Chemically amplified positive resist material and pattern formation method

Abstract

To provide a resist material that has high sensitivity and improved LWR and CDU regardless of whether it is a positive one or negative one, and a patterning method using the same.SOLUTION: A resist material contains a polymer containing a repeat unit represented by the following formula (a1) or (a2).SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] As LSIs become more highly integrated and faster, pattern rules are becoming increasingly miniaturized. This is due to the increasing popularity of 5G high-speed communications and artificial intelligence (AI), which require high-performance devices to process these. The most advanced miniaturization technology is extreme ultraviolet (EUV) lithography with a wavelength of 13.5 nm, which is currently used to mass-produce 5 nm node devices. Furthermore, the use of EUV lithography is being considered for next-generation 3 nm node devices and the next-generation 2 nm node devices.

[0003] As patterns become finer, line edge roughness (LWR) and dimensional uniformity (CDU) of hole and dot patterns become issues. The effects of uneven distribution and aggregation of base polymers and acid generators, as well as the effects of acid diffusion, have been pointed out. Furthermore, as resist films become thinner, LWR and CDU tend to increase, and the degradation of LWR and CDU due to thinning as miniaturization progresses is becoming a serious problem.

[0004] EUV resist materials must simultaneously achieve high sensitivity, high resolution, and low LWR. Shortening the acid diffusion distance improves LWR and CDU, but reduces sensitivity. For example, lowering the post-exposure bake (PEB) temperature improves LWR and CDU, but reduces sensitivity. Increasing the amount of quencher added also improves LWR and CDU, but reduces sensitivity. It is necessary to break the trade-off between sensitivity and LWR.

[0005] To suppress acid diffusion, resist materials have been proposed that contain an acid generator that generates sulfonic acid attached to the polymer main chain upon exposure (Patent Documents 1 and 2). Acid generators attached to a polymer (polymer-bound acid generators) have an extremely short acid diffusion time, which can improve LWR.

[0006] Resist materials containing acid generators that generate sulfonic acids having iodine or bromine atoms between the polymer main chain and the sulfonic acid group have been proposed (Patent Documents 3 and 4). These aim to improve sensitivity by increasing the efficiency of secondary electron generation during exposure and by increasing the amount of absorbed photons, by increasing the absorption of EUV light or by ionizing the light, and to improve physical contrast. However, because these do not control acid diffusion, further control of acid diffusion is required. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 4425776 [Patent Document 2] Patent No. 4893580 [Patent Document 3] Japanese Patent Application Publication No. 2018-197853 [Patent Document 4] Japanese Patent Application Publication No. 2019-8280 Summary of the Invention [Problem to be solved by the invention]

[0008] There is a need for the development of a resist material that is more sensitive than conventional resist materials and that can improve the LWR of line patterns and the CDU of hole patterns.

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a resist material, whether positive or negative, which has high sensitivity and improved LWR and CDU, and a pattern formation method using the same. [Means for solving the problem]

[0010] As a result of extensive research into achieving the above-mentioned object, the present inventors have found that by using, as a polymer-bonded acid generator, a polymer that contains a repeating unit derived from a sulfonium salt or iodonium salt, which has a polymerizable unsaturated bond and in which the polymerizable unsaturated bond and the fluorosulfonic acid moiety have a benzene ring substituted with a nitro group at the linkage, it is possible to obtain a resist material that has high sensitivity, improved LWR and CDU, high contrast, excellent resolution, and a wide process margin, and have completed the present invention.

[0011] That is, the present invention provides the following resist material and pattern forming method. 1. A resist material comprising a polymer containing a repeating unit represented by the following formula (a1) or (a2): [ka] (In the formula, R A is a hydrogen atom or a methyl group. X 1 is a single bond, an ester bond, an amide bond or -X 1A -X 1C -X 1B -X 1A and X 1B are each independently a single bond, an ether bond, or an ester bond. 1C represents a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, in which a portion of the -CH2- may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group, or a sultone ring-containing group, and a portion or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom, or a nitro group. X 2 is a single bond, an ether bond, an ester bond or -X 2A -X 2C -X2B -X 2A and X 2B are each independently a single bond, an ether bond, or an ester bond. 2C represents a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, in which a portion of the -CH2- may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group, or a sultone ring-containing group, and a portion or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom, or a nitro group. Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 may combine to form a carbonyl group. R 1 represents an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, or a halogen atom. R 2 ~R 6 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 2 and R 3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. m is an integer of 0 to 3, and n is 1 or 2. 2. The resist material of 1, wherein the repeating unit represented by formula (a1) is represented by the following formula (a1-1), and the repeating unit represented by formula (a2) is represented by the following formula (a2-1). [ka] (In the formula, R A , X 1 , Rf 1 ~Rf 4 , R1 ~R 6 , m and n are the same as above. 3. The resist material of 1 or 2, wherein the polymer further contains a repeating unit represented by the following formula (b1) or (b2): [ka] (In the formula, R A are each independently a hydrogen atom or a methyl group. Y 1 is a linking group having 1 to 12 carbon atoms and containing at least one bond selected from a single bond, a phenylene group, a naphthylene group, an ester bond, an ether bond, and a lactone ring. Y 2 is a single bond or an ester bond. R 11 and R 12 are each independently an acid labile group. R 13 represents 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. R 14 is a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a is an integer from 0 to 4. 4. The resist material of 3, which is a chemically amplified positive resist material. 5. The resist material of 1 or 2, wherein the polymer does not contain an acid labile group. 6. The resist material of 5, which is a chemically amplified negative resist material. 7. The resist material of any one of 1 to 6, further comprising an organic solvent. 8. The resist material of any one of 1 to 7, further comprising a quencher. 9. The resist material according to any one of 1 to 8, further comprising a surfactant. 10. A pattern forming method comprising the steps of forming a resist film on a substrate using a resist material according to any one of 1 to 9, exposing the resist film to high-energy rays, and developing the exposed resist film using a developer. 11. The pattern formation method according to 10, wherein the high-energy beam is ArF excimer laser light with a wavelength of 193 nm, KrF excimer laser light with a wavelength of 248 nm, electron beam (EB), or EUV with a wavelength of 3 to 15 nm. [Effects of the Invention]

[0012] A resist film containing a polymer containing a repeating unit derived from a sulfonium salt or iodonium salt having a polymerizable unsaturated bond and a benzene ring substituted with a nitro group at the link between the polymerizable unsaturated bond and the fluorosulfonic acid moiety has the characteristic that the nitro group suppresses acid diffusion. This prevents a decrease in resolution due to blurring caused by acid diffusion and improves LWR and CDU. Furthermore, the resist material of the present invention is a self-sensitizing resist material in which secondary electrons are generated from the non-polarized electron cloud of the nitro group during EUV exposure, and energy is transferred to the acid generator, resulting in high sensitivity. Because the nitro group and the acid generator are present in close proximity within the same repeating unit, image blurring due to secondary electron diffusion does not occur. This makes it possible to construct a resist material with high sensitivity and improved LWR and CDU. DETAILED DESCRIPTION OF THE INVENTION

[0013] [Resist materials] The resist material of the present invention contains a polymer-bound acid generator. Specifically, the polymer-bound acid generator contains a polymer having a polymerizable unsaturated bond and a repeating unit derived from a sulfonium salt or iodonium salt having a benzene ring substituted with a nitro group at the linkage between the polymerizable unsaturated bond and the fluorosulfonic acid moiety. The resist material of the present invention may also contain an acid generator other than the polymer-bound acid generator that generates a sulfonic acid, an imide acid, or a methide acid.

