TW202332672A - Radiation-sensitive resin composition and pattern formation method - Google Patents

Abstract

Provided are a radiation-sensitive resin composition that has suitable storage stability and makes it possible to form a resist film with excellent sensitivity, LWR performance, water repellency, and development defect-suppressing performance, and a pattern formation method. The radiation-sensitive resin composition contains: a first resin including a structural unit (I) represented by formula (1), a structural unit (II) represented by formula (2) (excluding the structural unit represented by formula (1)), and a structural unit (III) having an acid-cleavable group; and a solvent. (In formula (1), RK1 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. L1 is an alkanediyl group having 1-5 carbon atoms. Rf1 is a monovalent fluorinated hydrocarbon group having 2-10 carbon atoms and 5-7 fluorine atoms. In formula (2), RK2 is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. Lf is a fluorine-substituted or unsubstituted divalent organic group having 1-20 carbon atoms. L2 is *-COO- or *-OCO-. * is a bond on the Lf side. p is an integer of 0-2. When a plurality of Lf and L2 are present, the plurality of Lf and L2 may be the same or different from each other. Rf2 is a fluorine-substituted or unsubstituted monovalent organic group having 1-20 carbon atoms. Lf and Rf2 have a total of one or more fluorine atoms.).

Description

Radiation-sensitive resin composition and pattern forming method

The present invention relates to a radiation-sensitive resin composition and a pattern forming method.

Photolithography technology using a resist composition is used to form fine circuits in semiconductor devices. As a representative process, for example, a film of a resist composition is exposed with radiation irradiation through a mask pattern to generate an acid, and a reaction using the acid as a catalyst generates a reaction between the exposed portion and the unexposed portion. The difference in solubility of the resin relative to an alkali-based or organic solvent-based developer is generated, thereby forming a resist pattern on the substrate.

In the photolithography technology, short-wavelength radiation such as ArF excimer laser is used, or the ArF exposure is combined with a liquid immersion exposure method (liquid immersion lithography) to promote pattern miniaturization.

In the resist composition used in the liquid immersion exposure method, attempts are being made to add water-repellent compounds to the resist composition for the purpose of improving process efficiency through surface modification of the resist film. For example, a technique has been proposed in which a water-repellent compound that maintains hydrophobicity and exhibits solubility in an alkaline developer is added to a resist composition in order to improve resist performance or defect prevention properties (see Japanese Patent No. No. 6774214). [Prior art documents] [Patent Document]

[Patent Document 1] Japanese Patent No. 6774214

[Problem to be solved by the invention] As the next generation technology after ArF exposure, it is being achieved by using radiation with shorter wavelengths such as electron beams, X-rays and extreme ultraviolet (EUV). Regarding resist compositions containing water-repellent compounds, the next-generation technology is also required to have sensitivity or Line Width Roughness (LWR) performance indicating deviations in the line width of a resist pattern. Water-based, development defect inhibitory property.

However, if the solubility of a water-repellent compound in a developer is increased in order to improve the development defect suppression property, it may not be suitable for long-term storage due to its reactivity. There is a so-called trade-off relationship between storage stability and development defect suppression properties, but it is required to take both storage stability and development defect suppression properties into consideration.

An object of the present invention is to provide a radiation-sensitive resin composition and a pattern forming method that can form a resist film with excellent sensitivity, LWR performance, water repellency, and development defect suppression properties and have good storage stability. [Means to solve the problem]

The inventors of the present invention have made repeated efforts to solve the problem, and as a result found that the above object can be achieved by adopting the following structure, and completed the present invention.

That is, in one embodiment, the present invention relates to a radiation-sensitive resin composition containing: a structural unit (I) represented by the following formula (1) and a structural unit represented by the following formula (2) (II) A first resin (excluding the structural unit represented by the following formula (1)) and the structural unit (III) having an acid-dissociating group, and a solvent. [Chemical 1] (In the formula (1), R ^K1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ¹ is an alkanediyl group having 1 to 5 carbon atoms; R ^f1 is an alkyl group having five to seven fluorine atoms A monovalent fluorinated hydrocarbon group with 2 to 10 carbon atoms; In the formula (2), R ^K2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ^f is a fluorine-substituted or unsubstituted carbon A divalent organic group with a number of 1 to 20; L ² is *-COO- or *-OCO-; * is a bond on the L ^f side; p is an integer from 0 to 2; when there are multiple L ^f and L ² In the case of , multiple L ^f and L ² are the same or different from each other respectively; R ^f2 is a fluorine-substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms; among them, L ^f and R ^f2 have more than one in total of fluorine atoms)

This radiation-sensitive resin composition can construct a resist film that satisfies not only sensitivity, LWR performance, and water repellency, but also storage stability and development defect suppression properties. The reason is not clear and not limited, but it can be presumed as follows. The first resin can exhibit high water repellency due to the fluorine atoms contained in the structural unit (I) and the structural unit (II). In addition, during the development step, a dissociation reaction occurs in one or both of the structural unit (I) and the structural unit (II) in the first resin, which can improve the solubility of the first resin in the developer. As a result, development defect suppression properties can be improved. On the other hand, the relatively high-volume structure introduced around the portion of the structural unit (I) and the structural unit (II) that causes the developer dissociation reaction (mainly the ester bond at the end of the side chain) serves as a reaction barrier and can Unexpected dissociation reactions caused by moisture and the like during storage of the radiation-sensitive resin composition are suppressed. It is presumed that the mutually opposite required performances of storage stability and development defect suppression properties can be achieved by the composite effect of these. Furthermore, it is presumed that sensitivity and LWR performance can be ensured by the first resin including the structural unit (I), the structural unit (II), and the structural unit (III) having an acid-dissociable group.

In this specification, "organic group" is a group having at least one carbon atom. "Hydrocarbon group" includes chain hydrocarbon groups, alicyclic hydrocarbon groups and aromatic hydrocarbon groups unless otherwise specified. The "hydrocarbon group" includes both saturated hydrocarbon groups and unsaturated hydrocarbon groups. The "chain hydrocarbon group" refers to a hydrocarbon group that does not contain a cyclic structure but only contains a chain structure, and includes both linear hydrocarbon groups and branched chain hydrocarbon groups. The "alicyclic hydrocarbon group" refers to a hydrocarbon group that contains only an alicyclic structure as a ring structure and does not include an aromatic ring structure, and includes both monocyclic alicyclic hydrocarbon groups and polycyclic alicyclic hydrocarbon groups. Among them, it is not necessary to include only an alicyclic structure, but may also include a chain structure in a part thereof. The "aromatic hydrocarbon group" refers to a hydrocarbon group containing an aromatic ring structure as a ring structure. Among them, it is not necessary to include only an aromatic ring structure, but may also include a chain structure or an alicyclic structure in a part thereof.

In another embodiment, the present invention relates to a pattern forming method, which includes: The step of directly or indirectly coating the radiation-sensitive resin composition on a substrate to form a resist film; The step of exposing the resist film; and The step of developing the exposed resist film using a developer.

According to this pattern forming method, the radiation-sensitive resin composition can be used to form a resist film that is excellent in sensitivity, LWR performance, water repellency, and development defect suppression property and has good storage stability, so it can be formed efficiently. High quality resist pattern.

Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

"Radiosensitive resin composition" The radiation-sensitive resin composition of this embodiment (hereinafter, also simply referred to as "composition") includes a first resin and a solvent. The composition preferably contains, in addition to the first resin, a second resin that contains a structural unit having an acid-dissociable group and has a lower mass content of fluorine atoms than the first resin. The composition preferably further contains a radiation-sensitive acid generator and an acid diffusion control agent. The composition may also contain other arbitrary components as long as the effects of the present invention are not impaired.

＜First Resin＞ The first resin includes the structural unit (I) represented by the formula (1), the structural unit (II) represented by the formula (2) (excluding the structural unit (I)), and a structural unit having an acid-dissociable group. (III). As long as the effects of the present invention are not impaired, the first resin may contain other structural units in addition to structural units (I) to (III). Each structural unit is explained below.

(Structural unit (I)) The structural unit (I) is represented by the following formula (1). [Chemicalization 2] (In the formula (1), R ^K1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ¹ is an alkanediyl group having 1 to 5 carbon atoms; R ^f1 is an alkyl group having five to seven fluorine atoms. Monovalent fluorinated hydrocarbon group with 2 to 10 carbon atoms)

R ^K1 is preferably a hydrogen atom or a methyl group in terms of providing copolymerizability of the monomer of the structural unit (I).

Examples of the alkanediyl group having 1 to 5 carbon atoms represented by L ¹ include a group obtained by removing two hydrogen atoms from a chain or branched alkane having a corresponding carbon number. Two hydrogen atoms can be removed from the same carbon atom or from different carbon atoms. Specific examples include: methanediyl, 1,1-ethanediyl, 1,2-ethanediyl, 1,1-dimethyl-1,2-ethanediyl, 1,1- Propanediyl, 1,2-propanediyl, 1,3-propanediyl, 2,2-propanediyl, 1,1-butanediyl, 2,2-butanediyl, 1,2- Butanediyl, 1,3-butanediyl, 1,4-butanediyl, 2,3-butanediyl, etc. Among them, L ¹ is preferably methanediyl or ethanediyl (1,1-ethanediyl or 1,2-ethanediyl).

Examples of the monovalent fluorinated hydrocarbon group having 2 to 10 carbon atoms and having five to seven fluorine atoms represented by R ^f1 include: a monovalent fluorinated hydrocarbon group having 2 to 10 carbon atoms and having five to seven fluorine atoms. Chain hydrocarbon groups, monovalent fluorinated alicyclic hydrocarbon groups having 5 to 7 fluorine atoms and having 3 to 10 carbon atoms, etc.

Examples of the monovalent fluorinated chain hydrocarbon group having 5 to 7 fluorine atoms and having 2 to 10 carbon atoms include: Pentafluoroethyl, 2,2,3,3,3-pentafluoropropyl, heptafluoropropyl, 1,1,1,3,3,3-hexafluoro-2-propyl, 1,1,1 , 3,3,3-hexafluoro-2-fluoropropyl, heptafluoro-n-propyl and other fluorinated alkyl groups; Fluorinated alkenyl groups such as pentafluoropropenyl; Pentafluorobutynyl and other fluorinated alkynyl groups, etc.

Examples of the monovalent fluorinated alicyclic hydrocarbon group having 5 to 7 fluorine atoms and having 3 to 10 carbon atoms include: Pentafluorocyclobutyl, hexafluorocyclobutyl, pentafluorocyclopentyl, hexafluorocyclopentyl, heptafluorocyclopentyl, pentafluorocyclohexyl, hexafluorocyclohexyl, pentafluorocyclohexylmethyl, pentafluorofluorine Bornyl, pentafluoroadamantyl, pentafluorobornyl, pentafluoroisobornyl and other fluorinated cycloalkyl groups; Fluorinated cycloalkenyl groups such as pentafluorocyclopentenyl, pentafluorocyclohexenyl, etc.

R ^f1 is preferably a monovalent fluorinated chain hydrocarbon group having 5 to 7 fluorine atoms and having 2 to 8 carbon atoms, and more preferably is a monovalent fluorinated chain hydrocarbon group having 5 to 7 fluorine atoms and having 2 to 6 carbon atoms. Fluorinated chain hydrocarbon group, more preferably a monovalent linear hydrocarbon group having 2 to 4 carbon atoms having five to seven fluorine atoms, particularly preferably a monovalent linear hydrocarbon group having 2 to 4 carbon atoms having five fluorine atoms The hydrocarbon group is preferably a monovalent straight-chain saturated hydrocarbon group having five fluorine atoms and having 2 to 4 carbon atoms.

Examples of monomers that provide the structural unit (I) include compounds represented by the following formulas (1-1) to (1-18). [Chemical 3]

The lower limit of the content ratio of the structural unit (I) in all the structural units constituting the first resin (total when there are multiple structural units (I)) is preferably 5 mol%, more preferably 10 mol%. Ear%, and the best is 15 mol%, and the best is 20 mol%. The upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, further preferably 60 mol%, and particularly preferably 50 mol%. By setting the content ratio of the structural unit (I) within the above range, the radiation-sensitive resin composition can further improve the water repellency, storage stability, and development defect suppression properties.

(Providing methods for synthesizing monomers of structural unit (I)) The monomer (i) that provides the structural unit (I) can be synthesized by the condensation reaction of an alcohol having a polymerizable group and a fluorine-containing carboxylic acid as shown in the following scheme. Other structures can be synthesized by changing the structure of alcohol or carboxylic acid.

[Chemical 4] (In the process, R ^K1 , L ¹ and R ^f1 have the same meaning as the above formula (1))

(Structural unit (II)) The structural unit (II) is represented by the following formula (2). [Chemistry 5] (In the formula (2), R ^K2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ^f is a fluorine-substituted or unsubstituted divalent organic group having 1 to 20 carbon atoms; L ² is *-COO- or *-OCO-; * is the bonding bond on the L ^f side; p is an integer from 0 to 2; when there are multiple L ^f and L ² , the multiple L ^f and L ² are respectively The same or different from each other; R ^f2 is a fluorine-substituted or unsubstituted monovalent organic group with 1 to 20 carbon atoms; among them, L ^f and R ^f2 have more than one fluorine atom in total)

R ^K2 is preferably a hydrogen atom or a methyl group in terms of providing copolymerizability of the monomer of the structural unit (II).

