Chemically amplified negative resist composition and resist pattern formation method

Abstract

To provide a chemically amplified negative resist composition which improves resolution in pattern formation and can give a resist pattern having good LER and pattern fidelity, and to provide a resist pattern forming method.SOLUTION: The chemically amplified negative resist composition contains: a photoacid generator comprising an onium salt represented by the following formula (A); and a base polymer which contains a polymer containing a repeating unit represented by a specific formula.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a chemically amplified negative-type resist composition and a resist pattern formation method. [Background technology]

[0002] In recent years, with the increasing integration and speed of LSIs, the miniaturization of pattern rules has been progressing rapidly. For processing patterns smaller than 0.2 μm, chemically amplified resist compositions using acid as a catalyst are primarily used. Furthermore, high-energy beams such as ultraviolet light, far-ultraviolet light, and electron beams (EB) are used as exposure sources. EB lithography, in particular, which is used as an ultra-fine processing technique, has become indispensable as a method for processing photomask blanks when creating photomasks for semiconductor manufacturing.

[0003] Polymers containing a large amount of aromatic skeletons with acidic side chains, such as polyhydroxystyrene, are useful as materials for resist compositions used in KrF lithography with KrF excimer lasers. However, they exhibit significant absorption of light around 200 nm, and therefore have not been used as materials for resist compositions used in ArF lithography with ArF excimer lasers. Nevertheless, they are important materials for resist compositions used in EB lithography and extreme ultraviolet (EUV) lithography, which are promising techniques for forming patterns smaller than the processing limit of ArF excimer lasers, due to their high etching resistance.

[0004] In the processing of photomask blanks, some photomask substrates have surface materials that easily affect the pattern shape of the chemically amplified resist film, such as chromium oxide and other chromium compound films deposited on the substrate. Therefore, maintaining a rectangular pattern profile of the resist film, regardless of the substrate type, is an important performance characteristic in order to maintain high resolution and shape after etching. Furthermore, in recent years, MBMW (Multi-Beam Mask Lighting) lithography processes are sometimes used to process mask blanks in order to achieve miniaturization. In such cases, a low-sensitivity resist composition (high-dose region) that is advantageous for roughness is used as the resist composition, and the optimization of the resist composition in this high-dose region has also attracted attention.

[0005] Resist compositions used in photolithography include positive-type resists that dissolve the exposed areas to form a pattern, and negative-type resists that leave the exposed areas intact to form a pattern. The type that is easier to use is selected depending on the desired form of the resist pattern. Chemically amplified negative-type resist compositions typically contain a polymer that dissolves in an aqueous alkaline developer, an acid generator that decomposes upon exposure to generate acid, and a crosslinking agent that uses acid as a catalyst to form crosslinks between polymers, making the polymer insoluble in the developer (in some cases the polymer and crosslinking agent are integrated). Furthermore, a quencher is usually added to control the diffusion of the acid generated by exposure.

[0006] Examples of alkali-soluble units constituting the polymer that dissolves in the aforementioned aqueous alkaline developer include units derived from phenols. Conventionally, many negative-type resist compositions of this type have been developed, particularly for exposure with KrF excimer laser light. However, these were not used for ArF excimer laser light because the units derived from phenols do not transmit light when the exposure light has a wavelength of 150 to 220 nm. However, in recent years, these negative-type resist compositions have attracted attention again as negative-type resist compositions for short-wavelength exposure light such as EB and EUV, which are exposure methods for obtaining finer patterns, and for example, Patent Documents 1, 2, and 3 have been reported.

[0007] Furthermore, one type of acid generator is a sulfonium salt that generates sulfonic acid having an aromatic group containing an iodine atom, as described in Patent Document 4. However, this is intended to enhance sensitivity in EUV lithography, and its role is primarily as a quencher for fluorinated alkanesulfonic acid. Therefore, it has not been studied as an acid generator, particularly for use in negative-type resist compositions using polyhydroxystyrene as the base polymer in the EB writing process during mask blanking.

[0008] Incidentally, in photolithography, various improvements have been made by changing the selection and combination of materials used in the resist composition, as well as the process conditions, in order to control sensitivity and pattern profiles. One of the focus of these improvements is the problem of acid diffusion, which has a significant impact on the resolution of chemically amplified resist compositions.

[0009] Quenchers suppress acid diffusion and are virtually essential components for improving the performance of resist compositions, particularly their resolution. Various quenchers have been studied, and generally, amines and weak onium acids are used. As an example of a weak onium acid, Patent Document 5 describes that the addition of triphenylsulfonium acetate can form T-tops, a difference in line width between isolated and dense patterns, and a good resist pattern without standing waves. Patent Document 6 describes that the addition of ammonium sulfonate or ammonium carboxylate improved sensitivity, resolution, and exposure margin. Furthermore, Patent Document 7 describes that resist compositions for KrF lithography and EB lithography containing a photoacid generator that generates fluorine atom-containing carboxylic acids exhibit excellent resolution and improved process tolerances such as exposure margin and depth of field. Furthermore, Patent Document 8 also describes a resist composition for F2 lithography using an F2 laser containing a photoacid generator that generates a fluorine atom-containing carboxylic acid, which exhibits excellent line edge roughness (LER) and improved hem-stripping problems. These are used in KrF lithography, EB lithography, or F2 lithography.

[0010] Patent Document 9 describes a positive-type photosensitive composition for ArF lithography containing an onium carboxylic acid salt. These compositions work by exchanging a strong acid (sulfonic acid) generated from a photoacid generator upon exposure with a weak onium acid salt, forming a weak acid and a strong onium acid salt. This replaces the highly acidic strong acid (sulfonic acid) with a weak acid (carboxylic acid), thereby suppressing the acid decomposition reaction of acid-unstable groups and reducing (controlling) the acid diffusion distance, thus seemingly functioning as a quencher.

[0011] However, in recent years, there has been a demand for resist compositions that not only offer further improvements in roughness, but also excel in line-and-space (LS), isoline (IL), isospace (IS), and dot pattern shape. The photoacid generator described in Patent Document 10, which generates a bulky acid and suppresses acid diffusion, yielded patterns with good resolution and roughness, but had the drawback of exhibiting corner rounding in the dot pattern. [Prior art documents] [Patent Documents]

[0012] [Patent Document 1] Japanese Patent Publication No. 2006-201532 [Patent Document 2] Japanese Patent Publication No. 2006-215180 [Patent Document 3] Japanese Patent Publication No. 2008-249762 [Patent Document 4] Patent No. 6645464 [Patent Document 5] Patent No. 3955384 [Patent Document 6] Japanese Patent Application Publication No. 11-327143 [Patent Document 7] Patent No. 4231622 [Patent Document 8] Patent No. 4116340 [Patent Document 9] Patent No. 4226803 [Patent Document 10] Patent No. 6248882 [Overview of the Initiative] [Problems that the invention aims to solve]

[0013] The present invention has been made in view of the above circumstances, and aims to provide a chemically amplified negative resist composition and a resist pattern formation method that can improve resolution during pattern formation and obtain a resist pattern with good LER and pattern fidelity. [Means for solving the problem]

[0014] The inventors, after diligent research to achieve the above objective, have discovered that when an alkanesulfone-type onium salt having a bulky substituent at the α-position of the sulfo group of the anion and a bulky aromatic ring structure is introduced into a resist composition as an acid generator, the generated acid has an appropriate acidity, and the bulkiness of the anion structure suppresses the rotation of the linking group, thereby suppressing excessive diffusion of the acid. This results in a pattern with a small LER, and furthermore, in the case of a dot pattern, a good rectangular pattern can be obtained due to appropriate dissolution inhibition. This led to the present invention.

[0015] In other words, the present invention provides the following chemically amplified negative resist composition and resist pattern formation method. 1. A chemically amplified negative resist composition comprising (A) a photoacid generator consisting of an onium salt represented by the following formula (A), and (B) a base polymer containing a polymer having repeating units represented by the following formula (B1). [ka] (In the formula, n1 is an integer between 0 and 2. When n1=0, n2 is an integer between 2 and 5; when n1=1, n2 is an integer between 2 and 7; and when n1=2, n2 is an integer between 2 and 9.) L is a single bond, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, or carbamate bond. R 1 and R 2 Each of these is a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms, which may independently contain a hydrogen atom or a heteroatom, but neither can be a hydrogen atom. Also, R 1 and R 2They may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. R 3 Each independently is a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms which may contain an iodine atom or a hetero atom, and at least one R 3 is bonded to a carbon atom adjacent to the carbon atom to which L is bonded. Z + is an onium cation.)

Chemical formula

Chemical formula

Chemical formula

Advantages of the Invention

[0016] The chemically amplified negative resist composition of the present invention effectively controls acid diffusion due to exposure during pattern formation through the action of the onium salt represented by formula (A). When forming a resist film and creating a pattern using this composition, it is possible to obtain a pattern with extremely high resolution, high pattern fidelity, and reduced LER. Furthermore, the action of the repeating unit represented by formula (B1) improves adhesion to the substrate when forming the resist film and controls solubility in alkaline developers. [Modes for carrying out the invention]

[0017] The present invention will be described in detail below. In the following description, depending on the structure represented by the chemical formula, an asymmetric carbon may be present, and enantiomers or diastereomers may exist. In such cases, one formula will represent all of these isomers. These isomers may be used individually or as a mixture of two or more.

[0018] [Chemically amplified negative-type resist composition] The chemically amplified negative resist composition of the present invention is characterized by comprising (A) a photoacid generator comprising an aromatic sulfonic acid type onium salt having a ring structure further condensed on an aromatic ring bonded to the sulfo group of an anion, and another aromatic ring structure containing a bulky substituent, wherein the rotational degrees of freedom between these two aromatic rings are suppressed by steric hindrance, and (B) a base polymer containing a predetermined polymer.

[0019] [(A) Acid Generator] The onium salt, which is the acid generator of component (A), is represented by the following formula (A). [ka]

[0020] In formula (A), n1 is an integer between 0 and 2. When n1=0, it represents a benzene ring; when n1=1, it represents a naphthalene ring; and when n1=3, it represents an anthracene ring. However, from the viewpoint of solvent solubility, it is preferable that n1=0, which represents a benzene ring. When n1=0, n2 is an integer between 2 and 5; when n1=1, it is an integer between 2 and 7; and when n1=2, it is an integer between 2 and 9.

