Monomer, photoresist resin, photoresist resin composition, and pattern forming method

Abstract

Provided is a monomer that imparts higher heat resistance to a resin while improving solubility in an organic solvent, hydrolyzability, and solubility in water after hydrolysis. This resin for photoresist contains a polymerization unit represented by formula (Y) [in the formula, Rh represents a halogen atom, or a C1-C6 alkyl group which has a halogen atom. R1 is a substituent bonded to a ring, and represents a halogen atom, a C1-C6 alkyl group which may have a halogen atom, a C1-C6 hydroxyalkyl group which may have a halogen atom, and of which the hydroxyl group moiety may be protected by a protecting group, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents a C1-C6 alkylene group, an oxygen atom, a sulfur atom, or non-bonding. m is the number of R1's, and represents an integer of 0-8. X represents an electron-withdrawing substituent, and n is the number of X's, and represents an integer of 1-9. B represents a single bond or a linking group. The three-dimensional position of a COOB- group bonded to a polymer chain may be either endo or exo.].

Description

[Technical field]

[0001] The present invention relates to a monomer, a resin, a resin composition, and a pattern forming method. This application claims priority to Japanese Patent Application No. 2019-139399, filed in Japan on July 30, 2019, the contents of which are incorporated herein by reference. [Background technology]

[0002] In semiconductor manufacturing, lithography technology for pattern formation has undergone a dramatic transformation. Initially, i-line and g-line were used for exposure in lithography, and the line width of the pattern was wide, so the capacity of the semiconductors manufactured was low. However, recent technological developments have made it possible to use KrF excimer lasers with short wavelengths and ArF excimer lasers with even shorter wavelengths, and the line width has become dramatically finer.

[0003] Novolac or styrene resins have been used in exposure with KrF excimer lasers, but the above resins contain aromatic groups, and therefore have the problem of absorbing the laser light of the ArF excimer laser. For this reason, in exposure with ArF excimer lasers, resins that do not contain aromatic groups (e.g., resins with alicyclic skeletons) are used instead of resins that contain aromatic groups. The resins used in exposure with ArF excimer lasers are mainly acrylic resins. This is based on the mechanism that, when a resin composition is used that contains an acrylic resin containing (meth)acrylic acid protected by a protecting group as a monomer unit and a radiation-sensitive acid generator, the protecting group of the monomer unit is eliminated by the acid generated by exposure to form a carboxyl group, which becomes alkali-soluble.

[0004] Many of the protecting groups currently in use are groups having a non-polar alicyclic skeleton, but due to poor adhesion to substrates and lack of affinity with alkaline developers, many acrylic monomers having a polar alicyclic skeleton (e.g., having an ester group) have been proposed. Among them, acrylic monomers having a lactone ring are highly regarded for their functionality and are widely used (Patent Documents 1 and 2).

[0005] In the above acrylic monomers, the lactone ring is introduced for the purpose of being hydrolyzed by alkali. However, such acrylic monomers have a problem that the desired function is not fully exhibited depending on the application because the lactone ring has low hydrolysis property. For example, when a resin in which the acrylic monomer is introduced as a polymerization unit is used for a resist application, problems such as a decrease in the accuracy of pattern formation occur because hydrolysis of the lactone ring by alkali does not proceed sufficiently. In order to solve such problems, acrylic monomers in which a specific electron-withdrawing substituent is introduced into the lactone skeleton have been proposed (Patent Documents 3 and 4).

[0006] Pattern formation is completed through the following steps: a pre-bake process in which resist (photoresist resin) is applied onto a wafer and the wafer is heated to solidify the resist, an exposure process in which the solidified resist is irradiated with light to cause a reaction, a development (rinse) process in which the exposed wafer is immersed in a developer to remove excess resist, and a post-bake process in which the developed wafer is heated. In the pre-bake and post-bake processes, the resist is exposed to high temperatures, and if the resist has low heat resistance, it will decompose, leading to deterioration of line edge roughness. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2000-026446 A [Patent Document 2] Japanese Patent Application Publication No. 10-274852 [Patent Document 3] Patent No. 4740951 [Patent Document 4] JP 2008-231059 A Summary of the Invention [Problem to be solved by the invention]

[0008] In recent years, with the trend toward finer patterns, there has been a demand for further improvement in line edge roughness, but it has become clear that the resins containing monomers proposed in Patent Documents 1 to 4 as constituent units have low heat resistance and therefore insufficient line edge roughness. For this reason, there is a demand for resins with higher heat resistance.

[0009] Therefore, an object of the present invention is to provide a monomer that imparts high heat resistance to a resin while improving solubility and hydrolysis in organic solvents. Another object of the present invention is to provide a resin having high solubility and hydrolysis in organic solvents and high heat resistance, and a resin composition containing the resin. Another object of the present invention is to provide a method for forming a fine pattern with high accuracy by using the resin composition. [Means for solving the problem]

[0010] As a result of intensive research to achieve the above object, the present inventors have found that by introducing a monomer having a specific structure into a resin, the hydrolysis property of the lactone ring of the resin is improved and the heat resistance of the resin is also improved. The present invention was completed based on these findings.

[0011] That is, in the present invention, [ka] [In the formula, R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1is a substituent bonded to the ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or no bond. m represents R 1 and n is the number of X and is an integer of 0 to 8. X represents an electron-withdrawing substituent, and n is the number of X and is an integer of 1 to 9. B represents a single bond or a linking group. The steric position of the COOB- group bonded to the polymer chain may be either endo or exo. The present invention provides a resin comprising a polymerized unit represented by the formula:

[0012] The resin further comprises a compound represented by the following formulae (a1) to (a4): [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, and A represents a single bond or a linking group. 2 ~R 4 are the same or different and each represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 2 and R 3 may be bonded to each other to form a ring. 5 , R 6 R is the same or different and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. 7 -COOR c R c represents a tertiary hydrocarbon group which may have a substituent, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group. n represents an integer of 1 to 3. R a is Z 1and are the same or different and each represents an oxo group, an alkyl group, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, or a carboxy group which may be protected by a protecting group. p represents an integer of 0 to 3. Ring Z 1 represents an alicyclic hydrocarbon ring having 3 to 20 carbon atoms.] It is preferable that the polymerized unit contains at least one type of polymerized unit selected from the group consisting of polymerized units represented by the following formula:

[0013] The resin further comprises a compound represented by 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, and A represents a single bond or a 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. Z represents a divalent organic group. V 1 ~V 3 are the same or different and are -CH 2 -, [-C(=O)-], or [-C(=O)-O-]. However, V 1 ~V 3 At least one of the groups is [-C(=O)-O-]. 8 ~R 14 are the same or different and each represents a hydrogen atom, a fluorine atom, an alkyl group which may have a fluorine atom, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group. It is preferable that the polymerized unit contains at least one type of polymerized unit selected from the group consisting of polymerized units represented by the formula (Y) (excluding those corresponding to the polymerized units represented by the formula (Y)).

[0014] The resin is represented by the following formula (c1): [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; A represents a single bond or a linking group. R b represents a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group. q represents an integer of 1 to 5. Ring Z 2 represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms.] It is preferable that the copolymer contains a polymer unit represented by the following formula:

[0015] The present invention also provides a resin composition containing at least the above resin and a radiation-sensitive acid generator.

[0016] The present invention also provides a pattern forming method comprising at least the steps of applying the composition to a substrate to form a coating film, exposing the coating film to light, and then dissolving the coating film in an alkali.

[0017] In the present invention, the compound represented by the following formula (X) [ka] [In the formula, R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1 is a substituent bonded to the ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. m represents R 1 X represents an electron-withdrawing substituent, and n represents the number of X and is an integer of 1 to 9. B represents a single bond or a linking group. CH 2 =C(R h The steric position of the COOB- group may be either endo or exo. The present invention provides a monomer represented by the formula: Effect of the Invention

[0018] According to the present invention, a monomer that improves solubility and hydrolysis in organic solvents and imparts high heat resistance to a resin is provided. Also provided is a resin having high solubility and hydrolysis in organic solvents and high heat resistance, and a resin composition containing the resin. Furthermore, a method for forming a fine pattern with high accuracy by using the resin composition is provided. [Brief description of the drawings]

[0019] [Figure 1] 1 shows the results of thermogravimetry of resins in Example 2 and Comparative Example 1. The solid line [1] shows the results of Example 2, and the dashed line [2] shows the results of Comparative Example 1. The vertical axis shows the amount of weight change (μg), and the horizontal axis shows the temperature (°C). [Diagram 2] 1 shows the results of thermogravimetry of resins in Example 3 and Comparative Example 2. The solid line [3] shows the results of Example 3, and the dashed line [4] shows the results of Comparative Example 2. The vertical axis shows the amount of weight change (μg), and the horizontal axis shows the temperature (°C). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Monomer> The monomer of the present invention is a polycyclic ester having an electron-withdrawing substituent and a lactone skeleton, represented by the following formula (X). [ka]

[0021] In formula (X), R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1 is [6-oxabicyclo[3.2.1 1,5 ]octane ring (when A is not a bond), 3-oxatricyclo[4.2.1.0 4,8]nonane ring (when A is a methylene group), etc.], and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group portion may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. m represents R 1 is an integer of 0 to 8. X represents an electron-withdrawing substituent, and n is [6-oxabicyclo[3.2.1 1,5 ]octane ring (when A is not a bond), 3-oxatricyclo[4.2.1.0 4,8 The number of X's bonded to the nonane ring (when A is a methylene group) or the like is an integer of 1 to 9. B represents a single bond or a linking group. CH 2 =C(R h The steric position of the COOB-group may be either endo or exo.

[0022] In addition, 6-oxabicyclo[3.2.1 1,5 ]octane ring position number, and 3-oxatricyclo[4.2.1.0 4,8 The position numbers in the ]nonane ring are shown below (the former is on the left, the latter is on the right). [ka]

[0023] In formula (X), X represents an electron-withdrawing substituent, and examples of the electron-withdrawing group include a halogen atom such as a fluorine atom, a halogenated hydrocarbon group such as a trifluoromethyl group, a carboxyl group, an alkoxycarbonyl group such as a methoxycarbonyl group, an aryloxycarbonyl group such as a phenoxycarbonyl group, an acyl group such as an acetyl group, a cyano group, an aryl group, a 1-alkenyl group, a nitro group, a sulfonic acid alkyl ester group, sulfonic acid, a sulfone group, a sulfoxy group, etc. Among these, a fluorine atom, a fluorine atom-containing group such as a trifluoromethyl group, a carboxyl group, an alkoxycarbonyl group such as a methoxycarbonyl group, an acyl group such as an acetyl group, a cyano group, and a nitro group are preferred.

