Chemically amplified negative resist composition and method of forming resist pattern

Abstract

To provide a chemically amplified negative resist composition containing a polymer-bonded acid generator having excellent etching resistance, solubility in an organic solvent and moderate acid strength and capable of generating an acid with little diffusion, and a method for forming a resist pattern using the chemically amplified resist composition.SOLUTION: A chemically amplified negative resist composition comprising (A) a base polymer comprising a polymer comprising a recurring unit having the formula (A1) and a recurring unit having a specific structure, the polymer having a solubility in alkaline aqueous solution that decreases under the action of acid.SELECTED DRAWING: None

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 and extreme ultraviolet (EUV) lithography, which are effective technologies for forming patterns smaller than the processing limit of ArF excimer lasers, 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 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 an acid, and a crosslinker (in some cases, the polymer and crosslinker are integrated) that uses the acid as a catalyst to form crosslinks between the polymers, making them insoluble in the developer, and typically also contain a quencher to control the diffusion of the acid generated by exposure.

[0005] A large number of negative resist compositions using units derived from phenols as alkali-soluble units constituting the polymer soluble in the aqueous alkaline developer have been developed, particularly for exposure with KrF excimer laser light. These have not been used for ArF excimer laser light because the phenol units do not transmit light when the exposure light has a wavelength of 150 to 220 nm. However, in recent years, these have once again attracted attention as negative resist compositions for EB and EUV exposure, which are exposure methods for obtaining finer patterns. For example, those described in Patent Documents 1, 2, and 3 have been proposed as resist compositions that provide very high resolution even when used in thin films.

[0006] In addition to the above, numerous materials have been developed for use in chemically amplified negative resist compositions. For example, crosslinking agents such as those described in Patent Documents 1 to 3 are used to insolubilize alkali-soluble polymers used in resist compositions that impart a negative mechanism through the action of acid generated upon irradiation with high-energy rays, and many crosslinking agents have been developed. Numerous attempts have also been made to impart the functionality of these crosslinking agents to polymers. Examples include a method of introducing styrene units substituted with an alkoxymethoxy group (Patent Document 4), a method of introducing repeating units having an alkoxymethylamino group (Patent Document 5), a method of introducing repeating units having an epoxy group (Patent Document 6), a method of introducing styrene-based repeating units having an acid-leaving group (Patent Document 7), a method of introducing adamantyl-based repeating units having an acid-leaving hydroxy group (Patent Document 8), and a method of introducing aliphatic hydrocarbon groups and alicyclic hydrocarbon-based repeating units having an acid-leaving hydroxy group (Patent Documents 9, 10, and 11). Materials having an acid-leaving hydroxy group have also been proposed in Patent Document 12, etc.

[0007] To suppress acid diffusion, polymers containing repeating units derived from onium salts of sulfonic acids with polymerizable unsaturated bonds have been proposed (Patent Document 13). Such so-called polymer-bound acid generators are characterized by extremely short acid diffusion because they generate polymeric sulfonic acids upon exposure. Furthermore, increasing the proportion of acid generator can improve sensitivity. Increasing the amount of additive-type acid generators also increases sensitivity, but this also increases the acid diffusion distance. Because acid diffuses nonuniformly, increased acid diffusion leads to deterioration of line edge roughness (LER) and dimensional uniformity (CDU). While polymer-bound acid generators offer a high level of sensitivity, LER, and CDU balance, the development of acid generators that generate acids with more suitable strength is desirable.

[0008] Patent Documents 14 and 15 describe examples of controlling acid diffusion by binding sulfonic acid, which is generated upon exposure as an acid generator that generates acid of a more suitable strength, to a polymer used in a resist composition to suppress diffusion. This method of suppressing acid diffusion by incorporating a repeating unit that generates acid upon exposure into a base polymer is effective for obtaining patterns with small LER. However, depending on the structure and incorporation rate of such repeating units, problems may arise with the solubility of base polymers bound to repeating units that generate acid upon exposure in organic solvents.

[0009]

[0003] With the recent progress in miniaturization of resist patterns, problems such as collapse of the resist pattern during development and poor resistance in the etching process have become an issue. Although the introduction of a repeating unit derived from an onium salt of a sulfonic acid having a polymerizable unsaturated bond has suppressed the acid diffusion of the generated acid to some extent, there remains room for improvement in various lithography performances, collapse of the resist pattern, and poor etching resistance. In order to meet the future demands for miniaturization, it is extremely important to develop a polymer-type acid generator that combines lithography performance with good resist pattern collapse and etching resistance. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-276910 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-164933 [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-249762 [Patent Document 4] Japanese Patent Application Publication No. 5-232702 [Patent Document 5] Japanese Patent Application Publication No. 8-202037 [Patent Document 6] Japanese Patent Application Laid-Open No. 2001-226430 [Patent Document 7] Japanese Patent Application Laid-Open No. 2003-337414 [Patent Document 8] Japanese Patent Application Laid-Open No. 2001-154357 [Patent Document 9] U.S. Patent No. 7,300,739 [Patent Document 10] U.S. Patent No. 7,393,624 [Patent Document 11] U.S. Patent No. 7,563,558 [Patent Document 12] Japanese Patent Application Laid-Open No. 2013-164588 [Patent Document 13] Japanese Patent Application Laid-Open No. 2012-177834 [Patent Document 14] Japanese Patent Application Laid-Open No. 2011-22564 [Patent Document 15] International Publication No. 2015 / 194330 Summary of the Invention [Problem to be solved by the invention]

[0011] 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 contains a polymer-bonded acid generator that has excellent etching resistance, organic solvent solubility, and appropriate acid strength, and is capable of generating an acid that diffuses little, and a method of forming a resist pattern that uses the chemically amplified resist composition. [Means for solving the problem]

[0012]

[0013] As a result of intensive research into achieving the above-mentioned object, the present inventors have found that a polymer that contains a repeating unit derived from an onium salt that contains an aromatic sulfonate anion having an aromatic ring substituted with a vinyl group, and a repeating unit that contains a phenolic hydroxy group, as a polymer-bound acid generator, has good solvent solubility, and that by using this polymer as a material for a chemically amplified negative resist composition, the resist composition not only achieves excellent lithography performance such as resolution, LER, and pattern shape, particularly in EB lithography and EUV lithography, but also provides resistance to pattern collapse and excellent pattern shape in the formation of fine patterns, thereby completing the present invention.

