Chemically amplified negative resist composition and resist pattern forming method

Abstract

The invention relates to a chemically amplified negative resist composition and a resist pattern forming method. The present invention addresses the problem of providing: a chemically amplified negative resist composition which is capable of improving resolution during pattern formation and which is capable of obtaining a resist pattern having excellent LER and pattern loyalty; and a method for forming a resist pattern. A chemically amplified negative resist composition containing (A) a photoacid generator comprising an onium salt represented by the following formula (A), and (B) a base polymer comprising a polymer containing a repeating unit represented by the following formula (B1). In the # imgabs0 # formula, one of R13 and R14 is a group having a partial structure represented by formula (a). # imgabs1 #

Description

Technical Field

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

[0002] In recent years, with the increasing integration and speed of LSIs, the miniaturization of pattern patterns has also progressed rapidly. For processing patterns smaller than 0.2μm, chemically amplified resist compositions, primarily using acid as a catalyst, are used. Furthermore, high-energy radiation such as ultraviolet (UV), extreme UV, and electron beam (EB) is used as an exposure source. EB lithography, an ultra-fine processing technology, has become indispensable for processing photomask blanks used in semiconductor manufacturing.

[0003] Polymers containing a large number of aromatic backbones with acidic side chains, such as polyhydroxystyrene, are useful as materials for resist compositions for KrF lithography using KrF excimer lasers. However, due to their significant absorption of light with a wavelength near 200 nm, they have not been used as materials for resist compositions for ArF lithography using ArF excimer lasers. However, they have become important materials for resist compositions for EB lithography and extreme ultraviolet (EUV) lithography, which are powerful technologies for forming patterns with processing limits lower than those achieved with ArF excimer lasers, due to their ability to achieve high etching resistance.

[0004] In the processing of photomask blanks, some have surface materials that can easily affect the pattern shape of chemically amplified resist films, such as chromium compounds, typically chromium oxide, formed on the photomask substrate. Therefore, maintaining a rectangular pattern profile on the resist film, regardless of the substrate type, is crucial for maintaining high resolution and a high post-etching shape. Furthermore, in recent years, MBMW (Multi-Beam Mask Writing) processes have been used in the processing of photomask blanks to achieve miniaturization. In these processes, low-sensitivity resist compositions (high-dose regions) are used as resist compositions, which are beneficial for roughness. Optimization of the resist composition in these high-dose regions has also attracted attention.

[0005] Resist compositions used in optical lithography come in two types: positive-type, which dissolves the exposed areas to form a pattern, and negative-type, which leaves the exposed areas exposed to form a pattern. The choice of resist is based on the desired resist pattern form. Chemically amplified negative-type resist compositions typically contain a polymer that dissolves in an aqueous alkaline developer, an acid generator that decomposes upon exposure to light to generate acid, and a crosslinker (sometimes the polymer and crosslinker are integrated) that uses the acid as a catalyst to form crosslinks between the polymers, rendering them insoluble in the developer. A quencher is also often added to control the diffusion of the acid generated by exposure.

[0006] The alkali-soluble units constituting the aforementioned polymer that dissolves in an aqueous alkaline developer include units derived from phenols. Previously, many such negative-working resist compositions have been developed, particularly for use with KrF excimer lasers. However, these compositions are not suitable for use with ArF excimer lasers because the phenol-derived units lack optical transparency when the exposure light has a wavelength of 150 to 220 nm. However, in recent years, negative-working resist compositions for use with short-wavelength exposure light, such as EB and EUV, have again attracted attention as exposure methods for obtaining finer patterns, as reported in Patent Documents 1, 2, and 3.

[0007] Furthermore, as one of the acid generators, there is a sulfonium salt described in Patent Document 4 that generates a sulfonic acid having an aromatic group containing an iodine atom. This salt is focused on enhancing sensitivity in EUV lithography, and its function is primarily to act as a quencher for fluorinated alkanesulfonic acids. However, there has been no discussion of acid generators used in negative-type resist compositions using polyhydroxystyrene as a base polymer in the EB drawing process used in blank mask processing.

[0008] Furthermore, in optical lithography, various improvements are being made to control sensitivity and pattern profiles by modifying the selection and combination of materials used in resist compositions, as well as processing conditions. One focus of these improvements is the issue of acid diffusion, which significantly affects the resolution of chemically amplified resist compositions.

[0009] Quenchers control acid diffusion and are essential for improving the performance of resist compositions, particularly resolution. Various quenchers have been explored to date, with amines and weak acid onium salts generally used. As an example of a weak acid onium salt, Patent Document 5 describes the addition of triphenylsulfonium acetate to form a good resist pattern without T-top formation, a line width difference between isolated and dense patterns, and standing waves. Patent Document 6 describes the addition of ammonium sulfonate or ammonium carboxylate salts to improve sensitivity, resolution, and exposure latitude. Furthermore, Patent Document 7 describes a resist composition for KrF lithography and EB lithography containing a combination of a photoacid generator that generates a fluorine-containing carboxylic acid, which exhibits excellent resolution and improved process latitudes such as exposure latitude and depth of focus. Furthermore, Patent Document 8 describes a resist composition for F2 lithography using an F2 laser, containing a photoacid generator that generates a fluorine-containing carboxylic acid, which exhibits excellent line edge roughness (LER) and reduced smearing. These are those used in KrF lithography, EB lithography, or F2 lithography.

[0010] Patent Document 9 describes a positive-working photosensitive composition for ArF lithography containing an onium carboxylate salt. These compositions, generated by a strong acid (sulfonic acid) generated from a photoacid generator upon exposure, exchange with a weak acid onium salt to form a weak acid and a strong acid onium salt. This substitution of the highly acidic strong acid (sulfonic acid) for a weak acid (carboxylic acid) suppresses the acid decomposition reaction of the acid-labile group and reduces (controls) the acid diffusion distance, apparently functioning as a quencher.

[0011] However, in recent years, there has been a demand for resist compositions that not only further improve roughness but also improve line and space (LS), isolated line (IL), isolated space (IS), and dot pattern shape. Patent Document 10 discloses a photoacid generator that generates a large volume of acid and suppresses acid diffusion. While this generator can produce patterns with good resolution and roughness, it suffers from the disadvantage of rounded corners in the dot pattern.

[0012] Prior art literature

[0013] Patent Literature

[0014] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-201532

[0015] [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-215180

[0016] [Patent Document 3] Japanese Patent Application Laid-Open No. 2008-249762

[0017] [Patent Document 4] Japanese Patent No. 6645464

[0018] [Patent Document 5] Japanese Patent No. 3955384

[0019] [Patent Document 6] Japanese Patent Application Laid-Open No. 11-327143

[0020] [Patent Document 7] Japanese Patent No. 4231622

[0021] [Patent Document 8] Japanese Patent No. 4116340

[0022] [Patent Document 9] Japanese Patent No. 4226803

[0023] [Patent Document 10] Japanese Patent No. 6248882 Summary of the Invention

[0024] [Problems to be Solved by the Invention]

[0025] The present invention is made in view of the above situation, and an object of the present invention is to provide a chemically amplified negative resist composition and a resist pattern forming method that can improve the resolution during pattern formation and obtain a resist pattern with good LER and pattern fidelity.

[0026] [Methods for solving the problem]

[0027] The inventors of this application have repeatedly conducted in-depth studies to achieve the aforementioned objectives, and as a result, have obtained the following insights, leading to the completion of the present invention: when an onium salt containing a sulfonic acid anion having a substituted ring structure and an aromatic sulfonic acid structure is introduced into a resist composition as an acid generator, the generated acid has an appropriate acidity, and at the same time, due to the bulky anion structure, excessive diffusion of the acid is suppressed, thereby obtaining a pattern with a small LER. In addition, in the halftone dot pattern, due to the appropriate dissolution inhibition, a better rectangular pattern can be obtained.

[0028] That is, the present invention provides the following chemically amplified negative resist composition and resist pattern forming method.

[0029] 1. A chemically amplified negative resist composition comprising:

[0030] (A) a photoacid generator consisting of an onium salt represented by the following formula (A), and

[0031] (B) The base polymer includes a polymer containing a repeating unit represented by the following formula (B1).

[0032] [Chemistry 1]

[0033]

[0034] Where R 1 ~R 12 Each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom.

[0035] R 13 and R 14 One of them is a group having a partial structure represented by the following formula (a), and the other is a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom.

[0036] Again, R 1 ~R 14 At least two of them may be bonded to each other and form a ring together with the carbon atoms to which they are bonded, or form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them.

[0037] Z + Onium cation.

[0038] [Chemistry 2]

[0039]

[0040] In the formula, m1 is 0 or 1. m2 is an integer from 0 to 4 when m1 is 0, and an integer from 0 to 6 when m1 is 1. m3 is an integer from 0 to 3 when m1 is 0, and an integer from 0 to 5 when m1 is 1. However, m2+m3 is 0 to 4 when m1 is 0, and 0 to 6 when m1 is 1.

[0041] R F It 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.

[0042] R 15 is a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and when m3 is 2 or more, multiple R 15 They may also bond to each other and to the carbon atoms to which they are bonded to form a ring.

[0043] L A and L B are each independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond or a carbamate bond.

[0044] X L It is a single bond or a alkylene group having 1 to 40 carbon atoms which may contain a heteroatom.

[0045] [Chemistry 3]

[0046]

[0047] In the formula, a1 is 0 or 1. a2 is 0, 1, or 2. a3 is an integer satisfying 0≤a3≤5+2(a2)-a4. a4 is 1, 2, or 3.

[0048] R Ais a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0049] R 21 It is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom.

[0050] A 1 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0051] 2. The chemically amplified negative resist composition according to 1., wherein the onium salt is represented by the following formula (A1).

[0052] [Chemistry 4]

[0053]

[0054] Where R 1 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + Same as above.

[0055] 3. The chemically amplified negative resist composition according to 2., wherein the onium salt is represented by the following formula (A2).

[0056] [Chemistry 5]

[0057]

[0058] Where R 5 、R 10 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + Same as above.

[0059] m4 and m5 are each independently an integer of 0-4.

[0060] R 16 and R 17 are independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 16 They may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded, or form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them. When m5 is 2 or more, multiple R17 They may also be bonded to each other and to form a ring together with the carbon atoms to which they are bonded, or to form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them.

[0061] 4. The chemically amplified negative resist composition according to any one of 1. to 3., wherein Z + It is a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2).

[0062] [Chemistry 6]

[0063]

[0064] Where R ct1 ~R ct5 are each independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom. ct1 and R ct2 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

[0065] 5. The chemically amplified negative resist composition according to any one of 1. to 4., wherein the polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B2) and a repeating unit represented by the following formula (B3).

[0066] [Chemistry 7]

[0067]

[0068] Wherein, b1 is 0 or 1. b2 is 0, 1, or 2. b3 is an integer satisfying 0 ≤ b3 ≤ 5 + 2(b2) - b4. b4 is 1, 2, or 3. b5 is 0, 1, or 2. b6 is 1 or 2.

[0069] R A are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0070] R 31 It is a hydrocarbon group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom.

[0071] R 32 and R 33 are independently a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbon group may be substituted with a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 32 and R 33 cannot be a hydrogen atom at the same time. 32 and R 33They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- in the ring may be substituted by -O- or -S-.

[0072] R 34 It is a hydrocarbon group having 1 to 20 carbon atoms which may contain a halogen atom or a heteroatom.

[0073] R 35 and R 36 are independently a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbon group may be substituted with a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 35 and R 36 cannot be a hydrogen atom at the same time. 35 and R 36 They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- in the ring may be substituted by -O- or -S-.

[0074] A 2 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0075] W 1 and W 2 Each of them is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aliphatic hydrocarbon carbonyl 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.

[0076] 6. The chemically amplified negative resist composition according to any one of 1. to 5., wherein the polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B4), a repeating unit represented by the following formula (B5), and a repeating unit represented by the following formula (B6).

[0077] [Chemistry 8]

[0078]

[0079] In the formula, c and d are each independently an integer of 0 to 4. e1 is 0 or 1. e2 is 0, 1 or 2. e3 is an integer of 0 to 5.

[0080] R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0081] R 41 and R 42Each of them is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom.

[0082] R 43 It is a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbon oxyhydrocarbyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiohydrocarbyl group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon sulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group having 1 to 20 carbon atoms.

[0083] A 3 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0084] 7. The chemically amplified negative resist composition of 5., wherein the polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B7), a repeating unit represented by the following formula (B8), a repeating unit represented by the following formula (B9), a repeating unit represented by the following formula (B10), a repeating unit represented by the following formula (B11), a repeating unit represented by the following formula (B12), a repeating unit represented by the following formula (B13), and a repeating unit represented by the following formula (B14).

[0085] [Chemistry 9]

[0086]

[0087] Where R B are each independently a hydrogen atom or a methyl group.