L ^f is a divalent organic group having 1 to 20 carbon atoms, and part or all of the hydrogen atoms may or may not be substituted with fluorine atoms (it may be unsubstituted). As the fluorine-substituted or unsubstituted divalent organic group having 1 to 20 carbon atoms represented by L ^f , a fluorine-substituted or unsubstituted divalent organic group represented by R ^f2 of the formula (2) can be preferably used. Since it is a group obtained by removing one hydrogen atom from a monovalent organic group having 1 to 20 carbon atoms, R ^f2 will be explained first.

R ^f2 is a monovalent organic group having 1 to 20 carbon atoms, and part or all of the hydrogen atoms may or may not be substituted by fluorine atoms (it may be unsubstituted). The monovalent organic group having 1 to 20 carbon atoms is not particularly limited, and may be a chain structure, a cyclic structure, or a combination thereof. Examples of the chain structure include chain hydrocarbon groups that may be saturated or unsaturated, linear or branched. Examples of the cyclic structure include alicyclic, aromatic, or heterocyclic cyclic hydrocarbon groups. Among them, the monovalent organic group is preferably a substituted or unsubstituted monovalent chain hydrocarbon group having 1 to 20 carbon atoms, a substituted or unsubstituted monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, A substituted or unsubstituted monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms or a combination thereof. In addition, a group in which a part or all of the hydrogen atoms contained in a group having a chain structure or a group having a cyclic structure is substituted with a substituent, a carbon-carbon space or a carbon chain terminal of these groups can also be cited. A group containing a divalent linking group selected from -CO-, -CS-, -O-, -S-, -SO ₂ - or -NR'-, or a combination of two or more of them, and the like. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. As the divalent linking group, -COO-, -OCO-, -OCOO-, -OCOCOO-, -CS-, -O-, -S- or -SO ₂ - is preferred.

Examples of substituents that substitute part or all of the hydrogen atoms of the organic group include: halogen atoms such as fluorine atom, chlorine atom, bromine atom, and iodine atom; hydroxyl group; carboxyl group; cyano group; nitro group; Alkyl group, alkoxy group, alkoxycarbonyl group, alkoxycarbonyloxy group, acyl group, acyloxy group or a group in which the hydrogen atoms of these groups are replaced by halogen atoms; side oxygen group (=O), etc. .

Examples of the monovalent chain hydrocarbon group having 1 to 20 carbon atoms include a linear or branched chain saturated hydrocarbon group having 1 to 20 carbon atoms, or a linear or branched chain unsaturated hydrocarbon group having 1 to 20 carbon atoms.

Examples of the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include a monocyclic or polycyclic saturated hydrocarbon group, a monocyclic or polycyclic unsaturated hydrocarbon group, and the like. As the monocyclic saturated hydrocarbon group, preferred are cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. As the polycyclic cycloalkyl group, bridged cycloalicyclic hydrocarbon groups such as norbornyl group, adamantyl group, tricyclodecyl group, and tetracyclododecyl group are preferred. Examples of the monocyclic unsaturated hydrocarbon group include monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl. Examples of the polycyclic unsaturated hydrocarbon group include polycyclic cycloalkenyl groups such as norbornenyl, tricyclodecenyl, and tetracyclododecenyl. Furthermore, the so-called bridged cycloalicyclic hydrocarbon group refers to a polycyclic alicyclic formula in which two carbon atoms that are not adjacent to each other among the carbon atoms constituting the alicyclic ring are bonded through a bonding chain containing one or more carbon atoms. hydrocarbyl.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthracenyl; benzyl, phenethyl, naphthylmethyl, etc. Aralkyl etc.

Examples of the heterocyclic cyclic hydrocarbon group include a group in which one hydrogen atom is removed from an aromatic heterocyclic structure and a group in which one hydrogen atom is removed from an alicyclic heterocyclic structure. The aromatic structure of a 5-membered ring that has aromatic properties by introducing a heteroatom is also included in the heterocyclic structure. Examples of heteroatoms include oxygen atoms, nitrogen atoms, sulfur atoms, and the like.

Examples of the aromatic heterocyclic structure include: Furan, pyran, benzofuran, benzopyran and other aromatic heterocyclic structures containing oxygen atoms; Aromatic heterocyclic structures containing nitrogen atoms such as pyrrole, imidazole, pyridine, pyrimidine, pyrazine, indole, quinoline, isoquinoline, acridine, phenazine, carbazole; Aromatic heterocyclic structures containing sulfur atoms such as thiophene; Thiazole, benzothiazole, thiazide, oxazine and other aromatic heterocyclic structures containing multiple heteroatoms.

Examples of the alicyclic heterocyclic structure include: Alicyclic heterocyclic structures containing oxygen atoms such as oxirane, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; Alicyclic heterocyclic structures containing nitrogen atoms such as aziridine, pyrrolidine, pyrazolidine, piperidine, and piperazine; Alicyclic heterocyclic structures containing sulfur atoms such as thietane, thiolane, and thiane; Alicyclic heterocyclic structures containing multiple heteroatoms such as morpholine, 1,2-oxathialane, 1,3-oxathialane, etc.

Examples of the cyclic structure include a lactone structure, a cyclic carbonate structure, a sultone structure, and a structure containing a cyclic acetal.

As described above, as the fluorine-substituted or unsubstituted divalent organic group having 1 to 20 carbon atoms represented by L ^f , the fluorine-substituted or unsubstituted divalent organic group represented by R ^f2 can be preferably used. A group formed by removing one hydrogen atom from a monovalent organic group having 1 to 20 carbon atoms.

p is preferably 1 or 2, more preferably 1.

L ^f and R ^f2 have one or more fluorine atoms in total. The lower limit of the total number of fluorine atoms contained in L ^f and R ^f2 may be 2 or 3. The upper limit of the total number may be 10, 8, or 6.

In the formula (2), it is preferred that one or two fluorine atoms or trifluoromethyl groups are bonded to at least one carbon atom adjacent to the carbonyl group in L ² .

Examples of the monomer providing the structural unit (II) include compounds represented by the following formulas (2-1) to (2-33). [Chemical 6]

[Chemical 7]

The lower limit of the content ratio of structural unit (II) in all structural units constituting the first resin (total when multiple structural units (II) are present) is preferably 5 mol%, more preferably 10 mol%. Ear%, and the best is 15 mol%, and the best is 20 mol%. The upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, further preferably 60 mol%, and particularly preferably 50 mol%. By setting the content ratio of the structural unit (II) within the above range, the radiation-sensitive resin composition can further improve the water repellency, storage stability, and development defect suppression properties.

(Structural unit (III)) The first resin contains a structural unit (III) having an acid-dissociating group. The "acid-dissociable group" refers to a group that substitutes a hydrogen atom of an alkali-soluble group such as a carboxyl group, a phenolic hydroxyl group, a sulfo group, or a sulfonamide group, and is a group that is dissociated by the action of an acid. Therefore, the acid-dissociable group is bonded to the oxygen atom bonded to the hydrogen atom in these functional groups. As the structural unit (III), it is preferably represented by the following formula (3).

[Chemical 8]

In the formula (3), R ⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ⁸ is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ⁹ and R ¹⁰ are each independently a monovalent chain hydrocarbon group with 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group with 3 to 20 carbon atoms, or it means that these groups are bonded to each other and to the carbon atoms to which they are bonded. A divalent alicyclic group with 3 to 20 carbon atoms composed of atoms.

From the viewpoint of providing copolymerizability of the monomer of the structural unit (III), R ⁷ is preferably a hydrogen atom or a methyl group, and more preferably a methyl group.

Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ⁸ include: a chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and a monovalent hydrocarbon group having 6 to 20 carbon atoms. Monovalent aromatic hydrocarbon groups, etc.

Examples of the chain hydrocarbon group having 1 to 10 carbon atoms represented by R ⁸ to R ¹⁰ include a linear or branched chain saturated hydrocarbon group having 1 to 10 carbon atoms, or a linear or branched chain hydrocarbon group having 1 to 10 carbon atoms. Saturated hydrocarbon group.

Examples of the alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ⁸ to R ¹⁰ include a monocyclic or polycyclic saturated hydrocarbon group, or a monocyclic or polycyclic unsaturated hydrocarbon group. As the monocyclic saturated hydrocarbon group, preferred are cyclopentyl, cyclohexyl, cycloheptyl and cyclooctyl. As the polycyclic cycloalkyl group, bridged cycloalicyclic hydrocarbon groups such as norbornyl group, adamantyl group, tricyclodecyl group, and tetracyclododecyl group are preferred.

Examples of the monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms represented by R ⁸ include: aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthracenyl; benzyl, phenethyl, Naphthylmethyl and other aralkyl groups, etc.

R ⁸ is preferably a linear or branched chain saturated hydrocarbon group having 1 to 10 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms.

The chain hydrocarbon group or alicyclic hydrocarbon group represented by R ⁹ and R ¹⁰ is bonded to each other and forms a divalent alicyclic group with a carbon number of 3 to 20 together with the bonded carbon atoms, as long as it is self-constituting. The group formed by removing two hydrogen atoms from the same carbon atom in the same carbon ring of the monocyclic or polycyclic alicyclic hydrocarbon with the above carbon number is not particularly limited. It can be either a monocyclic hydrocarbon group or a polycyclic hydrocarbon group. The polycyclic hydrocarbon group can be any one of a bridged cyclic alicyclic hydrocarbon group and a condensed alicyclic hydrocarbon group. It can also be any one of a saturated hydrocarbon group and an unsaturated hydrocarbon group. One kind. In addition, the condensed alicyclic hydrocarbon group refers to a polycyclic alicyclic hydrocarbon group composed of a plurality of alicyclic rings sharing an edge (a bond between two adjacent carbon atoms).

Among the monocyclic alicyclic hydrocarbon groups, the saturated hydrocarbon group is preferably cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, cyclooctanediyl, etc., and the unsaturated hydrocarbon group is preferably cyclopentanediyl. Pentenediyl, cyclohexenediyl, cycloheptenediyl, cyclooctenediyl, cyclodecenediyl, etc. As the polycyclic alicyclic hydrocarbon group, a bridged cycloalicyclic saturated hydrocarbon group is preferred, for example, a bicyclo[2.2.1]heptane-2,2-diyl (norbornane-2,2-diyl ), bicyclo[2.2.2]octane-2,2-diyl, tricyclo[3.3.1.1 ^3,7 ]decane-2,2-diyl (adamantane-2,2-diyl), etc.

Among these, it is preferable that R ⁸ is an alkyl group or phenyl group having 1 to 4 carbon atoms, and the alicyclic structure formed by R ⁹ and R ¹⁰ combined with each other and the bonded carbon atoms is polycyclic or monocyclic. The cycloalkane structure of the ring.

Examples of the structural unit (III) include structural units represented by the following formulas (3-1) to (3-7) (hereinafter also referred to as "structural units (III-1) to (III-)"). 7)”) etc.

[Chemical 9]

In the formula (3-1) to the formula (3-7), R ⁷ to R ¹⁰ have the same meaning as the formula (3). i and j are each independently an integer from 1 to 4. k and l are 0 or 1.

As i and j, 1 is preferred. R ⁸ is preferably a methyl group, an ethyl group, an isopropyl group or a phenyl group. R ⁹ and R ¹⁰ are preferably methyl or ethyl.

The first resin may contain one type or a combination of two or more types of structural units (III).

The lower limit of the content ratio of the structural unit (III) in all the structural units constituting the first resin (total when a plurality of structural units (III) is present) is preferably 5 mol %, more preferably 8 mol%, preferably 10 mol%, and particularly preferably 15 mol%. In addition, the upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, further preferably 60 mol%, and particularly preferably 50 mol%. By setting the content ratio of the structural unit (III) within the above range, the sensitivity, LWR performance and development defect suppression property of the radiation-sensitive resin composition can be further improved.

(Other Structural Units) The first resin may contain a structural unit having an alicyclic structure represented by the following formula (6) as a structural unit other than the structural units listed above. [Chemical 10] (In the formula (6), R ^1α is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R ^2α is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms)

In the formula (6), as the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by R ^2α , the monovalent alicyclic hydrocarbon group having 3 carbon atoms represented by R ⁸ to R ¹⁰ of the formula (3) can preferably be used. ~20 alicyclic hydrocarbon group.

When the first resin contains the structural unit having an alicyclic structure, the lower limit of the content ratio of the structural unit having an alicyclic structure is preferably 5 mol% relative to all structural units constituting the first resin. , more preferably 10 mol%, further preferably 15 mol%. The upper limit of the content ratio is preferably 40 mol%, more preferably 30 mol%, and still more preferably 20 mol%.

(Synthesis method of the first resin) The first resin can be synthesized, for example, by polymerizing monomers providing each structural unit in an appropriate solvent using a radical polymerization initiator or the like.

Examples of the free radical polymerization initiator include: Azobisisobutyronitrile (AIBN), 2,2'-Azobis(4-methoxy-2,4-dimethylvaleronitrile) , 2,2'-Azobis(2-cyclopropylpropionitrile), 2,2'-Azobis(2,4-dimethylvaleronitrile), 2,2'-Azobisisobutyric acid Azo radical initiators such as dimethyl ester; peroxide radical initiators such as benzyl peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, etc. Among these, AIBN and 2,2'-azobisisobutyric acid dimethyl ester are preferred, and AIBN is more preferred. These radical initiators may be used individually by 1 type or in mixture of 2 or more types.

Examples of the solvent used in the polymerization reaction include alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; cyclohexane, cycloheptane, cyclohexane, Naphthenes such as octane, decalin, norbornane; aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, cumene; chlorobutanes, hexane bromide, dichloroethane, Halogenated hydrocarbons such as hexamethylene dibromide and chlorobenzene; saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, methyl propionate; acetone, methyl ethyl ketone , 4-methyl-2-pentanone, 2-heptanone and other ketones; tetrahydrofuran, dimethoxyethanes, diethoxyethanes and other ethers; methanol, ethanol, 1-propanol, 2 -Propanol, 4-methyl-2-pentanol and other alcohols, etc. These solvents used in the polymerization reaction may be used alone or in combination of two or more.