[0024] R h The halogen atom in R is not particularly limited, but from the viewpoint of improving heat resistance, a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable. h The number of carbon atoms in the alkyl group in is not particularly limited as long as it is 1 to 6, but is preferably 1 to 3, and more preferably 1 or 2. That is, from the viewpoint of improving heat resistance, the alkyl group having 1 to 6 carbon atoms and having a halogen atom in Rh is preferably an alkyl group having 1 or 2 carbon atoms substituted with a fluorine atom, such as a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, or a 1,1,2,2,2-pentafluoroethyl group, and more preferably a trifluoromethyl group.

[0025] In addition, in the monomer represented by formula (X), the reason why the heat resistance of the resin into which the monomer is introduced is improved is not clear, but it is believed that R h This is believed to be related to the fact that the main chain of the resin containing the polymerization unit derived from the monomer (i.e., the polymerization unit represented by formula (Y)) is difficult to be cleaved when R is a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. hWe will use the case where R is fluorine as an example. Since the C-F bond has a larger bond energy than the C-H bond, the rotation of the carbon to which the fluorine atom is bonded and the carbon atom next to it, that is, the C-C bond that is the main chain of the resin, is suppressed, and the C-C bond is difficult to break. h Here, we will take the example of R being a fluoromethyl group. As mentioned above, the C-F bond has a larger bond energy than the C-H bond, so the rotation of the C-C bond in the main chain is suppressed. In addition, the rotation is also suppressed by the steric hindrance of the fluoromethyl group, making the C-C bond less likely to break. In addition, in order to improve the heat resistance of the resin, h is the above-mentioned substituent, and the fact that the monomer represented by formula (X) has an electron-withdrawing substituent and a lactone skeleton is considered to be closely related.

[0026] R 1 The halogen atom in R is not particularly limited and is, for example, a fluorine atom or a chlorine atom. 1 The number of carbon atoms in the alkyl group in R is not particularly limited as long as it is 1 to 6, but it is preferably 1 to 3, and more preferably 1 or 2. That is, 1 Examples of the alkyl group having 1 to 6 carbon atoms and having a halogen atom in the formula (I) include alkyl groups having 1 or 2 carbon atoms substituted with a fluorine atom, such as a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, and a 1,1,2,2,2-pentafluoroethyl group.

[0027] R 1In the above, examples of the hydroxyalkyl group having 1 to 6 carbon atoms include hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, and 6-hydroxyhexyl groups. Examples of the hydroxyalkyl group having 1 to 6 carbon atoms and having a halogen atom include difluorohydroxymethyl, 1,1-difluoro-2-hydroxyethyl, 2,2-difluoro-2-hydroxyethyl, and 1,1,2,2-tetrafluoro-2-hydroxyethyl groups. Among the hydroxyalkyl groups having 1 to 6 carbon atoms and optionally having a halogen atom, hydroxyalkyl groups or hydroxyhaloalkyl groups having 1 or 2 carbon atoms (particularly 1 carbon atom) are preferred. Examples of the protective group for the hydroxyl group of the hydroxyalkyl group having 1 to 6 carbon atoms and optionally having a halogen atom include protective groups commonly used as protective groups for the hydroxyl group in the field of organic synthesis, such as groups that form an ether or acetal bond together with an oxygen atom constituting a hydroxyl group, such as a methyl group or a methoxymethyl group; and groups that form an ester bond together with an oxygen atom constituting a hydroxyl group, such as an acetyl group or a benzoyl group. Examples of the salt of the carboxyl group include an alkali metal salt, an alkaline earth metal salt, and a transition metal salt.

[0028] R 1 Examples of the substituted oxycarbonyl group in the formula (I) include alkoxycarbonyl groups (C 1-4 Alkoxy-carbonyl groups, etc.; alkenyloxycarbonyl groups such as vinyloxycarbonyl and allyloxycarbonyl groups (C 2-4 alkoxy-carbonyl groups, etc.); cycloalkyloxycarbonyl groups such as cyclohexyloxycarbonyl group; aryloxycarbonyl groups such as phenyloxycarbonyl group, etc.

[0029] A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. Examples of the alkylene group having 1 to 6 carbon atoms include a methylene group which may be substituted with an alkyl group, an ethylene group which may be substituted with an alkyl group, and a propylene group which may be substituted with an alkyl group. Among these, an alkylene group having 1 to 6 carbon atoms or a non-bond is preferable as A.

[0030] m is not particularly limited as long as it is an integer of 0 to 8, but is preferably an integer of 0 to 6, and more preferably an integer of 0 to 3. 1 When there are a plurality of X's, they may be the same or different. n is not particularly limited as long as it is an integer of 1 to 9, but is preferably, for example, 1 to 5, and more preferably 1 or 2. When there are a plurality of X's, they may be the same or different. When A is not a bond, the substituent X is 6-oxabicyclo[3.2.1 1,5 Although it may be bonded to any of the 1st, 2nd, 3rd, 4th, 5th and 8th positions of the octane ring, the 1st position (α-position of the lactone) or the 2nd position is preferable, and the 1st position (α-position of the lactone) is particularly preferable. When A is an alkylene group having 1 to 6 carbon atoms, an oxygen atom or a sulfur atom, the substituent X is 3-oxatricyclo[4.2.1.0 4,8 ]nonane ring, etc., may be bonded to any position such as 1-position, 4-position, 5-position, 6-position, 7-position, 8-position, 9-position, etc., but 3-oxatricyclo[4.2.1.0 4,8 ]The 1- or 9-position of the nonane ring (or a position equivalent thereto) is preferred, and among these, the 1-position (or a position equivalent thereto; the α-position of the lactone) is particularly preferred.

[0031] B represents a single bond or a linking group. Examples of the linking group 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, and a group in which an alkylene group is linked to these. Examples of the alkylene group include linear or branched alkylene groups such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene groups, 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 groups.

[0032] Representative examples of the monomer represented by formula (X) include 1-substituted X-6-oxabicyclo[3.2.1 1,5 ]octan-7-one compounds (including stereoisomers), 2-substituted X-6-oxabicyclo[3.2.1 1,5 ]octan-7-one compounds (including stereoisomers), 1-substituted X-5-(meth)acryloyloxy-3-oxatricyclo[4.2.1.0 4,8 ]nonan-2-one compounds (including stereoisomers), 9-substituted X-5-(meth)acryloyloxy-3-oxatricyclo[4.2.1.0 4,8 ]nonan-2-one compounds (including stereoisomers), and corresponding compounds of formula (X) in which A is an alkylene group other than a methylene group, an oxygen atom, or a sulfur atom. In the formula, R represents an acryloyl group or a methacryloyl group, and Ac represents an acetyl group. The substituent X represents an electron-withdrawing substituent.

[0033] [ka]

[0034] [ka]

[0035] The monomer represented by formula (X) is, for example, a polycyclic alcohol having an electron-withdrawing substituent and a lactone skeleton represented by the following formula (X1) (4-hydroxy-6-oxabicyclo[3.2.1 1,5 ]octan-7-one derivatives, 5-hydroxy-3-oxatricyclo[4.2.1.0 4,8

[0046] nonan-2-one derivatives, etc.) with an unsaturated carboxylic acid represented by the following formula (X2) or a reactive derivative thereof. h , R 1 Specific examples and preferred examples (ranges) of m, n, X, A and B are the same as those described above.

[0036] [ka]

[0037] [ka]

[0038] Representative examples of the polycyclic alcohol having an electron-withdrawing substituent and a lactone skeleton represented by formula (X1) include compounds corresponding to the compounds given as representative examples of the monomer represented by formula (X) above (compounds in which R is a hydrogen atom).Reactive derivatives of the unsaturated carboxylic acid represented by formula (X2) include acid halides, acid anhydrides, esters, etc.

[0039] More specifically, the monomer represented by formula (X) can be obtained by (a) reacting a compound represented by formula (X1) with an unsaturated carboxylic acid represented by formula (X2) or a reactive derivative thereof in a solvent such as tetrahydrofuran, toluene, methylene chloride, etc., in the presence of a base such as triethylamine, pyridine, 4-dimethylaminopyridine, etc., if necessary, or (b) reacting a compound represented by formula (X1) with an ester of an unsaturated carboxylic acid represented by formula (X2) or a reactive derivative thereof in the presence of an ester exchange catalyst such as titanium isopropoxide, etc., in a solvent similar to that described above, or (c) reacting a compound represented by formula (X1) with an unsaturated carboxylic acid represented by formula (X2) or a reactive derivative thereof in the presence of a strong acid such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, etc., in a solvent similar to that described above.

[0040] The reaction conditions in these methods are the same as those in ordinary ester production methods. For example, in the method (a), the amount of the active reactive derivative of the unsaturated carboxylic acid used is, for example, about 1 to 1.5 moles per mole of the compound represented by formula (X1), the amount of the base used is, for example, about 1 to 3 moles (may be a large excess amount) per mole of the active reactive derivative of the unsaturated carboxylic acid, and the reaction temperature is, for example, about -20°C to 50°C. In addition, in the method (b), the amount of the unsaturated carboxylic acid ester used is, for example, about 1 to 10 moles (may be a large excess amount) per mole of the compound represented by formula (X1), the amount of the transesterification catalyst used is, for example, about 0.0001 to 1 mole per mole of the compound represented by formula (X1), and the reaction temperature is, for example, about 0 to 150°C. Furthermore, in the method (c), the amount of the unsaturated carboxylic acid used is, for example, about 1 to 5 moles (may be a large excess amount) relative to 1 mole of the compound represented by formula (X1), the amount of the strong acid used is, for example, about 0.0001 to 1 mole relative to 1 mole of the compound represented by formula (X1), and the reaction temperature is, for example, about 0 to 150° C. In addition, during these reactions, a polymerization inhibitor such as hydroquinone monomethyl ether or oxygen can be introduced to suppress polymerization.

[0041] The monomer represented by formula (X) produced by the reaction can be separated and purified by a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

[0042] The polycyclic alcohol having an electron-withdrawing substituent and a lactone skeleton represented by the above formula (X1) can be obtained by subjecting an epoxy compound represented by the following formula (X3) (a cyclohexene oxide derivative or a 2,3-epoxybicyclo[2.2.1]heptane derivative) to a cyclization reaction. [ka]

[0043] X and R in formula (X3) 1 is the same as above. m' is 0 to 8, preferably 0 to 6, and more preferably 0 to 3. n' is 1 to 9, preferably 1 to 5, and more preferably 1 or 2. R b is an organic group.

[0044] R b The organic group in may be any group that constitutes a carboxylate ester, and examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, and t-butyl groups (particularly, C1-6 alkyl groups); alkenyl groups such as vinyl and allyl groups (particularly, C 2-6 alkenyl groups; cycloalkenyl groups such as cyclohexyl groups; aryl groups such as phenyl groups; heterocyclic groups such as pyridyl groups, etc. b In particular, hydrogen atoms, as well as C groups such as methyl and ethyl groups, 1-4 Alkyl groups are preferred.

