Resist composition and pattern forming process

Abstract

The present invention aims to provide a resist material that is highly sensitive whether positive or negative and has improved LWR and CDU, and a pattern forming method using the same. A resist material comprising a biseonium salt comprising a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an onium cation.

Description

Technology Field

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

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern rules is progressing rapidly. This is because the widespread adoption of 5G high-speed communication and artificial intelligence (AI) is creating a need for high-performance devices to process them. As a cutting-edge miniaturization technology, mass production of 5 nm and 3 nm node devices is being carried out using extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm. Furthermore, the use of EUV lithography is being explored for next-generation 2 nm node devices and the next-next-generation 14 Å node devices, and IMEC of Belgium has announced the development of 2 Å devices.

[0003] With the progress of miniaturization, image blurring caused by acid diffusion is becoming a problem. It has been suggested that in order to secure resolution in fine patterns with a size of 45 nm or larger, control of acid diffusion is important in addition to the improvement of dissolution contrast that has been conventionally proposed (Non-patent Literature 1). However, since chemical amplification resist materials increase sensitivity and contrast through acid diffusion, if one attempts to suppress acid diffusion to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the time, sensitivity and contrast are significantly reduced.

[0004] For EUV resist materials, it is necessary to simultaneously achieve high sensitivity, high resolution, and low line with roughness (LWR). Shortening the acid diffusion distance improves LWR and dimensional uniformity (CDU), but reduces sensitivity. For example, lowering the PEB temperature improves LWR and CDU, but reduces sensitivity. Increasing the amount of quencher also improves LWR and CDU, but reduces sensitivity. It is necessary to overcome the trade-off relationship between sensitivity and LWR.

[0005] Resist materials have been proposed in which an onium salt containing an anion having an iodine atom or a bromine atom is added as an acid-generating agent (Patent Documents 1–4). By having an iodine atom with high EUV absorption or a bromine atom with high ionization efficiency, the efficiency of decomposition of the acid-generating agent during exposure is increased, thereby increasing sensitivity. The amount of photon absorption increases, which can increase physical contrast.

[0006] EUV light with a wavelength of 13.5 nm is more than an order of magnitude shorter than ArF excimer laser light with a wavelength of 193 nm, so it has high energy and is significantly affected by variations in the photon number (Non-patent Literature 2). Accordingly, it has been pointed out that LWR deteriorates (Non-patent Literature 3). In addition, with the progress of miniaturization, the influence of LWR deterioration due to variations in the components of the resist material (polymer, acid generator (PAG), quencher (PDQ)) (Resist Stochastics) has also been pointed out (Non-patent Literature 4).

[0007] A resist material comprising a polymer combining PAG and PDQ has been proposed (Patent Document 5). It is claimed that by integrating the polymer with PAG and PDQ, variations in their presence are suppressed, thereby improving LWR or CDU. Additionally, a resist material comprising an additive combining PAG and PDQ has also been proposed (Patent Documents 6 and 7).

[0008] The health effects of perfluoroalkyl compounds (PFAS) have been pointed out, and there are movements under the European REACH to restrict the manufacture and sale of PFAS compounds. In the field of semiconductor lithography, many compounds containing PFAS are currently being used. For example, materials containing them are used as surfactants, acid generators, etc.

[0009] A comparison of resist materials has been reported with an acid-generating agent that generates anions having fluorine atoms bound to a polymer main chain and an acid-generating agent that generates anions not having fluorine bound to a polymer main chain (Non-patent document 5). Here, it is stated that the polymer-bound acid-generating agent that generates anions having fluorine atoms has higher resolution. Sulfonic acid, which has high acid strength, has a higher efficiency of the deprotection reaction, and the introduction of fluorine atoms is effective to increase acid strength.

[0010] Resist materials that generate anions with increased acidity by introducing nitro groups or chlorine atoms without using fluorine atoms have been reported (Non-patent Literature 6). Resist materials with added acid-generating agents that generate anions substituted with nitro groups or chlorine atoms may have higher rectitude compared to resist materials with added acid-generating agents that generate anions substituted with fluorine atoms, but as shown in Table 2 of Non-patent Literature 6, they have the drawback of low sensitivity and high MEEF, which is due to the low acidity of the anions and the low dissolution contrast resulting from low deprotection reactivity. Prior art literature

[0011] [Patent Document 1] Japanese Patent Publication No. 2018-159744 [Patent Document 2] Japanese Patent Publication No. 2018-5224 [Patent Document 3] Japanese Patent Publication No. 2018-25789 [Patent Document 4] Japanese Patent Publication No. 2019-003175 [Patent Document 5] Japanese Patent Publication No. 2022-115072 [Patent Document 6] Japanese Patent Publication No. 2015-024989 [Patent Document 7] International Publication No. 2020 / 158313

[0012] [Non-patent Literature 1] SPIE Vol. 6520 65203L-1(2007)[Non-patent Literature 2] SPIE Vol. 331 535(1998)[Non-patent Literature 3] SPIE Vol. 7273 727343-1(2009)[Non-patent Literature 4] SPIE Vol. 9776 97760V-1(2016)[Non-patent Literature 5] SPIE Vol. 6519 65191F-1(2007)[Non-patent Literature 6] SPIE Vol. 7639 76390D-1(2010) The problem to be solved

[0013] There is a need to develop a resist material that is more sensitive than conventional resist materials and capable of improving the LWR of line patterns and the CDU of hole patterns.

[0014] The present invention, made in consideration of the above circumstances, aims to provide a resist material that is highly sensitive whether positive or negative and has improved LWR and CDU, and a pattern forming method using the same. means of solving the problem

[0015] The inventors, having repeatedly examined the above objective, discovered that by using a bis-onium salt containing an onium cation, a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an acid-generating agent and quencher, the acid-generating agent with high absorption is directly excited by radiation exposure, the influence of secondary electron diffusion is eliminated, acid diffusion is controlled by a nearby quencher, and the influence of phase blurring caused by diffusion is suppressed to a minimum, thereby enabling the production of a resist material with high sensitivity, improved LWR and CDU, high contrast, excellent resolution, and a wide process margin, and thus completed the present invention.

[0016] That is, the present invention provides the following resist material and pattern forming method.

[0017] 1. A resist material comprising a biseonium salt comprising a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an onium cation.

[0018] 2. A resist material of 1 in which the above biseonium salt is represented by the following formula (1).

[0019]

[0020] (In the expression, p is an integer from 1 to 5. q is an integer from 0 to 7.

[0021] X 1 ~X 3 Each is, independently, a single bond, an ether bond, an ester bond, or an amide bond.

[0022] R 1 ~R 3Each is independently a single bond or a hydrocarbylene group having 1 to 30 carbon atoms, and the hydrocarbylene group may include at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom. provided, however, R 1 ~R 3 The upper limit of the sum of the carbon numbers is 30.

[0023] R 4 is, hydrogen atom, hydroxyl group, carboxyl group, fluorine atom, chlorine atom, bromine atom, amino group, nitro group, cyano group, hydrocarbyl group with 1–20 carbon atoms, hydrocarbyloxy group with 1–20 carbon atoms, hydrocarbyloxycarbonyl group with 2–20 carbon atoms, hydrocarbylcarbonyloxy group with 2–20 carbon atoms, hydrocarbylsulfonyloxy group with 1–20 carbon atoms, -N(R 4A )-C(=O)-R 4B , -N(R 4A )-C(=O)-OR 4B or -N(R 4A )-S(=O)2-R 4B And, the above hydrocarbyl group, hydrocarbyloxy group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, hydrocarbylsulfonyloxy group may include at least one selected from a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, an amino group, an ester bond, an ether bond, a urethane bond, a urea bond, a carbonate bond, an amide bond, a sulfonic acid ester bond, a carbonyl group, a sulfide group, and a sulfonyl group. R 4A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and this saturated hydrocarbyl group may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. 4BThe aliphatic hydrocarbyl group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms.

[0024] Ar is an aromatic hydrocarbon group with 6 to 16 carbon atoms (p+q+1).