The reaction temperature in the polymerization reaction is usually 40°C to 150°C, preferably 50°C to 120°C. The reaction time is usually 1 hour to 48 hours, preferably 1 hour to 24 hours.

The molecular weight of the first resin is not particularly limited, but the lower limit of the polystyrene-converted weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is preferably 1,000, more preferably 2,000, and further The best is 3,000 and the extra best is 3,500. The upper limit of Mw is preferably 50,000, more preferably 30,000, further preferably 20,000, and particularly preferably 18,000. By setting the Mw of the first resin to the above range, the storage stability and development defect suppressing properties of the radiation-sensitive resin composition can be improved.

The ratio (Mw/Mn) of Mw of the first resin to the polystyrene-reduced number average molecular weight (Mn) obtained by GPC is usually 1 or more and 5 or less, preferably 1 or more and 3 or less, and still more preferably 1 Above and below 2.

The measuring methods of Mw and Mn of the first resin and the second resin described below were obtained by the description in the Examples.

The lower limit of the content of the first resin is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, further preferably 1 part by mass, and particularly preferably 2 parts by mass, based on 100 parts by mass of the second resin (base resin) described below. The upper limit of the content is preferably 15 parts by mass, more preferably 12 parts by mass, further preferably 10 parts by mass, and particularly preferably 8 parts by mass.

＜Second Resin＞ The second resin is a resin that contains a structural unit having an acid-dissociable group and has a lower mass content of fluorine atoms than the first resin (hereinafter, this resin is also referred to as a “base resin”). As the structural unit having an acid-dissociable group in the base resin, the structural unit (III) contained in the first resin (hereinafter, also referred to as "structural unit (III)" in the second resin) can be preferably used. ”). This radiation-sensitive resin composition has excellent pattern formability because the second resin as the base resin has the structural unit (III).

The lower limit of the content ratio of structural unit (III) in all structural units constituting the base resin (total when a plurality of structural units are present) is preferably 10 mol %, more preferably 20 mol % %, and the best is 25 mol%, and the best is 30 mol%. In addition, the upper limit of the content ratio is preferably 80 mol%, more preferably 70 mol%, further preferably 65 mol%, and particularly preferably 60 mol%. By setting the content ratio of the structural unit (III) in the base resin to the above range, the pattern formability of the radiation-sensitive resin composition can be further improved.

In addition to the structural unit having an acid-dissociable group, the base resin may further have a structural unit including at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure (described below). IV) or other structural units other than structural unit (III) and structural unit (IV). Each structural unit is explained below.

(structural unit (IV)) The structural unit (IV) is a structural unit containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure. By having a structural unit (IV) in the base resin, the solubility in the developer can be adjusted. As a result, the radiation-sensitive resin composition can improve lithography performance such as resolution. In addition, the adhesiveness between the resist pattern formed of the base resin and the substrate can be improved.

Examples of the structural unit (IV) include structural units represented by the following formulas (T-1) to (T-10).

[Chemical 11]

In the formula, R ^L1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R ^L2 to R ^L5 are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxyl group, a hydroxymethyl group, or a dimethylamino group. ^RL4 and ^RL5 may be a bivalent alicyclic group having 3 to 8 carbon atoms that is bonded to each other and constituted together with the bonded carbon atoms. L ^T is a single bond or a divalent linking group. X is an oxygen atom or methylene group. k is an integer from 0 to 3. m is an integer from 1 to 3.

Examples of the divalent alicyclic group having 3 to 8 carbon atoms in which R ^L4 and R ^L5 are bonded to each other and constituted together with the bonded carbon atoms include R ⁹ and R in the formula (3). The chain hydrocarbon group or alicyclic hydrocarbon group represented by ¹⁰ is bonded to each other and is a group with a carbon number of 3 to 8 among the divalent alicyclic groups having 3 to 20 carbon atoms formed together with the bonded carbon atoms. More than one hydrogen atom on the alicyclic group may be substituted by a hydroxyl group.

Examples of the divalent linking group represented by L ^T include a divalent linear or branched hydrocarbon group having 1 to 10 carbon atoms, a divalent alicyclic hydrocarbon group having 4 to 12 carbon atoms, or a divalent linking group containing the same. A group in which at least one of these hydrocarbon groups is at least one of -CO-, -O-, -NH- and -S-, etc.

As the structural unit (IV), among these, a structural unit containing a lactone structure is preferred, a structural unit containing a norbornane lactone structure is more preferred, and a structural unit derived from norbornane (meth)acrylate is still more preferred. Ester - The structural unit of ester.

The lower limit of the content ratio of the structural unit (IV) relative to all the structural units constituting the base resin is preferably 20 mol%, more preferably 25 mol%, and still more preferably 30 mol%. The upper limit of the content ratio is preferably 80 mol%, more preferably 75 mol%, and even more preferably 70 mol%. By setting the content ratio of the structural unit (IV) within the above range, the radiation-sensitive resin composition can further improve lithography performance such as resolution and the adhesion between the formed resist pattern and the substrate.

(structural unit (V)) In addition to the structural unit (III) and the structural unit (IV), the base resin may optionally have other structural units. Examples of the other structural units include structural units (V) containing polar groups (excluding structural units corresponding to the structural unit (IV)). By having the structural unit (V) in the base resin, the solubility in the developer can be adjusted. As a result, the resolution and other lithography properties of the radiation-sensitive resin composition can be improved. Examples of the polar group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, a sulfonamide group, and the like. Among these, a hydroxyl group and a carboxyl group are preferred, and a hydroxyl group is more preferred.

Examples of the structural unit (V) include structural units represented by the following formula.

[Chemical 12]

In the formula, R ^A is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

When the base resin has the polar group-containing structural unit (V), the lower limit of the content ratio of the structural unit (V) relative to all the structural units constituting the base resin is preferably 5 mol %. , more preferably 8 mol%, further preferably 10 mol%. The upper limit of the content ratio is preferably 40 mol%, more preferably 30 mol%, and still more preferably 25 mol%. By setting the content ratio of the structural unit (V) within the above range, the lithographic performance such as resolution of the radiation-sensitive resin composition can be further improved.

(structural unit (VI)) The structural unit (VI) is a structural unit derived from hydroxystyrene or a structural unit having a phenolic hydroxyl group. In addition to the polar group-containing structural unit (V), the base resin optionally has a structural unit (VI) as another structural unit. The structural unit (VI) contributes to improving etching resistance and increasing the difference in developer solubility (dissolution contrast) between the exposed portion and the unexposed portion. In particular, it can be preferably applied to pattern formation using exposure by radiation with a wavelength of 50 nm or less, such as electron beams or EUV. In this case, the resin preferably has the structural unit (VI), the structural unit (III), and the desired structural unit (V).

The structural unit derived from hydroxystyrene is represented by, for example, the following formula (4-1) to formula (4-2), and the structural unit having a phenolic hydroxyl group is, for example, represented by the following formula (4-3) to formula (4- 4) and so on.

[Chemical 13]

In the formula (4-1) to formula (4-4), R ¹¹ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group.

In the case where the structural unit (VI) is obtained, it is preferable to polymerize in a state where the phenolic hydroxyl group is protected by a protecting group such as a base-dissociating group (such as a acyl group) during polymerization, and then hydrolyze and deprotect it. This obtains the structural unit (VI).

In the case of a base resin for exposure by radiation with a wavelength of 50 nm or less, the lower limit of the content ratio of the structural unit (VI) relative to all structural units constituting the base resin is preferably 10 mol%, more preferably The best value is 20 mol%. In addition, the upper limit of the content ratio is preferably 70 mol%, more preferably 60 mol%.

The molecular weight of the base resin is not particularly limited, but the lower limit of the polystyrene-reduced weight average molecular weight (Mw) obtained by gel permeation chromatography (GPC) is preferably 1,000, more preferably 2,000, and still more preferably 3,000. , the best value is 4,000. The upper limit of Mw is preferably 30,000, more preferably 20,000, further preferably 15,000, and particularly preferably 10,000. If the Mw of the base resin is less than the lower limit, the heat resistance of the obtained resist film may decrease. If the Mw of the base resin exceeds the above upper limit, the developability of the resist film may decrease.

The ratio (Mw/Mn) of the Mw of the base resin to the polystyrene-reduced number average molecular weight (Mn) obtained by GPC is usually 1 or more and 5 or less, preferably 1 or more and 3 or less, and still more preferably 1 or more And less than 2.

(Synthesis method of the second resin) The second resin can be synthesized by the same method as the first resin.

＜Radiosensitive acid generator＞ The radiation-sensitive acid generator is a component that generates acid upon exposure to light. It is considered that the acid generated by exposure has two functions in the radiation-sensitive resin composition depending on the strength of the acid. As the first function, when the first resin and the second resin include the structural unit (III) having an acid-dissociative group, the acid generated by exposure can dissociate the acid of the structural unit (III). The function of dissociating the sexual group and producing a carboxyl group, etc. The radiation-sensitive acid generating agent having this first function is called a radiation-sensitive acid generating agent (I). As a second function, under the pattern formation conditions using the radiation-sensitive resin composition, the acid-dissociating group of the structural unit (III) is not substantially dissociated, and the radiation-sensitive radiation is suppressed in the unexposed portion. The function of diffusion of acid generated by the radioactive acid generator (I). The radiosensitive acid generator having this second function is called a radiosensitive acid generator (II). It can be said that the acid generated by the self-induced radioactive acid generator (II) is a relatively weak acid (an acid with a large pKa) compared with the acid generated by the self-induced radioactive acid generator (I). Whether the radioactive acid generator functions as the radioactive acid generator (I) or the radioactive acid generator (II) is determined by the structural unit (III) of the first resin and the second resin. It is determined by the energy required for dissociation of the acid-dissociable group and the thermal energy conditions provided when using the radiation-sensitive resin composition to form a pattern. The radiation-sensitive acid generator in the radiation-sensitive resin composition may be contained in a form in which it exists alone as a compound (free from the polymer), a form in which it is incorporated as a part of the polymer, or a form in which it is incorporated as a part of the polymer. These two forms may be present, but the form existing alone as a compound is preferred.

When the radiation-sensitive resin composition contains the radiation-sensitive acid generator (I), the polarity of the resin in the exposed part is increased, and when the resin in the exposed part is developed with an alkaline aqueous solution, it is Solubility, on the other hand, is poorly soluble with respect to a developer in the case of organic solvent development.

By containing the radiation-sensitive acid generator (II), the radiation-sensitive resin composition can form a resist pattern with better pattern developability and LWR performance.

Examples of the radiation-sensitive acid generator include onium salt compounds, sulfonimide compounds, halogen-containing compounds, and diazoketone compounds. Examples of onium salt compounds include sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, and pyridinium salts. Among these, strontium salt and iodine salt are preferred.

Examples of acids generated by exposure include those that generate sulfonic acid, carboxylic acid, and sulfonyl imine by exposure. Examples of such acids include: (1) Compounds in which the carbon atom adjacent to the sulfo group is substituted with more than one fluorine atom or fluorinated hydrocarbon group, (2) Compounds in which the carbon atoms adjacent to the sulfo group are not substituted by fluorine atoms or fluorinated hydrocarbon groups. Examples of carboxylic acids generated by exposure include: (3) Compounds in which the carbon atom adjacent to the carboxyl group is substituted with one or more fluorine atoms or fluorinated hydrocarbon groups, (4) Compounds in which the carbon atoms adjacent to the carboxyl group are not substituted by fluorine atoms or fluorinated hydrocarbon groups. Among these, as the radiosensitive acid generator (I), one equivalent to the above (1) is preferred, and one having a cyclic structure is particularly preferred. The radiation-sensitive acid generator (II) is preferably one equivalent to (2), (3) or (4), and particularly preferably one equivalent to (2) or (4).

These radiosensitive acid generators may be used alone, or two or more types may be used in combination. The lower limit of the content of the radiation-sensitive acid generator (I) is preferably 2 parts by mass and more preferably 5 parts by mass based on 100 parts by mass of the base resin from the viewpoint of ensuring sensitivity and developability as a resist. parts by mass, preferably 8 parts by mass. The upper limit of the content of the radiosensitive acid generator (I) is preferably 30 parts by mass, more preferably 25 parts by mass, based on 100 parts by mass of the base resin, from the viewpoint of ensuring transparency to radiation. The optimal amount is 20 parts by mass.

＜Acid diffusion control agent＞ The radiation-sensitive resin composition may also contain an acid diffusion control agent if necessary. As the acid diffusion control agent, the radiosensitive acid generator (II) among the radiosensitive acid generators can be preferably used. The acid diffusion control agent has the effect of controlling the diffusion phenomenon of the acid generated by the radioactive acid generator by exposure in the resist film and suppressing undesirable chemical reactions in the non-exposed area. In addition, the storage stability of the obtained radiation-sensitive resin composition is improved. Furthermore, the resolution of the resist pattern is further improved, and changes in the line width of the resist pattern caused by changes in the standing time from exposure to development can be suppressed, and radiation sensitivity with excellent process stability can be obtained. Resin composition.

Examples of other acid diffusion control agents include nitrogen-containing compounds having one to three nitrogen atoms in the same molecule, amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like. As these nitrogen-containing organic compounds, compounds having an acid-dissociating group can also be used.

