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

Abstract

The invention relates to an onium salt type monomer, a polymer, a chemically amplified resist composition and a pattern forming method. The present invention addresses the problem of providing: an onium salt-type monomer used in a chemically amplified resist composition which has excellent solvent solubility, high sensitivity, high contrast, excellent lithography performance such as exposure margin (EL), LWR, CDU, and depth of focus (DOF) in optical lithography using high-energy rays, and also has strong pattern collapse resistance and excellent etching resistance in fine pattern formation; a polymer comprising a repeating unit derived from the onium salt-type monomer; a chemically amplified resist composition comprising the polymer; and a pattern forming method using the chemically amplified resist composition. The solution of the present invention is an onium salt type monomer represented by formula (a). # imgabs0 #

Description

Technical Field

[0001] The invention relates to an onium salt type monomer, a polymer, a chemically amplified resist composition and a pattern forming method. Background Art

[0002] With the high integration and high speed of LSI, the miniaturization of pattern rules is progressing rapidly. In particular, the expansion of the flash memory market and the increase in memory capacity are driving miniaturization. As for the most advanced miniaturization technology, mass production of 65nm node devices using ArF lithography is underway, and preparations for mass production of 45nm node devices using the next-generation ArF immersion lithography are underway. For the next-generation 32nm node devices, research is underway on candidates such as immersion lithography using ultra-high NA lenses that combine liquids with a higher refractive index than water, high-refractive-index lenses, and high-refractive-index resist films, extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm, and double exposure (double patterning lithography) of ArF lithography.

[0003] As miniaturization progresses and the diffraction limit of light is approached, the contrast of light decreases. Due to the decrease in the contrast of light, the resolution of the hole pattern and the trench pattern in the positive resist film and the focus margin are reduced.

[0004] The miniaturization of patterns, line pattern edge roughness (LWR), and hole pattern size uniformity (CDU) are considered problems. Some people point out the uneven distribution of base polymers and acid generators, the influence of aggregation, and the influence of acid diffusion. Then, as the resist film becomes thinner, the LWR tends to increase, and the deterioration of LWR due to thinning accompanying miniaturization has become a serious problem.

[0005] In the resist composition for EUV lithography, it is necessary to achieve high sensitivity, high resolution and low LWR at the same time. If the acid diffusion distance is shortened, the LWR will be reduced but the sensitivity will be reduced. For example, by lowering the post-exposure bake (PEB) temperature, the LWR will be reduced, but the sensitivity will be reduced. Even if the amount of quencher added is increased, the LWR will be reduced, but the sensitivity will be reduced. The trade-off between sensitivity and LWR must be broken.

[0006] In order to inhibit acid diffusion, some people have proposed resist compounds containing repeating units of onium salts from sulfonic acids with polymerizable unsaturated bonds (patent documents 1 to 4). This so-called polymer-bonded acid generator has the characteristic of very short acid diffusion because it produces polymer-type sulfonic acid by exposure. In addition, by increasing the proportion of the acid generator, the sensitivity can also be improved. Although increasing the amount of additive acid generator will increase the sensitivity, the acid diffusion distance will also increase at this time. Because the acid diffuses unevenly, if the acid diffusion increases, the LWR and CDU will deteriorate. In the balance of sensitivity, LWR and CDU, it can be said that the polymer-type acid generator has a high degree of ability.

[0007] With the recent progress of miniaturization of resist patterns, the collapse of resist patterns during development and poor resistance during etching steps have become issues. Although the introduction of the repeating unit of the onium salt derived from sulfonic acid having the above-mentioned polymerizable unsaturated bond can suppress the acid diffusion of the generated acid to a certain extent, there is still room for improvement in various lithography performances, collapse of resist patterns, and poor etching resistance. In order to respond to the future demand for miniaturization, it is also extremely important to develop a polymer-type acid generator that can take into account both lithography performance and collapse of resist patterns and etching resistance.

[0008] Prior art literature

[0009] Patent Literature

[0010] [Patent Document 1] Japanese Patent No. 4425776

[0011] [Patent Document 2] Japanese Patent No. 5201363

[0012] [Patent Document 3] Japanese Patent No. 5231357

[0013] [Patent Document 4] International Publication No. 2008 / 081832 Summary of the invention

[0014] [Problems to be solved by the invention]

[0015] In a chemically amplified resist composition using an acid as a catalyst, there is a demand for the development of a resist composition that has a higher sensitivity, can improve the LWR of lines and the CDU of holes, and is excellent in etching resistance after patterning.

[0016] The present invention is made in view of the above circumstances, and its purpose is to provide: an onium salt-type monomer used in a chemically amplified resist composition that has excellent solvent solubility, high sensitivity, high contrast, and excellent lithography performance such as exposure margin (EL), LWR, CDU, and depth of focus (DOF), especially in optical lithography using high-energy rays such as KrF excimer laser, ArF excimer laser, electron beam (EB), and EUV, and at the same time has strong resistance to pattern collapse and excellent etching resistance in fine pattern formation; a polymer containing repeating units derived from the onium salt-type monomer; a chemically amplified resist composition containing the polymer; and a pattern forming method using the chemically amplified resist composition.

[0017] [Methods to solve the problem]

[0018] The inventors of the present application have conducted intensive studies to achieve the above-mentioned objectives and have found that by using a polymer comprising repeating units derived from an onium salt of an aromatic sulfonic acid anion having a vinyl-substituted aromatic ring as a polymer-bound acid generator, a chemically amplified resist composition having high sensitivity, improved LWR and CDU, high contrast and high resolution, and excellent etching resistance can be obtained, thereby completing the present invention.

[0019] That is, the present invention provides the following onium salt type monomer, polymer, chemically amplified resist composition and pattern forming method.

[0020] 1. An onium salt type monomer represented by the following formula (a);

[0021] [Chemistry 1]

[0022]

[0023] Wherein, n1 is 0 or 1; n2 is 0 or 1; n3 is an integer from 0 to 4; n4 is an integer from 0 to 4; n5 is an integer from 0 to 4; however, when n2=0, 0≤n4+n5≤4, and when n2=1, 0≤n4+n5≤6; and n1 to n5 may not all be 0;

[0024] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

[0025] R 1 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms; when n3 is 2, 3 or 4, the plural R 1 They may also be bonded to each other and to the carbon atoms of the aromatic rings to which they are bonded to form a ring;

[0026] R 2 is a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms; when n4 is 2, 3 or 4, the plural R 2They may also bond to each other and form a ring together with the carbon atoms to which they are bonded;

[0027] R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms;

[0028] L A and L B each independently a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonamide bond, a carbonate bond or a carbamate bond;

[0029] X L is a single bond or an alkylene group having 1 to 40 carbon atoms which may contain a hetero atom;

[0030] Z + It is an onium cation.

[0031] 2. The onium salt monomer of 1 is represented by the following formula (a1);

[0032] [Chemistry 2]

[0033]

[0034] In the formula, n2~n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z + Same as above.

[0035] 3. The onium salt monomer of 2 is represented by the following formula (a2);

[0036] [Chemistry 3]

[0037]

[0038] In the formula, n2~n5, R A , R 1 , R 2 , R F , L A and Z + Same as above.

[0039] 4. The onium salt-type monomer according to any one of 1 to 3, wherein Z + It is a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2);

[0040] [Chemistry 4]

[0041]

[0042] In the formula, R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom; and R ct1 and R ct2 They may also bond to each other to form a ring together with the sulfur atom to which they are bonded.

[0043] 5. A polymer comprising a repeating unit derived from the onium salt type monomer according to any one of 1 to 4.

[0044] 6. The polymer of 5, further comprising a repeating unit represented by the following formula (b1) or (b2);

[0045] [Chemistry 5]

[0046]

[0047] In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

[0048] X 1 is a single bond, phenylene, naphthylene, *-C(=O)-OX 11 - or *-C(=O)-NH-X 11 -, the phenylene or naphthylene group may be substituted by an alkoxy group having 1 to 10 carbon atoms which may also contain a fluorine atom or a halogen atom; X 11 A saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, wherein the saturated alkylene group may also contain a hydroxyl group, an ether bond, an ester bond or a lactone ring;

[0049] X 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-;

[0050] * indicates atomic bonds to carbon atoms of the backbone;

[0051] AL 1 and AL 2 are each independently an acid-labile group;

[0052] R 11 is a halogen atom, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom;

[0053] a is an integer from 0 to 4.

[0054] 7. The polymer of 5 or 6 further comprises a repeating unit represented by the following formula (c1);

[0055] [Chemistry 6]

[0056]

[0057] In the formula, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

[0058] Y 1 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * represents an atomic bond to a carbon atom of the main chain;

[0059] R 21 is a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom;

[0060] c is an integer from 1 to 4; d is an integer from 0 to 3; however, 1≤c+d≤5.

[0061] 8. The polymer according to any one of 5 to 7, further comprising a repeating unit represented by the following formula (d1);

[0062] [Chemistry 7]

[0063]

[0064] In the formula, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group;

[0065] Z 1 is a single bond, phenylene, naphthylene, *-C(=O)-OZ 11 - or *-C(=O)-NH-Z 11 -, or the phenylene or naphthylene group may be substituted by an alkoxy group having 1 to 10 carbon atoms which may also contain a fluorine atom or a halogen atom; * represents an atomic bond to a carbon atom of the main chain; Z 11 A saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, wherein the saturated alkylene group may also contain a hydroxyl group, an ether bond, an ester bond or a lactone ring;

[0066] R 31 A group having 1 to 20 carbon atoms and a structure containing at least one selected from the group consisting of a hydroxyl group other than a phenolic hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (—C(═O)—OC(═O)—).

[0067] 9. A chemically amplified resist composition comprising (A) a base polymer comprising the polymer according to any one of 5 to 8.

[0068] 10. The chemically amplified resist composition of 9 further comprises (B) an organic solvent.

[0069] 11. The chemically amplified resist composition of 9 or 10 further comprises (C) a quencher.

[0070] 12. The chemically amplified resist composition according to any one of items 9 to 11, further comprising (D) an acid generator.

[0071] 13. The chemically amplified resist composition according to any one of items 9 to 12, further comprising (E) a surfactant.

[0072] 14. The chemically amplified resist composition according to any one of items 9 to 13, further comprising (F) a dissolution inhibitor.

[0073] 15. A method for forming a pattern, comprising the following steps:

[0074] The steps of forming a resist film on a substrate using the chemically amplified resist composition as described in any one of items 9 to 14; exposing the resist film to high-energy rays; and developing the exposed resist film using a developer.

[0075] 16. The pattern forming method according to 15, wherein the high energy ray is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, EB, or EUV with a wavelength of 3 to 15 nm.

[0076] [Effects of the Invention]

[0077] The resist film containing a polymer containing a repeating unit derived from an onium salt-type monomer represented by formula (a) has good solvent solubility and the aromatic sulfonic acid structure is a rigid structure, so it has the characteristic of small acid diffusion. This can prevent the reduction of resolution due to blurring of acid diffusion, and can improve LWR and CDU. In addition, the vinyl aromatic ring derived from the polymerizable group will function as a good etching resistance group, which is ideal in fine pattern formation. DETAILED DESCRIPTION

[0078] [Onium salt type monomer]

[0079] The onium salt type monomer of the present invention is represented by the following formula (a).

