Chemically amplified negative resist composition and resist pattern formation method

Abstract

The present invention provides a chemically amplified negative resist composition and a resist pattern formation method that improve resolution during pattern formation and enable the creation of resist patterns with good LER and pattern fidelity. [Solution] (A) A chemically amplified negative resist composition comprising a photoacid generator consisting of an onium salt represented by the following formula (A), and a base polymer containing a polymer with repeating units of a specific structure. TIFF2026090781000379.tif29102

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 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 shapes. Patent Document 10 describes a photoacid generator that produces bulky generated acid and suppresses acid diffusion, which yielded patterns with good resolution and roughness, but had the drawback of exhibiting corner rounding in dot patterns. Patent Document 11 proposes a photoacid generator that produces non-fluorinated aromatic sulfonic acid having multiple bulky norbornyl groups, Patent Document 12 proposes a photoacid generator with a triarylbenzenesulfonic acid anion structure, and Patent Document 13 proposes a photoacid generator that produces non-fluorinated aromatic sulfonic acid with an introduced iodine-containing aromatic ring. Although the molecular weight of the generated acid is increased by multiple alkyl substituents, aromatic rings, and iodine atoms, thereby reducing acid diffusion, the suppression of acid diffusion is still insufficient when the goal is to form fine patterns, and there is still room for further improvement. [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 [Patent Document 11] Patent No. 7067271 [Patent Document 12] Patent No. 7032549 [Patent Document 13] Japanese Patent Publication No. 2023-177038 [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] As a result of diligent research to achieve the above objective, the present inventors have found that when an aromatic sulfonic acid type onium salt, which generates aromatic sulfonic acid, is introduced into a resist composition as a photoacid generator, in which the rotational degrees of freedom are suppressed by the bonding of an aromatic ring to which a sulfo group is bonded and another aromatic ring structure containing a bulky substituent via a sulfonamide bond, the acid generated therefrom has an appropriate acidity and excessive diffusion of the acid is suppressed, resulting in a pattern with good resolution and a small LER, and furthermore, a pattern with good rectangular shape due to appropriate dissolution inhibition, the present inventors have come to terms with this finding and have made 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 0 or 1. n2 is 1, 2, 3, 4 or 5 when n1 is 0, and n2 is 1, 2, 3, 4, 5, 6 or 7 when n1 is 1. n3 is 0 or 1. n4 is 0, 1, 2, 3 or 4. n5 is 0, 1, 2, 3 or 4. However, when n3 is 0, 0 ≤ n4 + n5 ≤ 4, and when n3 is 1, 0 ≤ n4 + n5 ≤ 6.) R , , A are each 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 1 is bonded to the carbon atom adjacent to the carbon atom to which S is bonded. When n2 is 2 or more, each R 1 may be the same as or different from each other, and a plurality of R 1 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded.) R 2 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom other than a fluorine atom or a heteroatom other than a fluorine atom. When n4 is 2, 3 or 4, each R 2 may be the same as or different from each other, and a plurality of R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded.) R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms or a fluorinated alkylthio group having 1 to 6 carbon atoms. When n5 is 2, 3 or 4, each R F may be the same as or different from each other.) Z + ​​​​​​​​​​​​​​11 This is a halogen atom, a nitro group, a carboxyl group, 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. When a3 is 2 or more, each R 11 They may be the same as or different from each other. A 1 (This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- groups of the saturated hydrocarbylene group may be substituted with -O- groups.) 2. A chemically amplified negative resist composition of type 1, wherein the onium salt is represented by the following formula (A1). [ka] (In the formula, n2, n3, n4, n5, R 1 , R 2 , R F and Z + (This is the same as above.) 3. A chemically amplified negative resist composition of type 2, wherein the onium salt is represented by the following formula (A2). [ka] (In the formula, n3, n4, n5, R 1 , R 2 , R F and Z + (This is the same as above.) 4.Z + A chemically amplified negative resist composition of any of 1 to 3, wherein the sulfonium cation is represented by the following formula (Z-1) or the iodonium cation is represented by the following formula (Z-2). [ka] (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 Rct2 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. 5.Z + However, the chemically amplified negative resist composition is one of 1 to 3, which are sulfonium cations represented by the following formula (Z-3). [ka] (In the formula, m1 is 0 or 1. m2 is 0 or 1. m3 is 0 or 1. m4 is 0, 1, 2, 3 or 4. m5 is 0, 1, 2, 3 or 4. m6 is 0, 1, 2, 3, 4, 5 or 6. m7 is 0, 1, 2, 3, 4, 5 or 6. m8 is 0, 1 or 2. m9 is 0, 1 or 2. m10 is 0, 1 or 2. m11 is 0 or 1. m12 is 0, 1, 2, 3 or 4. m13 is 0, 1 or 2. m14 is 0, It is either 1 or 2. However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4, and when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4, and when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4, and when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4, and when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1. R F1 ~R F3 Each of these is independently a fluorine atom, a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbylthio group having 1 to 6 carbon atoms. When m5 is 2, 3, or 4, each R F1 They may be the same or different from each other. When m6 is 2, 3, 4, 5 or 6, each R F2 They may be the same or different from each other. When m7 is 2, 3, 4, 5 or 6, each R F3 They may be the same as or different from each other. R ct6 ~R ct9This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than iodine and fluorine atoms, a nitro group, a cyano group, a heteroatom, a C1-C20 hydrocarbyloxy group which may contain a heteroatom, or a C1-C20 hydrocarbylthio group which may contain a heteroatom. When m8 is 2, two R ct6 The two Rs may be identical or different from each other. ct6 These may bond with each other to form a ring with the carbon atom to which they are bonded. When m9 is 2, two R ct7 The two Rs may be identical or different from each other. ct7 These may bond with each other to form a ring with the carbon atom to which they are bonded. When m10 is 2, two R ct8 The two Rs may be identical or different from each other. ct8 These may bond with each other to form a ring with the carbon atoms to which they are bonded. When m13 is 2, two R ct9 The two Rs may be identical or different from each other. ct9 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. Also, S in sulfonium cations + Aromatic rings that are directly bonded to each other are bonded to each other, forming S + They may form a ring together. L A and L B These are, independently, a single bond, an ether bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. X L This is a hydrocarbylene group having 1 to 40 carbon atoms, which may contain single bonds or heteroatoms. 6. Any one of 1 to 5 chemically amplified negative resist compositions wherein the polymer further comprises at least one selected from repeating units represented by the following formula (B2) and repeating units represented by the following formula (B3). [ka] (In the formula, b1 is 0 or 1. b2 is 0, 1 or 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is 1, 2 or 3. b5 is 0, 1 or 2. b6 is 1 or 2.) R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 This is a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. When b3 is 2 or more, each R 21 They may be the same as or different from each other. R 22 and R 23 Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. However, R 22 and R 23 They cannot become hydrogen atoms at the same time. Also, R 22 and R 23 These may bond to each other to form a ring with the carbon atoms to which they are bonded, and some of the -CH2- in the ring may be substituted with -O- or -S-. When b4 is 2 or 3, each R 22 These may be the same or different from each other. Also, when b4 is 2 or 3, each R 23 They may be the same as or different from each other. R 31 This is a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. When b5 is 2, each R 31 They may be the same as or different from each other. R 32 and R 33Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. However, R 32 and R 33 They cannot become hydrogen atoms at the same time. Also, R 32 and R 33 These may bond to each other and form a ring with the carbon atoms to which they are bonded, and some of the -CH2- in the ring may be substituted with -O- or -S-. When b6 is 2, each R 32 These may be the same or different from each other. Also, when b6 is 2, each R 33 They may be the same as or different from each other. A 2 This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- groups of the saturated hydrocarbylene group may be substituted with -O- groups. W 1 and W 2 Each of these is independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbyl carbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have substituents. When b4 is 2 or 3, each W 1 These may be the same or different from each other. Also, when b6 is 2 or 3, each W 2 They may be the same or different from each other. 7. Any one of 1 to 6 chemically amplified negative resist compositions, wherein the polymer further comprises at least one selected from repeating units represented by the following formula (B4), repeating units represented by the following formula (B5), and repeating units represented by the following formula (B6). [ka] (In the formula, c and d are independently 0, 1, 2, 3, or 4. e1 is 0 or 1. e2 is 0, 1, or 2. e3 is 0, 1, 2, 3, 4, or 5.) RA These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 and R 42 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. When c is 2, 3, or 4, each R 41 They may be the same or different from each other. When d is 2, 3 or 4, each R 42 They may be the same as or different from each other. R 43 This 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. When e3 is 2, 3, 4, or 5, each R 43 They may be the same as or different from each other. A 3 (This is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- groups of the saturated hydrocarbylene group may be substituted with -O- groups.) 8. Six chemically amplified negative resist compositions wherein the polymer comprises at least one selected from 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), and repeating units represented by the following formula (B11). [ka] (wherein, f1 and f2 are each independently 0, 1, 2 or 3; g1 is 0 or 1; g2 is 0, 1, 2, 3 or 4; g3 is 0, 1, 2, 3 or 4; provided that when g1 is 0, 0 ≦ g2 + g3 ≦ 4, and when g1 is 1, 0 ≦ g2 + g3 ≦ 6). R A is each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Z 1 is a single bond or a phenylene group which may have a substituent. Z 2 is a single bond, **-C(=O)-O-Z 21 -, **-C(=O)-NH-Z 21 - or **-O-Z 21 -. Z 21 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group or a divalent group obtained by combining these, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond or a hydroxy group. Z 3 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 4 is a single bond or an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group or a divalent group obtained by combining these, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond or a hydroxy group. Z 5 is each independently a single bond, a phenylene group which may have a substituent, a naphthylene group or *-C(=O)-O-Z 51 -. Z 51 is an aliphatic hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the aliphatic hydrocarbylene group may contain a halogen atom, a hydroxy group, an ether bond, an ester bond or a lactone ring. Z 6is a single bond, an ether bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 7 is, independently of each other, a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 - or ***-O-Z 71 -. Z 71 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a hetero atom. Z 8 is, independently of each other, a single bond, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 - or ****-O-Z 81 -. Z 81 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a hetero atom. Z 9 is a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-C(=O)-O-Z 91 -, *-C(=O)-N(H)-Z 91 - or *-O-Z 91 -. Z 91 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group or a phenylene group substituted with a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond or a hydroxy group. * represents a bond to a carbon atom of the main chain. ** represents a bond to 1 Z 6 *** represents a bond to 7 Z L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Rf 1 and Rf 2Each of these is independently either a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. However, all Rf 5 and Rf 6 They cannot simultaneously become hydrogen atoms. Rf 7 This is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. When g2 is 2, 3, or 4, each Rf 7 They may be the same as or different from each other. R 51 and R 52 Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms. Also, R 51 and R 52 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. R 53 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than fluorine atoms, or heteroatoms. When g3 is 2, 3, or 4, each R 53 They may be the same or different from each other, and there may be multiple R 53 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. M - It is a non-nucleophilic counterion. A + This is an onium cation. 9. Eight chemically amplified negative resist compositions, wherein the polymer comprises repeating units represented by the following formula (B1-1), repeating units represented by the following formulas (B2-1), (B2-2), or (B3-1), and repeating units represented by the following formula (B8-1). [ka] (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 32 , R 33 and A + The same applies as above. R HF This is either a hydrogen atom or a trifluoromethyl group. Z 10 This is a single bond or *****-Z 101 -C(=O)-O- Z 101 This is a hydroxylene group having 1 to 20 carbon atoms, which may contain heteroatoms. ***** represents the bond with the oxygen atom in the formula. 10. (B) A chemically amplified negative resist composition of 8 or 9 comprising a base polymer further comprising a polymer that includes repeating units represented by formula (B1) and repeating units represented by formula (B2) or (B3), and does not include repeating units represented by formulas (B7) to (B11). 11. A chemically amplified negative resist composition according to any one of 1 to 10, 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. 12. Furthermore, (C) any of the chemically amplified negative resist compositions 1 to 11 comprising a crosslinking agent. 13. A chemically amplified negative resist composition according to any of 1 to 11, which does not contain a crosslinking agent. 14. A chemically amplified negative resist composition of any one of 1 to 13, further comprising (D) a fluorine atom-containing polymer which comprises at least one selected from the repeating units represented by the following formula (D1), the repeating units represented by the following formula (D2), the repeating units represented by the following formula (D3), and the repeating units represented by the following formula (D4), and which may further comprise at least one selected from the repeating units represented by the following formula (D5) and the repeating units represented by the following formula (D6). [ka] (In the formula, j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3.) R B These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R C 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 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 R 103 , R 106 , R 107 and R 108 When the group is a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be interposed between the 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 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 a portion of the -CH2- of the saturated hydrocarbyl group may be substituted with an ester bond or an ether bond. X 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. X 2A is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * represents a bond with a carbon atom in the main chain. X 3 This is a single bond, -O-, *-C(=O)-OX 31 -X 32 - or *-C(=O)-NH-X 31 -X 32 - is X 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. 15. Furthermore, any of the negative-type resist compositions 1 to 14 comprising (E) a quencher. 16. A chemically amplified negative resist composition having a mass ratio of (A) photoacid generator to (E) quencher of less than 6. 17. Furthermore, (F) any of the chemically amplified negative resist compositions 1 to 16 comprising an organic solvent. 18. A chemically amplified negative resist composition according to any of 1 to 17, further comprising a photoacid generator other than component (G)(A). A method for forming a resist pattern, comprising the steps of: forming a resist film on a substrate using any of the chemically amplified negative resist compositions described in 19.1 to 18; irradiating the resist film with a pattern using high-energy rays; and developing the resist film irradiated with the pattern using an alkaline developer. 20. A resist pattern formation method 19 wherein the high-energy beam is an extreme ultraviolet beam or electron beam with a wavelength of 3 to 15 nm. 21. A method for forming a resist pattern 19 or 20, 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. 22. A resist pattern formation method according to any of 19 to 21, wherein the substrate is a transmissive or reflective mask blank. A transmissive or reflective mask blank coated with any of the chemically amplified negative resist compositions described in 23.1 to 23.18. [Effects of the Invention]

