a branched alkyl group having 3 to 8 carbon atoms. In general formula (4'), X is -CH ３ ien-CH ２ F, -CHF ２ , -CF ２ Cl, -CFCl ２ or -O-R Ａ (R Ａ is an alkyl group, and some or all of the hydrogen atoms bonded to the carbon atoms in the alkyl group may be substituted with fluorine atoms). In the general formula (4'), n is a natural number from 1 to 3.)

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