[0088] Y 1 Each of them is independently a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or *-OY 11 -、*-C(=O)-OY 11 - or *-C(=O)-NH-Y 11 -, and Y 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group.

[0089] Y 2 are independently a single bond or **-Y 21 -C(=O)-O-, and Y 21 It is a hydrocarbylene group having 1 to 20 carbon atoms which may contain a heteroatom.

[0090] Y 3 are independently a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-OY 31 -、*-C(=O)-OY 31 - or *-C(=O)-NH-Y 31 -.Y 31 It is an aliphatic hydrocarbylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted by a trifluoromethyl group, or a group having 7 to 20 carbon atoms obtained by combining these groups, and may contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group.

[0091] * represents an atomic bond to a carbon atom in the main chain, and ** represents an atomic bond to an oxygen atom in the formula.

[0092] Y 4 Each independently represents a single bond or a hydrocarbylene group having 1 to 30 carbon atoms which may contain a heteroatom.

[0093] f1 and f2 are independently 0 or 1, but in Y 4 When it is a single bond, f1 and f2 are 0.

[0094] R 51 ~R 68 are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 51 and R 52 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 53 and R 54 、R 56 and R 57 , or R 59 and R 60 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

[0095] R HF is a hydrogen atom or a trifluoromethyl group.

[0096] XA - It is a non-nucleophilic relative ion.

[0097] 8. A chemically amplified negative resist composition as described in 7., wherein the polymer contains a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (B2-1), (B2-2) or (B3-1), and a repeating unit represented by the following formula (B8).

[0098] [Chemistry 10]

[0099]

[0100] Where a4, b4, b6, R A 、RB 、Y 2 、R 32 、R 33 、R 35 、R 36 、R 53 、R 54 、R 55 and R HF Same as above.

[0101] 9. The chemically amplified negative resist composition of 7., wherein the base polymer (B) further comprises a polymer containing a repeating unit represented by formula (B1) and a repeating unit represented by formula (B2) or (B3), and does not contain a repeating unit represented by formulas (B7) to (B14).

[0102] 10. The chemically amplified negative resist composition according to any one of 1. to 9., wherein the content of repeating units having an aromatic ring skeleton in all repeating units of the polymer contained in the base polymer is 60 mol% or more.

[0103] 11. The chemically amplified negative resist composition according to any one of 1. to 10., further comprising (C) a crosslinking agent.

[0104] 12. The chemically amplified negative resist composition according to 5., which does not contain a cross-linking agent.

[0105] 13. The chemically amplified negative resist composition according to any one of 1. to 12., further comprising:

[0106] (D) A fluorine-containing polymer containing at least one selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6).

[0107] [Chemistry 11]

[0108]

[0109] In the formula, x is an integer from 1 to 3. y is an integer satisfying 0≤y≤5+2z-x. z is 0 or 1. g is an integer from 1 to 3.

[0110] R C are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0111] R D are each independently a hydrogen atom or a methyl group.

[0112] R 101 、R102 、R 104 and R 105 Each independently represents a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms.

[0113] R 103 、R 106 、R 107 and R 108 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 103 、R 106 、R 107 and R 108 In the case of a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds.

[0114] R 109 It is a hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds.

[0115] R 110 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds.

[0116] R 111 It is a saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom, and a portion of the -CH2- groups in the saturated hydrocarbon group may be substituted by an ester bond or an ether bond.

[0117] Z 1 It 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.

[0118] Z 2 It is a single bond, *-C(=O)-O- or *-C(=O)-NH-. * is an atomic bond to a carbon atom of the main chain.

[0119] Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -.Z 31 Z is a single bond or a saturated alkylene group having 1 to 10 carbon atoms. 32 It is a single bond, an ester bond, an ether bond or a sulfonamide bond.

[0120] * is the atomic bond to the carbon atom of the main chain.

[0121] 14. The chemically amplified negative resist composition according to any one of 1. to 13., further comprising (E) a quencher.

[0122] 15. The chemically amplified negative resist composition according to 14., wherein the content ratio of the (A) acid generator to the (E) quencher is less than 6 in terms of mass ratio.

[0123] 16. The chemically amplified negative resist composition according to any one of 1. to 15., further comprising (F) an organic solvent.

[0124] 17. A method for forming a resist pattern, comprising the following steps:

[0125] Using the chemically amplified negative resist composition according to any one of 1. to 16. to form a resist film on a substrate,

[0126] irradiating the resist film with a pattern of high-energy rays, and

[0127] The resist film having the irradiated pattern is developed using an alkaline developer.

[0128] 18. The resist pattern forming method according to 17., wherein the high-energy radiation is EUV or EB having a wavelength of 3 to 15 nm.

[0129] 19. The resist pattern forming method according to 17. or 18., 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.

[0130] 20. The resist pattern forming method according to any one of 17. to 19., wherein the substrate is a transmissive or reflective mask blank.

[0131] 21. A transmissive or reflective blank mask coated with the chemically amplified negative resist composition according to any one of 1. to 16.

[0132] [Effects of the Invention]

[0133] The chemically amplified negative resist composition of the present invention utilizes the onium salt represented by formula (A) to effectively control acid diffusion caused by exposure during pattern formation. When this composition is used to form a resist film and pattern, it exhibits extremely high resolution, high pattern fidelity, and reduced LER. Furthermore, the repeating unit represented by formula (B1) improves the adhesion of the formed resist film to the substrate and controls its solubility in alkaline developers. BRIEF DESCRIPTION OF THE DRAWINGS

[0134] [ Figure 1 ]NMR spectrum of the onium salt PAG-1 synthesized in Synthesis Example 1 ( 1 H-NMR / DMSO-d6). DETAILED DESCRIPTION

[0135] The present invention is described in detail below. In the following description, depending on the structure represented by the chemical formula, asymmetric carbon atoms may exist, and enantiomers and diastereomers may exist. In such cases, these isomers are represented by a single general formula. These isomers may be used alone or as a mixture of two or more.

[0136] [Chemically amplified negative resist composition]

[0137] The chemically amplified negative resist composition of the present invention is characterized by comprising:

[0138] (A) a photoacid generator composed of an onium salt containing a sulfonic acid anion having a condensed ring structure with a substituent and an aromatic sulfonic acid structure, and

[0139] (B) A base polymer comprising a predetermined polymer.

[0140] [(A) Photoacid generator]

[0141] The onium salt which is the photoacid generator of the component (A) is represented by the following formula (A).

[0142] [Chemistry 12]

[0143]

[0144] In formula (A), R 1 ~R 12 Each of R is independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. 13 and R 14 One of them is a group having a partial structure represented by formula (a) described later, and the other is a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0145] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 20 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-octyl, n-nonyl, n-decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, heptadecyl, octadecyl, nonadecyl, and eicosyl; cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclopropyl, cyclopentyl, cyclohexyl, cyclopropylmethyl, 4-methylcyclohexyl, cyclohexylmethyl, norbornyl, and adamantyl; alkenyl groups having 2 to 20 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated hydrocarbon groups having 3 to 20 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 20 carbon atoms, such as phenyl and naphthyl; aralkyl groups having 7 to 20 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl; and combinations thereof. Among these, aryl groups are preferred. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, the hydrocarbon group may contain a hydroxyl group, a cyano group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0146] Again, R 1 ~R 14 At least two of the -CH2- radicals may be bonded to each other and form a ring together with the carbon atoms to which they are bonded, or together with the carbon atoms to which they are bonded and the carbon atoms between them. Specific examples of the ring formed in this case include alicyclic rings such as cyclopropane, cyclobutane, cyclopentane, cyclohexane, norbornane, and adamantane, and aromatic rings such as benzene, naphthalene, and anthracene. Furthermore, some or all of the hydrogen atoms in the aforementioned rings may be substituted with groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and some of the -CH2- radicals in the aforementioned rings may be substituted with groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, the rings may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), or haloalkyl groups. The aforementioned rings are preferably aromatic rings, and more preferably benzene rings.

[0147] In formula (A), R 13 or R 14 Any of the following is a group having a partial structure represented by the following formula (a). 14It is preferably a group having a partial structure represented by the following formula (a).

[0148] [Chemistry 13]

[0149]

[0150] In formula (a), m1 is 0 or 1. When m1 is 0, it is a benzene ring, and when m1 is 1, it is a naphthalene ring. From the perspective of solvent solubility, m1 is preferably a benzene ring. When m1 is 0, m2 is an integer of 0 to 4, and when m1 is 1, it is an integer of 0 to 6. When m1 is 0, m2 is preferably 4, and when m1 is 1, it is preferably 4, 5, or 6. When m1 is 0, m3 is an integer of 0 to 3, and when m1 is 1, it is an integer of 0 to 5. However, when m1 is 0, m2+m3 is 0 to 4, and when m1 is 1, it is 0 to 6.

[0151] In formula (a), 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. F Preferably, it is 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 these substituents having a fluorine atom, the acid strength of the generated acid is improved due to the electron-withdrawing effect, so the deprotection reaction of the acid-labile group such as tertiary ester or tertiary ether described later proceeds smoothly. When m2 is 2, 3 or 4, each R F They can be the same or different from each other.

[0152] In formula (a), R 15 is a hydrocarbon group having 1 to 20 carbon atoms which may contain heteroatoms. The hydrocarbon group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples thereof include: 1 The same examples as those of the hydrocarbon groups represented are not limited thereto. When m3 is 2 or more, each R 15 They may be the same or different from each other. 15 They may also be bonded to each other and to form a ring together with the carbon atom to which they are bonded. The aforementioned ring is preferably a 5- to 8-membered ring.

[0153] In formula (a), L A and L B Each of the above groups is independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond, or a carbamate bond. Among these, a single bond, an ether bond, or an ester bond is preferred.

[0154] In formula (a), X LA single bond or a C1-40 alkylene group which may contain a heteroatom. The alkylene group may be linear, branched, or cyclic. Specific examples include alkanediyl, cyclic saturated alkylene, and arylene groups. Specific examples of the heteroatom include oxygen, nitrogen, and sulfur atoms.

[0155] X L Specific examples of the alkylene group having 1 to 40 carbon atoms which may contain heteroatoms are shown below, but are not limited thereto. A and L B atomic bonds.

[0156] [Chemistry 14]

[0157]

[0158] [Chemistry 15]

[0159]

[0160] [Chemistry 16]

[0161]

[0162] [Chemistry 17]

[0163]

[0164] Among them, X L -0~X L -22 and X L -47~X L -58.

[0165] The onium salt represented by formula (A) is preferably represented by the following formula (A1).

[0166] [Chemistry 18]

[0167]

[0168] Where R 1 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + The same as above. The onium salt represented by formula (A1) is preferably represented by the following formula (A2).

[0169] [Chemistry 19]

[0170]

[0171] Where R5 、R 10 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + Same as above.

[0172] In formula (A2), m4 and m5 are each independently an integer of 0 to 4. However, in view of the availability of raw materials, both are preferably 0 to 2.

[0173] In formula (A2), R 16 and R 17 Each independently represents a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. Specific examples of the halogen atom and the hydrocarbon group can be listed as R 1 ~R 14 The same examples apply to the halogen atoms and hydrocarbon groups represented by .

[0174] When m4 is 2 or more, multiple R 16 They can also be bonded to each other and form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them. When m5 is 2 or more, multiple R 17 They can also be bonded to each other and form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them. Specific examples of the ring formed in this case can be listed and exemplified as R 1 ~R 14 The same example is given for a ring that can be formed by at least two of the above being bonded to each other.

[0175] Specific examples of the anion of the onium salt represented by formula (A) include those shown below, but are not limited thereto. In addition, structures formed by combining functional groups of different structures in the following specific examples are also included in the present invention. In addition, in the following formula, Me is a methyl group.

[0176] [Chemistry 20]

[0177]

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[0534] [Chemistry 199]

[0535]

[0536] [Chemistry 200]

[0537]

[0538] In formula (A), Z + 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).

[0539] [Chemistry 201]

[0540]

[0541] In formula (cation-1) and (cation-2), R ct1 ~R ct5 Each independently represents a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a heteroatom.

[0542] R ct1 ~R ct5 Examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.

[0543] R ct1 ~R ct5The hydrocarbon group represented by may be saturated or unsaturated and may be linear, branched, or cyclic. Specific examples include: alkyl groups having 1 to 30 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and tert-butyl; cyclic saturated hydrocarbon 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; cyclic unsaturated hydrocarbon 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 combinations thereof, preferably aryl groups. Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, the hydrocarbon group may contain a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, a cyano group, a nitro group, a carbonyl group, an ether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like.

[0544] Again, R ct1 and R ct2 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. In this case, the structure of the ring may be represented by the following formula.

[0545] [Chemistry 202]

[0546]

[0547] Where, the dotted line is and R ct3 atomic bonds.