[0016] The chemically amplified negative resist composition of the present invention exhibits extremely high resolution and can produce patterns with low LER in microfabrication techniques, particularly EB lithography and EUV lithography. Furthermore, it is suitable as a chemically amplified negative resist material because it can produce patterns with good rectangular shape due to its appropriate dissolution inhibition properties. [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 consisting of an onium salt that generates a predetermined benzenesulfonic acid derivative, and (B) a base polymer containing a predetermined polymer.

[0019] [(A) Photoacid Generator] The photoacid generator of component (A) consists of an onium salt represented by the following formula (A). [ka]

[0020] In formula (A), n1 is 0 or 1. When n1 is 0, it is a benzene ring, and when n1 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that n1 is a benzene ring with n1 being 0. When n1 is 0, n2 is 1, 2, 3, 4, or 5, and when n1 is 1, it is 1, 2, 3, 4, 5, 6, or 7. From the viewpoint of raw material procurement, it is preferable that n2 is 1, 2, 3, or 4, and more preferably 2 or 3. n3 is 0 or 1. When n3 is 0, it is a benzene ring, and when n3 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that n3 is a benzene ring with n3 being 0. n4 is 0, 1, 2, 3, or 4. n5 is 0, 1, 2, 3, or 4. However, when n3 is 0, 0 ≤ n4 + n5 ≤ 4, and when n3 is 1, 0 ≤ n4 + n5 ≤ 6.

[0021] In formula (A), R 1 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 1 The sulfur atom is bonded to a carbon atom adjacent to the carbon atom to which S is bonded. Specific examples of the hydrocarbyl group include branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, tert-pentyl, and 2-ethylhexyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, oxanorbornyl, and tricyclo[5.2.1.0 2,6Examples include, but are not limited to, cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as decyl groups and adamantyl groups; aryl groups 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 groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, it may contain hydroxyl groups, cyano groups, halogen 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. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms, but fluorine atoms or iodine atoms are preferred. 1 Preferred C3-C20 branched alkyl groups such as isopropyl group, sec-butyl group, tert-butyl group, tert-pentyl group, and 2-ethylhexyl group; C3-C20 aliphatic cyclic hydrocarbyl groups such as cyclopentyl group, cyclohexyl group, norbornyl group, oxanorbornyl group, and adamantyl group; or C6-C20 aryl groups such as phenyl group and naphthyl group, which may have substituents. Preferred substituents that the aryl group may have include fluorine, chlorine, bromine, iodine, C1-C10 hydrocarbyl groups which may contain heteroatoms, C1-C10 hydrocarbyloxy groups which may contain heteroatoms, and C1-C10 hydrocarbyloxycarbonyl groups which may contain heteroatoms. When n2 is 2 or more, each R 1 They may be the same as or different from each other.

[0022] Also, when n2 is 2 or greater, multiple R 1 However, they may bond with each other to form a ring with the carbon atoms to which they are bonded. A 5- to 8-membered ring is preferred.

[0023] R in equation (A) 1Examples of the structure in which an aromatic ring is bonded include, but are not limited to, those represented below. In the following formulas, the dashed line represents a bond to S + and is a bond to.

Chemical formula

[0024]

Chemical formula

[0025]

Chemical formula

[0026]

Chemical formula

[0027]

Chemical formula

[0028] <000(0921>

Chemical formula

[0029]

Chemical formula

[0030]

Chemical formula

[0031]

Chemical formula

[0032] In formula (A), at least one R 1It is bonded to the carbon atom adjacent to the carbon atom to which S is bonded. This allows the other aromatic ring to which the sulfo group is bonded and R to bond. 1 The spatial proximity of these two elements creates steric hindrance, which suppresses the rotation of the sulfonamide bond, thus greatly inhibiting acid diffusion.

[0033] In formula (A), R 2 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than fluorine atoms, or heteroatoms other than fluorine atoms. Examples of halogen atoms other than fluorine atoms include chlorine atoms, bromine atoms, iodine atoms, etc. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, tert-pentyl group, n-hexyl group, n-octyl group, 2-ethylhexyl group, n-nonyl group, n-decyl group; cyclopentyl group, cyclohexyl group, cyclopentylmethyl group, cyclopentylethyl group, cyclopentylbutyl group, cyclohexylmethyl group, cyclohexylethyl group, cyclohexylbutyl group, norbornyl group, tricyclo[5.2.1.0 2,6 Examples include cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as decyl groups, adamantyl groups, and adamantylmethyl groups; and aryl groups having 6 to 20 carbon atoms, such as phenyl groups, naphthyl groups, and anthracenyl groups. Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, it may contain hydroxyl groups, cyano groups, 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. When n4 is 2, 3, or 4, each R 2They may be the same as or different from each other. Also, when n4 is 2, 3, or 4, a plurality of Rs 2 may combine with each other to form a ring together with the carbon atom to which they are attached. The ring is preferably a 5- to 8-membered ring.

[0034] In formula (A), R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. As R F , a fluorine atom, a trifluoromethyl group, a difluoromethyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, or a difluoromethylthio group is preferable, and a fluorine atom, a trifluoromethyl group, or a trifluoromethoxy group is more preferable. By including a fluorine atom or these substituents having a fluorine atom, the acid strength of the acid generated by the electron-withdrawing effect is improved, so that the deprotection reaction of acid-labile groups such as tertiary esters and tertiary ethers proceeds smoothly. When n5 is 2, 3, or 4, each R F may be the same as or different from each other.

[0035] As the onium salt represented by formula (A), those represented by the following formula (A1) are preferable.

Chemical formula

[0036] As the onium salt represented by formula (A), those represented by the following formula (A1) are preferable.

Chemical formula

[0037] Particularly preferred examples of anions of onium salts represented by formula (A) include, but are not limited to, those listed below. [ka]

[0038] [ka]

[0039] [ka]

[0040] [ka]

[0041] [ka]

[0042] [ka]

[0043] [ka]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047]

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[0048]

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[0049]

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[0050]

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[0051]

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[0052]

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[0053]

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[0054]

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[0055]

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[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077]

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[0078]

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[0079]

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[0080]

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[0081]

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[0082]

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[0083]

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[0084]

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[0085]

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[0086]

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[0087]

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[0088]

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[0089]

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[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] [ka]

[0095] [ka]

[0096] In formula (A), Z + This is an onium cation. The onium cation is preferably a sulfonium cation represented by the following formula (Z-1) or an iodonium cation represented by the following formula (Z-2). [ka]

[0097] In equations (Z-1) and (Z-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.

[0098] R ct1~R ct5 Specific examples of halogen atoms represented by include fluorine, chlorine, bromine, and iodine atoms.

[0099] R ct1 ~R ct5 The hydrocarbyl group represented by can be saturated or unsaturated, and can 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, 1-propenyl, 2-propenyl, butenyl, and hexenyl groups; C3-C30 cyclic unsaturated hydrocarbyl groups such as cyclohexenyl; 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 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 fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0100] 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, specific examples of the structure of the ring include those represented by the following formula. [ka] (In the formula, the dashed line represents R ct3 (This is a combination of the two.)

[0101] For specific examples of sulfonium cations represented by formula (Z-1), see paragraph of Japanese Patent Publication No. 2024-003744.

[0102] Examples include, but are not limited to, those described in paragraphs

[0125] and paragraphs

[0070] to

[0085] of Japanese Patent Publication No. 2023-169812.

[0102] Specific examples of iodonium cations represented by formula (Z-2) include, but are not limited to, those described in paragraph

[0181] of Japanese Patent Application Publication No. 2024-000259.

[0103] Z + As the onium cation represented by the following formula (Z-3), a sulfonium cation represented by the following formula is also preferred. [ka]

[0104] In formula (Z-3), m1 is either 0 or 1. When m1 is 0, it is a benzene ring, and when m1 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that m1 is a benzene ring with a value of 0. m2 is either 0 or 1. When m2 is 0, it is a benzene ring, and when m2 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that m1 is a benzene ring with a value of 0. m3 is either 0 or 1. When m3 is 0, it is a benzene ring, and when m3 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, it is preferable that m3 is a benzene ring with a value of 0.

[0105] In formula (Z-3), m4 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure there are, the higher the absorption, especially for EUV. However, this also leads to poor solvent solubility and concerns about precipitation in the resist composition. Therefore, m4 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0106] In formula (Z-3), m5 is 0, 1, 2, 3, or 4. From the viewpoint of raw material procurement, m5 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2. m6 is 0, 1, 2, 3, 4, 5, or 6. From the viewpoint of raw material procurement, m6 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2. m7 is 0, 1, 2, 3, 4, 5, or 6. From the viewpoint of raw material procurement, m7 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0107] In formula (Z-3), m8 is 0, 1, or 2. From the viewpoint of raw material procurement, it is preferable that m8 is 0 or 1. m9 is 0, 1, or 2. From the viewpoint of raw material procurement, it is preferable that m9 is 0 or 1. m10 is 0, 1, or 2. From the viewpoint of raw material procurement, it is preferable that m10 is 0 or 1.

[0108] In formula (Z-3), m11 is either 0 or 1. When m11 is 0, it is a benzene ring, and when m11 is 1, it is a naphthalene ring, but from the viewpoint of solvent solubility, a benzene ring with m11 being 0 is preferred.

