Onium salt type monomer, polymer, chemically amplified resist composition, and pattern forming method

Abstract

The invention relates to an onium salt type monomer, a polymer, a chemically amplified resist composition and a pattern forming method. The present invention addresses the problem of providing: a sulfonium salt-type monomer used in a chemically amplified resist composition having excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as LWR, CDU, EL, and DOF in optical lithography using high-energy rays; a polymer containing a repeating unit derived from the sulfonium salt-type monomer; a chemically amplified resist composition comprising the polymer; and a pattern forming method using the chemically amplified resist composition. The solution of the present invention is an onium salt type monomer represented by formula (A).

Description

Technical Field

[0001] This invention relates to onium salt type monomers, polymers, chemically amplified resist compositions, and methods for pattern formation. Background Technology

[0002] With the increasing integration and speed of LSI (Light Detection and Retina) technology, the miniaturization of patterned patterns is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving this miniaturization. Regarding the most advanced miniaturization technologies, mass production of 65nm node devices using ArF lithography is underway, and preparations for mass production of the next-generation 45nm node devices using ArF immersion lithography are in progress. For the next-generation 32nm node devices, candidates include immersion lithography using ultra-high nanometer (NA) lenses composed of liquids with a higher refractive index than water, high-refractive-index lenses, and high-refractive-index resist films; extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm; and double exposure (double patterning lithography) using ArF lithography, and research is ongoing.

[0003] As miniaturization progresses and the light diffraction limit approaches, the contrast of light decreases. This decrease in contrast leads to a reduction in the resolution of aperture and trench patterns, as well as a decrease in focus margin, within the positive resist film.

[0004] As patterns become more miniaturized, the linewidth roughness (LWR) of the line pattern and the dimensional uniformity (CDU) of the hole pattern become problems. Some have pointed to the uneven distribution of the base polymer, the effects of agglomeration, and the influence of acid diffusion. Furthermore, the LWR tends to increase due to the thinning of the resist film, and the degradation of LWR caused by thinning accompanying miniaturization becomes a significant issue.

[0005] In EUV lithography resist compositions, high sensitivity, high resolution, and low light-to-weight ratio (LWR) must be achieved simultaneously. Shortening the acid diffusion distance will decrease LWR but decrease sensitivity. For example, lowering the post-exposure baking (PEB) temperature will decrease LWR but decrease sensitivity. Increasing the amount of quencher will also decrease LWR but decrease sensitivity. A trade-off between sensitivity and LWR must be achieved.

[0006] To suppress acid diffusion, resist compounds containing repeating units from onium salts of sulfonic acids with polymeric unsaturated bonds have been proposed (Patent Document 1). These so-called polymer-bonded acid generators produce polymeric sulfonic acids upon exposure, thus exhibiting a very short acid diffusion distance. Furthermore, sensitivity can be improved by increasing the proportion of the acid generator. In additive acid generators, increasing the amount added also increases sensitivity, but this also increases the acid diffusion distance. Because acid diffuses unevenly, increased acid diffusion degrades LWR and CDU. In terms of balancing sensitivity, LWR, and CDU, polymeric acid generators can be said to have superior capabilities.

[0007] Iodine atoms exhibit significant absorption at a wavelength of 13.5 nm in EUV, confirming the effect of secondary electron generation by iodine atoms during exposure, making it a promising candidate for EUV lithography. Patent Document 2 describes a photoacid generator formed by introducing iodine atoms into anion, while Patent Document 3 describes a photoacid generator containing polymerizable groups formed by introducing iodine atoms into anion. This confirms a certain degree of improvement in lithography performance; however, the increased solubility of iodine atoms in organic solvents poses a risk of precipitation in the solvent.

[0008] Patent documents 4 and 5 describe onium salt type monomers that produce fluoroalkyl sulfonic acid, having acenaphthene and maleimide as polymerizable groups. Patent document 6 describes onium salt type monomers that produce acenaphthene sulfonic acid and indene sulfonic acid. Based on these descriptions, there has been some progress in improving photolithography performance, but there is still room for improvement, and the development of more effective resist materials for forming fine patterns is sought.

[0009] Existing technical documents

[0010] Patent documents

[0011] [Patent Document 1] Japanese Patent No. 4425776

[0012] [Patent Document 2] Japanese Patent No. 6720926

[0013] [Patent Document 3] Japanese Patent No. 6973274

[0014] [Patent Document 4] Japanese Patent Application Publication No. 2024-137079

[0015] [Patent Document 5] Japanese Patent Application Publication No. 2024-112755

[0016] [Patent Document 6] International Publication No. 2022 / 172689 Summary of the Invention

[0017] [The problem that the invention aims to solve]

[0018] In chemically amplified resist compositions that use acid as a catalyst, there is a desire to develop resist compositions with higher sensitivity and improved photolithography properties such as LWR, CDU, exposure margin (EL), and depth of focus (DOF).

[0019] In view of the foregoing, the present invention aims to provide a sulfonium salt monomer used in a chemically amplified resist composition, particularly in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV, exhibiting excellent solvent solubility, high sensitivity, high contrast, and excellent lithographic performance such as LWR, CDU, EL, and DOF; a polymer comprising repeating units derived from the sulfonium salt monomer; a chemically amplified resist composition comprising the polymer; and a patterning method using the chemically amplified resist composition.

[0020] [Methods for solving the problem]

[0021] To achieve the aforementioned objectives, the inventors of this application conducted repeated and dedicated research, and as a result, discovered that by using a polymer containing repeating units derived from onium salts containing aromatic sulfonic acid anions with maleimide structures as polymerizable groups as polymer-bonded acid generators, a chemically amplified resist composition with good sensitivity and highly controlled acid diffusion can be obtained, thereby improving the lithography performance of LWR, CDU, EL, DOF, etc., with high contrast, high resolution, and excellent etching resistance. This invention was thus completed.

[0022] That is, the present invention provides the following onium salt type monomers, polymers, chemically amplified resist compositions and patterning methods.

[0023] 1. An onium salt type monomer, represented by the following formula (A).

[0024] [Chemistry 1]

[0025]

[0026] In the formula, n1 is 0 or 1; n2 is 0, 1, 2, 3 or 4; n3 is 0, 1, 2, 3 or 4; but when n1 is 0, 0≤n2+n3≤4, and when n1 is 1, 0≤n2+n3≤6;

[0027] R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group;

[0028] R 1 The halogen atom other than fluorine, nitro, cyano, hydroxyl, carboxyl, hydrocarbon group with 1 to 20 carbon atoms, hydroxyl group with 1 to 20 carbon atoms, or hydrocarbon thio group with 1 to 20 carbon atoms may also contain heteroatoms other than fluorine; when n3 is 2, 3, or 4, each R1 Multiple Rs can be the same or different. 1 They can also bond with each other and form rings together with the carbon atoms they bond with;

[0029] R F It consists of a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms; when n2 is 2, 3, or 4, each R F They can be the same or different;

[0030] L A and L B Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond;

[0031] X L1 and X L2 Each is an independent single bond, or may contain heteroatoms, of a carbon-1 to 40 alkylene group; but L A L B X L1 and X L2 Not all of them will be single keys at the same time;

[0032] Z + It is a ium cation.

[0033] 2. As in 1., the onium salt type monomer is represented by the following formula (A1).

[0034] [Chemistry 2]

[0035]

[0036] In the formula, n1~n3, R A R 1 R F L A L B X L2 and Z + Same as above;

[0037] n4 is 0 or 1; n5 is 0, 1, 2, 3 or 4;

[0038] R 2 It can be a halogen atom, nitro group, cyano group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or an alkyloxy group with 1 to 20 carbon atoms containing heteroatoms; when n4 is 2, 3 or 4, each R 2 Multiple Rs can be the same or different. 2 They can also bond with each other and form rings together with the carbon atoms they bond with.

[0039] 3. As in 2., the onium salt type monomer is represented by the following formula (A2).

[0040] [Chemistry 3]

[0041]

[0042] In the formula, n4, n5, and R A R 2 L A and Z + Same as above.

[0043] 4. Onium salt type monomers such as any one of 1. to 3, wherein Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2).

[0044] [Chemistry 4]

[0045]

[0046] In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group consisting of halogen atoms, or may contain heteroatoms, and has 1 to 30 carbon atoms; furthermore, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they bond with.

[0047] 5. Onium salt type monomers such as any one of 1. to 3., wherein Z + The sulfonium cation is represented by the following formula (Z-3).

[0048] [Chemistry 5]

[0049]

[0050] In the formula, m1 is 0 or 1; m2 is 0 or 1; m3 is 0 or 1; m4 is 0, 1, 2, 3 or 4; m5 is 0, 1, 2, 3 or 4; m6 is 0, 1, 2, 3, 4, 5 or 6; m7 is 0, 1, 2, 3, 4, 5 or 6; m8 is 0, 1 or 2; m9 is 0, 1 or 2; m10 is 0, 1 or 2; m11 is 0 or 1; m12 is 0, 1, 2, 3 or 4; m13 is 0, 1 or 2; m14 is 0, 1 or 2. However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4; when m1 is 1, 0 ≤ m6 + m9 ≤ 6; when m2 is 0, 0 ≤ m7 + m10 ≤ 4; when m2 is 1, 0 ≤ m7 + m10 ≤ 6; when m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, 0 ≤ m12 + m13 ≤ 4; when m11 is 1, 0 ≤ m12 + m13 ≤ 6; and m4 + m12 ≥ 1.

[0051] R F 1 ~R F3 Each is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms; when m5 is 2, 3, or 4, each R F 1 They can be the same or different; when m6 is 2, 3, 4, 5 or 6, each R F2 They can be the same or different; when m7 is 2, 3, 4, 5 or 6, each R F3 They can be the same or different;

[0052] R ct6 ~R ct9 Halogen atoms other than iodine and fluorine atoms, nitro, cyano, hydrocarbon groups with 1 to 20 carbon atoms (which may also contain heteroatoms), hydroxyl groups with 1 to 20 carbon atoms (which may also contain heteroatoms), or thiol groups with 1 to 20 carbon atoms (which may also contain heteroatoms); when m8 is 2, there are 2 R ct6 They can be the same or different, 2 Rs ct6 They can also bond with each other and form rings together with the carbon atoms they bond with; when m9 is 2, the two R atoms... ct7 They can be the same or different, 2 Rs ct7 They can also bond with each other and form rings together with the carbon atoms they bond with; when m10 is 2, the two R atoms... ct8 They can be the same or different, 2 Rs ct8 They can also bond with each other and form rings together with the carbon atoms they bond with; when m13 is 2, the two R atoms... ct9 They can be the same or different, 2 Rs ct9 They can also bond with each other and form rings together with the carbon atoms they bond with;

[0053] Furthermore, S directly bonded to the sulfonium cation + The aromatic rings can also bond with each other and interact with S. + Together they form a ring;

[0054] L C and L D Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond;

[0055] X L3 It is a single bond, or may contain heteroatoms and a hydrocarbon group with 1 to 40 carbon atoms.

[0056] 6. A polymer comprising repeating units of an onium salt monomer from any one of 1 to 4.

[0057] 7. Polymers such as those in 6. function as polymer bonded acid generators.

[0058] 8. The polymer as in 6 or 7, further comprising at least one of the repeating units represented by formula (a1), formula (a2) and formula (a3).

[0059] [Chemistry 6]

[0060]

[0061] In the formula, R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group;

[0062] X 1 Single bond, phenylene, naphthylene, *-C(=O)-OX 11 -or *-C(=O)-NH-X 11 - The phenylene or naphthylene group may also be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydroxyl group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom; X 11 It is a saturated hydrocarbon group, phenylene or naphthylene with 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond or lactone ring;

[0063] X 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-;

[0064] * indicates an atomic bond with a carbon atom in the main chain;

[0065] R 11 It can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; or it can also be a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms; when a1 is 2, 3 or 4, each R 11 They can be the same or different;

[0066] AL 1 and AL 2 Each is an independent acid-labile group;

[0067] a1 can be 0, 1, 2, 3 or 4;

[0068] [Chemistry 7]

[0069]

[0070] In the formula, a11 is 0 or 1; a12 is 0, 1, 2 or 3 when a11 is 0, and 0, 1, 2, 3, 4 or 5 when a11 is 1;

[0071] R A It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups;

[0072] X 3 It represents a single bond, *-C(=O)-O- or *-C(=O)-NH-; * indicates an atomic bond with a carbon atom in the main chain;

[0073] X 4 It is a single bond, an aliphatic alkylene group, a carbonyl group, a sulfonyl group, or a combination thereof, having 1 to 4 carbon atoms;

[0074] X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom; but X 4 and X 6 It is bonded to an adjacent carbon atom of the aromatic ring;

[0075] R 12 and R 13 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms; also, R 12 and R 13 They can also bond with each other and form rings together with the carbon atoms they bond with;

[0076] R 14 It may contain halogen atoms, hydroxyl groups, cyano groups, nitro groups, or hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxygen groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxycarbonyl groups with 2 to 20 carbon atoms containing heteroatoms; or hydrocarbon thio groups with 1 to 20 carbon atoms containing heteroatoms, or -N(R) groups. 14A (R) 14B ); R 14A and R 14B Each is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; when a12 is 2 or more, each R 14 Multiple Rs can be the same or different. 14 They can also bond with each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0077] 9. The polymer of any one of 6 to 8 further comprises at least one of the repeating units represented by formula (b1) and formula (b2).

