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: an onium salt-type monomer which has excellent solvent solubility in lithography using a high-energy ray, and which is capable of forming a pattern using a high-energy ray; a polymer containing a repeating unit derived from the onium salt-type monomer; a chemically amplified resist composition containing the polymer; and a method for forming a pattern using the chemically amplified resist composition. Provided is a chemically amplified resist composition which has high sensitivity, high contrast, excellent lithography performance such as EL, LWR, CDU, and DOF, is not susceptible to pattern collapse even in the formation of fine patterns, and has excellent etching resistance. 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 LSIs, the miniaturization of patterned regularity is rapidly advancing. In particular, the market expansion and increasing memory capacity of flash memory have driven miniaturization. As the most advanced miniaturization method, mass production of 65nm node devices is being achieved using ArF lithography, and preparations are underway for mass production of 45nm node devices using next-generation ArF immersion lithography. For next-generation 32nm node devices, immersion lithography using ultra-high NA lenses combining liquids with a refractive index higher than water and 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 are among the candidates being researched.

[0003] As the technology advances towards miniaturization and approaches the diffraction limit of light, the contrast of light decreases. This decrease in contrast leads to a reduction in the resolution and focusing margin of hole and trench patterns in positive resist films.

[0004] As patterns become more miniaturized, the linewidth roughness (LWR) of the line pattern and the size uniformity (CDU) of the hole pattern are also considered problems. The effects of uneven distribution of the base polymer and acid-generating agent, aggregation, and acid diffusion have been identified. Furthermore, with the thinning of the resist film, there is a tendency for the LWR to increase, and the deterioration of LWR caused by thinning accompanying miniaturization becomes a serious problem.

[0005] In EUV lithography resist compositions, it is necessary to simultaneously achieve high sensitivity, high resolution, and low light-to-weight ratio (LWR). Shortening the acid diffusion distance reduces LWR but decreases sensitivity. For example, lowering the post-exposure baking (PEB) temperature reduces LWR but decreases sensitivity. Even increasing the amount of quencher reduces LWR but decreases sensitivity. A trade-off between sensitivity and LWR needs to be struck.

[0006] To suppress acid diffusion, a resist composition containing repeating units from onium salts of sulfonic acids with polymerizable unsaturated bonds has been proposed (Patent Document 1). This so-called polymer-bonded acid generator, due to the generation of polymeric sulfonic acid through exposure, exhibits a very short acid diffusion distance. Furthermore, sensitivity can be improved by increasing the ratio of the acid generator. In additive acid generators, increasing the amount increases sensitivity, but in this case, the acid diffusion distance also increases. Due to uneven acid diffusion, LWR and CDU deteriorate as acid diffusion increases. In terms of the balance between sensitivity, LWR, and CDU, polymeric acid generators can be said to have high capability.

[0007] Iodine atoms exhibit significant absorption at 13.5 nm in EUV, confirming the ability to generate secondary electrons from iodine atoms during exposure, thus attracting attention in EUV lithography. Patent Document 2 describes a photoacid generator in which iodine atoms are introduced into an anion, and Patent Document 3 describes a photoacid generator containing polymerizable groups in which iodine atoms are introduced into an anion. While this confirms a certain degree of improvement in lithography performance, the low solubility of iodine atoms in organic solvents raises concerns about precipitation in solvents.

[0008] To further suppress acid diffusion, it has been proposed to use polymers containing repeating units of sulfonium salts from weak acids with a pKa of -0.8 or higher that have polymeric groups as resist compositions for polymer-bonded quenchers (Patent Documents 4 to 7). In Patent Document 4, examples of weak acids include carboxylic acids, sulfonamides, phenols, and hexafluorools.

[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] International Publication No. 2019 / 167737

[0015] [Patent Document 5] International Publication No. 2022 / 264845

[0016] [Patent Document 6] Japanese Patent Application Publication No. 2022-115072

[0017] [Patent Document 7] Japanese Patent No. 7433394 Summary of the Invention

[0018] [The problem the invention aims to solve]

[0019] In chemically amplified resist compositions using acid as a catalyst, it is desirable to develop resist compositions with higher sensitivity, improved line patterns (LWR) and hole patterns (CDU), and excellent etch resistance after pattern formation.

[0020] The present invention was made in view of the above circumstances, and its object is to provide an onium salt type monomer, a polymer comprising repeating units from the onium salt type monomer, a chemically amplified resist composition comprising the polymer, and a patterning method using the chemically amplified resist composition. The aforementioned onium salt type monomer is particularly suitable for use in lithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), EUV, etc., exhibiting excellent solvent solubility, high sensitivity, high contrast, excellent lithography performance such as exposure margin (EL), LWR, CDU, and depth of focus (DOF), and is less prone to pattern collapse during the formation of fine patterns, as well as excellent etch resistance in chemically amplified resist compositions.

[0021] [Methods used to solve problems]

[0022] In order to achieve the above-mentioned objectives, the inventors have repeatedly conducted in-depth research and found that, in terms of polymer-bonded quenchers, by using polymers containing repeating units derived from onium salts containing aromatic ring carboxylic acid anions with iodine atoms as polymerizable groups, it is possible to obtain chemically amplified resist compositions with high sensitivity, improved LWR and CDU, high contrast and high resolution, and excellent etch resistance. This invention was thus completed.

[0023] That is, the present invention provides the following onium salt type monomer, polymer, chemically amplified resist composition and patterning method.

[0024] 1. A bellium salt type monomer, represented by the following formula (a),

[0025] [Chemistry 1]

[0026]

[0027] In the formula, n1 is 0 or 1, n2 is 0, 1, 2, 3 or 4, n3 is 0, 1, 2, 3 or 4, n4 is 0 or 1, n5 is 0, 1, 2, 3 or 4, and n6 is 0, 1 or 2. However, when n1 is 0, 1 ≤ n2 + n3 ≤ 4; when n1 is 1, 1 ≤ n2 + n3 ≤ 6. Also, when n4 is 0, 1 ≤ n5 + n6 ≤ 4; when n4 is 1, 1 ≤ n5 + n6 ≤ 6. Furthermore, 1 ≤ n2 + n5, and n7 is 0 or 1.

[0028] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0029] R 1 When n3 is 2, 3, or 4, each R 1 They can be the same or different, multiple Rs 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0030] R 2 For halogen atoms other than iodine atoms, nitro groups, hydrocarbon groups with 1 to 20 carbon atoms that may contain heteroatoms, hydroxyl groups with 1 to 20 carbon atoms that may contain heteroatoms, or hydrocarbon thiol groups with 1 to 20 carbon atoms that may contain heteroatoms, when n6 is 2, each R 2 They can be the same or different, multiple Rs 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0031] L A It can be a single bond, a sulfonate bond, or a sulfonamide bond.

[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, R A R 1 R 2 n1~n7 and Z + Similar to the above, L A1 It can be -O- or -NH-.

[0037] 3. As in 2., the onium salt type monomer is represented by the following formula (a2).

[0038] [Chemistry 3]

[0039]

[0040] In the formula, R A R 1 R 2 n1~n6 and Z + Same as above.

[0041] 4. Onium salt type monomers such as any one of 1. to 3, wherein Z +It is a sulfonium cation represented by the following formula (cation-1) or a monazine cation represented by the following formula (cation-2).

[0042] [Chemistry 4]

[0043]

[0044] In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms. Additionally, R... ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they are bonded to.

[0045] 5. Onium salt type monomers such as any one of 1. to 3, wherein Z + The sulfonium cation is represented by the following formula (A).

[0046] [Chemistry 5]

[0047]

[0048] 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, but m1 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; additionally, m4 + m12 ≥ 1.

[0049] 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. When m5 is 2 or more, each R F 1 They can be the same or different. When m6 is 2 or more, each R F2 They can be the same or different. When m7 is 2 or more, each R F3 They can be the same or different from each other.

[0050] R3 ~R 6 The radicals are 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 contain heteroatoms). When m8 is 2, there are 2 R radicals. 3 They can be the same or different from each other, and there are 2 Rs. 3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m9 is 2, there are 2 R atoms. 4 They can be the same or different from each other, and there are 2 Rs. 4 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m10 is 2, there are 2 R atoms. 5 They can be the same or different from each other, and there are 2 Rs. 5 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m13 is 2, there are 2 R atoms. 6 They can be the same or different from each other, and there are 2 Rs. 6 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0051] In addition, S in sulfonium cations + Directly bonded aromatic rings can also bond with each other and S + Together they form a ring.

[0052] L B and L C Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond.

[0053] X L It is a single bond, or may contain heteroatoms and a hydrocarbon group with 1 to 40 carbon atoms.

[0054] 6. As in 5., the onium salt type monomer, wherein the sulfonium cation is represented by the following formula (A1),

[0055] [Chemistry 6]

[0056]

[0057] In the formula, m4~m10, m12~m14, R F1 ~R F3 R 3 ~R 6 L B L C and X L Same as above.

[0058] 7. As in 6., the onium salt type monomer, wherein the sulfonium cation is represented by the following formula (A2),

[0059] [Chemistry 7]

[0060]

[0061] In the formula, m4~m10, R F 1 ~R F3 and R 3 ~R 5 Same as above.

[0062] 8. A monomeric photoacid generator, comprising an onium salt monomer as described in any one of 1 to 7.

[0063] 9. A polymer comprising repeating units from a monomeric photoacid generator as described in 8.

[0064] 10. The polymer as described in 9, further comprising repeating units represented by formula (b1) or (b2),

[0065] [Chemistry 8]

[0066]

[0067] In the formula, R A Each is independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0068] 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 by 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, or naphthylene group having 1 to 10 carbon atoms. This saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or a lactone ring. 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-.

[0069] * indicates an atomic bond with a carbon atom in the main chain.

[0070] 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, 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.

[0071] AL 1 and AL 2Each is an independent acid-labile group.

[0072] a can be 0, 1, 2, 3 or 4.

[0073] 11. Polymers such as those in 9 or 10, further comprising repeating units represented by formula (b3),

[0074] [Chemistry 9]

[0075]

[0076] In the formula, b1 is 0 or 1, and b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1.

[0077] R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0078] X 3 These are single bonds, *-C(=O)-O-, or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain.

[0079] R 12 and R 13 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms. Additionally, R... 12 and R 13 They can also bond to each other and form rings together with the carbon atoms they are bonded to.

[0080] R 14 This indicates a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms that may contain heteroatoms; a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms that may contain heteroatoms; or a hydrocarbon thio group or -N(R) group with 1 to 20 carbon atoms. 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 b2 is 2 or more, multiple R... 14 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0081] X 4 It is a single bond, an aliphatic hydrocarbon group, carbonyl group, sulfonyl group, or a combination thereof, consisting of 1 to 4 carbon atoms.

[0082] X 5 and X 6 Each can be independently an oxygen atom or a sulfur atom, but X 4 and X 6 It bonds with adjacent carbon atoms of the aromatic ring.

[0083] 12. The polymer of any one of 9. to 11. further comprises a repeating unit represented by formula (c).

[0084] [Chemistry 10]

[0085]

[0086] In the formula, R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0087] Y 1 These are single bonds, *-C(=O)-O-, or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain.

[0088] R 21 It can be a halogen atom, nitro group, cyano group, carboxyl 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.

[0089] c1 can be 1, 2, 3 or 4, and c2 can be 0, 1, 2 or 3, but 1≤c1+c2≤5.

[0090] 13. The polymer of any one of 9 to 12, further comprising a repeating unit derived from a fluorosulfonic acid anion having a polymerizable group and one or more iodine atoms in the anion and a sulfonium cation.

[0091] 14. The polymer of any one of 9. to 13. further comprises a repeating unit represented by formula (e).

[0092] [Chemistry 11]

[0093]

[0094] In the formula, R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0095] Z 1 Indicates single bond, phenylene, naphthylene, *-C(=O)-OZ 11 -or *-C(=O)-NH-Z 11 - The phenylene or naphthylene group may also be substituted by a hydroxyl, nitro, 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. * indicates an atomic bond with a carbon atom in the main chain. Z 11It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 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.

[0096] R 51 It is a hydrogen atom, or a group having 1 to 20 carbon atoms, selected from at least one of the following structures: 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)-).

[0097] 15. A chemically amplified resist composition comprising (A) a base polymer comprising any one of the polymers described in 9 to 14.

[0098] 16. As in 15, the chemically amplified resist composition further contains (B) an organic solvent.

[0099] 17. Chemically amplified resist compositions such as 15 or 16, further containing (C) quencher.

[0100] 18. A chemically amplified resist composition as described in any of 15 to 17, further comprising (D) an acid generating agent.

[0101] 19. A chemically amplified resist composition as described in any of 15 to 18, further comprising (E) a surfactant.

[0102] 20. A method for forming a pattern, comprising:

[0103] The step of forming a resist film on a substrate using a chemically amplified resist composition such as any one of 15. to 19;

[0104] The step of exposing the resist film with high-energy rays; and

[0105] The step of developing the exposed resist film using a developer.

[0106] 21. The pattern forming method of 20, wherein the high-energy ray is an ArF excimer laser with a wavelength of 193 nm or a KrF excimer laser with a wavelength of 248 nm, an electron beam or extreme ultraviolet light with a wavelength of 3 to 15 nm.

[0107] [The effects of the invention]

[0108] The resist film containing a polymer with repeating units derived from the onium salt monomer represented by formula (a) exhibits good solvent solubility and, due to the large atomic weight of iodine atoms, low acid diffusion. This prevents resolution degradation caused by acid diffusion blurring, improving both low-resolver ratio (LWR) and low-density chromatic ductility (CDU). Furthermore, the iodine-based absorption of EUV at a wavelength of 13.5 nm is very high, resulting in the generation of secondary electrons from iodine atoms during exposure, achieving high sensitivity. On the other hand, the high basicity of aromatic carboxylic acid anions effectively captures acids generated by acid generators. This allows for the construction of chemically amplified resist compositions with high sensitivity and improved LWR and CDU. Additionally, the aromatic ring acts as a good etch-resistant group, making it suitable for fine pattern formation. Detailed Implementation

[0109] [Onium salt type monomer]

[0110] The onium salt type monomer of the present invention is represented by the following formula (a).

[0111] [Chemistry 12]

[0112]

[0113] 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. From the viewpoint of solvent solubility, it is preferable that n1 is 0 and the ring is benzene. n2 is 0, 1, 2, 3, or 4. From the viewpoint of raw material supply, n2 is preferably 0, 1, 2, or 3, more preferably 0, 1, or 2. n3 is 0, 1, 2, 3, or 4, preferably 0, 1, 2, or 3, more preferably 0, 1, or 2, and even more preferably 0 or 1. n4 is 0 or 1. When n4 is 0, it is a benzene ring; when n4 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, it is preferable that n4 is 0 and the ring is benzene. n5 is 0, 1, 2, 3, or 4. n6 is 0, 1, or 2. However, when n1 is 0, 1 ≤ n2 + n3 ≤ 4; when n1 is 1, 1 ≤ n2 + n3 ≤ 6. Furthermore, when n4 is 0, 1 ≤ n5 + n6 ≤ 4; when n4 is 1, 1 ≤ n5 + n6 ≤ 6. Also, 1 ≤ n2 + n5.

