Polymers, methods for producing polymers, resin compositions, pattern forming methods, and methods for producing electronic devices

Abstract

The present invention provides a polymer that can improve the resolution of the resulting resin composition. [Solution] The formula NB contains constituent unit A and maleimide constituent unit B, and W is obtained by the following method. H / W P Polymers with a value of 0.40 or higher. The method involves dissolving 0.60 g of polymer in 1.40 g of propylene glycol monomethyl ether acetate (PGMEA), and adding heptane dropwise while stirring the solution until the solution becomes cloudy (W of heptane added). H (g) is measured. The mass of the PGMEA is W P (g) as W H / W P Calculate the value. TIFF2026058988000025.tif58153

Description

[Technical Field]

[0001] The present invention relates to polymers, methods for producing polymers, resin compositions, pattern forming methods, and methods for producing electronic devices. [Background technology]

[0002] Polymers containing structural units with a norbornene skeleton and structural units with a polyimide skeleton are sometimes used in resin compositions for resists.

[0003] Patent Document 1 describes a novel polymer compound useful as a base polymer for resist materials exhibiting excellent transparency and anti-negation effects in vacuum ultraviolet light at wavelengths of 180 nm or less, particularly F2 (157 nm), Kr2 (146 nm), KrAr (134 nm), and Ar2 (126 nm), as well as excellent dry etching resistance, alkali affinity, and adhesion. It also describes a chemically amplified resist material containing the same and a pattern formation method using this resist material. The invention aims to provide a polymer compound characterized by containing repeating units represented by the following general formula (1). [ka] (In the formula, R 1 R is a single bond or an alkylene group having 1 to 4 carbon atoms. 2 , R 3 R is a hydrogen atom, a fluorine atom, an alkyl group having 1 to 4 carbon atoms, or a fluorinated alkyl group having 1 to 4 carbon atoms. 2 , R 3 Both or either contain one or more fluorine atoms. 4 It is an acid-unstable group, and 0 5 (where X is a hydrogen atom, or a linear, branched, or cyclic alkyl group having 1 to 10 carbon atoms, which may contain heteroatoms such as oxygen, nitrogen, or sulfur. X is a methylene group, an ethylene group, an oxygen atom, or a sulfur atom.) [Prior art documents]​

Patent Document

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] The present invention provides a polymer capable of improving the resolution of a resulting resin composition, a method for producing the polymer, a resin composition with improved resolution, a pattern forming method, and a method for producing an electronic device.

Means for Solving the Problems

[0006] The inventors of the present invention intensively studied to solve the above problems. As a result, a polymer containing a structural unit (A) represented by a specific formula containing a norbornene skeleton and a structural unit (B) represented by a specific formula containing a maleimide skeleton, and having a value of W H / W P of 0.40 or more was found to be capable of improving the resolution of the resulting resin composition, and the present invention was completed.

[0007] According to the present invention, the following polymer, method for producing the polymer, resin composition, pattern forming method, and method for producing an electronic device are provided.

[0008] [1] A polymer containing a structural unit (A) represented by the following formula (NB) and a structural unit (B) represented by the following formula (MI), and having a value of W determined by the following method H / W P of 0.40 or more. (Method) Dissolve 0.60 g of the polymer in 1.40 g of propylene glycol monomethyl ether acetate to prepare a solution. Then, while stirring the solution at 200 rpm, add 0.05 mL of heptane dropwise to the solution until the solution becomes cloudy. The mass W of the heptane added is measured. H (g) is measured. At this time, the turbidity of the solution is confirmed by observing whether the solution remains turbid for 10 seconds after the addition of heptane. The addition of heptane is performed at 20-second intervals. The preparation of the solution, stirring of the solution, addition of heptane, and measurement of the heptane mass are all performed at a temperature of 23°C, a humidity of 50% RH, and atmospheric pressure. Next, the mass of the propylene glycol monomethyl ether acetate is measured. P When (g) is used, W H / W P Calculate the value. [ka] (In the above formula (NB), a1 is 0, 1 or 2, R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, a hydroxyl group, a halogen atom, or a hydrocarbon group having 1 to 30 carbon atoms, where any hydrogen atom may be substituted with a -C(CF3)2OH group, a hydroxyl group, or a halogen atom. [ka] (In the above formula (MI), X represents a hydrogen atom or a monovalent organic group.) [2] The polymer according to [1], wherein the content of the constituent unit (A) in the polymer is 40 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%. [3] The polymer according to [1] or [2], wherein the content of the constituent unit (B) in the polymer is 40 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%. [4] The aforementioned constituent unit (A) is R in formula (NB). 1 , R 2 , R 3 and R 4 The polymer according to any one of [1] to [3], wherein at least one of the constituent units (A-1) contains a -C(CF3)2OH group. [5] The aforementioned constituent unit (A) is R in formula (NB). 1 , R 2 , R 3 and R 4 None of them contain a -C(CF3)2OH group, R 1 , R 2 , R 3 and R 4 The polymer according to [4], further comprising a constituent unit (A-2) in which at least one of the constituent units contains a hydrocarbon group having 1 to 30 carbon atoms. [6] In the aforementioned constituent unit (A), R 1 , R 2 , R 3 and R 4 The polymer according to any one of [1] to [5], none of which contains an acid-unstable group. [7] The polymer according to any one of [1] to [6], wherein the constituent unit (B) comprises a constituent unit (B-1) in formula (MI) in which X contains an alkali-soluble group. [8] The polymer according to [7], wherein X contains a phenolic hydroxyl group. [9] The polymer according to [7] or [8], wherein the constituent unit (B) further comprises a constituent unit (B-2) in formula (MI) in which X does not contain an alkali-soluble group and contains a cyclic aliphatic group.

[10] A polymer according to any one of [1] to [9], further comprising the constituent unit (C) shown by the following formula. [ka] (In the above formula, R represents a hydrogen atom or a monovalent organic group.)

[11] A polymer according to any of [1] to

[10] , having a weight-average molecular weight of 500 or more and 10,000 or less.

[12] A polymer according to any one of [1] to

[11] , wherein the weight-average molecular weight is Mw and the number-average molecular weight is Mn, and the Mw / Mn value is 1.10 or more and 2.00 or less.

[13] A polymer according to any one of [1] to

[12] , used in a resin composition for resists.

[14] A method for producing the polymer described in any of [1] to

[13] , A process to obtain a copolymer by polymerizing a monomer containing a norbornene skeleton with maleic anhydride, A step of imidizing the structural units derived from maleic anhydride in the copolymer, A method for producing polymers that include the following features.

[15] A resin composition comprising any of the polymers described in [1] to

[13] .

[16] The resin composition according to

[15] further comprises one or more solvents selected from the group consisting of ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, and carbonate solvents.

[17] The resin composition according to

[15] or

[16] , further comprising a diazirine compound containing two or more diazirine structures in one molecule.

[18] A step of applying a resin composition described in any of

[15] to

[17] onto a substrate to form a resin film, The process involves irradiating the resin film with active light or radiation, The process of developing the resin film to obtain a substrate on which a resin pattern is formed, A pattern formation method including the following.

[19]

[18] A step of etching a substrate on which a resin pattern has been formed by the pattern forming method described above, A step of removing the resin pattern remaining on the substrate, A method for manufacturing an electronic device that includes [a specific component]. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a polymer that can improve the resolution of the resulting resin composition, a method for producing the polymer, and a resin composition with improved resolution, a pattern forming method, and a method for producing an electronic device. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below.

[0011] In this specification, the notation "X~Y" in descriptions of numerical ranges means "X or greater and Y or less" unless otherwise specified. For example, "1~5 mass%" means "1 mass% or greater and 5 mass% or less".

[0012] In this specification, when a group (atomic group) is not specified as substituted or unsubstituted, it includes both unsubstituted and substituted groups. For example, "alkyl group" includes not only unsubstituted alkyl groups but also substituted alkyl groups.

[0013] In this specification, unless otherwise specified, the term "organic group" refers to an atomic group obtained by removing one or more hydrogen atoms from an organic compound. For example, "monovalent organic group" refers to an atomic group obtained by removing one hydrogen atom from any organic compound.

[0014] In this specification, the term "electronic device" is used to encompass elements, devices, and final products to which electronic engineering technology is applied, such as semiconductor chips, semiconductor elements, printed circuit boards, electrical circuit display devices, information and communication terminals, light-emitting diodes, physical batteries, and chemical batteries. In this specification, the term "room temperature" refers to 23°C.

