Chemically amplified negative resist composition and method for forming resist pattern

Abstract

The present invention provides a chemically amplified negative resist composition that improves the resolution during pattern formation and enables the formation of a resist pattern with good LER and pattern fidelity, and a method for forming a resist pattern. (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 including a polymer containing a repeating unit represented by a specific structure: TIFF2026042374000379.tif25127

Description

[Technical Field]

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

[0002] In recent years, with the increasing integration and speed of LSIs, pattern rules have been rapidly becoming finer. Chemically amplified resist compositions using acid as a catalyst are used exclusively for processing patterns of 0.2 μm or less. High-energy beams such as ultraviolet, far ultraviolet, and electron beams (EB) are used as exposure sources. EB lithography, which is used as an ultrafine processing technology, is also indispensable as a method for processing photomask blanks when producing 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 for KrF lithography, which uses a KrF excimer laser, but because they exhibit high absorption of light with wavelengths around 200 nm, they have not been used as materials for resist compositions for ArF lithography, which uses an ArF excimer laser.However, they are important materials for resist compositions for EB lithography, a powerful technology for forming patterns smaller than the processing limit of ArF excimer lasers, and for extreme ultraviolet (EUV) lithography, because they provide high etching resistance.

[0004] In the processing of photomask blanks, some photomask substrates contain surface materials that can easily affect the pattern shape of the chemically amplified resist film, such as chromium oxide and other chromium compound films. To maintain high resolution and post-etching shape, maintaining a rectangular resist film pattern profile regardless of the type of substrate is an important performance requirement. In recent years, the MBMW (multi-beam mask writing) writing process has been used in the processing of mask blanks to achieve miniaturization. In this process, a low-sensitivity resist composition (high-dose range) that is advantageous for roughness is used as the resist composition, and optimization of resist compositions in this high-dose range has also been attracting attention.

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

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

[0007] Furthermore, one type of acid generator is a sulfonium salt that generates a sulfonic acid having an aromatic group containing an iodine atom, as described in Patent Document 4. However, this is intended to have a sensitizing effect on sensitivity in EUV lithography, and its main role is to be used as a quencher for fluorinated alkanesulfonic acids. Therefore, this acid generator has not been investigated as an acid generator, particularly as an acid generator for use in negative resist compositions that use polyhydroxystyrene as a base polymer for the EB writing process in mask blank processing.

[0008] In photolithography, various improvements have been made to control sensitivity and pattern profile by selecting and combining materials used in resist compositions, changing process conditions, etc. One focus of these improvements has been 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 essentially essential components for improving the performance of resist compositions, particularly resolution. Various quenchers have been investigated, with amines and weak acid onium salts typically being used. Patent Document 5, which describes an example of a weak acid onium salt, describes the formation of a favorable resist pattern free of T-top formation, linewidth differences between isolated and dense patterns, and standing waves by adding triphenylsulfonium acetate. Patent Document 6 describes the improvement of sensitivity, resolution, and exposure margin by adding an ammonium sulfonate salt or an ammonium carboxylate salt. Patent Document 7 also describes the improvement of process tolerances, such as exposure margin and depth of focus, in KrF lithography and EB lithography resist compositions containing a photoacid generator that generates a fluorine-containing carboxylic acid, with excellent resolution and improved process tolerances. Furthermore, Patent Document 8 describes that a resist composition for F2 lithography using an F2 laser, which contains a photoacid generator that generates a fluorine atom-containing carboxylic acid, is excellent in line edge roughness (LER) and has improved footing problems. These compositions are used in KrF lithography, EB lithography, or F2 lithography.

[0010] Patent Document 9 describes a positive-tone photosensitive composition for ArF lithography containing a carboxylic acid onium salt. In this composition, a strong acid (sulfonic acid) generated from a photoacid generator upon exposure is exchanged with a weak acid onium salt to form a weak acid and a strong acid onium salt, thereby replacing a highly acidic strong acid (sulfonic acid) with a weak acid (carboxylic acid), thereby suppressing the acid decomposition reaction of acid-labile groups and reducing (controlling) the acid diffusion distance, and apparently functioning as a quencher.

[0011] However, in recent years, there has been a demand for resist compositions that not only further improve roughness but also provide excellent line-and-space (LS), iso-line (IL), and iso-space (IS) patterns, as well as excellent dot pattern shape. Patent Document 10 describes a photoacid generator that generates a bulky acid and suppresses acid diffusion, which produced patterns with good resolution and roughness, but suffered from the drawback of corner rounding in dot patterns. Patent Document 11 proposes a photoacid generator that generates a non-fluorinated aromatic sulfonic acid having multiple bulky norbornyl groups. Patent Document 12 proposes a photoacid generator with a triarylbenzenesulfonate anion structure. Patent Document 13 proposes a photoacid generator that generates a non-fluorinated aromatic sulfonic acid incorporating an iodine-containing aromatic ring. While attempts have been made to reduce acid diffusion by increasing the molecular weight of the generated acid through the use of multiple alkyl substituents, aromatic rings, and iodine atoms, acid diffusion is still insufficiently suppressed when forming fine patterns, leaving room for further improvement. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-201532 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-215180 [Patent Document 3] Japanese Patent Application Laid-Open 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 Application Publication No. 2023-177038 Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a chemically amplified negative resist composition that improves resolution during pattern formation and is capable of obtaining a resist pattern with excellent LER and pattern fidelity, and a method of forming a resist pattern. [Means for solving the problem]

[0014] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that when an onium salt, which is a photoacid generator that generates a benzenesulfonic acid derivative, has a substituent on the carbon atom adjacent to the sulfo group of the anion, and further contains a triarylbenzene structure or a diarylbenzene structure, is introduced as an acid generator into a negative resist composition for alkali development, the acid generated thereby has appropriate acidity and is prevented from excessive diffusion, thereby enabling a pattern with excellent resolution and small LER to be obtained, and furthermore, due to appropriate dissolution-inhibiting properties, a pattern with excellent rectangularity can be obtained, which has led to the completion of the present invention.

[0015] That is, the present invention provides the following chemically amplified negative resist composition and method of forming a resist pattern. 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 comprising a polymer containing a repeating unit represented by the following formula (B1). [ka] (In the formula, n1 is 0 or 1. n2 is 0, 1, 2, 3, or 4. n3 is 1, 2, 3, or 4. n4 is 0 or 1. n5 is 0, 1, 2, 3, or 4. n6 is 0, 1, 2, 3, or 4. However, when n1 is 0, 1≦n2+n3≦5, and when n1 is 1, 1≦n2+n3≦7. R 1 is a hydrocarbyl group having 1 to 20 carbon atoms. R 2 is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom. When n2 is 2, 3, or 4, each R 2 may be the same or different, and multiple R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 3 is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyloxy group having 1 to 20 carbon atoms which may contain a heteroatom. When n5 is 2, 3, or 4, each R 3 may be the same or different, and multiple R 3 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 4is a halogen atom, a nitro group, a cyano group, a hydroxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. When n6 is 2, 3, or 4, each R 4 may be the same or different, but multiple R 4 do not bond to each other to form a ring together with the carbon atoms to which they are attached. L A , L B and L C are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, an amide bond, a sulfonamide bond, a carbonate bond or a carbamate bond. X L1 is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom. Z + is an onium cation. [ka] (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 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 represents a halogen atom, a nitro group, a carboxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. A 1 represents 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-. 2. The chemically amplified negative resist composition of 1, wherein the onium salt is represented by the following formula (A1): [ka] (In the formula, n2, n3, n5, n6, R 1 ~R 4 , L A , L B , L C , X L1 and Z + is the same as above.) 3. The chemically amplified negative resist composition of 2, wherein the onium salt is represented by the following formula (A2): [ka] (In the formula, n2, n3, n5, n6, R 1 ~R 4 , L A and Z + is the same as above.) 4.Z + is a sulfonium cation represented by the following formula (Z-1) or an iodonium cation represented by the following formula (Z-2): [ka] (In the formula, R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. ct1 and R ct2 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. 5.Z + is a sulfonium cation represented by the following formula (Z-3): [ka] (Wherein, 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, 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 are each 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 or more, each R F1 may be the same or different, and when m6 is 2 or more, each R F2 may be the same or different, and when m7 is 2 or more, each R F3 may be the same or different from each other. R ct6 ~R ct9 is a halogen atom other than an iodine atom or a fluorine atom, a nitro group, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. When m8 is 2, two R ct6 may be the same or different, and two R ct6 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and when m9 is 2, two Rct7 may be the same or different, and two R ct7 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m10 is 2, two R ct8 may be the same or different, and two R ct8 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m13 is 2, two R ct9 may be the same or different, and two R ct9 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. In addition, S in the sulfonium cation + The aromatic rings directly bonded to S + may form a ring together with L D and L E are each independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. X L2 is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. 6. The chemically amplified negative resist composition of any one of 1 to 5, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B2) and a repeating unit 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 that satisfies 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 are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 22 and R23 are each 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 hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be hydrogen atoms at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and a portion of -CH2- in the ring may be substituted with -O- or -S-. R 31 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 32 and R 33 are each 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 hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 32 and R 33 cannot be hydrogen atoms at the same time. 32 and R 33 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and a portion of -CH2- in the ring may be substituted with -O- or -S-. A 2 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-. W 1 and W 2 are each independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbylcarbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have a substituent. 7. The chemically amplified negative resist composition of any one of 1 to 6, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B4), a repeating unit represented by the following formula (B5), and a repeating unit represented by the following formula (B6): [ka] (In the formula, c and d are each 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 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 and R 42 are each independently a hydroxy group, a halogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. R 43 represents 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. A 3 represents 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-. 8. The chemically amplified negative resist composition of 6, wherein the polymer comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B7), a repeating unit represented by the following formula (B8), a repeating unit represented by the following formula (B9), a repeating unit represented by the following formula (B10), and a repeating unit represented by the following formula (B11). [ka] (In the formula, 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. However, when g1 is 0, 0≦e2+e3≦4, and when g1 is 1, 0≦e2+e3≦6. R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 represents a single bond or an optionally substituted phenylene group. Z 2 is a single bond, **-C(=O)-OZ 21 -, **-C(=O)-NH-Z 21 -or **-OZ 21 -It is. Z 21 represents 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 sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 4 represents a single bond, 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 each independently represents a single bond, an optionally substituted phenylene group, a naphthylene group, or *-C(=O)-OZ 51 -It is. 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 sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 7 are each independently a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 -or***-OZ 71 -It is. It is. Z 71 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 8 are each independently a single bond, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 -or ****-OZ 81 -It is. Z 81 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 9 represents 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)-OZ 91 -, *-C(=O)-N(H)-Z 91 -or*-OZ 91 -It is. Z 91 represents 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 in the main chain. ** represents Z 1 *** represents a bond with Z 6 **** represents a bond with Z 7 Represents a bond with . L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Rf 1 and Rf 2are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, provided that all Rf 5 and Rf 6 cannot simultaneously become a hydrogen atom. Rf 7 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. R 51 and R 52 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 51 and R 52 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R 53 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom other than a fluorine atom or a heteroatom. When g3 is 2, 3 or 4, each R 53 may be the same or different, and multiple R 53 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. M - is a non-nucleophilic counterion. A + is an onium cation. 9. The chemically amplified negative resist composition of 8, wherein the polymer comprises a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (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, RA , R 22 , R 23 , R 32 , R 33 and A + is the same as above. R HF is a hydrogen atom or a trifluoromethyl group. Z 10 is a single bond or *****-Z 101 -C(=O)-O-. Z 101 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. ***** is a bond to the oxygen atom in the formula. 10. A chemically amplified negative resist composition according to 8, wherein the (B) base polymer further comprises a polymer containing a repeating unit represented by formula (B1) and a repeating unit represented by formula (B2) or (B3), and does not contain any repeating unit represented by formulas (B7) to (B11). 11. The chemically amplified negative resist composition of 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. The chemically amplified negative resist composition according to any one of 1 to 11, further comprising (C) a crosslinking agent. 13. A chemically amplified negative resist composition according to any one of 1 to 12, which does not contain a crosslinking agent. 14. The chemically amplified negative resist composition according to any one of 1 to 13, further comprising (D) a fluorine atom-containing polymer that contains at least one selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and that may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6). [ka] (In the formula, j1 is 1, 2, or 3. j2 is an integer that satisfies 0≦j2≦5+2(j3)−j1. j3 is 0 or 1. k is 1, 2, or 3. R Bare each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R C are each independently a hydrogen atom or a methyl group. R 101 , R 102 , R 104 and R 105 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. R 103 , R 106 , R 107 and R 108 are each independently a hydrogen atom, a hydrocarbyl group having 1 to 15 carbon atoms, a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid labile group, and R 103 , 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 present between the carbon-carbon bonds. R 109 is a hydrogen atom or a linear or branched hydrocarbyl group having 1 to 5 carbon atoms which may have a group containing a heteroatom interposed between its carbon-carbon bond. R 110 is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms which may have a group containing a hetero atom interposed between its carbon-carbon bond. R 111 is a saturated hydrocarbyl group having 1 to 20 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom, and some of the -CH2- groups in the saturated hydrocarbyl group may be substituted with an ester bond or an ether bond. X 1 is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. X 2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * is a bond to a carbon atom in the main chain. X 3 is a single bond, -O-, *-C(=O)-OX 31 -X 32- or *-C(=O)-NH-X 31 -X 32 -X 31 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms. 32 is a single bond, an ester bond, an ether bond, or a sulfonamide bond. * is a bond to a carbon atom in the main chain. 15. The negative resist composition according to any one of 1 to 14, further comprising (E) a quencher. 16. The chemically amplified negative resist composition of 15, wherein the content ratio of the acid generator (A) to the quencher (E) is less than 6 in mass ratio. 17. Any one of the chemically amplified negative resist compositions of 1 to 16, further comprising (F) an organic solvent. 18. The chemically amplified negative resist composition of any one of 1 to 17, further comprising (G) a photoacid generator other than the component (A). 19. A method for forming a resist pattern, comprising the steps of: forming a resist film on a substrate using the chemically amplified negative resist composition according to any one of 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. The method for forming a resist pattern according to 19, wherein the high-energy radiation is EUV or EB having a wavelength of 3 to 15 nm. 21. The method for forming a resist pattern according to 19 or 20, wherein the outermost surface of the substrate is made of a material containing at least one selected from the group consisting of chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin. 22. The method for forming a resist pattern according to any one of 19 to 21, wherein the substrate is a transmission or reflection mask blank. 23. A transmission or reflection mask blank coated with any one of the chemically amplified negative resist compositions set forth in 1 to 18. [Effects of the Invention]

[0016] The chemically amplified negative resist composition of the present invention exhibits extremely high resolution and can provide patterns with small LER in microfabrication techniques, particularly EB lithography and EUV lithography. Furthermore, due to its moderate dissolution-inhibiting properties, it can provide patterns with good rectangularity, making it suitable as a chemically amplified negative resist material. [Brief explanation of the drawings]

[0017] [Figure 1] 1 is a nuclear magnetic resonance spectrum (H-NMR / DMSO-d) of the onium salt PAG-1 synthesized in Example 1-1. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will be described in detail below. In the following description, some structures represented by chemical formulas may have asymmetric carbon atoms, and enantiomers or diastereomers may exist. In such cases, a single formula will be used to represent all isomers. These isomers may be used singly or as a mixture of two or more.