[0114] In equation (a), n7 is 0 or 1. A higher number of iodine atoms in the anionic structure results in higher absorption of EUV, but it may become less solvent-soluble and precipitate in the resist composition. Therefore, the preferred number of iodine atoms in the anionic structure is 1, 2, 3, or 4, more preferably 1, 2, or 3. Thus, when n7 is 0, 1 ≤ n2 ≤ 4; when n7 is 1, 1 ≤ n2 + n5 ≤ 6.

[0115] In equation (a), R A Preferably, it is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, it is more preferably a hydrogen atom or a methyl group, and even more preferably a hydrogen atom.

[0116] In formula (a), the iodine atom on the aromatic ring of the anion is preferably bonded to L. A The adjacent positions of the bonded carbon atoms. Since iodine atoms are elements with large atomic radii, the rotation of the bonding axes between the aromatic rings bonded by the polymerizable groups and the aromatic rings bonded by the iodine atoms is suppressed, thus increasing the rigidity of the polymer.

[0117] In equation (a), R 1 The halogen atom (excluding iodine), a nitro group, a hydrocarbon group with 1 to 20 carbon atoms (which may also contain heteroatoms), a hydrocarbon oxygen group with 1 to 20 carbon atoms (which may also contain heteroatoms), or a hydrocarbon thio group with 1 to 20 carbon atoms (which may also contain heteroatoms). The halogen atom (excluding iodine) is preferably a fluorine atom, a chlorine atom, or a bromine atom, and more preferably a fluorine atom. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, 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; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon 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 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 also contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone 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.

[0118] Additionally, when n3 is 2, 3, or 4, multiple R 1They can also bond to each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. In addition, some or all of the hydrogen atoms in the above rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above rings can 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.

[0119] In equation (a), R 2 The halogen atom can be a halogen atom other than an iodine atom, a nitro group, a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms, a hydrocarbon oxygen group with 1 to 20 carbon atoms that may contain heteroatoms, or a hydrocarbon thio group with 1 to 20 carbon atoms that may contain heteroatoms. Specific examples of the halogen atom other than an iodine atom include fluorine, chlorine, and bromine atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include R... 1 The groups exemplified by the hydrocarbon groups are similar, but not limited to, those shown. When n6 is 2, each R 2 They can be the same or different.

[0120] Additionally, when n6 is 2, multiple R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Preferably, these rings are 5- to 8-membered rings.

[0121] In equation (a), L A It can be a single bond, a sulfonate bond, or a sulfonamide bond. Among them, as L... A Preferably, it is a sulfonate bond or a sulfonamide bond, and more preferably a sulfonate bond.

[0122] The onium salt type monomer represented by formula (a) is preferably the monomer represented by formula (a1).

[0123] [Chemistry 13]

[0124]

[0125] In the formula, R A R 1 R 2 n1~n7 and Z + Same as above. L A1 It can be -O- or -NH-.

[0126] The onium salt type monomer represented by formula (a1) is preferably the monomer represented by formula (a2).

[0127] [Chemistry 14]

[0128]

[0129] In the formula, R A R 1 R 2 n1~n6 and Z + Same as above.

[0130] Specific examples of anions of onium salt type monomers represented by formula (a) can be given as shown below, but are not limited to these. Furthermore, in the following formula, R... A As above, Me is methyl. Furthermore, the bonding positions of various substituents on the aromatic ring can be interchanged on the aromatic ring.

[0131] [Chemistry 15]

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[0200]

[0201] [Transformation 50]

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[0203] [Chemistry 51]

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[0221] [Transformation 60]

[0222]

[0223] [Chemistry 61]

[0224]

[0225] [Chemistry 62]

[0226]

[0227] [Chemistry 63]

[0228]

[0229] In equation (a), Z + The cation is a sulfonium cation. Preferably, the sulfonium cation represented by formula (cation-1) or the sulfonium cation represented by formula (cation-2) is a sulfonium cation.

[0230] [Chemistry 64]

[0231]

[0232] In equations (cation-1) and (cation-2), 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.

[0233] R ct1 ~R ct5 Specific examples of halogen atoms include fluorine, chlorine, bromine, and iodine atoms.

[0234] R ct1 ~R ct5 The represented hydrocarbon group can be saturated or unsaturated, and can be straight-chain, 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, allyl, 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, but aryl is preferred. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may also 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.

[0235] Additionally, R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, specific examples of the aforementioned ring structures can be listed, such as the structures shown in the following formula.

[0236] [Chemistry 65]

[0237]

[0238] In the formula, the dashed line represents the intersection with R. ct3 Atomic bonds.

[0239] Specific examples of sulfonium cations represented by formula (cation-1) are shown below, but are not limited to these.

[0240] [Chemistry 66]

[0241]

[0242] [Chemistry 67]

[0243]

[0244] [Chemistry 68]

[0245]

[0246] [Chemistry 69]

[0247]

[0248] [Chemistry 70]

[0249]

[0250] [Chemistry 71]

[0251]

[0252] [Chemistry 72]

[0253]

[0254] [Chemistry 73]

[0255]

[0256] [Chemistry 74]

[0257]

[0258] [Chemistry 75]

[0259]

[0260] [Chemistry 76]

[0261]

[0262] [Chemistry 77]

[0263]

[0264] [Chemistry 78]

[0265]

[0266] [Chemistry 79]

[0267]

[0268] [Chemistry 80]

[0269]

[0270] [Chemistry 81]

[0271]

[0272] [Chemistry 82]

[0273]

[0274] [Chemistry 83]

[0275]

[0276] [Chemistry 84]

[0277]

[0278] [Chemistry 85]

[0279]

[0280] [Chemistry 86]

[0281]

[0282] [Chemistry 87]

[0283]

[0284] [Chemistry 88]

[0285]

[0286] [Chemistry 89]

[0287]

[0288] [Chemistry 90]

[0289]

[0290] [Chemistry 91]

[0291]

[0292] [Chemistry 92]

[0293]

[0294] Specific examples of citric acid represented by formula (cation-2) include the following cations, but are not limited to these.

[0295] [Chemistry 93]

[0296]

[0297] [Chemistry 94]

[0298]

[0299] Z + The onium cation represented is preferably a sulfonium cation represented by the following formula (A).

[0300] [Chem. 95]

[0301]

[0302] In formula (A), m1 is 0 or 1. When m1 is 0, it is a benzene ring; when m1 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, it is preferable that m1 is 0 and the ring is benzene. m2 is 0 or 1. When m2 is 0, it is a benzene ring; when m2 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, it is preferable that m2 is 0 and the ring is benzene. m3 is 0 or 1. When m3 is 0, it is a benzene ring; when m3 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, it is preferable that m3 is 0 and the ring is benzene.

[0303] In formula (A), 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 becomes insufficient, and it may precipitate in the resist composition. Therefore, m4 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0304] In formula (A), m5 is 0, 1, 2, 3, or 4. From the viewpoint of raw material supply, m5 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2. m6 is 0, 1, 2, 3, 4, 5, or 6. From the viewpoint of raw material supply, m6 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2. m7 is 0, 1, 2, 3, 4, 5, or 6. From the viewpoint of raw material supply, m7 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0305] In formula (A), m8 is 0, 1, or 2. From the perspective of raw material supply, m8 is preferably 0 or 1. m9 is 0, 1, or 2. From the perspective of raw material supply, m9 is preferably 0 or 1. m10 is 0, 1, or 2. From the perspective of raw material supply, m10 is preferably 0 or 1.

[0306] In formula (A), m11 is 0 or 1. When m11 is 0, it is a benzene ring; when m11 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, it is preferable to have a benzene ring with m11 of 0.

[0307] In formula (A), 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 become insufficient, and it may precipitate in the resist composition. Therefore, m12 is preferably 0, 1, 2 or 3, and more preferably 0, 1 or 2.

[0308] In formula (A), m13 is 0, 1, or 2. From the viewpoint of raw material supply, m13 is preferably 0 or 1. m14 is 0, 1, or 2. From the viewpoint of synthesis, m14 is preferably 0 or 1.

[0309] 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.

[0310] In formula (A), 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 preferred. When m5 is 2 or more, each R F1 They can be the same or different. When m6 is 2 or more, each R F2 They can be the same or different. When m7 is 2 or more, each R F3 They may be the same as or different from each other.

[0311] In formula (A), R 3 ~R 6 The halogen atom (excluding iodine and fluorine atoms), nitro, cyano, a hydrocarbon group with 1 to 20 carbon atoms (which may also contain heteroatoms), an alkyloxy group with 1 to 20 carbon atoms (which may also contain heteroatoms), or a alkylthio group with 1 to 20 carbon atoms (which may also contain heteroatoms). The hydrocarbon group, as well as the hydrocarbon alkyloxy and alkylthio groups, can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include R... 1The groups exemplified by the hydrocarbon group are the same groups. In addition, part or all of the hydrogen atoms in the hydrocarbon group, hydroxyl group, and thiol group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. Part of the -CH2- of the aforementioned hydrocarbon group can 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, sulopentatone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0312] Additionally, when m8 is 2, there are 2 R... 3 They can be the same or different from each other, and there are 2 Rs. 3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m9 is 2, there are 2 R atoms. 4 They can be the same or different from each other, and there are 2 Rs. 4 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m10 is 2, there are 2 R atoms. 5 They can be the same or different from each other, and there are 2 Rs. 5 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m13 is 2, there are 2 R atoms. 6 They can be the same or different from each other, and there are 2 Rs. 6 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. In addition, some or all of the hydrogen atoms in the above rings can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above rings can 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.

[0313] In addition, S in the sulfonium cation represented by formula (A) + Directly bonded aromatic rings can also bond with each other and S + Together they form a ring. At this point, as a specific example of the aforementioned ring structure, structures such as those shown in the following formula can be listed.

[0314] [Chemistry 96]

[0315]

[0316] In the formula, the dashed lines represent atomic bonds.

[0317] In formula (A), L B and L C Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among them, L... B Preferably, it is a single bond, ether bond, ester bond, or sulfonate bond, more preferably an ester bond or sulfonate bond. As L C Preferably, it is a single bond, ether bond, or ester bond, and more preferably a single bond.

[0318] In formula (A), X L It is a single-bonded or heteroatom-containing hydrocarbon group with 1 to 40 carbon atoms. The aforementioned hydrocarbon group can be straight-chain, branched, or cyclic, and specific examples include alkyldiyl, cyclic saturated hydrocarbon groups, and arylyl groups. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, etc.

[0319] X L Specific examples of hydrocarbon groups with 1 to 40 carbon atoms that may also contain heteroatoms are shown below, but are not limited to these. Furthermore, in the following formulas, * denotes the groups related to L. B and L C Atomic bonds.

[0320] [Chemistry 97]

[0321]

[0322] [Chem. 98]

[0323]

[0324] [Chemistry 99]

[0325]

[0326] [Chemistry 100]

[0327]

[0328] Among them, X L -0~X L -22, X L -29~X L -34 and X L -47~X L -58 is better.

[0329] The sulfonium cation represented by formula (A) is preferably the sulfonium cation represented by formula (A1).

[0330] [Chemistry 101]

[0331]

[0332] In the formula, m4~m10, m12~m14, R F1 ~R F3 R 3 ~R 6 L B L C and X L Same as above.

[0333] The cation represented by formula (A1) is preferably the cation represented by formula (A2).

[0334] [Chemistry 102]

[0335]

[0336] In the formula, m4~m10, R F1 ~R F3 and R 3 ~R 5 Same as above.

[0337] Specific examples of sulfonium cations represented by formula (A) are shown below, but are not limited to these. Also, in the following formula, Me is a methyl group.

[0338] [Chemistry 103]

[0339]

[0340] [Chemistry 104]

[0341]

[0342] [Chemistry 105]

[0343]

[0344] [Chemistry 106]

[0345]

[0346] [Chemistry 107]

[0347]

[0348] [Chemistry 108]

[0349]

[0350] [Chemistry 109]

[0351]

[0352] [Chemical 110]

[0353]

[0354] [Chemistry 111]

[0355]

[0356] [Chemistry 112]

[0357]

[0358] [Chemistry 113]

[0359]

[0360] [Chemistry 114]

[0361]

[0362] [Chemistry 115]

[0363]

[0364] [Chemistry 116]

[0365]

[0366] [Chemistry 117]

[0367]

[0368] [Chemistry 118]

[0369]

[0370] [Chemistry 119]

[0371]

[0372] [Chemistry 120]

[0373]

[0374] [Chemistry 121]

[0375]

[0376] [Chemistry 122]

[0377]

[0378] [Chemistry 123]

[0379]

[0380] [Chemistry 124]

[0381]

[0382] [Chemistry 125]

[0383]

[0384] [Chemistry 126]

[0385]

[0386] [Chemistry 127]

[0387]

[0388] [Chemistry 128]

[0389]

[0390] [Chemistry 129]

[0391]

[0392] [Chemistry 130]

[0393]

[0394] As a specific example of the onium salt type monomer of the present invention, any combination of the above-mentioned anions and cations can be cited.

[0395] The onium salt type monomers of the present invention can be synthesized by known methods. As an example, a method for manufacturing an onium salt type monomer represented by the following formula (PDQ-1-ex) will be described, but the synthesis method is not limited thereto.

[0396] [Chemistry 131]

[0397]

[0398] In the formula, R A R 1 R 2 n1~n6 and Z + Same as above. X - It is a relative anion. X hal It can be a chlorine atom, a bromine atom, or an iodine atom. R Z It is a group that forms primary or secondary esters.

[0399] Step 1 involves the reaction of reactants SM-1 (obtained from commercially available products or through known synthetic methods) and SM-2 to obtain intermediate In-1. Various bases can be used when a sulfonyl ester bond is formed between the aromatic hydroxyl group of SM-1 and the sulfonyl chloride group of SM-2. Examples of bases used include triethylamine and pyridine. The reaction is carried out by dissolving SM-1 and SM-2 in an ether solvent such as THF, an aromatic hydrocarbon solvent such as toluene, or a halogen solvent such as dichloromethane, and then adding a base. Adding 4-dimethylaminopyridine (DMAP) as a catalyst can increase the reaction rate. For optimal yield, the reaction time is typically around 12–24 hours, ideally monitored by silica gel thin-layer chromatography (TLC). After stopping the reaction, the reaction solution is subjected to a standard aqueous work-up to obtain intermediate In-1. If necessary, intermediate In-1 can be purified using conventional methods such as chromatography or recrystallization.

[0400] Step 2 involves the hydrolysis of the ester bonds of the obtained intermediate In-1. The reaction is carried out by dissolving intermediate In-1 in an ether solvent such as THF or 1,4-dioxane, or an alcohol solvent such as methanol, and adding a base. Examples of bases used include sodium hydroxide, potassium hydroxide, and their aqueous solutions, potassium carbonate, and sodium carbonate. To accelerate the reaction, the reaction solution can be appropriately heated. From a yield perspective, the reaction time is typically 12–24 hours, which is expected to be completed by TLC monitoring. After the reaction is stopped, the reaction solution can be subjected to conventional aqueous work-up to obtain the corresponding carboxylate. If necessary, the obtained carboxylate can be purified by conventional methods such as chromatography or recrystallization, or it can be used in the unpurified state in the next step.

