Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
  • C08F20/00—Homopolymers and copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical or a salt, anhydride, ester, amide, imide or nitrile thereof
  • C08F20/02—Monocarboxylic acids having less than ten carbon atoms, Derivatives thereof
  • C08F20/10—Esters
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/038—Macromolecular compounds which are rendered insoluble or differentially wettable
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/039—Macromolecular compounds which are photodegradable, e.g. positive electron resists

Definitions

• the present invention relates to an actinic ray- or radiation-sensitive resin composition, a resist film, a pattern forming method, and a method for manufacturing an electronic device.
• a pattern formation method using chemical amplification has been used to compensate for the decrease in sensitivity due to light absorption.
• a photoacid generator contained in the exposed portion is decomposed by light irradiation to generate an acid.
• the catalytic action of the generated acid changes the alkali-insoluble group of the resin contained in the actinic ray-sensitive or radiation-sensitive resin composition to an alkali-soluble group, thereby changing the solubility in the developer.
• development is performed using, for example, a basic aqueous solution.
• the exposed portion is removed to obtain a desired pattern.
• the wavelength of the exposure light source has become shorter and the numerical aperture (NA) of the projection lens has become higher, and currently, an exposure machine using an ArF excimer laser having a wavelength of 193 nm as a light source has been developed.
• pattern formation methods using extreme ultraviolet (EUV) and electron beam (EB) as light sources are also being considered in recent years. Under these circumstances, various compositions have been proposed as actinic ray-sensitive or radiation-sensitive resin compositions.
• Patent Document 1 describes a positive resist composition that contains an ionic compound and a resin that has a repeating unit having an interactive group that interacts with the ionic group in the ionic compound, and whose main chain is decomposed by irradiation with X-rays, electron beams, or extreme ultraviolet rays.
• a resolution capable of forming an ultrafine pattern e.g., a line and space pattern with a line width of 15.0 nm or less and a line:space ratio of 1:1
• the present inventors have made it clear through their studies that the resist composition of Patent Document 1 has room for further improvement in terms of resolution.
• a resist composition may be stored for a certain period of time after preparation, and it is desirable for the resist composition to have excellent resolution even when a pattern is formed after the resist composition has been stored for a certain period of time.
• the resolution of a resist composition immediately after preparation is also called “initial resolution,” and the resolution of a resist composition after a certain period of time has passed since preparation is also called “resolution after aging.”
• An actinic ray-sensitive or radiation-sensitive resin composition contains a resin (A) whose main chain is decomposed when irradiated with actinic rays or radiation, an onium salt (b1), and an onium salt (b2), Among the anions contained in the onium salt (b1), when the anion having the largest pKa of the conjugate acid is designated as anion (an 1 ), the pKa of the conjugate acid of the anion (an 1 ) is 10 or less; Among the anions contained in the onium salt (b2), when the anion having the largest pKa of the conjugate acid is designated as an anion (an 2 ), the pKa of the conjugate acid of the anion (an 2 ) is 2 or more; the pKa of a conjugate acid of the anion (an 1 ) is greater than the pKa of a conjugate acid of the anion (an 2 ); [2] The actinic ray-sensitive or radiation
• Ar m1 , Ar m2 and Ar m3 each independently represent an aryl group, and at least two of Ar m1 , Ar m2 and Ar m3 may be bonded to each other.
• the actinic ray-sensitive or radiation-sensitive resin composition according to any one of [1] to [4], wherein the content of the onium salt (b1) is less than the content of the onium salt (b2).
• Ar m4 , Ar m5 and Ar m6 each independently represent an aryl group, and at least two of Ar m4 , Ar m5 and Ar m6 may be bonded to each other.
• X represents a halogen atom, a fluorinated alkyl group, or a fluorinated cycloalkyl group.
• R0 represents a hydrogen atom or an organic group.
• R1 represents a substituent. R0 and R1 may be bonded to form a ring.
• A1 represents a hydrogen atom, a halogen atom, or an organic group.
• R3 represents a hydrogen atom or a substituent.
• Ar1 represents a benzene ring or a naphthalene ring.
• R4 represents a substituent. When a plurality of R4s are present, the plurality of R4s may be the same or different from each other, and R4s may be bonded together to form a ring. R3 and R4 may be bonded together to form a ring.
• k1 represents an integer of 0 to 7.
• An actinic ray-sensitive or radiation-sensitive resin composition Contains a resin (A), an onium salt (b1), and an onium salt (b2),
• the resin (A) contains a repeating unit represented by the following formula (1):
• the anion having the largest pKa of the conjugate acid is designated as anion (an 1 )
• the pKa of the conjugate acid of the anion (an 1 ) is 10 or less
• the anions contained in the onium salt (b2) when the anion having the largest pKa of the conjugate acid is designated as an anion (an 2 ), the pKa of the conjugate acid of the anion (an 2 ) is 2 or more; the pKa of a conjugate acid of the anion (an 1 ) is greater than the pKa of a conjugate acid of the anion (an 2 );
• X represents a halogen atom, a fluorinated alkyl group, or a fluorinated cycloalkyl group.
• R0 represents a hydrogen atom or an organic group.
• R1 represents a substituent. R0 and R1 may be bonded to form a ring.
• A1 represents a hydrogen atom, a halogen atom, or an organic group.
• R3 represents a hydrogen atom or a substituent.
• Ar1 represents a benzene ring or a naphthalene ring.
• R4 represents a substituent. When a plurality of R4s are present, the plurality of R4s may be the same or different from each other, and R4s may be bonded together to form a ring. R3 and R4 may be bonded together to form a ring.
• k1 represents an integer of 0 to 7.
• an actinic ray-sensitive or radiation-sensitive resin composition which is excellent in initial resolution and resolution after aging. Furthermore, according to the present invention, there can be provided a resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method using the actinic ray-sensitive or radiation-sensitive resin composition, and a method for producing an electronic device.
• an "alkyl group” includes not only an alkyl group that has no substituent (unsubstituted alkyl group) but also an alkyl group that has a substituent (substituted alkyl group).
• an "organic group” in the present specification refers to a group that contains at least one carbon atom. Unless otherwise specified, the substituent is preferably a monovalent substituent.
• actinic rays or “radiation” refers to, for example, the emission line spectrum of a mercury lamp, far ultraviolet rays represented by excimer lasers, extreme ultraviolet rays (EUV: Extreme Ultraviolet), X-rays, electron beams (EB: Electron Beam), etc.
• light refers to actinic rays or radiation.
• exposure includes not only exposure to the emission line spectrum of a mercury lamp, far ultraviolet light represented by an excimer laser, extreme ultraviolet light, X-rays, EUV light, and the like, but also drawing with particle beams such as electron beams and ion beams.
• the word “to” is used to mean that the numerical values before and after it are included as the lower limit and upper limit.
• the bonding direction of the divalent group described in this specification is not limited unless otherwise specified. For example, when Y is -COO- in a compound represented by the formula "X-Y-Z", Y may be -CO-O- or -O-CO-. In addition, the above compound may be "X-CO-O-Z" or "X-O-CO-Z".
• the weight average molecular weight (Mw), number average molecular weight (Mn), and dispersity (also called molecular weight distribution) (Mw/Mn) of the resin are defined as polystyrene equivalent values measured using a Gel Permeation Chromatography (GPC) device (Tosoh HLC-8120GPC) (solvent: tetrahydrofuran, flow rate (sample injection amount): 10 ⁇ L, column: Tosoh TSK gel Multipore HXL-M, column temperature: 40°C, flow rate: 1.0 mL/min, detector: refractive index detector).
• GPC Gel Permeation Chromatography
• the acid dissociation constant (pKa) refers to the pKa in an aqueous solution, and is specifically a value calculated using the following software package 1 based on a database of Hammett's substituent constants and publicly known literature values. All pKa values described in this specification are values calculated using this software package.
• pKa can also be obtained by molecular orbital calculation.
• a specific example of this method is a method of calculating H + dissociation free energy in an aqueous solution based on a thermodynamic cycle.
• the H + dissociation free energy can be calculated, for example, by DFT (density functional theory), but various other methods have been reported in literature and are not limited to this.
• DFT density functional theory
• the pKa in this specification refers to a value calculated using the software package 1 based on a database of Hammett's substituent constants and known literature values.
• a value obtained by Gaussian 16 based on DFT density functional theory
• the pKa in this specification refers to "pKa in an aqueous solution” as described above, but when the pKa in an aqueous solution cannot be calculated, "pKa in a dimethyl sulfoxide (DMSO) solution” will be adopted.
• DMSO dimethyl sulfoxide
• halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.
• solids refers to components that form a resist film and does not include solvents.
• any component that forms a resist film is considered to be a solid even if it is in liquid form.
• the actinic ray-sensitive or radiation-sensitive resin composition of the present invention (hereinafter, also referred to as "resist composition”) is The composition contains a resin (A) whose main chain is decomposed when irradiated with actinic rays or radiation, an onium salt (b1), and an onium salt (b2), Among the anions contained in the onium salt (b1), when the anion having the largest pKa of the conjugate acid is designated as anion (an 1 ), the pKa of the conjugate acid of the anion (an 1 ) is 10 or less; Among the anions contained in the onium salt (b2), when the anion having the largest pKa of the conjugate acid is designated as anion (an 2 ), the pKa of the conjugate acid of the anion (an 2 ) is 2 or more;
• the actinic ray-sensitive or radiation-sensitive resin composition has a pKa of a conjugate
• the resist composition of the present invention contains a resin (A) whose main chain is decomposed by irradiation with actinic rays or radiation, an onium salt (b1), and an onium salt (b2).
• the onium salt (b1) and the onium salt (b2) typically contain a cation and an anion.
• the anion having the largest pKa of the conjugate acid among the anions contained in the onium salt (b1) is an anion (an 1 )
• the pKa of the conjugate acid of the anion (an 1 ) is 10 or less
• the anion having the largest pKa of the conjugate acid among the anions contained in the onium salt (b2) is an anion (an 2 )
• the pKa of the conjugate acid of the anion (an 2 ) is 2 or more
• the pKa of the conjugate acid of the anion (an 1 ) is larger than the pKa of the conjugate acid of the anion (an 2 ).
• the main chain of the resin (A) is decomposed in the exposed area (the area irradiated with actinic rays or radiation), and the solubility in the developer is increased.
• the main chain of the resin (A) is not decomposed, and the onium salt (b2) is present, so that the solubility in the developer is reduced (the above-mentioned action of the onium salt (b2) is also called "inhibition").
• the onium salt (b2) is a compound that decomposes upon irradiation with actinic rays or radiation
• the onium salt (b2) is decomposed in the exposed area, and the inhibition action is weakened, so that the resist film becomes more soluble in the developer.
• solubility in the developer dissolution contrast
• the onium salt (b2) decomposes, weakening the inhibition effect and lowering the dissolution contrast.
• the resist composition of the present invention contains onium salt (b1), which traps the conjugate acid of the anion generated from onium salt (b2) and restores the anion, thereby regenerating the onium salt having inhibition effect, improving the dissolution contrast and further increasing the resolution.
• onium salt (b1) which traps the conjugate acid of the anion generated from onium salt (b2) and restores the anion, thereby regenerating the onium salt having inhibition effect, improving the dissolution contrast and further increasing the resolution.
• the nucleophilicity of the onium salt (b1) can be suppressed, and the main chain decomposition reaction of the resin (A) can be suppressed, which is thought to result in excellent resolution even after aging.
