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 improved LER, resolution, pattern fidelity, and dose margin; and a method for forming a resist pattern. [Solution] A chemically amplified negative resist composition comprising (A) a quencher consisting of an onium salt represented by the following formula (A), (B) a base polymer including a polymer containing a repeating unit of a specific structure, and (C) a photoacid generator. TIFF2026044251000274.tif423 (In the formula, Xq - is an anion, where Xq - The acid (XqH) with as its conjugate base has a boiling point below 165°C and a molecular weight of 150 or less.

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] 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.

[0005] 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.

[0006] 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.

[0007] 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 4 describes, as an example of a weak acid onium salt, the addition of triphenylsulfonium acetate, which enables the formation of favorable resist patterns free of T-top formation, linewidth differences between isolated and dense patterns, and standing waves. Patent Document 5 describes the addition of ammonium sulfonate salts or ammonium carboxylate salts to improve sensitivity, resolution, and exposure margin. Patent Document 6 also describes the use of resist compositions for KrF lithography and EB lithography that contain a photoacid generator that generates a fluorine-containing carboxylic acid, resulting in excellent resolution and improved process tolerances, such as exposure margin and depth of focus. Furthermore, Patent Document 7 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.

[0008] Patent Document 8 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.

[0009] Patent Document 9 describes the use of a sulfonium salt of a carboxylic acid containing a nitrogen-containing heterocycle as a quencher, but its role is mainly as a quencher for an additive-type fluorinated alkanesulfonic acid, and in particular, sufficient consideration has not been given to its use as a quencher for a negative resist composition having a polyhydroxystyrene base polymer used in an EB writing process in mask blank processing.

[0010] However, when patterning is performed using a resist composition containing the above-mentioned onium carboxylate salt or onium fluorocarboxylate salt, LER and resolution are still insufficient despite the recent advances in miniaturization. Therefore, there has been a demand for the development of a quencher that can further reduce LER and improve resolution, pattern fidelity, and dose margin. [Prior art documents] [Patent documents]

[0011] [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. 3955384 [Patent Document 5] Japanese Patent Application Publication No. 11-327143 [Patent Document 6] Patent No. 4231622 [Patent Document 7] Patent No. 4116340 [Patent Document 8] Patent No. 4226803 [Patent Document 9] Patent No. 6512049 Summary of the Invention [Problem to be solved by the invention]

[0012] 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 the resolution during pattern formation, and that is capable of obtaining a resist pattern with improved LER, resolution, pattern fidelity, and dose margin, and a method of forming a resist pattern. [Means for solving the problem]

[0013] As a result of extensive research into achieving the above-mentioned object, the present inventors have found that when a quencher comprising an onium salt containing an anion whose conjugated acid (XqH) has a boiling point of less than 165°C and a molecular weight of 150 or less is incorporated into a chemically amplified resist composition comprising (A) a quencher, the quencher comprising an onium salt containing an anion whose conjugated acid (XqH) has a boiling point of less than 165°C and a molecular weight of 150 or less, (B) a base polymer containing a predetermined polymer, and (C) a photoacid generator, a pattern exhibiting good resolution and pattern shape as well as improved LER, pattern fidelity, and dose margin can be obtained, which has led to the completion of the present invention.

[0014] That is, the present invention provides the following chemically amplified negative resist composition and method of forming a resist pattern. 1. (A) A quencher consisting of an onium salt represented by the following formula (A): (B) a base polymer containing a polymer containing a repeating unit represented by the following formula (B1), and (C) Photoacid generator A chemically amplified negative resist composition comprising: [ka] [where, Xq - is an anion, where Xq - The acid (XqH) with as its conjugate base has a boiling point below 165°C and a molecular weight of 150 or less. Z + is a sulfonium cation represented by the following formula (Z-1), an iodonium cation represented by the following formula (Z-2), an ammonium cation represented by the following formula (Z-3), or a sulfonium cation represented by the following formula (Z-4). [ka] (In the formula, R 1 ~R 9 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 1 ~R 3 any two of may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and R 6 ~R 9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. [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+m8m+14≦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 RF3 may be the same or different from each other. R 10 ~R 13 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 10 may be the same or different, and two R 10 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 11 may be the same or different, and two R 11 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 12 may be the same or different, and two R 12 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 13 may be the same or different, and two R 13 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 A and L B 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 L is a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom.)] [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 21 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. Anion Xq - 2. The chemically amplified positive resist composition of claim 1, wherein the conjugate acid XqH is formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, pivalic acid, or nitric acid. 3. The chemically amplified negative resist composition of 1 or 2, 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 31 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 32 and R 33are 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-. R 34 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 35 and R 36 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. 35 and R 36 cannot be hydrogen atoms at the same time. 35 and R 36 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. 4. The chemically amplified negative resist composition of any one of 1 to 3, 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-. 5. The chemically amplified positive resist composition according to any one of 1 to 4, 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. 6. The chemically amplified negative resist composition of 5, 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 32 , R 33 , R 35 , R 36 , 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. 7. The chemically amplified negative resist composition of 5, 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). 8. The chemically amplified negative resist composition of any one of 1 to 7, 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. 9. The chemically amplified negative resist composition according to any one of 1 to 8, further comprising (D) a crosslinking agent. 10. A chemically amplified negative resist composition according to any one of 1 to 8, which does not contain a crosslinking agent. 11. The chemically amplified negative resist composition of any of 1 to 10, further comprising (E) a fluorine atom-containing polymer that contains at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (E1), a repeating unit represented by the following formula (E2), a repeating unit represented by the following formula (E3), and a repeating unit represented by the following formula (E4), and that may further contain at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (E5) and a repeating unit represented by the following formula (E6): [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. 12. The chemically amplified negative resist composition according to any one of 1 to 11, further comprising (F) an organic solvent. 13. The chemically amplified negative resist composition of any one of 1 to 12, further comprising (G) a quencher other than the component (A). 14. The chemically amplified negative resist composition of 13, wherein the content ratio of the acid generator (E) to the quencher (A) is less than 6 by mass. 15. 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 14; irradiating the resist film with a pattern using high-energy rays; and developing the resist film irradiated with the pattern using an alkaline developer. 16. The method for forming a resist pattern according to 15, wherein the high-energy radiation is EUV or EB having a wavelength of 3 to 15 nm. 17. The method for forming a resist pattern according to 15 or 16, 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. 18. The method for forming a resist pattern according to any one of 15 to 17, wherein the substrate is a transmission or reflection mask blank. 19. A transmission or reflection mask blank coated with any one of the chemically amplified negative resist compositions set forth in any one of 1 to 14. [Effects of the Invention]

