Positive-type resist material and pattern formation method

Abstract

To provide a positive resist material which has sensitivity and resolution higher than those of conventional positive resist materials, small edge roughness and CDU, and a good pattern shape after exposure, and to provide a pattern forming method.SOLUTION: A positive resist material contains a compound having: two or more urethane groups; a carboxy group bonded to a first urethane group via a first linking group and substituted with an acid-labile group; and a sulfonium salt or iodonium salt of a sulfonic acid bonded to a second urethane group directly or via a second linking group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] With the increasing integration and speed of LSIs, the miniaturization of pattern rules is progressing rapidly. This is because the spread of 5G high-speed communication and artificial intelligence (AI) is advancing, requiring high-performance devices to process them. As a cutting-edge miniaturization technology, mass production of 5nm node devices is underway using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm. Furthermore, EUV lithography is also being explored for next-generation 3nm node and the following-generation 2nm node devices, and IMEC in Belgium has announced a roadmap for device development down to 2 angstroms.

[0003] EUV lithography, with a wavelength of 13.5 nm, is expected to produce high contrast and high resolution because its wavelength is less than 1 / 10th that of ArF lithography, which uses a wavelength of 193 nm. However, because EUV has a short wavelength and high energy density, the acid generator is exposed to even a small number of photons. The number of photons in EUV exposure is said to be 1 / 14th that of ArF exposure. In EUV exposure, the variation in photons is a problem because it degrades the edge roughness (LER, LWR) of lines and the dimensional uniformity (CDU) of holes.

[0004] To reduce edge roughness, chemically amplified molecular resist materials using low-molecular-weight compounds as a base have been investigated (Non-Patent Documents 1, 2, Patent Document 1). This is based on the idea that a smaller molecular weight reduces the risk of increased edge roughness due to uneven dissolution of the resist film in the developer. However, there was a problem in that the edge roughness deteriorated due to insufficient control of acid diffusion. Rather, conventional polymer-type resist materials have lower edge roughness, and the advantage of the small molecular weight of molecular resist materials remains unrealized.

[0005] As miniaturization progresses, image blurring due to acid diffusion is becoming a problem. To ensure resolution in fine patterns with dimensions of 45 nm or larger, it has been suggested that controlling acid diffusion is important, in addition to improving the dissolution contrast as has been conventionally proposed (Non-Patent Literature 3). However, since chemically amplified resist materials increase sensitivity and contrast through acid diffusion, attempting to suppress acid diffusion to the extreme by lowering the post-exposure bake (PEB) temperature or shortening the time results in a significant decrease in sensitivity and contrast.

[0006] The relationship between sensitivity, resolution, and edge roughness (LWR) in a triangle trade-off is shown. To improve resolution, it is necessary to suppress acid diffusion, but as the acid diffusion distance decreases, sensitivity decreases.

[0007] Adding an acid generator that produces bulky acids is effective in suppressing acid diffusion. Therefore, it has been proposed to include repeating units derived from onium salts having polymerizable unsaturated bonds in the polymer. In this case, the polymer also functions as an acid generator (polymer-bound type acid generator). Patent document 2 proposes sulfonium salts and iodonium salts having polymerizable unsaturated bonds that generate specific sulfonic acids. Patent document 3 proposes sulfonium salts in which sulfonic acids are directly linked to the main chain. [Prior art documents] [Patent Documents]

[0008] [Patent Document 1] Japanese Patent Publication No. 2006-347974 [Patent Document 2] Japanese Patent Publication No. 2006-045311 [Patent Document 3] Japanese Patent Publication No. 2006-178317 [Non-patent literature]

[0009] [Non-Patent Document 1] SPIE Vol. 6519 65194B-1 (2007) [Non-Patent Document 2] SPIE Vol. 6923 69230J-1 (2008) [Non-Patent Document 3] SPIE Vol. 6520 65203L-1 (2007) [Overview of the project] [Problems that the invention aims to solve]

[0010] The present invention has been made in view of the above circumstances, and aims to provide a positive-type resist material and a pattern formation method that have higher sensitivity and resolution than conventional positive-type resist materials, have low edge roughness and CDU, and produce a good pattern shape after exposure. [Means for solving the problem]

[0011] To solve the above problems, the present invention provides a positive-type resist material comprising a compound having two or more urethane groups, a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium salt or iodonium salt of a sulfonic acid bonded directly to a second urethane group or via a second linking group.

[0012] Such a positive resist material has higher sensitivity and resolution than conventional positive resist materials, has small edge roughness and CDU, and provides a positive resist material with a good pattern shape after exposure.

[0013] Further, in the present invention, the compound is preferably one represented by the following formula (1).

Chemical Formula

[0014] With such a compound, the effect of the present invention can be further improved.

[0015] In this case, the R 1 preferably corresponds to any one of the following 1) to 3). 1) The carbon bonded to the ester group is tertiary, and the alkyl group bonded to the carbon does not contain a halogen atom, a cyano group, or a nitro group. 2) The carbon atom bonded to the ester group is secondary and has a cyclic structure, does not contain heteroatoms, and has double bonds, triple bonds, or aromatic groups on carbon atoms other than the carbon atom bonded to the ester group. 3) It is an acetal group having an ether group adjacent to the carbon atom bonded to the ester group.

[0016] Such acid-unstable groups are preferred as acid-unstable groups in the compounds contained in the positive-type resist material of the present invention.

[0017] Furthermore, it is preferable that the present invention further includes a compound having two or more urethane groups, and two or more carboxyl groups substituted with acid-unstable groups bonded to the urethane groups via linking groups.

[0018] Such a positive-type resist material can further enhance the effects of the present invention.

[0019] Furthermore, in the present invention, it is preferable that the invention further includes a base polymer.

[0020] Such a positive-type resist material can further enhance the effects of the present invention.

[0021] In this case, it is preferable that the base polymer contains repeating units in which the hydrogen atoms of the carboxyl group are substituted with acid-unstable groups and / or repeating units in which the hydrogen atoms of the phenolic hydroxyl group are substituted with acid-unstable groups.

[0022] With this type of positive-type resist material, it is possible to increase the dissolution contrast.

[0023] In this case, it is preferable that the repeating units in which the hydrogen atoms of the carboxyl group are substituted with an acid-unstable group and the repeating units in which the hydrogen atoms of the phenolic hydroxyl group are substituted with an acid-unstable group are the repeating units represented by the following formula (a1) and the following formula (a2), respectively. [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 1 X is a single bond, or a linking group having 1 to 14 carbon atoms that includes a phenylene group, a naphthylene group, an ester bond, an ether bond, or a lactone ring. 2 X is a single bond, an ester bond, or an amide bond. 3 These are single bonds, ether bonds, or ester bonds. 11 and R 12 R is an acid-unstable group. 13 R is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 14 (a is a single bond or a saturated hydrocarbylene group having 1 to 6 carbon atoms, some of which may be substituted with ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4, where 1 ≤ a + b ≤ 5.)

[0024] Using a base polymer containing such repeating units can further enhance the dissolution contrast.

[0025] Furthermore, in the present invention, it is preferable that the base polymer further comprises repeating units b having adhesive groups selected from hydroxyl groups, carboxyl groups, lactone rings, carbonate groups, thiocarbonate groups, carbonyl groups, cyclic acetal groups, ether bonds, ester bonds, sulfonic acid ester bonds, cyano groups, amide bonds, -OC(=O)-S-, and -OC(=O)-NH-.

[0026] The positive-type resist material of the present invention may include a base polymer having such repeating units.

[0027] Furthermore, in the present invention, it is preferable that the base polymer further contains repeating units c represented by any one or more of the following formulas (c1) to (c3). [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 1 It consists of a single bond, a phenylene group, a naphthylene group, and -OY 11 -, -C(=O)-OY 11 -or -C(=O)-NH-Y 11 - is Y 11 This is an aliphatic hydrocarbylene group, phenylene group, naphthylene group having 1 to 6 carbon atoms, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. 2 These are single bonds or ester bonds. 3 This is a single bond, -Y 31 -C(=O)-O-, -Y 31 -O- or -Y 31 -OC(=O)- Y 31 This is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, and a bromine atom. 4 This is a single bond, a methylene group, or a 2,2,2-trifluoro-1,1-ethanediyl group. 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, and -OY 51 -, -C(=O)-OY 51 -or -C(=O)-NH-Y 51 - is Y 51 This refers to an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. Rf 1 and Rf 2 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom. 21 ~R 28These are each a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. 23 and R 24 or R 26 and R 27 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded. - (It is a non-nucleophilic counterion.)

[0028] The positive-type resist material of the present invention may include a base polymer having such repeating units.

[0029] Furthermore, it is preferable that the present invention further includes an acid generator.

[0030] Furthermore, in the present invention, it is preferable that the product further contains an organic solvent.

[0031] Furthermore, it is preferable that the present invention further includes a quencher.

[0032] Furthermore, it is preferable that the present invention further contains a surfactant.

[0033] The positive resist material of the present invention may contain additives such as these.

[0034] Furthermore, the present invention provides a pattern formation method comprising the steps of: forming a resist film on a substrate using the positive-type resist material described above; exposing the resist film with high-energy rays; and developing the exposed resist film using a developer.

[0035] With this pattern formation method, the pattern shape after exposure is good.

[0036] In this case, it is preferable to use i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet light with a wavelength of 3 to 15 nm as the high-energy beam.

[0037] The pattern formation method of the present invention can use high-energy rays as described above. [Effects of the Invention]

[0038] The positive-type resist material of the present invention is a chemically amplified molecular resist. Because it is a low-molecular-weight compound material rather than a polymer-based material, it is less susceptible to aggregation and swelling in the developing solution. Conventional molecular resists have suffered from low rigidity, which can cause pattern collapse, and insufficient acid diffusion control, resulting in high edge roughness. However, the hydrogen bonding of the urethane groups provides high rigidity, and the urethane groups have high acid diffusion control capabilities, thus solving the aforementioned problems. Therefore, due to these excellent properties, it is extremely practical and is particularly useful as a material for forming fine patterns in photomasks for ultra-large-scale integrated circuits (ULSIs) or EB lithography, and as a pattern-forming material for EB or EUV exposure. The positive-type resist material of the present invention can be applied not only to lithography in semiconductor circuit formation, but also to the formation of mask circuit patterns, micromachines, and thin-film magnetic head circuits. [Brief explanation of the drawing]

[0039] [Figure 1] This figure shows a simulated example of a compound included in the positive-type resist material of the present invention. [Modes for carrying out the invention]

[0040] As described above, there has been a need to develop a positive-type resist material and pattern formation method that have higher sensitivity and resolution than conventional positive-type resist materials, have low edge roughness and CDU, and produce a good pattern shape after exposure.

[0041] The inventors of the present invention have diligently conducted research to obtain a positive-type resist material that is highly desired in recent years, exhibiting high resolution and low edge roughness and dimensional variation. As a result, they concluded that it is necessary to reduce the molecular size while minimizing the effects of diffusion, including acid diffusion. They found that a compound containing a carboxyl group substituted with an acid-unstable group bonded by multiple urethane groups and an acid generator can suppress acid diffusion to the greatest extent possible due to the high glass transition temperature of the resin caused by hydrogen bonding between the urethane bonds, and that the effect of swelling in alkaline developer is small due to the small molecular weight. They found that this compound is particularly effective when used as a base for chemically amplified positive-type resist materials.