[0109] In formula (Z-3), m12 is 0, 1, 2, 3, or 4. The more iodine atoms in the cation structure there are, the higher the absorption, especially for EUV. However, this also leads to poor solvent solubility and concerns about precipitation in the resist composition. Therefore, m12 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0110] In formula (Z-3), m13 is 0, 1, or 2. From the viewpoint of raw material procurement, it is preferable that m13 is 0 or 1. m14 is 0, 1, or 2. From the viewpoint of synthesis, it is preferable that m14 is 0 or 1.

[0111] However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4, and when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4, and when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4, and when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4, and when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1.

[0112] In formula (Z-3), R F1 ~R F3 Each of these is independently a fluorine atom, a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbylthio group having 1 to 6 carbon atoms. Among these, trifluoromethyl, trifluoromethoxy, and trifluorothiomethoxy groups are preferred. When m5 is 2, 3, or 4, each R F1 They may be the same or different from each other. When m6 is 2, 3, 4, 5 or 6, each R F2 They may be the same or different from each other. When m7 is 2, 3, 4, 5 or 6, each R F3 They may be the same as or different from each other.

[0113] In formula (Z-3), R ct6 ~R ct9 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than iodine and fluorine atoms, a nitro group, a cyano group, a heteroatom, a C1-C20 hydrocarbyloxy group which may contain a heteroatom, or a C1-C20 hydrocarbylthio group which may contain a heteroatom. The hydrocarbyl portion of the hydrocarbyl group, hydrocarbyloxy group, and hydrocarbylthio group may be saturated or unsaturated, and may be linear, branched, or cyclic. For example, in the explanation of formula (A), R 2Examples of hydrocarbyl groups represented by the above are similar to those exemplified. Furthermore, some or all of the hydrogen atoms in the hydrocarbyl portion of the hydrocarbyl group, hydrocarbyloxy group and hydrocarbylthio group may be substituted with a group containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and some of the -CH2- of the hydrocarbyl group may be substituted with a group containing heteroatoms such as oxygen, sulfur, and nitrogen atoms, and as a result, the group 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.

[0114] Also, when m8 is 2, the two R ct6 The two Rs may be identical or different from each other. ct6 These may bond with each other to form a ring with the carbon atom to which they are bonded. When m9 is 2, two R ct7 The two Rs may be identical or different from each other. ct7 These may bond with each other to form a ring with the carbon atom to which they are bonded. When m10 is 2, two R ct8 The two Rs may be identical or different from each other. ct8 These may bond with each other to form a ring with the carbon atoms to which they are bonded. When m13 is 2, two R ct9 The two Rs may be identical or different from each other. ct9These elements may bond with each other to form a ring with the carbon atoms to which they are bonded. Specific examples of the ring 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, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano 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.

[0115] Furthermore, S in the sulfonium cation represented by formula (Z-3) + Aromatic rings that are directly bonded to each other are bonded to each other, forming S + They may form a ring together. Specific examples of the ring structure include those represented by the following formula. [ka]

[0116] In formula (Z-3), L A and L B These are, independently, a single bond, an ether bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. Of these, L A The bond is preferably a single bond, an ether bond, an ester bond, or a sulfonic acid ester bond, and more preferably an ester bond or a sulfonic acid ester bond. B The bond is preferably a single bond, an ether bond, or an ester bond, and more preferably a single bond.

[0117] In formula (Z-3), X LThis is a 1-40 carbon atom hydrocarbylene group which may contain single bonds or heteroatoms. The hydrocarbylene group may be linear, branched, or cyclic, and specific examples include an alkanediyl group and a cyclic saturated hydrocarbylene group. Specific examples of the heteroatom include an oxygen atom, a nitrogen atom, and a sulfur atom.

[0118] X L Specific examples of C1-C40 hydrocarbylene groups that may contain heteroatoms represented by the formulas shown below are, but are not limited to, those shown below. In the formulas below, * represents L A and L B This represents a combination of two things. [ka]

[0119] [ka]

[0120] [ka]

[0121] [ka]

[0122] Of these, X L -0~X L -22 and X L -47~X L -58 is preferable.

[0123] The sulfonium cation represented by formula (Z-3) is preferably the one represented by formula (Z-3-1) below. [ka] (In the formula, m4~m10, m12~m14, R F1 ~RF3 , R ct6 ~R ct9 , L A , L B and X L (This is the same as above.)

[0124] The cation represented by formula (Z-3-1) is preferably the one represented by formula (Z-3-2) below. [ka] (In the formula, m4~m10, R F1 ~R F3 and R ct6 ~R ct8 (This is the same as above.)

[0125] Specific examples of sulfonium cations represented by formula (Z-3) are listed below, but are not limited to these. In the following formula, Me represents a methyl group. [ka]

[0126] [ka]

[0127] [ka]

[0128] [ka]

[0129] [ka]

[0130] [ka]

[0131]

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[0132]

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[0133]

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[0134]

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[0135]

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[0136]

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[0137]

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[0138]

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[0139]

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[0140]

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[0141]

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[0142]

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[0143]

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[0144]

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[0145]

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[0147]

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[0148]

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[0149]

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[0150]

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[0151]

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[0152] [ka]

[0153] Specific examples of the onium salt include any combination of the anion and cation mentioned above.

[0154] The aforementioned onium salt can be synthesized by known methods. As an example, a method for producing the onium salt represented by the following formula (PAG-1-ex) will be described. [ka] (In the formula, n1~n5, R 1 , R 2 , R F and Z + (This is the same as above.)

[0155] The reaction shown in the scheme above is a sulfonamidate reaction between starting material SM-1 and amino aromatic sulfonate SM-2 to obtain the onium aromatic sulfonic acid salt PAG-1-ex. The reaction can be carried out according to conventional methods. Suitable solvents for the reaction include ethers such as tetrahydrofuran (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, dimethyl sulfoxide (DMSO), and N,N-dimethylformamide (DMF); and chlorinated organic solvents such as methylene chloride, chloroform, and carbon tetrachloride. These solvents can be appropriately selected depending on the reaction conditions, and may be used individually or in combination of two or more. In these solvents, starting material SM-1, amino aromatic sulfonate SM-2, and a base are added sequentially or simultaneously, and the reaction is carried out by cooling or heating as necessary. Examples of bases that can be used in the reaction include ammonia; amines such as triethylamine, pyridine, lutidine, colidine, and N,N-dimethylaniline; 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. It is desirable to confirm the progress of the reaction by silica gel thin-layer chromatography (TLC) for yield. The onium salt PAG-1-ex can be obtained from the resulting reaction solution by conventional aqueous work-up. If necessary, it can be purified by conventional methods such as chromatography and recrystallization.

[0156] The onium salt represented by formula (A) is an onium salt of an aromatic sulfonic acid, and therefore can generate an acid of appropriate intensity by irradiation with high-energy rays. 1 It has one or more groups selected from branched alkyl groups, alicyclic groups, and aryl groups, and various functional groups can be introduced to the aryl group. Therefore, R 1If the group is an aryl group, it is preferable that the aryl group has a functional group. 1 When the group is an aryl group and has a hydrocarbyloxycarbonyl group as a functional group, acid diffusion can be reduced by having multiple heteroatoms due to ester bonds. Also, R 1 When the aryl group has a functional group containing a halogen atom, particularly a fluorine atom, the solvent solubility of the onium salt itself is increased, improving uniform dispersion, and the acidity of the generated sulfonic acid can be strengthened. This promotes the deprotection reaction of the protecting group of the base polymer, and an improvement in resolution can be expected. Furthermore, R 1 When the group is an aryl group and has branched alkyl or alicyclic groups, the exclusion volume of the anion increases, resulting in a bulky structure. This allows for the generation of low-diffusion acids, improving LER (Low Efficiency Diffusion). Furthermore, the multiple aromatic rings in the anion improve compatibility with the aromatic rings of the base polymer through mutual interaction (π-π stacking interaction), which is expected to suppress excessive acid diffusion. The nitrogen atom derived from the sulfonamide bond has reduced basicity due to the electron-withdrawing effect of the adjacent sulfon bond and does not have the effect of trapping protons of the generated acid. However, since the sulfonamide bond has multiple heteroatoms, the lone pairs of electrons and protons form hydrogen bonds, which can suppress excessive acid diffusion. Due to these effects, acids with controlled acid strength and diffusion can be uniformly generated in the resist film. As a result, even fine patterns can be obtained with good resolution and low LER, and in negative-type resist compositions using alkaline developers, patterns with good rectangularity can be obtained due to appropriate dissolution inhibition.

[0157] In the chemically amplified negative resist composition of the present invention, the content of (A) photoacid generator is preferably 0.1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, relative to 80 parts by mass of (B) base polymer, as described later. When the content of (A) photoacid generator is within the above range, the amount of acid necessary for deprotection of acid-unstable groups is generated, and storage stability is also good. (A) photoacid generator may be used alone or in combination of two or more types.

[0158] [(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]

[0159] In formula (B1), a1 is 0 or 1. a2 is 0, 1 or 2, where 0 is a benzene skeleton, 1 is a naphthalene skeleton, and 2 is anthracene skeleton. a3 is an integer satisfying 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is 1, 2 or 3. When a2 is 0, preferably a3 is 0, 1, 2 or 3 and a4 is 1, 2 or 3. When a2 is 1 or 2, preferably a3 is 0, 1, 2, 3 or 4 and a4 is 1, 2 or 3.

[0160] In formula (B1), R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0161] In formula (B1), R 11This is a halogen atom, a nitro group, a carboxyl group, 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.

[0162] 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.

[0163] 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.)

[0164] 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]

[0165] The repeating unit B1 may be used alone or in combination of two or more types.

[0166] Polymer B may contain at least one repeating unit selected from the repeating unit represented by the following formula (B2) (hereinafter also referred to as repeating unit B2) and the repeating unit represented by the following formula (B3) (hereinafter also referred to as repeating unit B3) (hereinafter, polymer B that further contains at least one selected from repeating unit B2 and repeating unit B3 will also be referred to as polymer B'). [ka]

[0167] Repeating units B2 and B3 are formed when irradiated with high-energy rays by the action of acid generated from the photoacid generator, resulting in -OW 1 Ya-OW 2 These repeating units undergo an elimination reaction, inducing insolubilization in the alkaline developer and crosslinking reactions between polymers. The action of repeating units B2 and B3 allows the negative conversion reaction to proceed more efficiently, thereby improving resolution performance.

[0168] In equation (B2), b1 is either 0 or 1. b2 is either 0, 1, or 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is either 1, 2, or 3.

[0169] In formula (B3), b5 is 0, 1, or 2, but is preferably 0 or 1. b6 is 1 or 2, but is preferably 1.

[0170] In formulas (B2) and (B3), R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. In formula (B3), among these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0171] In formula (B2), R 21 This is a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a halogen atom or a heteroatom. 21 Specific examples of halogen atoms represented by R include fluorine, chlorine, bromine, and iodine atoms. 21 The hydrocarbyl group having 1 to 20 carbon atoms, represented by , may be saturated or unsaturated, and may be linear, branched, or cyclic. For example, in the explanation of formula (A), R 2 Examples of hydrocarbyl groups represented by the same group as those exemplified include those shown above. 21 They may be the same as or different from each other.

[0172] In formula (B2), R 22 and R 23 Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. However, R 22 and R 23 They cannot become hydrogen atoms at the same time. Also, R 22 and R 23 These may bond to each other to form a ring with the carbon atoms to which they are bonded, and some of the -CH2- in the ring may be substituted with -O- or -S-. 22 and R 23 Preferably, examples include alkyl groups such as methyl, ethyl, propyl, and butyl groups, and structural isomers thereof, or those in which some of the hydrogen atoms are substituted with hydroxyl groups or saturated hydrocarbyloxy groups. 22These may be the same or different from each other. Also, when b4 is 2 or 3, each R 23 They may be the same as or different from each other.