[0548] Specific examples of the sulfonium cation represented by formula (cation-1) include the following, but are not limited thereto.

[0549] [Chemistry 203]

[0550]

[0551] [Chemistry 204]

[0552]

[0553] [Chemistry 205]

[0554]

[0555] [Chemistry 206]

[0556]

[0557] [Chemistry 207]

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[0559] [Chemistry 208]

[0560]

[0561] [Chemistry 209]

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[0563] [Chemistry 210]

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[0565] [Chemistry 211]

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[0567] [Chemistry 212]

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[0569] [Chemistry 213]

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[0599] [Chemistry 228]

[0600]

[0601] Specific examples of the iodonium cation represented by formula (cation-2) include the following, but are not limited thereto.

[0602] [Chemistry 229]

[0603]

[0604] [Chemistry 230]

[0605]

[0606] Specific examples of the onium salt include any combination of the anions and cations described above.

[0607] The onium salt can be synthesized by a known method. As an example, a method for producing an onium salt represented by the following formula (PAG-1-ex) will be described, but the synthesis method is not limited thereto.

[0608] [Chemistry 231]

[0609]

[0610] Where R 1 ~R 13 、R F 、R 15 、L A 、X L , m1~m3 and Z + Same as above. + For the cation. X - For the anion.

[0611] The first step is a step of obtaining the intermediate In-1 by reacting the raw material SM-1 obtained by a commercial product or a known synthesis method with the raw material SM-2. When the carboxyl group of the raw material SM-1 and the hydroxyl group of the raw material SM-2 directly form an ester bond, various condensing agents can be used. Examples of the condensing agents used include: N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-[3-(dimethylamino)propyl]-3-ethylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, etc. Considering the ease of removing the urea compound generated as a by-product after the reaction, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride is preferably used. The reaction is carried out by dissolving the raw materials SM-1 and SM-2 in a halogen-based solvent such as dichloromethane and adding a condensing agent. Adding 4-dimethylaminopyridine (DMAP) as a catalyst can improve the reaction rate. The reaction time is typically about 12 to 24 hours, ideal for yield, if monitored by silica gel thin-layer chromatography (TLC) and completed. After the reaction is terminated, the by-product urea compound is removed by filtration or washing, as needed. The reaction mixture is then subjected to a standard aqueous workup to obtain the intermediate In-1. If necessary, the resulting intermediate In-1 can be purified using conventional methods such as chromatography and recrystallization.

[0612] The second step is to make the intermediate In-1 and Z + X - The step of performing salt exchange on the onium salt (raw material SM-3) represented by X to obtain an onium salt (PAG-1-ex). - Chloride, bromide, iodide, or methylsulfate anion is preferred for ease of quantitative exchange reaction. Confirming the progress of the reaction by TLC is ideal for high yield. The onium salt (PAG-1-ex) can be obtained from the reaction mixture by conventional aqueous workup. If necessary, purification can be performed using conventional methods such as chromatography and recrystallization.

[0613] In the above process, the ion exchange in the second step can be easily performed using a known method, for example, refer to Japanese Patent Application Laid-Open No. 2007-145797.

[0614] The above-mentioned production method is merely an example, and the production method of the above-mentioned onium salt is not limited thereto.

[0615] The structural characteristics of the above-mentioned onium salts can be listed in that the anion has a condensed ring structure and an aromatic sulfonic acid structure with a substituent. The condensed ring structure with a substituent has a large exclusion volume, acts as a bulky substituent, and highly suppresses the diffusion of the generated acid. In addition, due to its resistance to alkaline developer, the film loss of the pattern of the unexposed part is reduced. On the other hand, the structure of the acid generated by the aromatic sulfonic acid structure is rigid, which will show the effect of suppressing the diffusion of the acid. The aromatic ring forming the aromatic sulfonic acid structure preferably has a fluorine atom or an electron-withdrawing sulfonic acid ester bond as a connecting group, thereby increasing the acidity of the generated acid and efficiently deprotecting the acid-labile group of the base polymer. In addition, although the fluorine atom is not as good as the iodine atom, it is still an element with a high absorption effect of EUV light. Therefore, by increasing the number of fluorine atoms, the amount of secondary electrons generated will increase, and the decomposition of cations will be promoted, which will contribute to high sensitivity. Japanese Patent No. 7109178 proposes an alkanesulfonic acid-type photoacid generator containing 2 to 4 fluorine atoms. However, due to the alkanesulfonic acid, the acid diffusion is large and the solvent solubility is poor, which raises concerns about development defects. Due to these synergistic effects, resist compositions containing the aforementioned onium salts have high sensitivity and low acid diffusion. This results in excellent LWR of line patterns and CDU of hole patterns, and allows for the formation of patterns with strong pattern collapse resistance, making them ideal for forming fine patterns.

[0616] In the chemically amplified negative resist composition of the present invention, the content of the photoacid generator (A) is preferably 0.1 to 40 parts by mass, and more preferably 1 to 20 parts by mass, relative to 80 parts by mass of the base polymer (B) described below. When the content of the photoacid generator (A) is within the aforementioned range, the photoacid generator (A) generates the amount of acid required for deprotection of the acid-labile group and also provides excellent storage stability. The photoacid generators (A) may be used alone or in combination of two or more.

[0617] The chemically amplified negative resist composition of the present invention may further contain an acid generator other than the onium salt represented by formula (A) (hereinafter also referred to as other acid generators) for the purpose of correcting the shape of the pattern, etc. The other acid generator can be a well-known acid generator for use in resist compositions. The content of the other acid generator is preferably 0 to 40 parts by mass, more preferably 0 to 30 parts by mass, relative to 80 parts by mass of the base polymer (B) described later, considering the sensitivity and the acid diffusion inhibition effect. The other acid generators may be used alone or in combination of two or more.

[0618] [(B) Base polymer]

[0619] The base polymer of component (B) comprises a polymer (hereinafter referred to as polymer B) containing a repeating unit represented by the following formula (B1) (hereinafter referred to as repeating unit B1). Repeating unit B1 provides etching resistance, adhesion to the substrate, and solubility in alkaline developer.

[0620] [Chemistry 232]

[0621]

[0622] In formula (B1), a1 is 0 or 1. a2 is 0, 1, or 2, and represents a benzene skeleton when 0, a naphthalene skeleton when 1, and an anthracene skeleton when 2. a3 is an integer satisfying 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.

[0623] In formula (B1), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0624] In formula (B1), R 21 It is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom. The saturated hydrocarbon group, the saturated hydrocarbon group portion of the saturated hydrocarbon oxy group and the saturated hydrocarbon carbonyloxy group may be any of linear, branched, or cyclic. Specific examples thereof include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these groups. If the number of carbon atoms is below the upper limit, the solubility in alkaline developer is good. When a3 is 2 or more, each R 21 They can be the same or different from each other.

[0625] In formula (B1), A 1represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- residues of the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include: alkylene 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, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, when a1 in formula (B1) is 1, it may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When a1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and a second ether bond may be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Furthermore, it is preferred that the carbon number of the saturated alkylene group is 10 or less, since sufficient solubility in an alkaline developer can be achieved.

[0626] a1 is 0 and A 1 When it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (that is, there is no connecting group (-C(=O)-OA 1 -)), preferable examples of the repeating unit B1 include units derived from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. The repeating unit represented by the following formula (B1-1) is particularly preferable.

[0627] [Chemistry 233]

[0628]

[0629] Where R A and a4 are the same as above.

[0630] a1 is 1 (i.e., has -C(=O)-OA 1 - as a linking group), the following are examples of desirable repeating units B1, but are not limited thereto. A Same as above.

[0631] [Chemistry 234]

[0632]

[0633] The repeating unit B1 may be used alone or in combination of two or more.

[0634] Polymer B may also contain at least one type selected from the repeating unit represented by the following formula (B2) (hereinafter also referred to as repeating unit B2) and the repeating unit represented by the following formula (B3) (hereinafter also referred to as repeating unit B3) (hereinafter, the polymer B further containing at least one type selected from the repeating unit B2 and the repeating unit B3 will also be referred to as polymer B').

[0635] [Chemistry 235]

[0636]

[0637] Repeating units B2 and B3 are oxidized by the action of acid generated from the acid generator when irradiated with high energy radiation. 1 、-OW 2 This repeating unit causes a separation reaction, inducing insolubilization in alkaline developer and cross-linking between polymers. The effects of repeating units B2 and B3 allow for more efficient negative-tone conversion, thus improving resolution.

[0638] In formula (B2), b1 is 0 or 1. b2 is 0, 1, or 2. b3 is an integer satisfying 0≤b3≤5+2(b2)-b4. b4 is 1, 2, or 3.

[0639] In formula (B3), b5 is 0, 1 or 2, preferably 0 or 1. b6 is 1 or 2, preferably 1.

[0640] In formulas (B2) and (B3), R A Each of them is independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. In formula (B3), among these, a hydrogen atom or a methyl group is preferred, and a hydrogen atom is more preferred.

[0641] In formula (B2), R 31 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 31 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. 31 The hydrocarbon group having 1 to 20 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified as R in the description of formula (A). 1 ~R 12 The same example applies to hydrocarbon groups represented by 31 They can be the same or different from each other.

[0642] In formula (B2), R 32 and R 33are independently a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbon group may be substituted with a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent. 32 and R 33 cannot be a hydrogen atom at the same time. 32 and R 33 They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- in the ring may be substituted by -O- or -S-. 32 and R 33 Preferred examples include alkyl groups such as methyl, ethyl, propyl, butyl, and structural isomers thereof, and groups in which a part of the hydrogen atoms is substituted with a hydroxyl group or a saturated hydrocarbon oxy group.

[0643] In formula (B3), R 34 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 34 Specific examples of the halogen atom represented by R include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like. 34 The hydrocarbon group having 1 to 20 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include those exemplified as R in the description of formula (A). 1 ~R 12 The same example applies to hydrocarbon groups represented by 34 They can be the same or different from each other.

[0644] In formula (B3), R 35 and R 36 Each independently represents a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms. The hydrocarbon group may be substituted with a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent.

[0645] R 35 and R 36 The saturated hydrocarbon group having 1 to 15 carbon atoms represented by may be linear, branched, or cyclic. Specific examples thereof include and are exemplified as R 32 and R 33 The same examples are given for the saturated hydrocarbon groups represented by .

[0646] R 35 and R 36 Specific examples of the aryl group having 6 to 15 carbon atoms represented by include phenyl, naphthyl, anthracenyl, etc., among which phenyl is preferred. Furthermore, the aryl group may have a substituent, and specific examples of the substituent include a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom.

[0647] Again, R 35 and R 36 It cannot be a hydrogen atom at the same time. 35 and R 36 When any one of them is an aryl group which may have a substituent, the other substituent is preferably a hydrogen atom.

[0648] R 35 and R 36 They are preferably the same group, more preferably methyl groups.

[0649] Again, R 35 and R 36 They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- in the ring may be substituted by -O- or -S-. Examples of the aforementioned ring include cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, norbornane ring, adamantane ring, tricyclic [5.2.1.0 2,6 ]Decane ring, tetracyclic [6.2.1.1 3,6 .0 2,7 ] dodecane ring, oxa norbornane ring, thia norbornane ring, etc., but are not limited thereto.

[0650] In formula (B2), A 2 represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- in the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include: methylene, ethane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, if b1 in formula (B2) is 1, it may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When b1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and the second ether bond may be inserted at any position other than between the carbon atom at the α position and the carbon atom at the β position relative to the etheric oxygen atom.

[0651] In formulas (B2) and (B3), W 1 and W 2 Each of them is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aliphatic hydrocarbon carbonyl 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.

[0652] W 1 and W 2The aliphatic hydrocarbon group having 1 to 10 carbon atoms represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. 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, neopentyl, n-hexyl, n-heptyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclic saturated hydrocarbon groups having 3 to 10 carbon atoms, such as cyclopentyl and cyclohexyl; alkenyl groups having 2 to 10 carbon atoms, such as vinyl, 1-propenyl, 2-propenyl, butenyl, and hexenyl; and cyclic unsaturated hydrocarbon groups having 3 to 10 carbon atoms, such as cyclohexenyl. W 1 and W 2 The hydrocarbon moiety of the aliphatic hydrocarbon carbonyl group having 2 to 10 carbon atoms represented by W 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 hydrocarbon groups having 1 to 10 carbon atoms described above. 1 and W 2 Specific examples of the aryl group having 6 to 15 carbon atoms represented by include phenyl, naphthyl, anthracenyl, etc., among which phenyl is preferred. Furthermore, the aryl group may have a substituent, and specific examples of the substituent include a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted with a halogen atom, and a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted with a halogen atom.

[0653] The repeating unit B2 is preferably represented by the following formula (B2-1) or (B2-2).

