Polymers, resin compositions, pattern forming methods, and methods for manufacturing electronic devices

Abstract

The present invention provides a polymer that can improve the performance balance between etching resistance and the resist sensitivity of the resulting resin composition. [Solution] A polymer comprising a constituent unit (A) represented by the following formula (NB) and an N-substituted maleimide constituent unit (B), wherein the P value determined by the following formula is 3.20 or less. P = (Total number of atoms per polymer molecule) / {(Number of carbon atoms per polymer molecule) - (Number of oxygen atoms per polymer molecule)} TIFF2026102338000022.tif58153

Description

[Technical Field]

[0001] The present invention relates to polymers, resin compositions, pattern forming methods, and methods for manufacturing 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 Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2002-145962 [Overview of the project] [Problems that the invention aims to solve]

[0005] The present invention provides a polymer that can improve the performance balance between etching resistance and the resist sensitivity of the resulting resin composition, as well as a resin composition with improved performance balance between etching resistance and resist sensitivity, a pattern forming method, and a method for manufacturing an electronic device. [Means for solving the problem]

[0006] The inventors diligently conducted research to solve the above problems. As a result, they discovered that a polymer containing a norbornene skeleton represented by a specific formula (A) and a maleimide skeleton represented by a specific formula (B), and having a P value of 3.20 or less, calculated by the formula P = (total number of atoms per polymer molecule) / {(number of carbon atoms per polymer molecule) - (number of oxygen atoms per polymer molecule)}, can improve the balance of etching resistance and the resist sensitivity of the resulting resin composition, thus completing the present invention.

[0007] According to the present invention, the following polymers, resin compositions, pattern forming methods, and methods for manufacturing electronic devices are provided.

[0008] [1] It includes a constituent unit (A) represented by the following formula (NB) and a constituent unit (B) represented by the following formula (MI), A polymer whose P value, calculated using the following formula, is 3.20 or less. P = (Total number of atoms per polymer molecule) / {(Number of carbon atoms per polymer molecule) - (Number of oxygen atoms per polymer molecule)} [Chemical formula] (In the above formula (NB), a1 is 0, 1 or 2, and R 1 , R 2 , R 3 and R 4 each independently represent a hydrogen atom, a hydroxy group, a halogen atom, or an organic group having 1 to 30 carbon atoms which may contain one or more selected from the group consisting of a hydroxy group, an ether bond, a halogen atom and an aryl group.) [Chemical formula] (In the above formula (MI), X represents a hydrogen atom or a monovalent organic group.) [2] In the above formula (NB), at least one of R 1 , R 2 , R 3 and R 4 contains a phenolic hydroxy group, the polymer according to [1]. [3] In the above formula (NB), at least one of R 1 , R 2 , R 3 and R 4 contains a structure represented by the following formula, the polymer according to [2]. [Chemical formula] (In the above formula, * represents a bond, Y represents a linear or branched alkylene group having 1 to 10 carbon atoms, and R 5 , R 6 , R 7 , R 8 and R 9 each independently represent a hydrogen atom, a hydroxy group or a linear or branched alkyl group having 1 to 10 carbon atoms which may contain an ether bond, and at least one of R 5 , R 6 , R 7 , R 8 and R 9 represents a hydroxy group.) [4] The polymer according to any one of [1] to [3], wherein the constituent unit (B) comprises a constituent unit (B-1) in formula (MI) in which X contains an alkali-soluble group. [5] The polymer according to [4], wherein X contains a phenolic hydroxyl group. [6] The polymer according to [4] or [5], wherein the content of the constituent unit (B-1) in the polymer is 1 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%. [7] The polymer according to any one of [4] to [6], wherein the constituent unit (B) further comprises a constituent unit (B-2) in which X in formula (MI) does not contain an alkali-soluble group and contains one or more selected from the group consisting of cyclic aliphatic groups and aryl groups. [8] The polymer according to [7], wherein the content of the constituent unit (B-2) in the polymer is 10 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%. [9] The polymer according to any one of [1] to [8], wherein the content of the constituent unit (A) in the polymer is 10 mol% or more and 60 mol% or less, when the total content of all constituent units in the polymer is 100 mol%.

[10] The polymer according to any one of [1] to [9], wherein the content of the constituent unit (B) in the polymer is 40 mol% or more and 90 mol% or less, when the total content of all constituent units in the polymer is 100 mol%.

[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 polymer according to any of [1] to

[13] , wherein the etching rate E1 measured by the method 1 below is 190 nm / min or less. (Method 1) The polymer is dissolved in propylene glycol monomethyl ether acetate and filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 μm to prepare a polymer solution with a non-volatile component concentration of 10% by mass. Next, the polymer solution is spin-coated onto a silicon wafer to a thickness of 0.5 μm. Then, the polymer solution is dried at 80°C for 1 minute and cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film is plasma-etched under the following conditions, and the decrease in film thickness (nm) of the resin film before and after plasma etching is measured using a stylus-type step meter. Next, the decrease in film thickness is divided by the etching time to calculate the etching rate E1 (nm / min). Etchant: CF4 gas (100 sccm), O2 gas (10 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

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

[14] , wherein the etching rate E2 measured by method 2 below is 95 nm / min or less. (Method 2) The polymer is dissolved in propylene glycol monomethyl ether acetate and filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 μm to prepare a polymer solution with a non-volatile component concentration of 10% by mass. Next, the polymer solution is spin-coated onto a silicon wafer to a thickness of 0.5 μm. Then, the polymer solution is dried at 80°C for 1 minute and cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film is plasma-etched under the following conditions, and the decrease in film thickness (nm) of the resin film before and after plasma etching is measured using a stylus-type step meter. Next, the decrease in film thickness is divided by the etching time to calculate the etching rate E2 (nm / min). Etchant: CF4 gas (100 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

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

[15] .