[0019] [Chemically amplified negative resist composition] The chemically amplified negative resist composition of the present invention is characterized by comprising (A) a photoacid generator comprising an onium salt that generates a predetermined benzenesulfonic acid derivative, and (B) a base polymer containing a predetermined polymer.

[0020] [(A) Photoacid generator] The onium salt serving as the photoacid generator of the component (A) is represented by the following formula (A). [ka]

[0021] 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; however, from the viewpoint of solvent solubility, it is preferable that n1 is a benzene ring of 0. n2 is 0, 1, 2, 3, or 4. From the viewpoint of raw material procurement, it is preferable that n2 is 0 or 1. n3 is 1, 2, 3, or 4. From the viewpoint of raw material procurement, it is preferable that n3 is 1, 2, or 3; from the viewpoint of acid diffusion control, it is preferable that n3 is 2 or 3. n4 is 0 or 1. When n4 is 0, it is a benzene ring, and when n4 is 1, it is a naphthalene ring; however, from the viewpoint of solvent solubility, it is preferable that n4 is a benzene ring of 0. n5 is 0, 1, 2, 3, or 4. From the viewpoint of raw material procurement, it is preferable that n5 is 0, 1, 2, or 3. n6 is 0, 1, 2, 3, or 4. From the viewpoint of raw material procurement, it is preferable that n6 is 1 or 2. However, when n1 is 0, 1≦n4+n5≦5, and when n1 is 1, 1≦n4+n5≦7.

[0022] In formula (A), R 1 is a hydrocarbyl group having 1 to 20 carbon atoms. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include an isopropyl group, a sec-butyl group, a tert-butyl group, a tert-pentyl group, a 2-ethylhexyl group, Alkyl groups having 1 to 20 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 groups; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0] 2,6 ] aliphatic cyclic hydrocarbyl groups having 3 to 20 carbon atoms such as a decyl group and an adamantyl group; aryl groups having 6 to 20 carbon atoms such as a phenyl group, a naphthyl group and anthracenyl group; and groups obtained by combining these groups, but are not limited to these. 1Preferred examples of the alkyl group include branched alkyl groups having 3 to 20 carbon atoms, such as an isopropyl group, a sec-butyl group, a tert-butyl group, a tert-pentyl group, and a 2-ethylhexyl group; aliphatic cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopentyl group and a cyclohexyl group; and aryl groups having 6 to 20 carbon atoms, such as a phenyl group and a naphthyl group.

[0023] In formula (A), R 2is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, with a fluorine atom or an iodine atom being preferred. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH2- constituting the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, resulting in the hydrocarbyl group containing a hydroxy group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride, a haloalkyl group, etc. When n2 is 2, 3 or 4, multiple R 2 may be the same as or different from each other.

[0024] When n2 is 2, 3, or 4, multiple R2 However, they may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. In this case, the ring is preferably a 5- to 8-membered ring.

[0025] In formula (A), R 3 R is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyloxy group having 1 to 20 carbon atoms which may contain a heteroatom. 3 Specific examples of the halogen atom and the hydrocarbyl moiety of the hydrocarbyl group, hydrocarbyloxy group, hydrocarbylthio group, hydrocarbyloxycarbonyl group and hydrocarbylcarbonyloxy group represented by the formula: 2 Specific examples of the halogen atom and hydrocarbyl group represented by the formula (I) include, but are not limited to, the same as those exemplified above. When n5 is 2, 3 or 4, a plurality of R 3 may be the same as or different from each other.

[0026] Also, when n5 is 2, 3, or 4, multiple R 3 However, they may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. In this case, the ring is preferably a 5- to 8-membered ring.

[0027] In formula (A), R 4 R is a halogen atom, a nitro group, a cyano group, a hydroxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. 4 A specific example of this is R 2Examples include, but are not limited to, the following: 4 is preferably a hydrocarbyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 20 carbon atoms, an aliphatic cyclic hydrocarbyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. 4 is -SO3 - Preferably, R is bonded to the ortho or meta position of R. 4 Ga-SO3 - If bonded to the ortho position of R 4 As the alkyl group, a branched alkyl group having 3 to 20 carbon atoms, an aliphatic cyclic hydrocarbyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms is preferred.

[0028] In formula (A), L A , L B and L C are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, an amide bond, a sulfonamide bond, a carbonate bond or a carbamate bond. A is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably an ester bond or a sulfonate ester bond. B is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably a single bond, an ester bond or a sulfonate ester bond. C is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably a single bond, an ester bond or a sulfonate ester bond. B is -SO3 - It is preferred that the bond is at the para position of

[0029] In formula (A), X Lis a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbylene group may be linear, branched, or cyclic, and specific examples thereof 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.

[0030] X L Specific examples of the hydrocarbylene group having 1 to 40 carbon atoms and optionally containing a hetero atom, represented by the formula (I), include, but are not limited to, those shown below. In the formula (I), * represents L A and L B Represents a bond with . [ka]

[0031] [ka]

[0032] [ka]

[0033] [ka]

[0034] Of these, X L -0~X L -22 and X L -47~X L -58 is preferred.

[0035] The onium salt represented by formula (A) is preferably one represented by the following formula (A1). [ka] (In the formula, n2, n3, n5, n6, R 1 ~R 4 , LA , L B , L C , X L1 and Z + is the same as above.)

[0036] The onium salt represented by formula (A1) is preferably one represented by the following formula (A2). [ka] (In the formula, n2, n3, n5, n6, R 1 ~R 4 , L A and Z + is the same as above.)

[0037] Particularly preferred examples of the anion of the onium salt represented by formula (A) include, but are not limited to, those shown below. [ka]

[0038] [ka]

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[0117] In formula (A), Z +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]

[0118] In formulas (Z-1) and (Z-2), R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom.

[0119] R ct1 ~R ct5 Specific examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0120] R ct1 ~R ct5The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 30 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 30 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 30 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 30 carbon atoms, such as phenyl, naphthyl, and thienyl; aralkyl groups having 7 to 30 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, with aryl groups being 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, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0121] Also, R ct1 and R ct2 However, they may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the ring structure include those represented by the following formulas. [ka] (In the formula, the dashed line indicates R ct3 )

[0122] Specific examples of the sulfonium cation represented by formula (Z-1) include those described in paragraphs

[0102] to

[0125] of JP-A No. 2024-003744 and those described in paragraphs

[0070] to

[0085] of JP-A No. 2023-169812, but are not limited thereto.

[0123] Specific examples of the iodonium cation represented by formula (Z-2) include, but are not limited to, those described in paragraph

[0181] of JP-A No. 2024-000259.

[0124] Z + As the onium cation represented by the formula (Z-1), a sulfonium cation represented by the following formula (Z-3) is also preferred. [ka]

[0125] In formula (Z-3), m1 is 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 preferably a benzene ring with m1 being 0. m2 is 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 preferably a benzene ring with m1 being 0. m3 is 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 preferably a benzene ring with m3 being 0.

[0126] In formula (Z-3), m4 is 0, 1, 2, 3, or 4. As the number of iodine atoms in the cation structure increases, absorption, particularly of EUV, increases. However, solvent solubility decreases, raising concerns about precipitation in the resist composition. Therefore, m4 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0127] 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.

[0128] In formula (Z-3), m8 is 0, 1, or 2. From the viewpoint of raw material procurement, m8 is preferably 0 or 1. m9 is 0, 1, or 2. From the viewpoint of raw material procurement, m9 is preferably 0 or 1. m10 is 0, 1, or 2. From the viewpoint of raw material procurement, m10 is preferably 0 or 1.

[0129] In formula (Z-3), m11 is 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, it is preferable that m11 is 0 and is a benzene ring.

[0130] In formula (Z-3), m12 is 0, 1, 2, 3, or 4. As the number of iodine atoms in the cation structure increases, absorption, particularly of EUV, increases. However, solvent solubility decreases, raising concerns about precipitation in the resist composition. Therefore, m12 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0131] In formula (Z-3), m13 is 0, 1 or 2. From the viewpoint of raw material procurement, m13 is preferably 0 or 1. m14 is 0, 1 or 2. From the viewpoint of synthesis, m14 is preferably 0 or 1.

[0132] 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.

[0133] In formula (Z-3), R F1 ~R F3 are each 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, a trifluoromethyl group, a trifluoromethoxy group, or a trifluorothiomethoxy group is preferred. When m5 is 2 or more, each R F1 may be the same or different, and when m6 is 2 or more, each R F2 may be the same or different, and when m7 is 2 or more, each R F3 may be the same or different from each other.

[0134] In formula (Z-3), R ct6 ~R ct9 is a halogen atom other than iodine and fluorine atoms, a nitro group, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group and the hydrocarbyl moiety of the hydrocarbyloxy group and hydrocarbylthio group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 1In addition, some or all of the hydrogen atoms in the hydrocarbyl moiety of the hydrocarbyl group, hydrocarbyloxy group, and hydrocarbylthio 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- in the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, sulfur atom, or nitrogen atom, so that the hydrocarbyl group may contain a hydroxy group, cyano group, fluorine atom, chlorine atom, bromine atom, iodine atom, carbonyl group, ether bond, ester bond, sulfonate ester bond, carbonate bond, lactone ring, sultone ring, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl group, etc.

[0135] Also, when m8 is 2, two R ct6 may be the same or different, and two R ct6 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and when m9 is 2, two R ct7 may be the same or different, and two R ct7 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m10 is 2, two R ct8 may be the same or different, and two R ct8 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m13 is 2, two R ct9 may be the same or different, and two R ct9may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. Specific examples of the ring formed in this case include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, and an adamantane ring. Furthermore, some or all of the hydrogen atoms in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH- groups in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the ring containing a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0136] In addition, S in the sulfonium cation represented by formula (Z-3) + The aromatic rings directly bonded to S + In this case, specific examples of the ring structure include those represented by the following formulas: [ka]

[0137] In formula (Z-3), L D and L E are each independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. D is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably an ester bond or a sulfonate ester bond. E is preferably a single bond, an ether bond or an ester bond, and more preferably a single bond.

[0138] In formula (Z-3), X L2is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom. Specific examples of the hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom include X L1 Specific examples of the hydrocarbylene group having 1 to 40 carbon atoms and optionally containing a hetero atom, represented by the following formula, include, but are not limited to, the same as those exemplified above.

[0139] The sulfonium cation represented by formula (Z-3) is preferably one represented by the following formula (Z-3-1). [ka] (In the formula, m4~m10, m12~m14, R F1 ~R F3 , R ct6 ~R ct9 , L D , L E and X L is the same as above.)

[0140] The cation represented by formula (Z-3-1) is preferably one represented by the following formula (Z-3-2). [ka] (In the formula, m4~m10, R F1 ~R F3 and R ct6 ~R ct8 is the same as above.)

[0141] Specific examples of the sulfonium cation represented by formula (Z-3) include, but are not limited to, the following: In the following formula, Me is a methyl group. [ka]

[0142] [ka]

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[0169] Specific examples of the onium salt of the present invention include any combination of the above-mentioned anions and cations.

[0170] The onium salt of the present invention can be synthesized by a known method. 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~n6, R 1 ~R 4 , L C and Z + is the same as above. + is an alkali metal cation.

[0171] The first step is to obtain aromatic sulfonate chloride intermediate In-1 by reacting alkali metal salt SM-1 of sulfonate anion, which is commercially available or can be synthesized by a known synthetic method, with oxalyl chloride or thionyl chloride. The reaction can be carried out by a known organic synthesis method. Specifically, starting material SM-1 is dissolved in a halogenated solvent such as methylene chloride or chloroform, and oxalyl chloride or thionyl chloride is added dropwise to the solution. The reaction can be accelerated by adding a catalytic amount of N,N-dimethylformamide. Heating is recommended as needed. The reaction temperature ranges from room temperature to the boiling point of the solvent used, but heating is preferred for smooth reaction progression. The reaction time is typically 2 to 10 hours, although tracking the reaction by silica gel thin-layer chromatography (TLC) to complete the reaction is desirable from the viewpoint of yield. The reaction is then quenched with water, and the target product is extracted from the reaction mixture. Intermediate In-1 can be obtained by conventional aqueous work-up. The resulting intermediate In-1 can be purified, if necessary, by a conventional method such as chromatography or recrystallization.