[0654] [Chemistry 236]

[0655]

[0656] Where b4, R A 、R 32 and R 33 Same as above.

[0657] Preferred examples of repeating unit B2 include, but are not limited to, the following. A Same as above, Me is methyl and Ac is acetyl.

[0658] [Chemistry 237]

[0659]

[0660] [Chemistry 238]

[0661]

[0662] [Chemistry 239]

[0663]

[0664] [Chemistry 240]

[0665]

[0666] [Chemistry 241]

[0667]

[0668] [Chemistry 242]

[0669]

[0670] [Chemistry 243]

[0671]

[0672] [Chemistry 244]

[0673]

[0674] [Chemistry 245]

[0675]

[0676] [Chemistry 246]

[0677]

[0678] [Chemistry 247]

[0679]

[0680] The repeating unit B2 may be used alone or in combination of two or more. The repeating unit B3 is preferably represented by the following formula (B3-1).

[0681] [Chemistry 248]

[0682]

[0683] Where b6, R A 、R 35 and R 36 Same as above.

[0684] Preferred examples of repeating unit B3 include those shown below, but are not limited thereto. A Same as above, Me is methyl and Ac is acetyl.

[0685] [Chemistry 249]

[0686]

[0687] [Chemistry 250]

[0688]

[0689] [Chemistry 251]

[0690]

[0691] [Chemistry 252]

[0692]

[0693] [Chemistry 253]

[0694]

[0695] [Chemistry 254]

[0696]

[0697] [Chemistry 255]

[0698]

[0699] [Chemistry 256]

[0700]

[0701] [Chemistry 257]

[0702]

[0703] [Chemistry 258]

[0704]

[0705] [Chemistry 259]

[0706]

[0707] [Chemistry 260]

[0708]

[0709] [Chemistry 261]

[0710]

[0711] [Chemistry 262]

[0712]

[0713] [Chemistry 263]

[0714]

[0715] [Chemistry 264]

[0716]

[0717] [Chemistry 265]

[0718]

[0719] [Chemistry 266]

[0720]

[0721] [Chemistry 267]

[0722]

[0723] [Chemistry 268]

[0724]

[0725] [Chemistry 269]

[0726]

[0727] [Chemistry 270]

[0728]

[0729] [Chemistry 271]

[0730]

[0731] [Chemistry 272]

[0732]

[0733] [Chemistry 273]

[0734]

[0735] [Chemistry 274]

[0736]

[0737] [Chemistry 275]

[0738]

[0739] [Chemistry 276]

[0740]

[0741] [Chemistry 277]

[0742]

[0743] [Chemistry 278]

[0744]

[0745] [Chemistry 279]

[0746]

[0747] [Chemistry 280]

[0748]

[0749] [Chemistry 281]

[0750]

[0751] The repeating unit B3 may be used alone or in combination of two or more.

[0752] In order to improve etching resistance, polymers B and B' may also contain at least one selected from the repeating unit represented by the following formula (B4) (hereinafter also referred to as repeating unit B4), the repeating unit represented by the following formula (B5) (hereinafter also referred to as repeating unit B5) and the repeating unit represented by the following formula (B6) (hereinafter also referred to as repeating unit B6).

[0753] [Chemistry 282]

[0754]

[0755] In formulae (B4) and (B5), c and d are each independently an integer of 0 to 4.

[0756] In formulas (B4) and (B5), R 41 and R 42 Each of the following is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, and saturated hydrocarbon carbonyloxy group may be linear, branched, or cyclic. When c is 2 or more, each R 41 They may be the same or different from each other. When d is 2 or more, each R 42 They can be the same or different from each other.

[0757] In formula (B6), e1 is 0 or 1. e2 is 0, 1, or 2, and represents a benzene skeleton when 0, a naphthalene skeleton when 1, and an anthracene skeleton when 2. e3 is an integer from 0 to 5. When e2 is 0, e3 is preferably an integer from 0 to 3, and when e2 is 1 or 2, e3 is preferably an integer from 0 to 4.

[0758] In formula (B6), R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0759] In formula (B6), R43 is a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbon oxy group having 1 to 20 carbon atoms, a saturated hydrocarbon carbonyl oxy group having 2 to 20 carbon atoms, a saturated hydrocarbon oxyhydrocarbon group having 2 to 20 carbon atoms, a saturated hydrocarbon thiohydrocarbon group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbon sulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbon sulfonyl group having 1 to 20 carbon atoms. The saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, saturated hydrocarbon oxyhydrocarbon group, saturated hydrocarbon thiohydrocarbon group, saturated hydrocarbon sulfinyl group, and saturated hydrocarbon sulfonyl group may be straight-chain, branched, or cyclic. When e3 is 2 or more, each R 43 They can be the same or different from each other.

[0760] R 43 Preferred are halogen atoms such as chlorine, bromine, and iodine; saturated hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, and structural isomers thereof; and saturated hydrocarbon oxy groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopentyloxy, cyclohexyloxy, and structural isomers of the hydrocarbon moieties thereof. Among these, methoxy and ethoxy are particularly useful.

[0761] Furthermore, saturated hydrocarbon carbonyloxy groups can be easily introduced by chemical modification after polymer polymerization, allowing for fine-tuning of the base polymer's solubility in alkaline developer solutions. Examples of such saturated hydrocarbon carbonyloxy groups include methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, and structural isomers of their hydrocarbon moieties. A carbon number of 20 or less allows for an appropriate control and adjustment of the base polymer's solubility in alkaline developer solutions (primarily a reduction effect), and can suppress the generation of residues (development defects).

[0762] Among the above-mentioned preferred substituents, particularly those that are easily prepared as monomers and can be effectively used include a chlorine atom, a bromine atom, an iodine atom, a methyl group, an ethyl group, and a methoxy group.

[0763] In formula (B6), A 3represents a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of the -CH2- residues of the saturated alkylene group may be substituted with -O-. The saturated alkylene group may be linear, branched, or cyclic. Specific examples include: alkylene 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, hexane-1,6-diyl, and their structural isomers; cyclic saturated alkylene groups having 3 to 10 carbon atoms, such as cyclopropanediyl, cyclobutanediyl, cyclopentanediyl, and cyclohexanediyl; and combinations thereof. When the saturated alkylene group contains an ether bond, if e1 in formula (B6) is 1, it may be inserted at any position other than between the carbon atom at the alpha position and the carbon atom at the beta position relative to the ester oxygen atom. When e1 is 0, the atom bonded to the main chain becomes an etheric oxygen atom, and a second ether bond may be inserted at any position other than between the carbon atom at the α-position and the carbon atom at the β-position relative to the etheric oxygen atom. Furthermore, it is preferred that the carbon number of the saturated alkylene group is 10 or less, since sufficient solubility in an alkaline developer can be achieved.

[0764] e1 is 0 and A 3 When it is a single bond, that is, the aromatic ring is directly bonded to the main chain of the polymer (that is, there is no connecting group (-C(=O)-OA 3 -)), preferable examples of the repeating unit B6 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene, and the like.

[0765] Moreover, when e1 is 1 (ie, having -C(=O)-OA 3 - as a linking group), the following are examples of desirable repeating units B6, but are not limited thereto. A Same as above.

[0766] [Chemistry 283]

[0767]

[0768] [Chemistry 284]

[0769]

[0770] When at least one of the repeating units B4 to B6 is used as a constituent unit of the polymer, the etching resistance of the aromatic ring can be improved. In addition, the etching resistance due to the addition of a ring structure to the main chain and the EB irradiation resistance during pattern inspection can be improved.

[0771] The repeating units B4 to B6 may be used alone or in combination of two or more.

[0772] Polymer B' may further contain at least one selected from the group consisting of a repeating unit represented by the following formula (B7) (hereinafter referred to as repeating unit B7), a repeating unit represented by the following formula (B8) (hereinafter referred to as repeating unit B8), a repeating unit represented by the following formula (B9) (hereinafter referred to as repeating unit B9), a repeating unit represented by the following formula (B10) (hereinafter referred to as repeating unit B10), a repeating unit represented by the following formula (B11) (hereinafter referred to as repeating unit B11), a repeating unit represented by the following formula (B12) (hereinafter referred to as repeating unit B12), a repeating unit represented by the following formula (B13) (hereinafter referred to as repeating unit B13), and a repeating unit represented by the following formula (B14) (hereinafter referred to as repeating unit B14). In this case, acid diffusion can be effectively suppressed, resolution can be improved, and a pattern with reduced LER can be obtained.

[0773] [Chemistry 285]

[0774]

[0775] In formulas (B7) to (B14), R B are independently a hydrogen atom or a methyl group. 1 Each of them is independently a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or *-OY 11 -、*-C(=O)-OY 11 - or *-C(=O)-NH-Y 11 -, and Y 11 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 are independently a single bond or **-Y 21 -C(=O)-O-, and Y 21 Y is a C1-20 alkylene group which may contain a heteroatom. 3 are independently a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-OY 31 -、*-C(=O)-OY 31 - or *-C(=O)-NH-Y 31 -.Y 31 It is an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or a group having 7 to 20 carbon atoms obtained by combining these groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. * represents an atomic bond to a carbon atom in the main chain, and ** represents an atomic bond to an oxygen atom in the formula. Y4 Each of f1 and f2 is independently a single bond or a carbon number 1 to 30 alkylene group which may contain a hetero atom. 4 When it is a single bond, f1 and f2 are 0.

[0776] In formulas (B7) and (B11), Xa - It is a non-nucleophilic counter ion. - Examples of the non-nucleophilic counter ion represented by include those described in JP-A-2010-113209 and JP-A-2007-145797.

[0777] In formulas (B8) and (B12), Y 2 -Y 21 -C(=O)-O-, Y 21 Examples of the hydrocarbylene group which may contain a hetero atom include the following, but are not limited thereto.

[0778] [Chemistry 286]

[0779]

[0780] In the formula, the dotted lines are atomic bonds.

[0781] In formulas (B8) and (B12), R HF is a hydrogen atom or a trifluoromethyl group. In the repeating units B8 and B12, R HF Specific examples of hydrogen atoms include those described in Japanese Patent Application Laid-Open No. 2010-116550, HF Specific examples of the trifluoromethyl group include those described in JP-A-2010-77404. Examples of the repeating units B8 and B12 include those described in JP-A-2012-246265 and JP-A-2012-246426.

[0782] Preferred examples of the anion of the monomer providing the repeating unit B10 or B14 include the following, but are not limited thereto.

[0783] [Chemistry 287]

[0784]

[0785] [Chemistry 288]

[0786]

[0787] In formulas (B7) to (B14), R 51 ~R 68Each independently represents a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom. The hydrocarbon group may be saturated or unsaturated and may be linear, branched or cyclic. Specific examples of the halogen atom and hydrocarbon group include those exemplified as R in the description of formula (cation-1) and (cation-2). ct1 ~R ct5 The same applies to the halogen atoms and hydrocarbon groups represented by . In addition, some or all of the hydrogen atoms of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and some of the -CH2- in the hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, the hydrocarbon groups may contain hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, nitro groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, lactone rings, sultone rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, and the like.

[0788] Again, R 51 and R 52 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 53 and R 54 、R 56 and R 57 , or R 59 and R 60 They may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. The ring formed in this case can be exemplified as R in the description of formula (cation-1). ct1 and R ct2 The same example is true of the rings that can be formed by bonding to each other and to the sulfur atoms to which they are bonded.

[0789] Specific examples of the sulfonium cations in repeating units B8 to B10 are the same as those exemplified as the sulfonium cations represented by formula (cation-1). Specific examples of the iodonium cations in repeating units B12 to B14 are the same as those exemplified as the iodonium cations represented by formula (cation-2).

[0790] Repeating units B7 to B14 generate acid upon exposure to high-energy radiation. Inclusion of these units in the polymer is believed to moderately suppress acid diffusion, resulting in a pattern with reduced LER. Furthermore, inclusion of these units in the polymer is believed to suppress the volatilization of acid from exposed areas and its subsequent reattachment to unexposed areas during vacuum baking, contributing to reduced LER and the reduction of defects caused by suppressing undesirable negative-tone reactions in unexposed areas.

[0791] The repeating units B7 to B14 may be used alone or in combination of two or more.

[0792] The polymers B and B′ may contain a (meth)acrylate unit having a lactone structure, an adhesive group such as a hydroxyl group other than a phenolic hydroxyl group, or other repeating units in order to fine-tune the properties of the resist film.

[0793] Examples of the (meth)acrylate unit having an adhesive group include a repeating unit represented by the following formula (B15) (hereinafter also referred to as repeating unit B15), a repeating unit represented by the following formula (B16) (hereinafter also referred to as repeating unit B16), and a repeating unit represented by the following formula (B17) (hereinafter also referred to as repeating unit B17). These units do not exhibit acidity but can be used auxiliaryly as units that provide adhesion to substrates or units that adjust solubility.