[0042] Furthermore, in order to improve dissolution contrast, we discovered that by using a base polymer containing repeating units in which hydrogen atoms of carboxyl groups or phenolic hydroxyl groups are substituted with acid-unstable groups, and by hybridizing polymer-type and monomer-type chemically amplified resists, we can obtain a positive-type resist material that is highly sensitive, has significantly high alkali dissolution rate contrast before and after exposure, has high resolution, and exhibits good pattern shape, edge roughness, and CDU after exposure, making it particularly suitable as a material for forming fine patterns in ultra-large-scale integrated circuits (ULSIs) or photomasks, thus completing the present invention.

[0043] In other words, the present invention is a positive-type resist material comprising a compound having two or more urethane groups, a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium salt or iodonium salt of a sulfonic acid bonded directly to a second urethane group or via a second linking group.

[0044] The present invention will be described in detail below, but the present invention is not limited to these descriptions.

[0045] [Positive-type resist material] The positive-type resist material of the present invention comprises a compound having two or more urethane groups, a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium salt or iodonium salt of a sulfonic acid bonded directly to a second urethane group or via a second linking group. In this specification, the compound is also referred to as a urethane PAG compound.

[0046] [Urethane PAG compound] The aforementioned compound is preferably one represented by the following formula (1). [ka] (In formula (1), R 1 These are the same or different acid-unstable groups. 2 R is the first linking group, which is a p+1 valent hydrocarbylene group having 1 to 20 carbon atoms, and may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom. 3 R is a q+r valent hydrocarbylene group having 2 to 33 carbon atoms, and may contain oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 4 Rf is a single bond or the second linking group, a divalent hydrocarbylene group having 1 to 20 carbon atoms, which may contain oxygen, sulfur, nitrogen, and halogen atoms. 1 ~Rf 4 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. Also, Rf 1 and Rf 2 These may combine to form a carbonyl group. q is in the range of 1 ≤ q ≤ 4, p is 1 or 2, and r is in the range of 1 ≤ r ≤ 4. M + (This is a sulfonium cation or an iodonium cation.)

[0047] Examples of the anionic portion of the aforementioned compound are, but are not limited to, those listed below.

[0048] [ka]

[0049]

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[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] [ka]

[0075] [ka]

[0076] [ka]

[0077] Here, R 1 R is an acid-unstable group. 1 The acid-unstable group may have the same or different structures within the molecule. Furthermore, the urethane PAG compound may be a blend of compounds with multiple structures or compounds with different acid-unstable groups.

[0078] The aforementioned R 1 However, it is preferable that it falls under any of the following 1) to 3). 1) The carbon bonded to the ester group is tertiary, and the alkyl group bonded to the carbon does not contain a halogen atom, a cyano group, or a nitro group. 2) The carbon atom bonded to the ester group is secondary and has a cyclic structure, does not contain heteroatoms, and has double bonds, triple bonds, or aromatic groups on carbon atoms other than the carbon atom bonded to the ester group. 3) It is an acetal group having an ether group adjacent to the carbon atom bonded to the ester group.

[0079] The urethane PAG compound can be synthesized by reacting a compound having two or more isocyanate groups with a compound having both a hydroxyl group and a carboxyl group substituted with an acid-unstable group, and a hydroxyl group with a sulfonium salt or iodonium salt of a sulfonic acid. This reaction may be carried out without a catalyst, but a catalyst may be used. The catalyst is not particularly limited, but known examples include organotin compounds such as dibutyltin dilaurate, bismuth salts, and zinc carboxylates such as zinc 2-ethylhexanoate and zinc acetate. Compounds having two or more isocyanate groups are described in paragraphs

[0082] and

[0083] of Japanese Patent Application Publication No. 2020-023668.

[0080] In reactions involving compounds containing two or more isocyanate groups, the presence of impurities such as water, amine compounds, alcohol compounds, and carboxyl compounds can lead to a decrease in the purity of the target compound due to reactions with these impurities. Therefore, it is necessary to thoroughly remove impurities before the reaction.

[0081] Compounds having two or more blocked isocyanate groups can also be used. Blocked isocyanate groups are formed when the blocked group is deprotected by heating or the above-mentioned catalyst, and specific examples include isocyanate groups substituted with alcohols, phenols, thioalcohols, imines, ketimines, amines, lactams, pyrazoles, oximes, β-diketones, etc.

[0082] Regarding the molar ratio of isocyanate group a, acid compound b having both a hydroxy group and a carboxy group substituted with an acid-labile group, and sulfonium salt or iodonium salt c of sulfonic acid, the ideal relationship is a=b+c, but the relationship may be a<b+c or a>b+c. Further, as the molar ratio of b to c, b≧c is desirable. It is acceptable that the proportion of c is low, and there exist compounds in which c does not react with any isocyanate group in one molecule.

[0083] For example, a compound (molecule) contained in the positive resist composition of the present invention, in which a carboxy group substituted with an acid-labile group and a sulfonium salt of fluorosulfonic acid (PAG) are each bonded via urethane bonds, is shown below. A simulation of this molecule is shown in Figure 1. Here, as component a, a molecule in which three isocyanate groups extend from the center is assumed. When reacting component a with components b and c, for example, Figure 1 shows the case where 80% of the isocyanate groups contained in component a are reacted with component b, and 20% are reacted with component c. When attention is paid to the distribution of PAG, molecules having PAG and molecules not having PAG are present in a mixed state.

[0084] The reaction between component a and components b and c is a reaction in a solution, and components b and c are considered to be uniformly distributed. In conventional chemically amplified resists obtained by blending a PAG and a quencher into a polymer having an acid-labile group, it has been pointed out that uneven distribution of these three components (Resist stochastics) causes edge roughness and dimensional variation, but the method of the present invention can be expected to achieve uniform dispersion, thereby reducing edge roughness and dimensional variation.

[0085]

Chemical Formula

[0086] A compound in which c does not react with any isocyanate group in one molecule, that is, a reaction product of a and b, may be blended with the reaction product of a, b and c according to the present invention.

[0087] [Urethane compound] Furthermore, it is preferable that the positive-type resist material of the present invention further contains a compound having two or more urethane groups, and two or more carboxyl groups substituted with acid-unstable groups bonded to the urethane groups via linking groups. In this specification, the compound is also referred to as a urethane compound.

[0088] The urethane compound is preferably one represented by the following formula (1'). [ka] (In formula (1'), R' 1 R' is an identical or non-identical acid-unstable group. 2 R' is the aforementioned linking group, which is an n'+1 or p'+1 valent hydrocarbylene group having 1 to 20 carbon atoms, and may contain oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 3 (This refers to a hydroxylene group with 2 to 33 carbon atoms and an m'+1 valency, which may contain oxygen, sulfur, nitrogen, and halogen atoms. m' is an integer between 1 and 6, and n' and p' are 1 or 2.)

[0089] Examples of the urethane compound mentioned above include, but are not limited to, those listed below.

[0090] [ka]

[0091] Here, R' 1 R' is an acid-unstable group. 1 The acid-unstable group may have the same or different structures within the molecule. Furthermore, the urethane compound may be a blend of compounds with multiple structures or compounds with different acid-unstable groups.

[0092] The aforementioned compound can be obtained by reacting a compound having two or more isocyanate groups with an acid compound having both a hydroxyl group and a carboxyl group substituted with an acid-unstable group. This reaction may be carried out without a catalyst, but a catalyst may also be used. The catalyst is not particularly limited, but known examples include organotin compounds such as dibutyltin dilaurate, bismuth salts, and zinc carboxylates such as zinc 2-ethylhexanoate and zinc acetate. Compounds having two or more isocyanate groups are described in paragraphs

[0082] and

[0083] of Japanese Patent Application Publication No. 2020-023668.

[0093] In reactions involving compounds containing two or more isocyanate groups, the presence of impurities such as water, amine compounds, alcohol compounds, and carboxyl compounds can lead to a decrease in the purity of the target compound due to reactions with these impurities. Therefore, it is necessary to thoroughly remove impurities before the reaction.

[0094] Compounds having two or more blocked isocyanate groups can also be used. Blocked isocyanate groups are formed when the blocked group is deprotected by heating or the above-mentioned catalyst, and specific examples include isocyanate groups substituted with alcohols, phenols, thioalcohols, imines, ketimines, amines, lactams, pyrazoles, oximes, β-diketones, etc.

[0095] [Base polymer] The positive-type resist material of the present invention is a molecular resist material based on the urethane PAG compound, but it may also be a positive-type resist material that further includes a base polymer.

[0096] The base polymer preferably contains repeating units in which the hydrogen atoms of the carboxyl group are substituted with acid-unstable groups (hereinafter also referred to as repeating unit a1) and / or repeating units in which the hydrogen atoms of the phenolic hydroxyl group are substituted with acid-unstable groups (hereinafter also referred to as repeating unit a2) in order to enhance the solubility contrast.

[0097] Examples of the repeating units a1 and a2 include those represented by the following formulas (a1) and (a2), respectively.

Chemical Formula

[0098] In formulas (a1) and (a2), R A each independently represent a hydrogen atom or a methyl group. X 1 is a single bond, a phenylene group, a naphthylene group, or a linking group having 1 to 14 carbon atoms containing an ester bond, an ether bond or a lactone ring. X 2 is a single bond, an ester bond or an amide bond. X 3 is a single bond, an ether bond or an ester bond. R 11 and R 12 are acid-labile groups. R 13 is a fluorine atom, a trifluoromethyl group, a cyano group or a saturated hydrocarbyl group having 1 to 6 carbon atoms. R 14 is a single bond or a saturated hydrocarbylene group having 1 to 6 carbon atoms, wherein a part of the carbon atoms thereof may be substituted with an ether bond or an ester bond. a is 1 or 2. b is an integer of 0 to 4. Provided that 1≦a+b≦5.

[0099] Examples of the monomer that gives the repeating unit a1 include, but are not limited to, those shown below. In the following formulas, R A and R 11 are the same as defined above.

Chemical Formula

[0100]

Chemical Formula

[0101] Examples of the monomer that gives the repeating unit a2 include, but are not limited to, those shown below. In the following formulas, R A and R 12This is the same as described above. [ka]

[0102] R 1 , R' 1 , R 11 or R 12 Various acid-unstable groups can be selected, but examples include those represented by the following formulas (AL-1) to (AL-3). [ka] (In the equation, dashed lines represent connections.)

[0103] In formula (AL-1), R L1 This group is a tertiary hydrocarbyl group having 4 to 61 carbon atoms, preferably 4 to 15 carbon atoms; a trihydrocarbylsilyl group in which each hydrocarbyl group is a saturated hydrocarbyl group having 1 to 6 carbon atoms; a carbonyl group; a saturated hydrocarbyl group having 4 to 20 carbon atoms including an ether bond or an ester bond; or a group represented by formula (AL-3). A1 is an integer from 0 to 6. Note that a tertiary hydrocarbyl group refers to a group obtained by the removal of a hydrogen atom from a tertiary carbon atom of a hydrocarbon.