The lower limit of the content of the acid diffusion control agent is preferably 0.5 parts by mass, more preferably 1 part by mass, and still more preferably 1.5 parts by mass based on 100 parts by mass of the total radioactive acid generator. The upper limit of the content is preferably 20 parts by mass, more preferably 10 parts by mass, and still more preferably 5 parts by mass.

By setting the content of the acid diffusion control agent within the above range, the lithographic performance of the radiation-sensitive resin composition can be further improved. The radiation-sensitive resin composition may contain one or more acid diffusion control agents.

＜Solvent＞ The radiation-sensitive resin composition contains a solvent. The solvent is not particularly limited as long as it is a solvent that can dissolve or disperse at least the first resin, optional second resin, radiation-sensitive acid generator, acid diffusion control agent, and the like.

Examples of the solvent include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, hydrocarbon-based solvents, and the like.

Examples of alcohol-based solvents include: Isopropyl alcohol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol , diacetone alcohol and other monoalcohol solvents with 1 to 18 carbon atoms; Ethylene glycol, 1,2-propanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol, etc. Carbon number 2 ~18 polyol solvent; Polyol partial ether solvents, etc., are obtained by etherifying part of the hydroxyl groups of the polyol solvent.

Examples of ether solvents include: Dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether; Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran; Diphenyl ether, anisole (methyl phenyl ether) and other ether solvents containing aromatic rings; Polyol ether solvents obtained by etherifying the hydroxyl groups of the polyol solvent.

Examples of ketone solvents include chain ketone solvents such as acetone, methyl ethyl ketone, and methyl-isobutyl ketone; Cyclic ketone solvents such as cyclopentanone, cyclohexanone, and methylcyclohexanone; 2,4-pentanedione, acetonylacetone, acetophenone, etc.

Examples of amide solvents include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylethyl Chain amide solvents such as amide and N-methylpropylamine.

Examples of ester solvents include: Monocarboxylate solvents such as n-butyl acetate and ethyl lactate; Polyol partial ether acetate solvents such as diethylene glycol mono-n-butyl ether acetate, propylene glycol monomethyl ether acetate, and dipropylene glycol monomethyl ether acetate; Lactone solvents such as γ-butyrolactone and valerolactone; Carbonate solvents such as diethyl carbonate, ethyl carbonate, propyl carbonate, etc.; Polycarboxylic acid diester solvents such as propylene glycol diacetate, methoxytriethylene glycol acetate, diethyl oxalate, ethyl acetate, ethyl lactate, and diethyl phthalate.

Examples of hydrocarbon solvents include: Aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; Aromatic hydrocarbon solvents such as benzene, toluene, diisopropylbenzene, n-pentylnaphthalene, etc.

Among these, ester-based solvents, ether-based solvents, and ketone-based solvents are preferred, and polyol partial ether acetate-based solvents, polyol ether-based solvents, polycarboxylic acid diester-based solvents, and cyclic ketone-based solvents are more preferred. The solvent and the lactone solvent are preferably propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, cyclohexanone, and γ-butyrolactone. The radiation-sensitive resin composition may also contain one or more than two solvents.

＜Other optional ingredients＞ The radiation-sensitive resin composition may contain other arbitrary components in addition to the above-mentioned components. Examples of the other optional components include cross-linking agents, localization accelerators, surfactants, alicyclic skeleton-containing compounds, sensitizers, and the like. These other arbitrary components may be used individually by 1 type or in combination of 2 or more types.

<Preparation method of radiation-sensitive resin composition> The radiation-sensitive resin composition can be prepared, for example, by mixing a first resin and optionally a second resin, a radiation-sensitive acid generator, an acid diffusion control agent, and a solvent in a prescribed ratio. The radiation-sensitive resin composition is preferably filtered after mixing, for example, using a filter with a pore size of approximately 0.05 μm to 0.2 μm. The solid content concentration of the radiation-sensitive resin composition is usually 0.1 mass% to 50 mass%, preferably 0.5 mass% to 30 mass%, and more preferably 1 mass% to 20 mass%.

＜Pattern formation method＞ A pattern forming method according to an embodiment of the present invention includes: The step (1) of directly or indirectly coating the radiation-sensitive resin composition on a substrate to form a resist film (hereinafter, also referred to as the "resist film forming step"); The step (2) of exposing the resist film (hereinafter also referred to as the "exposure step"); and The step (3) of developing the exposed resist film (hereinafter also referred to as the "development step").

According to the resist pattern forming method, a high-quality resist pattern can be efficiently formed by using the radiation-sensitive resin composition that is excellent in sensitivity, LWR performance, storage stability, and development defect suppression. . Each step is explained below.

[Resist film formation step] In this step (the step (1)), the radiation-sensitive resin composition is used to form a resist film. Examples of the substrate on which the resist film is formed include conventionally known ones such as silicon wafers, silicon dioxide, and aluminum-coated wafers. In addition, an organic or inorganic antireflection film disclosed in Japanese Patent Application Publication No. 6-12452, Japanese Patent Application Publication No. 59-93448, etc. may also be formed on the substrate. Examples of the coating method include spin coating, cast coating, roll coating, and the like. After coating, prebake (PB) can also be performed if necessary to evaporate the solvent in the coating film. The PB temperature is usually 60°C to 140°C, preferably 80°C to 120°C. The PB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds. The film thickness of the resist film to be formed is preferably 10 nm to 1,000 nm, more preferably 10 nm to 500 nm.

The receding contact angle of the resist film after prebaking is preferably 70° or more, more preferably 72° or more, and still more preferably 74° or more. The method for measuring the receding contact angle is as described in the Examples.

In the case of liquid immersion exposure, regardless of the presence or absence of water-repellent polymer additives such as the first resin in the radiation-sensitive resin composition, for the purpose of avoiding direct contact between the liquid immersion liquid and the resist film, A liquid immersion protective film that is insoluble in the liquid immersion liquid may be provided on the formed resist film. As the protective film for liquid immersion, a solvent-releasable protective film that is peeled off by a solvent before the development step (for example, refer to Japanese Patent Application Laid-Open No. 2006-227632) or a developer-releasable protective film that is peeled off simultaneously with the development in the development step can also be used. Any type of protective film (for example, see WO2005-069076 and WO2006-035790). Among them, from the viewpoint of productivity, it is preferable to use a developer-releasable type liquid immersion protective film.

In addition, when performing the exposure step as the next step using radiation with a wavelength of 50 nm or less, it is preferable to use the structural unit (III), the structural unit (VI), and the optional structural unit (V). resin as the base resin in the composition.

[Exposure steps] In this step (the step (2)), the resist film formed in the resist film forming step of the step (1) is exposed through a photomask (via a liquid immersion medium such as water as the case may be). Exposure is performed by irradiating radiation. Examples of radiation used for exposure include electromagnetic waves such as visible rays, ultraviolet rays, far ultraviolet rays, EUV (extreme ultraviolet rays), X-rays, and gamma rays; and charged particle beams such as electron beams and alpha rays, etc., depending on the line width of the target pattern. . Among these, far ultraviolet, electron beam, and EUV are preferred, and ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), electron beam, and EUV are more preferred, and further preferred positions are Next-generation exposure technology of electron beams and EUV with wavelengths below 50 nm.

When exposure is performed by liquid immersion exposure, examples of the liquid immersion liquid used include water, fluorine-based inert liquid, and the like. The immersion liquid is preferably a liquid that is transparent to the exposure wavelength and has a temperature coefficient of refractive index as small as possible to suppress the deformation of the optical image projected onto the film to a minimum, especially when the exposure light source is an ArF excimer laser. In the case of irradiating light (wavelength 193 nm), based on the above-mentioned viewpoints, it is preferable to use water in terms of ease of acquisition, ease of operation, etc. When using water, an additive that reduces the surface tension of water and increases the interfacial active force may be added in a slight proportion. The additive is preferably one that does not dissolve the resist film on the wafer and has negligible influence on the optical coating on the lower surface of the lens. As the water used, distilled water is preferred.

Preferably, a post-exposure bake (PEB) is performed after the exposure, so that the acid generated by the self-induced radioactive acid generator by exposure is used in the exposed portion of the resist film. Promotes the dissociation of acid-dissociating groups contained in resins and the like. The PEB causes a difference in solubility to the developer between the exposed portion and the unexposed portion. The PEB temperature is usually 50°C to 180°C, preferably 80°C to 130°C. The PEB time is usually 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.

[Development step] In this step (the step (3)), the resist film exposed in the exposure step of the step (2) is developed. Thereby, a predetermined resist pattern can be formed. Generally speaking, after development, the eluent such as water or alcohol is used for cleaning and drying.

In the case of alkali development, examples of the developer used for the development include solutions in which sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, etc. are dissolved. methylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethyl ammonium hydroxide (TMAH), Pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, 1,5-diazabicyclo-[4.3.0]-5-nonene and other bases an alkaline aqueous solution of at least one kind of organic compound. Among these, a TMAH aqueous solution is preferred, and a 2.38 mass% TMAH aqueous solution is more preferred.

In the case of organic solvent development, organic solvents such as hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, and alcohol solvents, or solvents containing organic solvents can be used. Examples of the organic solvent include one, two or more solvents listed as solvents for the radiation-sensitive resin composition, and the like. Among these, ether solvents, ester solvents, and ketone solvents are preferred. As the ether solvent, a glycol ether solvent is preferred, and ethylene glycol monomethyl ether and propylene glycol monomethyl ether are more preferred. As the ester solvent, an acetate solvent is preferred, and n-butyl acetate and amyl acetate are more preferred. As the ketone solvent, a chain ketone is preferred, and 2-heptanone is more preferred. The content of the organic solvent in the developer is preferably 80 mass% or more, more preferably 90 mass% or more, further preferably 95 mass% or more, and particularly preferably 99 mass% or more. Examples of components other than the organic solvent in the developer include water, silicone oil, and the like.

As mentioned above, the developer may be either an alkaline developer or an organic solvent developer. Preferably, the developer contains an alkaline aqueous solution, and the obtained pattern is a positive pattern.

Examples of the development method include: a method in which the substrate is immersed in a tank filled with a developer for a fixed period of time (immersion method); a method in which the developer is deposited on the surface of the substrate using surface tension and left to stand for a fixed period of time to develop (coating method). puddle method); a method of spraying a developer onto the surface of a substrate (spray method); a method of continuously spraying the developer onto a substrate rotating at a fixed speed while scanning the developer discharge nozzle at a fixed speed (dynamic distribution method) wait. [Example]

Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited to these Examples. Methods for measuring various physical property values are shown below.

[Weight average molecular weight (Mw) and number average molecular weight (Mn)] The Mw and Mn of the first resin and the second resin were measured by gel permeation chromatography (GPC) using Tosoh Co., Ltd.'s GPC columns (2 "G2000HXL", 1 "G3000HXL" and "G4000HXL" 1 piece), measured using the following conditions. In addition, the degree of dispersion (Mw/Mn) is calculated based on the measurement results of Mw and Mn. Dissolution solvent: tetrahydrofuran Flow: 1.0 mL/min Sample concentration: 1.0 mass% Sample injection volume: 100 μL Tube string temperature: 40℃ Detector: Differential Refractometer Standard material: monodisperse polystyrene

[ ¹³ C-Nuclear Magnetic Resonance ( ¹³ C-NMR) Analysis] ¹³ C-NMR analysis of the first resin and the second resin was carried out using a nuclear magnetic resonance equipment (JNM-Delta400 of Japan Electronics ^Co. , Ltd. ”) to proceed.

＜Synthesis of [F] compound (monomer)＞ [Synthesis example 1] (Synthesis of compound (F-1)) Compound (F-1) is synthesized according to the following synthesis process.

[Chemical 14]

In a reaction vessel, 20 mmol of 2-hydroxyethyl methacrylate, 20.0 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 1-dimethyl Mix 4.0 mmol of aminopyridine and 50 g of methylene chloride and cool to 0°C. To this solution, 20.0 mmol of pentafluoropropionic acid was added dropwise and stirred for 1 hour. Then, after adding water for dilution, methylene chloride was added for extraction, and the organic layer was separated. The obtained organic layer was washed with a saturated sodium chloride aqueous solution and water in sequence. After drying with sodium sulfate, the solvent was distilled off and purified by column chromatography to obtain compound (F-1) in good yield.

[Synthesis Example 2 to Synthesis Example 9] (Synthesis of Compound (F-2) to Compound (F-9)) Compounds represented by the following formulas (F-2) to (F-9) were synthesized in the same manner as in Synthesis Example 1 except that the raw materials and precursors were appropriately changed (hereinafter, formulas (F-2) to The compound represented by formula (F-9) is described as "compound (F-2)" to "compound (F-9)" or "monomer (F-2)" to "monomer (F-9)" )").

[Chemical 15]

Among the monomers used for synthesis of the first resin and the second resin, monomers other than the monomers (F-1) to (F-9) described above are shown below. In addition, in the following synthesis examples, unless otherwise specified, the mass part refers to the value when the total amount of the monomers used is 100 mass parts, and the mole % refers to the value of the monoliths used. The value when the total mole number of the body is set to 100 mol%.

[Chemical 16]

[Chemical 17]

[Chemical 18]

[Chemical 19]

[Synthesis Example 10] (Synthesis of the Second Resin (A-1)) The monomer (M-1), the monomer (M-2), and the monomer (M-10) were adjusted to a molar ratio of 35 /20/45 (mol%) was dissolved in 2-butanone (200 parts by mass), and azobisisobutyronitrile (AIBN) was added as a starting agent (relative to the total of the monomers used 100 mol% and 5 mol%) to prepare a single volume solution. 2-Butanone (100 parts by mass) was placed in the reaction vessel, and after flushing with nitrogen for 30 minutes, the temperature in the reaction vessel was set to 80°C, and the monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction is completed, the polymerization solution is water-cooled to below 30°C. The cooled polymerization solution was put into methanol (2,000 parts by mass), and the precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with methanol, separated by filtration, and dried at 50° C. for 24 hours to obtain the second resin (A-1) in the form of white powder (yield: 74%). Mw of the second resin (A-1) is 5,800, and Mw/Mn is 1.53. In addition, the results of ¹³ C-NMR analysis showed that the content ratios of each structural unit derived from (M-1), (M-2), and (M-10) were 34.8 mol%, 19.4 mol%, and 45.8 mol%, respectively. Ear%.

