Polymer compound, photoresist resin composition, and method for producing semiconductor

Abstract

To provide a polymer compound which, when used in a resin composition for a photoresist, has high sensitivity, excels in resolution, can form a fine pattern with good accuracy, and can reduce the occurrence of development defects. And to provide a photoresist resin composition having high sensitivity, excellent in resolution, capable of accurately forming a fine pattern and capable of reducing the occurrence of development defects.SOLUTION: A polymer compound comprising at least a monomer unit a represented by the formula (a) and a monomer unit b having an alicyclic skeleton having a polar group (provided that a monomer unit c represented by the formula (c) is not included), wherein the content of the monomer unit c is less than 5 mol% based on all monomer units constituting the polymer compound.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a polymer compound used in performing microfabrication of semiconductors, a photoresist resin composition, and a method for producing a semiconductor. [Background technology]

[0002] Positive photoresists used in semiconductor manufacturing processes must have properties such as the ability to change the irradiated area to alkali-soluble upon light irradiation, adhesion to silicon wafers, and plasma etching resistance. Positive photoresists generally contain a polymer as the main component, a photoacid generator, and several additives to adjust the above properties.

[0003] As semiconductor integrated circuits become increasingly miniaturized, the wavelength of the exposure light source for lithography used in semiconductor manufacturing is becoming shorter every year, transitioning from a KrF excimer laser with a wavelength of 248 nm to an ArF excimer laser with a wavelength of 193 nm, and further to extreme ultraviolet (EUV) with a wavelength of 13.5 nm. In resist polymers used for KrF or ArF excimer laser exposure, known monomer units that are eliminated by an acid generated from a photoacid generator and exhibit solubility in an alkaline developer include those having an acid-eliminating group containing a large alicyclic structure, such as a monomer unit derived from 2-methyl-2-methacryloyloxyadamantane or a monomer unit derived from 1-(1-methacryloyloxy-1-methylethyl)adamantane (Patent Documents 1 to 3).

[0004] On the other hand, as a monomer unit having an acid-dissociable group containing a small alicyclic structure, for example, a monomer unit derived from 1-(1-methacryloyloxy-1-methylethyl)cyclohexane is known (Patent Document 4). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 09-073173 [Patent Document 2] Japanese Patent Application Laid-Open No. 2003-167347 [Patent Document 3] Japanese Patent Application Laid-Open No. 2003-223001 [Patent Document 4] Japanese Patent Application Laid-Open No. 2007-240967 Summary of the Invention [Problem to be solved by the invention]

[0006] However, the photoresist resins containing the monomer units disclosed in Patent Documents 1 to 3 were not fully satisfactory in terms of resolution, fine pattern formation, and developability. Also, the photoresist resin containing the monomer unit disclosed in Patent Document 4 was not fully satisfactory in terms of resolution and fine pattern formation.

[0007] Therefore, an object of the present disclosure is to provide a polymer compound that, when used in a photoresist resin composition, has high sensitivity, excellent resolution, is capable of forming a fine pattern with high precision, and is capable of reducing the occurrence of development defects. Another object of the present disclosure is to provide a photoresist resin composition that has high sensitivity, excellent resolution, is capable of forming a fine pattern with high precision, and is capable of reducing the occurrence of development defects. Another object of the present disclosure is to provide a method for producing a semiconductor using the photoresist resin composition. [Means for solving the problem]

[0008] The inventors of the present disclosure conducted extensive research to achieve the above-mentioned object and found that a polymer compound containing a monomer unit that is highly reactive to acid and becomes alkali-soluble upon cleavage of an acid-leaving group by a specific acid, and a monomer unit having an alicyclic skeleton with a polar group, wherein the content of the monomer unit having a specific structure is within a specific range, can achieve high sensitivity, excellent resolution, and a rectangular pattern shape when used in a photoresist resin composition. Furthermore, they found that the alicyclic structure contained in the monomer unit having the acid-leaving group has a relatively small carbon number of 5 to 8, thereby providing excellent solubility in organic solvents, and the compound cleaved by acid is easily removed during development, making it less likely to cause defects. The present disclosure was completed based on these findings.

[0009] That is, the present disclosure provides a polymer compound comprising at least a monomer unit a represented by the following formula (a) and a monomer unit b having an alicyclic skeleton having a polar group (however, the monomer unit c represented by the following formula (c) is not included), wherein the content of the monomer unit c is less than 5 mol % based on all the monomer units constituting the polymer compound: [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 1 is a single bond or -B 1 -C(=O)-O-(B 1 R represents a divalent linking group. 1 is an alkyl group having 2 to 6 carbon atoms which may have a substituent, R 2 represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 1 R represents an alicyclic hydrocarbon ring having 5 to 8 carbon atoms. 3 is Ring Z 1 and n is an integer of 0 to 3. When n is 2 or more, two or more R3 may be the same or different.] [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 2 represents a single bond or a divalent linking group. 2 R represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. 4 is Ring Z 2 and m is an integer of 1 to 3. When m is 2 or more, two or more R 4 may be the same or different.]

[0010] The polar group of the monomer unit b is -O-, -C(=O)-, -C(=O)-O-, -OC(=O)-O-, -C(=O)-OC(=O)-, -C(=O)-NH-, -S(=O)-O-, -S(=O)2-O-, -OR a , and -C(=O)-OR a (R a It is preferable that the alkyl group is at least one selected from the group consisting of: an alkyl group which may have a substituent;

[0011] The monomer unit b is preferably at least one selected from the group consisting of the following formulae (b1) to (b5). [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 2 represents a single bond or a divalent linking group. X represents a non-bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom. Y represents a methylene group or a carbonyl group. R 5 ~R 9is a substituent attached to the ring, and represents an alkyl group, a hydroxy group protected by a protecting group, a hydroxyalkyl group protected by a protecting group, a carboxy group protected by a protecting group, or a cyano group. 5 ~R 9 The number of is an integer greater than or equal to 0.