[0015] The chemically amplified negative resist composition of the present invention can effectively control acid diffusion due to exposure during pattern formation due to the action of the onium salt represented by formula (A), and when a resist film is formed using this composition to form a pattern, it can obtain a pattern with extremely high resolution, high pattern fidelity, and improved LER and dose margin. Furthermore, the action of the repeating unit represented by formula (B1) not only provides good solubility in alkaline developers, but also improves adhesion to substrates during resist film formation.

[0016] A method of forming a resist pattern using the chemically amplified negative resist composition of the present invention can form a pattern that has high resolution and pattern fidelity while also improving LER and dose margin, and therefore can be suitably used in microfabrication techniques, in particular EUV lithography and EB lithography. DETAILED DESCRIPTION OF THE INVENTION

[0017] 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 alone or as a mixture.

[0018] [Chemically amplified negative resist composition] The chemically amplified positive resist composition of the present invention is characterized by comprising: (A) a quencher composed of an onium salt containing an anion whose conjugated acid (XqH) has a boiling point of less than 165°C and a molecular weight of 150 or less; (B) a base polymer containing a predetermined polymer; and (C) a photoacid generator.

[0019] [(A) Quencher] The onium salt serving as the quencher of component (A) is represented by the following formula (A). [ka]

[0020] In formula (A), Xq - is an anion, where Xq - The acid (XqH) having as its conjugate base has a boiling point of less than 165°C and a molecular weight of 150 or less. Examples of XqH include formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, pivalic acid, and nitric acid. XqH preferably has a boiling point of less than 150°C and a molecular weight of 120 or less.

[0021] In formula (A), Z + is an onium cation. The onium cation is preferably a sulfonium cation represented by the following formula (Z-1), an iodonium cation represented by the following formula (Z-2), or an ammonium cation represented by the following formula (Z-3). [ka]

[0022] In formulas (Z-1) to (Z-3), R 1 ~R 9 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom.

[0023] R 1 ~R 9 Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0024] R 1 ~R 9The 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, allyl, 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 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 anhydride (-C(=O)-OC(=O)-), a haloalkyl group, or the like.

[0025] Also, R 1 and R 2 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, examples of the sulfonium cation represented by formula (Z-1) include those represented by the following formulas. [ka] (In the formula, the dashed line indicates R 3 )

[0026] Furthermore, R6 ~R 9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached.

[0027] Specific examples of sulfonium cations represented by formula (Z-1) include, but are not limited to, those described in paragraphs

[0102] to

[0125] of JP 2024-003744 A and those described in paragraphs

[0070] to

[0085] of JP 2023-169812 A. Specific examples of iodonium cations represented by formula (Z-2) include, but are not limited to, those described in paragraph

[0181] of JP 2024-000259 A. Specific examples of ammonium cations represented by formula (Z-3) include, but are not limited to, those described in paragraph

[0221] of JP 2024-000259 A.

[0028] The onium cation is also preferably a sulfonium cation represented by the following formula (Z-4). [ka]

[0029] In formula (Z-4), 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.

[0030] In formula (Z-4), 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, and there is a concern that precipitation may occur in the resist composition. Therefore, m4 is preferably 0, 1, 2, or 3, and more preferably 0, 1, or 2.

[0031] In formula (Z-4), 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.

[0032] In formula (Z-4), 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.

[0033] In formula (Z-4), 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.

[0034] In formula (Z-4), 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.

[0035] In formula (Z-4), 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.

[0036] 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.

[0037] In formula (Z-4), 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.

[0038] In formula (Z-4), R 10 ~R 13 is a halogen atom other than iodine atom and 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. 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 1 ~R 9In 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.

[0039] Also, when m8 is 2, two R 10 may be the same or different, and two R 10 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 11 may be the same or different, and two R 11 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 12 may be the same or different, and two R 12 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 13 may be the same or different, and two R 13may 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.

[0040] In addition, S in the sulfonium cation represented by formula (Z-4) + The aromatic rings directly bonded to S + In this case, specific examples of the ring structure include those represented by the following formulas: [ka] (In the formula, the dashed lines represent bonds.)

[0041] In formula (Z-4), L A and L B 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. 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 or an ester bond, and more preferably a single bond.

[0042] In formula (Z-4), 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.

[0043] 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]

[0044] [ka]

[0045] [ka]

[0046] [ka]

[0047] Of these, X L -0~X L -22 and X L -47~X L -58 is preferred.

[0048] The sulfonium cation represented by formula (Z-4) is preferably one represented by the following formula (Z-4-1). [ka] (In the formula, m4~m10, m12~m14, R F1 ~RF3 , R 10 ~R 13 , L A , L B and X L is the same as above.)

[0049] The cation represented by formula (Z-4-1) is preferably one represented by the following formula (Z-4-2). [ka] (In the formula, m4~m10, R F1 ~R F3 and R 10 ~R 12 is the same as above.)

[0050] Specific examples of the sulfonium cation represented by formula (Z-4) include, but are not limited to, the following: In the following formula, Me is a methyl group. [ka]

[0051] [ka]

[0052] [ka]

[0053] [ka]

[0054] [ka]

[0055] [ka]

[0056]

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[0057]

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[0058]

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[0059]

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[0060]

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[0061]

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[0062]

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[0063]

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[0064]

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[0065]

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[0066]

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[0067]

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[0068]

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[0069]

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[0070]

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[0071]

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[0072]

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[0073]

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[0074]

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[0075]

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[0076]

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[0077] [ka]

[0078] Specific examples of the onium salt include any combination of the above-mentioned anions and cations.