[Synthesis Example 11 to Synthesis Example 20] (Synthesis of second resin (A-2) to second resin (A-11)) The second resin (A-2) to the second resin (A-11) were synthesized in the same manner as in Synthesis Example 10, except that the monomers of the types and blending ratios shown in Table 1 below were used. The content ratio (mol%) and physical property values (Mw and Mw/Mn) of each structural unit of the obtained second resin are shown in Table 1 below. In addition, "-" in Table 1 below indicates that the corresponding monomer is not used (the same applies to subsequent tables).

[Table 1] [A] Second resin Provide monomers of structural unit (III) Provides singletons of structural units (IV) Provides singletons of structural units (V) Mw Mw/Mn Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Synthesis example 10 A-1 M-1 35 34.8 M-10 45 45.8 - - - 5800 1.53 M-2 20 19.4 Synthesis Example 11 A-2 M-1 30 29.8 M-9 40 43.0 - - - 6300 1.58 M-2 30 27.2 Synthesis example 12 A-3 M-1 25 25.2 M-11 60 60.4 - - - 6700 1.58 M-3 15 14.4 Synthesis example 13 A-4 M-1 35 34.5 M-8 45 46.1 - - - 6500 1.58 M-3 20 19.4 Synthesis Example 14 A-5 M-1 45 46.0 M-5 45 44.9 - - - 5900 1.56 M-4 10 9.1 Synthesis Example 15 A-6 M-1 40 38.6 M-7 45 48.0 - - - 7700 1.61 M-16 15 13.4 Synthesis Example 16 A-7 M-1 40 39.7 M-12 45 46.1 M-14 15 14.2 5400 1.53 Synthesis Example 17 A-8 M-1 40 39.5 M-6 45 47.4 M-15 15 13.1 5300 1.52 Synthesis example 18 A-9 M-1 30 31.1 M-5 20 21.7 M-14 10 8.1 5200 1.52 M-3 20 18.5 M-11 20 20.6 Synthesis example 19 A-10 M-1 30 31.5 M-6 20 21.1 M-15 10 9.6 6500 1.59 M-16 20 18.1 M-12 20 19.7 Synthesis example 20 A-11 M-16 40 38.7 M-5 30 31.2 - - - 6100 1.55 M-13 30 30.1

[Synthesis Example 21] (Synthesis of the Second Resin (A-12)) The monomer (M-1) and the monomer (M-18) were adjusted to a molar ratio of 50/50 (mol%). It was dissolved in 1-methoxy-2-propanol (200 parts by mass), and AIBN (5 mol%) was added as a starting agent to prepare a monomer solution. 1-Methoxy-2-propanol (100 parts by mass) was put into the reaction vessel, and after flushing with nitrogen for 30 minutes, the temperature in the reaction vessel was set to 80°C, and the single amount was added dropwise over 3 hours while stirring. body solution. The start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction is completed, the polymerization solution is water-cooled to below 30°C. The cooled polymerization solution was put into hexane (2,000 parts by mass), and the precipitated white powder was separated by filtration. The white powder separated by filtration was washed twice with hexane, separated by filtration, and dissolved in 1-methoxy-2-propanol (300 parts by mass). Next, methanol (500 parts by mass), triethylamine (50 parts by mass) and ultrapure water (10 parts by mass) were added, and a hydrolysis reaction was performed at 70° C. for 6 hours while stirring. After the reaction, the residual solvent was distilled off, the solid obtained was dissolved in acetone (100 parts by mass), and added dropwise to water (500 parts by mass) to solidify the resin. The obtained solid was separated by filtration and dried at 50° C. for 13 hours to obtain a white powdery second resin (A-12) (yield: 75%). Mw of the second resin (A-12) is 6,100, and Mw/Mn is 1.49. In addition, the results of ¹³ C-NMR analysis showed that the content ratios of each structural unit derived from (M-1) and (M-18) were 49.2 mol% and 50.8 mol% respectively.

[Synthesis Example 22 to Synthesis Example 24] (Synthesis of the second resin (A-13) to the second resin (A-15)) The second resin (A-13) to the second resin (A-15) were synthesized in the same manner as in Synthesis Example 21, except that the monomers of the types and blending ratios shown in Table 2 below were used. The content ratio (mol%) and physical property values (Mw and Mw/Mn) of each structural unit of the obtained resin are shown in Table 2 below.

[Table 2] [A] Second resin Provide monomers of structural unit (III) Provides singletons of structural units (V) Provides singletons of structural units (VI) Mw Mw/Mn Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Synthesis Example 21 A-12 M-1 50 49.2 - - - M-18 50 50.8 6100 1.49 Synthesis example 22 A-13 M-3 40 38.1 M-14 20 19.5 M-19 40 42.4 6300 1.51 Synthesis example 23 A-14 M-2 45 43.6 M-15 10 13.2 M-18 45 43.2 6500 1.54 Synthesis example 24 A-15 M-16 50 47.2 M-14 25 25.1 M-19 25 27.7 6400 1.51

[Synthesis Example 25] (Synthesis of the first resin (E-1)) The monomer (F-1), the monomer (fa-4), and the monomer (M-1) were adjusted to a molar ratio of 45 /45/10 (mol%) was dissolved in 2-butanone (200 parts by mass), and AIBN (2 mol%) was added as a starting agent to prepare a monomer solution. 2-Butanone (100 parts by mass) was placed in the reaction vessel, and after flushing with nitrogen for 30 minutes, the temperature in the reaction vessel was set to 80°C, and the monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was set as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction is completed, the polymerization solution is water-cooled to below 30°C. After replacing the solvent with acetonitrile (400 parts by mass), hexane (100 parts by mass) was added, stirred, and the acetonitrile layer was recovered. This operation was repeated three times. By replacing the solvent with propylene glycol monomethyl ether acetate, a solution of the first resin (E-1) was obtained (yield: 69%). Mw of the first resin (E-1) is 10,600, and Mw/Mn is 1.54. In addition, the results of ¹³ C-NMR analysis showed that the content ratios of each structural unit derived from (F-1), (fa-4), and (M-1) were 44.6 mol%, 45.8 mol%, and 9.6 mol%, respectively. Ear%.

[Synthesis Example 26 to Synthesis Example 83] (Synthesis of first resin (E-2) to first resin (E-47) and first resin (CE-1) to first resin (CE-12)) The first resin (E-2) to the first resin (E-2) were synthesized in the same manner as in Synthesis Example 25, except that the types, the blending ratio of the monomers, and the blending ratio of the polymerization initiator shown in the following Tables 3 and 4 were changed. One resin (E-47) and first resin (CE-1) ~ first resin (CE-12). The content ratio (mol%) and physical property values (Mw and Mw/Mn) of each structural unit of the obtained first resin are shown in Table 3 and Table 4 below.

[table 3] [E]First resin Provides singletons of structural units (I) Providing monomers of structural units (II) Provide monomers of structural unit (III) Mw Mw/Mn Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Synthesis example 25 E-1 F-1 45 44.6 fa-4 45 45.8 M-1 10 9.6 10600 1.54 Synthesis Example 26 E-2 F-1 30 30.9 fa-5 35 35.2 M-1 35 33.9 12100 1.55 Synthesis Example 27 E-3 F-1 40 40.1 fa-6 20 21.2 M-1 40 38.7 11100 1.59 Synthesis example 28 E-4 F-1 40 40.4 fa-7 45 44.2 M-1 15 15.4 11200 1.52 Synthesis Example 29 E-5 F-1 45 44.1 fa-8 45 46.0 M-1 10 9.9 11300 1.49 Synthesis example 30 E-6 F-1 20 20.6 fa-9 40 40.8 M-1 40 38.6 14200 1.59 Synthesis Example 31 E-7 F-1 35 34.4 fb-1 30 31.2 M-1 35 34.4 14400 1.46 Synthesis example 32 E-8 F-1 35 35.3 fb-2 35 34.4 M-1 30 30.3 13200 1.59 Synthesis example 33 E-9 F-1 35 35.5 fb-3 30 29.1 M-1 35 35.4 12100 1.54 Synthesis example 34 E-10 F-1 40 40.8 fb-4 45 45.0 M-1 15 14.2 11000 1.58 Synthesis Example 35 E-11 F-1 30 30.6 fb-5 20 20.8 M-1 50 48.6 10900 1.54 Synthesis Example 36 E-12 F-1 45 44.8 fb-6 45 45.4 M-1 10 9.8 10500 1.52 Synthesis Example 37 E-13 F-1 35 34.9 fb-7 35 35.2 M-1 30 29.9 10400 1.51 Synthesis example 38 E-14 F-1 20 20.1 fb-8 20 19.8 M-1 60 60.1 11400 1.50 Synthesis Example 39 E-15 F-1 45 45.2 fb-9 40 39.6 M-1 15 15.2 12100 1.49 Synthesis Example 40 E-16 F-1 35 35.1 fb-10 30 29.8 M-1 35 35.1 12200 1.44 Synthesis Example 41 E-17 F-1 35 34.4 fb-11 30 31.2 M-1 35 34.4 11700 1.54 Synthesis Example 42 E-18 F-1 30 30.7 fb-12 40 40.6 M-1 30 28.7 11800 1.54 Synthesis Example 43 E-19 F-1 30 30.2 fb-13 40 40.2 M-1 30 29.6 11600 1.54 Synthesis Example 44 E-20 F-1 30 30.1 fc-1 40 40.5 M-1 30 29.4 11500 1.53 Synthesis Example 45 E-21 F-1 30 29.9 fc-2 40 39.9 M-1 30 30.2 11600 1.55 Synthesis Example 46 E-22 F-1 30 30.4 fc-3 20 19.8 M-1 50 49.8 10900 1.54 Synthesis Example 47 E-23 F-1 30 30.0 fc-4 40 39.6 M-1 30 30.4 10500 1.52 Synthesis Example 48 E-24 F-1 30 30.3 fc-5 30 29.8 M-1 40 39.9 10400 1.51 Synthesis Example 49 E-25 F-2 35 34.9 fb-1 30 30.2 M-1 35 34.9 9800 1.60 Synthesis example 50 E-26 F-3 35 35.1 fb-1 30 29.8 M-1 35 35.1 9900 1.43 Synthesis Example 51 E-27 F-4 35 35.6 fb-1 30 28.8 M-1 35 35.6 11200 1.52 Synthesis example 52 E-28 F-5 35 34.6 fb-1 30 30.8 M-1 35 34.6 12100 1.55 Synthesis example 53 E-29 F-6 35 35.2 fb-1 30 29.6 M-1 35 35.2 11000 1.49 Synthesis example 54 E-30 F-7 35 35.5 fb-1 30 29.1 M-1 35 35.4 9800 1.43 Synthesis Example 55 E-31 F-8 35 35.1 fb-1 30 29.8 M-1 35 35.1 9500 1.47 Synthesis Example 56 E-32 F-9 35 34.8 fb-1 30 30.4 M-1 35 34.8 11500 1.49 Synthesis Example 57 E-33 F-1 45 45.2 fb-1 40 39.6 M-2 15 15.2 11000 1.48 Synthesis Example 58 E-34 F-1 45 45.4 fb-1 40 40.1 M-3 15 14.5 10900 1.46 Synthesis Example 59 E-35 F-1 20 20.6 fb-1 40 39.6 M-4 40 39.8 14400 1.46 Synthesis Example 60 E-36 F-1 35 34.4 fb-1 40 40.1 M-16 25 25.5 13200 1.59 Synthesis Example 61 E-37 F-1 35 35.3 fb-1 30 29.8 M-17 35 34.9 12100 1.54 Synthesis example 62 E-38 F-1 35 35.5 fb-1 30 28.8 M-20 35 35.7 11000 1.58 Synthesis example 63 E-39 F-1 40 40.8 fb-1 30 30.8 M-21 30 28.4 10900 1.54 Synthesis Example 64 E-40 F-1 30 30.6 fb-1 30 29.6 M-22 40 39.8 10000 1.60 Synthesis example 65 E-41 F-1 45 45.2 fb-1 30 28.8 M-23 25 26.0 12200 1.55 Synthesis example 66 E-42 F-1 45 44.5 fb-1 40 40.3 M-24 15 15.2 10800 1.47 Synthesis Example 67 E-43 F-1 40 41.2 fa-9 20 19.3 M-4 10 10.0 11100 1.50 fb-10 20 20.0 M-17 10 9.5 Synthesis example 68 E-44 F-1 40 42.4 fb-4 20 20.2 M-20 10 11.0 10700 1.54 fc-5 20 19.3 M-22 10 7.1 Synthesis example 69 E-45 F-1 40 42.0 fb-7 20 20.4 M-21 10 8.9 7200 1.65 fc-3 20 19.5 M-16 10 9.2 Synthesis Example 70 E-46 F-1 40 40.2 fb-4 20 19.7 M-2 10 8.7 3600 1.76 fb-12 20 20.3 M-3 10 11.1 Synthesis Example 71 E-47 F-1 40 40.4 fa-9 20 19.4 M-3 10 9.2 8200 1.77 fc-6 20 21.2 M-16 10 9.8

[Table 4] [E]First resin Provides singletons of structural units (I) Providing monomers of structural units (II) Provide monomers of structural unit (III) Mw Mw/Mn Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Kind Blending ratio (mol%) Structural unit content ratio (mol%) Synthesis Example 72 CE-1 F-1 45 44.1 fb-1 55 55.9 - - - 11100 1.51 Synthesis Example 73 CE-2 F-1 45 46.0 fa-4 55 54.0 - - - 12300 1.60 Synthesis Example 74 CE-3 F-1 45 45.7 fa-9 55 54.3 - - - 12100 1.55 Synthesis Example 75 CE-4 - - - fb-1 45 44.4 M-1 55 55.6 10500 1.49 Synthesis Example 76 CE-5 F-1 60 59.8 - - - M-1 40 40.2 11200 1.51 Synthesis Example 77 CE-6 F-1 60 60.6 - - - M-16 40 39.4 11000 1.56 Synthesis Example 78 CE-7 F-1 100 100 - - - - - - 10300 1.55 Synthesis Example 79 CE-8 - - - fb-1 100 100 - - - 11000 1.58 Synthesis example 80 CE-9 - - - fa-1 30 31.2 M-1 10 9.8 11200 1.48 fb-1 60 59.0 Synthesis example 81 CE-10 - - - fa-2 30 29.6 M-1 10 11.1 10200 1.49 fb-1 60 59.3 Synthesis example 82 CE-11 - - - fa-3 30 29.8 M-1 10 10.0 11100 1.51 fb-1 60 60.2 Synthesis example 83 CE-12 - - - fb-5 30 31.7 M-1 10 9.1 10500 1.53 fb-1 60 59.2

<Preparation of radiation-sensitive resin composition> Components other than [A] the second resin and [E] the first resin used in the preparation of each radiation-sensitive resin composition are shown below.