[0173] In formula (B3), R 31 This is a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a halogen atom or a heteroatom. 31 Specific examples of halogen atoms represented by R include fluorine, chlorine, bromine, and iodine atoms. 31 The hydrocarbyl group having 1 to 20 carbon atoms, represented by , may be saturated or unsaturated, and may be linear, branched, or cyclic. For example, in the explanation of formula (A), R 2 Examples of hydrocarbyl groups represented by the same as those exemplified include those shown above. 31 They may be the same as or different from each other.

[0174] In formula (B3), R 32 and R 33 Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. When b6 is 2, each R 32 These may be the same or different from each other. Also, when b6 is 2, each R 33 They may be the same as or different from each other.

[0175] R 32 and R 33 The saturated hydrocarbyl group having 1 to 15 carbon atoms, represented by R, can be linear, branched, or cyclic. A specific example is R 22 and R 23 Examples of saturated hydrocarbyl groups represented by the formula shown are similar to those exemplified above.

[0176] R 32 and R 33Specific examples of the aryl group having 6 to 15 carbon atoms represented by include phenyl, naphthyl, and anthryl groups, with phenyl being preferred. The aryl group may also have substituents, and specific examples of such substituents include halogen atoms, saturated hydrocarbyl groups having 1 to 6 carbon atoms that may be substituted with halogen atoms, and saturated hydrocarbyloxy groups having 1 to 6 carbon atoms that may be substituted with halogen atoms.

[0177] Also, R 32 and R 33 They cannot simultaneously become hydrogen atoms. 32 and R 33 If either of the substituents is an aryl group which may have substituents, the other substituent is preferably a hydrogen atom.

[0178] R 32 and R 33 It is preferable that they are the same group, and more preferably that they are both methyl groups.

[0179] Also, R 32 and R 33 These may bond to each other to form a ring with the carbon atoms to which they are bonded, and some of the -CH2- in the ring may be substituted with -O- or -S-. The ring may be a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, an adamantane ring, or a tricyclo[5.2.1.0 2,6 ] Decane ring, tetracyclo[6.2.1.1 3,6 .0 2,7 Examples include, but are not limited to, dodecane rings, oxanorbornane rings, and thianorbornane rings.

[0180] 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 and β-carbon atoms relative to the esterifying 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.

[0181] In formulas (B2) and (B3), W 1 and W 2 Each of these is independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbyl carbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have substituents.

[0182] W 1 and W 2The aliphatic hydrocarbyl group having 1 to 10 carbon atoms, represented by , may be saturated or unsaturated, and 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, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms such as cyclopentyl and cyclohexyl; alkenyl groups having 2 to 10 carbon atoms such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; and cyclic unsaturated hydrocarbyl groups having 3 to 10 carbon atoms such as cyclohexenyl. 1 and W 2 The hydrocarbyl portion of the aliphatic hydrocarbyl carbonyl group having 2 to 10 carbon atoms, represented by , may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include those with 1 to 9 carbon atoms among the aforementioned examples of aliphatic hydrocarbyl groups having 1 to 10 carbon atoms. 1 and W 2 Specific examples of the aryl group having 6 to 15 carbon atoms represented by include the phenyl group, naphthyl group, and anthryl group, but the phenyl group is preferred among these. The aryl group may also have substituents, and specific examples of such substituents include halogen atoms, saturated hydrocarbyl groups having 1 to 6 carbon atoms that may be substituted with halogen atoms, and saturated hydrocarbyloxy groups having 1 to 6 carbon atoms that may be substituted with halogen atoms. When b4 is 2 or 3, each W 1 These may be the same or different from each other. Also, when b6 is 2 or 3, each W 2 They may be the same as or different from each other.

[0183] The repeating unit B2 is preferably one represented by the following formula (B2-1) or (B2-2). [ka] (In the formula, b4, R A , R22 and R 23 (This is the same as above.)

[0184] 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]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] [ka]

[0189] [ka]

[0190] [ka]

[0191] [ka]

[0192] [ka]

[0193]

change

[0194]

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[0195]

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[0196]

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[0197]

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[0198]

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[0199]

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[0200]

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[0201]

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[0202]

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[0203]

change

[0204] Repeating unit B2 may be used alone or in combination of two or more types.

[0205] The repeating unit B3 is preferably one that can be represented by the following formula (B3-1). [ka] (In the formula, b6, R A , R 32 and R 33 (This is the same as above.)

[0206] Preferred examples of repeating unit B3 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]

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] [ka]

[0212]

change

[0213]

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[0214]

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[0215]

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[0216]

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[0217]

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[0218]

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[0219]

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[0220]

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[0221]

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[0222]

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[0223]

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[0224]

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[0225]

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[0226]

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[0227]

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[0228]

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[0229]

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[0230]

change

[0231]

change

[0232]

change

[0233] [ka]

[0234] [ka]

[0235] [ka]

[0236] [ka]

[0237] [ka]

[0238] [ka]

[0239] Repeating unit B3 may be used alone or in combination of two or more types.

[0240] Polymers B and B' may contain at least one selected from the repeating units represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), the repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5), and the repeating unit represented by the following formula (B6) (hereinafter also referred to as repeating unit B6), for the purpose of improving etching resistance. [ka]

[0241] In equations (B4) and (B5), c and d are independently 0, 1, 2, 3, or 4.

[0242] In formulas (B4) and (B5), R 41 and R 42 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, 3, or 4, each R 41 They may be the same or different from each other. When d is 2, 3 or 4, each R 42 They may be the same as or different from each other.

[0243] In formula (B6), e1 is 0 or 1. e2 is 0, 1 or 2. When e is 0, it is a benzene skeleton; when e is 1, it is a naphthalene skeleton; and when e is 2, it is an anthracene skeleton. e3 is 0, 1, 2, 3, 4 or 5. When e2 is 0, e3 is preferably 0, 1, 2 or 3, and when e2 is 1 or 2, e3 is preferably 0, 1, 2, 3 or 4.

[0244] In formula (B6), R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0245] In formula (B6), R 43The 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, 3, 4, or 5, each R 43 They may be the same as or different from each other.

[0246] R 43 Preferred 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.

[0247] 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.

[0248] Among the preferred substituents mentioned above, those that are particularly easy to prepare as monomers and are useful to use include chlorine atoms, bromine atoms, iodine atoms, methyl groups, ethyl groups, and methoxy groups.

[0249] In formula (B6), 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 esterifying 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.

[0250] 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 B6 does not have a (-), preferred examples of the repeating unit B6 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene, etc.

[0251] Also, if e1 is 1 (i.e., -C(=O)-OA as the linker), 3 -If it has, preferred examples of repeating unit B6 are, but are not limited to, the following. Note that in the following formula, R A This is the same as described above. [ka]

[0252] [ka]

[0253] When at least one of the repeating units B4 to B6 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.

[0254] Repeating units B4 to B6 may be used individually or in combination of two or more types.

[0255] Polymer B' may further include at least one selected from the following repeating units: repeating unit B7 (hereinafter also referred to as repeating unit B7), repeating unit B8 (hereinafter also referred to as repeating unit B8), repeating unit B9 (hereinafter also referred to as repeating unit B9), repeating unit B10 (hereinafter also referred to as repeating unit B10), and repeating unit B11 (hereinafter also referred to as repeating unit B11). [ka]

[0256] In formulas (B7) to (B11), R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 This is a phenylene group which may have a single bond or a substituent. 2 This is a single bond, **-C(=O)-OZ 21 -,**-C(=O)-NH-Z 21 - or **-OZ 21 - is Z 21This is a divalent group obtained by combining an aliphatic hydrocarbylene group, a phenylene group, or a combination thereof, having 1 to 6 carbon atoms, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 3 These are single bonds, ether bonds, ester bonds, amide bonds, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. 4 This is a single bond, or a divalent group obtained by combining an aliphatic hydrocarbylene group, a phenylene group, or a combination thereof, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 5 Each of these independently comprises a single bond, a phenylene group which may have substituents, a naphthylene group which may have substituents, or a *-C(=O)-OZ 51 - is Z 51 This is an aliphatic hydrocarbylene group, a phenylene group, or a naphthylene group having 1 to 10 carbon atoms, and the aliphatic hydrocarbylene group may contain a halogen atom, a hydroxyl group, an ether bond, an ester bond, or a lactone ring. 6 These are single bonds, ether bonds, ester bonds, amide bonds, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. 7 Each of these is independently a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 -or ***-OZ 71 - is. is. Z 71 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. 8 These are, independently, single bonds, ****-Z 81 -C(=O)-O-,****-C(=O)-NH-Z 81 -or ****-OZ 81 - is Z 81 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. 9 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, trifluoromethyl groups, and *-C(=O)-OZ.91 -, *-C(=O)-N(H)-Z 91 -or *-OZ 91 - is Z 91 This is a phenylene group substituted with an aliphatic hydrocarbylene group, phenylene group, fluorinated phenylene group, or trifluoromethyl group having 1 to 6 carbon atoms, and may contain a carbonyl group, ester bond, ether bond, or hydroxyl group. * represents a bond with a carbon atom of the main chain. ** represents Z 1 This represents a combination with Z. *** represents Z 6 This represents a combination with Z. **** is Z 7 This represents a combination of two things.

[0257] Z 21 , Z 51 and Z 91 The aliphatic hydrocarbylene group represented by can be linear, branched, or cyclic, and 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- Examples include alkanediyl groups such as 2,3-diyl group, butane-1,4-diyl group, 1,1-dimethylethane-1,2-diyl group, pentane-1,5-diyl group, 2-methylbutane-1,2-diyl group, and hexane-1,6-diyl group; cycloalkanediyl groups such as cyclopropanediyl group, cyclobutanediyl group, cyclopentanediyl group, and cyclohexanediyl group; and groups obtained by combining these.

[0258] Z 71 and Z 81 The hydrocarbylene group, which may contain a heteroatom represented by , may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples are listed below, but are not limited to these. [ka] (In the equation, dashed lines represent connections.)

[0259] In formula (B7), R 51 and R 52 Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include C1-C20 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl groups; C3-C20 cyclic saturated hydrocarbyl groups such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups; C2-C20 alkenyl groups such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl groups; C3-C20 cyclic unsaturated hydrocarbyl groups such as cyclohexenyl; C6-C20 aryl groups such as phenyl, naphthyl, and thienyl groups; C7-C20 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 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 fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, 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.

[0260] Also, R 51 and R 52 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. Specific examples of such a ring include those represented by the following formula. [ka] (In the formula, the dashed line represents Z 4 (This is a combination of the two.)

[0261] Specific examples of cations of repeating unit B7 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0262] [ka]

[0263] [ka]

[0264] [ka]

[0265] [ka]

[0266] [ka]

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] [ka]

[0271] In formula (B7), M - The first is a non-nucleophilic counterion. Preferred non-nucleophilic counterions include halide ions, sulfonate anions, imidate anions, and methidate anions. Specific examples of halide ions include chloride ions and bromide ions. Specific examples of sulfonate anions (sulfonate ions) include fluoroalkyl sulfonate ions such as triflate ions, 1,1,1-trifluoroethanesulfonate ions, and nonafluorobutanesulfonate ions; aryl sulfonate ions such as tosylate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, and 1,2,3,4,5-pentafluorobenzenesulfonate ions; and alkyl sulfonate ions such as mesylate ions and butanesulfonate ions. Specific examples of imidate anions (imide ions) include bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, and bis(perfluorobutylsulfonyl)imide ions. Specific examples of the aforementioned methidate anion (methide ion) include tris(trifluoromethylsulfonyl)methide ion and tris(perfluoroethylsulfonyl)methide ion.