[0078] [Chemistry 8]

[0079]

[0080] In the formula, R AEach can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group;

[0081] Y 1 It represents a single bond or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain;

[0082] R 21 It is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group other than phenolic hydroxyl group, cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring and carboxylic anhydride (-C(=O)-OC(=O)-);

[0083] R 22 It can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; when b2 is 2, 3 or 4, each R 22 They can be the same or different;

[0084] b1 can be 1, 2, 3 or 4; b2 can be 0, 1, 2, 3 or 4; but 1≤b1+b2≤5.

[0085] 10. A chemically amplified resist composition comprising (A) a base polymer containing a polymer of any one of 6 to 9.

[0086] 11. As in 10, the chemically amplified resist composition also contains (B) an organic solvent.

[0087] 12. Chemically amplified resist compositions such as 10 or 11, further comprising (C) a quencher.

[0088] 13. A chemically amplified resist composition as described in any of 10 to 12, further comprising (D) a photoacid generator.

[0089] 14. A chemically amplified resist composition as described in any of 10 to 13, further comprising (E) a surfactant.

[0090] 15. A pattern forming method comprising the steps of: forming a resist film on a substrate using a chemically amplified resist composition as described in any one of 10 to 14; exposing the resist film to high-energy radiation; and developing the exposed resist film using a developer.

[0091] 16. The pattern forming method of 15, wherein the high-energy ray is a KrF excimer laser, an ArF excimer laser, an EB, or an EUV with a wavelength of 3 to 15 nm.

[0092] [The effects of the invention]

[0093] When patterning is performed using a chemically amplified resist composition containing a polymer that functions as a photoacid generator and includes repeating units of a polymer containing onium salt type monomers from the present invention, resist patterns with high contrast, good sensitivity, and excellent photolithographic properties such as LWR, CDU, EL, and DOF can be formed. Detailed Implementation

[0094] The present invention will now be described in detail. Furthermore, in the following description, depending on the structure represented by the chemical formula, there may be mirror-image isomers and non-mirror-image isomers due to the presence of asymmetric carbon; however, in these cases, a single chemical formula will be used to represent these isomers. These isomers may be used individually or in mixtures of two or more.

[0095] [Onium salt type monomer]

[0096] The onium salt type monomer of the present invention is represented by the following formula (A).

[0097] [Chemistry 9]

[0098]

[0099] In formula (A), n1 is 0 or 1. When n1 is 0, it is a benzene ring; when n1 is 1, it is a naphthalene ring. However, considering solvent solubility, a benzene ring with n1 of 0 is more ideal. n2 is 0, 1, 2, 3, or 4. n3 is 0, 1, 2, 3, or 4. However, when n1 is 0, 0 ≤ n2 + n3 ≤ 4; when n1 is 1, 0 ≤ n2 + n3 ≤ 6.

[0100] In formula (A), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, a hydrogen atom or a methyl group is more ideal, with a hydrogen atom being the most ideal.

[0101] In formula (A), R 1The halogen atom can be a halogen atom other than fluorine, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a hydrocarbon group with 1 to 20 carbon atoms, an hydroxyl group with 1 to 20 carbon atoms, or a hydrocarbon thiol group with 1 to 20 carbon atoms. This hydrocarbon group, hydroxyl group, and hydrocarbon thiol group may also contain heteroatoms other than fluorine. Specific examples of halogen atoms other than fluorine include chlorine atoms, bromine atoms, and iodine atoms. The hydrocarbon base of the aforementioned hydrocarbon group, hydroxyl group, and hydrocarbon thiol group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, 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, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as halogen atoms other than oxygen, sulfur, nitrogen, and fluorine atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, it may contain hydroxyl, cyano, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonate ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When n3 is 2, 3, or 4, each R... 1 They can be the same or different.

[0102] Furthermore, when n3 is 2, 3, or 4, multiple R 1 They can also bond with each other to form rings together with the carbon atoms they bond to. Examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, they may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride, and haloalkyl groups.

[0103] In formula (A), R FIt can be a fluorine atom, a fluorinated saturated hydrocarbon group with 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group with 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group with 1 to 6 carbon atoms. Among these, a fluorine atom, trifluoromethyl, trifluoromethoxy, or trifluoromethylthio group is more ideal, with a fluorine atom being even more ideal. When n2 is 2, 3, or 4, each R... F They can be the same or different.

[0104] In formula (A), L A and L B Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, single bonds, ether bonds, ester bonds, and sulfonate bonds are more ideal.

[0105] In formula (A), X L1 and X L2 Each is an alkylene group with 1 to 40 carbon atoms, which may be a single bond or contain heteroatoms. The alkylene groups can be linear, branched, or cyclic; specific examples include alkyldiyl groups and cyclic saturated alkylene groups. The heteroatoms can include oxygen atoms, nitrogen atoms, sulfur atoms, etc.

[0106] Regarding X L1 and X L2 For the representation of hydrocarbon groups with 1 to 40 carbon atoms that may contain heteroatoms, the following is more ideal. Additionally, in the following formula, * denotes an atomic bond.

[0107] [Chemistry 10]

[0108]

[0109] [Chemistry 11]

[0110]

[0111] [Chemistry 12]

[0112]

[0113] [Chemistry 13]

[0114]

[0115] Among these, X L1 In other words, for X L -50~X L -58 is more ideal. Regarding X... L2 In other words, for X L -0~X L -22, X L -29~X L -34 and X L -47~XL -60 is ideal.

[0116] In addition, in equation (A), L A L B X L1 and X L2 Not all of them will be single keys at the same time.

[0117] For onium salt type monomers represented by formula (A), the following formula (A1) is more ideal.

[0118] [Chemistry 14]

[0119]

[0120] In the formula, n1~n3, R A R 1 R F L A L B X L2 and Z + Same as above.

[0121] In formula (A1), n4 is 0 or 1. When n4 is 0, it is a benzene ring; when n4 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with n4 of 0 is more ideal. n5 is 0, 1, 2, 3, or 4.

[0122] In equation (A1), R 2 It can be a halogen atom, nitro group, cyano group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or an alkyloxy group with 1 to 20 carbon atoms containing heteroatoms. When n4 is 2, 3, or 4, each R 2 Multiple Rs can be the same or different. 2 They can also bond with each other to form rings with the carbon atoms they bond to. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include those related to R... 1 The hydrocarbon groups exemplified are the same, but not limited to these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms; similarly, a portion of the -CH2- group in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When n5 is 2, 3, or 4, each R... 2 They can be the same or different.

[0123] Furthermore, when n5 is 2, 3, or 4, multiple R 2 They can also bond with each other to form rings together with the carbon atoms they bond to. Examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- groups in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, they may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide, carboxylic anhydride, and haloalkyl groups.

[0124] For onium salt type monomers represented by formula (A1), the one represented by formula (A2) is more ideal.

[0125] [Chemistry 15]

[0126]

[0127] In the formula, n4, n5, and R A R 2 L A and Z + Same as above.

[0128] Regarding the anions of onium salt type monomers represented by formula (A), examples as shown below can be listed, but are not limited to these. Additionally, in the following formula, R... A As mentioned above. Furthermore, the positions of the various substituents on the aromatic ring can also be interchanged.

[0129] [Chemistry 16]

[0130]

[0131] [Chemistry 17]

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[0133] [Chemistry 18]

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[0135] [Chemistry 19]

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[0145] [Chemistry 24]

[0146]

[0147] [Chemistry 25]

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[0149] [Chemistry 26]

[0150]

[0151] [Chemistry 27]

[0152]

[0153] [Chemistry 28]

[0154]

[0155] [Chemistry 29]

[0156]

[0157] [Chemistry 30]

[0158]

[0159] [Chemistry 31]

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[0161] [Chemistry 32]

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[0163] [Chemistry 33]

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[0165] [Chemistry 34]

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[0167] [Chemistry 35]

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[0169] [Chemistry 36]

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[0171] [Chemistry 37]

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[0177] [Chemistry 40]

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[0185] [Chemistry 44]

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[0187] [Chemistry 45]

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[0189] [Chemistry 46]

[0190]

[0191] [Chemistry 47]

[0192]

[0193] [Chemistry 48]

[0194]

[0195] [Chemistry 49]

[0196]

[0197] [Transformation 50]

[0198]

[0199] [Chemistry 51]

[0200]

[0201] [Chemistry 52]

[0202]

[0203] [Chemistry 53]

[0204]

[0205] [Chemistry 54]

[0206]

[0207] [Chemistry 55]

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[0209] [Chemistry 56]

[0210]

[0211] [Chemistry 57]

[0212]

[0213] [Chem.58]

[0214]

[0215] [Chemistry 59]

[0216]

[0217] [Transformation 60]

[0218]

[0219] In formula (A), Z + It is an onium cation. As for the aforementioned onium cation, it is more ideal to be a sulfonium cation represented by formula (Z-1) or a sulfonium cation represented by formula (Z-2).

[0220] [Chemistry 61]

[0221]

[0222] In equations (Z-1) and (Z-2), R ct1 ~Rct5 Each is an independent hydrocarbon group consisting of halogen atoms or may contain heteroatoms, and has 1 to 30 carbon atoms.

[0223] Regarding R ct1 ~R ct5 Specific examples of halogen atoms that can be represented include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0224] R ct1 ~R ct5 The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 30 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups with 3 to 30 carbon atoms, such as cyclohexenyl; aryl groups with 6 to 30 carbon atoms, such as phenyl, naphthyl, and thiophene; aralkyl groups with 7 to 30 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups. Among these, aryl groups are preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0225] Also, R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they bond to. In this case, specific examples of the aforementioned ring structures can be listed as follows.

[0226] [Chemistry 62]

[0227]

[0228] In the formula, the dashed line represents the intersection with R. ct3 Atomic bonds.

[0229] Regarding specific examples of sulfonium cations represented by formula (Z-1), examples may be listed in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, and paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, but are not limited to these.

[0230] Regarding specific examples of citric acid represented by formula (Z-2), those described in paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259 can be cited, but are not limited to these.

[0231] Regarding Z + For onium cations, sulfonium cations represented by the following formula (Z-3) are also more desirable.

[0232] [Chemistry 63]

[0233]

[0234] In formula (Z-3), m1 is either 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m1 = 0 is more ideal. m2 is either 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m2 = 0 is more ideal. m3 is either 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m3 = 0 is more ideal.

[0235] In formula (Z-3), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the solvent solubility will be poor, and there is a concern about precipitation in the resist composition. Therefore, m4 is more ideal if it is 0, 1, 2, or 3, and even more ideal if it is 0, 1, or 2.

[0236] In formula (Z-3), m5 can be 0, 1, 2, 3, or 4. Considering raw material supply, m5 being 0, 1, 2, or 3 is more ideal, with 0, 1, or 2 being even more ideal. m6 can be 0, 1, 2, 3, 4, 5, or 6. Considering raw material supply, m6 being 0, 1, 2, or 3 is more ideal, with 0, 1, or 2 being even more ideal. m7 can be 0, 1, 2, 3, 4, 5, or 6. Considering raw material supply, m7 being 0, 1, 2, or 3 is more ideal, with 0, 1, or 2 being even more ideal.

[0237] In equation (Z-3), m8 can be 0, 1, or 2. From the perspective of raw material supply, m8 being 0 or 1 is more ideal. m9 can be 0, 1, or 2. From the perspective of raw material supply, m9 being 0 or 1 is more ideal. m10 can be 0, 1, or 2. From the perspective of raw material supply, m10 being 0 or 1 is more ideal.

[0238] In formula (Z-3), m11 is 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m11 of 0 is more ideal.

[0239] In formula (Z-3), m12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cationic structure, the higher the absorption of EUV, but the solvent solubility will be poor, and there is a concern about precipitation in the resist composition. Therefore, m12 is more ideal if it is 0, 1, 2, or 3, and even more ideal if it is 0, 1, or 2.

[0240] In equation (Z-3), m13 can be 0, 1, or 2. From the perspective of raw material supply, m13 being 0 or 1 is more ideal. m14 can be 0, 1, or 2. From the perspective of synthesis, m14 being 0 or 1 is more ideal.

[0241] However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4; when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4; when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4; when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0242] In equation (Z-3), R F 1 ~R F3 Each R is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy are more ideal. When m5 is 2, 3, or 4, each R F 1 They can be the same or different. When m6 is 2, 3, 4, 5 or 6, each R F2 They can be the same or different. When m7 is 2, 3, 4, 5 or 6, each R F3 They can be the same or different.

[0243] In equation (Z-3), R ct6 ~R ct9 The hydroxyl group can be a halogen atom other than iodine or fluorine, a nitro group, a cyano group, a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, an hydroxyl group with 1 to 20 carbon atoms that may contain heteroatoms, or a thiol group with 1 to 20 carbon atoms that may contain heteroatoms. The hydrocarbon group, hydroxyl group, and thiol group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples can be cited as shown in the description of formula (A) regarding R. 1The hydrocarbon groups represented are the same as those shown. Furthermore, some or all of the hydrogen atoms in the hydrocarbon groups, hydroxyl groups, and thiol groups can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon groups can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulfonolactone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0244] Also, when m8 is 2, there are 2 Rs. ct6 They can be the same or different, 2 Rs ct6 They can also bond with each other and form rings together with the carbon atoms they bond with. When m9 is 2, there are 2 R atoms. ct7 They can be the same or different, 2 Rs ct7 They can also bond with each other and form rings together with the carbon atoms they bond with. When m10 is 2, the two R atoms... ct8 They can be the same or different, 2 Rs ct8 They can also bond with each other and form rings together with the carbon atoms they bond with. When m13 is 2, there are 2 R atoms. ct9 They can be the same or different, 2 Rs ct9 They can also bond with each other to form rings together with the carbon atoms they bond to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0245] Furthermore, in the sulfonium cation represented by formula (Z-3), S is directly bonded. + The aromatic rings can also bond with each other and with S + Together they form a ring. In this case, specific examples of the aforementioned ring structure can be given by the following expressions, etc.

