Resist composition and pattern formation method

Abstract

The present invention provides a resist composition containing a photosensitive onium salt having a highly photosensitive cation, which exhibits good sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability, as well as a method for forming a pattern. [Solution] A resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1), and further comprising a photoacid generator (B) and / or a photodecayable base (C). TIFF2026081065000287.tif3868 (In the formula, R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms.

Description

[Technical Field]

[0001] The present invention relates to a resist composition and a pattern forming method. [Background technology]

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern rules is progressing rapidly. This is because the advancement of 5G high-speed communication and the proliferation of artificial intelligence (AI) necessitates high-performance devices to process this data. As a cutting-edge miniaturization technology, mass production of 5nm node devices is underway using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm. Furthermore, research using EUV lithography is progressing for next-generation 3nm node and even the next-generation 2nm node devices.

[0003] In lithography using DUV light sources, namely KrF excimer lasers and ArF excimer lasers, chemically amplified resist compositions that change the solubility in the developer by using the acid generated from a photosensitive compound (photoacid generator) upon exposure as a catalyst to react with the base polymer have enabled high-sensitivity and high-resolution lithography and have driven miniaturization as the main resist composition used in actual production processes.

[0004] Chemically amplified resist compositions continue to be widely studied and commercialized in next-generation lithography such as EUV. On the other hand, with miniaturization, the demand for improved resist performance is increasing. In particular, variations in resist pattern dimensions (e.g., line width roughness (LWR)) affect variations in pattern dimensions after substrate processing and can ultimately affect the operational stability of the device, so it is necessary to suppress this to the greatest extent possible. Furthermore, it is also required that the resist composition has good storage stability.

[0005] Recently used EUV light sources have low output but high energy due to their short wavelength, resulting in a very small number of photons during exposure. Consequently, the amount of photoacid generator that is sensitive during EUV exposure is less compared to DUV exposure, leading to a non-uniform distribution of acid within the resist film. It is known that this photon shot noise is a cause of reduced LWR performance (Non-Patent Literature 1).

[0006] To improve the performance degradation caused by the low number of photons, it is effective to add a photosensitive photoacid generator. For example, Patent Documents 1 and 2 propose onium salts of sulfonium cations substituted with fluorine atoms.

[0007] However, compounds with cations that have high quantum efficiency and high photoreactivity have problems in terms of storage stability due to their high reactivity. It is known that storage stability deteriorates when combined with highly nucleophilic anions, and Patent Document 3 reports that stability can be improved by adding carboxylic acids or fluoroalcohols such as acetic acid or lactic acid. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] International Publication No. 2019 / 130866 [Patent Document 2] Japanese Patent Publication No. 2010-175893 [Patent Document 3] International Publication No. 2024 / 105962 [Non-patent literature]

[0009] [Non-Patent Document 1] SPIE Vol.3331 p531 (1998) [Overview of the project] [Problems that the invention aims to solve]

[0010] There is a need for the development of chemically amplified resist compositions for EUV lithography that exhibit good sensitivity and excellent LWR performance. Photosensitive compounds containing onium salts with highly photosensitive cations are highly sensitive, but they suffer from poor storage stability.

[0011] The present invention has been made in view of the above circumstances and aims to provide a resist composition containing a photosensitive onium salt having a highly photosensitive cation that exhibits good sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability, as well as a method for forming a pattern. [Means for solving the problem]

[0012] To solve the above problems, the present invention provides a resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms.

[0013] Such a resist composition would be a photosensitive onium salt containing a highly photosensitive cation, exhibiting good sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability.

[0014] Furthermore, in the present invention, it is preferable that the carboxylic acid (D) is one or more selected from the carboxylic acids represented by the following general formulas (2) and (2)'. [ka] (In the formula, R 2is an organic group which may contain fluorine atoms having 1 to 8 carbon atoms. R 4 ~R 5 are each independently an organic group having 1 to 27 carbon atoms which may contain a hetero atom, a hydrogen atom, or a fluorine atom. However, the total number of carbon atoms of R 4 and R 5 is at most 28. Also, R 4 and R 5 may be bonded to each other to form a ring. Ar is an aromatic group having 6 to 30 carbon atoms which may have a substituent.)

[0015] Such a component (D) is preferable for the resist composition of the present invention.

[0016] In the present invention, it is preferable that pKa(C), which is the acid dissociation constant of the photo-cleavable base (C), satisfies pKa(C) > pKa(D), where pKa(D) is the acid dissociation constant of the carboxylic acid (D).

[0017] Such a resist composition has more excellent storage stability.

[0018] In the present invention, it is preferable that the photoacid generator (B) is represented by the following general formula (3), or the photo-cleavable base (C) is represented by the following general formula (4), or both.

Chemical formula

Chemical formula

[0019] The resist composition of the present invention preferably contains such (B) and (C) components.

[0020] At this time, the R in the general formula (3) 7 ~R 9 , and the R in the general formula (4) 11 ~R 13 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0021] It is more preferable that components (B) and (C) have such electron-withdrawing groups.

[0022] Furthermore, in the present invention, the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and it is preferable that the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. [ka] (In the formula, R 14 These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.) [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 3 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.)

[0023] The resist composition of the present invention may contain components (B) and (C) in the resin (A).

[0024] At this time, the M in the general formulas (5) and (6) + However, it is preferable that it be represented by the following general formula (7). [ka] (In the formula, R 16 ~R 18 is an electron-withdrawing group. o, p, and q are integers from 1 to 3. If o, p, and q are integers greater than or equal to 2, R 16 ~R 18 They may be the same or different.

[0025] When components (B) and (C) are contained in resin (A), it is preferable to use such sulfonium cations.

[0026] Furthermore, at this time, the R in the general formula (7) 16 ~R 18 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0027] It is more preferable that the sulfonium cation has such an electron-withdrawing group.

[0028] Furthermore, the present invention provides a pattern forming method, (i) A step of applying the resist composition described above onto a substrate to form a resist film, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. The present invention provides a pattern formation method that includes [specific details].

[0029] With this pattern formation method, since the resist composition of the present invention is used, it is possible to form a pattern with good sensitivity, small edge roughness and dimensional variation, and excellent resolution.

[0030] Furthermore, the present invention provides a resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1'), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R is an organic group having 1 to 30 carbon atoms, which may have substituents, and R' is an organic group that may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.)

[0031] Such a resist composition would be a photosensitive onium salt containing a highly photosensitive cation, exhibiting good sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability.

[0032] Furthermore, in the present invention, it is preferable that the carboxylic acid (D) is one or more selected from the carboxylic acids represented by the following general formulas (1a) and (1b). [ka] (In the formula, R 1aThis is a hydrocarbyl group having 1 to 30 carbon atoms, substituted or unsubstituted with a hydroxyl group, alkoxy group, halogen atom, nitro group, amide group, or heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group. However, it does not contain an ester group. 1a The linking group is a single bond or a divalent linking group, and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1a n is an integer between 0 and 3. 1a When R is 2 or greater, 1a These elements may be identical or different. However, the total number of carbon atoms in the formula is limited to a maximum of 58. [ka] (In the formula, R 2b L is a hydroxyl group, alkoxy group, nitro group, or a C1-C30 hydrocarbyl group substituted or unsubstituted with a heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group, and may also contain an alicyclic group or an aromatic cyclic group. 2b Rf is a single or divalent linking group and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1b and Rf 2b These are, independently, a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

[0033] The resist composition of the present invention also preferably contains such (D) component.

[0034] Furthermore, in the present invention, it is preferable that the acid dissociation constant pKa(C) of the photodisintegrable base (C) is pKa(C) > pKa(D) with respect to the acid dissociation constant pKa(D) of the carboxylic acid (D).

[0035] Such a resist composition would offer superior storage stability.

[0036] Furthermore, in the present invention, it is preferable that the photoacid generator (B) is represented by the following general formula (3), or that the photodecayable base (C) is represented by the following general formula (4), or both. [ka] (In the formula, R 6 R is an organic group with 1 to 40 carbon atoms. 7 ~R 9 is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, then R 7 ~R 9 They may be the same or different. [ka] (In the formula, R 10 R is an organic group with 1 to 40 carbon atoms. 11 ~R 13 is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R 11 ~R 13 They may be the same or different.

[0037] The resist composition of the present invention preferably contains such (B) and (C) components.

[0038] At this time, the R in the general formula (3) 7 ~R 9 , and the R in the general formula (4) 11 ~R 13 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0039] It is more preferable that components (B) and (C) have such electron-withdrawing groups.

[0040] Furthermore, in the present invention, the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and it is preferable that the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. [ka] (In the formula, R 14 These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.) [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 3 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.)

[0041] The resist composition of the present invention may contain components (B) and (C) in the resin (A).

[0042] At this time, the M in the general formulas (5) and (6) + However, it is preferable that it be represented by the following general formula (7). [ka] (In the formula, R 16 ~R 18 is an electron-withdrawing group. o, p, and q are integers from 1 to 3. If o, p, and q are integers greater than or equal to 2, R 16 ~R18 They may be the same or different.

[0043] When components (B) and (C) are contained in resin (A), it is preferable to use such sulfonium cations.

[0044] Furthermore, at this time, the R in the general formula (7) 16 ~R 18 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0045] It is more preferable that the sulfonium cation has such an electron-withdrawing group.

[0046] Furthermore, the present invention provides a pattern forming method, (i) A step of applying the resist composition described above onto a substrate to form a resist film, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. The present invention provides a pattern formation method that includes [specific details].

[0047] With this pattern formation method, since the resist composition of the present invention is used, it is possible to form a pattern with good sensitivity, small edge roughness and dimensional variation, and excellent resolution. [Effects of the Invention]

[0048] As described above, the resist composition of the present invention, obtained by adding a carboxylic acid having a specific structure to a resist composition containing a photosensitive onium salt having a highly photosensitive cation, exhibits high sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability because the carboxylic acid suppresses cation decomposition. Therefore, due to these excellent properties, it is extremely practical and is particularly useful as a material for forming fine patterns in photomasks for ultra-large-scale integrated circuits (ULSIs) or by EB writing, and as a pattern-forming material for EB or EUV lithography. The resist composition of the present invention can be applied not only to lithography in semiconductor circuit formation, but also to the formation of mask circuit patterns, micromachines, and thin-film magnetic head circuits. [Brief explanation of the drawing]

[0049] [Figure 1] This figure shows an example of the change in sensitivity when the storage period is extended in storage stability evaluation. [Modes for carrying out the invention]

[0050] As described above, there has been a need for the development of a resist composition containing a photosensitive onium salt with a highly photosensitive cation that exhibits good sensitivity, low edge roughness and dimensional variation, excellent resolution, and good storage stability, as well as a method for forming patterns.