[0021] In formula (A), L is a single bond, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, or a carbamate bond. Of these, an ester bond or a sulfonic acid ester bond is preferred, and a sulfonic acid ester bond is more preferred.

[0022] In formula (A), R 1 and R 2 Each of these is a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms, which may independently contain a hydrogen atom or a heteroatom, but neither can be a hydrogen atom. 1 and R 2 If both are hydrogen atoms or linear hydrocarbyl groups, then -SO3 - The reduced bulk near the substrate prevents apparent acid diffusion from being suppressed, leading to a deterioration in lithography performance.

[0023] R 1 and R 2 The hydrocarbyl group represented by may be saturated or unsaturated, and specific examples include branched alkyl groups having 3 to 20 carbon atoms such as isopropyl group, sec-butyl group, tert-butyl group, tert-pentyl group, and 2-ethylhexyl group; cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, oxanorbornyl group, and tricyclo[5.2.1.0 2,6Examples include, but are not limited to, cyclic aliphatic hydrocarbyl groups having 3 to 20 carbon atoms, such as decyl groups and adamantyl groups; aryl groups having 6 to 20 carbon atoms, such as phenyl groups, naphthyl groups and anthracenyl groups; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, the group may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of the halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, but among these, fluorine atoms and iodine atoms are preferred.

[0024] Also, R 1 and R 2 These may bond with each other to form a ring with the carbon atoms to which they are bonded. Examples of rings formed in this case include cyclopropane rings, cyclobutane rings, cyclopentane rings, cyclohexane rings, norbornane rings, adamantane rings, etc. Furthermore, some or all of the hydrogen atoms in the ring may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, halogen atoms, etc., and some of the -CH2- in the ring may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, etc. As a result, the ring may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0025] In formula (A), R 3Each is independently a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms, which may contain an iodine atom or a heteroatom, and at least one R 3 L is bonded to a carbon atom adjacent to the carbon atom to which it is bonded. A specific example of the hydrocarbyl group is R 1 and R 2 Examples of hydrocarbyl groups represented by the same formula as those exemplified above include those shown.

[0026] R in equation (A) 3 The following are examples of structures in which the aromatic ring is bonded, but are not limited to these. In the following formulas, the dashed lines represent bonds with L. [ka]

[0027] [ka]

[0028] [ka]

[0029] [ka]

[0030] [ka]

[0031] [ka]

[0032] The onium salt represented by formula (A) is preferably the one represented by formula (A1) below. [ka] (In the formula, L, R 1 , R 2 , R 3 and Z + (The same as above. n3 is an integer between 1 and 4.)

[0033] The onium salt represented by formula (A1) is preferably the one represented by formula (A2) below. [ka] (In the formula, n3, R 1 , R 2 , R 3 and Z + (This is the same as above.)

[0034] Particularly preferred examples of anions of onium salts represented by formula (A) include, but are not limited to, those listed below. [ka]

[0035] [ka]

[0036] [ka]

[0037] [ka]

[0038] [ka]

[0039] [ka]

[0040]

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[0094] [ka]

[0095] In formula (A), Z + This is an onium cation. The onium cation is preferably a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2). [ka]

[0096] In formulas (cation-1) and (cation-2), R ct1 ~R ct5 Each of these is independently a hydrocarbyl group having 1 to 30 carbon atoms, which may contain a halogen atom or a heteroatom.

[0097] Examples of the halogen atoms mentioned above include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0098] The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C30 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; C3-C30 cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; C2-C30 alkenyl groups such as vinyl, allyl, propenyl, butenyl, and hexenyl groups; C3-C30 cyclic unsaturated hydrocarbyl groups such as cyclohexenyl groups; C6-C30 aryl groups such as phenyl, naphthyl, and thienyl groups; C7-C30 aralkyl groups such as benzyl, 1-phenylethyl, and 2-phenylethyl groups; and groups obtained by combining these, but aryl groups are preferred. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, or nitrogen atoms, and as a result, the material may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0099] Also, R ct1 and R ct2 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, examples of sulfonium cations represented by formula (cation-1) include those represented by the following formula. [ka] (In the formula, the dashed line represents R ct3 (This is a combination of the two.)

[0100] Examples of sulfonium cations represented by formula (cation-1) include, but are not limited to, those listed below. [ka]

[0101] [ka]

[0102] [ka]

[0103] [ka]

[0104] [ka]

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[0126] Examples of iodonium cations represented by formula (cation-2) include, but are not limited to, those listed below. [ka]

[0127] [ka]

[0128] Specific examples of onium salts represented by formula (A) include any combination of the anion and cation mentioned above.

[0129] Onium salts represented by formula (A) can be synthesized by known methods. An example is given below, but is not limited to, the case where L in formula (A) is a sulfonic acid ester bond. [ka] (In the formula, n1, n2, R 1 , R 2 , R 3 and Z + This is the same as above. M + X is a lithium ion, a sodium ion, or a potassium ion. - (These are halide ions or methyl sulfate ions.)

[0130] The first step is to obtain sulfonate (S-3) by the reaction of sulfonate (S-1) and hydroxysulfonate (S-2). The reaction can be carried out according to conventional methods, and it is preferable to add sulfonate (S-1), hydroxysulfonate (S-2), and base sequentially or simultaneously in a solvent, and to cool or heat as necessary.

[0131] Solvents that can be used in the first step of the reaction include water, tetrahydrofuran (THF), ethers such as diethyl ether, diisopropyl ether, di-n-butyl ether, and 1,4-dioxane, hydrocarbons such as n-hexane, n-heptane, benzene, toluene, and xylene, aprotic polar solvents such as acetonitrile, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide (DMF), and chlorinated organic solvents such as methylene chloride, chloroform, and carbon tetrachloride. These solvents may be selected and used as appropriate depending on the reaction conditions, and may be used individually or in mixtures of two or more.

[0132] Furthermore, examples of bases that can be used in the first step of the reaction include ammonia, triethylamine, pyridine, lutidine, colidine, N,N-dimethylaniline and other amines, hydroxides such as sodium hydroxide, potassium hydroxide, and tetramethylammonium hydroxide, and carbonates such as potassium carbonate and sodium bicarbonate. These bases may be used individually or in combination of two or more.

[0133] The second step involves obtaining the onium salt (A') through an ion exchange reaction between the sulfonate (S-3) and the onium salt (S-4). The sulfonate (S-3) may be isolated after the reaction in the first step through a normal aqueous work-up, or it may be used without any special work-up after the reaction has been stopped.

[0134] When using isolated sulfonate (S-3), dissolve the sulfonate (S-3) in water, ethers such as THF, diethyl ether, diisopropyl ether, di-n-butyl ether, and 1,4-dioxane, hydrocarbons such as n-hexane, n-heptane, benzene, toluene, and xylene, aprotic polar solvents such as acetonitrile, DMSO, and DMF, or chlorinated organic solvents such as methylene chloride, chloroform, and carbon tetrachloride, mix with onium salt (S-4), and, if necessary, cool or heat to obtain the reaction mixture. Subsequently, onium salt (A') can be obtained from the reaction mixture by conventional aqueous post-treatment. If necessary, purification may be carried out by conventional methods such as distillation, recrystallization, and chromatography.

[0135] If the reaction to synthesize the sulfonate (S-3) has been stopped and no special work-up is to be used, the onium salt (S-4) can be added to the mixture from which the sulfonate (S-3) synthesis reaction has been stopped, and the mixture can be cooled or heated as needed to obtain the onium salt (A'). In this case, water, THF, ethers such as diethyl ether, diisopropyl ether, di-n-butyl ether, and 1,4-dioxane, hydrocarbons such as n-hexane, n-heptane, benzene, toluene, and xylene, aprotic polar solvents such as acetonitrile, DMSO, and DMF, and chlorinated organic solvents such as methylene chloride, chloroform, and carbon tetrachloride can be added as needed. The onium salt (A') can be obtained from the reaction mixture by conventional aqueous work-up. If necessary, the mixture can be purified by conventional methods such as recrystallization and chromatography.

[0136] The onium salt represented by formula (A) has an onium salt structure of sulfonic acid that is not substituted with fluorine atoms, and therefore can generate an acid of appropriate intensity by high-energy ray irradiation. - The presence of a bulky substituent at the α-position shields the vicinity of the generated sulfonic acid, and the presence of a bulky substituent at the α-position and another bulky substituent on the aromatic ring suppresses the rotation of the L bond axis connecting them due to steric hindrance, thereby suppressing excessive acid diffusion of the generated acid. Due to these synergistic effects, the contrast between exposed and unexposed areas is good, and even in the formation of fine patterns, it is possible to form patterns with low roughness. As a result of these effects, it is possible to generate an acid in the resist film with controlled acid strength and acid diffusion, so even in fine patterns, patterns with good resolution and low LER can be obtained, and even in negative-type resist compositions using alkaline developers, good rectangular patterns can be obtained due to appropriate dissolution inhibition.

[0137] In the chemically amplified negative resist composition of the present invention, the content of the onium salt represented by formula (A) is preferably 0.001 to 50 parts by mass, and more preferably 0.01 to 40 parts by mass, relative to 80 parts by mass of the (B) base polymer described later, from the viewpoint of sensitivity and acid diffusion suppression effect.

[0138] The chemically amplified negative resist composition of the present invention may further contain an acid generator other than the onium salt represented by formula (A) (hereinafter also referred to as "other acid generator") for the purpose of correcting the shape of the pattern. As the other acid generator, those known as acid generators for resist compositions can be used. The content of the other acid generator is preferably 0 to 40 parts by mass, and more preferably 0 to 30 parts by mass, relative to 80 parts by mass of the (B) base polymer described later, from the viewpoint of sensitivity and acid diffusion suppression effect. The other acid generator may be used alone or in combination of two or more types.

[0139] [(B) Base polymer] The base polymer of component (B) contains a polymer (hereinafter also referred to as polymer B) that includes repeating units represented by the following formula (B1) (hereinafter also referred to as repeating unit B1). Repeating unit B1 is a repeating unit that provides etching resistance, as well as adhesion to the substrate and solubility in alkaline developers. [ka]

[0140] In formula (B1), a1 is 0 or 1. a2 is an integer between 0 and 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is an integer between 1 and 3. When a2 is 0, preferably a3 is an integer between 0 and 3 and a4 is an integer between 1 and 3. When a2 is 1 or 2, preferably a3 is an integer between 0 and 4 and a4 is an integer between 1 and 3.