[0013] That is, the present invention provides the following chemically amplified negative resist composition and method of forming a resist pattern. 1. (A) A chemically amplified negative resist composition comprising a base polymer containing a polymer that contains a repeating unit represented by the following formula (A1) and a repeating unit represented by the following formula (A2), and whose solubility in an alkaline aqueous solution decreases due to the action of an acid. [ka] (In the formula, n1 is 0 or 1. n2 is 0 or 1. n3 is 0, 1, 2, 3, or 4. n4 is 0, 1, 2, 3, or 4. n5 is 0, 1, 2, 3, or 4. However, when n2 is 0, 0≦n4+n5≦4, and when n2 is 1, 0≦n4+n5≦6. Furthermore, n1 to n5 cannot all be 0. R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 1 is a halogen atom, a nitro group, a cyano group, or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. When n3 is 2 or more, each R 1 may be the same or different, and multiple R 1 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 2is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. When n4 is 2 or more, each R 2 may be the same or different, and multiple R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. When n5 is 2 or more, each R F may be the same as or different from each other. L A and L B are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, a sulfonate amide bond, a carbonate bond or a carbamate bond. X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a hetero atom. Z + is an onium cation. [ka] (In the formula, a1 is 0 or 1. a2 is 0, 1, or 2. a3 is an integer that satisfies 0≦a3≦5+2(a2)−a4. a4 is 1, 2, or 3. R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 is a halogen atom, 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. 11 may be the same as or different from each other. A 1represents a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and some of the -CH2- in the saturated hydrocarbylene group may be substituted with -O-. 2. The chemically amplified negative resist composition of 1, wherein the repeating unit represented by formula (A1) is represented by the following formula (A1-1): [ka] (In the formula, n2~n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z + is the same as above.) 3. The chemically amplified negative resist composition of 2, wherein the repeating unit represented by formula (A1-1) is represented by the following formula (A1-2): [ka] (In the formula, n2~n5, R A , R 1 , R 2 , R F , L A and Z + is the same as above.) 4.Z + is a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2): [ka] (In the formula, R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom. ct1 and R ct2 may be bonded to each other to form a ring together with the sulfur atom to which they are attached. 5. The chemically amplified negative resist composition of any one of 1 to 4, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (A3) and a repeating unit represented by the following formula (A4): [ka] (In the formula, b1 is 0 or 1. b2 is 0, 1, or 2. b3 is an integer that satisfies 0≦b3≦5+2(b2)−b4. b4 is 1, 2, or 3. b5 is 0, 1, or 2. b6 is 1 or 2. R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. When b3 is 2 or more, each R 21 may be the same as or different from each other. R 22 and R 23 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be hydrogen atoms at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded, and a portion of -CH2- in the ring may be substituted with -O- or -S-. R 24 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. When b5 is 2 or more, each R 24 may be the same as or different from each other. R 25 and R 26are 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. 25 and R 26 cannot be hydrogen atoms at the same time. 25 and R 26 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. 6. The chemically amplified negative resist composition of any one of 1 to 5, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (A5), a repeating unit represented by the following formula (A6), and a repeating unit represented by the following formula (A7): [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 31 and R 32are 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. When c is 2 or more, each R 31 may be the same or different. When d is 2 or more, each R 32 may be the same as or different from each other. R 33 is a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbyloxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbylthiohydrocarbyl group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbylsulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbylsulfonyl group having 1 to 20 carbon atoms. When e3 is 2 or more, each R 33 may be the same as or different from each other. 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-. 7. The chemically amplified negative resist composition of 5, wherein the polymer comprises a repeating unit represented by formula (A1), a repeating unit represented by the following formula (A2-1), and a repeating unit represented by the following formula (A3-1), (A3-2), or (A4-1). [ka] (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 25 and R 26 is the same as above.) 8. A chemically amplified negative resist composition according to 5, wherein the (A) base polymer further comprises a polymer containing a repeating unit represented by formula (A2) and a repeating unit represented by the following formula (A3) or (A4), and does not contain a repeating unit represented by formula (A1). 9. The chemically amplified negative resist composition of 1, wherein the content of repeating units having an aromatic ring skeleton among all repeating units of the polymer contained in the base polymer is 60 mol % or more. 10. The chemically amplified negative resist composition according to any one of 1 to 9, further comprising (B) a crosslinking agent. 11. The chemically amplified negative resist composition of 5, which does not contain a crosslinking agent. 12. The chemically amplified negative resist composition according to any one of 1 to 11, further comprising (C) a fluorine atom-containing polymer which contains at least one selected from the group consisting of a repeating unit represented by the following formula (C1), a repeating unit represented by the following formula (C2), a repeating unit represented by the following formula (C3), and a repeating unit represented by the following formula (C4), and which may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (C5) and a repeating unit represented by the following formula (C6): [ka] (In the formula, x is 1, 2, or 3. y is an integer satisfying 0≦y≦5+2z−x. z is 0 or 1. g is 1, 2, or 3. R C are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R D 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 108are 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 heteroatom-containing group interposed between its carbon-carbon bonds. When x is 2 or more, each R 109 may be the same as or different from each other. 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. When y is 2 or more, each R 110 may be the same as or different from each other. 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. Z 1 is a (g+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (g+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. Z 2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * is a bond to a carbon atom in the main chain. Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 -or*-C(=O)-NH-Z 31 -Z 32 -It is. Z 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. * indicates a bond to a carbon atom in the main chain.) 13. A negative resist composition according to any one of 1 to 12, further comprising (D) a quencher. 14. The chemically amplified negative resist composition according to any one of 1 to 13, further comprising (E) an organic solvent. 15. The chemically amplified negative resist composition according to any one of 1 to 14, further comprising (F) a photoacid generator. 16. 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 15; irradiating the resist film with a pattern using high-energy rays; and developing the resist film irradiated with the pattern using an alkaline developer. 17. The method for forming a resist pattern according to 16, wherein the high-energy radiation is EUV or EB having a wavelength of 3 to 15 nm. 18. The method for forming a resist pattern according to 16 or 17, wherein the outermost surface of the substrate is made of a material containing at least one selected from the group consisting of chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten, and tin. 19. The method for forming a resist pattern according to any one of 16 to 18, wherein the substrate is a transmission or reflection mask blank. 20. A transmission or reflection mask blank coated with any one of the chemically amplified negative resist compositions described in 1 to 15. [Effects of the Invention]

[0014] 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 repeating unit derived from the onium salt monomer represented by formula (A1), and when a resist film is formed using this composition to form a pattern, it is possible to obtain a pattern with extremely high resolution, high pattern fidelity, and reduced LER. Furthermore, the action of the repeating unit represented by formula (A2) can improve adhesion to the substrate during resist film formation and control solubility in an alkaline developer. DETAILED DESCRIPTION OF THE INVENTION

[0015] [Chemically amplified negative resist composition] The chemically amplified negative resist composition of the present invention comprises, as component (A), a base polymer that contains a polymer that decomposes under the action of an acid and whose solubility in an alkaline developer decreases (hereinafter, also referred to as polymer A).

[0016] [(A) Base polymer] Polymer A contains a repeating unit represented by the following formula (A1) (hereinafter also referred to as repeating unit A1). [ka]

[0017] In formula (A1), n1 is 0 or 1. When n1 is 0, it is a benzene ring, and when n1 is 1, it is a naphthalene ring. However, from the viewpoint of solvent solubility, n1 is preferably a benzene ring of 0. n2 is 0 or 1. n3 is 0, 1, 2, 3, or 4, but is preferably 0, 1, or 2. n4 is 0, 1, 2, 3, or 4, but is preferably 0, 1, or 2. n5 is 0, 1, 2, 3, or 4, but is preferably 1, 2, 3, or 4, and more preferably 2, 3, or 4, from the viewpoint of the acid strength of the generated acid. However, when n2 is 0, 0≦n4+n5≦4, and when n2 is 1, 0≦n4+n5≦6. Furthermore, from the viewpoint of solvent solubility, n1 to n5 cannot all be 0.

[0018] In formula (A1), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Among these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0019] In formula (A1), R 1is a halogen atom, a nitro group, a cyano group, or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. The halogen atom is preferably a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and more preferably a fluorine atom or an iodine atom. 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, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and icosyl groups; cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, and 4-methyl Examples of such groups include saturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; unsaturated cyclic hydrocarbyl groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 2 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and groups obtained by combining these groups. Of these, aryl groups are preferred. In addition, some or all of the hydrogen atoms of the hydrocarbyl group may be substituted with a group containing a heteroatom such as an oxygen atom, a sulfur atom, a nitrogen atom or a halogen atom, and some of the -CH2- 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, resulting in the hydrocarbyl group containing a hydroxy group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic acid anhydride (-C(=O)-OC(=O)-), a haloalkyl group, etc. When n3 is 2 or more, each R 1 may be the same as or different from each other.

[0020] Also, when n3 is 2 or more, multiple R 1 may 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.

[0021] In formula (A1), R 2 is 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 R 1 When n4 is 2 or more, each R 2 may be the same or different. When n4 is 2 or more, a plurality of R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are bonded. The ring is preferably a 5- to 8-membered ring.

[0022] In formula (A1), R F R 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. Fis 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. By containing a fluorine atom or one of these substituents having a fluorine atom, the acid strength of the generated acid is improved due to an electron-withdrawing effect, so that the deprotection reaction of acid labile groups such as tertiary esters and tertiary ethers described below proceeds smoothly. When n5 is 2 or more, each R F may be the same as or different from each other.

[0023] In formula (A1), L A and L B are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, a sulfonate amide bond, a carbonate bond, or a carbamate bond. A is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably an ester bond or a sulfonate ester bond. B is preferably a single bond, an ether bond, an ester bond or a sulfonate ester bond, and more preferably a single bond, an ester bond or a sulfonate ester bond.

[0024] In formula (A1), X L is 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, a cyclic saturated hydrocarbylene group, and an arylene group. Specific examples of the heteroatom include an oxygen atom, a nitrogen atom, and a sulfur atom.

[0025] 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 BIt is a combination of. [ka]

[0026] [ka]

[0027] [ka]

[0028] [ka]

[0029] Of these, X L -0~X L -22, X L -29~X L -34 and X L -47~X L -58 is preferred.

[0030] The repeating unit A1 is preferably one represented by the following formula (A1-1). [ka] (In the formula, n2~n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z + is the same as above.)

[0031] The repeating unit represented by formula (A1-1) is preferably one represented by the following formula (A1-2). [ka] (In the formula, n2~n5, R A , R 1 , R2 , R F , L A and Z + is the same as above.)

[0032] Specific examples of the anion of the monomer that gives the repeating unit A1 include, but are not limited to, those shown below. In the following formula, Me is a methyl group. The bonding positions of the various substituents on the aromatic ring may be interchanged. [ka]

[0033] [ka]

[0034] [ka]

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[0079] In formula (A1), Z + is an onium cation. The onium cation is preferably a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2). [ka]

[0080] In formulas (cation-1) and (cation-2), R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbyl group having 1 to 30 carbon atoms which may contain a heteroatom.

[0081] R ct1 ~R ct5 Specific examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0082] R ct1 ~R ct5 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 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 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.

