Pattern forming method and resist material

Abstract

The invention relates to a pattern forming method and a resist material. The present invention addresses the problem of providing a pattern forming method whereby a fine pattern having a high aspect ratio can be formed without pattern collapse. A pattern forming method includes preparing a resist material containing a polymer in which a carboxyl group bonded to a polymer main chain is protected by an acid-labile group, forming a resist film using the resist material, exposing and heating the resist film, and forming a pattern on the resist film. Developing by using dry etching to form a pattern; the present invention is characterized in that the polymer is a polymer having either or both of repeating units represented by general formulae (a1) and (a2). [chemical] # imgabs0 #

Description

Technical Field

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

[0002] With the high integration and high speed of LSI, the miniaturization of pattern rules is also progressing rapidly. This is due to the popularization of 5G high-speed communication and artificial intelligence (AI), which requires high-performance devices to handle them. As for the most advanced miniaturization technology, mass production of 5nm node and 3nm node devices using extreme ultraviolet (EUV) lithography with a wavelength of 13.5nm is already underway. In addition, in the next generation of 2nm node devices and the next generation of The use of EUV lithography has also been explored in the node, and IMEC in Belgium has published Device development.

[0003] As miniaturization progresses, image blurring caused by acid diffusion has become a problem. To ensure resolution for fine patterns below 45 nm in size, some have proposed that controlling acid diffusion is important, in addition to improving dissolution contrast, as previously advocated (Non-Patent Document 1). However, chemically amplified resist materials utilize acid diffusion to improve sensitivity and contrast. Therefore, lowering the post-exposure bake (PEB) temperature or shortening the time to limit acid diffusion significantly reduces sensitivity and contrast.

[0004] There is a triangular trade-off between sensitivity, resolution, and edge roughness (LWR). Improving resolution requires suppressing acid diffusion, but shortening the acid diffusion distance reduces sensitivity.

[0005] Adding an acid generator that generates bulky acids to inhibit acid diffusion is effective. Therefore, some have proposed incorporating repeating units derived from onium salts with polymerizable unsaturated bonds into polymers. In this case, the polymer also functions as an acid generator (polymer-bonded acid generator). Patent Document 1 proposes sulfonium salts and iodonium salts with polymerizable unsaturated bonds that generate specific sulfonic acids. Patent Document 2 proposes sulfonium salts in which sulfonic acids are directly bonded to the main chain.

[0006] It has been reported that the resolution limit of the resist is determined by pattern collapse (Non-patent Document 1). During spin drying after rinsing in alkaline water development, the stress applied to the pattern will cause pattern collapse. In order to reduce the stress during spin drying, it is effective to reduce the surface tension of the rinsing liquid, so a rinsing liquid with added surfactants is used, but it is not sufficient for line patterns with a pattern pitch of less than 20nm. There have been studies on rinsing with carbon dioxide in a supercritical state with a surface tension of 0, but a special chamber is required to achieve a high-pressure supercritical state, which is not practical from the perspective of improving production volume. A method of filling the space between patterns with a water-soluble silicon-containing rinsing liquid and performing dry etching with oxygen has been proposed, but there is a problem of image inversion.

[0007] A patterning method has been proposed in which a resist pattern obtained by shrinking the exposed portion by exposure and deprotection of acid-labile groups by PEB is subjected to dry etching to thereby open the exposed portion (Patent Document 3). If the amount of shrinkage in the exposed portion is large, problems such as deformation of two-dimensional patterns such as L-shaped patterns or the formation of triangular cross-sectional shapes of lines may occur.

[0008] Prior art literature

[0009] Patent Literature

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-045311

[0011] [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-178317

[0012] [Patent Document 3] Japanese Patent Application Laid-Open No. 2023-157346

[0013] Non-patent literature

[0014] [Non-Patent Document 1] SPIE Vol. 6153 p61531C-1 (2006) Summary of the Invention

[0015] [Problems to be Solved by the Invention]

[0016] As described above, as LSIs become increasingly integrated and faster, a pattern forming method is required that prevents pattern collapse and pattern deformation from occurring as pattern rules become finer.

[0017] The present invention has been made in view of the above-mentioned situation, and an object of the present invention is to provide a pattern forming method capable of forming a high aspect ratio and fine pattern without causing pattern collapse.

[0018] [Methods for solving the problem]

[0019] To solve the above-mentioned problems, the present invention provides a pattern forming method comprising the steps of: preparing a resist material containing a polymer in which a carboxyl group bonded to a polymer backbone is protected by an acid-labile group; forming a resist film using the resist material; exposing the resist film to light, heating it, and then developing it by dry etching to form a pattern; wherein the method comprises:

[0020] As the polymer, a polymer having either or both of repeating units represented by the following general formulae (a1) and (a2) is used.

[0021] [Chemistry 1]

[0022]

[0023] Where R A R are independently a hydrogen atom or a methyl group. 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl (CF3) group, a trifluoromethoxy (CF3O) group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring that may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6. X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

[0024] The pattern forming method of the present invention can form a high aspect ratio and fine pattern without causing pattern collapse.

[0025] In this case, the resist material may further contain an acid generator, or a polymer containing the repeating unit and the repeating unit b having an acid-generating moiety may be used. The two may be combined.

[0026] In the present invention, the acid generating function in the resist material can be adjusted to an ideal one by incorporating an acid generator into the resist material (external addition), using a polymer incorporating an acid generating portion (polymer-bonded acid generator) (internal addition), or combining them.

[0027] When a polymer incorporating a repeating unit b having an acid-generating moiety is used, the repeating unit b having an acid-generating moiety is preferably a repeating unit selected from the repeating units represented by the following formulae (b1) to (b5).

[0028] [Chemistry 2]

[0029]

[0030] Where R A R are independently a hydrogen atom or a methyl group. B are independently a hydrogen atom, or Z 6 Bond and form a ring. Z 1 is a single bond, an aliphatic alkylene 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 groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene 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 groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond or an ester bond. 3 is a single bond, -Z 31 -C(=O)-O- or -Z 31 -O-.Z 31 It is a C1-12 alkylene group, a phenylene group, or a C7-18 group obtained by combining these groups, and may contain a carbonyl group, a nitro group, a cyano group, an ester bond, an ether bond, a urethane bond, a fluorine atom, an iodine atom, or a bromine atom. 4 is a single bond, methylene or ethylene. 5 is a single bond, methylene, ethylene, phenylene, methylphenylene, dimethylphenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a methylphenylene group, a dimethylphenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a hydroxyl group, or a halogen atom. 6 is a single bond, a phenylene ring, a naphthalene ring, an ester bond or an amide bond.7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 7B It is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 8 Z is a single bond, an ether bond, an ester bond, a thioether bond, or an alkanediyl group having 1 to 6 carbon atoms. 9 It is a trivalent organic group having 1 to 12 carbon atoms and may have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom. 1 ~Rf 4 are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 They can also combine and form a carbonyl group together with the carbon atom to which they are bonded. 21 and R 22 Each of R is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 23 is a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group. Ring R is a (d+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. d is an integer from 0 to 5. - It is a non-nucleophilic relative ion. + It is a sulfonium cation or an iodonium cation.

[0031] In the present invention, by using a polymer incorporating such a repeating unit b having an acid-generating portion, a high aspect ratio and fine pattern can be formed more desirably without pattern collapse.

[0032] In this case, as the repeating unit b having an acid generating portion, Z in the above formula can be used. 3 、Z 7A 、Z 7B or M + A repeating unit containing one or more iodine atoms.

[0033] By using such a repeating unit containing iodine atoms, a more ideal pattern can be formed.

[0034] Furthermore, in the present invention, the exposure may be performed using extreme ultraviolet light having a wavelength of 3 to 15 nm and an electron beam having an acceleration voltage of 1 to 150 kV.

[0035] In the present invention, such high-energy rays can be used to more ideally form high-aspect-ratio and fine patterns without pattern collapse.

[0036] The present invention also provides a resist material for pattern formation by dry etching, characterized in that it contains a polymer having either or both of the repeating units represented by the following general formulae (a1) and (a2).

[0037] [Chemistry 3]

[0038]

[0039] Where R A R are independently a hydrogen atom or a methyl group. 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6. X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

[0040] Such a resist material can be preferably used in the pattern forming method of the present invention.

[0041] [Effects of the Invention]

[0042] In the pattern formation method of the present invention, when acid is generated in the resist film due to exposure, the acid-labile groups containing phenolic groups in the polymer are deprotected, generating carboxyl groups. When using a positive resist material, dry etching is used to open the exposed areas where carboxyl groups are generated, forming a positive pattern. Using free radicals generated within the dry etching chamber, the exposed areas experience improved etching rates due to backbone decomposition and the generation of carbon dioxide gas, while the unexposed areas experience slower etching rates due to free radical absorption by phenolic groups. By increasing the etching rate difference between the exposed and unexposed areas, a positive pattern is formed. Development performed by dry etching avoids pattern collapse due to capillary forces, enabling the formation of fine patterns with high aspect ratios. DETAILED DESCRIPTION

[0043] As described above, there is a demand for a pattern forming method that does not cause pattern collapse or pattern deformation as pattern rules become finer with the increasing integration and speed of LSIs.

