Organometallic compounds, photosensitive materials for photoresists, and photoresists

Abstract

To provide an organometallic compound suitable for resist materials that enable the formation of a resist film with high-resolution patterns and superior etching resistance through exposure to ultrashort-wavelength light.SOLUTION: An organometallic compound includes a metal or metal oxide (1), and a ligand (2) bound to the (1). The (2) includes a ligand represented by the formula (2) (where L is a single bond or a linking group, and X- is a monovalent counter anion. A carbon atom constituting a benzene ring may be combined with a substituent. If two or more substituents are combined with one benzene ring, the two or more substituents may be linked to each other, forming a ring together with a carbon atom with which the substituents are combined).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a novel organometallic compound, a photosensitive material for photoresists containing the organometallic compound, and a photoresist containing the organometallic compound. [Background technology]

[0002] In the manufacturing of semiconductor devices, a method is used in which a resist film with a pattern is formed using a photoresist (chemically amplified photoresist) containing a photosensitive resin and a photoacid generator, which has the property of changing its solubility in an alkaline developer upon exposure, and the substrate is etched (for example, dry etching using reactive gas or plasma) using the obtained resist film. As the pattern becomes smaller, the exposure wavelength is becoming shorter.

[0003] Patent Document 1 describes that when a positive-type resist resin containing triphenylsulfonium trifluoromethanesulfonate, which is a photoacid generator, and a photosensitive resin is irradiated with KrF excimer laser light (wavelength 248 nm), fine patterns can be formed with high precision. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2003-177541 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, further miniaturization, increased capacity, and performance improvements have necessitated even finer pattern design in electronic devices. Therefore, the use of ultrashort wavelength light, such as extreme ultraviolet (EUV; wavelength 13.5 nm), as exposure light is being considered.

[0006] However, ultrashort wavelength light is easily absorbed by photoresists, and if the resist film is thick, the light does not easily reach the bottom of the film, making it difficult to form patterns with good accuracy. Also, while thinning the resist film can improve pattern accuracy, it has the problem of reducing etching resistance.

[0007] Therefore, the object of the present invention is to provide an organometallic compound suitable for use as a resist material that forms a resist film having a high-resolution pattern and excellent etching resistance when exposed to ultrashort wavelength light. Another object of the present invention is to provide a resist material that forms a resist film having a high resolution pattern and excellent etching resistance when exposed to ultrashort wavelength light. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the inventors of the present invention have found that organometallic compounds, in which a ligand represented by the following formula (2) is bonded to a metal or metal oxide (1), have photoresponsive properties, meaning that when irradiated with light, even if the irradiated light is of an ultrashort wavelength, they rapidly aggregate and form aggregates (or lumps). The present invention was completed based on this finding.

[0009] That is, it comprises a metal or metal oxide (1) and a ligand (2) bonded to (1), The present invention provides an organometallic compound comprising a ligand represented by the following formula (2) above. [ka] (In the formula, L represents a single bond or linking group, X -represents a monovalent counter anion. A substituent may be bonded to the carbon atom constituting the benzene ring. When two or more substituents are bonded to one benzene ring, the two or more substituents may be linked to each other to form a ring together with the carbon atom to which the substituent is bonded)

[0010] The present invention also provides the organometallic compound in which the ligand represented by the formula (2) is a ligand represented by the following formula (2-1).

Chemical formula

[0011] The present invention also provides the organometallic compound in which the ligand represented by the formula (2) is a ligand represented by the following formula (2-3).

Chemical formula

[0012] The present invention also provides the organometallic compound wherein (1) is at least one selected from hafnium, zirconium, tin, cobalt, palladium, antimony, and oxides thereof.

[0013] The present invention also provides a photosensitive material for photoresists containing the organometallic compound.

[0014] The present invention also provides a photosensitive material for photoresists, which is a photosensitive material for extreme ultraviolet light or an electron beam.

[0015] The present invention also provides a photoresist comprising the organometallic compound and a solvent. [Effects of the Invention]

[0016] The organometallic compound of the present invention is an organic-inorganic composite having a structure in which a ligand (2) is coordinated to a metal or metal oxide (1), and exhibits good solubility in solvents. Furthermore, the organometallic compound has excellent photoresponsiveness, and when irradiated with light, it efficiently senses even ultrashort wavelength light and forms aggregates. The aggregates of the organometallic compound no longer exhibit solubility in solvents. Moreover, because the aggregates have a structure in which metal or metal oxide (1) is aggregated, they have toughness that can withstand etching. Therefore, if a layer containing the organometallic compound in a highly dispersed state is thinned to a thickness that allows ultrashort wavelength light to reach the bottom, and then exposed to a pattern shape using ultrashort wavelength light, followed by washing with a solvent, the organometallic compound in the unexposed areas will be washed away, but the organometallic compound in the exposed areas will aggregate and remain without being washed away, thus enabling the precise manufacture of a resist film with a high-resolution fine pattern. Furthermore, the resist film obtained in this way possesses etching resistance even when thin. By using the resist film manufactured by the above method to perform etching (for example, dry etching using reactive gas or plasma) on a substrate, semiconductor devices with high-resolution patterns (e.g., wiring patterns, circuit patterns, etc.) can be manufactured with a high yield. [Modes for carrying out the invention]

[0017] [Organometallic compound] The organometallic compound of the present invention is an aggregate (=organic-inorganic complex) of a metal or metal oxide (1) and a ligand (2). In the organometallic compound, the ligand (2) is contained in a state bonded to the metal or metal oxide (1).

[0018] The organometallic compound may contain components other than the metal or metal oxide (1) and ligand (2), but the proportion of the total weight of the metal or metal oxide (1) and ligand (2) in the total amount of the organometallic compound (100% by weight) is, for example, 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more. The upper limit is 100% by weight.

[0019] The aforementioned organometallic compounds exhibit excellent solubility (or dispersibility) in solvents, and their average particle size (particle size determined by dynamic light scattering) in a solvent (e.g., PGMEA) is, for example, 200 nm or less, preferably 100 nm or less, and particularly preferably 50 nm or less. The lower limit is, for example, 1 nm.

[0020] The organometallic compound has excellent sensitivity to light, and upon irradiation with light, it generates acid (HX) and rapidly aggregates. The wavelength of the light is, for example, 100 nm or less (e.g., 0 to 100 nm), preferably 80 nm or less, particularly preferably 50 nm or less, most preferably 30 nm or less, and especially preferably 20 nm or less. The light includes, for example, X-rays, electron beams (EB), EUV, etc.

[0021] (Metal or metal oxide (1)) The metal or metal oxide (1) is a component that forms the core of the organometallic compound and includes at least one selected from metals and metal oxides.

[0022] Examples of the aforementioned metals include hafnium, zirconium, tin, cobalt, palladium, antimony, titanium, and aluminum.

[0023] The aforementioned metal oxides include oxides of the metal and their partial hydroxides (or hydrates). Examples of the aforementioned metal oxides include hafnium oxide (HfO2), zirconium oxide (ZrO2, Zr6O4(OH)4), and tin oxide (SnO2, Sn2O3, Sn3O4, Sn6O4). 12 Sn 12 O 25 H 16 (C4H9Sn) 12 O 14 Examples include (OH)6), cobalt oxide (CoO, Co2O3, Co3O4), palladium oxide (PdO), antimony oxide (Sb2O3), titanium oxide (TiO2), and aluminum oxide (Al2O3).

