Radiation-sensitive resin composition, pattern formation method, substrate manufacturing method, and compound

Abstract

Provided are: a radiation-sensitive resin composition that can be formed into a resist film having satisfactory levels of sensitivity and CDU performance even when a next-generation technology is applied; and a pattern formation method.　The radiation-sensitive resin composition contains a compound A represented by formula (I). [Chemical 1] (In the formula, R1 is a (m+m')-valent organic group and has a cyclopropane ring skeleton, a cyclobutane ring skeleton, or both.　X1 is a group represented by formula (1-1) or a group represented by formula (1-2).　X2 is a group represented by formula (2-1) or a group represented by formula (2-2).　Y+ is a monovalent onium cation.　m is an integer of 1-2.　m' is an integer of 0-1.)　[Chemical 2] (In the formula, * represents a bond with another group.)　The radiation-sensitive resin composition also contains a resin B including a structural unit having an acid-dissociable group, a radiation-sensitive acid generator other than the compound A, and a solvent.

Description

[Technical Field]

[0001] The present invention relates to a radiation-sensitive resin composition, a pattern-forming method, a method for manufacturing a substrate, and compounds that can be used in the same. [Background technology]

[0002] Photolithography, which uses resist compositions, is employed to form fine circuits in semiconductor devices. A typical procedure involves, for example, generating acid by irradiating a resist composition film with radiation through a mask pattern. This acid then acts as a catalyst, creating a difference in the solubility of the resin in alkaline or organic solvent-based developers between the exposed and unexposed areas, thereby forming a resist pattern on the substrate.

[0003] The above-mentioned photolithography technology utilizes short-wavelength radiation such as ArF excimer lasers, or combines this radiation with liquid immersion lithography to advance pattern miniaturization. As a next-generation technology, efforts are being made to utilize even shorter-wavelength radiation such as electron beams, X-rays, and EUV (extreme ultraviolet) radiation, and resist materials containing acid generators with benzene rings that enhance the absorption efficiency of such radiation are also being investigated (Japanese Patent Publication No. 2014-2359). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2014-2359 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Even with the aforementioned next-generation technologies, the resist performance is required to be equal to or better than conventional methods in terms of sensitivity, critical dimension uniformity (CDU) performance (an indicator of the uniformity of line width and hole diameter), and other aspects.

[0006] The present invention aims to provide a radiation-sensitive resin composition and a pattern-forming method that can form a resist film having sufficient sensitivity and CDU performance even when next-generation technologies are applied. [Means for solving the problem]

[0007] The inventors of this invention conducted extensive research to solve this problem and, as a result, found that the above objective can be achieved by adopting the following configuration, thus completing the present invention.

[0008] In one embodiment, the present invention is Compound A, represented by the following formula (I), [ka] (In the formula, R 1 This is an organic group with (m+m') valency, and includes a cyclopropane ring skeleton, a cyclobutane ring skeleton, or both. X 1 This is a group represented by the following formula (1-1) or a group represented by the following formula (1-2). X 2 This is a group represented by the following formula (2-1) or the following formula (2-2). Y + This is a monovalent onium cation. m is an integer between 1 and 2. m' is an integer between 0 and 1. [ka] (In the formula, * represents a bond with another group.) Resin B containing a structural unit having an acid-dissociable group, Other radiation-sensitive acid generators besides compound A, solvent This invention relates to a radiation-sensitive resin composition containing [a specific substance].

[0009] Furthermore, in another embodiment, the present invention states that (1) A step of applying the above radiation-sensitive resin composition directly or indirectly onto a substrate to form a resist film. (2) A step of exposing the above-mentioned resist film, and The present invention relates to a method for forming a pattern, which includes a step (3) of developing the exposed resist film.

[0010] Furthermore, in another embodiment, the present invention states that The present invention relates to a method for manufacturing a substrate, which includes a step (4) of forming a pattern on the substrate using the pattern formed by the above method as a mask.

[0011] Furthermore, in another embodiment, the present invention states that This relates to the compound represented by the following formula (I). [ka] (In the formula, R 1 This is an organic group with (m+m') valency, and includes a cyclopropane ring skeleton, a cyclobutane ring skeleton, or both. X 1 This is a group represented by the following formula (1-1) or a group represented by the following formula (1-2). X 2 This is a group represented by the following formula (2-1) or the following formula (2-2). Y + This is a monovalent onium cation. m is an integer between 1 and 2. m' is an integer between 0 and 1. [ka] (In the formula, * represents a bond with another group.) [Effects of the Invention]

[0012] By using the radiation-sensitive resin composition of the present invention, a resist film that satisfies sensitivity and CDU performance can be constructed.

[0013] Furthermore, according to the pattern formation method of the present invention, by using the above-mentioned radiation-sensitive resin composition which has excellent sensitivity and CDU performance, high-quality resist patterns can be efficiently formed.

[0014] Furthermore, by using the substrate manufacturing method of the present invention, high-quality substrates can be efficiently formed.

[0015] Furthermore, the above-mentioned radiation-sensitive resin composition can be obtained by using the compound of the present invention. [Modes for carrying out the invention]

[0016] The embodiments of the present invention will be described in detail below, but the present invention is not limited to these embodiments.

[0017] <Radiation sensitive resin composition> The radiation-sensitive resin composition according to this embodiment (hereinafter also simply referred to as "the composition") comprises a compound that is a predetermined onium salt (hereinafter also referred to as "the compound" or "compound A"), a resin containing a structural unit having an acid-dissociable group (hereinafter also referred to as "resin B"), a radiation-sensitive acid generator other than compound A, and a solvent. It also contains other resins as needed. The composition may contain other optional components as long as they do not impair the effects of the present invention. By containing the predetermined compound, the radiation-sensitive resin composition can be given a high level of sensitivity and CDU performance.

[0018] In this specification, an organic group refers to a group containing at least one carbon atom.

[0019] <Compound> Compound (Compound A) is represented by the above formula (I).

[0020] Since Compound A has a highly transparent, small-sized anionic moiety containing a cyclopropane ring skeleton, a cyclobutane ring skeleton, or both, it is presumed that the radiation-sensitive resin composition containing this Compound A can form a resist film that satisfies sensitivity and CDU performance.

[0021] In the above formula (I), R 1 is an (m+m')-valent organic group, and contains a cyclopropane ring skeleton, a cyclobutane ring skeleton, or both.

[0022] The above cyclopropane ring skeleton is not particularly limited as long as it contains a cyclopropane ring structure.

[0023] The above cyclobutane ring skeleton is not particularly limited as long as it contains a cyclobutane ring structure.

[0024] In the above formula (I), X 1 is a group represented by the above formula (1-1) or a group represented by the above formula (1-2).

[0025] In the above formula (I), X 2 is a group represented by the above formula (2-1) or a group represented by the above formula (2-2).

[0026] In the above formula (I), m is an integer of 1 to 2. When m is 2, a plurality of X 1 are identical or different.

[0027] In the above formula (I), m' is an integer of 0 to 1.

[0028] In the above formula (I), Y + is a monovalent onium cation.

[0029] The above Y + is preferably a monovalent radiation-decomposable onium cation.

[0030] Examples of the monovalent onium cations mentioned above include radiation-sensitive onium cations containing elements such as S, I, O, N, P, Cl, Br, F, As, Se, Sn, Sb, Te, and Bi. Examples of cations containing the element S (sulfur) include sulfonium cations and tetrahydrothiophenium cations, while examples of cations containing the element I (iodine) include iodonium cations.

[0031] The above Y + Examples include the cation represented by the following formula (Q-1) (hereinafter also referred to as "cation (Q-1)"), the cation represented by the following formula (Q-2) (hereinafter also referred to as "cation (Q-2)"), and the cation represented by the following formula (Q-3) (hereinafter also referred to as "cation (Q-3)").

[0032] [ka]

[0033] In the above equation (Q-1), R c1 , R c2 and R c3 Each of these independently represents a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, -OSO2-RP' or -SO2-RQ', or a ring structure formed by combining two or more of these groups. RP' and RQ' independently represent a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k1, k2, and k3 are each independently integers from 0 to 5. c1 ~R c3 Furthermore, if there are multiple RP' and RQ' respectively, multiple R c1 ~R c3 Furthermore, RP' and RQ' may be the same or different.