[0044] The present inventors have conducted in-depth studies to achieve the aforementioned objectives and have discovered that by using a polymer-based resist material having repeating units in which carboxyl groups are protected by acid-labile groups having phenolic groups, the unexposed portions have phenolic groups, and the exposed portions generate carboxyl groups due to deprotection. When dry etching is performed on these portions, free radicals generated in the etching chamber are absorbed by the phenols, slowing the etching rate of the unexposed portions, while the exposed portions etch faster due to decarboxylation and main chain decomposition. This increases the selectivity of the etching rates between the exposed and unexposed portions, allowing the formation of high-aspect-ratio and fine patterns without relying on film shrinkage in the exposed portions, thereby completing the present invention.

[0045] Specifically, the present invention provides a pattern forming method comprising the steps of preparing a resist material containing a polymer (base polymer) in which the carboxyl groups bonded to the polymer backbone are protected by acid-labile groups; forming a resist film using the resist material; exposing the resist film to light, heating it, and then developing it by dry etching to form a pattern. The method is characterized in that the polymer used is a polymer having a specific repeating unit described below. The base polymer may also be referred to as a base resin hereinafter.

[0046] The present invention will be described in detail below, but the present invention is not limited thereto. In this specification, the endpoints of a numerical range are defined as including all values ​​included in the range.

[0047] [Pattern Formation Method]

[0048] The pattern forming method of the present invention comprises the following steps (i) to (iv):

[0049] (i) preparing a resist material comprising a polymer in which a carboxyl group bonded to a polymer main chain is protected by an acid-labile group,

[0050] (ii) forming a resist film using the resist material and exposing the resist film to light,

[0051] (iii) a step of heating (baking) the exposed resist film, and

[0052] (iv) developing the heated resist film by dry etching to form a pattern;

[0053] As the polymer, a polymer having either or both of repeating units represented by the following general formulae (a1) and (a2) is used.

[0054] [Chemistry 4]

[0055]

[0056] Where R A R are independently a hydrogen atom or a methyl group. 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6. X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

[0057] [Step (i)]

[0058] Step (i) is a step of preparing a resist material containing a polymer (base resin) in which the carboxyl groups bonded to the polymer main chain are protected by acid-labile groups. The resist material will be described in detail later.

[0059] [Step (ii)]

[0060] Step (ii) is a step of forming a resist film using the resist material and exposing the resist film. The resist film can be formed by, for example, applying a resist material containing the base resin on a substrate and then performing a heat treatment.

[0061] Specifically, for example, a resist material is applied to a substrate for integrated circuit manufacturing or a processed layer thereon (Si, SiO 2 , SiN, SiON, TiN, WSi, BPSG, SOG, an organic antireflection film, etc.), or a substrate for mask circuit manufacturing or a processed layer thereon (Cr, CrO, CrON, MoSi 2 , SiO 2 , Ru, Ta, TaB, TaBN, TaBO, etc.) by a suitable coating method such as spin coating, roller coating, flow coating, dip coating, spray coating, or scraping coating to a coating thickness of 0.1 to 2.0 μm. The resist material is then pre-baked on a hot plate at 60 to 150° C. for 10 seconds to 30 minutes, preferably at 80 to 120° C. for 30 seconds to 20 minutes, to form a resist film.

[0062] Then, the resist film is patterned to its intended purpose through a predetermined mask or direct exposure using high-energy rays such as ultraviolet rays, far ultraviolet rays, electron beams (EB) with an acceleration voltage of 1 to 150 kV, extreme ultraviolet rays (EUV) with a wavelength of 3 to 15 nm, X-rays, soft X-rays, excimer lasers, gamma rays, and synchrotron radiation.

[0063] The pattern forming method of the present invention is preferably performed by using extreme ultraviolet rays with a wavelength of 3 to 15 nm, or by using an electron beam with an acceleration voltage of 1 to 150 kV.

[0064] Exposure is about 1-300 mJ / cm 2 , especially about 10 to 200 mJ / cm 2 or 1~500μC / cm 2 , 5~400μC / cm 2 Very good.

[0065] [Step (iii)]

[0066] Step (iii) is a step of baking (PEB) the resist film at 30-170° C. after exposure. The PEB temperature is preferably 40-160° C., more preferably 50-150° C., and the treatment time is preferably 10 seconds to 30 minutes, more preferably 10 seconds to 20 minutes.

[0067] In the pattern forming method of the present invention, the PEB after exposure can be heated not only by a hot plate but also by infrared irradiation, laser irradiation, hot air blowing, or by inserting the wafer into an environment at a baking temperature.

[0068] Currently, wafer heating methods typically use a hot plate. The silicon wafer is placed on a hot plate, and the resist film is heated using conductive heat from the wafer. The temperature of the resist film is controlled by the hot plate.

[0069] [Step (iv)]

[0070] Step (iv) is a step of developing the resist film by dry etching after baking. The dry etching gas used can be a mixed gas of oxygen, hydrogen, ammonia, fluorocarbon, chlorine, or bromine diluted with nitrogen, argon, helium, carbon dioxide, carbon monoxide, sulfur dioxide, or the like.

[0071] [Resist material]

[0072] As described above, the resist film is formed using a resist material based on a polymer having a repeating unit in which a carboxyl group is substituted with an acid-labile group having a phenol group.

[0073] The base polymer contained in the resist material used in the present invention is a polymer having either or both of the repeating units represented by the above-mentioned general formulae (a1) and (a2) (these repeating units are also collectively referred to as repeating units a).

[0074] The repeating units constituting the main chain of the base polymer have a carboxyl group, and the carboxyl group is protected (substituted) by an acid-labile group. The acid-labile group has a phenolic group. The carboxyl group bonded to the main chain of the base polymer is protected by the acid-labile group to form a resist film. Furthermore, by exposing the resist film to light, the protection is removed by the action of an acid.

[0075] The group substituting the carboxyl group of the repeating unit, that is, the acid-labile group having a phenolic group is represented by the following formula (a11) or the following formula (a22).

[0076] [Chemistry 5]

[0077]

[0078] Where R 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5Each of the rings is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6.

[0079] The monomers that provide the repeating unit represented by the above formula (a1) (hereinafter also referred to as repeating unit a1) include the following, but are not limited thereto. A Same as above.

[0080] [Chemistry 6]

[0081]

[0082] [Chemistry 7]

[0083]

[0084] [Chemistry 8]

[0085]

[0086] [Chemistry 9]

[0087]

[0088] [Chemistry 10]

[0089]

[0090] [Chemistry 11]

[0091]

[0092] [Chemistry 12]

[0093]

[0094] [Chemistry 13]

[0095]

[0096] In the formula, the vinyl group on the aromatic ring can also be replaced by an isopropenyl group.

[0097] [Chemistry 14]

[0098]

[0099] [Chemistry 15]

[0100]

[0101] [Chemistry 16]

[0102]

[0103] [Chemistry 17]

[0104]

[0105] The monomers that provide the repeating unit represented by formula (a2) (hereinafter also referred to as repeating unit a2) include the following, but are not limited thereto. A Same as above.

[0106] [Chemistry 18]

[0107]

[0108] [Chemistry 19]

[0109]

[0110] [Chemistry 20]

[0111]

[0112] [Chemistry 21]

[0113]

[0114] [Chemistry 22]

[0115]

[0116] [Chemistry 23]

[0117]

[0118] [Chemistry 24]

[0119]

[0120] The present invention is characterized by repeating units having an acid-labile group of a phenolic hydroxyl group represented by the above-mentioned general formula (a1) or (a2), but repeating units having a known type of acid-labile group without a phenolic hydroxyl group may also be copolymerized.

[0121] Examples of such known repeating units ax include those represented by the following formulae (ax1) and (ax2) (also referred to as repeating unit ax1 and repeating unit ax2, respectively. The same shall apply hereinafter).

[0122] [Chemistry 25]

[0123]

[0124] In formulas (ax1) and (ax2), R A are independently a hydrogen atom or a methyl group. 1 Y is a single bond, a phenylene group or a naphthylene group, or a carbon number 1 to 12 linking group having an ester bond, an ether bond or a lactone ring, and may also have a halogen atom, a nitro group, a hydroxyl group, an alkoxy group, an acyloxy group or an alkoxycarbonyloxy group. 2 is a single bond, an ester bond or an amide bond. 11 and R 12 is an acid-labile group. 13 is a fluorine atom, a trifluoromethyl group, a cyano group, or an alkyl group having 1 to 6 carbon atoms. 14 It is a single bond, or a linear or branched alkanediyl group having 1 to 6 carbon atoms, and a portion of its carbon atoms may be substituted with an ether bond or an ester bond. a is 1 or 2. b is an integer of 0 to 4.

[0125] The monomers providing the repeating unit ax1 include, but are not limited to, the following. A and R 11 Same as above.

[0126] [Chemistry 26]

[0127]

[0128] [Chemistry 27]

[0129]

[0130] The monomers providing the repeating unit ax2 may be exemplified by the following, but are not limited thereto. A and R 12 Same as above.

[0131] [Chemistry 28]

[0132]

[0133] R 11 or R 12 There are various options for the acid-labile group represented by , and examples thereof include those represented by the following formulae (AL-1) to (AL-3).