[0172] The second step is a sulfonate esterification reaction between intermediate In-1 and hydroxyaromatic sulfonate SM-2 to obtain aromatic sulfonate onium salt PAG-1-ex. The reaction can be carried out according to a conventional method. Examples of solvents that can be used in the reaction include water; 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 selected appropriately depending on the reaction conditions. They may be used alone or in combination. Intermediate In-1, hydroxyaromatic sulfonate SM-2, and a base are added sequentially or simultaneously to these solvents, and the reaction is carried out with cooling or heating as necessary. Examples of bases that can be used in the reaction include ammonia; amines such as triethylamine, pyridine, lutidine, collidine, 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 alone or in combination. It is desirable to monitor the progress of the reaction by TLC in terms of yield. The onium salt PAG-1-ex can be obtained by subjecting the resulting reaction solution to a standard aqueous workup. If necessary, the product can be purified by standard methods such as chromatography and recrystallization.

[0173] The onium salt represented by formula (A) is an onium salt of sulfonic acid that is not substituted with fluorine atoms, and therefore can generate an acid of appropriate strength upon irradiation with high-energy radiation. It also has a triarylbenzene or diarylbenzene structure, and various functional groups can be introduced into the aryl group. Therefore, functional groups are preferred for the aryl group. When the functional group contains a hydrocarbyloxycarbonyl group, the presence of multiple heteroatoms via ester bonds can reduce acid diffusion. Furthermore, when the functional group contains a halogen atom, particularly a fluorine atom, the onium salt itself exhibits increased solvent solubility, improving uniform dispersion. This also increases the acidity of the generated sulfonic acid, thereby accelerating the deprotection reaction of the base polymer's protecting groups and potentially improving resolution. Furthermore, when the onium salt contains a branched alkyl group or an alicyclic group, the excluded volume of the anion increases, resulting in a bulky structure, which generates a low-diffusion acid, thereby improving LER and other issues. Furthermore, the multiple aromatic rings in the anion have improved compatibility with the aromatic rings in the base polymer through mutual (π-π stacking interactions), which is expected to have the effect of suppressing excessive acid diffusion. These effects enable the acid with excessive acid strength and acid diffusion controlled to be uniformly generated in the resist film, resulting in patterns with good resolution and small LER even in fine patterns. In addition, when using a negative resist composition with an alkaline developer, the appropriate dissolution inhibition properties enable patterns with good rectangularity to be obtained.

[0174] In the chemically amplified negative resist composition of the present invention, the content of the (A) photoacid generator is preferably 0.1 to 40 parts by mass, more preferably 1 to 20 parts by mass, relative to 80 parts by mass of the (B) base polymer described below. When the content of the (A) photoacid generator is within the above range, an amount of acid necessary for deprotecting the acid labile groups is generated, and storage stability is also good. The (A) photoacid generators may be used alone or in combination of two or more.

[0175] [(B) Base polymer] The base polymer of component (B) contains a polymer (hereinafter also referred to as polymer B) containing a repeating unit represented by the following formula (B1) (hereinafter also referred to as repeating unit B1). Repeating unit B1 is a repeating unit that imparts etching resistance, adhesion to substrates, and solubility in alkaline developers. [ka]

[0176] In formula (B1), a1 is 0 or 1. a2 is 0, 1, or 2; when it is 0, it is a benzene skeleton, when it is 1, it is a naphthalene skeleton, and when it is 2, it is an anthracene skeleton. a3 is an integer that satisfies 0≦a3≦5+2(a2)−a4. a4 is 1, 2, or 3. When a2 is 0, a3 is preferably 0, 1, 2, or 3, and a4 is 1, 2, or 3; when a2 is 1 or 2, a3 is preferably 0, 1, 2, 3, or 4, and a4 is 1, 2, or 3.

[0177] In formula (B1), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0178] In formula (B1), R 11is a halogen atom, a nitro group, a carboxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. The saturated hydrocarbyl group and the saturated hydrocarbyl moiety 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 structural isomers thereof; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. When the number of carbon atoms is equal to or less than the upper limit, the solubility in alkaline developers is good. When a3 is 2 or more, each R 11 may be the same as or different from each other.

[0179] In formula (B1), A 1is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and a portion 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 thereof include alkanediyl groups having 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl, and structural isomers thereof; cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining these. When the saturated hydrocarbylene group contains an ether bond, when a1 in formula (B1) is 1, the ether bond may be located anywhere except between the carbon atom at the α-position and the carbon atom at the β-position relative to the ester oxygen atom. When a1 is 0, the atom bonding to the main chain is an etheric oxygen atom, and the second ether bond may be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Note that if the number of carbon atoms in the saturated hydrocarbylene group is 10 or less, sufficient solubility in an alkaline developer can be obtained, which is preferable.

[0180] a1 is 0 and A 1 is a single bond, i.e., the aromatic ring is directly attached to the polymer backbone (i.e., the linker (-C(=O)-OA 1 When the repeating unit B1 does not have -), 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.)

[0181] a1 is 1 (i.e., -C(=O)-OA as a linker) 1In the case where R A is the same as above. [ka]

[0182] The repeating unit B1 may be used alone or in combination of two or more.

[0183] Polymer B may contain at least one 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]

[0184] When the repeating units B2 and B3 are irradiated with high-energy rays, they are converted into -OW by the action of the acid generated from the acid generator. 1 Ya-OW 2 The repeating units B2 and B3 undergo an elimination reaction, which makes the compound insoluble in alkaline developer and induces a crosslinking reaction between polymers. The action of repeating units B2 and B3 allows the negative conversion reaction to proceed more efficiently, thereby improving resolution.

[0185] In formula (B2), b1 is 0 or 1. b2 is 0, 1, or 2. b3 is an integer that satisfies 0≦b3≦5+2(b2)−b4. b4 is 1, 2, or 3.

[0186] In formula (B3), b5 is 0, 1 or 2, and preferably 0 or 1. b6 is 1 or 2, and preferably 1.

[0187] In formulas (B2) and (B3), R A are each 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.

[0188] In formula (B2), R 21 R is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 21 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. 21 The hydrocarbyl group having 1 to 20 carbon atoms represented by the formula (A1) may be saturated or unsaturated, and may be linear, branched, or cyclic. 1 When b3 is 2 or more, each R 21 may be the same as or different from each other.

[0189] In formula (B2), R 22 and R 23 are each 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 hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be hydrogen atoms at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and some of the -CH2- in the ring may be substituted with -O- or -S-. 22 and R 23 Preferred examples of the alkyl group include alkyl groups such as methyl, ethyl, propyl, and butyl groups, and structural isomers thereof, as well as alkyl groups in which some of the hydrogen atoms have been substituted with hydroxy groups or saturated hydrocarbyloxy groups.

[0190] In formula (B3), R 31 R is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 31 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. 31 The hydrocarbyl group having 1 to 20 carbon atoms represented by the formula (A1) may be saturated or unsaturated, and may be linear, branched, or cyclic. 1 When b5 is 2 or more, each R 31 may be the same as or different from each other.

[0191] In formula (B3), R 32 and R 33 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, the hydrocarbyl group optionally being substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group optionally having a substituent.

[0192] R 32 and R 33 The saturated hydrocarbyl group having 1 to 15 carbon atoms represented by the formula (I) may be linear, branched, or cyclic. Specific examples thereof include R 22 and R 23 Examples of the saturated hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0193] R 32 and R 33 Specific examples of the aryl group having 6 to 15 carbon atoms represented by the formula (I) include a phenyl group, a naphthyl group, an anthryl group, etc., of which a phenyl group is preferred. The aryl group may have a substituent, and specific examples of the substituent include a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom.

[0194] Also, R 32 and R 33 cannot simultaneously become a hydrogen atom. 32 and R 33 When either of the groups is an aryl group which may have a substituent, the other substituent is preferably a hydrogen atom.

[0195] R 32 and R 33 are preferably the same group, and more preferably both are methyl groups.

[0196] Also, R 32 and R 33 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and a portion of the -CH2- in the ring may be substituted with -O- or -S-. Examples of the ring include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, an adamantane ring, a tricyclo[5.2.1.0 2,6 ] decane ring, tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodecane ring, oxanorbornane ring, thianorbornane ring, and the like, but are not limited to these.

[0197] In formula (B2), A 2is 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 thereof include alkanediyl groups such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl, and structural isomers thereof; cyclic saturated hydrocarbylene groups such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining these. When the saturated hydrocarbylene group contains an ether bond, when b1 in formula (B2) is 1, the ether bond may be located anywhere except between the carbon atom α and the carbon atom β to the ester oxygen atom. When b1 is 0, the atom bonding to the main chain is an ether oxygen atom, and the second ether bond may be inserted anywhere except between the carbon atom at the α-position and the carbon atom at the β-position relative to the ether oxygen atom.

[0198] In formulas (B2) and (B3), W 1 and W 2 are each independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbylcarbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have a substituent.

[0199] W 1 and W 2The aliphatic hydrocarbyl group having 1 to 10 carbon atoms represented by the formula (I) 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; saturated cyclic 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 unsaturated cyclic 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 the formula (I), may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those having 1 to 9 carbon atoms among the specific examples of the aliphatic hydrocarbyl groups having 1 to 10 carbon atoms described above. W 1 and W 2 Specific examples of the aryl group having 6 to 15 carbon atoms represented by the formula (I) include a phenyl group, a naphthyl group, an anthryl group, etc., of which a phenyl group is preferred. The aryl group may have a substituent, and specific examples of the substituent include a halogen atom, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom.

[0200] The repeating unit B2 is preferably one represented by the following formula (B2-1) or (B2-2). [ka] (In the formula, b4, R A , R 22 and R 23 is the same as above.)

[0201] Preferred examples of the repeating unit B2 include, but are not limited to, the following: A is the same as above, Me is a methyl group, and Ac is an acetyl group. [ka]

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] [ka]

[0212] The repeating unit B2 may be used alone or in combination of two or more.

[0213] The repeating unit B3 is preferably one represented by the following formula (B3-1). [ka] (In the formula, b6, R A , R 32 and R 33 is the same as above.)

[0214] Preferred examples of the repeating unit B3 include, but are not limited to, the following: A is the same as above, Me is a methyl group, and Ac is an acetyl group. [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] [ka]

[0219]

change

[0220]

change

[0221]

change

[0222]

change

[0223]

change

[0224]

change

[0225]

change

[0226]

change

[0227]

change

[0228]

change

[0229]

change

[0230]

change

[0231]

change

[0232]

change

[0233]

change

[0234]

change

[0235]

change

[0236]

change

[0237]

change

[0238]

change

[0239]

change

[0240] [ka]

[0241] [ka]

[0242] [ka]

[0243] [ka]

[0244] [ka]

[0245] [ka]

[0246] [ka]

[0247] The repeating unit B3 may be used alone or in combination of two or more.

[0248] For the purpose of improving etching resistance, polymers B and B' may contain at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), a repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5), and a repeating unit represented by the following formula (B6) (hereinafter also referred to as repeating unit B6). [ka]

[0249] In formulae (B4) and (B5), c and d each independently represent 0, 1, 2, 3, or 4.

[0250] In formulas (B4) and (B5), R 41 and R 42 are each independently a hydroxy group, a halogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, and saturated hydrocarbylcarbonyloxy group may be linear, branched, or cyclic. When c is 2 or more, each R 41 may be the same or different. When d is 2 or more, each R 42 may be the same as or different from each other.

[0251] In formula (B6), e1 is 0 or 1. e2 is 0, 1, or 2. When e is 0, it is a benzene skeleton, when it is 1 it is a naphthalene skeleton, and when it 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.

[0252] In formula (B6), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0253] In formula (B6), R 43is a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbyloxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbylthiohydrocarbyl group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbylsulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbylsulfonyl group having 1 to 20 carbon atoms. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, saturated hydrocarbyloxyhydrocarbyl group, saturated hydrocarbylthiohydrocarbyl group, saturated hydrocarbylsulfinyl group, and saturated hydrocarbylsulfonyl group may be linear, branched, or cyclic. When e3 is 2 or more, each R 43 may be the same as or different from each other.

[0254] R 43 Preferred examples of the alkyl group 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 structural isomers thereof; and saturated hydrocarbyloxy groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopentyloxy, and cyclohexyloxy groups, and structural isomers of the hydrocarbon moiety thereof. Of these, methoxy and ethoxy groups are particularly useful.

[0255] Furthermore, saturated hydrocarbyl carbonyloxy groups can be easily introduced by chemical modification even after polymer polymerization and can be used to finely adjust the solubility of the base polymer in alkaline developers. Examples of the saturated hydrocarbyl carbonyloxy group include methyl carbonyloxy groups, ethyl carbonyloxy groups, propyl carbonyloxy groups, butyl carbonyloxy groups, pentyl carbonyloxy groups, hexyl carbonyloxy groups, cyclopentyl carbonyloxy groups, cyclohexyl carbonyloxy groups, benzoyloxy groups, and structural isomers of the hydrocarbon moieties thereof. If the number of carbon atoms is 20 or less, the effect of controlling and adjusting (mainly the effect of reducing) the solubility of the base polymer in alkaline developers can be made appropriate, and the occurrence of scum (development defects) can be suppressed.

[0256] Among the above-mentioned preferred substituents, examples of substituents that are particularly easy to prepare as a monomer and are usefully used include a chlorine atom, a bromine atom, an iodine atom, a methyl group, an ethyl group, and a methoxy group.