[0104] R L1The tertiary hydrocarbyl group represented by can be saturated or unsaturated, and can be branched or cyclic. Specific examples include tert-butyl group, tert-pentyl group, 1,1-diethylpropyl group, 1-ethylcyclopentyl group, 1-butylcyclopentyl group, 1-ethylcyclohexyl group, 1-butylcyclohexyl group, 1-ethyl-2-cyclopentenyl group, 1-ethyl-2-cyclohexenyl group, and 2-methyl-2-adamantyl group. Examples of the trihydrocarbyl silyl group include trimethylsilyl group, triethylsilyl group, and dimethyl-tert-butylsilyl group. The saturated hydrocarbyl group containing the carbonyl group, ether bond, or ester bond may be linear, branched, or cyclic, but cyclic is preferred. Specific examples include 3-oxocyclohexyl group, 4-methyl-2-oxooxan-4-yl group, 5-methyl-2-oxooxolan-5-yl group, 2-tetrahydropyranyl group, and 2-tetrahydrofuranyl group.

[0105] Examples of acid-unstable groups represented by formula (AL-1) include tert-butoxycarbonyl group, tert-butoxycarbonylmethyl group, tert-pentyloxycarbonyl group, tert-pentyloxycarbonylmethyl group, 1,1-diethylpropyloxycarbonyl group, 1,1-diethylpropyloxycarbonylmethyl group, 1-ethylcyclopentyloxycarbonyl group, 1-ethylcyclopentyloxycarbonylmethyl group, 1-ethyl-2-cyclopentenyloxycarbonyl group, 1-ethyl-2-cyclopentenyloxycarbonylmethyl group, 1-ethoxyethoxycarbonylmethyl group, 2-tetrahydropyranyloxycarbonylmethyl group, and 2-tetrahydrofuranyloxycarbonylmethyl group.

[0106] Furthermore, other acid-unstable groups represented by formula (AL-1) include those represented by the following formulas (AL-1)-1 to (AL-1)-16. [ka] (In the equation, dashed lines represent connections.)

[0107] In formulas (AL-1)-1 to (AL-1)-16, A1 is the same as defined above. R L8 each independently represents a saturated or unsaturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. R L9 represents a hydrogen atom or a saturated or unsaturated hydrocarbyl group having 1 to 10 carbon atoms. R L10 represents a saturated or unsaturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R L11 represents a hydrogen atom, a saturated or unsaturated hydrocarbyl group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms, and R L12 represents a hydrogen atom, a halogen atom, a difluoromethyl group, a trifluoromethyl group, a difluoromethoxy group, a trifluoromethoxy group, a cyano group, a nitro group, or a saturated or unsaturated hydrocarbyl group having 1 to 6 carbon atoms, which may optionally have an ether group or a sulfide group, and a plurality of R L12 groups may be bonded to each other to form a ring. R L13 represents a hydrogen atom, or a saturated or unsaturated hydrocarbyl group having 1 to 6 carbon atoms. The saturated or unsaturated hydrocarbyl group may be linear, branched or cyclic. r is an integer of 1 to 6.

[0108] In formula (AL-2), R L2 and R L3 each independently represent a hydrogen atom or a saturated hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbyl group may be linear, branched or cyclic, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, a cyclopentyl group, a cyclohexyl group, a 2-ethylhexyl group, an n-octyl group, and the like.

[0109] In formula (AL-2), R L4is a hydrocarbyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may contain a hetero atom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched or cyclic. Examples of the hydrocarbyl group include saturated hydrocarbyl groups having 1 to 18 carbon atoms, and a part of hydrogen atoms in these groups may be substituted with a hydroxy group, an alkoxy group, an oxo group, an amino group, an alkylamino group, or the like. Examples of such substituted saturated hydrocarbyl groups include those shown below.

Chemical Formula

[0110] R L2 and R L3 and, R L2 and R L4 and, and R L3 and R L4 may be bonded to each other to form a ring together with the carbon atom to which they are bonded, or together with the carbon atom and the oxygen atom; in this case, R L2 and R L3 , R L2 and R L4 , or R L3 and R L4 are each independently an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The number of carbon atoms in the ring formed by bonding these groups is preferably 3 to 10, more preferably 4 to 10.

[0111] Among the acid-labile groups represented by formula (AL-2), linear or branched groups include, but are not limited to, those represented by the following formulas (AL-2)-1 to (AL-2)-69. In the following formulas, the broken line is a bonding hand.

Chemical Formula

[0112]

Chemical Formula

[0113] [ka]

[0114] [ka]

[0115] Among the acid-unstable groups represented by formula (AL-2), cyclic groups include tetrahydrofuran-2-yl group, 2-methyltetrahydrofuran-2-yl group, tetrahydropyran-2-yl group, and 2-methyltetrahydropyran-2-yl group.

[0116] Furthermore, examples of acid-unstable groups include groups represented by the following formulas (AL-2a) or (AL-2b). The base polymer may be intermolecularly or intramolecularly crosslinked by these acid-unstable groups. [ka] (In the equation, dashed lines represent connections.)

[0117] In formula (AL-2a) or (AL-2b), R L11 and R L12 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 8 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. Also, R L11 and R L12 These may bond with each other to form a ring with the carbon atoms to which they are bonded, in which case R L11 and R L12 These are, independently, alkanediyl groups having 1 to 8 carbon atoms. L13 Each of these is independently a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group may be linear, branched, or cyclic. B1 and D1 are each independently integers from 0 to 10, preferably from 0 to 5, and C1 is an integer from 1 to 7, preferably from 1 to 3.

[0118] In formula (AL-2a) or (AL-2b), L A These are (C1+1) valent aliphatic saturated hydrocarbon groups having 1 to 50 carbon atoms, (C1+1) valent alicyclic saturated hydrocarbon groups having 3 to 50 carbon atoms, (C1+1) valent aromatic hydrocarbon groups having 6 to 50 carbon atoms, or (C1+1) valent heterocyclic groups having 3 to 50 carbon atoms. Furthermore, some of the carbon atoms of these groups may be substituted with heteroatom-containing groups, and some of the hydrogen atoms bonded to the carbon atoms of these groups may be substituted with hydroxyl groups, carboxyl groups, acyl groups, or fluorine atoms. A Preferred examples include saturated hydrocarbon groups such as saturated hydrocarbylene groups, trivalent saturated hydrocarbon groups, and tetravalent saturated hydrocarbon groups having 1 to 20 carbon atoms, and arylene groups having 6 to 30 carbon atoms. The saturated hydrocarbon groups may be linear, branched, or cyclic. B These are -C(=O)-O-, -NH-C(=O)-O-, or -NH-C(=O)-NH-.

[0119] Examples of crosslinked acetal groups represented by formula (AL-2a) or (AL-2b) include groups represented by the following formulas (AL-2)-70 to (AL-2)-77. [ka] (In the equation, dashed lines represent connections.)

[0120] In formula (AL-3), R L5 , R L6 and R L7 Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, and may contain heteroatoms such as oxygen, sulfur, nitrogen, and fluorine atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms, cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, cyclic unsaturated hydrocarbyl groups having 3 to 20 carbon atoms, and aryl groups having 6 to 10 carbon atoms. L5 and R L6 And, R L5 and R L7 and R L6 and RL7 These atoms may bond with each other to form an alicyclic ring with 3 to 20 carbon atoms.

[0121] Examples of groups represented by formula (AL-3) include tert-butyl group, 1,1-diethylpropyl group, 1-ethylnorbonyl group, 1-methylcyclohexyl group, 1-ethylcyclopentyl group, 2-(2-methyl)adamantyl group, 2-(2-ethyl)adamantyl group, and tert-pentyl group.

[0122] In addition, the groups represented by formula (AL-3) include those represented by the following formulas (AL-3)-1 to (AL-3)-19. [ka] (In the equation, dashed lines represent connections.)

[0123] In equations (AL-3)-1 to (AL-3)-19, R L14 Each of these is independently a saturated hydrocarbyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms. L15 and R L17 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 20 carbon atoms. L16 This is an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbyl group may be linear, branched, or cyclic. Furthermore, a phenyl group is preferred as the aryl group. F The atoms are fluorine, iodine, difluoromethyl, trifluoromethyl, cyano, and nitro. g is an integer from 0 to 5.

[0124] Furthermore, examples of acid-unstable groups include those represented by the following formulas (AL-3)-20 or (AL-3)-21. The polymer may be intramolecularly or intermolecularly crosslinked by these acid-unstable groups. [ka] (In the equation, dashed lines represent connections.)

[0125] In equations (AL-3)-20 and (AL-3)-21, R L14 This is the same as above. R L18 This is a saturated or unsaturated hydrocarbylene group with 1 to 20 carbon atoms and an (E1+1) valency, or an arylene group with 6 to 20 carbon atoms and an (E1+1) valency, which may contain heteroatoms such as oxygen, sulfur, or nitrogen atoms. The saturated hydrocarbylene group may be linear, branched, or cyclic. E1 is an integer from 1 to 3.

[0126] Examples of monomers that give repeating units containing an acid-unstable group represented by formula (AL-3) include (meth)acrylic acid esters containing the exo-isomer structure represented by the following formula (AL-3)-22. [ka]

[0127] In formula (AL-3)-22, R A This is the same as above. R Lc1 This is a saturated hydrocarbyl group having 1 to 8 carbon atoms or an aryl group having 6 to 20 carbon atoms, which may be substituted. The saturated hydrocarbyl group may be linear, branched, or cyclic. Lc2 ~R Lc11 Each of these is independently a C1-C15 hydrocarbyl group which may contain a hydrogen atom or a heteroatom. Examples of the heteroatom include an oxygen atom. Examples of the hydrocarbyl group include a C1-C15 alkyl group and a C6-C15 aryl group. Lc2 and R Lc3 And, R Lc4 and R Lc6 And, R Lc4 and R Lc7 And, R Lc5 and R Lc7 And, R Lc5 and R Lc11 And, R Lc6 and R Lc10 And, R Lc8 and R Lc9 and or R Lc9 and R Lc10These may be bonded to each other and form a ring with the carbon atoms to which they are bonded, and in this case, the groups involved in the bonding may be hydrocarbylene groups that include heteroatoms having 1 to 15 carbon atoms. Lc2 and R Lc11 And, R Lc8 and R Lc11 or R Lc4 and R Lc6 This means that adjacent carbon atoms bond to each other without any intermediary, forming a double bond. Furthermore, this formula also represents enantiomers.

[0128] Here, examples of monomers that give repeating units represented by formula (AL-3)-22 include those described in Japanese Patent Publication No. 2000-327633. Specifically, these include, but are not limited to, the following. Note that in the following formula, R A This is the same as described above. [ka]

[0129] Examples of monomers that give repeating units containing an acid-unstable group represented by formula (AL-3) include (meth)acrylic acid esters containing a franziyl group, a tetrahydrofranziyl group, or an oxanorbornanediyl group, represented by the following formula (AL-3)-23. [ka]

[0130] In formula (AL-3)-23, R A This is the same as above. R Lc12 and R Lc13 These are, independently, hydrocarbyl groups having 1 to 10 carbon atoms. Lc12 and R Lc13 These atoms may bond with each other to form an alicyclic ring with the carbon atoms to which they are bonded. Lc14 This is a franziyl group, a tetrahydrofranziyl group, or an oxanorbornanediyl group. Lc15This is a C1-C10 hydrocarbyl group which may contain hydrogen atoms or heteroatoms. The hydrocarbyl group may be linear, branched, or cyclic. Specific examples include a saturated C1-C10 hydrocarbyl group.