[0045] The cyclization reaction is b When R is a hydrogen atom, for example, the reaction proceeds by simply dissolving the compound represented by formula (X3) in a solvent. b When R is an organic group, the compound represented by formula (X3) is subjected to a conventional hydrolysis reaction (alkali hydrolysis reaction, acid hydrolysis reaction, neutral hydrolysis, etc.) to obtain R bis a hydrogen atom, a cyclization reaction immediately proceeds to produce a compound represented by formula (X1). The polycyclic alcohol having an electron-withdrawing substituent and a lactone skeleton represented by formula (X1) produced in the reaction can be separated and purified by a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

[0046] Among the compounds represented by the formula (X1), a compound having one or more fluorine atoms bonded to a ring can also be produced by subjecting a compound having at least one hydrogen atom bonded to a ring to a conventional fluorination reaction using a fluorinating agent such as fluorine.

[0047] The epoxy compound represented by the formula (X3) can be produced, for example, according to the following reaction scheme. 1a is a substituent bonded to a diene chain or a cyclopentadiene ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group portion may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, a substituted oxycarbonyl group, or an electron-withdrawing substituent. 1b is a substituent bonded to a carbon atom constituting a carbon-carbon double bond, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, a substituted oxycarbonyl group, or an electron-withdrawing substituent. 1a j is an integer of 0 to 6. 1b represents an integer of 0 to 3. 1a and j R 1b At least one of the groups is an electron-withdrawing group. A and X are the same as above. 1 , R b The meanings, specific examples and preferred examples (ranges) of m and n are the same as those described above.1b At least one of the substituents is preferably an electron-withdrawing substituent, particularly preferably -CO 2 R b Preferably, the group has an electron-withdrawing substituent attached to the alpha position.

[0048] [ka]

[0049] That is, a diene compound such as butadienes or cyclopentadiene derivatives represented by the above formula (X4) and an unsaturated carboxylic acid or its ester represented by the above formula (X5) are subjected to a Diels-Alder reaction to obtain a cycloaddition product such as a cyclohexene derivative or bicyclo[2.2.1]heptan-2-ene derivative represented by the above formula (X6), which is then reacted with a peracid or peroxide to obtain an epoxy compound represented by formula (X3) (such as a cyclohexene oxide derivative or a 2,3-epoxybicyclo[2.2.1]heptane derivative). Note that, in cases where Rb is a hydrogen atom, etc., a compound represented by formula (X6) may be reacted with a peracid or peroxide to cyclize immediately after epoxidation, and the compound represented by formula (X1) may be obtained as the main product.

[0050] Representative examples of diene compounds such as butadienes or cyclopentadiene derivatives represented by formula (X4) include butadiene, isoprene, 1,3-cyclopentadiene, 1-methyl-1,3-cyclopentadiene, 2-methyl-1,3-cyclopentadiene, 5-methyl-1,3-cyclopentadiene, 1,2-dimethyl-1,3-cyclopentadiene, 1,4-dimethyl-1,3-cyclopentadiene, 2,3-dimethyl-1,3-cyclopentadiene, 1,2,3,4-tetramethyl- Examples of the diene compound represented by formula (X4), in which A is an oxygen atom or a sulfur atom, include furan, 2-methylfuran, 3-methylfuran, 2,3-dimethylfuran, thiophene, 2-methylthiophene, 3-methylthiophene, 2,3-dimethylthiophene, and the like.

[0051] The reaction between the compound represented by formula (X4) and the compound represented by formula (X5) is carried out in the presence or absence of a solvent. Examples of the solvent include esters such as ethyl acetate; organic acids such as acetic acid; alcohols such as t-butyl alcohol; halogenated hydrocarbons such as chloroform, dichloromethane, and 1,2-dichloroethane; aromatic hydrocarbons such as benzene and toluene; aliphatic hydrocarbons such as hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, and benzonitrile; chain or cyclic ethers such as ethyl ether and tetrahydrofuran. These solvents are used alone or in combination of two or more.

[0052] To improve the reaction rate and selectivity (stereoselectivity, etc.), a Lewis acid may be added to the system. Examples of Lewis acids include AlCl 3 , SnCl 4 , TiCl 4 , B.F. 3 , ZnI 2 Examples include, but are not limited to, the following. The reaction temperature can be appropriately selected depending on the type of reaction raw material, and is preferably, for example, -80°C to 300°C, and more preferably -70°C to 250°C. The reaction is carried out under normal pressure or pressure. The reaction may be carried out in any manner, such as batchwise, semi-batchwise, or continuous. The produced compound represented by formula (X6) can be separated and purified by, for example, a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, or column chromatography, or a combination of these.

[0053] Among the peracids or peroxides to be reacted with the compound represented by formula (X6), examples of the peracid include organic peracids such as performic acid, peracetic acid, trifluoroperacetic acid, perbenzoic acid, m-chloroperbenzoic acid, and monoperoxyphthalic acid; and inorganic peracids such as permanganic acid. The peracid can also be used in the form of a salt. The organic peracid may be an equilibrium peracid (e.g., equilibrium performic acid, equilibrium peracetic acid, etc.). That is, for example, an organic acid such as formic acid or acetic acid may be used in combination with hydrogen peroxide to generate the corresponding organic peracid in the system. When an equilibrium peracid is used, a small amount of a strong acid such as sulfuric acid may be added as a catalyst. The amount of the peracid used is, for example, about 0.8 to 2 mol, preferably about 0.9 to 1.5 mol, and more preferably about 0.95 to 1.2 mol, relative to 1 mol of the compound represented by formula (X6).

[0054] Examples of the peroxide to be reacted with the compound represented by formula (X6) include hydrogen peroxide, peroxide, hydroperoxide, peroxoacid, and salts of peroxoacid. As the hydrogen peroxide, pure hydrogen peroxide may be used, but from the viewpoint of handling, it is usually used in a form diluted with an appropriate solvent, for example, water (for example, 30% by weight hydrogen peroxide solution). The amount of the peroxide such as hydrogen peroxide to be used is, for example, about 0.9 to 5 mol, preferably about 0.9 to 3 mol, and more preferably about 0.95 to 2 mol, relative to 1 mol of the compound represented by formula (X6).

[0055] Hydrogen peroxide is often used together with a metal compound. Examples of the metal compound include oxides containing metal elements such as W, Mo, V, Mn, and Re, oxoacids or their salts, sulfides, halides, oxyhalides, borides, carbides, silicides, nitrides, phosphides, peroxides, complexes (inorganic complexes and organic complexes), and organometallic compounds. These metal compounds can be used alone or in combination of two or more.

[0056] Examples of oxides include tungsten oxide (WO 2 , WO 3 etc.), molybdenum oxide (MoO 2 , MoO 3 etc.), vanadium oxide (VO, V 2 O 3 , V.O. 2 , V 2 O 5 etc.), manganese oxide (MnO, Mn 2 O 3 , Mn 3 O 4 , MnO 2 , Mn 2 O 7 etc.), and composite oxides containing metal elements such as W, Mo, V, and Mn.

[0057] Examples of oxoacids include tungstic acid, molybdic acid, vanadic acid, manganic acid, etc., as well as isopolyacids such as isopolytungstic acid, isopolymolybdic acid, isopolyvanadic acid, etc., and heteropolyacids consisting of the above-mentioned metal elements and other metal elements, etc., such as phosphotungstic acid, silicotungstic acid, phosphomolybdenum acid, silicomolybdic acid, phosphovanadomolybdic acid, etc. As the other metal element, etc. in the heteropolyacid, phosphorus or silicon, particularly phosphorus, is preferred.

[0058] Examples of the salt of an oxoacid include alkali metal salts such as sodium salts and potassium salts of the oxoacids, alkaline earth metal salts such as magnesium salts, calcium salts and barium salts, ammonium salts, transition metal salts, etc. The salt of an oxoacid (e.g., a salt of a heteropolyacid) may be a salt in which a part of the hydrogen atoms corresponding to the cation is replaced with another cation.

[0059] Examples of peroxides containing a metal element include peroxoacids (e.g., peroxotungstic acid, peroxomolybdic acid, peroxovanadic acid, etc.), salts of peroxoacids (alkali metal salts, alkaline earth metal salts, ammonium salts, transition metal salts of the peroxoacids, etc.), peracids (permanganic acid, etc.), salts of peracids (alkali metal salts, alkaline earth metal salts, ammonium salts, transition metal salts of the peracids, etc.), and the like.

[0060] The amount of the metal compound used together with hydrogen peroxide is, for example, about 0.0001 to 2 mol, preferably about 0.0005 to 0.5 mol, and more preferably about 0.001 to 0.2 mol, per mol of the compound represented by Formula (X6).

[0061] The reaction of the compound represented by formula (X6) with a peracid or peroxide is carried out in the presence or absence of a solvent. Examples of the solvent include alcohols such as t-butyl alcohol; halogenated hydrocarbons such as chloroform, dichloromethane, and 1,2-dichloroethane; aromatic hydrocarbons such as benzene; aliphatic hydrocarbons such as hexane, heptane, and octane; alicyclic hydrocarbons such as cyclohexane; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, and benzonitrile; linear or cyclic ethers such as ethyl ether and tetrahydrofuran; esters such as ethyl acetate; organic acids such as acetic acid; and water. These solvents are used alone or in combination. When the reaction is carried out in a heterogeneous system, water or a solvent containing water is often used as the solvent.

[0062] The reaction temperature can be appropriately selected in consideration of the reaction rate and reaction selectivity, and is, for example, preferably −10 to 100° C., more preferably 0 to 80° C. The reaction may be carried out by any method such as a batch method, a semi-batch method, or a continuous method.

[0063] The above reaction causes epoxidation of the double bond of the compound represented by formula (X6), producing an epoxy compound represented by formula (X3). Note that, for example, when Rb is a hydrogen atom, an intramolecular cyclization reaction accompanied by ring-opening of the epoxy ring then proceeds, and a polycyclic alcohol containing an electron-withdrawing substituent and a lactone skeleton represented by formula (X1) can be produced.

[0064] The epoxy compound represented by formula (X3) or the compound represented by formula (X1) produced by the reaction can be separated and purified by a separation means such as filtration, concentration, distillation, extraction, crystallization, recrystallization, column chromatography, or a combination of these.

[0065] In addition, a compound having one or more fluorine atoms bonded to the ring represented in formula (X) can also be produced by subjecting a compound having a hydrogen atom bonded to the ring represented in formula (X) to a conventional fluorination reaction using a fluorinating agent such as fluorine.

