Onium salt monomer, monomeric photoacid generator, polymer, chemically amplified resist composition, and pattern forming method

Abstract

This invention relates to onium salt monomers, monomeric photoacid generators, polymers, chemically amplified resist compositions, and patterning methods. The objective of this invention is to provide onium salt monomers for use in chemically amplified resist compositions that exhibit excellent photolithographic performance and resist pattern collapse even during the formation of fine patterns. The solution of this invention is an onium salt monomer represented by the following formula (A). [Chemical 1] In the formula, m4 is 0~1. m5 is 2~5. m6 is 0~4. R A It is a hydrogen atom or a methyl group. R 2 These include halogen atoms other than iodine atoms, nitro groups, hydroxyl groups, cyano groups, and hydrocarbon groups. However, sulfonic acid "SO3" ‑ "None of the two adjacent carbon atoms of the substituted carbon atom are bonded to an iodine atom." A L B and L C It is a single bond, or an alkylene group, etc. X L1 It is a single bond or a hydrocarbon group. W is a single bond or a hydrocarbon group. Z + It is a sulfonium cation or a sulfonium cation.

Description

Technical Field

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

[0002] With the increasing integration and speed of LSI (Light Detector System), the miniaturization of patterned regularity is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving miniaturization. Regarding the most advanced miniaturization technologies, mass production of 65nm node devices using ArF lithography has been implemented, and preparations for mass production of the next-generation 45nm node devices using ArF immersion lithography are underway. For the next-generation 32nm node devices, immersion lithography combining a liquid with a higher refractive index than water and a high-refractive-index lens, an ultra-high NA lens made of a high-refractive-index resist film, extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm, and double exposure (double patterning lithography) using ArF lithography are among the candidates being explored.

[0003] As patterns become increasingly finer, the linewidth roughness (LWR) of line patterns and the dimensional uniformity (CDU) of hole and dot patterns are considered problems. Some have pointed to the effects of uneven distribution and aggregation of the base polymer and acid-generating agents, as well as the influence of acid diffusion. Furthermore, with the thinning of resist films, there is a tendency for LWR and CDU to increase; accompanying further miniaturization, the degradation of LWR and CDU caused by thinning becomes a serious problem.

[0004] In EUV lithography, the resist composition needs to simultaneously achieve high sensitivity, high resolution, and low light-to-weight ratio (LWR). Shortening the acid diffusion distance will decrease LWR but decrease sensitivity. For example, lowering the post-exposure baking (PEB) temperature will decrease LWR but decrease sensitivity. Even increasing the amount of quencher will decrease LWR but still result in low sensitivity. Therefore, a trade-off between sensitivity and LWR needs to be overcome.

[0005] To suppress acid diffusion, a resist compound 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 upon exposure, exhibits a very short acid diffusion distance. Furthermore, sensitivity can be improved by increasing the ratio of the acid generator. Increasing the amount of an additive acid generator also results in higher sensitivity, but this also increases the acid diffusion distance. Since the acid diffuses unevenly, increased acid diffusion degrades LWR and CDU. The polymeric acid generator demonstrates a high level of capability in balancing sensitivity, LWR, and CDU.

[0006] Iodine atoms have very high absorption in EUV at a wavelength of 13.5 nm, thus confirming the effect of secondary electrons generated by iodine atoms during exposure, which has attracted attention in EUV lithography. Patent document 2 describes a photoacid generator in which iodine atoms are introduced into anions, and patent document 3 describes a photoacid generator containing polymerizable groups in which iodine atoms are introduced into anions.

[0007] On the other hand, the health effects of perfluoroalkane compounds (PFAS) have been pointed out, leading to restrictions on the manufacture and sale of PFAS compounds under the European REACH agreement. Numerous compounds containing PFAS are currently used in semiconductor lithography. For example, they are used in surfactants and acid generators. The photoacid generators described in Patent Documents 1, 2, and 3 are all based on alkane sulfonic acid units, and their significant health and environmental impacts have been noted.

[0008] Patent Document 4 describes the use of onium salts of fluorobenzenesulfonic acid as a substitute for PFAS. Patent Document 5 describes the use of onium salts of benzenesulfonic acid. On the other hand, the sulfonic acid of these benzenesulfonic acid units has low acid strength and needs improvement.

[0009] Existing technical documents

[0010] Patent documents

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

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

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

[0014] [Patent Document 4] Japanese Patent Application Publication No. 2018-159744

[0015] [Patent Document 5] Japanese Patent No. 7531671

[0016] [Patent Document 6] Japanese Patent No. 7032549 Summary of the Invention

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

[0018] In chemically amplified resist compositions using acid as a catalyst, it is hoped that a resist composition with higher sensitivity, improved line pattern LWR and hole pattern CDU, and excellent resolution can be developed.

[0019] The present invention was made in view of the foregoing circumstances, and aims to provide a chemically amplified resist composition used in optical lithography using high-energy rays, which has excellent lithographic performance such as high sensitivity, exposure margin (EL), LWR, CDU, and depth of focus (DOF), and also resists pattern collapse during the formation of fine patterns. The composition includes an onium salt monomer, a polymer containing repeating units from the onium salt monomer, a chemically amplified resist composition containing the polymer, and a pattern formation method using the chemically amplified resist composition.

[0020] [Methods for solving the problem]

[0021] To address the aforementioned issues, the present invention provides an onium salt monomer represented by the following formula (A).

[0022] [Chemistry 1]

[0023]

[0024] In the formula, m4 is an integer of 0 or 1; m5 is an integer of 2 or 3 when m4 is 0, and an integer of 2, 3, 4 or 5 when m4 is 1; m6 is an integer of 0, 1 or 2 when m4 is 0, and an integer of 0, 1, 2, 3 or 4 when m4 is 1; however, when m4 is 0, then 2≤m5+m6≤4, and when m4 is 1, then 2≤m5+m6≤6;

[0025] R A It is a hydrogen atom or a methyl group;

[0026] R 2 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m6 is 2 or more, 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 bond to; however, this is not the case with sulfonic acid "SO3". - "Among the two adjacent carbon atoms of the substituted carbon atom, neither of them is bonded to an iodine atom."

[0027] L A L B and L C Each group is independently a single bond, ester group, ether group, amide group, sulfonate group, or a straight-chain, branched, or cyclic alkylene group having 1 to 12 carbon atoms. The alkylene group may also contain one or more groups selected from ester group, ether group, amide group, and sulfonate group.

[0028] X L1 It is a single bond, or may contain a heteroatom and consist of 1 to 40 carbon atoms in a hydrocarbon group;

[0029] W is a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may also have at least one selected from oxygen, nitrogen, sulfur and halogen atoms;

[0030] Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2);

[0031] [Chemistry 2]

[0032]

[0033] In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; and R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0034] If so, then especially in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV, it will become a high-sensitivity, high-contrast chemical amplification resist composition with excellent lithography performance such as exposure margin (EL), LWR, CDU, and depth of focus (DOF), and will also resist pattern collapse in the formation of fine patterns.

[0035] Furthermore, the onium salt monomer of the present invention is preferably represented by the following formula (A1).

[0036] [Chemistry 3]

[0037]

[0038] In the formula, m1 is an integer of 0 or 1; m2 is an integer of 0, 1, 2 or 3 when m1 is 0, and an integer of 0, 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, then 0 ≤ m2 + m3 ≤ 4, and when m1 is 1, then 0 ≤ m2 + m3 ≤ 6;

[0039] R 1 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m3 is 2 or more, 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 bond to;

[0040] m4~m6、R AR 2 X L1 L A L B L C and Z + Same as above.

[0041] At this point, the onium salt monomer of the present invention is preferably represented by the following formula (A2).

[0042] [Chemistry 4]

[0043]

[0044] In the formula, m1~m3, m6, R A R 1 R 2 X L1 L A L B L C and Z + Same as above.

[0045] If the onium salt monomer of the present invention has such a structure, the effects of the present invention can be further fully utilized.

[0046] Furthermore, the present invention provides a monomeric photoacid generator composed of the above-mentioned onium salt monomers.

[0047] The onium salt monomer of the present invention is suitable for use as a monomeric photoacid generator.

[0048] Furthermore, the present invention provides a polymer comprising repeating units derived from the aforementioned monomeric photoacid generator.

[0049] The onium salt monomers of the present invention are particularly suitable for use as polymer-bonded photoacid generators.

[0050] Furthermore, it is preferable that the aforementioned polymer also contains repeating units represented by formula (b1) or (b2).

[0051] [Chemistry 5]

[0052]

[0053] In the formula, R A Each can be independently a hydrogen atom or a methyl group;

[0054] Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the following: a hydroxyl group, a halogen atom, a saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms.

[0055] Y 2 It is a single bond or an ester bond;

[0056] Y 3 It is a single bond, an ether bond, or an ester bond;

[0057] R 11 and R 12 Each is an unstable acid group;

[0058] R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms;

[0059] R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxy group with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxy group with 2 to 8 carbon atoms, ether bond and ester bond;

[0060] A is an integer between 0 and 4.

[0061] If so, it is suitable for use in chemically amplified resist compositions.

[0062] Furthermore, the present invention provides a chemically amplified resist composition comprising the above-mentioned polymer as a base polymer.

[0063] If so, then especially in optical lithography using high-energy rays such as KrF excimer lasers, ArF excimer lasers, electron beams (EB), and EUV, it will become a chemically amplified resist composition with high sensitivity, high contrast, excellent lithography performance such as exposure margin (EL), LWR, CDU, and depth of focus (DOF), and will also resist pattern collapse during the formation of fine patterns.

[0064] The chemically amplified resist composition of the present invention further preferably includes at least one selected from organic solvents, quenchers, acid generators, surfactants, and solvent inhibitors.

[0065] The chemically amplified resist composition of the present invention may also include these components as needed.