[0079] The onium salt can be synthesized by a method similar to that for the onium salt described in, for example, JP 2020-91312 A, but is not limited thereto.

[0080] The onium salt can be suitably used as a quencher. In the present invention, a quencher refers to a material that traps a strong acid generated by a photoacid generator, thereby preventing its diffusion to unexposed areas and forming a desired pattern. A photoacid generator is a compound that generates a strong acid upon irradiation with high-energy rays, and a strong acid is a compound that has sufficient acidity to induce a deprotection reaction of an acid labile group. Acids such as acetic acid, nitric acid, and trifluoroacetic acid generated from the onium salt of the present invention are not acidic enough to induce a deprotection reaction when the acid labile group is a tertiary ester or tertiary ether. Therefore, as described below, it is effective to separately add a photoacid generator that generates a strong acid, such as an α-fluorinated sulfonic acid, imidic acid, or methidic acid, to induce a deprotection reaction of the acid labile group. The photoacid generator that generates an α-fluorinated sulfonic acid, imidic acid, or methidic acid may be an additive type or a polymer-bound type that is bound to a base polymer.

[0081] When a mixture of an onium salt of the present invention that generates acids such as acetic acid, nitric acid, and trifluoroacetic acid and a photoacid generator that generates a strong acid, sulfonic acid, is irradiated with light, acids such as acetic acid, nitric acid, and trifluoroacetic acid and sulfonic acid are generated. Because the photoacid generator is not completely decomposed, some undecomposed photoacid generators are present nearby. When an onium salt that generates acids such as acetic acid, nitric acid, and trifluoroacetic acid coexists with a sulfonic acid, the sulfonic acid first undergoes ion exchange with the onium salt that generates carboxylic acid and nitric acid, generating an onium sulfonate salt, which then releases acids such as acetic acid, nitric acid, and trifluoroacetic acid. This is because sulfonate salts, which have a higher acid strength, are more stable. On the other hand, ion exchange does not occur when an onium sulfonate salt is mixed with an acid such as acetic acid, nitric acid, or trifluoroacetic acid.

[0082] A structural feature of the onium salt of the present invention is that the conjugate acid (XqH) has a boiling point of less than 165°C and an anion with a molecular weight of 150 or less. Because the weak acid generated by the onium salt of the present invention has a low boiling point, it is presumed that the generated acid partially volatilizes. In the case of a negative resist using an alkaline developer, the weak acid generated in the exposed area has a high affinity with the developer, which attracts the alkaline developer to the exposed area, causing the pattern to collapse or peel off from the substrate. In contrast, if the weak acid volatilizes, as in the case of the onium salt, this phenomenon can be reduced. That is, the limiting resolution can be improved. Furthermore, because the anion has a small molecular weight, it is easily washed away by the developer. Therefore, traces of unreacted onium salt remaining in the unexposed area are less likely to remain undissolved, resulting in improved LWR. The onium salt-type quencher generates a weak acid that is not a sulfonic acid, resulting in low acid diffusion. It is more preferable that the acid generator is a polymer-bound type in which a photoacid-generating unit is incorporated into the base polymer used, since this makes it possible to further control acid diffusion.

[0083] In the chemically amplified negative resist composition of the present invention, the content of (A) quencher is preferably 0.1 to 40 parts by mass, and more preferably 0.5 to 30 parts by mass, relative to 80 parts by mass of the base polymer described below. A content of (A) quencher within this range is preferred because it provides good sensitivity and resolution and there is no risk of problems with foreign matter occurring after development of the resist film or during stripping. The (A) quenchers may be used alone or in combination of two or more.

[0084] [(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]

[0085] 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.

[0086] In formula (B1), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0087] In formula (B1), R 21is 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 21 may be the same as or different from each other.

[0088] 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.

[0089] 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.)

[0090] a1 is 1 (i.e., -C(=O)-OA as a linker) 1In the case where R A is the same as above. [ka]

[0091] The repeating unit B1 may be used alone or in combination of two or more.

[0092] 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]

[0093] 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.

[0094] 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.

[0095] In formula (B3), b5 is 0, 1 or 2, and preferably 0 or 1. b6 is 1 or 2, and preferably 1.

[0096] 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.

[0097] In formula (B2), 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 b3 is 2 or more, each R 31 may be the same as or different from each other.

[0098] In formula (B2), 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 attached, and some of the -CH2- in the ring may be substituted with -O- or -S-. 32 and R 33 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.

[0099] In formula (B3), R 34 R is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 34 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. 34 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 34 may be the same as or different from each other.

[0100] In formula (B3), R 35 and R 36 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.

[0101] R 35 and R 36 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 35 and R 36 Examples of the saturated hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0102] R 35 and R 36 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.

[0103] Also, R 35 and R 36 cannot simultaneously become a hydrogen atom. 35 and R 36 When either of the groups is an aryl group which may have a substituent, the other substituent is preferably a hydrogen atom.

[0104] R 35 and R 36 are preferably the same group, and more preferably both are methyl groups.

[0105] Also, R 35 and R 36 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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 32 and R 33 is the same as above.)

[0110] 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]

[0111] [ka]

[0112] [ka]

[0113] [ka]

[0114] [ka]

[0115] [ka]

[0116] [ka]

[0117] [ka]

[0118] [ka]

[0119] [ka]

[0120] [ka]

[0121] The repeating unit B2 may be used alone or in combination of two or more.

[0122] The repeating unit B3 is preferably one represented by the following formula (B3-1). [ka] (In the formula, b6, R A , R 35 and R 36 is the same as above.)

[0123] 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]

[0124] [ka]

[0125] [ka]

[0126] [ka]

[0127] [ka]

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[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] [ka]

[0153] [ka]

[0154] [ka]

[0155] [ka]

[0156] The repeating unit B3 may be used alone or in combination of two or more.

[0157] 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]

[0158] In formulae (B4) and (B5), c and d each independently represent 0, 1, 2, 3, or 4.

[0159] 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.

[0160] 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.

[0161] In formula (B6), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0162] 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.

[0163] 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.