[0066] The polycyclic esters of the present invention having an electron-withdrawing substituent and a lactone skeleton can be used as raw materials for functional polymers such as paints and photoresists, and raw materials for pharmaceuticals, agricultural chemicals, and other precision chemicals.

[0067] <Resin> The resin of the present invention exhibits high heat resistance by containing a polymerization unit corresponding to the monomer represented by the above formula (X), i.e., a polymerization unit represented by the following formula (Y), and is therefore preferably used as a photoresist resin, for example. [ka]

[0068] In formula (Y), R h , R 1 , A, B, n, and m are the same as those described in formula (X). That is, R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1 is a substituent bonded to the ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. m represents R 1 and represents an integer of 0 to 8. X represents an electron-withdrawing substituent, and n represents the number of X bonded to the ring and represents an integer of 1 to 9. B represents a single bond or a linking group. The steric position of the COOB- group bonded to the polymer chain may be either endo or exo.

[0069] The resin of the present invention may have a group (sometimes referred to as an "acid-decomposable group") that is partially eliminated by the action of an acid to generate a polar group. As a result, the polarity of the resin of the present invention increases by the action of an acid, and the solubility in an alkaline developer increases.

[0070] Examples of the polar group include acidic groups such as phenolic hydroxyl groups, carboxy groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), sulfonic acid groups, sulfonamide groups, sulfonylimide groups, (alkylsulfonyl)(alkylcarbonyl)methylene groups, (alkylsulfonyl)(alkylcarbonyl)imide groups, bis(alkylcarbonyl)methylene groups, bis(alkylcarbonyl)imide groups, bis(alkylsulfonyl)methylene groups, bis(alkylsulfonyl)imide groups, tris(alkylcarbonyl)methylene groups, and tris(alkylsulfonyl)methylene groups, and alcoholic hydroxyl groups. Among these, carboxy groups, fluorinated alcohol groups (preferably hexafluoroisopropanol groups), and sulfonic acid groups are preferred.

[0071] The acid-decomposable group is preferably a group in which a hydrogen atom of the polar group is substituted with a group that is cleaved by an acid. I )(R II )(R III ), -C(R IV )(R V )(OR VI In the above formula, R I ~R III , R VI R each independently represents an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. IV and R V R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, or an alkenyl group. I ~R III At least two of the groups may be bonded to each other to form a ring. IV and R V may be bonded to each other to form a ring.

[0072] The number of carbon atoms in the acid-decomposable group is not particularly limited, but is preferably at least 4, and more preferably at least 5. The upper limit of the number of carbon atoms is not particularly limited, but is preferably 20.

[0073] R I ~R VI The alkyl group is preferably an alkyl group having 1 to 8 carbon atoms, and examples thereof include a methyl group, an ethyl group, a propyl group, an n-butyl group, an s-butyl group, a t-butyl group, a hexyl group, and an octyl group.

[0074] R I ~R VI The cycloalkyl group may be a monocyclic hydrocarbon group or a polycyclic (bridged ring) hydrocarbon group. The monocyclic hydrocarbon group is preferably a cycloalkyl group having 3 to 8 carbon atoms, such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cyclooctyl group. The polycyclic hydrocarbon group is preferably a cycloalkyl group having 6 to 20 carbon atoms, such as an adamantyl group, a norbornyl group, an isobornyl group, a camphanyl group, a dicyclopentyl group, an α-pinel group, a tricyclodecanyl group, a tetracyclododecyl group, and an androstanyl group. At least one carbon atom in the cycloalkyl group may be substituted with a heteroatom such as an oxygen atom.

[0075] R I ~R VI The aryl group is preferably an aryl group having 6 to 14 carbon atoms, and examples thereof include a phenyl group, a naphthyl group, and an anthryl group.

[0076] R I ~R VI The aralkyl group is preferably an aralkyl group having 7 to 12 carbon atoms, and examples thereof include a benzyl group, a phenethyl group, and a naphthylmethyl group.

[0077] R I ~R VIThe alkenyl group is preferably an alkenyl group having 2 to 8 carbon atoms, and examples thereof include a vinyl group, an allyl group, a butenyl group, and a cyclohexenyl group.

[0078] R I ~R III A ring formed by bonding at least two of the groups, and R IV and R V The ring formed by bonding with each other is preferably a cycloalkane ring. The cycloalkane ring is preferably a monocyclic cycloalkane ring such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, or a cyclohexane ring; or a polycyclic cycloalkane ring such as a norbornane ring, a tricyclodecane ring, a tetracyclododecane ring, or an adamantane ring.

[0079] In addition, R I ~R VI The alkyl group, cycloalkyl group, aryl group, aralkyl group, alkenyl group, and the cycloalkane ring in the above formula (I) may each have a substituent.

[0080] Of the above acid-decomposable groups, t-butyl group, t-amyl group, and groups represented by the following formulae (I) to (IV) are preferred.

[0081] [ka]

[0082] R in the above formulas (I) to (IV) 2 ~R 7 , R a , n, p, and ring Z 1 respectively represent R in the formulas (a1) to (a4) described later. 2 ~R 7 , R a , n, p, and ring Z 1 indicates the same thing.

[0083] The acid-decomposable group may be provided via a spacer. The spacer has the same linking group as exemplified and explained as A in formula (1) described later.

[0084] The resin of the present invention preferably contains an acid-decomposable group as a polymerization unit having an acid-decomposable group. Examples of the polymerization unit having an acid-decomposable group include a polymerization unit represented by the following formula (1).

[0085] [ka]

[0086] In the formula (1), R 1 represents the acid-decomposable group. In addition, in the formula (1), R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom. Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, propyl, isopropyl, n-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 include a group in which one or more hydrogen atoms constituting the alkyl group are replaced with a halogen atom (halo(C 1-6 ) alkyl group) and the like.

[0087] In the formula (1), A represents a single bond or a linking group. Examples of the linking group 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, and a group in which an alkylene group is linked to these. Examples of the alkylene group include linear or branched alkylene groups such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene groups, 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 groups.

[0088] The polymerization unit represented by the formula (1) preferably contains at least one type of polymerization unit selected from the group consisting of polymerization units represented by the following formulae (a1) to (a4). The "at least one type of polymerization unit selected from the group consisting of polymerization units represented by the formulae (a1) to (a4)" may be referred to as "monomer unit a".

[0089] [ka]

[0090] In the polymerized units represented by the formulae (a1) to (a4), R, like R in the formula (1), represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, and A represents a single bond or a linking group. Among them, A in the formulae (a1) to (a4) is preferably a single bond or a group in which an alkylene group and a carbonyloxy group are bonded (alkylene-carbonyloxy group). R 2 ~R 4 are the same or different and each represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 2 and R 3 may be bonded to each other to form a ring. 5 , R6 R is the same or different and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. 7 -COOR c R c represents a tertiary hydrocarbon group which may have a substituent, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group. n represents an integer of 1 to 3. When n is 2 or 3, R 7 may be the same or different. a is Z 1 and are the same or different and each represents an oxo group, an alkyl group, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, or a carboxy group which may be protected by a protecting group. p represents an integer of 0 to 3. Ring Z 1 represents an alicyclic hydrocarbon ring having 3 to 20 carbon atoms. When p is 2 or 3, R a may be the same or different.

[0091] R a Examples of the alkyl group in the formula (I) include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, and n-hexyl groups.

[0092] R a Examples of the hydroxyalkyl group in the formula (I) include hydroxymethyl, 2-hydroxyethyl, 1-hydroxyethyl, 3-hydroxypropyl, 2-hydroxypropyl, 4-hydroxybutyl, and 6-hydroxyhexyl groups. 1-6 Examples of such groups include alkyl groups.

[0093] R a Examples of the protecting group that the hydroxy group and the hydroxyalkyl group in the formula (I) may have include C groups such as methyl, ethyl, and t-butyl groups. 1-4 Alkyl group; a group that forms an acetal bond together with the oxygen atom constituting a hydroxyl group (e.g., C such as methoxymethyl group)1-4 Alkyl-OC 1-4 alkyl group; groups which form an ester bond together with the oxygen atom constituting a hydroxy group (for example, an acetyl group, a benzoyl group, etc.), and the like.

[0094] R a Examples of the protecting group for the carboxyl group in the formula (I) include methyl, ethyl, propyl, isopropyl, n-butyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, and hexyl groups. 1-6 Examples of the group include an alkyl group, a 2-tetrahydrofuranyl group, a 2-tetrahydropyranyl group, and a 2-oxepanyl group.

[0095] R 2 ~R 6 Examples of the alkyl group having 1 to 6 carbon atoms in the formula include linear or branched alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, pentyl, isoamyl, s-amyl, t-amyl, and hexyl groups. 1-4 Alkyl groups are preferred, and C 1-3 Alkyl groups, more preferably C 1-2 It is an alkyl group.

[0096] R 2 ~R 6 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 (e.g., a C group such as a methoxy, ethoxy, or propoxy group). 1-4 Examples of the alkyl group having 1 to 6 carbon atoms and having a substituent include halo (C alkoxy group, etc.) in which one or more hydrogen atoms constituting the alkyl group are replaced with halogen atoms, such as trifluoromethyl and 2,2,2-trifluoroethyl groups. 1-6 ) alkyl groups, hydroxymethyl, 2-hydroxyethyl, methoxymethyl, 2-methoxyethyl, ethoxymethyl, 2-ethoxyethyl, cyanomethyl, and 2-cyanoethyl groups.

[0097] R 2 and R 3 When they are bonded to each other to form a ring, examples of the ring include an alicyclic hydrocarbon ring having 3 to 12 carbon atoms which may have a substituent.

[0098] R c Examples of the tertiary hydrocarbon group in the formula include a t-butyl group and a t-amyl group.

[0099] R c Examples of the substituent that the tertiary hydrocarbon group in the formula (I) may have include halogen atoms, hydroxy groups, substituted hydroxy groups (e.g., C groups such as methoxy, ethoxy, and propoxy groups). 1-4 alkoxy group, cyano group, etc.

[0100] The ring Z 1 Examples of the alicyclic hydrocarbon ring having 3 to 20 carbon atoms in the formula (5.2.1.0) include cycloalkane rings having about 3 to 20 members (preferably 3 to 15 members, particularly preferably 5 to 12 members), such as a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, or a cyclooctane ring; monocyclic alicyclic hydrocarbon rings such as cycloalkene rings having about 3 to 20 members (preferably 3 to 15 members, particularly preferably 5 to 10 members), such as a cyclopropene ring, a cyclobutene ring, a cyclopentene ring, or a cyclohexene ring; an adamantane ring; a norbornane ring, a norbornene ring, a bornane ring, an isobornane ring, or a tricyclo[5.2.1.0 2,6 ] Decane ring, tetracyclo[4.4.0.1 2,5 .1 7,10 ]dodecane ring or other rings containing a norbornane ring or a norbornene ring; perhydroindene ring, decalin ring (perhydronaphthalene ring), perhydrofluorene ring (tricyclo[7.4.0.0 3,8 ]tridecane ring), perhydroanthracene ring, etc., in which the aromatic condensed rings of the polycyclic rings are hydrogenated (preferably completely hydrogenated); tricyclo[4.2.2.1 2,5]Undecane ring and other bicyclic, tricyclic, and tetracyclic bridged hydrocarbon rings (for example, bridged hydrocarbon rings having about 6 to 20 carbon atoms) and other bridged cyclic hydrocarbon rings having about 2 to 6 rings.