[0080] [Chemistry 8]

[0081]

[0082] In formula (a), n1 is 0 or 1. When n1 is 0, it is a benzene ring, and when n1 is 1, it is a naphthalene ring. In view of solvent solubility, n1 is preferably a benzene ring of 0. n2 is 0 or 1. n3 is an integer of 0 to 4, and preferably 0, 1 or 2. n4 is an integer of 0 to 4, and preferably 0, 1 or 2. n5 is an integer of 0 to 4, and in view of the acid strength of the generated acid, preferably 1, 2, 3 or 4, and more preferably 2, 3 or 4. However, when n2=0, 0≤n4+n5≤4, and when n2=1, 0≤n4+n5≤6. In addition, in view of solvent solubility, n1 to n5 are not all 0.

[0083] In formula (a), R A It is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Among them, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0084] In formula (a), R 1 It is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, and more preferably a fluorine atom or an iodine atom. The hydrocarbon group may be saturated or unsaturated, and may be straight chain, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, eicosyl, etc.; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, adamantyl, etc.; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, hexenyl, etc.; cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl, etc.; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl, aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, 2-phenylethyl, etc.; and groups obtained by combining these. Among these, aryl groups are more preferred. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 2 - may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. When n3 is 2, 3, or 4, each R 1 They can be the same as each other or different from each other.

[0085] When n3 is 2, 3 or 4, the complex R 1 They may also be bonded to each other to form a ring together with the carbon atoms of the aromatic ring to which they are bonded. Specific examples of the ring formed in this case include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, norbornane ring, and adamantane ring. In addition, part or all of the hydrogen atoms in the aforementioned ring may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. The -CH 2 - may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0086] In formula (a), R 2 is a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated, and may be straight chain, branched, or cyclic. 1 The hydrocarbon groups represented by are the same as those exemplified above, but are not limited thereto. When n4 is 2, 3 or 4, each R 2 They may be the same or different from each other. Also, when n4 is 2, 3 or 4, the plural R 2 They may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. The above-mentioned ring is preferably a 5- to 8-membered ring.

[0087] In formula (a), R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. F For example, fluorine atom, trifluoromethyl, difluoromethyl, trifluoromethoxy, difluoromethoxy, trifluoromethylthio or difluoromethylthio is more preferred, and fluorine atom, trifluoromethyl or trifluoromethoxy is more preferred. By containing or having these substituents of fluorine atoms, the acid strength of the acid generated by the electron-attracting effect is increased, so the deprotection reaction of the acid-labile group of the tertiary ester, tertiary ether, etc. described later can be smoothly performed. When n5 is 2, 3 or 4, each R F They can be the same as each other or different from each other.

[0088] In formula (a), L A and L B Each is independently a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonamide bond, a carbonate bond or a carbamate bond. A For L, it is preferably a single bond, an ether bond, an ester bond or a sulfonate bond, and more preferably an ester bond or a sulfonate bond. BFor example, it is preferably a single bond, an ether bond, an ester bond or a sulfonate bond, and is more preferably a single bond, an ester bond or a sulfonate bond.

[0089] In formula (a), X L is a single bond or a alkylene group having 1 to 40 carbon atoms which may contain a hetero atom. The alkylene group may be linear, branched or cyclic, and specific examples thereof include alkanediyl and cyclic saturated alkylene groups. Specific examples of the hetero atom include oxygen, nitrogen and sulfur atoms.

[0090] Just X L Specific examples of the alkylene group having 1 to 40 carbon atoms which may contain a hetero atom represented by the formula include those shown below, but are not limited to these. A and L B of atomic bonds.

[0091] [Chemistry 9]

[0092]

[0093] [Chemistry 10]

[0094]

[0095] [Chemistry 11]

[0096]

[0097] [Chemistry 12]

[0098]

[0099] Among these, X L -0~X L -22, X L -29~X L -34, and X L -47~X L The onium salt type monomer represented by the formula (a) is preferably one represented by the following formula (a1).

[0100] [Chemistry 13]

[0101]

[0102] In the formula, n2~n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z +The same as above. The onium salt type monomer represented by formula (a1) is preferably represented by the following formula (a2).

[0103] [Chemistry 14]

[0104]

[0105] In the formula, n2~n5, R A , R 1 , R 2 , R F , L A and Z + Same as above.

[0106] Specific examples of the anion of the onium salt-type monomer represented by formula (a) include those shown below, but are not limited to these. A As mentioned above, Me is a methyl group. In addition, the bonding positions of various substituents on the aromatic ring may also be interchangeable.

[0107] [Chemistry 15]

[0108]

[0109] [Chemistry 16]

[0110]

[0111] [Chemistry 17]

[0112]

[0113] [Chemistry 18]

[0114]

[0115] [Chemistry 19]

[0116]

[0117] [Chemistry 20]

[0118]

[0119] [Chemistry 21]

[0120]

[0121] [Chemistry 22]

[0122]

[0123] [Chemistry 23]

[0124]

[0125] [Chemistry 24]

[0126]

[0127] [Chemistry 25]

[0128]

[0129] [Chemistry 26]

[0130]

[0131] [Chemistry 27]

[0132]

[0133] [Chemistry 28]

[0134]

[0135] [Chemistry 29]

[0136]

[0137] [Chemistry 30]

[0138]

[0139] [Chemistry 31]

[0140]

[0141] [Chemistry 32]

[0142]

[0143] [Chemistry 33]

[0144]

[0145] [Chemistry 34]

[0146]

[0147] [Chemistry 35]

[0148]

[0149] [Chemistry 36]

[0150]

[0151] [Chemistry 37]

[0152]

[0153] [Chemistry 38]

[0154]

[0155] [Chemistry 39]

[0156]

[0157] [Chemistry 40]

[0158]

[0159] [Chemistry 41]

[0160]

[0161] [Chemistry 42]

[0162]

[0163] [Chemistry 43]

[0164]

[0165] [Chemistry 44]

[0166]

[0167] [Chemistry 45]

[0168]

[0169] [Chemistry 46]

[0170]

[0171] [Chemistry 47]

[0172]

[0173] [Chemistry 48]

[0174]

[0175] [Chemistry 49]

[0176]

[0177] [Chemistry 50]

[0178]

[0179] [Chemistry 51]

[0180]

[0181] [Chemistry 52]

[0182]

[0183] [Chemistry 53]

[0184]

[0185] [Chemistry 54]

[0186]

[0187] [Chemistry 55]

[0188]

[0189] [Chemistry 56]

[0190]

[0191] [Chemistry 57]

[0192]

[0193] [Chemistry 58]

[0194]

[0195] [Chemistry 59]

[0196]

[0197] [Chemistry 60]

[0198]

[0199] [Chemistry 61]

[0200]

[0201] In formula (a), Z + The onium cation is preferably a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2).

[0202] [Chemistry 62]

[0203]

[0204] In formula (cation-1) and (cation-2), R ct1 ~R ct5 Each is independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom.

[0205] Just R ct1 ~Rct5 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0206] R ct1 ~R ct5 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 30 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups having 3 to 30 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 30 carbon atoms, such as phenyl, naphthyl, and thienyl; aralkyl groups having 7 to 30 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups, and aryl groups are more preferably aryl groups. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 2 - may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0207] Again, R ct1 and R ct2 They may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the structure of the ring may be represented by the following formula.

[0208] [Chemistry 63]

[0209]

[0210] In the formula, the dotted line is the ct3 of atomic bonds.

[0211] Specific examples of the sulfonium cation represented by the formula (cation-1) include those shown below, but are not limited to these.

[0212] [Chemistry 64]

[0213]

[0214] [Chemistry 65]

[0215]

[0216] [Chemistry 66]

[0217]

[0218] [Chemistry 67]

[0219]

[0220] [Chemistry 68]

[0221]

[0222] [Chemistry 69]

[0223]

[0224] [Chemistry 70]

[0225]

[0226] [Chemistry 71]

[0227]

[0228] [Chemistry 72]

[0229]

[0230] [Chemistry 73]

[0231]

[0232] [Chemistry 74]

[0233]

[0234] [Chemistry 75]

[0235]

[0236] [Chemistry 76]

[0237]

[0238] [Chemistry 77]

[0239]

[0240] [Chemistry 78]

[0241]

[0242] [Chemistry 79]

[0243]

[0244] [Chemistry 80]

[0245]

[0246] [Chemistry 81]

[0247]

[0248] [Chemistry 82]

[0249]

[0250] [Chemistry 83]

[0251]

[0252] [Chemistry 84]

[0253]

[0254] [Chemistry 85]

[0255]

[0256] [Chemistry 86]

[0257]

[0258] [Chemistry 87]

[0259]

[0260] [Chemistry 88]

[0261]

[0262] [Chemistry 89]

[0263]

[0264] [Chemistry 90]

[0265]

[0266] Specific examples of the iodonium cation represented by the formula (cation-2) include those shown below, but are not limited to these.

[0267] [Chemistry 91]

[0268]

[0269] [Chemistry 92]

[0270]

[0271] Specific examples of the onium salt-type monomer represented by the formula (a) include any combination of the above-mentioned anions and cations.

[0272] The onium salt-type monomer represented by the formula (a) can be synthesized, for example, by the same method as the sulfonium salt having a polymerizable anion described in Japanese Patent No. 5201363, but the present invention is not limited thereto.

[0273] [polymer]

[0274] The polymer of the present invention includes a repeating unit derived from an onium salt-type monomer represented by formula (a) (hereinafter, also referred to as repeating unit a).

[0275] The polymer of the present invention is a polymer-bonded photoacid generator that functions as a photoacid generator in a chemically amplified resist composition and also functions as a base polymer. The structural features of the onium salt-type monomer of the present invention include the use of an aromatic vinyl structure as a polymerizable group and the presence of an aromatic sulfonic acid anion. By having an aromatic ring directly bonded to the main chain, the main chain of the base polymer becomes rigid, so the glass transition temperature (Tg) of the base polymer is increased. It is believed that: by the interaction of aromatic rings within or between base polymers (π-π stacking effect), the base polymer will be regularly and correctly arranged, and will show resistance to pattern collapse to the developer even when a fine pattern is formed. In addition, even in the etching step after the fine pattern is formed, excellent etching resistance is shown by having an aromatic ring directly bonded to the main chain. The aromatic sulfonic acid site of the generated acid has a more rigid structure than the known partially fluorinated alkanesulfonic acid anion, so it will inhibit excessive acid diffusion. Due to these synergistic effects, the polymer of the present invention can form a pattern that is excellent in LWR of a line pattern and CDU of a hole pattern and is resistant to pattern collapse, and is therefore particularly ideal as a material for a chemically amplified positive resist composition.

[0276] The aforementioned polymer may further contain a repeating unit represented by the following formula (b1) (hereinafter, also referred to as repeating unit b1) or a repeating unit represented by the following formula (b2) (hereinafter, also referred to as repeating unit b2).

[0277] [Chemistry 93]

[0278]

[0279] In formula (b1) and (b2), R A Each is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0280] In formula (b1), X 1 is a single bond, phenylene, naphthylene, *-C(=O)-OX 11- or *-C(=O)-NH-X 11 -, the phenylene group or naphthylene group may be substituted with an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom or a halogen atom. 11 It is a saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group. The saturated alkylene group may contain a hydroxyl group, an ether bond, an ester bond or a lactone ring. * represents an atomic bond to a carbon atom of the main chain.