[17] The resin composition according to

[16] 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.

[18] The resin composition according to

[16] or

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

[19] A resin composition according to any one of

[16] to

[18] , wherein the alkali dissolution rate measured by method 3 below is 0.1 nm / sec or more and 50.0 nm / sec or less. (Method 3) The resin composition is spin-coated onto a silicon wafer, and the solvent is dried to obtain a resin film with a thickness T of 100 nm. Next, the 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. Then, the alkali dissolution rate (nm / sec) is calculated by calculating T / t.

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

[16] to

[19] 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. [twenty one]

[20] A step of etching a substrate on which the resin pattern described in

[20] 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]. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a polymer that can improve the balance between etching resistance and the resist sensitivity of the resulting resin composition, as well as a resin composition with improved balance between etching resistance and resist sensitivity, a pattern forming method, and a method for manufacturing 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. 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.

[0013] <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).

[0014] [ka]

[0015] In equation (NB), a1 is 0, 1, or 2, and R 1 , R 2 , R 3 and R 4 Each of these independently represents an organic group having 1 to 30 carbon atoms, which may contain one or more elements selected from the group consisting of a hydrogen atom, a hydroxyl group, a halogen atom, or a hydroxyl group, an ether bond, a halogen atom, and an aryl group.

[0016] [ka]

[0017] In formula (MI), X represents a hydrogen atom or a monovalent organic group.

[0018] In formula (NB), a1 is preferably 0 or 1, more preferably 0.

[0019] In equation (NB), R 1 , R2 , R 3 and R 4 Preferably, the organic group has 1 to 30 carbon atoms and may contain one or more selected from the group consisting of a hydrogen atom, a hydroxyl group, an ether bond, a halogen atom, and an aryl group; more preferably, the organic group has 1 to 20 carbon atoms and contains one or more selected from the group consisting of a hydrogen atom, a hydroxyl group, an ether bond, and an aryl group; and even more preferably, the organic group has 5 to 15 carbon atoms and contains one or more selected from the group consisting of a hydrogen atom, a hydroxyl group, an ether bond, and an aryl group.

[0020] 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 one or more selected from the group consisting of a cyclohexyl group, a phenyl group, and a phenol group.

[0021] The polymer of this embodiment has a P value of 3.20 or less, which can be calculated by the following formula. P = (Total number of atoms per polymer molecule) / {(Number of carbon atoms per polymer molecule) - (Number of oxygen atoms per polymer molecule)}

[0022] According to the inventors' research, they found that in a polymer containing a constituent unit containing a norbornene skeleton and a constituent unit containing a maleimide skeleton, there is a correlation between the P value and the performance balance between etching resistance and the resist sensitivity of the resulting resin composition. Based on the above findings, the inventors conducted further studies and discovered that in a polymer containing a norbornene skeleton represented by a specific formula (A) and a maleimide skeleton represented by a specific formula (B), the balance between etching resistance and the resist sensitivity of the resulting resin composition can be improved by setting the P value to 3.20 or less, thus completing the present invention.

[0023] The P value of the polymer in this embodiment is 3.20 or less, preferably 3.16 or less, more preferably 3.13 or less, even more preferably 3.10 or less, even more preferably 3.07 or less, even more preferably 3.04 or less, even more preferably 3.02 or less, even more preferably 3.00 or less, and even more preferably 2.98 or less, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition. The lower limit of the P value of the polymer in this embodiment is not particularly limited, but for example it may be 1.00 or more, 1.50 or more, 2.00 or more, 2.30 or more, 2.50 or more, or 2.60 or more.

[0024] From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, the P value of the polymer in this embodiment is preferably 1.00 to 3.20, more preferably 1.00 to 3.16, even more preferably 1.00 to 3.13, even more preferably 1.00 to 3.10, even more preferably 1.50 to 3.07, even more preferably 2.00 to 3.04, even more preferably 2.30 to 3.02, even more preferably 2.50 to 3.00, and even more preferably 2.60 to 2.98.

[0025] The P value of the polymer in this embodiment can be adjusted, for example, by appropriately selecting the type and content of each constituent unit contained in the polymer in this embodiment, as well as the manufacturing method.

[0026] From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, the polymer of this embodiment preferably comprises R in formula (NB). 1 , R 2 , R 3 and R 4 At least one of them contains a phenolic hydroxyl group, more preferably in formula (NB), R 1 , R 2 , R 3 and R 4At least one of them includes the structure shown by the following formula.

[0027] [ka]

[0028] In the above formula, * indicates a bond, Y indicates a linear or branched alkylene group having 1 to 10 carbon atoms, and R 5 , R 6 , R 7 , R 8 and R 9 Each independently represents a linear or branched alkyl group having 1 to 10 carbon atoms, which may contain a hydrogen atom, a hydroxyl group, or an ether bond, and R 5 , R 6 , R 7 , R 8 and R 9 At least one of them shows a hydroxyl group.

[0029] In the above formula, Y is preferably a linear alkylene group having 1 to 10 carbon atoms, more preferably a linear alkylene group having 1 to 6 carbon atoms, even more preferably a linear alkylene group having 1 to 4 carbon atoms, even more preferably a methylene group or an ethylene group, and even more preferably a methylene group.

