Monomer, polymer, chemically amplified negative resist composition, and resist pattern forming method

Abstract

The invention relates to a monomer, a polymer, 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 and a method for forming a resist pattern, the chemically amplified negative resist composition being capable of improving the resolution at the time of pattern formation and obtaining a resist pattern having improved LER, pattern loyalty, and dose tolerance. [Solution] A monomer represented by formula (A1), a polymer containing a repeating unit derived from the monomer, and a chemically amplified negative resist composition containing a base polymer containing the polymer. # imgabs0 #

Description

Technical Field

[0001] The invention relates to monomers, polymers, chemically amplified negative resist compositions and resist pattern forming methods. Background Art

[0002] In recent years, with the high integration and high speed of LSI, the pattern rules have been rapidly miniaturized. Among them, for the processing of patterns below 0.2μm, chemically amplified resist compositions using acid as a catalyst are mainly used. In addition, high-energy rays such as ultraviolet rays, far ultraviolet rays, and electron beams (EB) are used as exposure sources. In particular, EB lithography, which is used in ultra-fine processing technology, has become an indispensable element in the processing method of blank photomasks when making photomasks for semiconductor manufacturing.

[0003] Polymers having a large number of aromatic skeletons having acidic side chains, such as polyhydroxystyrene, are useful as materials for KrF lithography resist compositions using KrF excimer lasers, but they exhibit significant absorption of light having a wavelength of around 200 nm and therefore cannot be used as materials for ArF lithography resist compositions using ArF excimer lasers. However, as materials for EB lithography resist compositions and extreme ultraviolet (EUV) lithography resist compositions, which are powerful technologies for forming patterns with a processing limit smaller than that formed by ArF excimer lasers, they are important materials from the viewpoint of obtaining high etching resistance.

[0004] As for the resist composition used in optical lithography, there are positive type which dissolves the exposed part to form a pattern and negative type which leaves the exposed part to form a pattern, and they can be selected according to the desired resist pattern form for the convenience of the user. Chemically amplified negative resist composition usually contains a polymer dissolved in an aqueous alkaline developer, an acid generator which decomposes and generates an acid by the light of exposure, and a crosslinking agent which uses the acid as a catalyst and forms crosslinks between polymers to make the polymer insoluble in the aforementioned developer (sometimes the polymer and the crosslinking agent are integrated in some cases), and a quencher is usually further added to control the diffusion of the acid generated by exposure.

[0005] As for the alkaline soluble units constituting the polymer dissolved in the aforementioned aqueous alkaline developer, the units derived from phenols can be cited. In the past, a large number of such negative resist compositions have been developed, especially for exposure by KrF excimer laser. However, for these, the units derived from phenols do not have light penetrability when the exposure light is a wavelength of 150 to 220 nm, so they cannot be used for ArF excimer laser. However, in recent years, negative resist compositions for short-wavelength exposure light such as EB and EUV, which are exposure methods for obtaining finer patterns, have again attracted attention. For example, patent documents 1, 2 and 3 have been reported.

[0006] In addition to the above, a large number of materials for chemically amplified negative resist compositions have been developed so far. For example, Patent Documents 4 and 5 use a crosslinking agent as described below, which makes the alkaline soluble polymer that provides a negative mechanism used in the resist composition insoluble through the acid generated when it is irradiated with high-energy rays, and a large number of crosslinking agents have been developed. On the other hand, a large number of attempts have been made to give the polymer the function of the crosslinking agent, and some people have proposed a method of introducing a styrene unit substituted with an alkoxymethoxy group (Patent Document 6), a method of introducing a repeating unit having an alkoxymethylamino group (Patent Document 7), a method of introducing a repeating unit having an epoxy group (Patent Document 8), a method of introducing a styrene-based repeating unit having an acid leaving group (Patent Document 9), a method of introducing adamantane-based repeating units having an acid leaving hydroxyl group (Patent Document 10), and a method of introducing aliphatic hydrocarbon groups and alicyclic hydrocarbon-based repeating units having an acid leaving hydroxyl group (Patent Documents 9 to 15).

[0007] Although these methods have confirmed some degree of performance improvement, satisfactory results have not yet been obtained. In order to meet the demand for further miniaturization, it is important to develop chemically amplified negative resist materials with excellent sensitivity, limiting resolution, and high contrast.

[0008] Prior art literature

[0009] Patent Literature

[0010] [Patent Document 1] Japanese Patent No. 4396849

[0011] [Patent Document 2] Japanese Patent No. 4478589

[0012] [Patent Document 3] Japanese Patent No. 4678383

[0013] [Patent Document 4] Japanese Patent No. 4955732

[0014] [Patent Document 5] Japanese Patent No. 4801190

[0015] [Patent Document 6] Japanese Patent Application Laid-Open No. 5-232702

[0016] [Patent Document 7] Japanese Patent Application Laid-Open No. 8-202037

[0017] [Patent Document 8] Japanese Patent No. 3914363

[0018] [Patent Document 9] Japanese Patent Application Publication No. 2003-337414

[0019] [Patent Document 10] Japanese Patent No. 4648526

[0020] [Patent Document 11] U.S. Patent No. 7,300,739

[0021] [Patent Document 12] U.S. Patent No. 7,393,624

[0022] [Patent Document 13] U.S. Patent No. 7,563,558

[0023] [Patent Document 14] Japanese Patent Application Publication No. 2013-164588

[0024] [Patent Document 15] Japanese Patent Application Publication No. 2019-203103 Summary of the invention

[0025] [Problems to be solved by the invention]

[0026] In view of the above situation, the present invention aims 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 improved LER, pattern fidelity and dose tolerance.

[0027] [Methods to solve the problem]

[0028] The inventors of the present application have repeatedly and diligently studied to achieve the aforementioned objectives and have discovered that when a polymer containing repeating units from a monomer having a specific dehydration functional group is introduced into a chemically amplified negative resist composition, a pattern exhibiting good resolution and pattern shape, improved LER, pattern fidelity and dose tolerance, and excellent etching resistance can be obtained, thereby completing the present invention.

[0029] That is, the present invention provides the following monomers, polymers, chemically amplified negative resist compositions, and resist pattern forming methods.

[0030] 1. A monomer represented by the following formula (A1):

[0031] [Chemistry 1]

[0032]

[0033] In the formula, a1 is 1 or 2, a2 ​​is 0, 1 or 2,

[0034] R A , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

[0035] R 1 , is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom,

[0036] R 2 and R 3 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms. The aryl group may also have a substituent. However, R 2 and R 3 , are not hydrogen atoms at the same time, and R 2 and R 3 , or they may be bonded to each other and to the carbon atoms to which they are bonded to form a ring, a part of the -CH2- of the ring may also be substituted by -O- or -S-,

[0037] W 1 , is 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.

[0038] 2. The monomer of 1 is a monomer represented by the following formula (A1-1),

[0039] [Chemistry 2]

[0040]

[0041] In the formula, a2, R A , R 1 , R 2 , R 3 and W 1 , the same as above.

[0042] 3. The monomer of 2 is a monomer represented by the following formula (A1-2),

[0043] [Chemistry 3]

[0044]

[0045] In the formula, a2, R A , R 1 , R 2 and R 3 , the same as above.

[0046] 4. A polymer comprising repeating units derived from the monomers of any one of 1 to 3.

[0047] 5. The polymer of 4 further comprises a repeating unit represented by the following formula (A2):

[0048] [Chemistry 4]

[0049]

[0050] 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,

[0051] R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

[0052] R 11 , is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom,

[0053] A 1 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a portion of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0054] 6. The polymer of 4 or 5 further comprises at least one selected from the group consisting of a repeating unit represented by the following formula (A3), a repeating unit represented by the following formula (A4), and a repeating unit represented by the following formula (A5),

[0055] [Chemistry 5]

[0056]

[0057] 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, and e3 is an integer of 0 to 5.

[0058] R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

[0059] R 21 and R 22 , each independently represents 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 hydrocarbonoxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom,

[0060] R 23 , 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 oxyalkyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiol 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,

[0061] A 2 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a portion of the -CH2- in the saturated alkylene group may be substituted by -O-.

[0062] 7. The polymer according to any one of 4 to 6, further comprising a repeating unit represented by the following formula (A6):

[0063] [Chemistry 6]

[0064]

[0065] Wherein, f1 is 0 or 1, f2 is 0, 1 or 2, f3 is an integer satisfying 0≤f3≤5+2(f2)-f4, f4 is 1, 2 or 3,

[0066] R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

[0067] R 31 , is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom,

[0068] R 32 and R 33 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms. The aryl group may also have a substituent. However, R 32 and R 33 , are not hydrogen atoms at the same time, and R 32 and R 33 , can also bond to each other and to the carbon atoms to which they are bonded to form a ring,

[0069] A 3 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein the -CH2- of the saturated alkylene group may be substituted by -O-,

[0070] W 2 , is 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.

[0071] 8. The polymer according to any one of 4 to 7, further comprising at least one repeating unit selected from the group consisting of the following formulae (A7) to (A14):

[0072] [Chemistry 7]

[0073]

[0074] In the formula, R B , are each independently a hydrogen atom or a methyl group,

[0075] X 1, each independently represents 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, -OX 11 -、-C(=O)-OX 11 -or-C(=O)-NH-X 11 -, X 11 , 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group,

[0076] X 2 , each independently a single bond or -X 21 -C(=O)-O-,X 21 , is an alkylene group having 1 to 20 carbon atoms which may contain a hetero atom,

[0077] X 3 , each independently a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OX 31 -、-C(=O)-OX 31 -or-C(=O)-NH-X 31 -, X 31 , 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group,

[0078] X 4 , each independently represents a single bond or an alkylene group having 1 to 30 carbon atoms which may contain a heteroatom,

[0079] g1 and g2 are each independently 0 or 1, X 4 When it is a single bond, g1 and g2 are 0.

[0080] R 41 ~R 58 , are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and R 41 and R 42 , can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 43 and R 44 , R 46 and R 47 , or R 49 and R 50 , can also bond to each other and to the sulfur atoms to which they are bonded to form a ring,

[0081] R HF , is a hydrogen atom or a trifluoromethyl group,

[0082] XA - , which is a non-nucleophilic relative ion.

[0083] 9. A chemically amplified negative resist composition comprising a base polymer comprising the polymer according to any one of 4 to 8.

[0084] 10. The chemically amplified negative resist composition according 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.

[0085] 11. The chemically amplified negative resist composition of 9 or 10 further comprises (B) an acid generator.

[0086] 12. The chemically amplified negative resist composition according to any one of items 9 to 11, further comprising (C) a cross-linking agent.

[0087] 13. The chemically amplified negative resist composition according to any one of 9 to 11, which does not contain a cross-linking agent.

[0088] 14. The chemically amplified negative resist composition according to any one of items 9 to 13, further comprising (D) a fluorine-containing polymer comprising 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 comprise 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),

[0089] [Chemistry 8]

[0090]

[0091] Wherein, x is 1, 2 or 3, y is an integer satisfying 0≤y≤5+2z-x, z is 0 or 1, k is 1, 2 or 3,

[0092] R C , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group,

[0093] R D , are each independently a hydrogen atom or a methyl group,

[0094] R 101 , R 102 , R 104 and R 105 , each independently a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms,

[0095] R 103 , R 106 , R 107 and R 108, each 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, R 103 , R 106 , R 107 and R 108 When it is a hydrocarbon group or a fluorinated hydrocarbon group, the carbon-carbon bond may be separated by an ether bond or a carbonyl group.