[0257] In formula (B6), A 3is 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 thereof include alkanediyl groups having 1 to 10 carbon atoms, such as methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, and hexane-1,6-diyl, and structural isomers thereof; cyclic saturated hydrocarbylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and groups obtained by combining these. When the saturated hydrocarbylene group contains an ether bond, when f1 in formula (B5) is 1, the ether bond may be located anywhere except between the carbon atom at the α-position and the carbon atom at the β-position relative to the ester oxygen atom. When f1 is 0, the atom bonding to the main chain is an etheric oxygen atom, and the second ether bond may be inserted at any position except between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Note that if the number of carbon atoms in the saturated hydrocarbylene group is 10 or less, sufficient solubility in an alkaline developer can be obtained, which is preferable.

[0258] e1 is 0 and A 3 is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (i.e., the linker (-C(=O)-OA 3 When the repeating unit B6 does not have -), 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.

[0259] Also, when e1 is 1 (i.e., -C(=O)-OA as a linker 3 In the case where R A is the same as above. [ka]

[0260] [ka]

[0261] When at least one of the repeating units B4 to B6 is used as a structural unit of the polymer, the addition of a ring structure to the main chain provides the effect of improving the etching resistance of the aromatic ring as well as the resistance to EB irradiation during pattern inspection.

[0262] The repeating units B4 to B6 may be used alone or in combination of two or more.

[0263] Polymer B' may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (B7) (hereinafter also referred to as repeating unit B7), a repeating unit represented by the following formula (B8) (hereinafter also referred to as repeating unit B8), a repeating unit represented by the following formula (B9) (hereinafter also referred to as repeating unit B9), a repeating unit represented by the following formula (B10) (hereinafter also referred to as repeating unit B10), and a repeating unit represented by the following formula (B11) (hereinafter also referred to as repeating unit B11). [ka]

[0264] In formulas (B7) to (B11), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 1 Z is a single bond or an optionally substituted phenylene group. 2 is a single bond, **-C(=O)-OZ 21 -, **-C(=O)-NH-Z 21 -or **-OZ 21 -It is. Z 21Z 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. 3 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. 4 Z is a single bond, 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. 5 each independently represents a single bond, an optionally substituted phenylene group, a naphthylene group, or *-C(=O)-OZ 51 -It is. 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. 6 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. 7 are each independently a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 -or***-OZ 71 -It is. It is. Z 71 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. 8 are each independently a single bond, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 -or ****-OZ 81 -It is. Z 81 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. 9 represents 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)-OZ91 -, *-C(=O)-N(H)-Z 91 -or*-OZ 91 -It is. 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 in the main chain. ** represents a bond to a carbon atom in the main chain. Z 1 *** represents a bond with Z 6 **** represents a bond with Z 7 Represents a bond with .

[0265] Z 21 , Z 51 and Z 91 The aliphatic hydrocarbylene group represented by the formula (I) may be linear, branched or cyclic, and specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a butane-1,1-diyl group, a butane-1,2-diyl group, a butane-1,3-diyl group, a butane- Examples of the alkyl group include alkanediyl groups such as a 2,3-diyl group, a butane-1,4-diyl group, a 1,1-dimethylethane-1,2-diyl group, a pentane-1,5-diyl group, a 2-methylbutane-1,2-diyl group, and a hexane-1,6-diyl group; cycloalkanediyl groups such as a cyclopropanediyl group, a cyclobutanediyl group, a cyclopentanediyl group, and a cyclohexanediyl group; and groups obtained by combining these groups.

[0266] Z 71 and Z 81 The hydrocarbylene group optionally containing a heteroatom, represented by the formula (I), may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include, but are not limited to, those shown below. [ka] (In the formula, the dashed lines represent bonds.)

[0267] In formula (B7), R 51 and R 52 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and thienyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these, with aryl groups being 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, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc.

[0268] Also, R 51 and R 52 However, they may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, specific examples of the ring include those represented by the following formulas. [ka] (In the formula, the dashed line represents Z 4 )

[0269] Specific examples of the cation of the repeating unit B7 include, but are not limited to, the following: A is the same as above. [ka]

[0270] [ka]

[0271] [ka]

[0272] [ka]

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] [ka]

[0277] [ka]

[0278] [ka]

[0279] In formula (B7), M - is a non-nucleophilic counter ion. Examples of the non-nucleophilic counter ion include halide ions, sulfonate anions, imidate anions, and methide anions. Specific examples of the halide ions include chloride ions and bromide ions. Specific examples of the sulfonate anions (sulfonate ions) include fluoroalkylsulfonate ions such as triflate ions, 1,1,1-trifluoroethanesulfonate ions, and nonafluorobutanesulfonate ions; arylsulfonate ions such as tosylate ions, benzenesulfonate ions, 4-fluorobenzenesulfonate ions, and 1,2,3,4,5-pentafluorobenzenesulfonate ions; and alkylsulfonate ions such as mesylate ions and butanesulfonate ions. Specific examples of the imidate anions (imide ions) include bis(trifluoromethylsulfonyl)imide ions, bis(perfluoroethylsulfonyl)imide ions, and bis(perfluorobutylsulfonyl)imide ions. Specific examples of the methide acid anion (methide ion) include tris(trifluoromethylsulfonyl)methide ion, tris(perfluoroethylsulfonyl)methide ion, and the like.

[0280] Other examples of the non-nucleophilic counter ion include anions represented by any of the following formulae (B7-1) to (B7-4). [ka]

[0281] In formula (B7-1), R fais a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (B7-1-1) described below. fa1 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0282] The anion represented by formula (B7-1) is preferably one represented by the following formula (B7-1-1). [ka]

[0283] In formula (B7-1-1), Q 1 and Q 2 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, but in order 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 is particularly preferably 1. R fa1 is a hydrocarbyl group having 1 to 35 carbon atoms which may contain a heteroatom. The heteroatom is preferably an oxygen atom, a nitrogen atom, a sulfur atom, a halogen atom, or the like, and more preferably an oxygen atom. From the viewpoint of obtaining high resolution in the formation of a fine pattern, the hydrocarbyl group is particularly preferably one having 6 to 30 carbon atoms.

[0284] In formula (B7-1-1), R fa1The hydrocarbyl group having 1 to 35 carbon atoms and represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 35 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a neopentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, a nonyl group, an undecyl group, a tridecyl group, a pentadecyl group, a heptadecyl group, and an icosyl group; a cyclopentyl group, a cyclohexyl group, a 1-adamantyl group, a 2-adamantyl group, a 1-adamantylmethyl group, a norbornyl group, a norbornyl group, and an alkyl group having 1 to 35 carbon atoms. Examples of such alkyl groups include saturated cyclic hydrocarbyl groups having 3 to 35 carbon atoms, such as a 2-cyclohexylmethyl group, a tricyclodecyl group, a tetracyclododecyl group, a tetracyclododecylmethyl group, and a dicyclohexylmethyl group; unsaturated aliphatic hydrocarbyl groups having 2 to 35 carbon atoms, such as a 2-propenyl group and a 3-cyclohexenyl group; aryl groups having 6 to 35 carbon atoms, such as a phenyl group, a 1-naphthyl group, a 2-naphthyl group, and a 9-fluorenyl group; aralkyl groups having 7 to 35 carbon atoms, such as a benzyl group and a diphenylmethyl group; and groups obtained by combining these groups.

[0285] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. Specific examples of hydrocarbyl groups containing hetero atoms include tetrahydrofuryl, methoxymethyl, ethoxymethyl, methylthiomethyl, acetamidomethyl, trifluoroethyl, (2-methoxyethoxy)methyl, acetoxymethyl, 2-carboxy-1-cyclohexyl, 2-oxopropyl, 4-oxo-1-adamantyl, and 3-oxocyclohexyl groups.

[0286] In formula (B7-1-1), L a1 is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond, but from the viewpoint of synthesis, an ether bond or an ester bond is preferred, and an ester bond is more preferred.

[0287] Specific examples of the anion represented by formula (B7-1) include, but are not limited to, the following: 1 is the same as above, and Ac is an acetyl group. [ka]

[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] [ka]

[0293] [ka]

[0294] [ka]

[0295] [ka]

[0296] [ka]

[0297] In formula (B7-2), R fb1 and R fb2 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (B7-1-1): fa1 Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fb1 and R fb2 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fb1 and R fb2 are bonded to each other and form the bonded group (-CF2-SO2-N - -SO2-CF2-) together may form a ring, in which case R fb1 and R fb2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0298] In formula (B7-3), R fc1 , R fc2 and R fc3 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a fluorine atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (B6-1-1): fa1 Examples of the hydrocarbyl group represented by R include the same as those exemplified above. fc1 , R fc2 and Rfc3 is preferably a fluorine atom or a linear fluorinated alkyl group having 1 to 4 carbon atoms. fc1 and R fc2 are bonded to each other and form the bonded group (-CF2-SO2-C - -SO2-CF2-) together may form a ring, in which case R fc1 and R fc2 The group obtained by bonding together is preferably a fluorinated ethylene group or a fluorinated propylene group.

[0299] In formula (B7-4), R fd is a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R in formula (B7-1-1): fa1 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0300] Specific examples of the anion represented by formula (B7-4) include, but are not limited to, those shown below. [ka]

[0301] [ka]

[0302] Further examples of the non-nucleophilic counter ion include anions having an aromatic ring substituted with an iodine atom or a bromine atom. Specific examples of such anions include those represented by the following formula (B7-5): [ka]

[0303] In formula (B7-5), x is 1, 2, or 3. y is 1, 2, 3, 4, or 5. z is 0, 1, 2, or 3, provided that 1≦y+z≦5. y is preferably 1, 2, or 3, and more preferably 2 or 3. z is preferably 0, 1, or 2.

[0304] In formula (B7-5), X BI is an iodine atom or a bromine atom, and when x and / or y are 2 or more, they may be the same or different.

[0305] In formula (B7-5), L 11 is a single bond, an ether bond, an ester bond, or a saturated hydrocarbylene group having 1 to 6 carbon atoms which may contain an ether bond or an ester bond. The saturated hydrocarbylene group may be linear, branched, or cyclic.

[0306] In formula (B7-5), L 12 represents a single bond or a divalent linking group having 1 to 20 carbon atoms when x is 1, and represents an (x+1)-valent linking group having 1 to 20 carbon atoms when x is 2 or 3, and the linking group may contain an oxygen atom, a sulfur atom, or a nitrogen atom.

[0307] In formula (B7-5), R fe is a hydroxy group, a carboxy group, a fluorine atom, a chlorine atom, a bromine atom or an amino group, or a hydrocarbyl group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, a hydrocarbylcarbonyl group having 2 to 20 carbon atoms, a hydrocarbyloxycarbonyl group having 2 to 20 carbon atoms, a hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms or a hydrocarbylsulfonyloxy group having 1 to 20 carbon atoms which may contain a fluorine atom, a chlorine atom, a bromine atom, a hydroxy group, an amino group or an ether bond, or feA )(R feB ), -N(R feC )-C(=O)-R feD or -N(R feC )-C(=O)-OR feD R feA and R feBare each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. feC is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms, and may contain a halogen atom, a hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. feD 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 hydroxy group, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyl group having 2 to 6 carbon atoms, or a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms. The aliphatic hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. The hydrocarbyl group, hydrocarbyloxy group, hydrocarbylcarbonyl group, hydrocarbyloxycarbonyl group, hydrocarbylcarbonyloxy group, and hydrocarbylsulfonyloxy group may be linear, branched, or cyclic. When x and / or z is 2 or more, each R fe may be the same or different from each other.

[0308] Of these, R fe Examples of the hydroxyl group include -N(R feC )-C(=O)-R feD , -N(R feC )-C(=O)-OR feD fluorine atom, chlorine atom, bromine atom, methyl group, methoxy group, etc. are preferred.

[0309] In formula (B7-5), Rf 11 ~Rf 14 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, and at least one of them is a fluorine atom or a trifluoromethyl group. 11 and Rf 12 may combine to form a carbonyl group. 13 and Rf 14 are preferably both fluorine atoms.

[0310] Specific examples of the anion represented by formula (B7-5) include, but are not limited to, the following: BI is the same as above. [ka]

[0311] [ka]

[0312] [ka]

[0313] [ka]

[0314] [ka]

[0315] [ka]

[0316] [ka]

[0317] [ka]

[0318] [ka]

[0319] [ka]

[0320]

change

[0321]

change

[0322]

change

[0323]

change

[0324]

change

[0325]

change

[0326]

change

[0327]

change

[0328]

change

[0329]

change

[0330] [ka]

[0331] [ka]

[0332] [ka]

[0333] Examples of the non-nucleophilic counter ion include a fluorobenzenesulfonate anion bonded to an aromatic group containing an iodine atom, as described in Japanese Patent No. 6648726, an anion having a mechanism for decomposing with an 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.

[0334] Further examples of the non-nucleophilic counter ion include anions of bulky benzenesulfonic acid derivatives that do not contain fluorine atoms, as described in JP 2006-276759 A, JP 2015-117200 A, JP 2016-65016 A, and JP 2019-202974 A, and benzenesulfonic acid anions and alkylsulfonic acid anions that do not contain fluorine atoms bonded to aromatic groups containing iodine atoms, as described in Japanese Patent No. 6645464 A.

[0335] Further examples of the non-nucleophilic counter ion include anions of bissulfonic acid described in JP 2015-206932 A, anions of sulfonamides or sulfonimides having a sulfonic acid on one side and a different sulfonic acid on the other side described in WO 2020 / 158366 A, and anions of sulfonic acid on one side and carboxylic acid on the other described in JP 2015-24989 A.

[0336] In formulae (B8) and (B9), f1 and f2 each independently represent 0, 1, 2 or 3, with 1 being preferred.

[0337] In formula (B10), 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≦h2+h3≦4, and when g1 is 1, 0≦h2+h3≦6.

[0338] In formulas (B8), (B9), (B10), L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. Among these, from the viewpoint of synthesis, an ether bond, an ester bond, or a carbonyl group is preferred, and an ester bond or a carbonyl group is more preferred.