[0134] [Chemistry 29]

[0135]

[0136] In the formula, the dotted lines are atomic bonds.

[0137] In formula (AL-1), c is an integer of 0 to 6. L1A tertiary hydrocarbon group having 4 to 20 carbon atoms, preferably 4 to 15 carbon atoms, a trihydrocarbylsilyl group in which each hydrocarbon group is a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group having 4 to 20 carbon atoms containing a carbonyl group, an ether bond or an ester bond, or a group represented by the formula (AL-3).

[0138] R L1 The tertiary hydrocarbon group represented by may be saturated or unsaturated, and may be branched or cyclic. Specific examples include tert-butyl, tert-amyl, 1,1-diethylpropyl, 1-ethylcyclopentyl, 1-butylcyclopentyl, 1-ethylcyclohexyl, 1-butylcyclohexyl, 1-ethyl-2-cyclopentenyl, 1-ethyl-2-cyclohexenyl, and 2-methyl-2-adamantyl. Examples of the trialkylsilyl group include trimethylsilyl, triethylsilyl, and dimethyl-tert-butylsilyl. The aforementioned saturated hydrocarbon group containing a carbonyl group, an ether bond, or an ester bond may be any of linear, branched, or cyclic, but is preferably cyclic. Specific examples thereof include 3-oxocyclohexyl, 4-methyl-2-oxooxan-4-yl, 5-methyl-2-oxooxolan-5-yl, 2-tetrahydropyranyl, and 2-tetrahydrofuranyl.

[0139] Examples of the acid-labile group represented by formula (AL-1) include tert-butoxycarbonyl, tert-butoxycarbonylmethyl, tert-amyloxycarbonyl, tert-amyloxycarbonylmethyl, 1,1-diethylpropyloxycarbonyl, 1,1-diethylpropyloxycarbonylmethyl, 1-ethylcyclopentyloxycarbonyl, 1-ethylcyclopentyloxycarbonylmethyl, 1-ethyl-2-cyclopentenyloxycarbonyl, 1-ethyl-2-cyclopentenyloxycarbonylmethyl, 1-ethoxyethoxycarbonylmethyl, 2-tetrahydropyranyloxycarbonylmethyl, and 2-tetrahydrofuranyloxycarbonylmethyl.

[0140] Examples of the acid-labile group represented by the formula (AL-1) include groups represented by the following formulae (AL-1)-1 to (AL-1)-10.

[0141] [Chemistry 30]

[0142]

[0143] In the formula, the dotted lines are atomic bonds.

[0144] In formulas (AL-1)-1 to (AL-1)-10, c is the same as described above. L8 R is independently a saturated hydrocarbon group having 1 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. L9 is a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. L10 It is a saturated hydrocarbon group having 2 to 10 carbon atoms or an aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic.

[0145] In formula (AL-2), R L2 and R L3 Each of the above groups is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. Specific examples thereof include methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, cyclopentyl, cyclohexyl, 2-ethylhexyl, and n-octyl.

[0146] In formula (AL-2), R L4 It is a hydrocarbon group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated and may be linear, branched, or cyclic. Examples of the hydrocarbon group include saturated hydrocarbon groups having 1 to 18 carbon atoms, and some of these hydrogen atoms may be substituted with hydroxyl groups, alkoxy groups, oxo groups, amino groups, alkylamino groups, etc. Examples of such substituted saturated hydrocarbon groups include those listed below.

[0147] [Chemistry 31]

[0148]

[0149] In the formula, the dotted lines are atomic bonds.

[0150] R L2 With R L3 、R L2 With R L4 , or R L3 With R L4 They can also form a ring with each other and with the carbon atoms to which they are bonded or with carbon atoms and oxygen atoms. In this case, R L2 and R L3 、R L2 and R L4 , or R L3 and R L4 Each independently represents an alkanediyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms. The carbon number of the ring formed by these groups is preferably 3 to 10, more preferably 4 to 10 carbon atoms.

[0151] Among the acid-labile groups represented by formula (AL-2), linear or branched ones include, but are not limited to, those represented by the following formulae (AL-2)-1 to (AL-2)-69.

[0152] [Chemistry 32]

[0153]

[0154] [Chemistry 33]

[0155]

[0156] [Chemistry 34]

[0157]

[0158] [Chemistry 35]

[0159]

[0160] Among the acid-labile groups represented by formula (AL-2), cyclic ones include tetrahydrofuran-2-yl, 2-methyltetrahydrofuran-2-yl, tetrahydropyran-2-yl, and 2-methyltetrahydropyran-2-yl.

[0161] Examples of the acid-labile group include groups represented by the following formula (AL-2a) or (AL-2b): The base polymer can also be cross-linked between or within molecules by the acid-labile group.

[0162] [Chemistry 36]

[0163]

[0164] In the formula, the dotted lines are atomic bonds.

[0165] In formula (AL-2a) or (AL-2b), R L11 and R L12 are independently a hydrogen atom or a saturated hydrocarbon group having 1 to 8 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. L11 With R L12 They can also bond to each other and form a ring together with the carbon atoms to which they are bonded. In this case, R L11 and R L12 Each of R is independently an alkanediyl group having 1 to 8 carbon atoms. L13 Each of d and e is independently a saturated alkylene group having 1 to 10 carbon atoms. The saturated alkylene group may be linear, branched, or cyclic. d and e are independently an integer of 0 to 10, preferably an integer of 0 to 5. f is an integer of 1 to 7, preferably an integer of 1 to 3.

[0166] In formula (AL-2a) or (AL-2b), L A It is an aliphatic saturated hydrocarbon group with a valence of (f+1) and having 1 to 50 carbon atoms, an alicyclic saturated hydrocarbon group with a valence of (f+1) and having 3 to 50 carbon atoms, an aromatic hydrocarbon group with a valence of (f+1) and having 6 to 50 carbon atoms, or a heterocyclic group with a valence of (f+1) and having 3 to 50 carbon atoms. Furthermore, some of the carbon atoms in these groups may be substituted with a group containing a heteroatom, and some of the hydrogen atoms bonded to the carbon atoms in these groups may be substituted with a hydroxyl group, a carboxyl group, an acyl group, or a fluorine atom. AIt is preferably a saturated hydrocarbon group such as a saturated hydrocarbon group having 1 to 20 carbon atoms, a trivalent saturated hydrocarbon group, a tetravalent saturated hydrocarbon group, or an arylene group having 6 to 30 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. B It is -C(=O)-O-, -NH-C(=O)-O- or -NH-C(=O)-NH-.

[0167] Examples of the cross-linked acetal group represented by formula (AL-2a) or (AL-2b) include groups represented by the following formulae (AL-2)-70 to (AL-2)-77.

[0168] [Chemistry 37]

[0169]

[0170] In the formula, the dotted lines are atomic bonds.

[0171] In formula (AL-3), R L5 、R L6 and R L7 Each independently represents a hydrocarbon group having 1 to 20 carbon atoms, and may also contain heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and fluorine atoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include: an alkyl group having 1 to 20 carbon atoms, a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, a cyclic unsaturated hydrocarbon group having 3 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, and the like. In addition, R L5 With R L6 、R L5 With R L7 , or R L6 With R L7 They may also bond to each other and to the carbon atoms to which they are bonded to form an alicyclic ring having 3 to 20 carbon atoms.

[0172] Examples of the group represented by formula (AL-3) include tert-butyl, 1,1-diethylpropyl, 1-ethylnorbornyl, 1-methylcyclopentyl, 1-isopropylcyclopentyl, 1-ethylcyclopentyl, 1-methylcyclohexyl, 2-(2-methyl)adamantyl, 2-(2-ethyl)adamantyl, and tert-amyl.

[0173] Furthermore, examples of the group represented by the formula (AL-3) include groups represented by the following formulae (AL-3)-1 to (AL-3)-19.

[0174] [Chemistry 38]

[0175]

[0176] In the formula, the dotted lines are atomic bonds.

[0177] In formula (AL-3)-1~(AL-3)-19, R L14 R is independently a hydrogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms, or an aryl group having 6 to 20 carbon atoms. L15 and R L17 R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 20 carbon atoms. L16 is an aryl group having 6 to 20 carbon atoms. The aforementioned saturated hydrocarbon group may be any of linear, branched, or cyclic. In addition, the aforementioned aryl group is preferably a phenyl group. F is a fluorine atom or a trifluoromethyl group. g is an integer of 1 to 5.

[0178] The acid-labile group further includes a group represented by the following formula (AL-3)-20 or (AL-3)-21. The acid-labile group can also crosslink the polymer intramolecularly or intermolecularly.

[0179] [Chemistry 39]

[0180]

[0181] In the formula, the dotted lines are atomic bonds.

[0182] In formula (AL-3)-20 and (AL-3)-21, R L14 Same as above. L18 It is a saturated alkylene group having 1 to 20 carbon atoms and a valence of (h+1) or an arylene group having 6 to 20 carbon atoms and a valence of (h+1), and may contain heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. The saturated alkylene group may be linear, branched, or cyclic. h is an integer of 1 to 3.