[0015] <polymer> The polymer of this embodiment includes a constituent unit (A) represented by the following formula (NB) and a constituent unit (B) represented by the following formula (MI).

[0016] [ka]

[0017] In equation (NB), a1 is 0, 1, or 2, and R 1 , R 2 , R 3 and R 4 Each of these independently represents a hydrogen atom, a hydroxyl group, a halogen atom, or a hydrocarbon group having 1 to 30 carbon atoms in which any hydrogen atom may be substituted with a -C(CF3)2OH group, a hydroxyl group, or a halogen atom.

[0018] [ka]

[0019] In formula (MI), X represents a hydrogen atom or a monovalent organic group.

[0020] In formula (NB), a1 is preferably 0 or 1, more preferably 0.

[0021] In equation (NB), R 1 , R 2 , R 3 and R 4 Preferably, the hydrocarbon group having 1 to 30 carbon atoms may have a hydrogen atom or any hydrogen atom substituted with a -C(CF3)2OH group, a hydroxyl group, or a halogen atom; more preferably, the hydrocarbon group having 1 to 20 carbon atoms may have a hydrogen atom or any hydrogen atom substituted with a -C(CF3)2OH group; and even more preferably, the hydrocarbon group having 1 to 10 carbon atoms may have a hydrogen atom or any hydrogen atom substituted with a -C(CF3)2OH group.

[0022] In formula (MI), X is preferably a monovalent organic group containing a cyclic skeleton, more preferably a monovalent organic group containing an aromatic group or a cyclic aliphatic group, and even more preferably a monovalent organic group containing a cycloalkyl group or a phenyl group.

[0023] The polymer of this embodiment is obtained by the following method: H / W P The value is 0.40 or greater. (method) Dissolve 0.60 g of polymer in 1.40 g of propylene glycol monomethyl ether acetate to prepare a solution. Then, while stirring the solution at 200 rpm, add heptane dropwise at 0.05 mL intervals until the solution becomes cloudy. The mass of heptane added until the solution becomes cloudy is measured (W). H (g) is measured. At this time, the turbidity of the solution is confirmed by observing whether the solution remains turbid for 10 seconds after the addition of heptane dropwise. Heptane is added dropwise at 20-second intervals. Solution preparation, stirring of the solution, addition of heptane dropwise, and measurement of the heptane mass are all performed at a temperature of 23°C, a humidity of 50% RH, and atmospheric pressure. Next, the mass of propylene glycol monomethyl ether acetate is measured. P When (g) is used, W H / W P Calculate the value.

[0024] In pattern formation using resin compositions such as resist compositions, a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) has traditionally been used as the developer. Ideally, both the resin composition and the developer should be improved and optimized to form fine resin patterns. However, changing the developer requires the cost of introducing new equipment, so there is a need within the industry to continue using a 2.38% by mass TMAH aqueous solution as the developer. Furthermore, with the advancement of miniaturization in electronic device wiring, there is a growing demand for forming high-resolution patterns using resin compositions such as resist compositions.

[0025] This invention has been made in view of these circumstances. This invention relates to W obtained by the above method. H / W P By setting the value of 0.40 or higher, the present invention provides a polymer that can be obtained to form a resin composition capable of forming a high-resolution pattern by developing it using, for example, a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution.

[0026] Furthermore, in the polymer of the present invention, propylene glycol monomethyl ether acetate is a good solvent, and heptane is a poor solvent. Therefore, W H / W P The polymer of the present invention, having a value of 0.40 or higher, is understood to have high solvent solubility. Therefore, the polymer of the present invention also provides effects such as suppression of precipitation during storage and the ability to form a uniform film.

[0027] W of the polymer in this embodiment H / W P The value of is 0.40 or higher, preferably 0.42 or higher, more preferably 0.44 or higher, even more preferably 0.46 or higher, even more preferably 0.48 or higher, even more preferably 0.50 or higher, even more preferably 0.52 or higher, even more preferably 0.54 or higher, even more preferably 0.56 or higher, and even more preferably 0.58 or higher, from the viewpoint of further improving the resolution of the resulting resin composition. H / W P There is no particular upper limit to the value of , but for example it may be 3.00 or less, 2.00 or less, 1.50 or less, 1.30 or less, or 1.10 or less.

[0028] W of the polymer in this embodiment H / W PFrom the viewpoint of further improving the resolution of the resulting resin composition, the value of is preferably 0.40 to 3.00, more preferably 0.42 to 3.00, even more preferably 0.44 to 3.00, even more preferably 0.46 to 3.00, even more preferably 0.48 to 3.00, even more preferably 0.50 to 3.00, even more preferably 0.52 to 2.00, even more preferably 0.54 to 1.50, even more preferably 0.56 to 1.30, and even more preferably 0.58 to 1.10.

[0029] W of the polymer in this embodiment H / W P The value of can be adjusted, for example, by appropriately selecting the type and content of each constituent unit contained in the polymer of this embodiment, as well as the manufacturing method. The manufacturing method preferably comprises the steps of polymerizing a monomer containing a norbornene skeleton with maleic anhydride to obtain a copolymer, and imidizing the constituent units derived from maleic anhydride in the copolymer.

[0030] From the viewpoint of further improving the resolution of the resulting resin composition, the content of constituent unit (A) in the polymer of this embodiment is preferably 40 mol% to 60 mol%, more preferably 45 mol% to 55 mol%, and even more preferably 47 mol% to 53 mol%, when the total content of all constituent units in the polymer is set to 100 mol%.

[0031] From the viewpoint of further improving the resolution of the resulting resin composition, the content of constituent unit (B) in the polymer of this embodiment is preferably 40 mol% to 60 mol%, more preferably 40 mol% to 55 mol%, and even more preferably 40 mol% to 50 mol%, when the total content of all constituent units in the polymer is set to 100 mol%.

[0032] In this embodiment, the ratio of each constituent unit in the polymer is, for example, 1 H-NMR or 13Using 1C-NMR, measurements can be performed under the following conditions, and the result can be determined by the ratio of the integral values ​​of the peaks originating from each constituent unit. < 1 H-NMR measurement conditions > ·Measuring device: JEOL Ltd., JNM-ECZ-400S ·Resonance frequency: 400MHz • Measurement nucleus: 1 H • Measurement method: NNE measurement (inverse gate decoupling method) Pulse width: 6.99 μsec • Pulse repetition waiting time: 5 seconds • Total number of times: 8 ·Measurement temperature: room temperature • Measurement solvent: DMSO-d6 (deuterated dimethyl sulfoxide) • Sample concentration: 3% (w / v) < 13 CNMR measurement conditions > ·Measuring device: JEOL Ltd., JNM-ECZ-400S ·Resonance frequency: 100MHz • Measurement nucleus: 13 C • Measurement method: NNE measurement (inverse gate decoupling method) Pulse width: 11.8 μsec • Pulse repetition waiting time: 2 seconds • Total number of times: 8192 ·Measurement temperature: room temperature • Measurement solvent: DMSO-d6 (deuterated dimethyl sulfoxide) • Sample concentration: 20% (w / v) • Relaxation agent: Cr(AcAc)3 (chromium(III) acetylacetonate) • Amount of relaxation reagent added: 10 parts by mass per 100 parts by mass of polymer

[0033] <Component Unit (A)> In this embodiment, the constituent unit (A) is preferably, from the viewpoint of further improving the resolution of the resulting resin composition, R in formula (NB). 1 , R 2 , R 3 and R4 At least one of them contains a constituent unit (A-1) that includes a -C(CF3)2OH group.

[0034] The constituent unit (A-1) of this embodiment is R 1 , R 2 , R 3 and R 4 Preferably, 1 to 3 of these contain a -C(CF3)2OH group, more preferably 1 or 2 contain a -C(CF3)2OH group, and even more preferably 1 contains a -C(CF3)2OH group.

[0035] The group containing the -C(CF3)2OH group in the constituent unit (A-1) of this embodiment is preferably a hydrocarbon group having 1 to 30 carbon atoms in which one hydrogen atom is substituted with a -C(CF3)2OH group, more preferably a hydrocarbon group having 1 to 15 carbon atoms in which one hydrogen atom is substituted with a -C(CF3)2OH group, even more preferably a hydrocarbon group having 1 to 5 carbon atoms in which one hydrogen atom is substituted with a -C(CF3)2OH group, and still more preferably a -C(CF3)2OH group.