[0034] In the above equation (Q-2), Rd1 k4 is an integer from 0 to 7. d1 If there are multiple, then multiple R d1 They may be the same or different, and multiple Rs may also be used. d1 R may represent a ring structure formed by combining with other elements. d2 k5 is an integer from 0 to 6. d2 If there are multiple, then multiple R d2 They may be the same or different, and multiple R d2 t may represent a ring structure formed by combining with other elements. t is an integer between 0 and 3.

[0035] In the above equation (Q-3), R e1 and R e2 Each of these independently comprises a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, and -OSO2-R R Or -SO2-R S This represents a ring structure formed by combining two or more of these groups. R and R S Each of these is independently a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alicyclic hydrocarbon group having 5 to 25 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms. k6 and k7 are each independently integers from 0 to 5. R e1 , R e2 , R R and R S If each of them is multiple, then multiple R e1 , R e2 , R R and R S These may be the same or different.

[0036] The above R c1 ~Rc3 , R d1 , R d2 , R e1 and R e2 Examples of unsubstituted linear alkyl groups represented by include methyl, ethyl, n-propyl, and n-butyl groups.

[0037] The above R c1 ~R c3 , R d1 , R d2 , R e1 and R e2 Examples of unsubstituted branched alkyl groups represented by include i-propyl, i-butyl, sec-butyl, and t-butyl groups.

[0038] The above R c1 ~R c3 , R e1 and R e2 Examples of unsubstituted aromatic hydrocarbon groups represented by include aryl groups such as phenyl, tolyl, xyl, mesityl, and naphthyl groups; and aralkyl groups such as benzyl and phenethyl groups.

[0039] The above R d1 and R d2 Examples of unsubstituted aromatic hydrocarbon groups represented by include phenyl groups, tolyl groups, and benzyl groups.

[0040] Examples of substituents that may substitute hydrogen atoms in the alkyl and aromatic hydrocarbon groups mentioned above include halogen atoms such as fluorine, chlorine, bromine, and iodine, as well as hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkoxy groups, alkoxycarbonyl groups, alkoxycarbonyloxy groups, acyl groups, and acyloxy groups. Among these, halogen atoms are preferred, and fluorine atoms are more preferred.

[0041] The above R c1 ~R c3 , R d1 , R d2 , R e1 and R e2The preferred elements are unsubstituted linear or branched alkyl groups, fluorinated alkyl groups, unsubstituted monovalent aromatic hydrocarbon groups, -OSO2-R**, and -SO2-R**, more preferably fluorinated alkyl groups and unsubstituted monovalent aromatic hydrocarbon groups, and even more preferably fluorinated alkyl groups. R** is an unsubstituted monovalent alicyclic hydrocarbon group or an unsubstituted monovalent aromatic hydrocarbon group.

[0042] In the above formula (Q-1), k1, k2, and k3 are preferably integers between 0 and 2, more preferably 0 or 1, and even more preferably 0.

[0043] In the above formula (Q-2), k4 is preferably an integer between 0 and 2, more preferably 0 or 1, and even more preferably 1. For k5, an integer between 0 and 2 is preferably, more preferably 0 or 1, and even more preferably 0.

[0044] In the above formula (Q-3), k6 and k7 are preferably integers between 0 and 2, more preferably 0 or 1, and even more preferably 0.

[0045] Examples of the above-mentioned cation (Q-1) include cations represented by the following formulas (i-1) to (i-21).

[0046] [ka]

[0047] Among these, the cation represented by formula (i-1) and the cation represented by formula (i-21) are preferred.

[0048] Examples of the above-mentioned cation (Q-2) include cations represented by the following formulas (i'-1) to (i'-4).

[0049] [ka]

[0050] Among these, for example, the cation represented by the above formula (i'-2) is preferred.

[0051] Examples of the above-mentioned cation (Q-3) include cations represented by the following formulas (ii-1) to (ii-25).

[0052] [ka]

[0053] Among these, the cation represented by formula (ii-11) above is preferred.

[0054] Furthermore, compound A is preferably a compound represented by, for example, the following formula (1) or formula (2). [ka] (In the formula, R 1 , Y + , m and m' are the same as in equation (I) above.

[0055] [ka] (In the formula, R 1 , Y + , m and m' are the same as in equation (I) above.

[0056] Furthermore, compound A is, for example, the following: 式(3) It is preferable that the compound is represented by [formula]. [ka] (In the formula, R 3 This is a monovalent organic group, a fluorine atom, or a hydroxyl group. L 1 and L 2 Each of these is independently a single-bonded or divalent organic group. X 1 , X 2 , Y +m and m' are the same as in equation (I). Z is -C(R 4 It is a divalent group represented as 2- or -CO-. R 4 Each of these is independently a hydrogen atom, a monovalent organic group, a fluorine atom, or a hydroxyl group. q is an integer between 0 and 1. p is an integer between 0 and (6 - m - m').

[0057] In equation (3) above, R 3 This is a monovalent organic group, a fluorine atom, or a hydroxyl group.

[0058] Examples of the monovalent organic groups mentioned above include monovalent hydrocarbon groups.

[0059] Examples of the monovalent hydrocarbon groups mentioned above include chain hydrocarbon groups, alicyclic hydrocarbon groups, and aromatic hydrocarbon groups.

[0060] Examples of the above-mentioned chain-like hydrocarbon groups are: Alkyl groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, sec-butyl, and t-butyl groups; Alkenyl groups such as ethenyl, propenyl, and butenyl groups; Examples include ethylenyl groups, propynyl groups, butynyl groups, and other alkynyl groups.

[0061] Examples of the above alicyclic hydrocarbon groups are: Monocyclic cycloalkyl groups such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl groups; Monocyclic cycloalkenyl groups such as cyclobutenyl, cyclopentenyl, and cyclohexenyl groups; Polycyclic cycloalkyl groups such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups; Examples include polycyclic cycloalkenyl groups such as norborneyl, tricyclodecenyl, and tetracyclododecenyl.

[0062] Examples of the above aromatic hydrocarbon group include, aryl groups such as phenyl group, tolyl group, xylyl group, naphthyl group, and anthryl group; aralkyl groups such as benzyl group, phenethyl group, phenylpropyl group, and naphthylmethyl group, and the like.

[0063] In the above formula (3), L 1 and L 2 are each independently a single bond or a divalent organic group.

[0064] Examples of the above divalent organic group include a group obtained by removing one hydrogen atom from the monovalent hydrocarbon group in the above R 3 , and the like.

[0065] In the above formula (3), Z is a divalent group represented by -C(R 4 )2- or -CO-.

[0066] R in the above Z 4 are each independently a hydrogen atom, a monovalent organic group, a fluorine atom, or a hydroxyl group.

[0067] Examples of the above monovalent organic group include the monovalent hydrocarbon group in the above R 3 , and the like.

[0068] In the above formula (3), q is an integer of 0 to 1.

[0069] In the above formula (3), p is an integer of 0 to (6-m-m').

[0070] Moreover, the above compound A is preferably, for example, a compound represented by the following formula (4-1), the following formula (4-2), or the following formula (4-3). [Chemical Formula] (In the formula, L 1 , L 2 , X1 , X 2 , R 3 , Y + Z, m, m', p, and q are the same as in equation (3).

[0071] Compound A comprises the above-described anionic moiety and the above-described cationic moiety. More specifically, compound A may be, for example, a compound containing any of the anionic moiety and any of the cationic moiety described below.

[0072] More specifically, the anion portion mentioned above includes, for example, the following anions. [ka]

[0073] More specifically, examples of the cation portion mentioned above include the following cations. [ka]

[0074] [ka]

[0075] More specifically, compound A includes, for example, compounds represented by the following formulas (A-1) to (A-21) (hereinafter also referred to as "compounds (A-1) to (A-21)").

[0076] [ka]

[0077] The lower limit of the content of compound A is preferably 0.1% by mass, more preferably 0.5% by mass, even more preferably 1% by mass, and particularly preferably 3% by mass, relative to the total solids content of the radiation-sensitive resin composition. The upper limit of the above content is preferably 30% by mass, more preferably 20% by mass, even more preferably 15% by mass, and particularly preferably 10% by mass, relative to the total solids content. If the content of compound A is below the lower limit, the lithographic performance, such as resolution, of the radiation-sensitive resin composition may decrease. If the content of compound A exceeds the upper limit, the sensitivity of the radiation-sensitive resin composition may decrease. Here, "total solids" refers to the components of the radiation-sensitive resin composition other than the solvent.