[0101] Specific examples of the monomer unit a include a monomer unit represented by the following formula: d represents a methyl group or a hydrogen atom, R e R represents a methyl group or a hydrogen atom. e The bonding position of R is not particularly limited, and e may be bonded to any one of the carbon atoms constituting the alicyclic hydrocarbon ring. e When the group has two or more R e may be the same or different. The monomer unit a can be introduced into the resin by polymerizing the corresponding unsaturated carboxylic acid ester.

[0102] [ka]

[0103] [ka]

[0104] As the polymerized unit represented by the formula (1), in addition to the polymerized unit represented by the monomer unit a, it is also possible to use a polymerized unit corresponding to an unsaturated carboxylic acid ester containing a lactone ring, in which an oxygen atom constituting an ester bond is bonded to the β-position of the lactone ring and at least one hydrogen atom is located at the α-position of the lactone ring (excluding a polymerized unit corresponding to the monomer unit b described below), and the like.

[0105] The polymerization unit represented by the formula (1) may be of only one type, or may be of two or more types in combination. The polymerization unit represented by the formula (1) preferably includes at least one type of polymerization unit selected from the group consisting of the polymerization units represented by the formulas (a1) to (a4). The polymerization unit represented by the formula (1) may be used in combination with at least one type of polymerization unit selected from the group consisting of the polymerization units represented by the formulas (a1) to (a4) and a polymerization unit represented by the formula (1) other than the at least one type of polymerization unit selected from the group consisting of the polymerization units represented by the formulas (a1) to (a4) (polymerization unit represented by other formula (1)). The polymerization unit represented by the other formula (1) may be, for example, R 1 is a group having a tertiary hydrocarbon group (for example, a t-butyl group, a t-amyl group, etc.), is preferred.

[0106] In addition, the resin of the present invention is a [-C(=O)-O-], [-S(=O) 2 It is preferable that the resin contains an alicyclic skeleton having at least [-C(=O)-O-], [-S(=O)-OC(=O)-]. When the resin contains the alicyclic skeleton, it is possible to impart high substrate adhesion and etching resistance to the resin. It is preferable that the resin of the present invention contains the alicyclic skeleton as a polymerization unit having the alicyclic skeleton. Note that the [-C(=O)-O-], [-S(=O) 2 A polymerization unit containing an alicyclic skeleton having at least [-O-] or [-C(=O)-OC(=O)-] may be referred to as a "monomer unit b". Note that the monomer unit b does not include a polymerization unit represented by formula (Y).

[0107] The monomer unit b preferably contains at least one type of polymerization unit selected from the group consisting of polymerization units represented by the following formulae (b1) to (b5) (excluding those corresponding to the polymerization unit represented by formula (Y)). In the following formulae (b1) to (b5), R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, and A represents a single bond or a 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. Z represents a divalent organic group (for example, an alkylene group exemplified and explained as an alkylene group which may be contained in A in the polymerization units represented by the formulae (a1) to (a4) (particularly, a linear alkylene group having 1 to 3 carbon atoms), etc.). V 1 ~V 3 are the same or different and are -CH 2 -, [-C(=O)-], or [-C(=O)-O-]. However, V 1 ~V 3 At least one of the groups is [-C(=O)-O-]. 8 ~R 14 are the same or different and represent a hydrogen atom, a fluorine atom, an alkyl group which may have a fluorine atom, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group.

[0108] [ka]

[0109] Examples of R and A in the polymerization units represented by formulae (b1) to (b5) include the same examples as those of R and A in the polymerization units represented by formulae (a1) to (a4). 8 ~R 14 The alkyl group, the hydroxy group which may be protected by a protecting group, the hydroxyalkyl group which may be protected by a protecting group, and the carboxy group which may be protected by a protecting group in the polymer units represented by the formulas (a1) to (a4) are each independently selected from R aExamples similar to those in

[0110] R 8 ~R 14 Examples of the alkyl group having a fluorine atom in the formula (I) include a group in which one or more hydrogen atoms constituting the alkyl group are replaced with a fluorine atom, such as a trifluoromethyl group or a 2,2,2-trifluoroethyl group [fluoro(C 1-6 ) alkyl group] and the like.

[0111] In the polymerization units represented by the formulas (b1) to (b4), 8 ~R 11 Each of the R 8 ~R 11 When the group has two or more R 8 ~R 11 may be the same or different.

[0112] Among the monomer units b, those represented by formula (b1) and R 8 is a cyano group, a group having an amide group, a group having an imide group, or a fluoro(C 1-6 The polymerization units represented by formula (b1), (b2), (b3) and (b4) are preferable in that they can impart excellent substrate adhesion and etching resistance to the resin, have excellent solubility in an alkaline developer, and can form fine patterns with high precision.

[0113] In the formula (b1), R 8 is a cyano group, a group having an amide group, a group having an imide group, or a fluoro(C 1-6 ) When R is an electron-withdrawing substituent such as an alkyl group, 8 is particularly preferably bonded to at least the carbon atom marked with * in formula (b1).

[0114] Specific examples of the monomer unit b include polymerization units represented by the following formulas: d represents a methyl group or a hydrogen atom. The monomer unit b can be introduced into the resin by polymerizing a corresponding unsaturated carboxylic acid ester.

[0115] [ka]

[0116] [ka]

[0117] The resin of the present invention may further contain a monomer unit c. The monomer unit c is a polymerized unit represented by the following formula (c1). When the resin of the present invention contains the monomer unit c as a polymerized unit, the photoresist resin can be provided with higher transparency and etching resistance. 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. A represents a single bond or a linking group. R b represents a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group, among which a hydroxy group and a cyano group are preferred. q represents an integer of 1 to 5. Ring Z 2 represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. When q is an integer of 2 to 5, 2 to 5 R b may be the same or different.

[0118] [ka]

[0119] Examples of R and A in the polymerization unit represented by formula (c1) include the same examples as those of R and A in the polymerization units represented by formulas (a1) to (a4).b The hydroxy group which may be protected by a protecting group, the hydroxyalkyl group which may be protected by a protecting group, and the carboxy group which may be protected by a protecting group in the polymer units represented by the formulas (a1) to (a4) are each independently selected from R a Examples similar to those in

[0120] Ring Z in the polymerization unit represented by formula (c1) 2 represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms, and examples thereof include cycloalkane rings having about 6 to 20 members (preferably 6 to 15 members, particularly preferably 6 to 12 members) such as a cyclohexane ring or a cyclooctane ring; monocyclic alicyclic hydrocarbon rings such as a cycloalkene ring having about 6 to 20 members (preferably 6 to 15 members, particularly preferably 6 to 10 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 other rings containing a norbornane ring or a norbornene ring; perhydroindene ring, decalin ring (perhydronaphthalene ring), perhydrofluorene ring (tricyclo[7.4.0.0 3,8 ]tridecane ring), perhydroanthracene ring, etc., in which the aromatic condensed rings of the polycyclic rings are hydrogenated (preferably completely hydrogenated); tricyclo[4.2.2.1 2,5 Examples of the bridged cyclic hydrocarbon ring include a bridged cyclic hydrocarbon ring having about 2 to 6 rings, such as a bridged cyclic hydrocarbon ring having about 2, 3 or 4 rings (for example, a bridged hydrocarbon ring having about 6 to 20 carbon atoms) such as an undecane ring. 2 Among these, a norbornane ring or a ring containing a norbornene ring, and an adamantane ring are preferable.

[0121] Specific examples of the monomer unit c include a polymerization unit represented by the following formula: d represents a methyl group or a hydrogen atom. The monomer unit c can be introduced into the resin by polymerizing a corresponding unsaturated carboxylic acid ester.

[0122] [ka]

[0123] The resin of the present invention preferably contains a polymerization unit represented by the formula (Y) and further contains at least one monomer unit selected from the group consisting of the monomer unit a, the monomer unit b, and the monomer unit c. In this case, the content of the polymerization unit represented by the formula (Y) in the resin of the present invention is, for example, 5 to 95 mol%, preferably 10 to 90 mol%, more preferably 20 to 80 mol%, and even more preferably 30 to 60 mol% based on all monomer units (polymerization units) constituting the resin. The content of the monomer unit a is, for example, 10 to 90 mol%, preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and even more preferably 40 to 60 mol% based on all monomer units constituting the resin. When the resin of the present invention has the monomer unit b, the content of the monomer unit b is, for example, 0 to 80 mol%, preferably 10 to 60 mol%, and more preferably 20 to 50 mol% based on all monomer units constituting the resin. When the resin of the present invention has the monomer unit c, the content of the monomer unit c is, for example, 0 to 40 mol %, preferably 1 to 30 mol %, and more preferably 3 to 25 mol % relative to all monomer units constituting the resin.

[0124] The weight average molecular weight (Mw) of the resin of the present invention is, for example, 1000 to 50000, preferably 2000 to 30000, more preferably 3000 to 20000, and particularly preferably 4000 to 15000. The molecular weight distribution (ratio of weight average molecular weight to number average molecular weight: Mw / Mn) of the resin of the present invention is not particularly limited as long as it is 2.5 or less, but is, for example, 1.0 to 2.2, preferably 1.0 to 2.0. In this specification, the weight average molecular weight (Mw) and the number average molecular weight (Mn) can be measured, for example, by GPC using polystyrene as a standard substance, and are preferably measured by the method used in the examples.

[0125] The acid value of the resin of the present invention is, for example, 0.10 mmol / g or less, preferably 0.05 mmol / g or less, more preferably 0.03 mmol / g or less. When the acid value is 0.10 mmol / g or less, the acid decomposable group in the resin is protected without being eliminated, so that the resist has excellent resist performance and good stability over time. The lower limit of the acid value is, for example, 0 mmol / g.

[0126] <Resin manufacturing method> The method for producing the resin of the present invention is not particularly limited, and examples thereof include a dropping polymerization method. Examples of the dropping polymerization method include a method in which a monomer or a solution containing a monomer is dropped in the presence of a polymerization initiator to polymerize the monomer. Specifically, examples of the dropping polymerization method include a step of dropping a solution containing a polymerization initiator and a monomer, and a step of dropping a monomer or a solution containing a monomer into a solution containing a polymerization initiator. In addition to the polymerization initiator, the dropping polymerization method may be performed in the presence of a chain transfer agent. Examples of the monomer include the monomer of the present invention and monomers corresponding to the monomer unit a, the monomer unit b, and the monomer unit c.