[0036] The group in the constituent unit (A-1) of this embodiment that does not contain a -C(CF3)2OH group is preferably a hydrogen atom or a hydrocarbon group having 1 to 30 carbon atoms, in which any hydrogen atom may be substituted with a hydroxyl group or a halogen atom, more preferably a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms, and even more preferably a hydrogen atom.

[0037] In a polymer in which the constituent unit (B) is composed solely of the constituent unit (B-1) described later, the constituent unit (A) of this embodiment is preferably, from the viewpoint of further improving the resolution of the resulting resin composition, R in formula (NB). 1 , R 2 , R 3 and R 4 None of them contain a -C(CF3)2OH group, R 1, R 2 , R 3 and R 4 Further includes a structural unit (A-2) in which at least one of them contains a hydrocarbon group having 1 to 30 carbon atoms.

[0038] From the viewpoint of further improving the resolution of the obtained resin composition, the structural unit (A-2) of the present embodiment is R 1 , R 2 , R 3 and R 4 Among them, preferably 1 to 3 contain a hydrocarbon group having 1 to 30 carbon atoms, more preferably 1 or 2 contain a hydrocarbon group having 1 to 30 carbon atoms, and still more preferably 1 contains a hydrocarbon group having 1 to 30 carbon atoms.

[0039] From the viewpoint of further improving the resolution of the obtained resin composition, the hydrocarbon group having 1 to 30 carbon atoms in the structural unit (A-2) of the present embodiment is preferably a linear hydrocarbon group having 1 to 30 carbon atoms, more preferably a linear hydrocarbon group having 1 to 20 carbon atoms, still more preferably a linear hydrocarbon group having 1 to 10 carbon atoms, and still more preferably a linear hydrocarbon group having 3 to 8 carbon atoms. The group that is not a hydrocarbon group having 1 to 30 carbon atoms in the structural unit (A-2) of the present embodiment is preferably a hydrogen atom.

[0040] The polymer of the present embodiment preferably does not contain any acid labile groups in the structural unit (A), R 1 , R 2 , R 3 and R 4

[0041] <Structural unit (B)> From the viewpoint of further improving the resolution of the obtained resin composition, the structural unit (B) of the present embodiment preferably contains a structural unit (B-1) in which X contains an alkali-soluble group in the formula (MI).

[0042] ​In this embodiment, the constituent unit (B-1) preferably contains one or more selected from the group consisting of a phenolic hydroxyl group, a carboxyl group, and a -C(CF3)2OH group, from the viewpoint of further improving the resolution of the resulting resin composition, X preferably contains a phenolic hydroxyl group, and even more preferably X contains a -C6H4-OH group.

[0043] In a polymer in which the constituent unit (A) is composed solely of constituent unit (A-1), the constituent unit (B) of this embodiment further includes a constituent unit (B-2) in formula (MI) in which X does not contain an alkali-soluble group but contains a cyclic aliphatic group, from the viewpoint of further improving the resolution of the resulting resin composition.

[0044] In this embodiment, the constituent unit (B-2) preferably comprises one or more selected from the group consisting of a cyclopentyl group, a cyclohexyl group, a cyclooctyl group, a norbornyl group, and more preferably, X is a cyclohexyl group, from the viewpoint of further improving the resolution of the resulting resin composition.

[0045] <Component Unit (C)> The polymer of this embodiment preferably further comprises a constituent unit (C) represented by the following formula.

[0046] [ka]

[0047] In the above formula, R represents a hydrogen atom or a monovalent organic group.

[0048] In a polymer in which constituent unit (B) is composed solely of constituent unit (B-1), the content of constituent unit (C) in the polymer of this embodiment is preferably 1 mol% to 20 mol%, more preferably 2 mol% to 15 mol%, and even more preferably 3 mol% to 12 mol%, when the total content of all constituent units in the polymer is 100 mol%.

[0049] In a polymer in which constituent unit (A) is composed solely of constituent unit (A-1), the content of constituent unit (C) in the polymer of this embodiment is preferably 0 mol% to 10 mol%, more preferably 0 mol% to 7 mol%, and even more preferably 0 mol% to 5 mol%, when the total content of all constituent units in the polymer is 100 mol%.

[0050] In a polymer in which constituent unit (B) is composed solely of constituent unit (B-1), the imidization rate of the polymer in this embodiment is preferably 75 mol% or more and 100 mol% or less, more preferably 80 mol% or more and 100 mol% or less, and even more preferably 85 mol% or more and 100 mol% or less.

[0051] In a polymer in which constituent unit (A) is composed solely of constituent unit (A-1), the imidization rate of the polymer of this embodiment is preferably 80 mol% or more and 100 mol% or less, more preferably 90 mol% or more and 100 mol% or less, and even more preferably 95 mol% or more and 100 mol% or less.

[0052] In this embodiment, the imidization rate of the polymer is, for example, 1 After determining the ratio of constituent units (B) and (C) using 1H-NMR, the result can be calculated using the following formula. Imidization rate (%) = {1 - ratio of constituent unit (C) / (ratio of constituent unit (B) + ratio of constituent unit (C))} × 100

[0053] <Molecular weight> The weight-average molecular weight of the polymer in this embodiment is preferably 500 to 10000, more preferably 1000 to 7000, even more preferably 1500 to 6000, even more preferably 2000 to 5000, and even more preferably 2500 to 4000.

[0054] The number-average molecular weight of the polymer in this embodiment is preferably 500 to 10000, more preferably 1000 to 7000, even more preferably 1500 to 5000, and even more preferably 1800 to 3000.

[0055] In this embodiment, when the weight-average molecular weight of the polymer is Mw and the number-average molecular weight is Mn, the Mw / Mn value is preferably 1.10 to 2.00, more preferably 1.15 to 1.80, even more preferably 1.20 to 1.70, even more preferably 1.25 to 1.60, and even more preferably 1.30 to 1.50.

[0056] In this embodiment, the weight-average molecular weight and number-average molecular weight of the polymer can be calculated, for example, by measuring the molecular weight distribution curve using GPC (Gel Permeation Chromatography) under the following measurement conditions, and using the polystyrene equivalent value obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. Measurement equipment: Tosoh Corporation, gel permeation chromatography system HLC-8320GPC EcoSEC Detector: RI detector for liquid chromatogram Measurement temperature: 40℃ Solvent: THF Pump flow rate: 0.350 mL / min Sample concentration: 2.5 mg / mL

[0057] <Alkali dissolution rate of polymers> In a polymer in which constituent unit (A) is composed solely of constituent unit (A-1), the alkali dissolution rate of the polymer of this embodiment is preferably 5.0 nm / sec or more and less than 400.0 nm / sec, more preferably 10.0 nm / sec or more and 300.0 nm / sec or less, and even more preferably 20.0 nm / sec or more and 200.0 nm / sec or less. In a polymer in which constituent unit (B) is composed solely of constituent unit (B-1), the alkali dissolution rate of the polymer of this embodiment is preferably 100.0 nm / sec to 500.0 nm / sec, more preferably 130.0 nm / sec to 400.0 nm / sec, even more preferably 160.0 nm / sec to 300.0 nm / sec, and even more preferably 180.0 nm / sec to 250.0 nm / sec.

[0058] In this embodiment, the alkali dissolution rate of the polymer can be determined, for example, by the following method. First, the polymer is dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a 10% by mass solution. Next, the obtained solution is spin-coated onto a silicon wafer, and the solvent is dried to obtain a resin film with a thickness T of approximately 300 nm. Then, the obtained resin film, along with the silicon wafer, is immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23°C, and the time t (sec) until the film thickness becomes 0 nm is measured. Next, the alkali dissolution rate of the polymer (nm / sec) is calculated by calculating T / t.

[0059] <Alkali dissolution rate of resin composition> In a polymer in which constituent unit (A) is composed solely of constituent unit (A-1), the alkali dissolution rate of the resin composition obtained from the polymer of this embodiment by the following method is preferably 1.0 nm / sec or more and less than 100.0 nm / sec, more preferably 2.0 nm / sec or more and 50.0 nm / sec or less, and even more preferably 4.0 nm / sec or more and 30.0 nm / sec or less. In a polymer in which constituent unit (B) is composed solely of constituent unit (B-1), the alkali dissolution rate of the resin composition obtained from the polymer of this embodiment by the following method is preferably 20.0 nm / sec to 200.0 nm / sec, more preferably 30.0 nm / sec to 150.0 nm / sec, even more preferably 40.0 nm / sec to 100.0 nm / sec, and even more preferably 50.0 nm / sec to 80.0 nm / sec. (method) A polymer and a diazirine compound (BLD-201 or BXW-202, manufactured by Xlynx Materials Inc.) are dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a resin composition. The amount of diazirine compound is 20 parts by mass per 100 parts by mass of polymer. The concentration of nonvolatile components is set to 10% by mass.