[0024] The aforementioned metal oxide can be produced, for example, by the sol-gel method. Specifically, a metal alkoxide is used as a starting material, and the metal oxide is ultimately obtained through hydrolysis, polycondensation, and a sol / gel state.

[0025] There are no particular restrictions on the shape of the metal or metal oxide (1), and examples include spherical (perfectly spherical, nearly spherical, ellipsoidal, etc.), polyhedral, rod-shaped (cylindrical, prismatic, etc.), plate-shaped, flake-shaped, and irregularly shaped. Furthermore, the metal or metal oxide (1) may be hollow, porous, or solid.

[0026] The average particle size of the metal or metal oxide (1) (particle size determined by dynamic light scattering) is, for example, 1 to 200 nm, preferably 2 to 100 nm, and particularly preferably 2 to 50 nm.

[0027] In the total amount of the organometallic compound (or the total weight of the metal or metal oxide (1) and the ligand (2)), the proportion of the metal or metal oxide (1) is, for example, 10 to 90% by weight, preferably 30 to 70% by weight.

[0028] (Ligand (2)) Ligand (2) is a compound that forms a coordinate bond with the above-mentioned metal or metal oxide (1). Ligand (2) includes at least a ligand represented by the following formula (2). [ka] (In the formula, L represents a single bond or linking group, X - This represents a monovalent counteranion. A substituent may be attached to the carbon atoms constituting the benzene ring. If two or more substituents are attached to a single benzene ring, the two or more substituents may be linked to each other and form a ring together with the carbon atoms to which the substituents are attached.

[0029] The L in the above-mentioned L represents a single bond or a linking group. The linking group is a divalent group having one or more atoms, and examples include a divalent hydrocarbon group, a carbonyl group (-CO-), an ether bond (-O-), a thioether bond (-S-), an ester bond (-COO-,-OCO-), an amide bond (-CONH-), a carbonate bond (-OCOO-), and a group formed by linking multiple such bonds.

[0030] Examples of the divalent hydrocarbon groups include linear or branched alkylene groups having 1 to 5 carbon atoms, such as methylene, methylmethylene, dimethylmethylene, ethylene, propylene, and trimethylene; cycloalkylene groups having 3 to 18 carbon atoms, such as 1,2-cyclopentylene, 1,3-cyclopentylene, cyclopentylidene, 1,2-cyclohexylene, 1,3-cyclohexylene, 1,4-cyclohexylene, and cyclohexylidene; and arylene groups having 6 to 14 carbon atoms, such as o-phenylene, m-phenylene, p-phenylene, and naphthylene.

[0031] Among the Ls, a divalent group is preferred in which an ether bond (-O-) or a thioether bond (-S-) is bonded to a divalent hydrocarbon group, and in particular, a divalent group is preferred in which an ether bond (-O-) or a thioether bond (-S-) is bonded to a linear or branched alkylene group having 1 to 5 carbon atoms [C n H 2n A divalent base formed by combining [an integer n=1 to 5] is preferred.

[0032] Therefore, the above L is given by the formula [-L 1 -C n H 2n A divalent group represented by - is preferred. In the above formula, L 1 L represents an oxygen atom or a sulfur atom, and n represents an integer from 1 to 5. 1 The bond extending to the left from the above formula bonds to the benzene ring represented by C in formula (2). The bond extending to the right from the above formula (i.e., to the right of the alkylene group) bonds to the carboxyl carbon in formula (2).

[0033] In formula (2), the benzene rings represented by A, B, and C may each have substituents bonded to one or more of their constituent carbon atoms. Examples of such substituents include halogen atoms, hydrocarbon groups, halogenated hydrocarbon groups, and groups represented by the following formula (r). -X 1 -R (r) (In formula (r), X 1 represents -O-, -S-, or -CO-, and R represents a hydrocarbon group or halogenated hydrocarbon group. (The bond emanating from the left end of formula (r) is bonded to a carbon atom constituting the benzene ring in formula (2-1).)

[0034] The halogen atom is preferably a fluorine atom or an iodine atom, and particularly preferably a fluorine atom.

[0035] The hydrocarbon groups include aliphatic hydrocarbon groups, alicyclic hydrocarbon groups, aromatic hydrocarbon groups, and groups in which two or more of these are linked by a single bond.

[0036] The aliphatic hydrocarbon group has 1 to 5 carbon atoms (=C 1-5Aliphatic hydrocarbon groups are preferred, for example alkyl groups such as methyl, ethyl, propyl, isopropyl, butyl, isobutyl, s-butyl, t-butyl, and pentyl groups; and alkenyl groups such as vinyl, allyl, and 1-butenyl groups.

[0037] The aforementioned alicyclic hydrocarbon group is C 3-10 Alicyclic hydrocarbon groups are preferred, for example, cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl groups; cycloalkenyl groups such as cyclopentenyl and cyclohexenyl groups; perhydronaphthalene-1-yl, norbornyl, adamantyl, and tricyclo[5.2.1.0 2,6 ] Decane-8-yl group, tetracyclo[4.4.0.1 2,5 .1 7,10 Examples include bridged cyclic hydrocarbon groups such as dodecane-3-yl groups.

[0038] The aforementioned aromatic hydrocarbon group is C 6-14 (Especially C 6-10 Aromatic hydrocarbon groups are preferred, for example, aryl groups such as phenyl groups and naphthyl groups.

[0039] Examples of the halogenated hydrocarbon group include a group in which at least one hydrogen atom of the hydrocarbon group is substituted with a halogen atom (for example, a fluorine atom and / or an iodine atom).

[0040] The group represented by formula (r) above includes, for example, acyl groups, acyl halogenated groups, alkoxy groups, aryloxy groups, alkylthio groups, and arylthio groups.

[0041] When two or more substituents are bonded to a benzene ring represented by A, B, or C in formula (2), the two or more substituents may be linked to each other and form a ring (for example, a fused ring such as a naphthalene ring) together with the carbon atoms to which the substituents are bonded (= carbon atoms that make up the benzene ring).

[0042] The benzene rings in formula (2) (especially the benzene rings represented by A and B in formula (2)) preferably have substituents in that they improve photosensitivity to ultrashort wavelength light, and among these, halogen atoms, C 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups and C 1-5 It is preferable to have at least one substituent selected from haloalkoxy groups, and in particular, a halogen atom, C 1-5 Haloalkyl groups and C 1-5 Preferably, it has at least one substituent selected from haloalkoxy groups, in particular halogen atoms and C 1-5 It is preferable that the substituent has at least one selected from haloalkyl groups.

[0043] The benzene ring represented by C in formula (2) preferably has substituents, in that it improves photosensitivity to ultrashort wavelength light, and among them, halogen atoms, C 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups and C 1-5 It is preferable to have at least one substituent selected from haloalkoxy groups, and in particular C 1-5 Alkyl and C 1-5 Preferably, it has at least one substituent selected from alkoxy groups, in particular C 1-5 It is preferable to have an alkyl group as a substituent.