• the resist composition of the present invention contains a resin (A) (hereinafter also referred to as the "specific resin”) whose main chain is decomposed upon exposure to actinic rays or radiation.
• the specific resin is preferably a resin whose main chain is decomposed by irradiation with X-rays, electron beams or extreme ultraviolet rays.
• the specific resin is a resin containing a repeating unit represented by the formula (1) described below (hereinafter, also referred to as "specific resin 1").
• the specific resin in terms of the superior effect of the present invention, as described below, it is preferable that the specific resin contains one or more functional groups (hereinafter also referred to as "specific functional groups") selected from the group consisting of hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), carboxyl groups, amino groups, amide groups, imide groups, thiol groups, acetyl groups, sulfonic acid groups, sulfonamide groups, and acetoxy groups, and it is more preferable that the specific resin contains one or more functional groups selected from the group consisting of phenolic hydroxyl groups and carboxyl groups.
• ionic compounds such as onium salt (b2)
• Specific resin 1 is a resin containing a repeating unit represented by the following formula (1).
• X represents a halogen atom, a fluorinated alkyl group, or a fluorinated cycloalkyl group.
• R0 represents a hydrogen atom or an organic group.
• R1 represents a substituent. R0 and R1 may be bonded to form a ring.
• X represents a halogen atom, a fluorinated alkyl group or a fluorinated cycloalkyl group.
• halogen atom represented by X a chlorine atom is preferred in that the effects of the present invention are more excellent.
• the alkyl group in the fluorinated alkyl group represented by X may be either linear or branched.
• the number of fluorine atoms substituted on the alkyl group may be one or more, but it is preferable that the alkyl group is a perfluoroalkyl group in terms of better effects of the present invention.
• the number of carbon atoms in the fluorinated alkyl group represented by X is not particularly limited, but for example, 1 to 12 is preferable, 1 to 6 is more preferable, and 1 to 3 is even more preferable.
• the cycloalkyl group in the fluorinated cycloalkyl group represented by X may be either a monocyclic or polycyclic cycloalkyl group.
• the cycloalkyl group may have one or more fluorine atoms substituted thereon, and may be a perfluorocycloalkyl group.
• the number of carbon atoms in the fluorinated cycloalkyl group represented by X is not particularly limited, but for example, 3 to 20 is preferable, 5 to 15 is more preferable, and 5 to 10 is particularly preferable.
• X is preferably a halogen atom, and more preferably a chlorine atom, in that the effects of the present invention are more excellent.
• R 0 represents a hydrogen atom or an organic group.
• the organic group represented by R 0 is not particularly limited, but is preferably an alkyl group or a cycloalkyl group.
• the alkyl group may be either straight-chain or branched-chain.
• the number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3.
• the cycloalkyl group may be either monocyclic or polycyclic.
• the number of carbon atoms in the cycloalkyl group is not particularly limited, but for example, 3 to 20 is preferable, 5 to 15 is more preferable, and 5 to 10 is particularly preferable.
• the alkyl group and the cycloalkyl group may have a substituent.
• the substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and a specific functional group.
• R 0 is preferably a hydrogen atom in that the effects of the present invention are more excellent.
• R 1 represents a substituent.
• the substituent represented by R1 is not particularly limited, and examples thereof include a group represented by the following formula (1-1), a hydroxyl group, and -NH2 .
• R X represents a hydrogen atom or an organic group.
• the organic group represented by R 1 X is not particularly limited, but is preferably, for example, an alkyl group or a cycloalkyl group.
• the alkyl group may be either straight-chain or branched-chain.
• the number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3.
• the cycloalkyl group may be either monocyclic or polycyclic.
• the number of carbon atoms in the cycloalkyl group is not particularly limited, but for example, 3 to 20 is preferable, 5 to 15 is more preferable, and 5 to 10 is particularly preferable.
• the alkyl group and the cycloalkyl group may have a substituent.
• the substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and a specific functional group.
• R 1 X is preferably a hydrogen atom in that the effects of the present invention are more excellent.
• R 1A represents a hydrogen atom or an organic group.
• the organic group represented by R 1A is not particularly limited, but examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, and a group containing an onium salt structure described below.
• the alkyl group may be either linear or branched.
• the number of carbon atoms in the alkyl group is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
• the cycloalkyl group may be either monocyclic or polycyclic.
• the number of carbon atoms in the cycloalkyl group is not particularly limited, but for example, 3 to 20 is preferable, 5 to 15 is more preferable, and 5 to 10 is particularly preferable.
• the cycloalkyl group includes monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group.
• the alkyl group and the cycloalkyl group may have a substituent.
• the substituent is not particularly limited, and examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and a specific functional group.
• the alkyl group includes a group represented by -C(R x1 )(R x2 )(R x3 ), where R x1 to R x3 each independently represent an alkyl group or a cycloalkyl group.
• the alkyl group represented by R X1 to R X3 may be either linear or branched.
• the number of carbon atoms in the alkyl group is not particularly limited, and is, for example, preferably 1 to 20, more preferably 1 to 10, and further preferably 1 to 6.
• the cycloalkyl group represented by R X1 to R X3 may be either a monocyclic or polycyclic group.
• the number of carbon atoms in the cycloalkyl group is not particularly limited, but is preferably 5 to 15, and more preferably 5 to 10.
• Examples of the cycloalkyl group include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group.
• R X1 to R X3 each independently represent a linear or branched alkyl group (preferably a linear alkyl group), or two of R X1 to R X3 combine to form a monocyclic or polycyclic 5- to 8-membered alicyclic ring.
• the alkyl group or cycloalkyl group represented by R to R may have a substituent.
• the substituent is not particularly limited, and examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and a specific functional group.
• L 1A preferably represents -O- or -N(R x )-, and more preferably represents -O-.
• the aryl group may be either a monocyclic or polycyclic ring, and is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms.
• the aryl group is preferably a phenyl group or a naphthyl group, and more preferably a phenyl group.
• the aryl group may have a substituent.
• the substituent is not particularly limited and may be a halogen atom (preferably a fluorine atom or an iodine atom) or a specific functional group, and among these, a fluorine atom, an iodine atom, or a hydroxyl group is preferable.
• the aralkyl group preferably has a structure in which one of the hydrogen atoms in the alkyl group is replaced with the aryl group.
• the number of carbon atoms in the aralkyl group is preferably 7 to 20, and more preferably 7 to 15.
• R 0 and R 1 may be bonded to form a ring.
• the ring may contain a heteroatom (e.g., a nitrogen atom, an oxygen atom, a sulfur atom, etc.) as a ring member atom.
• the repeating unit represented by formula (1) is preferably a repeating unit represented by the following formula (1A), in that the effect of the present invention is more excellent.
• X and R 0 have the same meanings as X and R 0 in formula (1), and the preferred embodiments are also the same.
• L 2A represents -O- or -N(R x )-.
• R x represents a hydrogen atom or an organic group. Examples of the organic group represented by R x include the same as R x in formula (1-1) above.
• R 1A represents a hydrogen atom or an organic group. Examples of the organic group represented by R 1A include the same as R 1A in formula (1-1) above.
• R 0 and R 1A may be bonded to each other to form a ring. Examples of the ring formed by R 0 and R 1A bonded to each other include the same rings as those formed by R 0 and R 1 in the above formula (1) bonded to each other.
• the content of the repeating unit represented by formula (1) is preferably 5 to 95 mol %, more preferably 10 to 90 mol %, and even more preferably 20 to 80 mol %, based on the total repeating units of the specific resin 1.
• the repeating unit represented by formula (1) may be one type or two or more types. When the repeating unit represented by formula (1) is two or more types, the total content thereof is preferably within the above numerical range.
• the specific resin 1 further contains other repeating units (hereinafter also referred to as "other repeating units") different from the repeating unit represented by formula (1).
• other repeating units a repeating unit represented by formula (2) is preferable, and in terms of superior effects of the present invention, a repeating unit represented by formula (3) or formula (4) is more preferable, and a repeating unit represented by formula (4) is particularly preferable.
• A1 represents a hydrogen atom, a halogen atom, or an organic group.
• R3 represents a hydrogen atom or a substituent.
• L1 represents a single bond or a divalent linking group.
• B1 represents a substituent.
• R3 may be bonded to at least one of L1 and B1 to form a ring.
• the organic group represented by A 1 is preferably an alkyl group or a cycloalkyl group.
• the alkyl group may be either linear or branched.
• the number of carbon atoms of the alkyl group is not particularly limited, but is preferably 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3.
• the cycloalkyl group may be either monocyclic or polycyclic.
• the number of carbon atoms of the cycloalkyl group is not particularly limited, but is preferably 3 to 20, more preferably 5 to 15, and particularly preferably 5 to 10.
• the alkyl group and the cycloalkyl group may have a substituent.
• the substituent is not particularly limited, but examples thereof include a halogen atom (preferably a fluorine atom or an iodine atom) and a specific functional group.
• the halogen atom represented by A1 is preferably a fluorine atom, a chlorine atom, a bromine atom or an iodine atom, more preferably a fluorine atom or a chlorine atom, and particularly preferably a chlorine atom.
• an alkyl group is preferable, an alkyl group having 1 to 6 carbon atoms is more preferable, an alkyl group having 1 to 3 carbon atoms is even more preferable, a methyl group or an ethyl group is particularly preferable, and a methyl group is most preferable.
• the substituent represented by R3 is not particularly limited, but is preferably an organic group, and more preferably an alkyl group or a cycloalkyl group.
• the alkyl group may be either linear or branched.
• the number of carbon atoms in the alkyl group is not particularly limited, but is preferably, for example, 1 to 12, more preferably 1 to 6, and even more preferably 1 to 3.
• the cycloalkyl group may be either monocyclic or polycyclic.
• the number of carbon atoms in the cycloalkyl group is not particularly limited, but is preferably, for example, 3 to 20, more preferably 5 to 15, and particularly preferably 5 to 10.
• R3 is preferably a hydrogen atom.
• L1 represents a single bond or a divalent linking group.
• the divalent linking group represented by L 1 is not particularly limited, and examples thereof include -CO-, -O-, -SO-, -SO 2 -, -NR A -, an alkylene group (preferably having 1 to 6 carbon atoms, which may be linear or branched), a cycloalkylene group (preferably having 3 to 15 carbon atoms), an arylene group (preferably having a 6- to 10-membered ring, more preferably a 6-membered ring), and a divalent linking group combining a plurality of these.
• the alkylene group, the cycloalkylene group, and the arylene group may have a substituent.
• R A is a hydrogen atom or a substituent, and is preferably a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
• L 1 is preferably a single bond, —COO— or —CONR A —.
• B1 represents a substituent.
• the substituent represented by B1 is not particularly limited, and examples thereof include an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, a cycloalkyloxy group, an acyloxy group, a cyano group, a nitro group, a halogen atom, a lactone group, a group containing an onium salt structure described later, and a specific functional group.
• the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, the alkenyl group, the cycloalkenyl group, the alkoxy group, the cycloalkyloxy group, the acyloxy group, and the lactone group may further have a substituent, and examples of the substituent include a halogen atom and a specific functional group, etc.
• the alkyl group has a fluorine atom, it may be a perfluoroalkyl group.
• the alkyl group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
• the cycloalkyl group may be either a monocyclic or polycyclic group.