[0012] The polymer compound preferably has a weight average molecular weight (Mw) of 1,000 to 50,000.

[0013] The polymer compound preferably has a molecular weight distribution (Mw / Mn) of 1.0 to 3.0.

[0014] The present disclosure also provides a photoresist resin composition containing at least the above polymer compound and a photoacid generator.

[0015] The present disclosure still further provides a method for manufacturing a semiconductor, comprising the step of forming a pattern using the photoresist resin composition. [Effects of the Invention]

[0016] When the polymer compound of the present disclosure is used as a photoresist resin composition, it is possible to form a fine pattern with high sensitivity and excellent resolution with high precision, and to reduce the occurrence of development defects. Furthermore, according to a semiconductor manufacturing method using the photoresist resin composition of the present disclosure, it is possible to form a fine pattern with high precision and to reduce the occurrence of development defects. DETAILED DESCRIPTION OF THE INVENTION

[0017] [High molecular compound] The polymer compound of the present disclosure contains at least a monomer unit a represented by the above formula (a) and a monomer unit b having an alicyclic skeleton with a polar group. However, the monomer unit b does not contain a monomer unit c represented by the above formula (c). The monomer unit a has a very high reactivity to acid, and the protecting group (acid-leaving group) of the carboxyl group is rapidly eliminated by acid, making the polymer alkali-soluble (dissolvable in a developer), thereby contributing to high sensitivity. The monomer unit b contributes to the formation of a rectangular pattern with high adhesion to the substrate when the polymer compound of the present disclosure is used in a photoresist resin composition. Furthermore, the polymer compound of the present disclosure contains a combination of the monomer unit a and the monomer unit b, thereby achieving both high levels of solvent solubility and pattern formability.

[0018] In the polymer compound of the present disclosure, the content of the monomer unit a is, for example, about 5 to 95 mol %, preferably 10 to 90 mol %, more preferably 20 to 80 mol %, and even more preferably 30 to 70 mol %, relative to all monomer units (100 mol %) constituting the polymer compound. When the content is within the above range, high solvent solubility of the polymer compound can be achieved, and high sensitivity can be achieved when the polymer compound is used as a photoresist resin composition.

[0019] In the polymer compound of the present disclosure, the content of the monomer unit b is, for example, about 5 to 95 mol %, preferably 10 to 80 mol %, more preferably 20 to 70 mol %, and even more preferably 30 to 60 mol %, relative to all monomer units (100 mol %) constituting the polymer compound. When the content is within the above range, the polymer compound exhibits excellent formability of a fine pattern shape when used as a photoresist resin composition.

[0020] In the polymer compound of the present disclosure, the content of the monomer unit c represented by the above formula (c) is less than 5 mol% relative to all monomer units (100 mol%) constituting the polymer compound. The content of less than 5 mol% results in excellent fine pattern formability when the polymer compound of the present disclosure is used as a photoresist resin composition. The content of the monomer unit c is preferably 1 mol% or less, more preferably 0.1 mol% or less, and even more preferably 0.01 mol% or less, and it is particularly preferable that the monomer unit c is substantially free. In this specification, "substantially free" means that the monomer unit c is not intentionally blended, and excludes unavoidable contamination.

[0021] The weight average molecular weight (Mw) of the polymer compound is, for example, about 1,000 to 50,000, preferably 2,000 to 40,000, more preferably 3,000 to 30,000, and even more preferably 4,000 to 20,000.

[0022] The molecular weight distribution of the polymer compound (ratio of weight average molecular weight to number average molecular weight: Mw / Mn) is, for example, about 1.0 to 3.0, and preferably 1.0 to 2.5. Note that Mn represents the number average molecular weight, and both Mn and Mw are values ​​calculated in terms of polystyrene.

[0023] (monomer unit a) The monomer unit a is represented by the following formula (a): The monomer unit a can be introduced into a polymer compound by polymerizing a corresponding unsaturated carboxylic acid ester as a monomer. The polymer compound may have only one type of the monomer unit (a), or two or more types.

[0024] [ka] In the above formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 1 is a single bond or -B 1 -C(=O)-O-(B 1R represents a divalent linking group. 1 is an alkyl group having 2 to 6 carbon atoms which may have a substituent, R 2 represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 1 R represents an alicyclic hydrocarbon ring having 5 to 8 carbon atoms. 3 is Ring Z 1 and n is an integer of 0 to 3. When n is 2 or more, two or more R 3 may be the same or different.

[0025] Examples of the halogen atom in R include a fluorine atom and a chlorine atom. Examples of the alkyl group having 1 to 6 carbon atoms in R include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, and hexyl groups. Examples of the alkyl group having 1 to 6 carbon atoms and a halogen atom (haloalkyl group) include trifluoromethyl and 2,2,2-trifluoroethyl groups, and the like, in which one or more hydrogen atoms constituting the alkyl group are replaced with a halogen atom such as a fluorine atom or a chlorine atom.

[0026] B 1Examples of the linking group in the formula (I) include a carbonyl group (-C(=O)-), an ether bond (-O-), an ester bond (-C(=O)-O-), an amide bond (-C(=O)-NH-), a carbonate bond (-OC(=O)-O-), a group in which a plurality of these are linked together, a group in which an alkylene group is linked to another alkylene group, and an alkylene group. Examples of the alkylene group include linear or branched alkylene groups such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene, and divalent alicyclic hydrocarbon groups (particularly divalent cycloalkylene groups) such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene.