[0066] Furthermore, the present invention provides a pattern forming method comprising the following steps: forming a resist film on a substrate using the above-mentioned chemically amplified resist composition, exposing the aforementioned resist film to high-energy radiation, and developing the exposed resist film using a developing solution.

[0067] The pattern formation method of the present invention provides excellent lithographic performance in optical lithography using high-energy rays, including high sensitivity, high contrast, exposure margin (EL), LWR, CDU, and depth of focus (DOF), while also resisting pattern collapse in the formation of fine patterns.

[0068] Furthermore, the aforementioned high-energy rays are preferably ArF excimer lasers with a wavelength of 193nm or KrF excimer lasers with a wavelength of 248nm, electron beams, or extreme ultraviolet rays with a wavelength of 3~15nm.

[0069] The pattern forming method of the present invention can further maximize the effects of the present invention by using such high-energy rays.

[0070] [The effects of the invention]

[0071] Polymers containing benzenesulfonic acid with multiple iodine atoms substituted for each other, and which generate repeating units of acid upon exposure, exhibit high EUV absorption due to the iodine atom, resulting in the generation of secondary electrons from the iodine atom during exposure. Due to the resonance effect of aromatic groups, the iodine-substituted form becomes a stronger acid compared to arylsulfonic acids with only fluorine atoms substituted, and the high EUV absorption of the iodine atom further enhances the acid strength. Furthermore, the presence of the large iodine atom nearby reduces the mobility of the sulfonic acid, inhibiting acid diffusion and improving LWR and CDU. Characteristically, one of the two carbon atoms adjacent to the sulfonic acid atom is not bonded to the iodine atom, thus the sulfonic acid is not stereoscopically affected by the electron cloud of the large iodine atom, exhibiting good sensitivity / resolution. Detailed Implementation

[0072] As described above, there is a need to develop a chemically amplified resist composition that exhibits excellent lithographic performance in optical lithography using high-energy rays, including high sensitivity, exposure margin (EL), LWR, CDU, and depth of focus (DOF), while also resisting pattern collapse during the formation of fine patterns. This composition includes an onium salt monomer, a polymer containing repeating units from the onium salt monomer, a chemically amplified resist composition containing the polymer, and a patterning method using the chemically amplified resist composition.

[0073] Furthermore, Patent Document 6 shows a structure in which benzenesulfonic acid is substituted with an aryl group at the ortho position. It is believed that such a structure can be used as an alternative to PFAS, but due to the presence of a sterically large group near the sulfonic acid anion, the sensitivity and resolution are insufficient.

[0074] In order to achieve the aforementioned objectives, the inventors of this application conducted repeated and in-depth research and discovered that by using a polymer comprising repeating units of an onium salt monomer derived from benzenesulfonic acid with multiple iodine atoms substituted, characterized in that one of the two carbon atoms adjacent to the sulfonic acid is not bonded to an iodine atom, as a polymer-bonded photoresist generator, a chemically amplified resist composition with high sensitivity, high contrast, high resolution, and improved photolithography properties such as LWR and CDU can be obtained, thus completing this invention.

[0075] That is, the present invention is an onium salt monomer represented by the following formula (A).

[0076] [Chemistry 6]

[0077]

[0078] In the formula, m4 is an integer of 0 or 1; m5 is an integer of 2 or 3 when m4 is 0, and an integer of 2, 3, 4 or 5 when m4 is 1; m6 is an integer of 0, 1 or 2 when m4 is 0, and an integer of 0, 1, 2, 3 or 4 when m4 is 1; however, when m4 is 0, then 2≤m5+m6≤4, and when m4 is 1, then 2≤m5+m6≤6;

[0079] R A It is a hydrogen atom or a methyl group;

[0080] R 2 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m6 is 2 or more, 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 bond to; however, this is not the case with sulfonic acid "SO3". - "Among the two adjacent carbon atoms of the substituted carbon atom, neither of them is bonded to an iodine atom."

[0081] L A L B and L C Each group is independently a single bond, ester group, ether group, amide group, sulfonate group, or a straight-chain, branched, or cyclic alkylene group having 1 to 12 carbon atoms. The alkylene group may also contain one or more groups selected from ester group, ether group, amide group, and sulfonate group.

[0082] X L1 It is a single bond, or may contain a heteroatom and be a hydrocarbon group with 1 to 40 carbon atoms;

[0083] W is a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may also have at least one selected from oxygen, nitrogen, sulfur and halogen atoms;

[0084] Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2);

[0085] [Chemistry 7]

[0086]

[0087] In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group consisting of halogen atoms, or may also contain heteroatoms, having 1 to 30 carbon atoms; furthermore, R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0088] The present invention will now be described in detail, but the present invention is not limited thereto.

[0089] [Onium salt monomer]

[0090] The onium salt monomer of the present invention is represented by the following formula (A).

[0091] [Chemistry 8]

[0092]

[0093] In formula (A), m4 is an integer of 0 or 1. When m4 is 0, it is a benzene ring; when m4 is 1, it is a naphthalene ring. Considering solvent solubility, a benzene ring with m4 of 0 is preferred. When m4 is 0, m5 is an integer of 2 or 3; when m4 is 1, it is an integer of 2, 3, 4, or 5. Considering the availability of raw materials, m5 of 2 is preferred. When m4 is 0, m6 is an integer of 0, 1, or 2; when m4 is 1, it is an integer of 0, 1, 2, 3, or 4. However, when m4 is 0, 2 ≤ m5 + m6 ≤ 4; when m4 is 1, 2 ≤ m5 + m6 ≤ 6. Because multiple hydrogen atoms on benzenesulfonic acid are replaced by iodine atoms, its absorption of EUV light is increased. Furthermore, due to the influence of the size of the iodine atom, the degree of freedom of sulfonic acid decreases, resulting in a material with high sensitivity and low acid diffusion. On the other hand, SO3 - At least one of the adjacent positions is not substituted by an iodine atom, and it is even better if two adjacent positions are not substituted by an iodine atom. Such an onium salt monomer can reduce the steric hindrance around the sulfonate and effectively generate acid, thus providing a resist composition with excellent sensitivity and resolution.

[0094] In formula (A), W is a single bond or a hydrocarbon group with 1 to 30 carbon atoms, preferably 1 to 20. This hydrocarbon group may also have at least one atom selected from oxygen, nitrogen, sulfur, and halogen atoms. Specific examples are shown below, but are not limited to these. Furthermore, in the following formula, * represents the atom with L. A and L BAtomic bonds.

[0095] [Chemistry 9]

[0096]

[0097] [Chemistry 10]

[0098]

[0099] [Chemistry 11]

[0100]

[0101] [Chemistry 12]

[0102]

[0103] In formula (A), X L1 It is a single bond, or may contain heteroatoms, of a carbon group numbering 1 to 40. Specific examples include alkane diols, cyclic saturated alkylene groups, and aryl groups. The aforementioned heteroatoms may include oxygen atoms, nitrogen atoms, sulfur atoms, etc.

[0104] X L1 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 formula, * denotes the groups with respect to L. B L C Atomic bonds.

[0105] [Chemistry 13]

[0106]

[0107] [Chemistry 14]

[0108]

[0109] [Chemistry 15]

[0110]

[0111] [Chemistry 16]

[0112]

[0113] Among them, X L -0~X L -22, X L -29~X L -34, and X L -47~X L -63 is better.

[0114] R 2It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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. When m6 is 2 or more, 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 bond to. However, the aforementioned R 2 The preferred monomers are halogen atoms other than iodine, nitro, hydroxyl, cyano, or hydrocarbon groups with 1 to 3 carbon atoms that may contain heteroatoms. Fluorine atoms, nitro, cyano, or hydrocarbon groups with 1 to 3 carbon atoms that may contain heteroatoms are even more preferred. With such onium salt monomers, the area around the sulfonic acid anion is not sterically crowded, which is useful for achieving high sensitivity and high resolution.

[0115] Furthermore, when m6 is 2, 3, or 4, multiple R 2 They can also bond to each other and form rings together with the carbon atoms they bond to. Five- to eight-membered rings are preferred.

[0116] In formula (A), L A L B and L C Each group is independently a single bond, ester group, ether group, amide group, sulfonate group, or a straight-chain, branched, or cyclic alkylene group having 1 to 12 carbon atoms. The alkylene group may also contain one or more groups selected from ester, ether, amide, and sulfonate groups. Among them, L... A Single bonds and ester bonds are preferred, with single bonds being even better. L A When the bond is a single bond, the mobility around the main chain of the photoacid generator, which is incorporated into the polymer backbone, decreases, further inhibiting acid diffusion. B Single bonds, ether bonds, ester bonds, or sulfonate bonds are preferred, with single bonds and ester bonds being more desirable. Because the distance from the polymer backbone to the sulfonic acid is shortened, acid diffusion can be further suppressed. C Single bonds, ether bonds, ester bonds, or sulfonate bonds are preferred, with ether bonds, ester bonds, or sulfonate bonds being even more preferred.

[0117] The onium salt monomer represented by formula (A) is preferably represented by the following formula (A1).

[0118] [Chemistry 17]

[0119]

[0120] In the formula, m1 is an integer of 0 or 1; m2 is an integer of 0, 1, 2 or 3 when m1 is 0, and an integer of 0, 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, then 0 ≤ m2 + m3 ≤ 4, and when m1 is 1, then 0 ≤ m2 + m3 ≤ 6;

[0121] R 1 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m3 is 2 or more, 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 bond to;

[0122] m4~m6、R A R 2 X L1 L A L B L C and Z + Same as above.

[0123] The onium salt monomers represented by formulas (A) and (A1) are preferably represented by formula (A2).

[0124] [Chemistry 18]

[0125]

[0126] In the formula, m1~m3, m6, R A R 1 R 2 X L1 L A L B L C and Z + Same as above.