[0078] The lower limit of the content of compound A is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1 part by mass, and particularly preferably 3 parts by mass, per 100 parts by mass of resin B, as described later. The upper limit of the content of compound A is preferably 30 parts by mass, more preferably 20 parts by mass, even more preferably 15 parts by mass, and particularly preferably 10 parts by mass, per 100 parts by mass of resin B.

[0079] <Resin> The resin (resin B) is an aggregate of polymers containing a structural unit having an acid-dissociable group (hereinafter also referred to as "structural unit (I)") (hereinafter this resin is also referred to as the "base resin"). An "acid-dissociable group" is a hydrogen atom-substituting group such as a carboxyl group, phenolic hydroxyl group, alcoholic hydroxyl group, or sulfo group, which dissociates upon the action of an acid. The radiation-sensitive resin composition exhibits excellent pattern-forming properties because the resin contains structural unit (I).

[0080] The base resin preferably contains structural unit (II), which includes at least one selected from the group consisting of lactone structures, cyclic carbonate structures, and sultone structures, as described later, in addition to structural unit (I). It may also contain other structural units other than structural units (I) and (II). Each structural unit will be described below.

[0081] [Structural Unit (I)] Structural unit (I) is a structural unit containing an acid-dissociable group. The structural unit (I) is not particularly limited as long as it contains an acid-dissociable group, and examples thereof include a structural unit having a tertiary alkyl ester moiety, a structural unit in which a hydrogen atom of a phenolic hydroxyl group is substituted with a tertiary alkyl group, a structural unit having an acetal bond, and the like. From the viewpoint of improving the pattern formability of the radiation-sensitive resin composition, a structural unit represented by the following formula (6) (hereinafter also referred to as "structural unit (I-1)") is preferred.

[0082]

Chemical Formula

[0083] The above R 5 is preferably a hydrogen atom or a methyl group, and more preferably a methyl group, from the viewpoint of the copolymerizability of the monomer that gives the structural unit (I-1).

[0084] Examples of the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the above R 6 include a chain hydrocarbon group having 1 to 10 carbon atoms, a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms, and the like.

[0085] The above R 6 to R 8Examples of chain-like hydrocarbon groups having 1 to 10 carbon atoms include linear or branched saturated hydrocarbon groups having 1 to 10 carbon atoms, or linear or branched unsaturated hydrocarbon groups having 1 to 10 carbon atoms.

[0086] The above R 6 ~R 8 Examples of alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic or polycyclic saturated hydrocarbon groups, or monocyclic or polycyclic unsaturated hydrocarbon groups, having 3 to 20 carbon atoms. Preferred monocyclic saturated hydrocarbon groups are cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Preferred polycyclic cycloalkyl groups are bridged alicyclic hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups. A bridged alicyclic hydrocarbon group is a polycyclic alicyclic hydrocarbon group in which two carbon atoms constituting the alicyclic ring that are not adjacent to each other are bonded together by a bond chain containing one or more carbon atoms.

[0087] The above R 6 Examples of monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, represented by this formula, include: Aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthyl groups; Examples include aralkyl groups such as benzyl groups, phenethyl groups, and naphthylmethyl groups.

[0088] The above R 6 Preferred carbon atoms include linear or branched saturated hydrocarbon groups having 1 to 10 carbon atoms, and alicyclic hydrocarbon groups having 3 to 20 carbon atoms.

[0089] The above R 7 and R 8A divalent alicyclic group having 3 to 20 carbon atoms, formed by combining chain-like hydrocarbon groups or alicyclic hydrocarbon groups represented by the above formula with the carbon atoms to which they are bonded, is not particularly limited as long as it is a group obtained by removing two hydrogen atoms from the same carbon atom constituting the carbon ring of a monocyclic or polycyclic alicyclic hydrocarbon of the above carbon number. It may be either a monocyclic hydrocarbon group or a polycyclic hydrocarbon group, and as a polycyclic hydrocarbon group, it may be either a bridged alicyclic hydrocarbon group or a condensed alicyclic hydrocarbon group, and may be either a saturated hydrocarbon group or an unsaturated hydrocarbon group. A condensed alicyclic hydrocarbon group refers to a polycyclic alicyclic hydrocarbon group in which multiple alicyclics share an edge (a bond between two adjacent carbon atoms).

[0090] Among monocyclic alicyclic hydrocarbon groups, preferred saturated hydrocarbon groups include cyclopentanediyl, cyclohexanediyl, cycloheptanediyl, and cyclooctanediyl, while preferred unsaturated hydrocarbon groups include cyclopentenediyl, cyclohexenediyl, cycloheptenediyl, cyclooctenediyl, and cyclodecenediyl. Among polycyclic alicyclic hydrocarbon groups, bridged alicyclic saturated hydrocarbon groups are preferred, such as bicyclo[2.2.1]heptane-2,2-diyl (norbornane-2,2-diyl), bicyclo[2.2.2]octane-2,2-diyl, and tricyclo[3.3.1.1 3,7 A decane-2,2-diyl group (adamantane-2,2-diyl group) is preferred.

[0091] Among these, R 6 R is an alkyl group having 1 to 4 carbon atoms. 7 and R 8 It is preferable that the alicyclic structure formed by combining these elements with the carbon atoms to which they are bonded is a polycyclic or monocyclic cycloalkane structure.

[0092] Examples of structural units (I-1) include the structural units represented by the following formulas (6-1) to (6-6) (hereinafter also referred to as "structural units (I-1-1) to (I-1-6)").

[0093] [ka]

[0094] In the above equations (6-1) to (6-6), R 5 ~R 8 This is equivalent to equation (6) above. i and j are independent integers between 1 and 4. k and l are 0 or 1.

[0095] i and j are preferably 1. 6 As such, a methyl group, ethyl group, isopropyl group, or cyclopentyl group is preferred. 7 and R 8 A methyl group or an ethyl group is preferred.

[0096] The base resin may contain one or more structural units (I) in combination.

[0097] The lower limit of the content of structural unit (I) (total content if multiple types are included) is preferably 10 mol%, more preferably 20 mol%, even more preferably 30 mol%, and particularly preferably 35 mol%, relative to the total structural units constituting the base resin. The upper limit of the above content is preferably 80 mol%, more preferably 75 mol%, even more preferably 70 mol%, and particularly preferably 65 mol%. By setting the content of structural unit (I) within the above range, the pattern-forming properties of the radiation-sensitive resin composition can be further improved.

[0098] [Structural Units (II)] Structural unit (II) is a structural unit comprising at least one selected from the group consisting of lactone structures, cyclic carbonate structures, and sultone structures. By further comprising structural unit (II), the solubility of the base resin in the developer can be adjusted, and as a result, the radiation-sensitive resin composition can improve lithography performance such as resolution. Furthermore, the adhesion between the resist pattern formed from the base resin and the substrate can be improved.

[0099] Examples of structural units (II) include those represented by the following formulas (T-1) to (T-10).

[0100] [ka]

[0101] In the above formula, R L1 R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. L2 ~R L5 These are, independently, a hydrogen atom, a C1-C4 alkyl group, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxyl group, a hydroxymethyl group, and a dimethylamino group. L4 and R L5 These may be divalent alicyclic groups having 3 to 8 carbon atoms, which can be combined with each other and formed together with the carbon atoms to which they are bonded. 2 is a single bond or a divalent linking group. X is an oxygen atom or a methylene group. k is an integer from 0 to 3. m is an integer from 1 to 3.

[0102] The above R L4 and R L5 When these are combined with each other, the divalent alicyclic group having 3 to 8 carbon atoms that is formed together with the carbon atoms to which they are bonded is R in formula (3) above. 19 and R 20 Examples include divalent alicyclic groups with 3 to 8 carbon atoms, which are formed by combining chain-like hydrocarbon groups or alicyclic hydrocarbon groups represented by , together with the carbon atoms to which they are bonded. One or more hydrogen atoms on this alicyclic group may be substituted with hydroxyl groups.

[0103] The above L 2 Examples of divalent linking groups represented by include divalent linear or branched hydrocarbon groups having 1 to 10 carbon atoms, divalent alicyclic hydrocarbon groups having 4 to 12 carbon atoms, or groups composed of one or more of these hydrocarbon groups and at least one of the groups -CO-, -O-, -NH-, and -S-.