[0027] R 1 Examples of the alkyl group include alkyl groups having 2 to 6 carbon atoms, such as ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, n-hexyl, and cyclohexyl.

[0028] R 1 In the formula (I), examples of the substituent that the alkyl group having 2 to 6 carbon atoms may have include a halogen atom, a hydroxy group, a substituted hydroxy group (for example, an alkoxy group having 1 to 4 carbon atoms, such as a methoxy, ethoxy, or propoxy group), a cyano group, etc. Examples of the alkyl group having 2 to 6 carbon atoms having a substituent include a haloalkyl group in which one or more hydrogen atoms constituting the alkyl group have been replaced with a halogen atom, such as a fluorine atom or a chlorine atom, such as a 2,2,2-trifluoroethyl group; a 2-hydroxyethyl group, a 2-methoxyethyl group, a 2-ethoxyethyl group, a 2-cyanoethyl group, etc.

[0029] R 2Examples of the alkyl group in the formula include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, n-hexyl, and cyclohexyl.

[0030] R 2 In the formula (I), examples of the substituent that the alkyl group having 1 to 6 carbon atoms may have include a halogen atom, a hydroxy group, a substituted hydroxy group (for example, an alkoxy group having 1 to 4 carbon atoms, such as a methoxy, ethoxy, or propoxy group), a cyano group, etc. Examples of the alkyl group having 1 to 6 carbon atoms having a substituent include a haloalkyl group in which one or more hydrogen atoms constituting the alkyl group have been replaced with a halogen atom, such as a fluorine atom or a chlorine atom, such as a trifluoromethyl or 2,2,2-trifluoroethyl group; a hydroxymethyl, 2-hydroxyethyl, methoxymethyl, 2-methoxyethyl, ethoxymethyl, 2-ethoxyethyl, cyanomethyl, or 2-cyanoethyl group.

[0031] Z 1 In the above, examples of the alicyclic hydrocarbon ring having 5 to 8 carbon atoms include cycloalkanes such as cyclopentane, cyclohexane, and cyclooctane; and cycloalkenes such as cyclopentene and cyclohexene.

[0032] R 3 is Ring Z 1 and represents an oxa group, an oxo group, an alkyl group, a hydroxy group protected by a protecting group, a hydroxyalkyl group protected by a protecting group, or a carboxy group protected by a protecting group.

[0033] Examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, hexyl, and cyclohexyl.

[0034] Examples of the protecting group for the hydroxy group include C groups such as methyl, ethyl, and t-butyl groups. 1-4 Examples include alkyl groups; groups that form an acetal bond together with an oxygen atom constituting a hydroxy group, such as a methoxymethyl group; and groups that form an ester bond together with an oxygen atom constituting a hydroxy group, such as an acetyl group or a benzoyl group.

[0035] Examples of the hydroxyalkyl group include hydroxy C groups such as hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, and 6-hydroxyhexyl groups. 1-6 Examples include alkyl groups.

[0036] Examples of the protecting group for the hydroxyalkyl group include C groups such as methyl, ethyl, and t-butyl groups. 1-4 Examples include alkyl groups; groups that form an acetal bond together with an oxygen atom constituting a hydroxy group, such as a methoxymethyl group; and groups that form an ester bond together with an oxygen atom constituting a hydroxy group, such as an acetyl group or a benzoyl group.

[0037] Examples of the protective group for the carboxy group include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, hexyl, and cyclohexyl; 2-tetrahydrofuranyl, 2-tetrahydropyranyl, and 2-oxepanyl.

[0038] Specific examples of the monomer unit a include, but are not limited to, the polymerization units represented by the following formulas: b represents a methyl group or a hydrogen atom. [ka]

[0039] (monomer unit b) The monomer unit b is a monomer unit having an alicyclic skeleton having a polar group. The monomer unit b does not include the monomer unit c represented by the formula (c). The monomer unit b can be introduced into a polymer compound by polymerizing a corresponding unsaturated carboxylic acid ester as a monomer. The polymer compound may have only one type of the monomer unit (b), or two or more types.

[0040] From the viewpoint of realizing rectangular pattern formation when the polymer compound of the present disclosure is used in a photoresist resin composition, the polar group may be -O-, -C(=O)-, -C(=O)-O-, -OC(=O)-O-, -C(=O)-OC(=O)-, -C(=O)-NH-, -S(=O)-O-, -S(=O)-O-, -OR a , -C(=O)-OR a It is preferable that the functional group is at least one selected from the group consisting of: These functional groups may be present alone or in combination of two or more.

[0041] R a represents an alkyl group which may have a substituent. Examples of the alkyl group include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, n-hexyl, and cyclohexyl.

[0042] R a In the above, examples of the substituent that the alkyl group may have include halogen atoms such as fluorine, chlorine, and bromine atoms; C groups such as trifluoromethyl groups; 1-5 Haloalkyl groups; hydroxyl groups, methoxy groups, etc. 1-4 Alkoxy group; Amino group; DiC 1-4 C such as alkylamino group, carboxy group, methoxycarbonyl group 1-4 C such as alkoxycarbonyl group, nitro group, cyano group, acetyl group 1-6 Examples include an aliphatic acyl group.

[0043] It is particularly preferred that the monomer unit b contains at least one selected from the following formulae (b1) to (b5). The monomer units b represented by the following formulae (b1) to (b5) contain "-C(=O)-O-" or "-S(=O)2-O-", and are therefore highly hydrophilic. Therefore, when the monomer unit b contains at least one selected from the following formulae (b1) to (b5), it is possible to achieve high adhesion to the substrate and the formation of a rectangular pattern.