[0030] In the above formula, R 5 , R 6 , R 7 , R 8 and R 9 From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, it is preferably a linear alkyl group having 1 to 10 carbon atoms containing a hydrogen atom, a hydroxyl group, or an ether bond; more preferably a linear alkyl group having 1 to 6 carbon atoms containing a hydrogen atom, a hydroxyl group, or an ether bond; even more preferably a linear alkyl group having 1 to 2 carbon atoms containing a hydrogen atom, a hydroxyl group, or an ether bond; and still more preferably a hydrogen atom, a hydroxyl group, or an -O-CH3 group.

[0031] In the above formula, R 5 , R 6 , R 7 , R 8 and R 9 From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, preferably there are 1 to 3 hydroxyl groups, more preferably 1 to 2 hydroxyl groups, and even more preferably 1 hydroxyl group.

[0032] In the above formula, R 5 and R 9 Preferably, it is a hydrogen atom. In the above formula, R 6 and R 8 This is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, which may contain a hydrogen atom or an ether bond. In the above formula, R 7 Preferably, it is a hydroxyl group.

[0033] In this embodiment, the constituent unit (B) preferably includes a constituent unit (B-1) in formula (MI) in which X contains an alkali-soluble group, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition.

[0034] In this embodiment, the constituent unit (B-1) preferably comprises one or more selected from the group consisting of phenolic hydroxyl groups and carboxyl groups, more preferably comprising a phenolic hydroxyl group, and even more preferably comprising a -C6H4-OH group, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition.

[0035] From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, the content of the constituent unit (B-1) in the polymer of this embodiment is preferably 1 mol% to 60 mol%, more preferably 5 mol% to 55 mol%, even more preferably 8 mol% to 50 mol%, even more preferably 10 mol% to 45 mol%, and even more preferably 11 mol% to 40 mol%, when the total content of all constituent units in the polymer is 100 mol%.

[0036] In this embodiment, the constituent unit (B) preferably further includes a constituent unit (B-2) in which, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition, X in formula (MI) does not contain an alkali-soluble group and contains one or more selected from the group consisting of cyclic aliphatic groups and aryl groups.

[0037] In this embodiment, the constituent unit (B-2) preferably comprises one or more selected from the group consisting of cyclopentyl, cyclohexyl, cyclooctyl, norbornyl, adamantyl, phenyl, tolyl, xylyl, biphenyl, and naphthyl groups, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition. More preferably, X comprises one or more selected from the group consisting of cyclohexyl and phenyl groups.

[0038] From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, the content of the constituent unit (B-2) in the polymer of this embodiment is preferably 10 mol% to 60 mol%, more preferably 20 mol% to 55 mol%, even more preferably 30 mol% to 50 mol%, and even more preferably 35 mol% to 45 mol%, when the total content of all constituent units in the polymer is 100 mol%.

[0039] From the viewpoint of further improving the balance between etching resistance and the resist sensitivity of the resulting resin composition, the content of constituent unit (A) in the polymer of this embodiment is preferably 10 mol% to 60 mol%, more preferably 15 mol% to 55 mol%, even more preferably 18 mol% to 52 mol%, and even more preferably 20 mol% to 50 mol%, when the total content of all constituent units in the polymer is 100 mol%.

[0040] In this embodiment, the content of constituent unit (B) in the polymer is preferably 40 mol% to 90 mol%, more preferably 45 mol% to 85 mol%, even more preferably 48 mol% to 82 mol%, and even more preferably 50 mol% to 80 mol%, when the total content of all constituent units in the polymer is 100 mol%, in order to further improve the balance between etching resistance and the resist sensitivity of the resulting resin composition.

[0041] In this embodiment, the ratio of each constituent unit in the polymer can be determined, for example, by measuring the amount of each residual monomer in the polymer using gas chromatography under the following conditions, and then assuming that the amount of monomer introduced into the polymer is the amount of monomer added minus the amount of residual monomer. ·GC device: GC-2030 (manufactured by Shimadzu Corporation) • Carrier gas: N2 • Detector: Flame ionization (FID) detector ·FID temperature: 300℃ • Column: SH-RXi-1HT (inner diameter 0.25, length 30 m, film thickness 0.25 μm, manufactured by Shimadzu GLC Co., Ltd.) • Evaporation chamber temperature: 210℃ Column flow rate: 0.98 mL / min • Column heating conditions: Hold at 50°C for 5 minutes, heat at 20°C / min up to 300°C, hold at 300°C for 10 minutes.

[0042] In this embodiment, the ratio of each constituent unit in the polymer is, for example, 1 H-NMR or 13The results can also be obtained by using 1C-NMR under the following conditions and calculating 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

[0043] <Molecular weight> The weight-average molecular weight of the polymer in this embodiment is preferably 500 to 10000, more preferably 800 to 8000, even more preferably 1000 to 7000, even more preferably 1200 to 6000, and even more preferably 1300 to 5000.

[0044] The number-average molecular weight of the polymer in this embodiment is preferably 500 to 10000, more preferably 600 to 7000, even more preferably 700 to 5000, even more preferably 800 to 4000, and even more preferably 900 to 3500.

[0045] 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 1.20 to 1.80, even more preferably 1.30 to 1.70, and even more preferably 1.35 to 1.60.