[0083] Also, R ct1 and R ct2 However, they may be bonded to each other to form a ring together with the sulfur atom to which they are bonded. In this case, examples of the ring structure include those represented by the following formulas. [ka] (In the formula, the dashed line indicates R ct3 )

[0084] Specific examples of the sulfonium cation represented by formula (cation-1) include, but are not limited to, those shown below. [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] [ka]

[0089] [ka]

[0090] [ka]

[0091] [ka]

[0092] [ka]

[0093]

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[0094]

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[0095]

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[0096]

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[0097]

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[0098]

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[0099]

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[0100]

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[0101]

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[0102]

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[0103] [ka]

[0104] [ka]

[0105] [ka]

[0106] [ka]

[0107] [ka]

[0108] [ka]

[0109] [ka]

[0110] [ka]

[0111] Specific examples of the iodonium cation represented by formula (cation-2) include, but are not limited to, those shown below. [ka]

[0112] [ka]

[0113] Specific examples of the monomer represented by formula (A1) include any combination of the above-mentioned anions and cations.

[0114] The monomer represented by formula (A1) can be synthesized, for example, by a method similar to that for the sulfonium salt having a polymerizable anion described in Japanese Patent No. 5201363, but is not limited thereto.

[0115] The polymer A further contains a repeating unit A2 having a phenolic hydroxy group represented by the following formula (A2): The repeating unit A2 is a repeating unit that imparts etching resistance, adhesion to a substrate, and solubility in an alkaline developer. [ka]

[0116] In formula (A2), a1 is 0 or 1. a2 is 0, 1, or 2, and when 0, it represents a benzene skeleton, when 1, it represents a naphthalene skeleton, and when 2, it represents 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.

[0117] In formula (A2), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0118] In formula (A2), R 11is a halogen atom, 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 an alkaline developer is good. When a3 is 2 or more, each R 11 may be the same as or different from each other.

[0119] In formula (A2), 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 (A2) 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.

[0120] 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 A2 does not have -), preferred examples of the repeating unit A2 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 (A2-1) is preferred. [ka] (In the formula, R A and a4 are the same as above.)

[0121] a1 is 1 (i.e., -C(=O)-OA as a linker) 1In the case where R A is the same as above. [ka]

[0122] The repeating unit A2 may be used alone or in combination of two or more.

[0123] Polymer A may contain at least one selected from the repeating unit represented by the following formula (A3) (hereinafter also referred to as repeating unit A3) and the repeating unit represented by the following formula (A4) (hereinafter also referred to as repeating unit A4) (hereinafter, polymer A further containing at least one selected from repeating unit A3 and repeating unit A4 will also be referred to as polymer A'). [ka]

[0124] When the repeating units A3 and A4 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 These repeating units undergo an elimination reaction, which makes the compound insoluble in alkaline developers and induces crosslinking reactions between polymers. The effects of repeating units A3 and A4 allow the negative conversion reaction to proceed more efficiently, thereby improving resolution.

[0125] In formula (A3), 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.

[0126] In formula (A3), b5 is 0, 1 or 2, and preferably 0 or 1. b6 is 1 or 2, and preferably 1.

[0127] In formulas (A3) and (A4), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. In formula (A4), among these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0128] In formula (A3), R 21 R is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 21 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. 21 The hydrocarbyl group having 1 to 20 carbon atoms represented by the formula (A1) may be saturated or unsaturated, and may be linear, branched, or cyclic. 1 When b3 is 2 or more, each R 21 may be the same as or different from each other.

[0129] In formula (A3), R 22 and R 23 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbyl group may be substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be hydrogen atoms at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and some of the -CH2- in the ring may be substituted with -O- or -S-. 22 and R 23 Preferred examples of the alkyl group include alkyl groups such as methyl, ethyl, propyl, and butyl groups, and structural isomers thereof, as well as alkyl groups in which some of the hydrogen atoms have been substituted with hydroxy groups or saturated hydrocarbyloxy groups.

[0130] In formula (A4), R 24 R is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 24 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. 24 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 24 may be the same as or different from each other.

[0131] In formula (A4), R 25 and R 26 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.

[0132] R 25 and R 26 The saturated hydrocarbyl group having 1 to 15 carbon atoms represented by the formula (I) may be linear, branched, or cyclic. Specific examples thereof include R 22 and R 23 Examples of the saturated hydrocarbyl group represented by the formula (I) include the same as those exemplified above.

[0133] R 25 and R 26 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.

[0134] Also, R 25 and R 26 cannot simultaneously become a hydrogen atom. 25 and R 26 When either of the groups is an aryl group which may have a substituent, the other substituent is preferably a hydrogen atom.

[0135] R 25 and R 26 are preferably the same group, and more preferably both are methyl groups.

[0136] Also, R 25 and R 26 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.

[0137] In formula (A3), 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 (A3) is 1, it 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 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.

[0138] In formulas (A3) and (A4), 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.

[0139] 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.

[0140] The repeating unit A3 is preferably one represented by the following formula (A3-1) or (A3-2). [ka] (In the formula, b4, R A , R 22 and R 23 is the same as above.)

[0141] Preferred examples of the repeating unit A3 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]

[0142] [ka]

[0143] [ka]

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] [ka]

[0148] [ka]

[0149] [ka]

[0150] [ka]

[0151] [ka]

[0152] The repeating unit A3 may be used alone or in combination of two or more.

[0153] The repeating unit A4 is preferably one represented by the following formula (A4-1). [ka] (In the formula, b6, R A , R 25 and R 26 is the same as above.)

[0154] Preferred examples of the repeating unit A4 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]

[0155] [ka]

[0156] [ka]

[0157] [ka]

[0158] [ka]

[0159]

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[0160]

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[0161]

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[0162]

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[0163]

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[0164]

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[0165]

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[0166]

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[0167]

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[0168]

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[0169]

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[0170]

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[0171]

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[0172]

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[0173]

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[0174]

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[0175]

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[0176]

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[0177]

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[0178]

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[0179]

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[0180] [ka]

[0181] [ka]

[0182] [ka]

[0183] [ka]

[0184] [ka]

[0185] [ka]

[0186] [ka]

[0187] The repeating unit A4 may be used alone or in combination of two or more.

[0188] For the purpose of improving etching resistance, polymers A and A' may contain at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (A5) (hereinafter also referred to as repeating unit A5), a repeating unit represented by the following formula (A6) (hereinafter also referred to as repeating unit A6), and a repeating unit represented by the following formula (A7) (hereinafter also referred to as repeating unit A7). [ka]

[0189] In formulae (A5) and (A6), c and d each independently represent 0, 1, 2, 3, or 4.

[0190] In formulas (A5) and (A6), R 31 and R 32 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 31 may be the same or different. When d is 2 or more, each R 32 may be the same as or different from each other.

[0191] In formula (A7), e1 is 0 or 1. e2 is 0, 1, or 2, and when e2 is 0, it represents a benzene skeleton, when it is 1, it represents a naphthalene skeleton, and when it is 2, it represents 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.

[0192] In formula (A7), R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0193] In formula (A7), R 33is 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 33 may be the same as or different from each other.

[0194] R 33 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.

[0195] 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.

[0196] 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.

[0197] In formula (A7), A 3is 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 e1 in formula (A7) 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 e1 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.

[0198] 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 A7 does not have -), preferred examples of the repeating unit A7 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene, etc.

[0199] 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]

[0200] [ka]

[0201] When at least one of the repeating units A5 to A7 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.

[0202] The repeating units A5 to A7 may be used alone or in combination of two or more.

[0203] Polymers A and A' 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.

[0204] Examples of the (meth)acrylic acid ester unit having the adhesive group include a repeating unit represented by the following formula (A8) (hereinafter also referred to as repeating unit A8), a repeating unit represented by the following formula (A9) (hereinafter also referred to as repeating unit A9), and a repeating unit represented by the following formula (A10) (hereinafter also referred to as repeating unit A10). These units are not acidic and can be used auxiliary units that impart adhesion to substrates or adjust solubility. [ka]

[0205] In formulas (A8) to (A10), R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 41 is —O— or a methylene group. 42is a hydrogen atom or a hydroxy group. 43 is a saturated hydrocarbyl group having 1 to 4 carbon atoms. f is 0, 1, 2 or 3.

[0206] In polymer A, the content of repeating unit A1 is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, to obtain the effect of promoting the negativity reaction. The content of repeating unit A2 is preferably 30 to 95 mol %, more preferably 50 to 85 mol %, to obtain high contrast between the area negativity-imparted by high-energy ray irradiation and the area not negativity-imparted (non-negativity-imparted) for the purpose of achieving high resolution. Furthermore, the contents of repeating units A3 and A4 are preferably 5 to 70 mol %, more preferably 10 to 60 mol %, to obtain the effect of promoting the negativity reaction. The contents of repeating units A5 to A7 are preferably 0 to 30 mol %, more preferably 3 to 20 mol %, to obtain the effect of improving etching resistance. Note that other repeating units may be contained in an amount of 0 to 30 mol %, preferably 0 to 20 mol %.