[0183] Examples of the monomer providing a repeating unit containing an acid-labile group represented by the formula (AL-3) include (meth)acrylates containing an exo-stereoisomer structure represented by the following formula (AL-3)-22.

[0184] [Chemistry 40]

[0185]

[0186] In formula (AL-3)-22, R A Same as above. Lc1 It is a saturated hydrocarbon group having 1 to 8 carbon atoms or an optionally substituted aryl group having 6 to 20 carbon atoms. The saturated hydrocarbon group may be linear, branched, or cyclic. Lc2 ~R Lc11 Each of them is independently a hydrogen atom or a hydrocarbon group having 1 to 15 carbon atoms which may contain a hetero atom. Examples of the hetero atom include oxygen atoms. Examples of the hydrocarbon group include alkyl groups having 1 to 15 carbon atoms and aryl groups having 6 to 15 carbon atoms. Lc2 With R Lc3 、RLc4 With R Lc6 、R Lc4 With R Lc7 、R Lc5 With R Lc7 、R Lc5 With R Lc11 、R Lc6 With R Lc10 、R Lc8 With R Lc9 , or R Lc9 With R Lc10 They may also be bonded to each other and to form a ring together with the carbon atoms to which they are bonded. In this case, the group involved in the bond is an alkylene group having 1 to 15 carbon atoms and may also contain heteroatoms. Lc2 With R Lc11 、R Lc8 With R Lc11 , or R Lc4 With R Lc6 The carbon atoms bonded to adjacent carbon atoms may also bond to each other without any group to form a double bond.

[0187] Here, monomers providing repeating units represented by formula (AL-3)-22 include those described in Japanese Patent Application Publication No. 2000-327633. Specific examples include, but are not limited to, the following. In the following formula, R A Same as above.

[0188] [Chemistry 41]

[0189]

[0190] Examples of the monomer providing a repeating unit containing an acid-labile group represented by formula (AL-3) include (meth)acrylates containing a furandiyl group, a tetrahydrofurandiyl group, or an oxanorbornanediyl group represented by the following formula (AL-3)-23.

[0191] [Chemistry 42]

[0192]

[0193] In formula (AL-3)-23, R A Same as above. Lc12 and R Lc13 are each independently a hydrocarbon group having 1 to 10 carbon atoms. Lc12 With R Lc13 They can also bond to each other and to the carbon atoms to which they are bonded to form aliphatic rings. Lc14 R is furandiyl, tetrahydrofurandiyl or oxanorbornanediyl. Lc15is a hydrocarbon group having 1 to 10 carbon atoms and optionally containing a heteroatom. The hydrocarbon group may be linear, branched, or cyclic. Specific examples thereof include saturated hydrocarbon groups having 1 to 10 carbon atoms.

[0194] The monomers that provide the repeating unit represented by formula (AL-3)-23 include, but are not limited to, the following. A Same as above, Ac is acetyl and Me is methyl.

[0195] [Chemistry 43]

[0196]

[0197] [Chemistry 44]

[0198]

[0199] The base polymer preferably further contains at least one repeating unit b having an acid-generating moiety selected from the repeating units represented by the following formulae (b1) to (b5).

[0200] [Chemistry 45]

[0201]

[0202] Where R A R are independently a hydrogen atom or a methyl group. B are independently a hydrogen atom, or Z 6 Bond and form a ring. Z 1 is a single bond, an aliphatic alkylene 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 groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene 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 groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond or an ester bond. 3 is a single bond, -Z 31 -C(=O)-O- or -Z 31 -O-.Z 31 It is a C1-12 alkylene group, a phenylene group, or a C7-18 group obtained by combining these groups, and may contain a carbonyl group, a nitro group, a cyano group, an ester bond, an ether bond, a urethane bond, a fluorine atom, an iodine atom, or a bromine atom. 4 is a single bond, methylene or ethylene. 5is a single bond, methylene, ethylene, phenylene, methylphenylene, dimethylphenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a methylphenylene group, a dimethylphenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a hydroxyl group, or a halogen atom. 6 is a single bond, a phenylene ring, a naphthalene ring, an ester bond or an amide bond. 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 7B It is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 8 Z is a single bond, an ether bond, an ester bond, a thioether bond, or an alkanediyl group having 1 to 6 carbon atoms. 9 It is a trivalent organic group having 1 to 12 carbon atoms and may have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom. 1 ~Rf 4 are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 1 and Rf 2 They can also combine and form a carbonyl group together with the carbon atom to which they are bonded. 21 and R 22 Each of R is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 23 is a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group. Ring R is a (d+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. d is an integer from 0 to 5. - It is a non-nucleophilic relative ion. + It is a sulfonium cation or an iodonium cation.

[0203] The monomers providing the repeating unit b1 include, but are not limited to, the following. A Same as above.

[0204] [Chemistry 46]

[0205]

[0206] In formula (b1), X -It is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions such as chloride ion and bromide ion; fluoroalkylsulfonate ions such as trifluoromethanesulfonate ion, 1,1,1-trifluoroethanesulfonate ion, and nonafluorobutanesulfonate ion; arylsulfonate ions such as toluenesulfonate ion, benzenesulfonate ion, 4-fluorobenzenesulfonate ion, and 1,2,3,4,5-pentafluorobenzenesulfonate ion; alkylsulfonate ions such as methanesulfonate ion and butanesulfonate ion; imide acid ions such as bis(trifluoromethylsulfonyl)imide ion, bis(perfluoroethylsulfonyl)imide ion, and bis(perfluorobutylsulfonyl)imide ion; and methylate ions such as tris(trifluoromethylsulfonyl)methylate ion and tris(perfluoroethylsulfonyl)methylate ion.

[0207] Examples of the non-nucleophilic counter ion include a sulfonate ion represented by the following formula (b1-1) in which the α position is substituted with a fluorine atom, and a sulfonate ion represented by the following formula (b1-2) in which the α position is substituted with a fluorine atom and the β position is substituted with a trifluoromethyl group.

[0208] [Chemistry 47]

[0209] R 31 -CF2-SO3 - (b1-1)

[0210]

[0211] In formula (b1-1), R 31 The alkyl and alkenyl groups are hydrogen atoms, alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, or aryl groups having 6 to 20 carbon atoms, and may contain ether bonds, ester bonds, carbonyl groups, lactone rings, or fluorine atoms. The alkyl and alkenyl groups may be linear, branched, or cyclic.

[0212] In formula (b1-2), R 32 The alkyl group is a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, an acyl group having 2 to 30 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, or an aryloxy group having 6 to 20 carbon atoms, and may contain an ether bond, an ester bond, a carbonyl group, or a lactone ring. The alkyl group, acyl group, and alkenyl group may be linear, branched, or cyclic.

[0213] As the non-nucleophilic counter ion, an anion containing bromine or iodine represented by the following formula (b1-3) may be used.

[0214] [Chemistry 48]

[0215]

[0216] Specific examples of the anion represented by (b1-3) are as follows.

[0217] [Chemistry 49]

[0218]

[0219] [Chemistry 50]

[0220]

[0221] [Chemistry 51]

[0222]

[0223] [Chemistry 52]

[0224]

[0225] [Chemistry 53]

[0226]

[0227] [Chemistry 54]

[0228]

[0229] [Chemistry 55]

[0230]

[0231] [Chemistry 56]

[0232]

[0233] [Chemistry 57]

[0234]

[0235] [Chemistry 58]

[0236]

[0237] [Chemistry 59]

[0238]

[0239] [Chemistry 60]

[0240]

[0241] [Chemistry 61]

[0242]

[0243] [Chemistry 62]

[0244]

[0245] [Chemistry 63]

[0246]

[0247] [Chemistry 64]

[0248]

[0249] [Chemistry 65]

[0250]

[0251] [Chemistry 66]

[0252]

[0253] [Chemistry 67]

[0254]

[0255] [Chemistry 68]

[0256]

[0257] [Chemistry 69]

[0258]

[0259] [Chemistry 70]

[0260]

[0261] [Chemistry 71]

[0262]

[0263] Above, X BI is a bromine atom or an iodine atom.

[0264] The anion of the monomer providing the repeating unit b2 may be exemplified by the following, but is not limited thereto. A Same as above.

[0265] [Chemistry 72]

[0266]

[0267] [Chemistry 73]

[0268]

[0269] [Chemistry 74]

[0270]

[0271] [Chemistry 75]

[0272]

[0273] [Chemistry 76]

[0274]

[0275] [Chemistry 77]

[0276]

[0277] [Chemistry 78]

[0278]

[0279] [Chemistry 79]

[0280]

[0281] [Chemistry 80]

[0282]

[0283] [Chemistry 81]

[0284]

[0285] [Chemistry 82]

[0286]

[0287] [Chemistry 83]

[0288]

[0289] The anions of the monomers providing the repeating unit b3 may be exemplified by the following, but are not limited thereto. A Same as above.

[0290] [Chemistry 84]

[0291]

[0292] [Chemistry 85]

[0293]

[0294] Specific examples of anions of repeating units b4 and b5 include those shown below, but are not limited thereto. BI is an iodine atom or a bromine atom.