[0046] 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

[0047] <Alkali dissolution rate of polymers> The alkali dissolution rate of the polymer of this embodiment, as measured by the method described below, is preferably 5.0 nm / sec to 500.0 nm / sec, more preferably 10.0 nm / sec to 450.0 nm / sec, even more preferably 20.0 nm / sec to 400.0 nm / sec, and even more preferably 30.0 nm / sec to 350.0 nm / sec, from the viewpoint of further improving the performance balance between etching resistance and the resist sensitivity of the resulting resin composition. (method) The polymer is dissolved in propylene glycol monomethyl ether acetate (PGMEA), filtered through a polytetrafluoroethylene (PTFE) syringe filter with a pore size of 0.22 μm, and a polymer solution with a non-volatile component concentration of 10% by mass is prepared. Next, the polymer solution is spin-coated onto a silicon wafer, and the solvent is dried to obtain a resin film with a film thickness T of 100 nm. Then, the 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.

[0048] <Polymer etching rate E1> The etching rate E1 of the polymer of this embodiment, as measured by the method described below, is preferably 190 nm / min or less, more preferably 185 nm / min or less, even more preferably 180 nm / min or less, and even more preferably 175 nm / min or less, from the viewpoint of further improving etching resistance. The lower limit of the etching rate E1 is not particularly limited, but for example, it may be 50 nm / min or more, 100 nm / min or more, or 130 nm / min or more. (method) A polymer is dissolved in propylene glycol monomethyl ether acetate and filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 μm to prepare a polymer solution with a non-volatile component concentration of 10% by mass. The polymer solution is then spin-coated onto a silicon wafer to a thickness of 0.5 μm. The polymer solution is then dried at 80°C for 1 minute and cooled to room temperature to form a resin film on the silicon wafer. The resin film is then plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching is measured using a stylus-type step meter. The etching rate E1 (nm / min) is then calculated by dividing the film thickness reduction by the etching time. Etchant: CF4 gas (100 sccm), O2 gas (10 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0049] The etching rate E1 of the polymer of this embodiment, as measured by the method described above, is preferably 50 nm / min to 190 nm / min, more preferably 50 nm / min to 185 nm / min, even more preferably 100 nm / min to 180 nm / min, and even more preferably 130 nm / min to 175 nm / min, from the viewpoint of further improving etching resistance.

[0050] <Polymer etching rate E2> The etching rate E2 of the polymer of this embodiment, as measured by the method described below, is preferably 95 nm / min or less, more preferably 93 nm / min or less, and even more preferably 92 nm / min or less, from the viewpoint of further improving etching resistance. The lower limit of the etching rate E2 is not particularly limited, but for example, it may be 10 nm / min or more, 50 nm / min or more, or 75 nm / min or more. (method) A polymer is dissolved in propylene glycol monomethyl ether acetate and filtered through a polytetrafluoroethylene syringe filter with a pore size of 0.22 μm to prepare a polymer solution with a non-volatile component concentration of 10% by mass. Next, the polymer solution is spin-coated onto a silicon wafer to a thickness of 0.5 μm. Then, the polymer solution is dried at 80°C for 1 minute and cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film is plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching is measured using a stylus-type step meter. Finally, the etching rate E2 (nm / min) is calculated by dividing the film thickness reduction by the etching time. Etchant: CF4 gas (100 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0051] The etching rate E2 of the polymer of this embodiment, as measured by the method described above, is preferably 10 nm / min or more and 95 nm / min or less, more preferably 50 nm / min or more and 93 nm / min or less, and even more preferably 75 nm / min or more and 92 nm / min or less, from the viewpoint of further improving etching resistance.

[0052] <Application> The polymer of this embodiment is suitable for use in photosensitive resin compositions, and more preferably in resin compositions for resists, because it offers an improved balance of etching resistance and the resist sensitivity of the resulting resin composition. 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.

[0053] <Method for producing polymers> 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. The process may also include steps of polymerizing the monomer with maleic anhydride to obtain a copolymer, and imidizing the constituent units derived from maleic anhydride in the copolymer. Specific conditions for synthesis can be appropriately referenced from 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.

[0054] <Resin composition> The resin composition of this embodiment includes the polymer of this embodiment. The polymer of this embodiment has an improved balance of etching resistance and the resist sensitivity of the resulting resin composition; therefore, the resin composition of this embodiment has an improved balance of etching resistance and resist sensitivity.

[0055] <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.

[0056] 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.

[0057] 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.

[0058] <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 the action of active light or radiation.

[0059] 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.

[0060] <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.

[0061] 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, preferably, a diazirine compound containing two or more diazirine structures in one molecule is used, so 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.

[0062] 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.

[0063] The diazirine compound of this embodiment preferably includes 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.

[0064] [ka]

[0065] In general formula (b), R xrepresents a monovalent substituent, R represents a monovalent substituent if multiple Rs exist, n represents an integer from 0 to 4, and * represents a bond with another chemical structure.

[0066] The structures represented by general formula (b) 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 (b) where n is 0 and a structure represented by general formula (b) where n is 1 within a single molecule.