• the number of carbon atoms is not particularly limited, but is preferably 5 to 15, and more preferably 5 to 10.
• cycloalkyl group examples include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group.
• the aryl group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably, for example, 6 to 15, and more preferably 6 to 10.
• the aryl group is preferably a phenyl group, a naphthyl group, or an anthranyl group, and more preferably a phenyl group.
• the aralkyl group preferably has a structure in which one of the hydrogen atoms in the alkyl group is substituted with the aryl group.
• the number of carbon atoms in the aralkyl group is not particularly limited, but is preferably 7 to 20, and more preferably 7 to 15.
• the alkenyl group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6.
• the cycloalkenyl group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably 4 to 20, more preferably 5 to 15, and even more preferably 5 to 10.
• the alkoxy group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is, for example, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
• the cycloalkyloxy group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably, for example, 4 to 20, more preferably 5 to 15, and even more preferably 5 to 10.
• the acyloxy group may be linear, branched, or cyclic, and the number of carbon atoms is not particularly limited.
• the number of carbon atoms is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6.
• the lactone group is preferably a 5- to 7-membered lactone group, and more preferably a 5- to 7-membered lactone ring to which another ring structure is condensed to form a bicyclo or spiro structure.
• a 1 , R 3 and L 1 are the same as A 1 , R 3 and L 1 in formula (2), respectively.
• B 2 represents a linking group having a valence of m1+1.
• C 1 represents one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amide group, an imide group, a thiol group, an acetyl group, a sulfonic acid group, a sulfonamide group and an acetoxy group.
• m1 represents an integer of 1 or more.
• R 3 may be bonded to at least one of L 1 , B 1 and C 1 to form a ring.
• a 1 , R 3 and L 1 have the same meanings as A 1 , R 3 and L 1 in formula (2), respectively, and the preferred embodiments are also the same.
• B2 represents a linking group having a valence of m1+1.
• Examples of the (m+1) valent linking group represented by B2 include a group formed by removing m1 hydrogen atoms from a monovalent group selected from the group consisting of an alkyl group, a cycloalkyl group, an aryl group, an aralkyl group, an alkenyl group, a cycloalkenyl group, an alkoxy group, a cycloalkyloxy group, an acyloxy group, and a lactone group.
• the alkyl group, the cycloalkyl group, the aryl group, the aralkyl group, the alkenyl group, the cycloalkenyl group, the alkoxy group, the cycloalkyloxy group, the acyloxy group, and the lactone group may further have a substituent other than the specific type of functional group represented by C1 , and examples of the substituent include a halogen atom.
• the alkyl group has a fluorine atom, it may be a perfluoroalkyl group.
• the alkyl group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
• the cycloalkyl group may be either a monocyclic or polycyclic group.
• the number of carbon atoms is not particularly limited, but is preferably 5 to 15, and more preferably 5 to 10.
• cycloalkyl group examples include monocyclic cycloalkyl groups such as a cyclopentyl group and a cyclohexyl group, and polycyclic cycloalkyl groups such as a norbornyl group, a tetracyclodecanyl group, a tetracyclododecanyl group, and an adamantyl group.
• the aryl group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably, for example, 6 to 15, and more preferably 6 to 10.
• the aryl group is preferably a phenyl group, a naphthyl group, or an anthranyl group, and more preferably a phenyl group.
• the aralkyl group preferably has a structure in which one of the hydrogen atoms in the alkyl group is substituted with the aryl group, and the number of carbon atoms in the aralkyl group is preferably 7 to 20, and more preferably 7 to 15.
• the alkenyl group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6.
• the cycloalkenyl group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably 4 to 20, more preferably 5 to 15, and even more preferably 5 to 10.
• the alkoxy group may be either linear or branched, and the number of carbon atoms is not particularly limited, but is, for example, preferably 1 to 20, more preferably 1 to 10, and even more preferably 1 to 6.
• the cycloalkyloxy group may be either a monocyclic or polycyclic ring.
• the number of carbon atoms is not particularly limited, but is preferably, for example, 4 to 20, more preferably 5 to 15, and even more preferably 5 to 10.
• the acyloxy group may be linear, branched, or cyclic, and the number of carbon atoms is not particularly limited.
• the number of carbon atoms is preferably 2 to 20, more preferably 2 to 10, and even more preferably 2 to 6.
• the lactone group is preferably a 5- to 7-membered lactone group, and more preferably a 5- to 7-membered lactone ring to which another ring structure is condensed in the form of a bicyclo structure or a spiro structure.
• the m1+1 valent linking group represented by B2 is preferably an m1+1 valent aromatic hydrocarbon ring group (a group formed by removing m1 hydrogen atoms from an aryl group), more preferably an m1+1 valent benzene ring group or an m1+1 valent naphthalene ring group.
• the m1+1 valent benzene ring group and the m1+1 valent naphthalene ring group also preferably have a halogen atom as a substituent.
• C1 represents one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an amino group, an amide group, an imide group, a thiol group, an acetyl group, a sulfonic acid group, a sulfonamide group, and an acetoxy group. That is, C1 represents a specific functional group.
• the functional group one or more functional groups selected from the group consisting of a phenolic hydroxyl group and a carboxyl group are more preferable in terms of the effect of the present invention being more excellent.
• the m1+1 valent linking group represented by B2 preferably represents an m1+1 valent aromatic hydrocarbon ring group (a group formed by removing m1 hydrogen atoms from an aryl group).
• n1 represents an integer of 1 or more. As m1, for example, 1 to 6 is preferable, and 1 to 3 is more preferable. When m1 represents an integer of 2 or more, a plurality of C1 's may be the same or different.
• A1 represents a hydrogen atom, a halogen atom, or an organic group.
• R3 represents a hydrogen atom or a substituent.
• Ar1 represents a benzene ring or a naphthalene ring.
• R4 represents a substituent. When a plurality of R4s are present, the plurality of R4s may be the same or different from each other, and R4s may be bonded together to form a ring. R3 and R4 may be bonded together to form a ring.
• k1 represents an integer of 0 to 7.
• a 1 and R 3 have the same meanings as A 1 and R 3 in formula (2), respectively, and the preferred embodiments are also the same.
• R 4 represents a substituent.
• the substituent represented by R 4 is not particularly limited, but examples thereof include a halogen atom, an alkyl group, a cycloalkyl group, an aryl group, a fluorinated alkyl group, a hydroxyl group, a carboxyl group, an acyl group, an acyloxy group, an alkoxy group, a carbamoyl group, a sulfonamide group, an amino group, a thiol group, and an alkylsulfonyl group. It is preferable that at least one R 4 represents a specific functional group.
• the plurality of R4s may be the same or different from each other, and R4s may be bonded together to form a ring.
• R3 and R4 may be bonded together to form a ring.
• R3 may be bonded to R4 to form a ring by substituting a hydrogen atom represented by R3 .
• the ring formed by bonding R3 and R4 and the ring formed by bonding R4 together are not particularly limited, and may be either a monocyclic ring or a polycyclic ring.
• the ring may contain a heteroatom such as an oxygen atom, a nitrogen atom, or a sulfur atom as a ring member atom.
• the ring may also contain a carbonyl carbon as a ring member atom.
• the ring is preferably a 5- to 8-membered ring, and more preferably a 5- or 6-membered ring.
• Ar 1 represents a benzene ring or a naphthalene ring, and preferably represents a benzene ring.
• k1 represents an integer of 0 to 7.
• Ar 1 represents a benzene ring
• k1 represents an integer of 0 to 5, and preferably an integer of 0 to 3.
• Ar 1 represents a naphthalene ring
• k1 represents an integer of 0 to 7, and preferably an integer of 0 to 3.
• the content of the other repeating units in the specific resin 1 is preferably from 5 to 95 mol %, more preferably from 10 to 90 mol %, and even more preferably from 20 to 80 mol %, based on the total repeating units of the specific resin 1.
• the other repeating units may be one type or two or more types in the specific resin 1. When the other repeating units are two or more types, the total content thereof is preferably within the above numerical range.
• the specific resin 1 preferably contains a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2), more preferably contains a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (3), and particularly preferably contains a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (4).
• the total content of the repeating unit represented by the formula (1) and the repeating unit represented by the formula (2) (preferably the repeating unit represented by the formula (3), more preferably the repeating unit represented by the formula (4)) is preferably 90 mol % or more, and more preferably 95 mol % or more, based on the total repeating units of the specific resin 1.
• the upper limit is preferably 100 mol % or less.
• the specific resin 1 is a copolymer containing a repeating unit represented by the above formula (1) and a repeating unit represented by the above formula (2) (preferably a repeating unit represented by formula (3), more preferably a repeating unit represented by formula (4))
• the copolymer may be in the form of any one of a random copolymer, a block copolymer, and an alternating copolymer (a copolymer in which the repeating unit represented by the above formula (1) and the repeating unit represented by the above formula (2) (preferably a repeating unit represented by formula (3), more preferably a repeating unit represented by formula (4)) are arranged alternately like ABAB); etc., and among these, an alternating copolymer is preferable.
• a preferred embodiment of Specific Resin 1 is one in which the proportion of the alternating copolymer in Specific Resin 1 is 90% by mass or more (preferably 100% by mass) based on the total mass of Specific Resin 1.
• the onium salt structure is a structural moiety having an ion pair of a cation and an anion, and is preferably a structural moiety represented by “X n ⁇ nM + ” (wherein n represents, for example, an integer of 1 to 3, and preferably represents 1 or 2).
• M + represents a structural moiety containing a positively charged atom or atomic group
• Xn- represents a structural moiety containing a negatively charged atom or atomic group.
• the anion in the onium salt structure is preferably a non-nucleophilic anion (anion with a significantly low ability to cause a nucleophilic reaction).
• anion in the onium salt structure is a non-nucleophilic anion, it is likely to become a photodecomposition type onium salt structure.
• the non-nucleophilic anion is the same as the non-nucleophilic anion in the onium salt described below.
• the specific resin in terms of better effects of the present invention, as described above, it is preferable for the specific resin to contain one or more functional groups (specific functional groups) selected from the group consisting of hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), carboxyl groups, amino groups, amide groups, imide groups, thiol groups, acetyl groups, sulfonic acid groups, sulfonamide groups, and acetoxy groups, and it is more preferable for the specific resin to contain one or more functional groups selected from the group consisting of phenolic hydroxyl groups and carboxyl groups.
• functional groups selected from the group consisting of hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), carboxyl groups, amino groups, amide groups, imide groups, thiol groups, acetyl groups, sulfonic acid groups, sulfonamide groups, and acetoxy groups
• the phenolic hydroxyl group herein refers to a hydroxyl group substituted on a member atom of an aromatic ring.
• the aromatic ring is not limited to a benzene ring, and may be either an aromatic hydrocarbon ring or an aromatic heterocycle.
• the aromatic ring may be either a monocyclic ring or a polycyclic ring.
• An alcoholic hydroxyl group is to be differentiated from a phenolic hydroxyl group, and in this specification it refers to a hydroxyl group which substitutes for an aliphatic hydrocarbon group.
• the amino group is preferably a group represented by -N(R P ) 2.
• the amide group is preferably a group represented by -CO-N(R q ) 2 or a group represented by -CO-N(R q )-.
• the imide group is preferably a group represented by -CO-N(R q )-CO-.
• the sulfonamide group is preferably a group represented by -SO 2 -N(R q ) 2 or a group represented by -SO 2 -N(R q )-.