[0401] Step 3 is to combine the obtained carboxylate with Z + X - The step involves salt exchange of the onium salt (raw material SM-3) to obtain the onium salt (PDQ-1-ex). Also, as X... - Chloride, bromide, iodide, or methyl sulfate anions are preferred because the exchange reaction can be carried out quantitatively. From a yield perspective, the reaction time is preferably 4–12 hours, allowing the reaction to proceed using TLC. The reaction progress is preferably confirmed by TLC. The onium salt (PDQ-1-ex) can be obtained from the reaction mixture using conventional aqueous work-up. If necessary, purification can be performed using conventional methods such as chromatography and recrystallization.

[0402] In the above scheme, the ion exchange in step 3 can be easily carried out by known methods, for example, Japanese Patent Application Publication No. 2007-145797.

[0403] Furthermore, the above manufacturing method is only one example, and the manufacturing method of the onium salt type monomer of the present invention is not limited to this.

[0404] [polymer]

[0405] The polymer of the present invention comprises repeating units (hereinafter also referred to as repeating unit a) derived from the onium salt type monomer represented by formula (a).

[0406] The polymer of the present invention functions as a quencher in a chemically amplified resist composition and as a polymer-bonded quencher in a base polymer. Structural features of the polymer of the present invention include repeating units comprising onium salt monomers of the present invention, which have onium salt structures containing aromatic carboxylic acid anions. These aromatic carboxylic acid anions have benzene or naphthalene structures directly bonded to the main chain and have aromatic ring structures substituted with iodine atoms. Since iodine atoms have extremely high absorption at 13.5 nm EUV, secondary electrons are generated during exposure. The energy of these secondary electrons is transferred to the acid generator, thereby promoting decomposition and achieving high sensitivity. Compared to polymerizable groups such as methacrylates, the polymeric groups composed of styrene and vinylnaphthalene structures are more rigid, increasing the glass transition temperature (Tg) of the polymer. Furthermore, it is believed that through the interaction of aromatic rings within or between the base polymers (π-π stacking effect), the base polymers are regularly arranged, exhibiting resistance to pattern collapse in the developer during the formation of fine patterns. Furthermore, in the etching step following the formation of the fine pattern, the aromatic rings, which are directly bonded to the main chain, also exhibit excellent etching resistance. In the iodine-substituted aromatic rings, it is preferable that the iodine atom substitutes at the position adjacent to the carbon atom bonded to the polymeric group, thereby suppressing the rotation of the bond axis between the aromatic ring of the polymeric group and the iodine-substituted aromatic ring. On the other hand, the aromatic carboxylic acid anion has relatively high basicity, effectively capturing acids generated by acid-generating agents. Due to this synergistic effect, both LWR and CDU are improved for high sensitivity, enabling the formation of patterns resistant to pattern collapse, making it particularly suitable as a material for chemically amplified positive resist compositions.

[0407] The polymer described above may further comprise 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.).

[0408] [Chemistry 132]

[0409]

[0410] In equations (b1) and (b2), R A Each can be independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0411] In equation (b1), 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 hydroxyl, nitro, cyano, or a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or 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 having 1 to 10 carbon atoms. The saturated hydrocarbon group may also contain hydroxyl groups, ether bonds, ester bonds, or lactone rings. * indicates an atomic bond with a carbon atom in the main chain.

[0412] In equation (b2), 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 may contain a halogen atom, a cyano group, a hydroxyl group, a nitro group, or a hydrocarbon group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon oxy group with 1 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl group with 2 to 20 carbon atoms containing heteroatoms; a hydrocarbon carbonyl oxy group with 2 to 20 carbon atoms containing heteroatoms; or a hydrocarbon oxy carbonyl group with 2 to 20 carbon atoms containing heteroatoms. a is 0, 1, 2, 3, or 4, preferably 0 or 1.

[0413] In equations (b1) and (b2), AL 1 and AL 2 Each is an acid-indestructible group independently. Specific examples of the aforementioned acid-indestructible groups include, for example, the groups described in Japanese Patent Application Publication No. 2013-80033 and Japanese Patent Application Publication No. 2013-83821, but are not limited to these.

[0414] For representative examples, those represented by formulas (AL-1) to (AL-3) can be listed as specific examples of the aforementioned unstable acid groups.

[0415] [Chemistry 133]

[0416]

[0417] In the formula, * represents an atomic bond.

[0418] In equations (AL-1) and (AL-2), R L1 and R L2Each hydrocarbon group is independently a hydrocarbon group having 1 to 40 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, fluorine, and iodine atoms. The hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Preferably, the hydrocarbon group has 1 to 20 carbon atoms.

[0419] In formula (AL-1), a1 is an integer from 0 to 10, preferably 1, 2, 3, 4 or 5.

[0420] In equation (AL-2), R L3 and R L4 Each group is independently a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, fluorine, and iodine. The aforementioned hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Additionally, R... L2 R L3 and R L4 Any two atoms in the ring can also bond to each other and form a ring with 3 to 20 carbon atoms together with the carbon atoms they are bonded to, or with carbon and oxygen atoms. Preferably, the ring has 4 to 16 carbon atoms, and more preferably, it is an alicyclic ring.

[0421] 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, fluorine, and iodine. The hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Additionally, R... L5 R L6 and R L7 Any two of them can also bond to each other and together with the carbon atoms they are bonded to form a ring with 3 to 20 carbon atoms. As the above-mentioned ring, a ring with 4 to 16 carbon atoms is preferred, and an alicyclic ring is particularly preferred.

[0422] As specific examples of repeating unit b1, the following repeating units can be cited, but are not limited to these. Furthermore, in the following formula, R... A and AL 1 Same as above.

[0423] [Chemistry 134]

[0424]

[0425] [Chemistry 135]

[0426]

[0427] [Chemistry 136]

[0428]

[0429] [Chemistry 137]

[0430]

[0431] [Chemistry 138]

[0432]

[0433] [Chemistry 139]

[0434]

[0435] [Chemistry 140]

[0436]

[0437] As specific examples of repeating unit b2, the following repeating units can be cited, but are not limited to these. Furthermore, in the following formula, R... A and AL 2 Same as above.

[0438] [Chemistry 141]

[0439]

[0440] [Chemistry 142]

[0441]

[0442] [Chemistry 143]

[0443]

[0444] The polymer described above may further include repeating units represented by the following formula (b3) (hereinafter also referred to as repeating unit b3).

[0445] [Chemistry 144]

[0446]

[0447] In formula (b3), b1 is 0 or 1. When b1 is 0, it is a benzene ring; when b1 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, a benzene ring when b1 is 0 is preferred. b2 is 0, 1, 2, or 3 when b1 is 0, and 0, 1, 2, 3, 4, or 5 when b1 is 1. From the viewpoint of raw material supply, b2 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0448] In formula (b3), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atoms and methyl groups are preferred, and hydrogen atoms are even more preferred.

[0449] In formula (b3), X3 It is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * indicates an atomic bond with a carbon atom in the main chain. Among these, a single bond, *-C(=O)-O-, and more preferably a single bond are preferred.

[0450] In formula (b3), 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 straight-chain, 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; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon 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. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can 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.

[0451] Additionally, R 12 and R 13 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Specific examples of rings formed in this way include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornene rings, and adamantane rings. In addition, some or all of the hydrogen atoms in the above 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 above rings can 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.

[0452] In formula (b3), R 14It may contain halogen atoms, hydroxyl groups, cyano groups, nitro groups, or hydrocarbon groups with 1 to 20 carbon atoms containing heteroatoms; hydrocarbon oxy 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 halogen atom is independently a hydrogen atom or a hydrocarbon group having 1 to 6 carbon atoms. The aforementioned halogen atom is preferably a fluorine, chlorine, bromine, or iodine atom, more preferably a fluorine or iodine atom. The hydrocarbon group, as well as the hydrocarbon group of the aforementioned hydrocarbon group, hydrocarbon oxy group, hydrocarbon oxycarbonyl group, and hydrocarbon thio group, can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples can be given and described with respect to R. 12 and R 13 The groups represented are the same as those exemplified by the hydrocarbon groups. 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; 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, groups such as hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups may also be included. When b2 is 2 or more, each R... 14 They can be the same or different.

[0453] Additionally, when b2 is 2 or more, multiple R 14 They can also bond to each other and form 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, and adamantane rings. In addition, some or all of the hydrogen atoms in the above 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 above rings can 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.

[0454] In formula (b3), X 4 The group is a single bond, an aliphatic alkylene group having 1 to 4 carbon atoms, a carbonyl group, a sulfonyl group, or a combination thereof. Among these, from the viewpoint of raw material supply, a single bond, a carbonyl group, or a sulfonyl group is preferred, and from the viewpoint of the polar group generated after the reaction, a single bond or a carbonyl group is more preferred.

[0455] In formula (b3), X5 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 in the aromatic ring. X 5 and X 6 They can be the same or different; from a reactivity point of view, X 5 and X 6 Ideally, all atoms should be oxygen atoms.

[0456] As specific examples of repeating unit b3, the following repeating units can be cited, but are not limited to these. Furthermore, in the following formula, R... A As above, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0457] [Chemistry 145]

[0458]

[0459] [Chemistry 146]

[0460]

[0461] [Chemistry 147]

[0462]

[0463] [Chemistry 148]

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[0467] [Chemistry 150]

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[0470]

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[0473] [Chemistry 153]

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[0475] [Chemistry 154]

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[0503] [Chemistry 168]

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[0551] [Chemistry 192]

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[0553] [Chemistry 193]

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[0555] [Chemistry 194]

[0556]

[0557] The aforementioned base polymer preferably also includes a repeating unit represented by the following formula (c) (hereinafter also referred to as repeating unit c).

[0558] [Chemistry 195]

[0559]

[0560] In equation (c), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 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 21 It can be a halogen atom, nitro group, cyano group, carboxyl 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. c1 can be 1, 2, 3, or 4. c2 can be 0, 1, 2, or 3. However, 1 ≤ c1 + c2 ≤ 5.

[0561] As specific examples of repeating unit c, the following repeating units can be cited, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0562] [Chemistry 196]

[0563]

[0564] [Chemistry 197]

[0565]

[0566] [Chemistry 198]

[0567]

[0568] [Chemistry 199]

[0569]

[0570] [Chem.200]

[0571]

[0572] Ideally, the aforementioned basic polymer should further include repeating units (hereinafter also referred to as repeating units d) derived from onium salt type monomers consisting of onium salt monomers composed of onium salts having polymerizable groups and one or more iodine atoms in the anion.

[0573] Specific examples of anions of repeating unit d include the structures described in Japanese Patent No. 6973274

[0023] to

[0029] , Japanese Patent Application Publication No. 2023-172928

[0032] to

[0038] , and Japanese Patent Application Publication No. 2024-043941

[0032] to

[0047] .

[0574] Furthermore, as a specific example of the anion of the repeating unit d, it is more preferably the anion represented by the following formula (d1).

[0575] [Chemical Engineering 201]

[0576]

[0577] In formula (d1), d1 is 0 or 1. When d1 is 0, it is a benzene ring; when d1 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, a benzene ring with d1 = 0 is preferred. d2 is 0 or 1. When d2 is 0, it is a benzene ring; when d2 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, a benzene ring with d2 = 0 is preferred. d3 is 0, 1, 2, 3, or 4. From the viewpoint of raw material supply, d3 being 0, 1, or 2 is preferred, and 0 or 1 is even better. d4 is 0, 1, 2, 3, or 4. 0, 1, 2, or 3 is preferred, 0, 1, or 2 is even better, and 0 or 1 is still even better. d5 is 1, 2, 3, 4, 5, or 6. A higher number of iodine atoms in the anionic structure results in higher absorption, particularly for EUV, but also reduces solvent solubility, potentially leading to precipitation in the resist composition. Therefore, a d5 value of 1, 2, or 3 is preferred, with 1 or 2 being even better. However, when d2 is 0, the order is 1 ≤ d4 + d5 ≤ 4; when d2 is 1, the order is 1 ≤ d4 + d5 ≤ 6. For d6, a value of 0, 1, 2, 3, or 4 is preferred, with 1 being even better.

[0578] In equation (d1), R A Preferably, it is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atoms and methyl groups are preferred, and hydrogen atoms are even more preferred.

[0579] In formula (d1), the iodine atom in the aromatic ring of the anion is preferably bonded to L. B The adjacent positions of the bonded carbon atoms. Since iodine atoms are elements with large atomic radii, the rotation of the bonding axes between the aromatic rings bonded by the polymerizable groups and the aromatic rings bonded by the iodine atoms is suppressed, thus increasing the rigidity of the polymer.

[0580] In equation (d1), R 31The halogen atom is a hydrocarbon group with 1 to 20 carbon atoms, or may contain heteroatoms. The halogen atom is preferably a fluorine, chlorine, bromine, or iodine atom, and more preferably a fluorine or iodine atom. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, 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; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon 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 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 can contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. When d3 is 2, 3, or 4, each R... 31 They can be the same or different.

[0581] Additionally, when d3 is 2, 3, or 4, multiple R 31 They can also bond to each other and form 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, and adamantane rings. In addition, some or all of the hydrogen atoms in the above 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 above rings can 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.

[0582] In equation (d1), R 32A hydrocarbon group consisting of 1 to 20 carbon atoms, excluding iodine atoms, or which may contain heteroatoms. Specific examples of halogen atoms other than iodine atoms include fluorine, chlorine, and bromine atoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include R... 31 The groups represented by the hydrocarbon group are the same as, but not limited to, the groups. When d4 is 2, 3, or 4, each R 32 They can be the same or different.

[0583] Additionally, when d4 is 2, 3, or 4, multiple R 32 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Preferably, these rings are 5- to 8-membered rings.

[0584] In equation (d1), L D L E and L F Each bond can be independently a single bond, ether bond, ester bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. Among them, L... D Preferably, it is a single bond, ether bond, ester bond, or sulfonate bond, more preferably an ester bond or sulfonate bond. As L E Preferably, it is a single bond, ether bond, or ester bond, with a single bond being more preferred. As L... F Preferably, it is a single bond, ether bond, ester bond or sulfonate bond, and more preferably an ether bond or ester bond.

[0585] In equation (d1), X L1 A single-bonded or heteroatom-containing hydrocarbon group with 1 to 40 carbon atoms. The hydrocarbon group can be straight-chain, branched, or cyclic, and specific examples include alkyldiyl, cyclic saturated hydrocarbon groups, and arylyl groups. Specific examples of the aforementioned heteroatoms include oxygen, nitrogen, and sulfur atoms. X L1 Specific examples of hydrocarbon groups containing 1 to 40 carbon atoms that may be represented by heteroatoms can be cited in the description of formula (A) for example, X. L The example X, which may also contain heteroatoms and carbon-1 to 40 alkylene groups, is illustrated in the following examples. L -0~X L -58. Where X... L -0~X L -22, X L -29~X L -34 and X L -47~X L -58 is better.

[0586] From the perspective of the rigidity of the obtained polymer, X L1 A single key is preferable.

[0587] In equation (d1), Q1 and Q 2 Each group is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. A trifluoromethyl group having 1 to 6 carbon atoms is preferred.