[0104] Among these, structural units (II) are preferably those containing a lactone structure, more preferably those containing a norbornane lactone structure, and even more preferably those derived from norbornane lactone-yl (meth)acrylate.

[0105] The lower limit of the content of structural unit (II) is preferably 20 mol%, more preferably 30 mol%, and even more preferably 35 mol%, relative to the total structural units constituting the base resin. The upper limit of the content is preferably 75 mol%, more preferably 70 mol%, and even more preferably 65 mol%. By setting the content of structural unit (II) within the above range, the radiation-sensitive resin composition can further improve lithography performance such as resolution and the adhesion of the formed resist pattern to the substrate.

[0106] [Structural Unit (III)] The base resin may optionally contain other structural units in addition to the structural units (I) and (II) described above. Examples of these other structural units include structural unit (III) containing a polar group (excluding those corresponding to structural unit (II)). By further containing structural unit (III), the solubility of the base resin in the developer can be adjusted, and as a result, the lithographic performance such as resolution of the radiation-sensitive resin composition can be improved. Examples of these polar groups include hydroxyl groups, carboxyl groups, cyano groups, nitro groups, and sulfonamide groups. Among these, hydroxyl groups and carboxyl groups are preferred, and hydroxyl groups are more preferred.

[0107] Examples of structural units (III) include structural units represented by the following formula.

[0108] [ka]

[0109] In the above formula, R A This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0110] When the base resin has structural unit (III) having the polar group, the lower limit of the content of structural unit (III) is preferably 5 mol%, more preferably 8 mol%, and even more preferably 10 mol%, relative to the total structural units constituting the base resin. The upper limit of the content is preferably 40 mol%, more preferably 35 mol%, and even more preferably 30 mol%. By setting the content of structural unit (III) within the above range, the lithographic performance, such as resolution, of the radiation-sensitive resin composition can be further improved.

[0111] [Structural Units (IV)] The base resin may optionally contain structural units other than the polar group-containing structural unit (III) described above, such as structural units derived from hydroxystyrene or structural units containing phenolic hydroxyl groups (hereinafter, both are collectively referred to as "structural unit (IV)"). Structural unit (IV) contributes to improved etching resistance and improved difference in developer solubility between exposed and unexposed areas (dissolution contrast). In particular, it can be suitably applied to pattern formation using exposure with radiation of wavelengths of 50 nm or less, such as electron beams and EUV. In this case, it is preferable that the resin contains structural unit (I) along with structural unit (IV).

[0112] Structural units derived from hydroxystyrene are represented, for example, by the following formulas (7-1) to (7-2), and structural units having a phenolic hydroxyl group are represented, for example, by the following formulas (7-3) to (7-4).

[0113] [ka]

[0114] In the above equations (7-1) to (7-4), R 11 These are a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0115] When obtaining structural unit (IV), it is preferable to polymerize the phenolic hydroxyl group while protecting it with a protecting group such as an alkali-dissociable group (e.g., an acyl group), and then deprotect it by hydrolysis to obtain structural unit (IV).

[0116] For resins used for exposure with radiation of wavelength 50 nm or less, the lower limit of the content of structural unit (IV) is preferably 10 mol%, and more preferably 20 mol%, relative to the total structural units constituting the resin. The upper limit of the above content is preferably 70 mol%, and more preferably 60 mol%.

[0117] (Method of synthesizing the base resin) The base resin can be synthesized, for example, by polymerizing monomers that provide each structural unit in a suitable solvent using a radical polymerization initiator or the like.

[0118] Examples of the radical polymerization initiators mentioned above include azo-based radical initiators such as azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), and dimethyl-2,2'-azobisisobutyrate; and peroxide-based radical initiators such as benzoyl peroxide, t-butyl hydroperoxide, and cumene hydroperoxide. Among these, AIBN and dimethyl-2,2'-azobisisobutyrate are preferred, and AIBN is more preferred. These radical initiators can be used individually or in combination of two or more.

[0119] Examples of solvents used in the polymerization described above include: Alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane; Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decalin, and norbornane; Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene; Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, and chlorobenzene; Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, i-butyl acetate, and methyl propionate; Ketones such as acetone, methyl ethyl ketone, 2-butanone, 4-methyl-2-pentanone, and 2-heptanone; Ethers such as tetrahydrofuran, dimethoxyethanes, and diethoxyethanes; Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, and 4-methyl-2-pentanol. The solvent used in these polymerizations may be used alone or in combination of two or more.

[0120] The reaction temperature in the polymerization described above is typically 40°C to 150°C, with 50°C to 120°C being preferred. The reaction time is typically 1 hour to 48 hours, with 1 hour to 24 hours being preferred.

[0121] The molecular weight of the base resin is not particularly limited, but the lower limit of the polystyrene-equivalent weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC) is preferably 1,000, more preferably 2,000, even more preferably 3,000, and particularly preferably 4,000. The upper limit of Mw is preferably 50,000, more preferably 30,000, even more preferably 15,000, and particularly preferably 12,000. If the Mw of the base resin is below the above lower limit, the heat resistance of the resulting resist film may decrease. If the Mw of the base resin exceeds the above upper limit, the developability of the resist film may decrease.

[0122] The ratio of Mw (Mw / Mn) to the polystyrene-equivalent number-average molecular weight (Mn) of the base resin, calculated by GPC, is usually between 1 and 5, preferably between 1 and 3, and more preferably between 1 and 2.

[0123] In this specification, the Mw and Mn values ​​of the resin are measured using gel permeation chromatography (GPC) under the following conditions.

[0124] GPC columns: 2 x G2000HXL, 1 x G3000HXL, 1 x G4000HXL (all manufactured by Tosoh) Column temperature: 40℃ Leaching solvent: Tetrahydrofuran Flow rate: 1.0mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Detector: Differential refractometer Standard material: Monodisperse polystyrene

[0125] The base resin content is preferably 70% by mass or more, more preferably 80% by mass or more, and even more preferably 85% by mass or more, relative to the total solid content of the radiation-sensitive resin composition.

[0126] (Other resins) The radiation-sensitive resin composition of this embodiment may also contain, as another resin, a resin with a higher mass content of fluorine atoms than the base resin (hereinafter also referred to as "high-fluorine content resin"). When the radiation-sensitive resin composition contains a high-fluorine content resin, it can be unevenly distributed on the surface of the resist film relative to the base resin, and as a result, the water repellency of the surface of the resist film during immersion exposure can be improved.

[0127] As a high-fluorine-content resin, it is preferable to have a structural unit represented by the following formula (8) (hereinafter also referred to as "structural unit (V)"), and may optionally have structural unit (I) or structural unit (III) of the base resin.

[0128] [ka]

[0129] In the above equation (8), R 13 This is a hydrogen atom, a methyl group, or a trifluoromethyl group. LR is a single bond, an oxygen atom, a sulfur atom, -COO-, -SO2ONH-, -CONH-, or -OCONH-. 14 This is a monovalent fluorinated chain hydrocarbon group having 1 to 20 carbon atoms or a monovalent fluorinated alicyclic hydrocarbon group having 3 to 20 carbon atoms.

[0130] The above R 13 From the viewpoint of copolymerization of monomers that provide structural unit (V), hydrogen atoms and methyl groups are preferred, and methyl groups are more preferred.

[0131] The above G L From the viewpoint of copolymerization of monomers that provide structural unit (V), single bonds and -COO- are preferred, and -COO- is more preferred.

[0132] The above R 14 Examples of monovalent fluorinated linear hydrocarbon groups having 1 to 20 carbon atoms, represented by , include those in which some or all of the hydrogen atoms in a linear or branched alkyl group having 1 to 20 carbon atoms are substituted with fluorine atoms.

[0133] The above R 14 Examples of monovalent fluorinated alicyclic hydrocarbon groups having 3 to 20 carbon atoms, represented by , include those in which some or all of the hydrogen atoms in a monocyclic or polycyclic hydrocarbon group having 3 to 20 carbon atoms are substituted with fluorine atoms.

[0134] The above R 14 Preferably, the group is a fluorinated chain hydrocarbon group, more preferably a fluorinated alkyl group, and even more preferably a 2,2,2-trifluoroethyl group, a 1,1,1,3,3,3-hexafluoropropyl group, and a 5,5,5-trifluoro-1,1-diethylpentyl group.