[0164] 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.

[0165] 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.

[0166] 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.

[0167] 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.

[0168] 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]

[0169] [ka]

[0170] 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.

[0171] The repeating units B4 to B6 may be used alone or in combination of two or more.

[0172] 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]

[0173] 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 .

[0174] 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.

[0175] 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.)

[0176] 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.

[0177] 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 )

[0178] 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]

[0179] [ka]

[0180] [ka]

[0181] [ka]

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] [ka]

[0188] 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.

[0189] Other examples of the non-nucleophilic counter ion include anions represented by any of the following formulae (B7-1) to (B7-4). [ka]

[0190] 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.

[0191] The anion represented by formula (B7-1) is preferably one represented by the following formula (B7-1-1). [ka]

[0192] 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.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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]

[0197] [ka]

[0198] [ka]

[0199] [ka]

[0200] [ka]

[0201] [ka]

[0202] [ka]

[0203] [ka]

[0204] [ka]

[0205] [ka]

[0206] 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.

[0207] 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.

[0208] 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.

[0209] Specific examples of the anion represented by formula (B7-4) include, but are not limited to, those shown below. [ka]

[0210] [ka]

[0211] 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]

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] 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.

[0217] 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.

[0218] 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.

[0219] 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]

[0220] [ka]

[0221] [ka]

[0222] [ka]

[0223] [ka]

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] [ka]

[0228] [ka]

[0229]

change

[0230]

change

[0231]

change

[0232]

change

[0233]

change

[0234]

change

[0235]

change

[0236]

change

[0237]

change

[0238]

change

[0239] [ka]

[0240] [ka]

[0241] [ka]

[0242] 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.

[0243] 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.

[0244] 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.

[0245] In formulae (B8) and (B9), f1 and f2 each independently represent 0, 1, 2 or 3, with 1 being preferred.

[0246] 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.

[0247] In formulas (B8), (B9) and (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.

[0248] 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.

[0249] 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.

[0250] 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.

[0251] 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 ~R 9 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.

[0252] 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.

[0253] 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]

[0254] [ka]

[0255] [ka]

[0256] [ka]

[0257] [ka]

[0258] [ka]

[0259] [ka]

[0260] [ka]

[0261] [ka]

[0262] [ka]

[0263] [ka]

[0264] [ka]

[0265] [ka]

[0266] 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]

[0267] [ka]

[0268] [ka]

[0269] [ka]

[0270] [ka]

[0271] [ka]

[0272] [ka]

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] [ka]

[0277] 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]

[0278]

change

[0279]

change

[0280]

change

[0281]

change

[0282]

change

[0283]

change

[0284]

change

[0285]

change

[0286]

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[0287]

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[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292] [ka]

[0293] [ka]

[0294] Specific examples of anions of repeating unit B11 are listed below, but are not limited to these. Note that in the following formula, R A is the same as above. [ka]

[0295] 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-4). 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 (Z-3).

[0296] The specific structures of repeating units B7 to B11 include any combination of anions and cations as described above.

[0297] 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, thereby enabling the production of a pattern with reduced LER. Furthermore, the inclusion of these units in the polymer is believed to suppress the phenomenon in which acid volatilizes from the exposed areas and reattaches to the unexposed areas during baking in a vacuum, thereby effectively reducing LER and reducing defects due to the suppression of unwanted negative reactions in the unexposed areas.

[0298] Repeating units B7 to B11 may be used individually or in combination of two or more units.

[0299] 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.

[0300] Examples of (meth)acrylic acid ester units having the aforementioned adhesive group include the repeating unit represented by the following formula (B12) (hereinafter also referred to as repeating unit B12), the repeating unit represented by the following formula (B13) (hereinafter also referred to as repeating unit B13), and the repeating unit represented by the following formula (B14) (hereinafter also referred to as repeating unit B14). These units do not exhibit acidity and can be used auxiliaryly as units that provide adhesion to the substrate or as units that adjust solubility. [ka]

[0301] In formulas (B12) to (B14), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 61 R is either an -O- or a methylene group. 62 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.

[0302] In polymer B, the content of repeating unit B1 is preferably 30 to 95 mol%, and more preferably 50 to 85 mol%, in order to obtain high resolution and to produce high contrast between the parts that are negativeized by high-energy ray irradiation and the parts that are not irradiated (non-negativeized parts). The content of repeating units B2 and B3 is preferably 5 to 70 mol%, and more preferably 10 to 60 mol%, in order to obtain the effect of promoting the negativeization reaction. The content of repeating units B4 to B6 is preferably 0 to 30 mol%, and more preferably 3 to 20 mol%, in order to obtain the effect of improving etching resistance. In addition, other repeating units may be included in amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0303] If polymer B' does not contain repeating units B7 to B11, the content of repeating unit B1 in polymer B' is preferably 25 to 95 mol%, more preferably 40 to 85 mol%. The content of repeating units B4 to B6 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating units B2 and B3 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. Other repeating units may be included in amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0304] When polymer B' contains repeating units B7 to B11, the content of repeating unit B1 in polymer B' is preferably 25 to 94.5 mol%, more preferably 36 to 85 mol%. The content of repeating units B4 to B6 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating units B2 and B3 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. The total content of repeating units B1 to B6 is preferably 60 to 99.5 mol%. The content of repeating units B8 to B11 is preferably 0.5 to 20 mol%, more preferably 1 to 10 mol%. Other repeating units may be included in amounts of 0 to 30 mol%, preferably 0 to 20 mol%.

[0305] Furthermore, among the total repeating units constituting the polymer, repeating units B1 to B6 preferably account for 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. This ensures that the properties required for the chemically amplified negative resist composition of the present invention are reliably obtained.

[0306] 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 and R 33 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.

[0307] 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.

[0308] 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.

[0309] 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.

[0310] 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.

[0311] The polymer preferably has a narrow dispersion with a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, and particularly 1.0 to 1.8. When the dispersion is narrow in this way, after development, no foreign matter will be generated on the pattern, and the shape of the pattern will not deteriorate.