• Each of the above R P and R q independently preferably represents a hydrogen atom or a monovalent organic group (preferably an alkyl group having 1 to 6 carbon atoms), more preferably a hydrogen atom.
• the case where the specific resin contains a group represented by -CO-N(R q )-, -CO-N(R q )-CO- or -SO 2 -N(R q )- as a specific functional group corresponds to, for example, a case where Ra and R 1A in the repeating unit represented by formula (1) above are linked to each other to form a ring, and the ring has a structural moiety represented by -CO-N(R q )-, a structural moiety represented by -CO-N(R q )-CO- or a structural moiety represented by -SO 2 -N(R q )-.
• the specific resin preferably contains a repeating unit containing a specific functional group, in that the effects of the present invention are more excellent.
• the content of the repeating unit containing the specific functional group in the specific resin is preferably 5 to 100 mol %, more preferably 10 to 100 mol %, and even more preferably 20 to 100 mol %, based on all repeating units in the specific resin.
• the repeating unit containing the specific functional group may be one type or two or more types. When the repeating unit containing the specific functional group is two or more types, the total content thereof is preferably within the above numerical range.
• the repeating unit containing the specific functional group can be any repeating unit containing the specific functional group.
• repeating unit represented by the above formula (1) contains a specific functional group, it corresponds to the repeating unit containing the specific functional group.
• the repeating unit represented by the above formula (3) contains a specific functional group, so it corresponds to the repeating unit containing the specific functional group.
• the specific resin can be synthesized according to a conventional method (for example, radical polymerization).
• the weight average molecular weight of the specific resin is preferably 1,000 to 200,000, more preferably 2,500 to 150,000, and even more preferably 5,000 to 80,000.
• the weight average molecular weight is within the above numerical range, deterioration of heat resistance and dry etching resistance can be further suppressed.
• deterioration of developability and deterioration of film formability due to an increase in viscosity can be further suppressed.
• the dispersity (molecular weight distribution, Mw/Mn) of the specific resin is usually 1.0 to 5.0, preferably 1.0 to 3.0, more preferably 1.2 to 3.0, and even more preferably 1.2 to 2.0.
• the content of the specific resin (resin (A)) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 65% by mass or more, and particularly preferably 70% by mass or more, based on the total solid content of the resist composition.
• the upper limit is preferably 99% by mass or less, and more preferably 97% by mass or less.
• the specific resin may be used alone or in combination. When two or more types are used, the total content is preferably within the above-mentioned suitable content range.
• the resist composition of the present invention preferably contains a solvent.
• the solvent preferably contains (M1) propylene glycol monoalkyl ether carboxylate and (M2) at least one selected from the group consisting of propylene glycol monoalkyl ether, lactate ester, acetate ester, alkoxypropionate ester, linear ketone, cyclic ketone, lactone, and alkylene carbonate.
• the solvent may further contain components other than the components (M1) and (M2).
• component (M1) at least one selected from the group consisting of propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether propionate, and propylene glycol monoethyl ether acetate is preferred, with propylene glycol monomethyl ether acetate (PGMEA) being more preferred.
• PGMEA propylene glycol monomethyl ether acetate
• the propylene glycol monoalkyl ether propylene glycol monomethyl ether (PGME) and propylene glycol monoethyl ether (PGEE) are preferred.
• the lactate ester is preferably ethyl lactate, butyl lactate, or propyl lactate.
• the acetate ester is preferably methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, isoamyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, or 3-methoxybutyl acetate. Also preferred is butyl butyrate.
• alkoxypropionate methyl 3-methoxypropionate (MMP) or ethyl 3-ethoxypropionate (EEP) is preferred.
• chain ketone 1-octanone, 2-octanone, 1-nonanone, 2-nonanone, acetone, 2-heptanone, 4-heptanone, 1-hexanone, 2-hexanone, diisobutyl ketone, phenylacetone, methyl ethyl ketone, methyl isobutyl ketone, acetylacetone, acetonylacetone, ionone, diacetonyl alcohol, acetylcarbinol, acetophenone, methyl naphthyl ketone, or methyl amyl ketone is preferred.
• the cyclic ketone is preferably methylcyclohexanone, isophorone, cyclopentanone, or cyclohexanone.
• the lactone is preferably ⁇ -butyrolactone.
• the alkylene carbonate propylene carbonate is preferred.
• propylene glycol monomethyl ether PGME
• ethyl lactate ethyl 3-ethoxypropionate
• methyl amyl ketone cyclohexanone
• butyl acetate pentyl acetate, methyl 2-hydroxyisobutyrate, ⁇ -butyrolactone, or propylene carbonate
• propylene glycol monoethyl ether, ethyl lactate, pentyl acetate, or cyclohexanone is even more preferred, and propylene glycol monoethyl ether or ethyl lactate is particularly preferred.
• the solvent preferably includes an ester-based solvent having 7 or more carbon atoms (preferably 7 to 14, more preferably 7 to 12, and even more preferably 7 to 10) and 2 or less heteroatoms.
• an ester-based solvent having 7 or more carbon atoms and 2 or less heteroatoms amyl acetate, 2-methylbutyl acetate, 1-methylbutyl acetate, hexyl acetate, pentyl propionate, hexyl propionate, butyl propionate, isobutyl isobutyrate, heptyl propionate, or butyl butanoate is preferred, and isoamyl acetate is more preferred.
• the solvent preferably contains the component (M1). More preferably, the solvent consists essentially of the component (M1) alone, or is a mixed solvent of the component (M1) and other components. In the latter case, the solvent further preferably contains both the component (M1) and the component (M2).
• the mass ratio (M1/M2) of the component (M1) to the component (M2) is preferably in the range of "100/0" to "15/85", more preferably in the range of "100/0" to "40/60", and even more preferably in the range of "100/0" to "60/40".
• the solvent is preferably composed of only the component (M1) or contains both the component (M1) and the component (M2), and the mass ratio thereof is as follows.
• the mass ratio of the component (M1) to the component (M2) is preferably 15/85 or more, more preferably 40/60 or more, and even more preferably 60/40 or more.
• the mass ratio of component (M1) to component (M2) can be, for example, 99/1 or less.
• the solvent further contains components other than components (M1) and (M2)
• the content of the components other than components (M1) and (M2) is preferably 5 to 30 mass % based on the total amount of the solvent.
• the content of the solvent in the resist composition of the present invention is preferably determined so that the solids concentration is 0.5 to 30% by mass, and more preferably 1 to 20% by mass, in order to provide better coatability.
• the resist composition of the present invention contains at least two types of onium salts, that is, an onium salt (b1) and an onium salt (b2).
• an onium salt (b1) When the anion having the largest pKa of the conjugate acid among the anions contained in the onium salt (b1) is designated as anion (an 1 ), the pKa of the conjugate acid of the anion (an 1 ) is 10 or less.
• the anion having the largest pKa of the conjugate acid among the anions contained in the onium salt (b2) is designated as anion (an 2 ), the pKa of the conjugate acid of the anion (an 2 ) is 2 or more.
• the pKa of the conjugate acid of the anion (an 1 ) is greater than the pKa of the conjugate acid of the anion (an 2 ). It is believed that the resist composition will have particularly excellent resolution after aging when the pKa (also referred to as "pKa b1 ") of the conjugate acid of the anion (an 1 ) is 10 or less.
• pKa b1 is preferably 4 or more, more preferably 5 or more, even more preferably 6 or more, and particularly preferably 7 or more. It is believed that the initial resolution of the resist composition is particularly excellent when the pKa (also referred to as "pKa b2 ") of the conjugate acid of the anion ( an2 ) is 2 or more.
• pKa b2 is preferably less than 8, more preferably less than 7, and even more preferably less than 6. It is believed that when pKa b1 is greater than pKa b2 , the onium salt (b1) traps the anion generated from the onium salt (b2) in the weakly exposed area, regenerating the onium salt having an inhibition effect, thereby improving the dissolution contrast and increasing the resolution.
• the difference between pKa b1 and pKa b2 is preferably 1 or more, more preferably 2 or more, and even more preferably 3 or more.
• the onium salt (b1) may contain one kind of anion or two or more kinds of anions.
• the anion having the largest pKa among the anions contained in the onium salt (b1) is designated as (an 1 ).
• the onium salt (b1) may contain an anion whose conjugate acid has a pKa of less than 2.
• the anion (an 2 ) contained in the onium salt (b2) may be one type or two or more types.
• the anion having the largest pKa among the anions contained in the onium salt (b2) is designated as (an 2 ).
• the onium salt (b2) may contain an anion whose conjugate acid has a pKa of less than 2.
• an onium salt (also referred to as “onium salt (b)") that can be used as at least one of the onium salt (b1) and the onium salt (b2) will be described.
• the onium salt (b) preferably contains an anion and a cation.
• the onium salt (b) may be a compound that decomposes when irradiated with actinic rays or radiation, or may be a compound that does not decompose.
• the compound that decomposes when irradiated with actinic rays or radiation may be a compound that decomposes when irradiated with actinic rays or radiation to generate an acid, or may be a compound that decomposes when irradiated with actinic rays or radiation to generate a base.
• the onium salt (b) is preferably a compound that decomposes when irradiated with actinic rays or radiation, and is preferably a compound having an onium salt structure that decomposes when irradiated with actinic rays or radiation to generate an acid (a photodecomposable onium salt compound).
• the resin (A) is likely to aggregate with the onium salt (b) via the specific functional group that may be contained in the resin (A).
• the onium salt (b) dissociates from the specific functional group or the photodegradable onium salt compound is cleaved, so that the aggregated structure can be released.
• the above-mentioned action further increases the dissolution contrast between the unexposed portion and the exposed portion in the resist film, making the effect of the present invention more excellent.
• the photodecomposable onium salt compound is preferably a compound which has at least one salt structure moiety composed of an anion moiety and a cation moiety and which decomposes upon exposure to generate an acid (preferably an organic acid).
• the above-mentioned salt structure portion of the photodecomposable onium salt compound is preferably composed of an organic cation portion and an organic anion portion having extremely low nucleophilicity, since this portion is easily decomposed by exposure to light and has excellent organic acid generation properties.
• the salt structure moiety may be a part or the whole of the photodecomposable onium salt compound.
• the case where the salt structure moiety is a part of the photodecomposable onium salt compound corresponds to, for example, a structure in which two or more salt structure moieties are linked together, such as the photodecomposable onium salt PG2 described later.
• the number of salt structure moieties in the photodecomposable onium salt is not particularly limited, but is preferably 1 to 10, more preferably 1 to 6, and even more preferably 1 to 3.
• organic acid generated from the photodecomposable onium salt compound by the action of exposure to light examples include sulfonic acids (aliphatic sulfonic acids, aromatic sulfonic acids, camphorsulfonic acids, etc.), carboxylic acids (aliphatic carboxylic acids, aromatic carboxylic acids, aralkyl carboxylic acids, etc.), carbonylsulfonylimide acids, bis(alkylsulfonyl)imide acids, and tris(alkylsulfonyl)methide acids.
• the organic acid generated from the photodecomposable onium salt compound by the action of exposure may be a polyvalent acid having two or more acid groups.
• the organic acid generated by decomposition of the photodecomposable onium salt compound by exposure is a polyvalent acid having two or more acid groups.