[0295] [Chemistry 86]

[0296]

[0297] [Chemistry 87]

[0298]

[0299] [Chemistry 88]

[0300]

[0301] [Chemistry 89]

[0302]

[0303] [Chemistry 90]

[0304]

[0305] [Chemistry 91]

[0306]

[0307] [Chemistry 92]

[0308]

[0309] [Chemistry 93]

[0310]

[0311] [Chemistry 94]

[0312]

[0313] [Chemistry 95]

[0314]

[0315] [Chemistry 96]

[0316]

[0317] [Chemistry 97]

[0318]

[0319] [Chemistry 98]

[0320]

[0321] [Chemistry 99]

[0322]

[0323] [Chemistry 100]

[0324]

[0325] [Chemistry 101]

[0326]

[0327] [Chemistry 102]

[0328]

[0329] [Chemistry 103]

[0330]

[0331] [Chemistry 104]

[0332]

[0333] [Chemistry 105]

[0334]

[0335] [Chemistry 106]

[0336]

[0337] [Chemistry 107]

[0338]

[0339] [Chemistry 108]

[0340]

[0341] [Chemistry 109]

[0342]

[0343] [Chemistry 110]

[0344]

[0345] [Chemistry 111]

[0346]

[0347] [Chemistry 112]

[0348]

[0349] [Chemistry 113]

[0350]

[0351] [Chemistry 114]

[0352]

[0353] [Chemistry 115]

[0354]

[0355] [Chemistry 116]

[0356]

[0357] [Chemistry 117]

[0358]

[0359] [Chemistry 118]

[0360]

[0361] [Chemistry 119]

[0362]

[0363] [Chemistry 120]

[0364]

[0365] [Chemistry 121]

[0366]

[0367] [Chemistry 122]

[0368]

[0369] [Chemistry 123]

[0370]

[0371] [Chemistry 124]

[0372]

[0373] [Chemistry 125]

[0374]

[0375] [Chemistry 126]

[0376]

[0377] [Chemistry 127]

[0378]

[0379] [Chemistry 128]

[0380]

[0381] [Chemistry 129]

[0382]

[0383] [Chemistry 130]

[0384]

[0385] [Chemistry 131]

[0386]

[0387] [Chemistry 132]

[0388]

[0389] [Chemistry 133]

[0390]

[0391] [Chemistry 134]

[0392]

[0393] In the above-mentioned base polymer, as for the repeating unit b having an acid-generating portion, Z in the above-mentioned formulae (b2) to (b5) is preferably used. 3 、Z 7A 、Z 7B or M + A repeating unit containing one or more iodine atoms. By using such a repeating unit containing an iodine atom, a more ideal pattern can be formed.

[0394] The aforementioned base polymer may further contain a repeating unit c having an adhesive group 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 sulfonate bond, a cyano group, an amide group, -OC(=O)-S- and -OC(=O)-NH-.

[0395] The monomers providing the repeating unit c include, but are not limited to, the following. A Same as above.

[0396] [Chemistry 135]

[0397]

[0398] [Chemistry 136]

[0399]

[0400] [Chemistry 137]

[0401]

[0402] [Chemistry 138]

[0403]

[0404] [Chemical formula 139]

[0405]

[0406] [Chemical formula 140]

[0407]

[0408] [Chemical formula 141]

[0409]

[0410] [Chemical formula 142]

[0411]

[0412] The aforementioned base polymer may further contain a repeating unit d that does not contain an amino group but contains an iodine atom. The monomers that provide the repeating unit d are as follows, but are not limited thereto. In addition, in the following formula, R A is the same as the aforementioned one.

[0413] [Chemical formula 143]

[0414]

[0415] [Chemical formula 144] <​​​​​​​​​​​​Examples of organic solvents used during polymerization include toluene, benzene, tetrahydrofuran (THF), diethyl ether, dioxane, propylene glycol monomethyl ether, γ-butyrolactone, and mixtures thereof. Examples of polymerization initiators include 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2-azobis(2-methylpropionic acid)dimethyl ester, benzoyl peroxide, and lauroyl peroxide. The polymerization temperature is preferably 50-80°C. The reaction time is preferably 2-100 hours, more preferably 5-20 hours.

[0421] When copolymerizing hydroxyl-containing monomers, the hydroxyl groups can be replaced with acetal groups that are easily deprotected by acid, such as ethoxyethoxy, before polymerization, and then deprotected using a weak acid and water after polymerization. Alternatively, the hydroxyl groups can be replaced with acetyl groups, formyl groups, pivaloyl groups, etc. before polymerization, and then subjected to alkaline hydrolysis after polymerization.

[0422] When copolymerizing hydroxystyrene and hydroxyvinylnaphthalene, acetoxystyrene and acetoxyvinylnaphthalene may be used instead of hydroxystyrene and hydroxyvinylnaphthalene. After polymerization, the acetoxy group may be deprotected by alkaline hydrolysis to convert the hydroxystyrene and hydroxyvinylnaphthalene into hydroxystyrene and hydroxyvinylnaphthalene.

[0423] The base used in the alkaline hydrolysis may be ammonia water, triethylamine, etc. The reaction temperature is preferably -20 to 100°C, more preferably 0 to 60°C. The reaction time is preferably 0.2 to 100 hours, more preferably 0.5 to 20 hours.

[0424] The polystyrene-equivalent weight average molecular weight (Mw) of the base polymer, as determined by gel permeation chromatography (GPC) using THF as a solvent, is preferably 1,000 to 500,000, more preferably 2,000 to 30,000. An Mw of 1,000 or greater results in excellent heat resistance for the resist material, while an Mw of 500,000 or less provides sufficient alkali solubility and reduces the risk of tailing after pattern formation. The number average molecular weight (Mn) can also be determined using GPC.

[0425] 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 lead to the presence of foreign matter on the pattern after exposure, or to the degradation of the pattern shape. As pattern rules become finer, the influence of Mw and Mw / Mn increases. Therefore, in order to obtain a resist material ideally suited for fine pattern sizes, the base polymer preferably has an Mw / Mn of 1.0 to 2.0, with a narrow distribution of 1.0 to 1.5 being particularly preferred.

[0426] To obtain a narrowly dispersed polymer, not only conventional radical polymerization but also living radical polymerization can be used. Examples of living radical polymerization include nitroxide-mediated radical polymerization (NMP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT).

[0427] The base polymer may contain two or more polymers having different composition ratios, Mw, and Mw / Mn. In addition, a polymer containing repeating unit a and a polymer not containing repeating unit a may be blended.

[0428] [Acid generator]

[0429] In the present invention, the acid generator may be incorporated into the resist material in place of the polymer incorporating the acid generating moiety as described above (polymer-bonded acid generator), or a combination of these. The acid generation pattern can be adjusted by using an acid generator added separately from the base polymer (externally added acid generator), a polymer incorporating the acid generating moiety that also functions as an acid generator (internally added acid generator), or a combination thereof.

[0430] By containing such an acid generator, an externally added acid generator, an internally added acid generator, or a combination thereof, the acid generating function in the resist material can be adjusted to an ideal one.

[0431] The acid generator added externally is not particularly limited. If it is a substance that generates acid due to external stimuli such as heat and light, for example, a compound (photoacid generator) that senses active light or radiation and generates acid can be listed. If the component of the photoacid generator is a compound that generates acid due to high-energy ray irradiation, it is arbitrarily fine, but it is preferably an acid generator that generates sulfonic acid, imidic acid or methylated acid. Specific examples of ideal photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc. Specific examples of the aforementioned acid generators can be listed as follows: paragraphs

[0122] to

[0142] of Japanese Patent Application Publication No. 2008-111103, Japanese Patent Application Publication No. 2018-5224, and Japanese Patent Application Publication No. 2018-25789. When the resist material of the present invention contains such an externally added acid generator, the content thereof is preferably 0 to 200 parts by mass, more preferably 0.1 to 100 parts by mass, based on 100 parts by mass of the base polymer.

[0432] [Organic solvents]

[0433] The resist material of the present invention may also contain an organic solvent. The aforementioned organic solvent is not particularly limited as long as it can dissolve the aforementioned components and the components described below. Specific examples of the aforementioned organic solvent include: ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone described in paragraphs

[0144] to

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

[0434] In the resist material of the present invention, the content of the organic solvent is preferably 100 to 10,000 parts by mass, more preferably 200 to 8,000 parts by mass, relative to 100 parts by mass of the base polymer.

[0435] [Quencher]

[0436] The resist material of the present invention may also contain a quencher. The quencher is a compound that traps the acid generated from the acid generator in the resist material and prevents it from diffusing to the unexposed area.

[0437] The quencher can be a known basic compound. Specific examples of known basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Laid-Open No. 2008-111103 are preferred. Amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond, and compounds having a carbamate bond as described in Japanese Patent No. 3790649 are particularly preferred. By adding such a basic compound, for example, the diffusion rate of acid in the resist film can be further suppressed or the shape can be corrected.

[0438] Examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of sulfonic acids, carboxylic acids, or fluorinated alkoxides not fluorinated at the α-position as described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methylated acids fluorinated at the α-position are necessary for deprotecting the acid-labile group of the carboxylate. Salt exchange with the onium salt releases the sulfonic acid, carboxylic acid, or fluorinated alcohol not fluorinated at the α-position. Sulfonic acids, carboxylic acids, and fluorinated alcohols not fluorinated at the α-position do not cause a deprotection reaction and therefore function as quenchers.