[0067] R x The monovalent substituent 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 that is generally recognized as an electron-withdrawing group in the field of organic chemistry. x Specifically, examples include alkyl fluorides, alkyl chlorides, -NO2, -CN, -CHO, -COR, -COOR, -COOH, -SO2R, -SO3H, etc. Here, R is a monovalent organic group, and specifically examples include alkyl groups, alkenyl groups, alkynyl groups, alkylidene groups, aryl groups, aralkyl groups, alkalil groups, cycloalkyl groups, alkoxy groups, heterocyclic groups, carboxyl groups, etc. From the viewpoint of ease of synthesis, cost, and sensitivity to electron beams or EUV light, electron-withdrawing groups R are preferred. x A fluorinated alkyl group is preferred, a perfluoroalkyl group is more preferred, and a trifluoromethyl group is even more preferred. From the perspective of prioritizing storage stability, for example, of a photosensitive resin composition, R x The monovalent substituent does not have to be an electron-withdrawing group. For example, R x R may be a hydrogen atom. As another example, x R 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 A hydrogen atom or an alkyl group is preferred, a hydrogen atom or a methyl group is more preferred, and a hydrogen atom is even more preferred. From the viewpoint of ease of synthesis / obtaining the diazirine compound, n is preferably 0.

[0068] The diazirine compound of this embodiment more preferably includes a structure represented by the following general formula (b1).

[0069] [ka]

[0070] 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).

[0071] 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.

[0072] 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.

[0073] The diazirine compound of this embodiment can specifically have a structure represented by the following general formula (BB).

[0074] [ka]

[0075] 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.

[0076] 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.

[0077] 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.

[0078] When L is a divalent linking group, L can specifically be a linear or branched alkylene group, an alicyclic group with two hydrogen atoms removed, an arylene group, -O-, -CO-, -COO-, -OCO-, -NH-, -NR- (where R is a monovalent organic group), -S-, -SO2-, or a group in which two or more of these groups are linked. Preferably, L is a linear or branched alkylene group, an arylene group, -O-, or a group in which two or more of these groups are linked. 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.

[0079] 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 directly covalently bonded to one A in the diazirine compound represented by general formula (BB), to an atom directly covalently bonded to another A, by following only the covalent bonds in L until reaching that atom (the endpoint). However, if A is a group represented by general formula (b1), the oxygen atom linked 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 A 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 components, the shortest definable length is adopted as the "length". For example, if the diazirine compound has three A components, 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.

[0080] 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.

[0081] 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.

[0082] 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.

[0083] 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.

[0084] <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.

[0085] <Alkali dissolution rate of resin composition> The alkali dissolution rate of the resin composition of this embodiment, as measured by the method described below, is preferably 0.1 nm / sec to 50.0 nm / sec, more preferably 0.5 nm / sec to 30.0 nm / sec, and even more preferably 0.8 nm / sec to 15.0 nm / sec, from the viewpoint of further improving the balance of etching resistance and resist sensitivity. (method) A resin composition is spin-coated onto a silicon wafer, and the solvent is dried to obtain a resin film with a thickness T of 100 nm. Next, the resin film, along with the silicon wafer, is immersed in a 2.38 mass% tetramethylammonium hydroxide aqueous solution at 23°C, and the time t (sec) until the film thickness becomes 0 nm is measured. Then, the alkali dissolution rate (nm / sec) is calculated by T / t.

[0086] <Etching rate of resin composition E3> The etching rate E3 of the resin composition of this embodiment, as measured by the method described below, is preferably 200 nm / min or less, more preferably 190 nm / min or less, even more preferably 180 nm / min or less, and even more preferably 170 nm / min or less, from the viewpoint of further improving etching resistance. The lower limit of the etching rate E3 is not particularly limited, but for example, it may be 50 nm / min or more, 100 nm / min or more, or 150 nm / min or more. (method) The resin composition is spin-coated onto a silicon wafer to a thickness of 0.5 μm. The resin composition is then dried at 80°C for 1 minute, and then cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film is heated at 120°C for 5 minutes to cure it. Then, the resin film is plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching is measured using a stylus-type step meter. Next, the reduction in film thickness is divided by the etching time to calculate the etching rate E3 (nm / min). Etchant: CF4 gas (100 sccm), O2 gas (10 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0087] The etching rate E3 of the resin composition of this embodiment, as measured by the method described above, is preferably 50 nm / min to 200 nm / min, more preferably 50 nm / min to 190 nm / min, even more preferably 100 nm / min to 180 nm / min, and even more preferably 150 nm / min to 170 nm / min, from the viewpoint of further improving etching resistance.

[0088] <Etching rate of resin composition E4> The etching rate E4 of the resin composition of this embodiment, as measured by the method described below, is preferably 95 nm / min or less, more preferably 90 nm / min or less, and even more preferably 87 nm / min or less, from the viewpoint of further improving etching resistance. The lower limit of the etching rate E4 is not particularly limited, but for example, it may be 10 nm / min or more, 50 nm / min or more, or 75 nm / min or more. (method) The resin composition is spin-coated onto a silicon wafer to a thickness of 0.5 μm. The resin composition is then dried at 80°C for 1 minute, and then cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film is heated at 120°C for 5 minutes to cure it. Then, the resin film is plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching is measured using a stylus-type step meter. Next, the etching rate E4 (nm / min) is calculated by dividing the reduction in film thickness by the etching time. Etchant: CF4 gas (100 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0089] The etching rate E4 of the resin composition of this embodiment, as measured by the method described above, is preferably 10 nm / min or more and 95 nm / min or less, more preferably 50 nm / min or more and 90 nm / min or less, and even more preferably 75 nm / min or more and 87 nm / min or less, from the viewpoint of further improving etching resistance.

[0090] <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.

[0091] 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. Examples of electronic devices in this embodiment include semiconductor devices such as semiconductor chips and semiconductor packages, and printed circuit boards.

[0092] The following will explain these processes in detail.

[0093] <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.

[0094] The method for forming the resin film is not particularly limited. In the field of manufacturing electronic devices, spin 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 method, etc. may also be used.