[0141] In formula (B1), R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0142] In formula (B1), R 11This is a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms that may be substituted with a halogen atom. The saturated hydrocarbyl group, and the saturated hydrocarbyl portion of the saturated hydrocarbyloxy group and saturated hydrocarbylcarbonyloxy group, may be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. If the number of carbon atoms is below the upper limit, solubility in alkaline developer is good. When a3 is 2 or more, each R 11 They may be the same as or different from each other.

[0143] In formula (B1), A 1This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- in the saturated hydrocarbylene group may be substituted with -O-. The saturated hydrocarbylene group may be linear, branched, or cyclic, and specific examples include alkanediyl groups having 1 to 10 carbon atoms such as methylene group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, and structural isomers thereof; cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms such as cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, and cyclohexanediyl group; and groups obtained by combining these. If the saturated hydrocarbylene group contains an ether bond, when a1 in formula (B1) is 1, it may be placed at any position other than between the α-carbon and β-carbon atoms relative to the esterifying oxygen atom. Furthermore, when a1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and the second ether bond may be inserted at any position other than between the α-carbon and β-carbon atoms relative to the etheric oxygen atom. It is preferable that the saturated hydrocarbylene group has 10 or fewer carbon atoms, as this allows for sufficient solubility in alkaline developing solutions.

[0144] a1 is 0 and A 1 When it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (i.e., a linker (-C(=O)-OA) 1 If the repeating unit B1 does not have the -), preferred examples of the repeating unit B1 include units derived from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. In particular, the repeating unit represented by the following formula (B1-1) is preferred. [ka] (In the formula, R A (and a4 are the same as above.)

[0145] a1 is 1 (i.e., -C(=O)-OA as the linker) 1When R has -, preferred examples of repeating unit B1 are, but are not limited to, those shown below. Note that in the following formula, A This is the same as described above. [ka]

[0146] The repeating unit B1 may be used alone or in combination of two or more types.

[0147] Polymer B may contain repeating units represented by the following formula (B2) (hereinafter also referred to as repeating unit B2) (hereinafter, polymer B that further contains repeating unit B2 will also be referred to as polymer B'). [ka]

[0148] Repeating unit B2 is formed when exposed to high-energy radiation, by the action of acid generated from the acid generator, resulting in -OW 1 This repeating unit undergoes an elimination reaction, inducing insolubilization in the alkaline developer and crosslinking between polymers. The action of repeating unit B2 allows the negative conversion reaction to proceed more efficiently, thereby improving resolution performance.

[0149] In equation (B2), b1 is either 0 or 1. b2 is an integer between 0 and 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is an integer between 1 and 3.

[0150] In formula (B2), R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0151] In formula (B2), R 12This is a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms that may be substituted with a halogen atom. The saturated hydrocarbyl group, and the saturated hydrocarbyl portion of the saturated hydrocarbyloxy group and saturated hydrocarbylcarbonyloxy group may be linear, branched, or cyclic. Specific examples include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. When b3 is 2 or more, each R 12 They may be the same as or different from each other.

[0152] In formula (B2), R 13 and R 14 Each of these is independently a hydrogen atom, a hydroxyl group, or a saturated hydrocarbyl group having 1 to 15 carbon atoms which may be substituted with a saturated hydrocarbyloxy group, or an aryl group which may have substituents. However, R 13 and R 14 They cannot become hydrogen atoms at the same time. Also, R 13 and R 14 These may bond to each other, forming a ring with the carbon atoms to which they are bonded. 13 and R 14 Preferably, examples include alkyl groups such as methyl groups, ethyl groups, propyl groups, butyl groups, and structural isomers thereof, or alkyl groups in which some of the hydrogen atoms of these groups are substituted with hydroxyl groups or saturated hydrocarbyloxy groups.

[0153] In formula (B2), A 2This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- in the saturated hydrocarbylene group may be substituted with -O-. The saturated hydrocarbylene group may be linear, branched, or cyclic, and specific examples include alkanediyl groups such as methylene group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, and structural isomers thereof; cyclic saturated hydrocarbylene groups such as cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, and cyclohexanediyl group; and groups obtained by combining these. If the saturated hydrocarbylene group contains an ether bond, when b1 in formula (B2) is 1, it may be placed at any position other than between the α-carbon atom and the β-carbon atom with respect to the ester oxygen atom. Furthermore, when b1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and the second ether bond may be formed at any position other than between the α-position carbon atom and the β-position carbon atom relative to the etheric oxygen atom.

[0154] In formula (B2), W 1 The aliphatic hydrocarbyl group is a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, or an aryl group which may have substituents. The aliphatic hydrocarbyl group may be linear, branched, or cyclic, and specific examples include alkyl groups such as methyl, ethyl, propyl, and isopropyl groups; and cyclic aliphatic hydrocarbyl groups such as cyclopentyl, cyclohexyl, and adamantyl groups. The aryl group may be a phenyl group. Furthermore, some of the -CH2- of the aliphatic hydrocarbyl group may be substituted with -O-, -C(=O)-, -OC(=O)-, or -C(=O)-O-. The -CH2- of the hydrocarbyl group may be bonded to the oxygen atom in formula (B2). An example of such a substituted group is a methylcarbonyl group.

[0155] The repeating unit B2 is preferably one represented by the following formula (B2-1) or (B2-2). [ka] (In the formula, b4, R A , R 13 and R 14 (This is the same as above.)

[0156] Preferred examples of repeating unit B2 are, but are not limited to, those shown below. Note that in the following formula, R A The same as above, where Me is a methyl group and Ac is an acetyl group. [ka]

[0157] [ka]

[0158] [ka]

[0159] [ka]

[0160] [ka]

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [ka]

[0167] Repeating unit B2 may be used alone or in combination of two or more types.

[0168] Polymers B and B' may contain at least one selected from the repeating units represented by the following formula (B3) (hereinafter also referred to as repeating unit B3), the repeating unit represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), and the repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5), for the purpose of improving etching resistance. [ka]

[0169] In equations (B3) and (B4), c and d are each independent integers between 0 and 4.

[0170] In formulas (B3) and (B4), R 21 and R 22 Each of these is independently a hydroxyl group, a halogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms that may be substituted with a halogen atom. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, and saturated hydrocarbylcarbonyloxy group may be linear, branched, or cyclic. When c is 2 or more, each R 21They may be the same or different from each other. When d is 2 or greater, each R 22 They may be the same as or different from each other.

[0171] In formula (B5), e1 is 0 or 1. e2 is an integer between 0 and 2, where 0 represents the benzene skeleton, 1 represents the naphthalene skeleton, and 2 represents the anthracene skeleton. e3 is an integer between 0 and 5. When e2 is 0, e3 is preferably an integer between 0 and 3, and when e2 is 1 or 2, e3 is preferably an integer between 0 and 4.

[0172] In formula (B5), R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0173] In formula (B5), R 23 The saturated hydrocarbyl group is a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbyloxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbylthiohydrocarbyl group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbylsulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbylsulfonyl group having 1 to 20 carbon atoms. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, saturated hydrocarbyloxyhydrocarbyl group, saturated hydrocarbylthiohydrocarbyl group, saturated hydrocarbylsulfinyl group, and saturated hydrocarbylsulfonyl group may be linear, branched, or cyclic. When e3 is 2 or more, each R 23 They may be the same as or different from each other.

[0174] R 23Preferred groups include halogen atoms such as chlorine, bromine, and iodine; saturated hydrocarbyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, and cyclohexyl groups, and their structural isomers; and saturated hydrocarbyl groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopentyloxy, and cyclohexyloxy groups, and their structural isomers of the hydrocarbon portion. Of these, methoxy and ethoxy groups are particularly useful.

[0175] Furthermore, saturated hydrocarbyl carbonyloxy groups can be easily introduced by chemical modification even after polymer polymerization and can be used to fine-tune the solubility of the base polymer in alkaline developers. Examples of saturated hydrocarbyl carbonyloxy groups include methyl carbonyloxy, ethyl carbonyloxy, propyl carbonyloxy, butyl carbonyloxy, pentyl carbonyloxy, hexyl carbonyloxy, cyclopentyl carbonyloxy, cyclohexyl carbonyloxy, benzoyloxy, and structural isomers of their hydrocarbon portions. If the number of carbon atoms is 20 or less, the effect of controlling and adjusting the solubility of the base polymer in alkaline developers (mainly reducing it) can be appropriately achieved, and the occurrence of scum (development defects) can be suppressed.

[0176] Among the preferred substituents mentioned above, those that are particularly easy to prepare as monomers and are useful include chlorine atoms, bromine atoms, iodine atoms, methyl groups, ethyl groups, and methoxy groups.

[0177] In formula (B5), A 3This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- in the saturated hydrocarbylene group may be substituted with -O-. The saturated hydrocarbylene group may be linear, branched, or cyclic, and specific examples include alkanediyl groups having 1 to 10 carbon atoms such as methylene group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, and structural isomers thereof; cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms such as cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, and cyclohexanediyl group; and groups obtained by combining these. If the saturated hydrocarbylene group contains an ether bond, when f1 in formula (B5) is 1, it may be placed at any position other than between the α-carbon and β-carbon atoms relative to the ester oxygen atom. Furthermore, when f1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and the second ether bond may be inserted at any position other than between the α-carbon and β-carbon atoms relative to the etheric oxygen atom. It is preferable that the saturated hydrocarbylene group has 10 or fewer carbon atoms, as this allows for sufficient solubility in alkaline developing solutions.

[0178] e1 is 0 and A 3 If it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (i.e., a linker (-C(=O)-OA) 3 If the repeating unit B5 does not have a (-), preferred examples of the repeating unit B5 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene, etc.

[0179] Also, if e1 is 1 (i.e., -C(=O)-OA as the linker), 3 (If - is present), preferred examples of repeating unit B5 are, but are not limited to, those listed below. Note that in the following formula, R A This is the same as described above. [ka]

[0180] [ka]

[0181] When at least one of the repeating units B3 to B5 is used as a constituent unit of the polymer, in addition to the etching resistance of the aromatic ring, the addition of a ring structure to the main chain enhances etching resistance and EB irradiation resistance during pattern inspection.