[0794] [Chemistry 289]

[0795]

[0796] In formulas (B15) to (B17), R A R are independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 71 is -O- or methylene. 72 is a hydrogen atom or a hydroxyl group. 73 is a saturated hydrocarbon group having 1 to 4 carbon atoms. g is an integer of 0 to 3.

[0797] In polymer B, the content of repeating unit B1 is preferably 30 to 95 mol% in order to obtain high resolution and to draw a high contrast between the portion that is negatively typed due to high-energy ray irradiation and the portion that is not irradiated (the portion that is not negatively typed), and is more preferably 50 to 85 mol%. In addition, the content of repeating unit B2 and repeating unit B3 is preferably 5 to 70 mol% in order to obtain the effect of promoting the negative type reaction, and is more preferably 10 to 60 mol%. The content of repeating units B4 to B6 is preferably 0 to 30 mol% in order to obtain the effect of improving etching resistance, and is more preferably 3 to 20 mol%. In addition, other repeating units may also contain 0 to 30 mol%, and it is preferably 0 to 20 mol%.

[0798] When polymer B' does not contain repeating units B7 to B14, the content of repeating unit B1 in polymer B' is preferably 25 to 95 mol%, more preferably 40 to 85 mol%. The content of repeating units B4 to B6 is preferably 0 to 30 mol%, more preferably 3 to 20 mol%. The content of repeating units B2 and B3 is preferably 5 to 70 mol%, more preferably 10 to 60 mol%. In addition, other repeating units may be contained in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0799] When polymer B' contains repeating units B7 to B14, the content of repeating unit B1 in polymer B' is preferably 25 to 94.5 mol%, and more preferably 36 to 85 mol%. The content of repeating units B4 to B6 is preferably 0 to 30 mol%, and more preferably 3 to 20 mol%. The content of repeating units B2 and B3 is preferably 5 to 70 mol%, and more preferably 10 to 60 mol%. In addition, the total content of repeating units B1 to B6 is preferably 60 to 99.5 mol%. The content of repeating units B7 to B14 is preferably 0.5 to 20 mol%, and more preferably 1 to 10 mol%. In addition, other repeating units may also contain 0 to 30 mol%, and preferably contain 0 to 20 mol%.

[0800] Furthermore, of all the repeating units constituting the polymer, repeating units B1 to B6 preferably account for 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more. This ensures that the properties required for the chemically amplified negative resist composition of the present invention are achieved.

[0801] In this case, the polymer B' preferably contains a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (B2-1), (B2-2) or (B3-1), and a repeating unit represented by the following formula (B8).

[0802] [Chemistry 290]

[0803]

[0804] Where a4, b4, b6, R A 、R B 、Y 2 、R 32 、R 33 、R 35 、R 36 、R 53 、R 54 、R 55 and R HF Same as above.

[0805] When polymer B' is used as the base polymer (B), a polymer containing repeating units B7 to B14 and a polymer containing repeating units B7 to B14 may be used in combination. In this case, the content of the polymer containing repeating units B7 to B14 in the chemically amplified negative resist composition of the present invention is preferably 2 to 5000 parts by mass, more preferably 10 to 1000 parts by mass, based on 100 parts by mass of the polymer containing repeating units B7 to B14.

[0806] When a chemically amplified negative resist composition is used in mask production, the coating 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 generally 80 nm / s or less, preferably 50 nm / s or less, in order to further reduce defects caused by resist residue, often requiring strong development. Furthermore, when using the chemically amplified negative resist composition of the present invention in the production of LSI chips from wafers using EUV exposure, it is often necessary to pattern fine lines of 50 nm or less, so the coating thickness is often set to 100 nm or less. However, as thin films can degrade the pattern due to development, the dissolution rate of the polymer used is preferably 80 nm / s or less, preferably 50 nm / s or less.

[0807] The aforementioned polymers can be synthesized by copolymerizing monomers protected with protecting groups, as needed, using known methods, followed by deprotection reactions as needed. The copolymerization reaction is not particularly limited, and is preferably free radical polymerization or anionic polymerization. These methods can be found in International Publication No. 2006 / 121096, Japanese Patent Application Publication No. 2008-102383, Japanese Patent Application Publication No. 2008-304590, and Japanese Patent Application Publication No. 2004-115630.

[0808] The weight average molecular weight (Mw) of the aforementioned polymer is preferably 1,000 to 50,000, and more preferably 2,000 to 20,000. If Mw is 1,000 or more, there is no concern that the head of the pattern becomes rounded, the resolution decreases, and the LER deteriorates as is known. On the other hand, if Mw is 50,000 or less, there is no concern that the LER increases, especially when forming a pattern with a line width of 100 nm or less. In addition, Mw in the present invention is a polystyrene-converted measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) or dimethylformamide (DMF) as a solvent.

[0809] The molecular weight distribution (Mw / Mn) of the polymer is preferably 1.0 to 2.0, preferably 1.0 to 1.8. With such a narrow distribution, there is no possibility of foreign matter being generated on the pattern after development, or deterioration of the pattern shape.

[0810] [(C) Cross-linking agent]

[0811] When the base polymer (B) does not contain polymer B', the chemically amplified negative resist composition of the present invention preferably contains a crosslinking agent as component (C). On the other hand, when the base polymer (B) contains polymer B', it may or may not contain a crosslinking agent.

[0812] Specific examples of crosslinking agents that can be used in the present invention include epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl groups, melamine compounds, guanamine compounds, glycoluril compounds, urea compounds, isocyanate compounds, azide compounds, and compounds containing double bonds such as alkenyloxy groups. These can be used as additives or introduced into polymer side chains as pendant groups. Hydroxyl-containing compounds can also be used as crosslinking agents.

[0813] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0814] Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, compounds in which 1 to 6 methylol groups are methoxymethylated, such as hexamethylolmelamine, or mixtures thereof; and hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds in which 1 to 6 methylol groups are acyloxymethylated, such as hexamethylolmelamine, or mixtures thereof.

[0815] Examples of the guanamine compound include tetramethylolguanamine, tetramethoxymethylguanamine, tetramethylolguanamine and other compounds in which 1 to 4 hydroxymethyl groups are methoxymethylated, and mixtures thereof; and tetramethoxyethylguanamine, tetraacyloxyguanamine, tetramethylolguanamine and other compounds in which 1 to 4 hydroxymethyl groups are acyloxymethylated, and mixtures thereof.

[0816] Examples of the glycoluril compound include tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, tetramethylol glycoluril and compounds in which 1 to 4 hydroxymethyl groups are methoxymethylated, or mixtures thereof; and tetramethylol glycoluril and compounds in which 1 to 4 hydroxymethyl groups are acyloxymethylated, or mixtures thereof.

[0817] Examples of the urea compound include tetramethylolurea, tetramethoxymethylurea, compounds in which 1 to 4 methylol groups of tetramethylolurea are methoxymethylated, mixtures thereof, and tetramethoxyethylurea.

[0818] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0819] Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0820] Examples of the alkenyloxy group-containing compound 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.

[0821] In the chemically amplified negative resist composition of the present invention, the content of the crosslinking agent (C) is preferably 0.1 to 50 parts by mass, and more preferably 1 to 30 parts by mass, relative to 80 parts by mass of the base polymer (B). Within this range, patterns are connected, minimizing concerns about reduced resolution. The crosslinking agent (C) may be used alone or in combination of two or more.

[0822] [(D) Fluorine-containing polymer]

[0823] The chemically amplified negative resist composition of the present invention may contain, as component (D), a fluorine-containing polymer comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D1) (hereinafter also referred to as repeating unit D1), a repeating unit represented by the following formula (D2) (hereinafter also referred to as repeating unit D2), a repeating unit represented by the following formula (D3) (hereinafter also referred to as repeating unit D3), and a repeating unit represented by the following formula (D4) (hereinafter also referred to as repeating unit D4), and further comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D5) (hereinafter also referred to as repeating unit D5) and a repeating unit represented by the following formula (D6) (hereinafter also referred to as repeating unit D6), for the purpose of achieving high contrast, suppressing acid chemical flare during high-energy ray irradiation, shielding acid from mixing with the antistatic film during the process of coating the antistatic film material on the resist film, and suppressing unintended unnecessary pattern degradation. Since the fluorine-containing polymer also functions as a surfactant, it can prevent insoluble matter that may be generated during the development process from re-adhering to the substrate, thereby also having an effect on preventing development defects.

[0824] [Chemistry 291]

[0825]

[0826] In formulas (D1) to (D6), x is an integer of 1 to 3. y is an integer satisfying 0≤y≤5+2z-x. z is 0 or 1. g is an integer of 1 to 3. R C R are independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. D R are independently a hydrogen atom or a methyl group. 101 、R 102、R 104 and R 105 R is independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. 103 、R 106 、R 107 and R 108 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 103 、R 106 、R 107 and R 108 When it is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between carbon-carbon bonds. 109 R is a hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds. 110 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds. 111 It is a saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is substituted by a fluorine atom, and a portion of the -CH2- in the saturated hydrocarbon group may be substituted by an ester bond or an ether bond. 1 Z 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 an atomic bond to a carbon atom of the main chain. Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -.Z 31 Z is a single bond or a saturated alkylene group having 1 to 10 carbon atoms. 32 is a single bond, ester bond, ether bond or sulfonamide bond. * is an atomic bond to a carbon atom of the main chain.

[0827] In formulas (D1) and (D2), R 101 、R 102 、R 104 and R 105 The saturated hydrocarbon group having 1 to 10 carbon atoms represented by may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 10 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl; and cyclic saturated hydrocarbon groups having 3 to 10 carbon atoms, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, adamantyl, and norbornyl. Among these, saturated hydrocarbon groups having 1 to 6 carbon atoms are preferred.

[0828] In formulas (D1) to (D4), R103 、R 106 、R 107 and R 108 The hydrocarbon group having 1 to 15 carbon atoms may be linear, branched, or cyclic. Specific examples include alkyl groups having 1 to 15 carbon atoms, alkenyl groups having 2 to 15 carbon atoms, and alkynyl groups having 2 to 15 carbon atoms. Alkyl groups having 1 to 15 carbon atoms are preferred. Examples of the aforementioned alkyl groups include 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. Fluorinated hydrocarbon groups include those in which some or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon groups are substituted with fluorine atoms.

[0829] In formula (D4), Z 1 The (g+1)-valent hydrocarbon group having 1 to 20 carbon atoms represented by can be exemplified by removing g hydrogen atoms from an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. 1 Examples of the (g+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms include groups in which at least one hydrogen atom in the aforementioned (g+1)-valent hydrocarbon group is substituted with a fluorine atom.

[0830] Specific examples of repeating units D1 to D4 include the following, but are not limited thereto. C Same as above.

[0831] [Chemistry 292]

[0832]

[0833] [Chemistry 293]

[0834]

[0835] [Chemistry 294]

[0836]

[0837] In formula (D5), R 109 and R 110 Examples of the hydrocarbon group having 1 to 5 carbon atoms represented by include alkyl, alkenyl, and alkynyl groups, preferably alkyl groups. Examples of the aforementioned alkyl groups include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and n-pentyl groups. Furthermore, groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms may be inserted between carbon-carbon bonds of the aforementioned hydrocarbon groups.

[0838] In formula (D5), -OR 109 It is preferably a hydrophilic group. 109Preferred are hydrogen atoms, alkyl groups having 1 to 5 carbon atoms with an oxygen atom inserted between carbon-carbon bonds, and the like.

[0839] In formula (D5), Z 2 It is preferably *-C(=O)-O- or *-C(=O)-NH-. In addition, R D Preferably it is methyl. 2 The presence of carbonyl groups improves the ability of the antistatic film to capture acid. D Methyl groups form a rigid polymer with a higher glass transition temperature (Tg), which inhibits acid diffusion. This results in a resist film with good stability over time, without deteriorating resolution or pattern shape.

[0840] The repeating unit D5 may be exemplified by the following, but is not limited thereto. D Same as above.

[0841] [Chemistry 295]

[0842]

[0843] [Chemistry 296]

[0844]

[0845] In formula (D6), Z 3 The saturated alkylene group having 1 to 10 carbon atoms may be linear, branched, or cyclic. Specific examples thereof include methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-1,1-diyl, butane-1,2-diyl, butane-1,3-diyl, butane-2,3-diyl, butane-1,4-diyl, and 1,1-dimethylethane-1,2-diyl.

[0846] In formula (D6), R 111 The saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom may be any of linear, branched, and cyclic. Specific examples thereof include an alkyl group having 1 to 20 carbon atoms or a cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom.

[0847] The repeating unit D6 may be exemplified by the following, but is not limited thereto. D Same as above.