[0095] Drying of the composition applied on 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 may be set from the viewpoints 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. When using a hot plate, it is usually 30 to 300 seconds, preferably about 60 to 180 seconds. When using a hot air oven, it is usually 5 to 60 minutes, preferably about 10 to 30 minutes.

[0096] The film thickness (dry thickness) of the resin film is not particularly limited and may be appropriately adjusted according to the size and aspect ratio of the pattern to be finally obtained. The film thickness can be adjusted by adjusting the concentration of the non-volatile component in the composition, changing the coating method, etc. The film thickness is, for example, 10 to 1000 nm, specifically 20 to 500 nm.

[0097] <Second step: Irradiation with actinic rays or radiation> The exposure process is usually performed by irradiating the resin film with actinic rays or radiation. Preferred examples of the actinic rays or radiation include far ultraviolet rays, extreme ultraviolet rays (EUV light), electron beams, etc. When irradiating with an electron beam as the actinic rays or radiation, the irradiation dose is, for example, 10 to 1000 μC / cm 2 specifically, 20 to 500 μC / cm 2 and can be set as such. 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 rays or EUV light, the irradiation dose is, for example, 0.1 to 500 mJ / cm 2 specifically, 1 to 250 mJ / cm 2 and can be set as such.

[0098] When irradiating a resin film with far-ultraviolet or EUV light to "pattern" it, the irradiation is usually done through a photomask.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] <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.

[0103] 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.

[0104] 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.

[0105] 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.

[0106] <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.

[0107] <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.

[0108] <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.

[0109] 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]

[0110] 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.

[0111] <Preparing the monomers> The following monomers were prepared.

[0112] [ka]

[0113] (Example 1) <Polymer synthesis (manufacturing)> The polymer of Example 1 was synthesized (manufactured) by the following procedure. (1) EugOHNB (6.98 g, 30.3 mmol), PhMI (6.82 g, 39.4 mmol), and HPMI (5.73 g, 30.3 mmol) were weighed out. These were added to polymerization solvent (23.38 g of cyclopentanone and 5.00 g of 2-heptanone). The monomer solution was then heated to 130°C under a nitrogen atmosphere with stirring to obtain a monomer polymerization solution. (2) As a polymerization initiator, 2,2'-azobis(2,4,4-trimethylpentane) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., VR-110, 0.51 g, 2.00 mmol) was added to the polymerization solvent (anisole, 18.38 g) to obtain a polymerization initiator solution. Next, the polymerization initiator solution was added to the monomer polymerization solution. The amount of polymerization initiator was 0.02 mol per 1 mol of monomer. Furthermore, the amount of monomer added and the amount of polymerization solvent were adjusted so that the non-volatile components of the monomer and polymerization initiator amounted to approximately 30% by mass. (3) The polymerization solvent containing the monomer and polymerization initiator described in (2) above was stirred under a nitrogen atmosphere at 130°C for 6 hours to obtain the reaction solution. (4) After heating and stirring were completed, the reaction solution was allowed to cool to room temperature. Next, the cooled reaction solution was added dropwise to four times the mass of heptane, and a white to yellow powder precipitated. The powder was filtered, washed with heptane, washed again with 2-isopropanol, and dried overnight in a vacuum dryer at 80°C to obtain the polymer of Example 1, which contains the constituent units (a-1) shown in the following formula, the constituent units (b-1) shown in the following formula, and the constituent units (b-2) shown in the following formula.

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] (Example 2) The polymer of Example 2 was obtained in the same manner as in Example 1, except that the types and ratios of monomers used were changed to EugOHNB (6.98 g, 30.3 mmol), CyMI (7.06 g, 39.4 mmol), and HPMI (5.73 g, 3.03 mmol), and the polymer of Example 2 containing the above constituent unit (a-1), the above constituent unit (b-1), and the constituent unit (b-3) shown by the following formula.

[0118] [ka]

[0119] (Example 3) The polymer of Example 3, containing the above-mentioned structural unit (a-1), structural unit (b-1), and structural unit (b-3), was obtained in the same manner as in Example 1, except that the types and ratios of monomers used were changed to EugOHNB (7.31 g, 31.7 mmol), CyMI (6.54 g, 36.5 mmol), and HPMI (6.01 g, 31.7 mmol).

[0120] (Comparative Example 1) A polymer of Comparative Example 1 was obtained in the same manner as in Example 1, except that the types and ratios of monomers used were changed to HFANB (62.7 g, 228 mmol), CyMI (61.5 g, 343 mmol), and H-MI (22.2 g, 229 mmol), and the polymer of Comparative Example 1 containing the constituent unit (c-1) shown in the following formula, the constituent unit (c-2) shown in the following formula, and the above constituent unit (b-3).

[0121] [ka]

[0122] [ka]

[0123] The ratio of each structural unit in the polymers of Examples 1-3 and Comparative Example 1 was determined by gas chromatography measurement of the amount of each residual monomer in the reaction solution after the completion of (3) above, under the following conditions. In other words, it was assumed that the amount of monomer introduced into the polymer was the amount of monomer added minus the amount of residual monomer. The results are shown in Table 1. ·GC device: GC-2030 (manufactured by Shimadzu Corporation) • Carrier gas: N2 • Detector: Flame ionization (FID) detector ·FID temperature: 300℃ • Column: SH-RXi-1HT (inner diameter 0.25, length 30 m, film thickness 0.25 μm, manufactured by Shimadzu GLC Co., Ltd.) • Evaporation chamber temperature: 210℃ Column flow rate: 0.98 mL / min • Column heating conditions: Hold at 50°C for 5 minutes, heat at 20°C / min up to 300°C, hold at 300°C for 10 minutes.