[0182] Repeating units B3 to B5 may be used individually or in combination of two or more types.

[0183] Polymer B' may further contain at least one selected from the repeating units represented by the following formula (B6) (hereinafter also referred to as repeating unit B6), the following formula (B7) (hereinafter also referred to as repeating unit B7), the following formula (B8) (hereinafter also referred to as repeating unit B8), the following formula (B9) (hereinafter also referred to as repeating unit B9), the following formula (B10) (hereinafter also referred to as repeating unit B10), the following formula (B11) (hereinafter also referred to as repeating unit B11), the following formula (B12) (hereinafter also referred to as repeating unit B12), and the following formula (B13) (hereinafter also referred to as repeating unit B13). In this case, acid diffusion can be effectively suppressed, resulting in improved resolution and a pattern with reduced LER. [ka]

[0184] In formulas (B6) to (B13), R B Each of these is independently either a hydrogen atom or a methyl group. 1This refers to a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or *-OY 11 -, *-C(=O)-OY 11 -or *-C(=O)-NH-Y 11 - and Y 11 This is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 is a single bond or **-Y 21 -C(=O)-O- and Y 21 This is a hydroxylene group having 1 to 20 carbon atoms, which may contain heteroatoms. 3 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, trifluoromethyl groups, and phenylene groups substituted with *-OY 31 -, *-C(=O)-OY 31 -or *-C(=O)-NH-Y 31 - is Y 31 This is a C1-C6 aliphatic hydrocarbylene group, phenylene group, fluorinated phenylene group, phenylene group substituted with a trifluoromethyl group, or a C7-C20 group obtained by combining these, and may contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * represents a bond with a carbon atom of the main chain, and ** represents a bond with an oxygen atom in the formula. Y 4 This is a hydroxylene group having 1 to 30 carbon atoms, which may contain single bonds or heteroatoms. f1 and f2 are independently 0 or 1, but Y 4 When it is a single bond, f1 and f2 are 0.

[0185] In equations (B6) and (B10), Xa - Xa is a non-nucleophilic counterion. - Examples of non-nucleophilic counterions represented by include those described in Japanese Patent Publication No. 2010-113209 and Japanese Patent Publication No. 2007-145797.

[0186] In formulas (B7) and (B11), Y 2 ga-Y 21 When -C(=O)-O-, Y 21 Examples of hydrocarbylene groups that may contain a heteroatom represented by the following are, but are not limited to, those listed below. [ka] (In the equation, dashed lines represent connections.)

[0187] In formulas (B7) and (B11), R HF is a hydrogen atom or a trifluoromethyl group. In repeating units B7 and B11, R HF A specific example of the case where is a hydrogen atom is described in Japanese Patent Publication No. 2010-116550, and R HF Specific examples of cases where is a trifluoromethyl group include those described in Japanese Patent Publication No. 2010-77404. Examples of repeating units B8 and B12 include those described in Japanese Patent Publication No. 2012-246265 and Japanese Patent Publication No. 2012-246426.

[0188] Preferred examples of monomer anions that give repeating units B9 or B13 include, but are not limited to, those listed below. [ka]

[0189] [ka]

[0190] In formulas (B6) to (B13), R 31 ~R 48Each of these is a hydrocarbyl group having 1 to 20 carbon atoms, which may independently contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples of the halogen atom and hydrocarbyl group are given in the explanation of formulas (cation-1) to (cation-3) as R c1 ~R c9 Examples of halogen atoms and hydrocarbyl groups represented by the symbols are similar to those exemplified. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- groups of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, the group may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, lactone rings, sultone rings, carboxylic acid anhydrides (-C(=O)-OC(=O)-), haloalkyl groups, etc.

[0191] Also, R 31 and R 32 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded, R 33 and R 34 , R 36 and R 37 , or R 39 and R 40 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. In this case, the ring formed is R as described in the explanation of formula (cation-1). c1 and R c2 Examples similar to those exemplified include rings that can be formed when these elements bond to each other, together with the sulfur atoms to which they bond.

[0192] Furthermore, specific examples of sulfonium cations in repeating units B7 to B9 are the same as those exemplified as the sulfonium cation represented by formula (cation-1). Specific examples of iodonium cations in repeating units B11 to B13 are the same as those exemplified as the iodonium cation represented by formula (cation-2).

[0193] Repeating units B6 to B13 are units that generate acid when irradiated with high-energy rays. It is believed that the inclusion of these units in the polymer moderately suppresses acid diffusion, resulting in a pattern with reduced LER. Furthermore, the inclusion of these units in the polymer suppresses the phenomenon of acid volatilizing from the exposed areas and reattaching to the unexposed areas during baking in a vacuum, which is thought to be effective in reducing LER and minimizing defects by suppressing unwanted negative reactions in the unexposed areas.

[0194] Repeating units B6 to B13 may be used individually or in combination of two or more types.

[0195] Polymers B and B' may contain (meth)acrylic acid ester units or other repeating units having adhesive groups such as lactone structures or hydroxyl groups other than phenolic hydroxyl groups, in order to fine-tune the properties of the resist film.

[0196] Examples of (meth)acrylic acid ester units having the aforementioned adhesive group include the repeating unit represented by the following formula (B14) (hereinafter also referred to as repeating unit B14), the repeating unit represented by the following formula (B15) (hereinafter also referred to as repeating unit B15), and the repeating unit represented by the following formula (B16) (hereinafter also referred to as repeating unit B16). These units do not exhibit acidity and can be used auxiliaryly as units that provide adhesion to the substrate or as units that adjust solubility. [ka]

[0197] In formulas (B14) to (B16), R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 51 R is either an -O- or a methylene group. 52 R is a hydrogen atom or a hydroxyl group. 53 is a saturated hydrocarbyl group having 1 to 4 carbon atoms. g is an integer from 0 to 3.

[0198] In polymer B, the content of repeating unit B1 is preferably 30 to 95 mol%, and more preferably 50 to 85 mol%, in order to obtain high resolution and to produce high contrast between the parts that are negativeized by high-energy ray irradiation and the parts that are not irradiated (non-negativeized parts). The content of repeating unit B2 is preferably 5 to 70 mol%, and more preferably 10 to 60 mol%, in order to obtain the effect of promoting the negativeization reaction. The content of repeating units B3 to B5 is preferably 0 to 30 mol%, and more preferably 3 to 20 mol%, in order to obtain the effect of improving etching resistance. In addition, other repeating units may be included in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0199] If polymer B' does not contain repeating units B6 to B13, the content of repeating unit B1 in polymer B' is preferably 25 to 95 mol%, more preferably 40 to 85 mol%. The content of repeating units B3 to B5 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating unit B5 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. Other repeating units may be included in amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0200] When polymer B' contains repeating units B6 to B13, the content of repeating unit B1 in polymer B' is preferably 25 to 94.5 mol%, more preferably 36 to 85 mol%. The content of repeating units B3 to B5 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating unit B5 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. The total content of repeating units B1 to B5 is preferably 60 to 99.5 mol%. The content of repeating units B6 to B13 is preferably 0.5 to 20 mol%, more preferably 1 to 10 mol%. Other repeating units may be included in amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0201] Furthermore, among the total repeating units constituting the polymer, repeating units B1 to B5 preferably account for 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. This ensures that the properties required for the chemically amplified negative resist composition of the present invention are reliably obtained.

[0202] Furthermore, in this case, polymer B' is preferably one that includes repeating units represented by the following formula (B1-1), repeating units represented by the following formula (B2-1) or (B2-2), and repeating units represented by the following formula (B7). [ka] (In the formula, a4, b4, R A , R B , Y 2 , R 13 , R 14 , R 33 , R 34 , R 35 and R HF (This is the same as above.)

[0203] (B) When polymer B' is used as the base polymer, a combination of polymers that do not contain repeating units B6 to B13 and polymers that contain repeating units B6 to B13 may be used. In this case, the content of polymers that do not contain repeating units B6 to B13 in the chemically amplified negative resist composition of the present invention is preferably 2 to 5000 parts by mass, and more preferably 10 to 1000 parts by mass, per 100 parts by mass of polymers that contain repeating units B6 to B13.

[0204] When a chemically amplified negative resist composition is used for mask fabrication, the coating film thickness in the most advanced generation is 150 nm or less, preferably 100 nm or less. The dissolution rate of the base polymer constituting the chemically amplified negative resist composition in an alkaline developer (e.g., 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution) is generally 80 nm / second or less, more preferably 50 nm / second or less, in order to minimize defects due to resist residue and to form fine patterns. Furthermore, when using the chemically amplified negative resist composition of the present invention in an EUV exposure process, for example, when fabricating an LSI chip from a wafer, it is often necessary to pattern fine lines of 50 nm or less, so the coating film thickness is often 100 nm or less. Since the pattern may deteriorate due to development because it is a thin film, the dissolution rate of the polymer used is preferably 80 nm / second or less, more preferably 50 nm / second or less.

[0205] The polymer can be synthesized by copolymerizing each monomer, which is optionally protected with a protecting group, using known methods, and then performing a deprotection reaction as necessary. The copolymerization reaction is not particularly limited, but radical polymerization and anionic polymerization are preferred. For these methods, refer to International Publication No. 2006 / 121096, Japanese Patent Publication No. 2008-102383, Japanese Patent Publication No. 2008-304590, and Japanese Patent Publication No. 2004-115630.

[0206] The polymer preferably has a weight-average molecular weight (Mw) of 1,000 to 50,000, and more preferably 2,000 to 20,000. If Mw is 1,000 or more, there is no risk of phenomena such as the pattern heads becoming rounded, reducing resolution, and LER degrading, as is conventionally known. On the other hand, if Mw is 50,000 or less, there is no risk of LER increasing, especially when forming patterns with a pattern line width of 100 nm or less. In this invention, Mw is a polystyrene-converted measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylformamide (DMF) as a solvent.

[0207] The polymer preferably has a narrow dispersion with a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, and particularly 1.0 to 1.8. When the dispersion is narrow in this way, after development, no foreign matter will be generated on the pattern, and the shape of the pattern will not deteriorate.