[0060] In this embodiment, the alkali dissolution rate of the resin composition can be determined, for example, by the following method. First, the resin composition is applied to a silicon wafer by spin coating, and the solvent is dried to obtain a resin film with a thickness T of approximately 100 nm. Next, the obtained resin film, along with the silicon wafer, is immersed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23°C. Then, the time t (sec) until the film thickness becomes 0 nm is measured, and the alkali dissolution rate (nm / sec) of the resin composition is calculated by T / t.

[0061] <Resolution> In a polymer in which constituent unit (A) is composed solely of constituent unit (A-1), the resist line width roughness (LWR) in the 100 nm L / S pattern of the polymer of this embodiment is preferably 0.1 nm to 8.0 nm, more preferably 0.5 nm to 7.0 nm, even more preferably 1.0 nm to 6.0 nm, and even more preferably 1.5 nm to 5.0 nm, from the viewpoint of further improving resolution. In a polymer in which constituent unit (B) is composed solely of constituent unit (B-1), the resist line width roughness (LWR) in the 100 nm L / S pattern of the polymer of this embodiment is preferably 0.1 nm to 28.0 nm, more preferably 1.0 nm to 25.0 nm, even more preferably 2.0 nm to 22.0 nm, even more preferably 3.0 nm to 20.0 nm, and even more preferably 4.0 nm to 18.0 nm, from the viewpoint of further improving resolution.

[0062] In this embodiment, the resist line width roughness (LWR) in a 100 nm L / S pattern of the polymer can be determined, for example, by the following method. First, a polymer and a diazirine compound (BLD-201 or BXW-202, manufactured by Xlynx Materials Inc.) are dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare a resin composition. The amount of diazirine compound is 20 parts by mass per 100 parts by mass of polymer. The non-volatile component concentration is set to 3% by mass. Next, the resin composition is applied to a silicon wafer by spin coating, and a resin film with a thickness of 100 nm is formed by drying the solvent. Then, the obtained resin film is irradiated with an electron beam at an accelerating voltage of 130 keV. The electron beam irradiation is performed selectively so as to form a 100 nm line-and-space (L / S) pattern. Next, the resin film, along with the silicon wafer, is immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The development time is set to any time in the range of 5 to 60 seconds, depending on the alkali dissolution rate of the resin composition. Next, the resist line width roughness (LWR) in the L / S pattern on the surface of the silicon wafer after development is measured.

[0063] <Application> The polymer of this embodiment is suitably used in photosensitive resin compositions, and more suitably in resin compositions for resists, because the resolution of the resulting resin composition is improved. On the other hand, the polymer of this embodiment is useful in itself because it possesses alkali solubility and other desirable properties. In other words, the polymer of this embodiment can be applied to various uses on its own and can be used for various purposes other than photosensitive resin compositions.

[0064] <Method for producing polymers> The polymer production method of this embodiment preferably comprises the steps of polymerizing a monomer containing a norbornene skeleton with maleic anhydride to obtain a copolymer, and imidizing the constituent units derived from maleic anhydride in the copolymer, from the viewpoint of further improving the resolution of the resulting resin composition. The polymer produced in this manner exhibits, for example, the aforementioned polymer properties (W) compared to polymers obtained by other manufacturing methods.H / W P There is a tendency to easily satisfy the following conditions (e.g., the value of ):

[0065] In this embodiment, the polymer can typically be synthesized (produced) by radical polymerization. That is, the polymer can be synthesized (produced) by polymerizing each monomer (having a radically polymerizable carbon-carbon double bond) in a suitable organic solvent using the action of a radical initiator. Specific synthesis conditions can be appropriately referred to publicly available information. Furthermore, publicly known information can be appropriately referenced regarding methods for purifying the synthesized polymer (methods for reducing impurities). In particular, when using the resin composition of this embodiment as a resist composition, it is preferable to reduce impurities as much as possible.

[0066] <Resin composition> The resin composition of this embodiment includes the polymer of this embodiment. The polymer of this embodiment has improved resolution in the resulting resin composition, thus improving the resolution of the resin composition of this embodiment.

[0067] <Solvent> The resin composition of this embodiment preferably further comprises one or more solvents selected from the group consisting of ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, and carbonate solvents. In other words, the resin composition of this embodiment preferably contains at least a polymer dissolved or dispersed in a solvent.

[0068] The solvent of this embodiment preferably comprises one or more selected from the group consisting of propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), ethyl lactate, methyl isobutylcarbinol (MIBC), gamma butyrolactone (GBL), N-methylpyrrolidone (NMP), methyl-n-amyl ketone (MAK), diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, and cyclohexanone, and more preferably comprises propylene glycol monomethyl ether acetate (PGMEA). The solvent of this embodiment may be a single solvent or a mixed solvent.

[0069] The amount of solvent used in this embodiment is appropriately adjusted so that the concentration of nonvolatile components in the resin composition is preferably 1 to 20% by mass, more preferably 1 to 15% by mass.

[0070] <Components for making a resin composition photosensitive> For the resin composition of this embodiment to be used as a resin composition for resists, it is preferable that the resin composition is photosensitive. "Photosensitive" means that its solubility in an alkaline developer changes upon exposure to active light or radiation.

[0071] As an example, the resin composition of this embodiment preferably contains a compound that generates acid upon the action of active light or radiation (acid generator) and a compound that undergoes a crosslinking reaction upon the action of acid (crosslinking agent). A negative-type resin pattern can be formed by irradiating a resin film formed from a resin composition containing the acid generator and the crosslinking agent with active light or radiation, and then developing the resin film.

[0072] <Diazirine compound> As another example, the resin composition of this embodiment preferably further comprises a diazirine compound containing two or more diazirine structures in one molecule. A negative-type resin pattern can be formed by irradiating a resin film formed from the resin composition containing the diazirine compound with active light or radiation, and then developing the resin film.

[0073] When a diazirine compound is irradiated with active light or radiation, N2 is removed from the diazirine structure, and a carbene (a two-coordinate carbon atom with only six valence electrons and no charge) is generated. The generated carbene reacts with the polymer to form a bond. In particular, since the generated carbene is inserted into the CH bond, the polymer that reacts with the carbene does not need to have any special functional groups. Therefore, diazirine compounds can form bonds with a variety of polymers. In this embodiment, since a diazirine compound containing "two or more diazirine structures in one molecule" is used, the polymer is "crosslinked" by the diazirine compound. As a result, the portion of the resin film irradiated with active light or radiation becomes insoluble or sparingly soluble in the developer. Therefore, a pattern can be formed by selectively irradiating the resin film with active light or radiation and then developing it.

[0074] The number of diazirine structures in one molecule of the diazirine compound in this embodiment is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 to 3.

[0075] The diazirine compound of this embodiment preferably contains a structure represented by the following general formula (b). Specifically, the diazirine compound preferably contains two or more structures represented by the following general formula (b) in one molecule.

[0076] [ka]

[0077] In general formula (b), R xrepresents a monovalent substituent, R, when there are a plurality of them, each independently represents a monovalent substituent, n represents an integer from 0 to 4, and * represents a bond to another chemical structure.

[0078] The structures represented by the general formula (b) that are present two or more times in one molecule of the diazirine compound may be the same structure or different structures. Examples of the latter include compounds having a structure represented by the general formula (b) where n is 0 and a structure represented by the general formula (b) where n is 1 in one molecule.

[0079] R x The monovalent substituent of is preferably an electron-withdrawing group from the viewpoint of increasing the sensitivity of the photosensitive resin composition. The electron-withdrawing group can be any group generally recognized as an electron-withdrawing group in the field of organic chemistry. R which is an electron-withdrawing group x Specific examples of include perfluoroalkyl groups, chlorinated alkyl groups, -NO2, -CN, -CHO, -COR, -COOR, -COOH, -SO2R, -SO3H, etc. Here, R is a monovalent organic group, and specifically, alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkaryl groups, cycloalkyl groups, alkoxy groups, heterocyclic groups, carboxyl groups, etc., can be mentioned. From the viewpoints of ease of synthesis and cost, and sensitivity to electron beams or EUV light, R x as an electron-withdrawing group is preferably a perfluoroalkyl group, more preferably a perfluoroalkyl group, and even more preferably a trifluoromethyl group. From the viewpoint of emphasizing, for example, the storage stability of the photosensitive resin composition, the monovalent substituent of R x does not have to be an electron-withdrawing group. As an example, R x may be a hydrogen atom. As another example, R x may be an organic group not substituted with fluorine (alkyl group, alicyclic group, aromatic group, etc.). Considering ease of availability or synthesis, appropriate reactivity, etc., R x is preferably a hydrogen atom or an alkyl group, more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom. From the viewpoint of ease of synthesis / obtaining the diazirine compound, n is preferably 0.