[0044] As for the ligand represented by formula (2), the ligand represented by the following formula (2-1), the ligand represented by the following formula (2-1'), and the ligand represented by the following formula (2-1") are preferred in that they improve photosensitivity to ultrashort wavelength light, and the ligand represented by the following formula (2-1) is particularly preferred. [ka]

[0045] In the above formula, R 11 , R12 For example, halogen atoms, C 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups and C 1-5 A group selected from haloalkoxy groups, consisting of a halogen atom and C 1-5 Haloalkyl groups and C 1-5 It is particularly preferable that the group is selected from a haloalkoxy group, and consists of a halogen atom and C 1-5 It is particularly preferable that the group be selected from haloalkyl groups.

[0046] In the above formula, R 13 For example, halogen atoms, C 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups and C 1-5 A group selected from haloalkoxy groups, C 1-5 Alkyl alkyl groups, and C 1-5 It is particularly preferable that the group is selected from alkoxy groups, C 1-5 It is particularly preferable that the alkyl group be an alkyl group.

[0047] In the above formula, n11 and n12 each independently represent an integer from 1 to 5, preferably an integer from 1 to 3, particularly preferably 1 or 2, and most preferably 2. n13 represents an integer from 0 to 4, preferably an integer from 1 to 4, particularly preferably 1 or 2, and most preferably 2.

[0048] In the above formula, R 11 , R 12 There are no particular restrictions on the bonding position of the group represented by the group to the benzene ring.

[0049] In the above formula, R 13 There are no particular restrictions on the bonding position of the group represented by the above formula to the benzene ring, but the meta position is preferred relative to the position to which the sulfur atom shown in the above formula is bonded.

[0050] In the above formula, [-L-COO -The preferred bonding position of the group represented by ] to the benzene ring is the para position relative to the position where the sulfur atom shown in the above formula is bonded.

[0051] In the above formula, L is the same as described above.

[0052] As the ligand represented by formula (2) above, the ligand represented by the following formula (2-2) is preferred in that it improves photosensitivity to ultrashort wavelength light. [ka]

[0053] In the above formula, L 1 X represents an oxygen atom or a sulfur atom, and n is an integer from 1 to 5. - This indicates a monovalent pair anion.

[0054] The carbon atoms constituting the benzene ring in the above formula may have substituents attached. When two or more substituents are attached to a single benzene ring, the two or more substituents may be linked to each other and form a ring together with the carbon atoms to which the substituents are attached. Examples of the substituents and rings that may be formed are the same as those that may be present in the ligand represented by formula (2) above.

[0055] Based on the above, among the ligands represented by formula (2), the ligands represented by the following formulas (2-3) are particularly preferred in that they improve photosensitivity to ultrashort wavelength light. In the following formulas, R 11 , R 12 , R 13 n11, n12, n13, L 1 , n, X - The same applies as above. [ka]

[0056] In the above formula, X -represents a monovalent counter anion, for example, a halogen ion, a halogen oxoacid anion, a boron anion, a phosphate anion, a sulfate anion, a sulfonic acid anion, a sulfonylimide anion, a carboxylic acid anion, a methide anion, an antimony anion, OH - , SCN - , NO2 - , NO3 - and the like.

[0057] Examples of the halogen ion include Cl - , Br - , I - and the like.

[0058] Examples of the halogen oxoacid anion include ClO4 - , IO3 - , BrO3 - and the like.

[0059] Examples of the boron anion include inorganic boron anions such as Br3 - , BF4 - , and organic boron anions such as (C6F5)4B - , ((CF3)2C6H3)4B - , tetraphenylborate, tetrakis(monofluorophenyl)borate, tetrakis(difluorophenyl)borate, tetrakis(trifluorophenyl)borate and the like.

[0060] Examples of the phosphate anion include inorganic phosphate anions such as PF6 - , PF(C2F5)5[[ID=C47]] - , PF2(C2F5)4 - , PF3(C2F5)3 - , PF4(C2F5)2 - , PF5(C2F5) - , PO4 3- and the like.

[0061] The sulfonic acid anion is represented by, for example, the following formula (s1). R s1 -SO3- (s1) (In the formula, R s1 (This indicates an organic group.)

[0062] R s1 The organic group in this may be, for example, a C which may have substituents. 1-30 A hydrocarbon group, a heterocyclic group which may have substituents, and two or more of the said groups are connected by a single bond or by -O-, -CO2-, -S-, -SO3-, and -SO2N(R s2 )- A group linked by a linking group selected from the above R s2 is a hydrogen atom or an alkyl group (for example, C 1-30 The alkyl group is represented. Examples of the substituents include halogen atoms such as fluorine atoms.

[0063] Said C 1-30 The hydrocarbon group is C 1-30 Aliphatic hydrocarbon group, C 3-30 Alicyclic hydrocarbon group, C 6-30 This includes aromatic hydrocarbon groups and groups formed by the bonding of two of these groups.

[0064] Said C 1-30 As for hydrocarbon groups, C 1-30 Alkyl alkyl group, C 6-15 Aryl group, C 6-15 Cycloalkylene group, C 6-15 Bridged cyclic hydrocarbon groups and groups formed by the bonding of two such groups are preferred.

[0065] The heterocyclic group is a group obtained by removing one hydrogen atom from the structural formula of a heterocycle. The heterocycle includes aromatic heterocycles and non-aromatic heterocycles. Examples of such heterocycles include 3- to 10-membered rings (preferably 4- to 6-membered rings) having carbon atoms and at least one heteroatom (e.g., oxygen atom, sulfur atom, nitrogen atom, etc.) as atoms constituting the ring, and fused rings thereof.

[0066] A specific example of the sulfonic acid anion is CH3SO3 - , C4H9SO3 - CF3SO3 -, C2F5C4H4SO3 - , C4F9SO3 - Examples include benzenesulfonate anions, p-toluenesulfonate anions, and camphorsulfonate anions.

[0067] The aforementioned sulfonylimide anion can be represented, for example, by the following formula (n1). (R n1 SO2)2N - (n1) (In the formula, two R n1 (Each of these independently represents an organic group.)

[0068] R n1 As for organic groups in this context, R s1 Similar examples can be given to organic groups in the context of [the subject].

[0069] A specific example of the sulfonylimide anion is (FSO2)2N - , (CF3SO2)2N - (C4F9SO2)2N - (C2F5SO2)2N - These are some examples.

[0070] The carboxylic acid anion can be represented, for example, by the following formula (c1). R c1 -COO - (c1) (In the formula, R c1 (This indicates an organic group.)

[0071] R c1 As for organic groups in this context, R s1 Similar examples can be given to organic groups in the context of [the subject].

[0072] A specific example of the carboxylic acid anion is, for example, CF3CO2 - CH3CO2 - , C2H5CO2 - PhCO2 - These are some examples.

[0073] Examples of the methide anion include the sulfonylmethide anion represented by the following formula (m1). (R m1 SO2)3C - (m1) (In the formula, three R m1 (Each of these independently represents an organic group.)