[0339] In formula (B8), Rf 1 and Rf 2 are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. 1 and Rf 2 In order to increase the acid strength of the generated acid, it is preferable that Rf be a fluorine atom. 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Of these, Rf 3 and Rf 4 At least one of these is preferably a trifluoromethyl group.

[0340] In formula (B9), Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms, provided that all Rf 5 and Rf 6 cannot be simultaneously hydrogen atoms. Among these, Rf 5 and Rf 6At least one of these is preferably a trifluoromethyl group.

[0341] 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. 7 is preferably a fluorine atom, a trifluoromethyl group, a difluoromethyl group, a trifluoromethoxy group, a difluoromethoxy group, a trifluoromethylthio group, or a difluoromethylthio group, and more preferably a fluorine atom, a trifluoromethyl group, or a trifluoromethoxy group. 7 may be the same as or different from each other.

[0342] In formula (B10), R 53 is a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a halogen atom other than a fluorine atom, or a heteroatom. The hydrocarbyl group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include R 1 Examples of the hydrocarbyl group represented by the formula (I) include, but are not limited to, the same as those exemplified above. When g3 is 2, 3, or 4, each R 53 may be the same as or different from each other.

[0343] Also, when g3 is 2, 3, or 4, multiple R 53may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. Specific examples of the ring formed in this case include a cyclopropane ring, a cyclobutane ring, a cyclopentane ring, a cyclohexane ring, a norbornane ring, and an adamantane ring. Furthermore, some or all of the hydrogen atoms in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and some of the -CH- groups in the ring may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in the ring containing a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0344] Specific examples of the anion of the repeating unit B8 include, but are not limited to, those shown below. A is the same as above, and Me is a methyl group. [ka]

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] [ka]

[0349] [ka]

[0350] [ka]

[0351] [ka]

[0352] [ka]

[0353] [ka]

[0354] [ka]

[0355] [ka]

[0356] [ka]

[0357] Specific examples of the anion of the repeating unit B9 include, but are not limited to, those shown below. A is the same as above. [ka]

[0358] [ka]

[0359] [ka]

[0360] [ka]

[0361] [ka]

[0362] [ka]

[0363] [ka]

[0364] [ka]

[0365] [ka]

[0366] [ka]

[0367] [ka]

[0368] Specific examples of the anion of the repeating unit B10 include, but are not limited to, the following: A is the same as above. [ka]

[0369]

change

[0370]

change

[0371]

change

[0372]

change

[0373]

change

[0374]

change

[0375]

change

[0376]

change

[0377]

change

[0378]

change

[0379] [ka]

[0380] [ka]

[0381] [ka]

[0382] [ka]

[0383] [ka]

[0384] [ka]

[0385] Specific examples of the anion of the repeating unit B11 include, but are not limited to, those shown below. A is the same as above. [ka]

[0386] In formulas (B8) to (B11), A +is an onium cation. Examples of the onium cation include sulfonium cation, iodonium cation, ammonium cation, etc., with sulfonium cation or iodonium cation being preferred. Specific examples of the sulfonium cation include, but are not limited to, the same as those exemplified as specific examples of the sulfonium cation represented by formula (Z-1) and the sulfonium cation represented by formula (Z-3). Specific examples of the iodonium cation include, but are not limited to, the same as those exemplified as specific examples of the iodonium cation represented by formula (Z-2). Specific examples of the ammonium cation include, but are not limited to, the same as those exemplified as the ammonium cation represented by formula (am-1) described below.

[0387] Specific structures of the repeating units B7 to B11 include any combination of the above-mentioned anions and cations.

[0388] The repeating units B7 to B11 are units that generate acid upon irradiation with high-energy rays. It is believed that the inclusion of these units in the polymer appropriately suppresses acid diffusion, resulting in a pattern with reduced LER. Furthermore, the inclusion of these units in the polymer suppresses the phenomenon in which acid volatilizes from the exposed area and reattaches to the unexposed area during baking in a vacuum, which is believed to be effective in reducing LER and reducing defects due to the suppression of unwanted negative reactions in the unexposed area.

[0389] The repeating units B7 to B11 may be used alone or in combination of two or more.

[0390] Polymers B and B' may contain a lactone structure, a (meth)acrylic acid ester unit having an adhesive group such as a hydroxy group other than a phenolic hydroxy group, or other repeating units in order to finely adjust the properties of the resist film.

[0391] Examples of the (meth)acrylic acid ester unit having the adhesive group include a repeating unit represented by the following formula (B12) (hereinafter also referred to as repeating unit B12), a repeating unit represented by the following formula (B13) (hereinafter also referred to as repeating unit B13), and a 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 auxiliary as units that impart adhesion to substrates or units that adjust solubility. [ka]

[0392] In formulas (B12) to (B14), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 61 is —O— or a methylene group. 62 is a hydrogen atom or a hydroxy group. 63 is a saturated hydrocarbyl group having 1 to 4 carbon atoms; and h is 0, 1, 2, or 3.

[0393] In polymer B, the content of repeating unit B1 is preferably 30 to 95 mol%, more preferably 50 to 85 mol%, to achieve high contrast between the area negatively irradiated by high-energy radiation and the area not irradiated (non-negative area) for the purpose of achieving high resolution. The contents of repeating units B2 and B3 are preferably 5 to 70 mol%, more preferably 10 to 60 mol%, to achieve the effect of accelerating the negative reaction. The contents of repeating units B4 to B6 are preferably 0 to 30 mol%, more preferably 3 to 20 mol%, to achieve the effect of improving etching resistance. Other repeating units may be contained in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0394] When 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 contained in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0395] 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 contained in an amount of 0 to 30 mol %, preferably 0 to 20 mol %.

[0396] Of all the repeating units constituting the polymer, the 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, which ensures that the properties required for the chemically amplified negative resist composition of the present invention are obtained.

[0397] In this case, the polymer B' preferably contains a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (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 , R23 , R 32 , R 33 and A + is the same as above. R HF is a hydrogen atom or a trifluoromethyl group. 10 is a single bond or *****-Z 101 -C(=O)-O-. Z 101 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. ***** is a bond to the oxygen atom in the formula.

[0398] When polymer B' is used as the (B) base polymer, one that does not contain repeating units B7 to B14 may be used in combination with one that does contain repeating units B7 to B14. In this case, the content of the polymer that does 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 the polymer that contains repeating units B7 to B14.

[0399] When a chemically amplified negative resist composition is used to fabricate a mask, 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., a 2.38% by mass tetramethylammonium hydroxide (TMAH) aqueous solution) is preferably 80 nm / sec or less, more preferably 50 nm / sec or less, in order to form a fine pattern, which is generally achieved through a strong development process to minimize defects caused by resist residues. 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, the coating film thickness is often 100 nm or less because it is necessary to pattern fine lines of 50 nm or less. Because the film is thin, pattern degradation due to development is anticipated. Therefore, the dissolution rate of the polymer used is preferably 80 nm / sec or less, more preferably 50 nm / sec or less.

[0400] The polymer can be synthesized by copolymerizing monomers protected with protecting groups as needed using a known method, followed by deprotection as needed. The copolymerization reaction is not particularly limited, but is preferably radical polymerization or anionic polymerization. For these methods, reference can be made to WO 2006 / 121096, JP 2008-102383 A, JP 2008-304590 A, and JP 2004-115630 A.

[0401] The polymer preferably has a weight-average molecular weight (Mw) of 1,000 to 50,000, more preferably 2,000 to 20,000. If Mw is 1,000 or more, there is no risk of the conventionally known phenomenon of pattern heads becoming rounded, resulting in reduced resolution and LER degradation. On the other hand, if Mw is 50,000 or less, there is no risk of LER increasing, particularly when forming a pattern with a line width of 100 nm or less. In the present invention, Mw is a value measured in terms of polystyrene by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylformamide (DMF) as a solvent.

[0402] The polymer preferably has a narrow molecular weight distribution (Mw / Mn) of 1.0 to 2.0, particularly 1.0 to 1.8, such that foreign matter does not appear on the pattern after development and the pattern shape does not deteriorate.

[0403] [(C) Crosslinking agent] When the (B) 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, when the (B) base polymer contains polymer B', it may or may not contain a crosslinking agent.

[0404] Specific examples of crosslinking agents that can be used in the present invention include epoxy compounds, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds, such as alkenyloxy groups, all of which are substituted with at least one group selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. These may be used as additives or may be introduced as pendant groups into polymer side chains. Compounds containing hydroxy groups may also be used as crosslinking agents.

[0405] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0406] Examples of the melamine compound include compounds in which 1 to 6 methylol groups are methoxymethylated, such as hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine, and mixtures thereof; and compounds in which 1 to 6 methylol groups are acyloxymethylated, such as hexamethoxyethyl melamine, hexaacyloxymethyl melamine, and hexamethylol melamine, and mixtures thereof.

[0407] Examples of the guanamine compound include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine, and mixtures thereof; and compounds in which 1 to 4 methylol groups are acyloxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, and mixtures thereof.

[0408] Examples of the glycoluril compound include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethyl glycoluril, and tetramethylol glycoluril, or mixtures thereof; and compounds in which 1 to 4 methylol groups are acyloxymethylated in tetramethylol glycoluril, or mixtures thereof.

[0409] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylol urea, or mixtures thereof, and tetramethoxyethyl urea.

[0410] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0411] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0412] Examples of the compound containing an alkenyloxy group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propanediol divinyl ether, 1,4-butanediol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, pentaerythritol trivinyl ether, pentaerythritol tetravinyl ether, sorbitol tetravinyl ether, sorbitol pentavinyl ether, and trimethylolpropane trivinyl ether.

[0413] In the chemically amplified negative resist composition of the present invention, the content of the (C) crosslinking agent is preferably 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass, relative to 80 parts by mass of the (B) base polymer. Within this range, there is little risk of patterns being connected together and resolution decreasing. The (C) crosslinking agents may be used alone or in combination of two or more.

[0414] [(D) Fluorine atom-containing polymer] The chemically amplified negative resist composition of the present invention, for the purposes of achieving high contrast, suppressing chemical flare of acids upon irradiation with high-energy rays, shielding acid from mixing from the antistatic film during the process of applying an antistatic film material onto the resist film, and suppressing unexpected and unnecessary pattern degradation, may contain, as component (D), a fluorine-containing polymer that includes at least one selected from the group consisting of a repeating unit represented by formula (D1) below (hereinafter also referred to as repeating unit D1), a repeating unit represented by formula (D2) below (hereinafter also referred to as repeating unit D2), a repeating unit represented by formula (D3) below (hereinafter also referred to as repeating unit D3), and a repeating unit represented by formula (D4) below (hereinafter also referred to as repeating unit D4), and that may further include at least one selected from the group consisting of a repeating unit represented by formula (D5) below (hereinafter also referred to as repeating unit D5) and a repeating unit represented by formula (D6) below (hereinafter also referred to as repeating unit D6). The fluorine atom-containing polymer also functions as a surfactant, and is therefore effective in preventing insoluble matter from re-adhering to the substrate during the development process, thereby preventing development defects. [ka]

[0415] In formulas (D1) to (D6), j1 is 1, 2, or 3. j2 is an integer that satisfies 0≦j2≦5+2(j3)−j1. j3 is 0 or 1. k is 1, 2, or 3. R B are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Care each independently a hydrogen atom or a methyl group. 101 , R 102 , R 104 and R 105 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. 103 , R 106 , R 107 and R 108 are each independently a hydrogen atom, a hydrocarbyl group having 1 to 15 carbon atoms, a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid labile group, and R 103 , R 106 , R 107 and R 108 When R is a hydrocarbyl group or a fluorinated hydrocarbyl group, an ether bond or a carbonyl group may be present between the carbon-carbon bond. 109 R is a hydrogen atom or a linear or branched hydrocarbyl group having 1 to 5 carbon atoms which may have a heteroatom-containing group interposed between its carbon-carbon bond. 110 R is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms, which may have a heteroatom-containing group interposed between its carbon-carbon bond. 111 is a saturated hydrocarbyl group having 1 to 20 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom, and some of the -CH2- groups in the saturated hydrocarbyl group may be substituted with an ester bond or an ether bond. 1 is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. 2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * is a bond to a carbon atom in the main chain. X 3 is a single bond, -O-, *-C(=O)-OX 31 -X 32 - or *-C(=O)-NH-X 31 -X 32 -X 31 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms. 32 is a single bond, an ester bond, an ether bond, or a sulfonamide bond. * is a bond to a carbon atom of the main chain.

[0416] In formulas (D1) and (D2), R 101 , R 102 , R 104 and R 105 The saturated hydrocarbyl group having 1 to 10 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof 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; and cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl. Of these, saturated hydrocarbyl groups having 1 to 6 carbon atoms are preferred.

[0417] In formulas (D1) to (D4), R 103 , R 106 , R 107 and R 108 The hydrocarbyl group having 1 to 15 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, and an alkynyl group having 2 to 15 carbon atoms, with an alkyl group having 1 to 15 carbon atoms being preferred. Examples of the alkyl group include those mentioned above, as well as 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. Examples of the fluorinated hydrocarbyl group include groups in which some or all of the hydrogen atoms bonded to carbon atoms in the hydrocarbyl group mentioned above have been substituted with fluorine atoms.

[0418] In formula (D4), X 1Examples of the (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms and represented by the formula (1) include a group in which k hydrogen atoms have been further removed from an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbyl group having 3 to 20 carbon atoms. 1 Examples of the (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms and represented by the formula (I) include groups in which at least one hydrogen atom of the aforementioned (k+1)-valent hydrocarbon group has been substituted with a fluorine atom.