[0096] R 109 , is a hydrogen atom, or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be separated by a heteroatom-containing group between carbon-carbon bonds,

[0097] R 110 , is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be separated by a heteroatom-containing group between carbon-carbon bonds,

[0098] R 111 , 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 -CH2- in the saturated hydrocarbon group may also be substituted by an ester bond or an ether bond,

[0099] Z 1 , is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms,

[0100] Z 2 , is a single bond, *-C(=O)-O- or *-C(=O)-NH-,

[0101] 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,

[0102] *, is the atomic bond to the carbon atom of the main chain.

[0103] 15. The negative resist composition according to any one of items 9 to 14, further comprising (E) a quencher.

[0104] 16. The chemically amplified negative resist composition according to any one of items 9 to 15, further comprising (F) an organic solvent.

[0105] 17. A method for forming a resist pattern, comprising the following steps: forming a resist film on a substrate using a chemically amplified negative resist composition as described in any one of items 9 to 16, irradiating the resist film with a pattern using high-energy rays, and developing the resist film irradiated with the pattern using an alkaline developer.

[0106] 18. The resist pattern forming method according to 17, wherein the high-energy ray is extreme ultraviolet ray or electron beam.

[0107] 19. The resist pattern forming method according to 17 or 18, wherein the outermost surface of the substrate is composed of a material containing at least one selected from chromium, silicon, tantalum, molybdenum, cobalt, nickel, tungsten and tin.

[0108] 20. The method for forming a resist pattern according to any one of 17 to 19, wherein the substrate is a transmission type or reflection type blank mask.

[0109] 21. A transmission or reflection type blank mask coated with the chemically amplified negative resist composition according to any one of items 9 to 16.

[0110] [Effects of the Invention]

[0111] When a chemically amplified negative resist composition containing a polymer obtained from the monomer of the present invention as a base polymer is used for pattern formation, a polarity change is carried out with good sensitivity accompanied by a dehydration reaction, so that a pattern with high resolution and pattern fidelity can be formed. At the same time, the LER and dose tolerance are improved, and the etching resistance is also excellent. Therefore, it is suitable for use in micro-processing technology, especially EUV lithography and EB lithography. DETAILED DESCRIPTION

[0112] The present invention is described in detail below, but the present invention is not limited thereto. In the following description, depending on the structure represented by the chemical formula, there may be asymmetric carbon, mirror image isomers and non-mirror image isomers, and in this case, these isomers are represented by a single formula. These isomers may be used alone or as a mixture.

[0113] [monomer]

[0114] The monomer of the present invention is represented by the following formula (A1).

[0115] [Chemistry 9]

[0116]

[0117] In formula (A1), a1 is an integer of 1 or 2, preferably 1. a2 is 0, 1 or 2, preferably 0 or 1.

[0118] In formula (A1), R A , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. Among them, a hydrogen atom and a methyl group are preferred.

[0119] In formula (A1), R 1, is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0120] Just R 1 Specific examples of the halogen atom represented by include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom, and the like.

[0121] R 1 The hydrocarbon group having 1 to 20 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 20 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, tert-pentyl, n-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 20 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups having 6 to 20 carbon atoms, such as phenyl, naphthyl, and anthracenyl; groups obtained by combining them, etc. In addition, part 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 part of -CH2- of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, hydroxyl groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, cyano groups, carbonyl groups, ether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, amide bonds, imide bonds, lactone rings, sultone rings, thiolactone rings, lactam rings, sultam rings, carboxylic anhydride (-C(=O)-OC(=O)-), haloalkyl groups, etc. may be included.

[0122] In formula (A1), R 2 and R 3 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms, and the aryl group may have a substituent.

[0123] R 2 and R 3 The saturated hydrocarbon group having 1 to 15 carbon atoms represented by may be straight-chain, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 15 carbon atoms, such as methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, 2-ethylhexyl, n-octyl, n-nonyl and n-decyl; and cyclic saturated hydrocarbon groups having 3 to 15 carbon atoms, such as cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl and adamantyl.

[0124] Just R 2 and R3 Specific examples of the aryl group having 6 to 15 carbon atoms represented by , include phenyl, naphthyl, anthracenyl, etc., among which phenyl is preferred. In addition, 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 by a halogen atom, and a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom.

[0125] Again, R 2 and R 3 , are not hydrogen atoms at the same time. 2 and R 3 When any one of is an aryl group which may have a substituent, the substituent of the other one is preferably a hydrogen atom.

[0126] R 2 and R 3 , preferably they are the same group, more preferably they are all methyl groups.

[0127] Again, R 2 and R 3 , may also be bonded to each other and form a ring together with the carbon atoms to which they are bonded, and a portion of the -CH2- of the ring may also be substituted by -O- or -S-. As for the aforementioned ring, cyclopropane ring, cyclobutane ring, cyclopentane ring, cyclohexane ring, norbornane ring, adamantane ring, tricyclo[5.2.1.0 2,6 ]Decane ring, tetracyclic [6.2.1.1 3,6 .0 2,7 ] dodecane ring, oxonorbornane ring, thionorbornane ring, etc., but are not limited to these.

[0128] In formula (A1), W 1 , is 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.

[0129] W 1 The 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 1The hydrocarbon portion of the aliphatic hydrocarbon carbonyl group having 2 to 10 carbon atoms represented by may be saturated or unsaturated, and may be linear, branched, or cyclic. As specific examples thereof, among the specific examples of the aliphatic hydrocarbon group having 1 to 10 carbon atoms, those having 1 to 9 carbon atoms can be cited. 1 Specific examples of the aryl group having 6 to 15 carbon atoms represented by , include phenyl, naphthyl, anthracenyl, etc., among which phenyl is preferred. In addition, 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 by a halogen atom, and a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom.

[0130] Just W 1 As for the alkyl group, it is preferably a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, more preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, more preferably a hydrogen atom or a methyl group, and most preferably a hydrogen atom.

[0131] The monomer represented by the formula (A1) is preferably a monomer represented by the following formula (A1-1).

[0132] [Chemistry 10]

[0133]

[0134] In the formula, a2, R A , R 1 , R 2 , R 3 and W 1 , the same as above.

[0135] The monomer represented by the formula (A1-1) is more preferably represented by the following formula (A1-2).

[0136] [Chemistry 11]

[0137]

[0138] In the formula, a2, R A , R 1 , R 2 and R 3 , the same as above.

[0139] Specific examples of the monomer represented by formula (A1) include the following, but are not limited to these. A Same as above, Me is methyl and Ac is acetyl.

[0140] [Chemistry 12]

[0141]

[0142] [Chemistry 13]

[0143]

[0144] [Chemistry 14]

[0145]

[0146] [Chemistry 15]

[0147]

[0148] [Chemistry 16]

[0149]

[0150] [Chemistry 17]

[0151]

[0152] [Chemistry 18]

[0153]

[0154] [Chemistry 19]

[0155]

[0156] [Chemistry 20]

[0157]

[0158] [Chemistry 21]

[0159]

[0160] [Chemistry 22]

[0161]

[0162] [Chemistry 23]

[0163]

[0164] [Chemistry 24]

[0165]

[0166] [Chemistry 25]

[0167]

[0168] [Chemistry 26]

[0169]

[0170] [Chemistry 27]

[0171]

[0172] [Chemistry 28]

[0173]

[0174] [Chemistry 29]

[0175]

[0176] [Chemistry 30]

[0177]

[0178] [Chemistry 31]

[0179]

[0180] [Chemistry 32]

[0181]

[0182] [Chemistry 33]

[0183]

[0184] [Chemistry 34]

[0185]

[0186] [Chemistry 35]

[0187]

[0188] [Chemistry 36]

[0189]

[0190] [Chemistry 37]

[0191]

[0192] [Chemistry 38]

[0193]

[0194] [Chemistry 39]

[0195]

[0196] [Chemistry 40]

[0197]

[0198] [Chemistry 41]

[0199]

[0200] [Chemistry 42]

[0201]

[0202] [Chemistry 43]

[0203]

[0204] [Chemistry 44]

[0205]

[0206] The monomer of the present invention can be synthesized by a known method. For example, in the above formula (A1), R 2 and R 3 are the same group, W 1 Although monomer A1-ex which is a hydrogen atom is described, the synthesis method is not limited thereto.

[0207] [Chemistry 45]

[0208]

[0209] In the formula, a2, R A , R 1 and R 2 , the same as above. x , is a hydrocarbon group having 1 to 10 carbon atoms. hal , is a chlorine atom, a bromine atom or an iodine atom.

[0210] The above method is to react a commercially available ester compound SM-1 or a ketone compound SM-2 which can be synthesized by a known synthesis method with a Grignard reagent to obtain the target monomer A1-ex.

[0211] The reaction can be carried out using a known organic synthesis method. Specifically, magnesium metal is suspended in an ether solvent such as tetrahydrofuran (THF) or diethyl ether, and a halogen compound diluted with the solvent used is added dropwise to prepare a Grignard reagent. When preparing the Grignard reagent, especially when the halogen compound is a chloride, the reaction can be started efficiently by adding a small amount of 1,2-dibromoethane and iodine and then starting the dropwise addition of the halogen compound. For the prepared Grignard reagent, an ester compound SM-1 or a ketone compound SM-2 diluted with the solvent used is added dropwise. The reaction temperature is carried out at room temperature to about the boiling point of the solvent used. Considering the yield, the reaction time is preferably about 30 minutes to 2 hours, and the reaction is completed by tracking the reaction by gas chromatography (GC) or silica gel thin layer chromatography (TLC). The target monomer A1-ex can be obtained from the reaction mixture by conventional aqueous work-up. The obtained monomer A1-ex can be purified by conventional methods such as distillation, chromatography, and recrystallization, if necessary.

[0212] As for the structural characteristics of the monomer of the present invention, the characteristics of having an acenaphthylene structure as a polymerizable group and being bonded with an acid dehydration group (or an acid leaving group) can be cited. The acid dehydration group (acid leaving group) reacts with the acid generated by the acid generator to cause a dehydration reaction (leaving reaction) to generate a benzyl cation. By releasing the adjacent hydrogen atom as a proton, it becomes an olefin structure conjugated with the acenaphthylene structure and becomes hydrophobic. Alternatively, the phenolic hydroxyl group in the copolymerized polymer chain also enhances the hydrophobicity by carrying out a nucleophilic attack on the generated benzyl cation. In addition, the acenaphthylene structure is a rigid structure and exhibits good resistance in the etching step after the formation of the resist pattern. Through these addition effects, the chemically amplified negative resist composition containing a polymer using the monomer of the present invention as a copolymerization unit has the following effects: the contrast and resolution between the exposed part and the unexposed part are good, and even in the formation of a fine pattern, a resist pattern with excellent developer resistance and etching resistance can be formed.

[0213] [polymer]

[0214] The polymer of the present invention includes a repeating unit derived from the above-mentioned monomer (hereinafter referred to as repeating unit A1).