[0246] [Chemistry 64]

[0247]

[0248] In the formula, the dashed lines represent atomic bonds.

[0249] In equation (Z-3), LC and L D Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among these, L... C In this regard, single bonds, ether bonds, ester bonds, or sulfonate bonds are more ideal, with ester bonds or sulfonate bonds being even more ideal. Regarding L... D In this regard, single bonds, ether bonds, or ester bonds are more ideal, with single bonds being the most desirable.

[0250] In equation (Z-3), X L3 It is a single bond, or may contain heteroatoms, of a hydrocarbon group having 1 to 40 carbon atoms. Regarding specific examples of hydrocarbon groups having 1 to 40 carbon atoms that may also contain heteroatoms, examples include those related to X. L1 and X L2 The examples shown are the same as those that may contain heteroatoms and carbon subgroups with 1 to 40 carbon atoms, but are not limited to these.

[0251] For sulfonium cations represented by formula (Z-3), those represented by formula (Z-3-1) are more ideal.

[0252] [Chemistry 65]

[0253]

[0254] In the formula, m4~m10, m12~m14, R F1 ~R F3 R ct6 ~R ct9 L C L D and X L3 Same as above.

[0255] For the cation represented by formula (Z-3-1), the one represented by formula (Z-3-2) is more ideal.

[0256] [Chemistry 66]

[0257]

[0258] In the formula, m4~m10, R F1 ~R F3 and R ct6 ~R ct8 Same as above.

[0259] Specific examples of sulfonium cations represented by formula (Z-3) are shown below, but are not limited to these. Additionally, in the following formula, Me is a methyl group.

[0260] [Chemistry 67]

[0261]

[0262] [Chemistry 68]

[0263]

[0264] [Chemistry 69]

[0265]

[0266] [Chemistry 70]

[0267]

[0268] [Chemistry 71]

[0269]

[0270] [Chemistry 72]

[0271]

[0272] [Chemistry 73]

[0273]

[0274] [Chemistry 74]

[0275]

[0276] [Chemistry 75]

[0277]

[0278] [Chemistry 76]

[0279]

[0280] [Chemistry 77]

[0281]

[0282] [Chemistry 78]

[0283]

[0284] [Chemistry 79]

[0285]

[0286] [Chemistry 80]

[0287]

[0288] [Chemistry 81]

[0289]

[0290] [Chemistry 82]

[0291]

[0292] [Chemistry 83]

[0293]

[0294] [Chemistry 84]

[0295]

[0296] [Chemistry 85]

[0297]

[0298] [Chemistry 86]

[0299]

[0300] [Chemistry 87]

[0301]

[0302] [Chemistry 88]

[0303]

[0304] [Chemistry 89]

[0305]

[0306] [Chemistry 90]

[0307]

[0308] [Chemistry 91]

[0309]

[0310] [Chemistry 92]

[0311]

[0312] [Chemistry 93]

[0313]

[0314] [Chemistry 94]

[0315]

[0316] In particular, any combination of anions and cations as described above can be cited as examples of the onium salt type monomers of the present invention.

[0317] The onium salt type monomer of the present invention can be synthesized, for example, by the same method as the sulfonium salt having a polymerizable anion described in Japanese Patent No. 5201363. Furthermore, the aforementioned manufacturing method is merely one example, and the manufacturing method of the onium salt type monomer of the present invention is not limited thereto.

[0318] The onium salt monomers of the present invention are useful as raw materials for polymeric photoacid generators.

[0319] [polymer]

[0320] The polymer of the present invention comprises repeating units derived from the onium salt type monomer represented by formula (A) (hereinafter also referred to as repeating unit A).

[0321] The polymer of the present invention is a polymer-bonded photoacid generator that functions as both a photoacid generator and a base polymer in a chemically amplified resist composition. Regarding the structural features of the polymer of the present invention, examples include a maleimide structure in the main chain and an aromatic sulfonic acid anion structure in the side chains. The aromatic sulfonic acid anion structure is more rigid than the fluoroalkyl sulfonate anion structure, thus reducing the acid diffusion distance. On the other hand, maleimide possesses both rigidity from the imide bond and polymerizability. By having an imide ring in the main chain, the main chain of the base polymer becomes more rigid, and the glass transition temperature (Tg) of the base polymer is increased. Furthermore, although maleimide is not basic, it contains nitrogen atoms, exhibiting a high affinity for protons. By introducing this maleimide structure into the polymer main chain, excessive diffusion of the acid generated after exposure is suppressed. Furthermore, it is believed that aromatic ring bonds on the nitrogen atoms of maleimide are ideal, allowing the aromatic rings within or between the base polymers to interact (π-π stacking effect), resulting in a regular arrangement of the base polymers and exhibiting resistance to pattern collapse in the developer during micropattern formation. Additionally, the maleimide structure also exhibits excellent etching resistance during the etching step after micropattern formation. Through these synergistic effects, the polymer of the present invention can form patterns with suppressed excessive diffusion of generated acids, excellent photolithographic properties such as LWR for line patterns and CDU for hole patterns, and strong resistance to pattern collapse, making it particularly suitable as a material for chemically amplified positive resist compositions.

[0322] The aforementioned polymer may also contain repeating units represented by formula (a1) (hereinafter also referred to as repeating unit a1.) or repeating units represented by formula (a2) (hereinafter also referred to as repeating unit a2.).

[0323] [Chem. 95]

[0324]

[0325] In equations (a1) and (a2), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0326] In equation (a1), X 1 Single bond, phenylene, naphthylene, *-C(=O)-OX 11 -or *-C(=O)-NH-X 11 - The phenylene or naphthylene group may also be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. X 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group with 1 to 10 carbon atoms. The saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0327] In equation (a2), X 2 It represents a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. R 11 It can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms containing heteroatoms. a1 can be 0, 1, 2, 3, or 4, ideally 0 or 1. a1 can be 2, 3, or 4, each R 11 They can be the same or different.

[0328] In equations (a1) and (a2), AL 1 and AL 2 Each is an acid-indestructible group independently. Specific examples of the aforementioned acid-indestructible groups can be cited in Japanese Patent Application Publication Nos. 2013-80033 and 2013-83821.

[0329] For representativeness, specific examples of the aforementioned acid-instable groups can be listed as those represented by formulas (AL-1) to (AL-3).

[0330] [Chemistry 96]

[0331]

[0332] In the formula, * represents an atomic bond.

[0333] In equations (AL-1) and (AL-2), R L1 and R L2Each hydrocarbon group consists independently of a carbon group numbering 1 to 40, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Of these, hydrocarbon groups with 1 to 20 carbon atoms are considered ideal.

[0334] In equation (AL-1), a2 is an integer from 0 to 10, and it is more ideal to be 1, 2, 3, 4 or 5.

[0335] In equation (AL-2), R L3 and R L4 Each group is independently composed of a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, R... L2 R L3 and R L4 Any two of them can also bond to each other to form a ring with 3 to 20 carbon atoms, together with the carbon atoms they bond to, or carbon atoms and oxygen atoms. Among the aforementioned rings, rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0336] In equation (AL-3), R L5 R L6 and R L7 Each group is an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Furthermore, R... L5 R L6 and R L7 Any two of them can also bond to each other to form a ring with 3 to 20 carbon atoms. Among the aforementioned rings, rings with 4 to 16 carbon atoms are more ideal, especially alicyclic rings.

[0337] Other specific examples of the aforementioned acid-indestructible groups include those described in paragraphs

[0064] to

[0068] of Japanese Patent Application Publication No. 2023-123222 and those described in paragraphs

[0013] to

[0014] of Japanese Patent Publication No. 7492842. These groups, after the acid desorption reaction, use the formation of conjugated olefins and acrylate derivatives as the driving force for the reaction.

[0338] Regarding specific examples of the repeating unit a1, examples as shown below can be listed, but are not limited to these. Additionally, in the following formula, R... A and AL 1 Same as above.

[0339] [Chemistry 97]

[0340]

[0341] [Chem. 98]

[0342]

[0343] [Chemistry 99]

[0344]

[0345] [Chemistry 100]

[0346]

[0347] [Chemistry 101]

[0348]

[0349] Specific examples of the repeating unit a2 can be listed as shown below, but are not limited to these. Additionally, in the following formula, R... A and AL 2 Same as above.

[0350] [Chemistry 102]

[0351]

[0352] [Chemistry 103]

[0353]

[0354] [Chemistry 104]

[0355] The aforementioned polymer may also contain repeating units represented by the following formula (a3) ​​(hereinafter also referred to as repeating unit a3).

[0356] [Chemistry 105]

[0357]

[0358] In formula (a3), a11 is 0 or 1. When a11 is 0, it is a benzene ring; when a11 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with a11 of 0 is more ideal. a12 is 0, 1, 2, or 3 when a11 is 0, and 0, 1, 2, 3, 4, or 5 when a11 is 1. Considering raw material supply, a12 with a12 of 0, 1, 2, or 3 is more ideal, and 0, 1, or 2 is even more ideal.

[0359] In equation (a3), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, a hydrogen atom or a methyl group is more ideal, and a hydrogen atom is even more ideal.

[0360] In equation (a3), X 3The bonds are single bonds, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Among these, single bonds and *-C(=O)-O- are more ideal, with single bonds being the most desirable.

[0361] In equation (a3), X 4 The group can be a single bond, an aliphatic alkylene group with 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Among these, considering the availability of raw materials, a single bond, a carbonyl group, or a sulfonyl group is more ideal; considering the polar group formed after the reaction, a single bond or a carbonyl group is more ideal.

[0362] In equation (a3), X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom. However, X 4 and X 6 It is bonded to an adjacent carbon atom of the aromatic ring. X 5 and X 6 They can be the same or different, depending on the perspective of reactivity, X 5 and X 6 At the same time, oxygen atoms are more ideal.

[0363] In equation (a3), R 12 and R 13 Each hydrocarbon group consists of 1 to 20 carbon atoms, which may be hydrogen atoms or may contain heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, 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, heptadecanyl, octadecyl, nonadecanyl, and eicosyl; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; cyclounsaturated cycloalkyl 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 them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0364] Also, R 12 and R 13 They can also bond with each other to form rings together with the carbon atoms they bond to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0365] In equation (a3), R 14 It may contain halogen atoms, hydroxyl groups, cyano groups, nitro groups, or hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxygen groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxycarbonyl groups with 2 to 20 carbon atoms containing heteroatoms; or hydrocarbon thio groups with 1 to 20 carbon atoms containing heteroatoms, or -N(R) groups. 14A (R) 14B R 14A and R 14B Each group is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. Ideally, the aforementioned halogen atom should be a fluorine, chlorine, bromine, or iodine atom, with fluorine or iodine being more ideal. The hydrocarbon group, as well as the hydrocarbon oxy, hydroxyl, and thiol groups, can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include those related to R... 12 and R 13 The hydrocarbon groups represented are the same. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonate, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When a12 is 2 or more, each R... 14 They can be the same or different.

[0366] Furthermore, when a12 is 2 or more, multiple R... 14They can also bond with each other, forming rings together with the carbon atoms of the aromatic rings they are bonded to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and part of the -CH2- in the aforementioned rings can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, they may also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0367] Regarding specific examples of the repeating unit a3, examples as shown below can be listed, but are not limited to these. Additionally, in the following formula, R... A As mentioned above, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0368] [Chemistry 106]

[0369]

[0370] [Chemistry 107]

[0371]

[0372] [Chemistry 108]

[0373]

[0374] [Chemistry 109]

[0375]

[0376] [Chemical 110]

[0377]

[0378] [Chemistry 111]

[0379]

[0380] [Chemistry 112]

[0381]

[0382] [Chemistry 113]

[0383]

[0384] [Chemistry 114]

[0385]

[0386] [Chemistry 115]

[0387]

[0388] [Chemistry 116]

[0389]

[0390] [Chemistry 117]

[0391]

[0392] [Chemistry 118]

[0393]

[0394] [Chemistry 119]

[0395]

[0396] [Chemistry 120]

[0397]

[0398] [Chemistry 121]

[0399]

[0400] [Chemistry 122]

[0401]

[0402] [Chemistry 123]

[0403]

[0404] [Chemistry 124]

[0405]

[0406] [Chemistry 125]

[0407]

[0408] [Chemistry 126]

[0409]

[0410] [Chemistry 127]

[0411]

[0412] [Chemistry 128]

[0413]

[0414] [Chemistry 129]

[0415]

[0416] [Chemistry 130]

[0417]

[0418] [Chemistry 131]

[0419]

[0420] [Chemistry 132]

[0421]

[0422] [Chemistry 133]

[0423]

[0424] [Chemistry 134]

[0425]

[0426] [Chemistry 135]

[0427]

[0428] [Chemistry 136]

[0429]

[0430] [Chemistry 137]

[0431]

[0432] [Chemistry 138]

[0433]

[0434] [Chemistry 139]

[0435]

[0436] [Chemistry 140]

[0437]

[0438] [Chemistry 141]

[0439]

[0440] [Chemistry 142]

[0441]

[0442] [Chemistry 143]

[0443]

[0444] [Chemistry 144]

[0445]

[0446] [Chemistry 145]

[0447]

[0448] [Chemistry 146]

[0449]

[0450] [Chemistry 147]

[0451]

[0452] [Chemistry 148]

[0453]

[0454] [Chemistry 149]

[0455]

[0456] [Chemistry 150]

[0457]

[0458] [Chemistry 151]

[0459]

[0460] [Chemistry 152]

[0461]

[0462] [Chemistry 153]

[0463]

[0464] [Chemistry 154]

[0465]

[0466] [Chemistry 155]

[0467]

[0468] The aforementioned base polymer may also contain repeating units represented by formula (b1) (hereinafter also referred to as repeating unit b1.) or repeating units represented by formula (b2) (hereinafter also referred to as repeating unit b2.).