[[B]Radiosensitive acid generator] B-1 to B-8: Compounds represented by the following formulas (B-1) to formula (B-8)

[Chemistry 20]

[[C]Acid diffusion control agent] C-1 to C-7: Compounds represented by the following formulas (C-1) to formula (C-7)

[Chemistry 21]

[[D]solvent] D-1: Propylene glycol monomethyl ether acetate D-2: Propylene glycol monomethyl ether D-3: γ-butyrolactone D-4: Ethyl lactate

[Preparation of positive radiation sensitive resin composition for ArF exposure] [Example 1] 100 parts by mass of (A-1) as [A] second resin, 10.0 parts by mass of (B-1) as [B] radiation-sensitive acid generator, (C-) as [C] acid diffusion control agent 1) 2.0 parts by mass, (E-1) 5.0 parts by mass (solid content) as [E] first resin, and (D-1)/(D-2)/(D-3) as [D] solvent ), and filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-1).

[Example 2 to Example 75 and Comparative Example 1 to Comparative Example 12] Radiation-sensitive resin composition (J-2) - radiation-sensitive resin were prepared in the same manner as in Example 1, except that the types and contents of each component shown in Table 5-1 and Table 5-2 below were used. Composition (J-75) and radiation-sensitive resin composition (CJ-1) to radiation-sensitive resin composition (CJ-12).

[Table 5-1] Radiation sensitive resin composition [A] Second resin [B]Radiosensitive acid generator [C]Acid diffusion control agent [E]First resin [D]Solvent Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Example 1 J-1 A-1 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 2 J-2 A-1 100 B-1 10.0 C-1 2.0 E-2 5.0 D-1/D-2/D-3 2240/960/30 Example 3 J-3 A-1 100 B-1 10.0 C-1 2.0 E-3 5.0 D-1/D-2/D-3 2240/960/30 Example 4 J-4 A-1 100 B-1 10.0 C-1 2.0 E-4 5.0 D-1/D-2/D-3 2240/960/30 Example 5 J-5 A-1 100 B-1 10.0 C-1 2.0 E-5 5.0 D-1/D-2/D-3 2240/960/30 Example 6 J-6 A-1 100 B-1 10.0 C-1 2.0 E-6 5.0 D-1/D-2/D-3 2240/960/30 Example 7 J-7 A-1 100 B-1 10.0 C-1 2.0 E-7 5.0 D-1/D-2/D-3 2240/960/30 Example 8 J-8 A-1 100 B-1 10.0 C-1 2.0 E-8 5.0 D-1/D-2/D-3 2240/960/30 Example 9 J-9 A-1 100 B-1 10.0 C-1 2.0 E-9 5.0 D-1/D-2/D-3 2240/960/30 Example 10 J-10 A-1 100 B-1 10.0 C-1 2.0 E-10 5.0 D-1/D-2/D-3 2240/960/30 Example 11 J-11 A-1 100 B-1 10.0 C-1 2.0 E-11 5.0 D-1/D-2/D-3 2240/960/30 Example 12 J-12 A-1 100 B-1 10.0 C-1 2.0 E-12 5.0 D-1/D-2/D-3 2240/960/30 Example 13 J-13 A-1 100 B-1 10.0 C-1 2.0 E-13 5.0 D-1/D-2/D-3 2240/960/30 Example 14 J-14 A-1 100 B-1 10.0 C-1 2.0 E-14 5.0 D-1/D-2/D-3 2240/960/30 Example 15 J-15 A-1 100 B-1 10.0 C-1 2.0 E-15 5.0 D-1/D-2/D-3 2240/960/30 Example 16 J-16 A-1 100 B-1 10.0 C-1 2.0 E-16 5.0 D-1/D-2/D-3 2240/960/30 Example 17 J-17 A-1 100 B-1 10.0 C-1 2.0 E-17 5.0 D-1/D-2/D-3 2240/960/30 Example 18 J-18 A-1 100 B-1 10.0 C-1 2.0 E-18 5.0 D-1/D-2/D-3 2240/960/30 Example 19 J-19 A-1 100 B-1 10.0 C-1 2.0 E-19 5.0 D-1/D-2/D-3 2240/960/30 Example 20 J-20 A-1 100 B-1 10.0 C-1 2.0 E-20 5.0 D-1/D-2/D-3 2240/960/30 Example 21 J-21 A-1 100 B-1 10.0 C-1 2.0 E-21 5.0 D-1/D-2/D-3 2240/960/30 Example 22 J-22 A-1 100 B-1 10.0 C-1 2.0 E-22 5.0 D-1/D-2/D-3 2240/960/30 Example 23 J-23 A-1 100 B-1 10.0 C-1 2.0 E-23 5.0 D-1/D-2/D-3 2240/960/30 Example 24 J-24 A-1 100 B-1 10.0 C-1 2.0 E-24 5.0 D-1/D-2/D-3 2240/960/30 Example 25 J-25 A-1 100 B-1 10.0 C-1 2.0 E-25 5.0 D-1/D-2/D-3 2240/960/30 Example 26 J-26 A-1 100 B-1 10.0 C-1 2.0 E-26 5.0 D-1/D-2/D-3 2240/960/30 Example 27 J-27 A-1 100 B-1 10.0 C-1 2.0 E-27 5.0 D-1/D-2/D-3 2240/960/30 Example 28 J-28 A-1 100 B-1 10.0 C-1 2.0 E-28 5.0 D-1/D-2/D-3 2240/960/30 Example 29 J-29 A-1 100 B-1 10.0 C-1 2.0 E-29 5.0 D-1/D-2/D-3 2240/960/30 Example 30 J-30 A-1 100 B-1 10.0 C-1 2.0 E-30 5.0 D-1/D-2/D-3 2240/960/30 Example 31 J-31 A-1 100 B-1 10.0 C-1 2.0 E-31 5.0 D-1/D-2/D-3 2240/960/30 Example 32 J-32 A-1 100 B-1 10.0 C-1 2.0 E-32 5.0 D-1/D-2/D-3 2240/960/30 Example 33 J-33 A-1 100 B-1 10.0 C-1 2.0 E-33 5.0 D-1/D-2/D-3 2240/960/30 Example 34 J-34 A-1 100 B-1 10.0 C-1 2.0 E-34 5.0 D-1/D-2/D-3 2240/960/30 Example 35 J-35 A-1 100 B-1 10.0 C-1 2.0 E-35 5.0 D-1/D-2/D-3 2240/960/30 Example 36 J-36 A-1 100 B-1 10.0 C-1 2.0 E-36 5.0 D-1/D-2/D-3 2240/960/30 Example 37 J-37 A-1 100 B-1 10.0 C-1 2.0 E-37 5.0 D-1/D-2/D-3 2240/960/30 Example 38 J-38 A-1 100 B-1 10.0 C-1 2.0 E-38 5.0 D-1/D-2/D-3 2240/960/30 Example 39 J-39 A-1 100 B-1 10.0 C-1 2.0 E-39 5.0 D-1/D-2/D-3 2240/960/30 Example 40 J-40 A-1 100 B-1 10.0 C-1 2.0 E-40 5.0 D-1/D-2/D-3 2240/960/30 Example 41 J-41 A-1 100 B-1 10.0 C-1 2.0 E-41 5.0 D-1/D-2/D-3 2240/960/30 Example 42 J-42 A-1 100 B-1 10.0 C-1 2.0 E-42 5.0 D-1/D-2/D-3 2240/960/30 Example 43 J-43 A-1 100 B-1 10.0 C-1 2.0 E-43 5.0 D-1/D-2/D-3 2240/960/30 Example 44 J-44 A-1 100 B-1 10.0 C-1 2.0 E-44 5.0 D-1/D-2/D-3 2240/960/30 Example 45 J-45 A-1 100 B-1 10.0 C-1 2.0 E-45 5.0 D-1/D-2/D-3 2240/960/30 Example 46 J-46 A-1 100 B-1 10.0 C-1 2.0 E-46 5.0 D-1/D-2/D-3 2240/960/30 Example 47 J-47 A-1 100 B-1 10.0 C-1 2.0 E-47 5.0 D-1/D-2/D-3 2240/960/30 Example 48 J-48 A-2 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 49 J-49 A-3 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 50 J-50 A-4 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 51 J-51 A-5 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 52 J-52 A-6 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 53 J-53 A-7 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 54 J-54 A-8 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 55 J-55 A-9 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 56 J-56 A-10 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 57 J-57 A-11 100 B-1 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 58 J-58 A-1 100 B-2 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 59 J-59 A-1 100 B-4 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 60 J-60 A-1 100 B-5 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 61 J-61 A-1 100 B-6 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 62 J-62 A-1 100 B-7 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 63 J-63 A-1 100 B-8 10.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 64 J-64 A-1 100 B-1 10.0 C-2 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 65 J-65 A-1 100 B-1 10.0 C-3 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 66 J-66 A-1 100 B-1 10.0 C-4 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 67 J-67 A-1 100 B-1 10.0 C-5 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 68 J-68 A-1 100 B-1 10.0 C-6 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 69 J-69 A-1 100 B-1 10.0 C-7 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 70 J-70 A-1 100 B-1 10.0 C-1 2.0 E-1 2.5 D-1/D-2/D-3 2240/960/30 Example 71 J-71 A-1 100 B-1 10.0 C-1 2.0 E-1 10.0 D-1/D-2/D-3 2240/960/30 Example 72 J-72 A-1 100 B-1 10.0 C-1 2.0 E-1 15.0 D-1/D-2/D-3 2240/960/30 Example 73 J-73 A-1 100 B-2/B-3 5.0/5.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 74 J-74 A-1 100 B-4/B-5 5.0/5.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30 Example 75 J-75 A-1 100 B-6/B-8 5.0/5.0 C-1 2.0 E-1 5.0 D-1/D-2/D-3 2240/960/30

[Table 5-2] Radiation sensitive resin composition [A] Second resin [B]Radiosensitive acid generator [C]Acid diffusion control agent [E]First resin [D]Solvent Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Comparative example 1 CJ-1 A-1 100 B-1 10.0 C-1 2.0 CE-1 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 2 CJ-2 A-1 100 B-1 10.0 C-1 2.0 CE-2 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 3 CJ-3 A-1 100 B-1 10.0 C-1 2.0 CE-3 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 4 CJ-4 A-1 100 B-1 10.0 C-1 2.0 CE-4 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 5 CJ-5 A-1 100 B-1 10.0 C-1 2.0 CE-5 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 6 CJ-6 A-1 100 B-1 10.0 C-1 2.0 CE-6 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 7 CJ-7 A-1 100 B-1 10.0 C-1 2.0 CE-7 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 8 CJ-8 A-1 100 B-1 10.0 C-1 2.0 CE-8 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 9 CJ-9 A-1 100 B-1 10.0 C-1 2.0 CE-9 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 10 CJ-10 A-1 100 B-1 10.0 C-1 2.0 CE-10 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 11 CJ-11 A-1 100 B-1 10.0 C-1 2.0 CE-11 5.0 D-1/D-2/D-3 2240/960/30 Comparative example 12 CJ-12 A-1 100 B-1 10.0 C-1 2.0 CE-12 5.0 D-1/D-2/D-3 2240/960/30

<Formation of resist pattern using positive radiation-sensitive resin composition for ArF exposure> Using a spin coater (Tokyo Electron Co., Ltd.'s "CLEAN TRACK ACT12"), the composition for forming the lower antireflection film (Brewer Science's "ARC66") was applied to 12 After being mounted on a 205-inch silicon wafer, it is heated at 205°C for 60 seconds to form a lower anti-reflective film with an average thickness of 100 nm. The prepared positive radiation-sensitive resin composition (J-1) for ArF exposure was coated on the lower anti-reflective film using the spin coater, and pre-baked at 100°C for 60 seconds ( PB). Thereafter, the film was cooled at 23° C. for 30 seconds to form a resist film with an average thickness of 90 nm. Secondly, an ArF excimer laser liquid immersion exposure device (ASML's "TWINSCAN XT-1900i") was used, with numerical aperture (NA) = 1.35 and dipole (σ = 0.9/0.7) optics. Under the conditions, the resist film is exposed with a mask pattern separated by 40 nm lines and spaces. After exposure, perform a post-exposure bake (PEB) at 100°C for 60 seconds. Thereafter, a 2.38% by mass TMAH aqueous solution was used as an alkaline developer to perform alkali development on the resist film. After development, the resist film was washed with water and dried to form a positive resist pattern ( 40 nm line and space pattern).