[0127] As the polymerization initiator, a known radical polymerization initiator can be used, for example, an azo compound, a peroxide compound, or a redox compound. In particular, dimethyl-2,2'-azobisisobutyrate, azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), t-butyl peroxypivalate, di-t-butyl peroxide, iso-butyryl peroxide, lauroyl peroxide, succinic acid peroxide, dicinnamyl peroxide, di-n-propyl peroxydicarbonate, t-butyl peroxyallyl monocarbonate, benzoyl peroxide, hydrogen peroxide, ammonium persulfate, and the like are preferred.

[0128] The amount of the polymerization initiator used may be any amount necessary to obtain a resin having a desired molecular weight distribution, and is, for example, 0.05 to 120 mol, preferably 0.1 to 50 mol, and more preferably 0.5 to 10 mol, relative to the total amount of monomers (100 mol). The amount of the polymerization initiator used relative to the total amount of monomers (100 parts by weight) is, for example, 0.01 to 30 parts by weight, preferably 0.2 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight.

[0129] The chain transfer agent may be a known chain transfer agent used in radical polymerization. Examples of the chain transfer agent include thiols (n-dodecyl mercaptan, n-octyl mercaptan, n-butyl mercaptan, tert-butyl mercaptan, n-lauryl mercaptan, mercaptoethanol, mercaptopropanol, triethylene glycol dimercaptan, etc.), thiolic acid and its esters (mercaptopropionic acid, thiobenzoic acid, thioglycolic acid, thiomalic acid, etc., and alkyl esters thereof), alcohols (isopropyl alcohol, etc.), amines (dibutylamine, etc.), hypophosphites (sodium hypophosphite, etc.), α-methylstyrene dimer, turbinolene, myrcene, limonene, α-pinene, β-pinene, etc.

[0130] The amount of the chain transfer agent used is not particularly limited, but is preferably 0.001 to 100 mol, more preferably 0.01 to 50 mol, even more preferably 0.1 to 30 mol, and particularly preferably 1 to 10 mol, relative to the total amount of monomers (100 mol). The amount of the chain transfer agent used is not particularly limited, but is preferably 0.1 to 100 parts by weight, more preferably 0.5 to 50 parts by weight, and even more preferably 1 to 25 parts by weight, relative to the total amount of monomers (100 parts by weight).

[0131] The polymerization step may be carried out without a solvent or in the presence of a polymerization solvent. Examples of the polymerization solvent include glycol-based solvents (the glycol-based compounds), ester-based solvents, ketone-based solvents, ether-based solvents, amide-based solvents, sulfoxide-based solvents, monohydric alcohol-based solvents (the monohydric alcohol-based compounds), hydrocarbon-based solvents, and mixtures thereof. Examples of the glycol solvent include propylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, and ethylene glycol monobutyl ether acetate, in addition to the glycol-based compounds. Examples of the ester-based solvent include lactate ester-based solvents such as ethyl lactate; propionate ester-based solvents such as methyl 3-methoxypropionate; and acetate ester-based solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate. Examples of the ketone-based solvent include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclopentanone, and cyclohexanone. Examples of ether-based solvents include chain ethers such as diethyl ether, diisopropyl ether, dibutyl ether, and dimethoxyethane; and cyclic ethers such as tetrahydrofuran and dioxane. Examples of amide-based solvents include N,N-dimethylformamide. Examples of sulfoxide-based solvents include dimethyl sulfoxide. Examples of hydrocarbon-based solvents include 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.

[0132] Preferred polymerization solvents include glycol-based solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ester-based solvents such as ethyl lactate; ketone-based solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl amyl ketone, cyclopentanone, and cyclohexanone; and mixed solvents thereof.

[0133] The dropping of the monomer-containing solution may be continuous (dropping over a certain period of time) or intermittent (dropping in several separate portions). The dropping speed, etc. may be changed once or more during the dropping.

[0134] The total dropping time of the monomer-containing solution (the time from the start of the dropping to the end of the dropping) varies depending on the polymerization temperature and the type of monomer, and is, for example, preferably 1 to 10 hours, more preferably 2 to 9 hours, and further preferably 3 to 8 hours. The temperature of the monomer-containing solution to be dropped is preferably 40°C or lower. If the monomer-containing solution is 40°C or lower, it tends to be more difficult to produce a polymer with an excessively large molecular weight at the beginning of the reaction. In addition, the monomer-containing solution may crystallize if it is cooled too much, depending on the type of monomer.

[0135] The polymerization temperature is not particularly limited, and is, for example, 30 to 150° C., preferably 50 to 120° C., and more preferably 60 to 100° C. The polymerization temperature may be changed one or more times during the polymerization within the above polymerization temperature range.

[0136] In the polymerization step, after the completion of the dropping, a maturing time may be provided. The maturing time is not particularly limited, but is preferably, for example, 0.5 to 10 hours, and more preferably 1 to 5 hours.

[0137] The polymer generated in the polymerization step can be recovered, for example, by precipitation (including reprecipitation). For example, the polymerization solution (polymer dope) is added to a solvent (precipitation solvent) to precipitate the polymer, or the polymer is dissolved again in an appropriate solvent and this solution is added to a solvent (reprecipitation solvent) to reprecipitate, or a solvent (reprecipitation solvent or polymerization solvent) is added to the polymerization solution (polymer dope) to dilute it, thereby obtaining the target polymer. The precipitation or reprecipitation solvent may be either an organic solvent or water, or a mixed solvent.

[0138] As the precipitation or reprecipitation solvent, a well-known or conventional solvent can be used, and is not particularly limited. The precipitation or reprecipitation solvent may be the same solvent as the polymerization solvent, or may be a different solvent. Examples of the precipitation or reprecipitation solvent include the organic solvents exemplified as the polymerization solvent (glycol solvents, ester solvents, ketone solvents, ether solvents, amide solvents, sulfoxide solvents, monohydric alcohol solvents, and hydrocarbon solvents); halogenated hydrocarbons (halogenated aliphatic hydrocarbons such as methylene chloride, chloroform, and carbon tetrachloride; halogenated aromatic hydrocarbons such as chlorobenzene and dichlorobenzene); nitro compounds (nitromethane, nitroethane, and the like); nitriles (acetonitrile, benzonitrile, and the like); carbonates (dimethyl carbonate, diethyl carbonate, ethylene carbonate, propylene carbonate, and the like); carboxylic acids (acetic acid, and the like); and mixed solvents containing these solvents.

[0139] Among them, the precipitation or reprecipitation solvent is preferably a solvent containing at least a hydrocarbon (particularly, an aliphatic hydrocarbon such as hexane or heptane) or an alcohol (particularly, methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.). In such a solvent containing at least a hydrocarbon, the ratio of the hydrocarbon (e.g., an aliphatic hydrocarbon such as hexane or heptane) to the other solvent (e.g., an ester such as ethyl acetate) is, for example, the former / latter (volume ratio; 25°C)=10 / 90 to 99 / 1, preferably the former / latter (volume ratio: 25°C)=30 / 70 to 98 / 2, and more preferably the former / latter (volume ratio: 25°C)=50 / 50 to 97 / 3.

[0140] As the precipitation or reprecipitation solvent, a mixed solvent of alcohol (particularly, methanol) and water, or a mixed solvent of a glycol-based solvent (particularly, polyethylene glycol) and water is also preferred. In this case, the ratio (volume ratio; 25°C) of the organic solvent (alcohol or glycol-based solvent) to water is, for example, the former / latter (volume ratio; 25°C)=10 / 90 to 99 / 1, preferably the former / latter (volume ratio: 25°C)=30 / 70 to 98 / 2, and more preferably the former / latter (volume ratio: 25°C)=50 / 50 to 97 / 3.

[0141] The polymer obtained by precipitation (including reprecipitation) is subjected to a rinsing treatment or a treatment in which the polymer is loosened and dispersed in a solvent while being stirred and washed (sometimes called a "repulping treatment"). A rinsing treatment may be performed after the repulping treatment. By repulping or rinsing the polymer produced by polymerization with a solvent, residual monomers, low molecular weight oligomers, and the like adhering to the polymer can be efficiently removed.

[0142] In the manufacturing method of the present invention, the repulping and rinsing treatment solvents are preferably solvents containing at least a hydrocarbon (particularly, an aliphatic hydrocarbon such as hexane or heptane), an alcohol (particularly, methanol, ethanol, propanol, isopropyl alcohol, butanol, etc.), or an ester (particularly, ethyl acetate, etc.).

[0143] After the precipitation (including reprecipitation), repulping, or rinsing, the solvent may be removed by, for example, decantation, filtration, or the like, as necessary, and a drying treatment may be carried out.

[0144] <Resin composition> The resin composition of the present invention contains at least the resin of the present invention and a radiation-sensitive acid generator.

[0145] The radiation-sensitive acid generator can be a conventional or known compound that efficiently generates an acid by exposure to radiation such as visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays, and is a compound consisting of a mother nucleus and an acid to be generated. Examples of the mother nucleus include onium salt compounds such as iodonium salts, sulfonium salts (including tetrahydrothiophenium salts), phosphonium salts, diazonium salts, and pyridinium salts, sulfonimide compounds, sulfone compounds, sulfonic acid ester compounds, disulfonyldiazomethane compounds, disulfonylmethane compounds, oxime sulfonate compounds, and hydrazine sulfonate compounds. Examples of the acid generated by exposure include alkyl or fluorinated alkylsulfonic acids, alkyl or fluorinated alkyl carboxylic acids, and alkyl or fluorinated alkylsulfonylimide acids. These may be used alone or in combination of two or more.

[0146] The amount of the radiation-sensitive acid generator used can be appropriately selected depending on the strength of the acid generated by irradiation with radiation and the ratio of each repeating unit in the resin, and can be selected, for example, from the range of 0.1 to 30 parts by weight, preferably 1 to 25 parts by weight, and more preferably 2 to 20 parts by weight, per 100 parts by weight of the resin.

[0147] The resin composition can be prepared, for example, by mixing the resin and the radiation-sensitive acid generator in a solvent for resist. The solvent for resist can be any of the glycol solvents, ester solvents, ketone solvents, and mixtures thereof exemplified above as the polymerization solvent.

[0148] The resin composition has a resin concentration of, for example, 3 to 40% by weight. The resin composition may contain an alkali-soluble component such as an alkali-soluble resin (for example, a novolac resin, a phenol resin, an imide resin, or a carboxyl group-containing resin), a colorant (for example, a dye), etc.