[0014] When a mixture of the polymer-bonded acid generator used in the present invention and a sulfonium salt that generates a weaker sulfonic acid or carboxylic acid is irradiated with light, a polymeric fluorosulfonic acid containing a nitro-substituted benzene ring at the linking moiety and a weaker sulfonic acid or carboxylic acid are generated. Because the acid generator is not completely decomposed, undecomposed sulfonium salts are present nearby. When a polymeric fluorosulfonic acid containing a nitro-substituted benzene ring at the linking moiety and a weaker sulfonic acid or carboxylic acid sulfonium salt coexist, ion exchange occurs between the polymeric fluorosulfonic acid containing a nitro-substituted benzene ring at the linking moiety and the weaker sulfonic acid or carboxylic acid sulfonium salt, generating a sulfonium salt or iodonium salt of a polymeric fluorosulfonic acid containing a nitro-substituted benzene ring at the linking moiety, and releasing the weaker sulfonic acid or carboxylic acid. This is because the polymeric fluorosulfonic acid containing a nitro-substituted benzene ring at the linking moiety is more stable than the weaker sulfonic acid or carboxylic acid, which has a higher acid strength. On the other hand, ion exchange does not occur when a sulfonium salt of polymeric fluorosulfonic acid containing a benzene ring substituted with a nitro group at the linking portion is present with a weakly acidic sulfonic acid or carboxylic acid. This ion exchange based on the acid strength hierarchy occurs not only with sulfonium salts but also with iodonium salts. When combined with a fluorosulfonic acid acid generator, the weakly acidic sulfonium salt or iodonium salt functions as a quencher. Furthermore, secondary electrons are generated from the delocalized electron cloud of the nitro group during exposure, and the energy of the secondary electrons is transferred to the acid generator, promoting decomposition and thereby increasing sensitivity. The polymer-bound acid generator of the present invention can achieve low acid diffusion and high sensitivity.

[0015] The polymer-bound acid generator used in this invention not only has an anion moiety bound to the polymer backbone, but also has a nitro group introduced into it, resulting in low diffusion and high acid generation efficiency.Since the acid generator is mixed into the monomer before polymer polymerization, it is uniformly dispersed in the polymer, which can improve LWR and CDU.

[0016] The effect of improving LWR and CDU by the polymer-bonded acid generator used in the present invention is effective in both positive and negative pattern formation by aqueous alkaline solution development and negative pattern formation by organic solvent development.

[0017] [Polymer-bound acid generator] The polymer-bound acid generator used in the present invention, specifically, the polymer containing a repeating unit derived from a sulfonium salt or iodonium salt having a polymerizable unsaturated bond and having a benzene ring substituted with a nitro group at the linking portion between the polymerizable unsaturated bond and the fluorosulfonic acid moiety, contains a repeating unit represented by the following formula (a1) (hereinafter also referred to as repeating unit a1) or a repeating unit represented by the following formula (a2) (hereinafter also referred to as repeating unit a2): [ka]

[0018] In formulas (a1) and (a2), R A is a hydrogen atom or a methyl group.

[0019] In formulas (a1) and (a2), X 1 is a single bond, an ester bond, an amide bond or -X 1A -X 1C -X 1B -X 1A and X 1B are each independently a single bond, an ether bond, or an ester bond. 1C represents a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, in which a portion of the -CH2- may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group, or a sultone ring-containing group, and a portion or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom, or a nitro group.

[0020] In formulas (a1) and (a2), X 2 is a single bond, an ether bond, an ester bond or -X 2A -X 2C -X 2B -X 2A and X 2B are each independently a single bond, an ether bond, or an ester bond. 2C represents a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, in which a portion of the -CH2- may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group, or a sultone ring-containing group, and a portion or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom, or a nitro group.

[0021] X 1C and X 2CThe saturated hydrocarbylene group having 1 to 12 carbon atoms represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a butane-1,1-diyl group, a butane-1,2-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, a butane-1,4-diyl group, a 1,1-dimethylethane-1,2-diyl group, a pentane-1,5-diyl group, a 2-methylbutane-1,2-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a alkanediyl groups having 1 to 12 carbon atoms, such as cyclodiyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; cyclic saturated hydrocarbylene groups having 3 to 12 carbon atoms, such as cyclopropane-1,2-diyl, cyclobutane-1,2-diyl, cyclobutane-1,3-diyl, cyclopentane-1,1-diyl, cyclopentane-1,2-diyl, cyclopentane-1,3-diyl, cyclohexane-1,2-diyl, cyclohexane-1,3-diyl, cyclohexane-1,4-diyl, adamantane-1,3-diyl, norbornane-2,3-diyl, and norbornane-2,6-diyl; and groups obtained by combining these groups. 1C and X 2C Examples of the arylene group having 6 to 10 carbon atoms represented by the formula (I) include a 1,2-phenylene group, a 1,3-phenylene group, a 1,4-phenylene group, a 1,3-naphthylene group, a 1,4-naphthylene group, a 1,5-naphthylene group, a 1,6-naphthylene group, a 1,7-naphthylene group, a 1,8-naphthylene group, a 2,6-naphthylene group, and a 2,7-naphthylene group.

[0022] In formulas (a1) and (a2), Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. 1 and Rf 2may combine to form a carbonyl group.

[0023] In formulas (a1) and (a2), R 1 is an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, or a halogen atom. Examples of the alkyl group and the alkyl moiety of the alkyloxy group and alkylcarbonyloxy group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and a tert-butyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0024] Examples of anions of the monomers that provide the repeating units a1 and a2 include, but are not limited to, those shown below. [ka]

[0025] [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031]

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[0032]

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[0033]

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[0034]

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[0035]

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[0036]

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[0037]

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[0038]

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[0039]

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[0040]

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[0041] [ka]

[0042] [ka]

[0043] In formulas (a1) and (a2), R 2 ~R 6 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom.

[0044] R 2 ~R 6 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0045] R 2 ~R 6The hydrocarbyl group represented by the formula (I) 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 groups; cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, propenyl, butenyl, and hexenyl groups; and cyclohexyl. Examples of such alkyl groups include cyclic unsaturated aliphatic hydrocarbyl groups having 2 to 20 carbon atoms, such as phenyl, propynyl, and butynyl; alkynyl groups having 2 to 20 carbon atoms, such as ethynyl, propynyl, and butynyl; aryl groups having 6 to 20 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, and tert-butylnaphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl and phenethyl; and groups obtained by combining these groups. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0046] Also, R 2 and R 3 However, 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 ring preferably has the following structure: [ka] (In the formula, the dashed line indicates R 4 )

[0047] The sulfonium cation of the repeating unit a1 is preferably one represented by the following formula (M-1) or (M-2), and the iodonium cation of the repeating unit a2 is preferably one represented by the following formula (M-3). [ka]

[0048] In formulas (M-1) to (M-3), R M1 , R M2 , R M3 , R M4 and R M5 are each independently a halogen atom, a hydroxy group, a nitro group, a cyano group, a carboxy group, a hydrocarbyl group having 1 to 14 carbon atoms, a hydrocarbyloxy group having 1 to 14 carbon atoms, a hydrocarbylcarbonyl group having 2 to 14 carbon atoms, a hydrocarbylcarbonyloxy group having 2 to 14 carbon atoms, a hydrocarbyloxycarbonyl group having 2 to 14 carbon atoms, or a hydrocarbylthio group having 1 to 14 carbon atoms.