＜Evaluation＞ For the resist pattern formed using the positive-type radiation-sensitive resin composition for ArF exposure, the sensitivity, LWR performance, storage stability, and number of defects after development were evaluated according to the following method. In addition, regarding the resist film before ArF exposure, the receding contact angle was evaluated according to the following method. These results are shown in the following Table 6-1 and Table 6-2. In addition, a scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies (Co., Ltd.)) was used to measure the length of the resist pattern.

[Sensitivity] In the formation of a resist pattern using the positive-type radiation-sensitive resin composition for ArF exposure, the exposure amount for forming a 40 nm line and space pattern is the optimal exposure amount, and the optimal exposure amount is The quantity is set as sensitivity (mJ/cm ² ). Regarding the sensitivity, a sensitivity of 30 mJ/cm ² or less was evaluated as "good", and a sensitivity exceeding 30 mJ/cm ² was evaluated as "poor".

[LWR performance] The resist pattern was formed by irradiating at the optimal exposure amount determined by the evaluation of the sensitivity and adjusting the mask size to form a 40 nm line and space pattern. Using the scanning electron microscope, the formed resist pattern was observed from the top of the pattern. The variation in line width at a total of 500 locations was measured, and a 3 sigma value was calculated based on the distribution of the measured values. This 3 sigma value was defined as LWR (nm). The smaller the value of LWR, the smaller and better the line roughness is. Regarding the LWR performance, the case where it is 3.0 nm or less is evaluated as "good", and the case where it exceeds 3.0 nm is evaluated as "poor".

[Receding contact angle after prebaking (PB)] In the resist pattern forming method, the resist film before ArF exposure was measured at room temperature of 23°C, relative humidity of 40%, and normal pressure using DSA-10 of KRUS according to the following procedure. Receding contact angle.

After water is discharged from the needle of DSA-10 and a 25 μL water droplet is formed on the resist film, the water droplet is sucked with the needle at a speed of 10 μL/min for 90 seconds, and the contact angle is measured per second (90 times in total). . In this measurement, the average value of the contact angles at a total of 20 positions from the time when the contact angle became stable was calculated and set as the receding contact angle (°) after PB. The case where the receding contact angle after PB was 70° or more was evaluated as "good", and the case where it was less than 70° was evaluated as "poor".

[Storage Stability] After the radiation-sensitive resin composition for ArF exposure was stored at 40° C. for one month, the receding contact angle after PB was evaluated in the same manner as the above method. If the change rate represented by the following formula is 0.5% or less, the evaluation is "A" (extremely good). If it exceeds 0.5% and is 1.0% or less, the evaluation is "B" (good). If it exceeds 1.0%, the evaluation is "B" (good). The evaluation is "C" (poor). Change rate (%) = {(θ ₀ -θ ₁ )/θ ₀ }×100 (θ ₀ is the receding contact angle before storage, θ ₁ is the receding contact angle after one month of storage)

[Number of developing defects] The resist film was exposed at the optimal exposure amount to form a line and space pattern with a line width of 40 nm, which was used as a defect inspection wafer. The number of defects on the defect inspection wafer was measured using a defect inspection device ("KLA2810" manufactured by KLA-Tencor). Defects with a diameter of 50 μm or less are determined to originate from the resist film, and their number is calculated. Regarding the number of defects after development, the case where the number of defects determined to be derived from the resist film was 50 or less was evaluated as "good", and the case where it exceeded 50 was evaluated as "poor".

[Table 6-1] Radiation sensitive resin composition Sensitivity (mJ/cm ² ) LWR (nm) Receding contact angle after PB (°) Storage stability Number of developing defects (number) Example 1 J-1 25 2.5 75 A 6 Example 2 J-2 twenty one 2.3 78 A 1 Example 3 J-3 twenty two 2.4 73 A 2 Example 4 J-4 twenty four 2.5 80 A 0 Example 5 J-5 twenty one 2.7 74 A 3 Example 6 J-6 twenty two 2.5 78 A 1 Example 7 J-7 20 2.2 79 A 0 Example 8 J-8 twenty one 2.2 77 A 4 Example 9 J-9 twenty two 2.3 81 A 3 Example 10 J-10 25 2.4 78 A 6 Example 11 J-11 twenty four 2.2 77 A 4 Example 12 J-12 25 2.4 76 A 7 Example 13 J-13 twenty two 2.3 81 A 8 Example 14 J-14 twenty one 2.6 78 A 5 Example 15 J-15 twenty one 2.8 79 A 3 Example 16 J-16 twenty three 2.2 73 A 1 Example 17 J-17 twenty one 2.6 78 A 2 Example 18 J-18 25 2.2 77 A 10 Example 19 J-19 20 2.5 74 A 3 Example 20 J-20 twenty three 2.3 79 A 5 Example 21 J-21 twenty two 2.7 81 A 1 Example 22 J-22 twenty three 2.7 80 A 0 Example 23 J-23 twenty four 2.8 79 A 1 Example 24 J-24 twenty two 2.7 76 A 0 Example 25 J-25 twenty three 2.8 77 A 5 Example 26 J-26 twenty three 2.8 80 A 6 Example 27 J-27 twenty two 2.6 78 A 3 Example 28 J-28 twenty three 2.7 73 A 7 Example 29 J-29 twenty two 2.5 80 A 8 Example 30 J-30 twenty one 2.7 77 A 9 Example 31 J-31 25 2.6 76 A 3 Example 32 J-32 twenty four 2.6 73 A 5 Example 33 J-33 twenty two 2.5 79 A 7 Example 34 J-34 twenty one 2.5 77 A 3 Example 35 J-35 twenty two 2.7 77 A 7 Example 36 J-36 twenty one 2.4 81 A 3 Example 37 J-37 twenty two 2.4 78 A 2 Example 38 J-38 twenty four 2.3 80 A 4 Example 39 J-39 twenty four 2.7 77 A 6 Example 40 J-40 twenty three 2.6 77 A 8 Example 41 J-41 twenty four 2.6 73 A 5 Example 42 J-42 twenty two 2.5 72 A 4 Example 43 J-43 twenty one 2.7 79 A 3 Example 44 J-44 25 2.6 75 A 2 Example 45 J-45 twenty four 2.6 76 A 1 Example 46 J-46 twenty two 2.5 79 A 6 Example 47 J-47 twenty two 2.5 72 A 32 Example 48 J-48 twenty one 2.5 75 A 8 Example 49 J-49 twenty two 2.2 75 A 0 Example 50 J-50 twenty three 2.2 74 A 9 Example 51 J-51 twenty two 2.3 75 A 8 Example 52 J-52 twenty three 2.4 76 A 7 Example 53 J-53 twenty four 2.8 77 A 5 Example 54 J-54 twenty one 2.8 75 A 7 Example 55 J-55 twenty two 2.6 75 A 9 Example 56 J-56 twenty two 2.7 74 A 4 Example 57 J-57 twenty one 2.5 76 A 3 Example 58 J-58 twenty two 2.7 75 A 2 Example 59 J-59 twenty three 2.6 75 A 1 Example 60 J-60 25 2.6 76 A 3 Example 61 J-61 twenty two 2.5 77 A 6 Example 62 J-62 twenty four 2.5 76 A 3 Example 63 J-63 twenty two 2.7 76 A 4 Example 64 J-64 twenty four 2.4 75 A 3 Example 65 J-65 twenty two 2.4 75 A 7 Example 66 J-66 twenty three 2.3 74 A 1 Example 67 J-67 27 2.5 75 A 3 Example 68 J-68 26 2.6 75 A 7 Example 69 J-69 28 2.8 74 A 5 Example 70 J-70 25 2.5 72 A 11 Example 71 J-71 twenty four 2.7 78 A 9 Example 72 J-72 25 2.7 79 A 15 Example 73 J-73 27 2.2 75 A 5 Example 74 J-74 25 2.5 74 A 8 Example 75 J-75 25 2.3 76 A 13

[Table 6-2] Radiation sensitive resin composition Sensitivity (mJ/cm ² ) LWR (nm) Receding contact angle after PB (°) Storage stability Number of developing defects (number) Comparative example 1 CJ-1 31 3.8 66 A 232 Comparative example 2 CJ-2 32 3.2 62 A 281 Comparative example 3 CJ-3 32 3.4 63 A 251 Comparative example 4 CJ-4 33 2.9 68 A 247 Comparative example 5 CJ-5 31 3.1 62 A 281 Comparative example 6 CJ-6 32 3.2 61 A 233 Comparative example 7 CJ-7 33 3.2 62 A 275 Comparative example 8 CJ-8 32 3.4 62 A 256 Comparative example 9 CJ-9 31 3.8 63 C 410 Comparative example 10 CJ-10 33 2.9 62 A 266 Comparative example 11 CJ-11 32 3.2 66 C 244 Comparative example 12 CJ-12 31 2.8 62 A 210

From the results in Table 6-1 and Table 6-2, it is clear that when the radiation-sensitive resin composition of the Example is used for ArF exposure, the sensitivity, LWR performance, receding contact angle after PB, storage stability, and development The number of defects was good, but the comparative examples were inferior in each characteristic compared with the examples. Therefore, when the radiation-sensitive resin composition of the Example is used for ArF exposure, a resist pattern with high sensitivity and excellent water repellency, storage stability, and defect performance can be formed.

[Preparation of positive radiation-sensitive resin composition for extreme ultraviolet (EUV) exposure] [Example 76] 100 parts by mass of (A-12) as [A] second resin, 15.0 parts by mass of (B-5) as [B] radiation-sensitive acid generator, (C-) as [C] acid diffusion control agent 5) 10.0 parts by mass, 3.0 parts by mass (solid content) of (E-1) as [E] first resin, and 6,110 parts by mass of (D-1)/(D-4) mixed solvent as [D] solvent Mix the components and filter them through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-76).

[Example 77 to Example 91 and Comparative Example 13 to Comparative Example 19] Radiation-sensitive resin composition (J-77) to radiation-sensitive resin composition (J-91) were prepared in the same manner as in Example 76, except that the types and contents of each component shown in Table 7 below were used. and radiation-sensitive resin composition (CJ-13) to radiation-sensitive resin composition (CJ-19).

[Table 7] Radiation sensitive resin composition [A] Second resin [B]Radiosensitive acid generator [C]Acid diffusion control agent [E]First resin [D]Solvent Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Kind Content (mass parts) Example 76 J-76 A-12 100 B-5 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 77 J-77 A-12 100 B-5 15.0 C-5 10.0 E-6 3.0 D-1/D-4 4280/1830 Example 78 J-78 A-12 100 B-5 15.0 C-5 10.0 E-10 3.0 D-1/D-4 4280/1830 Example 79 J-79 A-12 100 B-5 15.0 C-5 10.0 E-22 3.0 D-1/D-4 4280/1830 Example 80 J-80 A-12 100 B-5 15.0 C-5 10.0 E-26 3.0 D-1/D-4 4280/1830 Example 81 J-81 A-12 100 B-5 15.0 C-5 10.0 E-37 3.0 D-1/D-4 4280/1830 Example 82 J-82 A-12 100 B-5 15.0 C-5 10.0 E-43 3.0 D-1/D-4 4280/1830 Example 83 J-83 A-12 100 B-5 15.0 C-5 10.0 E-44 3.0 D-1/D-4 4280/1830 Example 84 J-84 A-12 100 B-5 15.0 C-5 10.0 E-45 3.0 D-1/D-4 4280/1830 Example 85 J-85 A-12 100 B-5 15.0 C-5 10.0 E-46 3.0 D-1/D-4 4280/1830 Example 86 J-86 A-13 100 B-5 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 87 J-87 A-14 100 B-5 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 88 J-88 A-15 100 B-5 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 89 J-89 A-12 100 B-4 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 90 J-90 A-12 100 B-7 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Example 91 J-91 A-12 100 B-8 15.0 C-5 10.0 E-1 3.0 D-1/D-4 4280/1830 Comparative example 13 CJ-13 A-12 100 B-5 15.0 C-5 10.0 CE-1 3.0 D-1/D-4 4280/1830 Comparative example 14 CJ-14 A-12 100 B-5 15.0 C-5 10.0 CE-2 3.0 D-1/D-4 4280/1830 Comparative example 15 CJ-15 A-12 100 B-5 15.0 C-5 10.0 CE-3 3.0 D-1/D-4 4280/1830 Comparative example 16 CJ-16 A-12 100 B-5 15.0 C-5 10.0 CE-5 3.0 D-1/D-4 4280/1830 Comparative example 17 CJ-17 A-12 100 B-5 15.0 C-5 10.0 CE-7 3.0 D-1/D-4 4280/1830 Comparative example 18 CJ-18 A-12 100 B-5 15.0 C-5 10.0 CE-9 3.0 D-1/D-4 4280/1830 Comparative example 19 CJ-19 A-12 100 B-5 15.0 C-5 10.0 CE-11 3.0 D-1/D-4 4280/1830

<Formation of resist pattern using positive radiation sensitive resin composition for EUV exposure> Using a spin coater (Tokyo Electron Co., Ltd.'s "CLEAN TRACK ACT12"), the composition for forming the lower antireflection film (Brewer Science's "ARC66") was applied to 12 After being mounted on a 205-inch silicon wafer, it is heated at 205°C for 60 seconds to form a lower anti-reflective film with an average thickness of 105 nm. The prepared radiation-sensitive resin composition for EUV exposure was coated on the lower anti-reflective film using the spin coater, and PB was performed at 130° C. for 60 seconds. Thereafter, the film was cooled at 23° C. for 30 seconds, thereby forming a resist film with an average thickness of 55 nm. Next, the resist film was exposed using an EUV exposure device (ASML's "NXE3300") with NA=0.33, lighting conditions: Conventional s=0.89, and mask: imecDEFECT32FFR02. After exposure, perform PEB at 120°C for 60 seconds. Thereafter, a 2.38% by mass TMAH aqueous solution was used as an alkaline developer to perform alkali development on the resist film. After development, the resist film was washed with water and dried to form a positive resist pattern ( 32 nm line and space pattern).