[0281] In formula (b2), X 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * represents an atomic bond to a carbon atom of the main chain. 11 is a halogen atom, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom. a is an integer of 0 to 4, preferably 0 or 1.

[0282] In formula (b1) and (b2), AL 1 and AL 2 Each independently represents an acid-labile group. Specific examples of the acid-labile group include those described in JP-A-2013-80033 and JP-A-2013-83821, but are not limited thereto.

[0283] Representative examples of the acid-labile group include those represented by the following formulae (AL-1) to (AL-3).

[0284] [Chemistry 94]

[0285]

[0286] In the formula, * is an atomic bond.

[0287] In formula (AL-1) and (AL-2), R L1 and R L2 Each is independently a hydrocarbon group having 1 to 40 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, fluorine atoms, and iodine atoms. The aforementioned hydrocarbon group may be straight-chain, branched, or cyclic. As for the aforementioned hydrocarbon group, the one having 1 to 20 carbon atoms is more preferable.

[0288] In the formula (AL-1), b is an integer of 0-10, and preferably an integer of 1-5.

[0289] In formula (AL-2), R L3 and R L4Each independently represents a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, fluorine atoms, and iodine atoms. The aforementioned hydrocarbon group may be straight-chain, branched, or cyclic. L2 , R L3 and R L4 Any two of them may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atom or the carbon atom and oxygen atom to which they are bonded. The above-mentioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0290] In formula (AL-3), R L5 , R L6 and R L7 Each is independently a hydrocarbon group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, fluorine atoms, and iodine atoms. The aforementioned hydrocarbon group may be linear, branched, or cyclic. L5 , R L6 and R L7 Any two of them may be bonded to each other to form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded. The above-mentioned ring is preferably a ring having 4 to 16 carbon atoms, and an alicyclic ring is particularly preferred.

[0291] Specific examples of the repeating unit b1 include those shown below, but are not limited to these. A and AL 1 Same as above.

[0292] [Chemistry 95]

[0293]

[0294] [Chemistry 96]

[0295]

[0296] [Chemistry 97]

[0297]

[0298] [Chemistry 98]

[0299]

[0300] [Chemistry 99]

[0301]

[0302] [Chemical 100]

[0303]

[0304] [Chemistry 101]

[0305]

[0306] Specific examples of the repeating unit b2 include those shown below, but are not limited to these. A and AL 2 Same as above.

[0307] [Chemistry 102]

[0308]

[0309] [Chemistry 103]

[0310]

[0311] [Chemistry 104]

[0312]

[0313] The base polymer preferably further includes a repeating unit represented by the following formula (c1) (hereinafter also referred to as repeating unit c).

[0314] [Chemistry 105]

[0315]

[0316] In formula (c1), R A Y is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 1 is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * represents an atomic bond to a carbon atom of the main chain. 21 is a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom. c is an integer of 1 to 4. d is an integer of 0 to 3. However, 1≤c+d≤5.

[0317] Specific examples of the repeating unit c include those shown below, but are not limited to these. A Same as above.

[0318] [Chemistry 106]

[0319]

[0320] [Chemistry 107]

[0321]

[0322] [Chemistry 108]

[0323]

[0324] [Chemistry 109]

[0325]

[0326] [Chemistry 110]

[0327]

[0328] The base polymer preferably further includes a repeating unit represented by the following formula (d1) (hereinafter also referred to as repeating unit d).

[0329] [Chemistry 111]

[0330]

[0331] In formula (d1), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 1 is a single bond, phenylene, naphthylene, *-C(=O)-OZ 11 - or *-C(=O)-NH-Z 11 -, or the phenylene group or naphthylene group may be substituted with an alkoxy group having 1 to 10 carbon atoms which may contain a fluorine atom or a halogen atom. * represents an atomic bond to a carbon atom of the main chain. Z 11 R is a saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group. The saturated alkylene group may contain a hydroxyl group, an ether bond, an ester bond or a lactone ring. 31 A group having 1 to 20 carbon atoms and a structure containing at least one selected from the group consisting of a hydroxyl group other than a phenolic hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (—C(═O)—OC(═O)—).

[0332] Specific examples of the repeating unit d include those shown below, but are not limited to these. A Same as above.

[0333] [Chemistry 112]

[0334]

[0335] [Chemistry 113]

[0336]

[0337] [Chemistry 114]

[0338]

[0339] [Chemistry 115]

[0340]

[0341] [Chemistry 116]

[0342]

[0343] [Chemistry 117]

[0344]

[0345] [Chemistry 118]

[0346]

[0347] [Chemistry 119]

[0348]

[0349] [Chemistry 120]

[0350]

[0351] [Chemistry 121]

[0352]

[0353] [Chemistry 122]

[0354]

[0355] [Chemistry 123]

[0356]

[0357] [Chemistry 124]

[0358]

[0359] [Chemistry 125]

[0360]

[0361] [Chemistry 126]

[0362]

[0363] [Chemistry 127]

[0364]

[0365] As for the repeating unit c or d, those having a lactone ring are particularly preferred in ArF lithography, and those having a phenol moiety are particularly preferred in KrF lithography, EB lithography, and EUV lithography.

[0366] The aforementioned polymer may further contain a repeating unit having a structure in which the hydroxyl group is protected by an acid-labile group (hereinafter, also referred to as repeating unit e). The repeating unit e is not particularly limited as long as it has a structure in which one or two hydroxyl groups are protected and the protecting group is decomposed by the action of an acid to generate a hydroxyl group, but the repeating unit e represented by the following formula (e1) is more preferable.

[0367] [Chemistry 128]

[0368]

[0369] In formula (e1), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 41 It is a (e+1)-valent hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. 42 is an acid-labile group. e is an integer of 1-4.

[0370] In formula (e1), R 42 The acid-labile group represented by R may be any one that is deprotected by the action of an acid to generate a hydroxyl group. 42 The structure of is not particularly limited, and is preferably an acetal structure, a ketal structure, an alkoxycarbonyl group, an alkoxymethyl group represented by the following formula (e2), and particularly preferably an alkoxymethyl group represented by the following formula (e2).

[0371] [Chemistry 129]

[0372]

[0373] In the formula, * represents an atomic bond. 43 It is a hydrocarbon group having 1 to 15 carbon atoms.

[0374] Just R 42 Specific examples of the acid-labile group represented by the formula (e2), the alkoxymethyl group represented by the formula (e2), and the repeating unit e include the same ones as exemplified in the description of the repeating unit d described in JP-A-2020-111564.

[0375] The base polymer may further contain a repeating unit f derived from indene, benzofuran, benzothiophene, acenaphthene, chromone, coumarin, norbornadiene or a derivative thereof. Specific examples of the monomer providing the repeating unit f include those shown below, but are not limited thereto.

[0376] [Chemistry 130]

[0377]

[0378] The foregoing base polymer may further contain repeating unit g derived from styrene, indene, vinylpyridine, or vinylcarbazole.

[0379] In the polymer of the present invention, the content ratios of repeating units a, b1, b2, c, d, e, f, and g 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, 0 ≤ f ≤ 0.3, and 0 ≤ g ≤ 0.3, and 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, 0 ≤ f ≤ 0.2, and 0 ≤ g ≤ 0.2. However, a + b1 + b2 + c + d + e + f + g ≤ 1.0.

[0380] The weight average molecular weight (Mw) of the foregoing polymer is preferably 1,000 to 500,000, and more preferably 3,000 to 100,000. If Mw falls within this range, sufficient etching resistance can be obtained, and there is no risk of a decrease in resolution due to the inability to ensure the difference in dissolution rate before and after exposure. In addition, in the present invention, Mw is a polystyrene conversion measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or N,N-dimethylformamide (DMF) as a solvent.

[0381] Then, regarding the molecular weight distribution (Mw / Mn) of the foregoing polymer, since the influence of Mw / Mn tends to increase as the pattern rule becomes finer, in order to obtain a resist composition that can be ideally used in a fine pattern size, a narrow dispersion with Mw / Mn of 1.0 to 2.0 is preferable. If it falls within the foregoing range, there are fewer low molecular weight and high molecular weight polymers, and after exposure, there is no risk of finding foreign substances on the pattern or deterioration of the pattern shape.

[0382] Regarding the synthesis method of the foregoing polymer, examples include a method in which a monomer providing the foregoing repeating unit is added with a radical polymerization initiator in an organic solvent and heated to polymerize it.

[0383] As for the specific examples of the organic solvent used in the polymerization, toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, methyl ethyl ketone (MEK), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), etc. can be cited. As for the specific examples of the above-mentioned polymerization initiator, 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauroyl peroxide, etc. can be cited. The amount of these initiators added is preferably 0.01 to 25 mol% relative to the total amount of the monomers to be polymerized. The reaction temperature is preferably 50 to 150°C, and more preferably 60 to 100°C. The reaction time is preferably 2 to 24 hours, and 2 to 12 hours is more preferably considered from the perspective of production efficiency.

[0384] The aforementioned polymerization initiator may be added to the aforementioned monomer solution and then supplied to the reactor, or an initiator solution may be prepared separately from the aforementioned monomer solution, and they may be supplied to the reactor independently. During the standby time, there is a possibility that the polymerization reaction is carried out due to the free radicals generated by the initiator and ultra-high molecular weight bodies are generated. Therefore, considering the viewpoint of quality management, it is more ideal to prepare the monomer solution and the initiator solution independently and add them dropwise. The acid-labile group may be directly used in its original state and introduced into the monomer, or it may be protected or partially protected after polymerization. In addition, in order to adjust the molecular weight, a known chain transfer agent such as dodecanethiol and 2-mercaptoethanol may also be used in combination. At this time, the addition amount of these chain transfer agents is preferably 0.01 to 20 mol% relative to the total amount of the monomers to be polymerized.

[0385] In the case of a monomer containing a hydroxyl group, the hydroxyl group can be replaced by an acetal group such as ethoxyethoxy which is easily deprotected by an acid during polymerization, and then deprotected by a weak acid and water after polymerization; or it can be replaced by an acetyl group, a formyl group, a pivaloyl group, etc., and then hydrolyzed with an alkali after polymerization.

[0386] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, hydroxystyrene or hydroxyvinylnaphthalene and other monomers may be added with a free radical polymerization initiator in an organic solvent and heated for polymerization; acetoxystyrene or acetoxyvinylnaphthalene may also be used, and the acetoxy group may be deprotected by alkaline hydrolysis after polymerization to prepare polyhydroxystyrene or hydroxypolyvinylnaphthalene.

[0387] Specific examples of the base used in the alkaline hydrolysis include aqueous ammonia, triethylamine, etc. The reaction temperature is preferably -20 to 100° C., more preferably 0 to 60° C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0388] The amount of each monomer in the monomer solution may be appropriately set, for example, so as to achieve a preferred content ratio of the repeating unit.

[0389] As for the polymer obtained by the above-mentioned manufacturing method, the reaction solution obtained by the polymerization reaction can also be used as the final product; the polymerization solution can also be added to a poor solvent, and the powder obtained by a refining step such as a reprecipitation method that can obtain a powder can be treated as the final product. However, considering the operating efficiency and quality stability, it is more ideal to treat the polymer solution obtained by dissolving the powder obtained by the refining step in a solvent as the final product.