[0049] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The hydrocarbyl moiety of the hydrocarbyl group having 1 to 14 carbon atoms, the hydrocarbyloxy group having 1 to 14 carbon atoms, the hydrocarbylcarbonyl group having 2 to 14 carbon atoms, the hydrocarbylcarbonyloxy group having 2 to 14 carbon atoms, the hydrocarbyloxycarbonyl group having 2 to 14 carbon atoms, and the hydrocarbylthio group having 1 to 14 carbon atoms may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-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 such as decanyl, adamantyl, and adamantylmethyl; alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbyl groups such as cyclohexenyl; phenyl, naphthyl, thienyl, 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, 3-tert-butoxyphenyl, 2-methylphenyl, and 3-methylphenyl groups aryl groups such as a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-n-butylphenyl group, a 2,4-dimethylphenyl group, a 2,4,6-triisopropylphenyl group, a methylnaphthyl group, an ethylnaphthyl group, a methoxynaphthyl group, an ethoxynaphthyl group, an n-propoxynaphthyl group, an n-butoxynaphthyl group, a dimethylnaphthyl group, a diethylnaphthyl group, a dimethoxynaphthyl group, and a diethoxynaphthyl group; and aralkyl groups such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group.

[0050] In addition, some or all of the hydrogen atoms in the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a haloalkyl group, etc. In addition, -CH2- in the hydrocarbyl group may be replaced by -O-, -C(=O)-, -S-, -S(=O)-, -S(=O)2-, or -N(R N )-. R N represents a hydrogen atom or a hydrocarbyl group having 1 to 10 carbon atoms, and a hydrogen atom in the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, so that the hydrocarbyl group may contain a hydroxy group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a haloalkyl group or the like, and -CH2- in the hydrocarbyl group may be substituted with -O-, -C(=O)- or -S(=O)2-.

[0051] In formula (M-2), X is a single bond, -CH2-, -O-, -C(=O)-, -S-, -S(=O)-, -S(=O)2-, or -N(R N )-. R N is the same as above.

[0052] In formulas (M-1) to (M-3), k 1 , k 2 , k 3 , k 4 and k 5 are each independently an integer of 0 to 5. 1 When is 2 or more, each R M1 may be the same or different, and two R M1 may be bonded to each other to form a ring together with the carbon atoms on the benzene ring to which they are attached. 2 When is 2 or more, each R M2 may be the same or different, and two R M2 may be bonded to each other to form a ring together with the carbon atoms on the benzene ring to which they are attached. 3 When is 2 or more, each R M3may be the same or different, and two R M3 may be bonded to each other to form a ring together with the carbon atoms on the benzene ring to which they are attached. 4 When is 2 or more, each R M4 may be the same or different, and two R M4 may be bonded to each other to form a ring together with the carbon atoms on the benzene ring to which they are attached. 5 When is 2 or more, each R M5 may be the same or different, and two R M5 may be bonded to each other to form a ring together with the carbon atoms on the benzene ring to which they are attached.

[0053] Examples of the sulfonium cation of the repeating unit a1 include, but are not limited to, those shown below. [ka]

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] [ka]

[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] Examples of the iodonium cation of the repeating unit a2 include, but are not limited to, the following: [ka]

[0078] [ka]

[0079] In the formulae (a1) and (a2), m is an integer of 0 to 3, and n is 1 or 2.

[0080] The repeating units a1 and a2 are preferably those represented by the following formulae (a1-1) and (a2-1), respectively. [ka] (In the formula, R A , X 1 , Rf 1 ~Rf 4 , R 1 ~R 6 , m and n are the same as above.

[0081] The monomer that provides the repeating unit a1 or a2 can be synthesized, for example, by a method similar to that for the sulfonium salt having a polymerizable anion described in Japanese Patent No. 5201363.

[0082] The polymer-bonded acid generator can also function as a base polymer. In this case, in the case of a chemically amplified positive resist material, the polymer-bonded acid generator contains a repeating unit having an acid labile group. The repeating unit having an acid labile group is preferably 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). [ka]

[0083] In formulas (b1) and (b2), R A are each independently a hydrogen atom or a methyl group. 1 Y is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 12 carbon atoms and containing at least one bond selected from an ester bond, an ether bond, and a lactone ring. 2 is a single bond or an ester bond. 11 and R 12 are each independently an acid labile group. 13R is 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 represents a single bond or an alkanediyl group having 1 to 6 carbon atoms, and the alkanediyl group may contain an ether bond or an ester bond. a represents an integer of 0 to 4.

[0084] Examples of the repeating unit b1 include, but are not limited to, those shown below. A and R 11 is the same as above. [ka]

[0085] Examples of the repeating unit b2 include, but are not limited to, those shown below. A and R 12 is the same as above. [ka]

[0086] In formulas (b1) and (b2), R 11 and R 12 Examples of the acid labile group represented by the formula (I) include those described in JP-A Nos. 2013-80033 and 2013-83821.

[0087] Typical examples of the acid labile group include those represented by the following formulae (AL-1) to (AL-3). [ka]

[0088] In formulas (AL-1) and (AL-2), R L1 and R L2are each independently a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 40 carbon atoms, more preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms.

[0089] In formula (AL-1), b represents an integer of 0 to 10, and an integer of 1 to 5 is preferred.

[0090] In formula (AL-2), R L3 and R L4 are each independently a hydrogen atom or 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 linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms. In addition, R L2 , R L3 and R L4 Any two of these 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. As the ring, a ring having 4 to 16 carbon atoms is preferred, and an alicyclic ring is particularly preferred.

[0091] In formula (AL-3), R L5 , R L6 and R L7 are each independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a fluorine atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group is preferably a saturated hydrocarbyl group having 1 to 20 carbon atoms. In addition, R L5 , R L6 and R L7 Any two of these may be bonded to each other together with the carbon atoms to which they are bonded to form a ring having 3 to 20 carbon atoms. As the ring, a ring having 4 to 16 carbon atoms is preferred, and an alicyclic ring is particularly preferred.

[0092] When the polymer-bonded acid generator also functions as a base polymer, it may further contain a repeating unit c containing a phenolic hydroxy group as an adhesive group. Examples of monomers that provide the repeating unit c include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0093] When the polymer-bonded acid generator also functions as a base polymer, it may further contain a repeating unit d containing, as another adhesive group, a hydroxy group other than a phenolic hydroxy group, a lactone ring, a sultone ring, an ether bond, an ester bond, a sulfonate ester bond, a carbonyl group, a sulfonyl group, a cyano group, or a carboxy group. Examples of monomers that provide the repeating unit d include, but are not limited to, those shown below. In the following formula, R A is the same as above. [ka]

[0094] [ka]

[0095] [ka]

[0096] [ka]

[0097] [ka]

[0098] [ka]

[0099] [ka]

[0100] [ka]

[0101] [ka]

[0102] When the polymer-bound acid generator also functions as a base polymer, it may further contain a repeating unit e derived from indene, benzofuran, benzothiophene, acenaphthylene, chromone, coumarin, norbornadiene, or a derivative thereof. Examples of monomers that provide the repeating unit e include, but are not limited to, those shown below. [ka]

[0103] When the polymer-bound acid generator also functions as a base polymer, it may further contain a repeating unit f derived from indane, vinylpyridine, or vinylcarbazole.

[0104] The polymer-bonded acid generator may contain a repeating unit g derived from an onium salt containing a polymerizable unsaturated bond other than the repeating units a1 and a2. Examples of such a repeating unit g include those described in paragraph

[0060] of JP2017-008181A.