[0044] [ka] In the above formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 2 represents a single bond or a divalent linking group. X represents a non-bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom. Y represents a methylene group or a carbonyl group. R 5 ~R 9 is a substituent attached to the ring, and represents an alkyl group, a hydroxy group protected by a protecting group, a hydroxyalkyl group protected by a protecting group, a carboxy group protected by a protecting group, or a cyano group. 5 ~R 9 The number of is an integer greater than or equal to 0.

[0045] Examples of R represented by the above formulas (b1) to (b5) include the same examples as R in the monomer unit a represented by the above formula (a).

[0046] A 2Examples of the linking group in the formula (I) include an alkylene group, a carbonyl group (-C(=O)-), an ether bond (-O-), an ester bond (-C(=O)-O-), an amide bond (-C(=O)-NH-), a carbonate bond (-OC(=O)-O-), and groups in which multiple of these are linked together. Examples of the alkylene group include linear or branched alkylene groups such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene, and divalent alicyclic hydrocarbon groups (particularly divalent cycloalkylene groups) such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene.

[0047] In the monomer units b represented by the above formulae (b1) to (b5), 5 ~R 9 may each be 0, 1, or 2 or more, and preferably 1 to 3. In addition, in the monomer units b represented by the above formulae (b1) to (b5), 5 ~R 9 If there are two or more of the above R 5 ~R 9 may be the same or different.

[0048] R 5 ~R 9 Examples of the alkyl group in the formula include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, n-hexyl, and cyclohexyl.

[0049] Examples of the protecting group for the hydroxy group include C groups such as methyl, ethyl, and t-butyl groups. 1-4 Examples include alkyl groups; groups that form an acetal bond together with an oxygen atom constituting a hydroxy group, such as a methoxymethyl group; and groups that form an ester bond together with an oxygen atom constituting a hydroxy group, such as an acetyl group or a benzoyl group.

[0050] R 5 ~R 9 Examples of the hydroxyalkyl group in the formula (I) include hydroxy C groups such as hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, and 6-hydroxyhexyl groups. 1-6 Examples include alkyl groups.

[0051] Examples of the protecting group for the hydroxyalkyl group include C groups such as methyl, ethyl, and t-butyl groups. 1-4 Examples include alkyl groups; groups that form an acetal bond together with an oxygen atom constituting a hydroxy group, such as a methoxymethyl group; and groups that form an ester bond together with an oxygen atom constituting a hydroxy group, such as an acetyl group or a benzoyl group.

[0052] Examples of the protective group for the carboxy group include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, hexyl, and cyclohexyl; 2-tetrahydrofuranyl, 2-tetrahydropyranyl, and 2-oxepanyl.

[0053] Specific examples of the monomer unit b include, but are not limited to, polymerization units represented by the following formulas: b represents a methyl group or a hydrogen atom. [ka]

[0054] (monomer unit c) The monomer unit c of the present disclosure is represented by the following formula (c): The monomer unit c can be introduced into a polymer compound by polymerizing a corresponding unsaturated carboxylic acid ester as a monomer.

[0055] [ka] In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 2 represents a single bond or a divalent linking group. 2 R represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. 4 is Ring Z 2 and m is an integer of 1 to 3. When m is 2 or more, two or more R 4 may be the same or different.

[0056] Examples of R represented by the above formula (c) include the same examples as R in the monomer unit a represented by the above formula (a).

[0057] A represented by the above formula (c) 2 As for A in the monomer units b represented by the above formulas (b1) to (b5), 2 Similar examples include:

[0058] Z 2 Examples of the alicyclic hydrocarbon ring having 6 to 20 carbon atoms in the above formula include a cycloalkane ring having about 6 to 20 members, such as a cyclohexane ring or a cyclooctane ring; a monocyclic alicyclic carbon ring, such as a cycloalkene ring having about 6 to 20 members, such as a cyclohexene ring; an adamantane ring, a norbornane ring, a norbornene ring, a bornane ring, an isobornane ring, a tricyclo[5.2.1.0 2,6 ] decane ring, tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring or a ring containing a norbornane ring or a norbornene ring; a perhydroindene ring, a decalin ring (perhydronaphthalene ring), a perhydrofluorene ring (tricyclo[7.4.0.0 3,8 ]tridecane ring), perhydroanthracene ring, etc., polycyclic aromatic condensed rings hydrogenated; tricyclo[4.2.2.1 2,5] Examples include bridged carbocycles having about 2 to 6 rings, such as bridged carbocycles of 2, 3 or 4 rings (for example, bridged carbocycles having about 6 to 20 carbon atoms) such as an undecane ring.

[0059] Specific examples of the monomer unit c include, but are not limited to, polymerization units represented by the following formulas: b represents a methyl group or a hydrogen atom.

[0060] [ka]

[0061] To obtain the polymer compound of the present disclosure, polymerization of a monomer mixture containing an unsaturated carboxylic acid ester corresponding to monomer unit a and a polymerizable monomer corresponding to monomer unit b can be carried out by conventional methods used in producing acrylic polymers, such as solution polymerization, bulk polymerization, suspension polymerization, bulk-suspension polymerization, and emulsion polymerization. Solution polymerization is particularly preferred. Among solution polymerization methods, dropwise polymerization is preferred. Examples of dropwise polymerization methods include: [1] preparing a monomer solution dissolved in a polymerization solvent and a polymerization initiator solution dissolved in a polymerization solvent, respectively, and then adding the monomer solution and the polymerization initiator solution dropwise to the polymerization solvent maintained at a constant temperature; [2] adding a mixed solution of a monomer and a polymerization initiator dissolved in a polymerization solvent dropwise to the polymerization solvent maintained at a constant temperature; and [3] preparing a monomer solution dissolved in a polymerization solvent and a polymerization initiator solution dissolved in a polymerization solvent, respectively, and then adding the polymerization initiator solution dropwise to the monomer solution maintained at a constant temperature. Examples of monomers to be polymerized include monomers corresponding to the monomer units a and b.