[0419] Specific examples of the repeating units D1 to D4 include, but are not limited to, the following: B is the same as above. [ka]

[0420] [ka]

[0421] [ka]

[0422] In formula (D5), R 109 and R 110 Examples of the hydrocarbyl group having 1 to 5 carbon atoms represented by the formula (I) include an alkyl group, an alkenyl group, and an alkynyl group, with an alkyl group being preferred. Examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, and an n-pentyl group. In addition, a group containing a heteroatom such as an oxygen atom, a sulfur atom, or a nitrogen atom may be present between the carbon-carbon bonds of the hydrocarbyl group.

[0423] In formula (D5), -OR 109 is preferably a hydrophilic group. In this case, R 109 As the alkyl group, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms and an oxygen atom intervening between the carbon-carbon bonds, and the like are preferred.

[0424] In formula (D5), X 2 is preferably *-C(=O)-O- or *-C(=O)-NH-. C is preferably a methyl group. 2 The presence of a carbonyl group in R improves the acid trapping ability of the antistatic film. D When the methyl group is used, the polymer becomes more rigid with a higher glass transition temperature (Tg), which suppresses acid diffusion, resulting in good stability of the resist film over time and preventing degradation of resolution and pattern shape.

[0425] Examples of the repeating unit D5 include, but are not limited to, those shown below. C is the same as above. [ka]

[0426] [ka]

[0427] In formula (D6), X 3 The saturated hydrocarbylene group having 1 to 10 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,1-diyl group, a propane-1,2-diyl group, a propane-1,3-diyl group, a propane-2,2-diyl group, a butane-1,1-diyl group, a butane-1,2-diyl group, a butane-1,3-diyl group, a butane-2,3-diyl group, a butane-1,4-diyl group, and a 1,1-dimethylethane-1,2-diyl group.

[0428] In formula (D6), R 111The saturated hydrocarbyl group having 1 to 20 carbon atoms, represented by the formula (I) above, in which at least one hydrogen atom has been substituted with a fluorine atom, may be linear, branched, or cyclic, and specific examples thereof include an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbyl group having 3 to 20 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom.

[0429] Examples of the repeating unit D6 include, but are not limited to, those shown below. C is the same as above. [ka]

[0430] [ka]

[0431] [ka]

[0432] [ka]

[0433] The content of repeating units D1 to D4 is preferably 15 to 95 mol %, more preferably 20 to 85 mol %, of all repeating units in the fluorine atom-containing polymer. The content of repeating units D5 and / or D6 is preferably 5 to 85 mol %, more preferably 15 to 80 mol %, of all repeating units in the fluorine atom-containing polymer. The repeating units D1 to D6 may be used alone or in combination of two or more.

[0434] The (D) fluorine atom-containing polymer may contain repeating units other than the repeating units described above. Examples of such repeating units include those described in paragraphs

[0046] to

[0078] of JP 2014-177407 A. When the (D) fluorine atom-containing polymer contains other repeating units, the content of such other repeating units is preferably 50 mol % or less of all repeating units of the fluorine atom-containing polymer.

[0435] (D) The fluorine atom-containing polymer can be synthesized by copolymerizing each monomer, optionally protected with a protecting group, according to a known method, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but is preferably radical polymerization or anionic polymerization. For these methods, reference can be made to JP-A-2004-115630.

[0436] The Mw of the (D) fluorine atom-containing polymer is preferably 2,000 to 50,000, more preferably 3,000 to 20,000. If the Mw is less than 2,000, the diffusion of the acid is promoted, which may result in a deterioration in resolution and a loss of stability over time. If the Mw is too large, the solubility in solvents may decrease, which may cause coating defects. Furthermore, the (D) fluorine atom-containing polymer preferably has an Mw / Mn ratio of 1.0 to 2.2, more preferably 1.0 to 1.7.

[0437] When the chemically amplified negative resist composition of the present invention contains (D) a fluorine atom-containing polymer, the content thereof 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, relative to 80 parts by mass of (B) base polymer. The (D) fluorine atom-containing polymer may be used alone, or two or more types may be used in combination.

[0438] [(E) Quencher] The chemically amplified negative resist composition of the present invention preferably contains a quencher as component (E). In this invention, a quencher is a material that traps the acid generated by the photoacid generator in the chemically amplified resist composition, thereby preventing it from diffusing to unexposed areas and allowing the desired pattern to be formed.

[0439] Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of JP 2008-111103 A are preferred, including amine compounds having a hydroxy group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate ester bond, and compounds having a carbamate group described in JP 3790649 A. Preferred examples include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, imidazole derivatives, etc. Addition of such basic compounds can, for example, further suppress the diffusion rate of acid in the resist film or correct the shape.

[0440] Further, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of carboxylic acids not fluorinated at the α-position, as described in JP-A-2008-158339. Sulfonic acids, imide acids, or methide acids fluorinated at the α-position are necessary for deprotecting acid labile groups, and salt exchange with onium salts not fluorinated at the α-position releases carboxylic acids not fluorinated at the α-position. Carboxylic acids not fluorinated at the α-position hardly undergo deprotection reactions, and therefore function as quenchers.

[0441] Examples of onium salts of carboxylic acids that are not fluorinated at the α-position include those represented by the following formula (E1). [ka]

[0442] In formula (E1), R 201 represents a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the carboxy group is substituted with a fluorine atom or a fluoroalkyl group.

[0443] R 201 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 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 having 3 to 40 carbon atoms such as a decyl group, an adamantyl group, and an adamantylmethyl group; alkenyl groups having 2 to 40 carbon atoms such as a vinyl group, an allyl group, a propenyl group, a butenyl group, and a hexenyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 40 carbon atoms such as a cyclohexenyl group; phenyl group, naphthyl group, alkylphenyl groups (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert-butylphenyl group, Examples of aryl groups include aryl groups having 6 to 40 carbon atoms such as arylphenyl groups (e.g., 2,4-n-butylphenyl group, 4-n-butylphenyl group), di- or trialkylphenyl groups (e.g., 2,4-dimethylphenyl group, 2,4,6-triisopropylphenyl group), alkylnaphthyl groups (e.g., methylnaphthyl group, ethylnaphthyl group), and dialkylnaphthyl groups (e.g., dimethylnaphthyl group, diethylnaphthyl group); and aralkyl groups having 7 to 40 carbon atoms such as benzyl group, 1-phenylethyl group, and 2-phenylethyl group.

[0444] Furthermore, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH- groups of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom or a nitrogen atom, and as a result, the hydrocarbyl group may contain a hydroxy group, a cyano group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like. Examples of the hydrocarbyl group containing a heteroatom include heteroaryl groups such as a thienyl group; alkoxyphenyl groups such as a 4-hydroxyphenyl group, a 4-methoxyphenyl group, a 3-methoxyphenyl group, a 2-methoxyphenyl group, a 4-ethoxyphenyl group, a 4-tert-butoxyphenyl group, and a 3-tert-butoxyphenyl group; alkoxynaphthyl groups such as a methoxynaphthyl group, an ethoxynaphthyl group, an n-propoxynaphthyl group, and an n-butoxynaphthyl group; dialkoxynaphthyl groups such as a dimethoxynaphthyl group and a diethoxynaphthyl group; and aryloxoalkyl groups such as a 2-aryl-2-oxoethyl group, a 2-(1-naphthyl)-2-oxoethyl group, and a 2-(2-naphthyl)-2-oxoethyl group.

[0445] In formula (E1), Mq A + 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 JP-A No. 2024-003744, those described in paragraphs

[0070] to

[0085] of JP-A No. 2023-169812, and those represented by formula (A2). Specific examples of iodonium cations include, but are not limited to, those described in paragraph

[0181] of JP-A No. 2024-000259.

[0446] The ammonium cation is preferably one represented by the following formula (am-1). [ka]

[0447] In formula (am-1), R q11 ~R q14 are each independently a hydrocarbyl group having 1 to 40 carbon atoms which may contain a heteroatom. q11 ~R q14 Any two of these may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Specific examples of the hydrocarbyl group include R 1 Examples of the hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0448] Specific examples of the ammonium cation represented by formula (am-1) include, but are not limited to, those shown below. [ka]

[0449] Examples of the anion of the onium salt represented by formula (E1) include, but are not limited to, those shown below. [ka]

[0450] [ka]

[0451] [ka]

[0452] As the quencher, a sulfonium salt of an iodinated benzene ring-containing carboxylic acid represented by the following formula (E2) can also be suitably used. [ka]

[0453] In formula (E2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3, provided that 1≦s+t≦5. u is 1, 2, or 3.

[0454] In formula (E2), R 211 is a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano 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 saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B and some or all of the hydrogen atoms of the saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group or saturated hydrocarbylsulfonyloxy group may be substituted with halogen atoms. 211A 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 is 2 or more, each R 211 may be the same or different from each other.

[0455] In formula (E2), L 21 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 hydroxy group, and a carboxy group. The saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group, and saturated hydrocarbylsulfonyloxy group may be linear, branched, or cyclic.

[0456] In formula (E2), R212 , R 213 and R 214 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. The hydrocarbyl group may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. Some or all of the hydrogen atoms in the hydrocarbyl group may be substituted with a hydroxy group, a carboxy group, a halogen atom, an oxo group, a cyano group, a nitro group, a sultone ring, a sulfo group, or a sulfonium salt-containing group. Some of the -CH2- groups in the hydrocarbyl group may be substituted with an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate ester bond. Furthermore, R 212 and R 213 may be bonded to each other to form a ring together with the sulfur atom to which they are attached.

[0457] Specific examples of the compound represented by formula (E2) include those described in JP 2017-219836 A. The compound represented by formula (E2) has high absorption, a high sensitizing effect, and a high acid diffusion control effect.

[0458] As the quencher, a nitrogen atom-containing carboxylate compound represented by the following formula (E3) can also be used. [ka]

[0459] In formula (E3), R 221 ~R 224 are each independently a hydrogen atom, -L 22 -CO2 - or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hetero atom. 221 and R 222 and R 222 and R 223 and, or R 223 and R 224and may be bonded to each other to form a ring together with the carbon atoms to which they are attached. 22 R is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. 225 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydrogen atom or a heteroatom.

[0460] In formula (E3), ring R r is a ring containing carbon atoms and nitrogen atoms and having 2 to 6 carbon atoms, and some or all of the hydrogen atoms bonded to the carbon atoms of the ring are hydrocarbyl groups having 1 to 20 carbon atoms, or -L 22 -CO2 - and a portion of -CH2- in 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- or 6-membered ring, specific examples of which include a pyridine ring, a pyrrole ring, a pyrrolidine ring, a piperidine ring, a pyrazole ring, an imidazoline ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, an imidazoline ring, an oxazole ring, a thiazole ring, a morpholine ring, a thiazine ring, and a triazole ring.

[0461] The onium carboxylic acid salt represented by formula (E3) has at least one -L 22 -CO2 - group, i.e., R 221 ~R 224 At least one of the 22 -CO2 - and / or ring R r At least one of the hydrogen atoms bonded to the carbon atom of 22 -CO2 - is replaced by

[0462] In formula (E3), Mq B +is a sulfonium cation, an iodonium cation, or an ammonium cation, preferably a sulfonium cation. Specific examples of the sulfonium cation include those described in paragraphs

[0102] to

[0125] of JP-A No. 2024-003744, those described in paragraphs

[0070] to

[0085] of JP-A No. 2023-169812, and the same as those exemplified as specific examples of the sulfonium cation represented by formula (Z-3), but are not limited thereto.

[0463] Examples of the anion of the compound represented by formula (E3) include, but are not limited to, those shown below. [ka]

[0464] [ka]

[0465] [ka]

[0466] [ka]

[0467] [ka]

[0468] [ka]

[0469] Furthermore, a weak acid betaine type compound can also be used as the quencher. Specific examples thereof include, but are not limited to, the following: [ka]

[0470] Further examples of the quencher include the polymer-type quencher described in JP 2008-239918 A. This quencher enhances the rectangularity of the resist pattern by orienting on the surface of the resist film. The polymer-type quencher also has the effect of preventing pattern film loss and pattern top rounding when a protective film for immersion lithography is applied.

[0471] When the chemically amplified negative resist composition of the present invention contains a quencher (E), the content thereof is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass, relative to 80 parts by mass of the base polymer (B). The quenchers (E) may be used singly or in combination of two or more.

[0472] When the chemically amplified negative resist composition of the present invention contains a photoacid generator as component (A) and a quencher as component (E), the content ratio of the photoacid generator to the quencher ((A) / (E)) is preferably less than 6 by mass, more preferably less than 5, and even more preferably less than 4. When the content ratio of the photoacid generator to the quencher contained 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.

[0473] [(F) Organic solvent] 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 is capable of dissolving 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] and

[0145] of JP-A No. 2008-111103; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, and diacetone alcohol; propylene glycol monomethyl ether (PGME), ethylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethylene glycol monoethyl ether. Examples of suitable solvents include ethers such as ethylene glycol 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 mono-tert-butyl ether acetate; lactones such as γ-butyrolactone; and mixed solvents thereof.

[0474] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixed solvents thereof are preferred.

[0475] When the chemically amplified negative resist composition of the present invention contains an organic solvent (F), the content thereof is preferably 200 to 10,000 parts by mass, and more preferably 400 to 6,000 parts by mass, relative to 80 parts by mass of the base polymer (B). The organic solvent (F) may be used alone or in combination of two or more types.

[0476] [(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 photoacid generator consisting of an onium salt represented by formula (A) (hereinafter also referred to as "other photoacid generators"). The other photoacid generators are not particularly limited as long as they are compounds that generate acid upon exposure to high-energy rays. Suitable photoacid generators include sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, and oxime-O-sulfonate-type acid generators.