[0469] [Chemistry 156]

[0470]

[0471] In equations (b1) and (b2), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 It represents a single bond or *-C(=O)-O-. * indicates an atomic bond with a carbon atom in the main chain. R 21 It is a hydrogen atom, or a group having 1 to 20 carbon atoms, comprising at least one of the following: hydroxyl group (other than phenolic hydroxyl), cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring, and carboxylic anhydride (-C(=O)-OC(=O)-). R 22 It can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxygen group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms. When b2 is 2, 3, or 4, each R 22 They can be the same or different. b1 can be 1, 2, 3 or 4. b2 can be 0, 1, 2, 3 or 4. However, 1 ≤ b1 + b2 ≤ 5.

[0472] Regarding specific examples of the repeating unit b1, examples as shown below can be listed, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0473] [Chemistry 157]

[0474]

[0475] [Chemistry 158]

[0476]

[0477] [Chemistry 159]

[0478]

[0479] [Chemistry 160]

[0480]

[0481] [Chemistry 161]

[0482]

[0483] [Chemistry 162]

[0484]

[0485] [Chemistry 163]

[0486]

[0487] [Chemistry 164]

[0488]

[0489] [Chemistry 165]

[0490]

[0491] [Chemistry 166]

[0492]

[0493] [Chemistry 167]

[0494]

[0495] [Chemistry 168]

[0496]

[0497] [Chemistry 169]

[0498]

[0499] [Chemistry 170]

[0500]

[0501] [Chemistry 171]

[0502]

[0503] [Chemistry 172]

[0504]

[0505] Regarding specific examples of the repeating unit b2, examples as shown below can be listed, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0506] [Chemistry 173]

[0507]

[0508] [Chemistry 174]

[0509]

[0510] [Chemistry 175]

[0511]

[0512] [Chemistry 176]

[0513]

[0514] [Chemistry 177]

[0515]

[0516] Regarding repeating units b1 or b2, in ArF lithography, those with lactone rings as polar groups are more ideal, while in KrF lithography, EB lithography, and EUV lithography, those with phenolic sites are more ideal.

[0517] The aforementioned polymer may also contain repeating units (hereinafter also referred to as c) with a structure in which hydroxyl groups are protected by acid-indestructible groups. As for repeating unit c, it is not particularly limited as long as it has a structure in which one or two or more hydroxyl groups are protected, and the protecting groups can decompose and generate hydroxyl groups due to the action of acid, but it is more ideal to be represented by the following formula (c1).

[0518] [Chemistry 178]

[0519]

[0520] In equation (c1), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 It can also be a hydrocarbon group with a carbon number of 1 to 30 and a (c+1) valence that contains heteroatoms. R 42 It is an acid-labile group. c can be 1, 2, 3 or 4.

[0521] In equation (c1), R 42 The acid-insecure group can be any group that will deprotect under the action of an acid, resulting in the formation of a hydroxyl group. R 42 The structure is not particularly limited, but acetal, ketal, alkoxy carbonyl, and hydrocarbon methoxy groups represented by formula (c2) are more ideal, especially hydrocarbon methoxy groups represented by formula (c2).

[0522] [Chemistry 179]

[0523]

[0524] In the formula, * represents an atomic bond. R 43 It consists of hydrocarbon groups with 1 to 15 carbon atoms.

[0525] Regarding the acid-labile group represented by R 42 For specific examples of the hydrocarbon methoxy group represented by formula (c2) and the repeating unit c, those exemplified in the description of the repeating unit c described in Japanese Patent Application Laid-Open No. 2020-111564 can be cited as the same ones.

[0526] The aforementioned polymer may also contain a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, norbornadiene or their derivatives. Specific examples of the monomer that provides the repeating unit d are as shown below, but are not limited to these.

[0527] [Chemical Formula 180]

[0528]

[0529] The aforementioned polymer may also contain a repeating unit e derived from indan, vinylpyridine or vinylcarbazole.

[0530] In the polymer of the present invention, the content ratios of the repeating units A, a1, a2, a3, b1, b2, c, d and e are preferably 0 < A ≤ 0.4, 0 ≤ a1 ≤ 0.8, 0 ≤ a2 ≤ 0.8, 0 ≤ a3 ≤ 0.6, 0 < a1 + a2 + a3 ≤ 0.8, 0 ≤ b1 ≤ 0.6, 0 ≤ b2 ≤ 0.6, 0 ≤ c ≤ 0.5, 0 ≤ d ≤ 0.3 and 0 ≤ e ≤ 0.3, and more preferably 0 < A ≤ 0.3, 0 ≤ a1 ≤ 0.7, 0 ≤ a2 ≤ 0.7, 0 ≤ a3 ≤ 0.5, 0 < a1 + a2 + a3 ≤ 0.7, 0 ≤ b1 ≤ 0.5, 0 ≤ b2 ≤ 0.5, 0 ≤ c ≤ 0.3, 0 ≤ d ≤ 0.3 and 0 ≤ e ≤ 0.3. However, A + a1 + a2 + a3 + b1 + b2 + c + d + e ≤ 1.0.

[0531] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1000 to 500000, and more preferably 3000 to 100000. If Mw falls within this range, sufficient etching resistance can be obtained without the risk of reducing the resolution due to the inability to ensure the difference in dissolution rate before and after exposure. In addition, in the present invention, Mw is a polystyrene conversion measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent.

[0532] Then, regarding the molecular weight distribution (Mw / Mn) of the aforementioned polymers, as the pattern becomes more regular and refined, the influence of Mw / Mn tends to increase. Therefore, in order to obtain a resist composition that can be ideally used in fine pattern sizes, a narrow dispersion of Mw / Mn of 1.0 to 2.0 is preferable. If it falls within the aforementioned range, there will be fewer low-molecular-weight and high-molecular-weight polymers, and there will be no risk of foreign matter being found on the pattern after exposure or the shape of the pattern deteriorating.

[0533] Regarding the aforementioned methods for synthesizing polymers, examples include methods that polymerize monomers providing the aforementioned repeating units by adding a free radical polymerization initiator to an organic solvent and heating the mixture.

[0534] Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), and γ-butyrolactone (GBL). Specific examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, and lauroyl peroxide. The ideal amount of these initiators added relative to the total monomers used in polymerization is 0.01–25 mol%. A reaction temperature of 50–150°C is ideal, with 60–100°C being more ideal. A reaction time of 2–24 hours is ideal, and from a production efficiency perspective, 2–12 hours is more ideal.

[0535] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or an initiator solution can be prepared separately from the monomer solution and then supplied to the reactor independently. During the standby time, there is a possibility that polymerization may proceed due to free radicals generated by the initiator, resulting in the formation of ultrapolymers. Therefore, from a quality management perspective, it is ideal to prepare and add the monomer solution and initiator solution independently. Acid-labile groups can also be used in a state where they are introduced into the monomer, or for post-polymerization protection or partial protection. Furthermore, to adjust the molecular weight, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used concurrently. In this case, the amount of these chain transfer agents added relative to the total amount of monomers used for polymerization is ideally 0.01–20 mol%.

[0536] In the case of monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy-ethoxy, which are easily deprotected by acids, during polymerization. Then, deprotection can be carried out by weak acid and water after polymerization. Alternatively, they can be replaced with acetyl, formyl, trimethylacetyl, etc., and then alkaline hydrolysis can be carried out after polymerization.

[0537] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene can also be copolymerized with other monomers in an organic solvent with the addition of a free radical polymerization initiator and heated. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and polyhydroxystyrene or hydroxyvinylnaphthalene can be obtained by deprotecting the acetoxy group after polymerization through alkaline hydrolysis.

[0538] For specific examples of alkali used in alkaline hydrolysis, ammonia, triethylamine, etc., can be used. Furthermore, the ideal reaction temperature is -20 to 100°C, and more ideally 0 to 60°C. The ideal reaction time is 0.2 to 100 hours, and more ideally 0.5 to 20 hours.

[0539] In addition, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that forms a preferred content ratio for the aforementioned repeating unit.

[0540] The polymer obtained by the aforementioned manufacturing method can also be used as the final product by the reaction solution obtained by the polymerization reaction, or the polymerization liquid can be added to a poor solvent and the powder obtained by the refining steps such as the reprecipitation method can be used as the final product. Considering the viewpoints of work efficiency and quality stability, it is more ideal to use the polymer solution obtained by dissolving the powder obtained by the refining step in the solvent as the final product.

[0541] Specific examples of solvents used at this time include ketones such as cyclohexanone and methyl-2-n-pentyl ketone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; and propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, and propylene glycol dimethyl ether. Ethers such as diethylene glycol dimethyl ether; 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 alcohol solvents such as diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, and 1,3-butanediol; and their mixed solvents.

[0542] In the aforementioned polymer solution, a polymer concentration of 0.01–30% by mass is ideal, and 0.1–20% by mass is even more ideal.

[0543] The aforementioned reaction solutions and polymer solutions are ideally filtered using filter media. By using filter media, foreign matter and gel that could cause defects can be removed, which is effective in terms of quality stability.

[0544] Regarding the materials used in the aforementioned filter media filtration, examples include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon-based materials. In the filtration step involving the resist composition, filter media formed from fluorocarbon (such as Teflon, a registered trademark), polyethylene, polypropylene, or nylon are more ideal. The pore size of the filter media can be appropriately selected according to the target cleanliness level, ideally below 100 nm, and even more ideally below 20 nm. Furthermore, these filter media can be used individually or in combination. The filtration method can involve passing the solution through only once, but multiple filtrations through solution circulation are more ideal. The filtration steps can be performed in any order and number of times during the polymer manufacturing process; filtering the reaction solution, polymer solution, or both after the polymerization reaction is more ideal.

[0545] [Chemical amplification resist composition]

[0546] [(A) Basic Polymer]

[0547] The chemically amplified resist composition of the present invention comprises a base polymer containing the aforementioned polymer as component (A).

[0548] The aforementioned polymers may be used alone or in combination of two or more with different composition ratios, Mw and / or Mw / Mn. Furthermore, (A) the base polymer, in addition to the aforementioned polymers, may also contain hydrides of ring-opening metathesis polymers; in this regard, those described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0549] [(B) Organic solvents]

[0550] The chemically amplified resist composition of the present invention may also contain an organic solvent as component (B). As for the organic solvent (B), there is no particular limitation as long as it can dissolve the aforementioned components and the components described below. Specific examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; 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; and mixed solvents thereof.

[0551] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, ethyl lactate, DAA, and their mixed solvents are particularly ideal, as they have excellent solubility for the base polymer of component (A).

[0552] In the chemically amplified resist composition of the present invention, the content of (B) organic solvent relative to 80 parts by mass of (A) base polymer is preferably 200-7000 parts by mass, and more preferably 400-5000 parts by mass. (B) organic solvent can be used alone or in combination of two or more.

[0553] [(C) Quenching agent]

[0554] The chemically amplified resist composition of the present invention may also contain a quencher as component (C). Furthermore, the quencher referred to in the present invention is a material used to capture the acid generated from the photoacid generator in the chemically amplified resist composition, thereby preventing it from diffusing to the unexposed areas to form the desired pattern.

[0555] For specific examples of (C) quenchers, onium salts represented by formulas (1) or (2) can be listed.

[0556] [Chemistry 181]

[0557]

[0558] In equation (1), R q1 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, but excludes the hydrogen atom at the α-position of the sulfonic acid group which is replaced by a fluorine atom or a fluoroalkyl group. In formula (2), R q2 Hydrocarbon groups consisting of 1 to 40 carbon atoms, which may also contain heteroatoms.

[0559] Regarding R q1 Specifically, the hydrocarbon groups representing 1 to 40 carbon atoms can be exemplified by alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl, which have 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, and tricyclic [5.2.1.0]. 2,6Decyl, adamantyl, and other cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms; phenyl, naphthyl, anthracene, and other aryl groups with 6 to 40 carbon atoms. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc.

[0560] Regarding R q2 Specifically, the hydrocarbon group represented, except for R q1 In addition to the substituents exemplified in the examples, other examples include fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0561] Specific examples of the anions of the onium salts represented by formula (1) can be listed as shown below, but are not limited to these.