[0105] As the base polymer for the positive resist material, repeating units a1 and / or a2, and repeating units b1 and / or b2 having an acid-labile group are used as essential units. In this case, the content ratios of the repeating units a1, a2, b1, b2, c, d, e, f, and g are preferably 0 ≦ a1 < 1.0, 0 ≦ a2 < 1.0, 0 < a1 + a2 < 1.0, 0 ≦ b1 < 1.0, 0 ≦ b2 < 1.0, 0 < b1 + b2 < 1.0, 0 ≦ c ≦ 0.9, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, and 0 ≦ g ≦ 0.4, more preferably 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.02 ≦ a1 + a2 ≦ 0.7, 0 ≦ b1 ≦ 0.9, 0 ≦ b2 ≦ 0.9, 0.1 ≦ b1 + b2 ≦ 0.9, 0 ≦ c ≦ 0.8, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7, and 0 ≦ g ≦ 0.3, and even more preferably 0 ≦ a1 ≦ 0.5, 0 ≦ a2 ≦ 0.5, 0.03 ≦ a1 + a2 ≦ 0.5, 0 ≦ b1 ≦ 0.8, 0 ≦ b2 ≦ 0.8, 0.1 ≦ b1 + b2 ≦ 0.8, 0 ≦ c ≦ 0.7, 0 ≦ d ≦ 0.7, 0 ≦ e ≦ 0.6, 0 ≦ f ≦ 0.6, and 0 ≦ g ≦ 0.2. Note that a1 + a2 + b + b2 + c + d + e + f + g = 1.0.

[0106] On the other hand, as the base polymer for the negative resist material, an acid-labile group is not necessarily required, and repeating units a1 and / or a2 are used as essential units, and further those containing repeating units c, d, e, f, and / or g are included. The content ratios of these repeating units are preferably 0 ≦ a1 < 1.0, 0 ≦ a2 < 1.0, 0 < a1 + a2 < 1.0, 0 ≦ c ≦ 1.0, 0 ≦ d ≦ 0.9, 0 ≦ e ≦ 0.8, 0 ≦ f ≦ 0.8, and 0 ≦ g ≦ 0.4, more preferably 0 ≦ a1 ≦ 0.7, 0 ≦ a2 ≦ 0.7, 0.02 ≦ a1 + a2 ≦ 0.7, 0.2 ≦ c ≦ 1.0, 0 ≦ d ≦ 0.8, 0 ≦ e ≦ 0.7, 0 ≦ f ≦ 0.7, and 0 ≦ g ≦ 0.3, and even more preferably 0 ≦ a1 ≦ 0.5, 0 ≦ a2 ≦ 0.5, 0.03 ≦ a1 + a2 ≦ 0.5, 0.3 ≦ c ≦ 1.0, 0 ≦ d ≦ 0.75, 0 ≦ e ≦ 0.6, 0 ≦ f ≦ 0.6, and 0 ≦ g ≦ 0.2. Note that a1 + a2 + c + d + e + f + g = 1.0.

[0107] To synthesize the polymer-bound acid generator, for example, a monomer that provides the repeating unit described above may be polymerized by adding a radical polymerization initiator to the monomer in an organic solvent and heating the mixture.

[0108] Examples of organic solvents used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, and dioxane. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl 2,2-azobis(2-methylpropionate), benzoyl peroxide, and lauroyl peroxide. The polymerization temperature is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, and more preferably 5 to 20 hours.

[0109] When a monomer containing a hydroxy group is copolymerized, the hydroxy group may be substituted with an acetal group, such as an ethoxyethoxy group, which is easily deprotected by an acid, during polymerization, and then deprotected with a weak acid and water after polymerization. Alternatively, the hydroxy group may be substituted with an acetyl group, a formyl group, a pivaloyl group, or the like, and then subjected to alkaline hydrolysis after polymerization.

[0110] When hydroxystyrene or hydroxyvinylnaphthalene is copolymerized, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and after polymerization, the acetoxy groups may be deprotected by the alkaline hydrolysis to form hydroxystyrene units or hydroxyvinylnaphthalene units.

[0111] The base that can be used in alkaline hydrolysis includes 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.

[0112] The polymer-bonded acid generator preferably has a weight average molecular weight (Mw) in terms of polystyrene measured by gel permeation chromatography (GPC) using THF as a solvent of 1,000 to 500,000, more preferably 2,000 to 30,000. If the Mw is within this range, the resist film will have good heat resistance.

[0113] Furthermore, if the molecular weight distribution (Mw / Mn) of the polymer-bonded acid generator is broad, the presence of low-molecular-weight and high-molecular-weight polymers may result in the appearance of foreign matter on the pattern after exposure, or the pattern shape may be deteriorated. As the pattern rule becomes finer, the effects of Mw and Mw / Mn tend to become greater. Therefore, in order to obtain a resist material that is suitable for fine pattern dimensions, it is preferable that the molecular weight distribution of the polymer-bonded acid generator is narrow, i.e., 1.0 to 2.0, and particularly 1.0 to 1.5.

[0114] The polymer-bound acid generator may contain two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0115] [Organic solvents] The resist material of the present invention may contain an organic solvent. The organic solvent is not particularly limited as long as it can dissolve the components described above and below. Examples of the organic solvent include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] and

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

[0116] In the resist composition of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, per 100 parts by mass of the base polymer. The organic solvents may be used singly or in combination of two or more.

[0117] [Quencher] The resist material of the present invention may contain a quencher. The quencher refers to a compound that can trap the acid generated by the acid generator in the resist material, thereby preventing the acid from diffusing into unexposed areas.

[0118] Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. Particularly preferred are the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP 2008-111103 A, particularly amine compounds having a hydroxy group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate ester bond, and compounds having a carbamate group described in Japanese Patent No. 3790649 A. Addition of such basic compounds can, for example, further suppress the diffusion rate of acid in the resist film or correct the shape.

[0119] Further, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids that are not fluorinated at the α-position. Sulfonic acids, imide acids, or methide acids that are fluorinated at the α-position are necessary for deprotecting the acid labile group of a carboxylic acid ester, and salt exchange with an onium salt that is not fluorinated at the α-position releases sulfonic acids or carboxylic acids that are not fluorinated at the α-position. Sulfonic acids and carboxylic acids that are not fluorinated at the α-position do not undergo a deprotection reaction, and therefore function as quenchers.

[0120] Furthermore, a carboxylic acid onium salt represented by the following formula (1) can also be suitably used as a quencher. [ka]

[0121] In formula (1), R 101is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl groups; cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.02,6]decanyl, adamantyl, and adamantylmethyl groups; vinyl, allyl, propenyl, butenyl, and hexenyl groups; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 40 carbon atoms, such as a cyclohexenyl group; aryl groups having 6 to 40 carbon atoms, such as a phenyl group, a naphthyl group, an alkylphenyl group (e.g., a 2-methylphenyl group, a 3-methylphenyl group, a 4-methylphenyl group, a 4-ethylphenyl group, a 4-tert-butylphenyl group, a 4-n-butylphenyl group), a dialkylphenyl group (e.g., a 2,4-dimethylphenyl group, a 2,4,6-triisopropylphenyl group), an alkylnaphthyl group (e.g., a methylnaphthyl group, an ethylnaphthyl group), and a dialkylnaphthyl group (e.g., a dimethylnaphthyl group, a diethylnaphthyl group); and aralkyl groups having 7 to 40 carbon atoms, such as a benzyl group, a 1-phenylethyl group, and a 2-phenylethyl group.

[0122] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of the hydrocarbyl group containing a heteroatom include fluorine-containing alkyl groups such as a trifluoromethyl group, a trifluoroethyl group, a 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, and a 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl group; fluorine-containing aryl groups such as a pentafluorophenyl group and a 4-trifluoromethylphenyl group; heteroaryl groups such as a thienyl group and an indolyl group; a 4-hydroxyphenyl group, a 4-methoxyphenyl group, a 3-methoxyphenyl group, a 2-methoxyphenyl group, a 4-ethoxyphenyl group, and a 5-hydroxyphenyl group. alkoxyphenyl groups such as an alkoxyphenyl group, a 4-tert-butoxyphenyl group, and a 3-tert-butoxyphenyl group; alkoxynaphthyl groups such as a methoxynaphthyl group, an ethoxynaphthyl group, an n-propoxynaphthyl group, and an n-butoxynaphthyl group; dialkoxynaphthyl groups such as a dimethoxynaphthyl group and a diethoxynaphthyl group; and aryloxoalkyl groups such as a 2-aryl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, and a 2-(2-naphthyl)-2-oxoethyl group.