＜Evaluation＞ For the resist pattern formed using the positive-type radiation-sensitive resin composition for EUV exposure, sensitivity, LWR performance, storage stability, receding contact angle, and number of defects after development were evaluated according to the following method. The results are shown in Table 8 below. In addition, a scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies (Co., Ltd.)) was used to measure the length of the resist pattern.

[Sensitivity] In the formation of a resist pattern using the positive-type radiation-sensitive resin composition for EUV exposure, the exposure amount for forming the 32 nm line and space pattern is the optimal exposure amount, and the optimal exposure amount is The quantity is set as sensitivity (mJ/cm ² ). Regarding the sensitivity, a sensitivity of 25 mJ/cm ² or less was evaluated as "good", and a sensitivity exceeding 25 mJ/cm ² was evaluated as "poor".

[LWR performance] The resist pattern was formed by irradiation with the optimal exposure amount determined from the sensitivity evaluation and adjusting the mask size to form a 32 nm line and space pattern. Using the scanning electron microscope, the formed resist pattern was observed from the top of the pattern. The variation in line width at a total of 500 locations was measured, and a 3 sigma value was calculated based on the distribution of the measured values. This 3 sigma value was defined as LWR (nm). The smaller the value of LWR, the smaller and better the line roughness is. Regarding the LWR performance, the case where it is 3.0 nm or less is evaluated as "good", and the case where it exceeds 3.0 nm is evaluated as "poor".

[Receding contact angle after prebaking (PB)] In the resist pattern forming method, the resist film before EUV exposure was measured at room temperature of 23°C, relative humidity of 40%, and normal pressure using KRUS's DSA-10 according to the following procedure. Receding contact angle.

After water is discharged from the needle of DSA-10 and a 25 μL water droplet is formed on the resist film, the water droplet is sucked with the needle at a speed of 10 μL/min for 90 seconds, and the contact angle is measured per second (90 times in total). . In this measurement, the average value of the contact angles at a total of 20 positions from the time when the contact angle became stable was calculated and set as the receding contact angle (°) after PB. The case where the receding contact angle after PB was 70° or more was evaluated as "good", and the case where it was less than 70° was evaluated as "poor".

[Storage Stability] After the radiation-sensitive resin composition for EUV exposure was stored at 40° C. for one month, the receding contact angle after PB was evaluated in the same manner as the above method. If the change rate represented by the following formula is 0.5% or less, the evaluation is "A" (extremely good). If it exceeds 0.5% and is 1.0% or less, the evaluation is "B" (good). If it exceeds 1.0%, the evaluation is "B" (good). The evaluation is "C" (poor). Change rate (%) = {(θ ₀ -θ ₁ )/θ ₀ }×100 (θ ₀ is the receding contact angle before storage, θ ₁ is the receding contact angle after one month of storage)

[Number of developing defects] The resist film was exposed at the optimal exposure amount to form a line and space pattern with a line width of 32 nm, which was used as a defect inspection wafer. The number of defects on the defect inspection wafer was measured using a defect inspection device ("KLA2810" manufactured by KLA-Tencor). Defects with a diameter of 50 μm or less are determined to originate from the resist film, and their number is calculated. Regarding the number of defects after development, the case where the number of defects determined to be derived from the resist film was 50 or less was evaluated as "good", and the case where it exceeded 50 was evaluated as "poor".

[Table 8] Radiation sensitive resin composition Sensitivity (mJ/cm ² ) LWR (nm) Receding contact angle after PB (°) Storage stability Number of developing defects (number) Example 76 J-76 twenty three 2.5 75 A 6 Example 77 J-77 twenty two 2.6 76 A 8 Example 78 J-78 twenty three 2.7 73 A 9 Example 79 J-79 twenty four 2.2 78 A 6 Example 80 J-80 twenty two 2.8 77 A 5 Example 81 J-81 twenty two 2.5 72 A 2 Example 82 J-82 twenty two 2.2 74 A 5 Example 83 J-83 twenty one 2.6 73 A 16 Example 84 J-84 twenty one 2.3 79 A 12 Example 85 J-85 20 2.4 75 A 4 Example 86 J-86 twenty two 2.6 76 A 7 Example 87 J-87 twenty two 2.5 75 A 6 Example 88 J-88 twenty one 2.4 77 A 7 Example 89 J-89 twenty one 2.6 75 A 5 Example 90 J-90 19 2.8 77 A 8 Example 91 J-91 18 2.2 75 A 7 Comparative example 13 CJ-13 27 3.3 62 A 320 Comparative example 14 CJ-14 26 3.5 66 A 289 Comparative example 15 CJ-15 28 3.2 64 A 277 Comparative example 16 CJ-16 27 2.7 62 A 250 Comparative example 17 CJ-17 28 3.1 61 A 312 Comparative example 18 CJ-18 27 3.2 63 C 451 Comparative example 19 CJ-19 28 3.2 67 C 316

From the results in Table 8, it is clear that the radiation-sensitive resin compositions of the examples have good sensitivity, LWR performance, receding contact angle after PB, storage stability, and number of development defects when used for EUV exposure. Compared with this , compared with the examples, the comparative examples are inferior in each characteristic. Therefore, when the radiation-sensitive resin composition of the Example is used for EUV exposure, a resist pattern with high sensitivity and excellent water repellency, storage stability, and defect performance can be formed.

[Preparation of negative radiation-sensitive resin composition for ArF exposure, formation and evaluation of resist patterns using the composition] [Example 92] 100 parts by mass of (A-1) as [A] second resin, 10.0 parts by mass of (B-7) as [B] radiation-sensitive acid generator, (C-) as [C] acid diffusion control agent 3) 4.0 parts by mass, (E-6) 5.0 parts by mass (solid content) as [E] first resin, and (D-1)/(D-2)/(D-3) as [D] solvent ), and filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-92).

Using a spin coater (Tokyo Electron Co., Ltd.'s "CLEAN TRACK ACT12"), the composition for forming the lower antireflection film (Brewer Science's "ARC66") was applied to 12 After being mounted on a 205-inch silicon wafer, it is heated at 205°C for 60 seconds to form a lower anti-reflective film with an average thickness of 100 nm. The prepared negative radiation-sensitive resin composition (J-92) for ArF exposure was coated on the lower anti-reflective film using the spin coater, and pre-baked at 100°C for 60 seconds ( PB). Thereafter, the film was cooled at 23° C. for 30 seconds to form a resist film with an average thickness of 90 nm. Next, an ArF excimer laser liquid immersion exposure device (ASML's "TWINSCAN XT-1900i") was used, with optical conditions of NA=1.35 and annular (σ=0.8/0.6), with a 40 nm hole, Expose the resist film with a mask pattern of 105 nm pitch. After exposure, perform a post-exposure bake (PEB) at 100°C for 60 seconds. Thereafter, using n-butyl acetate as an organic solvent developer, the resist film was developed with an organic solvent and dried to form a negative resist pattern (40 nm holes, 105 nm pitch).

A resist pattern using the negative radiation-sensitive resin composition for ArF exposure and a resist film before ArF exposure, and a resist pattern using the positive radiation-sensitive resin composition for ArF exposure In the same evaluation, sensitivity, receding contact angle after PB, number of defects after development, and storage stability were evaluated. As a result, the radiation-sensitive resin composition of Example 92 has high sensitivity even when a negative resist pattern is formed by ArF exposure, and has high receding contact angle after PB, number of defects after development, and storage stability. Sex is also good.

[Preparation of negative radiation-sensitive resin composition for EUV exposure, formation and evaluation of resist patterns using the composition] [Example 93] 100 parts by mass of (A-12) as [A] second resin, 21.0 parts by mass of (B-8) as [B] radiation-sensitive acid generator, (C-) as [C] acid diffusion control agent 6) 5.0 parts by mass, 3.0 parts by mass (solid content) of (E-10) as [E] first resin, and 6,110 parts by mass of (D-1)/(D-4) mixed solvent as [D] solvent A portion was filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-93).

Using a spin coater (Tokyo Electron Co., Ltd.'s "CLEAN TRACK ACT12"), the composition for forming the lower antireflection film (Brewer Science's "ARC66") was applied to 12 After being mounted on a 205-inch silicon wafer, it is heated at 205°C for 60 seconds to form a lower anti-reflective film with an average thickness of 105 nm. The prepared negative radiation-sensitive resin composition (J-93) for EUV exposure was coated on the lower anti-reflective film using the spin coater, and PB was performed at 130°C for 60 seconds. Thereafter, the film was cooled at 23° C. for 30 seconds, thereby forming a resist film with an average thickness of 55 nm. Next, the resist film was exposed using an EUV exposure device (ASML's "NXE3300") with NA=0.33, lighting conditions: Conventional s=0.89, and mask: imecDEFECT32FFR15. After exposure, perform PEB at 120°C for 60 seconds. Thereafter, using n-butyl acetate as an organic solvent developer, the resist film was developed with an organic solvent and dried to form a negative resist pattern (40 nm holes, 105 nm pitch).

The resist pattern using the negative radiation-sensitive resin composition for EUV exposure was evaluated in the same manner as the evaluation of the resist pattern using the negative radiation-sensitive resin composition for ArF exposure. As a result, the radiation-sensitive resin composition of Example 93 has high sensitivity even when a negative resist pattern is formed by EUV exposure, and has high receding contact angle after PB, number of defects after development, and storage stability. Sex is also good. [Industrial availability]

According to the radiation-sensitive resin composition and pattern forming method of the present invention, the composition has excellent storage stability, good sensitivity to exposure light, excellent LWR performance and water repellency, and can form a resist pattern with few defects. Therefore, these can be preferably used in processing processes of semiconductor devices that are expected to be further miniaturized in the future.

without

Claims (10)

A radiation-sensitive resin composition comprising: a structural unit (I) represented by the following formula (1), a structural unit (II) represented by the following formula (2) (represented by the following formula (1) (excluding structural units) and the first resin having a structural unit (III) having an acid-dissociable group; and a solvent; (In the formula (1), R ^K1 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ¹ is an alkanediyl group having 1 to 5 carbon atoms; R ^f1 is an alkyl group having five to seven fluorine atoms. A monovalent fluorinated hydrocarbon group with 2 to 10 carbon atoms; In the formula (2), R ^K2 is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; L ^f is a fluorine-substituted or unsubstituted carbon A divalent organic group with a number of 1 to 20; L ² is *-COO- or *-OCO-; * is a bond on the L ^f side; p is an integer from 0 to 2; when there are multiple L ^f and L ² In the case of , a plurality of L ^f and L ² are the same or different from each other respectively; R ^f2 is a fluorine-substituted or unsubstituted monovalent organic group having 1 to 20 carbon atoms; among them, L ^f and R ^f2 have more than one in total of fluorine atoms). The radiation-sensitive resin composition according to claim 1, wherein in the formula (1), R ^f1 is a monovalent fluorinated linear hydrocarbon group having five fluorine atoms and having 2 to 4 carbon atoms. The radiation-sensitive resin composition according to claim 1, wherein in the formula (1), L ¹ is a methanediyl group or an ethanediyl group. The radiation-sensitive resin composition according to claim 1, wherein in the formula (2), p is 1 or 2, and one or two fluorine atoms or trifluoromethyl groups are at least one of the carbonyl groups adjacent to L ² One carbon atom bonded. The radiation-sensitive resin composition according to claim 1, further comprising a second resin containing a structural unit having an acid-dissociable group and having a lower mass content of fluorine atoms than the first resin. The radiation-sensitive resin composition according to any one of claims 1 to 5, wherein the structural unit having an acid-dissociating group is represented by the following formula (3); (In the formula (3), R ⁷ is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group; R ⁸ is a monovalent hydrocarbon group having 1 to 20 carbon atoms; R ⁹ and R ¹⁰ are each independently a carbon number A monovalent chain hydrocarbon group of 1 to 10 or a monovalent alicyclic hydrocarbon group of 3 to 20 carbon atoms, or a divalent chain hydrocarbon group of 3 to 20 carbon atoms that is composed of these groups combined with each other and the bonded carbon atoms. valence alicyclic radical). The radiation-sensitive resin composition according to any one of claims 1 to 5, further comprising a radiation-sensitive acid generator. The radiation-sensitive resin composition according to any one of claims 1 to 5, further comprising an acid diffusion control agent. A pattern forming method comprising: The step of directly or indirectly applying the radiation-sensitive resin composition as described in any one of claims 1 to 5 on a substrate to form a resist film; The step of exposing the resist film; and The step of developing the exposed resist film using a developer. The pattern forming method according to claim 9, wherein the development is performed using an alkaline aqueous solution.