[0390] Specific examples of the solvent used in this case include ketones such as cyclohexanone and methyl-2-n-pentyl ketone described in paragraphs

[0144] to

[0145] of Japanese Patent Application Laid-Open No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether; Ethers such as ether, diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, 3-methoxypropionic acid methyl ester, 3-ethoxypropionic acid ethyl ester, tert-butyl acetate, tert-butyl propionate, propylene glycol monotert-butyl ether acetate; lactones such as GBL; alcohols such as diacetone alcohol (DAA); high-boiling point alcohol solvents such as diethylene glycol, propylene glycol, glycerol, 1,4-butanediol, 1,3-butanediol, etc.; and mixed solvents thereof.

[0391] In the polymer solution, the concentration of the polymer is preferably 0.01 to 30% by mass, more preferably 0.1 to 20% by mass.

[0392] It is preferable to filter the reaction solution and polymer solution through a filter medium. By filtering through a filter medium, foreign matter and gel that may cause defects can be removed, which is effective in terms of quality stability.

[0393] As for the material of the filter material used in the aforementioned filter material filtration, materials such as fluorocarbon, cellulose, nylon, polyester, hydrocarbon, etc. can be cited, but in the filtering step of the chemically amplified resist composition, it is more ideal to form a filter material with a hydrocarbon system or nylon such as fluorocarbon, polyethylene, polypropylene, etc., which is called Teflon (registered trademark). The pore size of the filter material can be appropriately selected in conjunction with the cleanliness set as the target, but it is more ideal to be less than 100nm, and more ideal to be less than 20nm. In addition, these filter materials can also be used alone, or a plurality of filter materials can be used in combination. As for the filtering method, it is also possible to pass the solution only once, but it is more ideal to circulate the solution and filter it multiple times. As for the filtering step, it can be carried out in any order and number of times in the manufacturing step of the polymer, but it is more ideal to filter the reaction solution, polymer solution or both of them after the polymerization reaction.

[0394] [Chemically amplified resist composition]

[0395] [(A) Base polymer]

[0396] The chemically amplified resist composition of the present invention contains the base polymer containing the above-mentioned polymer as the component (A).

[0397] The aforementioned polymers may be used alone or in combination of two or more polymers having different composition ratios, Mw and / or Mw / Mn. In addition, the base polymer (A) may contain a hydrogenated ring-opening metathesis polymer in addition to the aforementioned polymers, and in this regard, the polymers described in Japanese Patent Application Publication No. 2003-66612 may be used.

[0398] [(B) Organic solvent]

[0399] The chemically amplified resist composition of the present invention may also contain an organic solvent as the component (B). The organic solvent (B) is not particularly limited as long as it can dissolve the above-mentioned components and the components described below. Specific examples of such organic solvents include ketones such as cyclopentanone, cyclohexanone, and methyl-2-n-pentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, and 1-ethoxy-2-propanol; ketoalcohols such as DAA; ethers such as PGME, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as PGMEA, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol mono-tert-butyl ether acetate; lactones such as GBL, and mixed solvents thereof.

[0400] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, cyclohexanone, GBL, DAA, and mixed solvents thereof are particularly preferred because they have particularly excellent solubility in the base polymer of the component (A).

[0401] In the chemically amplified resist composition of the present invention, the content of the organic solvent (B) is preferably 200 to 5000 parts by mass, and more preferably 400 to 3500 parts by mass, relative to 80 parts by mass of the base polymer (A). The organic solvent (B) may be used alone or in combination of two or more.

[0402] [(C) Quencher]

[0403] The chemically amplified resist composition of the present invention may also contain a quencher as component (C). In addition, the quencher in the present invention refers to a material that forms a desired pattern by capturing the acid generated from the photoacid generator in the chemically amplified resist composition to prevent it from diffusing to the unexposed area.

[0404] Specific examples of the (C) quencher include onium salts represented by the following formula (1) or (2).

[0405] [Chemistry 131]

[0406]

[0407] In formula (1), R q1 is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom, but excludes a case where the hydrogen atom bonded to the carbon atom at the α-position of the sulfonic acid group is substituted with a fluorine atom or a fluoroalkyl group. q2 It is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom.

[0408] Just R q1 Specific examples of the hydrocarbon group having 1 to 40 carbon atoms include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl and adamantyl; aryl groups having 6 to 40 carbon atoms, such as phenyl, naphthyl, anthracenyl, etc. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and the -CH 2- may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0409] Just R q2 Specifically, in addition to R q1 In addition to the substituents exemplified in the specific examples of , fluorinated saturated hydrocarbon groups such as trifluoromethyl and trifluoroethyl and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl can be mentioned.

[0410] Specific examples of the anion of the onium salt represented by the formula (1) include those shown below, but are not limited to these.

[0411] [Chemistry 132]

[0412]

[0413] [Chemistry 133]

[0414]

[0415] [Chemistry 134]

[0416]

[0417] Specific examples of the anion of the onium salt represented by the formula (2) include those shown below, but are not limited to these.

[0418] [Chemistry 135]

[0419]

[0420] [Chemistry 136]

[0421]

[0422] [Chemistry 137]

[0423]

[0424] In formula (1) and (2), Mq + The onium cation is preferably a sulfonium cation represented by the above formula (cation-1), an iodonium cation represented by the above formula (cation-2), or an ammonium cation represented by the following formula (cation-3).

[0425] [Chemistry 138]

[0426]

[0427] In formula (cation-3), R ct6 ~R ct9 are each independently a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. ct6 and R ct7 They may also be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Specific examples of the aforementioned hydrocarbon group include those in the description of formula (cation-1) and (cation-2). ct1 ~R ct5 The hydrocarbon groups exemplified are the same as those exemplified above.

[0428] Specific examples of the ammonium cation represented by the formula (cation-3) include those shown below, but are not limited to these.

[0429] [Chemistry 139]

[0430]

[0431] As for the specific example of the onium salt represented by formula (1) or (2), any combination of the above-mentioned anions and cations can be listed. In addition, these onium salts can be easily prepared by ion exchange reaction using known organic chemical methods. For ion exchange reaction, reference can be made to, for example, Japanese Patent Publication No. 2007-145797.

[0432] The onium salt represented by formula (1) or (2) functions as a quencher in the chemically amplified resist composition of the present invention. This is because each of the counter anions of the onium salt is a conjugate base of a weak acid. Here, the so-called weak acid refers to an acid that exhibits an acidity that makes it impossible to deprotect the acid-labile group of the unit containing the acid-labile group used in the base polymer. The onium salt represented by formula (1) or (2) functions as a quencher when used in combination with an onium salt-type photoacid generator having a conjugate base of a strong acid such as sulfonic acid fluorinated at the α-position as a counter anion. That is, when an onium salt that generates a strong acid such as sulfonic acid fluorinated at the α-position is combined with an onium salt that generates a weak acid such as sulfonic acid or carboxylic acid that is not fluorinated, if the strong acid generated from the photoacid generator due to high-energy ray irradiation collides with the unreacted onium salt having a weak acid anion, the weak acid is released due to salt exchange, and an onium salt having a strong acid anion is generated. In this process, the strong acid will be exchanged for the weaker acid with lower catalyst energy, so the acid will be deactivated on the surface and the acid diffusion can be controlled.

[0433] In addition, as for the (C) quencher, an onium salt having a sulfonium cation and a phenoxide anion site in the same molecule as described in Patent No. 6848776, an onium salt having a sulfonium cation and a carboxylate anion site in the same molecule as described in Patent No. 6583136 and Japanese Patent Application Publication No. 2020-200311, and an onium salt having an iodonium cation and a carboxylate anion site in the same molecule as described in Patent No. 6274755 can also be used.

[0434] Here, when the photoacid generator that generates a strong acid is an onium salt, as described above, the strong acid generated by high-energy ray irradiation is exchanged for a weak acid, but on the other hand, it is thought that the weak acid generated by high-energy ray irradiation is difficult to collide with the unreacted onium salt that generates a strong acid and salt exchange occurs. This is due to the phenomenon that the onium cation easily forms an ion pair with the anion of a stronger acid.

[0435] When the chemically amplified resist composition of the present invention contains an onium salt represented by formula (1) or (2) as the quencher (C), the content thereof is preferably 0.1 to 20 parts by mass, and more preferably 0.1 to 10 parts by mass, relative to 80 parts by mass of the base polymer (A). If the onium salt-type quencher of component (C) falls within the aforementioned range, the resolution is good and the sensitivity is not significantly reduced, so it is more ideal. The onium salt represented by formula (1) or (2) may be used alone or in combination of two or more.

[0436] The chemically amplified resist composition of the present invention may also contain a nitrogen-containing compound as (C) a quencher. Specific examples of the nitrogen-containing compound of the component (C) include primary, secondary or tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103, and in particular, amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond. In addition, compounds in which primary or secondary amines are protected with carbamate groups, such as the compounds described in Japanese Patent Publication No. 3790649, may also be mentioned.

[0437] In addition, a sulfonium sulfonate salt having a nitrogen-containing substituent may be used as a nitrogen-containing compound. Such a compound functions as a quencher in the unexposed portion, and loses its quencher function in the exposed portion due to neutralization with the acid generated by itself, and functions as a so-called photodisintegration base. By using a photodisintegration base, the contrast between the exposed portion and the unexposed portion can be made stronger. As for the photodisintegration base, for example, Japanese Patent Publication No. 2009-109595, Japanese Patent Publication No. 2012-46501, etc. can be used as reference.

[0438] When the chemically amplified resist composition of the present invention contains a nitrogen-containing compound as the (C) quencher, its content is preferably 0.001 to 12 parts by mass, more preferably 0.01 to 8 parts by mass, relative to 80 parts by mass of the (A) base polymer. The nitrogen-containing compound may be used alone or in combination of two or more.

[0439] [(D) Acid generator]

[0440] The chemically amplified resist composition of the present invention may also contain an acid generator within the range that does not impair the effect of the present invention. As for the aforementioned acid generator, compounds that can generate acid by induction of active light or radiation (photoacid generators) can be cited. As for the photoacid generator, it is not particularly limited as long as it is a compound that can generate acid due to high-energy ray irradiation, and it is more ideal to generate sulfonic acid, imidic acid or methylated acid. As for ideal photoacid generators, there are sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. As for specific examples of acid generators, those described in paragraphs

[0122] to

[0142] of Japanese Patent Gazette No. 2008-111103 can be cited.

[0441] Furthermore, a sulfonium salt represented by the following formula (3-1) or an iodonium salt represented by the following formula (3-2) can also be preferably used as the photoacid generator.

[0442] [Chemistry 140]

[0443]

[0444] In formula (3-1) and (3-2), R 101 ~R 105 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Specific examples of the halogen atom and the hydrocarbon group include the following: ct1 ~R ct5 The halogen atoms and hydrocarbon groups represented by are the same as those exemplified. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 2 - may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. 101 and R 102They may also be bonded to each other to form a ring together with the sulfur atom to which they are bonded. Specific examples of the ring formed in this case include the following: ct1 and R ct2 The examples of the rings that can be formed together with the sulfur atoms to which they are bonded are the same as those exemplified.

[0445] Specific examples of the cation of the sulfonium salt represented by formula (3-1) include the same ones as those exemplified for the sulfonium cation represented by formula (cation-1). Specific examples of the cation of the iodonium salt represented by formula (3-2) include the same ones as those exemplified for the iodonium cation represented by formula (cation-2).

[0446] In formula (3-1) and (3-2), Xa - is an anion selected from the following formulae (3A) to (3D).