[0207] In polymer A', the content of repeating unit A1 is preferably 1 to 20 mol %, more preferably 2 to 15 mol %, in order to obtain the effect of promoting the negativity reaction. The content of repeating unit A2 is preferably 25 to 94.5 mol %, more preferably 36 to 85 mol %. The content of repeating units A5 to A7 is preferably 0 to 30 mol %, more preferably 3 to 20 mol %. The content of repeating unit A3 and repeating unit A4 is preferably 5 to 70 mol %, more preferably 10 to 60 mol %. The total content of repeating units A2 to A7 is preferably 60 to 99.5 mol %. The content of repeating unit A1 is preferably 0.5 to 20 mol %, more preferably 1 to 10 mol %. Note that other repeating units may be contained in an amount of 0 to 30 mol %, preferably 0 to 20 mol %.

[0208] Of all the repeating units constituting the polymer, repeating units A2 to A7 preferably account for 60 mol % or more, more preferably 70 mol % or more, and even more preferably 80 mol % or more, which ensures that the properties required for the chemically amplified negative resist composition of the present invention are obtained.

[0209] Furthermore, polymer A' preferably contains a repeating unit represented by formula (A1), a repeating unit represented by the following formula (A2-1), and a repeating unit represented by the following formula (A3-1), (A3-2), or (A4-1). [ka] (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 25 and R 26 is the same as above.)

[0210] When polymer A' is used as the (A) base polymer, polymer A' may be used in combination with a polymer containing repeating units A2 and A3 or A4, but not A1 (hereinafter also referred to as polymer A''). In this case, the content of repeating units A2 in polymer A'' is preferably 25 to 95 mol %, more preferably 40 to 85 mol %. The content of repeating units A5 to A7 is preferably 0 to 30 mol %, more preferably 3 to 20 mol %. The content of repeating units A3 and A4 is preferably 5 to 70 mol %, more preferably 10 to 60 mol %. Other repeating units may be contained in an amount of 0 to 30 mol %, preferably 0 to 20 mol %. When polymer A' and polymer A'' are used in combination, the content of polymer A'' in the chemically amplified negative resist composition of the present invention is preferably 2 to 5,000 parts by mass, more preferably 10 to 1,000 parts by mass, per 100 parts by mass of the polymer containing repeating unit A1.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] The polymer preferably has a narrow molecular weight distribution (Mw / Mn) of 1.0 to 2.0, particularly 1.0 to 1.8, such that foreign matter does not appear on the pattern after development and the pattern shape does not deteriorate.

[0215] [(B) Crosslinking agent] When the (A) base polymer does not contain polymer A', the chemically amplified negative resist composition of the present invention preferably contains a crosslinking agent as component (B). On the other hand, when the (A) base polymer contains polymer A', it may or may not contain a crosslinking agent.

[0216] 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.

[0217] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0218] Examples of the melamine compound include compounds in which 1 to 6 methylol groups are methoxymethylated, such as hexamethylol melamine, hexamethoxymethyl melamine, and hexamethylol melamine, and mixtures thereof; and compounds in which 1 to 6 methylol groups are acyloxymethylated, such as hexamethoxyethyl melamine, hexaacyloxymethyl melamine, and hexamethylol melamine, and mixtures thereof.

[0219] Examples of the guanamine compound include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and tetramethylolguanamine, and mixtures thereof; and compounds in which 1 to 4 methylol groups are acyloxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, and mixtures thereof.

[0220] Examples of the glycoluril compound include compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylol glycoluril, tetramethoxyglycoluril, tetramethoxymethyl glycoluril, and tetramethylol glycoluril, or mixtures thereof; and compounds in which 1 to 4 methylol groups are acyloxymethylated in tetramethylol glycoluril, or mixtures thereof.

[0221] 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.

[0222] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0223] Examples of the azide compound include 1,1'-biphenyl-4,4'-bisazide, 4,4'-methylidenebisazide, and 4,4'-oxybisazide.

[0224] 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.

[0225] In the chemically amplified negative resist composition of the present invention, the content of the (B) crosslinking agent is preferably 0.1 to 50 parts by mass, more preferably 1 to 30 parts by mass, relative to 80 parts by mass of the (A) base polymer. Within this range, there is little risk of patterns being connected together and resolution decreasing. The (B) crosslinking agents may be used alone or in combination of two or more.

[0226] [(C) Fluorine atom-containing polymer] The chemically amplified negative resist composition of the present invention, for the purposes of achieving high contrast, suppressing chemical flare of acids upon irradiation with high-energy rays, shielding acid from mixing from the antistatic film during the process of applying an antistatic film material onto the resist film, and suppressing unexpected and unnecessary pattern degradation, may comprise, as component (C), a fluorine-containing polymer that includes at least one selected from the group consisting of a repeating unit represented by formula (C1) below (hereinafter also referred to as repeating unit C1), a repeating unit represented by formula (C2) below (hereinafter also referred to as repeating unit C2), a repeating unit represented by formula (C3) below (hereinafter also referred to as repeating unit C3), and a repeating unit represented by formula (C4) below (hereinafter also referred to as repeating unit C4), and that may further include at least one selected from the group consisting of a repeating unit represented by formula (C5) below (hereinafter also referred to as repeating unit C5) and a repeating unit represented by formula (C6) below (hereinafter also referred to as repeating unit C6). The fluorine atom-containing polymer also functions as a surfactant, and is therefore effective in preventing insoluble matter from re-adhering to the substrate during the development process, thereby preventing development defects. [ka]

[0227] In formulas (C1) to (C6), x is 1, 2, or 3. y is an integer that satisfies 0≦y≦5+2z−x. z is 0 or 1. g is 1, 2, or 3. R C are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. D are each independently a hydrogen atom or a methyl group. 101 , R 102 , R 104 and R 105 are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 10 carbon atoms. 103 , R 106 , R 107 and R 108 are each independently a hydrogen atom, a hydrocarbyl group having 1 to 15 carbon atoms, a fluorinated hydrocarbyl group having 1 to 15 carbon atoms, or an acid labile group, and 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 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 bonds. When x is 2 or more, each R 109 R may be the same or different. 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. When y is 2 or more, each R 110 R may be the same or different. 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 (g+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (g+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. Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 -or*-C(=O)-NH-Z 31 -Z 32 -It is. Z 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.

[0228] In formulas (C1) and (C2), R 101 , R 102 , R 104 and R 105The saturated hydrocarbyl group having 1 to 10 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbyl groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl. Of these, saturated hydrocarbyl groups having 1 to 6 carbon atoms are preferred.

[0229] In formulas (C1) to (C4), R 103 , R 106 , R 107 and R 108 The hydrocarbyl group having 1 to 15 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include an alkyl group having 1 to 15 carbon atoms, an alkenyl group having 2 to 15 carbon atoms, and an alkynyl group having 2 to 15 carbon atoms, with an alkyl group having 1 to 15 carbon atoms being preferred. Examples of the alkyl group include those mentioned above, as well as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, n-tridecyl, n-tetradecyl, and n-pentadecyl. Examples of the fluorinated hydrocarbyl group include groups in which some or all of the hydrogen atoms bonded to carbon atoms in the hydrocarbyl group mentioned above have been substituted with fluorine atoms.

[0230] In formula (C4), Z 1 Examples of the (g+1)-valent hydrocarbon group having 1 to 20 carbon atoms and represented by the formula (I) include a group in which g hydrogen atoms have been further removed from an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbyl group having 3 to 20 carbon atoms. 1Examples of the (g+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms and represented by the formula (I) include groups in which at least one hydrogen atom of the aforementioned (g+1)-valent hydrocarbon group has been substituted with a fluorine atom.

[0231] Specific examples of the repeating units C1 to C4 include, but are not limited to, the following: C is the same as above. [ka]

[0232] [ka]

[0233] [ka]

[0234] In formula (C5), 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.

[0235] In formula (C5), -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.

[0236] In formula (C5), Z 2 is preferably *-C(=O)-O- or *-C(=O)-NH-. Dis preferably a methyl group. 2 The presence of a carbonyl group in R improves the acid trapping ability of the antistatic film. D When the methyl group is used, the polymer becomes more rigid with a higher glass transition temperature (Tg), which suppresses acid diffusion, resulting in good stability of the resist film over time and preventing degradation of resolution and pattern shape.

[0237] Examples of the repeating unit C5 include, but are not limited to, those shown below. D is the same as above. [ka]

[0238] [ka]

[0239] In formula (C6), Z 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.

[0240] In formula (C6), 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.