[0080] The diazirine compound of this embodiment more preferably includes a structure represented by the following general formula (b1).

[0081] [ka]

[0082] In formula (b1), R X The definitions of R, n, and * are the same as those in general formula (b). X Preferred embodiments of R and n are the same as those given in general formula (b).

[0083] In the structure represented by general formula (b1), the electron-donating nature of the oxygen atom increases the reactivity of the diazirine structure, making it easier to generate carbenes upon irradiation with electron beams or EUV light. In other words, using diazirine compounds containing the structure represented by general formula (b1) tends to increase sensitivity.

[0084] The structures represented by general formula (b1) present in two or more molecules of a diazirine compound may be identical or different. An example of the latter is a compound having both a structure represented by general formula (b1) where n is 0 and a structure represented by general formula (b1) where n is 1 within a single molecule.

[0085] The diazirine compound of this embodiment can specifically have a structure represented by the following general formula (BB).

[0086] [ka]

[0087] In general formula (BB), A represents a group represented by general formula (b) or general formula (b1), k is an integer greater than or equal to 2, and L is a k-valence linking group.

[0088] In the general formula (BB), there can be multiple A's. These multiple A's may have the same structure or may have different structures.

[0089] From the viewpoint of ease of synthesis and availability, and balance of various performance characteristics, k is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 to 3.

[0090] When L is a divalent linking group, L can specifically be a linear or branched alkylene group, a group obtained by removing two hydrogen atoms from an alicyclic group, an arylene group, -O-, -CO-, -COO-, -OCO-, -NH-, -NR- (where R is a monovalent organic group), -S-, -SO2-, or a group formed by linking two or more of these groups. Preferably, L is a linear or branched alkylene group, an arylene group, -O-, or a group formed by linking two or more of these groups. If L is a linking group with three or more valent atoms, then L can specifically be a group obtained by removing one or more hydrogen atoms from the above-mentioned divalent linking group. L is typically a k-valent organic group.

[0091] In terms of ease of synthesis of the diazirine compound and appropriate curability, it is preferable that the "length" of the L portion be appropriate. Here, the "length" of the L portion is defined as the number of atoms in the shortest path from an atom to which a certain A is directly covalently bonded in L, starting from that atom, and following only the covalent bonds in L, to an atom to which another A is directly covalently bonded (the endpoint). However, if the A in the L portion is a group represented by general formula (b1), the oxygen atom bonded to the benzene ring in general formula (b1) is also included in L when determining the "length" of the L portion. In other words, if the A in the L portion is a group represented by general formula (b1), the oxygen atom in general formula (b1) is used as the starting or ending point. Furthermore, if the diazirine compound has three or more A atoms, the shortest length among the definable lengths is adopted as the "length". For example, if a diazirine compound A has three parts A1, A2, and A3, and the "length" from A1 to A2 is 10, and the "length" from A1 to A3 is 12, then the "length" of the L portion in this compound (B) is 10. For example, the "length" of the L portion in BLD-201 used in the embodiment shown later is 10.

[0092] In terms of ease of synthesis of the diazirine compound and appropriate curability, the "length" of the L portion is, for example, 1 to 20, preferably 1 to 16. As another example, the "length" of the L portion is preferably 6 to 20, more preferably 8 to 20. If the L portion is "moderately long," the diazirine compound (or carbene produced from the diazirine compound) in the film when the composition is formed into a film will react more easily with the polymer, which may lead to a further improvement in sensitivity. On the other hand, if the L portion is "not too long," contact between the diazirine compound (or carbene produced from the diazirine compound) and the polymer is suppressed, which may lead to an improvement in the long-term stability of the composition.

[0093] The time-dependent stability of a composition tends to be enhanced if L is electron-withdrawing or substituted with an electron-withdrawing group. For example, using diazirine compounds in general formula (BB) where L is a fluorine atom, diazirine compounds in general formula (BB) where L is an organic group substituted with a fluorine atom, or diazirine compounds in general formula (BB) where L is a fluorinated alkylene group tends to enhance the time-dependent stability of a composition. If L is electron-withdrawing, or if L is substituted with an electron-withdrawing group, the thermodynamically unfavorable process of carbene generation through N2 elimination becomes slightly less likely, meaning that carbene generation is slightly reduced. Therefore, unintended decomposition of the diazirine compound is suppressed, and sensitivity is expected to improve. Although sensitivity may be slightly reduced, if the long-term stability of the composition is important, it is preferable to select a diazirine compound in which L is electron-withdrawing, or in which L is substituted with an electron-withdrawing group.

[0094] The molecular weight of the diazirine compound in this embodiment is preferably 100 to 2000, more preferably 100 to 1000. The diazirine compound is typically a low molecular weight compound and not a polymer.

[0095] When using diazirine compounds, you may use only one diazirine compound, or you may use two or more diazirine compounds in combination. From the viewpoint of balancing various performance characteristics, when using a diazirine compound, the amount is preferably 5 to 50 parts by mass, more preferably 8 to 40 parts by mass, and even more preferably 10 to 30 parts by mass, per 100 parts by mass of polymer.

[0096] <Other optional ingredients> The resin composition of this embodiment may contain optional components other than those mentioned above. Examples of optional components include developing aids, plasticizers, antioxidants, leveling agents, and surfactants.

[0097] <Method for forming patterns and method for manufacturing electronic devices> The pattern forming method of this embodiment includes the steps of: applying the resin composition of this embodiment onto a substrate to form a resin film; irradiating the resin film with active light or radiation; and developing the resin film to obtain a substrate on which a resin pattern has been formed. Includes.

[0098] The method for manufacturing the electronic device of this embodiment includes the steps of etching a substrate on which the resin pattern obtained as described above is formed, and removing the resin pattern remaining on the substrate.

[0099] The following will explain these processes in detail.

[0100] <First step: Formation of resin film> The substrate on which the resin film is formed is not particularly limited. Examples include glass substrates, silicon wafers, ceramic substrates, aluminum substrates, SiC wafers, GaN wafers, copper substrates, copper-plated substrates, and the like. The substrate may be an unprocessed substrate, or it may be a substrate with electrodes or elements formed on its surface. An anti-reflective coating may be pre-applied to the substrate. Both inorganic film types such as titanium, titanium dioxide, titanium nitride, chromium oxide, carbon, and amorphous silicon can be used as the anti-reflective coating, and organic film types consisting of a light absorber and polymer material can be used. Furthermore, commercially available organic anti-reflective coatings such as Brewer Science's DUV30 series and DUV-40 series, and Cypree's AR-2, AR-3, and AR-5 can also be used.

[0101] The method for forming the resin film is not particularly limited. In the field of electronic device manufacturing, rotary coating using a spinner is common, but other methods may also be used. For example, spray coating using a spray coater, dipping, printing, roll coating, inkjet methods, etc., may also be used.

[0102] Drying of the composition applied to the substrate is typically performed by heat treatment. The heating temperature is usually 50 to 140°C, preferably 60 to 120°C. An appropriate drying temperature should be set from the viewpoint of rapid and sufficient drying of the solvent and suppression of carbene generation from the diazirine compound. The heating time varies depending on the heating device, but when using a hot plate, it is usually 30 to 300 seconds, preferably 60 to 180 seconds, and when using a hot air oven, it is usually 5 to 60 minutes, preferably 10 to 30 minutes.

[0103] The film thickness (dry thickness) of the resin film is not particularly limited and can be adjusted as appropriate according to the size and aspect ratio of the pattern to be ultimately obtained. The film thickness can be adjusted by adjusting the concentration of non-volatile components in the composition or changing the coating method. The film thickness is, for example, 10 to 1000 nm, specifically 20 to 500 nm.