[0439] Specific examples of such quenchers include compounds represented by the following formula (4) (onium salt of sulfonic acid whose α-position is not fluorinated), compounds represented by the following formula (5) (onium salt of carboxylic acid), and compounds represented by the following formula (6) (onium salt of alkoxide).

[0440] [Chemistry 145]

[0441]

[0442] In formula (4), R 101 It is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom, but excludes those where the hydrogen atom bonded to the carbon atom at the α-position of the sulfonic group is substituted with a fluorine atom or a fluoroalkyl group.

[0443] R 101 The hydrocarbon group having 1 to 40 carbon atoms represented by may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); aralkyl groups having 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc.

[0444] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, and as a result, the group may contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like. Specific examples of the hydrocarbon group containing a heteroatom include: heteroaryl groups such as thienyl; 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; aryl pendant oxyalkyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl.

[0445] In formula (5), R 102 It is a hydrocarbon group having 1 to 40 carbon atoms which may contain a hetero atom. 102 Specific examples of the hydrocarbon group represented by can be listed and exemplified as R 101 Other specific examples include fluorinated alkyl groups such as trifluoromethyl, trifluoroethyl, 2,2,2-trifluoro-1-methyl-1-hydroxyethyl, and 2,2,2-trifluoro-1-(trifluoromethyl)-1-hydroxyethyl; and fluorinated aryl groups such as pentafluorophenyl and 4-trifluoromethylphenyl.

[0446] In formula (6), R 103 It is a saturated hydrocarbon group having 1 to 8 carbon atoms and having at least 3 fluorine atoms, or an aryl group having 6 to 10 carbon atoms and having at least 3 fluorine atoms, and may also contain a nitro group.

[0447] In formulas (4), (5) and (6), Mq + The onium cation is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and is more preferably a sulfonium cation. Specific examples of the sulfonium cation include those in the description of formulas (b2) to (b5), as exemplified by M + The same example is shown for the sulfonium cation.

[0448] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (7) can also be preferably used.

[0449] [Chemistry 146]

[0450]

[0451] In formula (7), x is an integer of 1 to 5, y is an integer of 0 to 3, and z is an integer of 1 to 3.

[0452] In formula (7), R 111 is a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, or a saturated hydrocarbon group having 1 to 6 carbon atoms in which a part or all of the hydrogen atoms are substituted with halogen atoms, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon group carbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbon group sulfonyloxy group having 1 to 4 carbon atoms, or -N(R 111A )-C(=O)-R 111B or -N(R 111A )-C(=O)-OR 111B . R 111A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 111B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. 111 They can be the same or different.

[0453] In formula (7), L 1 The alkyl group is a single bond or a (z+1)-valent linking group having 1 to 20 carbon atoms, and may contain at least one selected from the group consisting of an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic.

[0454] In formula (7), R 112 、R 113 and R 114 Each independently represents a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include those exemplified as R in the description of formulas (2) and (3). 4 ~R 8 The same examples apply to the hydrocarbon groups represented by .

[0455] Specific examples of the compound represented by formula (7) include those described in JP-A-2017-219836 and JP-A-2021-91666.

[0456] Other examples of the aforementioned quencher include the polymer quenchers described in Japanese Patent Application Laid-Open No. 2008-239918. These quenchers improve the rectangularity of the resist pattern by aligning on the resist film surface. Polymer quenchers also prevent film loss and doming of the pattern when using a protective film for immersion exposure.

[0457] In addition, betaine-type sulfonium salts described in Japanese Patent No. 6848776 and Japanese Patent Application Laid-Open No. 2020-37544, methylated acids not containing fluorine atoms described in Japanese Patent Application Laid-Open No. 2020-55797, sulfonium salts of sulfonamides described in Japanese Patent No. 5807552, sulfonium salts of sulfonamides containing iodine atoms described in Japanese Patent Application Laid-Open No. 2019-211751, and acid generators that generate phenols, halogens, or carbonic acid can also be used as quenchers.

[0458] When the resist material of the present invention contains the quencher, its content is preferably 0 to 5 parts by mass, more preferably 0 to 4 parts by mass, relative to 100 parts by mass of the base polymer. The quencher may be used alone or in combination of two or more.

[0459] [Other ingredients]

[0460] In addition to the aforementioned components, a surfactant, a dissolution inhibitor, a cross-linking agent, a water repellency improver, acetylene alcohols, and the like may be contained.

[0461] Specific examples of the surfactant include those described in paragraphs

[0165] and

[0166] of Japanese Patent Application Laid-Open No. 2008-111103. The addition of a surfactant can further improve or control the coating properties of the resist material. When the resist material of the present invention contains a surfactant, its content is preferably 0.0001 to 10 parts by mass relative to 100 parts by mass of the base polymer. The surfactant may be used alone or in combination of two or more.

[0462] When the resist material of the present invention is a positive type, by adding a dissolution inhibitor, the difference in dissolution rate between the exposed and unexposed areas can be further increased, and resolution can be further improved. Specific examples of the dissolution inhibitor include compounds having a molecular weight preferably of 100 to 1000, more preferably 150 to 800, wherein the hydrogen atoms of the phenolic hydroxyl groups in a compound containing two or more phenolic hydroxyl groups in the molecule are replaced by acid-labile groups at a ratio of 0 to 100 mol % overall, or compounds containing carboxyl groups in a compound containing carboxyl groups in the molecule are replaced by acid-labile groups at an average ratio of 50 to 100 mol % overall. Specific examples include compounds in which the hydrogen atoms of the hydroxyl and carboxyl groups of bisphenol A, trisphenol, phenolphthalein, cresol novolac resins, naphthalenecarboxylic acid, adamantanecarboxylic acid, and cholic acid are replaced by acid-labile groups, such as those described in paragraphs

[0155] to

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

[0463] When the resist material of the present invention is positive and contains the dissolution inhibitor, its content is preferably 0 to 50 parts by mass, more preferably 5 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The dissolution inhibitor may be used alone or in combination of two or more.

[0464] On the other hand, when the resist material of the present invention is negative-type, a negative-type pattern can be obtained by adding a crosslinking agent to reduce the dissolution rate of the exposed portion. Specific examples of the crosslinking agent include epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl groups, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups. These can be used as additives or incorporated into polymer side chains as pendant groups. Hydroxyl-containing compounds can also be used as crosslinking agents.

[0465] Specific examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0466] Specific examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are methoxymethylated, or mixtures thereof, hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which 1 to 6 hydroxymethyl groups in hexamethylolmelamine are acyloxymethylated, or mixtures thereof.

[0467] Specific examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, compounds in which 1 to 4 hydroxymethyl groups in tetramethylolguanamine are methoxymethylated, or mixtures thereof, tetramethoxyethylguanamine, tetraacyloxyguanamine, compounds in which 1 to 4 hydroxymethyl groups in tetramethylolguanamine are acyloxymethylated, or mixtures thereof.

[0468] Specific examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are methoxymethylated, or mixtures thereof, compounds in which 1 to 4 hydroxymethyl groups in tetramethylol glycoluril are acyloxymethylated, or mixtures thereof. Specific examples of the urea compound include tetramethylolurea, tetramethoxymethylurea, compounds in which 1 to 4 hydroxymethyl groups in tetramethylolurea are methoxymethylated, or mixtures thereof, and tetramethoxyethylurea.

[0469] Specific examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0470] Specific examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0471] Specific examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0472] When the resist material of the present invention is negative-type and contains the crosslinking agent, its content is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts by mass, relative to 100 parts by mass of the base polymer. The crosslinking agent may be used alone or in combination of two or more.

[0473] The aforementioned water repellency improver is a material that improves the water repellency of the surface of the resist film and can be used in immersion photolithography without using a topcoat. The aforementioned water repellency improver is preferably a polymer containing a fluorinated alkyl group, a polymer containing a 1,1,1,3,3,3-hexafluoro-2-propanol residue of a specific structure, and the like, and is preferably exemplified by Japanese Patent Application Publication No. 2007-297590 and Japanese Patent Application Publication No. 2008-111103. The aforementioned water repellency improver must be soluble in an alkaline developer or an organic solvent developer. The aforementioned specific water repellency improver having a 1,1,1,3,3,3-hexafluoro-2-propanol residue has good solubility in a developer. As for the water repellency improver, a polymer containing repeating units containing an amino group or an amine salt has a high effect of preventing the evaporation of acid during PEB and preventing poor opening of the hole pattern after development. When the resist material of the present invention contains the water repellency improver, its content is preferably 0 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, relative to 100 parts by mass of the base polymer. The water repellency improver may be used alone or in combination of two or more.

[0474] Specific examples of the acetylene alcohols include those described in paragraphs

[0179] to

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

[0475] When the resist material of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be used as needed.