[0124] (Example 4) The polymer of Example 4 was synthesized (manufactured) by the following procedure. (1) The following solutions A1 and B1 were prepared. Solution A1: 25% by mass Eugohnb anisole solution (prepared by dissolving 13.96 g, 60.6 mmol of Eugohnb in anisole) Solution B1: 35% by mass HPMI / PhMI + VR-110 cyclopentanone solution (prepared by dissolving 11.46 g, 60.6 mmol of HPMI, 13.64 g, 78.8 mmol of PhMI, and 1.02 g, 4.00 mmol of VR-110 in anisole). (2) Solution A1 was heated to 130°C in a nitrogen-purged flask. Then, while maintaining the temperature in the flask at 130°C, solution B1 was added to the flask at a rate of 0.46 mass% / min using a syringe pump. In other words, when the total volume of solution B1 prepared in (1) was set to 100, 0.46 was added to the flask per minute. After the addition was complete, the reaction solution in the flask was allowed to cool naturally to room temperature. (3) The cooled reaction solution was added dropwise to heptane. A white to yellow precipitate was obtained. The precipitate was filtered, washed with heptane, washed again with 2-isopropanol, and dried overnight in a vacuum dryer at 80°C. This yielded the polymer of Example 4, which contains the above constituent units (a-1), (b-1), and (b-2).

[0125] (Comparative Example 2) A polymer of Comparative Example 2 was obtained in the same manner as in Example 4, except that the types and ratios of monomers used were changed to HFANB (62.7 g, 228 mmol), CyMI (61.5 g, 343 mmol), and H-MI (22.2 g, 229 mmol), and the polymer of Comparative Example 2 containing the above constituent units (c-1), (c-2), and (b-3).

[0126] The ratio of each structural unit in the polymers of Example 4 and Comparative Example 2 was determined by gas chromatography measurement of the amount of each residual monomer in the reaction solution after the completion of (2) above, under the same conditions as in Examples 1-3 and Comparative Example 1. In other words, it was assumed that the amount of monomer introduced into the polymer was the amount of monomer added minus the amount of residual monomer. The results are shown in Table 1.

[0127] (Example 5) First, the raw material polymer was synthesized (manufactured) using the following procedure. (1) 26.97 g (275 mmol) of maleic anhydride (hereinafter also referred to as MA) and 54.07 g (250 mmol) of EugOHNB were placed in a separable flask. Next, 125.37 g of anisole was added to the separable flask to dissolve each component and prepare a solution. (2) The obtained solution was heated to 130°C, and 2.54 g of VR-110 was added as a polymerization initiator. Then, nitrogen was passed through to remove the oxygen, and MA and EugOHNB were polymerized at 130°C for 6 hours to prepare a polymerization solution. (3) After the obtained polymerization solution was allowed 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 a raw material polymer containing constituent units derived from MA and constituent units derived from EugOHNB.

[0128] Next, the polymer was synthesized (manufactured) using the following procedure. (4) 16.00 g of raw polymer (54.3 mmol in MA equivalent, calculated from the amount of raw polymer used), 4.85 g of cyclohexylamine (48.9 mmol), and 1.78 g of p-aminophenol (16.3 mmol) were placed in a separable flask. Next, 94.81 g of γ-butyrolactone and 23.70 g of toluene were added to the separable flask to dissolve each component and prepare a solution. (5) 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 mixture was then reacted 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 mixture was reacted at 170°C for 18 hours to prepare the reaction solution. (6) After the obtained reaction solution was allowed 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 the polymer of Example 5 containing the above constituent units (a-1), (b-1), and (b-3).

[0129] (Example 6) First, the raw material polymer was synthesized (manufactured) using the following procedure. (1) 22.06 g (225 mmol) of maleic anhydride (hereinafter also referred to as MA) and 48.66 g (225 mmol) of EugOHNB were placed in a separable flask. Next, 24.27 g of anisole was added to the separable flask to dissolve each component and prepare a solution. (2) The obtained solution was heated to 80 °C, and 2.54 g of V-601 was added as a polymerization initiator. Subsequently, nitrogen was bubbled through to remove oxygen, and MA and EugOHNB were polymerized at 80 °C for 6 hours to prepare a polymerization solution. (3) After allowing the obtained polymerization solution to cool to room temperature, the reaction solution was diluted 2-fold with acetone, and the diluted reaction solution was dropped into a mixed solution of 3 times the mass of IPA and 3 times the mass of water to precipitate a white solid. The obtained white solid was washed with heptane and then dried overnight in a vacuum dryer at 80 °C to obtain a raw material polymer containing structural units derived from MA and structural units derived from EugOHNB.

[0130] Based on the obtained raw material polymer, in the same manner as in (4) to (6) of Example 5, the polymer of Example 6 containing the above structural unit (a-1), the above structural unit (b-1), and the above structural unit (b-3) was obtained.