[0127] Specific examples of onium salt anions represented by formula (A) are shown below, but are not limited to these. Furthermore, in the following formula, R... A As mentioned above, Me is methyl. Furthermore, the bonding positions of the various substituents on the aromatic ring can also be interchanged.

[0128] [Chemistry 19]

[0129]

[0130] [Chemistry 20]

[0131]

[0132] [Chemistry 21]

[0133]

[0134] [Chemistry 22]

[0135]

[0136] [Chemistry 23]

[0137]

[0138] [Chemistry 24]

[0139]

[0140] [Chemistry 25]

[0141]

[0142] [Chemistry 26]

[0143]

[0144] [Chemistry 27]

[0145]

[0146] [Chemistry 28]

[0147]

[0148] [Chemistry 29]

[0149]

[0150] [Chemistry 30]

[0151]

[0152] [Chemistry 31]

[0153]

[0154] [Chemistry 32]

[0155]

[0156] [Chemistry 33]

[0157]

[0158] [Chemistry 34]

[0159]

[0160] [Chemistry 35]

[0161]

[0162] [Chemistry 36]

[0163]

[0164] [Chemistry 37]

[0165]

[0166] [Chemistry 38]

[0167]

[0168] [Chemistry 39]

[0169]

[0170] [Chemistry 40]

[0171]

[0172] [Chemistry 41]

[0173]

[0174] [Chemistry 42]

[0175]

[0176] [Chemistry 43]

[0177]

[0178] [Chemistry 44]

[0179]

[0180] [Chemistry 45]

[0181]

[0182] [Chemistry 46]

[0183]

[0184] [Chemistry 47]

[0185]

[0186] In formula (A), Z + It is an onium cation. The aforementioned onium cation is preferably a sulfonium cation represented by formula (Z-1) or a sulfonium cation represented by formula (Z-2).

[0187] [Chemistry 48]

[0188]

[0189] In equations (Z-1) and (Z-2), R ct1 ~R ct5Each is a hydrocarbon group with 1 to 30 carbon atoms that is independently a halogen atom or may also contain heteroatoms.

[0190] R ct1 ~R ct5 Specific examples of halogen atoms that can be represented include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0191] R ct1 ~R ct5 The hydrocarbon group represented can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups with 1 to 30 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups with 3 to 30 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl; alkenyl groups with 2 to 30 carbon atoms such as vinyl, 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, with aryl being preferred. Furthermore, some or all of the hydrogen atoms in the aforementioned 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- group in the aforementioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can 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.

[0192] Also, 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 shown by the following formulas, etc.

[0193] [Chemistry 49]

[0194]

[0195] In the formula, the dashed line represents the intersection with R. ct3 Atomic bonds.

[0196] Specific examples of sulfonium cations represented by formula (Z-1) are shown below, but are not limited to these.

[0197] [Transformation 50]

[0198]

[0199] [Chemistry 51]

[0200]

[0201] [Chemistry 52]

[0202]

[0203] [Chemistry 53]

[0204]

[0205] [Chemistry 54]

[0206]

[0207] [Chemistry 55]

[0208]

[0209] [Chemistry 56]

[0210]

[0211] [Chemistry 57]

[0212]

[0213] [Chem.58]

[0214]

[0215] [Chemistry 59]

[0216]

[0217] [Transformation 60]

[0218]

[0219] [Chemistry 61]

[0220]

[0221] [Chemistry 62]

[0222]

[0223] [Chemistry 63]

[0224]

[0225] [Chemistry 64]

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[0227] [Chemistry 65]

[0228]

[0229] [Chemistry 66]

[0230]

[0231] [Chemistry 67]

[0232]

[0233] [Chemistry 68]

[0234]

[0235] [Chemistry 69]

[0236]

[0237] [Chemistry 70]

[0238]

[0239] [Chemistry 71]

[0240]

[0241] [Chemistry 72]

[0242]

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[0249] [Chemistry 76]

[0250]

[0251] [Chemistry 77]

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[0253] [Chemistry 78]

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[0255] [Chemistry 79]

[0256]

[0257] [Chemistry 80]

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[0259] [Chemistry 81]

[0260]

[0261] [Chemistry 82]

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[0263] [Chemistry 83]

[0264]

[0265] [Chemistry 84]

[0266]

[0267] [Chemistry 85]

[0268]

[0269] Specific examples of monazine cations represented by formula (Z-2) are shown below, but are not limited to these.

[0270] [Chemistry 86]

[0271]

[0272] [Chemistry 87]

[0273]

[0274] Specific examples of the onium salt monomers of the present invention can be listed as any combination of the aforementioned anions and cations.

[0275] The onium salt monomer of the present invention can be synthesized, for example, using the same method as that described in Japanese Patent No. 5201363 for the sulfonium salt having a polymerizable anion, but is not limited thereto.

[0276] [Monomer-type photoacid generator]

[0277] Furthermore, the present invention provides a monomeric photoacid generator composed of the above-described onium salt monomer. The onium salt monomer of the present invention is suitable for use as a monomeric photoacid generator.

[0278] [polymer]

[0279] The polymer of the present invention comprises repeating units (hereinafter also referred to as repeating unit a) derived from the onium salt monomer (monomer-type photoacid generator) represented by formula (A).

[0280] The polymer of this invention functions as a photoacid generator in a chemically amplified resist composition, while also functioning as a base polymer—a polymer-bonded photoacid generator. Structural features of the polymer include repeating units from sulfonate or monazite salts containing an iodobenzenesulfonic acid anion with an aromatic ring. Iodine atoms, due to their extremely high absorption at 13.5 nm EUV wavelength, generate secondary electrons during exposure. These secondary electrons move to the acid generator, promoting decomposition and thus increasing sensitivity. The iodobenzenesulfonic acid anion enhances the acid strength of sulfonic acids, especially when the meta or para positions of the carbon atoms bonded to the sulfonic acid are replaced by iodine atoms, further increasing acid strength. Specifically, one of the two carbon atoms adjacent to the sulfonic acid atom is not bonded to an iodine atom; therefore, the sulfonic acid is not affected by the electron cloud of the sterically large iodine atom, exhibiting good sensitivity / resolution. The polymers of this invention are particularly suitable as materials for chemically amplified positive resist compositions because they can form excellent line patterns (LWR) and hole patterns (CDU), as well as patterns resistant to pattern collapse.

[0281] When the polymer of the present invention is a positive resist material, it may contain repeating units containing acid-labile groups. The repeating units containing acid-labile groups are preferably 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.).

[0282] [Chemistry 88]

[0283]

[0284] In equations (b1) and (b2), R A Each can be independently a hydrogen atom or a methyl group. Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene, and linking group may also have at least one selected from hydroxyl groups, halogen atoms, saturated hydrocarbon oxygen groups having 1 to 8 carbon atoms, and saturated hydrocarbon carbonyl oxygen groups having 2 to 8 carbon atoms. 2 It is a single bond or an ester bond. Y 3 It is a single bond, an ether bond, or an ester bond. R 11 and R 12 Each is an unstable acid group. R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms. R 14 It is a single bond or an alkane diene having 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxy group having 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxy group having 2 to 8 carbon atoms, ether bond, and ester bond. A is an integer from 0 to 4.

[0285] Specific examples of a single entity providing repeating unit b1 may be listed below, but are not limited to these. Furthermore, in the following formula, R... A and R 11 Same as above.

[0286] [Chemistry 89]

[0287]

[0288] [Chemistry 90]

[0289]

[0290] Specific examples of repeating unit b2 may be provided, but are not limited to, those shown below. Furthermore, in the following formula, R... A and R 12 Same as above.

[0291] [Chemistry 91]

[0292]

[0293] R 11 Or R 12 The acid-unstable group can be represented in various ways, for example, those represented by formulas (AL-1) to (AL-3) can be listed.

[0294] [Chemistry 92]

[0295]

[0296] In the formula, the dashed lines represent atomic bonds.

[0297] In equation (AL-1), b is an integer from 0 to 6. L1 It is a tertiary hydrocarbon group with 4 to 20 carbon atoms, preferably 4 to 15; a trialkylsilyl group where each hydrocarbon group is a saturated hydrocarbon group with 1 to 6 carbon atoms; a saturated hydrocarbon group with 4 to 20 carbon atoms containing a carbonyl group, an ether bond, or an ester bond; or a group represented by formula (AL-3). Furthermore, a tertiary hydrocarbon group refers to a group obtained by removing a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0298] R L1The tertiary hydrocarbon group can be saturated or unsaturated, and can be branched or cyclic. Specific examples include tert-butyl, tert-pentyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. The aforementioned trialkylsilyl group can be trimethylsilyl, triethylsilyl, or dimethyltert-butylsilyl. The aforementioned saturated hydrocarbon groups containing carbonyl, ether, or ester bonds can be linear, branched, or cyclic, with cyclic being preferred. Specific examples include 3-oxocyclohexyl, 4-methyl-2-oxotetrahydropyran-4-yl, 5-methyl-2-oxotetrahydrofuran-5-yl, 2-tetrahydropyranyl, and 2-tetrahydrofuranyl.

[0299] Examples of acid-instable groups represented by formula (AL-1) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-pentyloxycarbonyl, tert-pentyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, and 2-tetrahydrofuranyloxycarbonylmethyl.

[0300] Furthermore, the acid-instable groups represented by formula (AL-1) can also be listed as groups represented by formulas (AL-1)-1 to (AL-1)-10.

[0301] [Chemistry 93]

[0302]

[0303] In the formula, the dashed lines represent atomic bonds.

[0304] In equations (AL-1)-1 to (AL-1)-10, b is the same as described above. R L8 Each is independently a saturated hydrocarbon group with 1 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. R L9 It is a hydrogen atom or a saturated hydrocarbon group with 1 to 10 carbon atoms. R L10 It is a saturated hydrocarbon group with 2 to 10 carbon atoms or an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic.