[0208] [(C) Crosslinking agent] (B) If the base polymer does not contain polymer B', the chemically amplified negative resist composition of the present invention preferably contains a crosslinking agent as component (C). On the other hand, if the base polymer (B) contains polymer B', it is not necessary to include a crosslinking agent.

[0209] Specific examples of crosslinking agents usable in the present invention include epoxy compounds, melamine compounds, guanamine compounds, glycoluryl compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups, which are substituted with at least one group selected from methylol, alkoxymethyl, and acyloxymethyl groups. These may be used as additives or introduced as pendant groups into polymer side chains. Compounds containing hydroxyl groups can also be used as crosslinking agents.

[0210] Examples of the epoxy compound include tris(2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0211] Examples of the melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are methoxymethylated, or mixtures thereof; and hexamethoxyethylmelamine, hexaacyloxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are acyloxymethylated, or mixtures thereof.

[0212] Examples of the guanamine compounds include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine, or mixtures thereof; and compounds in which 1 to 4 methylol groups are acyxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, or mixtures thereof.

[0213] Examples of the glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, tetramethylol glycoluryl, and other compounds in which 1 to 4 methylol groups are methoxymethylated, or mixtures thereof; and compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated, or mixtures thereof.

[0214] Examples of the urea compounds include tetramethylolurea, tetramethoxymethylurea, tetramethylolurea, and other compounds in which 1 to 4 methylol groups are methoxymethylated, or mixtures thereof, and tetramethoxyethylurea.

[0215] Examples of the isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0216] Examples of the aforementioned azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0217] Examples of compounds containing the aforementioned alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0218] In the chemically amplified negative resist composition of the present invention, the content of (C) crosslinking agent is preferably 0.1 to 50 parts by mass, and more preferably 1 to 30 parts by mass, per 80 parts by mass of (B) base polymer. Within this range, the patterns are connected and there is little risk of a decrease in resolution. (C) crosslinking agent may be used alone or in combination of two or more types.

[0219] [(D) Fluorine atom-containing polymer] The chemically amplified negative resist composition of the present invention may contain a fluorine atom-containing polymer as component (D) for the purpose of increasing contrast, suppressing chemical flare of acids during high-energy ray irradiation, shielding from acid mixing from the antistatic film during the process of coating the resist film with an antistatic film material, and suppressing unexpected and unwanted pattern degradation. This polymer may further contain at least one selected from the following repeating units: a repeating unit represented by the following formula (D1) (hereinafter also referred to as repeating unit D1), a repeating unit represented by the following formula (D2) (hereinafter also referred to as repeating unit D2), a repeating unit represented by the following formula (D3) (hereinafter also referred to as repeating unit D3), and a repeating unit represented by the following formula (D4) (hereinafter also referred to as repeating unit D4), and may further contain at least one selected from the following repeating units: a repeating unit represented by the following formula (D5) (hereinafter also referred to as repeating unit D5) and a repeating unit represented by the following formula (D6) (hereinafter also referred to as repeating unit D6). Since the fluorine atom-containing polymer also functions as a surfactant, it can prevent the re-adhesion of insoluble substances to the substrate that may occur during the development process, thus also exhibiting an effect against development defects. [ka]

[0220] In equations (D1) to (D6), x is an integer between 1 and 3. y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x. z is either 0 or 1. k is an integer between 1 and 3. R C These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. D Each of these is independently either a hydrogen atom or a methyl group. 101 , R 102 , R 104 and R 105 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. 103 , R 106 , R 107 and R 108 Each of these is independently a hydrogen atom, a C1-C15 hydrocarbyl group, a C1-C15 fluorinated hydrocarbyl group, or an acid-unstable group, and R103 , R 106 , R 107 and R 108 When is a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be interposed between the carbon-carbon bonds. 109 This is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms, which may have a hydrogen atom or a group containing a heteroatom between the carbon-carbon bonds. 110 This is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms, which may have a heteroatom interposed between the carbon-carbon bonds. 111 This is a saturated hydrocarbyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and a portion of the -CH2- of the saturated hydrocarbyl group may be substituted with an ester bond or an ether bond. 1 This is a (k+1) valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1) valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. 2 The bond is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * represents a bond with a carbon atom in the main chain. 3 This is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 -or *-C(=O)-NH-Z 31 -Z 32 - is Z 31 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms. 32 A is a single bond, ester bond, ether bond, or sulfonamide bond. * indicates a bond with a carbon atom of the main chain.

[0221] In equations (D1) and (D2), R 101 , R 102 , R 104 and R 105The saturated hydrocarbyl group having 1 to 10 carbon atoms, represented by , may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; and cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl groups. Of these, saturated hydrocarbyl groups having 1 to 6 carbon atoms are preferred.

[0222] In formulas (D1) to (D4), R 103 , R 106 , R 107 and R 108 The C1-C15 hydrocarbyl group represented by can be linear, branched, or cyclic. Specific examples include C1-C15 alkyl groups, C2-C15 alkenyl groups, and C2-C15 alkynyl groups, but C1-C15 alkyl groups are preferred. Examples of alkyl groups include, in addition to those mentioned above, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecyl groups. Fluorinated hydrocarbyl groups include groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbyl group mentioned above are substituted with fluorine atoms.

[0223] In formula (D4), Z 1 Examples of (k+1) valent hydrocarbon groups having 1 to 20 carbon atoms, represented by , include alkyl groups with 1 to 20 carbon atoms or cyclic saturated hydrocarbyl groups with 3 to 20 carbon atoms from which k hydrogen atoms have been removed. Also, Z 1Examples of (k+1) valent fluorinated hydrocarbon groups having 1 to 20 carbon atoms, as represented by the formula, include groups in which at least one hydrogen atom of the aforementioned (k+1) valent hydrocarbon group is substituted with a fluorine atom.

[0224] Specific examples of repeating units D1 to D4 are shown below, but are not limited to these. Note that in the following formula, R C This is the same as described above. [ka]

[0225] [ka]

[0226] [ka]

[0227] In formula (D5), R 109 and R 110 Examples of C1-C5 hydrocarbyl groups represented by include alkyl groups, alkenyl groups, and alkynyl groups, but alkyl groups are preferred. Examples of alkyl groups include methyl groups, ethyl groups, n-propyl groups, isopropyl groups, n-butyl groups, isobutyl groups, sec-butyl groups, and n-pentyl groups. In addition, a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom may be interposed between the carbon-carbon bonds of the hydrocarbyl group.

[0228] In formula (D5), -OR 109 It is preferable that R is a hydrophilic group. In this case, R 109 Preferred elements include hydrogen atoms, C1-C5 alkyl groups with oxygen atoms interposed between carbon-carbon bonds, etc.

[0229] In formula (D5), Z 2 It is preferable that *-C(=O)-O- or *-C(=O)-NH-. Furthermore, R DIt is preferable that it is a methyl group. 2 The presence of a carbonyl group improves the acid trapping ability derived from the antistatic film. Also, R D When the group is a methyl group, a more rigid polymer with a higher glass transition temperature (Tg) is formed, thus suppressing acid diffusion. This results in good temporal stability of the resist film, and the resolution and pattern shape do not deteriorate.

[0230] The repeating unit D5 can be, but is not limited to, the following. Note that in the following formula, R D This is the same as described above. [ka]

[0231] [ka]

[0232] In formula (D6), Z 3 The saturated hydrocarbylene group having 1 to 10 carbon atoms, represented by , may be linear, branched, or cyclic. Specific examples include methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,1-diyl group, propane-1,2-diyl group, propane-1,3-diyl group, propane-2,2-diyl group, butane-1,1-diyl group, butane-1,2-diyl group, butane-1,3-diyl group, butane-2,3-diyl group, butane-1,4-diyl group, and 1,1-dimethylethane-1,2-diyl group.

[0233] In formula (D6), R 111 A saturated hydrocarbyl group having 1 to 20 carbon atoms, represented by , in which at least one hydrogen atom is substituted with a fluorine atom, may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom.

[0234] The repeating unit D6 can be, but is not limited to, the following. Note that in the following formula, R D This is the same as described above. [ka]

[0235] [ka]

[0236] [ka]

[0237] [ka]

[0238] The content of repeating units D1 to D4 is preferably 15 to 95 mol%, and more preferably 20 to 85 mol%, of the total repeating units of the fluorine atom-containing polymer. The content of repeating units D5 and / or D6 is preferably 5 to 85 mol%, and more preferably 15 to 80 mol%, of the total repeating units of the fluorine atom-containing polymer. Repeating units D1 to D6 may be used individually or in combination of two or more types.

[0239] The fluorine atom-containing polymer may contain other repeating units besides those described above. Examples of such repeating units include those described in paragraphs

[0046] to

[0078] of Japanese Patent Application Publication No. 2014-177407. If the fluorine atom-containing polymer contains other repeating units, the content thereof is preferably 50 mol% or less of the total repeating units of the fluorine atom-containing polymer.

[0240] The aforementioned fluorine atom-containing polymer can be synthesized by copolymerizing each monomer, which is optionally protected with a protecting group, using known methods, and then performing a deprotection reaction as necessary. The copolymerization reaction is not particularly limited, but radical polymerization and anionic polymerization are preferred. For these methods, refer to Japanese Patent Application Publication No. 2004-115630.

[0241] The Mw of the fluorine atom-containing polymer is preferably 2000 to 50000, and more preferably 3000 to 20000. If the Mw is less than 2000, it may promote acid diffusion, leading to a deterioration in resolution and impaired stability over time. If the Mw is too high, the solubility in the solvent will decrease, potentially causing coating defects. Furthermore, the Mw / Mn of the fluorine atom-containing polymer is preferably 1.0 to 2.2, and more preferably 1.0 to 1.7.

[0242] When the chemically amplified negative resist composition of the present invention contains (D) a fluorine atom-containing polymer, its content is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.5 to 10 parts by mass, based on 80 parts by mass of (B) the base polymer. The (D) fluorine atom-containing polymer may be used alone or in combination of two or more types.

[0243] [(E) Quencher] The chemically amplified negative resist composition of the present invention preferably contains a quencher as component (E). In the present invention, a quencher is a material that traps the acid generated from the photoacid generator in the chemically amplified resist composition, thereby preventing its diffusion to unexposed areas and forming a desired pattern.