[0447] [Chemistry 141]

[0448]

[0449] In formula (3A), R fa is a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in the formula (3A') described later. fa1 Those exemplified in the description of are the same.

[0450] The anion represented by the formula (3A) is preferably represented by the following formula (3A').

[0451] [Chemistry 142]

[0452]

[0453] In formula (3A'), R HF It is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group.

[0454] In formula (3A'), R fa1 The hydrocarbon group may contain a hetero atom and has 1 to 38 carbon atoms. The hetero atom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, etc., and is more preferably an oxygen atom. The hydrocarbon group is preferably one having 6 to 30 carbon atoms from the viewpoint of obtaining high resolution in fine pattern formation.

[0455] R fa1The hydrocarbon group having 1 to 38 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 38 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 38 carbon atoms, such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbon groups having 2 to 38 carbon atoms, such as allyl and 3-cyclohexenyl; aryl groups having 6 to 38 carbon atoms, such as phenyl, 1-naphthyl, and 2-naphthyl; aralkyl groups having 7 to 38 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining these.

[0456] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 2 - may be substituted by a group containing heteroatoms such as an oxygen atom, a sulfur atom, and a nitrogen atom, and as a result, may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like. In addition, as for the aforementioned heteroatoms, an oxygen atom is more preferable. As for the hydrocarbon group containing heteroatoms, examples thereof include tetrahydrofuranyl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl.

[0457] The synthesis of the anion-containing sulfonium salt represented by formula (3A') is described in Japanese Patent Application Publication No. 2007-145797, Japanese Patent Application Publication No. 2008-106045, Japanese Patent Application Publication No. 2009-7327, Japanese Patent Application Publication No. 2009-258695, etc. Also, sulfonium salts described in Japanese Patent Application Publication No. 2010-215608, Japanese Patent Application Publication No. 2012-41320, Japanese Patent Application Publication No. 2012-106986, Japanese Patent Application Publication No. 2012-153644, etc. can be preferably used.

[0458] Specific examples of the anion represented by formula (3A) include those shown below, but are not limited to these. In the following formula, Ac is an acetyl group.

[0459] [Chemistry 143]

[0460]

[0461] [Chemistry 144]

[0462]

[0463] [Chemistry 145]

[0464]

[0465] [Chemistry 146]

[0466]

[0467] In formula (3B), R fb1 and R fb2 Each is independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: fa1 The hydrocarbon groups represented by are the same as those exemplified above. fb1 and R fb2 In particular, R is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 With R fb2 They can also bond to each other and to the groups they bond to (-CF 2 -SO 2 -N - -SO 2 -CF 2 -) together to form a ring, at this time, R fb1 With R fb2 The group obtained by bonding to each other is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0468] In formula (3C), R fc1 , R fc2 and R fc3 Each is independently a fluorine atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: fa1 The hydrocarbon groups represented by are the same as those exemplified above. fc1 , R fc2 and R fc3 In particular, R is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 With R fc2 They can also bond to each other and to the groups they bond to (-CF 2 -SO 2 -C - -SO2 -CF 2 -) together to form a ring, at this time, R fc1 With R fc2 The group obtainable by mutual bonding is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0469] In formula (3D), R fd is a hydrocarbon group having 1 to 40 carbon atoms which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated, and may be straight chain, branched, or cyclic. Specific examples thereof include: fa1 The hydrocarbon groups exemplified are the same as those exemplified above.

[0470] The synthesis of the sulfonium salt containing the anion represented by the formula (3D) is described in detail in Japanese Patent Application Laid-Open Nos. 2010-215608 and 2014-133723.

[0471] Specific examples of the anion represented by the formula (3D) include those shown below, but are not limited to these.

[0472] [Chemistry 147]

[0473]

[0474] [Chemistry 148]

[0475]

[0476] In addition, the photoacid generator containing the anion represented by formula (3D) has no fluorine atom at the α position of the sulfonic acid group, but has two trifluoromethyl groups at the β position, so it has sufficient acidity to cut off the acid-labile group in the base polymer. Therefore, it can be used as a photoacid generator.

[0477] As the photoacid generator, a photoacid generator represented by the following formula (4) can also be preferably used.

[0478] [Chemistry 149]

[0479]

[0480] In formula (4), R 201 and R 202 Each independently represents a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. 203 is a alkylene group having 1 to 30 carbon atoms which may contain a hetero atom. 201 , R 202 and R 203Any two of them may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the aforementioned ring may be exemplified as in the description of formula (cation-1) with respect to R ct1 and R ct2 The examples of the rings that can be formed together with the sulfur atoms to which they are bonded are the same as those exemplified.

[0481] R 201 and R 202 The hydrocarbon group having 1 to 30 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl, tricyclo[5.2.1.0 2,6 ] cyclic saturated hydrocarbon groups having 3 to 30 carbon atoms, such as decyl and adamantyl; aryl groups having 6 to 30 carbon atoms, such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, anthracenyl, etc.; groups obtained by combining them, etc. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and the -CH 2 - may be substituted by a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0482] R 203The alkylene group having 1 to 30 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptane-1,17-diyl, and heptadecane-1,18-diyl. ,17-diyl and other alkanediyl groups having 1 to 30 carbon atoms; cyclic saturated alkylene groups having 3 to 30 carbon atoms such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; arylene groups having 6 to 30 carbon atoms such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, and tert-butylnaphthylene; groups obtained by combining them, etc. In addition, part or all of the hydrogen atoms of the aforementioned alkylene groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and the -CH 2 - may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. As for the hetero atom, an oxygen atom is preferably used.

[0483] In formula (4), L A is a single bond, an ether bond, or an alkylene group having 1 to 20 carbon atoms which may contain heteroatoms. The aforementioned alkylene group may be saturated or unsaturated, and may be straight chain, branched, or cyclic. Specific examples thereof include: 203 The alkylene groups exemplified are the same as those exemplified above.

[0484] In formula (4), X A , X B , X C and X D Each independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group. A , X B , X C and X D At least one of them is a fluorine atom or a trifluoromethyl group.

[0485] In formula (4), k is an integer from 0 to 3.

[0486] The photoacid generator represented by the formula (4) is preferably represented by the following formula (4').

[0487] [Chemistry 150]

[0488]

[0489] In formula (4'), L A Same as above. HF R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 301 , R 302 and R 303 Each is independently a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: fa1 The hydrocarbon groups represented by are the same as those exemplified above. x and y are each independently an integer of 0 to 5. z is an integer of 0 to 4.

[0490] Examples of the photo-acid generator represented by formula (4) include the same ones as exemplified for the photo-acid generator represented by formula (2) in JP-A-2017-26980.

[0491] Among the above-mentioned photoacid generators, those containing anions represented by formula (3A') or (3D) are particularly preferred because they have low acid diffusion and excellent solubility in solvents. Those represented by formula (4') are particularly preferred because they have extremely low acid diffusion.

[0492] Moreover, as other acid generators, sulfonium salts and iodonium salts containing an anion having an aromatic ring substituted with an iodine atom represented by the following formula (5-1) or (5-2) can also be used.

[0493] [Chemistry 151]

[0494]

[0495] In formula (5-1) and (5-2), p is 1, 2 or 3. q and r are integers satisfying 1≤q≤5, 0≤r≤3 and 1≤q+r≤5. q is preferably 1, 2 or 3, more preferably 2 or 3. r is preferably 0, 1 or 2.

[0496] In formula (5-1) and (5-2), L 1 It is a single bond, an ether bond, or an ester bond, or a saturated alkylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond. The saturated alkylene group may be linear, branched, or cyclic.

[0497] In formula (5-1) and (5-2), L 2 When p is 1, it is a single bond or a divalent linking group having 1 to 20 carbon atoms. When p is 2 or 3, it is a (p+1)-valent linking group having 1 to 20 carbon atoms. The linking group may also contain an oxygen atom, a sulfur atom or a nitrogen atom.

[0498] In formula (5-1) and (5-2), R 401 is a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbonoxy group having 1 to 20 carbon atoms, a hydrocarboncarbonyl group having 2 to 20 carbon atoms, a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms or a hydrocarbonsulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group or an ether bond, or -N(R 401A )(R 401B )、-N(R 401C )-C(=O)-R 401D or -N(R 401C )-C(=O)-OR 401D . R 401A and R 401B Each R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 401C R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. 401D It is an aliphatic hydrocarbon group having 1 to 16 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms. The aforementioned aliphatic hydrocarbon group may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. The aforementioned hydrocarbon group, hydrocarbonoxy group, hydrocarbon carbonyl group, hydrocarbon oxycarbonyl group, hydrocarbon carbonyloxy group, and hydrocarbon sulfonyloxy group may be straight-chain, branched, or cyclic. When p and / or r are 2 or more, each R 401 They can be the same as or different from each other.

[0499] Among these, R 401 For hydroxyl, -N(R 401C )-C(=O)-R 401D 、-N(R 401C )-C(=O)-OR 401D , fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group and the like are preferred.

[0500] In formula (5-1) and (5-2), Rf 11 ~Rf 14 Each independently represents a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group.11 With Rf 12 They may also be combined to form a carbonyl group. In particular, Rf 13 and Rf 14 Preferably, they are all fluorine atoms.

[0501] In formula (5-1) and (5-2), R 402 ~R 406 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include the following: ct1 ~R ct5 The hydrocarbon groups exemplified in the above are the same as those exemplified. In addition, part or all of the hydrogen atoms of the above hydrocarbon groups may be substituted by hydroxyl groups, carboxyl groups, halogen atoms, cyano groups, nitro groups, thiol groups, sultone rings, sulfonic acid groups or groups containing sulfonium salts. 2 - may be substituted by an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond or a sulfonate bond. 402 and R 403 They may also be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring may be exemplified by the same formula (cation-1) with respect to R ct1 and R ct2 The examples of the rings that can be formed together with the sulfur atoms to which they are bonded are the same as those exemplified.

[0502] Specific examples of the cation of the sulfonium salt represented by formula (5-1) include the same ones as those exemplified for the sulfonium cation represented by formula (cation-1). Specific examples of the cation of the iodonium salt represented by formula (5-2) include the same ones as those exemplified for the iodonium cation represented by formula (cation-2).

[0503] Specific examples of the anion of the onium salt represented by the formula (5-1) or (5-2) include those shown below, but are not limited to these.

[0504] [Chemistry 152]

[0505]

[0506] [Chemistry 153]

[0507]

[0508] [Chemistry 154]

[0509]

[0510] [Chemistry 155]

[0511]

[0512] [Chemistry 156]

[0513]

[0514] [Chemistry 157]

[0515]

[0516] [Chemistry 158]

[0517]

[0518] [Chemistry 159]

[0519]

[0520] [Chemistry 160]

[0521]

[0522] [Chemistry 161]

[0523]

[0524] [Chemistry 162]

[0525]

[0526] [Chemistry 163]

[0527]

[0528] [Chemistry 164]

[0529]

[0530] [Chemistry 165]

[0531]

[0532] [Chemistry 166]

[0533]

[0534] [Chemistry 167]

[0535]

[0536] [Chemistry 168]

[0537]

[0538] [Chemistry 169]

[0539]

[0540] [Chemistry 170]

[0541]

[0542] [Chemistry 171]

[0543]

[0544] [Chemistry 172]

[0545]

[0546] [Chemistry 173]

[0547]

[0548] When the chemically amplified resist composition of the present invention contains (D) an acid generator, its content is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 20 parts by mass relative to 80 parts by mass of the base polymer (A). If the amount of the acid generator of the component (D) added falls within the aforementioned range, the resolution is good, and there is no concern of foreign matter after the development or peeling of the resist film, so it is more ideal. The (D) acid generator may be used alone or in combination of two or more.