[0305] In equation (AL-2), R L2 and R L3Each group is independently composed of hydrogen atoms or 1 to 18 carbon atoms, preferably 1 to 10 saturated hydrocarbon groups. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic, and specific examples include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, n-octyl, etc.

[0306] In equation (AL-2), R L4 It may also contain a hydrocarbon group with 1 to 18 carbon atoms, preferably 1 to 10. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Examples of the aforementioned hydrocarbon group include saturated hydrocarbon groups with 1 to 18 carbon atoms, and some of these hydrogen atoms may be replaced by hydroxyl, alkoxy, oxo, amino, alkylamino, etc. Examples of such substituted saturated hydrocarbon groups are shown below.

[0307] [Chemistry 94]

[0308]

[0309] In the formula, the dashed lines represent atomic bonds.

[0310] R L2 and R L3 R L2 and R L4 、or R L3 and R L4 They can also bond to each other and form rings with the carbon atoms they are bonded to, or carbon atoms and oxygen atoms. In this case, R participates in the ring formation. L2 and R L3 R L2 and R L4 、or R L3 and R L4 Each of the atoms is an alkane diester with 1 to 18 carbon atoms, preferably 1 to 10. The ring formed by their bonding preferably has 3 to 10 carbon atoms, more preferably 4 to 10.

[0311] Among the acid-labile groups represented by formula (AL-2), those that are straight-chain or branched can be listed as those represented by formulas (AL-2)-1 to (AL-2)-69, but are not limited to these. Furthermore, in the following formulas, the dashed lines represent atomic bonds.

[0312] [Chem. 95]

[0313]

[0314] [Chemistry 96]

[0315]

[0316] [Chemistry 97]

[0317]

[0318] [Chem. 98]

[0319]

[0320] Among the acid-labile groups represented by formula (AL-2), those that are cyclic include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

[0321] Furthermore, acid-indestructible groups can be represented by groups indicated by formulas (AL-2a) or (AL-2b). Depending on the aforementioned acid-indestructible groups, the base polymer can also undergo intermolecular or intramolecular crosslinking.

[0322] [Chemistry 99]

[0323]

[0324] In the formula, the dashed lines represent atomic bonds.

[0325] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The aforementioned saturated hydrocarbon groups can be straight-chain, branched, or cyclic. Furthermore, R... L11 and R L12 They can also bond to each other and form a ring together with the carbon atoms they bond to. In this case, R L11 and R L12 Each is an independent alkane diol with 1 to 8 carbon atoms. R L13 Each is an independent saturated hydrocarbon group with 1 to 10 carbon atoms. The aforementioned saturated hydrocarbon groups can be straight-chain, branched, or cyclic. c and d are each independent integers from 0 to 10, preferably integers from 0 to 5, and e is an integer from 1 to 7, preferably an integer from 1 to 3.

[0326] In formula (AL-2a) or (AL-2b), L A These are aliphatic saturated hydrocarbon groups with 1 to 50 carbon atoms (e+1), alicyclic saturated hydrocarbon groups with 3 to 50 carbon atoms (e+1), aromatic hydrocarbon groups with 6 to 50 carbon atoms (e+1), or heterocyclic groups with 3 to 50 carbon atoms (e+1). Furthermore, a portion of the -CH2- group can be substituted by a group containing a heteroatom, and a portion of the hydrogen atom in these groups can be substituted by a hydroxyl, carboxyl, acyl, or fluorine atom. A It is preferable to use saturated hydrocarbon groups with 1-20 carbon atoms, such as saturated hydrocarbon groups with trivalent or tetravalent carbon atoms, or aryl groups with 6-30 carbon atoms. The aforementioned saturated hydrocarbon groups can be linear, branched, or cyclic. BIt is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0327] The cross-linked acetal group represented by formula (AL-2a) or (AL-2b) can be exemplified by groups represented by formulas (AL-2)-70 to (AL-2)-77.

[0328] [Chemistry 100]

[0329]

[0330] In the formula, the dashed lines represent atomic bonds.

[0331] In equation (AL-3), R L5 It is a hydrogen atom or a hydrocarbon group with 1 to 20 carbon atoms. This hydrocarbon group may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. R L6 and R L7 Each group is an independent hydrocarbon group with 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. These hydrocarbon groups can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 20 carbon atoms, cyclic saturated hydrocarbon groups with 3 to 20 carbon atoms, alkenyl groups with 2 to 20 carbon atoms, cyclic unsaturated hydrocarbon groups with 3 to 20 carbon atoms, and aryl groups with 6 to 10 carbon atoms. Furthermore, R... L5 and R L6 R L5 and R L7 、or R L6 and R L7 They can also bond to each other and together with the carbon atoms they bond to form alicyclic rings with 3 to 20 carbon atoms.

[0332] Groups represented by formula (AL-3) can include tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornel, 1-methylcyclopentyl, 1-ethylcyclopentyl, 1-isopropylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, tert-pentyl, etc.

[0333] Furthermore, the groups represented by formula (AL-3) can also be represented by the groups represented by formulas (AL-3)-1 to (AL-3)-22.

[0334] [Chemistry 101]

[0335]

[0336] In the formula, the dashed lines represent atomic bonds.

[0337] In equations (AL-3)-1 to (AL-3)-22, R L14Each is independently a hydrogen atom, an aliphatic hydrocarbon group with 1 to 8 carbon atoms, or an aryl group with 6 to 20 carbon atoms. L15 and R L17 Each is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. R L16 It is an aryl group with 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group can be straight-chain, branched, or cyclic. Furthermore, the aforementioned aryl group is preferably phenyl, etc. R L18 It is a fluorine atom, an iodine atom, a nitro group, or a trifluoromethyl group. R L19 Each of the following groups can be independently represented by a hydrogen atom, a fluorine atom, an iodine atom, a nitro group, a saturated hydrocarbon group with 1 to 8 carbon atoms, or a hydrocarbon oxygen group with 1 to 8 carbon atoms. F is an integer from 1 to 5.

[0338] Furthermore, acid-indestructible groups can be represented by groups with the following formulas (AL-3)-23 or (AL-3)-24. Depending on the aforementioned acid-indestructible groups, the polymer can also undergo intramolecular or intermolecular crosslinking.

[0339] [Chemistry 102]

[0340]

[0341] In the formula, the dashed lines represent atomic bonds.

[0342] In equations (AL-3)-23 and (AL-3)-24, R L14 Same as above. R L20 It is a (g+1) valent saturated or unsaturated alkylene group with 1 to 20 carbon atoms or a (g+1) valent arylene group with 6 to 20 carbon atoms, and may also contain heteroatoms such as oxygen, sulfur, and nitrogen atoms. The aforementioned saturated or unsaturated alkylene groups can be straight-chain, branched, or cyclic. G is an integer from 1 to 3.

[0343] In addition to these acid-labile groups, acid-labile groups containing aromatic groups as described in Japanese Patent Nos. 5565293, 5434983, 5407941, 5655756 and 5655755 may also be used.

[0344] The aforementioned polymer may also contain repeating unit c, which includes a phenolic hydroxyl group as a binding group. Specific examples of monomers providing repeating unit c are shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0345] [Chemistry 103]

[0346]

[0347] The aforementioned polymer may also contain repeating units d, other than phenolic hydroxyl groups, lactone rings, sulfonyl rings, ether bonds, ester bonds, sulfonate bonds, carbonyl groups, sulfonyl groups, cyano groups, or carboxyl groups. Specific examples of monomers providing repeating units d are shown below, but are not limited to these. Furthermore, in the following formula, R... A Same as above.

[0348] [Chemistry 104]

[0349]

[0350] [Chemistry 105]

[0351]

[0352] [Chemistry 106]

[0353]

[0354] [Chemistry 107]

[0355]

[0356] [Chemistry 108]

[0357]

[0358] [Chemistry 109]

[0359]

[0360] [Chemical 110]

[0361]

[0362] [Chemistry 111]

[0363]

[0364] The aforementioned polymer may also contain repeating unit e derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, northodiene, or derivatives thereof. Specific examples of monomers providing repeating unit e may be listed below, but are not limited to these.

[0365] [Chemistry 112]

[0366]

[0367] The aforementioned polymer may also contain repeating units f derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methylene dihydroindene, vinylpyridine, or vinylcarbazole.

[0368] In the polymer of the present invention, the content ratios of the repeating units a, b1, b2, c, d, e, and f are preferably 0<a≤0.4, 0<b1≤0.8, 0≤b2≤0.8, 0<c≤0.6, 0≤d≤0.6, 0≤e≤0.3, and 0≤f≤0.3, more preferably 0<a≤0.3, 0<b1≤0.7, 0≤b2≤0.7, 0<c≤0.5, 0≤d≤0.5, 0≤e≤0.2, and 0≤f≤0.2. However, a+b1+b2+c+d+e+f≤1.0.

[0369] When used as a base polymer for a positive resist material, the polymer of the present invention needs to have the repeating unit b1 or b2 containing an acid-labile group in addition to the repeating unit a. At this time, the content ratios of the repeating units a, b1, b2, c, d, e and f are preferably 0<a≤0.5, 0≤b1<1.0, 0≤b2<1.0, 0<b1+b2<1.0, 0≤c≤0.9, 0≤d≤0.9, 0≤e≤0.8 and 0≤f≤0.8, more preferably 0.02≤a≤0.4, 0≤b1≤0.9, 0≤b2≤0.9, 0.1≤b1+b2≤0.9, 0≤c≤0.8, 0≤d≤0.8, 0≤e≤0.7, 0≤f≤0.7, still more preferably 0.05≤a≤0.35, 0≤b1≤0.8, 0≤b2≤0.8, 0.1≤b1+b2≤0.8, 0≤c≤0.75, 0≤d≤0.75, 0≤e≤0.6 and 0≤f≤0.6. Further, a+b1+b2+c+d+e+f=1.0.