[0025] Q - is a group having a sulfonimide anion structure or a sulfonamide anion structure.

[0026] M + is a sulfonium cation or an iodonium cation.)

[0027] 3. Q - a. A resist material of 2, represented by any one of the following formulas (Q-1) to (Q-4).

[0028]

[0029] (during food, R 5 Each is independently a saturated hydrocarbyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted with at least one group selected from a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbyl group having 1 to 8 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 8 carbon atoms, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group. * is R 1 It is a combined hand with.)

[0030] 4. Any one of 1 to 3 further comprising a base polymer.

[0031] 5. A resist material of 4 in which the base polymer comprises repeating units represented by the following formula (a1) or (a2).

[0032]

[0033] (during food, R A Each is independently a hydrogen atom or a methyl group.

[0034] Y 1 The linker has 1 to 12 carbon atoms and comprises at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond, an ether bond, and a lactone ring, and the phenylene group, the naphthylene group and the linker may have at least one selected from a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms, and a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms.

[0035] Y 2 is a single bond or an ester bond.

[0036] Y 3 It is a single bond, an ether bond, or an ester bond.

[0037] R 11 and R 12 Each is independently a wildfire stable period.

[0038] R 13 It is silver, a saturated hydrocarbyl group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbylcarbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbyloxycarbonyl group having 2 to 5 carbon atoms.

[0039] R 14 is a single bond or an alkandyl group having 1 to 6 carbon atoms, and the alkandyl group may include an ether bond or an ester bond.

[0040] a is an integer from 0 to 4.

[0041] 6. Resist material of 5, which is a chemically amplified positive type resist material.

[0042] 7. A resist material of 4 in which the base polymer does not contain acid instability groups.

[0043] 8. Resist material of 7, which is a chemically amplified negative type resist material.

[0044] 9. Any one of 1 to 8, further comprising an organic solvent.

[0045] 10. Any one of 1 to 9, further comprising a quencher.

[0046] 11. Any one of 1 to 10 resist materials further comprising an acid-generating agent.

[0047] 12. Any one of 1 to 11, further comprising a surfactant.

[0048] 13. A pattern forming method comprising: a process of forming a resist film on a substrate using any one of 1 to 12 resist materials; a process of exposing the resist film to high-energy rays; and a process of developing the exposed resist film using a developer solution.

[0049] 14. A method for forming a pattern of 13 in which the high-energy line is an ArF excimer laser light with a wavelength of 193 nm, a KrF excimer laser light with a wavelength of 248 nm, an electron beam (EB), or an EUV with a wavelength of 3 to 15 nm. Effects of the invention

[0050] Onium salts of arylsulfonic acids substituted with iodine atoms have the characteristics of having higher absorption of EUV light and higher acid intensity than unsubstituted arylsulfonic acids, and furthermore, arylsulfonic acids substituted with fluorine, and also inhibiting acid diffusion. The diffusion of secondary electrons is inhibited by increasing the ratio of direct excitation reactions due to high absorption. Bis-onium salts having an anion structure in which a quencher is further bonded to arylsulfonic acids substituted with iodine atoms have a high effect of inhibiting acid diffusion and can suppress phase blurring caused by the diffusion of both secondary electrons and acid to the extreme. Since the above-mentioned bis-onium salt is in a form in which an acid-generating agent, which is an onium salt that generates sulfonic acid, and an onium salt that is a quencher are combined so that the acid-generating agent and the quencher are always arranged at a constant distance, the resist film containing this improves the aforementioned Resist Stochastics, thereby improving LWR and CDU. In other words, by the above-mentioned biseonium salt, it becomes possible to construct a resist material that is highly sensitive and has improved LWR and CDU. Specific details for implementing the invention

[0051] [Resist Material]

[0052] The resist material of the present invention comprises a biseonium salt comprising a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an onium cation. The biseonium salt exhibits high reactivity due to the absorption of iodine atoms and high acidity, combined with acid diffusion control properties due to the constant presence of a quencher nearby, resulting in low acid diffusion and uniform diffusion distance. Accordingly, LWR or CDU can be improved.

[0053] The enhancement effect of LWR or CDU by the above-mentioned biseonium salt is effective in both positive pattern formation and negative pattern formation by alkaline aqueous solution phenomenon, and negative pattern formation in organic solvent phenomenon.

[0054] [Bisonium salts]

[0055] The above biseonium salt is preferably represented by the following formula (1).

[0056]

[0057] In Equation (1), p is an integer from 1 to 5. q is an integer from 0 to 7.

[0058] In Equation (1), X 1 ~X 3 Each is, independently, a single bond, an ether bond, an ester bond, or an amide bond.

[0059] In Equation (1), R 1 ~R 3 Each is independently a single bond or a hydrocarbylene group having 1 to 30 carbon atoms, and the hydrocarbylene group may include at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom. However, R 1 ~R 3 The upper limit of the sum of the carbon numbers is 30.

[0060] R 1 ~R 3The hydrocarbylene group represented by may be saturated or unsaturated, and may be a straight chain, a branched chain, or a cyclic chain. Specific examples include a hydrocarbylene group having 1 to 24 carbon atoms in which some or all of the hydrogen atoms are substituted with iodine atoms or bromine atoms. As the above hydrocarbylene group having 1 to 24 carbon atoms, the methane diyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, tridecane-1,13-diyl group, tetradecane-1,14-diyl group, pentadecane-1,15-diyl group, hexadecane-1,16-diyl group, heptadecane-1,17-diyl group, Alkanedyl groups such as octadecane-1,18-diyl group, nonadecane-1,19-diyl group, eicosan-1,20-diyl group; cyclic saturated hydrocarbylene groups such as cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, methylcyclopentanediyl group, dimethylcyclopentanediyl group, trimethylcyclopentanediyl group, tetramethylcyclopentanediyl group, cyclohexanedyl group, methylcyclohexanedyl group, dimethylcyclohexanedyl group, trimethylcyclohexanedyl group, tetramethylcyclohexanedyl group, norbornandyl group, adamantandiyl group; alkenidyl groups having 2 to 20 carbon atoms such as etenediyl group, propenediyl group, butenediyl group; Examples include alkyndiyl groups having 2 to 20 carbon atoms, such as ethindiyl, propindiyl, and buthindiyl; arylene groups, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, isobutylphenylene, sec-butylphenylene, tert-butylphenylene, naphthylene, methylnaphthylene, ethylnaphthylene, n-propylnaphthylene, isopropylnaphthylene, n-butylnaphthylene, isobutylnaphthylene, sec-butylnaphthylene, tert-butylnaphthylene, tetrahydronaphthylene, biphenyldiyl, methylbiphenyldiyl, and dimethylbiphenyldiyl; and groups obtained by combining these.In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group comprising at least one selected from oxygen atoms, nitrogen atoms, sulfur atoms, and halogen atoms, and some of the -CH2- of the hydrocarbylene group may be substituted with a group comprising at least one selected from oxygen atoms, nitrogen atoms, and sulfur atoms, and as a result, may include a hydroxyl group, an ester bond, an ether bond, an amide bond, a carbamate bond, a urea bond, etc.

[0061] In Equation (1), R 4 is, hydrogen atom, hydroxyl group, carboxyl group, fluorine atom, chlorine atom, bromine atom, amino group, nitro group, cyano group, hydrocarbyl group with 1–20 carbon atoms, hydrocarbyloxy group with 1–20 carbon atoms, hydrocarbyloxycarbonyl group with 2–20 carbon atoms, hydrocarbylcarbonyloxy group with 2–20 carbon atoms, hydrocarbylsulfonyloxy group with 1–20 carbon atoms, -N(R 4A )-C(=O)-R 4B , -N(R 4A )-C(=O)-OR 4B or -N(R 4A )-S(=O)2-R 4B And, the above hydrocarbyl group, hydrocarbyloxy group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, hydrocarbylsulfonyloxy group may include at least one selected from a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, an amino group, an ester bond, an ether bond, a urethane bond, a urea bond, a carbonate bond, an amide bond, a sulfonic acid ester bond, a carbonyl group, a sulfide group, and a sulfonyl group. R 4A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and this saturated hydrocarbyl group may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms.4B The aliphatic hydrocarbyl group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms.