[0588] In equation (d1), Q 3 and Q 4 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. A trifluoromethyl group having 1 to 6 carbon atoms is preferred. As Q 3 and Q 4 A further preferred option is fluorine atoms.

[0589] In equation (d1), -[C(Q 1 (Q) 2 )] d6 -C(Q 3 (Q) 4 )-SO3 - The specific examples of the partial structures shown below are preferred, but not limited to these. Also, in the following formula, * indicates the relationship with L. C Atomic bonds.

[0590] [Chemical Engineering 202]

[0591]

[0592] Of these, Acid-1 to Acid-7 are better, and Acid-1 to Acid-3, Acid-6 and Acid-7 are even better.

[0593] The anion represented by formula (d1) is preferably the anion represented by formula (d1-1).

[0594] [Chemical Engineering 203]

[0595]

[0596] In the formula, d1~d6, R A R 1 R 2 L A L C Q 1 ~Q 4 and Z + Same as above.

[0597] The anion represented by formula (d1-1) is preferably the anion represented by formula (d1-2).

[0598] [Chemical 204]

[0599]

[0600] In the formula, d1~d6, R A R 1 R 2 L A Q 1 Q 2 and Z + Same as above.

[0601] As specific examples of anions represented by formula (d1), the following anions can be cited, but are not limited to these. Furthermore, in the following formula, R... A and Q 1 As above, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0602] [Chemical Engineering 205]

[0603]

[0604] [Chemical Engineering 206]

[0605]

[0606] [Chemical 207]

[0607]

[0608] [Chemical Engineering 208]

[0609]

[0610] [Chemical Engineering 209]

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[0612] [Chemical 210]

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[0614] [Chemistry 211]

[0615]

[0616] [Chemistry 212]

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[0618] [Chemistry 213]

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[0620] [Chemistry 214]

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[0660] [Chemistry 234]

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[0664] [Chemistry 236]

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[0666] [Chemistry 237]

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[0670] [Chemistry 239]

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[0672] [Chemistry 240]

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[0674] [Chemistry 241]

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[0676] [Chemistry 242]

[0677]

[0678] [Chemistry 243]

[0679]

[0680] [Chemistry 244]

[0681]

[0682] [Chemistry 245]

[0683]

[0684] [Chemistry 246]

[0685]

[0686] [Chemistry 247]

[0687]

[0688] [Chemistry 248]

[0689]

[0690] [Chemistry 249]

[0691]

[0692] [Chemistry 250]

[0693]

[0694] [Chemistry 251]

[0695]

[0696] [Chemistry 252]

[0697]

[0698] [Chemistry 253]

[0699]

[0700] [Chemistry 254]

[0701]

[0702] [Chemistry 255]

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[0704] [Chemistry 256]

[0705]

[0706] [Chemistry 257]

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[0708] [Chemistry 258]

[0709]

[0710] [Chemistry 259]

[0711]

[0712] [Chemistry 260]

[0713]

[0714] [Chemistry 261]

[0715]

[0716] Furthermore, the anion that is the repeating unit d is preferably represented by the following formula (d2).

[0717] [Chemistry 262]

[0718]

[0719] In formula (d2), d11 is 0 or 1. When d11 is 0, it is a benzene ring; when d11 is 1, it is a naphthalene ring. From the viewpoint of solvent solubility, a benzene ring with d11 of 0 is preferred. d12 is 1, 2, 3, or 4. From the viewpoint of raw material supply, d12 is preferably 1, 2, or 3, more preferably 1 or 2, and even more preferably 1. d13 is 0, 1, or 2. However, when d11 is 0, 1 ≤ d12 + d13 ≤ 4; when d11 is 1, 1 ≤ d12 + d13 ≤ 6.

[0720] In formula (d2), d14 is 0 or 1. When d14 is 0, it is a benzene ring; when d14 is 1, it is a naphthalene ring. However, from the viewpoint of solvent solubility, a benzene ring with d14 of 0 is preferred. d15 is 1, 2, 3, or 4, preferably 1, 2, or 3. The more iodine atoms in the anionic structure, the higher the absorption, especially for EUV, but it may become less soluble in the solvent and precipitate in the resist composition. Therefore, the number of iodine atoms in the anion is preferably 2, 3, 4, or 5, and more preferably 2, 3, or 4. d16 is 0, 1, or 2. However, when d14 is 0, 1 ≤ d15 + d16 ≤ 4; when d14 is 1, 1 ≤ d15 + d16 ≤ 6.

[0721] In formula (d2), d17 is 0, 1, 2, 3 or 4, preferably 0, 1, 2 or 3, more preferably 1, 2 or 3, and even more preferably 1.

[0722] In equation (d2), R APreferably, it is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, hydrogen atoms and methyl groups are preferred, and hydrogen atoms are even more preferred.

[0723] In equation (d2), R 41 The halogen atom (excluding iodine), a nitro group, a hydrocarbon group with 1 to 20 carbon atoms (which may also contain heteroatoms), an hydroxyl group with 1 to 20 carbon atoms (which may also contain heteroatoms), or a thiol group with 1 to 20 carbon atoms (which may also contain heteroatoms). The halogen atom (excluding iodine) is preferably a fluorine atom, a chlorine atom, or a bromine atom, and more preferably a fluorine atom. The hydrocarbon group, hydroxyl group, and thiol group may be saturated or unsaturated, and may be straight-chain, 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; cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norcamphenyl, and adamantyl; alkenyl groups with 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon 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 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, groups may also include hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), and haloalkyl groups. When d13 is 2, each R... 41 They can be the same or different.

[0724] Additionally, when d13 is 2, there are 2 Rs. 41They can also bond to each other and form 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, and adamantane rings. In addition, some or all of the hydrogen atoms in the above 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 above rings can 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.

[0725] In equation (d2), R 42 The halogen atom (excluding iodine) can be a nitro group, a hydrocarbon group with 1 to 20 carbon atoms (which may also contain heteroatoms), an hydroxyl group with 1 to 20 carbon atoms (which may also contain heteroatoms), or a thiol group with 1 to 20 carbon atoms (which may also contain heteroatoms). Specific examples of the halogen atom (excluding iodine) include fluorine, chlorine, and bromine atoms. The hydrocarbon group, hydroxyl group, and thiol group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include R... 41 The group represented by the hydrocarbon group is the same as, but not limited to, the group. When d16 is 2, R 42 They can be the same or different.

[0726] Additionally, when d16 is 2, there are 2 R... 42 They can also bond to each other and form rings together with the carbon atoms they are bonded to. Preferably, these rings are 5- to 8-membered rings.

[0727] In equation (d2), L G1 L G2 L H1 and L H2 Each bond can be independently a single bond, ether bond, ester bond, sulfonate bond, amide bond, sulfonamide bond, carbonate bond, or carbamate bond. Among them, L... G1 Preferably, it is a single bond, ether bond, ester bond, or sulfonate bond, more preferably an ester bond or sulfonate bond. As L G2 Preferably, it is a single bond, ether bond, ester bond, or sulfonate bond, more preferably an ester bond or sulfonate bond. As L H1 Preferred single bonds, ether bonds, ester bonds, or sulfonate bonds, especially single bonds, ether bonds, or ester bonds. As L H2 Preferably, it is a single bond, ether bond, ester bond or sulfonate bond, and more preferably a single bond, ether bond or ester bond.

[0728] L G1 and L G2Preferably, the substituents are bonded to adjacent carbon atoms of the aromatic ring. In this case, since the substituents containing the fluorosulfonic acid anion structure and the substituents containing the aromatic ring substituted with iodine atoms are located in spatially closer positions, higher sensitivity can be expected.

[0729] In equation (d2), X L2 and X L3 Each is an alkylene group with 1 to 40 carbon atoms, which may be a single bond or contain heteroatoms. These alkylene groups can be straight-chain, branched, or cyclic, and specific examples include alkyldiyl, cyclic saturated alkylene groups, and arylyl groups. Specific examples of the aforementioned heteroatoms include oxygen atoms, nitrogen atoms, and sulfur atoms. L2 and X L3 Specific examples of hydrocarbon groups containing 1 to 40 carbon atoms, which may also contain heteroatoms, can be listed in the description of formula (A) regarding X. L X represents a specific example of a hydrocarbon group containing 1 to 40 carbon atoms that may contain heteroatoms. L -0~X L -58. Where X... L -0~X L -22, X L -29~X L -34 and X L -47~X L -58 is better.

[0730] In equation (d2), Q 11 and Q 12 Each is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. The fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms is preferably trifluoromethyl.

[0731] In equation (d2), Q 13 and Q 14 Each is independently a fluorine atom or a fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms. The fluorinated saturated hydrocarbon group having 1 to 6 carbon atoms is preferably trifluoromethyl. Regarding Q... 13 and Q 14 In particular, fluorine atoms are preferred.

[0732] In equation (d2), -[C(Q 11 (Q) 12 )] d17 -C(Q 13 (Q) 14 )-SO3 - The specific examples of the partial structures shown below are preferred, but not limited to these. Also, in the following formula, * indicates the relationship with L. H1 Atomic bonds.

[0733] [Chemistry 263]

[0734]

[0735] Of these, Acid-1 to Acid-7 are preferred, and Acid-1 to Acid-3, Acid-6, and Acid-7 are even more preferred. The anion represented by formula (d2) is preferably the anion represented by formula (d2-1).

[0736] [Chemistry 264]

[0737]

[0738] In the formula, R A R 41 R 42 L G1 L G2 Q 11 ~Q 14 The same applies to d11 to d17. Preferably, the anion represented by formula (d2-1) is the anion represented by formula (d2-2).

[0739] [Chemistry 265]

[0740]

[0741] In the formula, R A R 41 R 42 L G2 Q 11 ~Q 14 The same applies to d11 to d17.

[0742] Specific examples of anions represented by formula (d2) can be given as shown below, but are not limited to these. Furthermore, in the following formula, R... A Q 1 As above, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0743] [Chemistry 266]

[0744]

[0745] [Chemistry 267]

[0746]

[0747] [Chemistry 268]

[0748]

[0749] [Chemistry 269]

[0750]

[0751] [Chemistry 270]

[0752]

[0753] [Chemistry 271]

[0754]

[0755] [Chemistry 272]

[0756]

[0757] [Chemistry 273]

[0758]

[0759] [Chemistry 274]

[0760]

[0761] [Chemistry 275]

[0762]

[0763] [Chemistry 276]

[0764]

[0765] [Chemistry 277]

[0766]

[0767] [Chemistry 278]

[0768]

[0769] [Chemistry 279]

[0770]

[0771] [Chemistry 280]

[0772]

[0773] [Chemistry 281]

[0774]

[0775] [Chemistry 282]

[0776]

[0777] [Chemistry 283]

[0778]

[0779] [Chemistry 284]

[0780]

[0781] [Chemistry 285]

[0782]

[0783] [Chemistry 286]

[0784]

[0785] [Chemistry 287]

[0786]

[0787] [Chemistry 288]

[0788]

[0789] [Chemistry 289]

[0790]

[0791] [Chemistry 290]

[0792]

[0793] [Chemistry 291]

[0794]

[0795] [Chemistry 292]

[0796]

[0797] [Chemistry 293]

[0798]

[0799] [Chemistry 294]

[0800]

[0801] [Chemistry 295]

[0802]

[0803] [Chemistry 296]

[0804]

[0805] [Chemistry 297]

[0806]

[0807] [Chemistry 298]

[0808]

[0809] [Chemistry 299]

[0810]

[0811] [Chemical 300]

[0812]

[0813] [Chemical Engineering 301]

[0814]

[0815] [Chemical 302]

[0816]

[0817] [Chemical 303]

[0818]

[0819] [Chemical 304]

[0820]

[0821] [Chemical 305]

[0822]

[0823] [Chemical 306]

[0824]

[0825] [Chemical 307]

[0826]

[0827] [Chemical 308]

[0828]

[0829] [Chemical 309]

[0830]

[0831] [Chemical 310]

[0832]

[0833] [Chemistry 311]

[0834]

[0835] [Chemistry 312]

[0836]

[0837] [Chemistry 313]

[0838]

[0839] [Chemical 314]

[0840]

[0841] [Chemical 315]

[0842]

[0843] [Chemistry 316]

[0844]

[0845] [Chemistry 317]

[0846]

[0847] [Chemistry 318]

[0848]

[0849] [Chemistry 319]

[0850]

[0851] [Chemistry 320]

[0852]

[0853] [Chemistry 321]

[0854]

[0855] [Chemistry 322]

[0856]

[0857] [Chemistry 323]

[0858]

[0859] [Chemistry 324]

[0860]

[0861] Specific examples of sulfonium cations in repeating unit d can be listed as Z in the description of equation (a).+ Examples of sulfonium cations are the same as those shown, but not limited to these.

[0862] Ideally, the aforementioned base polymer should further include repeating units represented by the following formula (e) (hereinafter also referred to as repeating unit e).

[0863] [Chemistry 325]

[0864]

[0865] In equation (e), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 Indicates single bond, phenylene, naphthylene, *-C(=O)-OZ 11 -or *-C(=O)-NH-Z 11 - The phenylene or naphthylene group can be substituted by a hydroxyl group, a nitro group, a cyano group, or a saturated hydrocarbon group containing fluorine atoms with 1 to 10 carbon atoms, or a saturated hydrocarbon oxygen group containing fluorine atoms with 1 to 10 carbon atoms, or a halogen atom. * indicates an atomic bond with the carbon atoms of the main chain. Z 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms. The saturated hydrocarbon group may also contain a hydroxyl group, an ether bond, an ester bond, or an lactone ring. R 51 It is a hydrogen atom, or a group having 1 to 20 carbon atoms, selected from at least one of the following structures: 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)-).

[0866] As specific examples of repeating unit e, the following repeating units can be cited, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0867] [Chemistry 326]

[0868]

[0869] [Chemistry 327]

[0870]

[0871] [Chemistry 328]

[0872]

[0873] [Chemistry 329]

[0874]

[0875] [Chemistry 330]

[0876]

[0877] [Chemistry 331]

[0878]

[0879] [Chemistry 332]

[0880]

[0881] [Chemistry 333]

[0882]

[0883] [Chemistry 334]

[0884]

[0885] [Chemistry 335]

[0886]

[0887] [Chemistry 336]

[0888]

[0889] [Chemistry 337]

[0890]

[0891] [Chemistry 338]

[0892]

[0893] [Chemistry 339]

[0894]

[0895] [Transformation 340]

[0896]

[0897] [Chemistry 341]

[0898]

[0899] As a repeating unit e, in ArF lithography, it is particularly preferred to have a repeating unit with a lactone ring as a polar group, and in KrF lithography, EB lithography and EUV lithography, it is preferred to have a repeating unit with a phenolic site.

[0900] The polymer described above may further comprise repeating units (hereinafter also referred to as repeating units f) having a structure in which hydroxyl groups are protected by acid-indestructible groups. As repeating unit f, there are no particular limitations as long as it has a structure in which one or more hydroxyl groups are protected and the protecting groups are decomposed by the action of acid to generate hydroxyl groups, but it is preferred to be a repeating unit represented by the following formula (f).

[0901] [Chemistry 342]

[0902]

[0903] In equation (f), R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 61 It can also contain heteroatoms and is a (e+1) valence hydrocarbon group with 1 to 30 carbon atoms. R 62 It is an acid-labile group. e can be 1, 2, 3 or 4.