[0477] Specific examples of the other photoacid generators include nonafluorobutanesulfonate, the partially fluorinated sulfonates described in paragraphs

[0247] to

[0251] of JP 2012-189977 A, the partially fluorinated sulfonates described in paragraphs

[0261] to

[0265] of JP 2013-101271 A, and those described in paragraphs

[0122] to

[0142] of JP 2008-111103 A and paragraphs

[0080] to

[0081] of JP 2010-215608 A. Among the specific examples, arenesulfonate- or alkanesulfonate-type photoacid generators are preferred because they generate an acid of appropriate strength for deprotecting the acid labile group in the repeating unit B2.

[0478] The photoacid generator is preferably a salt compound containing an anion having the structure shown below. [ka]

[0479] [ka]

[0480] [ka]

[0481] [ka]

[0482] [ka]

[0483] [ka]

[0484] [ka]

[0485] [ka]

[0486] [ka]

[0487] [ka]

[0488] [ka]

[0489] Furthermore, as the photoacid generator, a salt compound containing an anion represented by the following formula (G1) is also preferred. [ka]

[0490] In formula (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.

[0491] In formula (G1), L 31is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond.

[0492] In formula (G1), L 32 is an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond.

[0493] In formula (G1), L F represents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms when p is 1, and represents a (p+1)-valent hydrocarbon group having 1 to 20 carbon atoms when p is 2 or 3, and the hydrocarbylene 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 hydroxy group, and a carboxy group.

[0494] L F The hydrocarbylene group having 1 to 20 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, and a dodecane-1,12-diyl group. alkanediyl groups having 1 to 20 carbon atoms; cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms such as cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group, and adamantanediyl group; unsaturated aliphatic hydrocarbylene groups having 2 to 20 carbon atoms such as vinylene group and propene-1,3-diyl group; arylene groups having 6 to 20 carbon atoms such as phenylene group and naphthylene group; and groups obtained by combining these. FThe (p+1)-valent hydrocarbon group having 1 to 20 carbon atoms, represented by the formula (1), may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include groups obtained by further removing one or two hydrogen atoms from the specific examples of the hydrocarbylene group having 1 to 20 carbon atoms described above.

[0495] In formula (G1), Rf 21 and Rf 22 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one is a fluorine atom or a trifluoromethyl group.

[0496] In formula (G1), R 301 is a hydroxy group, a carboxy 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, -N(R 301A )(R 301B ), -N(R 301C )-C(=O)-R 301D or -N(R 301C )-C(=O)-OR 301D R 301A and R 301B are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301D is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0497] R 301 , R 301A and R 301BThe saturated hydrocarbyl group having 1 to 6 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof 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 Examples of the saturated hydrocarbyl moiety of the saturated hydrocarbyloxy group having 1 to 6 carbon atoms and represented by the formula (I) include the same as the specific examples of the saturated hydrocarbyl group described above, and R 301 Examples of the saturated hydrocarbyl moiety of the saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms represented by the formula include those having 1 to 5 carbon atoms among the specific examples of the saturated hydrocarbyl groups having 1 to 6 carbon atoms mentioned above.

[0498] R 301B The unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkenyl groups having 2 to 8 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl groups; alkynyl groups having 2 to 8 carbon atoms such as ethynyl, propynyl, and butynyl groups; and cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 8 carbon atoms such as cyclohexenyl and norbornenyl groups.

[0499] In formula (G1), R 302 represents a saturated hydrocarbylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms, and some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with halogen atoms other than fluorine atoms, or some or all of the hydrogen atoms of the arylene group may be substituted with a substituent 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 hydroxy group.

[0500] R 302The saturated hydrocarbylene group having 1 to 20 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkanediyl groups having 1 to 20 carbon atoms such as methanediyl group, ethane-1,1-diyl group, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group, and dodecane-1,12-diyl group; and cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms such as cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group, and adamantanediyl group.

[0501] R 302 Specific examples of the arylene group having 6 to 20 carbon atoms represented by the formula (I) include a phenylene group, a naphthylene group, a phenanthrenediyl group, and an anthracenediyl group. The hydrocarbyl moiety 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, and specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and icosyl group; and cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, and adamantyl group. Specific examples of the arylene group having 6 to 14 carbon atoms that is the substituent of the arylene group include a phenylene group, a naphthylene group, a phenanthrenediyl group, and an anthracenediyl group.

[0502] The anion represented by formula (G1) is preferably an anion represented by the following formula (G2). [ka]

[0503] In formula (G2), p, q, r, L 31 , L F and R 301 is the same as above. s2 is 1, 2, 3 or 4. R 302A is a saturated hydrocarbyl group having 1 to 14 carbon atoms, a saturated hydrocarbyloxy group having 1 to 14 carbon atoms, an aryl group having 6 to 14 carbon atoms, a halogen atom, or a hydroxy group. When s2 is 2, 3, or 4, each R 302A may be the same as or different from each other.

[0504] Specific examples of the anion represented by formula (G1) include, but are not limited to, those shown below. [ka]

[0505] [ka]

[0506] [ka]

[0507] [ka]

[0508] [ka]

[0509] [ka]

[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]

change

[0528]

change

[0529]

change

[0530]

change

[0531]

change

[0532] In the (G) other photoacid generators, the cation paired with the anion is preferably a sulfonium cation or an iodonium cation. 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) and those exemplified as specific examples of 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).

[0533] The acid generated by the other photoacid generator preferably has a pKa of -2.0 or higher, more preferably -1.0 or higher. The upper limit of the pKa is preferably 2.0. The pKa value was calculated using the pKa DB in the software ACD / Chemsketch ver. 9.04 manufactured by Advanced Chemistry Development, Inc.

[0534] When 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, more preferably 1 to 5 parts by mass, relative to 80 parts by mass of the base polymer. The inclusion of the other photoacid generators makes it possible to appropriately adjust the amount of acid generated in exposed areas and the dissolution inhibition properties of unexposed areas. The (G) other photoacid generators may be used alone or in combination of two or more.

[0535] [(H) Surfactant] The chemically amplified negative resist composition of the present invention may contain a commonly used surfactant as component (H) to improve its coatability onto substrates. Examples of such surfactants include PF-636 (manufactured by OMNOVA SOLUTIONS) and FC-4430 (manufactured by 3M). Many surfactants are known, as described in JP-A-2004-115630, and these can be used as references for selection. When the chemically amplified negative resist composition of the present invention contains surfactant (H), the content is preferably 0 to 5 parts by mass per 80 parts by mass of base polymer (B). The surfactant (H) may be used alone, or two or more types may be used in combination.

[0536] [Method for forming resist pattern] The method for forming a resist pattern of the present invention includes the steps of: forming a resist film on a substrate using the aforementioned chemically amplified negative resist composition; irradiating the resist film with a pattern using high-energy rays (i.e., exposing the resist film using high-energy rays); and developing the resist film irradiated with the pattern using an alkaline developer.

[0537] The substrate may be, for example, a substrate for manufacturing integrated circuits (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflective coating, etc.), or a substrate for manufacturing transmission or reflection mask circuits (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2, etc.). 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 the composition 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.

[0538] Next, the resist film is exposed to high-energy rays to irradiate a pattern. Examples of the high-energy rays include ultraviolet rays, far ultraviolet rays, excimer laser light (KrF, ArF, etc.), EUV rays with a wavelength of 3 to 15 nm, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, exposure using EUV or EB is preferred.

[0539] When ultraviolet rays, far ultraviolet rays, excimer laser light, EUV, X-rays, gamma rays, or synchrotron radiation is used as the high-energy rays, a mask for forming a desired pattern is used, and the exposure dose is preferably 1 to 500 mJ / cm. 2 , more preferably 10 to 400 mJ / cm 2 When EB is used, the exposure dose is preferably 1 to 500 μC / cm 2 directly to form the desired pattern. 2 , more preferably 10 to 400 μC / cm 2 Irradiate so that

[0540] The exposure may be performed by a conventional exposure method or, in some cases, by an immersion method in which the space between the mask and the resist film is immersed in liquid. In this case, a water-insoluble protective film may be used.

[0541] Next, post-exposure baking (PEB) is carried out 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.

[0542] Thereafter, the substrate is developed using a developer such as an aqueous alkaline solution of 0.1 to 5 mass %, preferably 2 to 3 mass %, TMAH, etc., by a conventional method such as dipping, puddling, or spraying for preferably 0.1 to 3 minutes, more preferably 0.5 to 2 minutes, to form a desired pattern on the substrate.

[0543] The chemically amplified negative resist composition of the present invention is useful because it can form a pattern with particularly good resolution and small LER. Furthermore, the chemically amplified negative resist composition of the present invention is particularly useful for pattern formation on a substrate having a surface made of a material that is prone to pattern peeling or pattern collapse, since it is difficult to obtain adhesion of the resist pattern. Examples of such substrates include substrates having a sputtering film formed on the outermost surface by sputtering a film of metallic chromium or a chromium compound containing one or more light elements selected from oxygen, nitrogen, and carbon, SiO , SiO x Examples of the chemically amplified negative resist composition include a substrate containing, as an outermost layer, a tantalum compound, a molybdenum compound, a cobalt compound, a nickel compound, a tungsten compound, or a tin compound. 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.

[0544] As a transmission mask blank, a photomask blank having a light-shielding film made of a chromium-based material may be a photomask blank for a binary mask or a photomask blank for a phase shift mask. In the case of a photomask blank for a binary mask, the light-shielding film may have an antireflection layer and a light-shielding layer made of a chromium-based material, or the entire antireflection film on the surface layer side or only the layer further above the antireflection film on the surface layer side may be made of a chromium-based material, with the remaining portion being made of a silicon-based compound material that may contain, for example, a transition metal. In addition, in the case of a photomask blank for a phase shift mask, the target photomask blank may be a photomask blank for a phase shift mask having a chromium-based light-shielding film on a phase shift film.

[0545] The above-mentioned photomask blank having a chromium-based material in the outermost layer is very well known, as is disclosed in JP-A Nos. 2008-26500 and 2007-302873, or as examples of prior art therein. Therefore, detailed description will be omitted. However, for example, when a light-shielding film having an antireflection layer and a light-shielding layer is formed using a chromium-based material, the following film configuration can be used.

[0546] When a light-shielding film having an anti-reflection layer and a light-shielding layer is formed using a chromium-based material, the layer structure may be such that the anti-reflection layer and the light-shielding layer are laminated in this order from the surface side, or the anti-reflection layer, the light-shielding layer, and the anti-reflection layer are laminated in this order. The anti-reflection layer and the light-shielding layer may each be multi-layered, and the composition between layers with different compositions may change discontinuously or continuously. The chromium-based material used includes metallic chromium and metallic chromium containing light elements such as oxygen, nitrogen, and carbon. Specifically, metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium oxide nitride, chromium carbide oxide, chromium nitride carbonitride, chromium oxynitride carbonitride, etc. may be used.

[0547] A reflective mask blank includes a substrate, a multilayer reflective film formed on one main surface (front surface) 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 reflectance. From the reflective mask blank (EUV reflective mask blank), a reflective mask (EUV reflective mask) having an absorber pattern (absorber film pattern) formed by patterning the absorber film is manufactured. The wavelength of EUV light used in EUV lithography is 13 to 14 nm, and is typically light with a wavelength of about 13.5 nm.

[0548] Although the multilayer reflective film is preferably provided in contact with one main surface of the substrate, a base film may be provided between the substrate and the multilayer reflective film as long as 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 repair. Furthermore, the protective film preferably 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. Meanwhile, a conductive film used for electrostatically chucking the reflective mask to an exposure device may be provided under the other main surface (back surface) of the substrate, which is the surface opposite to the one main surface, preferably in contact with the other main surface. Here, one main surface of the substrate is the front surface and the upper side, and the other main surface is the back surface and the lower side, but the front and back and top and bottom of both are defined for convenience, and the one main surface and the other main surface are either of the two main surfaces (film formation surfaces) of the substrate, and the front and back and top and bottom are interchangeable. More specifically, it can be formed by a method such as that described in JP 2021-139970 A or exemplified as prior art therein.

[0549] According to the method for forming a resist pattern of the present invention, even when a substrate (for example, a transmission type or a reflection type mask blank) is used whose outermost surface is made of a material that is likely to affect the shape of the resist pattern, such as a material containing chromium, silicon, or tantalum, it is possible to obtain a pattern that has extremely high resolution, small LER, excellent rectangularity, and excellent pattern fidelity. [Example]

[0550] The present invention will be specifically explained below by showing synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. The apparatuses used are as follows. IR: Thermo Fisher Scientific NICOLET 6700 · 1 H-NMR: ECA-500 manufactured by JEOL Ltd. MALDI TOF-MS: JEOL S3000

[0551] [1] Synthesis of onium salts [Example 1-1] Synthesis of onium salt PAG-1 [ka]

[0552] (1) Synthesis of intermediate In-1 Under a nitrogen atmosphere, raw materials SM-1 (14.5 g) and N,N-dimethylformamide (0.2 g) were dissolved in methylene chloride (100 g) in a reaction vessel, and the temperature inside the reaction vessel was raised to 40°C. Then, oxalyl chloride (9.5 g) was added dropwise. After the dropwise addition, the reaction vessel was aged for 2 hours while maintaining the temperature inside the reaction vessel at 40°C. After aging, the reaction solution was cooled, and water (50 g) was added to quench the reaction. Methylene chloride (50 g) was added to extract the target product, which was then subjected to a standard aqueous work-up. The solvent was evaporated, and hexane was added to recrystallize the product, yielding 13.7 g of intermediate In-1 as white crystals (yield 95%).