[0074] R m1 As for organic groups in this context, R s1 Similar examples can be given to organic groups in the context of [the subject].

[0075] A specific example of the aforementioned methidoanion is (CF3SO2)3C - These are some examples.

[0076] Examples of the antimony anion include SbF6. - These are some examples.

[0077] In addition to those mentioned above, the monovalent counter anions include, for example, the anions described in Japanese Patent Publication Nos. 2013-47211, 2021-81708, 2013-80245, 2013-80240, and 2013-33161.

[0078] As the counter anion, sulfonic acid anions or sulfonylimide anions are preferred in terms of their excellent solvent solubility and fine pattern formation properties.

[0079] The organometallic compound may contain ligands other than the ligand represented by formula (2) as ligand (2). In other words, the metal or metal oxide (1) may have one or more other ligands in coordination bonds in addition to the ligand represented by formula (2).

[0080] Other ligands include, for example, carboxylates, phosphates, phosphonates, and sulfonates.

[0081] Examples of coordinating compounds that form the carboxylate salt include citric acid, oxalic acid, malic acid, maleic acid, tartaric acid, glutaric acid, adipic acid, pimelic acid, succinic acid, malonic acid, fumaric acid, phthalic acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, 2-methylbutyric acid, n-hexanoic acid, 3,3-dimethylbutyric acid, 2-ethylbutyric acid, 4-methylpentanoic acid, n-heptanoic acid, 2-methylhexanoic acid, n-octanoic acid, 2-ethylhexanoic acid, glycolic acid, glyceric acid, lactic acid, etc. 1-10 Alkyl carboxylic acids; such as acrylic acid, methacrylic acid, 2-methylisocrotonic acid, 3-methylcrotonic acid, etc. 2-10 Alkenyl carboxylic acids; such as benzoic acid, salicylic acid, and crotonic acid. 6-10 Examples include aryl carboxylic acids.

[0082] Examples of coordinating compounds that form the phosphate include methyl phosphate, ethyl phosphate, propyl phosphate, butyl phosphate, hexyl phosphate, phenyl phosphate, dimethyl phosphate, diethyl phosphate, dipropyl phosphate, dibutyl phosphate, and dihexyl phosphate. 1-10 Alkyl phosphates; diphenyl phosphates, etc. 6-10 Examples include aryl phosphates.

[0083] Examples of coordinating compounds that form the phosphonate include methylphosphonic acid, ethylphosphonic acid, propylphosphonic acid, butylphosphonic acid, hexylphosphonic acid, etc. 1-10 Alkylphosphonic acid; vinylphosphonic acid, etc. 2-10 Alkenylphosphonic acid; phenylphosphonic acid, etc. 6-10 Arylphosphonic acids are one example.

[0084] Examples of coordinating compounds that form the sulfonate include methylsulfonic acid, ethylsulfonic acid, propylsulfonic acid, butylsulfonic acid, hexylsulfonic acid, etc. 1-10 Alkyl sulfonic acid; C such as phenyl sulfonic acid 6-10 Aryl sulfonic acid; vinyl sulfonic acid, etc. 2-10 Alkenyl sulfonic acid is one example.

[0085] Among the other ligands mentioned above, C is particularly noteworthy for its ability to impart good dispersibility to organometallic compounds. 6-10 Ligands containing an aryl group (e.g., carboxylates, phosphates, phosphonates, or sulfonates) are preferred, and C is particularly preferred. 6-10 Arylcarboxylate salts are preferred.

[0086] When ligand (2) contains other ligands along with the ligand represented by formula (2), the proportion of the ligand represented by formula (2) in the total amount of ligands is, for example, 0.1% by weight or more, preferably 0.5% by weight or more, and particularly preferably 1.0% by weight or more. The upper limit is, for example, 50% by weight, preferably 30% by weight.

[0087] In the total amount of the organometallic compound (or the total weight of the metal or metal oxide (1) and the ligand (2)), the proportion of the ligand represented by formula (2) is, for example, 0.1 to 50% by weight, preferably 0.5 to 30% by weight.

[0088] Furthermore, the amount of ligand represented by formula (2) above is, for example, 0.1 to 50 parts by weight, preferably 0.5 to 30 parts by weight, and particularly preferably 1 to 20 parts by weight, per 100 parts by weight of metal or metal oxide (1).

[0089] The aforementioned organometallic compounds aggregate when irradiated with light. The reaction shown in the following equation is considered to be the mechanism of this aggregation. In other words, although the metal or metal oxide (1) is a fine particle and has a tendency to aggregate, the organometallic compound achieves dispersibility by suppressing aggregation between the metal or metal oxide (1) particles through the binding of ligands represented by formula (2) to the surface of the metal or metal oxide (1). When irradiated with light, it is thought that the number of bound ligands decreases through the reactions 1, 2, and 3 below, resulting in a loss of dispersibility and the formation of aggregates. 1. Some of the ligand represented by equation (2) decomposes to produce acid (HX). 2. The generated acid (HX) reacts with the metal oxide (1), causing the ligands that were bonded to the surface to be detached. 3. Dispersibility is lost due to a decrease in the number of ligands bonded to the surface of the metal or metal oxide (1).

[0090] In the following formulas, M represents a metal or metal oxide (1). L and X are the same as L and X in formula (2). Furthermore, substituents may be attached to the carbon atoms constituting the benzene ring in the following formulas. In the following formulas, R represents the part of the ligand represented by formula (2) other than the carboxyl group (i.e., the part enclosed by the dashed line in the following formulas). [ka]

[0091] [Method for producing organometallic compounds] The organometallic compounds can be produced, for example, by mixing a metal or metal oxide (1) with a compound represented by the following formula (2a) that exhibits coordinating properties with (1) (hereinafter sometimes referred to as "metal-coordinating compound (2a)") in a solvent.

[0092] The compound represented by formula (3) below is an example of the organometallic compound, schematically illustrating how a ligand derived from the metal-coordinating compound (2a) is bonded to a metal or metal oxide (1) to form an organic-inorganic complex. In the following formula, M represents a metal or metal oxide (1). X in equation (2a) below - , L is X in equation (2) - , is the same as L. Also, the benzene ring in formula (2a) below may have substituents, similar to the benzene ring in formula (2). In formula (3) below, R represents the part of the compound represented by formula (2a) other than the carboxyl group (i.e., the part enclosed by the dashed line). [ka]

[0093] The amount of metal-coordinating compound (2a) used is, for example, 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, per 1 part by weight of the above-mentioned metal or metal oxide (1).

[0094] Examples of the aforementioned solvents include ethers such as diethyl ether, diisopropyl ether, dibutyl ether, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, and cyclopentyl methyl ether. These can be used individually or in combination of two or more.

[0095] The amount of solvent used is, for example, about 50 to 300% by weight of the total amount of the metal or metal oxide (1) and the ligand (2).

[0096] After this reaction is complete, the resulting reaction product can be separated and purified by conventional precipitation, washing, and filtration methods.