[0370] On the other hand, when used as a base polymer for a negative resist material, an acid-labile group is not necessarily required. Examples of such a base polymer include those containing the repeating unit c in addition to the repeating unit a, and optionally further containing the repeating units d, e and / or f as needed. The content ratios of these repeating units are preferably 0<a≤0.5, 0<c≤1.0, 0≤d≤0.9, 0≤e≤0.8 and 0≤f≤0.8, more preferably 0.02≤a≤0.4, 0.2≤c≤1.0, 0≤d≤0.8, 0≤e≤0.7 and 0≤f≤0.7, still more preferably 0.05≤a≤0.35, 0.3≤c≤1.0, 0≤d≤0.75, 0≤e≤0.6 and 0≤f≤0.6. Further, a+c+d+e+f=1.0.

[0371] To synthesize the aforementioned base polymer, for example, the monomers that provide the aforementioned repeating units may be polymerized by adding a radical polymerization initiator in an organic solvent and heating.

[0372] Examples of organic solvents used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2-azobis(2-methylpropionic acid), benzoyl peroxide, and lauroyl peroxide. The polymerization temperature is preferably 50–80°C. The reaction time is preferably 2–100 hours, more preferably 5–20 hours.

[0373] When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups can be replaced with acetal groups such as ethoxy-ethoxy, which are easily deprotected by acids, before polymerization. After polymerization, deprotection can be carried out using weak acids and water. Alternatively, acetyl, formyl, neopentyl, etc., can be replaced before polymerization, followed by alkaline hydrolysis.

[0374] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene can be used instead of hydroxystyrene and hydroxyvinylnaphthalene. After polymerization, the aforementioned alkaline hydrolysis is used to deprotect the acetoxy group to obtain hydroxystyrene and hydroxyvinylnaphthalene.

[0375] The alkali used in alkaline hydrolysis can be ammonia, triethylamine, etc. The reaction temperature should preferably be -20 to 100°C, more preferably 0 to 60°C. The reaction time should preferably be 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0376] For the aforementioned polymers, the converted weight-average molecular weight (Mw) of polystyrene obtained by gel permeation chromatography (GPC) using THF or DMF as solvents is preferably 1,000 to 500,000, more preferably 2,000 to 30,000, and even more preferably 5,000 to 20,000. If Mw is within the aforementioned range, the resist film exhibits good heat resistance and solubility in alkaline developing solutions. GPC determination is typically performed at room temperature around 23 degrees Celsius, but can also be performed at higher or lower temperatures.

[0377] Furthermore, when the aforementioned polymer has a wide molecular weight distribution (Mw / Mn), the presence of both low and high molecular weight polymers raises concerns about the observation of foreign matter and deterioration of the pattern shape after exposure. As the pattern becomes more regular and refined, the influence of Mw and Mw / Mn tends to increase. Therefore, in order to obtain a resist material suitable for fine pattern sizes, the aforementioned polymer has a narrow dispersion of Mw / Mn of 1.0 to 2.0, preferably 1.0 to 1.5.

[0378] The aforementioned polymer may also include two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0379] [Chemical amplification resist composition]

[0380] Furthermore, the present invention provides a chemically amplified resist composition containing the aforementioned polymer as a base polymer. The proportion of the base polymer in the composition is not particularly limited; for example, it may be 0.1 to 10 parts by mass relative to 100 parts by mass of the composition, preferably 1 to 5 parts by mass. Hereinafter, components other than the base polymer contained in the chemically amplified resist composition of the present invention will be described.

[0381] [Organic solvents]

[0382] The chemically amplified resist composition of the present invention may also contain organic solvents. There are no particular limitations on the organic solvent if it can dissolve the aforementioned components and the components described below. Specific examples of the aforementioned organic solvents include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 2-heptanone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, 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; and lactones such as γ-butyrolactone.

[0383] In the chemically amplified resist composition of the present invention, the content of the aforementioned organic solvent is preferably 100 to 10,000 parts by weight relative to 100 parts by weight of the base polymer, and more preferably 200 to 8,000 parts by weight. The aforementioned organic solvent may be used alone or in combination with two or more other solvents.

[0384] [Quenching Agent]

[0385] The chemically amplified resist composition of the present invention may also include a quencher, depending on the need. In this invention, a quencher refers to a compound that can prevent diffusion toward unexposed areas by capturing the acid generated by the photoacid generator.

[0386] Specific examples of the aforementioned quenching agents include amine compounds, sulfonates, or carboxylates. The aforementioned amine compounds are first-, second-, or third-order amine compounds as described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103, and amine compounds having any one of the following: hydroxyl group, ether bond, ester bond, lactone ring, cyano group, or sulfonate bond are particularly preferred. Furthermore, compounds as described in Japanese Patent No. 3790649, where the first- or second-order amine is protected with a carbamate group, are also preferred. Such protected amine compounds are effective when the resist composition contains components that are unstable to alkalis.

[0387] Specific examples of the aforementioned sulfonates include compounds represented by formula (E1). Similarly, specific examples of the aforementioned carboxylates include compounds represented by formula (E2).

[0388] [Chemistry 113]

[0389]

[0390] In equation (E1), R 31 It is a hydrocarbon group with 1 to 40 carbon atoms, which may also contain heteroatoms, but excludes the hydrogen atom at the α-position of the sulfonic acid group that is substituted with a fluorine atom or a fluorinated alkyl group.

[0391] R 31 The hydrocarbon group represented has 1 to 40 carbon atoms and can be saturated or unsaturated, and can be straight-chain, branched, or cyclic. Specific examples include alkyl groups with 1 to 40 carbon atoms such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornel, and tricyclic [5.2.1.0]. 2,6 [Cyclic saturated hydrocarbon groups with 3-40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups with 2-40 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; unsaturated aliphatic cyclic hydrocarbon groups with 3-40 carbon atoms, such as cyclohexenyl; aryl groups with 6-40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), dialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), and dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); and aralkyl groups with 7-40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl.]

[0392] Furthermore, some or all of the hydrogen atoms in the aforementioned 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- group in the aforementioned hydrocarbon group can also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it can also contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc. Hydrocarbon groups containing heteroatoms can include heteroaryl groups such as thiophene; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; and aryloxoalkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0393] R 32 It can also contain hydrocarbon groups with 1 to 40 carbon atoms, including heteroatoms. R 32 The hydrocarbon group represented can be listed in relation to R. 31 The hydrocarbon group represented is the same as that shown. In addition, other specific examples may also be listed as fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0394] Specific examples of sulfonate anions represented by formula (E1) are shown below, but are not limited to these.

[0395] [Chemistry 114]

[0396]

[0397] [Chemistry 115]

[0398]

[0399] Specific examples of the anions of carboxylate salts represented by formula (E2) are shown below, but are not limited to these.

[0400] [Chemistry 116]

[0401]

[0402] [Chemistry 117]

[0403]

[0404] [Chemistry 118]

[0405]

[0406] [Chemistry 119]

[0407]

[0408] [Chemistry 120]

[0409]

[0410] In equations (E1) and (E2), Mq + It is an onium cation. Examples of onium cations include sulfonium cations, monium cations, and ammonium cations. It is preferred that the sulfonium cation be represented by formula (Z-1), and specific examples can be given that are the same as those exemplified in the specific examples of sulfonium cations represented by formula (Z-1). It is preferred that the monium cation be represented by formula (Z-2), and specific examples can be given that are the same as those exemplified in the specific examples of monium cations represented by formula (Z-2).

[0411] Other examples of the aforementioned quenchers include the polymeric quencher described in Japanese Patent Application Publication No. 2008-239918. This quencher improves the rectangularity of the resist pattern by aligning with the resist surface. It also prevents film reduction and dome-shaped formation of the pattern when the polymeric quencher is used to wet a protective film for exposure.

[0412] Furthermore, the quenching agent may be an onium salt having a sulfonium cation and a benzene oxide anion site within the same molecule as described in Japanese Patent No. 6848776, or further may be an onium salt having a sulfonium cation and a carboxylate anion site within the same molecule as described in Japanese Patent No. 6583136, Japanese Patent Application Publication No. 2020-200311, or an onium salt having a monazine cation and a carboxylate anion site within the same molecule as described in Japanese Patent No. 6274755.

[0413] When the chemically amplified resist composition of the present invention includes a quencher, its content is preferably 0.001 to 12 parts by mass relative to 80 parts by mass of the base polymer, and more preferably 0.01 to 8 parts by mass. By incorporating a quencher, not only is it easier to adjust the sensitivity of the resist film, but the diffusion of acid in the resist film is also suppressed, thereby improving resolution, suppressing sensitivity changes after exposure, reducing substrate and environmental dependence, or improving exposure margin, pattern outline, etc. Furthermore, the addition of the aforementioned quencher can also improve substrate adhesion. The quencher can be used alone or in combination of two or more.

[0414] [Other ingredients]

[0415] In addition to the aforementioned components, it may also include acid generating agents, surfactants, anti-solubilizing agents, crosslinking agents, water-repellent enhancing agents, acetylene alcohols, etc.

[0416] The aforementioned acid-generating agents can include compounds that generate acid in response to active light or radiation (photoacid generators). The components of the photoacid generator can be any compound that generates acid upon irradiation with high-energy rays; acid generators that generate sulfonic acid, imine acid, or methyl acid are preferred. Specific examples of preferred photoacid generators include sulfonium salts, sulfonyl diazomethanes, N-sulfonyloxyimide, and oxime-O-sulfonate type acid generators. Specific examples of the aforementioned acid generators can be cited in paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, Japanese Patent Application Publication No. 2018-5224, and Japanese Patent Application Publication No. 2018-25789. When the chemically amplified resist composition of the present invention contains an acid generator, its content is preferably 0 to 200 parts by weight, and preferably 0.1 to 100 parts by weight, relative to 100 parts by weight of the base polymer.