[0062] R 4 The hydrocarbyl group represented by, and the hydrocarbyl portion of the hydrocarbyloxy group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group, may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples 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, and icosyl; Cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl groups; alkynyl groups having 2 to 20 carbon atoms, such as ethinyl, propynyl, and butynyl groups; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl groups; Examples include aryl groups having 6 to 20 carbon atoms, such as phenyl groups, methylphenyl groups, ethylphenyl groups, n-propylphenyl groups, isopropylphenyl groups, n-butylphenyl groups, isobutylphenyl groups, sec-butylphenyl groups, tert-butylphenyl groups, naphthyl groups, methyl naphthyl groups, ethyl naphthyl groups, n-propyl naphthyl groups, isopropyl naphthyl groups, n-butyl naphthyl groups, isobutyl naphthyl groups, sec-butyl naphthyl groups, and tert-butyl naphthyl groups; aryl groups having 7 to 20 carbon atoms, such as benzyl groups and phenethyl groups; and groups obtained by combining these.

[0063] In formula (1), Ar is a (p+q+1) aromatic hydrocarbon group having 6 to 16 carbon atoms. Specific examples of the above aromatic hydrocarbon group include a group obtained by removing (p+q+1) hydrogen atoms from aromatic hydrocarbons such as benzene, naphthalene, anthracene, and pyrene.

[0064] In Equation (1), Q - is a group having a sulfonimide anion structure or a sulfonamide anion structure. As such a group, it is preferable to represent it with any one of the following formulas (Q-1) to (Q-4).

[0065]

[0066] Among equations (Q-1) to (Q-4), R 5 Each is independently a saturated hydrocarbyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted with at least one group selected from a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbyl group having 1 to 8 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 8 carbon atoms, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group. * is R 1 It is a combined hand with.

[0067] R 5The saturated hydrocarbyl group having 1 to 12 carbon atoms represented by may be any one of a straight chain, a branched chain, or a cyclic chain, and specific examples thereof include an alkyl group having 1 to 12 carbon atoms such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a tert-pentyl group, an n-hexyl group, an n-octyl group, a 2-ethylhexyl group, an n-nonyl group, an n-decyl group, an undecyl group, a dodecyl group, etc.; Examples include cyclic saturated hydrocarbyl groups having 3 to 12 carbon atoms, such as cyclopentyl group, methylcyclopentyl group, ethylcyclopentyl group, propylcyclopentyl group, isopropylcyclopentyl group, n-butylcyclopentyl group, isobutylcyclopentyl group, sec-butylcyclopentyl group, tert-butylcyclopentyl group, cyclohexyl group, methylcyclohexyl group, ethylcyclohexyl group, propylcyclohexyl group, isopropylcyclohexyl group, n-butylcyclohexyl group, isobutylcyclohexyl group, sec-butylcyclohexyl group, tert-butylcyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, and adamantyl group.

[0068] R 5 Specific examples of aryl groups having 6 to 12 carbon atoms represented by phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, etc.

[0069] Specific examples of the anions of the above-mentioned biseonium salts include those shown below, but are not limited to these.

[0070]

[0071]

[0072]

[0073]

[0074]

[0075]

[0076]

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] In Equation (1), M + is a sulfonium cation or an iodine cation. 2 M + One side may be a sulfonium cation and the other an iodonium cation, both may be sulfonium cations, or both may be iodonium cations. 2 M + When both are sulfonium cations, they may be identical or different. Also, two M + When both are iodine cations, they may be identical or different.

[0111] The above sulfonium cation is preferably represented by the following formula (2), and the above iodine cation is preferably represented by the following formula (3).

[0112]

[0113] Among equations (2) and (3), R 6 ~R 10 Each is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom.

[0114] R 6 ~R 10Specific examples of halogen atoms represented by this include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc.

[0115] R 6 ~R 10 The hydrocarbyl group having 1 to 20 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 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, and icosyl; Cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornel, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl groups; alkynyl groups having 2 to 20 carbon atoms, such as ethinyl, propynyl, and butynyl groups; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl and norbornenyl groups; Examples include aryl groups having 6 to 20 carbon atoms, such as phenyl groups, methylphenyl groups, ethylphenyl groups, n-propylphenyl groups, isopropylphenyl groups, n-butylphenyl groups, isobutylphenyl groups, sec-butylphenyl groups, tert-butylphenyl groups, naphthyl groups, methyl naphthyl groups, ethyl naphthyl groups, n-propyl naphthyl groups, isopropyl naphthyl groups, n-butyl naphthyl groups, isobutyl naphthyl groups, sec-butyl naphthyl groups, and tert-butyl naphthyl groups; aryl groups having 7 to 20 carbon atoms, such as benzyl groups and phenethyl groups; and groups obtained by combining these.

[0116] In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, or halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, or nitrogen atoms, and as a result, may include a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a mercapto group, a pentafluorosulfanyl group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0117] Also, R 6 and R 7 These may also combine with each other to form a ring together with the sulfur atoms to which they are bonded. In this case, the ring is preferably of the structure shown below.

[0118]

[0119] (In the formula, dashed lines indicate joint loss.)

[0120] M + Specific examples of sulfonium cations represented by [ ] are those shown below, but are not limited to these.

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132]

[0133]

[0134]

[0135]

[0136]

[0137]

[0138]

[0139]

[0140]

[0141]

[0142]

[0143]

[0144]

[0145]

[0146]

[0147]

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154]

[0155]

[0156] M + Specific examples of iodine cations represented by [ ] are those shown below, but are not limited to these.

[0157]

[0158]

[0159] As a method for synthesizing the above biseonium salt, for example, a method of salt exchange can be used with a sulfonium salt or iodonium salt containing a halide anion and an ammonium salt containing a divalent anion having a sulfonic acid anion structure directly bonded to an aromatic group having an iodine atom or a bromine atom, and a sulfonimide anion structure or a sulfonamide anion structure bonded to the aromatic group having an iodine atom or a bromine atom through a linker having one or more carbon atoms.

[0160] Among the resist materials of the present invention, the content of the biseonium salt is preferably 0.01 to 1000 parts by mass with respect to 100 parts by mass of the base polymer described below, and more preferably 0.05 to 500 parts by mass for sensitivity and acid diffusion inhibition effect.

[0161] [Base Polymer]

[0162] The base polymer included in the resist material of the present invention, in the case of a positive-type resist material, comprises a repeating unit including an acid-unstable group. As the repeating unit including the acid-unstable group, a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the formula (a2) (hereinafter also referred to as repeating unit a2) is preferred.

[0163]

[0164] Among equations (a1) and (a2), R A is, independently, a hydrogen atom or a methyl group. Y 1Y is a linker having 1 to 12 carbon atoms comprising at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond, an ether bond, and a lactone ring, and said phenylene group, naphthylene group and linker may have at least one selected from a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms, and a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms. 2 is a single bond or an ester bond. Y 3 It is a single bond, an ether bond, or an ester bond. R 11 and R 12 is, independently, a wildfire stable period. R 13 It is silver, a saturated hydrocarbyl group having 1–4 carbon atoms, a halogen atom, a saturated hydrocarbylcarbonyl group having 2–5 carbon atoms, a cyano group, or a saturated hydrocarbyloxycarbonyl group having 2–5 carbon atoms. R 14 is a single bond or an alkandyl group having 1 to 6 carbon atoms, and the alkandyl group may include an ether bond or an ester bond. a is an integer from 0 to 4.

[0165] Specific examples of monomers that provide a repeating unit a1 include those shown below, but are not limited thereto. In addition, among the following formulas, R A and R 11 It is the same as above.

[0166]

[0167]

[0168]

[0169] Specific examples of monomers that provide the repeating unit a2 are those shown below, but are not limited thereto. In addition, among the following formulas, R A and R 12 is the same as above.