[0549] [(E) Surfactant]

[0550] The chemically amplified resist composition of the present invention may further contain a surfactant as the (E) component. As for the (E) surfactant, it is preferably a surfactant that is insoluble or poorly soluble in water and soluble in an alkaline developer, or a surfactant that is insoluble or poorly soluble in water and an alkaline developer. For such surfactants, reference may be made to those described in Japanese Patent Publication No. 2010-215608 and Japanese Patent Publication No. 2011-16746.

[0551] As for the surfactants that are insoluble or poorly soluble in water and alkali developer, among the surfactants described in the aforementioned gazette, FC-4430 (manufactured by 3M Co., Ltd.), Surflon (registered trademark) S-381 (manufactured by AGC Seimi Chemical Co., Ltd.), Olfine (registered trademark) E1004 (manufactured by Nissin Chemical Co., Ltd.), KH-20, KH-30 (manufactured by AGC Seimi Chemical Co., Ltd.), and the oxetane ring-opening polymer represented by the following formula (surf-1) are particularly preferable.

[0552] [Chemistry 174]

[0553]

[0554] Here, R, Rf, A, B, C, m, and n are irrelevant to the above description and apply only to formula (surf-1). R is a divalent to tetravalent aliphatic group having 2 to 5 carbon atoms. As for the aforementioned aliphatic group, divalent ones include ethylene, 1,4-butylene, 1,2-propylene, 2,2-dimethyl-1,3-propylene, 1,5-pentylene, etc., and trivalent or tetravalent ones include the following.

[0555] [Chemistry 175]

[0556]

[0557] In the formula, the dotted lines are atomic bonds, which are partial structures derived from glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol, respectively.

[0558] Among these, 1,4-butylene group, 2,2-dimethyl-1,3-propylene group and the like are particularly preferred.

[0559] Rf is trifluoromethyl or pentafluoroethyl, preferably trifluoromethyl. m is an integer of 0 to 3, n is an integer of 1 to 4, the sum of n and m is the valence of R, which is an integer of 2 to 4. A is 1. B is an integer of 2 to 25, preferably an integer of 4 to 20. C is an integer of 0 to 10, preferably 0 or 1. In addition, the arrangement of the constituent units in formula (surf-1) is not specified, and they may be bonded in blocks or randomly. The manufacture of surfactants of partially fluorinated oxetane ring-opening polymer system is described in detail in the specification of U.S. Patent No. 5,650,483.

[0560] A surfactant that is insoluble or poorly soluble in water and soluble in an alkaline developer has the function of reducing water penetration and leaching by aligning to the surface of the resist film when a resist protective film is not used in ArF immersion lithography. Therefore, it is useful for inhibiting the elution of water-soluble components from the resist film and reducing damage to the exposure device. In addition, it is useful because it can be dissolved during development with an alkaline aqueous solution after exposure or after post-exposure baking (PEB) and is not easy to form foreign matter that may cause defects. This type of surfactant has the property of being insoluble or poorly soluble in water and soluble in an alkaline developer. It is a polymer-type surfactant, also known as a hydrophobic resin, and is particularly ideal for having high water repellency and improving water sliding properties.

[0561] Specific examples of such polymeric surfactants include those containing at least one type of repeating units selected from the group consisting of the repeating units represented by the following formulae (6A) to (6E).

[0562] [Chemistry 176]

[0563]

[0564] In formulas (6A) to (6E), R B W is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 1 -CH 2 -、-CH 2 CH 2 -, -O- or two -H separated from each other. s1 Each R is independently a hydrogen atom or a hydrocarbon group having 1 to 10 carbon atoms. s2 is a single bond, or a linear or branched alkylene group having 1 to 5 carbon atoms. s3 Each R is independently a hydrogen atom, a hydrocarbon group or a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group. s3 When it is a hydrocarbon group or a fluorinated hydrocarbon group, the carbon-carbon bonds may be separated by ether bonds or carbonyl groups. s4 is a (u+1)-valent hydrocarbon group or a fluorinated hydrocarbon group having 1 to 20 carbon atoms. u is an integer of 1 to 3. s5 are each independently a hydrogen atom, or -C(=O)-OR sa Represents a group. sa is a fluorinated hydrocarbon group having 1 to 20 carbon atoms. s6 It is a hydrocarbon group or a fluorinated hydrocarbon group having 1 to 15 carbon atoms, and the carbon-carbon bonds thereof may be separated by ether bonds or carbonyl groups.

[0565] R s1 The hydrocarbon group having 1 to 10 carbon atoms represented by is preferably a saturated hydrocarbon group, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl. Among these, those having 1 to 6 carbon atoms are more preferred.

[0566] R s2 The alkylene group represented by is preferably a saturated alkylene group, and may be linear, branched or cyclic. Specific examples thereof include methylene, ethylene, propylene, butylene and pentylene.

[0567] R s3 or R s6 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include saturated hydrocarbon groups, alkenyl groups, alkynyl groups, and other aliphatic unsaturated hydrocarbon groups, but saturated hydrocarbon groups are more preferred. s1In addition to the hydrocarbon groups exemplified above, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl and the like can be mentioned. s3 or R s6 As for the fluorinated hydrocarbon groups represented by , some or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbon groups are substituted with fluorine atoms. As mentioned above, these carbon-carbon bonds may be separated by ether bonds or carbonyl groups.

[0568] Just R s3 Examples of the acid-labile group include groups represented by the above formulae (AL-3) to (AL-5), trialkylsilyl groups in which each alkyl group is an alkyl group having 1 to 6 carbon atoms, and alkyl groups having an oxo group having 4 to 20 carbon atoms.

[0569] Just R s4 The (u+1)-valent hydrocarbon group or fluorinated hydrocarbon group represented by may be linear, branched or cyclic, and specific examples thereof include groups obtained by removing u hydrogen atoms from the above-mentioned hydrocarbon group or fluorinated hydrocarbon group.

[0570] Just R sa The fluorinated hydrocarbon group represented by is preferably saturated, and may be linear, branched or cyclic. Specific examples thereof include those in which a part or all of the hydrogen atoms of the above-mentioned hydrocarbon groups are substituted with fluorine atoms. Specific examples thereof include trifluoromethyl, 2,2,2-trifluoroethyl, 3,3,3-trifluoro-1-propyl, 3,3,3-trifluoro-2-propyl, 2,2,3,3-tetrafluoropropyl, 1,1,1,3,3,3-hexafluoroisopropyl, 2,2,3,3,4,4,4-heptafluorobutyl, 2,2,3,3,4,4,5,5-octafluoropentyl, 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptyl, 2-(perfluorobutyl)ethyl, 2-(perfluorohexyl)ethyl, 2-(perfluorooctyl)ethyl, and 2-(perfluorodecyl)ethyl.

[0571] Specific examples of the repeating unit represented by any one of formulae (6A) to (6E) include those shown below, but are not limited to these. B Same as above.

[0572] [Chemistry 177]

[0573]

[0574] [Chemistry 178]

[0575]

[0576] [Chemistry 179]

[0577]

[0578] [Chemistry 180]

[0579]

[0580] [Chemistry 181]

[0581]

[0582] The aforementioned polymeric surfactant may also contain other repeating units other than the repeating units represented by formulas (6A) to (6E). As for other repeating units, repeating units obtained from methacrylic acid, α-trifluoromethylacrylic acid derivatives, etc. can be cited. In the polymeric surfactant, the content of the repeating units represented by formulas (6A) to (6E) is preferably 20 mol% or more, more preferably 60 mol% or more, and even more preferably 100 mol% in the total repeating units.

[0583] The Mw of the polymer surfactant is preferably 1,000 to 500,000, more preferably 3,000 to 100,000. The Mw / Mn is preferably 1.0 to 2.0, more preferably 1.0 to 1.6.

[0584] As for the method of synthesizing the aforementioned polymer surfactant, there can be cited a method in which a monomer containing an unsaturated bond which will provide repeating units represented by formulas (6A) to (6E) and other repeating units as needed is added with a free radical initiator to an organic solvent and heated to polymerize. As for the organic solvent used in the polymerization, there can be cited toluene, benzene, THF, diethyl ether, dioxane, etc. As for the polymerization initiator, there can be cited to be AIBN, 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide, etc. The reaction temperature is preferably 50 to 100°C. The reaction time is preferably 4 to 24 hours. Acid-labile groups can also be used directly introduced into the monomer, or they can be protected or partially protected after polymerization.

[0585] When synthesizing the polymer surfactant, a known chain transfer agent such as dodecanethiol or 2-mercaptoethanol may be used to adjust the molecular weight. In this case, the amount of the chain transfer agent added is preferably 0.01 to 10 mol% relative to the total molar number of the monomers to be polymerized.

[0586] When the chemically amplified resist composition of the present invention contains (E) surfactant, its content is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 10 parts by mass relative to 80 parts by mass of the base polymer (A). If the content of (E) surfactant is 0.1 parts by mass or more, the receding contact angle between the resist film surface and water will be sufficiently improved, and if it is 50 parts by mass or less, the dissolution rate of the resist film surface to the developer is low, which will fully ensure the height of the formed fine pattern. (E) Surfactants can be used alone or in combination of two or more.

[0587] [(F) Dissolution inhibitor]

[0588] The chemically amplified resist composition of the present invention may further contain a dissolution inhibitor as component (F). When the chemically amplified resist composition of the present invention is positive type, by adding a dissolution inhibitor, the difference in dissolution rate between the exposed part and the unexposed part can be increased, thereby further improving resolution.

[0589] As for the above-mentioned dissolution inhibitor, there can be mentioned compounds such as a molecular weight of preferably 100 to 1000, more preferably 150 to 800, wherein the hydrogen atom of the phenolic hydroxyl group of a compound containing two or more phenolic hydroxyl groups in the molecule is replaced by an acid-labile group at a ratio of 0 to 100 mol% in total, or a compound containing a carboxyl group in the molecule, wherein the hydrogen atom of the carboxyl group is replaced by an acid-labile group at a ratio of 50 to 100 mol% in total. Specifically, there can be mentioned compounds such as bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalenecarboxylic acid, adamantanecarboxylic acid, cholic acid, and the like, and those recorded in paragraphs

[0155] to

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

[0590] When the chemically amplified resist composition of the present invention contains (F) a dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, based on 80 parts by mass of the (A) base polymer.

[0591] [(G) Other ingredients]

[0592] The chemically amplified resist composition of the present invention may also contain compounds that decompose and generate acid due to acid (acid proliferation compounds), organic acid derivatives, fluorine-substituted alcohols, water repellency improvers, etc. as (G) other components. For the aforementioned acid proliferation compounds, reference may be made to the compounds described in Japanese Patent Publication No. 2009-269953 or Japanese Patent Publication No. 2010-215608. When the aforementioned acid proliferation compound is included, its content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the (A) base polymer, and more preferably 0 to 3 parts by mass. If the content is too much, it is difficult to control the diffusion of acid, and there is a risk of degradation of resolution and pattern shape. For the aforementioned organic acid derivatives and fluorine-substituted alcohols, reference may be made to the compounds described in Japanese Patent Publication No. 2009-269953 or Japanese Patent Publication No. 2010-215608.