[0123] The anion of the carboxylic acid onium salt is preferably one represented by the following formula (1A). [ka]

[0124] R 102 and R 103are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. 104 is a hydrogen atom, a hydroxy group, or a hydrocarbyl group having 1 to 35 carbon atoms which may contain a heteroatom. Examples of the hydrocarbyl group which may contain a heteroatom include R 101 Examples of the above-mentioned examples are the same as those given in the explanation of the above.

[0125] In formula (1), M q + is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. Examples of the sulfonium cation include the same cations as those exemplified as the cations of the repeating unit represented by formula (a1). Examples of the iodonium cation include the same cations as those exemplified as the cations of the repeating unit represented by formula (a2).

[0126] Another example of the quencher is the polymer-type quencher described in JP 2008-239918 A. This quencher enhances the rectangularity of the resist pattern by orienting on the surface of the resist film. The polymer-type quencher also has the effect of preventing pattern thinning and rounding of the pattern top when a protective film for immersion lithography is applied.

[0127] When the resist composition of the present invention contains the quencher, the content thereof is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, relative to 100 parts by mass of the base polymer. The quencher may be used alone or in combination of two or more types.

[0128] [Other ingredients] In addition to the components described above, the resist material of the present invention may also contain an acid generator other than the polymer-bound acid generator (hereinafter referred to as "other acid generator"), a surfactant, a dissolution inhibitor, a crosslinking agent, a water repellency improver, an acetylene alcohol, or the like.

[0129] Examples of the other acid generators include compounds (photoacid generators) that generate acid in response to actinic rays or radiation. The photoacid generator may be any compound that generates an acid upon exposure to high-energy rays, but is preferably one that generates a sulfonic acid, an imide acid, or a methide acid. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate-type acid generators. Specific examples of photoacid generators include those described in paragraphs

[0122] to

[0142] of JP 2008-111103 A.

[0130] Furthermore, as the photoacid generator, a sulfonium salt represented by the following formula (2-1) or an iodonium salt represented by the following formula (2-2) can also be suitably used. [ka]

[0131] In formulas (2-1) and (2-2), R 201 ~R 205 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. Examples of the halogen atom and the hydrocarbyl group having 1 to 20 carbon atoms include R 2 ~R 6 Examples of the hydrocarbyl group include the same as those exemplified above. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, so that the hydrocarbyl group may contain a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like. 201 and R202 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring formed is the same as that of R 2 and R 3 are bonded to each other to form a ring together with the sulfur atom to which they are bonded, the same as those exemplified above.

[0132] Examples of the cation of the sulfonium salt represented by formula (2-1) include the same cations as those exemplified for the repeating unit a1, and examples of the cation of the iodonium salt represented by formula (2-2) include the same cations as those exemplified for the repeating unit a2.

[0133] In formulas (2-1) and (2-2), Xa - is an anion selected from the following formulae (2A) to (2D). [ka]

[0134] In formula (2A), R fa is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A') described below. 211 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0135] The anion represented by formula (2A) is preferably one represented by the following formula (2A'). [ka]

[0136] In formula (2A'), R HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 211is a hydrocarbyl group having 1 to 38 carbon atoms which may contain a heteroatom. The heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, or the like, and more preferably an oxygen atom. In order to obtain high resolution in the formation of a fine pattern, the hydrocarbyl group is particularly preferably one having 6 to 30 carbon atoms.

[0137] R 211 The hydrocarbyl group represented by the formula (I) 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 a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, and an icosanyl group; a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-adamantylmethyl group, and a norbornyl group. cyclic saturated hydrocarbyl groups having 3 to 38 carbon atoms such as a norbornylmethyl group, a tricyclodecanyl group, a tetracyclododecanyl group, a tetracyclododecanylmethyl group, or a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 38 carbon atoms such as an allyl group or a 3-cyclohexenyl group; aryl groups having 6 to 38 carbon atoms such as a phenyl group, a 1-naphthyl group, or a 2-naphthyl group; aralkyl groups having 7 to 38 carbon atoms such as a benzyl group or a diphenylmethyl group; and groups obtained by combining these.

[0138] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of hydrocarbyl groups containing hetero atoms include tetrahydrofuryl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl groups.

[0139] Synthesis of sulfonium salts containing anions represented by formula (2A') is described in detail in JP-A Nos. 2007-145797, 2008-106045, 2009-7327, and 2009-258695. Sulfonium salts described in JP-A Nos. 2010-215608, 2012-41320, 2012-106986, and 2012-153644 are also suitable.

[0140] Examples of the anion represented by formula (2A) include the same anions as those exemplified as the anion represented by formula (1A) in JP 2018-197853 A.

[0141] In formula (2B), R fb1 and R fb2 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). 211Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fb1 and R fb2 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 means that the groups to which they are bonded (-CF2-SO2-N - -SO2-CF2-) together to form a ring, in which case, R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0142] In formula (2C), R fc1 , R fc2 and R fc3 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). 211 Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fc1 , R fc2 and R fc3 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 are groups that are bonded together and bonded to each other (-CF2-SO2-C - -SO2-CF2-) together to form a ring, in which case, R fc1 and R fc2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0143] In formula (2D), R fd is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). 211Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0144] The synthesis of sulfonium salts containing anions represented by formula (2D) is described in detail in JP-A-2010-215608 and JP-A-2014-133723.

[0145] Examples of the anion represented by formula (2D) include the same anions as those exemplified as the anion represented by formula (1D) in JP-A-2018-197853.

[0146] Although the photoacid generator containing the anion represented by formula (2D) does not have a fluorine atom at the α-position of the sulfo group, it has two trifluoromethyl groups at the β-position, and therefore has sufficient acidity to cleave the acid labile groups in the base polymer, making it suitable for use as a photoacid generator.

[0147] As the photoacid generator, a compound represented by the following formula (3) can also be suitably used. [ka]

[0148] In formula (2), R 301 and R 302 R are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 303 is a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom. 301 and R 302 or R 301 and R 303 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as R 2 and R 3 are bonded to each other to form a ring together with the sulfur atom to which they are bonded, the same as those exemplified above.

[0149] R301 and R 302 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 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, and an n-decyl group; a cyclopentyl group, a cyclohexyl group, a cyclopentylmethyl group, a cyclopentylethyl group, a cyclopentylbutyl group, a cyclohexylmethyl group, a cyclohexylethyl group, a cyclohexylbutyl group, a norbornyl group, and a tricyclo[5.2.1.0] 2,6 cyclic saturated hydrocarbyl groups having 3 to 30 carbon atoms such as a phenyl group, a methylphenyl group, an ethylphenyl group, an n-propylphenyl group, an isopropylphenyl group, an n-butylphenyl group, an isobutylphenyl group, a sec-butylphenyl group, a tert-butylphenyl group, a naphthyl group, a methylnaphthyl group, an ethylnaphthyl group, an n-propylnaphthyl group, an isopropylnaphthyl group, an n-butylnaphthyl group, an isobutylnaphthyl group, a sec-butylnaphthyl group, a tert-butylnaphthyl group, an anthracenyl group, and the like; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0150] R 303The hydrocarbylene group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkanediyl groups having 1 to 30 carbon atoms, such as methanediyl 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, and heptadecane-1,17-diyl group; cyclopentanediyl group, cyclohexene-1,18-diyl group, and the like. Examples of the alkylene groups include cyclic saturated hydrocarbylene groups having 3 to 30 carbon atoms, such as xanediyl, 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; and groups obtained by combining these groups. In addition, some or all of the hydrogen atoms of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH- groups of the hydrocarbylene group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the hydrocarbylene group containing a hydroxy 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 ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. As the heteroatom, an oxygen atom is preferred.