[0215] The polymer may further include a repeating unit represented by the following formula (A2) (hereinafter, also referred to as repeating unit A2). The repeating unit A2 is a repeating unit that provides etching resistance, adhesion to a substrate, and solubility in an alkaline developer.

[0216] [Chemistry 46]

[0217]

[0218] In formula (A2), b1 is 0 or 1. b2 is 0, 1 or 2, and when 0, it represents a benzene skeleton, when 1, it represents a naphthalene skeleton, and when 2, it represents an anthracene skeleton. b3 is an integer satisfying 0≤b3≤5+2(b2)-b4. b4 is 1, 2 or 3. When b2 is 0, preferably, b3 is an integer of 0 to 3, and b4 is 1, 2 or 3. When b2 is 1 or 2, preferably, b3 is an integer of 0 to 4, and b4 is 1, 2 or 3.

[0219] In formula (A2), R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0220] In formula (A2), R 11 , 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 oxy group, and the saturated hydrocarbon carbonyloxy group may be linear, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, butyl, pentyl, hexyl, and structural isomers thereof; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining them. If the number of carbon atoms is below the upper limit, the solubility in alkaline developer is good. When b3 is 2 or more, each R 11 , may be the same as or different from each other.

[0221] In formula (A2), A 1 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of -CH2- of the saturated alkylene group may be substituted by -O-. The saturated alkylene group may be linear, branched or cyclic. Specific examples thereof include alkane diyl 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 cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, and cyclohexane diyl; and groups obtained by combining these. When the saturated alkylene group includes an ether bond, when b1 in formula (A2) is 1, it may be inserted at any position with respect to the ester oxygen atom except between the carbon atom at the α position and the carbon atom at the β position. When b1 is 0, the atom bonded to the main chain is an etheric oxygen atom, and the second etheric oxygen atom can be inserted at any position except between the carbon atom at the α position and the carbon atom at the β position. Furthermore, if the carbon number of the saturated alkylene group is 10 or less, sufficient solubility in an alkaline developer can be obtained, which is preferred.

[0222] b1 is 0 and A 1When it is a single bond, that is, the aromatic ring and the main chain of the polymer are directly bonded (that is, there is no connecting group (-C(=O)-OA 1 -)), preferred examples of the repeating unit A2 include units derived from 3-hydroxystyrene, 4-hydroxystyrene, 5-hydroxy-2-vinylnaphthalene, 6-hydroxy-2-vinylnaphthalene, etc. In particular, the repeating unit represented by the following formula (A2-1) is preferred.

[0223] [Chemistry 47]

[0224]

[0225] In the formula, R A and b4, same as above.

[0226] b1 is 1 (i.e., having -C(=O)-OA as a linking group) 1 -), preferred examples of the repeating unit A2 include the following, but are not limited to these.

[0227] [Chemistry 48]

[0228]

[0229] In the formula, R A , the same as above.

[0230] The repeating unit A2 may be used alone or in combination of two or more.

[0231] The aforementioned polymer may also contain at least one selected from the repeating unit represented by the following formula (A3) (hereinafter, also referred to as repeating unit A3), the repeating unit represented by the following formula (A4) (hereinafter, also referred to as repeating unit A4) and the repeating unit represented by the following formula (A5) (hereinafter, also referred to as repeating unit A5), in order to improve the etching resistance.

[0232] [Chemistry 49]

[0233]

[0234] In formulae (A3) and (A4), c and d are each independently an integer of 0-4.

[0235] In formula (A3) and (A4), R 21 and R 22 , each independently represents 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 straight-chain, branched, or cyclic. When c is 2 or more, each R21 , may be the same as or different from each other. When d is 2 or more, each R 22 , may be the same as or different from each other.

[0236] In formula (A5), e1 is 0 or 1. e2 is 0, 1 or 2, and when it is 0, it represents a benzene skeleton, when it is 1, it represents a naphthalene skeleton, and when it is 2, it represents an anthracene skeleton. e3 is an integer of 0 to 5. When e2 is 0, e3 is preferably an integer of 0 to 3, and when e2 is 1 or 2, e3 is preferably an integer of 0 to 4.

[0237] In formula (A5), R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0238] In formula (A5), R 23 , 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 oxyalkyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiol 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 aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyloxy group, saturated hydrocarbon oxyalkyl group, saturated hydrocarbon thiol 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 23 , may be the same as or different from each other.

[0239] Just R 23 For example, halogen atoms such as chlorine atoms, bromine atoms, and iodine atoms are preferred; saturated hydrocarbon groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, and structural isomers thereof; and saturated hydrocarbonoxy groups such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, cyclopentyloxy, cyclohexyloxy, and structural isomers of their hydrocarbon moieties are preferred. Among them, methoxy and ethoxy are particularly useful.

[0240] Furthermore, the saturated hydrocarbon carbonyloxy group can be easily introduced by chemical modification even after the polymer is polymerized, and can be used to fine-tune the solubility of the base polymer in the alkaline developer. As for the aforementioned saturated hydrocarbon carbonyloxy group, methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, butylcarbonyloxy, pentylcarbonyloxy, hexylcarbonyloxy, cyclopentylcarbonyloxy, cyclohexylcarbonyloxy, benzoyloxy, and structural isomers of their hydrocarbon parts can be cited. If the number of carbon atoms is 20 or less, it can have an appropriate effect of controlling / adjusting the solubility of the base polymer in the alkaline developer (mainly a reducing effect), and can suppress the generation of scum (development defects).

[0241] Among the above-mentioned preferred substituents, particularly useful substituents that are easy to prepare in terms of a monomer include a chlorine atom, a bromine atom, an iodine atom, a methyl group, an ethyl group, and a methoxy group.

[0242] In formula (A5), A 2 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a part of -CH2- of the saturated alkylene group may be substituted by -O-. The saturated alkylene group may be linear, branched or cyclic. Specific examples thereof include alkane diyl 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 cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, and cyclohexane diyl; and groups obtained by combining these. When the saturated alkylene group contains an ether bond, when e1 in formula (A5) is 1, the ester oxygen atom may be inserted at any position except between the carbon atom at the α position and the carbon atom at the β position. When e1 is 0, the atom bonded to the main chain is an etheric oxygen atom, and the second ether bond can be inserted anywhere except between the carbon atom at the α position and the carbon atom at the β position. Furthermore, if the carbon number of the saturated alkylene group is 10 or less, sufficient solubility in an alkaline developer can be obtained, which is preferred.

[0243] e1 is 0 and A 2 When it is a single bond, that is, the aromatic ring and the main chain of the polymer are directly bonded (that is, there is no connecting group (-C(=O)-OA 2 -)), preferred examples of the repeating unit A5 include units derived from styrene, 4-chlorostyrene, 4-methylstyrene, 4-methoxystyrene, 4-bromostyrene, 4-acetoxystyrene, 2-hydroxypropylstyrene, 2-vinylnaphthalene, 3-vinylnaphthalene and the like.

[0244] When e1 is 1 (i.e., having -C(=O)-OA as a linking group) 2 -), as for the preferred examples of repeating unit A5, the following ones can be listed, but they are not limited to these. And, in the following formula, R A , the same as above.

[0245] [Chemistry 50]

[0246]

[0247] [Chemistry 51]

[0248]

[0249] When at least one of the repeating units A3 to A5 is used as a constituent unit of the polymer, in addition to the etching resistance of the aromatic ring, the etching resistance obtained by adding a ring structure to the main chain and the EB irradiation resistance during pattern inspection can be improved.

[0250] The repeating units A3 to A5 may be used alone or in combination of two or more.

[0251] The aforementioned polymer may further include a repeating unit represented by the following formula (A6) (hereinafter, also referred to as repeating unit A6).

[0252] [Chemistry 52]

[0253]

[0254] Repeating unit A6, like repeating unit A1, is irradiated with high-energy radiation, and the acid generated by the acid generator causes -OW 1 A repeating unit that undergoes a leaving reaction, thereby causing insolubilization in an alkaline developer and a cross-linking reaction between polymers. The negative tone reaction can be efficiently regulated by the action of the repeating unit A6, thereby improving the resolution performance.

[0255] In formula (A6), f1 is 0 or 1. f2 is 0, 1 or 2. f3 is an integer satisfying 0≤f3≤5+2(f2)-f4. f4 is 1, 2 or 3.

[0256] In formula (A6), R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

[0257] In formula (A6), R 31 , 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 oxy group, and the saturated hydrocarbon carbonyloxy group may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, pentyl, hexyl, and their structural isomers; cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl; and groups obtained by combining these. When f3 is 2 or more, each R 31 , may be the same as or different from each other.

[0258] In formula (A6), R 32 and R 33 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms, and the aryl group may also have a substituent. However, R 32 and R 33 , are not hydrogen atoms at the same time. 32 and R 33 , or they may bond to each other and to the carbon atoms to which they are bonded to form a ring. 13 and R14 Preferred examples include methyl, ethyl, propyl, butyl, alkyl groups such as structural isomers thereof, and groups in which a part of hydrogen atoms thereof is substituted with a hydroxyl group or a saturated hydrocarbonoxy group.

[0259] In formula (A6), A 3 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and the -CH2- of the saturated alkylene group may be substituted by -O-. The saturated alkylene group may be linear, branched or cyclic. Specific examples thereof include alkane diyl groups 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 such as cyclopropane diyl, cyclobutane diyl, cyclopentane diyl, and cyclohexane diyl; and groups obtained by combining them. In the case where the saturated alkylene group includes an ether bond, when f1 in formula (A6) is 1, it may be inserted at any position with respect to the ester oxygen atom except between the carbon atom at the α position and the carbon atom at the β position. When f1 is 0, the atom bonded to the main chain is an etheric oxygen atom, and the second ether bond may be inserted anywhere in the etheric oxygen atom except between the carbon atom at the α-position and the carbon atom at the β-position.

[0260] In formula (A6), W 2 , is 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 also have a substituent. 2 Specific examples of the group represented by include the same as W in the description of formula (A1). 1 The specific examples of the groups represented are the same as those exemplified above.

[0261] The repeating unit A6 is preferably represented by the following formula (A6-1) or (A6-2).

[0262] [Chemistry 53]

[0263]

[0264] In the formula, f4, R A , R 32 and R 33 , the same as above.

[0265] Preferred examples of repeating unit A6 include those shown below, but are not limited thereto. A As mentioned above, Me is a methyl group, Et is an ethyl group, and Ac is an acetyl group. In addition, the group extending from the aromatic ring may be bonded to any position of the carbon atoms forming the aromatic ring.

[0266] [Chemistry 54]

[0267]

[0268] [Chemistry 55]

[0269]

[0270] [Chemistry 56]

[0271]

[0272] [Chemistry 57]

[0273]

[0274] [Chemistry 58]

[0275]

[0276] The repeating unit A6 may be used alone or in combination of two or more.

[0277] The aforementioned polymer may further include at least one selected from the group consisting of a repeating unit represented by the following formula (A7) (hereinafter, also referred to as repeating unit A7), a repeating unit represented by the following formula (A8) (hereinafter, also referred to as repeating unit A8), a repeating unit represented by the following formula (A9) (hereinafter, also referred to as repeating unit A9), a repeating unit represented by the following formula (A10) (hereinafter, also referred to as repeating unit A10), a repeating unit represented by the following formula (A11) (hereinafter, also referred to as repeating unit A11), a repeating unit represented by the following formula (A12) (hereinafter, also referred to as repeating unit A12), a repeating unit represented by the following formula (A13) (hereinafter, also referred to as repeating unit A13), and a repeating unit represented by the following formula (A14) (hereinafter, also referred to as repeating unit A14). In this case, acid diffusion can be effectively suppressed, and a pattern with improved resolution and reduced LER can be obtained.