[0170]

[0171] Among the repeating units a1 and a2, R 11 and R 12 Examples of wildfire stabilizers indicated by [this] include those described in Japanese Patent Publication No. 2013-80033 or Japanese Patent Publication No. 2013-83821.

[0172] Typically, specific examples of the above-mentioned acid fire stabilizer may be represented by any one of the following formulas (AL-1) to (AL-3).

[0173]

[0174] (In the formula, dashed lines indicate joint loss.)

[0175] Among equations (AL-1) and (AL-2), R L1 and R L2 Each is independently a hydrocarbyl group having 1 to 40 carbon atoms and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be straight, branched, or cyclic. As for the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 40 carbon atoms is preferred, and a saturated hydrocarbyl group having 1 to 20 carbon atoms is more preferred.

[0176] In formula (AL-1), b is an integer from 0 to 10, and preferably an integer from 1 to 5.

[0177] In formula (AL-2), R L3 and R L4 Each is independently a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, or fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be straight, branched, or cyclic. As the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 20 carbon atoms is preferred. In addition, R L2 , R L3 and RL4 Any two of them may combine with 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 combine. As for the ring, a ring having 4 to 16 carbon atoms is preferred, and a ring is particularly preferred.

[0178] In formula (AL-3), R L5 , R L6 and R L7 Each is independently a hydrocarbyl group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be straight, branched, or cyclic. As for the hydrocarbyl group, a saturated hydrocarbyl group having 1 to 20 carbon atoms is preferred. In addition, R L5 , R L6 and R L7 Any two of them may combine with each other to form a ring having 3 to 20 carbon atoms together with the carbon atoms to which they are bonded. As for the ring, a ring having 4 to 16 carbon atoms is preferred, and a ring is particularly preferred.

[0179] The above base polymer may include a repeating unit b comprising a phenolic hydroxyl group as an adhesion group. Specific examples of the monomer imparting the repeating unit b may be those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above.

[0180]

[0181] The above base polymer may include a repeating unit c comprising, as another adhesion group, a hydroxyl group other than a phenolic hydroxyl group, a lactone ring, a sulfone ring, an ether link, an ester link, a sulfonic acid ester link, a carbonyl group, a sulfonyl group, a cyano group, or a carboxyl group. Specific examples of the monomer imparting the repeating unit c are those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above.

[0182]

[0183]

[0184]

[0185]

[0186]

[0187]

[0188]

[0189]

[0190] The above base polymer may include a repeating unit d derived from indene, benzofuran, benzothiophene, acenaphtylene, chromone, coumarin, norbornadiene, or derivatives thereof. Specific examples of monomers imparting the repeating unit d include those shown below, but are not limited thereto.

[0191]

[0192] The above base polymer may include repeating unit e derived from styrene, vinylnaphthalene, vinylanthracene, vinylpyrene, methyleneindane, vinylpyridine, or vinylcarbazole.

[0193] The above base polymer may include a repeating unit f derived from an onium salt containing polymerizable unsaturated bonds. Japanese Patent Publication No. 2005-84365 proposes a sulfonium salt or an iodonium salt comprising a polymerizable olefin that generates a specific sulfonic acid. Japanese Patent Publication No. 2006-178317 proposes a sulfonium salt in which a sulfonic acid is directly linked to the main chain.

[0194] Specific examples of a preferred repeating unit f include a repeating unit represented by the following formula (f1) (hereinafter also referred to as repeating unit f1), a repeating unit represented by the following formula (f2) (hereinafter also referred to as repeating unit f2), and a repeating unit represented by the following formula (f3) (hereinafter also referred to as repeating unit f3). Additionally, repeating units f1 to f3 may be used as a single type or in combination of two or more types.

[0195]

[0196] Among equations (f1) to (f3), R A is, independently, a hydrogen atom or a methyl group. Z 1 Silver, a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by a combination thereof, or -OZ 11 -, -C(=O)-OZ 11 - or -C(=O)-NH-Z 11 -is. Z 11 It is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by a combination thereof, and may include a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z 2 is a single bond or an ester bond. Z 3 Silver, single bond, -Z 31 -C(=O)-O-, -Z 31 -O- or -Z 31 -OC(=O)- is. Z31 It is a carbonyl group, an aliphatic hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, an iodine atom, or a bromine atom. Z 4 is a methylene group, a 2,2,2-trifluoro-1,1-ethanediyl group, or a carbonyl group. Z 5 is, single bond, methylene group, ethylene group, phenylene group, fluorinated phenylene group, phenylene group substituted with a trifluoromethyl group, -OZ 51 -, -C(=O)-OZ 51 - or -C(=O)-NH-Z 51 -is. Z 51 It is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may include a carbonyl group, an ester bond, an ether bond, a hydroxyl group, or a halogen atom.

[0197] Among equations (f1) to (f3), R 21 ~R 28 Each is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. Specific examples of the halogen atom include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The hydrocarbyl group may be saturated or unsaturated, and may be straight, branched, or cyclic. Specific examples thereof include R in the explanation of formulas (2) and (3). 6 ~R 10Examples of hydrocarbyl groups represented by [ ] may be identical to those exemplified. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms; as a result, it may include 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 sulfonic acid ester bond, a carbonate bond, a lactone ring, a sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Additionally, R 23 and R 24 or R 26 and R 27 These may combine with each other to form a ring together with the sulfur atom to which they combine. In this case, as a specific example of the above ring, R in the explanation of Equation (2) 6 and R 7 These can be combined with each other to form rings that are identical to those exemplified by the sulfur atoms they combine with.

[0198] In equation (f1), M -...is a non-nucleated counterion. Specific examples of the above non-nucleated counterion include halogen ions such as chloride ions and bromide ions, fluoroalkylsulfonate ions such as trilate ions, 1,1,1-trifluoroethanesulfonate ions and nonafluorobutanesulfonate ions, tosylate ions, arylsulfonate ions such as benzenesulfonate ions, 4-fluorobenzenesulfonate ions and 1,2,3,4,5-pentafluorobenzenesulfonate ions, alkylsulfonate ions such as mesylate ions and butanesulfonate ions, imide ions such as bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions and bis(perfluorobutylsulfonyl)imide ions, and methide ions such as tris(trifluoromethylsulfonyl)methide ions and tris(perfluoroethylsulfonyl)methide ions.

[0199] Specific examples of the above-mentioned non-nucleated counter-ions include, in addition, sulfonate ions in which the α position is substituted with a fluorine atom represented by the following formula (f1-1), and sulfonate ions in which the α position is substituted with a fluorine atom and the β position is substituted with a trifluoromethyl group represented by the following formula (f1-2).

[0200]

[0201] In equation (f1-1), R 31 It is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and the hydrocarbyl group may include at least one selected from an ether bond, an ester bond, a carbonyl group, a lactone ring, and a fluorine atom.

[0202] In equation (f1-2), R 32 The is a hydrogen atom, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbyl carbonyl group having 2 to 30 carbon atoms, and may include at least one selected from an ether bond, an ester bond, a carbonyl group, and a lactone ring.

[0203] R 31 or R 32The hydrocarbyl portion of the hydrocarbyl group and hydrocarbyl carbonyl group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and icosyl; Examples include cyclic saturated hydrocarbyl groups such as cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-adamantylmethyl group, norbornyl group, norbornylmethyl group, tricyclodecanyl group, tetracyclododecanyl group, tetracyclododecanylmethyl group, dicyclohexylmethyl group; alkenyl groups such as allyl group; cyclic unsaturated hydrocarbyl groups such as 3-cyclohexenyl group; aryl groups such as phenyl group, 1-naphthyl group, 2-naphthyl group; and aryl groups such as benzyl group, diphenylmethyl group.