[0562] [Chemistry 182]

[0563]

[0564] [Chemistry 183]

[0565]

[0566] [Chemistry 184]

[0567]

[0568] [Chemistry 185]

[0569]

[0570] [Chemistry 186]

[0571]

[0572] Specific examples of onium salt anions represented by equation (2) can be listed as shown below, but are not limited to these.

[0573] [Chemistry 187]

[0574]

[0575] [Chemistry 188]

[0576]

[0577] [Chemistry 189]

[0578]

[0579] [Chemistry 190]

[0580]

[0581] [Chemistry 191]

[0582]

[0583] In equations (1) and (2), Mq + The cation is a sulfonium cation. Examples of sulfonium cations include sulfonium cations, monium cations, and ammonium cations. Examples of sulfonium cations include those exemplified by sulfonium cations represented by formula (Z-1) and sulfonium cations represented by formula (Z-3), those described in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-3744, those described in paragraphs

[0044] to

[0049] of International Publication No. 2024 / 128017, and those described in paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, but are not limited to these.

[0584] Regarding specific examples of the aforementioned citric acid, those described in paragraph

[0181] of Japanese Patent Application Publication No. 2024-259 can be cited, but are not limited to these.

[0585] For specific examples of the aforementioned ammonium cations, those represented by the following formula (am-1) can be listed.

[0586] [Chemistry 192]

[0587]

[0588] In equation (am-1), R q11 ~R q14 Each can be an independent hydrocarbon group with 1 to 40 carbon atoms, and may also contain heteroatoms. Also, R q11 and R q12 They can also bond to each other and form rings together with the nitrogen atoms they are bonded to. Specific examples of the aforementioned hydrocarbon groups include those shown in the description of formula (A) regarding R. 1 The hydrocarbon groups represented are the same as those shown.

[0589] Specific examples of ammonium cations represented by formula (am-1) can be listed as shown below, but are not limited to these.

[0590] [Chemistry 193]

[0591]

[0592] For specific examples of onium salts represented by formula (1) or (2), any combination of anions and cations as described above can be listed. Furthermore, these onium salts can be readily prepared by ion exchange reactions using known organic chemical methods. Regarding ion exchange reactions, Japanese Patent Application Publication No. 2007-145797 can be referenced, for example.

[0593] The onium salts represented by formula (1) or (2) function as quenchers in the chemically amplified resist composition of the present invention. This is because the respective anions of the aforementioned onium salts are conjugate bases of weak acids. Here, a weak acid is defined as an acid that exhibits an acidity that cannot deprotect the acid-instable groups of units containing acid-instable groups used in the base polymer. The onium salts represented by formula (1) or (2) function as quenchers when used in combination with onium salt-type photoacid generators that have conjugate bases of strong acids such as α-fluorinated sulfonic acids as relative anions. That is, when an onium salt that produces a strong acid such as α-fluorinated sulfonic acid is mixed with an onium salt that produces a weak acid such as unfluorinated sulfonic acid or carboxylic acid, if the strong acid generated from the photoacid generator due to high-energy radiation conflicts with the unreacted onium salt with a weak acid anion, the weak acid will be released through salt exchange, producing an onium salt with a strong acid anion. Through this process, the strong acid is exchanged for a weaker acid with lower catalytic ability. Therefore, the acid appears to be deactivated, and acid diffusion can be controlled.

[0594] Furthermore, regarding the quencher (C), the onium salt having a sulfonium cation and a benzene oxide anion site in the same molecule as described in Japanese Patent No. 6848776, the onium salt having a sulfonium cation and a carboxylic acid ester anion site in the same molecule as described in Japanese Patent No. 6583136 and Japanese Patent Application Publication No. 2020-200311, and the onium salt having a monazine cation and a carboxylic acid ester anion site in the same molecule as described in Japanese Patent No. 6274755 may also be used.

[0595] In the case where the photoacid generator producing a strong acid is an onium salt, as mentioned above, the strong acid generated by high-energy ray irradiation can be exchanged for a weak acid. However, it is believed that the weak acid generated by high-energy ray irradiation is less likely to react with the unreacted onium salt that produces a strong acid, thus avoiding salt exchange. This is because onium cations readily form ion pairs with the anions of stronger acids.

[0596] When the chemically amplified resist composition of the present invention contains an onium salt represented by formula (1) or (2) as the quencher in (C), its content is preferably 0.1 to 20 parts by mass relative to 80 parts by mass of the base polymer in (A), and more preferably 0.1 to 10 parts by mass. If the content of the onium salt-type quencher in component (C) falls within the aforementioned range, the resolution is good and the sensitivity is not significantly reduced, which is ideal. The onium salt represented by formula (1) or (2) can be used alone or in combination of two or more.

[0597] The chemically amplified resist composition of the present invention may also contain a nitrogen-containing compound as a (C) quencher. Specific examples of the nitrogen-containing compound for component (C) include first-, second-, or third-order amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, particularly amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonate bonds. Also, compounds formed by protecting a first- or second-order amine with a carbamate group, as described in Japanese Patent Publication No. 3790649, may also be included.

[0598] Alternatively, sulfonate sulfonates with nitrogen-containing substituents can be used as nitrogen-containing compounds. These compounds function as quenchers in the unexposed areas, while the exposed areas lose their quencher properties through neutralization with the acid they generate, functioning as so-called photodegrading bases. Using photodegrading bases can enhance the contrast between the exposed and unexposed areas. For example, Japanese Patent Application Publication Nos. 2009-109595 and 2012-46501 can be referenced regarding photodegrading bases.

[0599] When the chemically amplified resist composition of the present invention includes a nitrogen-containing compound as a quencher (C), its content is preferably 0.001 to 12 parts by mass relative to 80 parts by mass of the base polymer (A), and more preferably 0.01 to 8 parts by mass. The aforementioned nitrogen-containing compound may be used alone or in combination of two or more.

[0600] [(D) Photoacid generator]

[0601] The chemically amplified resist composition of the present invention may also contain a photoacid generator as component (D). As for the aforementioned photoacid generator, there is no particular limitation as long as it is a compound that generates acid upon irradiation by high-energy rays. Ideal photoacid generators can be represented by the following formulas (3) or (4).

[0602] [Chemistry 194]

[0603]

[0604] In equation (3), R 101 ~R105 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 20 carbon atoms. Also, R 101 R 102 and R 103 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

[0605] Regarding specific examples of sulfonium salt cations represented by formula (3), examples can be cited such as those exemplified by specific examples of sulfonium cations represented by formula (Z-1) and formula (Z-3), those described in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-3744, those described in paragraphs

[0044] to

[0049] of International Publication No. 2024 / 128017, and those described in paragraphs

[0035] to

[0046] of Japanese Patent Application Publication No. 7491173, but are not limited to these. Regarding specific examples of ferrous salt cations represented by formula (4), examples can be cited such as those described in paragraph

[0181] of Japanese Patent Application Publication No. 2024-259, but are not limited to these.

[0606] In equations (3) and (4), Xa - It is the anion of a strong acid. Regarding the anions of the aforementioned strong acids, any one of the formulas (Xa-1) to (Xa-4) can be listed as an example.

[0607] [Chemistry 195]

[0608]

[0609] In formula (Xa-1), R fa It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain fluorine atoms or heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include R in formula (Xa-1-1) described later. fa1 The hydrocarbon groups represented are the same as those shown.

[0610] For anions represented by formula (Xa-1), the one represented by formula (Xa-1-1) is more ideal.

[0611] [Chemistry 196]

[0612]

[0613] In equation (Xa-1-1), Q 1 and Q 2 Each group can be independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms; however, considering the improvement in solvent solubility, at least one of them being trifluoromethyl is more ideal. m can be 0, 1, 2, 3, or 4, with 1 being particularly ideal. R fa1The hydrocarbon group may contain heteroatoms and has 1 to 35 carbon atoms. Regarding the aforementioned heteroatoms, oxygen, nitrogen, sulfur, and halogen atoms are preferred, with oxygen atoms being even more ideal. Considering the need for high resolution in the formation of fine patterns, hydrocarbon groups with 6 to 30 carbon atoms are particularly desirable.

[0614] In formula (Xa-1-1), R fa1 The hydrocarbon group represented has 1 to 35 carbon atoms and can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 35 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecanyl, and eicosyl; cyclic saturated hydrocarbon groups with 3 to 35 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornel, norbornelmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-fluorenyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0615] Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, it may contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidemethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, etc.

[0616] In equation (Xa-1-1), L a1 The bonds can be single bonds, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, or carbamate bonds, but from a synthetic point of view, ether bonds or ester bonds are more ideal, with ester bonds being even more ideal.

[0617] Specific examples of anions represented by formula (Xa-1) can be listed as shown below, but are not limited to these. Additionally, in the following formula, Q... 1 As mentioned above, Ac is an acetyl group.

[0618] [Chemistry 197]

[0619]

[0620] [Chemistry 198]

[0621]

[0622] [Chemistry 199]

[0623]

[0624] [Chemistry 200]

[0625]

[0626] [Chemical Engineering 201]

[0627]

[0628] [Chemical Engineering 202]

[0629]

[0630] [Chemical Engineering 203]

[0631]

[0632] [Chemical 204]

[0633]

[0634] [Chemical Engineering 205]

[0635]

[0636] [Chemical Engineering 206]

[0637]

[0638] [Chemical 207]

[0639]

[0640] [Chemical Engineering 208]

[0641]

[0642] In formula (Xa-2), R fb 1 and R fb2 Each of the above-mentioned hydrocarbon groups consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include R in formula (Xa-1-1).fa1 The hydrocarbon groups represented are the same. Regarding R... fb1 and R fb2 Ideally, it should be a straight-chain fluorinated alkyl group with fluorine atoms or 1 to 4 carbon atoms. Also, R fb 1 With R fb2 Groups that can also bond with each other (-CF2-SO2-N) - -SO2-CF2-) together form a ring, at which point R fb 1 With R fb2 The groups that can be obtained by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[0643] In formula (Xa-3), R fc1 R fc2 and R fc3 Each of the above-mentioned hydrocarbon groups consists independently of a fluorine atom or may contain heteroatoms and has 1 to 40 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include R in formula (Xa-1-1). fa1 The hydrocarbon groups represented are the same. Regarding R... fc1 R fc2 and R fc3 Ideally, it should be a straight-chain fluorinated alkyl group with fluorine atoms or 1 to 4 carbon atoms. Also, R fc1 With R fc2 Groups that can also bond with each other (-CF2-SO2-C) - -SO2-CF2-) together form a ring, at which point R fc1 With R fc2 The groups formed by mutual bonding are preferably fluorinated ethylidene or fluorinated propyleneide.

[0644] In formula (Xa-4), R fd It can be a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. For specific examples, R in formula (Xa-1-1) can be cited. fa1 The hydrocarbon groups represented are the same as those shown.

[0645] Specific examples of anions represented by formula (Xa-4) can be listed as shown below, but are not limited to these.

[0646] [Chemical Engineering 209]

[0647]

[0648] [Chemical 210]

[0649]

[0650] In addition to the aforementioned examples of non-nucleophilic relative ions, examples such as anions having aromatic rings substituted with iodine or bromine atoms can also be cited. Specific examples of such anions can be represented by the following formula (Xa-5).

[0651] [Chemistry 211]

[0652]

[0653] In equation (Xa-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3. However, 1 ≤ y + z ≤ 5. y being 1, 2, or 3 is more ideal, with 2 or 3 being even more ideal. z being 0, 1, or 2 is more ideal.

[0654] In equation (Xa-5), X BI It is an iodine atom or a bromine atom. When x and / or y are 2 or more, each X BI They can be the same or different.

[0655] In equation (Xa-5), L 1 It is a saturated hydrocarbon group with 1 to 6 carbon atoms, consisting of a single bond, ether bond, or ester bond, or may contain ether or ester bonds. The aforementioned saturated hydrocarbon group can be linear, branched, or cyclic.

[0656] In equation (Xa-5), L 2 When x is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when x is 2 or 3, it is a (x+1) valent linker with 1 to 20 carbon atoms. This linker may also contain oxygen, sulfur, or nitrogen atoms.

[0657] In formula (Xa-5), R fe It can be a hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino group, or may contain a fluorine, chlorine, bromine, hydroxyl, amino, or ether bond, and can be a hydrocarbon group with 1 to 20 carbon atoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, a hydrocarbon carbonyl group with 2 to 20 carbon atoms, or a hydrocarbon sulfonyl group with 1 to 20 carbon atoms, or -N(R feA (R) feB ), -N(R feC )-C(=O)-R feD or -N(R) feC )-C(=O)-OR feD R feA and R feB Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R feCIt is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms. R feD It can be an aliphatic hydrocarbon group with 1 to 16 carbon atoms, an aryl group with 6 to 12 carbon atoms, or an aralkyl group with 7 to 15 carbon atoms. It may also contain a halogen atom, a hydroxyl group, a saturated alkyloxy group with 1 to 6 carbon atoms, a saturated alkylcarbonyl group with 2 to 6 carbon atoms, or a saturated alkylcarbonyloxy group with 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. The aforementioned hydrocarbon group, alkyloxy group, alkylcarbonyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, and alkylsulfonyloxy group can be linear, branched, or cyclic. When x and / or z are 2 or more, each R... fe They can be the same or different.