[0312] [(C) Photoacid generator] The chemically amplified positive resist composition of the present invention may contain a photoacid generator as component (C). There are no particular restrictions on the photoacid generator, as long as it is a compound that generates an 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.

[0313] Specific examples of the photoacid generator include nonafluorobutanesulfonate, the partially fluorinated sulfonates described in Japanese Patent No. 5706778, paragraphs

[0247] to

[0251] , the partially fluorinated sulfonates described in Japanese Patent No. 5852851, paragraphs

[0261] to

[0265] , the partially fluorinated sulfonates described in Japanese Patent No. 4858714, paragraphs

[0122] to

[0142] , and the partially fluorinated sulfonates described in Japanese Patent No. 5368270, paragraphs

[0080] to

[0081] . Furthermore, examples of the anion of the photoacid generator include M in formula (B7). - Among these, arylsulfonate-type or alkanesulfonate-type photoacid generators are preferred because they generate an acid of suitable strength for deprotecting the acid labile group in the repeating unit B2.

[0314] Furthermore, in order to obtain the effect of improving LER and CDU by combining the photoacid generator with the quencher of component (A), the pKa of the acid generated from the photoacid generator is −3.0 or higher, preferably in the range of −3.0 to 2.0, and more preferably in the range of −2.0 to 1.5.

[0315] As the photoacid generator, salt compounds having the anions shown below are preferred. [ka]

[0316] As the anion of the photoacid generator, those described in

[0220] to

[0225] of Japanese Patent No. 7032549, those described in

[0027] to

[0029] of Japanese Patent No. 6248882, those described in

[0028] to

[0029] of Japanese Patent No. 7067271, those described in

[0039] to

[0066] of Japanese Patent Laid-Open No. 2023-177038, and those described in

[0229] to

[0231] of Japanese Patent Laid-Open No. 2024-077330 are also preferred.

[0317] As the anion of the photoacid generator, salt compounds having the anions shown below are also preferred.

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[0318]

change

[0319]

change

[0320]

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[0321]

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[0322]

change

[0323]

change

[0324]

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[0325]

change

[0326]

change

[0327]

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[0328]

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[0329]

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[0330]

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[0331]

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[0332]

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[0333]

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[0334]

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[0335]

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[0336]

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[0337]

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[0338]

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[0339] [ka]

[0340] [ka]

[0341] [ka]

[0342] [ka]

[0343] Examples of the cation paired with the anion include the sulfonium cations represented by formula (Z-1) and formula (Z-4), and the iodonium cations represented by formula (Z-2).

[0344] When the chemically amplified positive resist composition of the present invention contains a photoacid generator (C), the content thereof is preferably 1 to 30 parts by mass, more preferably 2 to 20 parts by mass, relative to 80 parts by mass of the base polymer (B). When the base polymer contains repeating units B6 to B13 (i.e., when a polymer-bound acid generator is used), the incorporation of the photoacid generator (C) may be omitted. The photoacid generators (C) may be used singly or in combination of two or more.

[0345] In the chemically amplified negative resist composition of the present invention, the quencher of the component (A) and the photoacid generator of the component (C) are contained so that the content ratio of the photoacid generator to the quencher ((C) / (A)) is, in mass ratio, preferably less than 6, more preferably less than 5, and even more preferably less than 4. When the content ratio of the photoacid generator to the quencher in the chemically amplified positive resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0346] [(D) 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 (D). On the other hand, when the (B) base polymer contains polymer B', it may or may not contain a crosslinking agent.

[0347] 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.

[0348] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0349] Examples of the melamine compounds include hexamethylmelamine, hexamethoxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are methoxymethylated, or mixtures thereof; and hexamethoxyethylmelamine, hexaacyloxymethylmelamine, hexamethylmelamine, and other compounds in which 1 to 6 methylol groups are acyloxymethylated, or mixtures thereof.

[0350] Examples of the guanamine compounds include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine, or mixtures thereof; and compounds in which 1 to 4 methylol groups are acyxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, or mixtures thereof.

[0351] Examples of the glycoluryl compounds include tetramethylol glycoluryl, tetramethoxy glycoluryl, tetramethoxymethyl glycoluryl, tetramethylol glycoluryl, and other compounds in which 1 to 4 methylol groups are methoxymethylated, or mixtures thereof; and compounds in which 1 to 4 methylol groups of tetramethylol glycoluryl are acyloxymethylated, or mixtures thereof.

[0352] 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.

[0353] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0354] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0355] 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.

[0356] In the chemically amplified negative resist composition of the present invention, the content of (D) 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 (B) base polymer. Within this range, there is little risk of patterns being connected together and resolution decreasing. The (C) crosslinking agent may be used alone or in combination of two or more types.

[0357] [(E) Fluorine atom-containing polymer] The chemically amplified negative resist composition of the present invention, for the purposes of achieving high contrast, suppressing acid chemical flare upon high-energy radiation irradiation, shielding acid from mixing from the antistatic coating during the process of applying an antistatic coating material onto the resist film, and suppressing unexpected and unnecessary pattern degradation, may comprise, as component (E), a fluorine-containing polymer that includes at least one selected from the group consisting of a repeating unit represented by formula (E1) below (hereinafter also referred to as repeating unit E1), a repeating unit represented by formula (E2) below (hereinafter also referred to as repeating unit E2), a repeating unit represented by formula (E3) below (hereinafter also referred to as repeating unit E3), and a repeating unit represented by formula (E4) below (hereinafter also referred to as repeating unit E4), and that may further include at least one selected from the group consisting of a repeating unit represented by formula (E5) below (hereinafter also referred to as repeating unit E5) and a repeating unit represented by formula (E6) below (hereinafter also referred to as repeating unit E6). Since the fluorine atom-containing polymer also functions as a surfactant, it can prevent the re-adhesion of insoluble substances to the substrate that may occur during the development process, thus exhibiting an effect against development defects. [ka]

[0358] In equations (E1) to (E6), j1 is 1, 2, or 3. j2 is an integer satisfying 0 ≤ j2 ≤ 5 + 2(j3) - j1. j3 is 0 or 1. k is 1, 2, or 3. R B are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. C are each independently a hydrogen atom or a methyl group. 101 , R 102 , R 104 and R 105 Each of these is independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. 103 , R 106 , R 107 and R 108 Each of these is independently a hydrogen atom, a C1-C15 hydrocarbyl group, a C1-C15 fluorinated hydrocarbyl group, or an acid-unstable group, and R103 , R 106 , R 107 and R 108 When 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 This is a single bond, -O-, *-C(=O)-OX 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 of the main chain.