[0151] In formula (3), LA is a single bond, an ether bond, or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 303 Examples of the hydrocarbylene group represented by the formula (I) include the same as those exemplified above.

[0152] In formula (3), X A , X B , X C and X D are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that X A , X B , X C and X D At least one of the groups is a fluorine atom or a trifluoromethyl group.

[0153] In formula (3), c is an integer of 0 to 3.

[0154] The photoacid generator represented by formula (3) is preferably one represented by the following formula (3'). [ka]

[0155] In formula (3'), L A is the same as above. R HF is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 304 , R 305 and R 306 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydrogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (2A'). 211 Examples of the hydrocarbyl group include the same as those exemplified above. Each of x and y is independently an integer of 0 to 5, and z is an integer of 0 to 4.

[0156] Examples of the photoacid generator represented by formula (3) include the same compounds as those exemplified as the photoacid generator represented by formula (2) in JP-A-2017-026980.

[0157] Among the photoacid generators, those containing an anion represented by formula (2A') or (2D) are particularly preferred because of their small acid diffusion and excellent solubility in resist solvents, and those containing an anion represented by formula (3') are particularly preferred because of their extremely small acid diffusion.

[0158] The photoacid generator may also be a sulfonium salt or iodonium salt containing an anion having an aromatic ring substituted with an iodine atom or a bromine atom, such as those represented by the following formula (4-1) or (4-2): [ka]

[0159] In formulas (4-1) and (4-2), p is an integer that satisfies 1≦p≦3. q and r are integers that satisfy 1≦q≦5, 0≦r≦3, and 1≦q+r≦5. q is preferably an integer that satisfies 1≦q≦3, more preferably 2 or 3. r is preferably an integer that satisfies 0≦r≦2.

[0160] In formulas (4-1) and (4-2), X BI is an iodine atom or a bromine atom, and when p and / or q is 2 or more, they may be the same or different.

[0161] In formulas (4-1) and (4-2), L 1 is a single bond, an ether bond, an ester bond, or a saturated hydrocarbylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0162] In formulas (4-1) and (4-2), L 2represents a single bond or a divalent linking group having 1 to 20 carbon atoms when p is 1, and represents a (p+1)-valent linking group having 1 to 20 carbon atoms when p is 2 or 3, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0163] In formulas (4-1) and (4-2), R 401 is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom or an amino group, or a hydrocarbyl group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, a hydrocarbylcarbonyl group having 2 to 20 carbon atoms, a hydrocarbyloxycarbonyl group having 2 to 10 carbon atoms, a hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms or a hydrocarbylsulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a hydroxy group, an amino group or an ether bond, or 401A )(R 401B ), -N(R 401C )-C(=O)-R 401D or -N(R 401C )-C(=O)-OR 401D R 401A and R 401B are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 401C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxy 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. 401Dis an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may contain a halogen atom, a hydroxy 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. The aliphatic hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. The hydrocarbyl group, hydrocarbyloxy group, hydrocarbylcarbonyl group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When p and / or r is 2 or more, each R 401 may be the same or different from each other.

[0164] Of these, R 401 Examples of the hydroxyl group include -N(R 401C )-C(=O)-R 401D , -N(R 401C )-C(=O)-OR 401D fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group, etc. are preferred.

[0165] In formulas (4-1) and (4-2), Rf 11 ~Rf 14 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of them is a fluorine atom or a trifluoromethyl group. 11 and Rf 12 may combine to form a carbonyl group. 13 and Rf 14 are preferably both fluorine atoms.

[0166] In formulas (4-1) and (4-2), R 402 ~R 406are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 2 ~R 6 Examples of the hydrocarbyl group include the same as those exemplified above. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a hydroxy group, a carboxy group, a halogen atom, a cyano group, a nitro group, a mercapto group, a sultone group, a sulfone group, or a sulfonium salt-containing group, and some of the -CH2- groups of the hydrocarbyl group may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate ester bond. 402 and R 403 may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, the ring is the same as R 2 and R 3 are bonded to each other to form a ring together with the sulfur atom to which they are bonded, the same as those exemplified above.

[0167] Examples of the cation of the sulfonium salt represented by formula (4-1) include the same cations as those exemplified for the repeating unit a1, and examples of the cation of the iodonium salt represented by formula (4-2) include the same cations as those exemplified for the repeating unit a2.

[0168] Examples of the anion of the onium salt represented by formula (4-1) or (4-2) include, but are not limited to, those shown below. BI is the same as above. [ka]

[0169] [ka]

[0170]

change

[0171]

change

[0172]

change

[0173]

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[0174]

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[0175]

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[0176]

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[0177]

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[0178]

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[0179]

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[0180]

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[0181]

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[0182]

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[0183]

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[0184]

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[0185]

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[0186]

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[0187]

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[0188]

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[0189]

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[0190]

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[0191] When the resist composition of the present invention contains the other acid generator, 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 other acid generators may be used alone or in combination of two or more.

[0192] Examples of the surfactant include those described in paragraphs

[0165] and

[0166] of JP 2008-111103 A. Adding a surfactant can further improve or control the coatability of the resist material. When the resist material of the present invention contains the surfactant, the content thereof is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the base polymer. The surfactant may be used alone or in combination of two or more types.

[0193] When the resist material of the present invention is a positive resist, the incorporation of a dissolution inhibitor can further increase the difference in dissolution rate between exposed and unexposed areas, thereby further improving resolution. Examples of dissolution inhibitors include compounds having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, containing two or more phenolic hydroxy groups in the molecule, in which the hydrogen atoms of the phenolic hydroxy groups have been substituted with acid labile groups at a rate of 0 to 100 mol % overall, and compounds containing carboxy groups in the molecule, in which the hydrogen atoms of the carboxy groups have been substituted with acid labile groups at an average rate of 50 to 100 mol % overall. Specific examples include compounds in which the hydroxyl groups or carboxyl groups of bisphenol A, trisphenol, phenolphthalein, cresol novolak, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid have been substituted with acid labile groups. These compounds are described, for example, in paragraphs

[0155] to

[0178] of JP 2008-122932 A.

[0194] When the resist composition of the present invention is a positive resist composition and contains the dissolution inhibitor, the content thereof is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, per 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more types.

[0195] On the other hand, when the resist material of the present invention is a negative resist, a negative pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed area. Examples of crosslinking agents include epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds, such as alkenyloxy groups, all substituted with at least one group selected from methylol groups, alkoxymethyl groups, and acyloxymethyl groups. These may be used as additives or may be introduced as pendant groups into polymer side chains. Hydroxy-containing compounds may also be used as crosslinking agents.

[0196] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0197] Examples of the melamine compound include hexamethylol melamine, hexamethoxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are methoxymethylated, or a mixture thereof, hexamethoxyethyl melamine, hexaacyloxymethyl melamine, a compound in which 1 to 6 methylol groups of hexamethylol melamine are acyloxymethylated, or a mixture thereof.

[0198] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are methoxymethylated, or a mixture thereof; tetramethoxyethylguanamine, tetraacyloxyguanamine, a compound in which 1 to 4 methylol groups of tetramethylolguanamine are acyloxymethylated, or a mixture thereof; and the like.

[0199] Examples of glycoluril compounds include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril have been methoxymethylated or mixtures thereof, compounds in which 1 to 4 methylol groups of tetramethylol glycoluril have been acyloxymethylated or mixtures thereof, etc. Examples of urea compounds include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups of tetramethylol urea have been methoxymethylated or mixtures thereof, tetramethoxyethyl urea, etc.