[0104] <Second step: Irradiation with active light or radiation> The exposure process is typically carried out by irradiating the resin film with active light or radiation. Preferred examples of active light or radiation include far ultraviolet light, extreme ultraviolet (EUV) light, electron beams, and the like. When irradiating with an electron beam as an active ray or radiation, the irradiation dose is, for example, 10 to 1000 μC / cm². 2 Specifically, 20-500 μC / cm² 2 This can be done. The acceleration voltage of the electron beam can be, for example, 10 to 200 keV, specifically 30 to 150 keV. When irradiating with far ultraviolet or EUV light, the irradiation dose is, for example, 0.1 to 500 mJ / cm². 2 Specifically, 1-250 mJ / cm² 2 It can be done this way.

[0105] When irradiating a resin film with far-ultraviolet or EUV light to "pattern" it, the irradiation is usually done through a photomask.

[0106] The alkali solubility of the resin composition of this embodiment is appropriately adjusted. Therefore, the resin composition of this embodiment is preferably used for forming fine patterns using electron beams or EUV light.

[0107] If necessary, the resin film may be heated after irradiation with active light or radiation and before the third step (development) (post-exposure baking). The temperature is, for example, 70 to 150°C, preferably 70 to 120°C. The time is usually 30 to 300 seconds, preferably 50 to 180 seconds, for example, when using a hot plate.

[0108] Typically, post-exposure heating is performed in chemically amplified compositions to promote a chain reaction mediated by acids generated by irradiation with active light or radiation. On the other hand, the resin composition of this embodiment is not necessarily chemically amplified. Specifically, the resin composition containing the aforementioned diazirine compound is not necessarily chemically amplified. For this reason, patterning is possible in principle even without post-exposure heating. However, post-exposure heating may be effective in some cases to promote the decomposition of the diazirine compound and / or to promote the bond formation between the polymer and the diazirine compound.

[0109] <Third step: Development> A pattern can be obtained by developing a resin film that has been irradiated with active light or radiation. Typically, development can be performed using a developer solution by methods such as immersion, paddle, or rotary spray. Development usually involves the dissolution and removal of unexposed areas of the photosensitive resin film, resulting in a negative-type pattern.

[0110] Typically, alkaline aqueous solutions are used as developing solutions. Specific examples of alkaline aqueous solutions include (i) inorganic alkaline aqueous solutions such as sodium hydroxide, sodium carbonate, sodium silicate, and ammonia; (ii) organic amine aqueous solutions such as ethylamine, diethylamine, triethylamine, and triethanolamine; and (iii) aqueous solutions of quaternary ammonium salts such as tetramethylammonium hydroxide and tetrabutylammonium hydroxide. As the developing solution, an aqueous solution of tetramethylammonium hydroxide is particularly preferred. The concentration of tetramethylammonium hydroxide is preferably 0.1 to 10% by mass, more preferably 0.5 to 5% by mass.

[0111] Furthermore, as the developer, a developer containing an organic solvent, specifically a developer whose main component is an organic solvent (where 50% or more by mass of the developer is an organic solvent), can also be used. Examples of organic solvents that can be used in the developer include ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, hydrocarbon solvents, etc.

[0112] A resin pattern can be obtained on the substrate through the third step. After development, it is preferable to wash the resin pattern and the substrate with a rinsing solution. Ultrapure water or alcohol are suitable as the rinsing solution.

[0113] <Fourth step: Etching> The substrate can be processed by etching the substrate on which the resin pattern obtained in the first to third steps described above has been formed. Specifically, by applying an etching gas to the substrate on which the resin pattern has been formed, a pattern can be formed in the areas of the substrate where the resin pattern has not yet been formed. In other words, the resin pattern functions as a "resist pattern" that prevents the substrate from being processed during etching. Etching can be done by wet etching, but dry etching is usually used because it makes it easier to perform microfabrication. The specific etching conditions and usable etching gases should be appropriately modified and optimized according to the structure and specifications of the electronic device to be manufactured.

[0114] <Fifth step: Removal> The resin pattern remaining after the fourth step (etching) is usually removed with a resist stripping solution. Furthermore, any residue generated by etching can be removed using an etching residue removal solution. As the resist stripping solution and etching residue removal solution, known solutions can be used as appropriate.

[0115] <Other processes> In the manufacture of electronic devices, various other processes besides those mentioned above may be carried out, such as ion implantation processes, bump electrode formation processes, and rewiring formation processes.

[0116] Although embodiments of the present invention have been described above, these are merely examples, and various other configurations can be adopted. Furthermore, the present invention is not limited to the embodiments described above, and modifications, improvements, etc., within the scope that can achieve the objectives of the present invention are included in the present invention. [Examples]

[0117] Embodiments of the present invention will be described in detail based on examples and comparative examples. It should be noted that the present invention is not limited to these examples.

[0118] (Example 1) <Synthesis of copolymer (P)> 39.22 g (0.4 mol) of maleic anhydride (hereinafter also referred to as MA) and 109.68 g (0.8 mol) of the compound shown in the following formula (hereinafter also referred to as HFANB) were placed in a separable flask. Next, 317.72 g of anisole was added to the separable flask to dissolve each component and prepare a solution.

[0119] [ka]

[0120] The resulting solution was heated to 130°C, and 4.07 g of 2,2'-azobis(2,4,4-trimethylpentane) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., VR-110) was added as a polymerization initiator. Next, nitrogen was passed through to remove oxygen, and MA and HFANB were polymerized at 130°C for 6 hours to prepare a polymerization solution.

[0121] After allowing the obtained polymerization solution to cool to room temperature, it was added dropwise to heptane six times the mass of the reaction solution to precipitate a white solid. The obtained white solid was washed with water and then dried overnight in a vacuum dryer at 80°C to obtain 65.90 g of copolymer (P) containing constituent units derived from MA and constituent units derived from HFANB.

[0122] <Polymer synthesis> In a separable flask, 19.00 g of copolymer (P) (calculated as 0.053 mol in MA equivalent based on the initial amount of copolymer (P)), 4.81 g of cyclohexylamine (0.049 mol), and 1.76 g of p-aminophenol (0.016 mol) were placed. Next, 134.93 g of γ-butyrolactone and 23.81 g of toluene were added to the separable flask to dissolve each component and prepare a solution.

[0123] 0.33 g of 4-aminopyridine was added to the separable flask containing the obtained solution, a Dean-Stark tube was attached, and the oxygen was removed by aeration with nitrogen. The reaction was then carried out at 100°C for 2 hours. Next, 1.03 g of p-toluenesulfonic acid monohydrate was added to the separable flask, the oxygen was removed by aeration with nitrogen, and the reaction was carried out at 170°C for 18 hours to prepare the reaction solution.

[0124] After allowing the obtained reaction solution to cool to room temperature, it was added dropwise to 15 times the mass of water to precipitate a yellowish-white solid. The obtained yellowish-white solid was washed with water and then dried overnight in a vacuum dryer at 80°C to obtain 20.32 g of the polymer of Example 1, which contains the constituent units (a-1), (b-1), and (b-2) shown in the following formulas.

[0125] [ka]

[0126] [ka]

[0127] [ka]

[0128] (Comparative Example 1) HFANB (10.32 g, 0.038 mol), CyMI (4.03 g, 0.023 mol) represented by the following formula, and HPMI (2.84 g, 0.015 mol) represented by the following formula were weighed out. These were added to polymerization solvents (35.07 g anisole and 28.06 g γ-butyrolactone) to obtain monomer solutions. The obtained monomer solutions were heated to 150°C under a nitrogen atmosphere with stirring.

[0129] [ka]

[0130] [ka]

[0131] 0.38 g of 2,2'-azobis(2,4,4-trimethylpentane) (Fujifilm Wako Pure Chemical Industries, Ltd., VR-110) was added to a solvent (anisole, 7.01 g) to obtain a polymerization initiator solution. The obtained polymerization initiator solution was added to a monomer solution heated to 150°C under a nitrogen atmosphere to obtain a polymerization solution. The amount of polymerization initiator was 0.02 mol per 1 mol of monomer. The amount of monomer added and the amount of polymerization solution were adjusted so that the non-volatile components of the monomer and polymerization initiator amounted to approximately 20% by mass.

[0132] The obtained polymerization solution was stirred at 150°C under a nitrogen atmosphere for 1.5 hours. Next, the polymerization solution was allowed to cool to room temperature, and then added dropwise to 0.5 times the mass of heptane to remove anisole and unreacted HFANB from the polymerization solution. Next, the polymerization solution was added dropwise to 10 times the mass of water to precipitate a yellowish-white solid. The obtained yellowish-white solid was filtered, washed with water, and then dried overnight in a vacuum dryer at 80°C to obtain 5.38 g of the polymer of Comparative Example 1 containing the above constituent units (a-1), (b-1), and (b-2).