[0417] Specific examples of the aforementioned surfactants can be found in paragraphs

[0165] to

[0166] of Japanese Patent Application Publication No. 2008-111103. By adding surfactants, the coatability of the chemically amplified resist composition can be further improved or controlled. When the chemically amplified resist composition of the present invention contains a surfactant, its content is preferably 0.0001 to 10 parts by weight relative to 100 parts by weight of the base polymer. The aforementioned surfactants can be used alone or in combination of two or more.

[0418] When the chemically amplified resist composition of the present invention is positive, by incorporating an anti-dissolution agent, the difference in dissolution rate between the exposed and unexposed areas can be further amplified, thereby further improving the resolution. Specific examples of the aforementioned anti-dissolution agent 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-instable groups at a ratio of 0 to 100 mol% of the total, or compounds in which the hydrogen atoms of the carboxyl groups of a compound containing carboxyl groups are replaced by acid-instable groups at an average ratio of 50 to 100 mol% of the total. 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-instable groups, for example, paragraphs

[0155] to

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

[0419] When the chemically amplified resist composition of the present invention is positive and contains the aforementioned solvent resist, its content relative to 100 parts by weight of the base polymer is preferably 0 to 50 parts by weight, and more preferably 5 to 40 parts by weight. The aforementioned solvent resist can be used alone or in combination of two or more.

[0420] On the other hand, when the chemically amplified resist composition of the present invention is negative, a negative pattern can also be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Specific examples of the aforementioned crosslinking agents include epoxy compounds, melamine compounds, guanidine compounds, glycourea compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing alkenyloxy groups or other double bonds, which are formed by substituting groups selected from at least one of hydroxymethyl, alkoxymethyl, and acyloxymethyl groups. These can be used as additives or introduced as dangling groups into the polymer side chains. Furthermore, hydroxyl-containing compounds can also be used as crosslinking agents.

[0421] Specific examples of the aforementioned epoxy compounds include tris(2,3-epoxypropyl)isocyanurate, trimethylolpropane trioxypropyl ether, trimethylolpropane trioxypropyl ether, and triethylolethane trioxypropyl ether.

[0422] Specific examples of the aforementioned melamine compounds include hexahydroxymethyl melamine, hexamethoxymethyl melamine, compounds formed by methoxymethylation of 1 to 6 hydroxymethyl groups of hexahydroxymethyl melamine, or mixtures thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, compounds formed by acyloxymethylation of 1 to 6 hydroxymethyl groups of hexahydroxymethyl melamine, or mixtures thereof.

[0423] Specific examples of the aforementioned guanidine compounds include tetrahydroxymethylguanidine, tetramethoxymethylguanidine, compounds formed by methoxymethylation of 1 to 4 hydroxymethyl groups of tetrahydroxymethylguanidine or mixtures thereof, tetramethoxyethylguanidine, tetraacyloxyguanidine, compounds formed by acyloxymethylation of 1 to 4 hydroxymethyl groups of tetrahydroxymethylguanidine or mixtures thereof, etc.

[0424] Specific examples of the aforementioned urea compounds include tetrahydroxymethylurea, tetramethoxymethylurea, tetramethoxymethylurea, compounds formed by methoxymethylation of 1 to 4 hydroxymethyl groups of tetrahydroxymethylurea, or mixtures thereof, compounds formed by acylmethylation of 1 to 4 hydroxymethyl groups of tetrahydroxymethylurea, or mixtures thereof. Specific examples of the aforementioned urea compounds include tetrahydroxymethylurea, tetramethoxymethylurea, compounds formed by methoxymethylation of 1 to 4 hydroxymethyl groups of tetrahydroxymethylurea, or mixtures thereof, tetramethoxyethylurea, etc.

[0425] Specific examples of the aforementioned isocyanate compounds include toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0426] Specific examples of the aforementioned azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylene bisazide, and 4,4'-oxy bisazide.

[0427] Specific examples of the aforementioned compounds containing alkenyloxy groups include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, neopentyl tetraethylene ether, neopentyl tetraethylene ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0428] The chemically amplified resist composition of the present invention is negative, and when it contains the aforementioned crosslinking agent, its content relative to 100 parts by weight of the base polymer is preferably 0.1 to 50 parts by weight, and more preferably 1 to 40 parts by weight. The aforementioned crosslinking agent can be used alone or in combination of two or more.

[0429] The aforementioned water-repellent enhancer improves the water repellency of the resist film surface and can be used in immersion lithography without a surface coating. The aforementioned water-repellent enhancer is preferably a polymer containing fluorinated alkyl groups, or a polymer with a specific structure containing 1,1,1,3,3,3-hexafluoro-2-propanol residues, as exemplified in Japanese Patent Application Publication Nos. 2007-297590 and 2008-111103. The aforementioned water-repellent enhancer needs to be soluble in alkaline or organic solvent developing solutions. The aforementioned specific water-repellent enhancer containing 1,1,1,3,3,3-hexafluoro-2-propanol residues exhibits good solubility in developing solutions. Regarding water-repellent enhancers, polymers containing repeating units including amino and ammonium salts are highly effective in preventing the evaporation of acid in PEB and in preventing poor opening of the hole pattern after development. When the chemically amplified resist composition of the present invention includes the aforementioned water-repellent enhancing agent, its content relative to 100 parts by weight of the base polymer is preferably 0 to 20 parts by weight, and more preferably 0.5 to 10 parts by weight. The aforementioned water-repellent enhancing agent can be used alone or in combination of two or more.

[0430] Specific examples of the aforementioned acetylenic alcohols can be found in paragraphs

[0179] to

[0182] of Japanese Patent Application Publication No. 2008-122932. When the chemically amplified resist composition of the present invention contains the aforementioned acetylenic alcohols, their content relative to 100 parts by weight of the base polymer is preferably 0 to 5 parts by weight. The aforementioned acetylenic alcohols can be used alone or in combination of two or more.

[0431] [Pattern Formation Method]

[0432] When using the chemically amplified resist composition of the present invention in the manufacture of various integrated circuits, known photolithography techniques can be employed. For example, a patterning method may include the steps of forming a resist film on a substrate using the aforementioned chemically amplified resist composition, exposing the aforementioned resist film to high-energy radiation, and developing the exposed resist film using a developer.

[0433] First, the chemically amplified resist composition of the present invention is applied to 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, etc.) using a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating, to achieve a coating thickness preferably of 0.01~2μm. The substrate is then placed on a hot plate and pre-baked, preferably at 60~150°C for 10 seconds~30 minutes, more preferably at 80~120°C for 30 seconds~20 minutes, to form a resist film.

[0434] Then, the aforementioned photoresist film is exposed using high-energy radiation. Specific examples of such high-energy radiation include ultraviolet light, far ultraviolet light, EB (electron beam), EUV (extreme ultraviolet light) with wavelengths of 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 as high-energy radiation, the exposure dose is preferably about 1-200 mJ / cm², either directly or using a mask specifically designed for forming the target pattern. 2 The optimal value is approximately 10~100 mJ / cm³. 2 Irradiation is performed in a manner that, when using EB as a high-energy ray, the optimal exposure dose is approximately 0.1~300 μC / cm. 2 The optimal value is approximately 0.5~200 μC / cm. 2The pattern can be drawn directly or using a mask designed to form the target pattern. Furthermore, the chemically amplified resist composition of the present invention is particularly suitable for fine patterning under high-energy radiation, including mid-wavelength KrF excimer lasers (248 nm), 193 nm ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, especially for EB or EUV.

[0435] After exposure, PEB can also be performed on a heating plate or in an oven, preferably at 30~150℃ for 10 seconds~30 minutes, more preferably at 50~120℃ for 30 seconds~20 minutes, or it can be omitted.

[0436] After exposure or PEB, the exposed resist film is developed using a developer solution containing 0.1-10% by mass, preferably 2-5% by mass, of an alkaline aqueous solution such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, or tetrabutylammonium hydroxide, via conventional methods such as dip, immersion, or spraying for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, thereby forming the target pattern. In the case of positive resist materials, the exposed areas dissolve in the developer solution, while the unexposed areas do not dissolve, thus forming the target positive pattern on the substrate. In the case of negative resist materials, the opposite is true: the exposed areas do not dissolve in the developer solution, while the unexposed areas dissolve.

[0437] Negative patterns can also be obtained by developing a positive resist material containing a base polymer with acid-inhibitory groups using organic solvents. 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, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl valerate, methyl crotonate, croton... Ethyl propionate, 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 phenyl acetate, 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.

[0438] At the end of development, rinsing is performed. For the rinsing solution, a solvent that is miscible with the developer but will not dissolve the resist film is preferred. Such solvents are preferably alcohols with 3-10 carbon atoms, ether compounds with 8-12 carbon atoms, alkanes with 6-12 carbon atoms, alkenes, alkynes, or aromatic solvents.

[0439] 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, and 1-octanol.

[0440] Specific examples of the aforementioned ether compounds with 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.

[0441] Specific examples of alkanes with 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 with 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, and cyclooctene. Specific examples of alkynes with 6 to 12 carbon atoms include hexyne, heptyne, and octyne.

[0442] Specific examples of the aforementioned aromatic solvents include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, and mesitylene.

[0443] Rinsing can reduce the collapse of the resist pattern and the formation of defects. However, rinsing is not always necessary, and omitting it can reduce the amount of solvent used.