[0200] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0201] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0202] Examples of compounds containing an 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 trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0203] When the resist composition of the present invention is a negative resist composition and contains a 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 agents may be used singly or in combination of two or more.

[0204] The water repellency improver improves the water repellency of the resist film surface and can be used in immersion lithography without a topcoat. Preferred examples of the water repellency improver include polymers containing fluorinated alkyl groups and polymers containing a specific 1,1,1,3,3,3-hexafluoro-2-propanol residue structure, with those exemplified in JP-A Nos. 2007-297590 and 2008-111103 being more preferred. The water repellency improver must be soluble in an alkaline developer or an organic solvent developer. The water repellency improver having the specific 1,1,1,3,3,3-hexafluoro-2-propanol residue described above has good solubility in the developer. As a water repellency improver, polymers containing repeating units containing an amino group or an amine salt are highly effective in preventing the evaporation of acid during PEB and preventing poor opening of the hole pattern after development. When the resist composition of the present invention contains a water repellency improver, the content thereof is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more.

[0205] Examples of the acetylene alcohols include those described in paragraphs

[0179] to

[0182] of JP 2008-122932 A. When the resist material of the present invention contains an acetylene alcohol, the content thereof is preferably 0 to 5 parts by mass per 100 parts by mass of the base polymer. The acetylene alcohols may be used alone or in combination of two or more.

[0206] [Pattern formation method] When the resist material of the present invention is used in the manufacture of various integrated circuits, known lithography techniques can be applied. For example, a pattern formation method can include a method comprising the steps of forming a resist film on a substrate using the resist material, exposing the resist film to high-energy radiation, and developing the exposed resist film using a developer.

[0207] First, the resist material of the present invention is applied to a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective coating, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) by an appropriate coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, doctor coating, etc., to a coating thickness of 0.01 to 2 μm. This is then prebaked 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.

[0208] Next, the resist film is exposed to high-energy radiation. Examples of the high-energy radiation include ultraviolet radiation, far ultraviolet radiation, EB, EUV radiation with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation. When ultraviolet radiation, far ultraviolet radiation, EUV radiation, X-rays, soft X-rays, excimer laser light, gamma rays, and synchrotron radiation are used as the high-energy radiation, the exposure dose is preferably 1 to 200 mJ / cm, either directly or using a mask for forming a desired pattern. 2 approximately, more preferably 10 to 100 mJ / cm 2 When EB is used as the high energy beam, the exposure dose is preferably 0.1 to 100 μC / cm 2 approximately, more preferably 0.5 to 50 μC / cm 2 The resist composition of the present invention is particularly suitable for fine patterning using high-energy radiation such as KrF excimer laser light, ArF excimer laser light, EB, EUV, X-rays, soft X-rays, γ-rays, and synchrotron radiation.

[0209] After the exposure, PEB may be performed on a hot plate or in an oven, 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.

[0210] After exposure or PEB, the exposed resist film is developed using a developer, preferably an aqueous alkaline solution of 0.1 to 10% by weight, more preferably 2 to 5% by weight, such as tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), tetrapropylammonium hydroxide (TPAH), or tetrabutylammonium hydroxide (TBAH), for 3 seconds to 3 minutes, preferably 5 seconds to 2 minutes, by a conventional method such as dipping, puddling, or spraying, to form the desired pattern on the substrate. In the case of a positive resist material, the irradiated portion dissolves in the developer, while the unexposed portion remains insoluble, forming a positive pattern. In the case of a negative resist material, the opposite occurs: the irradiated portion becomes insoluble in the developer, while the unexposed portion dissolves.

[0211] A negative pattern can also be obtained by organic solvent development using a positive resist material containing a base polymer containing an acid labile group. The developer used in this case includes 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, pentyl acetate, butenyl acetate, isopentyl acetate, propyl formate, butyl formate, isobutyl formate, pentyl formate, isopentyl formate, methyl valerate, methyl pentenoate, methyl crotonate, ethyl crotonate, Examples of the organic solvent include methyl propionate, ethyl propionate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl lactate, isopentyl 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.

[0212] After the development is completed, the resist film is rinsed. A solvent that is miscible with the developer but does not dissolve the resist film is preferred as the rinse solution. Preferred examples of such solvents include 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.

[0213] Specific examples of alcohols 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, and 3-hexanol. , 2,3-dimethyl-2-butanol, 3,3-dimethyl-1-butanol, 3,3-dimethyl-2-butanol, 2-ethyl-1-butanol, 2-methyl-1-pentanol, 2-methyl-2-pentanol, 2-methyl-3-pentanol, 3-methyl-1-pentanol, 3-methyl-2-pentanol, 3-methyl-3-pentanol, 4-methyl-1-pentanol, 4-methyl-2-pentanol, 4-methyl-3-pentanol, cyclohexanol, 1-octanol, and the like.

[0214] 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.

[0215] Examples of alkanes having 6 to 12 carbon atoms include hexane, heptane, octane, nonane, decane, undecane, dodecane, methylcyclopentane, dimethylcyclopentane, cyclohexane, methylcyclohexane, dimethylcyclohexane, cycloheptane, cyclooctane, cyclononane, etc. Examples of alkenes having 6 to 12 carbon atoms include hexene, heptene, octene, cyclohexene, methylcyclohexene, dimethylcyclohexene, cycloheptene, cyclooctene, etc. Examples of alkynes having 6 to 12 carbon atoms include hexyne, heptine, octyne, etc.

[0216] Examples of aromatic solvents include toluene, xylene, ethylbenzene, isopropylbenzene, tert-butylbenzene, and mesitylene.

[0217] Rinsing can reduce the occurrence of resist pattern collapse and defects. Rinsing is not always necessary, and not performing rinsing can reduce the amount of solvent used.

[0218] The developed hole or trench pattern can also be shrunk using thermal flow, RELACS, or DSA. A shrink agent is applied to the hole pattern, and the diffusion of an acid catalyst from the resist film during baking causes crosslinking of the shrink agent on the surface of the resist film, resulting in adhesion of the shrink agent 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. Excess shrink agent is removed, and the hole pattern is shrunk. [Example]

[0219] The present invention will be specifically explained below by showing synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[0220] The monomers PM-1 to PM-13, cPM-1, AM-1, AM-2 and FM-1 used in the synthesis examples are as follows. [ka]

[0221] [ka]

[0222] [ka]

[0223] [ka]