[0244] Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, hybrid amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxyl group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxyl group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, carbamates, and the like. In particular, primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103 are preferred, especially amine compounds having a hydroxyl group, ether bond, ester bond, lactone ring, cyano group, or sulfonic acid ester bond, or compounds having a carbamate group described in Japanese Patent Publication No. 3790649. Preferred examples include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, and imidazole derivatives. By adding such basic compounds, it is possible to further suppress the diffusion rate of the acid in the resist film or correct its shape, for example.

[0245] Furthermore, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of carboxylic acids whose α-position is not fluorinated, as described in Japanese Patent Publication No. 2008-158339. Sulfonic acids, imido acids, or methidic acids with α-position fluorinated are necessary for deprotecting acid-unstable groups, but salt exchange with onium salts whose α-position is not fluorinated releases carboxylic acids whose α-position is not fluorinated. Carboxylic acids whose α-position is not fluorinated hardly undergo deprotection reactions and therefore function as quenchers.

[0246] Examples of onium salts of carboxylic acids whose α-position is not fluorinated include those represented by the following formula (E1). [ka]

[0247] In formula (E1), R 201 This refers to a hydrocarbyl group having 1 to 40 carbon atoms, which may contain hydrogen atoms or heteroatoms, but excludes those in which the hydrogen atom bonded to the carbon atom at the α position of the carboxyl group is substituted with a fluorine atom or a fluoroalkyl group.

[0248] R 201 The hydrocarbyl group 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, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6 ]Cyclic saturated hydrocarbyl groups with 3 to 40 carbon atoms, such as decyl group, adamantyl group, and adamantylmethyl group; C2 to 40 alkenyl groups with 2 to 40 carbon atoms, such as vinyl group, allyl group, propenyl group, butenyl group, and hexenyl group; C3 to 40 cyclic unsaturated aliphatic hydrocarbyl groups with 3 to 40 carbon atoms, such as cyclohexenyl group; phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert Examples include aryl groups with 6 to 40 carbon atoms, such as butylphenyl group, 4-n-butylphenyl group, dialkylphenyl group (2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group, etc.), alkylnaphthyl group (methylnaphthyl group, ethylnaphthyl group, etc.), and dialkylnaphthyl group (dimethylnaphthyl group, diethylnaphthyl group, etc.); and aralkyl groups with 7 to 40 carbon atoms, such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group.

[0249] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, nitrogen atom, or halogen atom, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, and as a result, it may contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Examples of hydrocarbyl groups containing heteroatoms include heteroaryl groups such as thienyl groups; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl groups; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl groups; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl groups; and aryloxoalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl groups.

[0250] In formula (E1), Mq A + This is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. Specific examples of the sulfonium cation include those similar to those exemplified as the sulfonium cation represented by formula (cation-1). Specific examples of the iodonium cation include those similar to those exemplified as the iodonium cation represented by formula (cation-2).

[0251] The anions of the onium salt represented by formula (E1) include, but are not limited to, those listed below. [ka]

[0252] [ka]

[0253] [ka]

[0254] As the quencher, a sulfonium salt of an iodized benzene ring-containing carboxylic acid represented by the following formula (E2) can also be suitably used. [ka]

[0255] In equation (E2), s is an integer between 1 and 5, t is an integer between 0 and 3, where 1 ≤ s + t ≤ 5, and u is an integer between 1 and 3.

[0256] In formula (E2), R 211 This includes hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, amino groups, nitro groups, cyano groups, saturated hydrocarbyl groups with 1 to 6 carbon atoms, saturated hydrocarbyloxy groups with 1 to 6 carbon atoms, saturated hydrocarbylcarbonyloxy groups with 2 to 6 carbon atoms, saturated hydrocarbylsulfonyloxy groups with 1 to 4 carbon atoms, and -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, or saturated hydrocarbylsulfonyloxy group may have some or all of its hydrogen atoms substituted with halogen atoms. 211A R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 211B is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms. When t and / or u are 2 or more, each R211 They may be identical or different from one another.

[0257] In formula (E2), L 11 This is a single bond or a (u+1) valent linking group having 1 to 20 carbon atoms, and may contain at least one selected from 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 hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, and saturated hydrocarbylsulfonyloxy group may be linear, branched, or cyclic.

[0258] In formula (E2), R 212 , R 213 and R 214 Each of these is a C1-C20 hydrocarbyl group which may independently contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups, C2-C20 alkenyl groups, C6-C20 aryl groups, C7-C20 aralkyl groups, etc. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a hydroxyl group, carboxyl group, halogen atom, oxo group, cyano group, nitro group, sultone ring, sulfo group, or sulfonium salt-containing group, and some of the -CH2- of the hydrocarbyl group may be substituted with an ether bond, ester bond, carbonyl group, amide bond, carbonate bond, or sulfonic acid ester bond. 212 and R 213 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded.

[0259] A specific example of the compound represented by formula (E2) is the one described in Japanese Patent Publication No. 2017-219836. The compound represented by formula (E2) exhibits high absorption, high sensitization effect, and high acid diffusion control effect.

[0260] As the quencher, a nitrogen atom-containing carboxylate compound represented by the following formula (E3) can also be used. [ka]

[0261] In formula (E3), R 221 ~R 224 These are, independently, hydrogen atoms and -L 12 -CO2 - or a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms. 221 and R 222 And, R 222 and R 223 or R 223 and R 224 These may bond with each other to form a ring with the carbon atom to which they are bonded. 12 R is a hydroxylene group having 1 to 20 carbon atoms, which may contain single bonds or heteroatoms. 225 This is a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom.

[0262] In formula (E3), ring R r This is a ring having 2 to 6 carbon atoms, including carbon and nitrogen atoms in the formula, and some or all of the hydrogen atoms bonded to the carbon atoms of the ring are a hydrocarbyl group having 1 to 20 carbon atoms, or -L 12 -CO2 - The ring may be substituted with a sulfur atom, an oxygen atom, or a nitrogen atom. The ring may be an alicyclic ring or an aromatic ring, and is preferably a 5-membered or 6-membered ring. Specific examples include pyridine rings, pyrrole rings, pyrrolidine rings, piperidine rings, pyrazole rings, imidazoline rings, pyridazine rings, pyrimidine rings, pyrazine rings, imidazoline rings, oxazole rings, thiazole rings, morpholine rings, thiazine rings, triazole rings, and the like.

[0263] The onium carboxylate salt represented by formula (E3) contains at least one -L 12 -CO2 -It has a group. That is, R 221 ~R 224 At least one of them is -L 12 -CO2 - is and / or at least one hydrogen atom bonded to a carbon atom of ring R is -L 12 -CO2 - It has been replaced with this.

[0264] In formula (E3), Mq B + This is a sulfonium cation, an iodonium cation, or an ammonium cation, but a sulfonium cation is preferred. Specific examples of the sulfonium cation include those similar to those exemplified as the sulfonium cation represented by formula (cation-1).

[0265] The anions of the compound represented by formula (E3) include, but are not limited to, those listed below. [ka]

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] [ka]

[0271] Furthermore, a weak acidic betaine-type compound can also be used as the quencher. Specific examples are listed below, but are not limited to these. [ka]

[0272] As an example of the aforementioned quencher, a polymer-type quencher described in Japanese Patent Publication No. 2008-239918 can be cited. This enhances the rectangularity of the resist pattern by oriented on the surface of the resist film. The polymer-type quencher also has the effect of preventing film thinning of the pattern and rounding of the pattern top when a protective film for immersion lithography is applied.

[0273] If the chemically amplified negative resist composition of the present invention contains (E) a quencher, its content is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass, per 80 parts by mass of the (B) base polymer. The (E) quencher may be used alone or in combination of two or more types.

[0274] When the chemically amplified negative resist composition of the present invention contains a photoacid generator (A) and a quencher (E), it is preferable that the ratio of the photoacid generator to the quencher ((A) / (E)) is less than 6 by mass, more preferably less than 5, and even more preferably less than 4. If the ratio of the photoacid generator to the quencher in the chemically amplified negative resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0275] [(F) Organic solvents] The chemically amplified negative resist composition of the present invention may contain an organic solvent as component (F). The organic solvent is not particularly limited as long as it can dissolve each component. Examples of such organic solvents include ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone, as described in paragraphs

[0144] to

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

[0276] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixtures thereof are preferred.

[0277] If the chemically amplified negative resist composition of the present invention contains (F) an organic solvent, its content is preferably 200 to 10,000 parts by mass, and more preferably 400 to 6,000 parts by mass, per 80 parts by mass of the (B) base polymer. The (F) organic solvent may be used alone or as a mixture of two or more types.

[0278] [(G) Surfactants] The chemically amplified negative resist composition of the present invention may contain a commonly used surfactant to improve its applicability to the substrate. Examples of such surfactants include PF-636 (manufactured by OMNOVA SOLUTIONS) and FC-4430 (manufactured by 3M). Numerous other surfactants are also known, as many examples are described in Japanese Patent Application Publication No. 2004-115630, and can be selected by referring to these. When the chemically amplified negative resist composition of the present invention contains (G) surfactant, its content is preferably 0 to 5 parts by mass per 80 parts by mass of (B) base polymer. (G) surfactant may be used alone or in combination of two or more types.

[0279] [Method for forming a resist pattern] The resist pattern formation method of the present invention includes the steps of forming a resist film on a substrate using the chemically amplified negative resist composition described above, irradiating the resist film with a pattern using high-energy rays (i.e., exposing the resist film with high-energy rays), and developing the resist film irradiated with the pattern using an alkaline developer.

[0280] As the substrate, for example, substrates for integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coatings, etc.) or substrates for transmissive or reflective mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2, etc.) can be used. The chemically amplified negative resist composition is applied to the substrate by a method such as spin coating to a film thickness of 0.03 to 2 μm, and this is pre-baked on a hot plate, preferably at 60 to 150°C for 1 to 20 minutes, more preferably at 80 to 140°C for 1 to 10 minutes, to form a resist film.

[0281] Next, the resist film is exposed using high-energy rays to irradiate a pattern. Examples of high-energy rays include ultraviolet light, far-ultraviolet light, excimer laser light (KrF, ArF, etc.), EUV, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, exposure using EUV or EB is preferred.