[0204] In addition, some or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, etc., and as a result, they may include hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate groups, lactone rings, sulfone rings, carboxylic acid anhydrides, haloalkyl groups, etc. Specific examples of hydrocarbyl groups containing heteroatoms include tetrahydrofuryl groups, methoxymethyl groups, ethoxymethyl groups, methylthiomethyl groups, acetamide methyl groups, trifluoroethyl groups, (2-methoxyethoxy)methyl groups, acetoxymethyl groups, 2-carboxy-1-cyclohexyl groups, 2-oxopropyl groups, 4-oxo-1-adamantyl groups, 3-oxocyclohexyl groups, etc.

[0205] Specific examples of the monomer cations that impart the repeating unit f1 are those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above.

[0206]

[0207] As a specific example of a monomer cation that imparts a repeating unit f2 or f3, in the explanation of Equation (1), M + Examples of sulfonium cations represented as such include those identical to those exemplified.

[0208] Specific examples of monomers that impart a repeating unit f2 are those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above.

[0209]

[0210]

[0211]

[0212]

[0213]

[0214]

[0215]

[0216]

[0217]

[0218]

[0219]

[0220]

[0221]

[0222]

[0223] Specific examples of monomers that provide the repeating unit f3 are those shown below, but are not limited thereto. In addition, among the following formulas, R A is the same as above.

[0224]

[0225] Repeating units f1 to f3 function as acid-generating agents. By incorporating acid-generating agents into the polymer main chain, acid diffusion is minimized, thereby preventing a decrease in resolution caused by the blurring of acid diffusion. Furthermore, the uniform dispersion of acid-generating agents improves LWR and CDU.

[0226] The base polymer for positive-type resist materials requires a repeating unit a1 or a2 containing an acid-unstable group. In this case, the content ratios of repeating units a1, a2, b, c, d, e, and f are 0 ≤ a1 < 1.0, 0 ≤ a2 < 1.0, 0 <a1+a2<1.0, 0≤b≤0.9, 0≤c≤0.9, 0≤d≤0.8, 0≤e≤0.8 및 0≤f≤0.5가 바람직하고, 0≤a1≤0.9, 0≤a2≤0.9, 0.1≤a1+a2≤0.9, 0≤b≤0.8, 0≤c≤0.8, 0≤d≤0.7, 0≤e≤0.7 및 0≤f≤0.4가 보다 바람직하며, 0≤a1≤0.8, 0≤a2≤0.8, 0.1≤a1+a2≤0.8, 0≤b≤0.75, 0≤c≤0.75, 0≤d≤0.6, 0≤e≤0.6 및 0≤f≤0.3이 더욱 바람직하다. 또한, 반복 단위 f가 반복 단위 f1∼f3으로부터 선택되는 적어도 1종인 경우, f=f1+f2+f3이다. 또한, a1+a2+b+c+d+e+f=1.0이다.

[0227] Meanwhile, for base polymers for negative-type resist materials, an acid instability group is not strictly necessary. Examples of such base polymers include repeating unit b, and optionally further include repeating units c, d, e, and / or f. The content ratio of these repeating units is 0 <b≤1.0, 0≤c≤0.9, 0≤d≤0.8, 0≤e≤0.8 및 0≤f≤0.5가 바람직하고, 0.2≤b≤1.0, 0≤c≤0.8, 0≤d≤0.7, 0≤e≤0.7 및 0≤f≤0.4가 보다 바람직하며, 0.3≤b≤1.0, 0≤c≤0.75, 0≤d≤0.6, 0≤e≤0.6 및 0≤f≤0.3이 더욱 바람직하다. 또한, 반복 단위 f가 반복 단위 f1∼f3으로부터 선택되는 적어도 1종인 경우, f=f1+f2+f3이다. 또한, b+c+d+e+f=1.0이다.

[0228] To synthesize the above base polymer, for example, a monomer imparting the aforementioned repeating unit can be heated in an organic solvent with a radical polymerization initiator added to carry out polymerization.

[0229] Specific examples of organic solvents used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Specific examples of polymerization initiators include 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The temperature during polymerization is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0230] When copolymerizing monomers containing hydroxyl groups, the hydroxyl groups may be substituted with acetal groups that are easily deprotected by acids such as ethoxyethoxy groups during polymerization and deprotected with a weak acid and water after polymerization, or may be substituted with acetyl groups, formyl groups, pivaloyyl groups, etc. and alkaline hydrolysis may be performed after polymerization.

[0231] In the case of copolymerizing hydroxystyrene or hydroxyvinyl naphthalene, acetoxystyrene or acetoxyvinyl naphthalene may be used instead of hydroxystyrene or hydroxyvinyl naphthalene, and after polymerization, the acetoxy group may be deprotected by the above alkaline hydrolysis to obtain hydroxystyrene or hydroxyvinyl naphthalene.

[0232] As the base for alkaline hydrolysis, water ammonia, triethylamine, etc., may be used. In addition, 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.

[0233] The above base polymer has a polystyrene-equivalent weight average molecular weight (Mw) determined by gel permeation chromatography (GPC) using THF as a solvent, preferably 1,000 to 500,000, and more preferably 2,000 to 30,000. When Mw is within the above range, the heat resistance of the resist film and its solubility in an alkaline developer are good.

[0234] In addition, if the molecular weight distribution (Mw / Mn) of the above base polymer is wide, there is a risk that foreign substances may be visible on the pattern or the shape of the pattern may deteriorate after exposure because low molecular weight or high molecular weight polymers are present. As the pattern rule becomes finer, the influence of Mw or Mw / Mn tends to increase; therefore, in order to obtain a resist material suitable for use with fine pattern dimensions, it is preferable that the Mw / Mn of the above base polymer be narrowly dispersed, specifically 1.0 to 2.0, and particularly 1.0 to 1.5.

[0235] The above base polymer may include two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0236] [Organic Solvents]

[0237] The resist material of the present invention may include an organic solvent. The organic solvent is not particularly limited as long as it is capable of dissolving each of the aforementioned components and each of the components described below. Specific examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Publication No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; and ethers such as propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, ethylene glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether. Examples include esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; and lactones such as γ-butyrolactone.

[0238] Among the resist materials of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass and more preferably 200 to 8,000 parts by mass with respect to 100 parts by mass of the base polymer. The organic solvent may be used as a single type or as a mixture of two or more types.

[0239] [Kencher]

[0240] The resist material of the present invention may include a quencher. Furthermore, a quencher refers to a compound capable of preventing diffusion to an unexposed area by trapping acid generated from an acid-generating agent in the resist material.

[0241] Examples of the above quencher include conventional basic compounds. Specific examples of conventional basic compounds include first, second, and third aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates, etc. In particular, primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103, particularly amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, or sulfonic acid ester bonds, or compounds having carbamate bonds described in Japanese Patent Publication No. 3790649 are preferred. By adding such basic compounds, for example, the diffusion rate of acid in the resist film can be further suppressed or the shape can be corrected.

[0242] In addition, as the above quencher, examples include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids, carboxylic acids, or fluorinated alkoxides in which the α-position is not fluorinated, as described in Japanese Patent Publication No. 2008-158339. Sulfonic acids, imidic acids, or methic acids in which the α-position is fluorinated are required to deprotect the acid unstable groups of carboxylic acid esters, but sulfonic acids, carboxylic acids, or fluorinated alcohols in which the α-position is not fluorinated are released through salt exchange with the above onium salts. Sulfonic acids, carboxylic acids, and fluorinated alcohols in which the α-position is not fluorinated function as quenchers because they do not cause a deprotection reaction.

[0243] Specific examples of such quenchers include, for instance, a compound represented by the following formula (4) (an onium salt of a sulfonic acid in which the α position is not fluorinated), a compound represented by the following formula (5) (an onium salt of a carboxylic acid), and a compound represented by the following formula (6) (an onium salt of an alkoxide).

[0244]

[0245] In Equation (4), R 101 It is a hydrocarbyl group having 1 to 40 carbon atoms that may contain a hydrogen atom or a heteroatom, but excludes cases where the hydrogen atom bonded to the carbon atom at the α position of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group.