[0904] In equation (f), R 62 The acid-unstable group shown can be any group that, through the action of an acid, is deprotected to form a hydroxyl group. R 62 The structure is not particularly limited, but it is preferably an acetal structure, a ketal structure, an alkoxy carbonyl group, or an alkoxy methyl group represented by the following formula (f1), and is particularly preferably an alkoxy methyl group represented by the following formula (f1).

[0905] [Chemistry 343]

[0906]

[0907] In the formula, * represents an atomic bond. R 63 It consists of hydrocarbon groups with 1 to 15 carbon atoms.

[0908] R 62 Specific examples of the acid-unstable group, the alkoxymethyl group represented by formula (f1), and the repeating unit f can be listed as those exemplified in the description of the repeating unit d described in Japanese Patent Application Publication No. 2020-111564.

[0909] The aforementioned base polymer may further comprise repeating unit g derived from indene, benzofuran, benzothiophene, acenaphthene, crromone, coumarin, norcamphediene, or derivatives thereof. Specific examples of monomers providing repeating unit g include, but are not limited to, the monomers shown below.

[0910] [Chemistry 344]

[0911]

[0912] The aforementioned base polymer may further comprise repeating units h derived from styrene, indane, vinylpyridine, or vinylcarbazole.

[0913] In the polymer of the present invention, the content ratios of the repeating units a, b1, b2, b3, c, d, e, f, g, and h are preferably 0 < a ≤ 0.4, 0 < b1 ≤ 0.8, 0 ≤ b2 ≤ 0.8, 0 ≤ b3 ≤ 0.6, 0 < c ≤ 0.6, 0 ≤ d ≤ 0.4, 0 ≤ e ≤ 0.6, 0 ≤ f ≤ 0.3, 0 ≤ g ≤ 0.3, and 0 ≤ h ≤ 0.3, more preferably 0 < a ≤ 0.3, 0 < b1 ≤ 0.7, 0 ≤ b2 ≤ 0.7, 0 ≤ b3 ≤ 0.5, 0 < c ≤ 0.5, 0 ≤ d ≤ 0.3, 0 ≤ e ≤ 0.5, 0 ≤ f ≤ 0.2, 0 ≤ g ≤ 0.2, and 0 ≤ h ≤ 0.2. However, a + b1 + b2 + b3 + c + d + e + f + g + h ≤ 1.0.

[0914] The weight-average molecular weight (Mw) of the above polymer is preferably 1000 to 500000, more preferably 3000 to 100000. If Mw is within this range, sufficient etching resistance can be obtained, and there is no concern about a decrease in resolution due to the inability to ensure a difference in dissolution rate before and after exposure. Also, 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.

[0915] Also, for the molecular weight distribution (Mw / Mn) of the aforementioned polymer, as the pattern rule becomes finer, the influence of Mw / Mn tends to become larger. Therefore, in order to obtain a resist composition suitable for a fine pattern size, Mw / Mn is preferably a narrow distribution of 1.0 to 2.0. If it is within the above range, there are few low-molecular-weight and high-molecular-weight polymers, and after exposure, there is no risk of seeing foreign substances on the pattern or the pattern shape deteriorating.

[0916] As a method for synthesizing the above polymer, for example, a method of adding a radical polymerization initiator to monomers providing the above repeating units in an organic solvent and heating to polymerize them can be cited.

[0917] 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), γ-butyrolactone (GBL), etc. Specific examples of polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauroyl peroxide, etc. The amount of these initiators added relative to the total monomers being polymerized is preferably 0.01 to 25 mol%. The reaction temperature is preferably 50 to 150°C, more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and from a production efficiency point of view, 2 to 12 hours is more preferably.

[0918] The polymerization initiator described above can be added to the monomer solvent and supplied to the reactor, or the initiator solution can be prepared separately from the monomer solvent and supplied to the reactor independently. Since polymerization may occur during the standby time due to free radicals generated from the initiator, resulting in ultra-high molecular weight polymers, from a quality control perspective, it is preferable to prepare the monomer solution and initiator solution independently and add them dropwise. Acid-labile groups can be used directly introduced into the monomer, or they can be protected or partially protected after polymerization. Furthermore, to adjust the molecular weight, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can be used in combination. In this case, the amount of these chain transfer agents added relative to the total amount of monomers being polymerized is preferably 0.01 to 20 mol%.

[0919] In the case of monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxyethoxy that are easily deprotected by acids during polymerization, and deprotection can be carried out using weak acids and water after polymerization. Alternatively, they can be replaced with acetyl, formyl, trimethylacetyl, etc., and alkaline hydrolysis can be carried out after polymerization.

[0920] In the case of copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene can be polymerized with other monomers in an organic solvent by adding a free radical polymerization initiator and heating. Alternatively, acetoxystyrene or acetoxyvinylnaphthalene can be used, and after polymerization, the acetoxy groups can be deprotected by alkaline hydrolysis to produce polyhydroxystyrene or hydroxyvinylnaphthalene.

[0921] For example, ammonia or triethylamine can be used as the base in alkaline hydrolysis. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0922] Furthermore, the amount of each monomer in the above monomer solution can be appropriately set, for example, in a manner that forms a preferred content ratio for the above repeating units.

[0923] Regarding the polymer obtained by the above manufacturing method, the reaction solution obtained by the polymerization reaction can be used as the final product, or the powder obtained by purification steps such as adding the polymerization liquid to a poor solvent to obtain the powder can be used as the final product. From the point of view of work efficiency and quality stabilization, it is preferable to use the polymer solution obtained by dissolving the powder obtained by the purification step in the solvent as the final product.

[0924] As specific examples of solvents used at this time, ketones such as cyclohexanone and methyl-2-n-pentyl ketone described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103 can be cited; 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.

[0925] In the above polymer solution, the polymer concentration is preferably 0.01–30% by mass, more preferably 0.1–20% by mass.

[0926] The above-mentioned reaction solutions and polymer solutions are preferably filtered. By filtering, foreign matter and gel that may cause defects can be removed, which is effective in stabilizing the quality.

[0927] Filter materials used in the aforementioned filtration processes include fluorocarbon, cellulose, nylon, polyester, and hydrocarbon-based filters. In the filtration step involving chemically amplified resist components, filters made of fluorocarbons, polyethylene, polypropylene, or nylon (such as Teflon, a registered trademark) are preferred. The filter pore size can be appropriately selected based on the target cleanliness level, preferably below 100 nm, and more preferably below 20 nm. Furthermore, one type of filter can be used alone, or multiple filters can be used in combination. The filtration method can involve passing the liquid only once, but more preferably, multiple filtrations involving liquid circulation are performed. The filtration steps can be performed in any order and number of times during the polymer manufacturing process, preferably filtering the reaction solution, polymer solution, or both after the polymerization reaction.

[0928] [Chemical amplification resist composition]

[0929] [(A) Basic Polymer]

[0930] The chemically amplified resist composition of the present invention comprises a base polymer containing the above-mentioned polymer as component (A).

[0931] The aforementioned polymers may be used alone or in combination of two or more with different composition ratios, Mw and / or Mw / Mn. In addition, (A) the base polymer may also contain hydrides of ring-opening metathesis polymers in addition to the aforementioned polymers. In this regard, the substances described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0932] [(B) Organic solvents]

[0933] The chemically amplified resist composition of the present invention may contain an organic solvent as component (B). There are no particular limitations on the organic solution (B), as long as it can dissolve the above-mentioned components and the following components. 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.

[0934] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA, and mixtures thereof are preferred as having particularly excellent solubility in the base polymer of component (A).

[0935] In the chemically amplified resist composition of the present invention, the content of (B) organic solvent is preferably 200 to 5000 parts by mass, more preferably 400 to 3500 parts by mass, relative to 80 parts by mass of (A) base polymer. (B) Organic solvent may be used alone or in combination of two or more.

[0936] [(C) Quenching agent]

[0937] The chemically amplified resist composition of the present invention may also include a quencher as a component (C). Furthermore, in the present invention, a quencher refers to a material used to prevent the diffusion of acid generated by the photoacid generator in the chemically amplified resist composition into the unexposed area, thereby forming the desired pattern.

[0938] Specific examples of (C) quenchers include onium salts represented by formulas (1) or (2).

[0939] [Chemistry 345]

[0940]

[0941] In equation (1), R q1 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, except where the hydrogen atom at the α-position of the sulfonate group is substituted with 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.

[0942] R q1 The hydrocarbon groups representing 1 to 40 carbon atoms include, specifically: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, and other alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl and adamantyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, and anthracene. 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. 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, groups may also include hydroxyl, fluorine, chlorine, bromine, iodine, cyano, carbonyl, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), and haloalkyl groups.

[0943] R q2 The hydrocarbon group represented, specifically, besides being R q1 In addition to the substituents exemplified in the specific examples, other examples include fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl, and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0944] Specific examples of onium salt anions represented by formula (1) can be listed below, but are not limited to these.

[0945] [Chemistry 346]

[0946]

[0947] [Chemistry 347]

[0948]

[0949] [Chemistry 348]

[0950]

[0951] [Chemistry 349]

[0952]

[0953] [Chemical 350]

[0954]

[0955] Specific examples of onium salt anions represented by formula (2) can be listed below, but are not limited to these.

[0956] [Chemistry 351]

[0957]

[0958] [Chemistry 352]

[0959]

[0960] [Chemistry 353]

[0961]

[0962] [Chemistry 354]

[0963]

[0964] [Chemistry 355]

[0965]

[0966] In equations (1) and (2), Mq + The cation is an onium cation. Preferably, the onium cation is a sulfonium cation represented by the formula (cation-1), a monazine cation represented by the formula (cation-2), or an ammonium cation represented by the formula (cation-3).

[0967] [Chemistry 356]

[0968]

[0969] In equation (cation-3), R ct6 ~R ct9 Each can be an independent hydrocarbon group with 1 to 40 carbon atoms, and may also contain heteroatoms. Additionally, R... ct6 and R ct7 They can also bond to each other and form rings together with the nitrogen atoms to which they are bonded. Specific examples of the aforementioned hydrocarbon groups include those shown in the descriptions of formulas (cation-1) and (cation-2) regarding R. ct1 ~R ct5 The hydrocarbon group is the same group as the exemplified group.

[0970] Specific examples of ammonium cations represented by formula (cation-3) can be given as shown below, but are not limited to these.

[0971] [Chemistry 357]

[0972]

[0973] As specific examples of onium salts represented by formula (1) or formula (2), any combination of the aforementioned anions and cations can be listed. Furthermore, these onium salts can be readily prepared by ion exchange reactions using known organic chemical methods. For example, Japanese Patent Application Publication No. 2007-145797 can be consulted regarding ion exchange reactions.

[0974] The onium salts represented by formula (1) or (2) act as quenchers in the chemically amplified resist composition of the present invention. This is because the relative anions of the aforementioned onium salts are conjugate bases of weak acids. The weak acid referred to here is a weak 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 are conjugate bases of strong acids such as sulfonic acid with fluorinated α-positions as relative anions. That is, when an onium salt that generates a strong acid such as sulfonic acid with fluorinated α-positions is mixed with an onium salt that generates a weak acid such as unfluorinated sulfonic acid or carboxylic acid, if the strong acid generated by the photoacid generator by high-energy irradiation collides with the unreacted onium salt with a weak acid anion, the weak acid is released by salt exchange, and an onium salt with a strong acid anion is generated. In this process, the strong acid is exchanged for a weaker acid with lower catalytic ability. Therefore, the acid appears to be deactivated, allowing for the control of acid diffusion.

[0975] Alternatively, as the quencher (C), the onium salt having a sulfonium cation and a phenolic salt anion site in the same molecule as described in Japanese Patent No. 6848776, the onium salt having a sulfonium cation and a carboxylate 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 carboxylate anion site in the same molecule as described in Japanese Patent No. 6274755 may also be used.

[0976] Here, it is argued that when the photoacid generator producing a strong acid is an onium salt, as mentioned above, it is possible to exchange the strong acid generated by high-energy ray irradiation into a weak acid. However, on the other hand, the weak acid generated by high-energy ray irradiation is difficult to exchange with the unreacted onium salt that generates the strong acid. This is because onium cations more readily form ion pairs with the anions of strong acids.

[0977] When the chemically amplified resist composition of the present invention includes an onium salt represented by formula (1) or (2) as a quencher in (C), its content is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, relative to 80 parts by mass of the base polymer in (A). If the content of the onium salt-type quencher in component (C) is within the above 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.

[0978] The chemically amplified resist composition of the present invention may contain a nitrogen-containing compound as a (C) quencher. Specific examples of nitrogen-containing compounds as (C) components include primary, secondary, or tertiary 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. Furthermore, compounds with urethane groups protecting primary or secondary amines as described in Japanese Patent Publication No. 3790649 can also be cited.

[0979] Alternatively, sulfonate sulfonates with nitrogen-containing substituents can be used as nitrogen-containing compounds. Such compounds function as quenchers in the unexposed areas, while the exposed areas lose their quenching ability through neutralization with the acid they generate, functioning as so-called photodegradable bases. By using photodegradable bases, the contrast between the exposed and unexposed areas can be further enhanced. Examples of photodegradable bases can be found in, for example, Japanese Patent Application Laid-Open Nos. 2009-109595 and 2012-46501.

[0980] When the chemically amplified resist composition of the present invention includes a nitrogen-containing compound as a quencher (C), its content relative to 80 parts by mass of the base polymer (A) is preferably 0.001 to 12 parts by mass, 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.

[0981] [(D) Acid generating agent]

[0982] The chemically amplified resist composition of the present invention may include an acid-generating agent within a range that does not impair the effects of the present invention. Examples of such acid-generating agents include those that generate acid in response to active light or radiation (photo-acid generators). There is no particular limitation on photo-acid generators, as long as they generate acid through high-energy ray irradiation; however, acid generators that generate sulfonic acid, imide acid, or methyl acid are preferred. Preferred photo-acid generators include sulfonate salts, sulfonate salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generators. Specific examples of acid generators include those described in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103.

[0983] In addition, as photoacid generators, sulfonium salts represented by formula (3-1) and sulfonium salts represented by formula (3-2) can also be used appropriately.

[0984] [Chemistry 358]

[0985]

[0986] In equations (3-1) and (3-2), R 101 ~R 105 Each is an independent halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 20 carbon atoms. Specific examples of the aforementioned halogen atoms and hydrocarbon groups can be listed as follows, and are given in the descriptions of formulas (cation-1) and (cation-2) regarding R. ct1 ~R ct5 The halogen atom represented is the same group as the alkyl group exemplified above. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms; a portion of the -CH2- group in the aforementioned alkyl group can be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, it can contain hydroxyl, fluorine, chlorine, bromine, iodine, cyano, nitro, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Additionally, R... 101 and R 102 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. Specific examples of rings formed in this way include those shown in the explanation of formula (cation-1) regarding R. ct1 and R ct2 The same type of ring as the ring exemplified by the rings formed by the sulfur atoms bonded to each other.