• the cationic moiety constituting the salt structure moiety is preferably an organic cationic moiety, and among these, an organic cation represented by formula (ZaI) (cation (ZaI)) or an organic cation represented by formula (ZaII) (cation (ZaII)) as described below is preferred.
• Photodecomposable onium salt compound PG1 An example of a suitable embodiment of the photodecomposable onium salt compound is an onium salt compound represented by "M + X - ", which generates an organic acid upon exposure to light (hereinafter also referred to as "photodecomposable onium salt compound PG1").
• M + represents an organic cation
• X - represents an organic anion.
• the organic cation represented by M + in the photodecomposable onium salt compound PG1 is preferably an organic cation represented by formula (ZaI) (cation (ZaI)) or an organic cation represented by formula (ZaII) (cation (ZaII)).
• R 201 , R 202 and R 203 each independently represent an organic group.
• the number of carbon atoms in the organic group represented by R 201 , R 202 , and R 203 is usually 1 to 30, and preferably 1 to 20.
• Two of R 201 to R 203 may be bonded to form a ring structure, and the ring may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group.
• Examples of the group formed by bonding two of R 201 to R 203 include an alkylene group (e.g., a butylene group and a pentylene group) and -CH 2 -CH 2 -O-CH 2 -CH 2 -.
• Suitable embodiments of the organic cation in formula (ZaI) include cation (ZaI-1), cation (ZaI-2), an organic cation represented by formula (ZaI-3b) (cation (ZaI-3b)), and an organic cation represented by formula (ZaI-4b) (cation (ZaI-4b)), which will be described later.
• the cation (ZaI-1) is an arylsulfonium cation in which at least one of R 201 to R 203 in the above formula (ZaI) is an aryl group.
• the arylsulfonium cation all of R 201 to R 203 may be aryl groups, or some of R 201 to R 203 may be aryl groups, with the remainder being alkyl groups or cycloalkyl groups.
• one of R 201 to R 203 may be an aryl group, and the remaining two of R 201 to R 203 may be bonded to form a ring structure, which may contain an oxygen atom, a sulfur atom, an ester group, an amide group, or a carbonyl group in the ring.
• Examples of the group formed by bonding two of R 201 to R 203 include alkylene groups in which one or more methylene groups may be substituted with oxygen atoms, sulfur atoms, ester groups, amide groups, and/or carbonyl groups (e.g., butylene group, pentylene group, or -CH 2 -CH 2 -O-CH 2 -CH 2 -).
• arylsulfonium cation examples include triarylsulfonium cations, diarylalkylsulfonium cations, aryldialkylsulfonium cations, diarylcycloalkylsulfonium cations, and aryldicycloalkylsulfonium cations.
• the aryl group contained in the arylsulfonium cation is preferably a phenyl group or a naphthyl group, more preferably a phenyl group.
• the aryl group may be an aryl group having a heterocyclic structure with an oxygen atom, a nitrogen atom, or a sulfur atom. Examples of the heterocyclic structure include a pyrrole residue, a furan residue, a thiophene residue, an indole residue, a benzofuran residue, and a benzothiophene residue.
• the arylsulfonium cation has two or more aryl groups, the two or more aryl groups may be the same or different.
• the alkyl group or cycloalkyl group which the arylsulfonium cation optionally has is preferably a linear alkyl group having 1 to 15 carbon atoms, a branched alkyl group having 3 to 15 carbon atoms, or a cycloalkyl group having 3 to 15 carbon atoms, and more preferably, for example, a methyl group, an ethyl group, a propyl group, an n-butyl group, a sec-butyl group, a t-butyl group, a cyclopropyl group, a cyclobutyl group, or a cyclohexyl group.
• Preferred substituents that the aryl group, alkyl group, and cycloalkyl group of R 201 to R 203 may have are each independently an alkyl group (e.g., 1 to 15 carbon atoms), a cycloalkyl group (e.g., 3 to 15 carbon atoms), an aryl group (e.g., 6 to 14 carbon atoms), an alkoxy group (e.g., 1 to 15 carbon atoms), a cycloalkylalkoxy group (e.g., 1 to 15 carbon atoms), a halogen atom (e.g., fluorine, iodine), a hydroxyl group, a carboxyl group, an ester group, a sulfinyl group, a sulfonyl group, an alkylthio group, a phenylthio group, and the like.
• an alkyl group e.g., 1 to 15 carbon atoms
• the above-mentioned substituent may further have a substituent if possible.
• the above-mentioned alkyl group has a halogen atom as a substituent to form a halogenated alkyl group such as a trifluoromethyl group.
• Cation (ZaI-2) is a cation in which R 201 to R 203 in formula (ZaI) each independently represent an organic group not having an aromatic ring.
• the aromatic ring also includes an aromatic ring containing a heteroatom.
• the organic group not having an aromatic ring represented by R 201 to R 203 generally has 1 to 30 carbon atoms, and preferably has 1 to 20 carbon atoms.
• Each of R 201 to R 203 independently represents preferably an alkyl group, a cycloalkyl group, an allyl group, or a vinyl group, more preferably a linear or branched 2-oxoalkyl group, a 2-oxocycloalkyl group, or an alkoxycarbonylmethyl group, and still more preferably a linear or branched 2-oxoalkyl group.
• Examples of the alkyl group and cycloalkyl group for R 201 to R 203 include linear alkyl groups having 1 to 10 carbon atoms or branched alkyl groups having 3 to 10 carbon atoms (e.g., methyl, ethyl, propyl, butyl, and pentyl groups), and cycloalkyl groups having 3 to 10 carbon atoms (e.g., cyclopentyl, cyclohexyl, and norbornyl groups).
• R 201 to R 203 may be further substituted with a halogen atom, an alkoxy group (eg, having 1 to 5 carbon atoms), a hydroxyl group, a cyano group, or a nitro group.
• the cation (ZaI-3b) is a cation represented by the following formula (ZaI-3b).
• Each of R 1c to R 5c independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, an alkoxy group, an aryloxy group, an alkoxycarbonyl group, an alkylcarbonyloxy group, a cycloalkylcarbonyloxy group, a halogen atom, a hydroxyl group, a nitro group, an alkylthio group, or an arylthio group.
• R 6c and R 7c each independently represent a hydrogen atom, an alkyl group (such as a t-butyl group), a cycloalkyl group, a halogen atom, a cyano group, or an aryl group.
• R x and R y each independently represent an alkyl group, a cycloalkyl group, a 2-oxoalkyl group, a 2-oxocycloalkyl group, an alkoxycarbonylalkyl group, an allyl group, or a vinyl group.
• R 1c to R 5c , R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y may be bonded to each other to form a ring, and each of these rings may independently contain an oxygen atom, a sulfur atom, a ketone group, an ester bond, or an amide bond.
• the ring include an aromatic or non-aromatic hydrocarbon ring, an aromatic or non-aromatic heterocycle, and a polycyclic condensed ring formed by combining two or more of these rings.
• the ring include a 3- to 10-membered ring, preferably a 4- to 8-membered ring, and more preferably a 5- or 6-membered ring.
• the group formed by combining any two or more of R 1c to R 5c , R 6c and R 7c , and R x and R y includes alkylene groups such as butylene and pentylene, in which the methylene group may be substituted with a heteroatom such as an oxygen atom.
• the groups formed by combining R5c and R6c , and R5c and Rx are preferably a single bond or an alkylene group. Examples of the alkylene group include a methylene group and an ethylene group.
• R 1c to R 5c , R 6c , R 7c , R x , R y , and any two or more of R 1c to R 5c , R 5c and R 6c , R 6c and R 7c , R 5c and R x , and R x and R y may each have a substituent.
• the cation (ZaI-4b) is a cation represented by the following formula (ZaI-4b).
• l represents an integer of 0 to 2.
• r represents an integer of 0 to 8.
• R 13 represents a hydrogen atom, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), a hydroxyl group, an alkyl group, a halogenated alkyl group, an alkoxy group, a carboxyl group, an alkoxycarbonyl group, or a group having a cycloalkyl group (which may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent.
• a halogen atom e.g., a fluorine atom, an iodine atom, etc.
• R 13 represents a hydrogen atom, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), a hydroxyl group,
• R 14 represents a hydroxyl group, a halogen atom (e.g., a fluorine atom, an iodine atom, etc.), an alkyl group, a halogenated alkyl group, an alkoxy group, an alkoxycarbonyl group, an alkylcarbonyl group, an alkylsulfonyl group, a cycloalkylsulfonyl group, or a group having a cycloalkyl group (may be a cycloalkyl group itself or a group containing a cycloalkyl group as a part). These groups may have a substituent.
• a halogen atom e.g., a fluorine atom, an iodine atom, etc.
• each independently represents the above group such as a hydroxyl group.
• Each R 15 independently represents an alkyl group, a cycloalkyl group, or a naphthyl group. Two R 15 may be bonded to each other to form a ring. When two R 15 are bonded to each other to form a ring, the ring skeleton may contain a heteroatom such as an oxygen atom or a nitrogen atom. In one embodiment, it is preferable that two R 15 are alkylene groups and are bonded to each other to form a ring structure.
• the alkyl group, the cycloalkyl group, and the naphthyl group, as well as the ring formed by bonding two R 15 to each other may have a substituent.
• the alkyl groups of R 13 , R 14 , and R 15 are preferably linear or branched.
• the number of carbon atoms in the alkyl group is preferably 1 to 10.
• the alkyl group is more preferably a methyl group, an ethyl group, an n-butyl group, a t-butyl group, or the like.
• R 204 and R 205 each independently represent an aryl group, an alkyl group or a cycloalkyl group.
• the aryl group of R 204 and R 205 preferably has 2 to 20 carbon atoms, more preferably a phenyl group or naphthyl group, and particularly preferably a phenyl group.
• the aryl group of R 204 and R 205 may be an aryl group having a heterocycle containing an oxygen atom, a nitrogen atom, a sulfur atom, or the like.
• Examples of the skeleton of the aryl group having a heterocycle include pyrrole, furan, thiophene, indole, benzofuran, and benzothiophene.
• the alkyl group and cycloalkyl group of R 204 and R 205 are preferably a linear alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms (e.g., a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group), or a cycloalkyl group having 3 to 10 carbon atoms (e.g., a cyclopentyl group, a cyclohexyl group, or a norbornyl group).
• the aryl group, alkyl group, and cycloalkyl group of R 204 and R 205 may each independently have a substituent.
• substituents that the aryl group, alkyl group, and cycloalkyl group of R 204 and R 205 may have include an alkyl group (e.g., 1 to 15 carbon atoms), a cycloalkyl group (e.g., 3 to 15 carbon atoms), an aryl group (e.g., 6 to 15 carbon atoms), an alkoxy group (e.g., 1 to 15 carbon atoms), a halogen atom, a hydroxyl group, and a phenylthio group.
• the organic anion represented by X 1 - in the photodecomposable onium salt compound PG1 is preferably a non-nucleophilic anion (an anion having an extremely low ability to cause a nucleophilic reaction).
• non-nucleophilic anions include sulfonate anions (aliphatic sulfonate anions, aromatic sulfonate anions, camphorsulfonate anions, etc.), carboxylate anions (aliphatic carboxylate anions, aromatic carboxylate anions, aralkyl carboxylate anions, etc.), sulfonylimide anions, bis(alkylsulfonyl)imide anions, and tris(alkylsulfonyl)methide anions.
• the organic anion is preferably, for example, an organic anion represented by the following formula (DA):
• a 31- represents an anionic group.