[0149] <Pattern formation method> The resin composition of the present invention is applied onto a base material or a substrate, dried, and then exposed to light through a predetermined mask to form a latent image pattern on the coating film (resist film) (or further baked after exposure), followed by alkali dissolution, whereby a fine pattern having excellent heat resistance can be formed with high precision.

[0150] Examples of the base material or substrate include silicon wafers, metals, plastics, glass, ceramics, etc. The resin composition can be applied using a conventional coating means such as a spin coater, a dip coater, a roller coater, etc. The thickness of the coating film is, for example, preferably 0.05 to 20 μm, more preferably 0.1 to 2 μm.

[0151] For exposure, radiation such as visible light, ultraviolet light, far ultraviolet light, electron beams, and X-rays can be used.

[0152] Exposure causes the radiation-sensitive acid generator to generate an acid, which quickly removes protective groups (acid-decomposable groups) such as carboxy groups from polymer units (repeating units having an acid-decomposable group) in the resin composition that become alkali-soluble due to the action of the acid, generating carboxy groups that contribute to solubilization, etc. Therefore, a predetermined pattern can be formed with high accuracy by development with an alkaline developer. EXAMPLES

[0153] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. The weight average molecular weight (Mw) and number average molecular weight (Mn) of the resin were determined by GPC measurement (gel permeation chromatography) using tetrahydrofuran solvent. Polystyrene was used as a standard sample, and a refractometer (RI detector) was used as a detector. The GPC measurement was performed using three Showa Denko K.K. columns (product name "KF-806L") connected in series under the conditions of a column temperature of 40°C, an RI temperature of 40°C, and a tetrahydrofuran flow rate of 0.8 mL / min. The molecular weight distribution (Mw / Mn) was calculated from the measured values.

[0154] Example 1 (Preparation of Monomer A) 50g (0.33 mol) of ethyl 2-cyanoacrylate was dissolved in 200mL of toluene, and 45g (0.68 mol) of 1,3-cyclopentadiene was added dropwise while cooling to a temperature of 35°C or less. After stirring for 1 hour, the mixture was concentrated to obtain 72g of ethyl 5-cyanobicyclo[2.2.1]heptan-2-ene-5-carboxylate (crude product).

[0155] 69 g (0.36 mole equivalent) of ethyl 5-cyanobicyclo[2.2.1]heptan-2-ene-5-carboxylate (crude product) obtained above was dissolved in 501 g of methylene chloride, and 115 g of m-CPBA (m-chloroperbenzoic acid) was slowly added while cooling to 5°C or less. After 4 hours, an aqueous solution of sodium sulfite was added to decompose excess peroxide, and the organic layer was washed with an aqueous solution of sodium bicarbonate. 150 g of formic acid and 303 g of water were added to the organic layer, and the temperature was raised to 50°C and stirring was continued for 4 hours. Extraction was performed with ethyl acetate until no product remained in the aqueous layer. The organic layers were combined and concentrated to obtain 23 g of 1-cyano-5-hydroxy-3-oxatricyclo[4.2.1.0 4,8 ]nonan-2-one (crude product) was obtained.

[0156] 20 g (0.11 moles) of 1-cyano-5-hydroxy-3-oxatricyclo[4.2.1.0 4,8] Nonan-2-one (crude product) was dissolved in 200 g of THF, and 1.37 g of DMAP (N,N-dimethyl-4-aminopyridine), 25 g of sodium 2-fluoroacrylate, 10.0 mg of phenothiazine, and 10.8 mg of methoquinone were added. The solution was heated to 40°C, and 43 g of EDCI·HCl (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride) was added in five portions and stirred at 40°C for 2 hours. Then, 13 g of EDCI·HCl and 7.6 g of sodium 2-fluoroacrylate were added and stirred at 40°C for 3 hours. After adding 364 g of 1N hydrochloric acid, 200 g of ethyl acetate was added and the organic phase was separated. The organic phase was then washed in this order with 200 g of water, 117 g of an 8% aqueous solution of sodium bicarbonate, 200 g of a 2% aqueous solution of sodium bicarbonate twice, and 200 g of water, and then dried and concentrated (35°C, 70 Torr) to obtain 26 g of a crude product. This was purified by crystallization using a mixed solvent of acetonitrile / 2-propanol to obtain 19.0 g of monomer A represented by the following formula. The yield was 68%.

[0157] [ka]

[0158] Example 2 (Preparation of Resin A) In a round-bottom flask equipped with a reflux tube, a stirrer, and a three-way cock, 27.64 g of cyclohexanone was placed under a nitrogen atmosphere, and the temperature was kept at 80°C. A solution of 30.00 g (0.12 mol) of monomer A, 2.10 g of dimethyl-2,2'-azobisisobutyrate [manufactured by Wako Pure Chemical Industries, Ltd., product name "V-601"], and 156.64 g of cyclohexanone was added dropwise at a constant rate over 6 hours while stirring. After the dropwise addition was completed, stirring of the reaction solution was continued for another 2 hours.

[0159] After the polymerization reaction was completed, the reaction solution was dropped into a 14-fold amount of a mixture (25°C) of heptane and ethyl acetate (weight ratio 7:3) with stirring. The resulting precipitate was filtered and dried under reduced pressure to obtain 20.0 g of resin A. GPC analysis of the recovered resin A showed that Mw (weight average molecular weight) was 10200 and the molecular weight distribution (Mw / Mn) was 1.64.

[0160] Resin A has polymerized units represented by the following formula. [ka]

[0161] Example 3 (Preparation of Resin B) In a round-bottom flask equipped with a reflux tube, a stirrer, and a three-way cock, 13.67 g of propylene glycol monomethyl ether acetate and 13.67 g of methyl ethyl ketone were placed under a nitrogen atmosphere, and the temperature was kept at 80°C. While stirring, a solution containing 16.33 g (0.07 mol) of monomer A, 13.67 g (0.07 mol) of 1-(1-cyclohexyl)-1-methylethyl methacrylate, 3.60 g of dimethyl-2,2'-azobisisobutyrate, 54.67 g of propylene glycol monomethyl ether acetate, and 54.67 g of methyl ethyl ketone was added dropwise at a constant rate over 6 hours. After the dropwise addition, the reaction solution was stirred for another 2 hours.

[0162] After the polymerization reaction was completed, the reaction solution was dropped into a mixture (25°C) of 14 times the amount of heptane and ethyl acetate (weight ratio 8:2) with stirring. The resulting precipitate was filtered and dried under reduced pressure to obtain 29.1 g of resin B. GPC analysis of the recovered resin B showed that Mw (weight average molecular weight) was 5800 and the molecular weight distribution (Mw / Mn) was 1.56.

[0163] Resin B has polymerized units represented by the following formula. [ka]

[0164] Comparative Example 1 (Preparation of Resin C) In a round-bottom flask equipped with a reflux condenser, a stirrer, and a three-way cock, 27.64 g of cyclohexanone was placed in a nitrogen atmosphere and the temperature was kept at 80°C. 30.00 g (0.12 mol) of 6-cyano-5-oxo-4-oxatricyclo[4.2.1.0 3,7 ]nonan-2-yl methacrylate was added dropwise at a constant rate to a mixture obtained by using 1.50 g of dimethyl-2,2'-azobisisobutyrate and 156.64 g of cyclohexanone over a period of 6 hours. After the completion of the addition, the reaction solution was stirred for another 2 hours.

[0165] After the polymerization reaction was completed, the reaction solution was dropped into a 14-fold amount of a mixture (25°C) of heptane and ethyl acetate (weight ratio 7:3) with stirring. The resulting precipitate was filtered and dried under reduced pressure to obtain 22.9 g of resin C. The recovered polymer was analyzed by GPC and found to have a weight average molecular weight (Mw) of 9900 and a molecular weight distribution (Mw / Mn) of 1.70.

[0166] Resin C has polymerized units represented by the following formula. [ka]

[0167] Comparative Example 2 (Preparation of Resin D) In a round-bottom flask equipped with a reflux condenser, a stirrer, and a three-way cock, 13.67 g of propylene glycol monomethyl ether acetate and 13.67 g of methyl ethyl ketone were placed under a nitrogen atmosphere, and the temperature was kept at 80°C. 16.21 g (0.07 mol) of 6-cyano-5-oxo-4-oxatricyclo[4.2.1.0 3,7A mixture solution obtained by using 13.79 g (0.07 mol) of 1-(1-cyclohexyl)-1-methylethyl methacrylate, 3.60 g of dimethyl-2,2'-azobisisobutyrate, 54.67 g of propylene glycol monomethyl ether acetate, and 54.67 g of methyl ethyl ketone was added dropwise at a constant rate over 6 hours. After the dropwise addition was completed, the reaction solution was stirred for another 2 hours.

[0168] After the polymerization reaction was completed, the reaction solution was dropped into a mixture (25°C) of 14 times the amount of heptane and ethyl acetate (weight ratio 8:2) with stirring. The resulting precipitate was filtered and dried under reduced pressure to obtain 24.4 g of resin D. The recovered polymer was analyzed by GPC and found to have a weight average molecular weight (Mw) of 6,400 and a molecular weight distribution (Mw / Mn) of 1.52.

[0169] Resin D has polymerized units represented by the following formula. [ka]

[0170] [Heat resistance evaluation] Thermogravimetric measurements were performed on Resins A to D obtained in Examples 2 and 3 and Comparative Examples 1 and 2 using a TG-DTA6200 manufactured by Hitachi High-Tech Science Corp. The results of Example 2 and Comparative Example 1 are shown in Figure 1, and the results of Example 3 and Comparative Example 2 are shown in Figure 2. The measurement conditions were as follows. Temperature range: 30 to 350°C (Example 2 and Comparative Example 1), 30 to 200°C (Example 3 and Comparative Example 2) Heating rate: 20℃ / min.

[0171] As can be seen from the evaluation results (Figures 1 and 2), the resin of the present invention did not decompose even under high temperature conditions and had excellent heat resistance. Therefore, it is expected that the photoresist resin of the present invention will have excellent resist performance.