[0444] Alternatively, the developed hole and groove patterns can be shrunk using heat flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern. During baking, the acid catalyst from the resist film diffuses, causing the shrinking agent to cross-link on the surface of the resist film, and the shrinking agent adheres to the sidewalls of the hole pattern. The baking temperature is preferably 70~180℃, more preferably 80~170℃, and the baking time is preferably 10~300 seconds to remove excess shrinking agent and shrink the hole pattern.

[0445] Example

[0446] 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. The apparatus used is as follows.

[0447] MALDI TOF-MS: S3000 manufactured by Nippon Electronics Co., Ltd.

[0448] [1] Synthesis of onium salt monomers

[0449] [Example 1-1] Synthesis of onium salt monomer a-1

[0450] [Chemistry 121]

[0451]

[0452] (1) Synthesis of intermediate In-1

[0453] Under nitrogen atmosphere, starting materials SM-1 (25.1 g), SM-2 (31.6 g), DMAP (0.75 g), and dichloromethane (300 g) were added to a reaction vessel and cooled in an ice bath. The temperature inside the reaction vessel was maintained below 20°C, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride powder (13.3 g) was added simultaneously. After addition, the temperature was raised to room temperature and allowed to mature for 12 hours. After maturation, water was added to stop the reaction, and a standard aqueous work-up was performed. After distilling off the solvent, diisopropyl ether was added to wash away the residue, thereby obtaining 51.9 g of intermediate In-1 in the form of amber solid (98% yield).

[0454] (2) Synthesis of onium salt monomer a-1

[0455] Under nitrogen atmosphere, intermediate In-1 (51.9 g), starting material SM-3 (23.2 g), dichloromethane (200 g), and water (150 g) were added to a reaction vessel. After stirring for 30 minutes, the organic layer was separated and washed with water, followed by concentration under reduced pressure. The concentrate was purified by silica gel chromatography, and diisopropyl ether was added for recrystallization to obtain 61.0 g of brown crystalline ononium salt monomer a-1 as the target product (yield 89%).

[0456] MALDI TOF-MS:

[0457] POSITIVE M + 461 (equivalent to C) 18 H 10 F4IS + )

[0458] NEGATIVE M - 909 (equivalent to C) 19 H 13 I4O8S - )

[0459] [Examples 1-2~1-8] Synthesis of onium salt monomers a-2~a-8

[0460] Using the corresponding raw materials and known organic synthesis reactions, onium salt monomers a-2 to a-8 represented by the following formulas are synthesized.

[0461] [Chemistry 122]

[0462]

[0463] [Comparative Examples 1-1 to 1-6] Comparison of the synthesis of onium salt monomers Ca-1 to Ca-6

[0464] Using the corresponding raw materials and known organic synthesis reactions, the comparative onium salt monomers ca-1 to ca-6 represented by the following formulas were synthesized.

[0465] [Chemistry 123]

[0466]

[0467] [2] Synthesis of basic polymers

[0468] Among the monomers used in the synthesis of the basic polymer, those other than monomers a-1 to a-8 and comparative monomers ca-1 to ca-6 are as follows.

[0469] [Chemistry 124]

[0470]

[0471] [Chemistry 125]

[0472]

[0473] [Chemistry 126]

[0474]

[0475] [Example 2-1] Synthesis of Polymer P-1

[0476] Under nitrogen atmosphere, monomer-polymerization initiator solution was prepared by taking monomer a-1 (29.7 g), monomer b1-1 (35.6 g), monomer c-1 (10.4 g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals Co., Ltd.) 3.34 g, and MEK 139 g in a flask. In another flask under nitrogen atmosphere, MEK 46 g was taken, heated to 80°C with stirring, and the aforementioned monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was complete, the polymerization solution was maintained at 80°C and stirred for another 2 hours, then cooled to room temperature. The obtained polymerization solution was added dropwise to 3000 g of hexane under vigorous stirring, and the precipitated polymer was filtered. The obtained polymer was washed twice with 600 g of hexane and then vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 68.9 g, 91% yield). The Mw of polymer P-1 is 9200, and the Mw / Mn ratio is 1.73. Furthermore, Mw is a polystyrene conversion value obtained by GPC using DMF as a solvent.

[0477] [Chemistry 127]

[0478]

[0479] [Examples 2-2~2-15, Comparative Examples 2-1~2-12] Synthesis of polymers P-2~P-15 and comparative polymers CP-1~CP-12

[0480] Except for changing the type and blending ratio of each monomer, the polymers shown in Tables 1 and 2 were manufactured using the same method as in Example 2-1.

[0481] [Table 1]

[0482]

[0483] [Table 2]

[0484]

[0485] [3] Preparation of chemically amplified resist composition

[0486] [Examples 3-1 to 3-15, Comparative Examples 3-1 to 3-12]

[0487] A solution was prepared by dissolving predetermined components selected from the basic polymers (P-1 to P-15) of the present invention, the comparative basic polymers (CP-1 to CP-12), the acid generators (PAG-1, PAG-2), and the quenchers (SQ-1 to SQ-3, AQ-1) as shown in Tables 3 and 4 below in a solvent containing 0.01% by mass of 3M FC-4430 as a surfactant. The solution was then filtered through a 0.2 μm Teflon (registered trademark) filter to prepare chemically amplified resist compositions (R-1 to R-15, CR-1 to CR-12).

[0488] [Table 3]

[0489]

[0490] [Table 4]

[0491]

[0492] Tables 3 and 4 list the solvents, quenchers (SQ-1~SQ-3, AQ-1), and acid generators (PAG-1, PAG-2) as follows.

[0493] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[0494] DAA (diacetone alcohol)

[0495] Quenching agents: SQ-1~SQ-3, AQ-1

[0496] [Chemistry 128]

[0497]

[0498] • Acid generating agents: PAG-1, PAG-2

[0499] [Chemistry 129]

[0500]

[0501] [4] Evaluation of EUV lithography (1)

[0502] [Examples 4-1 to 4-15, Comparative Examples 4-1 to 4-12]

[0503] The chemically amplified resist compositions (R-1~R-15, CR-1~CR-12) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask (SHB-A940, 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. A 50 nm thick resist film was prepared by pre-baking at 100°C for 60 seconds using a hot plate. The aforementioned resist film was then subjected to exposure at the exposure edge of an 18 nm size, 36 nm pitch LS pattern on the wafer using an ASML EUV scanning exposure machine NXE3300 (NA 0.33, σ 0.9 / 0.6, dipole illumination). The exposure amount and focal length (exposure amount pitch: 1 mJ / cm) were adjusted. 2 The process involves exposure (focal length and pitch: 0.020 μm), followed by 60 seconds of PEB treatment at the temperatures shown in Tables 5 and 6. Subsequently, a 30-second immersion development with a 2.38% (w / w) TMAH aqueous solution is performed, followed by rinsing with a surfactant-containing rinsing material and rotary drying to obtain a positive pattern.

[0504] The obtained LS patterns were observed using a Hitachi Advanced Technology Co., Ltd. (GAD) CG6300 longitude SEM. Sensitivity, EL, LWR, DOF, and collapse limit were evaluated according to the methods described below. The results are shown in Tables 5 and 6.

[0505] [Sensitivity Evaluation]

[0506] The optimal exposure Eop (mJ / cm) for obtaining an LS pattern with a linewidth of 18nm and a pitch of 36nm was determined. 2 This value is defined as sensitivity. The smaller the value, the higher the sensitivity.

[0507] [EL Review]

[0508] The exposure amount within ±10% (16.2~19.8nm) of the aforementioned LS pattern, formed at a spacing of 18nm, is used to calculate the EL (unit: %) using the following formula. The larger this value, the better the performance.

[0509] EL(%) = (|E1-E2| / Eop) × 100

[0510] E1: Provides optimal exposure for LS patterns with a linewidth of 16.2nm and a pitch of 36nm.

[0511] E2: Provides optimal exposure for LS patterns with a linewidth of 19.8nm and a pitch of 36nm.

[0512] Eop: Provides optimal exposure for LS patterns with a linewidth of 18nm and a pitch of 36nm.

[0513] [LWR Evaluation]

[0514] The dimensions of the LS pattern obtained by Eop irradiation were measured at 10 points along the length of the line. The standard deviation (σ) of the results was calculated as three times the value (3σ) as the LWR. The smaller this value, the smaller the roughness and the more uniform the linewidth of the pattern.

[0515] [DOF Rating]

[0516] In terms of depth of focus evaluation, the focal length range within ±10% (16.2~19.8nm) of the 18nm size formed in the aforementioned LS pattern is obtained. The larger this value, the wider the depth of focus.

[0517] [Collapse Limit Assessment of Line Patterns]

[0518] The line dimensions of the aforementioned LS pattern at various exposures at the optimal focal length were measured along the length at 10 points. The finest line dimension obtained without collapse was defined as the collapse limit dimension. The smaller this value, the better the collapse limit.

[0519] [Table 5]

[0520]

[0521] [Table 6]

[0522]

[0523] As shown in Tables 5 and 6, the chemically amplified resist composition using a base polymer containing repeating units from the onium salt monomer of the present invention exhibits good sensitivity, with excellent EL, LWR, and DOF. Furthermore, a low collapse limit value was confirmed, demonstrating resistance to pattern collapse even during fine pattern formation. Therefore, the chemically amplified resist composition of the present invention is suitable as a material for EUV lithography. On the other hand, comparative examples using onium salt monomers with structures different from those of the onium salt monomer of the present invention in terms of the anion portion failed to obtain good lithographic properties.