[0133] (Example 2) <Synthesis of copolymer (Q)> 22.06 g (0.023 mol) of maleic anhydride (MA), 30.85 g (0.011 mol) of HFANB, and 20.06 g (0.011 mol) of HexNB, represented by the formula below, were placed in a separable flask. Next, 225.78 g of anisole was added to the separable flask to dissolve each component and prepare a solution.

[0134] [ka]

[0135] The resulting solution was heated to 130°C, and 2.29 g of 2,2'-azobis(2,4,4-trimethylpentane) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., VR-110) was added as a polymerization initiator. Next, nitrogen was passed through to remove oxygen, and MA, HFANB, and HexNB were polymerized at 130°C for 6 hours to prepare a polymerization solution.

[0136] After allowing the obtained polymerization solution to cool to room temperature, it was added dropwise to heptane six times the mass of the reaction solution to precipitate a white solid. The obtained white solid was washed with water and then dried overnight in a vacuum dryer at 80°C to obtain 38.06 g of copolymer (Q) containing constituent units derived from MA, HFANB, and HexNB.

[0137] <Polymer synthesis> 12.00 g of copolymer (Q) (calculated as 0.039 mol in MA based on the initial amount of copolymer (Q)) and 12.8 g (0.118 mol) of p-aminophenol were placed in a separable flask. Next, 140.73 g of γ-butyrolactone and 24.84 g of toluene were added to the separable flask to dissolve each component and prepare a solution.

[0138] 0.24 g of 4-aminopyridine was added to the separable flask containing the obtained solution, a Dean-Stark tube was attached, and the oxygen was removed by aeration with nitrogen. The reaction was then carried out at 100°C for 2 hours. Next, 0.75 g of p-toluenesulfonic acid monohydrate was added to the separable flask, the oxygen was removed by aeration with nitrogen, and the reaction was carried out at 170°C for 18 hours to prepare the reaction solution.

[0139] After allowing the obtained reaction solution to cool to room temperature, it was added dropwise to 15 times the mass of water to precipitate a white solid. The obtained white solid was washed with water and then dried overnight in a vacuum dryer at 80°C to obtain 13.75 g of the polymer of Example 2, which contains the above-mentioned constituent unit (a-1), the constituent unit (a-2) shown in the following formula, the above-mentioned constituent unit (b-1), and the constituent unit (c) shown in the following formula.

[0140] [ka]

[0141] [ka]

[0142] (Comparative Example 2) Except for using HFANB (1.71 g, 0.006 mol), HexNB (10.03 g, 0.056 mol), and HPMI (3.94 g, 0.021 mol) as raw materials, the same procedure as in Comparative Example 1 was used to obtain 3.06 g of the polymer of Comparative Example 2 containing the above constituent units (a-1), (a-2), and (b-1).

[0143] (Example 3) As raw materials, 19.00 g of copolymer (P) (calculated as 0.053 mol in MA equivalent from the amount of copolymer (P) used), 4.54 g of cyclohexylamine (0.046 mol), and 2.65 g of p-aminophenol (0.024 mol) were added. Next, 133.42 g of γ-butyrolactone and 23.54 g of toluene were added to a separable flask to dissolve each component and prepare a solution. The polymer synthesis method thereafter was the same as in Example 1, and 21.07 g of the polymer of Example 3, containing the above constituent units (a-1), (b-1), (b-2), and (c), was obtained.

[0144] (Comparative Example 3) Except for using HFANB (10.28 g, 0.038 mol), CyMI (3.36 g, 0.019 mol), and HPMI (3.55 g, 0.019 mol) as raw materials, the same procedure as in Comparative Example 1 was used to obtain 5.28 g of the polymer of Comparative Example 3 containing the above constituent units (a-1), (b-1), and (b-2).

[0145] <Composition> The ratios of each constituent unit in the polymers of Examples 1 and 3 and Comparative Examples 1 and 3 are as follows: 1 The measurements were performed using 1H-NMR under the following conditions, and the ratio of the integral values ​​of the peaks originating from each constituent unit was determined. The ratios of each constituent unit in the polymers of Example 2 and Comparative Example 2 were: 13 Measurements were performed using 1C-NMR under the following conditions, and the results were determined by the ratio of the integral values ​​of the peaks originating from each constituent unit. The results are shown in Table 1. < 1 H-NMR measurement conditions > ·Measuring device: JEOL Ltd., JNM-ECZ-400S ·Resonance frequency: 400MHz • Measurement nucleus: 1 H • Measurement method: NNE measurement (inverse gate decoupling method) Pulse width: 6.99 μsec • Pulse repetition waiting time: 5 seconds • Total number of times: 8 ·Measurement temperature: room temperature • Measurement solvent: DMSO-d6 (deuterated dimethyl sulfoxide) • Sample concentration: 3% (w / v) < 13 CNMR measurement conditions > ·Measuring device: JEOL Ltd., JNM-ECZ-400S ·Resonance frequency: 100MHz • Measurement nucleus: 13 C • Measurement method: NNE measurement (inverse gate decoupling method) Pulse width: 11.8 μsec • Pulse repetition waiting time: 2 seconds • Total number of times: 8192 ·Measurement temperature: room temperature • Measurement solvent: DMSO-d6 (deuterated dimethyl sulfoxide) • Sample concentration: 20% (w / v) • Relaxation agent: Cr(AcAc)3 (chromium(III) acetylacetonate) • Amount of relaxation reagent added: 10 parts by mass per 100 parts by mass of polymer

[0146] <Imidification rate> Regarding the polymer in each example, 1 Using H-NMR, the above 1 Measurements were performed under the same conditions as for 1H-NMR, and the ratios of constituent units (B) and (C) were determined. The imidization rate was then calculated using the following formula. The results are shown in Table 1. Imidization rate (%) = {1 - ratio of constituent unit (C) / (ratio of constituent unit (B) + ratio of constituent unit (C))} × 100

[0147] <W H / W P > For each example and comparative example, 0.60 g of polymer and 1.40 g of propylene glycol monomethyl ether acetate were placed in a screw-cap vial with an inner diameter of 14.5 mm, a body diameter of 27 mm, and a height of 55 mm. The polymer was then dissolved in the propylene glycol monomethyl ether acetate to prepare the solution. Next, while stirring the solution at a rotation speed of 200 rpm using a magnetic stirrer (Tokyo Rikakikai Co., Ltd., RCX-1100S) and a stirring bar with an outer diameter of 5 mm and a total length of 15 mm, 0.05 mL of heptane was added dropwise to the solution using a micropipette until the solution became cloudy. The mass W of heptane added was measured. H (g) was measured using a mass spectrometer (Mettler Toledo, MS304S). At this time, the turbidity of the solution was confirmed by observing whether the solution remained turbid for 10 seconds after the addition of heptane dropwise. Heptane was added dropwise at 20-second intervals. Solution preparation, stirring of the solution, addition of heptane dropwise, and heptane mass measurement were all performed at a temperature of 23°C, humidity of 50% RH, and atmospheric pressure. Next, the mass of propylene glycol monomethyl ether acetate was measured. P When (g) is used, W H / W P The value was calculated. The results are shown in Table 1. In Comparative Example 2, the solution was cloudy before heptane was added dropwise, so W H / W P The value was set to 0.00.

[0148] <Mw、Mn、Mw / Mn> The weight-average molecular weight (Mw), number-average molecular weight (Mn), and Mw / Mn values ​​for each example and comparative example polymer were calculated using GPC (Gel Permeation Chromatography) to measure the molecular weight distribution curve under the following measurement conditions, and then using the polystyrene equivalent values ​​obtained from the calibration curve of standard polystyrene (PS) obtained by GPC measurement. The results are shown in Table 1. Measurement equipment: Tosoh Corporation, gel permeation chromatography system HLC-8320GPC EcoSEC Column: TSK-GEL Supermultipore HZ-M manufactured by Tosoh Corporation Detector: RI detector for liquid chromatogram Measurement temperature: 40℃ Solvent: THF Pump flow rate: 0.350 mL / min Sample concentration: 2.5 mg / mL Sample injection volume: 10 μL

[0149] <Alkali dissolution rate of polymers> The polymers of each example and comparative example were dissolved in propylene glycol monomethyl ether acetate (PGMEA) to prepare 10% by mass solutions. The resulting solutions were then spin-coated onto silicon wafers at 1500 rpm for 30 seconds under conditions of 23°C, 50% RH humidity, and air. The solvent was dried at 80°C for 60 seconds to obtain resin films with a thickness T of 100 nm. The obtained resin films, along with the silicon wafers, were then immersed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide at 23°C, and the time t (sec) until the film thickness reached 0 nm was measured. The alkali dissolution rate of the polymer (nm / sec) was then calculated using the T / t ratio. The results are shown in Table 1.