[0097] Furthermore, an example of a method for producing the metal-coordinating compound (2a) is shown below. Through the following steps [I], [II], and [III], the compound represented by the above formula (2a-1) (among the compounds represented by the above formula (2a), L in the formula is [-OC n H 2n Compounds are obtained where n is an integer from 1 to 5. [ka]

[0098] (Process I) Step I is a step in which a compound represented by formula (11) (=compound (11)) and a compound represented by formula (12) (=compound (12)) are reacted to obtain a compound represented by formula (13) (=compound (13)).

[0099] The molar ratio of compound (11) to compound (12) subjected to the above reaction (compound (11) / compound (12)) is, for example, 1 / 50 to 3 / 1, preferably 1 / 10 to 2 / 1.

[0100] The above reaction is preferably carried out in the presence of a dehydrating agent (HX'). Examples of dehydrating agents (HX') include concentrated sulfuric acid, phosphoric anhydride, methanesulfonic acid, trifluoromethanesulfonic acid, or their anhydrides. These can be used individually or in combination of two or more.

[0101] (Process II) Step II involves adding M to the compound (13) obtained through Step I. 1 X(X represents a monovalent pair anion, M 1 This is a step in which an alkali metal is reacted with a compound represented by formula (14) to obtain a compound represented by formula (14) (= compound (14)).

[0102] Compound (13) and M to be subjected to the above reaction 1 Molar ratio of X (compound (13) / M) 1 X) is, for example, 1 / 3 to 3 / 1, preferably 1 / 2 to 2 / 1.

[0103] (Process III) Step III is a step in which the compound (14) obtained in Step II is reacted with the compound represented by formula (15) (= compound (15)) to obtain the compound represented by formula (2a-1).

[0104] X in equation (15) 1 X represents a halogen atom. 2 represents a hydrogen atom or a protecting group (e.g., a t-butyl group). Compound (15) acts as an alkylating agent.

[0105] The molar ratio of compound (14) to compound (15) subjected to the above reaction (compound (14) / compound (15)) is, for example, 1 / 3 to 3 / 1, preferably 1 / 2 to 2 / 1.

[0106] The above reaction can be carried out in the presence of a solvent. Examples of the solvent include acetone, acetonitrile, and dimethyl sulfoxide. These can be used individually or in combination of two or more.

[0107] The reaction atmosphere for each step is not particularly limited as long as it does not inhibit the reaction, and may be any of the following: air, nitrogen, argon, etc. Furthermore, the reaction can be carried out in batch, semi-batch, or continuous manner.

[0108] Furthermore, after the reaction in each step is complete, the resulting reaction product may be subjected to general separation and purification processes (e.g., precipitation, washing, filtration, etc.).

[0109] [Photosensitive material for photoresists] The aforementioned photosensitive material for photoresists is a photosensitive material used in the field of photolithography (for example, a compound whose solubility in a solvent changes upon irradiation with light), and includes the organometallic compound described above.

[0110] The photosensitive material for photoresist may contain other components besides the organometallic compounds described above (for example, ligands other than the ligand represented by formula (2) above), but the proportion of the organometallic compounds in the total amount of the photosensitive material for photoresist is, for example, 70% by weight or more, preferably 80% by weight or more, more preferably 90% by weight or more, particularly preferably 95% by weight or more, most preferably 99% by weight or more, and especially preferably 99.9% by weight or more. The upper limit is 100% by weight.

[0111] The photosensitive material for photoresist exhibits excellent solubility (or dispersibility) in solvents (e.g., PGMEA). The average particle size (particle size determined by dynamic light scattering) of the photosensitive material for photoresist in the solvent is, for example, 200 nm or less, preferably 100 nm or less, and particularly preferably 50 nm or less. The lower limit is, for example, 1 nm.

[0112] Furthermore, the photosensitive material for photoresist exhibits excellent sensitivity to ultrashort wavelength light, and upon irradiation with such light, it quickly forms aggregates. The wavelength of the light is, for example, 100 nm or less, preferably 80 nm or less, and particularly preferably 50 nm or less. The light includes, for example, X-rays, electron beams (EB), EUV, etc.

[0113] The aforementioned photosensitive material for photoresists possesses thermal stability, and aggregation is suppressed even when subjected to heat treatment (for example, heating at a temperature of 50°C to less than 130°C for 1 to 5 minutes). Therefore, the coating film containing the aforementioned photosensitive material for photoresists can be heat-dried while suppressing aggregation, resulting in excellent workability.

[0114] Because the aforementioned photosensitive material for photoresists has the above-described characteristics, it can be suitably used as a photosensitive material for negative-type photoresists. Furthermore, it can be suitably used as a photosensitive material for photoresists that use ultrashort wavelength light such as extreme ultraviolet light or electron beams.

[0115] [Photoresist] The photoresist of the present invention is a resist used in the field of photolithography for forming a patterned resist film, and comprises the above-mentioned organometallic compound and a solvent, wherein the organometallic compound is contained in the solvent in a dissolved (or highly dispersed) state.

[0116] In the photoresist, the organometallic compound is contained in a stably dissolved (or highly dispersed) state. The average particle size of the organometallic compound in the photoresist (particle size determined by dynamic light scattering) is, for example, 200 nm or less, preferably 100 nm or less, and particularly preferably 50 nm or less. The lower limit is, for example, 1 nm. Therefore, by using the photoresist, a resist film with a low LER and high resolution fine pattern can be obtained.

[0117] Examples of the aforementioned solvents include lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; and (poly)C such as ethylene glycol monoacetate, diethylene glycol monoacetate, diethylene glycol diacetate, propylene glycol monoacetate, propylene glycol diacetate, and dipropylene glycol monoacetate. 1-5 Alkylene glycol esters; (poly)C such as ethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monomethyl ether, propylene glycol n-propyl ether, propylene glycol phenyl ether, tripropylene glycol methyl-n-propyl ether, etc. 1-5 Alkylene glycol ethers; (poly)C such as ethylene glycol monomethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), etc. 1-5 Examples include alkylene glycol ether esters; cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic hydrocarbons such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenethole, butylphenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene; and dimethyl sulfoxide. These can be used individually or in combination of two or more.

[0118] The content of the organometallic compound is, for example, 0.5 to 50% by weight, preferably 1.0 to 30% by weight, of the total amount (100% by weight) of the photoresist.

[0119] The solvent content is, for example, 50 to 99.5% by weight, preferably 70 to 99% by weight, of the total amount of the photoresist (100% by weight).

[0120] The photoresist may contain other components besides the organometallic compound and solvent, such as a bearing agent or a quencher.

[0121] In the total amount (100% by weight) of the photoresist, the proportion of the total weight of the organometallic compound and the solvent is, for example, 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more. The upper limit is 100% by weight.

[0122] The photoresist contains at least the organometallic compound as nonvolatile content. The proportion of the organometallic compound in the total amount of nonvolatile content (100% by weight) is, for example, 60% by weight or more, preferably 70% by weight or more, more preferably 80% by weight or more, particularly preferably 90% by weight or more, most preferably 95% by weight or more, and especially preferably 99% by weight or more. The upper limit is 100% by weight.

[0123] In this specification, the non-volatile components of a photoresist refer to the components containing the organometallic compound, for example, the components remaining after heating the photoresist at 100°C for 1 hour under normal pressure.