[0241] Examples of the repeating unit C6 include, but are not limited to, those shown below. D is the same as above. [ka]

[0242] [ka]

[0243] [ka]

[0244] [ka]

[0245] The content of repeating units C1 to C4 in all repeating units of the fluorine atom-containing polymer is preferably 15 to 95 mol %, more preferably 20 to 85 mol %. The content of repeating units C5 and / or C6 in all repeating units of the fluorine atom-containing polymer is preferably 5 to 85 mol %, more preferably 15 to 80 mol %. The repeating units C1 to C6 may be used alone or in combination of two or more.

[0246] The 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 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.

[0247] The fluorine atom-containing polymer can be synthesized by copolymerizing each monomer, optionally protected with a protecting group, according to a known method, followed by a deprotection reaction as needed. The copolymerization reaction is not particularly limited, but is preferably radical polymerization or anionic polymerization. For these methods, reference can be made to JP 2004-115630 A.

[0248] The Mw of the fluorine atom-containing polymer is preferably 2000 to 50000, more preferably 3000 to 20000. If the Mw is less than 2000, 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 the solvent decreases, which may cause coating defects. Furthermore, the fluorine atom-containing polymer preferably has an Mw / Mn ratio of 1.0 to 2.2, more preferably 1.0 to 1.7.

[0249] When the chemically amplified negative resist composition of the present invention contains (C) 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 (A) base polymer. The (C) fluorine atom-containing polymer may be used alone or in combination of two or more types.

[0250] [(D) Quencher] The chemically amplified negative resist composition of the present invention preferably contains a quencher as component (D). In this invention, a quencher is a material that traps the acid generated by the photoacid generator in the chemically amplified resist composition, preventing it from diffusing to unexposed areas and allowing the desired pattern to be formed.

[0251] Examples of the quencher include conventional basic compounds. Examples of conventional basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having a carboxy group, nitrogen-containing compounds having a sulfonyl group, nitrogen-containing compounds having a hydroxy group, nitrogen-containing compounds having a hydroxyphenyl group, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

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

[0252] Further, examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of carboxylic acids not fluorinated at the α-position, as described in JP-A-2008-158339. Sulfonic acids, imide acids, or methide acids fluorinated at the α-position are necessary for deprotecting acid labile groups, and salt exchange with onium salts not fluorinated at the α-position releases carboxylic acids not fluorinated at the α-position. Carboxylic acids not fluorinated at the α-position hardly undergo deprotection reactions, and therefore function as quenchers.

[0253] Examples of onium salts of carboxylic acids that are not fluorinated at the α-position include those represented by the following formula (D1). [ka]

[0254] In formula (D1), R 201 represents a hydrocarbyl group having 1 to 40 carbon atoms which may contain a hydrogen atom or a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the carboxy group is substituted with a fluorine atom or a fluoroalkyl group.

[0255] R 201 The hydrocarbyl group represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, and tricyclo[5.2.1.0]. 2,6 ]Cyclic saturated hydrocarbyl groups having 3 to 40 carbon atoms such as a decyl group, an adamantyl group, and an adamantylmethyl group; alkenyl groups having 2 to 40 carbon atoms such as a vinyl group, an allyl group, a propenyl group, a butenyl group, and a hexenyl group; cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 40 carbon atoms such as a cyclohexenyl group; phenyl group, naphthyl group, alkylphenyl groups (2-methylphenyl group, 3-methylphenyl group, 4-methylphenyl group, 4-ethylphenyl group, 4-tert aryl groups having 6 to 40 carbon atoms such as aryl groups having 6 to 40 carbon atoms (e.g., 4-n-butylphenyl group, 4-n-butylphenyl group), dialkylphenyl 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.

[0256] 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.

[0257] In formula (D1), 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 the sulfonium cation represented by formula (cation-1). Specific examples of the iodonium cation include those exemplified as the iodonium cation represented by formula (cation-2).

[0258] Examples of the anion of the onium salt represented by formula (D1) include, but are not limited to, those shown below. [ka]

[0259] [ka]

[0260] [ka]

[0261] As the quencher, a sulfonium salt of an iodinated benzene ring-containing carboxylic acid represented by the following formula (D2) can also be suitably used. [ka]

[0262] In formula (D2), s is 1, 2, 3, 4, or 5. t is 0, 1, 2, or 3, provided that 1≦s+t≦5. u is 1, 2, or 3.

[0263] In formula (D2), R 211 is a hydroxy group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, a saturated hydrocarbylsulfonyloxy group having 1 to 4 carbon atoms, -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B and some or all of the hydrogen atoms of the saturated hydrocarbyl group, saturated hydrocarbyloxy group, saturated hydrocarbylcarbonyloxy group or saturated hydrocarbylsulfonyloxy group may be substituted with halogen atoms. 211A is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 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.

[0264] In formula (D2), L 1 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.

[0265] In formula (D2), 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.

[0266] Specific examples of the compound represented by formula (D2) include those described in JP 2017-219836 A. The compound represented by formula (D2) has high absorption, a high sensitizing effect, and a high acid diffusion control effect.

[0267] As the quencher, a nitrogen atom-containing carboxylate compound represented by the following formula (D3) can also be used. [ka]

[0268] In formula (D3), R 221 ~R 224 are each independently a hydrogen atom, -L 2 -CO2 - or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hetero atom. 221 and R 222 and R 222 and R 223 and, or R 223 and R 224 and may be bonded to each other to form a ring together with the carbon atoms to which they are attached. 2 R is a single bond or a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom. 225 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a hydrogen atom or a heteroatom.

[0269] In formula (D3), 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 2 -CO2 - and a portion of -CH2- in the ring may be substituted with a sulfur atom, an oxygen atom, or a nitrogen atom. The ring may be an alicyclic ring or an aromatic ring, and is preferably a 5- or 6-membered ring, specific examples of which include a pyridine ring, a pyrrole ring, a pyrrolidine ring, a piperidine ring, a pyrazole ring, an imidazoline ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, an imidazoline ring, an oxazole ring, a thiazole ring, a morpholine ring, a thiazine ring, and a triazole ring.

[0270] The onium carboxylic acid salt represented by formula (D3) has at least one -L 2 -CO2 - group, i.e., R 221 ~R 224 At least one of the -L 2 -CO2 - and / or at least one of the hydrogen atoms bonded to the carbon atom of the ring R is -L 2 -CO2 - is replaced by

[0271] In formula (D3), Mq B + is a sulfonium cation, an iodonium cation, or an ammonium cation, and is preferably a sulfonium cation. Specific examples of the sulfonium cation include the same as those exemplified as the sulfonium cation represented by formula (cation-1).

[0272] Examples of the anion of the compound represented by formula (D3) include, but are not limited to, those shown below. [ka]

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] [ka]

[0277] [ka]

[0278] 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]

[0279] Further examples of the quencher include the polymer-type quencher described in JP 2008-239918 A. This quencher enhances the rectangularity of the resist pattern by orienting on the surface of the resist film. The polymer-type quencher also has the effect of preventing pattern film loss and pattern top rounding when a protective film for immersion lithography is applied.

[0280] When the chemically amplified negative resist composition of the present invention contains a quencher (D), the content thereof is preferably 0 to 50 parts by mass, and more preferably 0.1 to 40 parts by mass, relative to 80 parts by mass of the base polymer (A). The quenchers (D) may be used singly or in combination of two or more.

[0281] When the chemically amplified negative resist composition of the present invention contains a photoacid generator, component (F), and a quencher, component (D), which will be described later, the content ratio of the photoacid generator to the quencher ((F) / (E)) is preferably less than 6 by mass, more preferably less than 5, and even more preferably less than 4. When the content ratio of the photoacid generator to the quencher contained in the chemically amplified negative resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0282] [(E) Organic solvent] The chemically amplified negative resist composition of the present invention may contain an organic solvent as component (E). 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.

[0283] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixed solvents thereof are preferred.

[0284] When the chemically amplified negative resist composition of the present invention contains an organic solvent (E), the content thereof is preferably 200 to 10,000 parts by mass, and more preferably 400 to 6,000 parts by mass, relative to 80 parts by mass of the base polymer (A). The organic solvent (E) may be used alone or in combination of two or more.

[0285] [(F) Photoacid generator] The chemically amplified positive resist composition of the present invention may contain a photoacid generator as component (F). There are no particular limitations 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.

[0286] Specific examples of the photoacid generator include nonafluorobutanesulfonate, the partially fluorinated sulfonates described in paragraphs

[0247] to

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

[0261] to

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

[0122] to

[0142] of JP 2008-111103 A and paragraphs

[0080] to

[0081] of JP 2010-215608 A. Among the specific examples, arenesulfonate- or alkanesulfonate-type photoacid generators are preferred because they generate an acid of appropriate strength for deprotecting the acid labile group in the repeating unit A3.