[0476] For example, the resist material of the present invention is applied to a substrate (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective film, etc.) for integrated circuit manufacturing or a substrate (Cr, CrO, CrON, MoSi2, SiO2, etc.) for mask circuit manufacturing by a suitable coating method such as spin coating, roller coating, flow coating, dip coating, spray coating, or blade coating to a coating thickness of 0.01 to 2 μm. The resist material is then pre-baked on a hot plate at a temperature of preferably 60 to 150° C. for 10 seconds to 30 minutes, and more preferably 80 to 120° C. for 30 seconds to 20 minutes to form a resist film.

[0477] When ultraviolet rays, extreme ultraviolet rays, EUV rays, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc. are used as the high-energy rays, the exposure dose is preferably about 1 to 200 mJ / cm2, either directly or through a mask for forming a desired pattern. 2 More preferably, it is about 10 to 100 mJ / cm 2 When using EB as high energy ray, the exposure dose should be about 0.1 to 300 μC / cm 2 More preferably, it is about 0.5 to 200 μC / cm 2 Drawing is performed directly or using a mask for forming the desired pattern. As described above, the resist material of the present invention is particularly suitable for fine patterning using high-energy radiation such as KrF excimer lasers, ArF excimer lasers, EB, EUV, X-rays, soft X-rays, gamma rays, and synchrotron radiation, and is particularly suitable for fine patterning using EB or EUV.

[0478] Specifically, there can be mentioned a pattern forming method in which exposure is performed using extreme ultraviolet rays having a wavelength of 3 to 15 nm, and a pattern forming method in which exposure is performed using an electron beam having an accelerating voltage of 1 to 150 kV.

[0479] After exposure, PEB can be performed on a hot plate or in an oven, preferably at 30-150°C for 10 seconds to 30 minutes, and more preferably at 50-120°C for 30 seconds to 20 minutes. The deprotection reaction during PEB deprotects the acid-labile groups of the phenolic groups, and the deprotected components evaporate from the film, generating a polymer containing carboxyl groups in the resist film.

[0480] As described above, dry etching is performed after PEB to remove the exposed areas and open the gaps. Dry etching is preferably performed using a gas containing oxygen, hydrogen, ammonia, or the like, and containing nitrogen, helium, argon, carbon dioxide, or carbon monoxide for dilution. Fluorocarbon, chlorine, bromine, or iodine-based gases may also be mixed.

[0481] As for the details of the dry etching conditions, the conditions described in Patent Document 3 mentioned above can be used.

[0482] After development, the hole and groove patterns can also be shrunk using heat flow, RELACS, or DSA techniques. A shrinking agent is applied to the hole pattern. During baking, the diffusion of the acid catalyst from the resist film causes cross-linking of the shrinking agent on the surface of the resist film, causing the shrinking agent to adhere to the sidewalls of the hole pattern. The baking temperature is preferably 70-180°C, preferably 80-170°C, and the baking time is preferably 10-300 seconds. This removes excess shrinking agent and shrinks the hole pattern.

[0483] The pattern forming method of the present invention is characterized by forming a pattern by using a base polymer having one or both of the repeating units represented by the general formulae (a1) and (a2) in combination with development by dry etching.

[0484] The present invention forms a resist film using a resist material containing the above-mentioned base polymer in which the carboxyl groups bonded to the polymer main chain are protected by acid-labile groups. The resist film is exposed and heated, and then developed by dry etching to form a pattern.

[0485] The present invention utilizes a resist material based on a polymer having repeating units in which carboxyl groups are protected by acid-labile groups containing phenolic groups. This results in phenolic groups in the unexposed portions, while deprotection generates carboxyl groups in the exposed portions. When dry etching is performed on these portions, free radicals generated within the etching chamber are absorbed by the phenolic groups, slowing the etching rate of the unexposed portions. However, the exposed portions etch faster due to decarboxylation and backbone decomposition. This increases the selectivity of the etching rates between the exposed and unexposed portions, allowing for the formation of high-aspect-ratio, fine patterns without relying on film shrinkage in the exposed portions.

[0486] Development by dry etching does not cause pattern collapse due to stress generated during spin drying in solution development, so it can form patterns with higher aspect ratios and higher resolution.

[0487] [Example]

[0488] Hereinafter, the present invention will be described in detail with reference to Synthesis Examples, Preparation Examples, Examples, and Comparative Examples. However, the present invention is not limited to the following Examples.

[0489] [Synthesis Example] Synthesis of base resin

[0490] The monomers were combined and copolymerized in THF, crystallized in methanol, and then washed repeatedly with hexane, separated, and dried to synthesize the base resins (polymers 1 to 12, comparative polymers 1 and 2) with the following compositions.1 The structure was confirmed by H-NMR, and the Mw and Mw / Mn were confirmed by GPC (solvent: THF, standard: polystyrene).

[0491] [Chemistry 147]

[0492]

[0493] [Chemistry 148]

[0494]

[0495] [Chemistry 149]

[0496]

[0497] [Chemistry 150]

[0498]

[0499] [Chemistry 151]

[0500]

[0501] [Preparation Examples 1 to 12, Comparative Preparation Examples 1 and 2] Preparation of Resist Materials

[0502] A solution prepared by dissolving the components shown in Table 1 in a solvent containing 50 ppm of OMNOVA surfactant Polyfox 636 was filtered through a 0.2 μm filter to prepare a positive resist material.

[0503] In Table 1, the components are as follows.

[0504] Acid generator: PAG-1, PAG-2

[0505] [Chemistry 152]

[0506]

[0507] Quencher: Quencher 1

[0508] [Chemistry 153]

[0509]

[0510] Organic solvent: PGMEA (propylene glycol monomethyl ether acetate)

[0511] DAA (Diacetone Alcohol)

[0512] [Table 1]

[0513]

[0514] [Examples 1-1 to 1-12, Comparative Examples 1-1 and 1-2] KrF Exposure and Dry Etching Evaluation

[0515] Each resist material (R-1 to R-7, CR-1, and CR-2) was spin-coated onto a Si substrate coated with a 60 nm thick antireflection film DUV-42 manufactured by Nissan Chemical Industries, Ltd., and prebaked for 60 seconds at 105°C on a hot plate to form a 140 nm thick resist film. This resist film was then exposed to a 90 nm line and space pattern using an ASML KrF excimer scanning exposure system (XT860N, NA 0.8, dipole illumination, and a 6% halftone phase shift mask). PEB was then performed on the hot plate for 60 seconds at the temperatures listed in Table 2.

[0516] The wafer after PEB was etched using a dry etching apparatus TELIUS manufactured by Tokyo Electron Co., Ltd. under the following conditions.

[0517]

[0518] The resist film and the antireflection film in the exposed portion are removed by dry etching, and dry etching is performed until the Si substrate surface is exposed.

[0519] Using a CG-6300 length measurement SEM manufactured by Hitachi Advanced Technologies Co., Ltd., the exposure dose for forming a 90nm line and space pattern with a 1:1 ratio was set as the sensitivity of the resist. The wafer was then cut and the cross-section of the 90nm line and space pattern was observed using an S-4100 electron microscope manufactured by Hitachi Advanced Technologies Co., Ltd.

[0520] The results are summarized in Table 2.

[0521] [Table 2]

[0522]

[0523]

[0524] [Examples 2-1 to 2-12, Comparative Examples 2-1 and 2-2] KrF Exposure and Film Thickness Evaluation

[0525] Each resist material (R-1 to R-7, CR-1, and CR-2) was spin-coated onto a Si substrate having a 60 nm thick antireflection film DUV-42 manufactured by Nissan Chemical Industries, Ltd., and prebaked at 105°C for 60 seconds using a hot plate to form a 140 nm thick resist film. This resist film was subjected to open frame exposure using an ASML KrF excimer scanning exposure system (XT860N, NA0.8 normal illumination). PEB was then performed on the hot plate for 60 seconds at the temperature listed in Table 3. The exposure dose was measured using an optical film thickness meter and was 0 mJ / cm 2 and 100mJ / cm 2 The film thickness of the exposure dose is 100mJ / cm 2 The film thickness of the exposure dose is divided by the exposure dose 0mJ / cm 2 Calculate the percentage of film shrinkage based on the film thickness.

[0526] The results are summarized in Table 3.

[0527] [Table 3]

[0528]

[0529]

[0530] The results shown in Tables 2 and 3 demonstrate that using a resist material based on a polymer copolymerized with an acid-labile group having a phenolic hydroxyl group enables pattern formation using dry etching development according to the present invention. In the case of the resist material CR-1 (Comparative Example 1-1), based on a polymer copolymerized with an acid-labile group not having a phenolic hydroxyl group, although film shrinkage was minimal (Comparative Example 2-1), the film disappeared not only in the exposed areas but also in the unexposed areas. In the case of the resist of Comparative Example 1-2, film shrinkage was significant in the exposed gaps after PEB (Comparative Example 2-2). Although the gaps remained open after dry etching, the significant film shrinkage during PEB caused pattern deformation, resulting in a triangular cross-section. Development using dry etching avoids pattern collapse caused by stress generated during spin drying during solution development, enabling the formation of patterns with higher aspect ratios and higher resolution.

[0531] This manual contains the following aspects.

[0532] [1]: A pattern forming method comprising the following steps: preparing a resist material containing a polymer in which a carboxyl group bonded to a polymer main chain is protected by an acid-labile group, forming a resist film using the resist material, exposing the resist film to light, heating it, and then developing it by dry etching to form a pattern; wherein the method is characterized by:

[0533] As the polymer, a polymer having either or both of repeating units represented by the following general formulae (a1) and (a2) is used.