[0848] [Chemistry 297]

[0849]

[0850] [Chemistry 298]

[0851]

[0852] [Chemistry 299]

[0853]

[0854] [Chemistry 300]

[0855]

[0856] The content of repeating units D1 to D4 is preferably 15 to 95 mol%, more preferably 20 to 85 mol%, of the total repeating units of the fluorine-containing polymer. The content of repeating units D5 and / or D6 is preferably 5 to 85 mol%, more preferably 15 to 80 mol%, of the total repeating units of the fluorine-containing polymer. Repeating units D1 to D6 may be used alone or in combination of two or more.

[0857] The fluorine-containing polymer may contain other repeating units in addition to the aforementioned repeating units. Examples of such repeating units include those described in paragraphs

[0046] to

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

[0858] The fluorine-containing polymers can be synthesized by copolymerizing monomers protected with protecting groups, as needed, using known methods, followed by deprotection reactions as needed. The copolymerization reaction is not particularly limited, but is preferably free radical polymerization or anionic polymerization. These methods can be found in Japanese Patent Application Laid-Open No. 2004-115630.

[0859] The Mw of the fluorine-containing polymer is preferably 2,000 to 50,000, more preferably 3,000 to 20,000. An Mw of less than 2,000 may promote acid diffusion, degrade resolution, or impair stability over time. Excessively high Mw may reduce solubility in solvents and cause coating defects. Furthermore, the Mw / Mn ratio of the fluorine-containing polymer is preferably 1.0 to 2.2, more preferably 1.0 to 1.7.

[0860] When the chemically amplified negative resist composition of the present invention contains a fluorine-containing polymer (D), its content is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.5 to 10 parts by mass, relative to 80 parts by mass of the base polymer (B). The fluorine-containing polymer (D) may be used alone or in combination of two or more.

[0861] [(E) Quencher]

[0862] The chemically amplified negative resist composition of the present invention preferably contains a quencher as component (E). The quencher, as used herein, traps the acid generated by the photoacid generator in the chemically amplified resist composition, preventing it from diffusing into unexposed areas and thereby forming a desired pattern.

[0863] Examples of the quencher include known basic compounds. Examples of known basic compounds include primary, secondary, and tertiary aliphatic amines, mixed amines, aromatic amines, heterocyclic amines, nitrogen-containing compounds having carboxyl groups, nitrogen-containing compounds having sulfonyl groups, nitrogen-containing compounds having hydroxyl groups, nitrogen-containing compounds having hydroxyphenyl groups, alcoholic nitrogen-containing compounds, amides, imides, and carbamates. In particular, the primary, secondary, and tertiary amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Application Laid-Open No. 2008-111103, particularly amine compounds having a hydroxyl group, an ether bond, an ester bond, a lactone ring, a cyano group, or a sulfonate bond, and compounds having a carbamate group as described in Japanese Patent No. 3790649 are particularly preferred. Preferred examples include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, and imidazole derivatives. By adding such a basic compound, for example, the diffusion rate of acid in the resist film can be further suppressed or the shape can be corrected.

[0864] Examples of the quencher include onium salts such as sulfonium salts, iodonium salts, and ammonium salts of α-unfluorinated carboxylic acids described in Japanese Patent Application Laid-Open No. 2008-158339. Sulfonic acids, imidic acids, or methylated acids fluorinated at the α-position are necessary for deprotecting acid-labile groups. Salt exchange with the α-unfluorinated onium salt releases the α-unfluorinated carboxylic acid. Since the α-unfluorinated carboxylic acid hardly undergoes a deprotection reaction, it functions as a quencher.

[0865] Examples of the onium salt of a carboxylic acid whose α-position is not fluorinated include those represented by the following formula (E1).

[0866] [Chemistry 301]

[0867] R 201 -CO2 - Mq A + (E1)

[0868] In formula (E1), R 201 It is a hydrogen atom or a hydrocarbon group having 1 to 40 carbon atoms which may contain a heteroatom, but excludes those in which the hydrogen atom bonded to the carbon atom at the α-position of the carboxyl group is substituted by a fluorine atom or a fluoroalkyl group.

[0869] R 201 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples include: alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.0 2,6 ] Cyclic saturated hydrocarbon groups having 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; alkenyl groups having 2 to 40 carbon atoms, such as vinyl, allyl, propenyl, butenyl, and hexenyl; cyclic unsaturated aliphatic hydrocarbon groups having 3 to 40 carbon atoms, such as cyclohexenyl; aryl groups having 6 to 40 carbon atoms, such as phenyl, naphthyl, alkylphenyl (2-methylphenyl, 3-methylphenyl, 4-methylphenyl, 4-ethylphenyl, 4-tert-butylphenyl, 4-n-butylphenyl, etc.), di- or trialkylphenyl (2,4-dimethylphenyl, 2,4,6-triisopropylphenyl, etc.), alkylnaphthyl (methylnaphthyl, ethylnaphthyl, etc.), dialkylnaphthyl (dimethylnaphthyl, diethylnaphthyl, etc.); aralkyl groups having 7 to 40 carbon atoms, such as benzyl, 1-phenylethyl, and 2-phenylethyl, etc.

[0870] Furthermore, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, a nitrogen atom, or a halogen atom, and part of the -CH2- of the hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom. As a result, the hydrocarbon group may contain a hydroxyl group, a cyano group, a carbonyl group, an ether bond, a thioether bond, an ester bond, a sulfonate bond, a carbonate bond, a lactone ring, a sultone ring, a carboxylic anhydride (-C(=O)-OC(=O)-), a haloalkyl group, and the like. Examples of the hydrocarbon group containing a heteroatom include heteroaryl groups such as thienyl; alkoxyphenyl groups such as 4-hydroxyphenyl, 4-methoxyphenyl, 3-methoxyphenyl, 2-methoxyphenyl, 4-ethoxyphenyl, 4-tert-butoxyphenyl, and 3-tert-butoxyphenyl; alkoxynaphthyl groups such as methoxynaphthyl, ethoxynaphthyl, n-propoxynaphthyl, and n-butoxynaphthyl; dialkoxynaphthyl groups such as dimethoxynaphthyl and diethoxynaphthyl; aryl pendant oxyalkyl groups such as 2-aryl-2-oxoethyl groups such as 2-phenyl-2-oxoethyl, 2-(1-naphthyl)-2-oxoethyl, and 2-(2-naphthyl)-2-oxoethyl; and the like.

[0871] In formula (E1), Mq A +is an onium cation. The onium cation is preferably a sulfonium cation, an iodonium cation, or an ammonium cation, and is more preferably a sulfonium cation or an iodonium cation. Specific examples of the sulfonium cation include the same examples as those exemplified for the sulfonium cation represented by formula (cation-1). Specific examples of the iodonium cation include the same examples as those exemplified for the iodonium cation represented by formula (cation-2).

[0872] Examples of the anion of the onium salt represented by formula (E1) include, but are not limited to, the following.

[0873] [Chemistry 302]

[0874]

[0875] [Chemistry 303]

[0876]

[0877] [Chemistry 304]

[0878]

[0879] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (E2) can also be preferably used.

[0880] [Chemistry 305]

[0881]

[0882] In formula (E2), s is an integer of 1 to 5. t is an integer of 0 to 3. However, 1≤s+t≤5. u is an integer of 1 to 3.

[0883] In formula (E2), R 211 is a hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, an amino group, a nitro group, a cyano group, a saturated hydrocarbon group having 1 to 6 carbon atoms, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, a saturated hydrocarbon carbonyloxy group having 2 to 6 carbon atoms, a saturated hydrocarbon sulfonyloxy group having 1 to 4 carbon atoms, -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B , and part or all of the hydrogen atoms of the saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group or saturated hydrocarbon sulfonyl oxy group may be substituted by halogen atoms. 211A R is a hydrogen atom or a saturated hydrocarbon group having 1 to 6 carbon atoms. 211B is a saturated hydrocarbon group having 1 to 6 carbon atoms or an unsaturated aliphatic hydrocarbon group having 2 to 8 carbon atoms. 211 They can be the same or different.

[0884] In formula (E2), L1 The alkyl group 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 the group consisting of an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyl oxy group, and saturated hydrocarbon sulfonyl oxy group may be linear, branched, or cyclic.

[0885] In formula (E2), R 212 、R 213 and R 214 Each is independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be any of linear, branched, and cyclic. Specific examples thereof include: alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, arylalkyl groups having 7 to 20 carbon atoms, etc. In addition, part or all of the hydrogen atoms of the aforementioned hydrocarbon group may be substituted by a hydroxyl group, a carboxyl group, a halogen atom, an oxo group, a cyano group, a nitro group, a sultone ring, a sulfo group, or a group containing a sulfonium salt, and part of the -CH2- of the hydrocarbon group may be substituted by an ether bond, an ester bond, a carbonyl group, an amide bond, a carbonate bond, or a sulfonate bond. In addition, R 212 and R 213 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

[0886] Specific examples of the compound represented by formula (E2) include those described in Japanese Patent Application Laid-Open No. 2017-219836. The compound represented by formula (E2) has a high sensitization effect due to its high absorption and also has a high acid diffusion control effect.

[0887] As the quencher, a carboxylate-type compound containing a nitrogen atom represented by the following formula (E3) may be used.

[0888] [Chemistry 306]

[0889]

[0890] In formula (E3), R 221 ~R 224 are independently a hydrogen atom, -L 2 -CO2 - , or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 221 With R 222 、R 222 With R 223 , or R 223 With R 224 They can also bond to each other and to the carbon atoms to which they are bonded to form a ring. 2 R is a single bond or a alkylene group having 1 to 20 carbon atoms which may contain a hetero atom. 225It is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0891] In formula (E3), ring R r It is a ring having 2 to 6 carbon atoms and a nitrogen atom in the formula, and part or all of the hydrogen atoms bonded to the carbon atoms in the ring may be replaced by a hydrocarbon group having 1 to 20 carbon atoms, or -L 2 -CO2 - The -CH2- ring may be substituted, and a portion of the -CH2- ring may be substituted by a sulfur atom, an oxygen atom, or a nitrogen atom. The aforementioned ring may be an alicyclic ring or an aromatic ring, and is preferably a 5-membered ring or a 6-membered ring. Specific examples thereof 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.

[0892] The carboxylate salt represented by formula (E3) has at least one -L 2 -CO2 - That is, R 221 ~R 224 At least one of them is -L 2 -CO2 - and / or bonded to ring R r At least one of the hydrogen atoms of the carbon atom is replaced by -L 2 -CO2 - Replacer.

[0893] In formula (E3), Mq B + It is a sulfonium cation, an iodonium cation or an ammonium cation, preferably a sulfonium cation. Specific examples of the sulfonium cation include the same examples as those exemplified as the sulfonium cation represented by formula (cation-1).

[0894] Examples of the anion of the compound represented by formula (E3) include, but are not limited to, the following.

[0895] [Chemistry 307]

[0896]

[0897] [Chemistry 308]

[0898]

[0899] [Chemistry 309]

[0900]

[0901] [Chemistry 310]

[0902]

[0903] [Chemistry 311]

[0904]

[0905] [Chemistry 312]

[0906]

[0907] Furthermore, the aforementioned quencher may also be a weak acid betaine type compound. Specific examples thereof include the following, but are not limited thereto.

[0908] [Chemistry 313]

[0909]

[0910] The aforementioned quencher further includes the polymer-type quenchers described in Japanese Patent Application Laid-Open No. 2008-239918. These quenchers improve the rectangularity of the resist pattern by aligning on the surface of the resist film. Polymer-type quenchers also prevent film loss and doming of the pattern when using a protective film for immersion exposure.

[0911] When the chemically amplified negative resist composition of the present invention contains a quencher (E), its content is preferably 0 to 50 parts by mass, more preferably 0.1 to 40 parts by mass, relative to 80 parts by mass of the base polymer (B). The quencher (E) may be used alone or in combination of two or more.

[0912] When the chemically amplified negative resist composition of the present invention contains a photoacid generator as component (A) and a quencher as component (E), the content ratio of the photoacid generator to the quencher ((A) / (E)) is preferably less than 6, more preferably less than 5, and even more preferably less than 4, in terms of mass ratio. When the content ratio of the photoacid generator to the quencher in the chemically amplified negative resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be achieved.

[0913] [(F) Organic solvent]

[0914] The chemically amplified negative resist composition of the present invention may also contain an organic solvent as the (F) component. The aforementioned organic solvent is not particularly limited as long as it can dissolve the various components. Examples of such organic solvents include: ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentyl ketone, and 2-heptanone as described in paragraphs

[0144] to

[0145] of Japanese Patent Application Laid-Open 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 (PGME), and propylene glycol monomethyl ether (PGME). Ethers such as propylene glycol monoethyl ether, ethylene glycol monoethyl 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.

[0915] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and mixed solvents thereof are preferred.

[0916] When the chemically amplified negative resist composition of the present invention contains (F) an organic solvent, its content is preferably 200 to 10,000 parts by mass, more preferably 400 to 6,000 parts by mass, relative to 80 parts by mass of the base polymer (B). The organic solvent (F) may be used alone or as a mixture of two or more.