[0287] As such a photoacid generator, a salt compound containing the anion shown below is preferred. [ka]

[0288] [ka]

[0289] [ka]

[0290] [ka]

[0291] [ka]

[0292]

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[0293]

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[0294]

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[0295]

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[0296]

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[0297]

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[0298]

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[0299]

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[0300]

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[0301]

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[0302]

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[0303]

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[0304]

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[0305]

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[0306]

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[0307]

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[0308]

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[0309]

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[0310]

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[0311]

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[0312]

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[0313]

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[0314]

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[0315]

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[0316]

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[0317]

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[0318]

change

[0319]

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[0320]

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[0321]

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[0322]

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[0323]

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[0324]

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[0325]

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[0326]

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[0327]

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[0328]

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[0329]

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[0330]

change

[0331]

change

[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]

change

[0338]

change

[0339]

change

[0340]

change

[0341]

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[0342]

change

[0343]

change

[0344]

change

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] Furthermore, as the photoacid generator, a salt compound containing an anion represented by the following formula (F1) is also preferred. [ka]

[0349] In formula (F1), m1 is 0 or 1. p is 1, 2, or 3. q is 1, 2, 3, 4, or 5. r is 0, 1, 2, or 3, provided that 1≦q+r≦5.

[0350] In formula (F1), L 11 is a single bond, an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond.

[0351] In formula (F1), L 12 is an ether bond, an ester bond, a sulfonate ester bond, a carbonate bond or a carbamate bond.

[0352] In formula (F1), L Crepresents a single bond or a hydrocarbylene group having 1 to 20 carbon atoms when p is 1, and represents a (p+1)-valent hydrocarbon group having 1 to 20 carbon atoms when p is 2 or 3, and the hydrocarbylene group and the (p+1)-valent hydrocarbon group may contain at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxy group, and a carboxy group.

[0353] L C The hydrocarbylene group having 1 to 20 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include a methanediyl group, an ethane-1,1-diyl group, an ethane-1,2-diyl group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, a heptane-1,7-diyl group, an octane-1,8-diyl group, a nonane-1,9-diyl group, a decane-1,10-diyl group, an undecane-1,11-diyl group, and a dodecane-1,12-diyl group. alkanediyl groups having 1 to 20 carbon atoms; cyclic saturated hydrocarbylene groups having 3 to 20 carbon atoms such as cyclopentanediyl group, cyclohexanediyl group, norbornanediyl group, and adamantanediyl group; unsaturated aliphatic hydrocarbylene groups having 2 to 20 carbon atoms such as vinylene group and propene-1,3-diyl group; arylene groups having 6 to 20 carbon atoms such as phenylene group and naphthylene group; and groups obtained by combining these. C The (p+1)-valent hydrocarbon group having 1 to 20 carbon atoms, represented by the formula (1), may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include groups obtained by further removing one or two hydrogen atoms from the specific examples of the hydrocarbylene group having 1 to 20 carbon atoms described above.

[0354] In formula (F1), Rf 1 and Rf 2 are each independently a hydrogen atom, a fluorine atom, or a trifluoromethyl group, provided that at least one is a fluorine atom or a trifluoromethyl group.

[0355] In formula (F1), R301 is a hydroxy group, a carboxy group, a saturated hydrocarbyl group having 1 to 6 carbon atoms, a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, a saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms, a fluorine atom, a chlorine atom, a bromine atom, -N(R 301A )(R 301B ), -N(R 301C )-C(=O)-R 301D or -N(R 301C )-C(=O)-OR 301D R 301A and R 301B are each independently a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301C is a hydrogen atom or a saturated hydrocarbyl group having 1 to 6 carbon atoms. 301D is a saturated hydrocarbyl group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms.

[0356] R 301 , R 301A , R 301B and R 301C The saturated hydrocarbyl group having 1 to 6 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkyl groups having 1 to 6 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, and n-hexyl groups; and cyclic saturated hydrocarbyl groups having 3 to 6 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups. 301 Examples of the saturated hydrocarbyl moiety of the saturated hydrocarbyloxy group having 1 to 6 carbon atoms and represented by the formula (I) include the same as the specific examples of the saturated hydrocarbyl group described above, and R 301 Examples of the saturated hydrocarbyl moiety of the saturated hydrocarbylcarbonyloxy group having 2 to 6 carbon atoms represented by the formula include those having 1 to 5 carbon atoms among the specific examples of the saturated hydrocarbyl groups having 1 to 6 carbon atoms mentioned above.

[0357] R 301DThe unsaturated aliphatic hydrocarbyl group having 2 to 8 carbon atoms represented by the formula (I) may be linear, branched, or cyclic, and specific examples thereof include alkenyl groups having 2 to 8 carbon atoms such as vinyl, propenyl, butenyl, and hexenyl groups; alkynyl groups having 2 to 8 carbon atoms such as ethynyl, propynyl, and butynyl groups; and cyclic unsaturated aliphatic hydrocarbyl groups having 3 to 8 carbon atoms such as cyclohexenyl and norbornenyl groups.

[0358] In formula (F1), R 302 represents a saturated hydrocarbylene group having 1 to 20 carbon atoms or an arylene group having 6 to 20 carbon atoms, and some or all of the hydrogen atoms of the saturated hydrocarbylene group may be substituted with halogen atoms other than fluorine atoms, or some or all of the hydrogen atoms of the arylene group may be substituted with a substituent selected from a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, a halogen atom, and a hydroxy group.

[0359] R 302 The hydrocarbylene group having 1 to 20 carbon atoms represented by the formula (I) may be saturated or unsaturated, and may be linear, branched, or cyclic. C Examples of the hydrocarbylene group having 1 to 20 carbon atoms represented by the following formula include the same as those exemplified above.

[0360] R 302Specific examples of the arylene group having 6 to 20 carbon atoms represented by the formula (I) include a phenylene group, a naphthylene group, a phenanthrenediyl group, and an anthracenediyl group. The hydrocarbyl moiety of the saturated hydrocarbyl group having 1 to 20 carbon atoms and the hydrocarbyloxy group having 1 to 20 carbon atoms, which are substituents on the arylene group, may be linear, branched, or cyclic, and specific examples thereof include alkyl groups having 1 to 20 carbon atoms, such as a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, n-octyl group, n-nonyl group, n-decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, heptadecyl group, octadecyl group, nonadecyl group, and icosyl group; and cyclic saturated hydrocarbyl groups having 3 to 20 carbon atoms, such as a cyclopropyl group, cyclopentyl group, cyclohexyl group, cyclopropylmethyl group, 4-methylcyclohexyl group, cyclohexylmethyl group, norbornyl group, and adamantyl group. Specific examples of the arylene group having 6 to 14 carbon atoms that is the substituent of the arylene group include a phenylene group, a naphthylene group, a phenanthrenediyl group, and an anthracenediyl group.

[0361] The anion represented by formula (F1) is preferably an anion represented by the following formula (F2). [ka]

[0362] In formula (F2), p, q, r, L 11 , L C and R 301 is the same as above. m2 is 1, 2, 3 or 4. R 302A is a saturated hydrocarbyl group having 1 to 20 carbon atoms, a saturated hydrocarbyloxy group having 1 to 20 carbon atoms, an aryl group having 6 to 14 carbon atoms, a halogen atom, or a hydroxy group. When m2 is 2, 3, or 4, each R 302A may be the same as or different from each other.

[0363] Specific examples of the anion represented by formula (F1) include, but are not limited to, those shown below. [ka]

[0364] [ka]

[0365] [ka]

[0366] [ka]

[0367] [ka]

[0368] [ka]

[0369] [ka]

[0370] [ka]

[0371] [ka]

[0372] [ka]

[0373]

change

[0374]

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[0375]

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[0376]

change

[0377]

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[0378]

change

[0379]

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[0380]

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[0381]

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[0382]

change

[0383]

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[0384]

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[0385]

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[0386]

change

[0387]

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[0388]

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[0389]

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[0390]

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[0391]

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[0392]

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[0393]

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[0394]

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[0395] [ka]

[0396] [ka]

[0397] [ka]

[0398] [ka]

[0399] [ka]

[0400] In the photoacid generator (F), the cation paired with the anion is preferably a sulfonium cation or an iodonium cation. Specific examples of the sulfonium cation include, but are not limited to, the same as those exemplified as the sulfonium cation represented by formula (cation-1). Specific examples of the iodonium cation include, but are not limited to, the same as those exemplified as the sulfonium cation represented by formula (cation-2).

[0401] The acid generated by the photoacid generator preferably has a pKa of -2.0 or higher, more preferably -1.0 or higher. The upper limit of the pKa is preferably 2.0. The pKa value was calculated using the pKa DB in the software ACD / Chemsketch ver. 9.04 manufactured by Advanced Chemistry Development, Inc.