• R a1 represents a hydrogen atom or a monovalent organic group.
• L a1 represents a single bond or a divalent linking group.
• a 31- and R a1 may be bonded to each other to form a ring.
• a 31- represents an anionic group.
• the anionic group represented by A 31- is not particularly limited, but is preferably a group selected from the group consisting of groups represented by formulae (BA-1) to (BA-13), more preferably formulae (BA-1), (BA-2), (BA-3), (BA-4), (BA-5), (BA-6), (BA-10), (BA-11), (BA-12) and (BA-13), and particularly preferably formulae (BA-4), (BA-6) and (BA-12).
• R 1 X1 each independently represents a monovalent organic group.
• each R X2 independently represents a hydrogen atom or a substituent other than a fluorine atom or a perfluoroalkyl group. The two R X2 in formula (BA-7) may be the same or different.
• R X3 represents a hydrogen atom, a halogen atom, or a monovalent organic group.
• n1 represents an integer of 0 to 4. When n1 represents an integer of 2 to 4, multiple R X3 may be the same or different.
• the bond to the bonding position represented by * in formula (BA-12) and formula (BA-13) is preferably an alkylene group or an arylene group, more preferably an alkylene group having 1 to 10 carbon atoms or an arylene group having 6 to 20 carbon atoms, and particularly preferably a phenylene group.
• the alkylene group and the arylene group may have a substituent, which is not particularly limited and examples thereof include a halogen atom.
• R 1 X1 each independently represents a monovalent organic group.
• R X1 is preferably an alkyl group (which may be linear or branched, and preferably has 1 to 15 carbon atoms), a cycloalkyl group (which may be monocyclic or polycyclic, and preferably has 3 to 20 carbon atoms), or an aryl group (which may be monocyclic or polycyclic, and preferably has 6 to 20 carbon atoms).
• the above group represented by R X1 may have a substituent.
• the atom in R X1 in formula (B-5) that is directly bonded to N- is neither a carbon atom in --CO-- nor a sulfur atom in --SO 2 --.
• the cycloalkyl group in R X1 may be a monocyclic or polycyclic group.
• Examples of the cycloalkyl group in R X1 include a norbornyl group and an adamantyl group.
• the substituent that the cycloalkyl group in R X1 may have is not particularly limited, but is preferably an alkyl group (which may be linear or branched, and preferably has 1 to 5 carbon atoms). One or more of the carbon atoms that are ring members of the cycloalkyl group in R X1 may be replaced with a carbonyl carbon atom.
• the alkyl group in R 1 X1 preferably has 1 to 10 carbon atoms, and more preferably has 1 to 5 carbon atoms.
• the substituent that the alkyl group in R may have is not particularly limited, but is preferably, for example, a cycloalkyl group, a fluorine atom, or a cyano group. Examples of the cycloalkyl group as the substituent are the same as those described when R is a cycloalkyl group.
• the alkyl group in R X1 has a fluorine atom as the above-mentioned substituent, the above-mentioned alkyl group may be a perfluoroalkyl group.
• the alkyl group in R X1 may have one or more -CH 2 - substituted with a carbonyl group.
• the aryl group in R X1 is preferably a phenyl group.
• the substituent that the aryl group in R may have is not particularly limited, but is preferably an alkyl group, a fluorine atom, or a cyano group. Examples of the alkyl group as the substituent are the same as those described in the case where R is an alkyl group.
• R X2 each independently represents a hydrogen atom or a substituent other than a fluorine atom or a perfluoroalkyl group (for example, an alkyl group not containing a fluorine atom and a cycloalkyl group not containing a fluorine atom).
• Two R X2 in formula (BA-7) may be the same or different.
• R X3 represents a hydrogen atom, a halogen atom, or a monovalent organic group.
• the halogen atom represented by R X3 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and a fluorine atom is preferable.
• the monovalent organic group represented by R 1 X3 is the same as the monovalent organic group described as R 1 X1 .
• n1 represents an integer of 0 to 4.
• n1 is preferably an integer of 0 to 2, and more preferably 0 or 1. When n1 represents an integer of 2 to 4, multiple R 3 X3 may be the same or different.
• the number of carbon atoms of the monovalent organic group for R a1 is not particularly limited, but preferably is 1 to 30 carbon atoms, and more preferably is 1 to 20 carbon atoms.
• R a1 is preferably an alkyl group, a cycloalkyl group or an aryl group.
• the alkyl group may be linear or branched, and is preferably an alkyl group having 1 to 20 carbon atoms, more preferably an alkyl group having 1 to 15 carbon atoms, and even more preferably an alkyl group having 1 to 10 carbon atoms.
• the cycloalkyl group may be monocyclic or polycyclic, and is preferably a cycloalkyl group having 3 to 20 carbon atoms, more preferably a cycloalkyl group having 3 to 15 carbon atoms, and even more preferably a cycloalkyl group having 3 to 10 carbon atoms.
• the aryl group may be monocyclic or polycyclic, and is preferably an aryl group having 6 to 20 carbon atoms, more preferably an aryl group having 6 to 15 carbon atoms, and even more preferably an aryl group having 6 to 10 carbon atoms.
• the cycloalkyl group may contain heteroatoms as ring members.
• the heteroatom is not particularly limited, but examples thereof include a nitrogen atom and an oxygen atom.
• the alkyl group, cycloalkyl group and aryl group may further have a substituent.
• a 31- and R a1 may be bonded to each other to form a ring.
• the divalent linking group represented by L a1 is not particularly limited, and examples thereof include an alkylene group, a cycloalkylene group, an aromatic group, -O-, -CO-, -COO-, and a group formed by combining two or more of these.
• the alkylene group may be linear or branched and preferably has 1 to 20 carbon atoms, and more preferably has 1 to 10 carbon atoms.
• the cycloalkylene group may be monocyclic or polycyclic and preferably has 3 to 20 carbon atoms, and more preferably has 3 to 10 carbon atoms.
• the aromatic group is a divalent aromatic group, preferably an aromatic group having 6 to 20 carbon atoms, and more preferably an aromatic group having 6 to 15 carbon atoms.
• the aromatic ring constituting the aromatic group may be an aromatic hydrocarbon ring or an aromatic heterocycle.
• the aromatic ring is not particularly limited, but may be, for example, an aromatic ring having 6 to 20 carbon atoms, specifically, a benzene ring, a naphthalene ring, an anthracene ring, a thiophene ring, etc.
• the aromatic ring constituting the aromatic group is preferably a benzene ring or a naphthalene ring, more preferably a benzene ring.
• the alkylene group, cycloalkylene group and aromatic group may further have a substituent, and the substituent is preferably a halogen atom.
• L a1 preferably represents a single bond.
• the photodecomposable onium salt compound PG1 it is also preferable to use, for example, the photoacid generators disclosed in paragraphs [0135] to [0171] of WO 2018/193954, paragraphs [0077] to [0116] of WO 2020/066824, and paragraphs [0018] to [0075] and [0334] to [0335] of WO 2017/154345.
• the molecular weight of the photodecomposable onium salt compound PG1 is not particularly limited, but is preferably 3,000 or less, more preferably 2,000 or less, and even more preferably 1,000 or less.
• the molecular weight of the photodecomposable onium salt compound PG1 may be 100 or more.
• Photodecomposable onium salt compound PG2 Another example of a suitable embodiment of the photodecomposable onium salt compound includes the following compound (I) and compound (II) (hereinafter, "compound (I) and compound (II)” are also referred to as “photodecomposable onium salt compound PG2").
• the photodecomposable onium salt compound PG2 has two or more of the above-mentioned salt structure moieties and is a compound that generates a polyvalent organic acid upon exposure to light.
• the photodecomposable onium salt compound PG2 will now be described.
• Compound (I) is a compound having one or more structural moieties X and one or more structural moieties Y, which generates an acid containing a first acidic moiety derived from the structural moiety X and a second acidic moiety derived from the structural moiety Y when irradiated with actinic rays or radiation:
• Structural moiety X a structural moiety consisting of an anionic moiety A 1 - and a cationic moiety M 1 + , and which forms a first acidic moiety represented by HA 1 upon exposure to actinic rays or radiation.
• Structural moiety Y a structural moiety consisting of an anionic moiety A 2 - and a cationic moiety M 2 + , and which forms a second acidic moiety represented by HA 2 upon exposure to actinic rays or radiation.
• compound (I) satisfies the following condition I.
• Compound PI which is obtained by replacing the cationic moiety M 1 + in the structural moiety X and the cationic moiety M 2 + in the structural moiety Y in compound (I) with H + , has an acid dissociation constant a1 derived from the acidic moiety represented by HA 1 , which is obtained by replacing the cationic moiety M 1 + in the structural moiety X with H + , and an acid dissociation constant a2 derived from the acidic moiety represented by HA 2 , which is obtained by replacing the cationic moiety M 2 + in the structural moiety Y with H + , and the acid dissociation constant a2 is greater than the acid dissociation constant a1.
• the compound PI corresponds to an acid generated when compound (I) is irradiated with actinic rays or radiation.
• the structural moieties X may be the same or different from each other.
• the two or more A 1 ⁇ and the two or more M 1 + may be the same or different from each other.
• the A 1 - and A 2 - , and the M 1 + and M 2 + may be the same or different, but it is preferable that the A 1 - and A 2 - are different.
• the anionic moiety A 1 - and the anionic moiety A 2 - are structural moieties containing a negatively charged atom or atomic group, and examples thereof include structural moieties selected from the group consisting of the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6). In the following formulae (AA-1) to (AA-3) and (BB-1) to (BB-6), * represents a bonding position.
• R A represents a monovalent organic group. Examples of the monovalent organic group represented by R A include a cyano group, a trifluoromethyl group, and a methanesulfonyl group.
• the cationic moiety M 1 + and the cationic moiety M 2 + are structural moieties containing a positively charged atom or atomic group, and examples thereof include organic cations having a monovalent charge.
• the organic cation is not particularly limited, but is preferably an organic cation represented by the above formula (ZaI) (cation (ZaI)) or an organic cation represented by the above formula (ZaII) (cation (ZaII)).
• Compound (II) is a compound having two or more of the above structural moieties X and one or more of the following structural moieties Z, and is a compound that generates an acid containing two or more of the first acidic moieties derived from the structural moiety X and the structural moiety Z when irradiated with actinic rays or radiation.
• Structural moiety Z a non-ionic moiety capable of neutralizing an acid
• the compound (II) can generate a compound PII (acid) having an acidic site represented by HA 1 in which the cationic site M 1 + in the structural site X is replaced with H + .
• the compound PII represents a compound having the acidic site represented by HA 1 and a structural site Z which is a nonionic site capable of neutralizing an acid.
• the definition of the structural moiety X and the definitions of A 1 - and M 1 + in compound (II) are the same as the definition of the structural moiety X and the definitions of A 1 - and M 1 + in compound (I) described above, and the preferred embodiments are also the same.
• the two or more structural moieties X may be the same or different from each other, and the two or more A 1 ⁇ and the two or more M 1 + may be the same or different from each other.
• the nonionic moiety capable of neutralizing an acid in the structural moiety Z is not particularly limited, and is preferably, for example, a moiety containing a functional group having an electron or a group capable of electrostatically interacting with a proton.
• functional groups having a group or electrons capable of electrostatically interacting with a proton include functional groups having a macrocyclic structure such as cyclic polyether, or functional groups having a nitrogen atom having an unshared electron pair that does not contribute to ⁇ conjugation.