[0272] Other examples of the aforementioned non-nucleophilic counterions include anions represented by any of the following formulas (B7-1) to (B7-4). [ka]

[0273] In formula (B7-1), R faR is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (B7-1-1) described later. fa1 Examples of hydrocarbyl groups represented by the symbol shown are similar to those exemplified.

[0274] The anion represented by formula (B7-1) is preferably the one represented by the following formula (B7-1-1). [ka]

[0275] In equation (B7-1-1), Q 1 and Q 2 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, but to improve solvent solubility, it is preferable that at least one of them is a trifluoromethyl group. m is 0, 1, 2, 3, or 4, but it is particularly preferable that it is 1. R fa1 This is a hydrocarbyl group having 1 to 35 carbon atoms, which may contain heteroatoms. The heteroatoms are preferably oxygen atoms, nitrogen atoms, sulfur atoms, halogen atoms, etc., with oxygen atoms being more preferred. From the viewpoint of obtaining high resolution in fine pattern formation, the hydrocarbyl group having 6 to 30 carbon atoms is particularly preferred.

[0276] In formula (B7-1-1), R fa1The C1-C35 hydrocarbyl group represented by can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include C1-C35 alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, pentyl, neopentyl, hexyl, heptyl, 2-ethylhexyl, nonyl, undecyl, tridecyl, pentadecyl, heptadecyl, and eicosyl; cyclopentyl, cyclohexyl, 1-adamantyl, 2-adamantyl, 1-adamantylmethyl, norbornyl, norbornyl Examples include cyclic saturated hydrocarbyl groups with 3 to 35 carbon atoms, such as nylmethyl, tricyclodecyl, tetracyclododecyl, tetracyclododecylmethyl, and dicyclohexylmethyl; unsaturated aliphatic hydrocarbyl groups with 2 to 35 carbon atoms, such as 2-propenyl and 3-cyclohexenyl; aryl groups with 6 to 35 carbon atoms, such as phenyl, 1-naphthyl, 2-naphthyl, and 9-fluorenyl; aralkyl groups with 7 to 35 carbon atoms, such as benzyl and diphenylmethyl; and groups obtained by combining these.

[0277] 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 fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Specific examples of hydrocarbyl groups containing heteroatoms include tetrahydrofuryl group, methoxymethyl group, ethoxymethyl group, methylthiomethyl group, acetamidomethyl group, trifluoroethyl group, (2-methoxyethoxy)methyl group, acetoxymethyl group, 2-carboxy-1-cyclohexyl group, 2-oxopropyl group, 4-oxo-1-adamantyl group, and 3-oxocyclohexyl group.

[0278] In formula (B7-1-1), L a1 The bond can be a single bond, an ether bond, an ester bond, a sulfonic acid ester bond, a carbonate bond, or a carbamate bond, but from a synthetic viewpoint, an ether bond or an ester bond is preferred, and an ester bond is even more preferred.

[0279] Specific examples of anions represented by formula (B7-1) are listed below, but are not limited to these. Note that in the formula below, Q 1 This is the same as above, and Ac is an acetyl group. [ka]

[0280] [ka]

[0281] [ka]

[0282] [ka]

[0283] [ka]

[0284] [ka]

[0285] [ka]

[0286] [ka]

[0287] [ka]

[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] In formula (B7-2), R fb1 and R fb2 Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may independently contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (B7-1-1). fa1 Examples of hydrocarbyl groups represented by R include those similar to those exemplified. fb1 and R fb2 Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 However, they bond to each other and the group to which they bond (-CF2-SO2-N - It may form a ring with -SO2-CF2-), in which case R fb1 and R fb2 The groups obtained by the bonding of these groups are preferably fluorinated ethylene groups or fluorinated propylene groups.

[0292] In formula (B7-3), R fc1 , R fc2 and R fc3Each of these is a hydrocarbyl group having 1 to 40 carbon atoms, which may independently contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (B6-1-1). fa1 Examples of hydrocarbyl groups represented by R include those similar to those exemplified. fc1 , R fc2 and R fc3 Preferably, R is a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 However, they bond to each other and the group to which they bond (-CF2-SO2-C - It may form a ring with -SO2-CF2-), in which case R fc1 and R fc2 The groups obtained by the bonding of these groups are preferably fluorinated ethylene groups or fluorinated propylene groups.

[0293] In formula (B7-4), R fd R is a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. A specific example is R in formula (B7-1-1). fa1 Examples of hydrocarbyl groups represented by the same formula as those exemplified above include those shown.

[0294] Specific examples of anions represented by formula (B7-4) are listed below, but are not limited to these. [ka]

[0295] [ka]

[0296] Further examples of the aforementioned non-nucleophilic counterions include anions having an aromatic ring substituted with an iodine or bromine atom. A specific example of such anion is represented by the following formula (B7-5). [ka]

[0297] In equation (B7-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3, where 1 ≤ y + z ≤ 5. y is preferably 1, 2, or 3, more preferably 2 or 3. z is preferably 0, 1, or 2.

[0298] In formula (B7-5), X BI is an iodine atom or a bromine atom. When x and / or y are 2 or more, each X BI They may be the same as or different from each other.

[0299] In formula (B7-5), L 11 This is a saturated hydrocarbylene group having 1 to 6 carbon atoms, which may contain a single bond, an ether bond, or an ester bond, or an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0300] In formula (B7-5), L 12 When x is 1, it is a single bond or a divalent linking group having 1 to 20 carbon atoms, and when x is 2 or 3, it is a (x+1) valent linking group having 1 to 20 carbon atoms, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0301] In formula (B7-5), R feThis may include a hydroxyl group, a carboxyl group, a fluorine atom, a chlorine atom, a bromine atom, or an amino group, or a fluorine atom, a chlorine atom, a bromine atom, a hydroxyl group, an amino group, or an ether bond, and may contain a C1-C20 hydrocarbyl group, a C1-C20 hydrocarbyloxy group, a C2-C20 hydrocarbylcarbonyl group, a C2-C20 hydrocarbyloxycarbonyl group, a C2-C20 hydrocarbylcarbonyloxy group, or a C1-C20 hydrocarbylsulfonyloxy group, or -N(R feA )(R feB ), -N(R feC )-C(=O)-R feD Or -N(R feC )-C(=O)-OR feD That is. R feA and R feB Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. feC R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may also contain a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. feD This is an aliphatic hydrocarbyl group having 1 to 16 carbon atoms, an aryl group having 6 to 12 carbon atoms, or an aralkyl group having 7 to 15 carbon atoms, and may contain a halogen atom, a hydroxyl group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. The hydrocarbyl group, hydrocarbyloxy group, hydrocarbylcarbonyl group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When x and / or z is 2 or more, each R fe These may be identical or different from one another.

[0302] Of these, R feExamples include hydroxyl groups, -N(R feC )-C(=O)-R feD , -N(R feC )-C(=O)-OR feD Fluorine atoms, chlorine atoms, bromine atoms, methyl groups, methoxy groups, etc. are preferred.

[0303] In formula (B7-5), Rf 11 ~Rf 14 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one of these is either a fluorine atom or a trifluoromethyl group. Also, Rf 11 and Rf 12 These may combine to form a carbonyl group. In particular, Rf 13 and Rf 14 It is preferable that both are fluorine atoms.

[0304] Specific examples of anions represented by formula (B7-5) are listed below, but are not limited to these. Note that in the following formula, X BI This is the same as described above. [ka]

[0305] [ka]

[0306] [ka]

[0307] [ka]

[0308] [ka]

[0309]

change

[0310]

change

[0311]

change

[0312]

change

[0313]

change

[0314]

change

[0315]

change

[0316]

change

[0317]

change

[0318]

change

[0319]

change

[0320]

change

[0321]

change

[0322]

change

[0323]

change

[0324]

change

[0325]

change

[0326]

change

[0327]

change

[0328] As the non-nucleophilic counterions, the following can also be used: a fluorobenzenesulfonic acid anion bonded to an aromatic group containing an iodine atom, as described in Japanese Patent No. 6648726; an anion having a mechanism for decomposition by acid, as described in International Publication No. 2021 / 200056 and Japanese Patent Application Publication No. 2021-70692; an anion having a cyclic ether group, as described in Japanese Patent Application Publication No. 2018-180525 and Japanese Patent Application Publication No. 2021-35935; and an anion described in Japanese Patent Application Publication No. 2018-92159.

[0329] As the non-nucleophilic counterions, anions of bulky benzenesulfonic acid derivatives that do not contain fluorine atoms, as described in Japanese Patent Publication No. 2006-276759, Japanese Patent Publication No. 2015-117200, Japanese Patent Publication No. 2016-65016, and Japanese Patent Publication No. 2019-202974, as well as benzenesulfonic acid anions or alkylsulfonic acid anions that do not contain fluorine atoms bonded to an aromatic group containing an iodine atom, as described in Japanese Patent No. 6645464.

[0330] As the non-nucleophilic counterion, other options include the bissulfonic acid anion described in Japanese Patent Publication No. 2015-206932, the sulfonamide or sulfonimide anion described in International Publication No. 2020 / 158366, which has a sulfonic acid on one end and a different sulfonamide or sulfonimide on the other, and the sulfonate anion described in Japanese Patent Publication No. 2015-24989.

[0331] In formulas (B8) and (B9), f1 and f2 are independently 0, 1, 2, or 3, but 1 is preferred.

[0332] In equation (B10), g1 is either 0 or 1. g2 is either 0, 1, 2, 3, or 4. g3 is either 0, 1, 2, 3, or 4. However, when g1 is 0, 0 ≤ g2 + g3 ≤ 4, and when g1 is 1, 0 ≤ g2 + g3 ≤ 6.

[0333] In formulas (B8), (B9), and (B10), L 1These are single bonds, ether bonds, ester bonds, carbonyl groups, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Of these, ether bonds, ester bonds, and carbonyl groups are preferred from a synthetic viewpoint, and ester bonds and carbonyl groups are more preferred.

[0334] In formula (B8), Rf 1 and Rf 2 Each of these is independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Of these, Rf 1 and Rf 2 To increase the acid strength of the generated acid, it is preferable that all atoms be fluorine atoms. Rf 3 and Rf 4 These are, independently, a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Of these, Rf is used to improve solvent solubility. 3 and Rf 4 At least one of them is preferably a trifluoromethyl group.

[0335] In formula (B9), Rf 5 and Rf 6 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. However, all Rf 5 and Rf 6 These cannot simultaneously become hydrogen atoms. Of these, Rf 5 and Rf 6 At least one of them is preferably a trifluoromethyl group.

[0336] In formula (B10), Rf 7 Rf is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. 7The preferred Rf groups are fluorine atoms, trifluoromethyl groups, difluoromethyl groups, trifluoromethoxy groups, difluoromethoxy groups, trifluoromethylthio groups, or difluoromethylthio groups, with fluorine atoms, trifluoromethyl groups, or trifluoromethoxy groups being more preferred. When g2 is 2, 3, or 4, each Rf 7 They may be the same as or different from each other.

[0337] In formula (B10), R 53 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than fluorine atoms, or heteroatoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. For example, in the explanation of formula (A), R 2 Examples of hydrocarbyl groups represented by the same as those exemplified are, but are not limited to, those shown. Also, when g3 is 2, 3, or 4, each R 53 They may be the same as or different from each other.

[0338] Also, when g3 is 2, 3, or 4, multiple R 53 These elements may bond with each other to form a ring with the carbon atoms to which they are bonded. Specific examples of the ring 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, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano 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.