[0135] When a high-fluorine-content resin has structural units (V), the content of structural units (V) is preferably 30 mol% or more, more preferably 40 mol% or more, even more preferably 45 mol% or more, and particularly preferably 50 mol% or more, relative to the total structural units constituting the high-fluorine-content resin. Furthermore, it is preferably 90 mol% or less, more preferably 85 mol% or less, and even more preferably 80 mol% or less. By setting the content of structural units (V) within the above range, the mass content of fluorine atoms in the high-fluorine-content resin can be more appropriately adjusted, further promoting the uneven distribution to the surface layer of the resist film, and as a result, the water repellency of the resist film during immersion exposure can be further improved.

[0136] High-fluorine content resins may have fluorine atom-containing structural units (hereinafter also referred to as structural unit (VI)) represented by the following formula (f-2), either together with or in place of structural unit (V). The presence of structural unit (f-2) in high-fluorine content resins improves solubility in alkaline developers and suppresses the occurrence of development defects.

[0137] [ka]

[0138] Structural units (VI) can be broadly classified into two types: (x) those having an alkali-soluble group, and (y) those having a group that dissociates upon the action of alkali, increasing its solubility in an alkaline developer (hereinafter also simply referred to as an "alkali-dissociable group"). In both (x) and (y), in the above formula (f-2), R C R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. D This is a single bond, a (s+1) valent hydrocarbon group with 1 to 20 carbon atoms, and the R of this hydrocarbon group E At the terminal end of the side are an oxygen atom, a sulfur atom, and -NR dd -, a structure to which a carbonyl group, -COO-, or -CONH- is bonded, or a structure in which some of the hydrogen atoms of this hydrocarbon group are replaced by an organic group having a heteroatom. ddis a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. s is an integer from 1 to 3.

[0139] If structural unit (VI) has (x) an alkali-soluble group, R F is a hydrogen atom, A 1 * is an oxygen atom, -COO-* or -SO2O-*. F This shows the site of binding. 1 A is a single bond, a hydrocarbon group having 1 to 20 carbon atoms, or a divalent fluorinated hydrocarbon group. 1 If is an oxygen atom, then W 1 is A 1 It is a fluorinated hydrocarbon group having a fluorine atom or a fluoroalkyl group at the carbon atom to which it is bonded. E is a single bond or a divalent organic group with 1 to 20 carbon atoms. If s is 2 or 3, there are multiple R E , W 1 , A 1 and R F These may be the same or different. Having (x) an alkali-soluble group in structural unit (VI) increases its affinity for alkaline developer and suppresses development defects. A structural unit (VI) having (x) an alkali-soluble group is A 1 is an oxygen atom and W 1 It is particularly preferable that the group is a 1,1,1,3,3,3-hexafluoro-2,2-methanediyl group.

[0140] If structural unit (VI) has an alkali-dissociable group (y), R F A is a monovalent organic group having 1 to 30 carbon atoms. 1 is an oxygen atom, -NR aa -, -COO-* or -SO2O-* aa * is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. F This shows the site of binding. 1 R is a single bond or a divalent fluorinated hydrocarbon group having 1 to 20 carbon atoms. E A is a single bond or a divalent organic group having 1 to 20 carbon atoms. 1 If is -COO-* or -SO2O-*, then W 1or R F is A 1 It has a fluorine atom on the carbon atom bonded to it or on an adjacent carbon atom. 1 If is an oxygen atom, then W 1 , R E It is a single bond, R D R is a hydrocarbon group with 1 to 20 carbon atoms. E It is a structure in which a carbonyl group is bonded to the terminal end, R F is an organic group containing a fluorine atom. When s is 2 or 3, multiple R E , W 1 , A 1 and R F These may be the same or different. The presence of (y) an alkali-dissociable group in structural unit (VI) causes the resist film surface to change from hydrophobic to hydrophilic during the alkali development process. As a result, the affinity for the developer is significantly increased, and development defects can be suppressed more efficiently. Examples of structural unit (VI) having (y) an alkali-dissociable group include A 1 is -COO-*, R F Or W 1 Alternatively, it is particularly preferable that both of these contain fluorine atoms.

[0141] R C From the viewpoint of copolymerizability of the monomer that gives structural unit (VI), hydrogen atoms and methyl groups are preferred, and methyl groups are more preferred.

[0142] R E When the group is a divalent organic group, a group having a lactone structure is preferred, a group having a polycyclic lactone structure is more preferred, and a group having a norbornane lactone structure is even more preferred.

[0143] When a high-fluorine-content resin has structural units (VI), the content of structural units (VI) is preferably 40 mol% or more, more preferably 50 mol% or more, and even more preferably 60 mol% or more, relative to the total structural units constituting the high-fluorine-content resin. Furthermore, it is preferably 95 mol% or less, more preferably 90 mol% or less, and even more preferably 85 mol% or less. By setting the content of structural units (VI) within the above range, the water repellency of the resist film during immersion exposure can be further improved.

[0144] [Other structural units] High-fluorine resins may also contain structural units having an alicyclic structure represented by the following formula (9), in addition to the structural units listed above. [ka] (In the above formula (9), R 1α R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 2α (It is a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms.)

[0145] In the above equation (9), R 2α As a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by the above formula (6), R 6 ~R 8 A cyclic hydrocarbon group having 3 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0146] When a high-fluorine-content resin contains structural units having the above-mentioned alicyclic structure, the content of these structural units is preferably 10 mol% or more, more preferably 20 mol% or more, and even more preferably 30 mol% or more, relative to the total structural units constituting the high-fluorine-content resin. Furthermore, it is preferably 70 mol% or less, more preferably 60 mol% or less, and even more preferably 50 mol% or less.

[0147] The lower limit of Mw for the high-fluorine-content resin is preferably 1,000, more preferably 2,000, even more preferably 3,000, and particularly preferably 5,000. The upper limit of Mw is preferably 50,000, more preferably 30,000, even more preferably 20,000, and particularly preferably 15,000.

[0148] The Mw / Mn ratio of high-fluorine-content resins is usually 1 or higher, more preferably 1.1 or higher. It is also usually 5 or lower, preferably 3 or lower, more preferably 2 or lower, and even more preferably 1.9 or lower.

[0149] The content of the high-fluorine resin is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 1 part by mass or more, and particularly preferably 1.5 parts by mass or more, per 100 parts by mass of the base resin. Furthermore, it is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, even more preferably 8 parts by mass or less, and particularly preferably 5 parts by mass or less.

[0150] By setting the content of the high-fluorine-content resin within the above range, the high-fluorine-content resin can be more effectively distributed to the surface layer of the resist film, and as a result, the water repellency of the surface of the resist film during immersion exposure can be further enhanced. The radiation-sensitive resin composition may contain one or more high-fluorine-content resins.

[0151] (Method for synthesizing high-fluorine content resins) High-fluorine-content resins can be synthesized by the same method as the base resin synthesis method described above.

[0152] <Radiation-sensitive acid generator> The radiation-sensitive acid generator other than the above Compound A (hereinafter, also referred to as "radiation-sensitive acid generator") includes an onium salt compound. The radiation-sensitive acid generator is a substance that generates an acid upon exposure. The generated acid dissociates the acid-dissociable group contained in Resin B and the like to produce a carboxy group and the like, which changes the solubility of these polymers in a developer, so that a resist pattern can be formed from the radiation-sensitive resin composition. The form of incorporation of the radiation-sensitive acid generator in the radiation-sensitive resin composition may be in the form of a low-molecular compound as described later, a form incorporated as part of a polymer, or both of these forms.

[0153] The radiation-sensitive acid generator may further contain, in addition to the onium salt compound, an N-sulfonyloxyimide compound, a halogen-containing compound, a diazoketone compound and the like, within a range not impairing the effects of the present invention.

[0154] Examples of the onium salt compound include, for example, sulfonium salts, tetrahydrothiophenium salts, iodonium salts, phosphonium salts, diazonium salts, pyridinium salts and the like.

[0155] Specific examples of the radiation-sensitive acid generator include, for example, the compounds described in paragraphs

[0080] to

[0113] of JP 2009-134088 A and the like.