[0593] The aforementioned water repellency improver can be used in immersion photolithography without top coat. As for the aforementioned water repellency improver, it is more ideal to be a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and the like, and it is more ideal to be exemplified in Japanese Patent Publication No. 2007-297590, Japanese Patent Publication No. 2008-111103, etc. The aforementioned water repellency improver is necessary to be dissolved in an alkaline developer or an organic solvent developer. The water repellency improver having the aforementioned specific 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As for the water repellency improver, a polymer containing a repeating unit containing an amino group or an ammonium salt has a high effect of preventing the evaporation of the acid in the PEB and preventing the poor opening of the hole pattern after development. When the chemically amplified resist composition of the present invention contains the water repellency improving agent, the content thereof is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, based on 80 parts by mass of the (A) base polymer.

[0594] [Pattern Formation Method]

[0595] When the chemically amplified resist composition of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be applied. For example, as for the pattern forming method, there can be cited a method including the following steps: forming a resist film on a substrate using the chemically amplified resist composition; exposing the resist film to high-energy radiation; and developing the exposed resist film using a developer.

[0596] First, the chemically amplified resist composition of the present invention is applied to a substrate (Si, SiO2) for integrated circuit manufacturing by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor blade coating so that the coating film thickness becomes 0.01 to 2.0 μm. 2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflection film, etc.) or substrates for mask circuit manufacturing (Cr, CrO, CrON, MoSi 2 、SiO 2 It is pre-baked on a hot plate at a temperature of preferably 60 to 150° C. for 10 seconds to 30 minutes, more preferably 80 to 120° C. for 30 seconds to 20 minutes, to form a resist film.

[0597] Then, the resist film is exposed using high-energy radiation. Examples of the high-energy radiation include ultraviolet rays, far ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. When ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. are used as the high-energy radiation, the exposure is preferably 1 to 200 mJ / cm directly or using a mask for forming a target pattern. 2 About 10 to 100 mJ / cm 2 When EB is used as the high energy ray, the exposure dose is preferably 0.1 to 100 μC / cm 2 About 0.5 to 50 μC / cm 2 The chemically amplified resist composition of the present invention is particularly suitable for fine patterning by ArF excimer laser with a wavelength of 193nm, KrF excimer laser with a wavelength of 248nm, EB or EUV with a wavelength of 3 to 15nm, X-ray, soft X-ray, gamma ray or synchrotron radiation.

[0598] After the exposure, PEB may be performed on a hot plate at preferably 60 to 150° C. for 10 seconds to 30 minutes, more preferably 80 to 120° C. for 30 seconds to 20 minutes.

[0599] After exposure or PEB, a developer containing 0.1 to 10% by mass, preferably 2 to 5% by mass, of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc. is used to develop by a general method such as a dip method, a puddle method, or a spray method for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, so that the portion irradiated with light is dissolved in the developer, while the portion not exposed is not dissolved, thereby forming a desired positive pattern on the substrate.

[0600] An organic solvent developer may be used instead of the alkaline aqueous solution to obtain a negative pattern. Specific examples of the developer used at this time include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, isoamyl formate, methyl valerate, methyl pentenoate, methyl croton ... Ethyl beanate, methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, benzyl formate, phenylethyl formate, methyl 3-phenylpropionate, benzyl propionate, ethyl phenylacetate, 2-phenylethyl acetate, etc. These organic solvents may be used alone or in combination of two or more.

[0601] When the development is terminated, rinsing may be performed. As for the rinsing liquid, a solvent that is miscible with the developer and does not dissolve the resist film is preferred. As for such a solvent, alcohols having 3 to 10 carbon atoms, ether compounds having 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents having 6 to 12 carbon atoms can be preferably used.

[0602] Specific examples of the alcohol having 3 to 10 carbon atoms include n-propanol, isopropanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentanol, neopentyl alcohol, 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-hexanol, 2,3-dimethyl-3-pentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 2,3-dimethyl-3-pentanol, 2,3-dimethyl-3-pentanol, ,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, etc.

[0603] Specific examples of the ether compound having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, and di-n-hexyl ether.

[0604] Specific examples of the aforementioned alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Specific examples of the aforementioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Specific examples of the aforementioned alkynes having 6 to 12 carbon atoms include hexyne, heptyne, octyne, etc.

[0605] Specific examples of the aromatic solvent include toluene, xylene, ethylbenzene, cumene, tert-butylbenzene, mesitylene, and the like.

[0606] By performing rinsing, the occurrence of collapse and defects of the resist pattern can be reduced. In addition, rinsing is not essential, and by not performing rinsing, the amount of solvent used can be reduced.

[0607] The developed hole pattern and trench pattern can also be shrunk by heat flow, RELACS technology or DSA technology. When a shrinking agent is applied to the hole pattern, the shrinking agent will crosslink on the surface of the resist film due to the diffusion of the acid catalyst from the resist film during baking, and the shrinking agent will adhere to the side wall of the hole pattern. The baking temperature is preferably 70-180°C, more preferably 80-170°C, and the baking time is preferably 10-300 seconds. The excess shrinking agent is removed to shrink the hole pattern.

[0608] Example

[0609] Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples. The following apparatuses were used.

[0610] ·MALDI TOF-MS: S3000 manufactured by JEOL Ltd.

[0611] [1] Synthesis of onium salt monomers

[0612] [Example 1-1] Synthesis of Onium Salt Monomer a-1

[0613] [Chemistry 182]

[0614]

[0615] (1) Synthesis of intermediate In-1

[0616] Under nitrogen environment, compound SM-1 (29.6 g), compound SM-2 (87.0 g), 4-dimethylaminopyridine (DMAP) (2.4 g) and dichloromethane (500 g) were fed into a reaction container and cooled with an ice bath. While maintaining the temperature in the reaction container below 20°C, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride (46.0 g) was added in the form of powder. After addition, the temperature was raised to room temperature and matured for 12 hours. After maturation, water was added to stop the reaction, and the usual aqueous work-up was performed to distill off the solvent, thereby obtaining the intermediate In-1 (yield 87.2 g, yield 83%) in the form of an oil.

[0617] (2) Synthesis of onium salt monomer a-1

[0618] Under nitrogen atmosphere, the intermediate In-1 (52.6 g) and the compound SM-3 (41.0 g) were mixed with dichloromethane (500 g) and water (300 g) and stirred at room temperature for 1 hour. After stirring, the mixture was subjected to a conventional aqueous work-up, the solvent was distilled off, and diisopropyl ether was added to wash the mixture, thereby obtaining the target onium salt monomer a-156.7 g (yield 89%) in the form of an oil.

[0619] MALDI TOF-MS:POSITIVE M + 261 (equivalent to C 18 H 13 S + )

[0620] NEGATIVE M - 375 (equivalent to C 15 H 7 F 4 O 5 S - )

[0621] [Examples 1-2 to 1-7] Synthesis of Onium Salt Monomers a-2 to a-7

[0622] Onium salt-type monomers a-2 to a-7 represented by the following formulae are synthesized using corresponding raw materials and known organic synthesis reactions.

[0623] [Chemistry 183]

[0624]

[0625] [Comparative Examples 1-1 to 1-6] Synthesis of Comparative Monomers ca-1 to ca-6

[0626] Comparative monomers ca1 to ca6 represented by the following formulae were synthesized using corresponding raw materials and known organic synthesis reactions.

[0627] [Chemistry 184]

[0628]

[0629] [2] Synthesis of base polymer

[0630] The monomers used for the synthesis of the base polymer other than monomer a-1 to monomer a-7 and comparative monomer ca-1 to monomer ca-6 are as follows.

[0631] [Chemistry 185]

[0632]

[0633] [Chemistry 186]

[0634]

[0635] [Chemistry 187]

[0636]

[0637] [Example 2-1] Synthesis of polymer P-1

[0638] Under a nitrogen environment, monomer a-1 (15.1 g), monomer b1-1 (19.4 g), monomer c-1 (5.7 g), 1.81 g of V-601 (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 56 g of MEK were placed in a flask to prepare a monomer-polymerization initiator solution. In another flask set in a nitrogen environment, 19 g of MEK was placed, and after heating to 80°C while stirring, the aforementioned monomer-polymerization initiator solution was added dropwise over 4 hours. After the addition was terminated, the temperature of the polymerization liquid was maintained at 80°C and stirred for 2 hours, and then cooled to room temperature. The obtained polymerization liquid was added dropwise to 1200 g of hexane after vigorous stirring, and the precipitated polymer was filtered. After the obtained polymer was washed twice with 240 g of hexane, it was vacuum dried at 50°C for 20 hours to obtain a white powdery polymer P-1 (yield 98.1 g, yield 98%). The Mw of polymer P-1 was 9300 and the Mw / Mn was 1.72. Mw is a polystyrene-equivalent measurement value obtained by GPC using DMF as a solvent.

[0639] [Chemistry 188]

[0640]

[0641] [Examples 2-2 to 2-20, Comparative Examples 2-1 to 2-15] Synthesis of Polymers P-2 to P-20 and Comparative Polymers CP-1 to CP-15

[0642] The polymers shown in Tables 1 and 2 were produced in the same manner as in Synthesis Example 2-1 except that the types and blending ratios of the monomers were changed.

[0643] [Table 1]

[0644]

[0645]

[0646] [Table 2]

[0647]

[0648]

[0649] [3] Preparation of chemically amplified resist compositions

[0650] [Examples 3-1 to 3-20, Comparative Examples 3-1 to 3-15]

[0651] Predetermined components selected from the base polymers (P-1 to P-20) of the present invention, the base polymers for comparison (CP-1 to CP-15), the acid generators (PAG-1, PAG-2) and the quenchers (SQ-1 to SQ-3, AQ-1) were dissolved in a solvent containing 0.01% by mass of FC-4430 manufactured by 3M Company as a surfactant in the compositions shown in the following Tables 3 and 4 to prepare a solution, and the solution was filtered through a 0.2 μm Teflon (registered trademark) type filter material to prepare chemically amplified resist compositions (R-1 to R-20, CR-1 to CR-15).

[0652] [Table 3]

[0653]

[0654] [Table 4]

[0655]

[0656] In Tables 3 and 4, the solvents, quenchers (SQ-1 to SQ-3, AQ-1) and acid generators (PAG-1, PAG-2) are as follows.

[0657] Solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0658] DAA (Diacetone Alcohol)

[0659] Quenching agent: SQ-1~SQ-3, AQ-1

[0660] [Chemistry 189]

[0661]

[0662] Acid generator: PAG-1, PAG-2

[0663] [Chemistry 190]

[0664]

[0665] [4]EUV lithography evaluation (1)

[0666] [Examples 4-1 to 4-20, Comparative Examples 4-1 to 4-15]

[0667] Each chemically amplified resist composition (R-1 to R-20, CR-1 to CR-15) shown in Tables 3 and 4 was spin-coated on a Si substrate on which a silicon-containing spin-coating hard mask SHB-A940 (containing 43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and pre-baked at 100° C. for 60 seconds using a hot plate to prepare a resist film with a film thickness of 50 nm. The resist film was exposed by an EUV scanning exposure machine NXE3300 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, dipole illumination) while changing the exposure amount and focus (exposure amount pitch: 1 mJ / cm 2 , focal pitch: 0.020 μm) while exposing an LS pattern with a size of 18 nm and a pitch of 36 nm on the wafer, and after exposure, PEB was performed for 60 seconds at the temperature shown in Tables 5 and 6. Thereafter, immersion development was performed for 30 seconds with a 2.38 mass % TMAH aqueous solution, rinsed with a rinse material containing a surfactant, and spin-dried to obtain a positive pattern.