[0339] Specific examples of anions with repeating unit B8 are shown below, but are not limited to these. Note that in the following formula, R A The same as above, and Me is a methyl group. [ka]

[0340] [ka]

[0341] [ka]

[0342] [ka]

[0343] [ka]

[0344] [ka]

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] [ka]

[0349] [ka]

[0350] [ka]

[0351] [ka]

[0352] Specific examples of anions with repeating unit B9 are shown below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0353] [ka]

[0354] [ka]

[0355] [ka]

[0356] [ka]

[0357] [ka]

[0358] [ka]

[0359] [ka]

[0360] [ka]

[0361] [ka]

[0362] [ka]

[0363] Specific examples of anions with repeating unit B10 are shown below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0364] [ka]

[0365] [ka]

[0366] [ka]

[0367] [ka]

[0368]

change

[0369]

change

[0370]

change

[0371]

change

[0372]

change

[0373]

change

[0374]

change

[0375]

change

[0376]

change

[0377]

change

[0378]

change

[0379] [ka]

[0380] Specific examples of anions of repeating unit B11 are listed below, but are not limited to these. Note that in the following formula, R A This is the same as described above. [ka]

[0381] In formulas (B8) to (B11), A + This is an onium cation. Examples of the onium cation include sulfonium cations, iodonium cations, and ammonium cations, but sulfonium cations or iodonium cations are preferred. Specific examples of the sulfonium cation include, but are not limited to, those exemplified as specific examples of sulfonium cations represented by formula (Z-1) and those exemplified as specific examples of sulfonium cations represented by formula (Z-3). Specific examples of the iodonium cation include, but are not limited to, those exemplified as specific examples of iodonium cations represented by formula (Z-2). Specific examples of the ammonium cation include, but are not limited to, those exemplified as ammonium cations represented by formula (am-1) described later.

[0382] The specific structures of repeating units B7 to B11 include any combination of anions and cations as described above.

[0383] Repeating units B7 to B11 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.

[0384] Repeating units B7 to B11 may be used individually or in combination of two or more units.

[0385] 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.

[0386] Examples of (meth)acrylic acid ester units having the aforementioned adhesive group include the repeating unit represented by the following formula (B12) (hereinafter also referred to as repeating unit B12), the repeating unit represented by the following formula (B13) (hereinafter also referred to as repeating unit B13), and the repeating unit represented by the following formula (B14) (hereinafter also referred to as repeating unit B14). 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]

[0387] In formulas (B12) to (B14), R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 61 R is either an -O- or a methylene group. 62 R is a hydrogen atom or a hydroxyl group. 63 is a saturated hydrocarbyl group having 1 to 4 carbon atoms. h is 0, 1, 2, or 3.

[0388] 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 units B2 and B3 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 B4 to B6 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 amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0389] If polymer B' does not contain repeating units B7 to B11, 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 B4 to B6 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating units B2 and B3 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%.

[0390] When polymer B' contains repeating units B7 to B11, 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 B4 to B6 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating units B2 and B3 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. The total content of repeating units B1 to B6 is preferably 60 to 99.5 mol%. The content of repeating units B8 to B11 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%.

[0391] Furthermore, among the total repeating units constituting the polymer, repeating units B1 to B6 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.

[0392] Furthermore, in this case, polymer B' is preferably one that includes a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formulas (B2-1), (B2-2), or (B3-1), and a repeating unit represented by the following formula (B8-1). [ka] (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 32 , R 33 and A + This is the same as above. R HF is a hydrogen atom or a trifluoromethyl group. 10 This is a single bond or *****-Z 101 -C(=O)-O- Z 101 This is a hydroxylene group having 1 to 20 carbon atoms, which may contain heteroatoms. ***** represents the bond with the oxygen atom in the formula.

[0393] (B) When polymer B' is used as the base polymer, a combination of polymers that do not contain repeating units B7 to B14 and polymers that contain repeating units B7 to B14 may be used. In this case, the content of polymers that do not contain repeating units B7 to B14 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 B7 to B14.

[0394] 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.

[0395] 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.

[0396] 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 THF or DMF as a solvent.

[0397] The polymer preferably has a narrow dispersion with a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, more preferably 1.0 to 1.8. When the dispersion is narrow in this way, no foreign matter is generated on the pattern after development, and the shape of the pattern does not deteriorate.

[0398] [(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 may or may not contain a crosslinking agent.

[0399] 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.

[0400] Examples of the epoxy compound include tris(2,3-epoxypropyl) isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0401] 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.

[0402] 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.

[0403] 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.

[0404] 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.

[0405] Examples of the isocyanate compounds include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0406] Examples of the aforementioned azide compounds include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0407] 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.

[0408] 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.

[0409] [(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: repeating unit (D1) (hereinafter also referred to as repeating unit D1), repeating unit (D2) (hereinafter also referred to as repeating unit D2), repeating unit (D3) (hereinafter also referred to as repeating unit D3), and repeating unit (D4) (hereinafter also referred to as repeating unit D4), and may further contain at least one selected from the following repeating units: repeating unit (D5) (hereinafter also referred to as repeating unit D5) and repeating unit (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]

[0410] In equations (D1) to (D6), j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3. R B These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. C 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. When j1 is 2 or 3, each R 209 These may be identical or different from each other. 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. When j2 is 2 or more, each R 210 These may be identical or different from each other. 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)-OX 31 -X 32 - or *-C(=O)-NH-X 31 -X 32 - is X 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.

[0411] 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.

[0412] 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.

[0413] In formula (D4), X 1 Examples of (k+1) valent hydrocarbon groups having 1 to 20 carbon atoms, represented by , include alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms from which k hydrogen atoms have been removed. Also, X 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.

[0414] Specific examples of repeating units D1 to D4 are shown below, but are not limited to these. Note that in the following formula, R B This is the same as described above. [ka]

[0415] [ka]

[0416] [ka]

[0417] 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.

[0418] 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.

[0419] In formula (D5), X 2 It is preferable that *-C(=O)-O- or *-C(=O)-NH-. Furthermore, R CIt 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.

[0420] The repeating unit D5 can be, but is not limited to, the following. Note that in the following formula, R C This is the same as described above. [ka]

[0421] [ka]

[0422] In formula (D6), X 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.

[0423] 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.

[0424] The repeating unit D6 can be, but is not limited to, the following. Note that in the following formula, R C This is the same as described above. [ka]

[0425] [ka]

[0426] [ka]

[0427] [ka]

[0428] 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.

[0429] (D) 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. (D) 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.

[0430] (D) Fluorine atom-containing polymers 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.

[0431] (D) The Mw of the fluorine atom-containing polymer is preferably 2000 to 50000, and more preferably 3000 to 20000. If the Mw is 2000 or higher, the acid does not diffuse, the resolution does not deteriorate, and the stability over time is not impaired. If the Mw is 50000 or lower, the solubility in the solvent is sufficient, and coating defects do not occur. Furthermore, the Mw / Mn of the (D) fluorine atom-containing polymer is preferably 1.0 to 2.2, and more preferably 1.0 to 1.7.

[0432] 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.

[0433] [(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.

[0434] 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.

[0435] 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.

[0436] Examples of onium salts of carboxylic acids whose α-position is not fluorinated include those represented by the following formula (E1). [ka]

[0437] 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.

[0438] 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, such as vinyl group, allyl group, propenyl group, butenyl group, and hexenyl group; C3 to 40 cyclic unsaturated aliphatic hydrocarbyl groups, such as cyclohexenyl group; phenyl group, naphthyl group, alkylphenyl group (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-methylphenyl group) Examples include aryl groups having 6 to 40 carbon atoms, such as ethylphenyl group, 4-n-butylphenyl group, di- or trialkylphenyl 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 having 7 to 40 carbon atoms, such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group.

[0439] 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.

[0440] 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 sulfonium cations include, but are not limited to, those described in paragraphs

[0102] to

[0125] of Japanese Patent Publication No. 2024-003744, those described in paragraphs

[0070] to

[0085] of Japanese Patent Publication No. 2023-169812, and those exemplified as specific examples of sulfonium cations represented by formula (Z-3). Specific examples of iodonium cations include, but are not limited to, those described in paragraph

[0181] of Japanese Patent Publication No. 2024-000259.

[0441] The ammonium cation is preferably one represented by the following formula (am-1). [ka]

[0442] In formula (am-1), R q11 ~R q14 Each of these is independently a hydrocarbyl group having 1 to 40 carbon atoms, which may contain heteroatoms. Also, R q11 ~R q14 Any two of these may bond with each other to form a ring with the nitrogen atom to which they are bonded. A specific example of the hydrocarbyl group is R in the explanation of formula (A). 2 Examples of hydrocarbyl groups represented by the same formula as those exemplified above include those shown.

[0443] Specific examples of ammonium cations represented by formula (am-1) are listed below, but are not limited to these. [ka]

[0444] The anions of the onium salt represented by formula (E1) include, but are not limited to, those listed below. [ka]

[0445] [ka]

[0446] [ka]

[0447] 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]

[0448] In equation (E2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3, where 1 ≤ s + t ≤ 5. u is 1, 2, or 3.

[0449] 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 R 211 They may be the same or different from one another.

[0450] In formula (E2), L 21This 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.

[0451] 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.

[0452] 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.

[0453] As the quencher, a nitrogen atom-containing carboxylate compound represented by the following formula (E3) can also be used. [ka]

[0454] In formula (E3), R 221 ~R 224 These are, independently, hydrogen atoms and -L 22 -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. 22 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.

[0455] 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 22 -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.

[0456] The onium carboxylate salt represented by formula (E3) contains at least one -L 22 -CO2 - It has a group. That is, R 221 ~R 224 At least one of them is -L 22 -CO2 - is and / or ring R rAt least one hydrogen atom bonded to the carbon atom is -L 22 -CO2 - It has been replaced with this.

[0457] In formula (E3), Mq B + The cation is a sulfonium cation, an iodonium cation, or an ammonium cation, with a sulfonium cation being preferred. Specific examples of the sulfonium cation include, but are not limited to, those described in paragraphs

[0102] to

[0125] of Japanese Patent Application Publication No. 2024-003744, those described in paragraphs

[0070] to

[0085] of Japanese Patent Application Publication No. 2023-169812, and those similar to those exemplified as specific examples of sulfonium cations represented by formula (Z-3).

[0458] The anions of the compound represented by formula (E3) include, but are not limited to, those listed below. [ka]

[0459] [ka]

[0460] [ka]

[0461] [ka]

[0462] [ka]

[0463] [ka]

[0464] 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]

[0465] 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.

[0466] 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.

[0467] 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.

[0468] [(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.

[0469] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixtures thereof are preferred.

[0470] 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.

[0471] [(G) Other photoacid generators] The chemically amplified negative resist composition of the present invention may contain, as component (G), a photoacid generator other than the onium salt represented by formula (A) (hereinafter also referred to as "other photoacid generator"). The other photoacid generator is not particularly limited as long as it is a compound that generates acid upon irradiation with high-energy rays. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxiimide, oxime-O-sulfonate type photoacid generators, and the like.

[0472] Specific examples of the aforementioned other photoacid generators include nonafluorobutanesulfonate, partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of Japanese Patent Publication No. 2012-189977, partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of Japanese Patent Publication No. 2013-101271, those described in paragraphs

[0122] to

[0142] of Japanese Patent Publication No. 2008-111103, and those described in paragraphs

[0080] to

[0081] of Japanese Patent Publication No. 2010-215608. Among these specific examples, arene sulfonate type or alkane sulfonate type photoacid generators are preferred because they generate an acid of appropriate strength for deprotecting the acid-unstable group of repeating unit B2.