[0172] As a summary of the above, the configuration of the present invention and its variations are described below. [1] Formula (Y) [where R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1 is a substituent bonded to the ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or no bond. m represents R 1 and n is the number of X and is an integer of 0 to 8. X is an electron-withdrawing substituent, and n is the number of X and is an integer of 1 to 9. B is a single bond or a linking group. The steric position of the COOB- group bonded to the polymer chain may be either endo or exo. [2] R h The photoresist resin according to [1], wherein the halogen atom is a fluorine atom or a chlorine atom. [3] R h The photoresist resin according to [1] or [2], wherein the alkyl group having 1 to 6 carbon atoms and a halogen atom is a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, or a 1,1,2,2,2-pentafluoroethyl group. [4] The photoresist resin according to any one of [1] to [3], wherein X is at least one selected from the group consisting of a halogen atom such as a fluorine atom, a halogenated hydrocarbon group such as a trifluoromethyl group, a carboxyl group, an alkoxycarbonyl group such as a methoxycarbonyl group, an aryloxycarbonyl group such as a phenoxycarbonyl group, an acyl group such as an acetyl group, a cyano group, an aryl group, a 1-alkenyl group, a nitro group, a sulfonic acid alkyl ester group, sulfonic acid, a sulfone group, and a sulfoxy group. [5] A is a non-bond and X is 6-oxabicyclo[3.2.1 1,5 The photoresist resin according to any one of [1] to [4], wherein the compound is bonded to the 1-position (the α-position of the lactone) or the 2-position of the octane ring. [6] A is an alkylene group having 1 to 6 carbon atoms, an oxygen atom, or a sulfur atom, and X is 3-oxatricyclo[4.2.1.0 4,8 ] The photoresist resin according to any one of [1] to [5], wherein the nonane ring or the like is bonded to the 1-position or the 9-position (or a position corresponding thereto). [7] Furthermore, the compounds represented by the formulae (a1) to (a4) may each be represented by 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, and A represents a single bond or a linking group. 2 ~R 4 are the same or different and each represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. 2 and R 3 may be bonded to each other to form a ring. 5 , R 6 R is the same or different and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. 7 -COOR c R c represents a tertiary hydrocarbon group which may have a substituent, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group. n represents an integer of 1 to 3. R a is Z 1 and are the same or different and each represents an oxo group, an alkyl group, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, or a carboxy group which may be protected by a protecting group. p represents an integer of 0 to 3. Ring Z 1 represents an alicyclic hydrocarbon ring having 3 to 20 carbon atoms.]. The photoresist resin according to any one of [1] to [6], comprising at least one polymerized unit selected from the group consisting of polymerized units represented by the following formulas: [8] The photoresist resin according to [7], wherein the content of at least one type of polymerization unit selected from the group consisting of polymerization units represented by formulas (a1) to (a4) is 10 to 90 mol %, 20 to 80 mol %, 30 to 70 mol %, or 40 to 60 mol %, based on all monomer units constituting the resin. [9] Furthermore, the following compounds are represented by the formulae (b1) to (b5): wherein R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, and A represents a single bond or a 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; and Z represents a divalent organic group. V 1 ~V 3 are the same or different and are -CH 2 -, [-C(=O)-], or [-C(=O)-O-]. However, V 1 ~V 3 At least one of the groups is [-C(=O)-O-]. 8 ~R 14 are the same or different and represent a hydrogen atom, a fluorine atom, an alkyl group which may have a fluorine atom, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group.] (excluding those corresponding to the polymerization unit represented by formula (Y).

[10] The photoresist resin according to [9], wherein the content of at least one type of polymerization unit selected from the group consisting of polymerization units represented by formulas (b1) to (b5) is 0 to 80 mol %, 10 to 60 mol %, or 20 to 50 mol %, based on all monomer units constituting the resin.

[11] Furthermore, the compound represented by the formula (c1) [wherein R represents a hydrogen atom, a halogen atom, or an alkyl group having 1 to 6 carbon atoms which may have a halogen atom; A represents a single bond or a linking group] b represents a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group. q represents an integer of 1 to 5. Ring Z 2 represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms.]. The photoresist resin according to any one of [1] to

[10] , comprising a polymerization unit represented by the following formula:

[12] The photoresist resin according to

[11] , wherein the content of the polymerization unit represented by formula (c1) is 0 to 40 mol %, 1 to 30 mol %, or 3 to 25 mol %, based on all monomer units constituting the resin.

[13] The photoresist resin according to any one of [1] to

[12] , wherein the content of the polymerization unit represented by formula (Y) is 5 to 95 mol %, 10 to 90 mol %, 20 to 80 mol %, or 30 to 60 mol %, based on all monomer units (polymerization units) constituting the resin.

[14] The photoresist resin according to any one of [1] to

[13] , which has a weight average molecular weight (Mw) of 1,000 to 50,000, 2,000 to 30,000, 3,000 to 20,000, or 4,000 to 15,000.

[15] The photoresist resin according to any one of [1] to

[14] , having a molecular weight distribution (ratio of weight average molecular weight to number average molecular weight: Mw / Mn) of 2.5 or less, 1.0 to 2.2, or 1.0 to 2.0.

[16] A photoresist resin composition comprising at least the photoresist resin according to any one of [1] to

[15] and a radiation-sensitive acid generator.

[17] A method for forming a pattern, comprising at least the steps of applying the photoresist resin composition according to

[16] to a substrate to form a coating film, exposing the coating film to light, and then dissolving the coating film in an alkali.

[18] Formula (X) [where R h R represents a halogen atom or an alkyl group having 1 to 6 carbon atoms and a halogen atom. 1 is a substituent bonded to the ring, and represents a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group moiety may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A represents an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. m represents R 1 X represents an electron-withdrawing substituent, and n represents the number of X and is an integer of 1 to 9. B represents a single bond or a linking group. CH 2 =C(R h) the steric position of the COOB- group may be either endo or exo.

[19] R h wherein the halogen atom is a fluorine atom or a chlorine atom.

[20] R h The monomer according to

[18] or

[19] , wherein the alkyl group having 1 to 6 carbon atoms and a halogen atom is a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, a 2,2,2-trifluoroethyl group, or a 1,1,2,2,2-pentafluoroethyl group.

[21] The monomer according to any one of

[18] to

[20] , wherein X (electron-withdrawing group) is at least one selected from the group consisting of a halogen atom such as a fluorine atom, a halogenated hydrocarbon group such as a trifluoromethyl group, a carboxyl group, an alkoxycarbonyl group such as a methoxycarbonyl group, an aryloxycarbonyl group such as a phenoxycarbonyl group, an acyl group such as an acetyl group, a cyano group, an aryl group, a 1-alkenyl group, a nitro group, a sulfonic acid alkyl ester group, sulfonic acid, a sulfone group, and a sulfoxy group.

[22] A is a non-bond and X is 6-oxabicyclo[3.2.1 1,5 The monomer according to any one of

[18] to

[21] , which is bonded to the 1-position (α-position of the lactone) or 2-position of the octane ring.

[23] A is an alkylene group having 1 to 6 carbon atoms, an oxygen atom, or a sulfur atom, and X is 3-oxatricyclo[4.2.1.0 4,8 ] The monomer according to any one of

[18] to

[22] , which is bonded to the 1-position or 9-position (or a position corresponding thereto) of a nonane ring or the like. [Industrial Applicability]

[0173] According to the present invention, a monomer that improves solubility and hydrolysis in organic solvents and imparts high heat resistance to a resin is provided. Also provided is a resin having high solubility and hydrolysis in organic solvents and high heat resistance, and a resin composition containing the resin. Furthermore, a method for forming a fine pattern with high accuracy by using the resin composition is provided.

Claims

1. The following formula (Y) 【Chemistry 1】 [In the formula, R ｈ R represents a fluorine atom. １ is a substituent bonded to the ring, and is a halogen atom, an alkyl group having 1 to 6 carbon atoms which may have a halogen atom, a hydroxyalkyl group having 1 to 6 carbon atoms in which the hydroxyl group portion may be protected with a protecting group and which may have a halogen atom, a carboxyl group which may form a salt, or a substituted oxycarbonyl group. A is an alkylene group having 1 to 6 carbon atoms, an oxygen atom, a sulfur atom, or a non-bond. m is R １ and represents an integer of 0 to 8. X represents an electron-withdrawing substituent. The electron-withdrawing substituent is a halogen atom, a halogenated hydrocarbon group, a carboxyl group, an alkoxycarbonyl group, an aryloxycarbonyl group, an acyl group, a cyano group, an aryl group, a 1-alkenyl group, a nitro group, a sulfonic acid alkyl ester group, sulfonic acid, a sulfone group, or a sulfoxy group. n represents the number of X and represents an integer of 1 to 9. B represents a single bond or a linking group. The steric position of the COOB- group bonded to the polymer chain may be either endo or exo. Photoresist resins containing a polymer unit represented by the following formula (however, resins (A-10), (A-11), (A-19), and (A-21) containing the following polymer units are excluded). 【Chemistry 2】 【Chemistry 3】 【Chemistry 4】 【Chemistry 5】

2. Furthermore, the following formulas (a1) to (a4) 【Chemistry 6】 [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, and A represents a single bond or a linking group. ２ ~R ４ are the same or different and each represents an alkyl group having 1 to 6 carbon atoms which may have a substituent. ２ and R ３ may be bonded to each other to form a ring. ５ , R ６ R may be the same or different and represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms which may have a substituent. ７ Ha-COOR ｃ group, and R ｃ represents a tertiary hydrocarbon group, a tetrahydrofuranyl group, a tetrahydropyranyl group, or an oxepanyl group, which may have a substituent. n represents an integer of 1 to 3. ａ Ring Z １ and are the same or different and each represents an oxo group, an alkyl group, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, or a carboxy group which may be protected by a protecting group. p represents an integer of 0 to 3. １ represents an alicyclic hydrocarbon ring having 3 to 20 carbon atoms.

2. The photoresist resin according to claim 1, comprising at least one polymerized unit selected from the group consisting of polymerized units represented by the following formula:

3. Furthermore, the following formulas (b1) to (b5) 【Chemistry 7】 [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, A represents a single bond or a 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, and Z represents a divalent organic group. V １ ~V ３ are the same or different and each represents -CH ２ -, [-C(=O)-], or [-C(=O)-O-]. However, V １ ~V ３ At least one of the groups is [-C(=O)-O-]. ８ ~R １４ are the same or different and each represents a hydrogen atom, a fluorine atom, an alkyl group which may have a fluorine atom, a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group.

3. The photoresist resin according to claim 1, comprising at least one polymerized unit selected from the group consisting of polymerized units represented by formula (Y)

4. Furthermore, the following formula (c1) 【Chemistry 8】 [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. A represents a single bond or a linking group. R ｂ represents a hydroxy group which may be protected by a protecting group, a hydroxyalkyl group which may be protected by a protecting group, a carboxy group which may be protected by a protecting group, or a cyano group. q represents an integer of 1 to 5. Ring Z ２ represents an alicyclic hydrocarbon ring having 6 to 20 carbon atoms. The photoresist resin according to any one of claims 1 to 3, comprising a polymerized unit represented by the following formula:

5. 5. A photoresist resin composition comprising at least the photoresist resin according to claim 1 and a radiation-sensitive acid generator.

6. A pattern forming method comprising at least the steps of applying the photoresist resin composition according to claim 5 to a substrate to form a coating film, exposing the coating film to light, and then dissolving the coating film in an alkali.

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