[0051] As mentioned above, photosensitive onium salts with highly photosensitive cations are unstable and gradually decompose during storage as resist solutions, resulting in fluctuations in resist sensitivity and deterioration of lithography performance. One possible mechanism for the decomposition of iodonium salts during storage is the reaction between nucleophilic components contained in the resist solution and highly photosensitive cations. Here, nucleophilic components include hydroxide ions, carboxylate ions, amines, etc., and include polymers, quenchers, solvents, etc., which are essential components of resist compositions.

[0052] Highly photosensitive cations have high absorption efficiency of EUV light and high electron-accepting capacity, allowing for the increased sensitivity of resists. However, due to the instability of the aforementioned highly photosensitive cations, the systems in which they can be handled stably were limited.

[0053] The inventors investigated various additives to suppress the decomposition of a photosensitive onium salt containing a photosensitive cation in a resist composition. As a result, they found that by adding a specific acid compound, they were able to achieve good sensitivity, low edge roughness and dimensional variation, excellent resolution, and overcome storage stability problems. The specific acid compound in this invention is a Brønsted acid that dissociates and releases a proton in a solution containing the resist composition. It is believed that the addition of the acid donates a proton to the aforementioned nucleophilic component, weakening its nucleophilicity and suppressing the decomposition reaction of the photosensitive cation. Further investigations revealed that a carboxylic acid containing an ester bond and a carboxyl group is the optimal additive for improving storage stability. Furthermore, they found that the above carboxylic acid does not affect the sensitivity during patterning and maintains the sensitivity of the resist, thus completing the present invention.

[0054] In other words, the present invention is a resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms.

[0055] Furthermore, the present invention relates to a resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1'), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R is an organic group having 1 to 30 carbon atoms, which may have substituents, and R' is an organic group that may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.)

[0056] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0057] [Resist composition] The resist composition of the present invention comprises (A) a resin (base polymer) whose alkali solubility increases with the action of an acid, and (D) a carboxylic acid having a specific structure, and further comprises (B) a photoacid generator and / or (C) a photodecayable base. The following is a detailed explanation of each component.

[0058] [(A) Resin] The resin contained in the resist composition of the present invention is not particularly limited as long as its alkali solubility increases with the action of an acid, but it is preferable that the resin component (component A-1) in the resist composition changes in solubility in the developer solution due to the action of an acid, or that the resin component (component A-2) functions as both a photoacid generator and a base polymer.

[0059] The above resin may also contain repeating units represented by the following general formula (b1) (hereinafter also referred to as repeating unit b1) or repeating units represented by the following general formula (b2) (hereinafter also referred to as repeating unit b2).

[0060] [ka]

[0061] In the above general formulas (b1) and (b2), R AThese are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0062] In the above general formula (b1), X 1 This consists of a single bond, a phenylene group, a naphthylene group, and *-C(=O)-OX. 11 -, or *-C(=O)-NH-X 11 -The phenylene group and naphthylene group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbyl group having 1 to 10 carbon atoms which may contain a fluorine atom, an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom, or a halogen atom. 11 This is a saturated hydrocarbylene group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * represents a bond with a carbon atom of the main chain.

[0063] In the general formula (b2) above, X 2 The bond is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * represents a bond with a carbon atom in the main chain. b2 is a C1-C20 hydrocarbyl group which may contain a halogen atom, a cyano group, a hydroxyl group, a nitro group, a heteroatom, a C1-C20 hydrocarbyloxy group which may contain a heteroatom, a C2-C20 hydrocarbylcarbonyl group which may contain a heteroatom, a C2-C20 hydrocarbylcarbonyloxy group which may contain a heteroatom, or a C2-C20 hydrocarbyloxycarbonyl group which may contain a heteroatom. a is an integer from 0 to 4, preferably 0 or 1.

[0064] In the above general formulas (b1) and (b2), AL 1 and AL 2 Each of these is an acid-unstable group. Specific examples of the acid-unstable groups include, but are not limited to, those described in Japanese Patent Publication No. 2013-080033 and Japanese Patent Publication No. 2013-083821.

[0065] Typically, specific examples of the acid-labile group include those represented by the following general formulas (AL-1) to (AL-3).

[0066]

Chemical formula

[0067] In the above general formula (AL-1), R L2 is a hydrocarbyl group having 1 to 40 carbon atoms and may contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, a fluorine atom, and an iodine atom. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. As the hydrocarbyl group, those having 1 to 20 carbon atoms are preferred.

[0068] In the above general formula (AL-1), R L3 and R L4 are each independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms and may contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, a fluorine atom, and an iodine atom. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. Also, any two of R L2 , R L3 and R L4 may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom to which they are bonded, or a carbon atom and an oxygen atom. As the ring, a ring having 4 to 16 carbon atoms is preferred, and an alicyclic ring is particularly preferred.

[0069] In the above general formula (AL-2), R L5 , R L6 and R L7 are each independently a hydrocarbyl group having 1 to 20 carbon atoms and may contain heteroatoms such as an oxygen atom, a sulfur atom, a nitrogen atom, a fluorine atom, and an iodine atom. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. Also, R L5 , R L6 and R L7Any two of them may combine with each other to form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are attached. As the ring, a ring having 4 to 16 carbon atoms is preferable, and an alicyclic ring is particularly preferable.

[0070] In the above general formula (AL-3), b is an integer of 0 to 10, and an integer of 1 to 5 is preferable.

[0071] In the above general formula (AL-3), R L1 has a structure represented by the above general formula (AL-1) or (AL-2).

[0072] Specific examples of the repeating unit b1 include, but are not limited to, those shown below. In the following formulas, R A and AL 1 are the same as described above. Further, R L7 is a hydrogen atom or an organic group having 1 to 30 carbon atoms.

[0073]

Chemical formula

[0074]

Chemical formula

[0075]

Chemical formula

[0076]

Chemical formula

[0077]

Chemical formula

[0078]

Chemical formula

[0079] [ka]

[0080] [ka]

[0081] Specific examples of repeating unit b2 are shown below, but are not limited to these. Note that in the following formula, R A and AL 2 This is the same as described above.

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] The repeating units b1 and b2 are particularly preferably the repeating units exemplified below. In the following formula, R A This is the same as described above.

[0086] [ka]

[0087] The resin (A) may further contain repeating units represented by the following general formula (b3) (hereinafter also referred to as repeating unit b3).

[0088] [ka]

[0089] In the above general formula (b3), b3l is either 0 or 1. When b3l is 0, it is a benzene ring, and when b3l is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that b3l is 0, which is a benzene ring. When b3l is 0, b3m is an integer from 0 to 3, and when b3l is 1, it is an integer from 0 to 5. From the viewpoint of raw material procurement, it is preferable that b3m is an integer from 0 to 3, and more preferably an integer from 0 to 2.

[0090] In the above general formula (b3), R A This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Of these, it is preferably a hydrogen atom or a methyl group, and more preferably a hydrogen atom.

[0091] In the above general formula (b3), X 3 The bond is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * represents a bond with a carbon atom of the main chain. Of these, a single bond or *-C(=O)-O- is preferred, and a single bond is even more preferred.

[0092] In the above general formula (b3), R b32 and R b33Each of these is a C1-C20 hydrocarbyl group, which may independently contain a hydrogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, and 4-methyl groups. Examples include cyclic saturated hydrocarbyl groups with 3 to 20 carbon atoms, such as cyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbyl groups with 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups with 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, the material may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0093] Also, R b32 and R b33These may bond with each other to form a ring with the carbon atoms to which they are bonded. Specific examples of the ring formed in this case include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, an adamantane ring, and so on. Furthermore, some or all of the hydrogen atoms in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, the ring may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and so on.

[0094] In the above general formula (b3), R b31 This may include a halogen atom, a hydroxyl group, a cyano group, a nitro group, a C1-C20 hydrocarbyl group which may contain a heteroatom, a C1-C20 hydrocarbyloxy group which may contain a heteroatom, a C2-C20 hydrocarbyloxycarbonyl group which may contain a heteroatom, a C1-C20 hydrocarbylthio group which may contain a heteroatom, or -N(R b31A )(R b31B ) is R b31A and R b31B Each of these is independently a hydrogen atom or a hydrocarbyl group having 1 to 6 carbon atoms. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom or an iodine atom. The hydrocarbyl group, as well as the hydrocarbyl portion of the hydrocarbyloxy group, hydrocarbyloxycarbonyl group, and hydrocarbylthio group, may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R b32 and R b33Examples of hydrocarbyl groups represented by the above are similar to those exemplified. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, and nitrogen atoms, and as a result, it may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. When b3m is 2 or more, each R b31 They may be the same as or different from each other.

[0095] Also, when b3m is 2 or more, multiple R b31 However, they may bond with each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded. Specific examples of the ring formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornane rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the ring may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- in the ring may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, the ring may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0096] In the above general formula (b3), X 4These are single bonds, aliphatic hydrocarbylene groups having 1 to 4 carbon atoms, carbonyl groups, sulfonyl groups, or groups obtained in combination thereof. Of these, single bonds, carbonyl groups, or sulfonyl groups are preferred from the viewpoint of raw material procurement, and single bonds or carbonyl groups are more preferred from the viewpoint of polar groups generated after the reaction.

[0097] In the above general formula (b3), X 5 and X 6 Each of these is independently either an oxygen atom or a sulfur atom. However, X 4 and X 6 It is bonded to the carbon atom adjacent to the aromatic ring. 5 and X 6 They may be the same or different from each other, but from the standpoint of reactivity, X 5 and X 6 Preferably, both are oxygen atoms.

[0098] Specific examples of repeating unit b3 are shown below, but are not limited to these. Note that in the following formula, R A The same as described above, where Me is a methyl group. Furthermore, the bonding positions of the various substituents on the aromatic ring may be interchanged.

[0099] [ka]

[0100] [ka]

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[0149] The resin (A) described above preferably has repeating units (P-1) having phenolic hydroxyl groups, and more preferably contains repeating units represented by the following general formula (p1) (hereinafter also referred to as repeating unit p1).