[0534] [Chemistry 154]

[0535]

[0536] Where R A R are independently a hydrogen atom or a methyl group. 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6. X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

[0537] [2]: The pattern forming method according to [1], wherein the resist material further contains an acid generator.

[0538] [3]: The pattern forming method according to [1] or [2], which uses a resist material containing a polymer having the aforementioned repeating unit and a repeating unit b having an acid-generating portion.

[0539] [4]: The pattern forming method according to [3], wherein the repeating unit b having an acid-generating portion is a repeating unit selected from the repeating units represented by the following formulae (b1) to (b5).

[0540] [Chemistry 155]

[0541]

[0542] Where R A R are independently a hydrogen atom or a methyl group.B are independently a hydrogen atom, or Z 6 Bond and form a ring. Z 1 is a single bond, an aliphatic alkylene 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 groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -.Z 11 It is an aliphatic alkylene 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 groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond or an ester bond. 3 is a single bond, -Z 31 -C(=O)-O- or -Z 31 -O-.Z 31 It is a C1-12 alkylene group, a phenylene group, or a C7-18 group obtained by combining these groups, and may contain a carbonyl group, a nitro group, a cyano group, an ester bond, an ether bond, a urethane bond, a fluorine atom, an iodine atom, or a bromine atom. 4 is a single bond, methylene or ethylene. 5 is a single bond, methylene, ethylene, phenylene, methylphenylene, dimethylphenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -.Z 51 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a methylphenylene group, a dimethylphenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, a hydroxyl group, or a halogen atom. 6 is a single bond, a phenylene ring, a naphthalene ring, an ester bond or an amide bond. 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 7B It is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom. 8 Z is a single bond, an ether bond, an ester bond, a thioether bond, or an alkanediyl group having 1 to 6 carbon atoms. 9 It is a trivalent organic group having 1 to 12 carbon atoms and may have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom. 1 ~Rf 4 are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one of them is a fluorine atom or a trifluoromethyl group. 1 and Rf 2They can also combine and form a carbonyl group together with the carbon atom to which they are bonded. 21 and R 22 Each of R is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 23 is a saturated hydrocarbon group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring R is a (d+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms. d is an integer from 0 to 5. - It is a non-nucleophilic relative ion. + It is a sulfonium cation or an iodonium cation.

[0543] [5]: The pattern forming method according to [4], wherein, as for the repeating unit b having an acid generating portion, Z in the above formula is used 3 、Z 7A 、Z 7B or M + A repeating unit containing one or more iodine atoms.

[0544] [6]: The pattern forming method according to any one of [1] to [5], wherein the exposure is performed using extreme ultraviolet light having a wavelength of 3 to 15 nm.

[0545] [7]: The pattern forming method according to any one of [1] to [5], wherein the exposure is performed using an electron beam having an accelerating voltage of 1 to 150 kV.

[0546] [8]: A resist material used for pattern formation by dry etching, characterized in that it contains a polymer having either or both of the repeating units represented by the following general formulae (a1) and (a2).

[0547] [Chemistry 156]

[0548]

[0549] Where R A R are independently a hydrogen atom or a methyl group. 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 They can also bond and form a ring. 4 A hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms which may have a double bond or a triple bond. 3 and R 5Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxycarbonyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group. Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms. m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6. X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

[0550] The present invention is not limited to the above-described embodiments, which are merely examples, and any other embodiments having substantially the same configuration and exhibiting the same functions and effects as those described in the claims of the present invention are intended to be within the technical scope of the present invention.

Claims

1. A pattern forming method comprising the steps of: preparing a resist material containing a polymer in which a carboxyl group bonded to a polymer backbone is protected by an acid-labile group; forming a resist film using the resist material; exposing the resist film to light, heating it, and then developing it by dry etching to form a pattern; wherein: As the polymer, a polymer having one or both of the repeating units represented by the following general formulae (a1) and (a2) is used; Where R A are independently a hydrogen atom or a methyl group; R 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 Can also bond and form a ring; R 4 is a hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms and optionally having a double bond or a triple bond; R 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 6 carbon atoms, an alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group; Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms; m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6; X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

2. The pattern forming method according to claim 1, wherein As the resist material, a resist material further containing an acid generator is used.

3. The pattern forming method according to claim 1, wherein a resist material containing a polymer having the repeating unit and a repeating unit b having an acid-generating portion is used.

4. The pattern forming method according to claim 3, wherein: As the repeating unit b having an acid-generating moiety, a repeating unit selected from the repeating units represented by the following formulae (b1) to (b5) is used; Where R A are independently a hydrogen atom or a methyl group; R B are independently a hydrogen atom, or Z 6 Bond and form a ring; Z 1 is a single bond, an aliphatic alkylene 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 groups, or -OZ 11 -、-C(=O)-OZ 11 -or-C(=O)-NH-Z 11 -;Z 11 Z is an aliphatic alkylene 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 groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; 2 is a single bond or an ester bond; Z 3 is a single bond, -Z 31 -C(=O)-O- or -Z 31 -O-;Z 31 is a C1-12 alkylene group, a C7-18 phenylene group, or a combination thereof, and may contain a carbonyl group, a nitro group, a cyano group, an ester bond, an ether bond, a carbamate bond, a fluorine atom, an iodine atom, or a bromine atom; Z 4 is a single bond, methylene or ethylene; Z 5 is a single bond, methylene, ethylene, phenylene, methylphenylene, dimethylphenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OZ 51 -、-C(=O)-OZ 51 -or-C(=O)-NH-Z 51 -;Z 51 Z is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a methylphenylene group, a dimethylphenylene group, a fluorinated phenylene group, or a phenylene group substituted with a trifluoromethyl group, and may also contain a carbonyl group, an ester bond, an ether bond, a hydroxyl group, or a halogen atom; 6 is a single bond, a phenylene ring, a naphthalene ring, an ester bond or an amide bond; Z 7A is a single bond or a divalent organic group having 1 to 24 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom; Z 7B is a monovalent organic group having 1 to 10 carbon atoms, and may have at least one selected from a halogen atom, an oxygen atom, a nitrogen atom, and a sulfur atom; Z 8 is a single bond, an ether bond, an ester bond, a thioether bond or an alkanediyl group having 1 to 6 carbon atoms; Z 9 is a trivalent organic group having 1 to 12 carbon atoms, and may have at least one selected from an oxygen atom, a nitrogen atom, and a sulfur atom; Rf 1 ~Rf 4 are independently a hydrogen atom, a fluorine atom or a trifluoromethyl group, but at least one is a fluorine atom or a trifluoromethyl group; and Rf 1 and Rf 2 They can also combine and form a carbonyl group together with the carbon atom to which they are bonded; R 21 and R 22 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom; R 23 is a saturated hydrocarbon group having 1 to 10 carbon atoms, an aromatic group having 6 to 10 carbon atoms, a fluorine atom, an iodine atom, a trifluoromethoxy group, a difluoromethoxy group, a cyano group, or a nitro group; Ring R is a (d+2)-valent aromatic hydrocarbon group having 6 to 10 carbon atoms; d is an integer from 0 to 5; X - is a non-nucleophilic counter ion; M + It is a sulfonium cation or an iodonium cation.

5. The pattern forming method according to claim 4, wherein As for the repeating unit b having an acid generating portion, Z in the formula 3 、Z 7A 、Z 7B or M + A repeating unit containing one or more iodine atoms. The pattern forming method according to claim 1 , wherein the exposure is performed using extreme ultraviolet light having a wavelength of 3 to 15 nm. 7 . The pattern forming method according to claim 1 , wherein the exposure is performed using an electron beam having an accelerating voltage of 1 to 150 kV.

8. A resist material for pattern formation by dry etching, characterized in that: A polymer containing either or both of the repeating units represented by the following general formulae (a1) and (a2); Where R A are independently a hydrogen atom or a methyl group; R 1 and R 2 are each independently a linear, branched or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may have a double bond or a triple bond, and R 1 With R 2 Can also bond and form a ring; R 4 is a hydrogen atom, or a linear, branched, or cyclic aliphatic hydrocarbon group having 1 to 14 carbon atoms and optionally having a double bond or a triple bond; R 3 and R 5 Each of the following is independently a linear, branched, or cyclic alkyl group having 1 to 6 carbon atoms, a linear, branched, or cyclic alkoxy group having 1 to 6 carbon atoms, an alkoxycarbonyl group having 1 to 6 carbon atoms, an alkanoyl group having 1 to 6 carbon atoms, a halogen atom, a cyano group, a trifluoromethyl group, a trifluoromethoxy group, or a nitro group; Ring A is an aryl group having 6 to 16 carbon atoms, Ring B is a 4- to 8-membered ring which may have a double bond, and Ring C is an aryl group having 6 to 16 carbon atoms; m and n are each an integer from 1 to 3, and p and q are each an integer from 0 to 6; X 1 It is a single bond or a linking group having 1 to 12 carbon atoms and containing at least one selected from an ester bond, a lactone ring, a phenylene group, and a naphthylene group.

Images