[0246] R 101 The hydrocarbyl group having 1 to 40 carbon atoms represented by may be saturated or unsaturated, and may be straight, branched, or cyclic. Specific examples thereof 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, and tricyclo[5.2.1.0 2,6] Cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl groups; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl groups; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 40 carbon atoms, such as cyclohexenyl groups; Examples include aryl groups having 6 to 40 carbon atoms, such as phenyl groups, naphthyl groups, alkylphenyl groups (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, 4-n-butylphenyl group, etc.), di- or trialkylphenyl groups (2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl groups (methylnaphthyl group, ethylnaphthyl group, etc.), and dialkylnaphthyl groups (dimethylnaphthyl group, diethylnaphthyl group, etc.); and aryl groups having 7 to 40 carbon atoms, such as benzyl groups, 1-phenylethyl groups, and 2-phenylethyl groups.

[0247] In addition, some or all of the hydrogen atoms of the above hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, or halogen atoms, and some of the -CH2- of the above hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, or nitrogen atoms, and as a result, may include a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sulfone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Specific examples of a hydrocarbyl group containing heteroatoms include a heteroaryl group such as a thienyl group; Examples include alkoxyphenyl groups such as 4-hydroxyphenyl group, 4-methoxyphenyl group, 3-methoxyphenyl group, 2-methoxyphenyl group, 4-ethoxyphenyl group, 4-tert-butoxyphenyl group, 3-tert-butoxyphenyl group; alkoxynaphthyl groups such as methoxynaphthyl group, ethoxynaphthyl group, n-propoxynaphthyl group, n-butoxynaphthyl group; diallkoxynaphthyl groups such as dimethoxynaphthyl group, diethoxynaphthyl group; and aryloxoalkyl groups such as 2-aryl-2-oxoethyl group, 2-(1-naphthyl)-2-oxoethyl group, 2-(2-naphthyl)-2-oxoethyl group.

[0248] In Equation (5), R 102 is a hydrocarbyl group having 1 to 40 carbon atoms that may contain heteroatoms. R 102 Specific examples of hydrocarbyl groups represented by R 101 Examples of hydrocarbyl groups represented by [ ] can be given as those identical to those exemplified. In addition, other specific examples include fluorinated alkyl groups such as trifluoromethyl groups, trifluoroethyl groups, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl groups, 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl groups; and fluorinated aryl groups such as pentafluorophenyl groups, 4-trifluoromethylphenyl groups.

[0249] In Equation (6), R 103It is a saturated hydrocarbyl group having 1 to 8 carbon atoms having at least 3 fluorine atoms or an aryl group having 6 to 10 carbon atoms having at least 3 fluorine atoms, and may include a nitro group.

[0250] Among equations (4), (5) and (6), Mq + is an onium cation. As the above onium cation, a sulfonium cation, an iodonium cation, or an ammonium cation is preferred, and a sulfonium cation is more preferred. As a specific example of the above sulfonium cation, in the explanation of Formula (1), M + Examples of sulfonium cations represented as such include those identical to those exemplified.

[0251] As a quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (7) can also be suitably used.

[0252]

[0253] In equation (7), x is an integer from 1 to 5. y is an integer from 0 to 3. z is an integer from 1 to 3.

[0254] In Equation (7), R 111 Silver, a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, or -N(R 111A )-C(=O)-R 111B or -N(R 111A )-C(=O)-OR 111B is. R 111A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 111B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms. When y and / or z is 2 or greater, each R111 They may be identical or different.

[0255] In formula (7), L 1 The group may be a single bond or a (z+1) group having 1 to 20 carbon atoms, and may include at least one selected from ether bonds, carbonyl groups, ester bonds, amide bonds, sulfone rings, lactam rings, carbonate bonds, halogen atoms, hydroxyl groups, and carboxyl groups. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, and saturated hydrocarbylsulfonyloxy group may be any one of a straight chain, a branched chain, or a cyclic chain.

[0256] In Equation (7), R 112 , R 113 and R 114 Each is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be straight, branched, or cyclic. As a specific example, in the explanation of formulas (2) and (3), R 6 ~R 10 One can cite the same as the example given as a hydrocarbyl group represented by .

[0257] Specific examples of the compound represented by formula (7) include those described in Japanese Patent Publication No. 2017-219836 and Japanese Patent Publication No. 2021-91666.

[0258] As another example of the above-mentioned quencher, a polymer-type quencher described in Japanese Patent Publication No. 2008-239918 can be cited. This enhances the rectangularity of the resist pattern by orienting it on the surface of the resist film. The polymer-type quencher also has the effect of preventing film reduction of the pattern or rounding of the pattern top when a protective film for immersion exposure is applied.

[0259] In addition, a beta-type sulfonium salt described in Japanese Patent Publication No. 6848776 and Japanese Patent Publication No. 2020-37544, a methic acid not containing a fluorine atom described in Japanese Patent Publication No. 2020-55797, a sulfonium salt of a sulfonamide described in Japanese Patent Publication No. 5807552, a sulfonium salt of a sulfonamide containing an iodine atom described in Japanese Patent Publication No. 2019-211751, a phenol, a halogen, or an acid-generating agent that generates carbonic acid may also be used as a quencher.

[0260] When the resist material of the present invention includes the quencher, the content thereof is preferably 0 to 5 parts by mass and more preferably 0 to 4 parts by mass per 100 parts by mass of the base polymer. The quencher may be used as a single type or in combination of two or more types.

[0261] [Other ingredients]

[0262] In addition to the above-mentioned components, an acid-generating agent other than the salt represented by Formula (1) (hereinafter referred to as other acid-generating agents), a surfactant, a solubility inhibitor, a crosslinking agent, a water-repellent enhancer, acetylene alcohols, etc. may be included.

[0263] Examples of other acid-generating agents mentioned above include compounds that generate acid in response to active light or radiation (photo-acid-generating agents). As for the components of the photo-acid-generating agent, any compound that generates acid upon irradiation with high-energy rays is acceptable, but acid-generating agents that generate sulfonic acid, imidic acid, or methic acid are preferred. Specific examples of suitable photo-acid-generating agents include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate type acid-generating agents. Specific examples of the above acid-generating agents include those described in paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103, Japanese Patent Publication No. 2018-5224, and Japanese Patent Publication No. 2018-25789. When the resist material of the present invention includes other acid-generating agents, the content thereof is preferably 0 to 200 parts by mass and 0.1 to 100 parts by mass with respect to 100 parts by mass of base polymer.

[0264] Specific examples of the above surfactant include those described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103. By adding a surfactant, the coating properties of the resist material can be further improved or controlled. When the resist material of the present invention contains a surfactant, the content thereof is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. The above surfactant may be used as a single type or in combination of two or more types.

[0265] When the resist material of the present invention is of the positive type, by incorporating a dissolution inhibitor, the difference in the dissolution rate between the exposed and unexposed parts can be further increased, thereby further improving the resolution. Specific examples of the dissolution inhibitor include a compound having a molecular weight preferably 100 to 1000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule, wherein the hydrogen atoms of the phenolic hydroxyl groups are substituted by acid unstable groups in a ratio of 0 to 100 mol% in total, or a compound having a carboxyl group in the molecule, wherein the hydrogen atoms of the carboxyl groups are substituted by acid unstable groups in a ratio of 50 to 100 mol% in total. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl group and carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalenecarboxylic acid, adamantan carboxylic acid, cholic acid are substituted with acid-unstable groups, and are described, for instance, in paragraphs

[0155] to

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

[0266] When the resist material of the present invention is of the positive type and includes the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass and more preferably 5 to 40 parts by mass per 100 parts by mass of the base polymer. The dissolution inhibitor may be used as a single type or in combination of two or more types.

[0267] Meanwhile, when the resist material of the present invention is of the negative type, a negative type pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Specific examples of the crosslinking agent include epoxy compounds, melamine compounds, guanamine compounds, glycoluryl compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups, which are substituted with at least one group selected from methylol groups, alkoxymethyl groups, and acyloxymethyl groups. These may be used as additives, but may also be introduced as pendant groups into the polymer side chains. In addition, compounds containing hydroxyl groups may also be used as crosslinking agents.