[0224] [Synthesis Example 1] Synthesis of Polymer P-1 In a 2 L flask, 8.4 g of 1-methyl-1-cyclopentyl methacrylate, 3.6 g of 4-hydroxyphenyl methacrylate, and 3-oxo-2,7-dioxatricyclo[4.2.1.0] methacrylate were added. 4,8 4.5 g of ]nonan-9-yl, 7.3 g of monomer PM-1, and 40 g of THF as a solvent were added. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown were repeated three times. After warming to room temperature, 1.2 g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C, followed by reaction for 15 hours. The reaction solution was precipitated in 1 L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-1 as a white solid. The composition of polymer P-1 was 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0225] [Synthesis Example 2] Synthesis of Polymer P-2 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 3.6g of 4-hydroxystyrene, 14.8g of monomer PM-2, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-2 as a white solid. The composition of polymer P-2 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0226] [Synthesis Example 3] Synthesis of Polymer P-3 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 4-hydroxystyrene, 12.2g of monomer PM-3, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-3 as a white solid. The composition of polymer P-3 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0227] [Synthesis Example 4] Synthesis of Polymer P-4 A 2L flask was charged with 11.1g of monomer AM-1, 4.2g of 3-hydroxystyrene, 9.8g of monomer PM-4, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C, followed by a reaction for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-4 as a white solid. The composition of polymer P-4 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0228] [Synthesis Example 5] Synthesis of Polymer P-5 A 2L flask was charged with 10.2g of monomer AM-2, 4.2g of 3-hydroxystyrene, 11.7g of monomer PM-5, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C, followed by a reaction for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-5 as a white solid. The composition of polymer P-5 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0229] [Synthesis Example 6] Synthesis of Polymer P-6 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 14.4g of monomer PM-6, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-6 as a white solid. The composition of polymer P-6 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0230] [Synthesis Example 7] Synthesis of Polymer P-7 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 14.1g of monomer PM-7, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-7 as a white solid. The composition of polymer P-7 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0231] [Synthesis Example 8] Synthesis of Polymer P-8 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 11.3g of monomer PM-8, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-8 as a white solid. The composition of polymer P-8 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0232] [Synthesis Example 9] Synthesis of Polymer P-9 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 11.9g of monomer PM-9, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-9 as a white solid. The composition of polymer P-9 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0233] [Synthesis Example 10] Synthesis of Polymer P-10 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 4.2g of 3-hydroxystyrene, 13.1g of monomer PM-10, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-10 as a white solid. The composition of polymer P-10 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0234] [Synthesis Example 11] Synthesis of Polymer P-11 A 2L flask was charged with 8.4g of 1-methyl-1-cyclopentyl methacrylate, 3.6g of 3-hydroxystyrene, 3.2g of monomer FM-1, 14.4g of monomer PM-11, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the mixture was heated to 60°C and reacted for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-11 as a white solid. The composition of polymer P-11 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0235] [Synthesis Example 12] Synthesis of Polymer P-12 A 2L flask was charged with 11.1g of monomer AM-1, 4.2g of 3-hydroxystyrene, 12.8g of monomer PM-12, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C, followed by a reaction for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-12 as a white solid. The composition of polymer P-12 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0236] [Synthesis Example 13] Synthesis of Polymer P-13 A 2L flask was charged with 12.2g of monomer AM-1, 4.2g of 3-hydroxystyrene, 7.6g of monomer PM-13, and 40g of THF as a solvent. The reaction vessel was cooled to -70°C under a nitrogen atmosphere, and degassed under reduced pressure and nitrogen blown three times. After warming to room temperature, 1.2g of AIBN was added as a polymerization initiator, and the temperature was raised to 60°C, followed by a reaction for 15 hours. The reaction solution was precipitated in 1L of isopropyl alcohol, and the resulting white solid was filtered and dried under reduced pressure at 60°C to obtain polymer P-13 as a white solid. The composition of polymer P-13 was as follows: 13 C-NMR and 1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0237] [Comparative Synthesis Example 1] Synthesis of comparative polymer cP-1 Comparative polymer cP-1 was obtained as a white solid in the same manner as in Synthesis Example 10, except that monomer PM-10 was changed to monomer cPM-1. The composition of comparative polymer cP-1 was: 13 C-NMR and1 Mw and Mw / Mn were confirmed by H-NMR and GPC, respectively. [ka]

[0238] [Examples 1 to 13, Comparative Example 1] (1) Preparation of resist material A resist material was prepared by filtering a solution of each component shown in Table 1 in a solvent containing 100 ppm of Omnova PolyFox PF-636 surfactant through a 0.2 μm filter.

[0239] In Table 1, the components are as follows: Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) EL (Ethyl lactate) DAA (diacetone alcohol)

[0240] Acid generator: PAG-1 [ka]

[0241] Quencher: Q-1 [ka]

[0242] (2) EUV lithography evaluation Each resist material shown in Table 1 was spin-coated onto a Si substrate with a 20 nm thick silicon-containing spin-on hard mask SHB-A940 (43% silicon by mass) manufactured by Shin-Etsu Chemical Co., Ltd., and pre-baked at 105°C for 60 seconds using a hot plate to produce a 50 nm thick resist film. The resist film was exposed to light using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, wafer dimensions 46 nm pitch, +20% bias hole pattern mask), and PEB was performed for 60 seconds using a hot plate at the temperature listed in Table 1. Development was performed for 30 seconds using a 2.38% by mass TMAH aqueous solution to form a 23 nm hole pattern. Using a Hitachi High-Technologies Corporation CD-SEM (CG6300), the exposure dose when a hole dimension of 23 nm was formed was measured and used as the sensitivity. The dimensions of 50 holes were also measured, and the standard deviation (σ) calculated from the results was tripled (3σ) to give the dimensional variation (CDU). The results are also shown in Table 1.

[0243] [Table 1]

[0244] The results shown in Table 1 demonstrate that the resist material of the present invention, which includes a polymer containing a repeating unit represented by formula (a1) or (a2), has high sensitivity and good CDU.

Claims

1. A chemically amplified positive resist material comprising a polymer containing a repeating unit represented by the following formula (a1) or (a2) and a repeating unit represented by the following formula (b1) or (b2): 【Chemistry 1】 (In the formula, R A is a hydrogen atom or a methyl group. X 1 represents a single bond, an ester bond, an amide bond or -X 1A -X 1C -X 1B - is. X 1A and X 1B are each independently a single bond, an ether bond, or an ester bond. 1C is a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, and its —CH 2 A part of the - may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group or a sultone ring-containing group, and a part or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom or a nitro group. X 2 is a single bond, an ether bond, an ester bond or -X 2A -X 2C -X 2B - is. X 2A and X 2B are each independently a single bond, an ether bond, or an ester bond. 2C is a saturated hydrocarbylene group having 1 to 12 carbon atoms, an arylene group having 6 to 10 carbon atoms, or a group obtained by combining these, and its —CH 2 A part of the - may be substituted with an ether bond, an ester bond, an amide bond, a lactone ring-containing group or a sultone ring-containing group, and a part or all of the hydrogen atoms on the aromatic ring may be substituted with an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, a halogen atom or a nitro group. Rf 1 ~Rf 4 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 may combine to form a carbonyl group. R 1 represents an alkyl group having 1 to 4 carbon atoms, an alkyloxy group having 1 to 4 carbon atoms, an alkylcarbonyloxy group having 2 to 5 carbon atoms, or a halogen atom. R 2 ~R 6 are each independently a halogen atom or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 2 and R 3 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. m is an integer of 0 to 3, and n is 1 or 2. 【Chemistry 2】 (In the formula, R A are each independently a hydrogen atom or a methyl group. Y 1 is a linking group having 1 to 12 carbon atoms and containing at least one bond selected from a single bond, a phenylene group, a naphthylene group, an ester bond, an ether bond, and a lactone ring. R 11 and R 12 are each independently an acid labile group. a is an integer of 0 to 4. The repeating unit represented by formula (b2) is derived from a monomer represented by any one of the following formulas: 【Transformation 3】 ）

2. 2. The chemically amplified positive resist material according to claim 1, wherein the repeating unit represented by formula (a1) is represented by the following formula (a1-1), and the repeating unit represented by formula (a2) is represented by the following formula (a2-1): 【Chemistry 4】 (In the formula, R A , X 1 , Rf 1 ~Rf 4 , R 1 ~R 6 , m and n are the same as above.)

3. 3. The chemically amplified positive resist composition according to claim 1, further comprising an organic solvent.

4. The chemically amplified positive resist composition according to any one of claims 1 to 3, further comprising a quencher.

5. 5. The chemically amplified positive resist composition according to claim 1, further comprising a surfactant.

6. A pattern formation method comprising the steps of: forming a resist film on a substrate using the chemically amplified positive resist material according to any one of claims 1 to 5; exposing the resist film to high-energy rays; and developing the exposed resist film using a developer.

7. 7. The pattern forming method according to claim 6, wherein the high-energy beam is ArF excimer laser light with a wavelength of 193 nm, KrF excimer laser light with a wavelength of 248 nm, an electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

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