[0278] [Chemistry 59]

[0279]

[0280] In formulas (A7) to (A14), R B , each independently a hydrogen atom or a methyl group. 1 , each independently represents 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, -OX 11 -、-C(=O)-OX 11 -or-C(=O)-NH-X 11 -, X 11, 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 2 , each independently a single bond or -X 21 -C(=O)-O-,X 21 , is an alkylene group having 1 to 20 carbon atoms which may contain a hetero atom. 3 , each independently a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OX 31 -、-C(=O)-OX 31 -or-C(=O)-NH-X 31 -, X 31 , 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group. 4 , each independently represents a single bond or an alkylene group having 1 to 30 carbon atoms which may contain a hetero atom. g1 and g2, each independently represents 0 or 1, X 4 When it is a single bond, g1 and g2 are 0.

[0281] In formula (A7) and (A11), Xa - , which is a non-nucleophilic relative ion. - Examples of the non-nucleophilic counter ion represented by include those described in JP-A-2010-113209 and JP-A-2007-145797.

[0282] In formula (A8) and (A12), X 2 -X 21 -C(=O)-O-, then X 21 As for the alkylene group which may contain a hetero atom, the following ones can be mentioned, but it is not limited to these.

[0283] [Chemistry 60]

[0284]

[0285] In the formula, the dotted lines are atomic bonds.

[0286] In formula (A8) and (A12), R HF , is a hydrogen atom or a trifluoromethyl group. In repeating units A8 and A12, R HF Specific examples of the case where R is a hydrogen atom include those described in Japanese Patent Application Laid-Open No. 2010-116550. HFSpecific examples of the trifluoromethyl group include those described in JP-A-2010-77404. Specific examples of the repeating units A9 and A13 include those described in JP-A-2012-246265 and JP-A-2012-246426.

[0287] In formula (A7) and (A11), Xa - , which is a non-nucleophilic relative ion. - Examples of the non-nucleophilic counter ion represented by include those described in JP-A-2010-113209 and JP-A-2007-145797.

[0288] Preferred examples of anions of the monomers providing the repeating units A10 and A14 include those shown below, but are not limited thereto.

[0289] [Chemistry 61]

[0290]

[0291] [Chemistry 62]

[0292]

[0293] In formulas (A7) to (A14), R 41 ~R 58 , each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may also contain a hetero atom. Examples of the aforementioned halogen atom include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. As specific examples thereof, examples include the same R as in the description of formula (A1): 1 The same as those exemplified for the hydrocarbon groups represented by . In addition, part 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 part of -CH2- of the aforementioned hydrocarbon groups may be substituted by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, and as a result, 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, etc. may be included.

[0294] Again, R 41 and R 42 , can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 43 and R 44 , R 46 and R 47 , or R 49 and R 50, may also be bonded to each other and form a ring together with the sulfur atom to which they are bonded. As for the ring formed in this case, the following formula may be mentioned.

[0295] [Chemistry 63]

[0296]

[0297] In the formula, the dotted lines are atomic bonds.

[0298] Specific examples of the sulfonium cations in the repeating units A8 to A10 include those shown below, but are not limited to these.

[0299] [Chemistry 64]

[0300]

[0301] [Chemistry 65]

[0302]

[0303] [Chemistry 66]

[0304]

[0305] [Chemistry 67]

[0306]

[0307] [Chemistry 68]

[0308]

[0309] [Chemistry 69]

[0310]

[0311] [Chemistry 70]

[0312]

[0313] [Chemistry 71]

[0314]

[0315] [Chemistry 72]

[0316]

[0317] [Chemistry 73]

[0318]

[0319] [Chemistry 74]

[0320]

[0321] [Chemistry 75]

[0322]

[0323] [Chemistry 76]

[0324]

[0325] [Chemistry 77]

[0326]

[0327] [Chemistry 78]

[0328]

[0329] [Chemistry 79]

[0330]

[0331] [Chemistry 80]

[0332]

[0333] [Chemistry 81]

[0334]

[0335] [Chemistry 82]

[0336]

[0337] [Chemistry 83]

[0338]

[0339] [Chemistry 84]

[0340]

[0341] [Chemistry 85]

[0342]

[0343] [Chemistry 86]

[0344]

[0345] [Chemistry 87]

[0346]

[0347] [Chemistry 88]

[0348]

[0349] [Chemistry 89]

[0350]

[0351] Specific examples of the iodonium cations in the repeating units A12 to A14 include those shown below, but are not limited to these.

[0352] [Chemistry 90]

[0353]

[0354] [Chemistry 91]

[0355]

[0356] Repeating units A7 to A14 are units that generate acid due to irradiation with high-energy rays. It is believed that by including these units in the polymer, acid diffusion is moderately suppressed, and a pattern with reduced LER can be obtained. In addition, it is believed that by including these units in the polymer, the phenomenon that the acid evaporates from the exposed part and re-attaches to the unexposed part during baking in a vacuum is suppressed, which is effective for reducing LER and reducing defects caused by suppressing undesirable negative-type reactions in the unexposed part.

[0357] The repeating units A7 to A14 may be used alone or in combination of two or more.

[0358] The polymer may contain a (meth)acrylate unit having a lactone structure or an adhesive group such as a hydroxyl group other than a phenolic hydroxyl group, or other repeating units in order to finely adjust the properties of the resist film.

[0359] Examples of the (meth)acrylate unit having the aforementioned adhesion group include a repeating unit represented by the following formula (A15) (hereinafter, also referred to as repeating unit A15), a repeating unit represented by the following formula (A16) (hereinafter, also referred to as repeating unit A16), and a repeating unit represented by the following formula (A17) (hereinafter, also referred to as repeating unit A17). These units do not exhibit acidity and can be used as auxiliary units for providing adhesion to a substrate or adjusting solubility.

[0360] [Chemistry 92]

[0361]

[0362] In formulas (A15) to (A17), R A , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. 61 , is -O- or methylene. 62 , is a hydrogen atom or a hydroxyl group. 63, is a saturated hydrocarbon group having 1 to 4 carbon atoms. h, is an integer of 0 to 3. The repeating units A15 to A17 may be used alone or in combination of two or more.

[0363] In the above-mentioned polymer, the total content of repeating units A1 and A6 is preferably 5 to 70 mol%, and more preferably 10 to 60 mol%, in order to obtain the effect of promoting the negative type reaction. The content of repeating unit A1 alone is preferably 5 to 70 mol%, and more preferably 10 to 50 mol%, in order to show good etching resistance. In addition, the content of repeating unit A2 is preferably 30 to 95 mol%, and more preferably 50 to 85 mol%, in order to obtain high resolution and to form a high contrast between the negative type part formed by high-energy ray irradiation and the non-irradiated part (non-negative type part). The content of repeating units A3 to A5 is preferably 0 to 30 mol%, and more preferably 0 to 20 mol%, in order to obtain the effect of improving etching resistance. In addition, other repeating units may also be included in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0364] In the case where the aforementioned polymer does not contain repeating units A7 to A14, the content of repeating unit A2 in the aforementioned polymer is preferably 25 to 95 mol%, preferably 40 to 85 mol%. The content of repeating units A3 to A5 is preferably 0 to 30 mol%, preferably 3 to 20 mol%. The content of repeating unit A5 is preferably 5 to 70 mol%, 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%.

[0365] In the case where the aforementioned polymer contains repeating units A7 to A14, the content of the repeating unit A2 in the aforementioned polymer is preferably 25 to 94.5 mol%, preferably 36 to 85 mol%. The content of repeating units A3 to A5 is preferably 0 to 30 mol%, preferably 3 to 20 mol%. The content of repeating units A5 is preferably 5 to 70 mol%, preferably 10 to 60 mol%. In addition, the total content of repeating units A1 to A5 is preferably 60 to 99.5 mol%. The content of repeating units A7 to A14 is preferably 0.5 to 20 mol%, preferably 1 to 10 mol%. In addition, other repeating units may also be included in an amount of 0 to 30 mol%, preferably 0 to 20 mol%.

[0366] The aforementioned polymer can utilize known methods, by making each monomer protected by blocking group be copolymerized as needed, and then synthesizing by deprotection reaction as needed. Copolymerization reaction is not particularly limited, and is preferably free radical polymerization, anionic polymerization. For these methods, reference can be made to International Publication No. 2006 / 121096, Japanese Patent Publication No. 2008-102383, Japanese Patent Publication No. 2008-304590, Japanese Patent Publication No. 2004-115630.

[0367] [Chemically amplified negative resist composition]

[0368] The chemically amplified negative resist composition of the present invention comprises (A) the aforementioned base polymer containing polymer.

[0369] In this case, in the polymer, the repeating units A1 to A6 preferably account for 60 mol% or more of all the repeating units, more preferably 70 mol% or more, and even more preferably 80 mol% or more. Thus, the desired properties of the chemically amplified negative resist composition of the present invention can be obtained.

[0370] For the above-mentioned polymer, the weight average molecular weight (Mw) is preferably 1000 to 50000, and more preferably 2000 to 20000. If Mw is above 1000, there will be no concerns about the phenomenon of pattern doming, reduced resolution, and LER degradation as known in the past. On the other hand, if Mw is below 50000, there will be no concern about increased LER when forming a pattern line width, especially a pattern with a line width of less than 100nm. In addition, Mw in the present invention is a polystyrene conversion measurement value obtained by gel permeation chromatography (GPC).

[0371] The polymer preferably has a molecular weight distribution (Mw / Mn) of 1.0 to 2.0, particularly preferably 1.0 to 1.8. With such a narrow distribution, foreign matter will not be generated on the pattern after development, and the shape of the pattern will not be deteriorated.

[0372] As for the (A) base polymer, it may also include two or more polymers with different composition ratios, Mw, and Mw / Mn. In particular, a polymer that does not contain repeating units A7 to A14 and a polymer that contains repeating units A7 to A14 may be used in combination. In this case, the content of the polymer that does not contain repeating units A7 to A14 in the chemically amplified negative resist composition of the present invention is preferably 2 to 5000 parts by mass, and more preferably 10 to 1000 parts by mass, relative to 100 parts by mass of the polymer that contains repeating units A7 to A14.

[0373] When the chemically amplified negative resist composition is used in mask production, the coating film thickness in the most advanced generation is 150 nm or less, preferably 100 nm or less. The dissolution rate of the aforementioned base polymer for alkaline developer (for example, 2.38 mass % tetramethylammonium hydroxide (TMAH) aqueous solution) is generally 80 nm / sec or less, preferably 50 nm / sec or less, in order to further reduce defects caused by resist residues, and strong development treatment is often performed. In order to form fine patterns, it is preferably 80 nm / sec or less, and more preferably 50 nm / sec or less. In addition, for example, when making LSI chips from wafers, using EUV exposure treatment and using the chemically amplified negative resist composition of the present invention, considering the need to pattern fine lines below 50 nm, the coating film thickness is often set to 100 nm or less. Since it is a thin film, the pattern formed by development is deteriorated. From the perspective of the dissolution rate of the polymer used, it is preferably 80 nm / sec or less, and more preferably 50 nm / sec or less.