[0268] Specific examples of the above epoxy compounds include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethanetriglycidyl ether, trimethylolpropanetriglycidyl ether, triethylolethanetriglycidyl ether, etc.

[0269] Specific examples of the above melamine compounds include hexamethylolmelamine, hexamethoxymethylmelamine, a compound in which 1 to 6 methylol groups of hexamethylolmelamine are methoxymethylated or a mixture thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, a compound in which 1 to 6 methylol groups of hexamethylolmelamine are acyloxymethylated or a mixture thereof.

[0270] Specific examples of the above guanamin compounds include tetramethylolguanamin, tetramethoxymethylguanamin, a compound in which 1 to 4 methylol groups of tetramethylolguanamin are methoxymethylated or a mixture thereof, tetramethoxyethylguanamin, tetraacyloxyguanamin, a compound in which 1 to 4 methylol groups of tetramethylolguanamin are acyloxymethylated or a mixture thereof.

[0271] Specific examples of the above glycoluryl compounds include tetramethylol glycoluryl, tetramethoxyglycoluryl, tetramethoxymethylglycoluryl, a compound or mixture thereof in which 1 to 4 methylol groups of tetramethylol glycoluryl are methoxymethylated, a compound or mixture thereof in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated, etc. Specific examples of the above urea compounds include tetramethylolurea, tetramethoxymethylurea, a compound or mixture thereof in which 1 to 4 methylol groups of tetramethylolurea are methoxymethylated, tetramethoxyethylurea, etc.

[0272] Specific examples of the above isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, cyclohexane diisocyanate, etc.

[0273] Specific examples of the above azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, 4,4'-oxybisazide, etc.

[0274] Specific examples of compounds containing the above alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane divinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol divinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, trimethylolpropane divinyl ether, etc.

[0275] When the resist material of the present invention is of the negative type and includes the crosslinking agent, the content thereof is preferably 0.1 to 50 parts by mass and more preferably 1 to 40 parts by mass per 100 parts by mass of the base polymer. The crosslinking agent may be used alone or in combination of two or more types.

[0276] The above-mentioned water repellency enhancer improves the water repellency of the resist film surface and can be used in immersion lithography without a top coat. As the above-mentioned water repellency enhancer, polymers containing fluoroalkyl groups, polymers containing 1,1,1,3,3,3-hexafluoro-2-propanol residues of a specific structure are preferred, and it is preferable that they be exemplified in Japanese Patent Publication No. 2007-297590, Japanese Patent Publication No. 2008-111103, etc. The above-mentioned water repellency enhancer needs to be dissolved in an alkaline developer or an organic solvent developer. The aforementioned water repellency enhancer having specific 1,1,1,3,3,3-hexafluoro-2-propanol residues has good solubility in the developer. As a water repellency enhancer, a polymer containing repeating units including amino groups or amine salts has a high effect of preventing the evaporation of acid in the PEB and preventing defects in the opening of the hole pattern after development. When the resist material of the present invention includes the water repellency enhancer, the content thereof is preferably 0 to 20 parts by mass and more preferably 0.5 to 10 parts by mass per 100 parts by mass of the base polymer. The water repellency enhancer may be used alone or in combination of two or more types.

[0277] Specific examples of the above acetylene alcohols include those described in paragraphs

[0179] to

[0182] of Japanese Patent Publication No. 2008-122932. When the resist material of the present invention includes the above acetylene alcohols, the content thereof is preferably 0 to 5 parts by mass per 100 parts by mass of the base polymer. The above acetylene alcohols may be used as a single type or in combination of two or more types.

[0278] [Pattern Formation Method]

[0279] When the resist material of the present invention is used in the manufacture of various integrated circuits, known lithography techniques may be applied. For example, a pattern formation method may include a process of forming a resist film on a substrate using the aforementioned resist material, a process of exposing the resist film to high-energy rays, and a process of developing the exposed resist film using a developer.

[0280] First, the resist material of the present invention is applied to a substrate for manufacturing an integrated circuit (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) or a substrate for manufacturing a mask circuit (Cr, CrO, CrON, MoSi2, SiO2, etc.) by a suitable application method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating so that the thickness of the coating film is 0.01 to 2 μm. This is pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0281] Next, the resist film is exposed using high-energy rays. Specific examples of the high-energy rays include ultraviolet rays, far-ultraviolet rays, EB, EUV with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. When ultraviolet rays, far-ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. are used as the high-energy rays, the exposure amount is preferably 1 to 200 mJ / cm², more preferably 10 to 100 mJ / cm², by direct irradiation or using a mask for forming a target pattern. When EB is used as the high-energy rays, the exposure amount is preferably 0.1 to 300 μC / cm², more preferably 0.5 to 200 μC / cm², by direct irradiation or using a mask for forming a target pattern. In addition, the resist material of the present invention is particularly suitable for fine patterning by high-energy rays, specifically KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, γ-rays, and synchrotron radiation, and is particularly suitable for fine patterning by EB or EUV.

[0282] After exposure, PEB may be performed on a hot plate or in an oven, preferably at 30 to 150°C for 10 seconds to 30 minutes, more preferably at 50 to 120°C for 30 seconds to 20 minutes, or not performed.

[0283] After exposure or after PEB, a target pattern is formed by developing a resist film exposed by a conventional method such as a dip method, puddle method, or spray method using a developer solution of an alkaline aqueous solution of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, etc., in an amount of 0.1 to 10 mass%, preferably 2 to 5 mass%, for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes. In the case of a positive-type resist material, the portion exposed to light is dissolved in the developer solution, and the portion not exposed is not dissolved, thereby forming a target positive-type pattern on the substrate. In the case of a negative-type resist material, the opposite is true to the case of a positive-type resist material, where the portion exposed to light becomes insoluble in the developer solution, and the portion not exposed is dissolved.

[0284] By using a positive-type resist material containing a base polymer containing an acid-free stabilizer, a negative-type pattern can also be obtained by organic solvent development. Specific examples of the developer used at this time include 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutylketone, methylcyclohexanone, acetophenone, methylacetophenone, propyl acetate, butyl acetate, isobutyl acetate, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl penthenate, methyl crotonicate, ethyl crotonicate, methyl propionate, ethyl propionate, 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl lactate, Examples include 2-methyl 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 individually or in a mixture of two or more types.

[0285] When the development is finished, a rinse is performed. As the rinse solution, a solvent that is mixed with the developer solution and does not dissolve the resist film is preferred. As 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 are preferably used.

[0286] Specific examples of the above alcohol having 3 to 10 carbon atoms include n-propyl alcohol, isopropyl alcohol, 1-butyl alcohol, 2-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, 1-pentanol, 2-pentanol, 3-pentanol, tert-pentyl alcohol, neopentyl alcohol, 2-methyl-1-butanol, 3-methyl-1-butanol, 3-methyl-3-pentanol, cyclopentanol, 1-hexanol, 2-hexanol, 3-hexanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol. Examples include 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.

[0287] Specific examples of the above ether compounds having 8 to 12 carbon atoms include di-n-butyl ether, diisobutyl ether, di-sec-butyl ether, di-n-pentyl ether, diisopentyl ether, di-sec-pentyl ether, di-tert-pentyl ether, di-n-hexyl ether, etc.

[0288] Specific examples of the above-mentioned 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 above-mentioned alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Specific examples of the above-mentioned alkynes having 6 to 12 carbon atoms include hexine, heptene, octene, etc.

[0289] Specific examples of the above aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, mesitylene, etc.

[0290] By rinsing, the breakdown of the resist pattern or the occurrence of defects can be reduced. In addition, rinsing is not strictly necessary, and the amount of solvent used can be reduced by not rinsing.