[0359] In equations (E1) and (E2), R 101 , R 102 , R 104 and R 105The saturated hydrocarbyl group having 1 to 10 carbon atoms, represented by , may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 10 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl groups; and cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl groups. Of these, saturated hydrocarbyl groups having 1 to 6 carbon atoms are preferred.

[0360] In formulas (E1) to (E4), R 103 , R 106 , R 107 and R 108 The C1-C15 hydrocarbyl group represented by can be linear, branched, or cyclic. Specific examples include C1-C15 alkyl groups, C2-C15 alkenyl groups, and C2-C15 alkynyl groups, but C1-C15 alkyl groups are preferred. Examples of alkyl groups include, in addition to those mentioned above, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecyl groups. Fluorinated hydrocarbyl groups include groups in which some or all of the hydrogen atoms bonded to the carbon atoms of the hydrocarbyl group mentioned above are substituted with fluorine atoms.

[0361] In formula (E4), X 1 Examples of (k+1) valent hydrocarbon groups having 1 to 20 carbon atoms, represented by , include alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms from which k hydrogen atoms have been removed. Also, X 1Examples of (k+1) valent fluorinated hydrocarbon groups having 1 to 20 carbon atoms, as represented by the formula, include groups in which at least one hydrogen atom of the aforementioned (k+1) valent hydrocarbon group is substituted with a fluorine atom.

[0362] Specific examples of the repeating units E1 to E4 include, but are not limited to, the following: B is the same as above. [ka]

[0363] [ka]

[0364] [ka]

[0365] In formula (E5), 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.

[0366] In formula (E5), -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.

[0367] In formula (E5), X 2 is preferably *-C(=O)-O- or *-C(=O)-NH-. CIt is preferable that it is a methyl group. 2 The presence of a carbonyl group improves the acid trapping ability derived from the antistatic film. Also, R D When the 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.

[0368] The repeating unit E5 can be, but is not limited to, the following. Note that in the following formula, R C is the same as above. [ka]

[0369] [ka]

[0370] In formula (E6), 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.

[0371] In formula (E6), R 111 The 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.

[0372] Examples of the repeating unit E6 include, but are not limited to, those shown below. C is the same as above. [ka]

[0373] [ka]

[0374] [ka]

[0375] [ka]

[0376] The content of repeating units E1 to E4 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 E5 and / or E6 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 E1 to E6 may be used alone or in combination of two or more.

[0377] The (E) 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 (E) 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.

[0378] The (E) 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.

[0379] The Mw of the (E) 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 decreases, which may cause coating defects. Furthermore, the (E) fluorine atom-containing polymer preferably has an Mw / Mn ratio of 1.0 to 2.2, more preferably 1.0 to 1.7.

[0380] When the chemically amplified negative resist composition of the present invention contains (E) 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 (E) fluorine atom-containing polymer may be used alone, or two or more types may be used in combination.

[0381] [(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.

[0382] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixtures thereof are preferred.

[0383] If the chemically amplified negative resist composition of the present invention contains (F) an organic solvent, its content is preferably 200 to 10,000 parts by mass, and more preferably 400 to 5,000 parts by mass, per 80 parts by mass of the (B) base polymer. The (F) organic solvent may be used alone or as a mixture of two or more types.

[0384] [(G) Other Quenchers] The chemically amplified positive resist composition of the present invention may optionally include a quencher other than the component (A) as component (G). This reduces the rate at which the acid generated from the acid generator diffuses into the resist film. Even in cases where the outermost surface of a substrate is made of a material containing chromium, this reduces the impact of the acid generated within the resist film on the chromium-containing material.

[0385] Examples of the other quenchers 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.

[0386] Furthermore, other quenchers include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of carboxylic acids whose α-position is not fluorinated, as described in Japanese Patent Publication No. 2008-158339. Sulfonic acids, imido acids, or methidic acids with α-position fluorinated are necessary for deprotecting acid-unstable groups, but salt exchange with onium salts whose α-position is not fluorinated releases carboxylic acids whose α-position is not fluorinated. Carboxylic acids whose α-position is not fluorinated hardly undergo deprotection reactions and therefore function as quenchers.

[0387] Examples of onium salts of carboxylic acids whose α-position is not fluorinated include those represented by the following formula (F1). [ka]

[0388] In formula (G1), R 201 This refers to a hydrocarbyl group having 1 to 40 carbon atoms, which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α position of the carboxyl group is substituted with a fluorine atom or a fluoroalkyl group.

[0389] R 201 The hydrocarbyl group represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 40 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0 2,6]Cyclic saturated hydrocarbyl groups 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.

[0390] 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.

[0391] In formula (G1), 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 the sulfonium cation include those exemplified as specific examples of the sulfonium cation represented by formula (Z-1) and the sulfonium cation represented by formula (Z-4). Specific examples of the iodonium cation include those exemplified as specific examples of the iodonium cation represented by formula (Z-2). Specific examples of the ammonium cation include those exemplified as specific examples of the ammonium cation represented by formula (Z-3).

[0392] The anions of the onium salt represented by formula (G1) include, but are not limited to, those listed below. [ka]

[0393] [ka]

[0394] [ka]

[0395] As the quencher, a sulfonium salt of an iodized benzene ring-containing carboxylic acid represented by the following formula (G2) can also be suitably used. [ka]

[0396] In equation (G2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3, where 1 ≤ s + t ≤ 5. u is 1, 2, or 3.

[0397] In formula (G2), R 211 This may be a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, or a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, or -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B R 211A R is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 211Bis 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.

[0398] In formula (G2), 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.

[0399] In formula (G2), R 212 , 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.