[0658] Of these, R fe In this regard, it is hydroxyl, -N(R) feC )-C(=O)-R feD -N(R) feC )-C(=O)-OR feD Fluorine, chlorine, bromine, methyl, and methoxy atoms are relatively ideal.

[0659] In equation (Xa-5), Rf 11 ~Rf 14 Each is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. Also, Rf 11 With Rf 12 They can also combine to form carbonyl groups. In particular, Rf 13 and Rf 14 At the same time, fluorine atoms are more ideal.

[0660] Specific examples of the anion represented by formula (Xa-5) can be listed as shown below, but are not limited to these. Furthermore, in the following formula, X... BI Same as above.

[0661] [Chemistry 212]

[0662]

[0663] [Chemistry 213]

[0664]

[0665] [Chemistry 214]

[0666]

[0667] [Chemical 215]

[0668]

[0669] [Chemistry 216]

[0670]

[0671] [Chemistry 217]

[0672]

[0673] [Chemistry 218]

[0674]

[0675] [Chemistry 219]

[0676]

[0677] [Chem.220]

[0678]

[0679] [Chemistry 221]

[0680]

[0681] [Chemistry 222]

[0682]

[0683] [Chemistry 223]

[0684]

[0685] [Chemistry 224]

[0686]

[0687] [Chemistry 225]

[0688]

[0689] [Chemistry 226]

[0690]

[0691] [Chemistry 227]

[0692]

[0693] [Chemistry 228]

[0694]

[0695] [Chemistry 229]

[0696]

[0697] [Chemistry 230]

[0698]

[0699] [Chemistry 231]

[0700]

[0701] [Chemistry 232]

[0702]

[0703] [Chemistry 233]

[0704]

[0705] [Chemistry 234]

[0706]

[0707] [Chemistry 235]

[0708]

[0709] Regarding the aforementioned non-nucleophilic relative ions, the following can also be used: fluorobenzenesulfonic acid anions bonded to aromatic groups containing iodine atoms as described in Japanese Patent No. 6648726; anions with a mechanism of decomposition by acid as described in International Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692; anions with cyclic ether groups as described in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935; and anions as described in Japanese Patent Application Publication No. 2018-92159.

[0710] Regarding the aforementioned non-nucleophilic relative ions, the anions of fluorine-free, bulky benzenesulfonic acid derivatives described in Japanese Patent Application Publication No. 2006-276759, Japanese Patent Application Publication No. 2015-117200, Japanese Patent Application Publication No. 2016-65016 and Japanese Patent Application Publication No. 2019-202974, as well as the fluorine-free benzenesulfonic acid anions and alkylsulfonic acid anions bonded to aromatic groups containing iodine atoms described in Japanese Patent No. 6645464, may also be used.

[0711] Regarding the aforementioned non-nucleophilic relative ions, the anions of disulfonic acid described in Japanese Patent Application Publication No. 2015-206932, the anions of sulfonamides and sulfonamides described in International Publication No. 2020 / 158366 where one side is sulfonic acid and the other side is different, and the anions of sulfonamides and sulfonamides described in Japanese Patent Application Publication No. 2015-24989 where one side is sulfonic acid and the other side is carboxylic acid, can also be used.

[0712] Furthermore, for the photoacid generator of component (D), the one represented by the following formula (5) is more ideal.

[0713] [Chemistry 236]

[0714]

[0715] In equation (5), R 201 and R 202 Each can be an independent hydrocarbon group with 1 to 30 carbon atoms, and may also contain heteroatoms. R 203 It can also contain a hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Also, R 201 R 202 and R 203 Any two of them can also bond to each other and form a ring together with the sulfur atoms they are bonded to.

[0716] R 201 and R 202 The hydrocarbon group represented has 1 to 30 carbon atoms and can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, oxanorbornel, and tricyclic [5.2.1.0]. 2,6] Decyl, adamantyl, and other cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms; phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, anthracene, and other aryl groups with 6 to 30 carbon atoms; groups obtained by combining them, etc. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- group in the aforementioned hydrocarbon group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0717] R 203 The derivatized hydrocarbon group, representing 1 to 30 carbon atoms, can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, and hexadecane-1,16-diyl. Alkyl groups with 1 to 30 carbon atoms, such as -diyl and heptadecan-1,17-diyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; and aryl groups such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene. Furthermore, some or all of the hydrogen atoms in the aforementioned alkylene group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms. Similarly, a portion of the -CH2- group in the aforementioned alkylene group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, it may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. Regarding the aforementioned heteroatoms, oxygen atoms are preferred.

[0718] In equation (5), L11 It is a hydrocarbon group with 1 to 20 carbon atoms, which may be a single bond, an ether bond, or may contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include those related to R... 203 The analyte groups represented are the same.

[0719] In equation (5), X a X b X c and X d Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl atom. However, X a X b X c and X d At least one of them is a fluorine atom or a trifluoromethyl group.

[0720] Regarding the photoacid generator represented by formula (5), the one represented by formula (5') is more ideal.

[0721] [Chemistry 237]

[0722]

[0723] In equation (5'), L 11 Same as above. X e It can be a hydrogen atom or a trifluoromethyl group, with trifluoromethyl being the more ideal. R 301 R 302 and R 303 Each hydrocarbon group consists independently of a hydrogen atom, or may contain heteroatoms, and has 1 to 20 carbon atoms. These hydrocarbon groups can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include R in formula (Xa-1-1). fa1 The hydrocarbon groups represented are the same. s and t are each independently 0, 1, 2, 3, 4 or 5, and u is 0, 1, 2, 3 or 4.

[0724] For specific examples of photoacid generators represented by formula (5), examples that are the same as those exemplified by the photoacid generators represented by formula (2) in Japanese Patent Application Publication No. 2017-26980 can be cited.

[0725] Among the aforementioned photoacid generators, those containing anions represented by formula (Xa-1-1) or (Xa-4) exhibit low acid diffusion and excellent solvent solubility, making them particularly desirable. Furthermore, those represented by formula (5') exhibit extremely low acid diffusion, making them particularly desirable.

[0726] When the chemically amplified resist composition of the present invention includes (D) a photoacid generating agent, its content is ideally 0.1 to 40 parts by mass relative to 80 parts by mass of the (A) base polymer, and more ideally 0.5 to 20 parts by mass. If the amount of (D) photoacid generating agent added is within the aforementioned range, the resolution is good, and there is no risk of foreign matter problems occurring after development or stripping of the resist film, which is therefore ideal. (D) A photoacid generating agent can be used alone or in combination of two or more.

[0727] [(E) Surfactant]

[0728] The chemically amplified resist composition of the present invention may also contain a surfactant as component (E). Regarding the surfactant (E), it is preferable to be a surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developing solution, or a surfactant that is insoluble or sparingly soluble in both water and alkaline developing solution. For such surfactants, refer to those described in Japanese Patent Application Publication Nos. 2010-215608 and 2011-16746.

[0729] Regarding surfactants that are insoluble or poorly soluble in water and alkaline developing solutions, among the surfactants described in the aforementioned announcement, FC-4430 (manufactured by 3M Corporation), Surflon (registered trademark) S-381 (manufactured by AGC SEIMI CHEMICAL), Olfine (registered trademark) E1004 (manufactured by Nissin Chemical Industry Co., Ltd.), KH-20, KH-30 (manufactured by AGC SEIMI CHEMICAL), and the oxobutane ring-opening polymer represented by the following formula (surf-1) are more ideal.

[0730] [Chemistry 238]

[0731]

[0732] Here, R, Rf, A, B, C, m, and n are not related to the foregoing description, but only apply to formula (surf-1). R is an aliphatic group with 2 to 5 carbon atoms, ranging from 2 to 4 valences. Examples of 2-valent aliphatic groups include ethylene, 1,4-butylene, 1,2-propylene, 2,2-dimethyl-1,3-propylene, and 1,5-pentane, while examples of 3- or 4-valent groups are as follows.

[0733] [Chemistry 239]

[0734]

[0735] In the formula, the dashed lines represent atomic bonds, and some are partial structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol.

[0736] Among these, 1,4-butylene and 2,2-dimethyl-1,3-propylene are particularly desirable.

[0737] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer from 0 to 3, n is an integer from 1 to 4, and the sum of n and m is the valence of R, which is an integer from 2 to 4. A is 1. B is an integer from 2 to 25, preferably an integer from 4 to 20. C is an integer from 0 to 10, preferably 0 or 1. Furthermore, the arrangement of the constituent units in formula (surf-1) is not fixed; they can be block-bonded or randomly bonded. For details on the manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymer systems, please refer to the specification in US Patent No. 5,650,483, etc.

[0738] A surfactant that is insoluble or sparingly soluble in water but soluble in alkaline developer has the function of reducing water penetration and leaching by aligning with the surface of the resist film when no resist protective film is used in ArF immersion lithography. Therefore, it is useful for inhibiting the leaching of water-soluble components from the resist film and reducing damage to the exposure equipment. Furthermore, it is soluble in alkaline aqueous solutions after exposure or post-exposure baking (PEB) and is unlikely to form foreign matter that could cause defects, thus making it useful. This type of surfactant, which is insoluble or sparingly soluble in water but soluble in alkaline developer, is a polymeric surfactant, also known as a hydrophobic resin, with those exhibiting high water repellency and enhancing hydrophobicity being particularly desirable.

[0739] Specific examples of such polymeric surfactants include those comprising at least one repeating unit selected from any of the following formulas (6A) to (6E).

[0740] [Chemistry 240]

[0741]

[0742] In equations (6A) to (6E), R B It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. W 1 It can be -CH2-, -CH2CH2-, -O-, or two separate -H groups. R s1 Each is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. R s2 It is a single bond, or a straight-chain or branched hydrocarbon group with 1 to 5 carbon atoms. R s3 Each is independently a hydrogen atom, a hydrocarbon group with 1 to 15 carbon atoms, a fluorinated hydrocarbon group, or an acid-labile group. R s3 When the group is a hydrocarbon group or a fluorinated hydrocarbon group, ether bonds or carbonyl groups may also be present between the carbon-carbon bonds. R s4 It is a (w+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. w can be 1, 2, or 3. Rs5 Each is independently a hydrogen atom, or -C(=O)-OR sa The group indicated by R. sa It is a fluorinated hydrocarbon group with 1 to 20 carbon atoms. R s6 It is a hydrocarbon group or fluorinated hydrocarbon group with 1 to 15 carbon atoms, and there may also be ether bonds or carbonyl groups between these carbon-carbon bonds.

[0743] R s1 Ideally, the hydrocarbon group representing 1 to 10 carbon atoms should be a saturated hydrocarbon group, and it can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornel. Among these, those with 1 to 6 carbon atoms are preferred.

[0744] R s2 The alkylene group represented is preferably a saturated alkylene group, and can be linear, branched, or cyclic. Specific examples include methylene, ethylene, propylene, butylene, and pentylene.

[0745] R s3 or R s6 The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include aliphatic unsaturated hydrocarbon groups such as saturated hydrocarbon groups, alkenyl groups, and alkynyl groups, but saturated hydrocarbon groups are preferred. Regarding the aforementioned specific examples of saturated hydrocarbon groups, besides R... s1 In addition to the hydrocarbon groups exemplified, examples include undecyl, dodecyl, tridecyl, tetradecyl, and pentadecyl. Regarding R... s3 or R s6 Specific examples of fluorinated hydrocarbon groups include groups in which some or all of the hydrogen atoms of the carbon atoms bonded to the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned above, these carbon-carbon bonds may also be separated by ether bonds or carbonyl groups.

[0746] Regarding R s3 Specific examples of acid-instable groups include groups represented by formulas (AL-3) to (AL-5) mentioned above, trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, and alkyl groups containing oxygen substituents in which each alkyl group has 4 to 20 carbon atoms.

[0747] R s4 The (w+1) valence hydrocarbon group or fluorinated hydrocarbon group can be straight-chain, branched, or cyclic. For specific examples, groups obtained by further removing w hydrogen atoms from the aforementioned hydrocarbon group or fluorinated hydrocarbon group can be listed.

[0748] Regarding R sa For the fluorinated hydrocarbon group, saturated groups are preferred, and straight-chain, branched, or cyclic groups are all acceptable. Specific examples include those in which some or all of the hydrogen atoms in the aforementioned hydrocarbon group are replaced by fluorine atoms. Specific examples include trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecylheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, 2-(perfluorodecyl)ethyl, etc.

[0749] For specific examples of the repeating units represented by any of equations (6A) to (6E), examples as shown below can be listed, but are not limited to these. Furthermore, in the following equation, R... B Same as above.

[0750] [Chemistry 241]

[0751]

[0752] [Chemistry 242]

[0753]

[0754] [Chemistry 243]

[0755]

[0756] [Chemistry 244]

[0757]

[0758] [Chemistry 245]

[0759]

[0760] [Chemistry 246]

[0761]

[0762] The aforementioned polymeric surfactants may also contain repeating units other than those represented by formulas (6A) to (6E). Specific examples of other repeating units include repeating units obtained from methacrylic acid, α-trifluoromethacrylic acid derivatives, etc. In polymeric surfactants, it is ideal for the content of repeating units represented by formulas (6A) to (6E) to be 20 mol% or more, more ideally 60 mol% or more, and even more ideally 100 mol%.