[0917] [(G) Surfactant]

[0918] The chemically amplified negative resist composition of the present invention may also contain a conventional surfactant to improve coating properties on a substrate. Examples of such surfactants include PF-636 (manufactured by OMNOVA SOLUTIONS) and FC-4430 (manufactured by 3M). Japanese Patent Application Laid-Open No. 2004-115630 also describes various examples. Many of these surfactants are known in the art and can be selected with reference to these examples. When the chemically amplified negative resist composition of the present invention contains a surfactant (G), its content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the base polymer (B). The surfactants (G) may be used alone or in combination of two or more.

[0919] [Resist Pattern Formation Method]

[0920] The resist pattern forming method of the present invention comprises the following steps:

[0921] Using the chemically amplified negative resist composition to form a resist film on a substrate,

[0922] irradiating the resist film with a pattern of high-energy rays (i.e., exposing the resist film with high-energy rays), and

[0923] The resist film having the irradiated pattern is developed using an alkaline developer.

[0924] The substrate may be, for example, a substrate used in integrated circuit manufacturing (e.g., Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film), or a substrate used in transmissive or reflective mask circuit manufacturing (e.g., Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2). The chemically amplified negative resist composition is applied to the substrate by spin coating or other methods to a film thickness of 0.03 to 2 μm. The resist composition is then pre-baked on a hot plate at preferably 60 to 150° C. for 1 to 20 minutes, more preferably 80 to 140° C. for 1 to 10 minutes, to form a resist film.

[0925] The resist film is then exposed to high-energy radiation in a pattern. Examples of such high-energy radiation include ultraviolet rays, extreme ultraviolet rays, excimer lasers (such as KrF and ArF), EUV radiation 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.

[0926] When ultraviolet rays, extreme ultraviolet rays, excimer lasers, EUV rays, X-rays, gamma rays or synchrotron radiation are used as the high energy radiation, a mask for forming a target pattern is used and the exposure dose is preferably 1 to 500 mJ / cm 2 More preferably, it is 10 to 400 mJ / cm 2 When using EB, in order to form the target pattern, the exposure dose should be 1 to 500 μC / cm 2 More preferably, it is 10 to 400 μC / cm 2 way of irradiation.

[0927] Exposure can be performed by a conventional exposure method or by a wetting method between a wetting mask and a resist film, depending on the situation. In this case, a water-insoluble protective film can also be used.

[0928] Then, a post-exposure bake (PEB) is performed on a hot plate at preferably 60-150° C. for 1-20 minutes, more preferably 80-140° C. for 1-10 minutes.

[0929] Thereafter, a developer containing 0.1 to 5% by mass, preferably 2 to 3% by mass, of an alkaline aqueous solution such as TMAH is used, and development is performed using a common method such as a dip method, a puddle method, or a spray method for preferably 0.1 to 3 minutes, and more preferably 0.5 to 2 minutes, thereby forming a desired pattern on the substrate.

[0930] In addition, the chemically amplified negative resist composition of the present invention is particularly useful in forming patterns with good resolution and low LER. Furthermore, the chemically amplified negative resist composition of the present invention is particularly useful in pattern formation on substrates whose surfaces have a material that is difficult to obtain adhesiveness of the resist pattern, which easily causes pattern peeling and pattern collapse. Examples of such substrates include substrates having a film of metallic chromium or a chromium compound containing one or more light elements selected from oxygen, nitrogen, and carbon sputtered on the outermost surface, and substrates containing SiO, SiO x , tantalum compounds, molybdenum compounds, cobalt compounds, nickel compounds, tungsten compounds, tin compounds, etc. The chemically amplified negative resist composition of the present invention is particularly useful for patterning using a blank photomask as a substrate. In this case, the blank photomask can be either transmissive or reflective.

[0931] Regarding transmissive mask blanks, those having a light-shielding film made of a chromium-based material can be used for either binary or phase-shift masks. Binary mask blanks can include an antireflection layer and a light-shielding layer made of a chromium-based material as the light-shielding film. Alternatively, the entire surface-side antireflection film may be made of a chromium-based material, or only the outermost layer of the surface-side antireflection film may be made of a chromium-based material, with the remainder being made of, for example, a silicon-based compound material that may also contain a transition metal. Furthermore, phase-shift mask blanks can include those having a chromium-based light-shielding film on a phase-shift film.

[0932] The aforementioned blank photomask having a chromium-based material as the outermost layer is already well known as the known current technology as exemplified in Japanese Patent Publication No. 2008-26500, Japanese Patent Publication No. 2007-302873 or therein, and detailed description thereof is omitted. For example, when a shading film having an anti-reflection layer and a shading layer is formed using a chromium-based material, a film structure as described below can be used.

[0933] When using chromium-based materials to form a light-shielding film having an antireflection layer and a light-shielding layer, the layer structure can be stacked sequentially from the surface side, or it can be stacked sequentially. Furthermore, the antireflection layer and the light-shielding layer can each be multiple layers, and the composition of the layers can vary discontinuously or continuously. Chromium-based materials can include metallic chromium and materials containing light elements such as oxygen, nitrogen, and carbon. Specifically, metallic chromium, chromium oxide, chromium nitride, chromium carbide, chromium nitride oxide, chromium carbide oxide, chromium carbide nitride, and chromium carbide oxide nitride.

[0934] A reflective mask blank comprises a substrate, a multilayer reflective film formed on one main surface (the outer 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 reflectivity. A reflective mask (EUV reflective mask) having an absorber pattern (absorber film pattern) formed by patterning the absorber film is manufactured from the reflective mask blank (EUV reflective mask blank). The EUV light used in EUV lithography has a wavelength of 13 to 14 nm, typically approximately 13.5 nm.

[0935] The multilayer reflective film is typically preferably provided in contact with one of the main surfaces of the substrate. However, 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 impaired. The absorber film may be formed in contact with the multilayer reflective film, or a protective film (a 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. More preferably, the protective film (a protective film for the multilayer reflective film) is provided in contact with both the multilayer reflective film and the absorber film. The protective film can be used to protect the multilayer reflective film during processing such as cleaning and correction. Furthermore, the protective film preferably has the function of protecting the multilayer reflective film and preventing oxidation of the multilayer reflective film when the absorber film is patterned by etching. Alternatively, a conductive film used for electrostatically clamping a reflective mask to an exposure apparatus may be provided on the other main surface (the inner surface) of the substrate, which is the surface opposite to the one main surface, preferably in contact with the other main surface. In addition, here, one main surface of the substrate is defined as the surface on the outer surface side and the upper side, and the other main surface is defined as the surface on the inner surface side and the lower side, but the outer surface, inner surface, and upper and lower sides of the two are defined for convenience of explanation. The one main surface and the other main surface can be either of the two main surfaces (film-forming surfaces) of the substrate, and the outer surface, inner surface, and upper and lower sides can be interchangeable. More specifically, it can be formed using a method as known in the art as exemplified in Japanese Patent Application Laid-Open No. 2021-139970 or the like.

[0936] According to the resist pattern forming method of the present invention, even when using a substrate (such as a transmission or reflection blank mask) whose outermost surface is made of a material that is easily affected by the shape of the resist pattern, such as a material containing chromium, silicon or tantalum, a pattern with extremely high resolution, small LER, excellent rectangularity and excellent pattern fidelity can still be obtained.

[0937] [Example]

[0938] Hereinafter, the present invention will be described in detail with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples.

[0939] IR: NICOLET 6700 manufactured by Thermo Fisher Scientific

[0940] · 1 H-NMR: ECA-500 manufactured by JEOL Ltd.

[0941] MALDI TOF-MS: S3000 manufactured by JEOL Ltd.

[0942] [1] Synthesis of onium salts

[0943] [Synthesis Example 1-1] Synthesis of PAG-1

[0944] [Chemistry 314]

[0945]

[0946] (1) Synthesis of intermediate In-1

[0947] Under a nitrogen atmosphere, raw material SM-1 (6.3 g), raw material SM-2 (9.8 g), DMAP (0.3 g) and dichloromethane (50 g) were added to the reaction vessel and cooled with an ice bath. While maintaining the temperature in the reaction vessel below 20°C, hydrochloric acid-1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (5.8 g) was added in a powdered state. After addition, the temperature was raised to room temperature and matured for 12 hours. After maturation, water was added to stop the reaction, and a usual aqueous work-up was performed. After distilling the solvent, diisopropyl ether was added to wash the residue, thereby obtaining 13.9 g of intermediate In-1 (yield 92%) as an oily substance.

[0948] (2) Synthesis of PAG-1

[0949] Under a nitrogen atmosphere, intermediate In-1 (13.9 g), raw material SM-3 (7.8 g), dichloromethane (50 g), and water (30 g) were added. After stirring for 15 minutes, the organic layer was separated, washed with water, and then concentrated under reduced pressure. Methyl isobutyl ketone (50 g) was added to the concentrate, and azeotropic dehydration was performed. Diisopropyl ether was further added for crystallization, resulting in 15.5 g of the target compound PAG-1 as white crystals (yield 92%).

[0950] The IR spectrum data and TOF-MS results of PAG-1 are shown below. 1 The results of H-NMR / DMSO-d6) are as follows Figure 1 shown.

[0951] IR(D-ATR): ν=3447,3064,3022,2971,1751,1626,1594,1583,1507,1464,1442,1379,1368,1322,1272,122 6,1204,1159,1132,1113,1064,1040,1021,998,905,886,832,816,762,706,684,632,601,577,534,493cm -1 .

[0952] MALDI TOF-MS:POSITIVE M + 277 (equivalent to C 18 H 13 OS + )

[0953] NEGATIVE M - 455 (equivalent to C 27 H 19 O5S - )

[0954] [Synthesis Examples 1-2 to 1-8] Synthesis of PAG-2 to PAG-8

[0955] Onium salts PAG-2 to PAG-8 represented by the following formulae were synthesized using corresponding raw materials and known organic synthesis reactions.

[0956] [Chemistry 315]

[0957]

[0958] [2] Preparation of chemically amplified negative resist compositions

[0959] [Examples 1-1 to 1-54, Comparative Examples 1-1 to 1-10]

[0960] Chemically amplified negative resist compositions (R-1 to R-54, CR-1 to CR-10) were prepared by dissolving the components shown in Tables 1 to 3 below in an organic solvent, and filtering the resulting solutions through a UPE filter and / or a nylon filter selected from 10 nm, 5 nm, 3 nm, and 1 nm sizes. The organic solvent was a mixed solvent of 790 parts by mass of PGMEA, 1580 parts by mass of EL, and 1580 parts by mass of PGME. Furthermore, fluorine-containing polymers (polymers FP-1 to FP-5) as additives, tetramethoxymethyl glycoluril (TMGU) as a crosslinking agent, and PF-636 (manufactured by OMNOVA SOLUTIONS) as a surfactant were added to a portion of the composition.

[0961] [Table 1]

[0962]

[0963]

[0964] [Table 2]

[0965]

[0966]

[0967] [Table 3]

[0968]

[0969]

[0970] In Tables 1 to 3, the structures of polymers P-1 to P-30 are shown in the following Table 4. Mw is a polystyrene-equivalent measurement value obtained by GPC using THF or DMF as a solvent.

[0971] [Table 4]

[0972]

[0973]

[0974] In Table 4, the structure of each unit is as follows.

[0975] [Chemistry 316]

[0976]

[0977] [Chemistry 317]

[0978]

[0979] [Chemistry 318]

[0980]

[0981] [Chemistry 319]

[0982]

[0983] [Chemistry 320]

[0984]

[0985] In Tables 1 to 3, other photoacid generator PAG-A, comparative photoacid generators cPAG-1 to cPAG-4, quenchers Q-1 to Q-4, and fluorine-containing polymers FP-1 to FP-5 are described below.

[0986] [Chemistry 321]

[0987]

[0988] [Chemistry 322]

[0989]

[0990] [Chemistry 323]

[0991]

[0992] [Chemistry 324]

[0993]

[0994] [3]EB lithography evaluation

[0995] [Examples 2-1 to 2-54, Comparative Examples 2-1 to 2-10]

[0996] Each chemically amplified negative resist composition (R-1 to R-54, CR-1 to CR-10) was spin-coated using ACT-M (manufactured by Tokyo Electron Co., Ltd.) on a 152 mm square blank mask with a silicon oxide film on the outermost surface after hexamethyldisilazane (HMDS) vapor prime treatment. The film was pre-baked at 110°C for 600 seconds on a hot plate to obtain a resist film with a thickness of 80 nm. The thickness of the obtained resist film was measured using an optical measuring instrument NANOSPEC (manufactured by Nanometrics). The measurement was performed at 81 locations within the surface of the blank substrate, excluding the outer edge portion from the periphery of the blank substrate to the inner side of 10 mm, and the average film thickness and the film thickness range were calculated.