[0124] Furthermore, the photoresist is irradiated with light (the integrated light intensity is, for example, 5 to 500 mJ / cm²). 2If this is done, the organometallic compounds contained in the photoresist will quickly form aggregates. Furthermore, from the viewpoint of further refining the pattern, it is preferable to shorten the wavelength of the light, for example, 100 nm or less (for example, 1 to 100 nm) is preferred, 80 nm or less is more preferred, 50 nm or less is particularly preferred, 30 nm or less is most preferred, and 20 nm or less is especially preferred. The light includes, for example, X-rays, electron beams (EB), EUV, etc.

[0125] Because the aforementioned photoresist has the above-described characteristics, it can be suitably used as a negative-type photoresist. Furthermore, it can be suitably used as a photolithography resist using ultrashort wavelength light such as extreme ultraviolet light or electron beams.

[0126] By using the aforementioned photoresist, for example, a resist film with a fine pattern that is highly accurate and has excellent etching resistance can be formed through the following steps 1 to 3.

[0127] Step 1: A step of applying and drying the photoresist onto a substrate to form an organometallic compound layer. Step 2: A step of transferring a pattern by irradiating the organometallic compound layer with light. Step 3: Development process

[0128] (Process 1) This process involves applying the photoresist onto the substrate to be etched and drying it to form an organometallic compound layer. Through this process, a [substrate / organometallic compound layer] laminate is obtained.

[0129] For coating the photoresist, known methods such as spin coating, curtain coating, roll coating, spray coating, and screen printing can be used.

[0130] The substrate on which the photoresist is coated may be subjected to surface treatment as needed. For example, an adhesion agent such as hexamethyldisilazane (HMDS) may be applied to the surface of the substrate to improve the adhesion of the resist film.

[0131] The photoresist coating can be dried by natural drying, but because the organometallic compound has thermal stability, it can also be dried by heating (for example, heating at a temperature of 50°C to less than 130°C for 1 to 5 minutes), which offers excellent workability.

[0132] The thickness of the organometallic compound layer is, for example, 1000 nm or less, preferably 100 nm or less. The lower limit of the thickness is, for example, 1 nm. The aggregate of the organometallic compound contains a metal or metal oxide and therefore possesses toughness. For this reason, even if the organometallic compound layer is thinned, a resist film with excellent etching resistance can be formed.

[0133] (Process 2) This step involves transferring a pattern to the organometallic compound layer obtained in step 1 by irradiating it with light, for example, by irradiating it with light through a photomask having a pattern.

[0134] When light is irradiated through a photomask with a pattern, the organometallic compounds in the exposed areas aggregate and adhere to the substrate, while the organometallic compounds in the unexposed areas do not aggregate and maintain their solubility.

[0135] While there are no particular restrictions on the light beam used for irradiation, as long as it can initiate the aggregation of organometallic compounds contained in the coating film, using an ultrashort wavelength light source such as EUV or electron beams is preferable because it allows for the precise transfer of extremely fine patterns.

[0136] Furthermore, because the aggregates of the organometallic compound are tough, etching resistance can be maintained even when the organometallic compound layer is thinned. By thinning the organometallic compound layer and irradiating it with ultrashort wavelength light, the light can reach the bottom of the organometallic compound layer, allowing for the formation of a highly accurate pattern.

[0137] (Step 3) This process involves subjecting the [substrate / organometallic compound layer] laminate, after light irradiation, to a development treatment. During the development treatment, the unexposed parts of the organometallic compound layer are washed away, while the exposed parts remain in close contact with the substrate.

[0138] For the developing process, alkaline aqueous solutions or organic solvents can be used, either individually or in combination of two or more.

[0139] Examples of the aforementioned alkaline aqueous solutions include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, aqueous ammonia, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, and 1,5-diazabicyclo-[4.3.0]-5-nonene.

[0140] Examples of the organic solvent include those similar to those used in photoresists. In particular, it is preferable to include at least one selected from polyhydric alcohols, esters, ethers, ketones, and aromatic hydrocarbons, especially to include at least an ester, and most preferably to include at least butyl acetate.

[0141] Examples of development methods include applying the developer solution to the [substrate / organometallic compound layer] laminate by methods such as dipping, showering, or spraying.

[0142] The temperature of the developing solution is, for example, 25-40°C. The development time is determined appropriately depending on the thickness of the organometallic compound layer, but is typically around 0.5-5 minutes.

[0143] Ideally, unexposed areas should be completely removed during the development process. This is because the presence of development residue can easily lead to problems such as abnormal wiring shapes. The photoresist of the present invention contains organometallic compounds that possess high dispersibility and thermal stability, so unexposed areas can be easily and completely removed by washing with a developer solution, and no development residue is generated. Therefore, products without defects can be manufactured with a high yield.

[0144] After step 3, a resist film can be formed on the substrate that has a fine pattern with high precision and excellent etching resistance, consisting of aggregates of organometallic compounds. By etching the substrate using the resist film thus obtained, high-precision electronic devices can be manufactured.

[0145] The aforementioned electronic devices include, for example, display devices such as organic EL displays and liquid crystal displays; input devices such as touch panels; light-emitting devices; sensor devices; and MEMS (Micro Electro Mechanical Systems) devices such as optical scanners, optical switches, accelerometers, pressure sensors, gyroscopes, microfluidics, and inkjet heads.

[0146] The configurations and combinations thereof described above are merely examples, and additions, omissions, substitutions, and modifications to the configurations are permitted as appropriate, without departing from the spirit of the present invention. [Examples]

[0147] The present invention will be described more specifically below with reference to examples, but the present invention is not limited to these examples.

[0148] Manufacturing Example 1 <Synthesis of bis(3,5-difluorophenyl) sulfoxide> A THF solution of 3,5-difluorophenylmagnesium bromide was prepared by dispersing 13.4 g (0.55 mol) of magnesium in 400 g of tetrahydrofuran (THF) to a dispersion, and then adding 96.5 g (0.50 mol) of 1-bromo-3,5-difluorobenzene dropwise while stirring, maintaining the system temperature in the range of 40-50°C. To a THF solution of the prepared 3,5-difluorophenylmagnesium bromide, a solution of 28.6 g (0.24 mol) of thionyl chloride diluted with 50 g of THF was added dropwise at a rate that did not exceed -5°C in system temperature. After the addition was complete, the reaction was allowed to continue at room temperature for 1 hour to complete the reaction.

[0149] The reaction solution was added to 500 g of deionized water at a rate that did not exceed 15°C, and the mixture was stirred for 1 hour. Then, 300 g of ethyl acetate was added and the mixture was stirred for 1 hour. After removing the aqueous layer, the mixture was washed three times with 300 g of deionized water. The organic layer was decolorized by passing it through a silica gel column. Subsequently, the decolorized organic layer was desolvented and recrystallized with cyclohexane to obtain 26.0 g of bis(3,5-difluorophenyl) sulfoxide.