[0374] [(B) Acid generator]

[0375] The chemically amplified negative resist composition of the present invention may also contain an acid generator as component (B). As for such an acid generator, for example, compounds that generate acid by induction of active light or radiation (photoacid generators) can be cited. As for the photoacid generator, there is no particular limitation as long as it is a compound that generates acid by irradiation with high-energy rays. As for preferred photoacid generators, there are sulfonium salts, iodonium salts, sulfonyldiazomethane, N-sulfonyloxyimide, oxime-O-sulfonate type acid generators, etc.

[0376] Specific examples of the photoacid generator include nonafluorobutanesulfonate, partially fluorinated sulfonates described in paragraphs

[0247] to

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

[0261] to

[0265] of Japanese Patent Application Laid-Open No. 2013-101271, paragraphs

[0122] to

[0142] of Japanese Patent Application Laid-Open No. 2008-111103, and paragraphs

[0080] to

[0081] of Japanese Patent Application Laid-Open No. 2010-215608. Among them, arylsulfonate-type or alkanesulfonate-type photoacid generators are preferred because they react with the crosslinking agent (C) and the base polymer (A) described later to generate an acid of appropriate strength.

[0377] In addition, since the LER improvement effect can be obtained by combining the photoacid generator with the quencher of the component (E) described later, the pKa of the acid generated by the photoacid generator is not less than -3.0, preferably in the range of -3.0 to 2.0, and more preferably in the range of -2.0 to 1.5.

[0378] Such an acid generator is preferably a compound having an anion structure shown below: As the counter cation, there are those exemplified in the specific examples of the sulfonium cation in the repeating units A8 to A10 and those exemplified in the specific examples of the iodonium cation in the repeating units A12 to A14.

[0379] [Chemistry 93]

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[0499] [Chemistry 153]

[0500]

[0501] When the chemically amplified negative resist composition of the present invention contains (B) an acid generator, its content is preferably 1 to 30 parts by mass, and more preferably 2 to 20 parts by mass, relative to 80 parts by mass of the (A) base polymer. Furthermore, when the base polymer contains repeating units A7 to A14 (i.e., in the case of a polymer-bonded acid generator), the addition of the (B) acid generator may be omitted. The (B) acid generator may be used alone or in combination of two or more.

[0502] [(C) Cross-linking agent]

[0503] The chemically amplified negative resist composition of the present invention may also contain a crosslinking agent as component (C). Specific examples of the aforementioned crosslinking agent include epoxy compounds substituted with at least one group selected from hydroxymethyl, alkoxymethyl, and acyloxymethyl, melamine compounds, guanamine compounds, glycoluril compounds or urea compounds, isocyanate compounds, azide compounds, compounds containing double bonds such as alkenyloxy groups, etc. These can be used as additives or introduced into polymer side chains as pendant groups. In addition, hydroxyl-containing compounds can also be used as crosslinking agents.

[0504] Examples of the epoxy compound include tris(2,3-epoxypropyl)isocyanurate, trimethylolmethane triglycidyl ether, trimethylolpropane triglycidyl ether, and triethylolethane triglycidyl ether.

[0505] Examples of the melamine compound include hexamethylolmelamine, hexamethoxymethylmelamine, compounds having 1 to 6 methylol groups methoxymethylated, such as hexamethylolmelamine, or mixtures thereof, and hexamethoxyethylmelamine, hexaacyloxymethylmelamine, compounds having 1 to 6 methylol groups acyloxymethylated, such as hexamethylolmelamine, or mixtures thereof.

[0506] Examples of the guanamine compounds include compounds in which 1 to 4 hydroxymethyl groups are methoxymethylated, such as tetramethylolguanamine, tetramethoxymethylguanamine, and mixtures thereof; and compounds in which 1 to 4 hydroxymethyl groups are acyloxymethylated, such as tetramethoxyethylguanamine, tetraacyloxyguanamine, and tetramethylolguanamine, and mixtures thereof.

[0507] Examples of the glycoluril compound include compounds in which 1 to 4 hydroxymethyl groups are methoxymethylated, such as tetramethylol glycoluril, tetramethoxy glycoluril, tetramethoxymethyl glycoluril, or mixtures thereof, and compounds in which 1 to 4 hydroxymethyl groups of tetramethylol glycoluril are acyloxymethylated, or mixtures thereof.

[0508] Examples of the urea compound include tetramethylol urea, tetramethoxymethyl urea, compounds in which 1 to 4 methylol groups are methoxymethylated, such as tetramethylol urea, or mixtures thereof, and tetramethoxyethyl urea.

[0509] Examples of the isocyanate compound include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and cyclohexane diisocyanate.

[0510] Examples of the azide compound include 1,1′-biphenyl-4,4′-bisazide, 4,4′-methylenebisazide, and 4,4′-oxybisazide.

[0511] Examples of the alkenyloxy group-containing compound include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,4-butylene glycol 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.

[0512] 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 (A). If it is within the above range, the patterns are connected and there is less concern about the reduction of resolution. The crosslinking agent (C) can be used alone or in combination of two or more.

[0513] [(D) Fluorine-containing polymer]

[0514] The chemically amplified negative resist composition of the present invention may also contain a fluorine atom-containing polymer as component (D), which contains at least one selected from the repeating unit represented by the following formula (D1) (hereinafter, also referred to as repeating unit D1), the repeating unit represented by the following formula (D2) (hereinafter, also referred to as repeating unit D2), the repeating unit represented by the following formula (D3) (hereinafter, also referred to as repeating unit D3) and the repeating unit represented by the following formula (D4) (hereinafter, also referred to as repeating unit D4), and may further contain at least one selected from the repeating unit represented by the following formula (D5) (hereinafter, also referred to as repeating unit D5) and the repeating unit represented by the following formula (D6) (hereinafter, also referred to as repeating unit D6). The aforementioned fluorine-atom-containing polymer also has a surfactant function, so it can prevent the insoluble matter that may be generated during the development process from re-adhering to the substrate, and thus it can also be effective in treating development defects.

[0515] [Chemistry 154]

[0516]

[0517] In formulas (D1) to (D6), x is 1, 2 or 3. y is an integer satisfying 0≤y≤5+2z-x. z is 0 or 1. k is 1, 2 or 3. R C , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. D , each independently a hydrogen atom or a methyl group. 101 , R 102 , R 104 and R 105 , each independently represents a hydrogen atom or a saturated hydrocarbon group having 1 to 10 carbon atoms. 103 , R 106 , R 107 and R 108 , each 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, R 103 , R 106 , R 107 and R 108 When it is a hydrocarbon group or a fluorinated hydrocarbon group, the carbon-carbon bond may be separated by an ether bond or a carbonyl group. 109 , is a hydrogen atom, or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, wherein a hetero atom-containing group may be present between carbon-carbon bonds. 110, is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be separated by a heteroatom-containing group between carbon-carbon bonds. 111 , 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 , is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms. 2 , is a single bond, *-C(=O)-O- or *-C(=O)-NH-. 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. 32 , is a single bond, ester bond, ether bond or sulfonamide bond. *, is an atomic bond to a carbon atom of the main chain.

[0518] In formula (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 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, 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 them, saturated hydrocarbon groups having 1 to 6 carbon atoms are preferred.

[0519] In formulas (D1) to (D4), R 103 , R 106 , R 107 and R 108 The hydrocarbon group having 1 to 15 carbon atoms represented by may be straight-chain, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 15 carbon atoms, alkenyl groups having 2 to 15 carbon atoms, alkynyl groups having 2 to 15 carbon atoms, etc., and alkyl groups having 1 to 15 carbon atoms are preferred. As for the aforementioned alkyl groups, in addition to the aforementioned examples, 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, n-pentadecyl, etc. may be mentioned. In addition, as for the fluorinated hydrocarbon groups, groups in which a part or all of the hydrogen atoms bonded to the carbon atoms of the aforementioned hydrocarbon groups are substituted with fluorine atoms may be mentioned.

[0520] In formula (D4), Z1 The (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms represented by , includes a group obtained by excluding k 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 As for the (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms represented by , there can be mentioned a group in which at least one hydrogen atom in the (k+1)-valent hydrocarbon group is substituted with a fluorine atom.

[0521] Specific examples of repeating units D1 to D4 include those shown below, but are not limited to these. C , the same as above.

[0522] [Chemistry 155]

[0523]

[0524] [Chemistry 156]

[0525]

[0526] [Chemistry 157]

[0527]

[0528] In formula (D5), R 109 and R 110 As for the hydrocarbon group having 1 to 5 carbon atoms represented by , alkyl, alkenyl, alkynyl, etc. can be mentioned, and alkyl is preferred. As for the aforementioned alkyl, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, etc. can be mentioned. In addition, the carbon-carbon bonds of the aforementioned hydrocarbon groups may be separated by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms.

[0529] In formula (D5), -OR 109 Preferably, it is a hydrophilic group. In this case, R 109 Preferred are hydrogen atoms, alkyl groups having 1 to 5 carbon atoms with an oxygen atom between carbon-carbon bonds, and the like.

[0530] In formula (D5), Z 2 , preferably *-C(=O)-O- or *-C(=O)-NH-. Furthermore, R D Preferably, Z is methyl. 2 The presence of a carbonyl group in the antistatic film can enhance the ability to capture acid from the antistatic film. D If the group is a methyl group, it will become a rigid polymer with a higher glass transition temperature (Tg), so the diffusion of acid will be suppressed. As a result, the stability of the resist film over time will be improved, and the resolution and pattern shape will not be deteriorated.

[0531] The repeating unit D5 includes the following, but is not limited thereto. D , the same as above.

[0532] [Chemistry 158]

[0533]

[0534] [Chemistry 159]

[0535]

[0536] 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.

[0537] 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 straight-chain, branched or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms or cyclic saturated hydrocarbon groups having 3 to 20 carbon atoms in which at least one hydrogen atom is replaced by a fluorine atom.

[0538] The repeating unit D6 includes the following, but is not limited thereto. D , the same as above.

[0539] [Chemistry 160]

[0540]

[0541] [Chemistry 161]

[0542]

[0543] [Chemistry 162]

[0544]

[0545] [Chemistry 163]

[0546]

[0547] The content of repeating units D1 to D4 is preferably 15 to 95 mol %, more preferably 20 to 85 mol %, of all repeating units of the aforementioned 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 all repeating units of the aforementioned fluorine-containing polymer. Repeating units D1 to D6 may be used alone or in combination of two or more.

[0548] The aforementioned fluorine-containing polymer may also contain other repeating units other than the aforementioned repeating units. As for such repeating units, those described in paragraphs

[0046] to

[0078] of Japanese Patent Publication No. 2014-177407 can be cited. When the aforementioned fluorine-containing polymer contains other repeating units, the content thereof is preferably less than 50 mol% of all repeating units of the aforementioned fluorine-containing polymer.

[0549] The aforementioned fluorine-containing polymer can be prepared by known methods by copolymerizing each monomer protected by a protecting group as required, and then synthesizing by deprotection reaction as required. The copolymerization reaction is not particularly limited, and is preferably free radical polymerization or anionic polymerization. For these methods, reference can be made to Japanese Patent Publication No. 2004-115630.