• the nitrogen atom having an unshared electron pair that does not contribute to ⁇ conjugation is, for example, a nitrogen atom having a partial structure shown in the following formula:
• Examples of partial structures of functional groups having groups or electrons that can electrostatically interact with protons include crown ether structures, azacrown ether structures, primary to tertiary amine structures, pyridine structures, imidazole structures, and pyrazine structures, with primary to tertiary amine structures being preferred.
• the molecular weight of the photodegradable onium salt compound PG2 is preferably 100 to 10,000, more preferably 100 to 2,500, and even more preferably 100 to 1,500.
• anions that the onium salt (b) may contain are shown below, but the present invention is not limited to these.
• the pKa of the conjugate acid of each anion is also listed in the specific examples below. For those having two anionic groups, the respective pKas (pKa1 and pKa2) are listed.
• the onium salt (b1) is preferably a compound that decomposes when irradiated with actinic rays or radiation.
• the onium salt (b1) preferably contains a cation represented by the following formula (Z-1):
• Ar m1 , Ar m2 and Ar m3 each independently represent an aryl group, and at least two of Ar m1 , Ar m2 and Ar m3 may be bonded to each other.
• the aryl group represented by Ar m1 , Ar m2 and Ar m3 is preferably an aryl group having 6 to 20 carbon atoms, more preferably a phenyl group or naphthyl group, and particularly preferably a phenyl group.
• the aryl group represented by Ar m1 , Ar m2 and Ar m3 may have a substituent.
• the substituent is not particularly limited, but preferable examples thereof include a halogen atom, an alkyl group, a cycloalkyl group, a fluorinated alkyl group, a hydroxyl group, a carboxyl group, an acyl group, an alkoxy group, a sulfonamide group and an alkylsulfonyl group.
• a halogen atom an alkyl group, a cycloalkyl group, a fluorinated alkyl group, a hydroxyl group, a carboxyl group, an acyl group, an alkoxy group, a sulfonamide group and an alkylsulfonyl group.
• At least two of Ar m1 , Ar m2 and Ar m3 may be bonded to each other. When at least two of Ar m1 , Ar m2 and Ar m3 are bonded to each other, they may be bonded to each other via a single bond.
• the onium salt (b1) preferably has an anionic group represented by the above-mentioned formula (BA-4), formula (BA-6), formula (BA-12) or formula (BA-13), more preferably has an anionic group represented by formula (BA-4), formula (BA-12) or formula (BA-13), and particularly preferably has an anionic group represented by formula (BA-12).
• the onium salt (b1) preferably contains at least one anion selected from the group consisting of a phenoxide ion and an alkoxide ion.
• the onium salt (b2) is preferably a compound that decomposes when irradiated with actinic rays or radiation.
• the onium salt (b2) preferably contains a cation represented by the following formula (Z-2).
• Ar m4 , Ar m5 and Ar m6 each independently represent an aryl group, and at least two of Ar m4 , Ar m5 and Ar m6 may be bonded to each other.
• Ar m4 , Ar m5 and Ar m6 have the same meanings as Ar m1 , Ar m2 and Ar m3 in the above formula (Z-1), and the preferred ranges are also the same.
• the onium salt (b2) preferably has an anionic group represented by the above-mentioned formula (BA-6), formula (BA-12) or formula (BA-13), more preferably has an anionic group represented by formula (BA-6) or formula (BA-12), and particularly preferably has an anionic group represented by formula (BA-6).
• the onium salt (b2) preferably contains at least one anion selected from the group consisting of a phenoxide ion and a carboxylate ion, and more preferably contains a carboxylate ion.
• the onium salt (b1) contains a cation represented by formula (Z-1) and the onium salt (b2) contains a cation represented by formula (Z-2).
• the content of the onium salt (b1) in the resist composition of the present invention is not particularly limited, but is preferably 0.25 mass% or more, more preferably 0.5 mass% or more, and even more preferably 1.0 mass% or more, based on the total solid content of the resist composition. Also, the content of the onium salt (b1) is preferably 50.0 mass% or less, and more preferably 40.0 mass% or less, based on the total solid content of the resist composition.
• the content of the onium salt (b2) in the resist composition of the present invention is not particularly limited, but is preferably 0.5 mass % or more, more preferably 1.0 mass % or more, and even more preferably 2.0 mass % or more, based on the total solid content of the resist composition.
• the content of the onium salt (b2) is preferably 50.0 mass % or less, and more preferably 40.0 mass % or less, based on the total solid content of the resist composition.
• the content of the onium salt (b1) is preferably less than the content of the onium salt (b2).
• the resist composition of the present invention may contain components other than those described above.
• the other components are not particularly limited, but examples thereof include hydrophobic resins and surfactants.
• the resist composition of the present invention may further contain a hydrophobic resin different from the resin (A).
• the hydrophobic resin is preferably designed to be unevenly distributed on the surface of the resist film, but unlike a surfactant, it does not necessarily have to have a hydrophilic group in the molecule, and does not necessarily have to contribute to uniform mixing of polar and non-polar substances.
• the effects of adding a hydrophobic resin include control of the static and dynamic contact angles of the resist film surface with respect to the developer, and suppression of outgassing.
• the hydrophobic resin preferably has at least one of fluorine atoms, silicon atoms, and CH3 partial structures contained in the side chain portion of the resin, more preferably has at least two of them.
• the hydrophobic resin preferably has a hydrocarbon group having 5 or more carbon atoms. These groups may be present in the main chain of the resin or may be substituted on the side chain. Examples of hydrophobic resins include the compounds described in paragraphs [0275] to [0279] of WO 2020/004306.
• the content of the hydrophobic resin is preferably from 0.01 to 20.0 mass %, and more preferably from 0.1 to 15.0 mass %, based on the total solid content of the resist composition.
• the hydrophobic resin may be used alone or in combination of two or more. When two or more types are used, the total content is preferably within the above-mentioned preferred content range.
• the resist composition may contain a surfactant, which can provide a pattern with better adhesion and fewer development defects.
• the surfactant is preferably a fluorine-based and/or silicon-based surfactant.
• fluorine-based and/or silicone-based surfactants include the surfactants disclosed in paragraphs [0218] and [0219] of WO 2018/193954.
• the content of the surfactant is preferably from 0.0001 to 2 mass %, and more preferably from 0.0005 to 1 mass %, based on the total solid content of the resist composition.
• the surfactant may be used alone or in combination of two or more. When two or more surfactants are used, the total content is preferably within the above-mentioned preferred content range.
• a preferred embodiment of the actinic ray-sensitive or radiation-sensitive resin composition of the present invention is Contains a resin (A), an onium salt (b1), and an onium salt (b2),
• the resin (A) contains a repeating unit represented by the following formula (1):
• the onium salt (b1) contains an anion (an 1 ) whose conjugate acid has a pKa of 10 or less
• the onium salt (b2) contains an anion (an 2 ) whose conjugate acid has a pKa of 2 or more
• the actinic ray-sensitive or radiation-sensitive resin composition has a pKa of a conjugate acid of the anion (an 1 ) that is greater than the pKa of a conjugate acid of the anion (an 2 ).
• X represents a halogen atom or a fluorinated alkyl group.
• R0 represents a hydrogen atom or an organic group.
• R1 represents a substituent. R0 and R1 may be bonded to form a ring.
• the resin (A) further contains a repeating unit represented by the following formula (4):
• A1 represents a hydrogen atom, a halogen atom, or an organic group.
• R3 represents a hydrogen atom or a substituent.
• Ar1 represents a benzene ring or a naphthalene ring.
• R4 represents a substituent. When a plurality of R4s are present, the plurality of R4s may be the same or different from each other, and R4s may be bonded together to form a ring. R3 and R4 may be bonded together to form a ring.
• k1 represents an integer of 0 to 7.
• the preferred embodiments of the resin (A), the onium salt (b1), and the onium salt (b2) are as described above. It is particularly preferred that the onium salt (b1) contains at least one anion selected from the group consisting of a phenoxide ion and an alkoxide ion.
• the present invention also relates to a resist film formed using the above resist composition, and a pattern forming method using the above resist film.
• the pattern forming method of the present invention is preferably a pattern forming method comprising the steps of forming a film using the resist composition, exposing the film to light, and developing the exposed film using a developer.
• the procedure of the above pattern formation method is not particularly limited, but it is preferable that the method includes the following steps. Step 1: Forming a resist film on a substrate using a resist composition; Step 2: Exposing the resist film; Step 3: Developing the exposed resist film using a developer containing an organic solvent.
• Step 1 Forming a resist film on a substrate using a resist composition
• Step 2 Exposing the resist film
• Step 3 Developing the exposed resist film using a developer containing an organic solvent.
• Step 1 is a step of forming a resist film on a substrate using a resist composition.
• An example of a method for forming a resist film on a substrate using a resist composition is a method in which the resist composition is applied onto a substrate. It is preferable to filter the resist composition before coating as necessary.
• the pore size of the filter is preferably 0.1 ⁇ m or less, more preferably 0.05 ⁇ m or less, and even more preferably 0.03 ⁇ m or less.
• the filter is preferably made of polytetrafluoroethylene, polyethylene, or nylon.
• the resist composition can be applied onto a substrate (e.g., silicon, silicon dioxide-coated) such as those used in the manufacture of integrated circuit elements by a suitable application method such as a spinner or coater.
• a suitable application method such as a spinner or coater.
• the application method is preferably spin coating using a spinner.
• the rotation speed when spin coating using a spinner is preferably 1000 to 3000 rpm (rotations per minute).
• the substrate may be dried to form a resist film. If necessary, various undercoats (inorganic films, organic films, anti-reflective films) may be formed under the resist film.
• the drying method may be, for example, a method of drying by heating. Heating can be performed by a means provided in a normal exposure machine and/or a developing machine, and may also be performed using a hot plate or the like.
• the heating temperature is preferably 80 to 150°C, more preferably 80 to 140°C, and even more preferably 80 to 130°C.
• the heating time is preferably 30 to 1000 seconds, more preferably 60 to 800 seconds, and even more preferably 60 to 600 seconds.
• the thickness of the resist film is not particularly limited, but is preferably 10 to 120 nm, since it allows for the formation of fine patterns with higher accuracy.
• the thickness of the resist film is more preferably 10 to 65 nm, and even more preferably 15 to 50 nm.
• the thickness of the resist film is more preferably 10 to 120 nm, and even more preferably 15 to 90 nm.
• a top coat may be formed on the resist film using a top coat composition. It is preferable that the top coat composition does not mix with the resist film and can be uniformly applied to the upper layer of the resist film.
• the top coat is not particularly limited, and a conventionally known top coat can be formed by a conventionally known method. For example, a top coat can be formed based on the description in paragraphs [0072] to [0082] of JP2014-059543A. For example, it is preferable to form a top coat containing a basic compound as described in JP-A-2013-061648 on the resist film.
• the top coat also preferably contains a compound containing at least one group or bond selected from the group consisting of an ether bond, a thioether bond, a hydroxyl group, a thiol group, a carbonyl bond, and an ester bond.
• Step 2 is a step of exposing the resist film to light.
• the exposure method may be a method in which the formed resist film is irradiated with actinic rays or radiation through a predetermined mask.