[0150] [ka]

[0151] In the above general formula (p1), R C1 represents a hydrogen atom and a methyl group. C R indicates a single bond or an ester bond. C2 represents a monovalent organic group having 1 to 10 carbon atoms, which may contain a fluorine atom, an iodine atom, a trifluoromethyl group, a trifluoromethoxy group, or a heteroatom, and the -CH2- in the organic group may be replaced by -O- or -C(=O)-. cs represents an integer from 0 to 4. cr represents an integer from 1 to 5. n is 0 or 1.

[0152] Specific examples of the repeating unit p1 are shown below, but are not limited to these. Note that in the following formula, R C1 This is the same as described above.

[0153] [ka]

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159] The resin (A) may further contain repeating units represented by the following general formula (d1) (hereinafter also referred to as repeating unit d).

[0160] [ka]

[0161] In the above general formula (d1), R A This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. d1 This consists of a single bond, a phenylene group, a naphthylene group, and *-C(=O)-OZ 11 -, or *-C(=O)-NH-Z 11 -The phenylene group or naphthylene group may be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbyl group having 1 to 10 carbon atoms which may contain a fluorine atom, an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom, or a halogen atom. * represents a bond with a carbon atom of the main chain. Z 11This is a saturated hydrocarbylene group, a phenylene group, or a naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group may contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. d1 This is a group having 1 to 20 carbon atoms that includes a hydrogen atom or at least one structure selected from a hydroxyl group other than a phenolic hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic acid anhydride (-C(=O)-OC(=O)-).

[0162] Specific examples of repeating units d are shown below, but are not limited to these. Note that in the following formula, R A This is the same as described above.

[0163] [ka]

[0164] [ka]

[0165] [ka]

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[0179] As for the repeating unit d, in ArF lithography, it is particularly preferable to have a lactone ring as a polar group, and in KrF lithography, EB lithography, and EUV lithography, it is preferable to have a phenol moiety.

[0180] The resin (A) may further contain repeating units (hereinafter also referred to as repeating unit e) having a structure in which a hydroxyl group is protected by an acid-unstable group. The repeating unit e is not particularly limited as long as it has one or more structures in which a hydroxyl group is protected and the protecting group decomposes upon the action of an acid to generate a hydroxyl group, but it is preferably represented by the following general formula (e1).

[0181] [ka]

[0182] In the above general formula (e1), R A R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. e11 R is a (e+1) valent hydrocarbon group having 1 to 30 carbon atoms, which may contain heteroatoms. e12 is an acid-unstable group. e is an integer between 1 and 4.

[0183] In the above general formula (e1), R e12 The acid-unstable group represented by can be any group that is deprotected by the action of an acid and generates a hydroxyl group. e12 The structure is not particularly limited, but acetal structures, ketal structures, alkoxycarbonyl groups, and alkoxymethyl groups represented by the following general formula (e2) are preferred, and alkoxymethyl groups represented by the following general formula (e2) are particularly preferred.

[0184] [ka] (In the formula, * represents a bond. R e21 (This refers to a hydrocarbyl group with 1 to 15 carbon atoms.)

[0185] R e12 Specific examples of the acid-unstable group represented by the above general formula (e2), the alkoxymethyl group represented by the above general formula (e2), and the repeating unit e are the same as those exemplified in the description of the repeating unit d described in Japanese Patent Application Publication No. 2020-111564.

[0186] The resin (A) may further contain repeating units f derived from styrene, vinylnaphthalene, methacrylates substituted with linear, branched, or cyclic hydrocarbon groups such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, isopropyl methacrylate, cyclohexane methacrylate, and 1-adamantane methacrylate, or derivatives thereof, as units for adjusting the resin solubility.

[0187] The resin (A) may further contain repeating units g derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or derivatives thereof. Specific examples of monomers that give repeating units g are listed below, but are not limited to these.

[0188] [ka]

[0189] The resin (A) may further contain repeating units (5) that generate acid upon exposure to light, represented by the following general formula (5).

[0190] [ka] (In the formula, R 14 These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. +(This is a sulfonium cation.)

[0191] As the repeating unit (5), a structure represented by the following general formulas (h2) to (h4) (hereinafter also referred to as repeating units h2 to h4) is preferred.

[0192] [ka]

[0193] Furthermore, the repeating unit that generates acid upon exposure to light may include a structure represented by the following general formula (h1) (hereinafter also referred to as repeating unit h1).

[0194] [ka]

[0195] In the above general formulas (h1) to (h4), R B This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. A It is a single bond, a phenylene group, -OZ A1 -, -C(=O)-OZ A1 -, or -C(=O)-NH-Z A1 - is Z A1 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. B and Z C Each of these is independently a hydroxylene group having 1 to 20 carbon atoms, which may contain single bonds or heteroatoms. D This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, and -OZ. D1 -, -C(=O)-OZ D1 -, or -C(=O)-NH-Z D1 - is Z D1 This is a phenylene group that may be substituted.

[0196] Z A1The hydrocarbylene group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkane diyl groups such as methylene group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,2-diyl group, propane-2,2-diyl group, propane-1,3-diyl group, 2-methylpropane-1,3-diyl group, butane-1,3-diyl group, butane-2,3-diyl group, butane-1,4-diyl group, pentane-1,3-diyl group, pentane-1,4-diyl group, 2,2-dimethylpropane-1,3-diyl group, pentane-1,5-diyl group, and hexane-1,6-diyl group; and cyclopene. Examples include cyclic saturated hydrocarbylene groups such as tan-1,2-diyl group, cyclopentane-1,3-diyl group, cyclohexane-1,6-diyl group, and adamantane-1,3-diyl group; alkenediyl groups such as ethene-1,2-diyl group, 1-propene-1,3-diyl group, 2-butene-1,4-diyl group, and 1-methyl-1-butene-1,4-diyl group; cyclic unsaturated aliphatic hydrocarbylene groups such as 2-cyclohexene-1,4-diyl group; aromatic hydrocarbylene groups such as phenylene group; and groups obtained by combining these. Furthermore, some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms (especially fluorine atoms or iodine atoms), and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0197] Z B and Z C The hydrocarbylene group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. A specific example is Z A1 Examples of hydrocarbylene groups represented by Z include those similar to those exemplified. B and Z C Preferably, it is an adamantyl group or a substituted phenylene group.

[0198] In the above general formulas (h1) to (h4), R 31 ~R 41 Each of these is independently a C1-C20 hydrocarbyl group which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbyl groups such as cyclohexenyl; aryl groups such as phenyl and naphthyl; heteroaryl groups such as thienyl; and aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl. Of these, aryl groups are preferred. Furthermore, some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0199] Z A and R 31 ~R 41 It contains a phenyl group, and the phenyl group is S in the formula. + A structure in which it is bonded is preferred.

[0200] Also, Z A , R 31 , and R 32 Any two of these may bond with each other to form a ring with the sulfur atom to which they are bonded, 33 , R 34 , and R 35Any two of the following, R 36 , R 37 , and R 38 Any two of the above, or R 39 , R 40 , and R 41 Any two of these may bond with each other to form a ring with the sulfur atom to which they are bonded.

[0201] In the above general formula (h2), R HF This is either a hydrogen atom or a trifluoromethyl group.

[0202] In the above general formula (h2), n 1 is 0 or 1, but Z B When it is a single bond, it is 0. In the general formula (h3) above, n 2 is 0 or 1, but Z C When it is a single bond, it is 0.

[0203] In the above general formula (h1), Xa - This is a non-nucleophilic counterion. The non-nucleophilic counterion is not particularly limited, but examples include: halide ions such as chloride ions and bromide ions; fluoroalkyl sulfonate ions such as triflate ions, 1,1,1-trifluoroethanesulfonate ions and nonafluorobutanesulfonate ions; aryl sulfonate ions such as tosylate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions and 1,2,3,4,5-pentafluorobenzenesulfonate ions; alkyl sulfonate ions such as mesylate ions and butanesulfonate ions; imide ions such as bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions and bis(perfluorobutylsulfonyl)imide ions; methide ions such as tris(trifluoromethylsulfonyl)methide ions and tris(perfluoroethylsulfonyl)methide ions, and preferably anions represented by the following general formulas (h1-1) to (h1-3).

[0204] [ka]

[0205] In the above general formulas (h1-1) to (h1-2), R 51 and R 52 Each of these is independently a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. HF R is a hydrogen atom or a trifluoromethyl group. In the above general formula (h1-3), 53 H4 is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a hydroxyl group, a halogen atom, or a heteroatom. H4 is an integer from 0 to 5.

[0206] Anions represented by the above general formula (h1-1) include, but are not limited to, those described in paragraphs

[0100] to

[0101] of Japanese Patent Publication No. 2014-177407, and those represented by the following formula. HF This is the same as above.

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] Anions represented by the above general formula (h1-2) include, but are not limited to, those described in paragraphs

[0080] to

[0081] of Japanese Patent Publication No. 2010-215608, and those represented by the following formula. In the following formula, Ac is an acetyl group.

[0211] [ka]

[0212] [ka]

[0213] Anions represented by the above general formula (h1-3) include, but are not limited to, those represented by the following formulas. In the following formulas, Me represents a methyl group.

[0214] [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219] Examples of anions in the repeating unit h2 include those described in paragraphs

[0021] to

[0026] of Japanese Patent Publication No. 2014-177407. Also, R HF As for the specific structure of the anion in which is a hydrogen atom, see paragraphs

[0021] to

[0028] of Japanese Patent Publication No. 2010-116550, R HF Specific examples of anion structures when the group is a trifluoromethyl group include those described in paragraphs

[0021] to

[0027] of Japanese Patent Publication No. 2010-077404.

[0220] As an example of an anion in repeating unit h3, in the case of an anion in repeating unit h2, -CH(R HF )CF2SO3 - Replace the part with -C(CF3)2CH2SO3 - Examples of replacements include:

[0221] Preferred examples of anions with repeating units h2~h4 are, but are not limited to, those listed below. Note that in the following formula, R B This is the same as above.

[0222] [ka]

[0223] [ka]

[0224] Specific structures of sulfonium cations in repeating units h2-h4 include those described in paragraph

[0223] of Japanese Patent Publication No. 2008-158339, and those shown below, but are not limited to these. In the following formula, Me is a methyl group and tBu is a tert-butyl group.