[0550] The Mw of the fluorine-containing polymer is preferably 2000 to 50000, more preferably 3000 to 20000. If the Mw is less than 2000, the diffusion of the acid is promoted, the resolution is deteriorated, and the stability over time is impaired. If the Mw is too large, the solubility in the solvent becomes small, and coating defects may occur. In addition, the Mw / Mn of the fluorine-containing polymer is preferably 1.0 to 2.2, more preferably 1.0 to 1.7.

[0551] When the chemically amplified negative resist composition of the present invention contains a fluorine-containing polymer (D), the content thereof is preferably 0.01 to 30 parts by mass, more preferably 0.1 to 20 parts by mass, and even more preferably 0.5 to 10 parts by mass relative to 80 parts by mass of the base polymer (A). The fluorine-containing polymer (D) may be used alone or in combination of two or more.

[0552] [(E) Quencher]

[0553] The chemically amplified negative resist composition of the present invention preferably contains a quencher as component (E). The quencher in the present invention is a material used to form a desired pattern by capturing the acid generated by the photoacid generator in the chemically amplified resist composition to prevent diffusion toward the unexposed portion.

[0554] As for the above-mentioned quencher, known basic compounds can be cited. As for the known basic compounds, first-order, second-order, and third-order 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 can be cited. In particular, first-order, second-order, and third-order amine compounds described in paragraphs

[0146] to

[0164] of Japanese Patent Publication No. 2008-111103, especially amine compounds having hydroxyl groups, ether bonds, ester bonds, lactone rings, cyano groups, and sulfonate ester bonds, or compounds having carbamate groups described in Japanese Patent No. 3790649 are preferred. Preferred ones include tris[2-(methoxymethoxy)ethyl]amine, tris[2-(methoxymethoxy)ethyl]amine-N-oxide, dibutylaminobenzoic acid, morpholine derivatives, imidazole derivatives, etc. By adding such a basic compound, for example, the diffusion rate of the acid in the resist film can be further suppressed or the shape can be corrected.

[0555] In addition, as for the above-mentioned quencher, onium salts such as sulfonium salts, iodonium salts, and ammonium salts of carboxylic acids not fluorinated at the α-position described in Japanese Patent Application Laid-Open No. 2008-158339 can be cited. Sulfonic acid, imidic acid, or methide acid fluorinated at the α-position is necessary to deprotect the acid-labile group, and the carboxylic acid not fluorinated at the α-position is released by salt exchange with the onium salt not fluorinated at the α-position. The carboxylic acid not fluorinated at the α-position hardly undergoes a deprotection reaction, so it can function as a quencher.

[0556] Examples of the onium salt of carboxylic acid not fluorinated at the α-position include those represented by the following formula (E1).

[0557] [Chemistry 164]

[0558]

[0559] In formula (E1), R 201 , 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.

[0560] R 201 The hydrocarbon group represented by may be saturated or unsaturated, and may be straight-chain, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 40 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, and n-decyl; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norbornyl, tricyclo[5.2.1.02,6 ] 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 cyclohexylalkenyl; 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.

[0561] 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 aforementioned hydrocarbon group may be substituted by a group containing a hetero atom such as an oxygen atom, a sulfur atom, or a nitrogen atom, resulting in 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; aryloxyalkyl 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.

[0562] In formula (E1), Mq A + , is an onium cation. As for the onium cation, it is preferably a sulfonium cation, an iodonium cation or an ammonium cation, and more preferably a sulfonium cation or an iodonium cation. As for specific examples of the sulfonium cation, the same ones as those exemplified for the sulfonium cations of the repeating units A7 to A9 can be cited. As for specific examples of the iodonium cation, the same ones as those exemplified for the iodonium cations of the repeating units A11 to A13 can be cited.

[0563] Examples of the anion of the onium salt represented by the formula (E1) include the following, but are not limited to these.

[0564] [Chemistry 165]

[0565]

[0566] [Chemistry 166]

[0567]

[0568] [Chemistry 167]

[0569]

[0570] As the quencher, a sulfonium salt of a carboxylic acid containing an iodinated benzene ring represented by the following formula (E2) can also be suitably used.

[0571] [Chemistry 168]

[0572]

[0573] 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.

[0574] 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, or 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, or a saturated hydrocarbon sulfonyloxy group having 1 to 4 carbon atoms, which may be partially or entirely substituted with halogen atoms, or -N(R 211A )-C(=O)-R 211B or -N(R 211A )-C(=O)-OR 211B . R 211A , 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. When t and / or u is 2 or more, each R 211 They may be the same or different from each other.

[0575] In formula (E2), L 1 , is a single bond or a (u+1)-valent linking group having 1 to 20 carbon atoms, and may also include at least one selected from an ether bond, a carbonyl group, an ester bond, an amide bond, a sultone ring, a lactam ring, a carbonate bond, a halogen atom, a hydroxyl group, and a carboxyl group. The aforementioned saturated hydrocarbon group, saturated hydrocarbon oxy group, saturated hydrocarbon carbonyloxy group, and saturated hydrocarbon sulfonyloxy group may be straight-chain, branched, or cyclic.

[0576] In formula (E2), R 212 , R 213 and R 214, each independently represents a halogen atom, or a hydrocarbon group having 1 to 20 carbon atoms which may also contain heteroatoms. The aforementioned hydrocarbon group may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples thereof include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms. Furthermore, a 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 sulfonic acid group, or a group containing a sulfonium salt, and a part of the -CH2- of the aforementioned 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. Furthermore, R 212 and R 213 , or they can bond to each other and to the sulfur atoms to which they are bonded to form a ring.

[0577] 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 high absorption, high sensitization effect, and high acid diffusion control effect.

[0578] As the quencher, a nitrogen atom-containing carboxylate type compound represented by the following formula (E3) may also be used.

[0579] [Chemistry 169]

[0580]

[0581] In formula (E3), R 221 ~R 224 , each independently a hydrogen atom, -L 2 -CO2 - , or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom. 221 and R 222 , R 222 and R 223 , or R 223 and R 224 , or they may bond to each other and to the carbon atoms to which they are bonded to form a ring. 2 , is a single bond or an alkylene group having 1 to 20 carbon atoms which may contain a hetero atom. 225 , is a hydrogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom.

[0582] In formula (E3), ring R r , 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 of the ring may be replaced by a hydrocarbon group having 1 to 20 carbon atoms, or -L 2 -CO2 -The ring may be substituted, and part of the carbon atoms of the ring may be substituted by sulfur atoms, oxygen atoms or nitrogen atoms. The aforementioned ring may be an alicyclic ring or an aromatic ring, and preferably a 5-membered ring or a 6-membered ring. Specific examples thereof include pyridine ring, pyrrole ring, pyrrolidine ring, piperidine ring, pyrazole ring, imidazoline ring, pyridazine ring, pyrimidine ring, pyrazine ring, imidazoline ring, oxazole ring, thiazole ring, morpholine ring, thiazine ring, triazole ring and the like.

[0583] The carboxylic acid onium 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 and ring R r At least one of the hydrogen atoms bonded to the carbon atom of 2 -CO2 - Replacer.

[0584] In formula (E3), Mq B + , is a sulfonium cation, an iodonium cation or an ammonium cation, preferably a sulfonium cation. Specific examples of the sulfonium cation include the same ones as those exemplified for the sulfonium cations of the repeating units A7 to A9.

[0585] Examples of the anion of the compound represented by the formula (E3) include the following, but are not limited to these.

[0586] [Chemistry 170]

[0587]

[0588] [Chemistry 171]

[0589]

[0590] [Chemistry 172]

[0591]

[0592] [Chemistry 173]

[0593]

[0594] [Chemistry 174]

[0595]

[0596] [Chemistry 175]

[0597]

[0598] Furthermore, as the quencher, a weakly acidic betaine-type compound may also be used. Specific examples thereof include those shown below, but are not limited thereto.

[0599] [Chemistry 176]

[0600]

[0601] As for the aforementioned quencher, a polymer quencher described in Japanese Patent Application Publication No. 2008-239918 can be further cited. This improves the rectangularity of the resist pattern by aligning the surface of the resist film. The polymer quencher also has the effect of preventing film loss and doming of the pattern when used in a protective film for wet exposure.

[0602] When the chemically amplified negative resist composition of the present invention contains (E) a quencher, its content is preferably 0 to 50 parts by weight, more preferably 0.1 to 40 parts by weight, relative to 80 parts by weight of the base polymer (A). The quencher (E) may be used alone or in combination of two or more.

[0603] When the chemically amplified negative resist composition of the present invention contains both the acid generator as component (B) and the quencher as component (E), the content ratio of the acid generator to the quencher ((B) / (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 acid generator to the quencher contained in the chemically amplified negative resist composition is within the above range, acid diffusion can be sufficiently suppressed, and excellent resolution and dimensional uniformity can be obtained.

[0604] [(F) Organic solvent]

[0605] The chemically amplified negative resist composition of the present invention may also contain an organic solvent as the component (F). As for the aforementioned organic solvent, there is no particular limitation as long as it can dissolve each component. As for such an organic solvent, for example, ketones such as cyclohexanone, cyclopentanone, methyl-2-n-pentanone, and 2-heptanone described in paragraphs

[0144] to

[0145] of Japanese Patent Gazette 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 mono Ethers such as methyl ether, 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 monotert-butyl ether acetate; lactones such as γ-butyrolactone; and mixed solvents thereof, etc.

[0606] Among these organic solvents, 1-ethoxy-2-propanol, PGMEA, PGME, cyclohexanone, EL, γ-butyrolactone, and a mixed solvent thereof are preferred.

[0607] 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 in combination of two or more.

[0608] [(G) Surfactant]

[0609] The chemically amplified negative resist composition of the present invention may also contain a conventional surfactant in order to improve the coating properties on the substrate. As for the aforementioned surfactant, PF-636 (manufactured by OMNOVA SOLUTIONS), FC-4430 (manufactured by 3M Company) and the like can be cited. Moreover, Japanese Patent Gazette No. 2004-115630 also records a large number of examples, and a large number of them are well-known and can be selected as references. When the chemically amplified negative resist composition of the present invention contains a (G) surfactant, its content is preferably 0 to 5 parts by mass relative to 80 parts by mass of the (B) base polymer. The (G) surfactant may be used alone or in combination of two or more.

[0610] [Resist pattern forming method]

[0611] The resist pattern forming method of the present invention comprises the following steps: using the aforementioned chemically amplified negative resist composition to form a resist film on a substrate, using high-energy rays to irradiate a pattern on the aforementioned resist film (i.e., using high-energy rays to expose the aforementioned resist film), and using an alkaline developer to develop the resist film irradiated with the aforementioned pattern.

[0612] As for the aforementioned substrate, for example, a substrate for integrated circuit manufacturing (Si, SiO, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic anti-reflection film, etc.), or a substrate for transmission or reflection mask circuit manufacturing (Cr, CrO, CrON, MoSi2, Si, SiO, SiO2, SiON, SiONC, CoTa, NiTa, TaBN, SnO2, etc.) can be used. On the aforementioned substrate, the aforementioned chemically amplified negative resist composition is applied by spin coating or the like to a film thickness of 0.03 to 2 μm, and the composition is placed on a heating plate, preferably at 60 to 150° C. for 1 to 20 minutes, more preferably at 80 to 140° C. for 1 to 10 minutes, to form a resist film.