[0156] As the radiation-sensitive acid generator, a compound represented by the following formula (10) is preferable. By using the compound represented by the following formula (10) as the radiation-sensitive acid generator, the diffusion length of the acid generated by exposure in the resist film is considered to be more appropriately shortened due to the interaction with the polar structure contained in Resin B and the like, and as a result, the lithography performance of the radiation-sensitive resin composition can be further improved. R b1 -R b2 -SO3 - M + (10) (In the formula, R b1 is a monovalent group containing an alicyclic structure or a monovalent group containing an aliphatic heterocyclic structure. R b2 is a fluorinated alkanediyl group having 1 to 10 carbon atoms. M + is a monovalent radiation-decomposable onium cation.)

[0157] The number of ring members of the alicyclic structure and aliphatic heterocyclic structure in the above R b1 is, for example, 3 or more and 20 or less. The "number of ring members" refers to the number of atoms constituting the ring of the alicyclic structure and the aliphatic heterocyclic structure, and in the case of a polycyclic alicyclic structure and a polycyclic aliphatic heterocyclic structure, it refers to the number of atoms constituting the polycycle.

[0158] Examples of the monovalent group containing an alicyclic structure represented by the above R b1 include, for example, monocyclic cycloalkyl groups such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, cyclooctyl group, cyclononyl group, cyclodecyl group, and cyclododecyl group; monocyclic cycloalkenyl groups such as cyclopropenyl group, cyclobutenyl group, cyclopentenyl group, cyclohexenyl group, cyclooctenyl group, and cyclodecenyl group; polycyclic cycloalkyl groups such as norbornyl group, adamantyl group, tricyclodecyl group, and tetracyclododecyl group; and polycyclic cycloalkenyl groups such as norbornenyl group and tricyclodecenyl group.

[0159] Examples of the monovalent group containing an aliphatic heterocyclic structure represented by the above R b1 include, for example, groups containing a lactone structure such as butyrolactone-yl group and norbornanelactone-yl group; groups containing a sultone structure such as norbornanesultone-yl group; oxygen atom-containing heterocyclic groups such as oxacyclopropyl group, oxacyclobutyl group, oxacyclopentyl group, oxacyclohexyl group, oxacycloheptyl group, and oxanorbornyl group; Nitrogen-containing heterocyclic groups such as azacyclopropyl, azacyclobutyl, azacyclopentyl, azacyclohexyl, azacycloheptyl, and diazabicyclooctanyl groups; Examples include sulfur atom-containing heterocyclic groups such as thiacyclopropyl group, thiacyclobutyl group, thiacyclopentyl group, thiacyclohexyl group, thiacycloheptyl group, and thianorbornyl group.

[0160] The above R b1 The number of ring members in the alicyclic and aliphatic heterocyclic structures of the group represented by is preferably 6 or more, more preferably 8 or more, even more preferably 9 to 15, and particularly preferably 10 to 13, from the viewpoint of further optimizing the diffusion length of the acid mentioned above.

[0161] The above R b1 Among these, monovalent groups containing alicyclic structures with 9 or more members and monovalent groups containing aliphatic heterocyclic structures with 9 or more members are preferred, adamantyl groups, hydroxyadamantyl groups, norbornanelactone-yl groups, and 5-oxo-4-oxatricyclo[4.3.1.13,8]undecane-yl groups are more preferred, and adamantyl groups are even more preferred.

[0162] The above R b2 Examples of fluorinated alkanediyl groups having 1 to 10 carbon atoms, as represented by the formula, include groups in which one or more hydrogen atoms of an alkanediyl group having 1 to 10 carbon atoms, such as a methanediyl group, an ethanediyl group, or a propanediyl group, are replaced with fluorine atoms.

[0163] Among these, SO3 - A fluorinated alkanediyl group in which a fluorine atom is bonded to a carbon atom adjacent to the group is preferred, and SO3 -A fluorinated alkanediyl group in which two fluorine atoms are bonded to carbon atoms adjacent to the group is more preferred, and 1,1-difluoromethanediyl group, 1,1-difluoroethanediyl group, 1,1,3,3,3-pentafluoro-1,2-propanediyl group, 1,1,2,2-tetrafluoroethanediyl group, 1,1,2,2-tetrafluorobutanediyl group, and 1,1,2,2-tetrafluorohexanediyl group are even more preferred.

[0164] The above M + As a monovalent radiodegradable onium cation represented by formula (1) of compound A, Y + Similar to the radiation-sensitive onium cation exemplified above can be used, such as sulfonium cations or iodonium cations.

[0165] Examples of radiation-sensitive acid generators include compounds represented by the following formulas (vi-1) to (vi-17) (hereinafter also referred to as "compounds (vi-1) to (vi-17)").

[0166] [ka]

[0167] [ka]

[0168] Among these, sulfonium salts are preferred as radiation-sensitive acid generators, with compounds (vi-1) to (vi-3) and compounds (vi-13) to (vi-17) being more preferred.

[0169] The lower limit of the content of the radiation-sensitive acid generator is preferably 2 parts by mass, more preferably 5 parts by mass, and even more preferably 10 parts by mass, per 100 parts by mass of compound A, from the viewpoint of improving the sensitivity and developability of the radiation-sensitive resin composition. The upper limit of the above content is preferably 100 parts by mass, more preferably 80 parts by mass, and even more preferably 50 parts by mass.

[0170] Further, the lower limit of the content of the radiation-sensitive acid generator is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, still more preferably 1 part by mass, and particularly preferably 3 parts by mass, relative to 100 parts by mass of Resin B. The upper limit of the above content is preferably 30 parts by mass, more preferably 20 parts by mass, and still more preferably 15 parts by mass. As the radiation-sensitive acid generator, one type or two or more types can be used.

[0171] <Acid diffusion control agent> The radiation-sensitive resin composition may optionally contain an acid diffusion control agent other than Compound A (hereinafter also referred to as "other acid diffusion control agent"). The other acid diffusion control agent exerts the effect of controlling the diffusion phenomenon in the resist film of the acid generated from the radiation-sensitive acid generator upon exposure, and suppressing undesirable chemical reactions in the unexposed 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 the change in the line width of the resist pattern due to the variation in the holding time from exposure to development processing can be suppressed, so that a radiation-sensitive resin composition with excellent process stability can be obtained.

[0172] Examples of the other acid diffusion control agent include a compound represented by the following formula (11) (hereinafter also referred to as "nitrogen-containing compound (I)"), a compound having two nitrogen atoms in the same molecule (hereinafter also referred to as "nitrogen-containing compound (II)"), a compound having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compound (III)"), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

[0173]

Chemical Formula

[0174] In the above formula (11), R 22 , R 23 and R 24Each of these is independently a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted aralkyl group.

[0175] Examples of nitrogen-containing compounds (I) include, Monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; Examples include trialkylamines such as triethylamine and aromatic amines such as aniline.

[0176] Examples of nitrogen-containing compounds (II) include ethylenediamine and N,N,N',N'-tetramethylethylenediamine.

[0177] Examples of nitrogen-containing compounds (III) include, Polyamine compounds such as polyethyleneimine and polyallylamine; Examples include polymers such as dimethylaminoethylacrylamide.

[0178] Examples of amide group-containing compounds include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, and N-methylpyrrolidone.

[0179] Examples of urea compounds include urea, methyl urea, 1,1-dimethyl urea, 1,3-dimethyl urea, 1,1,3,3-tetramethyl urea, 1,3-diphenyl urea, and tributylthiourea.

[0180] Examples of nitrogen-containing heterocyclic compounds include, Pyridines such as pyridine and 2-methylpyridine; Morpholines such as N-propylmorpholine and N-(undecylcarbonyloxyethyl)morpholine; Examples include pyrazines and pyrazoles.

[0181] Furthermore, compounds having acid-dissociable groups can also be used as the nitrogen-containing organic compounds mentioned above. Examples of nitrogen-containing organic compounds having acid-dissociable groups include Nt-butoxycarbonylpiperidine, Nt-butoxycarbonylimidazole, Nt-butoxycarbonylbenzimidazole, Nt-butoxycarbonyl-2-phenylbenzimidazole, N-(t-butoxycarbonyl)di-n-octylamine, N-(t-butoxycarbonyl)diethanolamine, N-(t-butoxycarbonyl)dicyclohexylamine, N-(t-butoxycarbonyl)diphenylamine, Nt-butoxycarbonyl-4-hydroxypiperidine, Nt-butoxycarbonyl-4-acetoxypiperidine, and Nt-amyloxycarbonyl-4-hydroxypiperidine.