[0987] Furthermore, as a specific example of the cation of the sulfonium salt represented by formula (3-1), the same cation as the cation exemplified as the ferrophosphate cation represented by formula (cation-2) can be given. Furthermore, as a specific example of the cation of the ferrophosphate salt represented by formula (3-2), the same cation as the ferrophosphate cation exemplified as the ferrophosphate cation represented by formula (cation-2) can be given.

[0988] In equations (3-1) and (3-2), Xa - The anions are selected from formulas (3A) to (3D).

[0989] [Chemistry 359]

[0990]

[0991] In equation (3A), 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 straight-chain, branched, or cyclic. As a specific example, R in formula (3A') described later can be cited. fa1 The examples shown in the description are the same.

[0992] The anion represented by formula (3A) is preferably a group represented by formula (3A').

[0993] [Hua360]

[0994]

[0995] In equation (3A'), R HF It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group.

[0996] In equation (3A'), R fa1 The hydrocarbon group may contain heteroatoms and has 1 to 38 carbon atoms. The aforementioned heteroatoms are preferably oxygen, nitrogen, sulfur, or halogen atoms, and more preferably oxygen atoms. From the viewpoint of obtaining high resolution in the formation of fine patterns, a hydrocarbon group with 6 to 30 carbon atoms is particularly preferred.

[0997] R fa1 The hydrocarbon groups represented by carbon numbers 1 to 38 can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 38 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 38 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norcamphenyl, norcamphenylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups with 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups with 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups with 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining them.

[0998] 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, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Oxide atoms are preferred as the heteroatoms. Specific examples of hydrocarbon groups containing heteroatoms include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetaminomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, 3-oxocyclohexyl, etc.

[0999] The synthesis of sulfonium salts containing anions represented by formula (3A') is described in detail in Japanese Patent Application Publications Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Furthermore, sulfonium salts described in Japanese Patent Application Publications Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also ideally applicable.

[1000] Specific examples of anions represented by formula (3A) can be listed below, but are not limited to these. Also, in the following formula, Ac represents an acetyl group.

[1001] [Chemistry 361]

[1002]

[1003] [Chemistry 362]

[1004]

[1005] [Chem.363]

[1006]

[1007] [Chem.364]

[1008]

[1009] In equation (3B), R fb1 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 straight-chain, branched, or cyclic. Specific examples include R in formula (3A'). fa1 The hydrocarbon group represented is the same group as the exemplified group. R fb 1 and R fb2 Preferably, it is a fluorine atom or a straight-chain fluorinated alkyl group having 1 to 4 carbon atoms. Additionally, R... fb 1 and R fb2 They can also bond to each other and to the bonded groups (-CF2-SO2-N). - -SO2-CF2-) together form a ring, at which point R fb1 and R fb2 The groups formed by mutual bonding are preferably fluorinated ethylidene or fluorinated propylene.

[1010] In equation (3C), Rfc1 , R fc2 and R fc3 are each independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched or cyclic. As specific examples thereof, groups similar to the groups exemplified for the hydrocarbon group represented by R fa1 in formula (3A') can be cited. R fc1 , R fc2 and R fc3 are preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. Further, R fc1 and R fc2 may also be bonded to each other and together with the group (-CF2-SO2-C - -SO2-CF2-) to which they are bonded form a ring. In this case, the group obtained by bonding R fc1 and R fc2 to each other is preferably fluoroethylene or fluoropropylene.

[1011] In formula (3D), R fd is a hydrocarbon group having 1 to 40 carbon atoms which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched or cyclic. As specific examples thereof, groups similar to the groups exemplified for the hydrocarbon group represented by R fa1 in formula (3A') can be cited.

[1012] For the synthesis of the sulfonium salt containing the anion represented by formula (3D), refer to Japanese Patent Application Laid-Open No. 2010-215608 and Japanese Patent Application Laid-Open No. 2014-133723.

[1013] As specific examples of the anion represented by formula (3D), those shown below can be cited, but are not limited thereto.

[1014] [Chemical formula 365]

[1015]

[1016] [Chemical formula 366]

[1017]

[1018] Furthermore, the photoacid generator containing the anion represented by formula (3D) does not have a fluorine atom at the α-position of the sulfo group, but since it has two trifluoromethyl groups at the β-position, it has an acidity sufficient to cleave the acid-labile group in the base polymer. Therefore, it can be used as a photoacid generator.

[1019] As the aforementioned photoacid generator, a substance represented by the following formula (4) can also be suitably used.

[1020] [Chemistry 367]

[1021]

[1022] In equation (4), 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. Additionally, R... 201 R 202 and R 203 Any two atoms in the group can also bond to each other and form a ring together with the sulfur atoms they are bonded to. In this case, specific examples of the aforementioned rings can be listed as follows: and in the explanation of formula (cation-1), R... ct1 and R ct2 The same type of ring as the rings that can bond to each other and form with the sulfur atoms they are bonded to.

[1023] R 201 and R 202 The hydrocarbon group representing 1 to 30 carbon atoms can be saturated or unsaturated, and can be straight-chain, 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, n-pentyl, tert-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. In addition, some or all of the hydrogen atoms in the above-mentioned hydrocarbon group can be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. A portion of the -CH2- in the above-mentioned hydrocarbon group can 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.

[1024] R 203The alkylene groups representing carbon atoms from 1 to 30 can be saturated or unsaturated, and can be straight-chain, 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, hexadecane-1,16-diyl, and heptadecane-1,1... Alkyl groups with 1 to 30 carbon atoms, such as 7-diyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; aryl groups with 6 to 30 carbon atoms, 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; and groups obtained by combining these groups. 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, the group may contain hydroxyl, cyano, fluorine, chlorine, bromine, iodine, carbonyl, ether, ester, sulfonate, carbonate, lactone ring, sulfonolactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl, etc. Oxygen atoms are preferred as the aforementioned heteroatoms.

[1025] In equation (4), L 1 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 straight-chain, branched, or cyclic. Specific examples include R... 203 The group represented by the alkylene group is the same group as the one exemplified by the alkylene group.

[1026] In equation (4), X a X b X c and X d Each can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. But X a X b X c and X d At least one of them is a fluorine atom or a trifluoromethyl atom.

[1027] In equation (4), k is 0, 1, 2 or 3.

[1028] As a photoacid generator represented by formula (4), it is preferred to be a group represented by formula (4').

[1029] [Chem.368]

[1030]

[1031] In equation (4)'), L 1 Same as above. X e It can be a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. R 301 R 302 and R 303 Each is independently a hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. As a specific example, R in formula (3A') can be cited. fa1 The alkyl group represents the same group as the exemplified group. x and y are each independently 0, 1, 2, 3, 4 or 5. z is 0, 1, 2, 3 or 4.

[1032] As a specific example of a photoacid generator represented by formula (4), the same photoacid generator as the photoacid generator represented by formula (2) in Japanese Patent Application Publication No. 2017-26980 can be cited.

[1033] Among the aforementioned photoacid generators, those containing anions represented by formula (3A') or (3D) exhibit low acid diffusion and excellent solubility in solvents, making them particularly desirable. Furthermore, compounds represented by formula (4') exhibit extremely low acid diffusion, making them also particularly desirable.

[1034] Alternatively, as other acid generating agents, sulfonium salts and sulfonium salts containing anions having an aromatic ring substituted with an iodine atom can also be used, represented by formula (5-1) or formula (5-2).

[1035] [Chemistry 369]

[1036]

[1037] In equations (5-1) and (5-2), p is 1, 2, or 3. q and r are integers satisfying 1≤q≤5, 0≤r≤3, and 1≤q+r≤5. q is preferably 1, 2, or 3, more preferably 2 or 3. r is preferably 0, 1, or 2.

[1038] In equations (5-1) and (5-2), L 11 It is a saturated hydrocarbon group with 1 to 6 carbon atoms, which can be a single bond, ether bond, or ester bond, or may contain an ether bond or ester bond. The above-mentioned saturated hydrocarbon group can be any of the following: straight-chain, branched, or cyclic.

[1039] In equations (5-1) and (5-2), L 12 When p is 1, it is a single bond or a divalent linker with 1 to 20 carbon atoms; when p is 2 or 3, it is a (p+1) valent linker with 1 to 20 carbon atoms. This linker may contain oxygen, sulfur, or nitrogen atoms.

[1040] In equations (5-1) and (5-2), R 401 The following groups represent hydroxyl, carboxyl, fluorine, chlorine, bromine, or amino groups, or may contain fluorine, chlorine, bromine, hydroxyl, amino, or ether bonds: hydrocarbon groups with 1 to 20 carbon atoms, hydrocarbon oxygen groups with 1 to 20 carbon atoms, hydrocarbon carbonyl groups with 2 to 20 carbon atoms, hydrocarbon carbonyl groups with 2 to 20 carbon atoms, or hydrocarbon sulfonyl oxygen groups with 1 to 20 carbon atoms, or -N(R 401A (R) 401B ), -N(R 401C )-C(=O)-R 401D or -N(R) 401C )-C(=O)-OR 401D R 401A and R 401B Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. R 401C It 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 oxygen group having 2 to 6 carbon atoms. R 401D It is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms. It may also contain halogen atoms, hydroxyl groups, saturated alkyloxy groups having 1 to 6 carbon atoms, saturated alkylcarbonyl groups having 2 to 6 carbon atoms, or saturated alkylcarbonyloxy groups having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, alkyloxy group, alkylcarbonyl group, alkyloxycarbonyl group, alkylcarbonyloxy group, and alkylsulfonyloxy group can be straight-chain, branched, or cyclic. When p and / or r is 2 or more, each R... 401 They can be the same or different.

[1041] Among them, as R 401 , is hydroxyl, -N(R 401C )-C(=O)-R 401D -N(R) 401 C )-C(=O)-OR 401D Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, and methoxy groups are preferred.

[1042] In equations (5-1) and (5-2), Rf 1 ~Rf 4Each of them can be independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of them must be a fluorine atom or a trifluoromethyl group. Additionally, Rf 1 and Rf 2 They can combine to form carbonyl groups. Specifically, Rf... 3 and Rf 4 Ideally, all atoms should be fluorine atoms.

[1043] In equations (5-1) and (5-2), R 402 ~R 406 Each is an independent hydrocarbon group with 1 to 20 carbon atoms, which may also contain heteroatoms. The aforementioned hydrocarbon groups may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples can be cited as shown in the descriptions of formulas (cation-1) and (cation-2) regarding R. ct1 ~R ct5 The alkyl group is the same group as the one exemplified by the alkyl group. Furthermore, some or all of the hydrogen atoms in the aforementioned alkyl group may be replaced by hydroxyl, carboxyl, halogen, cyano, nitro, mercapto, sulfonyl lactone ring, sulfonyl, or sulfonate-containing groups, and a portion of the -CH2- group in the aforementioned alkyl group may be replaced by ether, ester, carbonyl, amide, carbonate, or sulfonate bonds. Additionally, R 402 and R 403 They can also bond to each other and form rings together with the sulfur atoms they are bonded to. In this case, specific examples of the aforementioned rings can be listed as follows: and in the explanation of formula (cation-1), R... ct1 and R ct2 The same type of ring as the rings that can bond to each other and form with the sulfur atoms they are bonded to.

[1044] As a specific example of a cation of a sulfonium salt represented by formula (5-1), the same cation as that exemplified as a sulfonium cation represented by formula (cation-1) can be given. Similarly, as a specific example of a cation of a zirconia salt represented by formula (5-2), the same cation as that exemplified as a zirconia cation represented by formula (cation-2) can be given.

[1045] Specific examples of onium salt anions represented by formula (5-1) or (5-2) are shown below, but are not limited to these.

[1046] [Transformation 370]

[1047]

[1048] [Chemistry 371]

[1049]

[1050] [Chemistry 372]

[1051]

[1052] [Chemistry 373]

[1053]

[1054] [Chemistry 374]

[1055]

[1056] [Chemistry 375]

[1057]

[1058] [Chemistry 376]

[1059]

[1060] [Chemistry 377]

[1061]

[1062] [Chemistry 378]

[1063]

[1064] [Chemistry 379]

[1065]

[1066] [Chemistry 380]

[1067]

[1068] [Chemistry 381]

[1069]

[1070] [Chemistry 382]

[1071]

[1072] [Chemistry 383]

[1073]

[1074] [Chem. 384]

[1075]

[1076] [Chem.385]

[1077]

[1078] [Chemistry 386]

[1079]

[1080] [Chemistry 387]

[1081]

[1082] [Chem.388]

[1083]

[1084] [Chemistry 389]

[1085]

[1086] [Chemistry 390]

[1087]

[1088] [Chemistry 391]

[1089]

[1090] When the chemically amplified resist composition of the present invention includes an acid-generating agent (D), its content is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass, relative to 80 parts by mass of the base polymer (A). If the amount of acid-generating agent (D) added is within the above range, the resolution is good, and no foreign matter is generated after development or during stripping of the resist film, which is therefore ideal. One type of acid-generating agent (D) can be used alone, or two or more can be used in combination.

[1091] [(E) Surfactant]

[1092] The chemically amplified resist composition of the present invention may further include a surfactant as component (E). Preferably, the surfactant (E) is a surfactant that is insoluble or poorly soluble in water but soluble in alkaline developing solution, or a surfactant that is insoluble or poorly soluble in both water and alkaline developing solution. Such surfactants can be referred to in Japanese Patent Application Publication Nos. 2010-215608 and 2011-16746.

[1093] As surfactants that are insoluble or poorly soluble in water and alkaline developing solutions, the surfactants described in the above-mentioned publication are preferably FC-4430 (manufactured by 3M Corporation), Surflon (registered trademark) S-381 (manufactured by AGC SEIMI CHEMICAL CO.,LTD.), Olfine (registered trademark) E1004 (manufactured by Nissin Chemical Industry Co., Ltd.), KH-20, KH-30 (manufactured by AGC SEIMI CHEMICAL Co., Ltd.), and oxetane ring-opening polymers represented by the following formula (surf-1).

[1094] [Chemistry 392]

[1095]

[1096] Here, R, Rf, A, B, C, m, and n are irrelevant to the aforementioned descriptions and apply only to formula (surf-1). R is an aliphatic group with 2 to 5 carbon atoms in a 2 to 4-valent configuration. Examples of the aforementioned aliphatic groups that are divalent include ethylene, 1,4-butylene, 1,2-propylene, 2,2-dimethyl-1,3-propylene, and 1,5-pentylene; examples of groups that are trivalent or tetravalent include the following.

[1097] [Chemistry 393]

[1098]

[1099] In the formula, the dashed lines represent atomic bonds, which are partial structures derived from glycerol, trimethylolethane, trimethylolpropane, and neopentyl tertrol, respectively.

[1100] Among them, 1,4-butylene, 2,2-dimethyl-1,3-propylene, etc. are preferred.

[1101] 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 structural units in formula (surf-1) is not predetermined; they can be block-bonded or randomly bonded. The manufacture of surfactants based on partially fluorinated oxyheterocyclic butane ring-opening polymer systems is described in detail in U.S. Patent No. 5,650,483, etc.