[0400] Specific examples of the compound represented by formula (G2) include those described in JP 2017-219836 A. The compound represented by formula (G2) has high absorption, a high sensitizing effect, and a high acid diffusion control effect.

[0401] As the quencher, a nitrogen atom-containing carboxylate compound represented by the following formula (G3) can also be used. [ka]

[0402] In formula (G3), R 221 ~R 224 These are, independently, hydrogen atoms and -L 22 -CO2 - or a hydrocarbyl group having 1 to 20 carbon atoms, which may contain heteroatoms. 221 and R 222 and R 222 and R 223 and, or R 223 and R 224 These may bond with each other to form a ring with the carbon atom to which they are bonded. 22 R is a hydroxylene group having 1 to 20 carbon atoms, which may contain single bonds or heteroatoms. 225 This is a hydrocarbyl group having 1 to 20 carbon atoms, which may contain a hydrogen atom or a heteroatom.

[0403] In formula (G3), 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 - The ring may be substituted with a sulfur atom, an oxygen atom, or a nitrogen atom. The ring may be an alicyclic ring or an aromatic ring, and is preferably a 5-membered or 6-membered ring. Specific examples include pyridine rings, pyrrole rings, pyrrolidine rings, piperidine rings, pyrazole rings, imidazoline rings, pyridazine rings, pyrimidine rings, pyrazine rings, imidazoline rings, oxazole rings, thiazole rings, morpholine rings, thiazine rings, triazole rings, and the like.

[0404] The onium carboxylic acid salt represented by formula (G3) 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

[0405] In formula (G3), Mq B + This is a sulfonium cation, an iodonium cation, or an ammonium cation, but a sulfonium cation is preferred. Specific examples of the sulfonium cation include those similar to those exemplified as specific examples of the sulfonium cation represented by formula (Z-1) and formula (Z-4).

[0406] Examples of the anion of the compound represented by formula (G3) include, but are not limited to, those shown below. [ka]

[0407] [ka]

[0408] [ka]

[0409] [ka]

[0410] [ka]

[0411] [ka]

[0412] 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]

[0413] Further examples of the aforementioned quencher include the polymer-type quencher described in Japanese Patent Publication No. 2008-239918. This enhances the rectangularity of the resist pattern by oriented on the surface of the resist film. The polymer-type quencher also has the effect of preventing film thinning of the pattern and rounding of the pattern top when a protective film for immersion lithography is applied.

[0414] When the chemically amplified positive resist composition of the present invention contains (G) other quenchers, the content thereof is preferably from 0 to 50 parts by mass, and more preferably from 0.1 to 40 parts by mass, relative to 80 parts by mass of the (B) base polymer. (G) Other quenchers may be used singly or in combination of two or more.

[0415] [(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.

[0416] [Method for forming resist pattern] The resist pattern formation method of the present invention includes the steps of forming a resist film on a substrate using the chemically amplified negative resist composition described above, irradiating the resist film with a pattern using high-energy rays (i.e., exposing the resist film with high-energy rays), and developing the resist film irradiated with the pattern using an alkaline developer.

[0417] 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.

[0418] Next, the resist film is exposed to high-energy radiation to form a pattern. Examples of the high-energy radiation include ultraviolet radiation, far ultraviolet radiation, excimer laser light (KrF, ArF, etc.), EUV, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, exposure is preferably performed using KrF excimer laser light, EUV, or EB.

[0419] 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 / cm² 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 10-400 μC / cm² 2 Irradiate in such a way that it results in the following.

[0420] 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.

[0421] 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.

[0422] 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.

[0423] 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.

[0424] 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.

[0425] 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.

[0426] 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.

[0427] 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.

[0428] 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.

[0429] According to the resist pattern forming method of the present invention, even when a substrate (e.g., a photomask blank) is used whose outermost surface is made of a material that is likely to affect the resist pattern shape, such as a material containing chromium or silicon, the chemically amplified negative resist composition of the present invention efficiently controls acid diffusion at the substrate interface, making it possible to form a pattern that has high resolution and pattern fidelity, as well as improved LER and dose margin. [Example]

[0430] The present invention will be specifically explained below with reference to Synthesis Examples, Examples, and Comparative Examples, but the present invention is not limited to the following Examples. The apparatuses used are as follows. MALDI TOF-MS: JEOL S3000

[0431] [1] Synthesis of onium salts [Synthesis Example 1] Synthesis of Onium Salt SQ-1 [ka]

[0432] Under a nitrogen atmosphere, compound SM-1 (8.2 g), sodium nitrate (1.7 g), methylene chloride (40 g), and water (10 g) were added and stirred for 15 minutes. The organic layer was separated, washed with water, and then concentrated under reduced pressure. Methyl isobutyl ketone (50 g) was added to the concentrated solution, followed by azeotropic dehydration. Diisopropyl ether was added to wash the residue, yielding 5.7 g of the target onium salt SQ-1 as an oil (72% yield).

[0433] MALDI TOF-MS: POSITIVE M + 335(C 18 H 11 F4S + equivalent) NEGATIVE M - 62(NO3 - equivalent)

[0434] [Synthesis Examples 2 to 8] Synthesis of onium salts SQ-2 to SQ-8 Onium salts SQ-2 to SQ-8 represented by the following formulae were synthesized using the corresponding raw materials and known organic synthesis reactions. [ka]

[0435] [2] Preparation of chemically amplified negative resist composition [Examples 1-1 to 1-50, Comparative Examples 1-1 to 1-25] Chemically amplified negative resist compositions (R-1 to R-63, CR-1 to CR-8) were prepared by dissolving each component in an organic solvent in the compositions shown in Tables 1 to 3 below, and filtering the resulting solutions through UPE filters and / or nylon filters selected from sizes of 10 nm, 5 nm, 3 nm, and 1 nm. The organic solvent was a mixed solvent consisting of 790 parts by mass of PGMEA, 1580 parts by mass of EL, and 1580 parts by mass of PGME. In addition, some compositions were given fluorine atom-containing polymers (polymers FP-1 to FP-5) as additives, tetramethoxymethyl glycoluryl (TMGU) as a crosslinking agent, and PF-636 (manufactured by OMNOVA SOLUTIONS) as a surfactant.