[0150] <Synthesis of Metal-Coordinating Compounds> 6.86 g (0.025 mol) of the obtained bis(3,5-difluorophenyl) sulfoxide was dissolved in 15.3 g (0.125 mol) of 2,6-dimethylphenol and 24.0 g (0.25 mol) of methanesulfonic acid, and 7.1 g (0.05 mol) of anhydrous phosphoric acid was added dropwise at a rate that did not exceed 25°C in the system. After the addition was complete, the reaction was allowed to continue at room temperature for 24 hours to complete the reaction. Next, the reaction mixture was slowly added to 150 g of deionized water, stirred for a while, and then 50 g of methanol was added. 50 g of toluene was added to this solution, stirred for 30 minutes, and then allowed to stand to remove the upper toluene layer. This toluene washing was repeated two more times.

[0151] After removing the toluene layer, 4.7 g (0.025 mol) of potassium trifluoromethanesulfonate and 80 g of dichloromethane were added to the aqueous layer. The mixture was stirred for 1 hour, then allowed to stand, and the upper aqueous layer was removed. This washing procedure was repeated two more times. The dichloromethane layer after removing the aqueous layer was concentrated to obtain 3.1 g (0.006 mol) of a sulfonium intermediate.

[0152] Next, 10 g of acetonitrile, 1.7 g (0.009 mol) of t-butyl bromoacetate, and 2.5 g (0.018 mol) of potassium carbonate were added to this intermediate, and the reaction was carried out at 60°C for 36 hours. After that, the reaction mixture was filtered and the filtrate was collected. The collected filtrate was concentrated and washed with t-butyl methyl ether, and 3.5 g of the insoluble portion was collected.

[0153] The insoluble portion was dissolved in 100 g of isopropanol, then 1 g of sulfuric acid was added and the mixture was reacted at 70°C for 5 hours. The solvent was then removed by concentration. Next, 50 g of dichloromethane and 50 g of deionized water were added, and after stirring for 1 hour, the mixture was allowed to stand and the upper aqueous layer was removed. This washing procedure was repeated two more times. After concentrating the dichloromethane layer after the removal of the aqueous phase, it was recrystallized with butyl acetate. This yielded 2.3 g of the target product, [bis(3,5-difluorophenyl)](4-carboxymethoxy-3,5-dimethylphenyl)sulfonium trifluoromethanesulfonate.

[0154] Manufacturing Example 2 <Synthesis of bis(2-trifluoromethylphenyl) sulfoxide> 20.0 g of bis(2-trifluoromethylphenyl) sulfoxide was obtained by the same method as in Preparation Example 1, except that 112.5 g (0.50 mol) of 2-bromobenzotrifluoride was used instead of 96.5 g of 1-bromo-3,5-difluorobenzene.

[0155] <Synthesis of Metal-Coordinating Compounds> [Bis(2-trifluoromethylphenyl)](4-(1-carboxypropoxy)-3,5-dimethylphenyl)sulfonium nonafluorobutanesulfonate was obtained by the same method as in Production Example 1, except that bis(2-trifluoromethylphenyl)sulfoxide was used instead of bis(3,5-difluorophenyl)sulfoxide, 2-t-butyl bromobutyrate was used instead of t-butyl bromoacetate, and potassium nonafluorobutanesulfonate was used instead of potassium trifluoromethanesulfonate.

[0156] Manufacturing Example 3 <Synthesis of bis(4-trifluoromethylphenyl) sulfoxide> 29.1 g of bis(4-trifluoromethylphenyl) sulfoxide was obtained by the same method as in Preparation Example 1, except that 112.5 g (0.50 mol) of 4-bromobenzotrifluoride was used instead of 96.5 g of 1-bromo-3,5-difluorobenzene.

[0157] <Synthesis of Metal-Coordinating Compounds> [Bis(4-trifluoromethylphenyl)](4-carboxymethylthiophenyl)sulfonium bis(trifluoromethanesulfonyl)imide was obtained in the same manner as in Example 1, except that bis(4-trifluoromethylphenyl)](4-carboxymethylthiophenyl)sulfonium bis(trifluoromethanesulfonyl)imide was used instead of bis(3,5-difluorophenyl)sulfoxide, thiophenol was used instead of 2,6-dimethylphenol, and potassium bis(trifluoromethanesulfonyl)imide was used instead of potassium trifluoromethanesulfonate.

[0158] Manufacturing Example 4 <Synthesis of bis(4-iodophenyl) sulfoxide> 28.6 g (0.24 mol) of thionyl chloride and 100 g (0.48 mol) of iodobenzene were diluted with 500 g of THF to which 50 g (0.48 mol) of perchloric acid was added dropwise. After the addition was complete, the reaction was allowed to continue at room temperature for 5 hours to complete. Next, the reaction solution was slowly added to 1500 g of deionized water, followed by the addition of 300 g of dichloromethane. The mixture was stirred for 1 hour, and then allowed to stand to remove the upper aqueous layer. The dichloromethane layer after the removal of the aqueous phase was concentrated and recrystallized with butyl acetate to obtain 54 g of bis(4-iodophenyl) sulfoxide.

[0159] <Synthesis of Metal-Coordinating Compounds> [Bis(4-iodophenyl)](4-carboxyphenyl)sulfonium nonafluorobutanesulfonate was obtained in the same manner as in Example 1, except that bis(4-iodophenyl)sulfoxide was used instead of bis(3,5-difluorophenyl)sulfoxide, t-butyl benzoate was used instead of 2,6-dimethylphenol, potassium nonafluorobutanesulfonate was used instead of potassium trifluoromethanesulfonate, and t-butyl bromoacetate was not used.

[0160] Manufacturing Example 5 <Synthesis of bis(3,5-difluoro-2-iodophenyl) sulfoxide> 27.4 g (0.10 mol) of bis(3,5-difluorophenyl) sulfoxide was dissolved in 200 g of sulfuric acid, and 45.0 g (0.20 mol) of N-iodosuccinimide was added in portions. The reaction was then allowed to proceed at room temperature for 3 hours. Next, the reaction mixture was slowly added to 1500 g of deionized water, followed by the addition of 200 g of dichloromethane. The mixture was stirred for 1 hour, and then allowed to stand to remove the upper aqueous layer. The dichloromethane layer after the removal of the aqueous phase was concentrated and recrystallized with butyl acetate to obtain 23.3 g of bis(3,5-difluoro-2-iodophenyl) sulfoxide.

[0161] <Synthesis of Metal-Coordinating Compounds> [Bis(3,5-difluoro-2-iodophenyl)](4-carboxymethoxy-3,5-dimethylphenyl)sulfonium bis(trifluoromethanesulfonyl)imide was obtained by the same method as in Example 1, except that bis(3,5-difluoro-2-iodophenyl)sulfoxide was replaced with bis(3,5-difluoro-2-iodophenyl)sulfoxide and potassium bis(trifluoromethanesulfonyl)imide was replaced with potassium bis(trifluoromethanesulfonyl)imide.

[0162] Manufacturing Example 6 <Synthesis of Metal-Coordinating Compounds> Diphenyl-4-carboxymethoxy-3,5-dimethylphenyl)sulfonium trifluoromethanesulfonate was obtained by the same method as in Production Example 1, except that diphenyl sulfoxide was used instead of bis(3,5-difluorophenyl)sulfoxide.