[0553] (2) Synthesis of onium salt PAG-1 Under a nitrogen atmosphere, raw material SM-1 (8.7 g) was suspended in a mixed solvent of THF (30 g) and water (30 g) in a reaction vessel. 2.5 g of 25% by mass aqueous sodium hydroxide solution was added dropwise, and the mixture was stirred at room temperature for 5 hours. Subsequently, intermediate In-1 (8.7 g) was added, and the mixture was further aged at room temperature for 3 hours. After aging, water (50 g) was added to quench the reaction. Methylene chloride (60 g) was added to extract the target product, and after standard aqueous work-up, the solvent was evaporated. Diisopropyl ether was added to recrystallize the product, yielding 14.5 g of the onium salt PAG-1 as white crystals (yield 92%).

[0554] The IR spectrum data and TOF-MS results of PAG-1 are shown below. 1 The results of H-NMR / DMSO-d6) are shown in Figure 1. IR(D-ATR): ν= 3062, 2971, 1720, 1610, 1586, 1465, 1438, 1386, 1276, 1224, 1187, 1105, 1082, 1036, 1019, 966, 904, 886, 853, 821, 772, 707, 682, 643, 625, 548, 487 cm -1 . MALDI TOF-MS: POSITIVE M + 277(C 18 H 13 OS + equivalent) NEGATIVE M - 771(C 40 H 35 O 12 S2 + equivalent)

[0555] [Synthesis Examples 1-2 to 1-8] Synthesis of PAG-2 to PAG-8 Onium salts PAG-2 to PAG-8 represented by the following formulae were synthesized using the corresponding raw materials and known organic synthesis reactions. [ka]

[0556] [ka]

[0557] [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 according to the composition shown in Tables 1 to 3 below, and filtering the resulting solutions through UPE filters and / or nylon filters selected from 10 nm, 5 nm, 3 nm, and 1 nm sizes. The organic solvent was a mixed solvent of 790 parts by weight of PGMEA, 1580 parts by weight of EL, and 1580 parts by weight of PGME. Some compositions also contained fluorine-containing polymers (polymers FP-1 to FP-5) as additives, tetramethoxymethylglycoluril (TMGU) as a crosslinker, and PF-636 (manufactured by OMNOVA SOLUTIONS) as a surfactant.

[0558] [Table 1]

[0559] [Table 2]

[0560] [Table 3]

[0561] In Tables 1 to 3, the structures of polymers P-1 to P-30 are as shown in the following Table 4. Note that Mw is a value measured in terms of polystyrene by GPC using THF or DMF as a solvent.

[0562] [Table 4]

[0563] In Table 4, the structure of each unit is as follows: [ka]

[0564] [ka]

[0565] [ka]

[0566] [ka]

[0567] [ka]

[0568] [ka]

[0569] In Tables 1 to 3, 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]

[0570] [ka]

[0571] [ka]

[0572] [ka]

[0573] [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 with a silicon oxide outer surface that had been vapor primed with hexamethyldisilazane (HMDS) using ACT-M (Tokyo Electron Limited), and the resulting mask blank was pre-baked on a hot plate at 110°C for 600 seconds to produce an 80 nm thick resist film. The thickness of the resulting resist film was measured using an optical measuring device, Nanospec (Nanometrics). Measurements were performed at 81 locations on the blank substrate surface, excluding the outer edge extending 10 mm inward from the outer periphery, and the average thickness and thickness range were calculated.

[0574] The film was exposed using an electron beam exposure system (EBM-5000plus manufactured by NuFlare Technology, Inc., acceleration voltage 50 kV), subjected to PEB at 120°C for 600 seconds, and developed with a 2.38% by mass TMAH aqueous solution to obtain a negative pattern.

[0575] The obtained resist patterns were evaluated as follows: The prepared patterned mask blanks were observed with a top-down SEM (scanning electron microscope), and the exposure dose required to resolve 200 nm 1:1 line and space (LS) at 1:1 was determined as the optimal exposure dose (μC / cm 2 ), and the minimum dimension at the exposure dose required to resolve a 200 nm LS at a 1:1 ratio was defined as the resolution (limiting resolution). For a 200 nm LS pattern obtained by irradiation at the optimal exposure dose, 80 edge detection points were performed on each of the 32 edges of the 200 nm LS pattern using an SEM. The triple value (3σ) of the standard deviation (σ) was calculated and used as the LER (nm). The pattern shape was visually determined to be rectangular or not. Furthermore, for pattern fidelity evaluation, the area loss value (%) of one corner of a dot pattern was calculated when a 120 nm square dot pattern was arranged at a density of 36%, and the smaller the value, the better the rectangularity of the dot shape. The results are shown in Tables 5 to 7.

[0576] [Table 5]

[0577] [Table 6]

[0578] [Table 7]

[0579] The chemically amplified negative resist compositions of the present invention (R-1 to R-54) 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 acid generator design and exhibited insufficient performance in terms of resolution, LER, and pattern rectangularity.

[0580] The method for forming a resist pattern using the chemically amplified negative resist composition of the present invention is useful for the production of semiconductor devices, particularly for photolithography in the processing of transmission or reflection type photomask blanks.

Claims

1. A chemically amplified negative resist composition comprising: (A) a photoacid generator comprising an onium salt represented by the following formula (A); and (B) a base polymer comprising a polymer including a repeating unit represented by the following formula (B1). 【Chemistry 1】 (In the formula, n1 is 0 or 1. n2 is 0, 1, 2, 3, or 4. n3 is 1, 2, 3, or 4. n4 is 0 or 1. n5 is 0, 1, 2, 3, or 4. n6 is 0, 1, 2, 3, or 4. However, when n1 is 0, 1≦n2+n3≦5, and when n1 is 1, 1≦n2+n3≦7. R 1 is a hydrocarbyl group having 1 to 20 carbon atoms. R 2 is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom. 2 may be the same or different, and multiple R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 3 is a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxycarbonyl group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylcarbonyloxy group having 1 to 20 carbon atoms which may contain a heteroatom. 3 may be the same or different, and multiple R 3 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 4 is a halogen atom, a nitro group, a cyano group, a hydroxy group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. 4 may be the same or different, but multiple R 4 do not bond to each other to form a ring together with the carbon atoms to which they are attached. L A , L B and L C are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, an amide bond, a sulfonamide bond, a carbonate bond or a carbamate bond. X L1 is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. Z + 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 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 represents a halogen atom, a nitro group, a carboxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. A 1 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the —CH 2 A part of - may be replaced by -O-.)

2. 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, n5, n6, R 1 ~R 4 , L A , L B , L C , X L1 and Z + is the same as above.)

3. 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, n2, n3, n5, n6, R 1 ~R 4 , L A and Z + is the same as above.)

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

5. Z + 2. The chemically amplified negative resist composition according to claim 1, wherein is a sulfonium cation represented by the following formula (Z-3): 【Transformation 6】 (Wherein, 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, 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 are each 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. F1 may be the same or different, and when m6 is 2 or more, each R F2 may be the same or different, and when m7 is 2 or more, each R F3 may be the same or different from each other. R ct6 ~R ct9 is a halogen atom other than an iodine atom or a fluorine atom, a nitro group, a cyano group, a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom, a hydrocarbyloxy group having 1 to 20 carbon atoms which may contain a heteroatom, or a hydrocarbylthio group having 1 to 20 carbon atoms which may contain a heteroatom. ct6 may be the same or different, and two R ct6 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m9 is 2, two R ct7 may be the same or different, and two R ct7 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m10 is 2, two R ct8 may be the same or different, and two R ct8 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and when m13 is 2, two R ct9 may be the same or different, and two R ct9 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. In addition, S in the sulfonium cation + The aromatic rings directly bonded to S + may form a ring together with L D and L E are each independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. X L2 is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom.

6. 2. The chemically amplified negative resist composition according to claim 1, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B2) and a repeating unit 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 that satisfies 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 are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 22 and R 23 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, the hydrocarbyl group may be substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be a hydrogen atom at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and the —CH 2 A part of - may be substituted with -O- or -S-. R 31 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 32 and R 33 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, the hydrocarbyl group may be substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 32 and R 33 cannot be a hydrogen atom at the same time. 32 and R 33 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and the —CH 2 A part of - may be substituted with -O- or -S-. A 2 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the —CH 2 A part of - may be substituted with -O-. W 1 and W 2 are each independently a hydrogen atom, an aliphatic hydrocarbyl group having 1 to 10 carbon atoms, an aliphatic hydrocarbylcarbonyl group having 2 to 10 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the aryl group may have a substituent.

7. 2. The chemically amplified negative resist composition according to claim 1, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B4), a repeating unit represented by the following formula (B5), and a repeating unit represented by the following formula (B6): 【Transformation 8】 (In the formula, c and d are each 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 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 41 and R 42 are each independently a hydroxy group, a halogen atom, a saturated hydrocarbyl group having 1 to 8 carbon atoms which may be substituted with a halogen atom, a saturated hydrocarbyloxy group having 1 to 8 carbon atoms which may be substituted with a halogen atom, or a saturated hydrocarbylcarbonyloxy group having 2 to 8 carbon atoms which may be substituted with a halogen atom. R 43 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. A 3 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the —CH 2 A part of - may be replaced by -O-.)

8. 7. The chemically amplified negative resist composition according to claim 6, wherein the polymer comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (B7), a repeating unit represented by the following formula (B8), a repeating unit represented by the following formula (B9), a repeating unit represented by the following formula (B10), and a repeating unit represented by the following formula (B11): 【Chemistry 9】 (In the formula, 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. However, when g1 is 0, 0≦e2+e3≦4, and when g1 is 1, 0≦e2+e3≦6. R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Z 1 represents a single bond or an optionally substituted phenylene group. Z 2 is a single bond, **-C(=O)-O-Z 21 -, **-C(=O)-NH-Z 21 - or **-O-Z 21 - is. Z 21 represents 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 sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 4 represents a single bond, 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 each independently represents a single bond, an optionally substituted phenylene group, a naphthylene group, or *-C(=O)-O-Z 51 - is. 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 is a single bond, an ether bond, an ester bond, an amide bond, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Z 7 each independently represents a single bond, ***-Z 71 -C(=O)-O-, ***-C(=O)-NH-Z 71 - or ***-O-Z 71 - is. is. Z 71 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 8 are each independently a single bond, ****-Z 81 -C(=O)-O-, ****-C(=O)-NH-Z 81 - or ****-O-Z 81 - is. Z 81 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. Z 9 represents 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 - is. Z 91 represents 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 in the main chain. ** represents Z 1 *** represents a bond with Z 6 **** represents a bond with Z. 7 Represents a bond with . L 1 is a single bond, an ether bond, an ester bond, a carbonyl group, a sulfonate ester bond, a sulfonamide bond, a carbonate bond or a carbamate bond. Rf 1 and Rf 2 are each independently a fluorine atom or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 3 and Rf 4 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. Rf 5 and Rf 6 are each independently a hydrogen atom, a fluorine atom, or a fluorinated saturated hydrocarbyl group having 1 to 6 carbon atoms. 5 and Rf 6 cannot simultaneously become a hydrogen atom. Rf 7 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. R 51 and R 52 are each independently a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 51 and R 52 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. R 53 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom other than a fluorine atom or a heteroatom. When g3 is 2, 3, or 4, each R 53 may be the same or different, and multiple R 53 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. M - is a non-nucleophilic counterion. A + is an onium cation.

9. 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 formula (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 + is the same as above. R HF is a hydrogen atom or a trifluoromethyl group. Z 10 is a single bond or *****-Z 101 -C(=O)-O-. Z 101 is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. ***** is a bond to the oxygen atom in the formula.

10. 9. The chemically amplified negative resist composition according to claim 8, wherein the base polymer (B) further comprises a polymer containing a repeating unit represented by formula (B1) and a repeating unit represented by formula (B2) or (B3), but not containing any repeating unit represented by formulas (B7) to (B11).

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

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

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

14. 2. The chemically amplified negative resist composition according to claim 1, further comprising (D) a fluorine atom-containing polymer that contains at least one selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and that may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6): 【Chemistry 11】 (In the formula, j1 is 1, 2, or 3. j2 is an integer that satisfies 0≦j2≦5+2(j3)−j1. j3 is 0 or 1. k is 1, 2, or 3. R B are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R C are each independently a hydrogen atom or a methyl group. R 101 , R 102 , R 104 and R 105 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. R 103 , R 106 , R 107 and R 108 are each independently a hydrogen atom, a hydrocarbyl group having 1 to 15 carbon atoms, a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid labile group; R 103 , 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 present between the carbon-carbon bond. R 109 is a hydrogen atom or a linear or branched hydrocarbyl group having 1 to 5 carbon atoms which may have a group containing a heteroatom interposed between its carbon-carbon bonds. R 110 is a linear or branched hydrocarbyl group having 1 to 5 carbon atoms which may have a heteroatom-containing group interposed between its carbon-carbon bonds. R 111 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 —CH 2 A part of the - may be substituted with an ester bond or an ether bond. X 1 is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. X 2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * is a bond to a carbon atom in the main chain. X 3 is a single bond, -O-, *-C(=O)-O-X 31 -X 32 - or *-C(=O)-NH-X 31 -X 32 - is. X 31 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms. 32 is a single bond, an ester bond, an ether bond, or a sulfonamide bond. * is a bond to a carbon atom in the main chain.)

15. 2. The negative resist composition according to claim 1, further comprising (E) a quencher.

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

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

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

19. A method for forming a resist pattern, comprising: a step of forming a resist film on a substrate using the chemically amplified negative resist composition according to any one of claims 1 to 18; a step of irradiating the resist film with a pattern using high-energy rays; and a step of developing the resist film irradiated with the pattern using an alkaline developer.

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

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

22. 20. The method for forming a resist pattern according to claim 19, wherein the substrate is a transmission or reflection mask blank.

23. A transmission or reflection mask blank coated with the chemically amplified negative resist composition according to any one of claims 1 to 18.

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