[0062] Conventional polymerization solvents can be used, including, for example, ethers (chain ethers including glycol ethers such as diethyl ether and propylene glycol monomethyl ether, and cyclic ethers such as tetrahydrofuran and dioxane), esters (chain esters such as methyl acetate, ethyl acetate, butyl acetate, and ethyl lactate; glycol ether esters such as propylene glycol monomethyl ether acetate), ketones (acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.), amides (N,N-dimethylacetamide, N,N-dimethylformamide, etc.), sulfoxides (dimethyl sulfoxide, etc.), alcohols (methanol, ethanol, propanol, etc.), hydrocarbons (aromatic hydrocarbons such as benzene, toluene, and xylene; aliphatic hydrocarbons such as hexane; alicyclic hydrocarbons such as cyclohexane), and mixtures thereof. Conventional polymerization initiators can also be used. The polymerization temperature is, for example, about 30 to 150°C, preferably 50 to 120°C, and more preferably 60 to 100°C.

[0063] The polymer compound obtained by polymerization can be purified by precipitation or reprecipitation. The precipitation or reprecipitation solvent may be either an organic solvent or water, a mixed solvent of two or more organic solvents, or a mixed solvent of an organic solvent and water. Examples of organic solvents used as precipitation or reprecipitation solvents include hydrocarbons (aliphatic hydrocarbons such as pentane, hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; and aromatic hydrocarbons such as benzene, toluene, and xylene), halogenated hydrocarbons (halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride; and halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene), nitro compounds (nitromethane, nitroethane, and the like), nitriles (acetonitrile, benzonitrile, and the like), ethers (chain ethers such as diethyl ether, diisopropyl ether, and dimethoxyethane; and cyclic ethers such as tetrahydrofuran and dioxane), ketones (acetone, methyl ethyl ketone, and the like), esters (ethyl acetate, butyl acetate, and the like), carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, and the like), alcohols (methanol, ethanol, propanol, isopropyl alcohol, and the like), carboxylic acids (acetic acid, and the like), and mixed solvents thereof. Among these, the organic solvent used as the precipitation or reprecipitation solvent is preferably a solvent containing at least a hydrocarbon (preferably an aliphatic hydrocarbon such as hexane), and in the hydrocarbon-containing solvent, the ratio of the hydrocarbon to the other solvent [former / latter (weight ratio)] is, for example, about 10 / 90 to 99 / 1, preferably 30 / 70 to 98 / 2, and more preferably 50 / 50 to 97 / 3.

[0064] [Photoresist resin composition] When used in a photoresist resin composition, the polymer compound of the present disclosure has high sensitivity and excellent resolution, can form fine patterns with high precision, and can reduce the occurrence of development defects. For this reason, the polymer compound of the present disclosure is preferably used in a photoresist resin composition. A photoresist resin composition containing a polymer compound of the present disclosure may be referred to as the "photoresist resin composition of the present disclosure."

[0065] As described above, the photoresist resin composition of the present disclosure contains at least the polymer compound of the present disclosure and a photoacid generator. The polymer compound and the photoacid generator of the present disclosure may each contain only one type, or two or more types.

[0066] Examples of the photoacid generator include conventional compounds that efficiently generate acid upon exposure to light, such as diazonium salts; iodonium salts such as diphenyliodohexafluorophosphate; sulfonium salts such as triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphate, and triphenylsulfonium methanesulfonate; sulfonate esters such as 1-phenyl-1-(4-methylphenyl)sulfonyloxy-1-benzoylmethane, 1,2,3-trisulfonyloxymethylbenzene, 1,3-dinitro-2-(4-phenylsulfonyloxymethyl)benzene, and 1-phenyl-1-(4-methylphenylsulfonyloxymethyl)-1-hydroxy-1-benzoylmethane; oxathiazole derivatives; s-triazine derivatives; disulfone derivatives such as diphenyldisulfone; imide compounds; oxime sulfonates; diazonaphthoquinone; and benzoin tosylate.

[0067] The content of the photoacid generator can be appropriately selected depending on the strength of the acid generated by light irradiation, the ratio of each monomer unit in the polymer compound, etc., and is, for example, 0.1 to 30 parts by weight, preferably 0.5 to 20 parts by weight, and more preferably 1 to 10 parts by weight relative to 100 parts by weight of the polymer compound.

[0068] The photoresist resin composition may contain other components in addition to the polymer compound and photoacid generator of the present disclosure. Examples of such other components include basic compounds (e.g., triethylamine, 1,8-diazabicyclo[5.4.0]-7-undecene (DBU), 1,5-diazabicyclo[4.3.0]-5-nonene (DBN)) for improving stability over time during storage between the exposure step and the post-exposure bake step, additive resins for improving resist performance, surfactants for improving coatability during film formation, dissolution inhibitors for controlling solubility during development, stabilizers, plasticizers, photosensitizers, and light absorbers. Each of the other components may contain only one type, or two or more types.