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[0285] Since the repeating units h1 to h4 function as photoacid generators, when using resin (A) containing these units, the addition of the additive-type photoacid generator (B) described later can be omitted.

[0286] The resin (A) may further contain repeating units (6) represented by the following general formula (6). In this case, it is preferable that the repeating units (6) generate an acid with lower acidity than the repeating units (5).

[0287] [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 3 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.)

[0288] The following structures are examples of repeating units (6), but are not limited to these. Note that in the following formula, R A This is either a hydrogen atom or a methyl group.

[0289] [ka]

[0290] [ka]

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[0297] Since the repeating units (6) have the function of a photodecayable base, when using resin (A) containing these units, the addition of the additive photodecayable base (C) described later can be omitted.

[0298] In the resin (A) above, the content ratio of repeating units b1, b2, b3, P-1, d, e, f, g, h1, h2, h3, h4, and (6) is preferably 0 <b1≦0.8、0≦b2≦0.8、0≦b3≦0.5、0<P-1≦0.6、0≦d≦0.6、0≦e≦0.3、0≦f≦0.3、0≦g≦0.3、0≦h1≦0.4、0≦h2≦0.4、0≦h3≦0.4、0≦h4≦0.4、0≦(6)≦0.4である。ただし、b1+b2+b3+(P-1)+d+e+f+g+h1+h2+h3+h4+(6)≦1.0である。

[0299] That is, the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and it is preferable that the photoacid generator (B) is represented by the general formula (5), the photodecayable base (C) is represented by the general formula (6), or both.

[0300] At this time, the M in the general formulas (5) and (6) + However, it is preferable that it be represented by the following general formula (7). [ka] (In the formula, R 16 ~R 18 is an electron-withdrawing group. o, p, and q are integers from 1 to 3. If o, p, and q are integers greater than or equal to 2, R 16 ~R 18 They may be the same or different.

[0301] Furthermore, the R in the general formula (7) 16 ~R 18 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0302] The weight-average molecular weight (Mw) of the resin (A) is preferably 1,000 to 500,000, more preferably 3,000 to 100,000, and even more preferably 3,000 to 15,000. If Mw is within this range, sufficient etching resistance can be obtained and a difference in dissolution rate before and after exposure can be ensured, so that the resolution does not decrease. In this invention, Mw is a polystyrene-converted measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent. When measuring GPC, it is usually performed at room temperature around 23°C, but it may also be performed at higher or lower temperatures.

[0303] Furthermore, the molecular weight distribution (Mw / Mn) of the resin (A) tends to be more influential as the pattern rule becomes finer. Therefore, in order to obtain a resist composition suitable for fine pattern dimensions, it is preferable that the Mw / Mn is narrowly dispersed between 1.0 and 2.0. Within this range, there are fewer low molecular weight and high molecular weight polymers compared to Mw, and there is no risk of foreign matter being observed on the pattern or deterioration of the pattern shape after exposure.

[0304] In the resist composition of the present invention, there are no particular restrictions on the amount of resin (A) blended, but for example, it is preferably 1 to 50 parts by mass, more preferably 1 to 20 parts by mass, per 100 parts by mass of the resist composition.

[0305] As a method for synthesizing the polymer that is the resin (A) mentioned above, one example is to heat the monomer that provides the repeating units mentioned above in an organic solvent with a radical polymerization initiator and polymerize it.

[0306] Specific examples of organic solvents used during polymerization include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and γ-butyrolactone (GBL). Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The amount of these initiators added is preferably 0.01 to 25 mol% of the total amount of monomers to be polymerized. The reaction temperature is preferably 50 to 150°C, and more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and more preferably 2 to 12 hours from the viewpoint of production efficiency. The concentration of the polymerization solution (total monomer component weight / total component mixture weight) is preferably 30% to 50%, and more preferably 35% to 45%.

[0307] The polymerization initiator may be added to the monomer solution and supplied to the reaction vessel, or an initiator solution may be prepared separately from the monomer solution and each supplied to the reaction vessel independently. Since the polymerization reaction may proceed due to radicals generated from the initiator during the waiting time, potentially producing a superpolymer, it is preferable from a quality control viewpoint to prepare the monomer solution and the initiator solution independently and add them dropwise. The acid-unstable group may be used as is, introduced into the monomer, or it may be protected or partially protected after polymerization. In addition, chain transfer agents such as dodecyl mercaptan, 2-mercaptoethanol, thioglycolic acid, methyl thioglycolate, and tert-butyl thioglycolate may be used in combination to adjust the molecular weight. In this case, the amount of these chain transfer agents added is preferably 0.01 to 20 mol% of the total amount of monomers to be polymerized.

[0308] In the case of monomers containing hydroxyl groups, the hydroxyl groups may be substituted with acetal groups that are easily deprotected by acids such as ethoxyethoxy groups during polymerization, and then deprotected with a weak acid and water after polymerization. Alternatively, they may be substituted with acetyl groups, formyl groups, pivaloyl groups, etc., and then alkaline hydrolysis may be performed after polymerization.

[0309] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene may be polymerized by heating in an organic solvent with a radical polymerization initiator. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene may be used, and after polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to obtain polyhydroxystyrene or hydroxypolyvinylnaphthalene.

[0310] Specific examples of bases that can be used during alkaline hydrolysis include aqueous ammonia and triethylamine. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0311] The amount of each monomer in the monomer solution can be appropriately set, for example, to achieve a preferred content ratio of the repeating units described above.

[0312] The polymer obtained by the above manufacturing method may be treated as a final product if it is a reaction solution obtained by a polymerization reaction, or as a final product if it is a powder obtained by a purification process such as a reprecipitation method in which the polymerization solution is added to a poor solvent and a powder is obtained. However, from the viewpoint of work efficiency and quality stabilization, it is preferable to treat the polymer solution obtained by dissolving the powder obtained by the purification process in a solvent as the final product.

[0313] Specific examples of solvents used in this process include ketones such as cyclohexanone and methyl-2-n-pentyl ketone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether. Examples include ethers such as ethers; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as GBL; alcohols such as diacetone alcohol (DAA); high-boiling point alcoholic solvents such as diethylene glycol, propylene glycol, glycerin, 1,4-butanediol, and 1,3-butanediol; and mixed solvents thereof.

[0314] In the polymer solution, the concentration of the polymer is preferably 0.01 to 30% by mass, and more preferably 0.1 to 20% by mass.

[0315] It is preferable to filter the reaction solution or polymer solution. Filtering removes foreign matter and gel that may cause defects, which is effective in stabilizing quality.

[0316] Examples of filter materials used in the aforementioned filter filtration include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon materials. However, in the filtration process of the resist composition, filters made of fluorocarbon materials such as Teflon (registered trademark), hydrocarbon materials such as polyethylene and polypropylene, or nylon are preferred. The pore size of the filter can be appropriately selected according to the desired level of cleanliness, but is preferably 100 nm or less, and more preferably 20 nm or less. These filters may be used individually or in combination. The filtration method may involve passing the solution through only once, but it is more preferable to circulate the solution and filter it multiple times. The filtration process can be carried out in any order and number of times in the polymer manufacturing process, but it is preferable to filter the reaction solution after the polymerization reaction, the polymer solution, or both.

[0317] The aforementioned (A) resin may be used alone, or two or more resins with different composition ratios, Mw, and / or Mw / Mn may be used in combination.

[0318] [(B) Photoacid Generator] The photoacid generator (B) contained in the resist composition of the present invention is not particularly limited, but is preferably an onium salt. Furthermore, it is preferable that the photoacid generator (B) is represented by the following general formula (3). [ka] (In the formula, R 6 R is an organic group with 1 to 40 carbon atoms. 7 ~R 9 is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, then R 7 ~R 9 They may be the same or different.

[0319] In the above general formula (3), R 6 R is an organic group with 1 to 40 carbon atoms. 7 ~R9 is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, then R 7 ~R 9 These may be the same or different.

[0320] In the above general formula (3), R 6 Specific examples of anions containing the same elements as those represented by the general formulas (h1-1) to (h1-3) above, but are not limited to these examples.

[0321] In the above general formula (3), the R 7 ~R 9 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0322] Specific examples of sulfonium cations in the above general formula (3) are some of the same as the specific examples of sulfonium cations in the above general formulas (h2) to (h4), but are not limited to these.

[0323] The content of component (B) in the resist composition of the present invention is preferably 5 to 30 parts by mass, more preferably 10 to 20 parts by mass, per 80 parts by mass of component (A). Component (B) may be used alone or in combination of two or more types.

[0324] [(C) Photodecayable bases] The photo-decayable base (C) contained in the resist composition of the present invention is not particularly limited, but is preferably an onium salt. Furthermore, it is preferable that the photo-decayable base (C) is represented by the following general formula (4). The photo-decayable base (C) suppresses acid diffusion by undergoing ion exchange with the strong acid component generated from the photo-acid generator (B). [ka] (In the formula, R 10 R is an organic group with 1 to 40 carbon atoms.11 ~R 13 is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R 11 ~R 13 They may be the same or different.

[0325] In other words, in the present invention, it is preferable that the photoacid generator (B) is represented by the above general formula (3), or that the photodecayable base (C) is represented by the above general formula (4), or both.

[0326] (C) The anionic portion of the photodecayable base preferably contains an aromatic cyclic group.

[0327] (C) The anion portion of the photodecayable base preferably contains one or more iodine atoms.

[0328] (C) The anionic portion of the photodecayable base preferably contains one or more alkoxy groups.

[0329] Specific examples of anions in the general formula (4) above include, but are not limited to, the following structures.

[0330] [ka]

[0331] [ka]

[0332] [ka]

[0333] [ka]

[0334] [ka]

[0335] Specific examples of the anion in the general formula (4) above include, but are not limited to, those containing an iodine atom, as shown below. In the formula below, Me represents a methyl group.

[0336] [ka]

[0337] [ka]

[0338] [ka]

[0339] [ka]

[0340] In the above general formula (4), the R 11 ~R 13 Preferably, each of these is independently selected from one or more organic groups including a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and a carbonyl group, an amide bond, or an unsaturated bond.

[0341] Specific examples of sulfonium cations in the above general formula (4) are some of the same as the specific examples of sulfonium cations in the above general formulas (h2) to (h4), but are not limited to these.