[1102] In ArF immersion lithography, where no resist protective film is used, surfactants that are insoluble or sparingly soluble in water but soluble in alkaline developer can reduce water penetration or exudation by aligning with the surface of the resist film. Therefore, they can be used to reduce damage to the exposure apparatus by inhibiting the dissolution of water-soluble components from the resist film, and are useful because they become soluble in alkaline aqueous solutions after exposure or post-exposure baking (PEB) and are unlikely to become foreign matter causing defects. Such surfactants, which are insoluble or sparingly soluble in water but soluble in alkaline developer, are polymeric surfactants, also known as hydrophobic resins, and are particularly preferred to be surfactants with high water repellency and improved hydrophobicity.

[1103] As a specific example of such polymeric surfactants, those containing at least one of the repeating units selected from formulas (6A) to (6E) below can be cited.

[1104] [Chemistry 394]

[1105]

[1106] 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. 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 In the case of a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group can be inserted between the carbon-carbon bonds. R s4 It is a (u+1) valence hydrocarbon group or a fluorinated hydrocarbon group with 1 to 20 carbon atoms. u can be 1, 2, or 3. R s5 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 an ether bond or carbonyl group may be inserted between its carbon-carbon bonds.

[1107] R s1 The hydrocarbon group representing 1 to 10 carbon atoms is preferably a saturated hydrocarbon group, and can be straight-chain, 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, alkyl groups with 1 to 6 carbon atoms are preferred.

[1108] R s2 The represented hydrocarbon group is preferably a saturated hydrocarbon group, and can be straight-chain, branched, or cyclic. Specific examples include methylene, ethylene, propylene, butylene, and pentylene.

[1109] R s3 or R s6The represented hydrocarbon group can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include aliphatic unsaturated hydrocarbon groups such as saturated hydrocarbon groups, alkenyl groups, and alkynyl groups, with saturated hydrocarbon groups being preferred. As specific examples of the aforementioned saturated hydrocarbon groups, besides R... s 1 Besides the hydrocarbon group, examples include undecyl, dodecyl, tridecyl, tetradecyl, and pentadecyl groups. s3 or R s6 Specific examples of fluorinated hydrocarbon groups can be exemplified by groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms. As mentioned above, ether bonds or carbonyl groups can be inserted between these carbon-carbon bonds.

[1110] R s3 Specific examples of acid-instable groups can be listed as groups represented by formulas (AL-3) to (AL-5), trialkylsilyl groups in which each alkyl group has 1 to 6 carbon atoms, and alkyl groups containing oxy groups in which each alkyl group has 4 to 20 carbon atoms.

[1111] R s4 The (u+1) valence hydrocarbon group or fluorinated hydrocarbon group can be any of the following: straight chain, branched chain, or cyclic. As a specific example, groups obtained by further removing u hydrogen atoms from the above-mentioned hydrocarbon group or fluorinated hydrocarbon group can be given.

[1112] R sa The fluorinated hydrocarbon group is preferably saturated and can be straight-chain, branched, or cyclic. Specific examples include groups in which some or all of the hydrogen atoms of the aforementioned hydrocarbon group are replaced by fluorine atoms. 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.

[1113] Specific examples of repeating units represented by any of equations (6A) to (6E) can be listed below, but are not limited to these. Furthermore, in the following equation, R... B Same as above.

[1114] [Chemistry 395]

[1115]

[1116] [Chemistry 396]

[1117]

[1118] [Chemistry 397]

[1119]

[1120] [Chemistry 398]

[1121]

[1122] [Chemistry 399]

[1123]

[1124] The aforementioned polymeric surfactant may further 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 the polymeric surfactant, the content of the repeating units represented by formulas (6A) to (6E) is preferably 20 mol% or more, more preferably 60 mol% or more, and even more preferably 100 mol% of all repeating units.

[1125] The Mw of the aforementioned polymeric surfactant is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. The Mw / Mn ratio is preferably 1.0 to 2.0, more preferably 1.0 to 1.6.

[1126] One method for synthesizing the aforementioned polymeric surfactants is as follows: A monomer containing unsaturated bonds, providing repeating units represented by formulas (6A) to (6E), and other repeating units as needed, is polymerized in an organic solvent by adding a free radical initiator 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-methylpropionic acid), benzoyl peroxide, and lauroyl peroxide. The preferred reaction temperature is 50–100°C. The preferred reaction time is 4–24 hours. Acid-insecure groups can be directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[1127] 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, the amount of these chain transfer agents added is preferably 0.01 to 10 mol% relative to the total molar number of the monomers being polymerized.

[1128] When the chemically amplified resist composition of the present invention includes surfactant (E), its content is preferably 0.1 to 50 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 80 parts by mass of the base polymer (A). 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 is sufficiently increased; if it is 50 parts by mass or less, the dissolution rate of the resist film surface relative to the developer is low, thus sufficiently maintaining the height of the formed fine pattern. Surfactant (E) can be used alone or in combination of two or more.

[1129] [(F) Dissolution Inhibitor]

[1130] The chemically amplified resist composition of the present invention may further include a dissolution inhibitor as a component (F). When the chemically amplified resist composition of the present invention is positive, by incorporating a dissolution inhibitor, the difference in dissolution rate between the exposed and unexposed areas can be further increased, thereby further improving resolution.

[1131] Specific examples of the aforementioned dissolution inhibitors include compounds in which the hydrogen atoms of the phenolic hydroxyl groups of a compound having a molecular weight preferably of 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups are replaced by acid-unstable groups at a total ratio of 0 to 100 mol%, or compounds in which the hydrogen atoms of the carboxylic acid are replaced by acid-unstable groups at an average ratio of 50 to 100 mol%. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, triphenol, phenolphthalein, cresol phenolic varnish, naphtholic acid, adamantane carboxylic acid, and cholic acid are replaced by acid-unstable groups, such as the compounds described in paragraphs

[0155] to

[0178] of Japanese Patent Application Publication No. 2008-122932.

[1132] When the chemically amplified resist composition of the present invention includes a dissolution inhibitor (F), its content is preferably 0 to 50 parts by mass relative to 80 parts by mass of the base polymer (A), and more preferably 5 to 40 parts by mass. The dissolution inhibitor (F) can be used alone or in combination of two or more.

[1133] [(G) Other ingredients]

[1134] The chemically amplified resist composition of the present invention may also contain compounds that decompose upon contact with acid and produce acid (acid-increasing compounds), organic acid derivatives, fluorinated alcohols, water-repellent enhancers, etc., as other components in (G). As the aforementioned acid-increasing compounds, the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608 can be referenced. When containing the aforementioned acid-increasing compounds, their content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the base polymer in (A), more preferably 0 to 3 parts by mass. If the content is too high, it is difficult to control acid diffusion, and sometimes it may cause degradation of resolvability and pattern shape. As the aforementioned organic acid derivatives and fluorinated alcohols, the compounds described in Japanese Patent Application Publication No. 2009-269953 or Japanese Patent Application Publication No. 2010-215608 can be referenced.

[1135] The aforementioned water-repellent enhancer can be used in immersion lithography without a top coat. As the aforementioned water-repellent enhancer, polymers containing fluorinated alkyl groups or polymers containing 1,1,1,3,3,3-hexafluoro-2-propanol residues with a specific structure are preferred, and polymers exemplified in Japanese Patent Application Publication Nos. 2007-297590 and 2008-111103 are even more preferred. The aforementioned water-repellent enhancer needs to be soluble in alkaline or organic solvent developing solutions. The aforementioned water-repellent enhancer having specific 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in developing agents. As the water-repellent enhancer, polymers containing repeating units containing amino or amine salts are highly effective in preventing the evaporation of acid in PEB and thus preventing poor opening of the hole pattern after development. When the chemically amplified corrosion resist composition of the present invention includes the above-mentioned water repellency enhancer, its content is preferably 0 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight, relative to 80 parts by weight of the base polymer (A).

[1136] [Pattern Formation Method]

[1137] When the chemically amplified resist composition of the present invention is used to manufacture various integrated circuits, known photolithography techniques can be applied. For example, as a patterning method, a method including the following steps can be described: forming a resist film on a substrate using the above-described chemically amplified resist composition; exposing the above-described resist film to high-energy rays; and developing the exposed resist film using a developing solution.

[1138] First, the chemically amplified resist composition of the present invention is coated onto a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2) using a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor blade coating, with a coating film thickness of 0.01 to 2.0 μm. The resist film is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[1139] Then, the resist film is exposed using high-energy radiation. Examples of such high-energy radiation include ultraviolet light, far-ultraviolet light, EB, EUV (wavelength 3–15 nm), X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation. When using ultraviolet light, far-ultraviolet light, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, or synchrotron radiation, the exposure dose is preferably 1–200 mJ / cm², either directly or using a mask used to form the target pattern. 2 Around 10-100 mJ / cm² is preferred. 2 Irradiation is performed in a left-right manner. When using EB as the aforementioned high-energy ray, the preferred exposure dose is 0.1–100 μC / cm. 2 The optimal value is approximately 0.5–50 μC / cm. 2 The pattern can be drawn directly or using a mask to form the target pattern. The chemically amplified resist composition of the present invention is particularly suitable for fine patterning using high-energy rays such as ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, EB, or EUV, X-rays, soft X-rays, gamma rays, or synchrotron radiation with wavelengths of 3 to 15 nm.

[1140] After exposure, PEB can be applied on a hot plate at a temperature of 60–150°C for 10–30 seconds, or more preferably at 80–120°C for 30–20 seconds.

[1141] After exposure or PEB, a developer solution containing 0.1-10% by mass, preferably 2-5% by mass, of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc. is used. The development is performed for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, using conventional methods such as dip, puddle, or spray. As a result, the light-exposed areas dissolve in the developer solution, while the unexposed areas do not dissolve, thus forming a positive pattern of the target on the substrate.

[1142] Organic solvent developers can also be used instead of the alkaline aqueous solution to obtain negative patterns. Specific examples of developers used in this case 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, butenyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, methyl butenoate, and methyl valerate. Ethyl acrylate, 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, benzyl formate, ethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents can be used alone or in mixtures of two or more.

[1143] At the end of development, rinsing can be performed. The rinsing solution is preferably a solvent that is miscible with the developer and does not dissolve the resist film. Such a solvent is preferably an alcohol with 3 to 10 carbon atoms, an ether compound with 8 to 12 carbon atoms, an alkane, alkene, alkyne, or aromatic solvent with 6 to 12 carbon atoms.

[1144] Specific examples of alcohols with 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3, 3-Dimethyl-1-butanol, 3,3-Dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, etc.

[1145] Specific examples of the ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, disec-butyl ether, di-n-pentyl ether, diisopentyl ether, disec-pentyl ether, ditert-pentyl ether, and di-n-hexyl ether.

[1146] Specific examples of alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, and cyclononane. Specific examples of alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Specific examples of alkynes having 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[1147] Specific examples of solvents for the aforementioned aromatic systems include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[1148] Rinsing can reduce the collapse of the resist pattern and the formation of defects. Furthermore, rinsing is not always necessary; by omitting rinsing, the amount of solvent used can be reduced.

[1149] The developed hole or groove pattern can also be shrunk using heat transfer, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and through diffusion from the acidic catalyst in the resist film during baking, the shrinking agent cross-links on the surface of the resist film, adhering to the sidewalls of the hole pattern. The baking temperature is preferably 70–180°C, more preferably 80–170°C, and the baking time is preferably 10–300 seconds. This removes excess shrinking agent and shrinks the hole pattern.

[1150] [Example]

[1151] The present invention will now be specifically described with reference to synthetic examples, embodiments, and comparative examples, but the present invention is not limited to the embodiments described below. Furthermore, the apparatus used is as follows.

[1152] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[1153] [1] Synthesis of onium salt monomers

[1154] [Example 1-1] Synthesis of onium salt type monomer a-1

[1155] [Chemical 400]

[1156]

[1157] (1) Synthesis of intermediate In-1

[1158] Under a nitrogen atmosphere, starting material SM-1 (37.2 g), triethylamine (18.0 g), and 4-dimethylaminopyridine (1.50 g) were dissolved or suspended in THF (200 g) in a reaction vessel and cooled in an ice bath. Then, a solution of p-styrenesulfonyl chloride (16.4 g) dissolved in THF (50 g) was added dropwise. After the addition was complete, the temperature in the reaction vessel was raised to 50 °C and matured for 6 hours. The reaction solution was then cooled, and a saturated aqueous solution of sodium bicarbonate (100 g) was added to stop the reaction. The target compound was extracted twice with ethyl acetate (200 g), subjected to a standard aqueous work-up, and the solvent was distilled off. Recrystallization with hexane yielded 45.8 g of intermediate In-1 in crystalline form (97% yield).

[1159] (2) Synthesis of onium salt type monomer a-1

[1160] Under a nitrogen atmosphere, intermediate In-1 (45.8 g) was dissolved in THF (200 g). While cooling in an ice bath, a 25% (w / w) aqueous solution of sodium hydroxide (14.1 g) was added dropwise. After the addition was complete, the temperature in the reaction vessel was raised to 30 °C and allowed to mature for 12 hours. After maturation, the reaction solution was cooled, and starting material SM-2 (43.9 g), dichloromethane (300 g), and water (150 g) were added. After stirring for 30 minutes, the organic layer was separated, washed with water, and then concentrated under reduced pressure. The concentrate was purified by silica gel chromatography, yielding 68.6 g of the onium salt monomer a-1 (84% yield) as an oil.

[1161] MALDI TOF-MS: POSITIVEM + 461 (equivalent to C) 18 H 10 F4IS + )

[1162] NEGATIVEM - 555 (equivalent to C) 15 H9I2O5S - )

[1163] [Examples 1-2 to 1-7] Synthesis of onium salt type monomers a-2 to a-7

[1164] Using the corresponding raw materials and known organic synthesis reactions, onium salt type monomers a-2 to a-7 as shown in the following formula were synthesized.

[1165] [Chemical Engineering 401]

[1166]

[1167] [Comparative Examples 1-1 to 1-5] Comparison of the synthesis of onium salt type monomers Ca-1 to Ca-5

[1168] Using the corresponding raw materials and known organic synthesis reactions, comparative onium salt monomers ca-1 to ca-5 represented by the following formulas were synthesized.

[1169] [Chemical 402]

[1170]

[1171] [2] Synthesis of basic polymers

[1172] The monomers used in the synthesis of the basic polymer, excluding monomers a-1 to a-7 and comparative monomers ca-1 to ca-5, are as follows.

[1173] [Chemical 403]

[1174]

[1175] [Chemical 404]

[1176]

[1177] [Chemical 405]

[1178]

[1179] [Chemical 406]

[1180]

[1181] [Chemical 407]

[1182]

[1183] [Example 2-1] Synthesis of Polymer P-1

[1184] Under a nitrogen atmosphere, monomers a-1 (13.7 g), b1-1 (30.0 g), c-1 (9.7 g), d-1 (46.8 g), V-601 (manufactured by Fujifilm and Koichi Chemicals), 3.09 g, and MEK (139 g) were added to a flask to prepare a monomer-polymerization initiator solution. In another flask under a nitrogen atmosphere, 46 g of MEK was added, and the mixture was heated to 80°C with stirring. The aforementioned monomer-polymerization initiator was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was stirred for another 2 hours while maintaining the temperature at 80°C, and then cooled to room temperature. The resulting polymerization solution was added dropwise to 3000 g of vigorously stirred hexane, and the precipitated polymer was separated by filtration. The obtained polymer was washed twice with 600 g of hexane and then dried under vacuum at 50°C for 20 hours to obtain a white powder, polymer P-1 (yield 95.1 g, 95% yield). The Mw of polymer P-1 is 10400, and the Mw / Mn ratio is 1.54. Furthermore, Mw is a polystyrene conversion value obtained by GPC using DMF as a solvent.