[0150] <Preparation of resin composition> For Examples 1-2 and Comparative Examples 1-2, the polymer and a diazirine compound represented by the following formula (BLD-201, manufactured by Xlynx Materials Inc.) were dissolved in propylene glycol monomethyl ether acetate (PGMEA), and the mixture was filtered through a polytetrafluoroethylene (PTFE) syringe filter with a pore size of 0.22 μm to prepare the resin compositions of Examples 1-2 and Comparative Examples 1-2. For Example 3 and Comparative Example 3, the polymer and a diazirine compound (BWX-202, manufactured by Xlynx Materials Inc.) were dissolved in propylene glycol monomethyl ether acetate (PGMEA), and the mixture was filtered through a polytetrafluoroethylene (PTFE) syringe filter with a pore size of 0.22 μm to prepare the resin compositions for Example 3 and Comparative Example 3. Here, the structure of BXW-202 is encompassed by the general formula (BB) shown above.

[0151] The amount of diazirine compound was 20 parts by mass per 100 parts by mass of polymer. For the evaluation of the non-volatile component concentration, which will be described later, the concentration of non-volatile components was set to 10% by mass. For the evaluation of the resolution, the amount of PGMEA was adjusted so that the concentration of non-volatile components was 3% by mass.

[0152] [ka]

[0153] <Alkali dissolution rate of resin composition> For each example and comparative example, the resin composition was applied to a silicon wafer by spin coating at 1500 rpm for 30 seconds under conditions of 23°C, 50% RH humidity, and air. The solvent was then dried at 80°C for 60 seconds to obtain a resin film with a thickness T of 100 nm. Next, the obtained resin film, along with the silicon wafer, was immersed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23°C. The time t (sec) until the film thickness reached 0 nm was measured, and the alkali dissolution rate (nm / sec) of the resin composition was calculated by T / t. The results are shown in Table 1.

[0154] <Resolution> For each example and comparative example, the resin composition was applied to a silicon wafer by spin coating at 1500 rpm for 30 seconds under conditions of 23°C, 50% RH humidity, and air. A resin film with a thickness of 100 nm was then formed by drying the solvent at 80°C for 60 seconds. Subsequently, for Example 1 and Comparative Example 1, the obtained resin film was treated with an accelerating voltage of 130 keV and an irradiation dose of 250 μC / cm². 2 In Example 2 and Comparative Example 2, the acceleration voltage was 130 keV and the irradiation dose was 400 μC / cm². 2 The silicon wafer was irradiated with an electron beam. Electron beam irradiation was selectively performed to form either a 50 nm line-and-space (L / S) pattern or a 100 nm line-and-space (L / S) pattern. Next, the resin film, along with the silicon wafer, was immersed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23°C. The development time was 60 seconds for Example 1 and Comparative Example 1, 5 seconds for Example 2 and Comparative Example 2, and 15 seconds for Example 3 and Comparative Example 3. The L / S pattern on the developed silicon wafer surface was then observed using an electron microscope (JEOL Ltd., JSM-IT700HR) at an acceleration voltage of 10.0 kV and a magnification of 50,000x, and the resolution of the resin composition was evaluated according to the following criteria. The resist line width roughness (LWR) in the 100 nm L / S pattern was also measured. The results are shown in Table 1. A: 50 nmL / S and 100 nmL / S patterns were confirmed, and no bridges or breaks were observed. B: The 100 nm / S pattern can be confirmed and no bridges or breaks are observed, but the 50 nm / S pattern can either not be confirmed or bridges or breaks are observed. C: The 50 nm / S pattern and the 100 nm / S pattern are either not detectable or bridges or breaks are observed.

[0155] [Table 1]

Claims

1. It includes a constituent unit (A) represented by the following formula (NB) and a constituent unit (B) represented by the following formula (MI), W can be calculated using the method below. Ｈ / W Ｐ A polymer whose value is 0.40 or higher. (method) Dissolve 0.60 g of the polymer in 1.40 g of propylene glycol monomethyl ether acetate to prepare a solution. Then, while stirring the solution at 200 rpm, add 0.05 mL of heptane dropwise to the solution until the solution becomes cloudy. The mass W of the heptane added is then measured. Ｈ (g) is measured. At this time, the turbidity of the solution is confirmed by observing whether the solution remains turbid for 10 seconds after the addition of heptane. The heptane is added at 20-second intervals. The preparation of the solution, stirring of the solution, dropping of the heptane, and measurement of the heptane's mass are all carried out at a temperature of 23°C, a humidity of 50% RH, and atmospheric pressure. Then, the mass of the propylene glycol monomethyl ether acetate is measured by W Ｐ When (g) is used, W Ｈ / W Ｐ Calculate the value. 【Chemistry 1】 (In the above formula (NB), a １ is 0, 1 or 2, and R １ , R ２ , R ３ and R ４ each independently represents a hydrogen atom, a hydroxy group, a halogen atom, or a hydrocarbon group having 1 to 30 carbon atoms in which any hydrogen atom may be substituted with a -C(CF ３ )( ２ OH group, a hydroxy group or a halogen atom.) 【Chemistry 2】 (In the above formula (MI), X represents a hydrogen atom or a monovalent organic group.)

2. The polymer according to claim 1, wherein the content of the constituent unit (A) in the polymer is 40 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%.

3. The polymer according to claim 1 or 2, wherein the content of the constituent unit (B) in the polymer is 40 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%.

4. The aforementioned constituent unit (A) is R in the formula (NB). １ , R ２ , R ３ and R ４ At least one of them is -C(CF ３ ) ２ The polymer according to claim 1 or 2, comprising a constituent unit (A-1) containing an OH group.

5. The aforementioned constituent unit (A) is R in the formula (NB). １ , R ２ , R ３ and R ４ All of the above are -C(CF ３ ) ２ It does not contain an OH group, R １ , R ２ , R ３ and R ４ The polymer according to claim 4, further comprising a constituent unit (A-2) in which at least one of the constituent units contains a hydrocarbon group having 1 to 30 carbon atoms.

6. In the aforementioned structural unit (A), R １ , R ２ , R ３ and R ４ The polymer according to claim 1 or 2, wherein none of the members contain an acid-unstable group.

7. The polymer according to claim 1 or 2, wherein the constituent unit (B) includes a constituent unit (B-1) in formula (MI) in which X contains an alkali-soluble group.

8. The polymer according to claim 7, wherein X contains a phenolic hydroxyl group.

9. The polymer according to claim 7, wherein the constituent unit (B) further comprises a constituent unit (B-2) in formula (MI) in which X does not contain an alkali-soluble group and contains a cyclic aliphatic group.

10. The polymer according to claim 1 or 2, further comprising a constituent unit (C) represented by the following formula. 【Transformation 3】 (In the above formula, R represents a hydrogen atom or a monovalent organic group.)

11. The polymer according to claim 1 or 2, wherein the weight-average molecular weight is 500 or more and 10,000 or less.

12. The polymer according to claim 1 or 2, wherein the value of Mw / Mn is 1.10 or more and 2.00 or less, when Mw is the weight-average molecular weight and Mn is the number-average molecular weight.

13. A polymer according to claim 1 or 2, used in a resin composition for resists.

14. A method for producing the polymer described in claim 1 or 2, A process to obtain a copolymer by polymerizing a monomer containing a norbornene skeleton with maleic anhydride, A step of imidizing the structural units derived from maleic anhydride in the copolymer, A method for producing polymers that include the following features.

15. A resin composition comprising the polymer according to claim 1 or 2.

16. The resin composition according to claim 15, further comprising one or more solvents selected from the group consisting of ketone solvents, ester solvents, ether solvents, alcohol solvents, lactone solvents, and carbonate solvents.

17. The resin composition according to claim 15, further comprising a diazirine compound containing two or more diazirine structures in one molecule.

18. A step of applying the resin composition according to claim 15 onto a substrate to form a resin film, The process involves irradiating the resin film with active light or radiation, The process of developing the resin film to obtain a substrate on which a resin pattern is formed, A pattern formation method including the following.

19. A step of etching a substrate on which a resin pattern obtained by the pattern forming method described in claim 18 has been formed, A step of removing the resin pattern remaining on the substrate, A method for manufacturing an electronic device that includes [a specific component].

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