[0402] When the chemically amplified positive resist composition of the present invention contains a photoacid generator (F), the content thereof is preferably 1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 80 parts by mass of the base polymer. By including the photoacid generator (F), it is possible to appropriately adjust the amount of acid generated in the exposed area and the dissolution inhibition ability of the unexposed area. The photoacid generator (F) may be used alone or in combination of two or more types.

[0403] [(G) Surfactant] The chemically amplified negative resist composition of the present invention may contain a commonly used surfactant to improve its coatability onto a substrate. 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 surfactants can be used in conjunction with other known surfactants. When the chemically amplified negative resist composition of the present invention contains a surfactant (G), the content of the surfactant is preferably 0 to 5 parts by mass relative to 80 parts by mass of the base polymer (B). The surfactant (G) may be used alone or in combination of two or more types.

[0404] [Method for forming resist pattern] The method for forming a resist pattern of the present invention includes the steps of: forming a resist film on a substrate using the aforementioned chemically amplified negative resist composition; irradiating the resist film with a pattern using high-energy rays (i.e., exposing the resist film using high-energy rays); and developing the resist film irradiated with the pattern using an alkaline developer.

[0405] 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.

[0406] Next, the resist film is exposed to high-energy rays to irradiate a pattern. Examples of the high-energy rays include ultraviolet rays, far ultraviolet rays, excimer laser light (KrF, ArF, etc.), EUV rays with a wavelength of 3 to 15 nm, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, exposure using EUV or EB is preferred.

[0407] When ultraviolet rays, far ultraviolet rays, excimer laser light, EUV, X-rays, gamma rays, or synchrotron radiation is used as the high-energy rays, a mask for forming a desired pattern is used, and the exposure dose is preferably 1 to 500 mJ / cm. 2 , more preferably 10 to 400 mJ / cm 2 When EB is used, the exposure dose is preferably 1 to 500 μC / cm 2 directly to form the desired pattern. 2 , more preferably 10 to 400 μC / cm 2 Irradiate so that

[0408] 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.

[0409] 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.

[0410] 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.

[0411] 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.

[0412] 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.

[0413] 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.

[0414] 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.

[0415] 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.

[0416] 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.

[0417] According to the method for forming a resist pattern of the present invention, even when a substrate (for example, a transmission type or a reflection type mask blank) is used whose outermost surface is made of a material that is likely to affect the shape of the resist pattern, such as a material containing chromium, silicon, or tantalum, it is possible to obtain a pattern that has extremely high resolution, small LER, excellent rectangularity, and excellent pattern fidelity. [Example]

[0418] The present invention will be specifically explained below by showing synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples.

[0419] [1] Synthesis of base polymer [Synthesis Example 1-1] Synthesis of base polymer P-1 A monomer-polymerization initiator solution was prepared by placing 69.4 g of 3-hydroxystyrene, 10.4 g of 4-chlorostyrene, 20.2 g of PM-1, 12.7 g of V-601 (Fujifilm Wako Pure Chemical Industries, Ltd.), and 120 g of PGME in a flask under a nitrogen atmosphere. 60 g of PGME was placed in a separate flask under a nitrogen atmosphere and heated to 80°C with stirring. The monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition, the polymerization solution was stirred for 18 hours while maintaining the temperature at 80°C, and then cooled to room temperature. The resulting polymerization solution was added dropwise to 5,000 g of a stirred methanol and water mixture (methanol:water = 1:9), and the precipitated polymer was filtered off. The resulting polymer was washed twice with 1,000 g of a methanol and water mixture (methanol:water = 1:9) and then vacuum-dried at 40°C for 20 hours to obtain 85.4 g of white powdery polymer P-1. Polymer P-1 13 C-NMR, 1 Measurements by H-NMR and GPC gave the following analytical results. Note that Mw is a polystyrene-equivalent measurement value obtained by GPC using DMF as a solvent. [ka]

[0420] [Synthesis Examples 1-2 to 1-40, Synthesis Examples 2-1 to 2-7] Synthesis of base polymers P-2 to P-40 and base polymers AP-1 to AP-7 Base polymers P-2 to P-40 and AP-1 to AP-7 shown in Tables 1 to 3 were synthesized in the same manner as in Example 1-1, except that the type and compounding ratio of each monomer was changed. In Tables 1 to 3, the introduction ratio indicates the molar ratio.

[0421] [Table 1]

[0422] [Table 2]

[0423] [Table 3]

[0424] The structure of the repeating unit introduced into the polymer is shown below. [ka]

[0425] [ka]

[0426] [ka]

[0427] [ka]

[0428] [ka]

[0429] [ka]

[0430] The dissolution rates of the polymers in alkaline developers were calculated by spin-coating a polymer solution (polymer concentration: 12.0% by mass, solvent: PGME) onto an 8-inch silicon wafer, baking it at 150°C for 90 seconds to form a film with a thickness of 2000 nm, developing it in a 2.38% by mass aqueous TMAH solution at 23°C for 10 seconds, and measuring the amount of film loss. As a result, the dissolution rates of polymers P-1 to P-40 and AP-1 to AP-7 were 20 nm / sec or less.

[0431] [Comparative Synthesis Examples 1-1 to 1-4] Synthesis of polymers cP-1 to cP-4 Polymers cP-1 to cP-4 shown below were synthesized in the same manner as in Synthesis Example 1-1, except that the raw material compounds used were changed. [ka]

[0432] The dissolution rates of the comparative polymers cP-1 to cP-4 were 20 nm / sec or less.

[0433] [2] Preparation of chemically amplified negative resist composition [Examples 1-1 to 1-76, Comparative Examples 1-1 to 1-7] Chemically amplified negative resist compositions were prepared by dissolving each component in an organic solvent according to the formulations shown in Tables 4 to 7 below, and filtering the resulting solution through a 5 nm nylon filter and a sub-1 nm UPE filter. The organic solvent was a mixed solvent of 920 parts by weight of PGMEA, 1850 parts by weight of EL, and 1850 parts by weight of PGME. In Tables 4 to 7, the crosslinker TMGU is tetramethoxymethylglycoluril, and PF-636 is the surfactant PolyFox PF-636 manufactured by OMNOVA SOLUTIONS.

[0434] [Table 4]

[0435] [Table 5]

[0436] [Table 6]

[0437] [Table 7]

[0438] In Tables 4 to 7, the structures of quenchers Q-1 to Q-6, photoacid generators PAG-A to PAG-I, and polymers FP-1 to FP-5 are as follows: [ka]

[0439] [ka]

[0440] [ka]

[0441] [3] EB lithography evaluation [Examples 2-1 to 2-76, Comparative Examples 2-1 to 2-7] Each chemically amplified negative resist composition (R-1 to R-76 and CR-1 to CR-7) was spin-coated using ACT-M (Tokyo Electron Ltd.) onto a 152 mm square reflective mask blank for EUV exposure masks, the outermost surface of which was a chromium compound, and the resulting mask was 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 resulting resist film was measured using an optical measuring device, Nanospec (Nanometrics). Measurements were taken at 81 locations on the surface of the blank substrate, excluding the outer edge portion extending 10 mm inward from the outer periphery of the blank, and the average film thickness and film thickness range were calculated.

[0442] The film was then exposed using an electron beam exposure system (EBM-5000plus manufactured by NuFlare Technology, Inc., accelerating voltage 50 kV), subjected to PEB at 110°C for 600 seconds, and developed with a 2.38% by mass TMAH aqueous solution to obtain a negative pattern.

[0443] 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 minimum dimension at the exposure dose required to resolve a 200 nm LS at a 1:1 ratio was defined as the LS resolution (limiting resolution), and the minimum dimension at the exposure dose required to resolve a 200 nm square line width as a square was defined as the dot resolution (limiting resolution). The LER at 200 nm LS was measured using an SEM. The pattern shape was visually determined to be rectangular or not. The evaluation results for each resist composition are shown in Tables 8 to 11.

[0444] [Table 8]

[0445] [Table 9]

[0446] [Table 10]

[0447] [Table 11]

[0448] [4] Etching resistance evaluation [Examples 3-1 to 3-2, Comparative Examples 3-1 to 3-3] Each chemically amplified negative resist composition (R-34, R-49, CR-4, CR-5, and CR-6) was spin-coated onto a 152 mm square photomask blank with a chrome outermost surface using ACT-M (Tokyo Electron Limited). The blank was then pre-baked on a hot plate at 110°C for 600 seconds to produce a 120 nm thick resist film. The thickness of the resulting resist film was measured using an optical measuring device, Nanospec (Nanometrics). Measurements were performed at 81 locations on the blank substrate, excluding the outer edge extending 10 mm inward from the outer periphery, and the average film thickness and film thickness range were calculated. The resulting coated substrate was dry-etched using a dry etching apparatus (UNAXIS G4) under the following conditions, and the film loss rate (A / sec) was calculated from the remaining film after etching. The results are shown in Table 12.