[0763] For the aforementioned polymeric surfactants, a Mw of 1,000 to 500,000 is ideal, and a Mw of 3,000 to 100,000 is even more ideal. A Mw / Mn ratio of 1.0 to 2.0 is ideal, and a Mw / Mn ratio of 1.0 to 1.6 is even more ideal.

[0764] Regarding methods for synthesizing the aforementioned polymeric surfactants, examples include monomers containing unsaturated bonds, provided by formulas (6A) to (6E) and other repeating units as needed, are polymerized by adding a free radical initiator to an organic solvent and heating. Specific examples of organic solvents used in polymerization include toluene, benzene, THF, diethyl ether, and dioxane. Specific examples of polymerization initiators include AIBN, 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. A reaction temperature of 50–100°C is ideal. A reaction time of 4–24 hours is ideal. Acid-unstable groups that can be directly introduced into the monomer can also be protected or partially protected after polymerization.

[0765] In the synthesis of the aforementioned polymeric surfactants, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used to adjust the molecular weight. In this case, it is ideal for the amount of these chain transfer agents added to be 0.01 to 10 mol% relative to the total molar number of monomers used for polymerization.

[0766] When the chemically amplified resist composition of the present invention contains a surfactant (E), its content is ideally 0.1 to 50 parts by mass relative to 80 parts by mass of the base polymer (A), and more ideally 0.5 to 10 parts by mass. If the content of surfactant (E) is 0.1 parts by mass or more, the receding contact angle between the resist film surface and water will be sufficiently improved; if it is 50 parts by mass or less, the dissolution rate of the resist film surface to the developer will be low, thus ensuring the height of the formed fine pattern. Surfactant (E) can be used alone or in combination of two or more.

[0767] [(F) Other ingredients]

[0768] The chemically amplified resist composition of the present invention may also contain compounds that decompose due to acid and produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, and compounds with a Mw of 3000 or less that change their solubility in the developer due to acid (dissolution inhibitors) as other components in (F). Regarding the aforementioned acid-increasing compounds, reference can be made to the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608. When containing the aforementioned acid-increasing compounds, it is ideally 0 to 5 parts by mass relative to 80 parts by mass of the base polymer in (A), and more ideally 0 to 3 parts by mass. If the content is too high, acid diffusion control becomes difficult, and there is a possibility of degradation in resolvability and pattern shape. Regarding the aforementioned organic acid derivatives, fluorinated alcohols, and dissolution inhibitors, reference can be made to the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608.

[0769] [Pattern Formation Method]

[0770] The pattern forming method of the present invention includes: a step of forming a resist film on a substrate using the aforementioned chemically amplified resist composition; a step of exposing the aforementioned resist film to high-energy radiation; and a step of developing the aforementioned exposed resist film using a developing solution.

[0771] Regarding the aforementioned substrate, substrates such as those used for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or substrates used for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) can be used.

[0772] The resist film can be formed by, for example, coating the aforementioned chemically amplified resist composition onto a substrate with a film thickness of 0.05 to 2 μm by spin coating, and then pre-baking it on a hot plate at a temperature of 60 to 150°C for 1 to 10 minutes, or more preferably 80 to 140°C for 1 to 5 minutes.

[0773] Examples of high-energy rays used in the exposure of resist films include KrF excimer lasers, ArF excimer lasers, EB, and EUV with wavelengths of 3–15 nm. When using KrF excimer lasers, ArF excimer lasers, or EUV for exposure, a mask used to form the desired pattern can be used with an ideal exposure dose of 1–200 mJ / cm². 2 Ideally, it should be 10–100 mJ / cm². 2 Irradiation is performed in a manner that allows for the formation of the desired pattern. When using EB, a mask is used to form the desired pattern, or the exposure is ideally between 1 and 300 μC / cm. 2Ideally, the temperature should be 10–200 μC / cm. 2 Irradiation is performed in this manner.

[0774] In addition to the usual exposure method, an immersion method can also be used, in which a liquid with a refractive index of 1.0 or higher is placed between the resist film and the projection lens. In this case, a protective film that is insoluble in water can also be used.

[0775] The aforementioned water-insoluble protective film, used to prevent leaching from the resist film and improve the hydrophobicity of the film surface, can be broadly classified into two categories. One type is the organic solvent stripper, which must be removed by an organic solvent that does not dissolve the resist film before alkaline aqueous development. The other type is the alkaline aqueous solution soluble type, which is soluble in alkaline developing solution and removes the protective film simultaneously with the removal of the soluble portion of the resist film. The latter is particularly ideally based on polymers containing 1,1,1,3,3,3-hexafluoro-2-propanol residues that are water-insoluble but soluble in alkaline developing solution, and dissolved in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof. Materials can also be prepared by dissolving the aforementioned water-insoluble but alkaline developing solution soluble surfactants in alcohol solvents with 4 or more carbon atoms, ether solvents with 8 to 12 carbon atoms, or mixtures thereof.

[0776] After exposure, PEB can also be performed. PEB can be performed, for example, by heating on a hot plate at a temperature of 60–150°C for 1–5 minutes, or even more ideally 80–140°C for 1–3 minutes.

[0777] Development is performed using a developer solution containing an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH) of 0.1–5% by mass, or more preferably 2–3% by mass, and by conventional methods such as dip, immersion, or spraying for 0.1–3 minutes, or more preferably 0.5–2 minutes, thereby dissolving the exposed portion and forming the desired pattern on the substrate.

[0778] Furthermore, after the resist film is formed, it can be rinsed with pure water to extract acid-generating agents or wash away particles from the film surface, and it can also be rinsed to remove water remaining on the film after exposure.

[0779] Then, pattern formation can also be achieved using a dual-patterning method. Examples of dual-patterning methods include: a trenching method where a substrate with a 1:3 trench pattern is processed by a first exposure and etching, and after offsetting the position, a second exposure is used to form a 1:3 trench pattern and a 1:1 pattern; and a line method where a first substrate with a 1:3 isolation pattern is processed by a first exposure and etching, and after offsetting the position, a second exposure is used to process a second substrate with a 1:3 isolation pattern formed under the first substrate to form a 1:1 pattern with a pitch of half.

[0780] In the pattern forming method of the present invention, a negative tone development method in which an organic solvent is used instead of the aforementioned alkaline aqueous solution as a developer to dissolve the unexposed portion can also be used.

[0781] In the aforementioned organic solvent development, the developer may include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, methyl crotonate, etc. Ethyl crotonate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl formate, phenyl ethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more.

[0782] Example

[0783] The following examples, embodiments, and comparative examples are shown to specifically illustrate the present invention, but the present invention is not limited to the following embodiments. Additionally, the apparatus used is as follows.

[0784] • MALDITOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0785] [1] Synthesis of onium salt monomers

[0786] [Example 1-1] Synthesis of onium salt type monomer a-1

[0787] [Chemistry 247]

[0788]

[0789] (1) Synthesis of intermediate In-1

[0790] Under nitrogen atmosphere, starting material SM-1 (105.2 g), maleic anhydride (78.4 g), and p-toluenesulfonic acid monohydrate (7.5 g) were dissolved in toluene (500 g) in a reaction vessel. The reaction vessel was heated to 100°C and refluxed for 12 hours. After maturation, the reaction system was cooled, the solvent was concentrated, and hexane was added for recrystallization, thereby obtaining intermediate In-1 112.5 g (yield 82%) as white crystals.

[0791] (2) Synthesis of intermediate In-2

[0792] Under nitrogen atmosphere, intermediate In-1 (112.5 g), starting material SM-2 (136.2 g), 4-dimethylaminopyridine (4.0 g), and dichloromethane (500 g) were added to a reaction vessel and cooled in an ice bath. While maintaining the temperature inside the reaction vessel below 20°C, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (81.7 g) was added directly as a powder. After addition, the mixture was allowed to mature at room temperature for 12 hours. After maturation, water (300 g) was added to stop the reaction, and a standard aqueous work-up was performed. After distilling off the solvent, diisopropyl ether was added for recrystallization, thereby obtaining intermediate In-2 219.8 g (93% yield) as white crystals.

[0793] (3) Synthesis of onium salt type monomer a-1

[0794] Under nitrogen atmosphere, intermediate In-2 (72.0 g), starting material SM-3 (40.8 g), dichloromethane (300 g), and water (150 g) were added to a reaction vessel. After stirring for 30 minutes, the organic layer was separated and sampled, washed with water, and then concentrated under reduced pressure to obtain 85.1 g (94% yield) of monomer a-1 as the target compound in the form of an oil. MALDI TOF-MS:POSITIVEM + 335 (equivalent to C) 18 H 11 F4 S + )

[0795] NEGATIVE M - 570 (equivalent to C) 17 H5F4INO7S - )

[0796] [Examples 1-2 to 1-7] Synthesis of onium salt type monomers a-2 to a-7

[0797] Using the corresponding raw materials and known organic synthesis reactions, onium salt type monomers a-2 to a-7 represented by the following formula were synthesized.

[0798] [Chemistry 248]

[0799]

[0800] [Comparative Examples 1-1 to 1-4] Comparative synthesis of onium salt type monomers Ca-1 to Ca-4

[0801] Using the corresponding raw materials and known organic synthesis reactions, comparative onium salt monomers ca-1 to ca-4 represented by the following formulas were synthesized.

[0802] [Chemistry 249]

[0803]

[0804] [2] Synthesis of basic polymers

[0805] Among the monomers used in the synthesis of the basic polymer, those other than the onium salt monomers a-1 to a-7 and the comparative onium salt monomers ca-1 to ca-4 are as follows.

[0806] [Chemistry 250]

[0807]

[0808] [Chemistry 251]

[0809]

[0810] [Chemistry 252]

[0811]

[0812] [Example 2-1] Synthesis of Polymer P-1

[0813] Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by loading monomer a-1 (46.2 g), monomer b1-1 (41.8 g), monomer c-1 (12.3 g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals Co., Ltd.) 3.91 g, and MEK 140 g into a flask. In another flask under nitrogen atmosphere, MEK 46 g was loaded, and the mixture was heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was stopped, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of hexane after vigorous stirring, and the precipitated polymer was filtered. The obtained polymer was then washed twice with 600 g of hexane and dried under vacuum at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 98.3 g, 98% yield). The Mw of polymer P-1 is 9700, and the Mw / Mn ratio is 1.57. Additionally, Mw is a converted value of polystyrene obtained using GPC with DMF as a solvent.

[0814] [Chemistry 253]

[0815]

[0816] [Examples 2-2 to 2-30, Comparative Examples 2-1 to 2-24] Synthesis of polymers P-2 to P-30 and comparative polymers CP-1 to CP-24

[0817] By changing the type and blending ratio of each monomer, the polymers shown in Tables 1 and 2 were manufactured using the same method as in Example 2-1.

[0818] [Table 1]

[0819]

[0820] [Table 2]

[0821]

[0822]

[0823] [3] Preparation of the resist composition

[0824] [Examples 3-1 to 3-30, Comparative Examples 3-1 to 3-24]

[0825] The predetermined components selected from the basic polymers (P-1 to P-30), comparative basic polymers (CP-1 to CP-24), photoacid generators (PAG-X, PAG-Y), and quenchers (Q-1 to Q-4) of the present invention, as shown in Tables 3 and 4 below, were dissolved in a solvent containing 0.01% by mass of FC-4430 manufactured by 3M as a surfactant to prepare a solution. The solution was then filtered through a 0.2 μm Teflon (registered trademark) type filter media to prepare chemically amplified resist compositions (R-1 to R-30, CR-1 to CR-24).

[0826] [Table 3]

[0827]

[0828]

[0829] [Table 4]

[0830]

[0831]

[0832] In Tables 3 and 4, the solvents, photoacid generators PAG-X and PAG-Y, and quenchers Q-1 to Q-4 are as follows.

[0833] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[0834] EL (ethyl lactate)

[0835] DAA (diacetone alcohol)

[0836] • Photoacid generators: PAG-X, PAG-Y

[0837] [Chemistry 254]

[0838]

[0839] Quenching agents: Q-1 to Q-4

[0840] [Chemistry 255]

[0841]

[0842] [4] Evaluation of EUV lithography (1)

[0843] [Examples 4-1 to 4-30, Comparative Examples 4-1 to 4-24]

[0844] The chemically amplified resist compositions (R-1 to R-30, CR-1 to CR-24) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a 20 nm thick silicon spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Industries, Ltd. The substrate was pre-baked at 100°C for 60 seconds using a heated plate to create a 50 nm thick resist film. For the aforementioned resist film, an LS pattern with a wafer size of 18 nm and a pitch of 36 nm was exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, dipole illumination) while varying the exposure amount and focal length (exposure pitch: 1 mJ / cm², focal point pitch: 0.020 μm). After exposure, a PEB process was performed for 60 seconds at the temperatures shown in Tables 5 and 6. Subsequently, the sample was immersed in a 2.38% by mass TMAH aqueous solution for 30 seconds for development, rinsed with a rinsing material containing surfactant, and then vortexed to obtain a positive pattern.

[0845] The obtained LS patterns were observed using a Hitachi Advanced CD-SEM (CG6300), and the sensitivity, EL, LWR, depth of focus (DOF), and collapse limit were evaluated using the following methods. The results are presented in Tables 5 and 6.

[0846] [Sensitivity Evaluation]

[0847] Determine the optimal exposure E for obtaining an LS pattern with a linewidth of 18 nm and a pitch of 36 nm. op (mJ / cm 2 This value is used as the sensitivity. The smaller the value, the higher the sensitivity.