[0342] (B) The cation portion of the photoacid generator and (C) the photodecayable base is preferably represented by the following general formula (c). [ka] (In the formula, Rc1 , R c2 , and R c3 Each of these is an organic group independently having a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, a carboxyl group, a carbonyl group, or an amide group. l is an integer from 0 to 3, m is an integer from 0 to 3, and n is an integer from 1 to 3. If l, m, and n are integers of 2 or more, R c1 , R c2 , and R c3 They may be the same or different.

[0343] In the above general formula (c), l is an integer between 0 and 3, preferably between 1 and 2, and more preferably l=1. m is an integer between 0 and 3, preferably between 1 and 2, and more preferably m=2. n is an integer between 1 and 3, preferably between 1 and 2, and more preferably n=2.

[0344] The fluorine atoms contained in the above general formula (c) are preferably three or more, and more preferably four or more.

[0345] In the above general formula (c), R c2 and R c3 The component is preferably a fluorine atom or a trifluoromethyl group, and more preferably a fluorine atom.

[0346] In the above general formula (c), R c2 or R c3 If the atom is a fluorine atom, it is preferable that at least one fluorine atom is substituted at the meta position relative to the sulfur atom.

[0347] Such sulfonium cations can enhance electron-accepting properties, allowing for efficient conversion of secondary electrons generated by exposure into acid, thus enabling high sensitivity and high resolution.

[0348] Furthermore, the electron-accepting capacity of a triarylsulfonium cation can be estimated by calculating the molecule's LUMO (Lowest Unoccupied Molecular Orbital) level. The LUMO level can be calculated using DFT (Density Functional Theory). Software capable of performing DFT calculations includes, for example, Gaussian16.

[0349] DFT calculations performed using Gaussian16 with the functional B3LYP and the basis set 6-31G(d) yielded a LUMO level of -4.72 eV for the triphenylsulfonium cation. Since the LUMO level energy of the sulfonium cation represented by the general formula (c) above is lower than -4.72 eV, it is considered that the electron-accepting ability is high and the acid generation efficiency is improved.

[0350] The LUMO level of the sulfonium cation represented by the above general formula (c) is lower than -4.72 eV, preferably -5.00 eV or less, more preferably -5.10 eV or less, even more preferably -5.20 eV or less, and particularly preferably -5.30 eV or less.

[0351] For the sulfonium cation represented by the general formula (c) above, an example of LUMO level calculation is shown below, but preferred structures are not limited to these. Gaussian16 was used for the LUMO calculation, with B3LYP as the functional and 6-31G(d) as the basis set. For the iodine atom, the effective core-shell potential approximation was performed, and LanL2DZ was applied as the basis set.

[0352] [ka]

[0353] The content of component (C) in the resist composition of the present invention is preferably 10 to 40 parts by mass, more preferably 20 to 40 parts by mass, per 80 parts by mass of component (A). Component (C) may be used alone or in combination of two or more types.

[0354] [(D) Carboxylic acid] The (D) carboxylic acid contained in the resist composition of the present invention is a carboxylic acid represented by the following general formula (1). [ka] (In the formula, R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms.

[0355] In the above general formula (1), R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms having 1 to 8 carbon atoms.

[0356] Preferably, the carboxylic acid (D) is one or more selected from carboxylic acids represented by the following general formulas (2) and (2)'. [ka] (In the formula, R 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms. 4 ~R 5 Each of these is independently an organic group having 1 to 27 carbon atoms, which may contain heteroatoms, a hydrogen atom, or a fluorine atom. However, R 4 and R 5 The total number of carbon atoms is a maximum of 28. Also, R 4 and R 5 These may be bonded to each other to form a ring. Ar is an aromatic group having 6 to 30 carbon atoms, which may have substituents.

[0357] Examples of compounds with the above general formula (2) include, but are not limited to, the following structures.

[0358] [ka]

[0359] [ka]

[0360] Examples of compounds with the above general formula (2)' include, but are not limited to, the following structures.

[0361] [ka]

[0362] [ka]

[0363] Furthermore, another form of the (D) carboxylic acid contained in the resist composition of the present invention is a carboxylic acid represented by the following general formula (1'). [ka] (In the formula, R is an organic group having 1 to 30 carbon atoms, which may have substituents, and R' is an organic group that may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.)

[0364] In the above general formula (1'), R is an organic group having 1 to 30 carbon atoms, which may have substituents, and R' is an organic group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.

[0365] Preferably, the carboxylic acid (D) is one or more selected from the carboxylic acids represented by the following general formulas (1a) and (1b). [ka] (In the formula, R1a This is a hydrocarbyl group having 1 to 30 carbon atoms, substituted or unsubstituted with a hydroxyl group, alkoxy group, halogen atom, nitro group, amide group, or heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group. However, it does not contain an ester group. 1a The linking group is a single bond or a divalent linking group, and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1a n is an integer between 0 and 3. 1a When R is 2 or greater, 1a These elements may be identical or different. However, the total number of carbon atoms in the formula is limited to a maximum of 58. [ka] (In the formula, R 2b L is a hydroxyl group, alkoxy group, nitro group, or a C1-C30 hydrocarbyl group substituted or unsubstituted with a heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group, and may also contain an alicyclic group or an aromatic cyclic group. 2b Rf is a single or divalent linking group and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1b and Rf 2b These are, independently, a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

[0366] This makes it possible to suppress the deterioration of storage stability that occurs when certain sulfonium cations are combined with specific quenchers.

[0367] The boiling point of the (D) carboxylic acid represented by the general formulas (1a) and (1b) above is preferably 120°C or higher.

[0368] Furthermore, the content of the (D) carboxylic acid represented by the general formulas (1a) and (1b) is preferably 0.1% to 5.0% by mass, more preferably 0.1% to 3.0% by mass, and even more preferably 0.1% to 1.0% by mass, relative to the total solid content of the resist composition.

[0369] Furthermore, the (D) carboxylic acid represented by the general formula (1a) or (1b) is preferably represented by the following general formula (1a-1) or (1b-1). [ka] (In the formula, R 11a is a hydroxyl group, alkoxy group, halogen atom, nitro group, amide group, or heteroatom-substituted or unsubstituted C1-C30 hydrocarbyl group, which may contain a halogen atom, carbonyl group, amide group, or hydroxyl group. However, it does not contain an ester group. X is a hydrogen atom or a methyl group. 11a n is an integer between 0 and 3. 11a When R is 2 or greater, 11a These elements may be identical or different. However, the total number of carbon atoms in the formula is limited to a maximum of 58. [ka] (In the formula, R 21b L is a hydroxyl group, alkoxy group, nitro group, or a C1-C30 hydrocarbyl group substituted or unsubstituted with a heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group, and may also contain an alicyclic group or an aromatic cyclic group. 21b Rf is a single or divalent linking group and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 5 and Rf 6 These are, independently, a fluorine atom or a trifluoromethyl group.

[0370] The (D)carboxylic acids represented by the general formula (1a) above include, but are not limited to, those listed below.

[0371] [ka]

[0372] The (D)carboxylic acids represented by the general formula (1b) above include, but are not limited to, those listed below. In the following formulas, Me represents a methyl group. [ka]

[0373] [ka]

[0374] The content of component (D) in the resist composition of the present invention is preferably 0.001 to 5 parts by mass, more preferably 0.001 to 1 part by mass, per 80 parts by mass of component (A). Component (D) may be used alone or in combination of two or more types.

[0375] Furthermore, in the present invention, it is preferable that the acid dissociation constant pKa(C) of the photodecayable base (C) is greater than or equal to pKa(D) of the carboxylic acid (D). In a resist composition containing such a photodecayable base (C) and carboxylic acid (D), during storage, the anion of the photodecayable base (C) undergoes ion exchange with the carboxylic acid (D), releasing the weaker acid derived from the photodecayable base (C), resulting in a less nucleophilic state and thus improving stability.

[0376] In this invention, the acid dissociation constant is a value calculated using pKa DB in the ACD / Chemsketch ver:9.04 software from Advanced Chemistry Development Inc.

[0377] [(E) Surfactants] The resist composition of the present invention may further contain a surfactant as component (E). Examples of the surfactant include those described in paragraphs

[0165] to

[0166] of Japanese Patent Application Publication No. 2008-111103. By adding a surfactant, the coatability of the resist composition can be further improved or controlled. When the resist composition of the present invention contains component (E), its content is preferably 0.0001 to 10 parts by mass per 80 parts by mass of component (A). Component (E) may be used alone or in combination of two or more types.

[0378] [(F) Crosslinking agent] If the resist composition of the present invention is negative type, it is preferable to further add a crosslinking agent as component (F). This crosslinks the (A) resin in the exposed area and reduces the dissolution rate, thereby obtaining a negative type pattern.

[0379] Specific examples of the crosslinking agent include epoxy compounds, melamine compounds, guanamine compounds, or glycoluryl compounds, or compounds containing double bonds such as urea compounds, isocyanate compounds, azide compounds, or alkenyloxy groups, which are substituted with at least one group selected from methylol groups, alkoxymethyl groups, and acyloxymethyl groups.

[0380] Examples of the epoxy compound include tris(2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0381] Examples of the melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are methoxymethylated, or mixtures thereof; and hexamethoxyethylmelamine, hexaacyloxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are acyloxymethylated, or mixtures thereof.

[0382] Examples of the guanamine compounds include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine, or mixtures thereof; and compounds in which 1 to 4 methylol groups are acyxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, or mixtures thereof.

[0383] Examples of the glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, tetramethylol glycoluryl, and other compounds in which 1 to 4 methylol groups are methoxymethylated, or mixtures thereof; and compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated, or mixtures thereof.

[0384] Examples of the urea compounds include tetramethylolurea, tetramethoxymethylurea, tetramethylolurea, and other compounds in which 1 to 4 methylol groups are methoxymethylated, or mixtures thereof, and tetramethoxyethylurea.

[0385] Examples of the isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0386] Examples of the aforementioned azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0387] Examples of compounds containing the aforementioned alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0388] If the resist composition of the present invention contains component (F), its content is preferably 0.1 to 50 parts by mass, and more preferably 1 to 30 parts by mass, per 80 parts by mass of component (A). Component (F) may be used alone or in combination of two or more types.

[0389] [Pattern formation method] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, in the present invention, a pattern formation method is provided, (i) A step of applying the resist composition described above onto a substrate to form a resist film, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. A pattern formation method including the following can be mentioned.