[0449] RF1(RIE): Pulse 700V RF2 (ICP): CW 400W Pressure: 6mTorr Cl2: 185sccm O2: 55sccm He: 9.25 sccm Etching time: 75 seconds

[0450] [Table 12]

[0451] All of the chemically amplified negative resist compositions (R-1 to R-76) of the present invention exhibited good resolution, LER, and pattern rectangularity. On the other hand, among the comparative resist compositions (CR-1 to CR-6), CR-2 and CR-3 had low solubility in resist solvents, making it impossible to prepare the resist composition itself. CR-1, CR-4, and CR-5 exhibited insufficient optimization of acid diffusion, resulting in degradation of resolution, LER, and pattern rectangularity. Furthermore, dry etching evaluation using R-34 and R-49 also showed better etching resistance than CR-4, CR-5, and CR-6, suggesting that the inclusion of the repeating unit A1 in the polymer is effective in mask processing.

[0452] [5] Evaluation of development residue [Examples 4-1 to 4-20, Comparative Examples 4-1 to 4-4] Each chemically amplified negative resist composition (R-4, R-9, R-14, R-19 to R-33, R-49, R-71, CR-1, CR-4, CR-5, and CR-7) was spin-coated onto a 152 mm square reflective mask blank for EUV exposure masks, whose outermost surface was a chromium compound, using ACT-M (Tokyo Electron Limited). The resulting resist was pre-baked on a hot plate at 110°C for 600 seconds to produce an 80 nm thick resist film. The thickness of the resulting resist film was measured using an optical measuring device, Nanospec (Nanometrics). Measurements were performed at 81 locations on the blank substrate surface, excluding the outer edge extending 10 mm inward from the outer periphery, and the average thickness and thickness range were calculated.

[0453] Each resist film was baked at 120°C for 600 seconds without any patterning, and then developed in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide. The development residue was then evaluated using a mask defect inspection system (M9650 manufactured by Lasertec Corporation). The total number of defects after development is shown in Table 13.

[0454] [Table 13]

[0455] As is clear from the results shown in Table 13, the polymer containing the repeating unit A1 can significantly reduce the number of defects caused by development residues compared to conventional negative resist compositions.

[0456] The method of forming a resist pattern using the chemically amplified negative resist composition of the present invention is useful in the production of semiconductor devices, particularly in photolithography in the processing of transmission and reflection photomask blanks.

Claims

1. (A) A chemically amplified negative resist composition comprising a base polymer containing a polymer that includes a repeating unit represented by the following formula (A1) and a repeating unit represented by the following formula (A2), and whose solubility in an alkaline aqueous solution decreases due to the action of an acid. 【Chemistry 1】 (In the formula, n1 is 0 or 1. n2 is 0 or 1. n3 is 0, 1, 2, 3, or 4. n4 is 0, 1, 2, 3, or 4. n5 is 0, 1, 2, 3, or 4. However, when n2 is 0, 0≦n4+n5≦4, and when n2 is 1, 0≦n4+n5≦6. Furthermore, n1 to n5 cannot all be 0. R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 1 is a halogen atom, a nitro group, a cyano group, or a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. 1 may be the same or different, and multiple R 1 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R 2 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a heteroatom. When n4 is 2 or more, each R 2 may be the same or different, and multiple R 2 may be bonded to each other to form a ring together with the carbon atoms to which they are attached. R F is a fluorine atom, a fluorinated alkyl group having 1 to 6 carbon atoms, a fluorinated alkoxy group having 1 to 6 carbon atoms, or a fluorinated alkylthio group having 1 to 6 carbon atoms. When n5 is 2 or more, each R F may be the same as or different from each other. L A and L B are each independently a single bond, an ether bond, an ester bond, a sulfonate ester bond, a sulfonate amide bond, a carbonate bond or a carbamate bond. X L is a hydrocarbylene group having 1 to 40 carbon atoms which may contain a heteroatom. Z + is an onium cation. 【Chemistry 2】 (In the formula, a1 is 0 or 1. a2 is 0, 1, or 2. a3 is an integer that satisfies 0≦a3≦5+2(a2)−a4. a4 is 1, 2, or 3. R A is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 11 is a halogen atom, 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. 11 may be the same as or different from each other. A 1 is a single bond or a saturated hydrocarbylene group having 1 to 10 carbon atoms, and the —CH 2 A part of - may be replaced by -O-.)

2. 2. The chemically amplified negative resist composition according to claim 1, wherein the repeating unit represented by formula (A1) is represented by the following formula (A1-1): 【Transformation 3】 (In the formula, n2 to n5, R A , R 1 , R 2 , R F , L A , L B , X L and Z + is the same as above.)

3. 3. The chemically amplified negative resist composition according to claim 2, wherein the repeating unit represented by formula (A1-1) is a repeating unit represented by the following formula (A1-2): 【Chemistry 4】 (In the formula, n2 to n5, R A , R 1 , R 2 , R F , L A and Z + is the same as above.)

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

5. 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 (A3) and a repeating unit represented by the following formula (A4): 【Transformation 6】 (In the formula, b1 is 0 or 1. b2 is 0, 1, or 2. b3 is an integer that satisfies 0≦b3≦5+2(b2)−b4. b4 is 1, 2, or 3. b5 is 0, 1, or 2. b6 is 1 or 2. R A are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R 21 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 21 may be the same as or different from each other. R 22 and R 23 are each independently a hydrogen atom, a saturated hydrocarbyl group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, the hydrocarbyl group may be substituted with a hydroxy group or a saturated hydrocarbyloxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 22 and R 23 cannot be a hydrogen atom at the same time. 22 and R 23 may be bonded to each other to form a ring together with the carbon atoms to which they are attached, and the —CH 2 A part of - may be substituted with -O- or -S-. R 24 is a hydrocarbyl group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom. 24 may be the same as or different from each other. R 25 and R 26 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. 25 and R 26 cannot be a hydrogen atom at the same time. 25 and R 26 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.

6. 2. The chemically amplified negative resist composition according to claim 1, wherein the polymer further comprises at least one repeating unit selected from the group consisting of a repeating unit represented by the following formula (A5), a repeating unit represented by the following formula (A6), and a repeating unit represented by the following formula (A7): 【Transformation 7】 (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 31 and R 32 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. 31 may be the same or different. When d is 2 or more, each R 32 may be the same as or different from each other. R 33 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. 33 may be the same as or different from each other. 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-.)

7. 6. The chemically amplified negative resist composition according to claim 5, wherein the polymer comprises a repeating unit represented by formula (A1), a repeating unit represented by the following formula (A2-1), and a repeating unit represented by the following formula (A3-1), (A3-2), or (A4-1): 【Transformation 8】 (In the formula, a4, b4, b6, R A , R 22 , R 23 , R 25 and R 26 is the same as above.)

8. 6. The chemically amplified negative resist composition according to claim 5, wherein the base polymer (A) further comprises a polymer containing a repeating unit represented by formula (A2) and a repeating unit represented by the following formula (A3) or (A4), but not containing a repeating unit represented by formula (A1):

9. 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.

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

11. 6. The chemically amplified negative resist composition according to claim 5, which does not contain a crosslinking agent.

12. 2. The chemically amplified negative resist composition according to claim 1, further comprising (C) a fluorine atom-containing polymer that contains at least one selected from the group consisting of a repeating unit represented by the following formula (C1), a repeating unit represented by the following formula (C2), a repeating unit represented by the following formula (C3), and a repeating unit represented by the following formula (C4), and that may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (C5) and a repeating unit represented by the following formula (C6): 【Chemistry 9】 (In the formula, x is 1, 2, or 3. y is an integer satisfying 0≦y≦5+2z−x. z is 0 or 1. g is 1, 2, or 3. R C are each independently a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R D 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 heteroatom-containing group interposed between its carbon-carbon bonds. When x is 2 or more, each R 109 may be the same as or different from each other. 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. When y is 2 or more, each R 110 may be the same as or different from each other. 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. Z 1 is a (g+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (g+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. Z 2 is a single bond, *-C(=O)-O-, or *-C(=O)-NH-. * is a bond to a carbon atom in the main chain. Z 3 is a single bond, -O-, *-C(=O)-O-Z 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 - is. Z 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. * indicates a bond to a carbon atom in the main chain.)

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

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

15. 2. The chemically amplified negative resist composition according to claim 1, further comprising (F) a photoacid generator.

16. 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 claims 1 to 15; irradiating the resist film with a pattern using high-energy rays; and developing the resist film that has been irradiated with the pattern using an alkaline developer.

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

18. 17. The method for forming a resist pattern according to claim 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.

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

20. A transmission or reflection mask blank coated with the chemically amplified negative resist composition according to any one of claims 1 to 15.

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