[0282] When using ultraviolet light, far ultraviolet light, excimer laser light, EUV, X-rays, gamma rays, or synchrotron radiation as the high-energy rays, a mask is used to form the desired pattern, and the exposure amount is preferably 1 to 500 mJ / cm². 2 More preferably 10 to 400 mJ / cm² 2 Irradiate in such a manner. When using an EB, direct exposure is preferred to form the desired pattern, with an exposure dose of 1 to 500 μC / cm². 2 More preferably 10-400 μC / cm² 2 Irradiate in such a way that it results in the following.

[0283] In addition to conventional exposure methods, immersion methods, which involve immersing the mask and the resist film in liquid, can also be used in some cases. In such cases, a water-insoluble protective film can be used.

[0284] Next, post-exposure baking (PEB) is performed on a hot plate, preferably at 60-150°C for 1-20 minutes, more preferably at 80-140°C for 1-10 minutes.

[0285] Subsequently, the substrate is developed using a developer solution of an alkaline aqueous solution such as TMAH in a concentration of 0.1 to 5% by mass, preferably 2 to 3% by mass, by conventional methods such as dipping, puddling, or spraying, preferably for 0.1 to 3 minutes, more preferably for 0.5 to 2 minutes, thereby forming the desired pattern on the substrate.

[0286] Furthermore, the chemically amplified negative resist composition of the present invention is particularly useful because it can form patterns with good resolution and a low LER. In addition, the chemically amplified negative resist composition of the present invention is particularly useful for pattern formation on substrates having a surface material that is prone to pattern peeling or pattern collapse because it is difficult to achieve good adhesion of the resist pattern. Suitable substrates include substrates in which a chromium compound containing one or more light elements selected from metallic chromium, oxygen, nitrogen, and carbon is sputtered onto the outermost surface, SiO, SiO x Examples include substrates containing tantalum compounds, molybdenum compounds, cobalt compounds, nickel compounds, tungsten compounds, and tin compounds in their outermost layer. The chemically amplified negative resist composition of the present invention is particularly useful for pattern formation using a photomask blank as the substrate. In this case, the photomask blank may be either a transmissive or reflective type.

[0287] As a transmissive mask blank, a photomask blank having a light-shielding film made of a chromium-based material may be a photomask blank for binary masks or a photomask blank for phase-shift masks. In the case of a photomask blank for binary masks, the light-shielding film may consist of an anti-reflective layer and a light-shielding layer made of a chromium-based material, or the entire anti-reflective film on the surface side, or only the surface side of the anti-reflective film on the surface side, may be made of a chromium-based material, and the remaining part may consist of a silicon-based compound material which may contain, for example, a transition metal. In the case of a photomask blank for phase-shift masks, a photomask blank for phase-shift masks having a chromium-based light-shielding film on the phase-shift film may be considered.

[0288] The aforementioned photomask blank having a chromium-based material on the outermost layer is very well known, as exemplified in Japanese Patent Publication No. 2008-26500, Japanese Patent Publication No. 2007-302873, or as prior art in those publications. A detailed explanation will be omitted, but for example, when constructing a light-shielding film having an anti-reflective layer and a light-shielding layer using a chromium-based material, the following film configuration can be used.

[0289] When forming a light-shielding film having an anti-reflective layer and a light-shielding layer using a chromium-based material, the layer configuration may be such that the anti-reflective layer and the light-shielding layer are laminated in that order from the surface side, or the anti-reflective layer, light-shielding layer, and anti-reflective layer are laminated in that order. Furthermore, the anti-reflective layer and the light-shielding layer may each be multilayered, and the composition may change discontinuously or continuously between layers with different compositions. As for the chromium-based material to be used, metallic chromium and materials containing light elements such as oxygen, nitrogen, and carbon in metallic chromium can be used. Specifically, metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium oxide nitride, chromium carbide nitride, chromium oxide nitride, chromium oxide nitride, etc. can be used.

[0290] Furthermore, a reflective mask blank comprises a substrate, a multilayer reflective film formed on one of the main surfaces (front side) of the substrate, specifically a multilayer reflective film that reflects exposure light such as EUV light, and an absorber film formed on the multilayer reflective film, specifically an absorber film that absorbs exposure light such as EUV light and reduces reflectivity. A reflective mask (EUV reflective mask) having an absorber pattern (pattern of the absorber film) formed by patterning the absorber film is manufactured from the reflective mask blank (EUV reflective mask blank). The wavelength of EUV light used in EUV lithography is 13-14 nm, and is usually light with a wavelength of about 13.5 nm.

[0291] The multilayer reflective film is usually preferably provided in contact with one of the main surfaces of the substrate, but it is also possible to provide an underlayer film between the substrate and the multilayer reflective film, provided that the effects of the present invention are not lost. The absorber film may be formed in contact with the multilayer reflective film, but a protective film (protective film for the multilayer reflective film) may be provided between the multilayer reflective film and the absorber film, preferably in contact with the multilayer reflective film, and more preferably in contact with both the multilayer reflective film and the absorber film. The protective film is used to protect the multilayer reflective film during processing such as cleaning and correction. Furthermore, it is preferable that the protective film has the function of protecting the multilayer reflective film when the absorber film is patterned by etching, and preventing oxidation of the multilayer reflective film. On the other hand, a conductive film used for electrostatically chucking the reflective mask to the exposure apparatus may be provided under the other main surface (back surface), which is the surface opposite to one of the main surfaces of the substrate, preferably in contact with the other main surface. Here, one main surface of the substrate is referred to as the front and upper side, and the other main surface as the back and lower side. However, the front and back sides and top and bottom are defined for convenience only, and the one main surface and the other main surface are either of the two main surfaces (film-forming surfaces) on the substrate, and the front and back sides and top and bottom are interchangeable. More specifically, it can be formed by methods such as those exemplified as prior art in Japanese Patent Application Publication No. 2021-139970 or therein.

[0292] According to the resist pattern formation method of the present invention, even when the outermost surface is made of a material that easily affects the resist pattern shape, such as a material containing chromium, silicon, or tantalum (for example, a transmissive or reflective mask blank), it is possible to obtain a pattern with extremely high resolution, low LER, excellent rectangularity, and excellent pattern fidelity. [Examples]

[0293] The present invention will be specifically described below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0294] The structures of polymers P-1 to P-30 used in the resist composition are shown in Table 1 below. Note that Mw is a polystyrene-converted value measured by GPC using THF or DMF as the solvent.

[0295] [Table 1]

[0296] In Table 1, the structure of each unit is as follows: [ka]

[0297] [ka]

[0298] [ka]

[0299] [ka]

[0300] [ka]

[0301] [1] Preparation of chemically amplified negative resist composition [Examples 1-1 to 1-54, Comparative Examples 1-1 to 1-10] Chemically amplified negative resist compositions (R-1 to R-54, CR-1 to CR-10) were prepared by dissolving each component in an organic solvent in the compositions shown in Tables 2 to 4 below, and filtering the resulting solutions through UPE filters and / or nylon filters selected from sizes of 10 nm, 5 nm, 3 nm, and 1 nm. The organic solvent was a mixed solvent consisting of 790 parts by mass of PGMEA, 1580 parts by mass of EL, and 1580 parts by mass of PGME. In addition, some compositions were given fluorine atom-containing polymers (polymers FP-1 to FP-5) as additives, tetramethoxymethyl glycoluryl (TMGU) as a crosslinking agent, and PF-636 (manufactured by OMNOVA SOLUTIONS) as a surfactant.

[0302] [Table 2]

[0303] [Table 3]

[0304] [Table 4]

[0305] In Tables 2-4, the photoacid generators PAG-1 to PAG-9, comparative photoacid generators cPAG-1 to cPAG-4, quenchers Q-1 to Q-4, and fluorine atom-containing polymers FP-1 to FP-5 are as follows: [ka]

[0306] [ka]

[0307] [ka] [ka]

[0308] [ka]

[0309] [2] EB lithography evaluation [Examples 2-1 to 2-54, Comparative Examples 2-1 to 2-10] Each chemically amplified negative resist composition (R-1 to R-54, CR-1 to CR-10) was spin-coated onto a 152 mm square mask blank, whose outermost surface was a silicon oxide film, which had been treated with hexamethyldisilazane (HMDS) vapor priming using ACT-M (manufactured by Tokyo Electron Limited). The blanks were then pre-baked on a hot plate at 110°C for 600 seconds to produce a resist film with a thickness of 80 nm. The thickness of the obtained resist films was measured using an optical measuring instrument, NanoSpec (manufactured by Nanometrics). Measurements were taken at 81 locations within the plane of the blank substrate, excluding the outer edge portion from the outer edge of the blank to 10 mm inward, and the average thickness and thickness range were calculated.

[0310] Exposure was performed using an electron beam lithography system (EBM-5000plus, manufactured by Newflare Technology Co., Ltd., accelerating voltage 50kV), followed by PEB at 120°C for 600 seconds, and development with a 2.38 mass% TMAH aqueous solution to obtain a negative-type pattern.

[0311] The obtained resist patterns were evaluated as follows: The fabricated patterned mask blanks were observed using an overhead SEM (scanning electron microscope), and the optimal exposure amount (μC / cm²) was determined to resolve 200 nm 1:1 line-and-space (LS) lines at a 1:1 ratio. 2The resolution (limiting resolution) was defined as the minimum dimension at the exposure dose that resolves a 200nm LS at a 1:1 ratio. For the 200nm LS pattern obtained by irradiation with the optimal exposure dose, 80 edge detection points were performed on each of the 32 edges of the 200nm LS pattern using a SEM, and the value three times the variation (standard deviation, σ) (3σ) was calculated and defined as LER (nm). The pattern shape was determined visually to determine whether it was rectangular or not. Furthermore, for pattern fidelity evaluation, the area loss value (%) of one corner of the dot pattern was calculated when a 120nm size square dot pattern was placed at a density of 36%, and a smaller value indicates better rectangularity of the dot shape. The results are shown in Tables 5 to 7.

[0312] [Table 5]

[0313] [Table 6]

[0314] [Table 7]

[0315] The chemically amplified negative resist compositions (R-1 to R-54) of the present invention all exhibited good resolution, LER, pattern rectangularity, and pattern fidelity. On the other hand, the comparative resist compositions (CR-1 to CR-10) had insufficient design of the acid generator, resulting in inadequate performance in terms of resolution, LER, and pattern rectangularity.