• actinic rays or radiation include infrared light, visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light, X-rays, and electron beams, and preferably far ultraviolet light having a wavelength of 250 nm or less, more preferably 220 nm or less, and particularly preferably 1 to 200 nm, specifically, KrF excimer laser (248 nm), ArF excimer laser (193 nm), F2 excimer laser (157 nm), EUV (13 nm), X-rays, and electron beams.
• the heating temperature is preferably from 80 to 150°C, more preferably from 80 to 140°C, and even more preferably from 80 to 130°C.
• the heating time is preferably from 10 to 1,000 seconds, more preferably from 10 to 180 seconds, and even more preferably from 30 to 120 seconds. Heating can be carried out by a means provided in a normal exposure machine and/or developing machine, and may be carried out using a hot plate or the like.
• Step 3 is a step of developing the exposed resist film with a developer to form a pattern.
• the developer may be an alkaline developer or a developer containing an organic solvent (hereinafter also referred to as an organic developer), but is preferably an organic developer.
• Examples of the developing method include a method of immersing a substrate in a tank filled with a developing solution for a certain period of time (dip method), a method of piling up the developing solution on the substrate surface by surface tension and leaving it still for a certain period of time to develop (paddle method), a method of spraying the developing solution on the substrate surface (spray method), and a method of continuously discharging the developing solution while scanning a developing solution discharge nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispense method).
• dip method a method of immersing a substrate in a tank filled with a developing solution for a certain period of time
• spray method a method of spraying the developing solution on the substrate surface
• dynamic dispense method a method of continuously discharging the developing solution while scanning a developing solution discharge nozzle at a constant speed onto a substrate rotating at a constant speed
• the development time is not particularly limited as long as the resin in the unexposed area is sufficiently dissolved, and is preferably from 10 to 300 seconds, more preferably from 20 to 120 seconds.
• the temperature of the developer is preferably from 0 to 50°C, and more preferably from 15 to 35°C.
• the alkaline developer is preferably an aqueous alkaline solution containing an alkali.
• aqueous alkaline solution containing an aqueous alkaline solution containing a quaternary ammonium salt such as tetramethylammonium hydroxide, an inorganic alkali, a primary amine, a secondary amine, a tertiary amine, an alcohol amine, or a cyclic amine.
• the alkaline developer is preferably an aqueous solution of a quaternary ammonium salt such as tetramethylammonium hydroxide (TMAH).
• TMAH tetramethylammonium hydroxide
• Appropriate amounts of alcohols, surfactants, etc. may be added to the alkaline developer.
• the alkaline concentration of the alkaline developer is usually preferably 0.1 to 20% by mass.
• the pH of the alkaline developer is usually preferably 10.0 to 15.0.
• the organic developer preferably contains at least one organic solvent selected from the group consisting of ketone solvents, ester solvents, alcohol solvents, amide solvents, ether solvents, and hydrocarbon solvents.
• the above-mentioned solvents may be mixed in combination, or may be mixed with a solvent other than the above or with water.
• the water content of the developer as a whole is preferably less than 50% by mass, more preferably less than 20% by mass, even more preferably less than 10% by mass, and particularly preferably substantially free of water.
• the content of the organic solvent in the organic developer is preferably 50% by mass or more and 100% by mass or less, more preferably 80% by mass or more and 100% by mass or less, still more preferably 90% by mass or more and 100% by mass or less, and particularly preferably 95% by mass or more and 100% by mass or less, based on the total amount of the developer.
• the above pattern forming method preferably includes, after step 3, a step of washing with a rinsing liquid.
• the rinse liquid used in the rinse step following the step of developing with an alkaline developer is, for example, pure water, to which an appropriate amount of a surfactant may be added.
• a suitable amount of a surfactant may be added to the rinse solution.
• the rinse liquid used in the rinse step following the development step using an organic developer is not particularly limited as long as it does not dissolve the pattern, and a solution containing a general organic solvent can be used. It is preferable to use a rinse liquid containing at least one organic solvent selected from the group consisting of hydrocarbon solvents, ketone solvents, ester solvents, alcohol solvents, amide solvents, and ether solvents.
• the method of the rinsing step is not particularly limited, and examples thereof include a method of continuously discharging a rinsing liquid onto a substrate rotating at a constant speed (spin coating method), a method of immersing a substrate in a tank filled with the rinsing liquid for a certain period of time (dip method), and a method of spraying the rinsing liquid onto the substrate surface (spray method).
• the pattern forming method of the present invention may also include a heating step (Post Bake) after the rinsing step. This step removes the developer and rinsing solution remaining between the patterns and inside the pattern due to baking. This step also has the effect of annealing the resist pattern and improving the surface roughness of the pattern.
• the heating step after the rinsing step is usually performed at 40 to 250°C (preferably 90 to 200°C) for usually 10 seconds to 3 minutes (preferably 30 seconds to 120 seconds).
• the formed pattern may be used as a mask to perform an etching process on the substrate. That is, the pattern formed in step 3 may be used as a mask to process the substrate (or the underlayer film and the substrate) to form a pattern on the substrate.
• the method for processing the substrate (or the underlayer film and the substrate) is not particularly limited, a method for forming a pattern on the substrate is preferred by performing dry etching on the substrate (or the underlayer film and the substrate) using the pattern formed in step 3 as a mask.
• the dry etching is preferably oxygen plasma etching.
• the resist composition and various materials used in the pattern formation method of the present invention preferably do not contain impurities such as metals.
• the content of impurities contained in these materials is preferably 1 mass ppm (parts per million) or less, more preferably 10 mass ppb (parts per billion) or less, even more preferably 100 mass ppt (parts per trillion) or less, particularly preferably 10 mass ppt or less, and most preferably 1 mass ppt or less.
• examples of metal impurities include Na, K, Ca, Fe, Cu, Mg, Al, Li, Cr, Ni, Sn, Ag, As, Au, Ba, Cd, Co, Pb, Ti, V, W, and Zn.
• methods for reducing impurities such as metals contained in various materials include, for example, selecting raw materials with low metal content as the raw materials that make up the various materials, filtering the raw materials that make up the various materials, and performing distillation under conditions that minimize contamination as much as possible, such as lining the inside of the equipment with Teflon (registered trademark).
• impurities may be removed using an adsorbent, or a combination of filtration and an adsorbent may be used.
• adsorbent known adsorbents can be used, for example, inorganic adsorbents such as silica gel and zeolite, and organic adsorbents such as activated carbon.
• inorganic adsorbents such as silica gel and zeolite
• organic adsorbents such as activated carbon.
• the content of metal components contained in the cleaning solution after use is preferably 100 ppt by mass or less, more preferably 10 ppt by mass or less, and even more preferably 1 ppt by mass or less.
• the resist composition may contain water as an impurity.
• water When water is contained as an impurity, the smaller the water content, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass of water as a whole.
• the resist composition may contain residual monomers as impurities (for example, monomers derived from the raw material monomers used in the synthesis of the resin (A)).
• residual monomers when residual monomers are contained as impurities, the smaller the content of the residual monomers, the more preferable, but the resist composition may contain 1 to 30,000 ppm by mass relative to the total solid content of the resist composition.
• An organic processing liquid such as a rinse liquid may contain a conductive compound to prevent breakdown of chemical liquid piping and various parts (filters, O-rings, tubes, etc.) due to static electricity buildup and subsequent static electricity discharge.
• the conductive compound is not particularly limited, but an example thereof is methanol.
• the amount added is not particularly limited, but from the viewpoint of maintaining favorable development characteristics or rinsing characteristics, it is preferably 10% by mass or less, and more preferably 5% by mass or less.
• the chemical liquid piping may be made of, for example, stainless steel (SUS), or various piping coated with antistatic polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.).
• the filter and O-ring may be made of antistatic polyethylene, polypropylene, or fluororesin (polytetrafluoroethylene, perfluoroalkoxy resin, etc.).
• the present invention also relates to a method for manufacturing an electronic device, which includes the above-mentioned pattern formation method, and an electronic device manufactured by this manufacturing method.
• the electronic device of the present invention is suitably mounted in electric and electronic equipment (such as home appliances, OA (Office Automation), media-related equipment, optical equipment, and communication equipment).
• A-1 to A-15 correspond to resin (A).
• RA-1 does not correspond to resin (A) because the main chain of the resin is not decomposed by exposure to actinic rays or radiation, but for the sake of convenience, RA-1 is listed in the resin (A) column in Table 3 below.
• Onium salt The structural formulas of onium salts B-1 to B-19, RB-1, and RB-2 are shown below.
• the pKa of the conjugate acid of the anion contained in B-1 to B-19, RB-1, and RB-2 is shown in Table 2 below. Since B-5 and B-6 have two anion sites, the pKa of each is shown.
• B-1 to B-19 correspond to onium salt (b1) or onium salt (b2).
• RB-1 and RB-2 do not correspond to onium salt (b1) or onium salt (b2), but for the sake of convenience, RB-1 is listed in the onium salt (b2) column and RB-2 is listed in the onium salt (b1) column in Table 3 below.
• the larger pKa is the pKa (pKa b1 ) of the conjugate acid of the anion (an 1 ) of the onium salt ( b1 ) or the pKa (pKa b2 ) of the conjugate acid of the anion (an 2 ) of the onium salt ( b2 ), respectively .
• An underlayer film-forming composition SHB-A940 (manufactured by Shin-Etsu Chemical Co., Ltd.) was applied onto a silicon wafer and baked at 205° C. for 60 seconds to form an underlayer film with a thickness of 20 nm.
• a resist composition shown in Table 4 was applied onto the underlayer film and baked at 100° C. for 60 seconds to form a resist film with a thickness of 30 nm. In this way, a silicon wafer having a resist film was formed.
• the silicon wafer having the resist film obtained by the above procedure was subjected to pattern irradiation using an EUV exposure device (Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36, manufactured by Exitech).
• EUV exposure device Micro Exposure Tool, NA 0.3, Quadrupol, outer sigma 0.68, inner sigma 0.36, manufactured by Exitech.
• a reticle a mask with a line size of 20 nm and a line:space ratio of 1:1 was used.
• the exposed resist film was baked at 90° C. for 60 seconds, developed for 30 seconds with a developer shown in Table 4, rinsed with a rinse shown in Table 4, and then spin-dried to obtain a pattern.
• the resolution is preferably 15.0 nm or less, more preferably 14.0 nm or less, even more preferably 13.0 nm or less, particularly preferably 12.0 nm or less, and most preferably 11.0 nm or less.
• the resolution when a resist composition was used immediately after preparation (within 12 hours after preparation) was defined as the "initial" resolution, and the resolution when a resist composition was used after storage at 4°C for 3 months after preparation was defined as the "aged" resolution.
• Table 4 shows the difference (pKa b1 -pKa b2) between the pKa (pKa b1 ) of the conjugate acid of the anion (an 1 ) of the onium salt (b1) and the pKa (pKa b2 ) of the conjugate acid of the anion (an 2 ) of the onium salt (b2 ) in each resist composition.
• an actinic ray-sensitive or radiation-sensitive resin composition which is excellent in initial resolution and resolution after aging. Furthermore, according to the present invention, there can be provided a resist film formed using the actinic ray-sensitive or radiation-sensitive resin composition, a pattern forming method using the actinic ray-sensitive or radiation-sensitive resin composition, and a method for producing an electronic device.

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  • 2023-11-22 JP JP2024562674A patent/JPWO2024122346A1/ja active Pending
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