[0390] [Process (i)] The resist composition of the present invention is applied to a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coatings, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, so that the coating thickness is 0.01 to 2 μm. This is then pre-baked on a hot plate for 30 seconds to 20 minutes to form a resist film.

[0391] [Step (ii)] Next, the resist film is exposed using high-energy rays. Examples of high-energy rays include ultraviolet rays, far ultraviolet rays, electron beams (EB), extreme ultraviolet rays (EUV) with wavelengths of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, or synchrotron radiation as the high-energy rays, the exposure amount is preferably 1 to 200 mJ / cm², either directly or using a mask to form the desired pattern. 2 To the extent, more preferably 10 to 100 mJ / cm² 2 Irradiate to the extent of [a certain degree]. When using EB as the high-energy beam, the exposure dose is preferably 0.1 to 100 μC / cm². 2 To a degree, more preferably 0.5 to 50 μC / cm² 2 The pattern is drawn either directly or using a mask to form the desired pattern. The resist composition of the present invention is particularly suitable for fine patterning using high-energy rays, including KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, and is especially suitable for fine patterning using EB or EUV.

[0392] After exposure, post-exposure baking (PEB) may be performed on a hot plate or in an oven, preferably at 50-150°C for 10 seconds to 30 minutes, more preferably at 60-120°C for 30 seconds to 20 minutes.

[0393] [Step (iii)] After exposure or PEB, the exposed resist film is developed using a developer solution containing 0.1 to 10% by mass, preferably 2 to 5% by mass, of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by conventional methods such as the dip method, puddle method, or spray method, thereby forming the desired pattern. In the case of positive-type resist materials, the parts irradiated with light dissolve in the developer solution, while the parts that were not exposed do not dissolve, forming a positive-type pattern on the substrate. In the case of negative-type resist materials, the opposite is true; that is, the parts irradiated with light become insoluble in the developer solution, while the parts that were not exposed dissolve.

[0394] A negative pattern can be obtained by developing an organic solvent using a positive-type resist material containing a resin with acid-unstable groups. The organic solvent developer can be 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotate, ethyl crotate, propyl formate, methyl methyl acetate, methyl methyl crotate, ethyl crotate, propyl methyl methyl methyl methyl methyl methyl chlorotate,chlorotate, methyl methyl methyl chlorotate, methyl methyl chlorotate, methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl chlorotate, methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chlorotate, methyl methyl methyl chloro Examples include methyl ropionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenyl acetate, and 2-phenylethyl acetate. These organic solvents may be used individually or in mixtures of two or more.

[0395] Rinsing may be performed at the end of development. A solvent that mixes with the developer but does not dissolve the resist film is preferred as the rinsing solution. Preferred solvents include C3-C10 alcohols, C8-C12 ether compounds, C6-C12 alkanes, alkenes, alkynes, and aromatic solvents.

[0396] The C3-C10 alcohols include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, Examples include 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, and 1-octanol.

[0397] Examples of the ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, and di-n-hexyl ether.

[0398] Examples of C6-C12 alkanes include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Examples of C6-C12 alkenes include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Examples of C6-C12 alkynes include hexine, heptine, and octin.

[0399] Examples of the aforementioned aromatic solvents having 6 to 12 carbon atoms include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0400] Rinsing can reduce the occurrence of resist pattern deformation and defects. However, rinsing is not always necessary, and omitting it can reduce the amount of solvent used.

[0401] The developed hole patterns and trench patterns can also be shrunk using thermal flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and crosslinking of the shrinking agent occurs on the surface of the resist film due to the diffusion of an acid catalyst from the resist film during baking, causing the shrinking agent to adhere to the side walls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds, during which excess shrinking agent is removed and the hole pattern is reduced in size. [Examples]

[0402] The present invention will be specifically described below using synthesis examples, examples, and comparative examples, but the present invention is not limited to these. The pKa values ​​were calculated using the pKa DB in the ACD / Chemsketch ver:9.04 software from Advanced Chemistry Development Inc.

[0403] • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol) EL (Ethyl Lactate)

[0404] In Tables 1 and 2, the components are as follows: • Base polymer (resin): P-1~P-15 [ka]

[0405] [ka]

[0406] [ka]

[0407] • Photoacid generators: PAG-1~PAG-3 [ka]

[0408] • Quenchers (photodecayable bases): Q-1 to Q-7, cQ-1 [ka]

[0409] • Acid additives (carboxylic acids): A-1 to A-8, cA-1 to cA-2 [ka]

[0410] [ka]

[0411] Preparation of chemically amplified positive-type resist compositions [Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-9] Chemically amplified positive resist compositions R-1 to R-16 and cR-1 to cR-9 were prepared by dissolving each component in an organic solvent with the compositions shown in Tables 1 and 2 below, and filtering the resulting solutions through a 5 nm nylon filter and a 1 nm UPE filter. The organic solvent was a mixed solvent consisting of 1639 parts by mass of PGMEA, 2166 parts by mass of EL, and 445 parts by mass of DAA.

[0412] [Table 1]

[0413] [Table 2]

[0414] • Storage stability evaluation [Examples 2-1 to 2-16, Comparative Examples 2-1 to 2-8] Resist compositions R-1 to R-16 and cR-1 to cR-8 were stored at 40°C for two weeks, then spin-coated onto Nissan Chemical Industries' DUV-42 anti-reflective coating, manufactured to a thickness of 61 nm, on an 8-inch (20.3 cm) wafer. The mixture was then pre-baked for 60 seconds using a hot plate to produce a resist film with a thickness of approximately 50 nm. Similarly, resist compositions R-1 to R-16 and cR-1 to cR-8 were stored at -10°C for two weeks, then spin-coated onto Nissan Chemical Industries' DUV-42 anti-reflective coating, manufactured to a thickness of 61 nm, on an 8-inch (20.3 cm) wafer. The mixture was then pre-baked for 60 seconds using a hot plate to produce a resist film with a thickness of approximately 50 nm. A Hitachi High-Tech Film Thickness Gauge VM-2210 was used to measure the film thickness. The resist film was exposed using a KrF exposure machine (Nikon Corporation S206D, NA 0.68, σ 0.75, 2 / 3 ring illumination, 6% halftone phase shift), and PEB was performed on a hot plate at 95°C for 60 seconds. After PEB, development was performed in a 2.38 mass% TMAH aqueous solution for 30 seconds. The developed pattern was observed using a Hitachi High-Tech SEM (S9380) and the sensitivity was evaluated.

[0415] The exposure amount at which the pattern line width becomes 90 nm was defined as the sensitivity of the resist film, and the sensitivity was measured when stored at 40°C and when stored at -10°C. Furthermore, storage stability was evaluated based on the following criteria. The results for Examples 2-1 to 2-16 are shown in Table 3, and the results for Comparative Examples 2-1 to 2-8 are shown in Table 4. Table 3 also includes the pKa of the quencher and acid additives contained in the base polymer. In addition, Example 2-8 and Comparative Example 2-6 were selected as representative compositions for the storage stability evaluation, and Figure 1 shows the change in sensitivity when the storage period was extended. The formula for calculating the change in sensitivity is as follows. Sensitivity fluctuation = (D -10 -D 40 ) / D -10 ×100 Here, D -10 The sensitivity of the sample stored at -10°C for two weeks, D 40 This is the sensitivity of samples stored at 40°C for two weeks. (Judgment criteria) ◎: Sensitivity variation is less than 0.5% ○: Sensitivity variation of 0.5% or more but less than 1% ×: Sensitivity variation of 1% or more

[0416] [Table 3]

[0417] [Table 4]

[0418] As shown in Tables 3 and 4, and Figure 1, Comparative Examples 2-1 to 2-6, which used resist compositions cR-1 to cR-6 that did not contain an acid additive (carboxylic acid), gradually became more sensitive when stored at 40°C, resulting in a large difference in sensitivity compared to the product stored at -10°C. On the other hand, Examples 2-1 to 2-16, which used resist compositions R-1 to R-16 of the present invention containing an acid additive of a specific structure, showed smaller sensitivity fluctuations. This is thought to be because the acid additive suppressed the decomposition of sulfonium salts during storage. In particular, Examples 2-1 to 2-14 and 2-16, which used R-1 to R-14 and R-16, where the pKa of the quencher was greater than the pKa of the acid additive, showed even smaller sensitivity fluctuations.

[0419] EUV lithography evaluation [Examples 3-1 to 3-16, Comparative Examples 3-1 to 3-9] The resist compositions R-1 to R-16 and cR-1 to cR-9 were spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed to a thickness of 20 nm. A resist film with a thickness of 50 nm was then fabricated by pre-baking at 130°C for 60 seconds using a hot plate. The resist film was then exposed to an LS pattern with a wafer dimension of 18 nm and a pitch of 36 nm using an ASML EUV scanner NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination) by varying the exposure dose and focus of the 13.5 nm wavelength EUV (exposure dose pitch: 1 mJ / cm²). 2The exposure was performed while adjusting the focus pitch (0.020 μm), and after exposure, PEB was performed at 95°C for 60 seconds. After PEB, paddle development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds, rinsed with ultrapure water, and spin-dried to obtain a positive pattern. The developed LS pattern was observed with a Hitachi High-Tech Corporation measuring SEM (CG6300) and the optimal exposure amount Eop (mJ / cm²) obtained to obtain an LS pattern with a line width of 18 nm and a pitch of 36 nm was determined. 2 The standard deviation (σ) was calculated and defined as the sensitivity. In addition, the pattern width variation (LWR) was determined by taking three times the standard deviation (σ) calculated from the pattern dimension measurement results (3σ). The results for Examples 3-1 to 3-16 are shown in Table 5, and the results for Comparative Examples 3-1 to 3-9 are shown in Table 6. (Judgment criteria) ◎: Eop is 20 mJ / cm² 2 Less than and with an LWR value of less than 4.0 nm ○: Eop is 20 mJ / cm² 2 Less than and with an LWR value of 4.0nm or more and less than 4.5nm ×: Eop is 20 mJ / cm² 2 Above or above, or with an LWR value of 4.5 nm or higher.

[0420] [Table 5]

[0421] [Table 6]

[0422] As shown in Tables 5 and 6, Comparative Examples 3-1 to 3-9, which used resist compositions cR-1 to cR-9 that did not contain the specific acid additive (carboxylic acid), exhibited large edge roughness and dimensional variations. On the other hand, Examples 3-1 to 3-16, which used resist compositions R-1 to R-16 of the present invention that contained the specific acid additive, exhibited small edge roughness and dimensional variations.