[0316] The resist pattern formation method using the chemically amplified negative resist composition of the present invention is useful for semiconductor device manufacturing, particularly for photolithography in the processing of transmissive or reflective photomask blanks.

Claims

1. A chemically amplified negative resist composition comprising (A) a photoacid generator consisting of an onium salt represented by the following formula (A), and (B) a base polymer containing a polymer having repeating units represented by the following formula (B1). 【Chemistry 1】 (In the formula, n1 is an integer between 0 and 2. When n1=0, n2 is an integer between 2 and 5; when n1=1, n2 is an integer between 2 and 7; and when n1=2, n2 is an integer between 2 and 9.) L is a single bond, ether bond, ester bond, sulfonic acid ester bond, carbonate bond, or carbamate bond. R 1 and R 2 Each of these is a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms, which may independently contain a hydrogen atom or a heteroatom, but neither can be a hydrogen atom. Also, R 1 and R 2 These elements may bond with each other to form a ring with the carbon atoms to which they are bonded. R 3 Each is independently a branched or cyclic hydrocarbyl group having 3 to 20 carbon atoms, which may contain an iodine atom or a heteroatom, and at least one R 3 L is bonded to a carbon atom adjacent to the carbon atom to which it is bonded. Z + This is an onium cation. 【Chemistry 2】 (In the formula, a1 is 0 or 1. a2 is an integer between 0 and 2. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is an integer between 1 and 3.) R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 is a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom. A 1 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group is -CH 2 (Some of the hyphens may be replaced with -O-.)

2. The chemically amplified negative resist composition according to claim 1, wherein component (A) is an onium salt represented by the following formula (A1). 【Transformation 3】 (In the formula, L, R 1 , R 2 , R 3 and Z + (The same as above. n3 is an integer between 1 and 4.)

3. The chemically amplified negative resist composition according to claim 2, wherein component (A) is an onium salt represented by the following formula (A2). 【Chemistry 4】 (In the formula, n3, R 1 , R 2 , R 3 and Z + (This is the same as above.)

4. Z + The chemically amplified negative resist composition according to claim 1, wherein the sulfonium cation represented by the following formula (caten-1) or the iodonium cation represented by the following formula (caten-2). 【Transformation 5】 (In the formula, R ct1 ~R ct5 Each of these is independently a hydrocarbyl group having 1 to 30 carbon atoms, which may contain a halogen atom or a heteroatom. Also, R ct1 and R ct2 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded.

5. The chemically amplified negative resist composition according to claim 1, wherein the polymer further comprises repeating units represented by the following formula (B2). 【Transformation 6】 (In the formula, b1 is 0 or 1. b2 is an integer between 0 and 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is an integer between 1 and 3.) R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 12 This is a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms that may be substituted with a halogen atom. R 13 and R 14 Each of these is independently a hydrogen atom, a hydroxyl group, or a saturated hydrocarbyl group having 1 to 15 carbon atoms which may be substituted with a saturated hydrocarbyloxy group, or an aryl group which may have substituents. However, R 13 and R 14 They cannot simultaneously become hydrogen atoms. Also, R 13 and R 14 These atoms may bond to each other, forming a ring with the carbon atoms to which they are bonded. A 2 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group is -CH 2 Some of the hyphens may be replaced with -O-. W 1 (This is a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, or an aryl group which may have substituents.)

6. The chemically amplified negative resist composition according to claim 1, wherein the polymer further comprises at least one selected from repeating units represented by the following formula (B3), repeating units represented by the following formula (B4), and repeating units represented by the following formula (B5). 【Transformation 7】 (In the formula, c and d are each independently integers between 0 and 4. e1 is 0 or 1. e2 is an integer between 0 and 5. e3 is an integer between 0 and 2.) R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 and R 22 These are, independently, a hydroxyl group, a halogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms that may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms that may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms that may be substituted with a halogen atom. R 23 These are saturated hydrocarbyl groups having 1 to 20 carbon atoms, saturated hydrocarbyloxy groups having 1 to 20 carbon atoms, saturated hydrocarbylcarbonyloxy groups having 2 to 20 carbon atoms, saturated hydrocarbyloxyhydrocarbyl groups having 2 to 20 carbon atoms, saturated hydrocarbylthiohydrocarbyl groups having 2 to 20 carbon atoms, halogen atoms, nitro groups, cyano groups, saturated hydrocarbylsulfinyl groups having 1 to 20 carbon atoms, or saturated hydrocarbylsulfonyl groups having 1 to 20 carbon atoms. A 3 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the saturated hydrocarbylene group is -CH 2 (Some of the hyphens may be replaced with -O-.)

7. The chemically amplified negative resist composition according to claim 5, wherein the polymer further comprises at least one selected from repeating units represented by the following formula (B6), repeating units represented by the following formula (B7), repeating units represented by the following formula (B8), repeating units represented by the following formula (B9), repeating units represented by the following formula (B10), repeating units represented by the following formula (B11), repeating units represented by the following formula (B12), and repeating units represented by the following formula (B13). 【Transformation 8】 (In the formula, R B Each of these is independently either a hydrogen atom or a methyl group. Y 1 This is a single bond, an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, or *-O-Y 11 -, *-C(=O)-O-Y 11 - or * - C (= O) - NH - Y 11 - and Y 11 This is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Y 2 is a single bond or **-Y 21 -C(=O)-O- and Y 21 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. Y 3 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, trifluoromethyl groups, and phenylene groups substituted with *-O-Y. 31 -, *-C(=O)-O-Y 31 - or * - C (= O) - NH - Y 31 - is Y 31 This refers to a C1-C6 aliphatic hydrocarbylene group, phenylene group, fluorinated phenylene group, phenylene group substituted with a trifluoromethyl group, or a C7-C20 group obtained by combining these, which may contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * represents a bond with a carbon atom in the main chain, and ** represents a bond with an oxygen atom in the formula. Y 4 This is a hydroxylene group having 1 to 30 carbon atoms, which may contain single bonds or heteroatoms. f1 and f2 are independently either 0 or 1, but Y 4 When it is a single bond, f1 and f2 are 0. R 31 ~R 48 Each of these is independently a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. 31 and R 32 However, they may bond to each other and form a ring with the sulfur atom to which they are bonded, R 33 and R 34 , R 36 and R 37 , or R 39 and R 40 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. R HF This is either a hydrogen atom or a trifluoromethyl group. Xa - (It is a non-nucleophilic counterion.)

8. The chemically amplified negative resist composition according to claim 7, wherein the polymer comprises a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (B2-1), or a repeating unit represented by the following formula (B2-2), and a repeating unit represented by the following formula (B7). 【Chemistry 9】 (In the formula, a4, b4, R A , R B , Y 2 , R 13 , R 14 , R 33 , R 34 , R 35 and R HF (This is the same as above.)

9. Furthermore, the chemically amplified negative resist composition according to claim 7, wherein the (B) base polymer further comprises a polymer that includes repeating units represented by formula (B1) and repeating units represented by formula (B2), and does not include repeating units represented by formulas (B6) to (B13).

10. The chemically amplified negative resist composition according to claim 1, wherein the content of repeating units having an aromatic ring skeleton among all repeating units of the polymer contained in the base polymer is 60 mol% or more.

11. Furthermore, the chemically amplified negative resist composition according to claim 1, further comprising (C) a crosslinking agent.

12. A chemically amplified negative resist composition according to claim 5, which does not contain a crosslinking agent.

13. Furthermore, the chemically amplified negative resist composition according to claim 1, comprising (D) a fluorine atom-containing polymer which comprises at least one selected from repeating units represented by the following formula (D1), repeating units represented by the following formula (D2), repeating units represented by the following formula (D3), and repeating units represented by the following formula (D4), and which may further comprise at least one selected from repeating units represented by the following formula (D5) and repeating units represented by the following formula (D6). 【Chemistry 10】 (In the formula, x is an integer between 1 and 3. y is an integer satisfying 0 ≤ y ≤ 5 + 2z - x. z is 0 or 1. k is an integer between 1 and 3.) R C These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R D Each of these is independently either a hydrogen atom or a methyl group. R 101 , R 102 , R 104 and R 105 Each of these is independently either a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. R 103 、 R 106 、 R 107 and R 108 are each independently a hydrogen atom, a hydrocarbyl group having 1 to 15 carbon atoms, a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid-labile group, and when R 103 、 R 106 、 R 107 and R 108 are a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be interposed between carbon-carbon bonds. R 109 This is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms, which may have a hydrogen atom or a group containing a heteroatom between the carbon-carbon bonds. R 110 This is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms, which may have a group containing a heteroatom interposed between the carbon-carbon bonds. R 111 This is a saturated hydrocarbyl group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted with a fluorine atom, and the saturated hydrocarbyl group is -CH 2 A portion of the - may be substituted with an ester bond or an ether bond. Z 1 is a (k + 1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k + 1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. Z 2 The bond is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. The asterisk (*) is a bond with a carbon atom in the main chain. Z 3 This is a single bond, -O-, *-C(=O)-O-Z 31 -Z 32 - or * - C (= O) - NH - Z 31 -Z 32 - is Z 31 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms. 32 A is a single bond, ester bond, ether bond, or sulfonamide bond. * indicates a bond to a carbon atom in the main chain.

14. Furthermore, the negative-type resist composition according to claim 1, further comprising (E) a quencher.

15. Furthermore, the chemically amplified negative resist composition according to claim 14, wherein the content ratio of (A) acid generator to (E) quencher is less than 6 by mass.

16. Furthermore, the chemically amplified negative resist composition according to claim 1, further comprising (F) an organic solvent.

17. A method for forming a resist pattern, comprising the steps of: forming a resist film on a substrate using a chemically amplified negative resist composition according to any one of claims 1 to 16; irradiating the resist film with a pattern using high-energy rays; and developing the resist film irradiated with the pattern using an alkaline developer.

18. The resist pattern formation method according to claim 17, wherein the high-energy ray is an extreme ultraviolet ray or an electron ray.

19. The resist pattern forming method according to claim 17, wherein the outermost surface of the substrate is made of a material containing at least one selected from chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin.

20. The resist pattern forming method according to claim 17, wherein the substrate is a transmissive or reflective mask blank.

21. A transmissive or reflective mask blank coated with a chemically amplified negative resist composition according to any one of claims 1 to 16.

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