[0131] The monomers that give the repeating unit represented by formula (AL-3)-23 include, but are not limited to, the following. Note that in the following formula, R A The same applies as above, where Ac is an acetyl group and Me is a methyl group. [ka]

[0132] [ka]

[0133] The base polymer may further contain repeating units b having adhesive groups selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonic acid ester bond, a cyano group, an amide bond, -OC(=O)-S-, and -OC(=O)-NH-.

[0134] Examples of monomers that give repeating unit b are listed below, but are not limited to these. Note that in the following formula, R A This is the same as above. [ka]

[0135] [ka]

[0136] [ka]

[0137] [ka]

[0138] [ka]

[0139] [ka]

[0140] [ka]

[0141] [ka]

[0142] [ka]

[0143] [ka]

[0144] The base polymer may further contain repeating units c derived from an onium salt containing polymerizable unsaturated bonds. Preferred repeating units c include the repeating unit represented by the following formula (c1) (hereinafter also referred to as repeating unit c1), the repeating unit represented by the following formula (c2) (hereinafter also referred to as repeating unit c2), and the repeating unit represented by the following formula (c3) (hereinafter also referred to as repeating unit c3). Repeating units c1 to c3 can be used individually or in combination of two or more. That is, it is preferable that the base polymer further contains repeating units c represented by any one or more of the following formulas (c1) to (c3). [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 1 It consists of a single bond, a phenylene group, a naphthylene group, and -OY 11 -, -C(=O)-OY 11 -or -C(=O)-NH-Y 11 - is Y 11 This is an aliphatic hydrocarbylene group, phenylene group, naphthylene group having 1 to 6 carbon atoms, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. 2 These are single bonds or ester bonds. 3 This is a single bond, -Y 31 -C(=O)-O-, -Y 31 -O- or -Y 31 -OC(=O)- Y 31 This is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, and a bromine atom. 4 This is a single bond, a methylene group, or a 2,2,2-trifluoro-1,1-ethanediyl group. 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, and -OY 51 -, -C(=O)-OY 51 -or -C(=O)-NH-Y 51 - is Y 51 This refers to an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. Rf 1 and Rf 2 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom. 21 ~R 28These are each a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. 23 and R 24 or R 26 and R 27 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded. - (It is a non-nucleophilic counterion.)

[0145] In formulas (c1) to (c3), R A Each of these is independently either a hydrogen atom or a methyl group. 1 It consists of a single bond, a phenylene group, a naphthylene group, and -OY 11 -, -C(=O)-OY 11 -or -C(=O)-NH-Y 11 - is Y 11 This is an aliphatic hydrocarbylene group, phenylene group, naphthylene group having 1 to 6 carbon atoms, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. 2 These are single bonds or ester bonds. 3 This is a single bond, -Y 31 -C(=O)-O-, -Y 31 -O- or -Y 31 -OC(=O)- Y 31 This is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, and a bromine atom. 4 This is a single bond, a methylene group, or a 2,2,2-trifluoro-1,1-ethanediyl group. 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, and -OY 51 -, -C(=O)-OY 51 -or -C(=O)-NH-Y 51 - is Y 51This refers to an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, and a hydroxyl group.

[0146] In formula (c2), Rf 1 and Rf 2 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom. In particular, Rf 1 and Rf 2 It is preferable that both are fluorine atoms.

[0147] In formulas (c1) to (c3), R 21 ~R 28 These are C1-C20 hydrocarbyl groups that may each independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. The hydrocarbyl group may be linear, branched, or cyclic, and specific examples include R in formulas (2-1) and (2-2) described later. 101 ~R 105 Examples similar to those given in the explanation can be cited.

[0148] Also, R 23 and R 24 , or R 26 and R 27 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded. In this case, the ring is defined as R in the explanation of formula (2-1). 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those described later.

[0149] In formula (c1), M -This is a non-nucleophilic counterion. Examples of the aforementioned non-nucleophilic counterions include halide ions such as chloride ions and bromide ions, fluoroalkyl sulfonate ions such as triflate ions, 1,1,1-trifluoroethanesulfonate ions and nonafluorobutanesulfonate ions, aryl sulfonate ions such as tosylate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions and 1,2,3,4,5-pentafluorobenzenesulfonate ions, alkyl sulfonate ions such as mesylate ions and butanesulfonate ions, imide ions such as bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions and bis(perfluorobutylsulfonyl)imide ions, and methide ions such as tris(trifluoromethylsulfonyl)methide ions and tris(perfluoroethylsulfonyl)methide ions.

[0150] Examples of the aforementioned non-nucleophilic counterions include a sulfonate ion in which the α-position is substituted with a fluorine atom, represented by the following formula (c1-1), and a sulfonate ion in which the α-position is substituted with a fluorine atom and the β-position is substituted with a trifluoromethyl group, represented by the following formula (c1-2). [ka]

[0151] In formula (c1-1), R 31 R is a hydrogen atom or a hydrocarbyl group having 1 to 20 carbon atoms, and may contain ether bonds, ester bonds, carbonyl groups, lactone rings, and fluorine atoms. The hydrocarbyl group may be linear, branched, or cyclic. A specific example is R in formula (2A'). 107 Examples of hydrocarbyl groups represented by this formula include those similar to those described later.

[0152] In formula (c1-2), R 32R in formula (2A') is a hydrogen atom, a hydrocarbyl group having 1 to 30 carbon atoms, or a hydrocarbylcarbonyl group having 2 to 30 carbon atoms, and may contain ether bonds, ester bonds, carbonyl groups, and lactone rings. The hydrocarbyl portion of the hydrocarbyl group and hydrocarbylcarbonyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example of the hydrocarbyl group is R in formula (2A'). 107 Examples of hydrocarbyl groups represented by this formula include those similar to those described later.

[0153] Examples of monomer cations that give repeating units c1 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0154] Specific examples of monomer cations that give repeating units c2 or c3 include those similar to those described later as cations of sulfonium salts represented by formula (2-1).

[0155] Examples of monomer anions that give the repeating unit c2 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] [ka]

[0168] Examples of monomer anions that give repeating units c3 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0169] The repeating units c1 to c3 function as acid generators. By attaching the acid generator to the polymer backbone, acid diffusion is reduced, preventing a decrease in resolution due to blurring caused by acid diffusion. Furthermore, the uniform dispersion of the acid generator improves the low-weight ratio (LWR). When using a base polymer containing repeating unit c, the addition of the additive-type acid generator described later can be omitted.

[0170] The base polymer may further contain repeating units d that do not contain amino groups but contain iodine atoms. Examples of monomers that give repeating units d are, but are not limited to, those listed below. In the following formula, R A This is the same as described above. [ka]

[0171] [ka]

[0172] [ka]

[0173] The base polymer may contain repeating units e other than those described above. Examples of repeating units e include those derived from styrene, acenaphthylene, indene, coumarin, coumarone, and the like.

[0174] In the base polymer described above, the content ratios of the repeating units a1, a2, b, c1, c2, c3, d and e preferably satisfy 0≦a1≦0.9, 0≦a2≦0.9, 0<a1+a2≦0.9, 0≦b≦0.9, 0≦c1≦0.5, 0≦c2≦0.5, 0≦c3≦0.5, 0≦c1+c2+c3≦0.5, 0≦d≦0.5 and 0≦e≦0.5, more preferably satisfy 0≦a1≦0.8, 0≦a2≦0.8, 0<a1+a2≦0.8, 0≦b≦0.8, 0≦c1≦0.4, 0≦c2≦0.4, 0≦c3≦0.4, 0≦c1+c2+c3≦0.4, 0≦d≦0.4 and 0≦e≦0.4, and still more preferably satisfy 0≦a1≦0.7, 0≦a2≦0.7, 0<a1+a2≦0.7, 0≦b≦0.7, 0≦c1≦0.3, 0≦c2≦0.3, 0≦c3≦0.3, 0≦c1+c2+c3≦0.3, 0≦d≦0.3 and 0≦e≦0.3, provided that a1+a2+b+c1+c2+c3+d+e=1.0.

[0175] To synthesize the base polymer described above, for example, polymerization may be carried out by adding a radical polymerization initiator to monomers that provide the aforementioned repeating units in an organic solvent and heating the mixture.

[0176] Examples of the organic solvent used in polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, and the like. Examples of the polymerization initiator include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), dimethyl-2,2-azobis(2-methylpropionate), benzoyl peroxide, lauroyl peroxide, and the like. The polymerization temperature is preferably 50 to 80°C. The reaction time is preferably 2 to 100 hours, more preferably 5 to 20 hours.

[0177] When copolymerizing a monomer containing a hydroxy group, the hydroxy group may be substituted with an acetal group that is easily deprotected by an acid, such as an ethoxyethoxy group, during polymerization, followed by deprotection 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 before polymerization, followed by alkaline hydrolysis after polymerization.

[0178] When copolymerizing hydroxystyrene or hydroxyvinylnaphthalene, acetoxystyrene or acetoxyvinylnaphthalene may be used instead of hydroxystyrene or hydroxyvinylnaphthalene, and the acetoxy group may be deprotected by alkaline hydrolysis after polymerization to obtain hydroxystyrene or hydroxyvinylnaphthalene.

[0179] Ammonia water, triethylamine, etc., can be used as the base during alkaline hydrolysis. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0180] The base polymer has a polystyrene-based weight-average molecular weight (Mw) of 1,000 to 500,000, more preferably 2,000 to 30,000, determined by gel permeation chromatography (GPC) using THF as a solvent. If Mw is 1,000 or higher, the resist material will have excellent heat resistance, and if it is 500,000 or lower, alkali solubility will not decrease, and the trailing phenomenon will not occur after pattern formation.

[0181] Furthermore, if the molecular weight distribution (Mw / Mn) of the base polymer is broad, the presence of low-molecular-weight and high-molecular-weight polymers may cause foreign matter to be observed on the pattern or deterioration of the pattern shape after exposure. As the pattern rule becomes finer, the influence of Mw and Mw / Mn tends to increase. Therefore, in order to obtain a resist material suitable for fine pattern dimensions, it is preferable that the Mw / Mn of the base polymer be narrowly dispersed, between 1.0 and 2.0, and particularly between 1.0 and 1.5.

[0182] When the positive resist material of the present invention contains a base polymer, its content is preferably 10 to 1,000 parts by mass, more preferably 20 to 500 parts by mass, and even more preferably 50 to 200 parts by mass, per 100 parts by mass of the urethane PAG compound. The base polymer may contain two or more polymers with different composition ratios, Mw, and Mw / Mn.