[0524] [5] Evaluation of EUV lithography (2)

[0525] [Examples 5-1 to 5-15, Comparative Examples 5-1 to 5-12]

[0526] The chemically amplified resist compositions (R-1~R-15, CR-1~CR-12) shown in Tables 3 and 4 were spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-coated hard mask (SHB-A940, 43% by mass) manufactured by Shin-Etsu Chemical Industry Co., Ltd. A 50 nm thick resist film was prepared by pre-baking at 105°C for 60 seconds using a heated plate. Exposure was performed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, 46 nm pitch, +20% tolerance hole pattern mask on wafer). PEB was performed for 60 seconds using a heated plate at the temperatures described in Tables 7 and 8, followed by 30 seconds of development with a 2.38% by mass TMAH aqueous solution to form a 23 nm hole pattern.

[0527] Using a Hitachi Advanced Technologies (AG) CG6300 length-measuring SEM, the exposure was measured when the hole size was 23 nm, and this was defined as the sensitivity. Furthermore, the size of 50 holes at this point was measured, and three times the standard deviation (σ) calculated from this result (3σ) was defined as the size deviation (CDU). The results are shown in Tables 7 and 8.

[0528] [Table 7]

[0529]

[0530] [Table 8]

[0531]

[0532] The results shown in Tables 7 and 8 confirm that the chemically amplified resist composition of the present invention exhibits good sensitivity and excellent CDU. On the other hand, comparative examples using onion salt monomers with structures different in the anion portion from those of the present invention could not achieve good photolithographic properties.

[0533] This specification includes the following inventions.

[0534] [1]: An onium salt monomer, characterized by the following formula (A);

[0535] [Chemistry 130]

[0536]

[0537] In the formula, m4 is an integer of 0 or 1; m5 is an integer of 2 or 3 when m4 is 0, and an integer of 2, 3, 4 or 5 when m4 is 1; m6 is an integer of 0, 1 or 2 when m4 is 0, and an integer of 0, 1, 2, 3 or 4 when m4 is 1; however, when m4 is 0, then 2≤m5+m6≤4, and when m4 is 1, then 2≤m5+m6≤6;

[0538] RA It is a hydrogen atom or a methyl group;

[0539] R 2 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m6 is 2 or more, 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 bond to; however, this is not the case with sulfonic acid "SO3". - "Among the two adjacent carbon atoms of the substituted carbon atom, neither of them is bonded to an iodine atom."

[0540] L A L B and L C Each group is independently a single bond, ester group, ether group, amide group, sulfonate group, or a straight-chain, branched, or cyclic alkylene group having 1 to 12 carbon atoms. The alkylene group may also contain one or more groups selected from ester group, ether group, amide group, and sulfonate group.

[0541] X L1 It is a single bond, or may contain a heteroatom and consist of 1 to 40 carbon atoms in a hydrocarbon group;

[0542] W is a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may also have at least one selected from oxygen, nitrogen, sulfur and halogen atoms;

[0543] Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2);

[0544] [Chemistry 131]

[0545]

[0546] In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; and R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they bond to.

[0547] [2]: The onium salt monomers as described in [1] above are represented by the following formula (A1);

[0548] [Chemistry 132]

[0549]

[0550] In the formula, m1 is an integer of 0 or 1; m2 is an integer of 0, 1, 2 or 3 when m1 is 0, and an integer of 0, 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, then 0 ≤ m2 + m3 ≤ 4, and when m1 is 1, then 0 ≤ m2 + m3 ≤ 6;

[0551] R 1 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m3 is 2 or more, 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 bond to;

[0552] m4~m6、R A R 2 X L1 L A L B L C and Z + Same as above.

[0553] [3]: The onium salt monomers as described in [2] above are represented by the following formula (A2);

[0554] [Chemistry 133]

[0555]

[0556] In the formula, m1~m3, m6, R A R 1 R 2 X L1 L A L B L C and Z + Same as above.

[0557] [4]: A monomeric photoacid generator, characterized in that it is composed of an onium salt monomer as described in any of [1] to [3] above.

[0558] [5]: A polymer characterized by comprising repeating units from a monomeric photoacid generator as described above [4].

[0559] [6]: The polymer as described in [5] above, wherein the polymer further comprises repeating units represented by formula (b1) or (b2);

[0560] [Chemistry 134]

[0561]

[0562] In the formula, R A Each can be independently a hydrogen atom or a methyl group;

[0563] Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the following: a hydroxyl group, a halogen atom, a saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms.

[0564] Y 2 It is a single bond or an ester bond;

[0565] Y 3 It is a single bond, an ether bond, or an ester bond;

[0566] R 11 and R 12 Each is an unstable acid group;

[0567] R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms;

[0568] R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxy group with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxy group with 2 to 8 carbon atoms, ether bond and ester bond;

[0569] A is an integer between 0 and 4.

[0570] [7]: A chemically amplified resist composition characterized by comprising a polymer as described in [5] or [6] above as a base polymer.

[0571] [8]: The chemically amplified resist composition as described in [7] above also includes at least one selected from organic solvents, quenchers, acid generators, surfactants, and solvent inhibitors.

[0572] [9]: A method for forming a pattern, characterized by comprising the following steps:

[0573] A resist film is formed on a substrate using a chemically amplified resist composition as described in [7] or [8] above, the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer.

[0574]

[10] : The pattern forming method described above [9], 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 3~15 nm.

[0575] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any embodiment having a substantially identical structure to the technical concept described in the claims of the present invention and achieving the same effect is covered within the technical scope of the present invention.

Claims

1. A onium salt monomer, characterized by the following formula (A); In the formula, m4 is an integer of 0 or 1; m5 is an integer of 2 or 3 when m4 is 0, and an integer of 2, 3, 4 or 5 when m4 is 1; m6 is an integer of 0, 1 or 2 when m4 is 0, and an integer of 0, 1, 2, 3 or 4 when m4 is 1; however, when m4 is 0, then 2≤m5+m6≤4, and when m4 is 1, then 2≤m5+m6≤6; R A It is a hydrogen atom or a methyl group; R 2 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m6 is 2 or more, 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 bond to; however, this is not the case with sulfonic acid "SO3". - "Among the two adjacent carbon atoms of the substituted carbon atom, neither of them is bonded to an iodine atom." L A L B and L C Each group is independently a single bond, ester group, ether group, amide group, sulfonate group, or a straight-chain, branched, or cyclic alkylene group having 1 to 12 carbon atoms. The alkylene group may also contain one or more groups selected from ester group, ether group, amide group, and sulfonate group. X L1 It is a single bond, or may contain a heteroatom and consist of 1 to 40 carbon atoms in a hydrocarbon group; W is a single bond or a hydrocarbon group having 1 to 30 carbon atoms, and the hydrocarbon group may also have at least one selected from oxygen, nitrogen, sulfur and halogen atoms; Z + It is a sulfonium cation represented by formula (Z-1) or a monazine cation represented by formula (Z-2); In the formula, R ct1 ~R ct5 Each is an independent hydrocarbon group with 1 to 30 carbon atoms, which may also contain heteroatoms; and R ct1 and R ct2 They can also bond to each other and form rings together with the sulfur atoms they bond to.

2. The onium salt monomer according to claim 1 is represented by the following formula (A1); In the formula, m1 is an integer of 0 or 1; m2 is an integer of 0, 1, 2 or 3 when m1 is 0, and an integer of 0, 1, 2, 3, 4 or 5 when m1 is 1; m3 is an integer of 0, 1, 2, 3 or 4 when m1 is 0, and an integer of 0, 1, 2, 3, 4, 5 or 6 when m1 is 1; however, when m1 is 0, then 0 ≤ m2 + m3 ≤ 4, and when m1 is 1, then 0 ≤ m2 + m3 ≤ 6; R 1 It can be a halogen atom other than an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon 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; when m3 is 2 or more, 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 bond to; m4~m6、R A R 2 X L1 L A L B L C and Z + Same as above.

3. The onium salt monomer according to claim 2 is represented by the following formula (A2); In the formula, m1~m3, m6, R A R 1 R 2 X L1 L A L B L C and Z + Same as above.

4. A monomeric photoacid generator, characterized by being composed of... It is composed of an onium salt monomer according to any one of claims 1 to 3.

5. A polymer characterized by comprising repeating units from the monomeric photoacid generator according to claim 4.

6. The polymer according to claim 5, wherein, The polymer also contains repeating units represented by formula (b1) or (b2); In the formula, R A Each can be independently a hydrogen atom or a methyl group; Y 1 It is a single bond, a phenylene or naphthylene group, or a linking group having 1 to 12 carbon atoms selected from ester bonds, ether bonds, and lactone rings. The phenylene, naphthylene group, and the linking group may also have at least one of the following: a hydroxyl group, a halogen atom, a saturated hydrocarbon oxygen group having 1 to 8 carbon atoms, and a saturated hydrocarbon carbonyl oxygen group having 2 to 8 carbon atoms. Y 2 It is a single bond or an ester bond; Y 3 It is a single bond, an ether bond, or an ester bond; R 11 and R 12 Each is an independent acid-labile group; R 13 It is a saturated hydrocarbon group with 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbon carbonyl group with 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbon oxycarbonyl group with 2 to 5 carbon atoms; R 14 It is a single bond or an alkane diene with 1 to 6 carbon atoms, and the alkane diene may also contain at least one selected from hydroxyl, saturated hydrocarbon oxy group with 1 to 8 carbon atoms, saturated hydrocarbon carbonyl oxy group with 2 to 8 carbon atoms, ether bond and ester bond; A is an integer between 0 and 4.

7. A chemically amplified resist composition, characterized in that it comprises the polymer according to claim 6 as a base polymer.

8. The chemically amplified resist composition according to claim 7 further comprises at least one selected from organic solvents, quenchers, acid generators, surfactants, and solvent inhibitors.

9. A method for forming a pattern, characterized by comprising the following steps: A resist film is formed on a substrate using the chemically amplified resist composition according to claim 7, the resist film is exposed to high-energy rays, and the exposed resist film is developed using a developer.

10. The pattern forming method according to claim 9, 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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