[0423] In other words, the results shown in Tables 3 to 6 demonstrate that the resist composition of the present invention, because it contains a carboxylic acid of a specific structure, exhibits low edge roughness and dimensional variation, and good storage stability.

[0424] [Polymer synthesis] The PAG monomers (PAGU-1 to 11), ALG monomers (ALU-1 to 4), PDQ monomers (QU-1 to 4), and other monomers (SU-1 to 3) used in the synthesis of the polymers are as follows. The Mw of the polymers is a polystyrene-converted measurement obtained by GPC using THF as the solvent.

[0425] [ka]

[0426] [ka]

[0427] [ka]

[0428] [ka]

[0429] [Synthesis Example 1-1] Synthesis of Polymer 1 PAGU-1, ALU-2, and SU-1 were dissolved in 1-methoxy-2-propanol in a molar ratio of 10 / 50 / 40. After three cycles of vacuum degassing and nitrogen blowing, AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. This reaction solution was added to 1 L of isopropyl alcohol, and the precipitated white solid was filtered off. The obtained white solid was dried under reduced pressure at 60°C to obtain polymer 1. The composition of polymer 1 is 13 C-NMR and 1 Mw and Mw / Mn were confirmed by GPC using 1H-NMR. [ka]

[0430] [Synthesis Examples 1-2 to 1-25] Synthesis of Polymers 2 to 25 Polymers 2-25 were synthesized in the same manner as in Synthesis Example 1-1, except that the monomers and their ratios were changed as shown in Table 7.

[0431] [Table 7]

[0432] Preparation of positive-type resist compositions [Examples 4-1 to 4-43, Comparative Examples 4-1 to 4-7] Positive-type resist compositions were prepared by dissolving each component in a solvent containing 50 ppm of Polyfox636, a surfactant manufactured by Omnova, as the surfactant, according to the compositions shown in Tables 8 to 12, and then filtering the solution through a 0.2 μm filter.

[0433] The components in Tables 8-12 are as follows: • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol) EL (Ethyl Lactate)

[0434] • Quencher: Q-11~19, cQ-11~13 [ka]

[0435] [ka]

[0436] • Photoacid generator: PAG-11~14 [ka]

[0437] • Acid additives (carboxylic acids): A-11~18, cA-11~13 [ka]

[0438] [ka]

[0439] [Table 8]

[0440] [Table 9]

[0441] [Table 10]

[0442] [Table 11]

[0443] [Table 12]

[0444] EUV exposure evaluation [Examples 5-1 to 5-43, Comparative Examples 5-1 to 5-3] Each resist composition shown in Tables 13-15 was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43 mass%) had been formed to a thickness of 20 nm. A resist film with a thickness of 40 nm was then fabricated by pre-baking at 130°C for 60 seconds using a hot plate. An LS pattern with a wafer-level pitch of 36 nm was exposed to this 40 nm resist film using an ASML EUV scanner NXE34000 (NA 0.33, σ 0.9 / 0.6, dipole illumination). PEB was performed on a hot plate at the temperatures listed in Tables 13-15 for 60 seconds, and development was performed with a 2.38 mass% TMAH aqueous solution for 30 seconds to form an LS pattern with a dimension of 18 nm. The obtained patterns were observed using a Hitachi High-Technologies Corporation length measuring SEM (CG6300), and the sensitivity and LWR were evaluated according to the method described below.

[0445] [Sensitivity evaluation] Optimal exposure amount E for obtaining an LS pattern with a line width of 18 nm and a pitch of 36 nm op (mJ / cm 2 The value of ) was calculated and defined as the sensitivity. A smaller value indicates higher sensitivity. The evaluation results are shown in Tables 13-15.

[0446] [LWR rating] E op The LS pattern obtained by irradiation was measured at 10 points along the longitudinal direction of the line, and the LWR was calculated as three times the standard deviation (σ) (3σ) from the results. The smaller this value, the less roughness and the more uniform the line width pattern. The evaluation results are shown in Tables 13-15.

[0447] [Table 13]

[0448] [Table 14]

[0449] [Table 15]

[0450] As shown in Tables 13-15, Comparative Examples 5-1 to 5-3, which used resist compositions cR-101 to cR-103 that did not contain both a quencher (photodecayable base) and an acid additive of a specific structure (carboxylic acid), exhibited large edge roughness and dimensional variations. On the other hand, Examples 5-1 to 5-43, which used resist compositions R-101 to R-143 of the present invention that contained both a quencher and an acid additive of a specific structure, exhibited small edge roughness and dimensional variations.

[0451] • Storage stability evaluation [Examples 6-1 to 6-9, Comparative Examples 6-1 to 6-4] The resist compositions described in Tables 16-17 were stored at 40°C for two weeks, then spin-coated onto Nissan Chemical Industries' DUV-42 anti-reflective coating, manufactured to a thickness of 61 nm, on an 8-inch (20.3 cm) wafer. A resist film with a thickness of approximately 50 nm was then pre-baked using a hot plate for 60 seconds. The resist compositions described in Tables 16-17 were also stored at -10°C for two weeks, then spin-coated onto Nissan Chemical Industries' DUV-42 anti-reflective coating, manufactured to a thickness of 61 nm, on an 8-inch (20.3 cm) wafer. A resist film with a thickness of approximately 50 nm was then pre-baked using a hot plate for 60 seconds. A Hitachi High-Tech VM-2210 film thickness gauge was used to measure the film thickness. The samples were exposed using a KrF exposure machine (Nikon Corporation; S206D, NA 0.68, σ 0.75, 2 / 3 wheel illumination, 6% halftone phase shift), subjected to PEB on a hot plate at 90°C for 60 seconds, and developed in a 2.38 mass% TMAH aqueous solution for 30 seconds. The developed patterns were observed with a Hitachi High-Technologies Corporation length measuring SEM (S9380) and the sensitivity was evaluated.

[0452] The exposure amount at which the pattern line width becomes 100 nm was defined as the sensitivity of the resist, and the sensitivity was measured when stored at 40°C and when stored at -10°C. The sensitivity variation is shown in Tables 16-17. Furthermore, storage stability was evaluated based on the following criteria. The formula for calculating sensitivity variation is as follows. (Sensitivity fluctuations) Sensitivity fluctuation = (D -10 -D 40 ) / D -10 ×100 Here, D -10 The sensitivity of the sample stored at -10°C for two weeks, D 40 This is the sensitivity of samples stored at 40°C for two weeks. (Judgment criteria) ○: Sensitivity variation is less than ±1% ×: Sensitivity variation of ±1% or more

[0453] [Table 16]

[0454] [Table 17]

[0455] As shown in Tables 16-17, Comparative Examples 6-1 to 6-4, which used resist compositions cR-104 to cR-107 that do not contain acid additives (carboxylic acids), gradually became more sensitive when stored at 40°C, resulting in a large difference in sensitivity compared to the samples stored at -10°C. On the other hand, Examples 6-1 to 6-9, which used resist compositions R-104, R-131 to R-138 of the present invention that contain acid additives of a specific structure, showed smaller sensitivity fluctuations. This is thought to be because the acid additive suppressed the decomposition of sulfonium salts during storage.

[0456] In other words, the results shown in Tables 13-17 demonstrate that the resist composition of the present invention, because it contains a carboxylic acid of a specific structure, exhibits low edge roughness and dimensional variation, and good storage stability.

[0457] This specification includes the following embodiments: [1] A resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R 1 R is an organic group having 1 to 30 carbon atoms. 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms. [2]: The resist composition according to [1], characterized in that the carboxylic acid (D) is one or more selected from carboxylic acids represented by the following general formulas (2) and (2)'. [ka] (In the formula, R 2 This is an organic group that may contain fluorine atoms with 1 to 8 carbon atoms. 4 ~R 5 Each of these is independently an organic group having 1 to 27 carbon atoms, which may contain heteroatoms, a hydrogen atom, or a fluorine atom. However, R 4 and R 5 The total number of carbon atoms is a maximum of 28. Also, R 4 and R 5 These may be bonded to each other to form a ring. Ar is an aromatic group having 6 to 30 carbon atoms, which may have substituents. [3]: The resist composition according to [1] or [2] above, characterized in that the pKa(C), which is the acid dissociation constant of the photodecayable base (C), is pKa(C) > pKa(D) with respect to the pKa(D), which is the acid dissociation constant of the carboxylic acid (D). [4]: A resist composition according to any one of the above [1] to [3], characterized in that the photoacid generator (B) is represented by the following general formula (3), the photodecayable base (C) is represented by the following general formula (4), or both. [ka] (In the formula, R 6 R is an organic group with 1 to 40 carbon atoms. 7 ~R 9 is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, then R7 ~R 9 They may be the same or different. [ka] (In the formula, R 10 R is an organic group with 1 to 40 carbon atoms. 11 ~R 13 is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R 11 ~R 13 They may be the same or different. [5]: The R in the general formula (3) 7 ~R 9 , and the R in the general formula (4) 11 ~R 13 The resist composition according to [4] above, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond. [6]: A resist composition according to any one of the above [1] to [5], characterized in that the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. [ka] (In the formula, R 14 These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.) [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 3 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.) [7]: The M in the general formulas (5) and (6) + The resist composition of [6] described above, characterized in that it is represented by the following general formula (7). [ka] (In the formula, R 16 ~R 18 is an electron-withdrawing group. o, p, and q are integers from 1 to 3. If o, p, and q are integers greater than or equal to 2, R 16 ~R 18 They may be the same or different. [8]: The R in the general formula (7) 16 ~R 18 The resist composition according to [7] above, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond. [9] A method for forming a pattern, (i) A step of forming a resist film by applying one of the resist compositions [1] to [8] above onto a substrate, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. A pattern forming method characterized by including the following.

[10] A resist composition comprising a resin (A) whose alkali solubility increases by the action of an acid, and a carboxylic acid (D) represented by the following general formula (1'), and further comprising a photoacid generator (B) and / or a photodecayable base (C). [ka] (In the formula, R is an organic group having 1 to 30 carbon atoms, which may have substituents, and R' is an organic group that may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.)