[0163] Example 1 3 g of zirconium isopropoxide was dissolved in 20 g of THF. To this, a solution obtained by mixing 4 g of benzoic acid, 1 g of the metal-coordinating compound obtained in Preparation Example 1, and 20 g of THF was added at room temperature. The resulting mixture was kept at a temperature of 65°C, and 2 mL of deionized water was added to carry out a sol-gel reaction for 24 hours. After the reaction was complete, the precipitate was collected and washed with acetone / water (1:4, by volume). Then, it was dried under vacuum at 40°C for 24 hours. This yielded an organometallic compound. The resulting organometallic compounds 19 F-NMR analysis (using a JEOL Ltd. instrument named "JNM-ECX400P") revealed peaks originating from the cation (-104 ppm) and anion (-78 ppm) of the metal-coordinating compound, confirming that the metal-coordinating compound was present.

[0164] 0.3 g of the obtained organometallic compound was dissolved in 9.0 g of PGMEA, and then filtered through a 0.20 μm pore size filter to remove undissolved aggregates. This yielded a photoresist.

[0165] Examples 2-7 An organometallic compound and a photoresist were obtained in the same manner as in Example 1, except that the ligand, metal, or metal oxide was changed as shown in Tables 1 and 2 below.

[0166] Comparative Examples 1-2 0.3 g of a metal or metal oxide listed in Table 3 below and 0.15 g of a photoacid generator were dissolved in 9.0 g of PGMEA, and then filtered through a 0.20 μm pore size filter to remove undissolved aggregates. A photoresist was obtained.

[0167] The photosensitivity of the photoresists obtained in the examples and comparative examples was evaluated using the following method. <Method for evaluating photosensitivity> A photoresist was applied to a substrate treated with hexamethyldisilazane using a spin coater, and then the solvent was removed by heating at 80°C for 60 seconds to obtain a coating with a thickness of approximately 50 nm. The obtained coating film was placed in BL-3 of the NewSUBARU Synchrotron Radiation Facility at the University of Hyogo, and irradiated with 13.5 nm synchrotron radiation, with irradiation times varied from 1 to 30 seconds. After that, the coating film was developed by immersing it in butyl acetate for 30 seconds and then dried. The developed and dried coating was observed under a microscope, and the minimum exposure dose (Eth) required to achieve a resist thickness of 40 nm or more in the light-irradiated area was measured. The ratio of the minimum exposure dose (Eth) to the minimum exposure dose (Eth') when using the photoresist of Comparative Example 1 was calculated using the following formula and used as an indicator of photosensitivity. A smaller minimum exposure dose ratio indicates better photosensitivity. Minimum exposure ratio = Eth / Eth'

[0168] [Table 1]

[0169] [Table 2]

[0170] [Table 3]

[0171] From the table above, it can be seen that the organometallic compounds of the present invention have high sensitivity to ultrashort wavelength light, and that the sensitivity is further improved by introducing a halogen atom or a haloalkyl group as a substituent to the benzene ring constituting the cation part. On the other hand, in the comparative example, the photoacid generator is not coordinated to the metal or metal oxide, and therefore, it is found to have low sensitivity to ultrashort wavelength light.

[0172] In summary, the configuration of the present invention and its variations are described below. [1] comprising a metal or metal oxide (1) and a ligand (2) bonded to (1), The above (2) is a ligand represented by formula (2) (wherein L represents a single bond or linking group, X - (This represents a monovalent counteranion. Substituents may be attached to the carbon atoms constituting the benzene ring. If two or more substituents are attached to one benzene ring, the two or more substituents may be linked to each other and form a ring together with the carbon atoms to which the substituents are attached.) An organometallic compound containing this compound. [2] The ligand represented by formula (2) above is the ligand represented by formula (2-1) (wherein R 11 , R 12 Each is independently a halogen atom or C 1-5 R indicates a halo-alkyl group. 13 C is a halogen atom. 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups, or C 1-5 This represents a haloalkoxy group. n11 and n12 each independently represent integers from 1 to 5, and n13 represents an integer from 0 to 4. L represents a single bond or a linking group, and X - The organometallic compounds described in [1] (where represents a monovalent counter anion). [3] The ligand represented by formula (2) above is the ligand represented by formula (2-3) (wherein R11 , R 12 Each is independently a halogen atom or C 1-5 R indicates a halo-alkyl group. 13 C is a halogen atom. 1-5 Alkyl alkyl group, C 1-5 Alkoxy group, C 1-5 Haloalkyl groups, or C 1-5 This represents a haloalkoxy group. n11 and n12 each independently represent integers from 1 to 5, and n13 represents an integer from 0 to 4. 1 X represents an oxygen atom or a sulfur atom, and n is an integer from 1 to 5. - The organometallic compounds described in [1] (where represents a monovalent counter anion). [4] The organometallic compound according to any one of [1] to [3], wherein (1) is at least one selected from hafnium, zirconium, tin, cobalt, palladium, antimony, and oxides thereof. [5] A photosensitive material for photoresists containing an organometallic compound as described in any one of [1] to [4]. [6] The photosensitive material for photoresists according to [5], which is a photosensitive material for extreme ultraviolet light or an electron beam. [7] A photoresist comprising an organometallic compound and a solvent as described in any one of [1] to [4].

Claims

1. The material comprises a metal or metal oxide (1) and a ligand (2) bonded to (1), An organometallic compound wherein (2) contains a ligand represented by the following formula (2-1). 【Chemistry 1】 (In the formula, R 11 and R 12 each independently represent a halogen atom or a C 1-5 haloalkyl group. R 13 represents a halogen atom, a C 1-5 alkyl group, a C 1-5 alkoxy group, a C 1-5 haloalkyl group, or a C 1-5 haloalkoxy group. n11 and n12 each independently represent an integer from 1 to 5, and n13 represents an integer from 0 to 4. L represents a linking group which is a divalent group formed by bonding a single bond, an ether bond, or a thioether bond to a divalent hydrocarbon group, and X- represents a monovalent counteranion.)

2. The organometallic compound according to claim 1, wherein R13 is a C1-5 alkyl group.

3. The organometallic compound according to claim 1, wherein the ligand represented by formula (2-1) is the ligand represented by the following formula (2-3). 【Chemistry 2】 (wherein, R １ , R １２ each independently represents a halogen atom or a C １－５ haloalkyl group. R １３ represents a halogen atom, a C １－５ alkyl group, a C １－５ alkoxy group, a C １－５ haloalkyl group, or a C １－５ haloalkoxy group. n11 and n12 each independently represent an integer of 1 to 5, and n13 represents an integer of 0 to 4. L １ represents an oxygen atom or a sulfur atom, and n represents an integer of 1 to 5. X － represents a monovalent counter anion)

4. The organometallic compound according to any one of claims 1 to 3, wherein (1) is at least one selected from hafnium, zirconium, tin, cobalt, palladium, antimony, and oxides thereof.

5. A photosensitive material for photoresists comprising an organometallic compound according to any one of claims 1 to 3.

6. The photosensitive material for photoresists according to claim 5, which is a photosensitive material for extreme ultraviolet light or an electron beam.

7. A photoresist comprising an organometallic compound and a solvent according to any one of claims 1 to 3.

Images