[0473] As the photoacid generator, a salt compound containing an anion having the structure shown below is preferred. [ka]

[0474] [ka]

[0475] [ka]

[0476] [ka]

[0477] [ka]

[0478] [ka]

[0479] [ka]

[0480] [ka]

[0481] [ka]

[0482] [ka]

[0483] [ka]

[0484] Furthermore, as the photoacid generator, salt compounds containing an anion represented by the following formula (G1) are also preferred. [ka]

[0485] In equation (G1), p is 1, 2, or 3. q is 1, 2, 3, 4, or 5. r is 0, 1, 2, or 3. s1 is 0 or 1.

[0486] In formula (G1), L 31These are single bonds, ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, or carbamate bonds.

[0487] In formula (G1), L 32 These are ether bonds, ester bonds, sulfonic acid ester bonds, carbonate bonds, or carbamate bonds.

[0488] In formula (G1), L C When p is 1, it is a single bond or a hydroxylene group having 1 to 20 carbon atoms, and when p is 2 or 3, it is a (p+1) valent hydrocarbon group having 1 to 20 carbon atoms. The hydroxylene group and the (p+1) valent hydrocarbon group 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.

[0489] L C The hydroxylene group, represented by , having 1 to 20 carbon atoms, can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, dodecane-1,12-diyl group, etc. Examples include alkanediyl groups with 1 to 20 carbon atoms; cyclic saturated hydrocarbylene groups with 3 to 20 carbon atoms such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl; unsaturated aliphatic hydrocarbylene groups with 2 to 20 carbon atoms such as vinylene and propene-1,3-diyl; arylene groups with 6 to 20 carbon atoms such as phenylene and naphthylene; and groups obtained by combining these. Also, L CThe (p+1) valent hydrocarbon group having 1 to 20 carbon atoms, represented by , may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include groups obtained by removing one or two hydrogen atoms from the aforementioned specific examples of the 1 to 20 carbon atom hydrocarbylene group.

[0490] In formula (G1), Rf 21 and Rf 22 Each of these is independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, but at least one is either a fluorine atom or a trifluoromethyl group.

[0491] In formula (G1), R 301 This includes a hydroxyl group, a carboxyl group, a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, and -N(R 301A )(R 301B ), -N(R 301C )-C(=O)-R 301D or -N(R 301C )-C(=O)-OR 301D That is. R 301A and R 301B Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301C R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301D This is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0492] R 301 , R 301A and R 301BThe saturated hydrocarbyl group having 1 to 6 carbon atoms, represented by R, may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 6 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl groups; and cyclic saturated hydrocarbyl groups having 3 to 6 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. 301 The saturated hydrocarbyl portion of the saturated hydrocarbyloxy group having 1 to 6 carbon atoms, as represented by R, is the same as the specific examples of saturated hydrocarbyl groups mentioned above. 301 Examples of the saturated hydrocarbyl portion of the saturated hydrocarbyl carbonyloxy group having 2 to 6 carbon atoms, as described above, include those having 1 to 5 carbon atoms.

[0493] R 301B The carbon-2-carbon unsaturated aliphatic hydrocarbyl groups represented by can be linear, branched, or cyclic. Specific examples include carbon-2-carbon alkenyl groups such as vinyl, propenyl, butenyl, and hexenyl groups; carbon-2-carbon alkynyl groups such as ethynyl, propynyl, and butynyl groups; and carbon-3-carbon cyclic unsaturated aliphatic hydrocarbyl groups such as cyclohexenyl and norbornenyl groups.

[0494] In formula (G1), R 302 This is a saturated hydrocarbylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms, wherein some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with halogen atoms other than fluorine atoms, and some or all of the hydrogen atoms of the arylene group may be substituted with substituents selected from a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, a halogen atom, and a hydroxyl group.

[0495] R 302The saturated hydrocarbylene groups having 1 to 20 carbon atoms, represented by , may be linear, branched, or cyclic. Specific examples include alkane diyl groups having 1 to 20 carbon atoms, such as methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1,11-diyl, and dodecane-1,12-diyl; and cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norbornanediyl, and adamantanediyl.

[0496] R 302 Specific examples of arylene groups with 6 to 20 carbon atoms, represented by , include phenylene groups, naphthylene groups, phenanthrendiyl groups, and anthracenediyl groups. The hydrocarbyl portion of the saturated hydrocarbyl group having 1 to 20 carbon atoms and the hydrocarbyloxy group having 1 to 20 carbon atoms, which are substituents on the arylene group, may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 20 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl groups; and cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl groups. Specific examples of arylene groups having 6 to 14 carbon atoms that are substituents on the aforementioned arylene group include phenylene group, naphthylene group, phenanthrendiyl group, anthracenediyl group, and the like.

[0497] The anion represented by formula (G1) is preferably the anion represented by formula (G2) below. [ka]

[0498] In formula (G2), p, q, r, L 31 , L C and R 301 The same as above. s2 is 1, 2, 3, or 4. R 302A These are saturated hydrocarbyl groups having 1 to 14 carbon atoms, saturated hydrocarbyloxy groups having 1 to 14 carbon atoms, aryl groups having 6 to 14 carbon atoms, halogen atoms, or hydroxyl groups. Note that when s2 is 2, 3, or 4, each R 302A They may be the same as or different from each other.

[0499] Specific examples of anions represented by formula (G1) are listed below, but are not limited to these. [ka]

[0500] [ka]

[0501] [ka]

[0502] [ka]

[0503] [ka]

[0504] [ka]

[0505]

change

[0506]

change

[0507]

change

[0508]

change

[0509]

change

[0510]

change

[0511]

change

[0512]

change

[0513]

change

[0514]

change

[0515]

change

[0516]

change

[0517]

change

[0518]

change

[0519]

change

[0520]

change

[0521]

change

[0522]

change

[0523]

change

[0524]

change

[0525]

change

[0526]

change

[0527] (G) In other photoacid generators, a sulfonium cation or an iodonium cation is preferred as the cation paired with the anion described above. Specific examples of the sulfonium cation include, but are not limited to, those exemplified as specific examples of the sulfonium cation represented by formula (Z-1) or the sulfonium cation represented by formula (Z-3). Specific examples of the iodonium cation include, but are not limited to, those exemplified as specific examples of the iodonium cation represented by formula (Z-2).

[0528] The acid generated by the aforementioned other photoacid generators is preferably of a pKa of -2.0 or higher, and more preferably of -1.0 or higher. Furthermore, the upper limit of the pKa is preferably 2.0. The pKa values ​​were calculated using the pKa DB in the ACD / Chemsketch ver:9.04 software from Advanced Chemistry Development, Inc.

[0529] If the chemically amplified negative resist composition of the present invention contains (G) other photoacid generators, the content thereof is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 80 parts by mass of the base polymer. By including other photoacid generators, the amount of acid generated in the exposed areas and the dissolution inhibition of the unexposed areas can be appropriately adjusted. (G) Other photoacid generators may be used alone or in combination of two or more.

[0530] [(H) Surfactants] The chemically amplified negative resist composition of the present invention may contain a commonly used surfactant as component (H) to improve its applicability to substrates. 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 a surfactant (H), its content is preferably 0 to 5 parts by mass per 80 parts by mass of the (B) base polymer. The surfactant (H) may be used alone or in combination of two or more types.

[0531] [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.

[0532] 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.

[0533] Next, the resist film is exposed using high-energy rays to irradiate a pattern. Examples of such high-energy rays include ultraviolet light, far-ultraviolet light, excimer laser light (KrF, ArF, etc.), EUV with wavelengths of 3 to 15 nm, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, exposure using EUV or EB is preferred.

[0534] 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.

[0535] 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.

[0536] 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.

[0537] Subsequently, the substrate is developed using a developer solution, preferably an alkaline aqueous solution such as a 0.1-5% by mass, more preferably 2-3% by mass TMAH aqueous solution, by conventional methods such as dipping, puddling, or spraying, preferably for 0.1-3 minutes, more preferably for 0.5-2 minutes, thereby forming the desired pattern on the substrate.

[0538] 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.

[0539] 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.

[0540] 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.

[0541] 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.

[0542] 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.

[0543] 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.

[0544] 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]

[0545] The present invention will be specifically described below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. The apparatus used is as follows. • MALDI TOF-MS: S3000 manufactured by JEOL Ltd.

[0546] [1] Synthesis of onium salts [Example 1-1] Synthesis of onium salt PAG-1 [ka]

[0547] (1) Synthesis of intermediate In-1 Under a nitrogen atmosphere, the starting materials SM-1 (14.5g) and N,N-dimethylformamide (0.2g) were dissolved in methylene chloride (100g) in a reaction vessel, and the temperature in the reaction vessel was raised to 40°C. Then, oxalyl chloride (9.5g) was added dropwise. After the dropwise addition, the reaction vessel was aged for 2 hours while maintaining the temperature at 40°C. After aging, the reaction mixture was cooled, and water (50g) was added to stop the reaction. Methylene chloride (50g) was added to extract the target product, followed by a normal aqueous work-up, and after removing the solvent by distillation, hexane was added and recrystallization was performed to obtain 13.7g of intermediate In-1 as white crystals (yield 95%).

[0548] (2) Synthesis of onium salt PAG-1 Under a nitrogen atmosphere, intermediate In-1 (5.8g) and starting material SM-2 (5.0g) were suspended in methylene chloride (70g) in a reaction vessel. Triethylamine (1.4g) was added dropwise, and the mixture was aged at room temperature for 10 hours. After aging, water (30g) was added to stop the reaction. Methylene chloride (30g) was added to extract the target product, followed by a normal aqueous work-up. After removing the solvent by distillation, the mixture was purified by silica gel chromatography to obtain 8.6g of onium salt PAG-1 as white crystals (yield 83%).

[0549] The TOF-MS results for PAG-1 are shown below. MALDI TOF-MS: POSITIVE M + 277(C 18 H 13 OS + equivalent) NEGATIVE M - 764(C 40 H 30 NO 11 S2 - equivalent)

[0550] [Examples 1-2 to 1-8] Synthesis of onium salts PAG-2 to PAG-8 Using corresponding raw materials and known organic synthesis reactions, onium salts PAG-2 to PAG-8, represented by the following formulas, were synthesized. [ka] [ka]

[0551] [2] 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 1 to 3 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.

[0552] [Table 1]

[0553] [Table 2]

[0554] [Table 3]

[0555] The structures of polymers P-1 to P-30 in Tables 1 to 3 are shown in Table 4 below. Note that Mw is the polystyrene equivalent value measured by GPC using THF or DMF as the solvent.

[0556] [Table 4]

[0557] In Table 4, the structure of each unit is as follows: [ka]

[0558] [ka]

[0559] [ka]

[0560] [ka]

[0561] [ka]

[0562] [ka]

[0563] In Tables 1-3, the other photoacid generator PAG-A, 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]

[0564] [ka]

[0565] [ka]

[0566] [ka]

[0567] [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.

[0568] 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.

[0569] 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.

[0570] [Table 5]

[0571] [Table 6]

[0572] [Table 7]

[0573] 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 photoacid generator, resulting in inadequate performance in terms of resolution, LER, and pattern rectangularity.

[0574] 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 0 or 1. n2 is 1, 2, 3, 4 or 5 when n1 is 0, and 1, 2, 3, 4, 5, 6 or 7 when n1 is 1. n3 is 0 or 1. n4 is 0, 1, 2, 3 or 4. n5 is 0, 1, 2, 3 or 4, provided that when n3 is 0, 0 ≤ n4 + n5 ≤ 4, and when n3 is 1, 0 ≤ n4 + n5 ≤ 6.) R 1 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 1 S is bonded to a carbon atom adjacent to the carbon atom to which it is bonded. When n2 is 2 or more, each R 1 They may be the same or different from each other, and there may be multiple R 1 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. R 2 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than fluorine atoms, or heteroatoms other than fluorine atoms. When n4 is 2, 3, or 4, each R 2 They may be the same or different from each other, and there may be multiple R 2 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. R F This is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. When n5 is 2, 3 or 4, each R F may be the same as or different from each other. Z + This is an onium cation. 【Chemistry 2】 (In the formula, a1 is 0 or 1. a2 is 0, 1 or 2. a3 is an integer that satisfies 0 ≤ a3 ≤ 5 + 2(a2) - a4. a4 is 1, 2 or 3.) R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 This is a halogen atom, a nitro group, a carboxyl group, 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. When a3 is 2 or more, each R 11 They may be the same as or different from each other. 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 the onium salt is represented by the following formula (A1). 【Transformation 3】 (In the formula, n2, n3, n4, n5, R 1 , R 2 , R F and Z + (This is the same as above.)