[0182] Furthermore, as another acid diffusion control agent, a radiation-sensitive weak acid generator that generates a weak acid upon exposure can also be suitably used. The acid generated from the above-mentioned radiation-sensitive weak acid generator is a weak acid that does not induce the dissociation of the acid-dissociable groups in resin B under conditions that would normally cause dissociation of those groups. In this specification, "dissociation" of an acid-dissociable group refers to dissociation that occurs when post-exposure baking is performed at 110°C for 60 seconds.

[0183] Examples of radiation-sensitive weak acid generators include onium salt compounds that decompose upon exposure and lose their ability to control acid diffusion. Examples of onium salt compounds include sulfonium salt compounds represented by the following formula (12-1) and iodonium salt compounds represented by the following formula (12-2).

[0184] [ka]

[0185] In equations (12-1) and (12-2) above, J + It is a sulfonium cation, U + This is an iodonium cation.

[0186] J + Examples of sulfonium cations represented by the above formulas (X-1) to (X-3) include U + Examples of iodonium cations represented by the above formulas (X-4) to (X-5) include iodonium cations represented by the above formulas (X-4) to (X-5).

[0187] E - and Q - Each of them is independent of OH - , R α -COO - , R α -SO3 - This is an anion represented by [formula].

[0188] R α R is an alkyl group, an aryl group, or an aralkyl group. α The hydrogen atoms of the aromatic ring of the aryl or aralkyl group represented by may be substituted with a hydroxyl group, a fluorine-substituted or unsubstituted C1-C12 alkyl group, or a C1-C12 alkoxy group.

[0189] Examples of the above-mentioned radiation-sensitive weak acid generating agent include compounds represented by the following formula.

[0190] [ka]

[0191] [ka]

[0192] Among the above-mentioned radiation-sensitive weak acid generating agents, sulfonium salts are preferred, triarylsulfonium salts are more preferred, and triphenylsulfonium salicylate and triphenylsulfonium 10-camphorsulfonate are even more preferred.

[0193] The lower limit of the content of other acid diffusion control agents is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, even more preferably 1 part by mass, and particularly preferably 2 parts by mass, per 100 parts by mass of resin B. The upper limit of the above content is preferably 20 parts by mass, more preferably 15 parts by mass, and even more preferably 10 parts by mass.

[0194] By setting the content of other acid diffusion control agents within the above range, the lithography performance of the radiation-sensitive resin composition can be further improved. The radiation-sensitive resin composition may contain one or more other acid diffusion control agents.

[0195] <Solvent> The radiation-sensitive resin composition according to this embodiment contains a solvent. The solvent is not particularly limited as long as it is capable of dissolving or dispersing at least compound A, the base resin (at least one of the radiation-sensitive acid-generating resin and the resin), the radiation-sensitive acid-generating agent, and optionally contained additives.

[0196] Examples of solvents include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents.

[0197] Examples of alcohol-based solvents include, Monoalcohol solvents with 1 to 18 carbon atoms, such as iso-propanol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol, and diacetone alcohol; Polyhydric alcohol solvents with 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propylene glycol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol; Examples include polyhydric alcohol partial ether solvents, in which some of the hydroxyl groups of the above-mentioned polyhydric alcohol solvents have been etherified.

[0198] Examples of ether-based solvents include, Dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether; Cyclic ether solvents such as tetrahydrofuran and tetrahydropyran; Aromatic ring-containing ether solvents such as diphenyl ether and anisole (methylphenyl ether); Examples include polyhydric alcohol ether solvents, which are obtained by etherifying the hydroxyl groups of the above-mentioned polyhydric alcohol solvents.

[0199] Examples of ketone solvents include chain-like ketone solvents such as acetone, butanone, and methyl-iso-butyl ketone: Cyclopentanone, cyclohexanone, methylcyclohexanone, and other cyclic ketone solvents: Examples include 2,4-pentanedione, acetonylacetone, and acetophenone.

[0200] Examples of amide solvents include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; Examples include chain-like amide solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.

[0201] Examples of ester-based solvents include, Monocarboxylic acid ester solvents such as n-butyl acetate and ethyl lactate; Polyhydric alcohol 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-based solvents such as γ-butyrolactone and valerolactone; Carbonate-based solvents such as diethyl carbonate, ethylene carbonate, and propylene carbonate; Examples of polycarboxylic acid diester solvents include propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoacetate, ethyl lactate, and diethyl phthalate.

[0202] Examples of hydrocarbon solvents include, Aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; Examples include aromatic hydrocarbon solvents such as benzene, toluene, di-iso-propylbencene, and n-amylnaphthalene.

[0203] Among these, ester solvents and ketone solvents are preferred, polyhydric alcohol partial ether acetate solvents, cyclic ketone solvents, and lactone solvents are more preferred, and propylene glycol monomethyl ether acetate, cyclohexanone, and γ-butyrolactone are even more preferred. The above radiation-sensitive resin composition may contain one or more solvents.

[0204] <Other optional ingredients> The above-mentioned radiation-sensitive resin composition may contain other optional components in addition to the components listed above. Examples of these other optional components include crosslinking agents, segregation promoters, surfactants, alicyclic skeleton-containing compounds, sensitizers, and the like. These other optional components may be used individually or in combination of two or more types.

[0205] <Method for preparing a radiation-sensitive resin composition> The above radiation-sensitive resin composition can be prepared, for example, by mixing compound A, a base resin (at least one of a radiation-sensitive acid-generating resin and a regular resin), a radiation-sensitive acid-generating agent, a solvent, and other optional components as needed, in predetermined proportions. After mixing, the above radiation-sensitive resin composition is preferably filtered using a filter with a pore size of approximately 0.05 μm to 0.2 μm. The solid content concentration of the above radiation-sensitive resin composition is usually 0.1% to 50% by mass, preferably 0.5% to 30% by mass, and more preferably 1% to 20% by mass.

[0206] <Pattern Formation Method> The pattern formation method in this embodiment is The above radiation-sensitive resin composition is applied directly or indirectly to a substrate to form a resist film (1) (hereinafter also referred to as the "resist film formation step"), The above resist film is exposed (2) (hereinafter also referred to as the "exposure step"), and The process includes the step (3) of developing the exposed resist film with a developer solution (hereinafter also referred to as the "development step").

[0207] According to the pattern formation method described above, a high-quality resist pattern can be formed because the above-mentioned radiation-sensitive resin composition, which has excellent sensitivity and CDU performance in the exposure process, is used. The following describes each step.

[0208] [Resist film formation process] In this step (step (1) above), a resist film is formed using the radiation-sensitive resin composition. Examples of substrates for forming this resist film include conventionally known materials such as silicon wafers, silicon dioxide wafers, and aluminum-coated wafers. Alternatively, an organic or inorganic anti-reflective film, such as those disclosed in Japanese Patent Publication No. 6-12452 or Japanese Patent Publication No. 59-93448, may be formed on the substrate. Examples of coating methods include spin coating, casting, and roll coating. After coating, pre-baking (PB) may be performed as needed to volatilize the solvent in the coating film. The PB temperature is usually 60°C to 140°C, with 80°C to 120°C being preferred. The PB time is usually 5 seconds to 600 seconds, with 10 seconds to 300 seconds being preferred. The thickness of the formed resist film is preferably 10 nm to 1,000 nm, and more preferably 10 nm to 500 nm.

[0209] When performing immersion exposure, regardless of the presence or absence of water-repellent polymer additives such as the high-fluorine-content resin in the above-mentioned radiation-sensitive resin composition, a protective immersion film insoluble in the immersion liquid may be provided on the formed resist film to avoid direct contact between the immersion liquid and the resist film. As the protective immersion film, either a solvent-peelable protective film that is peeled off with a solvent before the development process (see, for example, Japanese Patent Application Publication No. 2006-227632) or a developer-peelable protective film that is peeled off simultaneously with development in the development process (see, for example, Japanese Patent Application Publication Nos. WO2005-069076 and WO2006-035790) may be used. However, from the viewpoint of throughput, it is preferable to use a developer-peelable protective immersion film.