[0613] Then, the resist film is exposed using high-energy radiation and the pattern is irradiated. Examples of the high-energy radiation include ultraviolet rays, far ultraviolet rays, excimer lasers (KrF, ArF, etc.), EUV, X-rays, gamma rays, synchrotron radiation, and EB. In the present invention, it is preferred to use EUV or EB for exposure.

[0614] When ultraviolet rays, extreme ultraviolet rays, excimer lasers, EUV, X-rays, gamma rays or synchrotron radiation are used as the high-energy rays, irradiation is performed using a mask for forming a target pattern, and the exposure amount is preferably 1 to 500 mJ / cm 2 , preferably 10 to 400 mJ / cm 2 When using EB, the exposure amount is preferably 1 to 500 μC / cm2 in order to form the target pattern by direct irradiation. 2 , preferably 10 to 400 μC / cm 2 .

[0615] Exposure In addition to the usual exposure method, an immersion method in which the space between the mask and the resist film is wetted may be used as appropriate. In this case, a water-insoluble protective film may also be used.

[0616] Then, a post-exposure bake (PEB) is performed on a hot plate, preferably at 60 to 150° C. for 1 to 20 minutes, more preferably at 80 to 140° C. for 1 to 10 minutes.

[0617] Thereafter, a developer containing 0.1 to 5% by mass, preferably 2 to 3% by mass, of an alkaline aqueous solution of TMAH or the like is used to form a target pattern on the substrate by development using conventional methods such as dipping, puddle, and spraying for preferably 0.1 to 3 minutes, more preferably 0.5 to 2 minutes.

[0618] Furthermore, the chemically amplified negative resist composition of the present invention is particularly useful because it can form patterns with good resolution and low LER. Furthermore, the chemically amplified negative resist composition of the present invention is particularly useful for pattern formation on substrates with a material on the surface that is difficult to adhere to the resist pattern and is prone to pattern peeling and pattern collapse. For such substrates, there can be cited substrates with 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 a outermost layer 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 when a blank photomask is used as a substrate for pattern formation. In this case, the blank photomask can be either a transmissive type or a reflective type.

[0619] The blank photomask having a light shielding film made of a chromium-based material as a transmission type blank photomask may be a blank photomask for a binary mask or a blank photomask for a phase shift mask. In the case of a blank photomask for a binary mask, it may be a blank photomask having an anti-reflection layer and a light shielding layer made of a chromium-based material as a light shielding film, or the entire anti-reflection film on the surface side or only the more surface side of the anti-reflection film on the surface side may be a chromium-based material, and the remaining part may be composed of, for example, a silicon-based compound material that may also contain a transition metal. In the case of a blank photomask for a phase shift mask, a blank photomask for a phase shift mask having a chromium-based light shielding film on the phase shift film may be used as an object.

[0620] The aforementioned blank photomask having a chromium-based material as the outermost layer is well known, as exemplified in Japanese Patent Publication No. 2008-26500, Japanese Patent Publication No. 2007-302873 or any of them as the current technology, and a detailed description thereof is omitted. For example, when a shading film having an anti-reflection layer and a shading layer is formed by a chromium-based material, a film structure as described below can be used.

[0621] When a light-shielding film having an anti-reflection layer and a light-shielding layer is formed by using a chromium-based material, the anti-reflection layer and the light-shielding layer may be laminated in the order of the surface layer side, or in the order of the anti-reflection layer, the light-shielding layer, and the anti-reflection layer. In addition, the anti-reflection layer and the light-shielding layer may be multiple layers, respectively, and the composition of the layers with different compositions may be discontinuously changed or continuously changed. As for the chromium-based material used, metal chromium and a material containing light elements such as oxygen, nitrogen, and carbon in metal chromium are used. Specifically, metal chromium, chromium oxide, chromium nitride, chromium carbide, chromium oxide nitride, chromium oxide carbide, chromium nitride carbide, chromium oxide nitride carbide, chromium oxide nitride carbide, and chromium oxide nitride carbide.

[0622] Furthermore, the reflective blank mask comprises a substrate, a multilayer reflective film formed on one main surface (surface side) of the substrate, specifically, a multilayer reflective film that reflects exposure light such as EUV light, and an absorber film formed on the multilayer reflective film, specifically, an absorber film that absorbs exposure light such as EUV light and reduces reflectivity. A reflective mask (reflective mask for EUV) having an absorber pattern (absorber film pattern) formed by patterning the absorber film is manufactured from the reflective blank mask (reflective blank mask for EUV). The wavelength of EUV light used in EUV lithography is 13 to 14 nm, and is generally light with a wavelength of about 13.5 nm.

[0623] The multilayer reflective film is usually preferably arranged in contact with one main surface of the substrate. If the effect of the present invention is not impaired, a base film can also be arranged between the substrate and the multilayer reflective film. The absorber film can also be formed in contact with the multilayer reflective film, but the protective film (protective film of the multilayer reflective film) can also be arranged between the multilayer reflective film and the absorber film, preferably in contact with the multilayer reflective film, and more preferably in contact with the multilayer reflective film and the absorber film. The protective film is used to protect the multilayer reflective film during processing such as cleaning and correction. In addition, it is preferred that the protective film has the function of protecting the multilayer reflective film during patterning by etching the absorber film and preventing the oxidation of the multilayer reflective film. On the other hand, under one main surface of the substrate and the other main surface (back side) on the opposite side, a conductive film for electrostatically clamping the reflective mask in the exposure device can also be arranged in contact with the other main surface. Moreover, here, one main surface of the substrate is set as the surface and the upper side of the front side, and the other main surface is set as the back side and the lower side, but the front and back and the top and bottom of the two are set for convenience, and one main surface and the other main surface are any of the two main surfaces (film forming surfaces) in the substrate, and the front and back and the top and bottom can be replaced. More specifically, it can be formed using a method such as Japanese Patent Publication No. 2021-139970 or therein as an example of the current technology.

[0624] According to the resist pattern forming method of the present invention, even if a substrate (for example, a transmission type or reflection type 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 be obtained.

[0625] [Example]

[0626] Hereinafter, the present invention will be specifically described by showing synthesis examples, embodiments and comparative examples, but the present invention is not limited to the following embodiments. In addition, the structure of the compound is confirmed by measuring the molecular ion peak using mass spectrometry (LC is Agilent 1100 type, MASS is Agilent LC / MSD type). The value of the molecular ion peak is represented by "MASS".

[0627] [1]Synthesis of monomers

[0628] [Example 1-1] Synthesis of Monomer A-1

[0629] [Chemistry 177]

[0630]

[0631] In the formula, Me is a methyl group.

[0632] Under nitrogen atmosphere, methylmagnesium chloride (3.0M THF solution, 160mL) and THF (160mL) were added to the reaction vessel and heated until the temperature in the reaction vessel reached 50°C. A solution of THF (80mL) in which methyl 3-acenaphthylenecarboxylate (42.0g) was dissolved was added dropwise to the reaction vessel, and the temperature in the reaction vessel was maintained below 60°C. After the addition, the temperature in the reaction vessel was set to 60°C and solidified for 3 hours. After solidification, the reaction solution was cooled in an ice bath, and a solution consisting of ammonium chloride (48g), 20% by mass hydrochloric acid (48g) and water (240g) was added dropwise to stop the reaction. Ethyl acetate (400mL) was added to the reaction solution to extract the target product, and general aqueous work-up was performed. After the solvent was distilled, it was purified by silica gel chromatography to obtain monomer A-1 as a colorless oil (yield 35.3g, yield 84%).

[0633] The results of mass analysis of monomer A-1 are shown below.

[0634] MASS:211.1[M+H] +

[0635] [Examples 1-2 to 1-6] Synthesis of Monomers A-2 to A-6

[0636] The following monomers A-2 to A-6 were synthesized using corresponding raw materials.

[0637] [Chemistry 178]

[0638]

[0639] In the formula, Ac is acetyl.

[0640] [2] Synthesis of polymers

[0641] Among the monomers used for synthesis of the polymer, those other than monomers A-1 to A-6 are as follows.

[0642] [Chemistry 179]

[0643]

[0644] [Chemistry 180]

[0645]

[0646] [Chemistry 181]

[0647]

[0648] [Chemistry 182]

[0649]

[0650] [Chemistry 183]

[0651]

[0652] [Example 2-1] Synthesis of polymer P-1

[0653] In a nitrogen atmosphere, 23.6 g of 4-acetoxystyrene, 16.4 g of monomer A-1, 8.2 g of dimethyl-2,2'-azobis(2-methylpropionate) (Wako Pure Chemical Industries, Ltd., trade name V601), and 112 g of methyl ethyl ketone as a solvent were added to a 200 mL dropping cylinder to prepare a solution A. Then, 38 g of methyl ethyl ketone was added to another 500 mL polymerization flask under a nitrogen atmosphere, and the mixture was heated at 80°C. While maintaining the temperature, the solution A was added dropwise over 4 hours. After the addition was completed, the polymerization temperature was maintained at 80°C, stirring was continued for 18 hours, and then the mixture was cooled to room temperature. The obtained polymerization solution was added dropwise to 1400 g of hexane to filter the precipitated solid. The filtered solid was washed twice with 280 g of hexane. The obtained solid was dissolved in 160 g of THF in a 1 L flask under a nitrogen atmosphere, 17.7 g of ethanolamine was added, and the mixture was stirred at 60°C for 3 hours. The reaction solution was concentrated under reduced pressure, and the obtained concentrate was dissolved in a mixed solvent of 225 g of ethyl acetate and 100 g of water. The obtained solution was transferred to a separatory funnel, and 29 g of acetic acid was added to perform a separation operation. The lower layer was removed, and 100 g of water and 39 g of pyridine were added to the obtained organic layer, and a separation operation was performed. The lower layer was removed, and 100 g of water was further added to the obtained organic layer to perform water washing and separation. The water washing and separation were performed a total of 5 times. After the organic layer after the separation was concentrated, it was dissolved in 150 g of acetone, and the obtained acetone solution was added dropwise to 2000 g of water, and the obtained crystallized precipitate was filtered and washed with water. After suction filtration for 2 hours, the filtrate obtained was dissolved in 150 g of acetone again, and the obtained acetone solution was added dropwise to 2000 g of water, and the obtained crystallized precipitate was filtered, washed with water, and dried to obtain 26.5 g of the target polymer P-1 as a white solid. Polymer P-1 was prepared using 13 C-NMR, 1 The following polymers were confirmed by H-NMR and GPC measurements: Mw is a polystyrene-converted measurement value obtained by GPC using DMF as a solvent.

[0654] [Chemistry 184]

[0655]

[0656] [Examples 2-2 to 2-30, Comparative Examples 1-1 to 1-15] Synthesis of polymers P-2 to P-30, CP-1 to CP-15

[0657] The polymers shown in the following Tables 1 to 3 were synthesized in the same manner as in Example 2-1 except that the types and blending ratios of the monomers were changed.