[0131] The ratios of the respective structural units in the polymers of Examples 5 to 6 were 1 measured under the following conditions using H-NMR, and determined by the ratio of the integral values of the peaks derived from each structural unit. The results are shown in Table 1. < 1 Measurement conditions for H-NMR · Measuring device: JNM-ECZ-400S manufactured by JEOL Ltd. · Resonance frequency: 400 MHz · Measured nucleus: 1 H · Measurement method: NNE measurement (inverse gated decoupling method) · Pulse width: 6.99 μsec · Pulse repetition waiting time: 5 sec · Number of integrations: 8 times · Measurement temperature: Room temperature · Measurement solvent: DMSO-d6 (deuterated dimethyl sulfoxide) · Sample concentration: 3% (w / v)

[0132] For the polymers of each example and each comparative example, based on the structural formula and ratio of each structural unit, the P value was determined by the following formula. The results are shown in Table 1. P = (Total number of atoms per polymer molecule) / {(Number of carbon atoms per polymer molecule) - (Number of oxygen atoms per polymer molecule)}

[0133] <Molecular weight> 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 Detector: RI detector for liquid chromatogram Measurement temperature: 40℃ Solvent: THF Pump flow rate: 0.350 mL / min Sample concentration: 2.5 mg / mL

[0134] <Preparation of polymer solution> For each example and comparative example, the polymer was dissolved in propylene glycol monomethyl ether acetate (PGMEA), filtered through a polytetrafluoroethylene (PTFE) syringe filter with a pore size of 0.22 μm, and a polymer solution with a non-volatile component concentration of 10% by mass was prepared.

[0135] <Preparation of resin composition> For each example and comparative example, 100 parts by mass of polymer and 20 parts by mass of diaziline compound (Xlynx Materials Inc., BXW-202) 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 a resin composition with a non-volatile component concentration of 10% by mass.

[0136] <Alkali dissolution rate> For Examples 1-2, 4-6, and Comparative Examples 1-2, polymer solutions were spin-coated onto silicon wafers, and the solvent was dried 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 by T / t. The alkali dissolution rates for the resin compositions of each example and comparative example were also calculated using the same method. The results are shown in Table 1.

[0137] <Polymer etching rate E1> For each example and comparative example, a polymer solution was spin-coated onto a silicon wafer to a thickness of 0.5 μm. The polymer solution was then dried at 80°C for 1 minute, and cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film was plasma-etched under the following conditions, and the reduction in resin film thickness (nm) before and after plasma etching was measured using a stylus-type step meter. The etching rate E1 (nm / min) was then calculated by dividing the reduction in film thickness by the etching time. The results are shown in Table 1. Etchant: CF4 gas (100 sccm), O2 gas (10 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0138] <Polymer etching rate E2> For each example and comparative example, a polymer solution was spin-coated onto a silicon wafer to a thickness of 0.5 μm. The polymer solution was then dried at 80°C for 1 minute, and then cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film was plasma-etched under the following conditions, and the reduction in resin film thickness (nm) before and after plasma etching was measured using a stylus-type step meter. The etching rate E2 (nm / min) was then calculated by dividing the reduction in film thickness by the etching time. The results are shown in Table 1. Etchant: CF4 gas (100 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0139] <Etching rate of resin composition E3> For Examples 1 and 5 and Comparative Example 3, the resin composition was spin-coated onto a silicon wafer to a thickness of 0.5 μm. The resin composition was then dried at 80°C for 1 minute, and cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film was cured by heating at 120°C for 5 minutes. Then, the resin film was plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching was measured using a stylus-type step meter. The etching rate E3 (nm / min) was then calculated by dividing the film thickness reduction by the etching time. The results are shown in Table 1. Etchant: CF4 gas (100 sccm), O2 gas (10 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0140] <Etching rate of resin composition E4> For Examples 1 and 5 and Comparative Example 3, the resin composition was spin-coated onto a silicon wafer to a thickness of 0.5 μm. The resin composition was then dried at 80°C for 1 minute, and then cooled to room temperature to form a resin film on the silicon wafer. Next, the resin film was cured by heating at 120°C for 5 minutes. Then, the resin film was plasma-etched under the following conditions, and the reduction in film thickness (nm) before and after plasma etching was measured using a stylus-type step meter. The etching rate E4 (nm / min) was then calculated by dividing the reduction in film thickness by the etching time. The results are shown in Table 1. Etchant: CF4 gas (100 sccm) Source power: 180W Pressure: 10 Pa Etching time: 1 minute

[0141] <Evaluation of resist sensitivity> For each example and each comparative example, the resin composition was applied onto a silicon wafer by spin coating, and the solvent was dried to form a resin film with a film thickness of 100 nm. Then, the obtained resin film was irradiated with an electron beam having an acceleration voltage of 130 keV. At this time, in one resin film, regions irradiated with electron beams having different dose amounts of 50 μC / cm 2 , 100 μC / cm 2 and 200 μC / cm 2 were provided. Next, the resin film together with the silicon wafer was immersed in an aqueous solution of 2.38 mass% tetramethylammonium hydroxide and developed. The development time was 30 sec for Examples 1 to 4, 6 and Comparative Examples 1 to 2, and 90 sec for Example 5. Then, the resin film after development was observed to confirm whether a residual film existed in each region irradiated with an electron beam of a different dose, and the resist sensitivity of the resin composition was evaluated based on the following criteria. The results are shown in Table 1. A: There is a residual film in the region where the dose amount is less than 100 μC / cm 2 . B: There is no residual film in the region where the dose amount is less than 100 μC / cm 2 , but there is a residual film in the region where the dose amount is 100 μC / cm 2 or more and less than 200 μC / cm 2 . C: There is no residual film in the region where the dose amount is less than 200 μC / cm 2 , but there is a residual film in the region where the dose amount is 200 μC / cm 2 or more.

[0142]

Table 1

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