3. The chemically amplified negative resist composition according to claim 2, wherein the onium salt is represented by the following formula (A2). 【Chemistry 4】 (In the formula, n3, n4, n5, R 1 , R 2 , R F 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 (Z-1) or the iodonium cation represented by the following formula (Z-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. Z + The chemically amplified negative resist composition according to claim 1, wherein the sulfonium cation is represented by the following formula (Z-3). 【Transformation 6】 (In the formula, m1 is 0 or 1. m2 is 0 or 1. m3 is 0 or 1. m4 is 0, 1, 2, 3 or 4. m5 is 0, 1, 2, 3 or 4. m6 is 0, 1, 2, 3, 4, 5 or 6. m7 is 0, 1, 2, 3, 4, 5 or 6. m8 is 0, 1 or 2. m9 is 0, 1 or 2. m10 is 0, 1 or 2. m11 is 0 or 1. m12 is 0, 1, 2, 3 or 4. m13 is 0, 1 or 2. m14 is 0, It is either 1 or 2. However, when m1 is 0, 0 ≤ m6 + m9 ≤ 4, and when m1 is 1, 0 ≤ m6 + m9 ≤ 6. When m2 is 0, 0 ≤ m7 + m10 ≤ 4, and when m2 is 1, 0 ≤ m7 + m10 ≤ 6. When m3 is 0, 1 ≤ m4 + m5 + m8 + m14 ≤ 4, and when m3 is 1, 1 ≤ m4 + m5 + m8 + m14 ≤ 6. When m11 is 0, 0 ≤ m12 + m13 ≤ 4, and when m11 is 1, 0 ≤ m12 + m13 ≤ 6. Also, m4 + m12 ≥ 1. R F1 ~R F3 Each of these is independently a fluorine atom, a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, a fluorinated saturated hydrocarbyloxy group having 1 to 6 carbon atoms, or a fluorinated saturated hydrocarbylthio group having 1 to 6 carbon atoms. When m5 is 2, 3, or 4, each R F1 They may be the same as or different from each other. When m6 is 2, 3, 4, 5 or 6, each R F2 They may be the same as or different from each other. When m7 is 2, 3, 4, 5 or 6, each R F3 They may be the same as or different from each other. R ct6 ~R ct9 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than iodine and fluorine atoms, a nitro group, a cyano group, a heteroatom, a C1-C20 hydrocarbyloxy group which may contain a heteroatom, or a C1-C20 hydrocarbylthio group which may contain a heteroatom. When m8 is 2, two R ct6 The two Rs may be the same or different from each other. ct6 These may bond with each other to form a ring with the carbon atoms to which they are bonded. When m9 is 2, two R ct7 The two Rs may be the same or different from each other. ct7 These may bond with each other to form a ring with the carbon atoms to which they are bonded. When m10 is 2, two R ct8 The two Rs may be the same or different from each other. ct8 These may bond with each other to form a ring with the carbon atoms to which they are bonded. When m13 is 2, two R ct9 The two Rs may be the same or different from each other. ct9 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. Furthermore, S in sulfonium cations + Aromatic rings that are directly bonded to each other are bonded to each other and form S + They may form a ring together. L A and L B These are, independently, a single bond, an ether bond, an ester bond, an amide bond, a sulfonic acid ester bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. X L This is a hydrocarbylene group having 1 to 40 carbon atoms, which may contain single bonds or heteroatoms.

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 (B2) and repeating units represented by the following formula (B3). 【Transformation 7】 (In the formula, b1 is 0 or 1. b2 is 0, 1 or 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is 1, 2 or 3. b5 is 0, 1 or 2. b6 is 1 or 2.) R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 This is a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. When b3 is 2 or more, each R 21 They may be the same as or different from each other. R 22 and R 23 Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. However, R 22 and R 23 They cannot simultaneously become hydrogen atoms. Also, R 22 and R 23 These may bond to each other and form a ring with the carbon atoms to which they are bonded, and the -CH of the ring 2 Some of the - may be replaced with -O- or -S-. When b4 is 2 or 3, each R 22 These may be the same or different from each other. Also, when b4 is 2 or 3, each R 23 They may be the same as or different from each other. R 31 This is a C1-C20 hydrocarbyl group which may contain a halogen atom or a heteroatom. When b5 is 2, each R 31 They may be the same as or different from each other. R 32 and R 33 Each of these is independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxyl group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have substituents. However, R 32 and R 33 They cannot simultaneously become hydrogen atoms. Also, R 32 and R 33 These may bond to each other and form a ring with the carbon atoms to which they are bonded, and the -CH of the ring 2 Some of the -s may be replaced with -O- or -S-. When b6 is 2, each R 32 These may be the same or different from each other. Also, when b6 is 2, each R 33 They may be the same as or different from each other. 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 and W 2 Each of these is independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbyl carbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have substituents. When b4 is 2 or 3, each W 1 These may be the same or different from each other. Also, when b6 is 2 or 3, each W 2 They may be the same or different from each other.

7. 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 (B4), repeating units represented by the following formula (B5), and repeating units represented by the following formula (B6). 【Transformation 8】 (In the formula, c and d are independently 0, 1, 2, 3, or 4. e1 is 0 or 1. e2 is 0, 1, or 2. e3 is 0, 1, 2, 3, 4, or 5.) R A These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 and R 42 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. When c is 2, 3, or 4, each R 41 They may be the same as or different from each other. When d is 2, 3, or 4, each R 42 They may be the same as or different from each other. R 43 This 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. When e3 is 2, 3, 4 or 5, each R 43 They may be the same as or different from each other. 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-.)

8. The chemically amplified negative resist composition according to claim 6, wherein the polymer comprises at least one selected from 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), and repeating units represented by the following formula (B11). 【Chemistry 9】 (In the formula, f1 and f2 are independently 0, 1, 2, or 3. g1 is 0 or 1. g2 is 0, 1, 2, 3, or 4. g3 is 0, 1, 2, 3, or 4. However, when g1 is 0, 0 ≤ g2 + g3 ≤ 4, and when g1 is 1, 0 ≤ g2 + g3 ≤ 6.) R A These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 This is a phenylene group which may have a single bond or a substituent. Z 2 is a single bond, **-C(=O)-O-Z 21 -, **-C(=O)-NH-Z 21 - or **-O-Z 21 -. Z 21 is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group or a divalent group obtained by combining these, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond or a hydroxy group. Z 3 These are single bonds, ether bonds, ester bonds, amide bonds, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Z 4 This is a single bond, or a divalent group obtained by combining an aliphatic hydrocarbylene group, a phenylene group, or a combination thereof, and may contain a halogen atom, a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. Z 5 is, independently of each other, a single bond, a phenylene group, a naphthylene group which may have a substituent or *-C(=O)-O-Z 51 -. Z 51 is an aliphatic hydrocarbylene group having 1 to 10 carbon atoms, a phenylene group or a naphthylene group, and the aliphatic hydrocarbylene group may contain a halogen atom, a hydroxy group, an ether bond, an ester bond or a lactone ring. Z 6 These are single bonds, ether bonds, ester bonds, amide bonds, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Z 7 Each of these is independently a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 - or *** - O - Z 71 - is. is. Z 71 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. Z 8 These are, independently, single bonds, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 - or ****-O-Z 81 - is Z 81 This is a hydrocarbylene group having 1 to 20 carbon atoms, which may contain heteroatoms. Z 9 This includes single bonds, methylene groups, ethylene groups, phenylene groups, fluorinated phenylene groups, trifluoromethyl groups, and *-C(=O)-O-Z. 91 -, *-C(=O)-N(H)-Z 91 - or * - O - Z 91 - is Z 91 This is a phenylene group substituted with an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, or a trifluoromethyl group, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. * represents a bond with a carbon atom in the main chain. ** represents Z 1 This represents a combination with Z. *** represents Z 6 This represents a combination with Z. **** is Z 7 This represents a combination of two things. L 1 These are single bonds, ether bonds, ester bonds, carbonyl groups, sulfonic acid ester bonds, sulfonamide bonds, carbonate bonds, or carbamate bonds. Rf 1 and Rf 2 Each of these is independently either a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 Each of these is independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. However, all Rf 5 and Rf 6 They cannot simultaneously become hydrogen atoms. Rf 7 This is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. When g2 is 2, 3, or 4, each Rf 7 They may be the same as or different from each other. R 51 and R 52 Each of these is independently a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms. Also, R 51 and R 52 However, they may bond with each other to form a ring with the sulfur atom to which they are bonded. R 53 This is a C1-C20 hydrocarbyl group which may contain halogen atoms other than fluorine atoms, or heteroatoms.When g3 is 2, 3, or 4, each R 53 They may be the same or different from each other, and there may be multiple R 53 These atoms may bond with each other to form a ring with the carbon atoms to which they are bonded. M - It is a non-nucleophilic counterion. A + This is an onium cation.

9. The chemically amplified negative resist composition according to claim 8, wherein the polymer comprises a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formulas (B2-1), (B2-2), or (B3-1), and a repeating unit represented by the following formula (B8-1). 【Chemistry 10】 (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 32 , R 33 and A + The same applies as above. R HF This is either a hydrogen atom or a trifluoromethyl group. Z 10 This is a single bond or *****-Z 101 -C(=O)-O-. Z 101 This is a hydroxylene group having 1 to 20 carbon atoms, which may contain heteroatoms. ***** represents the bond with the oxygen atom in the formula.

10. (B) The chemically amplified negative resist composition according to claim 8, wherein the base polymer further comprises a polymer that includes repeating units represented by formula (B1) and repeating units represented by formula (B2) or (B3), and does not include repeating units represented by formulas (B7) to (B11).

11. 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.

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

13. A chemically amplified negative resist composition according to claim 1, which does not contain a crosslinking agent.

14. 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 11】 (In the formula, j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3.) R B These are, independently, a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R C 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 Each of these is independently a hydrogen atom, a C1-C15 hydrocarbyl group, a C1-C15 fluorinated hydrocarbyl group, or an acid-unstable group, R 103 , R 106 , R 107 and R 108 When the group is a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be interposed between the 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. X 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. X 2 The bond is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. The asterisk (*) is a bond to a carbon atom in the main chain. X 3 This is a single bond, -O-, *-C(=O)-O-X 31 -X 32 - or * - C (= O) - NH - X 31 -X 32 - is true. X 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.

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

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

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

18. Furthermore, the chemically amplified negative resist composition according to claim 1, further comprising a photoacid generator other than component (G)(A).

19. 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 18; irradiating the resist film with a pattern using a high-energy beam; and developing the resist film irradiated with the pattern using an alkaline developer.

20. The resist pattern formation method according to claim 19, wherein the high-energy beam is an extreme ultraviolet beam or an electron beam with a wavelength of 3 to 15 nm.

21. The resist pattern forming method according to claim 19, 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.

22. The resist pattern forming method according to claim 19, wherein the substrate is a transmissive or reflective mask blank.

23. A transmissive or reflective mask blank coated with a chemically amplified negative resist composition according to any one of claims 1 to 18.

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