[0183] [Acid Generator] The positive resist material of the present invention may further contain an acid generator that generates a strong acid (hereinafter also referred to as an additive-type acid generator). Here, a strong acid means a compound that has sufficient acidity to cause a deprotection reaction of acid-unstable groups of urethane PAG compounds, urethane compounds, and base polymers. Examples of the acid generator include compounds that generate acid in response to active light or radiation (photoacid generators). Any compound that generates acid upon irradiation with high-energy rays can be used as the photoacid generator, but those that generate sulfonic acid, imido acid, or methidoic acid are preferred. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. Specific examples of photoacid generators are those described in paragraphs

[0122] to

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

[0184] Furthermore, sulfonium salts represented by the following formula (2-1) and iodonium salts represented by the following formula (2-2) can also be suitably used as photoacid generators. [ka]

[0185] In equations (2-1) and (2-2), R 101 ~R 105 These are, independently, C1-C20 hydrocarbyl groups which may contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom.

[0186] R 101 ~R 105The hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups 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 eicosyl; C3-C20 cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; and C2-C20 alkenyl groups such as vinyl, propenyl, butenyl, and hexenyl. Examples of carbon-12 groups include: cyclic unsaturated aliphatic hydrocarbyl groups with 6 to 20 carbon atoms, such as cyclohexenyl group and norbornenyl group; alkynyl groups with 2 to 20 carbon atoms, such as ethynyl group, propynyl group and butynyl group; aryl groups with 6 to 20 carbon atoms, such as phenyl group, methylphenyl group, ethylphenyl group, n-propylphenyl group, isopropylphenyl group, n-butylphenyl group, isobutylphenyl group, sec-butylphenyl group, tert-butylphenyl group, naphthyl group, methylnaphthyl group, ethylnaphthyl group, n-propylnaphthyl group, isopropylnaphthyl group, n-butylnaphthyl group, isobutylnaphthyl group, sec-butylnaphthyl group and tert-butylnaphthyl group; and aralkyl groups with 7 to 20 carbon atoms, such as benzyl group and phenethyl group. Furthermore, some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate groups, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0187] Also, R 101 and R 102These may combine to form a ring with the sulfur atom to which they are bonded. In this case, the ring is preferably structured as shown below. [ka] (In the formula, the dashed line represents R 103 (This is a combination of the two.)

[0188] Examples of cations of sulfonium salts represented by general formulas (1) and (2-1) are listed below, but are not limited to these.

[0189] [ka]

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] [ka]

[0197]

change

[0198]

change

[0199]

change

[0200]

change

[0201]

change

[0202]

change

[0203]

change

[0204]

change

[0205]

change

[0206]

change

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] Examples of cations of iodonium salts represented by general formulas (1) and (2-2) are listed below, but are not limited to these. [ka]

[0212] In equations (2-1) and (2-2), X - This is an anion selected from the following equations (2A) to (2D). [ka]

[0213] In formula (2A), R fa This 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. A specific example of this is R, which will be described later. 107 The same things mentioned in the explanation are listed below.

[0214] The anion represented by formula (2A) is preferably the one represented by formula (2A') below. [ka]

[0215] In formula (2A'), R 106 R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 107 This is a hydrocarbyl group having 1 to 38 carbon atoms, which may contain heteroatoms. The heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., with oxygen atoms being more preferred. The hydrocarbyl group is particularly preferably one having 6 to 30 carbon atoms, from the viewpoint of obtaining high resolution in fine pattern formation.

[0216] R 107 The hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosanyl groups; cyclic saturated hydrocarbyl groups such as cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornylmethyl, tricyclodecanyl, tetracyclododecanyl, tetracyclododecanylmethyl, and dicyclohexylmethyl groups; unsaturated hydrocarbyl groups such as allyl and 3-cyclohexenyl groups; aryl groups such as phenyl, 1-naphthyl, and 2-naphthyl groups; and aralkyl groups such as benzyl and diphenylmethyl groups.

[0217] Furthermore, some or all of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, they may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate groups, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc. Examples of heteroatom-containing hydrocarbyl groups include tetrahydrofuryl group, methoxymethyl group, ethoxymethyl group, methylthiomethyl group, acetamidomethyl group, trifluoroethyl group, (2-methoxyethoxy)methyl group, acetoxymethyl group, 2-carboxy-1-cyclohexyl group, 2-oxopropyl group, 4-oxo-1-adamantyl group, and 3-oxocyclohexyl group.

[0218] For details on the synthesis of sulfonium salts containing the anion represented by formula (2A'), please refer to Japanese Patent Publication No. 2007-145797, Japanese Patent Publication No. 2008-106045, Japanese Patent Publication No. 2009-007327, Japanese Patent Publication No. 2009-258695, etc. In addition, sulfonium salts described in Japanese Patent Publication No. 2010-215608, Japanese Patent Publication No. 2012-041320, Japanese Patent Publication No. 2012-106986, Japanese Patent Publication No. 2012-153644, etc., can also be suitably used.

[0219] Examples of anions represented by formula (2A) include those similar to those exemplified as anions represented by formula (1A) in Japanese Patent Publication No. 2018-197853.

[0220] In formula (2B), R fb1 and R fb2 Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may each contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (2A'). 107 Examples similar to those given in the explanation can be cited. fb1 and R fb2Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 This refers to the groups that bond to each other (-CF2-SO2-N - It may form a ring with -SO2-CF2-), in which case R fb1 and R fb2 The group obtained by the bonding of these two elements is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0221] In formula (2C), R fc1 , R fc2 and R fc3 Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may each contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (2A'). 107 Examples similar to those given in the explanation can be cited. fc1 , R fc2 and R fc3 Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 This refers to the groups that bond to each other (-CF2-SO2-C - It may form a ring with -SO2-CF2-), in which case R fc1 and R fc2 The group obtained by the bonding of these two elements is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0222] In formula (2D), R fd R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (2A'). 107 Examples similar to those given in the explanation can be cited.

[0223] The synthesis of sulfonium salts containing the anion represented by formula (2D) is described in detail in Japanese Patent Publication No. 2010-215608 and Japanese Patent Publication No. 2014-133723.

[0224] Examples of anions represented by formula (2D) include those similar to those exemplified as anions represented by formula (1D) in Japanese Patent Publication No. 2018-197853.

[0225] Furthermore, the photoacid generator containing the anion represented by formula (2D) does not have fluorine at the α-position of the sulfo group, but has two trifluoromethyl groups at the β-position, which gives it sufficient acidity to cleave acid-unstable groups in the base polymer. Therefore, it can be used as a photoacid generator.

[0226] As a photoacid generator, one represented by the following formula (3) can also be suitably used. [ka]

[0227] In formula (3), R 201 and R 202 Each of these is independently a hydrocarbyl group having 1 to 30 carbon atoms, which may contain heteroatoms. 203 This is a hydrocarbylene group having 1 to 30 carbon atoms, which may contain heteroatoms. Also, R 201 and R 202 or R 201 and R 203 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is defined as R in the explanation of formula (2-1). 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those exemplified.

[0228] R 201 and R 202The hydrocarbyl group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 Examples include cyclic saturated hydrocarbyl groups such as decanyl and adamantyl groups; aryl groups such as phenyl, methylphenyl, ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, isobutylphenyl, sec-butylphenyl, tert-butylphenyl, naphthyl, methylnaphthyl, ethylnaphthyl, n-propylnaphthyl, isopropylnaphthyl, n-butylnaphthyl, isobutylnaphthyl, sec-butylnaphthyl, tert-butylnaphthyl, and anthracenyl groups. Furthermore, some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate groups, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc.

[0229] R 203The hydrocarbylene group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include alkanediyl groups such as methylene, ethylene, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, dodecane-1,12-diyl, tridecane-1,13-diyl, tetradecane-1,14-diyl, pentadecane-1,15-diyl, hexadecane-1,16-diyl, heptadecane-1,17-diyl; cyclopentanediyl, cyclo Examples include cyclic saturated hydrocarbylene groups such as hexanediyl group, norbornanediyl group, and adamantanediyl group; and arylene groups such as phenylene group, methylphenylene group, ethylphenylene group, n-propylphenylene group, isopropylphenylene group, n-butylphenylene group, isobutylphenylene group, sec-butylphenylene group, tert-butylphenylene group, naphthylene group, methylnaphthylene group, ethylnaphthylene group, n-propylnaphthylene group, isopropylnaphthylene group, n-butylnaphthylene group, isobutylnaphthylene group, sec-butylnaphthylene group, and tert-butylnaphthylene group. Furthermore, some of the hydrogen atoms of these groups may be substituted with alkyl groups such as methyl, ethyl, propyl, n-butyl, and tert-butyl groups, or some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen, sulfur, nitrogen, and halogen atoms, or some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen, sulfur, and nitrogen atoms. As a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate groups, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc. Oxygen atoms are preferred as the heteroatom.

[0230] In formula (3), L CThis is a 1-20 carbon atom hydrocarbylene group which may contain single bonds, ether bonds, or heteroatoms. The hydrocarbylene group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R 203 Examples of hydrocarbylene groups represented by the same formula as those exemplified above include the same groups as those shown.

[0231] In formula (3), X A , X B , X C and X D Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group. However, X A , X B , X C and X D At least one of these is a fluorine atom or a trifluoromethyl group.

[0232] In equation (3), k is an integer between 0 and 3.

[0233] The photoacid generator represented by formula (3) is preferably the one represented by the following formula (3'). [ka]

[0234] In formula (3'), L C This is the same as above. R HF R is a hydrogen atom or a trifluoromethyl group, preferably a trifluoromethyl group. 301 , R 302 and R 303 Each of these is 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. A specific example is R in formula (2A'). 107 Examples similar to those given in the explanation can be cited. x and y are independent integers between 0 and 5, and z is an integer between 0 and 4.

[0235] As a photoacid generator represented by formula (3), see formula (2) of Japanese Patent Publication No. 2017-026980. Examples include those similar to those exemplified as photoacid generators represented by ).

[0236] Of the aforementioned photoacid generators, those containing an anion represented by formula (2A') or (2D) are particularly preferred because they exhibit low acid diffusion and excellent solubility in resist solvents. Furthermore, those represented by formula (3') are particularly preferred because they exhibit extremely low acid diffusion.

[0237] Furthermore, as the photoacid generator, a sulfonium salt or iodonium salt having an anion containing an aromatic ring substituted with an iodine atom or a bromine atom can also be used. Examples of such salts are those represented by the following formulas (4-1) or (4-2). [ka]

[0238] In equations (4-1) and (4-2), r is an integer satisfying 1 ≤ r ≤ 3. s and t are integers satisfying 1 ≤ s ≤ 5, 0 ≤ t ≤ 3, and 1 ≤ s + t ≤ 5. s is preferably an integer satisfying 1 ≤ s ≤ 3, and more preferably 2 or 3. t is preferably an integer satisfying 0 ≤ t ≤ 2.

[0239] In equations (4-1) and (4-2), X BI These are iodine atoms or bromine atoms, and when s is 2 or greater, they may be the same or different from each other.