[0069] The photoresist resin composition can be prepared, for example, by mixing the photoresist resin composition, a photoacid generator, and, if necessary, other components in a resist solvent. Examples of the resist solvent include ethers (chain ethers including glycol ethers such as propylene glycol monomethyl ether, and cyclic ethers such as dioxane), esters (chain esters such as methyl acetate, ethyl acetate, butyl acetate, and ethyl lactate; cyclic esters such as γ-butyrolactone; glycol ether esters such as propylene glycol monomethyl ether acetate), and ketones (methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, etc.). Among these, at least one solvent selected from propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, γ-butyrolactone, cyclohexanone, etc. is preferred. These solvents can be used alone or in combination.

[0070] The content of the resist solvent can be appropriately selected depending on the thickness of the resist film to be formed, and is, for example, in the range such that the concentration of the polymer compound is 1 to 30% by weight, preferably 2 to 25% by weight, and more preferably 3 to 20% by weight.

[0071] [Semiconductor manufacturing method] A semiconductor can be produced using the photoresist resin composition of the present disclosure. The semiconductor production method of the present disclosure includes a step of forming a pattern using the photoresist resin composition. The photoresist resin composition is applied to a base material or substrate and dried to form a coating film. The coating film is then exposed to light through a predetermined mask (or further baked after exposure) to form a latent image pattern, which is then developed, thereby forming a fine pattern with high precision.

[0072] Examples of the base material or substrate include silicon wafers, metals, plastics, glass, and ceramics. The photoresist resin composition can be applied using a conventional coating method such as a spin coater, a dip coater, or a roller coater. The thickness of the coating film is, for example, about 0.01 to 1 μm, and preferably 0.03 to 0.5 μm.

[0073] For exposure, light rays of various wavelengths, such as ultraviolet rays and X-rays, can be used. In particular, for semiconductor resists, g-rays, i-rays, excimer lasers (e.g., XeCl, KrF, KrCl, ArF, ArCl, F2, Kr2, KRbr, Ar2, etc.), extreme ultraviolet rays (EUV), electron beams, etc. are usually used.

[0074] In the semiconductor manufacturing method of the present disclosure, an acid is generated from a photoacid generator upon irradiation with light, and this acid rapidly eliminates the acid-leaving group (protecting group for the carboxy group) of the monomer unit a of the polymer compound, generating a carboxy group that contributes to alkali solubilization. The eliminated compound can be washed away with a developer, but because the alicyclic structure of the acid-leaving group has a relatively small carbon number of 5 to 8, the compound eliminated by acid is easily removed during development, suppressing the generation of scum on the substrate surface and reducing the occurrence of development defects. Furthermore, the inclusion of the monomer unit b improves solubility in an alkaline developer, enabling the formation of a rectangular pattern. As a result, fine patterns can be formed with high precision.

[0075] Each aspect disclosed in this specification can be combined with any other feature disclosed in this specification. Each configuration and combination thereof in each embodiment is an example, and addition, omission, substitution, and other modifications of configurations are possible as appropriate within the scope of the spirit of this disclosure. Furthermore, each invention according to this disclosure is not limited by the embodiments or the following examples. [Example]

[0076] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymer were determined by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent. Polystyrene was used as the standard sample, and a refractive index detector (RI detector) was used as the detector. The GPC measurements were performed using three KF-806L columns (manufactured by Resonac Corporation) connected in series under the following conditions: column temperature 40°C, RI temperature 40°C, and a tetrahydrofuran flow rate of 0.8 mL / min. The dispersity (Mw / Mn) was calculated from the above measured values.

[0077] Example 1 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) In a round-bottom flask equipped with a reflux condenser, a stirrer, a three-way stopcock, and a thermometer, 35.7 g of cyclohexanone was placed under a nitrogen atmosphere. The temperature was maintained at 80°C, and 1-methacryloyloxy-4-oxatricyclo[4.3.1.1] as a monomer component was added while stirring. 3,8A monomer solution containing 16.30 g (65.2 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclopentane, 13.70 g (65.2 mmol), 1.80 g of dimethyl 2,2'-azobisisobutyrate (Fujifilm Wako Pure Chemical Industries, Ltd., trade name "V-601") as a polymerization initiator, and 66.3 g of cyclohexanone as a polymerization solvent was added dropwise at a constant rate over 6 hours. After the addition was completed, stirring was continued for an additional 2 hours. After the polymerization reaction was completed, the resulting reaction solution was filtered through a 0.1 μm pore size filter. The reaction solution was then added dropwise with stirring to a 9:1 (weight ratio) mixture of hexane and ethyl acetate (7 times the volume of the reaction solution). The resulting precipitate was filtered and dried to obtain 26.9 g of the desired polymer compound. The recovered polymer was analyzed by GPC and found to have a weight average molecular weight (Mw) of 8,200 and a polydispersity (Mw / Mn) of 1.81.

[0078] [ka]

[0079] Example 2 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) 4,8 The same procedure as in Example 1 was carried out except that 14.93 g (67.3 mmol) of ]nonan-2-one and 15.07 g (67.3 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.1 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,500 and a molecular weight distribution (Mw / Mn) of 1.83.

[0080] [ka]

[0081] Example 3 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 ]nonan-2-one 5.54 g (25.0 mmol), 5-(2-methacryloyloxyacetoxy)-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 10.48 g (37.4 mmol) of ]nonan-2-one and 13.98 g (62.4 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 26.8 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,400 and a molecular weight distribution (Mw / Mn) of 1.82.

[0082] [ka]

[0083] Example 4 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 9.40 g (42.3 mmol) of ]nonan-2-one, 4.80 g (28.2 mmol) of 3-methacryloyloxy-2-oxotetrahydrofuran, and 15.80 g (70.6 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.2 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,800 and a molecular weight distribution (Mw / Mn) of 1.88.