[0291] The hole pattern or trench pattern after development may be shrunk using thermal flow, RELACS technology, or DSA technology. A shrinking agent is applied onto the hole pattern, and crosslinking of the shrinking agent occurs on the surface of the resist film due to the diffusion of an acid catalyst from the resist film during baking, causing the shrinking agent to adhere to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the baking time is preferably 10 to 300 seconds, after which excess shrinking agent is removed and the hole pattern is shrunk.

[0292] Examples

[0293] The present invention has been specifically described below by presenting synthetic examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0294] The structures of biseonium salts PAG-PDQ-1 to PAG-PDQ-17, which are acid-generating and quenchers used in resist materials, are shown below.

[0295]

[0296]

[0297]

[0298]

[0299]

[0300]

[0301]

[0302] [Synthesization Example] Synthesis of base polymers (polymers P-1 to P-4)

[0303] Each monomer was combined and copolymerization was carried out in THF as a solvent. The mixture was then placed in methanol, and the precipitated solid was washed with hexane, isolated, and dried to obtain base polymers (polymers P-1 to P-4) with the compositions shown below. The composition of the obtained base polymers is 1 Mw and Mw / Mn were confirmed by H-NMR and GPC (solvent: THF, standard: polystyrene).

[0304]

[0305] [Examples 1–22, Comparative Examples 1–3] Preparation of Resist Materials and Evaluation thereof

[0306] (1) Preparation of resist material

[0307] A resist material was prepared by dissolving each component in the composition shown in Table 1 and filtering it through a 0.2 μm size filter.

[0308] In Table 1, each component is as follows.

[0309] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0310] EL (ethyl lactate)

[0311] DAA (diacetone alcohol)

[0312] Comparative acidogens: cPAG-1, cPAG-PDQ-1

[0313]

[0314] Blend acid-generating agent: bPAG-1

[0315]

[0316] Comparison Quencher: cPDQ-1

[0317]

[0318] (2) EUV lithography evaluation

[0319] Each resist material shown in Table 1 was spin-coated onto a Si substrate with a film thickness of 20 nm using a silicon-containing spin-on hard mask SHB-A940 (silicon content of 43 mass%) manufactured by Shin-Etsu Kagaku High School Co., Ltd., and pre-baked at 105°C for 60 seconds using a hot plate to produce a resist film with a film thickness of 40 nm. The resist film was exposed using an EUV scanner NXE3400 manufactured by ASML (NA 0.33, σ 0.9 / 0.7, dipole illumination), and PEB was performed on a hot plate at the temperature listed in Table 1 for 60 seconds, followed by development with a 2.38 mass% aqueous TMAH solution for 30 seconds to form a line and space with a pitch of 32 nm and a line width of 16 nm. Examples 1 to 21 and Comparative Examples 1 and 2 are positive-type resist materials, and Example 22 and Comparative Example 3 are negative-type resist materials.

[0320] Using a measuring SEM (CG6300) manufactured by Hitachi High-Tech Corporation, an exposure amount was determined in which a line pattern was formed with dimensions of 16 nm ± 1.6 nm, and the LWR at this exposure amount was measured. The results are shown in Table 1.

[0321]

[0322] From the results shown in Table 1, it was found that the resist material of the present invention, comprising a biseonium salt containing a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an onium cation, is highly sensitive and has good LWR.

Claims

Claim 1 A resist material comprising a bisionium salt comprising a sulfonic acid anion structure directly bonded to an aromatic group substituted with an iodine atom, a divalent anion having a sulfonimide anion structure or a sulfonamide anion structure bonded directly to the aromatic group or through a linker containing one or more atoms, and an onium cation, wherein the bisionium salt is represented by the following formula (1). (In the expression, p is an integer from 1 to 5. q is an integer from 0 to 7.X 1 ~X 3 Each is, independently, a single bond, an ether bond, an ester bond, or an amide bond. 1 ~R 3 Each is independently a single bond or a hydrocarbylene group having 1 to 30 carbon atoms, and the hydrocarbylene group may include at least one selected from an oxygen atom, a nitrogen atom, a sulfur atom, and a halogen atom. provided, however, R 1 ~R 3 The upper limit of the sum of the carbon numbers is 30.R 4 is, hydrogen atom, hydroxyl group, carboxyl group, fluorine atom, chlorine atom, bromine atom, amino group, nitro group, cyano group, hydrocarbyl group with 1–20 carbon atoms, hydrocarbyloxy group with 1–20 carbon atoms, hydrocarbyloxycarbonyl group with 2–20 carbon atoms, hydrocarbylcarbonyloxy group with 2–20 carbon atoms, hydrocarbylsulfonyloxy group with 1–20 carbon atoms, -N(R 4A )-C(=O)-R 4B , -N(R 4A )-C(=O)-OR 4B or -N(R 4A )-S(=O)2-R 4B And, the above hydrocarbyl group, hydrocarbyloxy group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, hydrocarbylsulfonyloxy group may include at least one selected from a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a hydroxyl group, an amino group, an ester bond, an ether bond, a urethane bond, a urea bond, a carbonate bond, an amide bond, a sulfonic acid ester bond, a carbonyl group, a sulfide group, and a sulfonyl group. R 4A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and this saturated hydrocarbyl group may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. 4B is an aliphatic hydrocarbyl group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may include a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. Ar is a (p+q+1) aromatic hydrocarbon group having 6 to 16 carbon atoms. Q - is a group having a sulfonimide anion structure or a sulfonamide anion structure. + is a sulfonium cation or an iodonium cation.) Claim 2 delete Claim 3 In Paragraph 1, Q - a. A resist material represented by any one of the following formulas (Q-1) to (Q-4). (during food, R 5 Each is independently a saturated hydrocarbyl group having 1 to 12 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may be substituted with at least one group selected from a halogen atom, a cyano group, a nitro group, a hydroxyl group, a saturated hydrocarbyl group having 1 to 8 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 8 carbon atoms, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, and a trifluoromethyl group. * is R 1 It is a combined hand with.) Claim 4 A resist material comprising a base polymer further comprising, in claim 1. Claim 5 In paragraph 4, the base polymer comprises a repeating unit represented by the following formula (a1) or (a2), in a resist material. (during food, R A Each is, independently, a hydrogen atom or a methyl group. 1 The linker has 1 to 12 carbon atoms and comprises at least one selected from a single bond, a phenylene group or a naphthylene group, or an ester bond, an ether bond, and a lactone ring, and the phenylene group, the naphthylene group, and the linker may have at least one selected from a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms, and a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms. 2 is a single bond or an ester bond. 3 It is a single bond, an ether bond, or an ester bond. 11 and R 12 is, independently, a wildfire stable period. 13 It is silver, a saturated hydrocarbyl group having 1 to 4 carbon atoms, a halogen atom, a saturated hydrocarbylcarbonyl group having 2 to 5 carbon atoms, a cyano group, or a saturated hydrocarbyloxycarbonyl group having 2 to 5 carbon atoms. 14 is a single bond or an alkandyl group having 1 to 6 carbon atoms, and the alkandyl group may include an ether bond or an ester bond. a is an integer from 0 to 4.) Claim 6 In paragraph 5, a resist material that is a chemically amplified positive type resist material. Claim 7 In paragraph 4, the base polymer is a resist material that does not contain an acid-unstable group. Claim 8 In paragraph 7, a resist material that is a chemically amplified negative type resist material. Claim 9 A resist material according to claim 1, further comprising an organic solvent. Claim 10 A resist material according to claim 1, further comprising a quencher. Claim 11 A resist material comprising an acid-generating agent in claim 1. Claim 12 A resist material according to claim 1, further comprising a surfactant. Claim 13 A pattern forming method comprising: a process of forming a resist film on a substrate using a resist material described in any one of claims 1 and 3 to 12; a process of exposing the resist film to high-energy rays; and a process of developing the exposed resist film using a developer. Claim 14 A pattern forming method according to claim 13, wherein the high-energy line is an ArF excimer laser light with a wavelength of 193 nm, a KrF excimer laser light with a wavelength of 248 nm, an electron beam, or an extreme ultraviolet light with a wavelength of 3 to 15 nm.

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