[0240] In equations (4-1) and (4-2), L 1 This is a saturated hydrocarbylene group having 1 to 6 carbon atoms, which may contain a single bond, an ether bond, an ester bond, or an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0241] In equations (4-1) and (4-2), L 2When r is 1, it is a single bond or a divalent linking group having 1 to 20 carbon atoms; when r is 2 or 3, it is a trivalent or tetravalent linking group having 1 to 20 carbon atoms, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0242] In equations (4-1) and (4-2), R 401 This may include a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, or a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, a saturated hydrocarbyloxycarbonyl group having 2 to 10 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms, or a saturated hydrocarbylsulfonyloxy group having 1 to 20 carbon atoms, or -NR 401A -C(=O)-R 401B Alternatively, -NR 401A -C(=O)-OR 401B That is. R 401A R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, an alkoxy group having 1 to 6 carbon atoms, a saturated hydrocarbyl carbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbyl carbonyloxy group having 2 to 6 carbon atoms. 401B This is an aliphatic hydrocarbyl group having 1 to 16 carbon atoms or an aryl group having 6 to 12 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbyloxycarbonyl group, saturated hydrocarbylcarbonyl group, and saturated hydrocarbylcarbonyloxy group may be linear, branched, or cyclic. When r is 2 or more, each R 401 They may be the same or different from one another.

[0243] Of these, R 401Examples include hydroxyl groups and -NR 401A -C(=O)-R 401B , -NR 401A -C(=O)-OR 401B Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc. are preferred.

[0244] Rf 11 ~Rf 14 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of these is either a fluorine atom or a trifluoromethyl group. Also, Rf 11 and Rf 12 These may combine to form a carbonyl group. In particular, Rf 13 and Rf 14 It is preferable that both are fluorine atoms.

[0245] In equations (4-1) and (4-2), R 402 , R 403 , R 404 , R 405 and R 406 Each of these is a C1-C20 hydrocarbyl group which may independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups, C3-C20 cyclic saturated hydrocarbyl groups, C2-C20 alkenyl groups, C2-C20 alkynyl groups, C3-C20 cyclic unsaturated aliphatic hydrocarbyl groups, C6-C20 aryl groups, C7-C20 aralkyl groups, and the like. Furthermore, some or all of the hydrogen atoms of these groups may be substituted with hydroxyl groups, carboxyl groups, halogen atoms, cyano groups, nitro groups, mercapto groups, sultone groups, sulfone groups, or sulfonium salt-containing groups, and some of the carbon atoms of these groups may be substituted with ether bonds, ester bonds, carbonyl groups, amide bonds, carbonate groups, or sulfonic acid ester bonds. 402 and R 403However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring is defined as R in the explanation of formula (2-1). 101 and R 102 Examples of rings that can be formed when these elements combine with the sulfur atom to which they are bonded are similar to those exemplified.

[0246] Examples of cations for the sulfonium salt represented by formula (4-1) are the same as those exemplified for the sulfonium salt represented by formula (2-1). Similarly, examples of cations for the iodonium salt represented by formula (4-2) are the same as those exemplified for the iodonium salt represented by formula (2-2).

[0247] The anions of the onium salt represented by formula (4-1) or (4-2) include, but are not limited to, those listed below. Note that in the following formulas, X BI This is the same as above. [ka]

[0248] [ka]

[0249] [ka]

[0250] [ka]

[0251] [ka]

[0252] [ka]

[0253]

change

[0254]

change

[0255]

change

[0256]

change

[0257]

change

[0258]

change

[0259]

change

[0260]

change

[0261]

change

[0262]

change

[0263]

change

[0264] [ka]

[0265] [ka]

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] If the positive-type resist material of the present invention does not contain a base polymer, the content of the additive-type acid generator 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 urethane PAG compound. If the positive-type resist material of the present invention contains a base polymer, the content of the additive-type acid generator 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 total of the urethane PAG compound and the base polymer. By the base polymer containing repeating units c1 to c3 and / or containing an additive-type acid generator, the positive-type resist material of the present invention can function as a chemically amplified positive-type resist material.

[0271] [Organic solvents] The positive-type 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 the components described later. Examples of such organic solvents include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Publication No. 2008-111103, 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 monoethyl ether. Examples include ethers such as ethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; lactones such as γ-butyrolactone; and mixed solvents thereof.

[0272] If the positive-type resist material of the present invention does not contain a base polymer, the content of the organic solvent is preferably 100 to 10,000 parts by mass, and more preferably 200 to 8,000 parts by mass, per 100 parts by mass of the urethane PAG compound. If the positive-type resist material of the present invention contains a base polymer, the content of the organic solvent is preferably 100 to 10,000 parts by mass, and more preferably 200 to 8,000 parts by mass, per 100 parts by mass of the total of the urethane PAG compound and the base polymer.

[0273] [Quencher] The positive resist material of the present invention may contain a quencher. Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates, and the like. In particular, primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Publication No. 2008-111103 are preferred, especially amine compounds having a hydroxyl group, ether bond, ester bond, lactone ring, cyano group, or sulfonic acid ester bond, or compounds having a carbamate group described in Japanese Patent No. 3790649. By adding such basic compounds, it is possible to further suppress the diffusion rate of acids in the resist film or correct its shape, for example.

[0274] Furthermore, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids and carboxylic acids whose α-position is not fluorinated, as described in Japanese Patent Publication No. 2008-158339. Sulfonic acids, imido acids, or methidic acids with α-position fluorinated are necessary to deprotect the acid-unstable group of the carboxylic acid ester, but the sulfonic acid or carboxylic acid with α-position fluorinated is released by salt exchange with an onium salt whose α-position is not fluorinated. Since sulfonic acids and carboxylic acids with α-position fluorinated do not undergo the deprotection reaction, they function as quenchers.

[0275] Examples of such quenchers include the compound represented by formula (5) below (an onium salt of a sulfonic acid whose α-position is not fluorinated) and the compound represented by formula (6) below (an onium salt of a carboxylic acid). [ka]

[0276] In formula (5), R 501 This refers to a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the α-carbon atom of the sulfo group is substituted with a fluorine atom or a fluoroalkyl group.

[0277] The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, tert-pentyl, n-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 Examples of cyclic saturated hydrocarbyl groups include decanyl, adamantyl, and adamantylmethyl groups; alkenyl groups include vinyl, allyl, propenyl, butenyl, and hexenyl groups; cyclic unsaturated aliphatic hydrocarbyl groups such as cyclohexenyl groups; aryl groups such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), dialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), and dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); heteroaryl groups such as thienyl groups; and aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl groups.

[0278] Furthermore, some of the hydrogen atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the carbon atoms of these groups may be substituted with heteroatom-containing groups such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides, haloalkyl groups, etc. Examples of hydrocarbyl groups containing heteroatoms include alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; and aryloxoalkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0279] In formula (6), R 502 R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. 502 The hydrocarbyl group represented by R is 501 Examples of hydrocarbyl groups represented by the same formulas as those exemplified above include the following. Other specific examples include fluorine-containing alkyl groups such as trifluoromethyl group, trifluoroethyl group, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl group, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl group; and fluorine-containing aryl groups such as pentafluorophenyl group and 4-trifluoromethylphenyl group.

[0280] As a quencher, a sulfonium salt of an iodized benzene ring-containing carboxylic acid represented by the following formula (7) can also be suitably used. [ka]

[0281] In formula (7), R 601 This may be a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, or -NR, where some or all of the hydrogen atoms may be substituted with halogen atoms, a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a halogen atom, or a saturated hydrocarbylsulfonyloxy group having 1 to 6 carbon atoms. 601A -C(=O)-R 601B Alternatively, -NR 601A -C(=O)-OR 601B That is. R 601A R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 601B This is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0282] In equation (7), x' is an integer between 1 and 5. y' is an integer between 0 and 3. x'+y' is an integer between 1 and 5. z' is an integer between 1 and 3. L D This is a single bond or a (z'+1) valence linking group having 1 to 20 carbon atoms, and may contain at least one selected from an ether bond, carbonyl group, ester bond, amide bond, sultone ring, lactam ring, carbonate group, halogen atom, hydroxyl group, and carboxyl group. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, and saturated hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When y' is 2 or more, each R 601 They may be the same or different from one another.

[0283] In formula (7), R 602 , R 603 and R 604Each of these is a C1-C20 hydrocarbyl group which may independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups, C2-C20 alkenyl groups, C6-C20 aryl groups, C7-C20 aralkyl groups, etc. Furthermore, some or all of the hydrogen atoms of these groups may be substituted with hydroxyl groups, carboxyl groups, halogen atoms, oxo groups, cyano groups, nitro groups, sultone groups, sulfone groups, and sulfonium salt-containing groups, and some of the carbon atoms of these groups may be substituted with ether bonds, ester bonds, carbonyl groups, amide bonds, carbonate groups, and sulfonic acid ester bonds. 602 and R 603 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded.

[0284] A specific example of the compound represented by formula (7) is the one described in Japanese Patent Publication No. 2017-219836. Iodine has a large absorption of EUV light at a wavelength of 13.5 nm, which generates secondary electrons during exposure. The energy of these secondary electrons is transferred to the acid generator, which promotes the decomposition of the quencher and thereby improves sensitivity.

[0285] If the positive-type resist material of the present invention does not contain a base polymer, the quencher content is preferably 0.01 to 100 parts by mass, and more preferably 0.01 to 50 parts by mass, per 100 parts by mass of the urethane PAG compound. If the positive-type resist material of the present invention contains a base polymer, the quencher content is preferably 0.01 to 100 parts by mass, and more preferably 0.01 to 50 parts by mass, per 100 parts by mass of the total of the urethane PAG compound and the base polymer.

[0286] [Other ingredients] In addition to the aforementioned components, by appropriately combining surfactants, dissolution inhibitors, etc., according to the purpose, to construct a positive-type resist material, the dissolution rate of the base polymer in the developer is accelerated by a catalytic reaction in the exposed area, making it possible to obtain an extremely sensitive positive-type resist material. In this case, the dissolution contrast and resolution of the resist film are high, there is exposure margin, it has excellent process adaptability, and the pattern shape after exposure is good, while in particular, acid diffusion is suppressed, resulting in small differences in dimensional density. For these reasons, it is highly practical and can be made a very effective resist material for ultra-large-scale integrated circuits (ULSIs).

[0287] Examples of the surfactants mentioned above include those described in paragraphs

[0165] to

[0166] of Japanese Patent Publication No. 2008-111103. By adding a surfactant, the coatability of the resist material can be further improved or controlled. When the positive-type resist material of the present invention does not contain a base polymer, the surfactant content is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the urethane PAG compound. When the positive-type resist material of the present invention contains a base polymer, the surfactant content is preferably 0.0001 to 10 parts by mass per 100 parts by mass of the total of the urethane PAG compound and the base polymer. The surfactant can be used alone or in combination of two or more types.