[0668] The obtained LS pattern was observed with CD-SEM (CG6300) manufactured by Hitachi Advanced Technologies Co., Ltd., and the sensitivity, EL, LWR, DOF and collapse limit were evaluated according to the following methods. The results are shown in Tables 5 and 6.

[0669] [Sensitivity evaluation]

[0670] Determine the optimal exposure E to obtain an LS pattern with a line width of 18 nm and a pitch of 36 nm. op (mJ / cm 2 ) and use it as the sensitivity. The smaller the value, the higher the sensitivity.

[0671] [EL evaluation]

[0672] The EL (unit: %) was calculated from the exposure amount formed in the range of ±10% (16.2 to 19.8 nm) of the interval width of 18 nm in the above LS pattern according to the following formula. The larger the value, the better the performance.

[0673] EL(%)=(|E 1 -E 2 | / E op )×100

[0674] E 1 :Provide the optimal exposure for LS pattern with line width of 16.2nm and pitch of 36nm

[0675] E 2 :Provide the optimal exposure for LS pattern with line width of 19.8nm and pitch of 36nm

[0676] E op :Provide the optimal exposure for LS pattern with line width of 18nm and pitch of 36nm

[0677] [LWR evaluation]

[0678] For E op The LS pattern obtained by irradiation is measured at 10 locations in the long side direction of the line, and the value (3σ) triple the standard deviation (σ) is calculated as LWR. The smaller the value, the smaller the roughness and the more uniform the line width pattern can be obtained.

[0679] [DOF evaluation]

[0680] The focal depth was evaluated by determining the focal range formed within the range of ±10% (16.2 to 19.8 nm) of the 18 nm size in the LS pattern. The larger the value, the wider the focal depth.

[0681] [Evaluation of the collapse limit of line patterns]

[0682] The line size of each exposure amount in the optimal focus of the LS pattern was measured at 10 locations in the long-side direction. The thinnest line size that can be obtained without collapse is defined as the collapse limit size. The smaller the value, the better the collapse limit.

[0683] [Table 5]

[0684]

[0685] [Table 6]

[0686]

[0687]

[0688] From the results shown in Tables 5 and 6, it can be understood that the chemically amplified resist composition using the base polymer containing the repeating unit derived from the onium salt-type monomer of the present invention has good sensitivity and is excellent in EL, LWR and DOF. In addition, it was confirmed that the value of the collapse limit is small, and the collapse resistance of the pattern is strong even in the formation of a fine pattern. Therefore, it is shown that the chemically amplified resist composition of the present invention is suitable as a material for EUV lithography.

[0689] [5]EUV lithography evaluation (2)

[0690] [Examples 5-1 to 5-20, Comparative Examples 5-1 to 5-15]

[0691] Each chemically amplified resist composition (R-1 to R-20, CR-1 to CR-15) shown in Tables 3 and 4 was spin-coated on a Si substrate on which a silicon-containing spin-coated hard mask SHB-A940 (containing 43% by mass of silicon) manufactured by Shin-Etsu Chemical Co., Ltd. was formed with a film thickness of 20 nm, and pre-baked at 105° C. for 60 seconds using a hot plate to prepare a resist film with a film thickness of 50 nm. This was exposed using an EUV scanner exposure machine NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, mask with a hole pattern having a size of 46 nm pitch and +20% deviation on the wafer), and PEB was performed for 60 seconds using a hot plate at the temperature described in Tables 7 and 8, and developed for 30 seconds using a 2.38% by mass TMAH aqueous solution to form a hole pattern having a size of 23 nm.

[0692] The exposure amount when a hole size of 23 nm was formed was measured using CD-SEM (CG6300) manufactured by Hitachi Advanced Technology Co., Ltd. and the sensitivity was taken. The size of 50 holes at this time was measured and the value (3σ) three times the standard deviation (σ) calculated from the result was taken as the size deviation (CDU). The results are shown in Tables 7 and 8.

[0693] [Table 7]

[0694]

[0695]

[0696] [Table 8]

[0697]

[0698] From the results shown in Tables 7 and 8, it was confirmed that the chemically amplified resist composition of the present invention had good sensitivity and excellent CDU.

[0699] [6] Dry etching resistance evaluation

[0700] [Examples 6-1 to 6-20, Comparative Examples 6-1 to 6-15]

[0701] 2 g of each polymer shown in Tables 1 and 2 (polymers P-1 to P-20, comparative polymers CP-1 to CP-15) was dissolved in 10 g of cyclohexanone, and the polymer solution obtained by filtering with a 0.2 μm filter material was spin-coated on a Si substrate to form a film with a thickness of 300 nm, which was evaluated under the following conditions.

[0702] In CHF 3 / CF 4 Etching test with gas:

[0703] Using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Co., Ltd., the difference in film thickness of the polymer film before and after etching was determined.

[0704] The etching conditions are as follows.

[0705] Chamber pressure 40Pa

[0706] RF power 1000W

[0707] Clearance 9mm

[0708] CHF 3 Gas flow rate 30mL / min

[0709] CF 4 Gas flow rate 30mL / min

[0710] Ar gas flow rate 100 mL / min

[0711] Time 60 seconds

[0712] In this evaluation, it was found that the film with less difference in film thickness, that is, the film with less reduction, had higher etching resistance.

[0713] Tables 9 and 10 show the results of the dry etching resistance.

[0714] [Table 9]

[0715]

[0716]

[0717] [Table 10]

[0718] polymer <![CDATA[CHF 3 / CF 4 Gas etching rate (nm / min)]]> Comparative Example 6-1 CP-1 108 Comparative Example 6-2 CP-2 99 Comparative Example 6-3 CP-3 110 Comparative Example 6-4 CP-4 107 Comparative Example 6-5 CP-5 99 Comparative Example 6-6 CP-6 98 Comparative Examples 6-7 CP-7 105 Comparative Examples 6-8 CP-8 108 Comparative Examples 6-9 CP-9 106 Comparative Examples 6-10 CP-10 104 Comparative Examples 6-11 CP-11 99 Comparative Examples 6-12 CP-12 98 Comparative Examples 6-13 CP-13 109 Comparative Examples 6-14 CP-14 108 Comparative Examples 6-15 CP-15 107

[0719] The results shown in Tables 9 and 10 confirm that the polymer of the present invention has a 3 / CF 4 The system gas has excellent dry etching resistance.

Claims

1. An onium salt type monomer represented by the following formula (a); Wherein, n1 is 0 or 1; n2 is 0 or 1; n3 is an integer from 0 to 4; n4 is an integer from 0 to 4; n5 is an integer from 0 to 4; however, when n2=0, 0≤n4+n5≤4, and when n2=1, 0≤n4+n5≤6; and n1 to n5 may not all be 0; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 1 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms; when n3 is 2, 3 or 4, the plural R 1 They may also be bonded to each other and to the carbon atoms of the aromatic rings to which they are bonded to form a ring; R 2 is a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms; when n4 is 2, 3 or 4, the plural R 2 They may also bond to each other and form a ring together with the carbon atoms to which they are bonded; R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms; L A and L B each independently a single bond, an ether bond, an ester bond, a sulfonate bond, a sulfonamide bond, a carbonate bond or a carbamate bond; X L is a single bond or an alkylene group having 1 to 40 carbon atoms which may contain a hetero atom; Z + It is an onium cation.

2. The onium salt type monomer according to claim 1, represented by the following formula (a1); In the formula, n2~n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z + Same as above.

3. The onium salt type monomer according to claim 2, represented by the following formula (a2); In the formula, n2~n5, R A , R 1 , R 2 , R F , L A and Z + Same as above.

4. The onium salt type monomer according to claim 1, wherein Z + It is a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2); In the formula, R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom; and R ct1 and R ct2 They may also bond to each other to form a ring together with the sulfur atom to which they are bonded. 5 . A polymer comprising a repeating unit derived from the onium salt type monomer according to claim 1 .

6. The polymer according to claim 5, further comprising a repeating unit represented by the following formula (b1) or (b2); In the formula, R A are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; X 1 is a single bond, phenylene, naphthylene, *-C(=O)-OX 11 - or *-C(=O)-NH-X 11 -, the phenylene or naphthylene group may be substituted by an alkoxy group having 1 to 10 carbon atoms which may also contain a fluorine atom or a halogen atom; X 11 A saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, wherein the saturated alkylene group may also contain a hydroxyl group, an ether bond, an ester bond or a lactone ring; X 2 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * indicates atomic bonds to carbon atoms of the backbone; AL 1 and AL 2 are each independently an acid-labile group; R 11 is a halogen atom, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom; a is an integer from 0 to 4.

7. The polymer according to claim 5, further comprising a repeating unit represented by the following formula (c1); In the formula, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; Y 1 is a single bond, *-C(=O)-O- or *-C(=O)-NH-; * represents an atomic bond to a carbon atom of the main chain; R 21 is a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarbonoxy group having 1 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom, a hydrocarboncarbonyloxy group having 2 to 20 carbon atoms which may contain a hetero atom, or a hydrocarbonoxycarbonyl group having 2 to 20 carbon atoms which may contain a hetero atom; c is an integer from 1 to 4; d is an integer from 0 to 3; however, 1≤c+d≤5.

8. The polymer according to claim 5, further comprising a repeating unit represented by the following formula (d1); In the formula, R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; Z 1 is a single bond, phenylene, naphthylene, *-C(=O)-OZ 11 - or *-C(=O)-NH-Z 11 -, or the phenylene or naphthylene group may be substituted by an alkoxy group having 1 to 10 carbon atoms which may also contain a fluorine atom or a halogen atom; * represents an atomic bond to a carbon atom of the main chain; Z 11 A saturated alkylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, wherein the saturated alkylene group may also contain a hydroxyl group, an ether bond, an ester bond or a lactone ring; R 31 A group having 1 to 20 carbon atoms and a structure containing at least one selected from the group consisting of a hydroxyl group other than a phenolic hydroxyl group, a cyano group, a carbonyl group, a carboxyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, and a carboxylic anhydride (—C(═O)—OC(═O)—). 9 . A chemically amplified resist composition comprising (A) a base polymer comprising the polymer according to claim 5 . 10 . The chemically amplified resist composition according to claim 9 , further comprising (B) an organic solvent.

11. The chemically amplified resist composition according to claim 9, further comprising (C) a quencher. 12 . The chemically amplified resist composition according to claim 9 , further comprising (D) an acid generator.

13. The chemically amplified resist composition according to claim 9, further comprising (E) a surfactant.

14. The chemically amplified resist composition according to claim 9, further comprising (F) a dissolution inhibitor.

15. A method for forming a pattern, comprising the following steps: The steps of forming a resist film on a substrate using the chemically amplified resist composition according to claim 9; exposing the resist film to high-energy rays; and developing the exposed resist film using a developer.

16. The pattern forming method according to claim 15, wherein: The high-energy radiation is ArF excimer laser with a wavelength of 193 nm, KrF excimer laser with a wavelength of 248 nm, electron beam, or extreme ultraviolet radiation with a wavelength of 3 to 15 nm.

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