[11] : The resist composition of

[10] , characterized in that the carboxylic acid (D) is one or more selected from carboxylic acids represented by the following general formulas (1a) and (1b). [ka] (In the formula, R 1a This is a hydrocarbyl group having 1 to 30 carbon atoms, substituted or unsubstituted with a hydroxyl group, alkoxy group, halogen atom, nitro group, amide group, or heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group. However, it does not contain an ester group. 1a The linking group is a single bond or a divalent linking group, and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1a n is an integer between 0 and 3. 1a When R is 2 or greater, 1a These elements may be identical or different. However, the total number of carbon atoms in the formula is limited to a maximum of 58. [ka] (In the formula, R 2b L is a hydroxyl group, alkoxy group, nitro group, or a C1-C30 hydrocarbyl group substituted or unsubstituted with a heteroatom, and may contain a halogen atom, carbonyl group, amide group, or hydroxyl group, and may also contain an alicyclic group or an aromatic cyclic group. 2b Rf is a single or divalent linking group and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. 1b and Rf 2bThese are, independently, a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

[12] : The resist composition according to

[10] or

[11] , characterized in that the pKa(C), which is the acid dissociation constant of the photodecayable base (C), is pKa(C) > pKa(D) with respect to the pKa(D), which is the acid dissociation constant of the carboxylic acid (D).

[13] : A resist composition according to any one of the above

[10] to

[12] , characterized in that the photoacid generator (B) is represented by the following general formula (3), the photodecayable base (C) is represented by the following general formula (4), or both. [ka] (In the formula, R 6 R is an organic group with 1 to 40 carbon atoms. 7 ~R 9 is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, then R 7 ~R 9 They may be the same or different. [ka] (In the formula, R 10 R is an organic group with 1 to 40 carbon atoms. 11 ~R 13 is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R 11 ~R 13 They may be the same or different.

[14] : The R in the general formula (3) 7 ~R 9 , and the R in the general formula (4) 11 ~R 13 The resist composition according to

[13] above, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

[15] : A resist composition according to any one of the above

[10] to

[14] , wherein the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. [ka] (In the formula, R 14 These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.) [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 3 This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. + (This is a sulfonium cation.)

[16] : The M in the general formulas (5) and (6) + The resist composition of

[15] described above, characterized in that it is represented by the following general formula (7). [ka] (In the formula, R 16 ~R 18 is an electron-withdrawing group. o, p, and q are integers from 1 to 3. If o, p, and q are integers greater than or equal to 2, R 16 ~R 18 They may be the same or different.

[17] : The R in the general formula (7)16 ~R 18 The resist composition according to

[16] , characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

[18] : A method for forming a pattern, (i) A step of forming a resist film by applying one of the resist compositions

[10] to

[17] above onto a substrate, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. A pattern forming method characterized by including the following.

[0458] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. A resist composition comprising a resin (A) whose alkali solubility increases upon the action of an acid, and a carboxylic acid (D) represented by the following general formula (1), and further comprising a photoacid generator (B) and / or a photodecayable base (C). 【Chemistry 1】 (In the formula, R １ R is an organic group having 1 to 30 carbon atoms. ２ This is an organic group that may contain fluorine atoms having 1 to 8 carbon atoms.

2. The resist composition according to claim 1, characterized in that the carboxylic acid (D) is one or more selected from carboxylic acids represented by the following general formulas (2) and (2)'. 【Chemistry 2】 (wherein, R ２ is an organic group which may contain a fluorine atom and has 1 to 8 carbon atoms. R ４ to R ５ are each independently an organic group having 1 to 27 carbon atoms which may contain a hetero atom, a hydrogen atom, or a fluorine atom. However, the total number of carbon atoms of R ４ and R ５ is at most 28. Further, R ４ and R ５ may be bonded to each other to form a ring. Ar is an aromatic group having 6 to 30 carbon atoms which may have a substituent.)

3. The resist composition according to claim 1, characterized in that the acid dissociation constant pKa(C) of the photodecayable base (C) is pKa(C) > pKa(D) with respect to the acid dissociation constant pKa(D) of the carboxylic acid (D).

4. The resist composition according to any one of claims 1 to 3, characterized in that the photoacid generator (B) is represented by the following general formula (3), the photodecayable base (C) is represented by the following general formula (4), or both. 【Transformation 3】 (In the formula, R ６ R is an organic group having 1 to 40 carbon atoms. ７ ~R ９ is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, R ７ ~R ９ These may be the same or different. 【Chemistry 4】 (In the formula, R １０ R is an organic group having 1 to 40 carbon atoms. １１ ~R １３ is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R １１ ~R １３ These may be the same or different.

5. In the general formula (3) above, R ７ ~R ９ , and the R in the general formula (4) １１ ~R １３ The resist composition according to claim 4, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

6. The resist composition according to any one of claims 1 to 3, characterized in that the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. 【Transformation 5】 (In the formula, R １４ These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. １ This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. ＋ (This is a sulfonium cation.) 【Transformation 6】 (In the formula, R Ａ Each of these is independently either a hydrogen atom or a methyl group. ３ This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. ＋ (This is a sulfonium cation.)

7. In the above general formulas (5) and (6), the M ＋ The resist composition according to claim 6, characterized in that it is represented by the following general formula (7). 【Transformation 7】 (In the formula, R １６ ~R １８ is an electron-withdrawing group. o, p, and q are integers from 1 to 3. When o, p, and q are integers greater than or equal to 2, R １６ ~R １８ These may be the same or different.

8. In the above general formula (7), the R １６ ~R １８ The resist composition according to claim 7, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

9. A pattern formation method, (i) A step of forming a resist film by applying the resist composition according to any one of claims 1 to 3 onto a substrate, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. A pattern forming method characterized by including the following.

10. A resist composition comprising a resin (A) whose alkali solubility increases upon the action of an acid, and a carboxylic acid (D) represented by the following general formula (1'), and further comprising a photoacid generator (B) and / or a photodecayable base (C). 【Transformation 8】 (In the formula, R is an organic group having 1 to 30 carbon atoms which may have substituents, and R' is an organic group which may contain a hydrogen atom, a halogen atom, a hydroxyl group, an alkoxy group, or a fluorine atom having 1 to 9 carbon atoms. k is an integer from 1 to 3, and when k is 2 or greater, R' may be the same or different from each other.)

11. The resist composition according to claim 10, characterized in that the carboxylic acid (D) is one or more selected from carboxylic acids represented by the following general formulas (1a) and (1b). 【Chemistry 9】 (In the formula, R １ａ This is a hydroxyl group, alkoxy group, halogen atom, nitro group, amide group, or heteroatom-substituted or unsubstituted C1-C30 hydrocarbyl group, which may contain a halogen atom, carbonyl group, amide group, or hydroxyl group. However, it does not contain an ester group. L １ａ n is a single or divalent linking group, and may contain an ester bond, an ether bond, a lactone ring, an aromatic ring, a fluorine atom, a bromine atom, or an iodine atom. １ａ n is an integer between 0 and 3. １ａ When R is 2 or more, １ａ These elements may be identical or different. However, the total number of carbon atoms in the formula is limited to a maximum of 58. 【Chemistry 10】 (In the formula, R ２ｂ This is a hydroxyl group, alkoxy group, nitro group, or a C1-C30 hydrocarbyl group substituted or unsubstituted with a heteroatom, which may contain a halogen atom, carbonyl group, amide group, or hydroxyl group, and may also contain an alicyclic group or an aromatic cyclic group. ２ｂ Rf is a single or divalent linking group and may contain an ester bond, ether bond, lactone ring, aromatic ring, fluorine atom, bromine atom, or iodine atom. １ｂ and Rf ２ｂ These are, independently, a hydrogen atom, a fluorine atom, or a trifluoromethyl group.

12. The resist composition according to claim 10, characterized in that the acid dissociation constant pKa(C) of the photodecayable base (C) is pKa(C) > pKa(D) with respect to the acid dissociation constant pKa(D) of the carboxylic acid (D).

13. The resist composition according to any one of claims 10 to 12, characterized in that the photoacid generator (B) is represented by the following general formula (3), the photodecayable base (C) is represented by the following general formula (4), or both. 【Chemistry 11】 (In the formula, R ６ R is an organic group having 1 to 40 carbon atoms. ７ ~R ９ is an electron-withdrawing group. l1, m1, and n1 are integers from 1 to 3. If l1, m1, and n1 are integers greater than or equal to 2, R ７ ~R ９ These may be the same or different. 【Chemistry 12】 (In the formula, R １０ R is an organic group having 1 to 40 carbon atoms. １１ ~R １３ is an electron-withdrawing group. l2, m2, and n2 are integers from 1 to 3. If l2, m2, and n2 are integers greater than or equal to 2, then R １１ ~R １３ These may be the same or different.

14. In the general formula (3) above, R ７ ~R ９ , and the R in the general formula (4) １１ ~R １３ The resist composition according to claim 13, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

15. The resist composition according to any one of claims 10 to 12, characterized in that the photoacid generator (B) and / or the photodecayable base (C) are included as repeating units of the resin (A), and the photoacid generator (B) is represented by the following general formula (5), or the photodecayable base (C) is represented by the following general formula (6), or both. 【Chemistry 13】 (In the formula, R １４ These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. １ This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. ＋ (This is a sulfonium cation.) 【Chemistry 14】 (In the formula, R Ａ Each of these is independently either a hydrogen atom or a methyl group. ３ This is a single bond or a divalent organic group having 1 to 40 carbon atoms, and may contain one or more selected from ester bonds, ether bonds, lactone rings, aromatic rings, fluorine atoms, bromine atoms, and iodine atoms. ＋ (This is a sulfonium cation.)

16. In the above general formulas (5) and (6), the M ＋ The resist composition according to claim 15, characterized in that it is represented by the following general formula (7). 【Chemistry 15】 (In the formula, R １６ ~R １８ is an electron-withdrawing group. o, p, and q are integers from 1 to 3. When o, p, and q are integers greater than or equal to 2, R １６ ~R １８ These may be the same or different.

17. In the above general formula (7), the R １６ ~R １８ The resist composition according to claim 16, characterized in that each of them is independently selected from one or more of the following: a fluorine atom, an iodine atom, a perfluoroalkyl group, a nitro group, a cyano group, and an organic group containing a carbonyl group, an amide bond, or an unsaturated bond.

18. A pattern formation method, (i) A step of forming a resist film by coating a resist composition according to any one of claims 10 to 12 onto a substrate, (ii) A step of exposing the resist film with a high-energy beam, (iii) A step of developing the exposed resist film using a developer solution. A pattern forming method characterized by including the following.

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