[0288] By incorporating a dissolution inhibitor, the difference in dissolution rate between the exposed and unexposed areas can be further increased, thereby further improving the resolution. Examples of the dissolution inhibitor include compounds having a molecular weight of preferably 100 to 1,000, more preferably 150 to 800, and containing two or more phenolic hydroxyl groups in the molecule, in which the hydrogen atoms of the phenolic hydroxyl groups are substituted with acid-unstable groups in a total proportion of 0 to 100 mol%, or compounds containing a carboxyl group in the molecule, in which the hydrogen atoms of the carboxyl group are substituted with acid-unstable groups in an average total proportion of 50 to 100 mol%. Specifically, examples include compounds in which the hydrogen atoms of the hydroxyl group or carboxyl group of bisphenol A, trisphenol, phenolphthalein, cresol novolac, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid are substituted with acid-unstable groups, as described in paragraphs

[0155] to

[0178] of Japanese Patent Application Publication No. 2008-122932. If the positive-type resist material of the present invention does not contain a base polymer, the content of the dissolution inhibitor is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass, per 100 parts by mass of the urethane PAG compound. If the positive-type resist material of the present invention contains a base polymer, the content of the dissolution inhibitor is preferably 0 to 50 parts by mass, and more preferably 5 to 40 parts by mass, per 100 parts by mass of the total of the urethane PAG compound and the base polymer. The dissolution inhibitor can be used alone or in combination of two or more types.

[0289] The positive resist material of the present invention may contain a water-repellent agent to improve the water repellency of the resist surface after spin coating. The water-repellent agent can be used in immersion lithography without a top coat. Preferred water-repellent agents include polymer compounds containing alkyl fluoride, polymer compounds containing 1,1,1,3,3,3-hexafluoro-2-propanol residues of a specific structure, and those exemplified in Japanese Patent Publication No. 2007-297590 and Japanese Patent Publication No. 2008-111103 are more preferred. The water-repellent agent needs to be soluble in an alkaline developer or an organic solvent developer. The water-repellent agent having the specific 1,1,1,3,3,3-hexafluoro-2-propanol residues mentioned above has good solubility in the developer. As a water-repellent agent, polymer compounds containing repeating units including amino groups or amine salts are highly effective in preventing acid evaporation during post-exposure baking (PEB) and preventing poor hole pattern opening after development. When the positive-type resist material of the present invention does not contain a base polymer, the content of the water-repellency enhancer is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the urethane PAG compound. When the positive-type resist material of the present invention contains a base polymer, the content of the water-repellency enhancer is preferably 0 to 20 parts by mass, and more preferably 0.5 to 10 parts by mass, per 100 parts by mass of the total of the urethane PAG compound and the base polymer. The water-repellency enhancer can be used alone or in combination of two or more types.

[0290] The positive-type resist material of the present invention may contain acetylene alcohols. Examples of acetylene alcohols include those described in paragraphs

[0179] to

[0182] of Japanese Patent Application Publication No. 2008-122932. When the positive-type resist material of the present invention does not contain a base polymer, the content of acetylene alcohols is preferably 0 to 5 parts by mass per 100 parts by mass of the urethane PAG compound. When the positive-type resist material of the present invention contains a base polymer, the content of acetylene alcohols is preferably 0 to 5 parts by mass per 100 parts by mass of the total of the urethane PAG compound and the base polymer.

[0291] [Pattern formation method] When the positive-type 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 may include a step of forming a resist film on a substrate using the positive-type resist material described above, a step of exposing the resist film with high-energy rays, and a step of developing the exposed resist film using a developer.

[0292] First, the positive resist material of the present invention is applied to a substrate for integrated circuit manufacturing (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coating, etc.) or a substrate for mask circuit manufacturing (Cr, CrO, CrON, MoSi2, SiO2, etc.) by a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, so that the coating thickness is 0.01 to 2 μm. This is then pre-baked on a hot plate, preferably at 60 to 150°C for 10 seconds to 30 minutes, more preferably at 80 to 120°C for 30 seconds to 20 minutes, to form a resist film.

[0293] Next, the resist film is exposed using high-energy rays. Examples of high-energy rays include ultraviolet rays, far ultraviolet rays, electron beams (EB), EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, and extreme ultraviolet rays with wavelengths of 3 to 15 nm. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer laser light, gamma rays, synchrotron radiation, etc. as the high-energy rays, a mask for forming the desired pattern is used, and the exposure amount is preferably 1 to 200 mJ / cm². 2 To the extent, more preferably 10 to 100 mJ / cm² 2 Irradiate to the extent of [a certain degree]. When using EB as the high-energy beam, the exposure dose is preferably 0.1 to 100 μC / cm². 2 To a degree, more preferably 0.5 to 50 μC / cm² 2The pattern is drawn either directly or using a mask to form the desired pattern. The positive-type resist material of the present invention is particularly suitable for fine patterning using high-energy rays, including i-rays with a wavelength of 365 nm, KrF excimer laser light, ArF excimer laser light, electron beams (EB), EUV, X-rays, soft X-rays, gamma rays, synchrotron radiation, and extreme ultraviolet rays with wavelengths of 3 to 15 nm, and is especially suitable for fine patterning using EB or EUV.

[0294] After exposure, PEB may be performed on a hot plate or in an oven, preferably at 50-150°C for 10 seconds to 30 minutes, more preferably at 60-120°C for 30 seconds to 20 minutes.

[0295] After exposure or PEB, the substrate is developed using a developer solution containing 0.1 to 10% by mass, preferably 2 to 5% by mass, of an alkaline aqueous solution 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 conventional methods such as the dip method, puddle method, or spray method. The areas exposed to light dissolve in the developer solution, while the areas not exposed do not dissolve, forming the desired positive-type pattern on the substrate.

[0296] The developed hole patterns and trench patterns can also be shrunk using thermal flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern, and crosslinking of the shrinking agent occurs on the surface of the resist due to the diffusion of an acid catalyst from the resist layer during baking, causing the shrinking agent to adhere to the sidewalls of the hole pattern. The baking temperature is preferably 70 to 180°C, more preferably 80 to 170°C, and the time is preferably 10 to 300 seconds, during which excess shrinking agent is removed and the hole pattern is reduced in size. [Examples]

[0297] The present invention will be specifically described below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0298] [1] Synthesis of urethane PAG compounds [Synthesis Examples 1-1 to 1-26] Synthesis of Urethane PAG Compounds 1-26 In a dehydrated 2-heptanone solution, isocyanate compounds, compounds having both a hydroxyl group and a carboxyl group substituted with an acid-unstable group, and sulfonium or iodonium salts of sulfonic acids having a hydroxyl group were reacted in the presence of 1% by mass of bismuth salt XK-640 manufactured by Kusumoto Chemical Co., Ltd. The bismuth salt was removed by liquid-liquid washing with pure water to synthesize urethane PAG compounds 1 to 26. [ka]

[0299] [ka]

[0300] [ka]

[0301] [ka]

[0302] [ka]

[0303] [ka]

[0304] [ka]

[0305] [ka]

[0306] [ka]

[0307] [ka]

[0308] [2] Synthesis of base polymers [Synthesis Examples 2-1 to 2-3] Synthesis of Polymers 1 to 3 Each monomer was combined and copolymerized in THF, crystallized in methanol, and then washed repeatedly with hexane. After isolation and drying, base polymers (polymers 1-3) with the following compositions were obtained. The compositions of the obtained base polymers are: 1 Mw and Mw / Mn were confirmed by H-NMR using GPC (solvent: THF, standard: polystyrene). [ka]

[0309] [3] Synthesis of urethane compounds [Synthesis Examples 3-1 to 3-3] Synthesis of Urethane Compounds 1-3 In a dehydrated 2-heptanone solution, an isocyanate compound and a compound having both a hydroxyl group and a carboxyl group substituted with an acid-unstable group were reacted in the presence of 1% by mass of bismuth salt XK-640 manufactured by Kusumoto Chemical Co., Ltd. The bismuth salt was removed by liquid-liquid washing with pure water to synthesize urethane compounds 1 to 3. [ka]

[0310] [4] Preparation and evaluation of positive-type resist materials [Examples 1-25, Comparative Example 1] (1) Preparation of positive-type resist material Positive-type resist materials were prepared by dissolving each component in a solvent containing 30 ppm of PolyFox PF-636 surfactant manufactured by Omnova, according to the compositions shown in Tables 1 and 2, and filtering the solution through a 0.2 μm filter.

[0311] In Tables 1 and 2, the components are as follows: • Organic solvent: PGMEA (propylene glycol monomethyl ether acetate) DAA (Diacetone Alcohol) 2-Heptanone

[0312] • Acid generator: PAG-1~3 [ka]

[0313] • Quencher: Q-1, 2 [ka]

[0314] (2) EUV exposure evaluation Each resist material shown in Tables 1 and 2 was spin-coated onto a Si substrate on which a silicon-containing spin-on hard mask SHB-A940 (silicon content 43 mass%) manufactured by Shin-Etsu Chemical Co., Ltd. had been formed to a thickness of 20 nm. A resist film with a thickness of 50 nm was fabricated by pre-baking at 100°C for 60 seconds using a hot plate. This was exposed using an ASML EUV scanner NXE3400 (NA 0.33, σ 0.9 / 0.6, quadruple pole illumination, wafer-mounted dimensions of 46 nm pitch, +20% bias hole pattern mask), and PEB was performed on a hot plate at the temperatures listed in Tables 1 and 2 for 60 seconds. Development was then performed with a 2.38 mass% TMAH aqueous solution for 30 seconds to obtain a hole pattern with dimensions of 23 nm. The exposure amount when each hole was formed with a dimension of 23 nm was measured and defined as the sensitivity. In addition, the dimensions of 50 holes were measured using a Hitachi High-Technologies Corporation length measuring SEM (CG6300) and the CDU (dimensional variation of 3σ) was determined. The results are shown in Tables 1 and 2.

[0315] [Table 1]

[0316] [Table 2]

[0317] The results shown in Tables 1 and 2 indicate that the positive-type resist material of the present invention, which includes a compound having two or more urethane groups, a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium or iodonium salt of a sulfonic acid bonded directly to a second urethane group or via a second linking group, exhibited high sensitivity and good CDU.