[0084] [ka]

[0085] Example 5 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 16.21 g (65.6 mmol) of ]nonan-2-one and 13.79 g (65.6 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclopentane were used, yielding 27.7 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,400 and a molecular weight distribution (Mw / Mn) of 1.82.

[0086] [ka]

[0087] Example 6 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 15.73 g (63.7 mmol) of ]nonan-2-one and 14.27 g (63.7 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.6 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,300 and a molecular weight distribution (Mw / Mn) of 1.82.

[0088] [ka]

[0089] Example 7 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 ]nonan-2-one 5.86 g (23.7 mmol), 1-cyano-5-(2-methacryloyloxyacetoxy)-3-oxatricyclo[4.2.1.04,8 The same procedure as in Example 1 was carried out except that 10.85 g (35.6 mmol) of ]nonan-2-one and 13.29 g (59.3 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.0 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,100 and a molecular weight distribution (Mw / Mn) of 1.80.

[0090] [ka]

[0091] Example 8 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was repeated except that 10.10 g (40.9 mmol) of ]nonan-2-one, 4.63 g (27.3 mmol) of 3-methacryloyloxy-2-oxotetrahydrofuran, and 15.27 g (68.2 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.5 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,500 and a molecular weight distribution (Mw / Mn) of 1.84.

[0092] [ka]

[0093] Example 9 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxa-2-thiatricyclo[4.2.1.0 4,8The same procedure as in Example 1 was carried out except that 10.39 g (40.3 mmol) of nonane-2,2-dione, 4.57 g (26.9 mmol) of 3-methacryloyloxy-2-oxotetrahydrofuran, and 15.04 g (67.1 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 28.0 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,500 and a molecular weight distribution (Mw / Mn) of 1.85.

[0094] [ka]

[0095] Example 10 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 14.01 g (56.7 mmol) of 1-{2-(2-methacryloyloxyacetoxy)-2-butyl}cyclohexane were used instead, yielding 26.9 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,100 and a molecular weight distribution (Mw / Mn) of 1.79.

[0096] [ka]

[0097] Comparative Example 1 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8The same procedure as in Example 1 was carried out except that 15.42 g (69.4 mmol) of ]nonan-2-one and 14.58 g (69.4 mmol) of 1-(2-methacryloyloxy-2-propyl)cyclohexane were used, yielding 27.2 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,600 and a molecular weight distribution (Mw / Mn) of 1.84.

[0098] [ka]

[0099] Comparative Example 2 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 1-cyano-5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was carried out except that 16.21 g (65.6 mmol) of ]nonan-2-one and 13.79 g (65.6 mmol) of 1-(2-methacryloyloxy-2-propyl)cyclohexane were used, yielding 27.7 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,400 and a molecular weight distribution (Mw / Mn) of 1.82.

[0100] [ka]

[0101] Comparative Example 3 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8The same procedure as in Example 1 was carried out except that 13.76 g (62.0 mmol) of ]nonan-2-one and 16.24 g (62.0 mmol) of 1-(2-methacryloyloxy-2-propyl)adamantane were used, yielding 27.6 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,300 and a molecular weight distribution (Mw / Mn) of 1.81.

[0102] [ka]

[0103] Comparative Example 4 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8 The same procedure as in Example 1 was repeated except that 5.86 g (26.4 mmol) of ]nonan-2-one, 9.35 g (39.6 mmol) of 1-methacryloyloxy-3-hydroxyadamantane, and 14.79 g (66.0 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.3 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,500 and a molecular weight distribution (Mw / Mn) of 1.83.

[0104] [ka]

[0105] Comparative Example 5 (Production of a polymer compound for photoresist having a monomer unit represented by the following formula) As a monomer component, 5-methacryloyloxy-3-oxatricyclo[4.2.1.0 4,8The same procedure as in Example 1 was carried out except that 8.72 g (39.3 mmol) of ]nonan-2-one, 6.60 g (26.2 mmol) of 1-methacryloyloxy-3,5-dihydroxyadamantane, and 14.67 g (65.5 mmol) of 1-(2-methacryloyloxy-2-butyl)cyclohexane were used, yielding 27.4 g of the desired polymer compound. GPC analysis of the recovered polymer revealed that it had a weight average molecular weight (Mw) of 8,400 and a molecular weight distribution (Mw / Mn) of 1.83.

[0106] [ka]

[0107] <Evaluation test> For each of the polymer compounds obtained in Examples 1 to 10 and Comparative Examples 1 to 5, 3 parts by weight of triphenylsulfonium hexafluoroantimonate and 0.3 parts by weight of 1,5-diazabicyclo[4.3.0]-5-nonene were added to 100 parts by weight of the polymer compound, and propylene glycol monomethyl ether acetate was further added to adjust the concentration of the polymer compound to 10% by weight. The resulting composition was filtered through a polyethylene filter with a pore size of 0.1 μm, applied to a silicon wafer by spin coating, and heat-treated at 120°C for 90 seconds to form a coating film with a thickness of approximately 0.3 μm. An ArF excimer laser with a wavelength of 193 nm was used, and the irradiation dose was 20 mJ / cm through a line-and-space pattern mask. 2 and 30 mJ / cm 2 After exposure, the resist was subjected to a heat treatment at 120° C. for 60 seconds, developed with a 0.3 M aqueous solution of tetramethylammonium hydroxide, and rinsed with pure water. As a result, when the photoresist polymer compound solutions of Examples 1 to 10 were used, a clear 0.12 μm line and space pattern was obtained with high precision at any exposure dose, demonstrating that high sensitivity, excellent resolution, and fine patterns could be formed with high precision. Furthermore, no scum was observed. On the other hand, when the photoresist polymer compound solutions of Comparative Examples 1 and 2 were used, the exposure dose of 30 mJ / cm 2When exposed to 20 mJ / cm , a clear 0.12 μm line and space pattern was obtained. 2 When the photoresist polymer compound solution of Comparative Example 3 was used, a pattern was obtained at any exposure dose, but a large amount of resist scum was observed in the space, resulting in development defects. When the photoresist polymer compound solutions of Comparative Examples 4 and 5 were used, a pattern was obtained at any exposure dose, but the pattern shape was not rectangular due to swelling during development.