[0997] Exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by NuFlare Technology Co., Ltd., accelerating voltage 50 kV), PEB was applied at 120° C. for 600 seconds, and development was performed with a 2.38% by mass TMAH aqueous solution to obtain a negative pattern.

[0998] The obtained resist pattern was evaluated as follows. The blank mask with the pattern was observed with an aerial SEM (scanning electron microscope), and the exposure dose that allowed a 1:1 resolution of 200 nm line and space (LS) was determined as the optimum exposure dose (μC / cm 2 ), and the minimum size of the exposure amount at which the 200nm LS is resolved at 1:1 is taken as the resolution (limiting resolution). For the 200nm LS pattern obtained by irradiation with the optimal exposure amount, edge detection is carried out on 80 points of each of the 32 edges of the 200nm LS pattern using SEM, and the 3 times value (3σ) of its variation (standard deviation, σ) is calculated and taken as LER (nm). The pattern shape is visually judged to see whether it is a rectangle. In addition, for the evaluation of pattern fidelity (Fidelity), the area loss (Area Loss) value (%) of one corner of the dot pattern is calculated when a square dot pattern with a density of 36% and a size of 120nm is arranged. The smaller the value, the better the rectangularity of the dot shape. The results are shown in Tables 5 to 7.

[0999] [Table 5]

[1000]

[1001]

[1002] [Table 6]

[1003]

[1004] [Table 7]

[1005]

[1006]

[1007] The chemically amplified negative resist compositions (R-1 to R-54) of the present invention all exhibited excellent resolution, LER, pattern rectangularity, and pattern fidelity. On the other hand, the comparative resist compositions (CR-1 to CR-10) had inadequately designed acid generators, resulting in insufficient performance in terms of resolution, LER, and pattern rectangularity.

[1008] The resist pattern forming method using the chemically amplified negative resist composition of the present invention is useful in semiconductor device manufacturing, particularly in optical lithography in processing transmissive or reflective photomask blanks.

Claims

1. A chemically amplified negative resist composition comprising: (A) a photoacid generator consisting of an onium salt represented by the following formula (A), and (B) a base polymer comprising a polymer containing a repeating unit represented by the following formula (B1); Where R 1 ~R 12 are each independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom; R 13 and R 14 One of them is a group having a partial structure represented by the following formula (a), and the other is a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a heteroatom; Again, R 1 ~R 14 At least two of them may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded, or form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them; Z + is an onium cation; In the formula, m1 is 0 or 1; m2 is an integer from 0 to 4 when m1 is 0, and an integer from 0 to 6 when m1 is 1; m3 is an integer from 0 to 3 when m1 is 0, and an integer from 0 to 5 when m1 is 1; however, m2+m3 is 0 to 4 when m1 is 0, and is 0 to 6 when m1 is 1; 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; R 15 is a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and when m3 is 2 or more, multiple R 15 They can also bond to each other and to the carbon atoms to which they are bonded to form rings; L A and L B are independently a single bond, an ether bond, an ester bond, an amide bond, a sulfonate bond, a sulfonamide bond, a carbonate bond or a carbamate bond; X L is a single bond or a alkylene group having 1 to 40 carbon atoms which may contain heteroatoms; Wherein, a1 is 0 or 1; a2 is 0, 1 or 2; a3 is an integer satisfying 0≤a3≤5+2(a2)-a4; a4 is 1, 2 or 3; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 21 is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom; A 1 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

2. The chemically amplified negative resist composition according to claim 1, wherein The onium salt is represented by the following formula (A1): Where R 1 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + Same as above.

3. The chemically amplified negative resist composition according to claim 2, wherein: The onium salt is represented by the following formula (A2): Where R 5 、R 10 ~R 13 、R 15 、L A 、X L 、R F , m1~m3 and Z + Same as above; m4 and m5 are each independently an integer from 0 to 4; R 16 and R 17 are independently a hydrogen atom, a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and when m4 is 2 or more, multiple R 16 They may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded, or form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them. When m5 is 2 or more, multiple R 17 They may also be bonded to each other and to form a ring together with the carbon atoms to which they are bonded, or to form a ring together with the carbon atoms to which they are bonded and the carbon atoms between them.

4. The chemically amplified negative resist composition according to claim 1, wherein Z + It is a sulfonium cation represented by the following formula (cation-1) or an iodonium cation represented by the following formula (cation-2); Where R ct1 ~R ct5 are independently a halogen atom or a hydrocarbon group having 1 to 30 carbon atoms which may contain a hetero atom; and R ct1 and R ct2 They may also bond to each other and to the sulfur atom to which they are bonded to form a ring.

5. The chemically amplified negative resist composition according to claim 1, wherein The polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B2) and a repeating unit represented by the following formula (B3); Wherein, b1 is 0 or 1; b2 is 0, 1 or 2; b3 is an integer satisfying 0≤b3≤5+2(b2)-b4; b4 is 1, 2 or 3; b5 is 0, 1 or 2; b6 is 1 or 2; R A are independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 31 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom; R 32 and R 33 are independently a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbon group may be substituted by a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may also have a substituent; however, R 32 and R 33 cannot be a hydrogen atom at the same time; and R 32 and R 33 They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- of the ring may be substituted by -O- or -S-; R 34 is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a heteroatom; R 35 and R 36 are independently a hydrogen atom, a saturated hydrocarbon group having 1 to 15 carbon atoms, or an aryl group having 6 to 15 carbon atoms, and the hydrocarbon group may be substituted by a hydroxyl group or a saturated hydrocarbon oxy group having 1 to 6 carbon atoms, and the aryl group may also have a substituent; however, R 35 and R 36 cannot be a hydrogen atom at the same time; and R 35 and R 36 They may also be bonded to each other and to the carbon atoms to which they are bonded to form a ring, and a portion of the -CH2- of the ring may be substituted by -O- or -S-; A 2 is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein a portion of -CH2- in the saturated alkylene group may be substituted by -O-; W 1 and W 2 Each of them is independently a hydrogen atom, an aliphatic hydrocarbon group having 1 to 10 carbon atoms, an aliphatic hydrocarbon carbonyl 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 according to claim 1, wherein The polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B4), a repeating unit represented by the following formula (B5), and a repeating unit represented by the following formula (B6); wherein c and d are each independently an integer of 0 to 4; e1 is 0 or 1; e2 is 0, 1 or 2; e3 is an integer of 0 to 5; R A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R 41 and R 42 Each of the groups is independently a hydroxyl group, a halogen atom, a saturated hydrocarbon group having 1 to 8 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbon oxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarbon carbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom; R 43 a saturated hydrocarbon group having 1 to 20 carbon atoms, a saturated hydrocarbonoxy group having 1 to 20 carbon atoms, a saturated hydrocarboncarbonyloxy group having 2 to 20 carbon atoms, a saturated hydrocarbonoxyhydrocarbon group having 2 to 20 carbon atoms, a saturated hydrocarbonthiohydrocarbon group having 2 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, a saturated hydrocarbonsulfinyl group having 1 to 20 carbon atoms, or a saturated hydrocarbonsulfonyl group having 1 to 20 carbon atoms; A 3 It is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of the -CH2- in the saturated alkylene group may be substituted by -O-.

7. The chemically amplified negative resist composition according to claim 5, wherein The polymer further contains at least one selected from the group consisting of a repeating unit represented by the following formula (B7), a repeating unit represented by the following formula (B8), a repeating unit represented by the following formula (B9), a repeating unit represented by the following formula (B10), a repeating unit represented by the following formula (B11), a repeating unit represented by the following formula (B12), a repeating unit represented by the following formula (B13), and a repeating unit represented by the following formula (B14); Where R B are each independently a hydrogen atom or a methyl group; Y 1 Each of them is independently a single bond, an aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining them, or *-OY 11 -、*-C(=O)-OY 11 - or *-C(=O)-NH-Y 11 -, and Y 11 An aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a naphthylene group, or a group having 7 to 18 carbon atoms obtained by combining these groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; Y 2 are independently a single bond or **-Y 21 -C(=O)-O-, and Y 21 is a hydrocarbon group having 1 to 20 carbon atoms which may also contain heteroatoms; Y 3 are independently a single bond, a methylene group, an ethylene group, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, *-OY 31 -、*-C(=O)-OY 31 - or *-C(=O)-NH-Y 31 -;Y 31 An aliphatic alkylene group having 1 to 6 carbon atoms, a phenylene group, a fluorinated phenylene group, a phenylene group substituted with a trifluoromethyl group, or a group having 7 to 20 carbon atoms obtained by combining these groups, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group; * is the atomic bond to the carbon atom of the main chain, ** is the atomic bond to the oxygen atom in the formula; Y 4 Each is independently a single bond or a carbonylene group having 1 to 30 carbon atoms which may contain a heteroatom; f1 and f2 are independently 0 or 1, but in Y 4 When it is a single bond, f1 and f2 are 0; R 51 ~R 68 are independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom; and R 51 and R 52 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 53 and R 54 、R 56 and R 57 , or R 59 and R 60 They can also bond to each other and to the sulfur atoms to which they are bonded to form a ring; R HF is a hydrogen atom or a trifluoromethyl group; XA - It is a non-nucleophilic relative ion.

8. The chemically amplified negative resist composition according to claim 7, wherein The polymer contains a repeating unit represented by the following formula (B1-1), a repeating unit represented by the following formula (B2-1), (B2-2) or (B3-1), and a repeating unit represented by the following formula (B8); Where a4, b4, b6, R A 、R B 、Y 2 、R 32 、R 33 、R 35 、R 36 、R 53 、R 54 、R 55 and R HF Same as above.

9. The chemically amplified negative resist composition according to claim 7, wherein The (B) base polymer further includes a polymer containing a repeating unit represented by formula (B1) and a repeating unit represented by formula (B2) or (B3), and not containing a repeating unit represented by formulae (B7) to (B14).

10. 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 the base polymer is 60 mol% or more. 11 . The chemically amplified negative resist composition according to claim 1 , further comprising (C) a cross-linking agent.

12. The chemically amplified negative resist composition according to claim 5, which does not contain a cross-linking agent.

13. The chemically amplified negative resist composition according to claim 1, further comprising: (D) a fluorine-containing polymer comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D1), a repeating unit represented by the following formula (D2), a repeating unit represented by the following formula (D3), and a repeating unit represented by the following formula (D4), and further comprising at least one member selected from the group consisting of a repeating unit represented by the following formula (D5) and a repeating unit represented by the following formula (D6); In the formula, x is an integer from 1 to 3; y is an integer satisfying 0≤y≤5+2z-x; z is 0 or 1; g is an integer from 1 to 3; R C are 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 hydrocarbon group having 1 to 10 carbon atoms; R 103 、R 106 、R 107 and R 108 are independently a hydrogen atom, a hydrocarbon group having 1 to 15 carbon atoms, a fluorinated hydrocarbon group having 1 to 15 carbon atoms, or an acid-labile group, and R 103 、R 106 、R 107 and R 108 When it is a hydrocarbon group or a fluorinated hydrocarbon group, an ether bond or a carbonyl group may be inserted between the carbon-carbon bonds; R 109 A hydrogen atom or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds; R 110 It is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may have a heteroatom-containing group inserted between carbon-carbon bonds; R 111 A saturated hydrocarbon group having 1 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom, wherein a portion of the -CH2- of the saturated hydrocarbon group may be replaced by an ester bond or an ether bond; Z 1 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 an atomic bond to a carbon atom of the main chain; Z 3 is a single bond, -O-, *-C(=O)-OZ 31 -Z 32 - or *-C(=O)-NH-Z 31 -Z 32 -;Z 31 is a single bond or a saturated alkylene group having 1 to 10 carbon atoms; Z 32 is a single bond, an ester bond, an ether bond or a sulfonamide bond; * is the atomic bond to the carbon atom of the main chain. 14 . The chemically amplified negative resist composition according to claim 1 , further comprising (E) a quencher.

15. The chemically amplified negative resist composition according to claim 14, wherein The content ratio of the (A) acid generator to the (E) quencher is less than 6 in terms of mass ratio. 16 . The chemically amplified negative resist composition according to claim 1 , further comprising (F) an organic solvent.

17. A method for forming a resist pattern, comprising the following steps: forming a resist film on a substrate using the chemically amplified negative resist composition according to any one of claims 1 to 16, The resist film is irradiated with a pattern of high-energy radiation, and The resist film having the irradiated pattern is developed using an alkaline developer.

18. The resist pattern forming method according to claim 17, wherein The high-energy rays are extreme ultraviolet rays or electron beams with a wavelength of 3 to 15 nm.

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

20. The resist pattern forming method according to claim 17, wherein The substrate is a transmission type or reflection type blank mask.

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

Images