[0318] This specification includes the following embodiments: [1]: A positive-type resist material comprising a compound having two or more urethane groups, wherein the compound includes a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium salt or iodonium salt of a sulfonic acid bonded directly to a second urethane group or via a second linking group. [2]: The positive resist material of [1], characterized in that the compound is represented by the following formula (1). [ka] (In formula (1), R 1 These are the same or different acid-unstable groups. 2R is the first linking group, which is a p+1 valent hydrocarbylene group having 1 to 20 carbon atoms, and may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom. 3 R is a q+r valent hydrocarbylene group having 2 to 33 carbon atoms, and may contain oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms. 4 Rf is a single bond or the second linking group, a divalent hydrocarbylene group having 1 to 20 carbon atoms, which may contain oxygen, sulfur, nitrogen, and halogen atoms. 1 ~Rf 4 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group. Also, Rf 1 and Rf 2 These may combine to form a carbonyl group. q is in the range of 1 ≤ q ≤ 4, p is 1 or 2, and r is in the range of 1 ≤ r ≤ 4. M + (This is a sulfonium cation or an iodonium cation.) [3]: The above R 1 The positive resist material of [2] described above, characterized in that it falls under any of the following 1) to 3). 1) The carbon bonded to the ester group is tertiary, and the alkyl group bonded to the carbon does not contain a halogen atom, a cyano group, or a nitro group. 2) The carbon atom bonded to the ester group is secondary and has a cyclic structure, does not contain heteroatoms, and has double bonds, triple bonds, or aromatic groups on carbon atoms other than the carbon atom bonded to the ester group. 3) It is an acetal group having an ether group adjacent to the carbon atom bonded to the ester group. [4]: A positive resist material according to any one of [1] to [3] above, further comprising a compound having two or more urethane groups and two or more carboxyl groups substituted with acid-unstable groups bonded to the urethane groups via linking groups. [5]: A positive-type resist material according to any one of the above [1] to [4], further characterized by containing a base polymer. [6]: The positive resist material according to [5], characterized in that the base polymer includes repeating units in which the hydrogen atoms of a carboxyl group are substituted with an acid-unstable group and / or repeating units in which the hydrogen atoms of a phenolic hydroxyl group are substituted with an acid-unstable group. [7]: The positive resist material of [6], characterized in that the repeating units in which the hydrogen atoms of the carboxyl group are substituted with an acid-unstable group and the repeating units in which the hydrogen atoms of the phenolic hydroxyl group are substituted with an acid-unstable group are the repeating units represented by the following formula (a1) and the repeating units represented by the following formula (a2), respectively. [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 1 X is a single bond, or a linking group having 1 to 14 carbon atoms that includes a phenylene group, a naphthylene group, an ester bond, an ether bond, or a lactone ring. 2 X is a single bond, an ester bond, or an amide bond. 3 These are single bonds, ether bonds, or ester bonds. 11 and R 12 R is an acid-unstable group. 13 R is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 14 (a is a single bond or a saturated hydrocarbylene group having 1 to 6 carbon atoms, some of which may be substituted with ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4, where 1 ≤ a + b ≤ 5.) [8]: A positive resist material according to any one of the above [5] to [7], characterized in that the base polymer further comprises repeating units b having adhesive groups selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonic acid ester bond, a cyano group, an amide bond, -OC(=O)-S- and -OC(=O)-NH-. [9]: A positive resist material according to any one of the above [5] to [8], characterized in that the base polymer further contains a repeating unit c represented by any one or more of the following formulas (c1) to (c3). [ka] (In the formula, R A Each of these is independently either a hydrogen atom or a methyl group. 1 It consists of a single bond, a phenylene group, a naphthylene group, and -OY 11 -, -C(=O)-OY 11 -or -C(=O)-NH-Y 11 - is Y 11 This is an aliphatic hydrocarbylene group, phenylene group, naphthylene group having 1 to 6 carbon atoms, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. 2 These are single bonds or ester bonds. 3 This is a single bond, -Y 31 -C(=O)-O-, -Y 31 -O- or -Y 31 -OC(=O)- Y 31 This is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, an iodine atom, and a bromine atom. 4 This is a single bond, a methylene group, or a 2,2,2-trifluoro-1,1-ethanediyl group. 5 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, and -OY 51 -, -C(=O)-OY 51 -or -C(=O)-NH-Y 51 - is Y 51 This refers to an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may include a carbonyl group, an ester bond, an ether bond, and a hydroxyl group. Rf 1 and Rf 2Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is a fluorine atom. 21 ~R 28 These are each a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. 23 and R 24 or R 26 and R 27 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded. - (It is a non-nucleophilic counterion.)

[10] : A positive resist material according to any one of the above [1] to [9], further characterized by containing an acid generator.

[11] : A positive resist material according to any one of the above [1] to

[10] , further characterized by containing an organic solvent.

[12] : A positive resist material according to any one of the above [1] to

[11] , further characterized by containing a quencher.

[13] : A positive resist material according to any one of the above [1] to

[12] , further characterized by containing a surfactant.

[14] : A pattern forming method comprising the steps of forming a resist film on a substrate using any one of the positive resist materials from [1] to

[13] above, exposing the resist film with high-energy rays, and developing the exposed resist film using a developer.

[15] : The pattern formation method of

[14] , characterized in that the high-energy beam is an i-ray, KrF excimer laser light, ArF excimer laser light, an electron beam, or extreme ultraviolet light with a wavelength of 3 to 15 nm.

[0319] It should be noted that the present invention is not limited to the embodiments described above. The embodiments described above are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of the present invention and achieves similar effects is included within the technical scope of the present invention.

Claims

1. A positive-type resist material comprising a compound having two or more urethane groups, a carboxyl group substituted with an acid-unstable group bonded to a first urethane group via a first linking group, and a sulfonium salt or iodonium salt of a sulfonic acid represented by *-C(Rf 1)(Rf 2)-C(Rf 3)(Rf 4)-SO3- (wherein Rf 1 to 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. Rf 1 and Rf 2 may also combine to form a carbonyl group. * is a bond with the second linking group), bonded to a second urethane group via a second linking group. The aforementioned compound is represented by the following formula (1), 【Chemistry 1】 (In formula (1), R1 is the same or different acid-unstable group. R2 is the first linking group, the same or different C6-C20 p+1 valent hydrocarbylene group containing a benzene ring, which may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom. R3 is a C6-C33 q+r valent hydrocarbylene group containing a benzene ring, which may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom. R4 is the second linking group, a C6-C20 divalent hydrocarbylene group containing a benzene ring, which may contain an oxygen atom, a sulfur atom, a nitrogen atom, and a halogen atom. Rf1 to Rf4 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. Also, Rf1 and Rf2 These may combine to form a carbonyl group. q is in the range of 1 ≤ q ≤ 4, p is 1 or 2, and r is in the range of 1 ≤ r ≤ 4. M+ is a sulfonium cation or an iodonium cation. A positive-type resist material characterized in that R1 falls under any of the following 1) to 3). 1) The carbon bonded to the ester group is tertiary, and the alkyl group bonded to the carbon does not contain a halogen atom, a cyano group, or a nitro group. 2) The carbon atom bonded to the ester group is secondary and has a cyclic structure, does not contain heteroatoms, and has double bonds, triple bonds, or aromatic groups on carbon atoms other than the carbon atom bonded to the ester group. 3) It is an acetal group having an ether group adjacent to the carbon atom bonded to the ester group.

2. Furthermore, the compound comprises having two or more urethane groups, and having two or more carboxyl groups substituted with acid-unstable groups bonded to the urethane groups via linking groups, The positive-type resist material according to claim 1, characterized in that the compound is represented by the following formula (1'). 【Chemistry 2】 (In formula (1'), R'1 is the same or different acid-unstable group. R'2 is the linking group, which is the same or different hydrocarbylene group containing a benzene ring, having 6 to 20 carbon atoms, n'+1 or p'+1 valency, and may contain oxygen, sulfur, nitrogen, and halogen atoms. R'3 is a hydrocarbylene group containing a benzene ring, having 6 to 33 carbon atoms, m'+1 valency, and may contain oxygen, sulfur, nitrogen, and halogen atoms. m' is an integer between 1 and 6, and n' and p' are 1 or 2.)

3. Furthermore, the positive-type resist material according to claim 1, characterized in that it further contains a base polymer.

4. The positive-type resist material according to claim 3, characterized in that the base polymer includes repeating units in which the hydrogen atoms of a carboxyl group are substituted with an acid-unstable group and / or repeating units in which the hydrogen atoms of a phenolic hydroxyl group are substituted with an acid-unstable group.

5. The positive-type resist material according to claim 4, characterized in that the repeating units in which the hydrogen atoms of the carboxyl group are substituted with an acid-unstable group and the repeating units in which the hydrogen atoms of the phenolic hydroxyl group are substituted with an acid-unstable group are the repeating units represented by the following formula (a1) and the repeating units represented by the following formula (a2), respectively. 【Transformation 3】 (In the formula, R Ａ Each of these is independently either a hydrogen atom or a methyl group. １ X is a single bond, or a linking group having 1 to 14 carbon atoms that includes a phenylene group, a naphthylene group, an ester bond, an ether bond, or a lactone ring. ２ These are single bonds, ester bonds, or amide bonds. ３ This is a single bond, an ether bond, or an ester bond. １１ and R １２ R is an acid-unstable group. １３ R is a fluorine atom, a trifluoromethyl group, a cyano group, or a saturated hydrocarbyl group having 1 to 6 carbon atoms. １４ (a is a single bond or a saturated hydrocarbylene group having 1 to 6 carbon atoms, some of which may be substituted with ether or ester bonds. a is 1 or 2. b is an integer from 0 to 4, where 1 ≤ a + b ≤ 5.)

6. The positive resist material according to claim 3, characterized in that the base polymer further comprises repeating units b having adhesive groups selected from a hydroxyl group, a carboxyl group, a lactone ring, a carbonate group, a thiocarbonate group, a carbonyl group, a cyclic acetal group, an ether bond, an ester bond, a sulfonic acid ester bond, a cyano group, an amide bond, -O-C(=O)-S- and -O-C(=O)-NH-.

7. The positive-type resist material according to claim 3, characterized in that the base polymer further contains repeating units c represented by any one or more of the following formulas (c1) to (c3). 【Chemistry 4】 (wherein R Ａ are each independently a hydrogen atom or a methyl group. Y １ is a single bond, a phenylene group, a naphthylene group, -O-Y １１ -, -C(=O)-O-Y １１ - or -C(=O)-NH-Y １１ -. Y １１ is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may optionally contain a carbonyl group, an ester bond, an ether bond and a hydroxy group. Y ２ is a single bond or an ester bond. Y ３ is a single bond, -Y ３１ -C(=O)-O-, -Y ３１ -O- or -Y ３１ -O-C(=O)-. Y ３１ is a hydrocarbylene group having 1 to 12 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may optionally contain a carbonyl group, an ester bond, an ether bond, an iodine atom and a bromine atom. Y ４ is a single bond, a methylene group or a 2,2,2-trifluoro-1,1-ethanediyl group. Y ５ is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, -O-Y ５１ -, -C(=O)-O-Y ５１ - or -C(=O)-NH-Y ５１ -. Y ５１ is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may optionally contain a carbonyl group, an ester bond, an ether bond and a hydroxy group. Rf １ and Rf ２ are each independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, provided that at least one of them is a fluorine atom. R ２１ to R ２８ are each independently a hydrocarbyl group having 1 to 20 carbon atoms that may optionally contain a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and a heteroatom. Further, R ２３ and R ２４ or R ２６ and R ２７ However, they may bond to each other and form a ring with the sulfur atom to which they are bonded. － (It is a non-nucleophilic counterion.)

8. Furthermore, the positive-type resist material according to claim 1 is characterized by containing an acid generator.

9. Furthermore, the positive-type resist material according to claim 1 is characterized in that it contains an organic solvent.

10. Furthermore, the positive-type resist material according to claim 1, characterized in that it further contains a quencher.

11. Furthermore, the positive-type resist material according to claim 1 is characterized by containing a surfactant.

12. A pattern forming method characterized by comprising the steps of: forming a resist film on a substrate using a positive-type resist material according to any one of claims 1 to 11; exposing the resist film with a high-energy beam; and developing the exposed resist film using a developer.

13. The pattern formation method according to claim 12, characterized in that i-rays, KrF excimer laser light, ArF excimer laser light, electron beams, or extreme ultraviolet light with a wavelength of 3 to 15 nm are used as the high-energy rays.

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