[0108] Variations of the invention according to the present disclosure are described below. [Appendix 1] A polymer compound comprising at least a monomer unit a represented by the following formula (a) and a monomer unit b having an alicyclic skeleton having a polar group (excluding a monomer unit c represented by the following formula (c)), wherein the content of the monomer unit c is less than 5 mol% of all the monomer units constituting the polymer compound: [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 1 is a single bond or -B 1 -C(=O)-O-(B 1 R represents a divalent linking group. 1 is an alkyl group having 2 to 6 carbon atoms which may have a substituent, R 2 represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 1 R represents an alicyclic hydrocarbon ring having 5 to 8 carbon atoms. 3 is Ring Z 1 and n is an integer of 0 to 3. When n is 2 or more, two or more R 3 may be the same or different.] [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 2 represents a single bond or a divalent linking group. 2 R represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. 4 is Ring Z 2 and m is an integer of 1 to 3. When m is 2 or more, two or more R 4 may be the same or different.] [Appendix 2] The polar group of the monomer unit b is -O-, -C(=O)-, -C(=O)-O-, -OC(=O)-O-, -C(=O)-OC(=O)-, -C(=O)-NH-, -S(=O)-O-, -S(=O)2-O-, -OR a , and -C(=O)-OR a (R a 10. The polymer compound according to claim 1, wherein the alkyl group is at least one selected from the group consisting of: an alkyl group which may have a substituent. [Appendix 3] 3. The polymer compound according to claim 1, wherein the monomer unit b is at least one selected from the group consisting of the following formulae (b1) to (b5): [ka] [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom.] 2 represents a single bond or a divalent linking group. X represents a non-bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom. Y represents a methylene group or a carbonyl group. R 5 ~R 9 is a substituent attached to the ring, and represents an alkyl group, a hydroxy group protected by a protecting group, a hydroxyalkyl group protected by a protecting group, a carboxy group protected by a protecting group, or a cyano group. 5 ~R9 The number of is an integer greater than or equal to 0. [Appendix 4] 4. The polymer compound according to any one of claims 1 to 3, having a weight average molecular weight (Mw) of 1,000 to 50,000. [Appendix 5] 5. The polymer compound according to any one of claims 1 to 4, having a molecular weight distribution (Mw / Mn) of 1.0 to 3.0. [Appendix 6] A resin composition for photoresist, comprising at least the polymer compound according to any one of claims 1 to 5 and a photoacid generator. [Appendix 7] A method for manufacturing a semiconductor, comprising the step of forming a pattern using the photoresist resin composition according to Appendix 6.

Claims

1. A polymer compound comprising at least a monomer unit a represented by the following formula (a) and a monomer unit b having an alicyclic skeleton having a polar group (excluding a monomer unit c represented by the following formula (c)), wherein the content of the monomer unit c is less than 5 mol % based on all monomer units constituting the polymer compound: 【Chemistry 1】 [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 1 is a single bond or -B 1 -C(=O)-O-(B 1 R represents a divalent linking group. 1 is an alkyl group having 2 to 6 carbon atoms which may have a substituent; R 2 represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 1 represents an alicyclic hydrocarbon ring having 5 to 8 carbon atoms. 3 Ring Z 1 and n is an integer of 0 to 3. When n is 2 or more, two or more R 3 may be the same or different.] 【Chemistry 2】 [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 2 represents a single bond or a divalent linking group. 2 represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. 4 Ring Z 2 and m is an integer of 1 to 3. When m is 2 or more, two or more R 4 may be the same or different.]

2. The polar group of the monomer unit b is -O-, -C(=O)-, -C(=O)-O-, -O-C(=O)-O-, -C(=O)-O-C(=O)-, -C(=O)-NH-, -S(=O)-O-, -S(=O) 2 -O-, -OR a and —C(═O)—OR a (R a 2. The polymer compound according to claim 1, wherein the alkyl group is at least one selected from the group consisting of: an alkyl group which may have a substituent;

3. 2. The polymer compound according to claim 1, wherein the monomer unit b is at least one selected from the group consisting of the following formulae (b1) to (b5): 【Transformation 3】 [In the formula, R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. 2 represents a single bond or a divalent linking group. X represents a non-bond, a methylene group, an ethylene group, an oxygen atom, or a sulfur atom. Y represents a methylene group or a carbonyl group. R 5 ~R 9 is a substituent bonded to the ring, and represents an alkyl group, a hydroxy group protected by a protecting group, a hydroxyalkyl group protected by a protecting group, a carboxy group protected by a protecting group, or a cyano group. 5 ~R 9 The number is an integer of 0 or more.

4. The polymer compound according to any one of claims 1 to 3, having a weight average molecular weight (Mw) of 1,000 to 50,000.

5. 5. The polymer compound according to claim 4, wherein the molecular weight distribution (Mw / Mn) is 1.0 to 3.

0.

6. A photoresist resin composition comprising at least the polymer compound according to any one of claims 1 to 3 and a photoacid generator.

7. A method for manufacturing a semiconductor, comprising a step of forming a pattern using the photoresist resin composition according to claim 6.

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