[0436] [Table 1]

[0437] [Table 2]

[0438] [Table 3]

[0439] 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.

[0440] [Table 4]

[0441] In Table 4, the structure of each unit is as follows: [ka]

[0442] [ka]

[0443] [ka]

[0444] [ka]

[0445] [ka]

[0446] [ka]

[0447] In Tables 1-3, the comparative quenchers cQ-1 to cQ-3, photoacid generators PAG-A to PAG-F, and fluorine atom-containing polymers FP-1 to FP-5 are as follows: [ka]

[0448] [ka]

[0449] [ka]

[0450] [2] EB lithography evaluation [Examples 2-1 to 2-50, Comparative Examples 2-1 to 2-25] Each chemically amplified negative resist composition (R-1 to R-50, CR-1 to CR-25) was spin-coated onto a 152 mm square mask blank, whose outermost surface was a silicon oxide film, which had been treated with hexamethyldisilazane (HMDS) vapor priming using ACT-M (manufactured by Tokyo Electron Limited). The blanks were then pre-baked on a hot plate at 110°C for 600 seconds to produce a resist film with a thickness of 80 nm. The thickness of the obtained resist films was measured using an optical measuring instrument, NanoSpec (manufactured by Nanometrics). Measurements were taken at 81 locations within the plane of the blank substrate, excluding the outer edge portion from the outer edge of the blank to 10 mm inward, and the average thickness and thickness range were calculated.

[0451] 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.

[0452] 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 The resolution (limiting resolution) was defined as the minimum dimension at the exposure dose that resolves a 200nm LS pattern at a 1:1 ratio. For the 200nm LS pattern obtained by irradiation with the optimal exposure dose, 80 edge detection points were performed on each of the 32 edges of the 200nm LS pattern using a SEM, and the value of three times the variation (standard deviation, σ) (3σ) was calculated and defined as LER (nm). In addition, the change in CD per 1 μC was determined from the dose curve when the exposure dose that resolves at a 1:1 ratio was used as the reference. The results are shown in Tables 5 to 7.

[0453] [Table 5]

[0454] [Table 6]

[0455] [Table 7]

[0456] The chemically amplified negative resist compositions (R-1 to R-50) of the present invention, containing the onium salt represented by formula (A), showed good resolution and good LER and dose margins compared to the comparative resist compositions (CR-1 to CR-25) due to effective acid diffusion control. Comparing R-49 and R-50, it was confirmed that the effects of the present invention are more pronounced when the optimal exposure dose is 50 μC or higher.

[0457] As described above, the chemically amplified negative resist composition of the present invention can be used to form patterns with extremely high resolution and good LER and dose margins. The resist pattern formation method using the chemically amplified negative resist composition of the present invention is useful for photolithography in semiconductor device manufacturing, particularly in the processing of transmissive or reflective mask blanks.

Claims

1. (A) a quencher comprising an onium salt represented by the following formula (A): (B) a base polymer containing a polymer containing a repeating unit represented by the following formula (B1), and (C) Photoacid generator A chemically amplified negative resist composition comprising: 【Chemistry 1】 [In the formula, Xq - is an anion. - The acid (XqH) having as its conjugate base has a boiling point of less than 165°C and a molecular weight of 150 or less. Z + is a sulfonium cation represented by the following formula (Z-1), an iodonium cation represented by the following formula (Z-2), an ammonium cation represented by the following formula (Z-3), or a sulfonium cation represented by the following formula (Z-4). 【Chemistry 2】 (In the formula, R 1 ~R 9 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. 1 ~R 3 Any two of may be bonded to each other to form a ring together with the sulfur atom to which they are attached, and R 6 ~R 9 Any two of may be bonded to each other to form a ring together with the nitrogen atom to which they are attached. 【Transformation 3】 (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+m8m+14≦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 10 ~R 13 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. 10 may be the same or different, and two R 10 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 11 may be the same or different, and two R 11 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 12 may be the same or different, and two R 12 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 13 may be the same or different, and two R 13 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 A and L B 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 L represents a single bond or a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. 【Chemistry 4】 (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 21 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. Anion Xq - 2. The chemically amplified positive resist composition according to claim 1, wherein the conjugate acid XqH is formic acid, acetic acid, propionic acid, butyric acid, trifluoroacetic acid, 3,3,3-trifluoropropionic acid, pivalic acid or nitric acid.

3. 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 5】 (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 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-. R 34 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. R 35 and R 36 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. 35 and R 36 cannot be a hydrogen atom at the same time. 35 and R 36 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.

4. 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 6】 (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-.)

5. 2. The chemically amplified positive resist composition according to claim 1, 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): 【Transformation 7】 (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.

6. 6. The chemically amplified negative resist composition according to claim 5, 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): 【Transformation 8】 (In the formula, a4, b4, b6, R A , R 32 , R 33 , R 35 , R 36 , 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.

7. 6. The chemically amplified negative resist composition according to claim 5, 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).

8. 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.

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

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

11. 2. The chemically amplified negative resist composition according to claim 1, further comprising (E) a fluorine atom-containing polymer which contains at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (E1), a repeating unit represented by the following formula (E2), a repeating unit represented by the following formula (E3), and a repeating unit represented by the following formula (E4), and which may further contain at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (E5) and a repeating unit represented by the following formula (E6): 【Chemistry 9】 (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.)

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

13. 2. The chemically amplified negative resist composition according to claim 1, further comprising: (G) a quencher other than component (A).

14. 14. The chemically amplified negative resist composition according to claim 13, wherein the content ratio of the acid generator (E) to the quencher (A) is less than 6 in terms of mass ratio.

15. 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 14; 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.

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

17. 16. The method for forming a resist pattern according to claim 15, 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.

18. 16. The method for forming a resist pattern according to claim 15, wherein the substrate is a transmission or reflection mask blank.

19. A transmission or reflection mask blank coated with the chemically amplified negative resist composition according to any one of claims 1 to 14.

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