[0848] [EL Review]

[0849] The EL (in %) is obtained from the exposure amount formed in the aforementioned LS pattern within a range of ±10% (16.2–19.8 nm) of an 18 nm spacing width. The larger the value, the better the performance.

[0850] EL(%)=(|E1-E2| / Eop)×100

[0851] E1: Provides optimal exposure for LS patterns with a linewidth of 16.2nm and a pitch of 36nm.

[0852] E2: Provides optimal exposure for LS patterns with a linewidth of 19.8nm and a pitch of 36nm.

[0853] Eop: Provides optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[0854] [LWR Evaluation]

[0855] The dimensions of the LS pattern obtained by Eop irradiation are measured at 10 points along the long side of the line, and the standard deviation (σ) is calculated as three times the value of the result (3σ) as the LWR. The smaller the value, the smaller the roughness and the more uniform the line width of the pattern can be obtained.

[0856] [DOF Rating]

[0857] The focal length range within ±10% (16.2–19.8 nm) of the aforementioned LS pattern is used as the depth of focus evaluation. The larger the value, the wider the depth of focus.

[0858] [Collapse Limit Assessment of Line Patterns]

[0859] The line dimensions of each exposure at the optimal focal length of the aforementioned LS pattern were measured at 10 points along the long side. The finest line dimension that could be obtained without collapse was taken as the collapse limit dimension. The smaller the value, the better the collapse limit.

[0860] [Table 5]

[0861]

[0862]

[0863] [Table 6]

[0864]

[0865]

[0866] Based on the results shown in Tables 5 and 6, it can be understood that the chemically amplified resist composition comprising polymers of the onium salt type monomers of the present invention exhibits good sensitivity and excellent EL, LWR, and DOF. Furthermore, it was confirmed that the collapse limit value is small, indicating strong resistance to pattern collapse during fine pattern formation. Therefore, the chemically amplified resist composition of the present invention is suitable as a material for EUV lithography.

[0867] [5] Evaluation of EUV lithography (2)

[0868] [Examples 5-1 to 5-30, Comparative Examples 5-1 to 5-24]

[0869] The chemically amplified resist compositions (R-1 to R-30, CR-1 to CR-24) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a 20 nm thick silicon spin-coating hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Industries, Ltd. The substrate was pre-baked at 105°C for 60 seconds using a heated plate to create a 50 nm thick resist film. The resist film was then exposed using an ASML NXE3400 EUV scanning exposure machine (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, a mask with a wafer-sized hole pattern of 46 nm pitch and +20% tolerance). The film was then subjected to PEB for 60 seconds at the temperatures described in Tables 7 and 8 using a heated plate, followed by development with a 2.38% by mass TMAH aqueous solution for 30 seconds to form a hole pattern with a size of 23 nm.

[0870] Using a Hitachi Advanced CD-SEM (CG6300), the exposure was measured when the aperture size was 23 nm, and this was used as the sensitivity. Furthermore, the size of 50 apertures at this time was measured, and three times the standard deviation (σ) calculated from the results (3σ) was taken as the CDU. The results are shown in Tables 7 and 8.

[0871] [Table 7]

[0872]

[0873]

[0874] [Table 8]

[0875]

[0876]

[0877] The results shown in Tables 7 and 8 confirm that the chemically amplified resist composition comprising polymers of the sulfonate type monomers of the present invention exhibits good susceptibility and excellent CDU.

[0878] [6] Evaluation of dry etching resistance

[0879] [Examples 6-1 to 6-30, Comparative Examples 6-1 to 6-24]

[0880] The polymer solutions (polymers P-1 to P-30 and comparative polymers CP-1 to CP-24) shown in Tables 1 and 2 were dissolved in 10g of cyclohexanone and filtered through a 0.2μm filter medium. The resulting polymer solutions were then spin-coated onto a Si substrate to form a film with a thickness of 300nm. The dry etching resistance was evaluated under the following conditions.

[0881] Etching experiments under CHF3 / CF4 gas:

[0882] The thickness difference of the polymer film before and after etching was determined using the TE-8500P dry etching apparatus manufactured by Tokyo Power Technology Co., Ltd.

[0883] Etching conditions are as follows.

[0884]

[0885]

[0886] In this evaluation, those with smaller film thickness variations, i.e., smaller reductions, showed higher etching resistance. The results of dry etching resistance are shown in Tables 9 and 10.

[0887] [Table 9]

[0888]

[0889]

[0890] [Table 10]

[0891]

[0892] Based on the results shown in Tables 9 and 10, it was confirmed that the polymer of the present invention has excellent dry etching resistance to the CHF3 / CF4 gas system.

Claims

1. A bellium salt type monomer, represented by the following formula (A); In the formula, n1 is 0 or 1; n2 is 0, 1, 2, 3 or 4; n3 is 0, 1, 2, 3 or 4; but when n1 is 0, 0≤n2+n3≤4, and when n1 is 1, 0≤n2+n3≤6; R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; R 1 The halogen atom other than fluorine, nitro, cyano, hydroxyl, carboxyl, hydrocarbon group with 1 to 20 carbon atoms, hydroxyl group with 1 to 20 carbon atoms, or hydrocarbon thio group with 1 to 20 carbon atoms may also contain heteroatoms other than fluorine; when n3 is 2, 3, or 4, each R 1 Multiple Rs can be the same or different. 1 They can also bond with each other and form rings together with the carbon atoms they bond with; R F It consists of a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms; when n2 is 2, 3, or 4, each R F They can be the same or different; L A and L B Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; X L1 and X L2 Each is an independent single bond, or may contain heteroatoms, of a carbon-1 to 40 alkylene group; but L A L B X L1 and X L2 Not all of them will be single keys at the same time; Z + It is a ium cation.

2. The onium salt type monomer according to claim 1 is represented by the following formula (A1); In the formula, n1~n3, R A R 1 R F L A L B X L2 and Z + Same as above; n4 is 0 or 1; n5 is 0, 1, 2, 3 or 4; R 2 It can be a halogen atom, nitro group, cyano group, hydroxyl group, carboxyl group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or an alkyloxy group with 1 to 20 carbon atoms containing heteroatoms; when n4 is 2, 3 or 4, each R 2 Multiple Rs can be the same or different. 2 They can also bond with each other and form rings together with the carbon atoms they bond with.

3. The onium salt type monomer according to claim 2 is represented by the following formula (A2); In the formula, n4, n5, and R A R 2 L A and Z + Same as above.

4. The onium salt type monomer according to claim 1, wherein, Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2); In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group consisting of halogen atoms, or may contain heteroatoms, and has 1 to 30 carbon atoms; furthermore, R ct1 and R ct2 They can also bond with each other and form rings together with the sulfur atoms they bond with.

5. The onium salt type monomer according to claim 1, wherein, Z + The sulfonium cation is represented by the following formula (Z-3); In the formula, m1 is 0 or 1; m2 is 0 or 1; m3 is 0 or 1; m4 is 0, 1, 2, 3 or 4; m5 is 0, 1, 2, 3 or 4; m6 is 0, 1, 2, 3, 4, 5 or 6; m7 is 0, 1, 2, 3, 4, 5 or 6; m8 is 0, 1 or 2; m9 is 0, 1 or 2; m10 is 0, 1 or 2; m11 is 0 or 1; m12 is 0, 1, 2, 3 or 4; m13 is 0, 1 or 2; m14 is 0, 1 or 2. However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4; when m1 is 1, 0 ≤ m6 + m9 ≤ 6; when m2 is 0, 0 ≤ m7 + m10 ≤ 4; when m2 is 1, 0 ≤ m7 + m10 ≤ 6; when m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4; when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6; when m11 is 0, 0 ≤ m12 + m13 ≤ 4; when m11 is 1, 0 ≤ m12 + m13 ≤ 6; and m4 + m12 ≥ 1. R F1 ~R F3 Each is independently a fluorine atom, a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbon oxygen group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbon thio group having 1 to 6 carbon atoms; when m5 is 2, 3, or 4, each R F1 They can be the same or different; when m6 is 2, 3, 4, 5 or 6, each R F2 They can be the same or different; when m7 is 2, 3, 4, 5 or 6, each R F3 They can be the same or different; R ct6 ~R ct9 Halogen atoms other than iodine and fluorine atoms, nitro, cyano, hydrocarbon groups with 1 to 20 carbon atoms (which may also contain heteroatoms), hydroxyl groups with 1 to 20 carbon atoms (which may also contain heteroatoms), or thiol groups with 1 to 20 carbon atoms (which may also contain heteroatoms); when m8 is 2, there are 2 R ct6 They can be the same or different, 2 Rs ct6 They can also bond with each other and form rings together with the carbon atoms they bond with; when m9 is 2, the two R atoms... ct7 They can be the same or different, 2 Rs ct7 They can also bond with each other and form rings together with the carbon atoms they bond with; when m10 is 2, the two R atoms... ct8 They can be the same or different, 2 Rs ct8 They can also bond with each other and form rings together with the carbon atoms they bond with; when m13 is 2, the two R atoms... ct9 They can be the same or different, 2 Rs ct9 They can also bond with each other and form rings together with the carbon atoms they bond with; Furthermore, S directly bonded to the sulfonium cation + The aromatic rings can also bond with each other and interact with S. + Together they form a ring; L C and L D Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond; X L3 It is a single bond, or may contain heteroatoms and a hydrocarbon group with 1 to 40 carbon atoms.

6. A polymer comprising repeating units from an onium salt monomer according to any one of claims 1 to 4.

7. The polymer according to claim 6 functions as a polymer-bonded acid generator.

8. The polymer according to claim 6 further comprises at least one selected from the repeating unit represented by formula (a1), the repeating unit represented by formula (a2), and the repeating unit represented by formula (a3); In the formula, R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; X 1 Single bond, phenylene, naphthylene, *-C(=O)-OX 11 -or *-C(=O)-NH-X 11 - The phenylene or naphthylene group may also be substituted with a hydroxyl group, a nitro group, a cyano group, a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, a saturated hydroxyl group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom; X 11 It is a saturated hydrocarbon group, phenylene or naphthylene with 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond or lactone ring; X 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * indicates an atomic bond with a carbon atom in the main chain; R 11 It can be a halogen atom, cyano group, hydroxyl group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon oxygen group with 1 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; it can also be a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; or it can also be a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms; when a1 is 2, 3 or 4, each R 11 They can be the same or different; AL 1 and AL 2 Each is an unstable acid group; a1 can be 0, 1, 2, 3 or 4; In the formula, a11 is 0 or 1; a12 is 0, 1, 2 or 3 when a11 is 0, and 0, 1, 2, 3, 4 or 5 when a11 is 1; R A It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; X 3 It represents a single bond, *-C(=O)-O- or *-C(=O)-NH-; * indicates an atomic bond with a carbon atom in the main chain; X 4 It is a single bond, an aliphatic alkylene group, a carbonyl group, a sulfonyl group, or a combination thereof, having 1 to 4 carbon atoms; X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom; but X 4 and X 6 It is bonded to an adjacent carbon atom of the aromatic ring; R 12 and R 13 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms; also, R 12 and R 13 They can also bond with each other and form rings together with the carbon atoms they bond with; R 14 It may contain halogen atoms, hydroxyl groups, cyano groups, nitro groups, or hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxygen groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxycarbonyl groups with 2 to 20 carbon atoms containing heteroatoms; or hydrocarbon thio groups with 1 to 20 carbon atoms containing heteroatoms, or -N(R) groups. 14A (R) 14B ); R 14A and R 14B Each is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms; when a12 is 2 or more, each R 14 Multiple Rs can be the same or different. 14 They can also bond with each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

9. The polymer according to claim 6, further comprising at least one of the repeating units represented by formula (b1) and formula (b2); In the formula, R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group; Y 1 It represents a single bond or *-C(=O)-O-; * indicates an atomic bond with a carbon atom in the main chain; R 21 It is a hydrogen atom, or a group containing at least one of the following structures with 1 to 20 carbon atoms: hydroxyl group other than phenolic hydroxyl group, cyano group, carbonyl group, carboxyl group, ether bond, ester bond, sulfonate bond, carbonate bond, lactone ring, sulcinolone ring and carboxylic anhydride (-C(=O)-OC(=O)-); R 22 It can be a halogen atom, carboxyl group, nitro group, cyano group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms, or a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; when b2 is 2, 3 or 4, each R 22 They can be the same or different; b1 can be 1, 2, 3 or 4; b2 can be 0, 1, 2, 3 or 4; but 1≤b1+b2≤5.

10. A chemically amplified resist composition comprising (A) a base polymer containing the polymer according to claim 6.

11. The chemically amplified resist composition according to claim 10, further comprising (B) an organic solvent.

12. The chemically amplified resist composition according to claim 10, further comprising (C) a quencher.

13. The chemically amplified resist composition according to claim 10, further comprising (D) a photoacid generator.

14. The chemically amplified resist composition according to claim 10, further comprising (E) a surfactant.

15. A method for forming a pattern, comprising the following steps: A resist film is formed on a substrate using the chemically amplified resist composition according to claim 10; The resist film was exposed to high-energy rays; and The exposed resist film was developed using a developer.

16. The pattern forming method according to claim 15, wherein, The high-energy rays are KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays with wavelengths of 3–15 nm.

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