[1185] [Chemical 408]

[1186]

[1187] [Examples 2-2 to 2-50, Comparative Examples 2-1 to 2-36] Synthesis of polymers P-2 to P-50 and comparative polymers CP-1 to CP-38

[1188] Except for changing the type and blending ratio of each monomer, the polymers shown in Tables 1 to 3 were produced by the same method as in Synthesis Example 2-1.

[1189] [Table 1]

[1190]

[1191]

[1192] [Table 2]

[1193]

[1194]

[1195] [Table 3]

[1196]

[1197]

[1198] [3] Preparation of chemically amplified resist composition

[1199] [Examples 3-1 to 3-53, Comparative Examples 3-1 to 3-40]

[1200] The specified components selected from the basic polymers (P-1 to P-50), comparative basic polymers (CP-1 to CP-38), acid generators (PAG-1, PAG-2), and quenchers (SQ-1, AQ-1) of the present invention were dissolved in a solvent containing 0.01% by mass of 3M FC-4430 as a surfactant to prepare a solution. The solution was filtered through a 0.2 μm Teflon (registered trademark) type filter to prepare chemically amplified resist compositions (R-1 to R-53, CR-1 to CR-40).

[1201] [Table 4]

[1202]

[1203]

[1204] [Table 5]

[1205]

[1206] [Table 6]

[1207]

[1208]

[1209] Tables 4-6 list the solvents, quenchers (SQ-1, AQ-1), and acid generators (PAG-1, PAG-2) as follows. • Solvent: PGMEA (propylene glycol monomethyl ether acetate)

[1210] EL (ethyl lactate)

[1211] DAA (Diacetone Alcohol)

[1212] Quenching agents: SQ-1, AQ-1

[1213] [Chemical 409]

[1214]

[1215] • Acid generating agents: PAG-1, PAG-2

[1216] [Chemical 410]

[1217]

[1218] [4] Evaluation of EUV lithography (1)

[1219] [Examples 4-1 to 4-53, Comparative Examples 4-1 to 4-40]

[1220] The chemically amplified resist compositions (R-1 to R-53, CR-1 to CR-40) shown in Tables 4-6 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coating hard mask SHB-A940 (43% by mass silicon) manufactured by Shin-Etsu Chemical Industry Co., Ltd. The substrate was pre-baked at 100°C for 60 seconds using a hot plate to create a 50 nm thick resist film. For the aforementioned resist film, an ASML EUV scanner NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination) was used, with varying exposure and focal length (exposure pitch: 1 mJ / cm). 2 Simultaneously, an LS pattern with a size of 18 nm and a pitch of 36 nm was exposed on the wafer (focusing pitch: 0.020 μm). After exposure, PEB was performed for 60 seconds at the temperatures shown in Tables 7-9. Then, immersion development was performed for 30 seconds using a 2.38% by mass TMAH aqueous solution, followed by rinsing with a rinsing material containing surfactant, and spin drying to obtain a positive pattern.

[1221] The obtained LS pattern was observed using a Hitachi Advanced Technology Length SEM (CG6300), and the sensitivity, EL, LWR, DOF, and collapse limit were evaluated according to the following methods. The results are shown in Tables 7-9.

[1222] [Sensitivity Evaluation]

[1223] Find the optimal exposure Eop (mJ / cm) for an LS pattern with a linewidth of 18nm and a pitch of 36nm. 2 This value is used as the sensitivity. The smaller the value, the higher the sensitivity.

[1224] [EL Review]

[1225] The EL (unit: %) is calculated using the following formula based on the exposure amount formed within ±10% (16.2 to 19.8 nm) of the 18 nm pitch width in the above LS pattern. The larger this value, the better the performance.

[1226] EL(%)=(|E1-E2| / Eop)×100

[1227] E1: Provides optimal exposure for LS patterns with a linewidth of 16.2nm and a pitch of 36nm.

[1228] E2: Provides optimal exposure for LS patterns with a linewidth of 19.8nm and a pitch of 36nm.

[1229] Eop: Provides optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[1230] [LWR Evaluation]

[1231] For an LS pattern obtained by Eop irradiation, the size of 10 locations along the length of the line is measured, and the standard deviation (σ) is calculated as three times the value (3σ) as the LWR. The smaller this value, the smaller the roughness and the more uniform the line width of the pattern.

[1232] [DOF Rating]

[1233] As an evaluation of depth of focus, the focal range formed within ±10% (16.2–19.8 nm) of the 18 nm size in the aforementioned LS pattern is determined. The larger this value, the wider the depth of focus.

[1234] [Collapse Limit Assessment of Line Patterns]

[1235] The line size at the optimal focal point of the LS pattern was measured at 10 locations along its length. The finest line size obtained without collapse was taken as the collapse limit. The smaller this value, the better the collapse limit.

[1236] [Table 7]

[1237]

[1238] [Table 8]

[1239]

[1240]

[1241] [Table 9]

[1242]

[1243]

[1244] As shown in Tables 7-9, the chemically amplified resist composition using a base polymer comprising repeating units from the onium salt monomers of this invention exhibits good sensitivity and excellent EL, LWR, and DOF. Furthermore, a low collapse limit value was confirmed, demonstrating resistance to pattern collapse during fine pattern formation. Therefore, the chemically amplified resist composition of this invention is suitable as a material for EUV lithography.

[1245] [5] Evaluation of EUV lithography (2)

[1246] [Examples 5-1 to 5-53, Comparative Examples 5-1 to 5-40]

[1247] The chemically amplified resist compositions (R-1 to R-53, CR-1 to CR-40) shown in Tables 4 to 6 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coating hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. The substrate was pre-baked at 105°C for 60 seconds using a hot plate to create a 50 nm thick resist film. The resist was then exposed using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple illumination, a 46 nm pitch, +20% tolerance hole pattern mask on the wafer). PEB was performed for 60 seconds at the temperatures listed in Tables 10 to 12 using a hot plate, followed by 30 seconds of development using a 2.38% by mass TMAH aqueous solution to form a 23 nm hole pattern.

[1248] Using a Hitachi Advanced Technologies (AG) CG6300 length measuring SEM, the exposure was measured when forming apertures at a size of 23 nm, and this was used as the sensitivity. In addition, the size of 50 apertures at this time was measured, and three times the standard deviation (σ) calculated from the results (3σ) was used as the size deviation (CDU). The results are shown in Tables 10-12.

[1249] [Table 10]

[1250]

[1251] [Table 11]

[1252]

[1253]

[1254] [Table 12]

[1255]

[1256]

[1257] Based on the results shown in Tables 10-12, it was confirmed that the chemically amplified resist composition of the present invention has good sensitivity and excellent CDU.

[1258] [6] Evaluation of dry etching resistance

[1259] [Examples 6-1 to 6-50, Comparative Examples 6-1 to 6-38]

[1260] The polymer solutions obtained by dissolving 2g of each of the polymers shown in Tables 1 and 2 (polymers P-1 to P-50, comparative polymers CP-1 to CP-10) in 10g of cyclohexanone and filtering them using a 0.2μm filter were spin-coated onto a Si substrate to form a film with a thickness of 300nm, and evaluated under the following conditions.

[1261] Etching test in CHF3 / CF4 based gases:

[1262] 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.

[1263] The etching conditions are as follows.

[1264] Chamber pressure 40 Pa

[1265] RF power 1000W

[1266] 9mm gap

[1267] CHF3 gas flow rate 30 mL / min

[1268] CF4 gas flow rate 30 mL / min

[1269] Ar gas flow rate 100 mL / min

[1270] 60 seconds

[1271] In this evaluation, a small difference in film thickness, i.e., a small reduction in amount, indicates high etching resistance. The results of dry etching resistance are shown in Tables 13-15.

[1272] [Table 13]

[1273]

[1274]

[1275] [Table 14]

[1276]

[1277] [Table 15]

[1278]

[1279]

[1280] Based on the results shown in Tables 13-15, it was confirmed that the polymer of the present invention has excellent dry etching resistance to CHF3 / CF4 gases.

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, n4 is 0 or 1, n5 is 0, 1, 2, 3 or 4, and n6 is 0, 1 or 2. However, when n1 is 0, 1 ≤ n2 + n3 ≤ 4; when n1 is 1, 1 ≤ n2 + n3 ≤ 6. Also, when n4 is 0, 1 ≤ n5 + n6 ≤ 4; when n4 is 1, 1 ≤ n5 + n6 ≤ 6. Furthermore, 1 ≤ n2 + n5, and n7 is 0 or 1. R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 1 When n3 is 2, 3, or 4, each R 1 They can be the same or different, multiple Rs 1 They can also bond to each other and form rings together with the carbon atoms they are bonded to. R 2 For halogen atoms other than iodine atoms, nitro groups, hydrocarbon groups with 1 to 20 carbon atoms that may contain heteroatoms, hydroxyl groups with 1 to 20 carbon atoms that may contain heteroatoms, or hydrocarbon thiol groups with 1 to 20 carbon atoms that may contain heteroatoms, when n6 is 2, each R 2 They can be the same or different, multiple Rs 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to. L A It can be a single bond, a sulfonate bond, or a sulfonamide bond. 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, R A R 1 R 2 n1~n7 and Z + Similar to the above, L A1 It can be -O- or -NH-.

3. The onium salt type monomer according to claim 2, represented by the following formula (a2), In the formula, R A R 1 R 2 n1~n6 and Z + Same as above.

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

5. The onium salt type monomer according to claim 1, wherein, Z + The sulfonium cation is represented by the following formula (A). 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, but m1 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; additionally, m4 + m12 ≥ 1. R F1 ~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. When m5 is 2 or more, each R F1 They can be the same or different. When m6 is 2 or more, each R F2 They can be the same or different. When m7 is 2 or more, each R F3 They can be the same or different from each other. R 3 ~R 6 The radicals are 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 contain heteroatoms). When m8 is 2, there are 2 R radicals. 3 They can be the same or different from each other, and there are 2 Rs. 3 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m9 is 2, there are 2 R atoms. 4 They can be the same or different from each other, and there are 2 Rs. 4 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m10 is 2, there are 2 R atoms. 5 They can be the same or different from each other, and there are 2 Rs. 5 They can also bond to each other and form rings together with the carbon atoms they are bonded to. When m13 is 2, there are 2 R atoms. 6 They can be the same or different from each other, and there are 2 Rs. 6 They can also bond to each other and form rings together with the carbon atoms they are bonded to. In addition, S in sulfonium cations + Directly bonded aromatic rings can also bond with each other and S + Together they form a ring. L B and L C Each bond can be independently a single bond, ether bond, ester bond, amide bond, sulfonate bond, sulfonamide bond, carbonate bond, or carbamate bond. X L It is a single bond, or may contain heteroatoms, and is a hydrocarbon group with 1 to 40 carbon atoms.

6. The onium salt type monomer according to claim 5, wherein, The sulfonium cation is represented by the following formula (A1). In the formula, m4~m10, m12~m14, R F1 ~R F3 R 3 ~R 6 L B L C and X L Same as above.

7. The onium salt type monomer according to claim 6, wherein, The sulfonium cation is represented by the following formula (A2). In the formula, m4~m10, R F1 ~R F3 and R 3 ~R 5 Same as above.

8. A monomeric photoacid generator, comprising an onium salt monomer according to any one of claims 1 to 7.

9. A polymer comprising repeating units from the monomeric photoacid generator according to claim 8.

10. The polymer according to claim 9, further comprising repeating units represented by formula (b1) or (b2), In the formula, R A Each is 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 by 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 group, or naphthylene group having 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. 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, 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. AL 1 and AL 2 Each is an independent acid-labile group. a can be 0, 1, 2, 3 or 4.

11. The polymer according to claim 9, further comprising a repeating unit represented by formula (b3), In the formula, b1 is 0 or 1, and b2 is 0, 1, 2 or 3 when b1 is 0, and 0, 1, 2, 3, 4 or 5 when b1 is 1. R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. X 3 These are single bonds, *-C(=O)-O-, or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain. R 12 and R 13 Each is an independent hydrocarbon group consisting of 1 to 20 carbon atoms, or may contain heteroatoms. Additionally, R... 12 and R 13 They can also bond to each other and form rings together with the carbon atoms they are bonded to. R 14 This indicates a halogen atom, hydroxyl group, cyano group, nitro group, or a hydrocarbon group with 1 to 20 carbon atoms that may contain heteroatoms; a hydrocarbon oxygen group with 1 to 20 carbon atoms that may contain heteroatoms; a hydrocarbon oxygen carbonyl group with 2 to 20 carbon atoms that may contain heteroatoms; or a hydrocarbon thio group or -N(R) group with 1 to 20 carbon atoms. 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 b2 is 2 or more, multiple R... 14 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. X 4 It is a single bond, an aliphatic hydrocarbon group, carbonyl group, sulfonyl group, or a combination thereof, consisting of 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 bonds with adjacent carbon atoms of the aromatic ring.

12. The polymer according to claim 9, further comprising a repeating unit represented by formula (c), In the formula, R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Y 1 These are single bonds, *-C(=O)-O-, or *-C(=O)-NH-, where * indicates an atomic bond with a carbon atom in the main chain. R 21 It can be a halogen atom, nitro group, cyano group, carboxyl 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. c1 can be 1, 2, 3 or 4, and c2 can be 0, 1, 2 or 3, but 1≤c1+c2≤5.

13. The polymer according to claim 9, further comprising repeating units derived from a fluorosulfonic acid anion having a polymerizable group and one or more iodine atoms in the anion and a sulfonium cation.

14. The polymer according to claim 9, further comprising a repeating unit represented by formula (e), In the formula, R A It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 Indicates single bond, phenylene, naphthylene, *-C(=O)-OZ 11 -or *-C(=O)-NH-Z 11 - The phenylene or naphthylene group may also be substituted by a hydroxyl, nitro, 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. * indicates an atomic bond with a carbon atom in the main chain. Z 11 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 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. R 51 It is a hydrogen atom, or a group having 1 to 20 carbon atoms, selected from at least one of the following structures: 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)-).

15. A chemically amplified resist composition comprising (A) a base polymer comprising the polymer according to claim 9.

16. The chemically amplified resist composition according to claim 15, further comprising (B) an organic solvent.

17. The chemically amplified resist composition according to claim 15, further comprising (C) a quencher.

18. The chemically amplified resist composition according to claim 15, further comprising (D) an acid generating agent.

19. The chemically amplified resist composition according to claim 15, further comprising (E) a surfactant.

20. A method for forming a pattern, comprising: The step of forming a resist film on a substrate using the chemically amplified resist composition according to claim 15; The step of exposing the resist film with high-energy rays; and The step of developing the exposed resist film using a developer.

21. The pattern forming method according to claim 20, wherein, The high-energy rays are ArF excimer lasers with a wavelength of 193 nm or KrF excimer lasers with a wavelength of 248 nm, electron beams, or extreme ultraviolet rays with a wavelength of 3–15 nm.

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