[0658] [Table 1]

[0659]

[0660]

[0661] [Table 2]

[0662]

[0663] [Table 3]

[0664]

[0665]

[0666] [3] Preparation of chemically amplified negative resist compositions

[0667] [Examples 3-1 to 3-35, Comparative Examples 2-1 to 2-18]

[0668] The components were dissolved in an organic solvent according to the compositions shown in Tables 4 to 6 below, and the obtained solutions were filtered using UPE filter membranes and / or nylon filter membranes selected from 10 nm, 5 nm, 3 nm and 1 nm sizes to prepare chemically amplified negative resist compositions (R-1 to R-35, CR-1 to CR-18). The organic solvent used was a mixed solvent of 790 parts by mass of PGMEA, 1580 parts by mass of EL and 1580 parts by mass of PGME. In addition, 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 some of the compositions.

[0669] [Table 4]

[0670]

[0671]

[0672] [Table 5]

[0673]

[0674]

[0675] [Table 6]

[0676]

[0677] The structures of the photoacid generators PAG-A to PAG-E, quenchers Q-1 to Q-5, and fluorine-containing polymers FP-1 to FP-5 used in the resist composition are as follows.

[0678] [Chemistry 185]

[0679]

[0680] [Chemistry 186]

[0681]

[0682] [Chemistry 187]

[0683]

[0684] [4]EB Lithography Evaluation

[0685] [Examples 4-1 to 4-35, Comparative Examples 3-1 to 3-18]

[0686] Each chemically amplified negative resist composition (R-1 to R-35, CR-1 to CR-18) was spin-coated on a blank mask of 152 mm square with a silicon oxide film on the outermost surface after hexamethyldisilazane vapor phase primer treatment using ACT-M (manufactured by Tokyo Electron Co., Ltd.), and pre-baked at 110°C for 600 seconds on a hot plate to produce a resist film with a film thickness of 80 nm. The film 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 blank periphery to the inner side of 10 mm, and the average film thickness and film thickness range were calculated.

[0687] Exposure was performed using an electron beam exposure apparatus (EBM-5000plus manufactured by Nuflare Technology Co., Ltd., accelerating voltage 50 kV), PEB was performed at 120° C. for 600 seconds, and development was performed using a 2.38 mass % TMAH aqueous solution to obtain a negative pattern.

[0688] The obtained resist pattern was evaluated as follows. The blank mask with the pattern was observed by overhead SEM (scanning electron microscope), and the exposure amount of a 1:1 line-space (LS) pattern of 200 nm with a resolution of 1:1 was defined as the optimal exposure amount (μC / cm 2), the minimum size of the 200nm LS pattern in the exposure amount with 1:1 resolution is the resolution (limiting resolution). For the 200nm LS pattern obtained by irradiation with the optimal exposure amount, 80-point edge detection is performed on the 32 edges of the 200nm LS pattern using SEM, and the 3 times value (3σ) of its deviation (standard deviation, σ) is obtained, which is defined as LER. The pattern shape is visually determined to be rectangular. For the pattern fidelity evaluation, when a square dot pattern with a configuration density of 36% and a size of 120nm is used, the smaller the calculated value of the Area Loss value (%) of one corner of the dot pattern, the better the rectangularity of the dot shape is judged. The results are shown in Tables 7 and 8.

[0689] [Table 7]

[0690]

[0691]

[0692] [Table 8]

[0693]

[0694] [5] Dry etching resistance evaluation

[0695] [Examples 5-1 to 5-30, Comparative Examples 4-1 to 4-18]

[0696] 2 g of each polymer shown in Tables 1 and 2 (polymers P-1 to P-30, comparative polymers CP-1 to CP-18) was dissolved in 10 g of cyclohexanone and the polymer solution was filtered through a 0.2 μm filter membrane. The film was formed by spin coating on a Si substrate to form a film with a thickness of 300 nm and evaluated under the following conditions.

[0697] Etching test using CHF3 / CF4 gas:

[0698] The difference in film thickness of the polymer film before and after etching was determined using a dry etching apparatus TE-8500P manufactured by Tokyo Electron Co., Ltd.

[0699] The etching conditions were as follows.

[0700] Chamber pressure 40Pa

[0701] RF power 1000W

[0702] Pitch 9mm

[0703] CHF3 gas flow rate 30mL / min

[0704] CF4 gas flow rate 30mL / min

[0705] Ar gas flow rate 100 mL / min

[0706] Time: 60 seconds

[0707] In this evaluation, a film with a smaller difference in film thickness, that is, a film with a smaller reduction, shows that its etching resistance is high.

[0708] Tables 9 and 10 show the results of dry etching resistance.

[0709] [Table 9]

[0710]

[0711]

[0712] [Table 10]

[0713]

[0714] As shown above, by using the chemically amplified negative resist composition of the present invention, a pattern with extremely high resolution and good LER, shape and pattern fidelity can be formed. In addition, it is confirmed that the polymer of the present invention has excellent dry etching resistance to CHF3 / CF4 gas. The resist pattern forming method using the chemically amplified negative resist composition of the present invention is useful for optical lithography in the manufacture of semiconductor devices, especially in the processing of transmission or reflection type blank masks.

Claims

1. A monomer represented by the following formula (A1): In the formula, a1 is 1 or 2, a2 ​​is 0, 1 or 2, R A , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 1 , is a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, R 2 and R 3 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms. The aryl group may also have a substituent. However, R 2 and R 3 , are not hydrogen atoms at the same time, and R 2 and R 3 , or they may be bonded to each other and to the carbon atoms to which they are bonded to form a ring, a part of the -CH2- of the ring may also be substituted by -O- or -S-, W 1 , is 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.

2. The monomer according to claim 1, represented by the following formula (A1-1), In the formula, a2, R A , R 1 , R 2 , R 3 and W 1 , the same as above.

3. The monomer according to claim 2, represented by the following formula (A1-2), In the formula, a2, R A , R 1 , R 2 and R 3 , the same as above.

4. A polymer comprising repeating units derived from the monomer according to claim 1.

5. The polymer according to claim 4, further comprising a repeating unit represented by the following formula (A2): 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, R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 11 , is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom, A 1 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a portion of the -CH2- in the saturated alkylene group may be substituted by -O-.

6. The polymer according to claim 4, further comprising at least one selected from the group consisting of a repeating unit represented by the following formula (A3), a repeating unit represented by the following formula (A4), and a repeating unit represented by the following formula (A5), 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, and 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 21 and R 22 , each independently represents 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 hydrocarbonoxy group having 1 to 8 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom, R 23 , 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 oxyalkyl group having 2 to 20 carbon atoms, a saturated hydrocarbon thiol 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, A 2 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, and a portion of the -CH2- in the saturated alkylene group may be substituted by -O-.

7. The polymer according to claim 4, further comprising a repeating unit represented by the following formula (A6): Wherein, f1 is 0 or 1, f2 is 0, 1 or 2, f3 is an integer satisfying 0≤f3≤5+2(f2)-f4, f4 is 1, 2 or 3, R A , is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R 31 , is a halogen atom, a saturated hydrocarbon group having 1 to 6 carbon atoms which may be substituted by a halogen atom, a saturated hydrocarbonoxy group having 1 to 6 carbon atoms which may be substituted by a halogen atom, or a saturated hydrocarboncarbonyloxy group having 2 to 8 carbon atoms which may be substituted by a halogen atom, R 32 and R 33 , 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 by a hydroxyl group or a saturated hydrocarbonoxy group having 1 to 6 carbon atoms. The aryl group may also have a substituent. However, R 32 and R 33 , are not hydrogen atoms at the same time, and R 32 and R 33 , can also bond to each other and to the carbon atoms to which they are bonded to form a ring, A 3 , is a single bond or a saturated alkylene group having 1 to 10 carbon atoms, wherein the -CH2- of the saturated alkylene group may be substituted by -O-, W 2 , is 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.

8. The polymer according to claim 4, further comprising at least one repeating unit selected from the group consisting of the following formulae (A7) to (A14): In the formula, R B , are each independently a hydrogen atom or a methyl group, X 1 , each independently represents 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, -OX 11 -、-C(=O)-OX 11 -or-C(=O)-NH-X 11 -, X 11 , 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group, X 2 , each independently a single bond or -X 21 -C(=O)-O-,X 21 , is an alkylene group having 1 to 20 carbon atoms which may contain a hetero atom, X 3 , each independently a single bond, methylene, ethylene, phenylene, fluorinated phenylene, phenylene substituted with trifluoromethyl, -OX 31 -、-C(=O)-OX 31 -or-C(=O)-NH-X 31 -, X 31 , 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 them, and may also contain a carbonyl group, an ester bond, an ether bond, or a hydroxyl group, X 4 , each independently represents a single bond or an alkylene group having 1 to 30 carbon atoms which may contain a heteroatom, g1 and g2 are each independently 0 or 1, X 4 When it is a single bond, g1 and g2 are 0. R 41 ~R 58 , are each independently a halogen atom or a hydrocarbon group having 1 to 20 carbon atoms which may contain a hetero atom, and R 41 and R 42 , can also bond to each other and to the sulfur atoms to which they are bonded to form a ring, R 43 and R 44 , R 46 and R 47 , or R 49 and R 50 , 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 - , which is a non-nucleophilic relative ion. 9 . A chemically amplified negative resist composition comprising a base polymer comprising the polymer according to claim 4 .

10. The chemically amplified negative resist composition according to claim 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. 11 . The chemically amplified negative resist composition according to claim 9 , further comprising (B) an acid generator. 12 . The chemically amplified negative resist composition according to claim 9 , further comprising (C) a cross-linking agent.

13. The chemically amplified negative resist composition according to claim 9, which does not contain a cross-linking agent.

14. The chemically amplified negative resist composition according to claim 9, further comprising (D) a fluorine-containing polymer comprising 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 comprising or not comprising 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), Wherein, x is 1, 2 or 3, y is an integer satisfying 0≤y≤5+2z-x, z is 0 or 1, k is 1, 2 or 3, R C , are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group, R D , are each independently a hydrogen atom or a methyl group, R 101 , R 102 , R 104 and R 105 , 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 , each 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, R 103 , R 106 , R 107 and R 108 When it is a hydrocarbon group or a fluorinated hydrocarbon group, the carbon-carbon bond may be separated by an ether bond or a carbonyl group. R 109 , is a hydrogen atom, or a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be separated by a heteroatom-containing group between carbon-carbon bonds, R 110 , is a linear or branched hydrocarbon group having 1 to 5 carbon atoms, which may be separated by a heteroatom-containing group between carbon-carbon bonds, R 111 , 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 -CH2- in the saturated hydrocarbon group may also be substituted by an ester bond or an ether bond, Z 1 , is a (k+1)-valent hydrocarbon group having 1 to 20 carbon atoms or a (k+1)-valent fluorinated hydrocarbon group having 1 to 20 carbon atoms, Z 2 , is a single bond, *-C(=O)-O- or *-C(=O)-NH-, 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. 15 . The negative resist composition according to claim 9 , further comprising (E) a quencher.

16. The chemically amplified negative resist composition according to claim 9, 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 claim 9, irradiating the resist film with a pattern using high-energy rays, and developing the resist film irradiated with the pattern 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.

19. The resist pattern forming method according to claim 17, wherein: The outermost surface of the substrate is made of a material including 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 transmission or reflection type blank mask coated with the chemically amplified negative resist composition according to claim 9.

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