[0210] Furthermore, when the subsequent exposure process is carried out with radiation of a wavelength of 50 nm or less, it is preferable to use a resin having the above structural units (I) to (IV), and optionally structural unit (V), as the base resin in the above composition.

[0211] [Synthesis process] In this step (step (2) above), the resist film formed in the resist film formation step (1) above is exposed by irradiating it with radiation through a photomask (and, in some cases, through an immersion medium such as water). The radiation used for exposure can be electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, EUV (extreme ultraviolet light), X-rays, and gamma rays, depending on the line width of the desired pattern; or charged particle beams such as electron beams and alpha rays. Among these, far ultraviolet light, electron beams, and EUV are preferred, ArF excimer laser light (wavelength 193 nm), KrF excimer laser light (wavelength 248 nm), electron beams, and EUV are more preferred, and electron beams and EUV with wavelengths of 50 nm or less, which are positioned as next-generation exposure technologies, are even more preferred.

[0212] When exposure is performed by immersion lithography, the immersion liquid used can be, for example, water or a fluorinated inert liquid. The immersion liquid is preferably transparent to the exposure wavelength and has the smallest possible temperature coefficient of refractive index to minimize distortion of the optical image projected onto the film. In particular, when the exposure light source is ArF excimer laser light (wavelength 193 nm), in addition to the above considerations, water is preferred due to its availability and ease of handling. When water is used, a small amount of an additive that reduces the surface tension of the water and increases its surfactant properties may be added. This additive is preferably one that does not dissolve the resist film on the wafer and has negligible effect on the optical coating on the underside of the lens. Distilled water is preferred as the water used.

[0213] After the exposure described above, it is preferable to perform a post-exposure bake (PEB) to promote the dissociation of acid-dissociable groups in the resin, etc., by the acid generated from the radiation-sensitive acid generator during exposure in the exposed portion of the resist film. This PEB creates a difference in solubility in the developer between the exposed and unexposed portions. The PEB temperature is usually 50°C to 180°C, with 80°C to 130°C being preferred. The PEB time is usually 5 seconds to 600 seconds, with 10 seconds to 300 seconds being preferred.

[0214] [Development process] In this step (step (3) above), the resist film exposed in the exposure step (step (2) above) is developed with a developer. This allows a predetermined resist pattern to be formed. After development, it is common to wash with a rinsing solution such as water or alcohol and then dry it.

[0215] In step (3), a negative pattern can be formed by developing with an organic solvent. Alternatively, in step (3), a positive pattern can be formed by developing with an alkaline developer.

[0216] Examples of developers used in the above development process include, in the case of alkaline development, an alkaline aqueous solution containing at least one alkaline compound such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0]-7-undecene, or 1,5-diazabicyclo-[4.3.0]-5-nonene. Among these, an aqueous TMAH solution is preferred, and a 2.38% by mass aqueous TMAH solution is more preferred.

[0217] Furthermore, in the case of organic solvent development, examples of organic solvents include hydrocarbon solvents, ether solvents, ester solvents, ketone solvents, alcohol solvents, or solvents containing organic solvents. Examples of the above organic solvents include one or more of the solvents listed above as solvents for the radiation-sensitive resin composition. Among these, ester solvents and ketone solvents are preferred. As for ester solvents, acetic acid ester solvents are preferred, and n-butyl acetate and amyl acetate are more preferred. As for ketone solvents, chain ketones are preferred, and 2-heptanone is more preferred. The content of organic solvent in the developer is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and particularly preferably 99% by mass or more. Examples of components other than organic solvents in the developer include water and silicone oil. The radiation-sensitive resin composition of the present invention can be used particularly suitably when the process includes a step of developing with an organic solvent to form a negative pattern.

[0218] Examples of development methods include immersing the substrate in a tank filled with developer solution for a certain period of time (dip method), developing by piling the developer solution onto the substrate surface using surface tension and letting it remain still for a certain period of time (paddle method), spraying the developer solution onto the substrate surface (spray method), and continuously dispensing the developer solution onto a substrate rotating at a constant speed while scanning the developer solution dispensing nozzle at a constant speed (dynamic dispensing method).

[0219] <Manufacturing method for substrates> The method for manufacturing the substrate in this embodiment is: The process includes (4) forming a pattern on a substrate using the pattern formed by the above method as a mask.

[0220] According to the above-described substrate manufacturing method, since the above-described pattern is used, a high-quality substrate can be efficiently formed.

[0221] In step (4) described above, a known method can be used as appropriate for forming a pattern on the substrate using the above pattern as a mask. [Examples]

[0222] The present invention will be specifically described below with reference to synthesis examples, examples, and comparative examples, but the present invention is not limited to the following examples. The methods for measuring various physical properties are shown below.

[0223] [Mw and Mn] The Mw and Mn of the polymer were measured by gel permeation chromatography (GPC) using Tosoh Corporation's GPC columns (two "G2000HXL", one "G3000HXL", and one "G4000HXL") under the following conditions. Eluent: Tetrahydrofuran (manufactured by Wako Pure Chemical Industries, Ltd.) Flow rate: 1.0mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Column temperature: 40℃ Detector: Differential refractometer Standard material: Monodisperse polystyrene

[0224] [ 13 C-NMR analysis] polymer 13 1C-NMR analysis was performed using a nuclear magnetic resonance spectrometer (JEOL Ltd.'s "JNM-Delta400"). Deuterated chloroform was used as the measurement solvent.

[0225] <Synthesis of resins and high-fluorine content resins> The monomers used in the synthesis of each resin and high-fluorine-content resin in each example and comparative example are shown below. In the following synthesis examples, unless otherwise specified, parts by mass refers to the value when the total mass of the monomers used is 100 parts by mass, and mol% refers to the value when the total number of moles of the monomers used is 100 mol%.

[0226] [ka]

[0227] [Synthesis Example 1] (Synthesis of resin (A-1)) Monomer (M-1), monomer (M-2), and monomer (M-13) were dissolved in 2-butanone (200 parts by mass) in a molar ratio of 40 / 15 / 45 (mol%), and AIBN (azobisisobutyronitrile) (3 mol% relative to the total 100 mol% of the monomers used) was added as an initiator to prepare monomer solutions.

[0228] 100 parts by mass of 2-butanone were placed in a reaction vessel, and after purging with nitrogen for 30 minutes, the temperature inside the reaction vessel was raised to 80°C. The monomer solution was then added dropwise over 3 hours while stirring. The start of the dropwise addition was defined as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was cooled to below 30°C by water cooling. The cooled polymerization solution was added to methanol (2,000 parts by mass), and the precipitated white powder was filtered off.

[0229] The filtered white powder was washed twice with methanol, filtered again, and dried at 50°C for 24 hours to obtain a white powdered resin (A-1) (yield: 83%). The Mw of resin (A-1) was 8,800, and the Mw / Mn ratio was 1.50. 13 13C-NMR analysis revealed that the content of each structural unit derived from (M-1), (M-2), and (M-13) was 41.3 mol%, 13.8 mol%, and 44.9 mol%, respectively.

[0230] [Synthesis Examples 1-11] (Synthesis of resins (A-2) to (A-11)) Resins (A-2) to (A-11) were synthesized in the same manner as in Synthesis Example 1, except that the monomers used were of the types and proportions shown in Table 1 below. The content (mol%), yield (%), and physical properties (Mw and Mw / Mn) of each structural unit of the obtained resins are also shown in Table 1 below. In Table 1 below, "-" indicates that the corresponding monomer was not used (the same applies to subsequent tables).

[0231] [Table 1]

[0232] [Synthesis Example 12] (Synthesis of resin (A-12)) Monomer (M-1) and monomer (M-18) were dissolved in 1-methoxy-2-propanol (200 parts by mass) to a molar ratio of 50 / 50 (mol%), and AIBN (5 mol%) was added as an initiator to prepare monomer solutions.

[0233] 100 parts by mass of 1-methoxy-2-propanol was placed in a reaction vessel, and after purging with nitrogen for 30 minutes, the temperature inside the reaction vessel was raised to 80°C, and the monomer solution was added dropwise over 3 hours while stirring. The start of the dropwise addition was defined as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was cooled to below 30°C by water cooling. The cooled polymerization solution was added to hexane (2,000 parts by mass), and the precipitated white powder was filtered off.

[0234] The filtered white powder was washed twice with hexane, filtered again, and dissolved in 1-methoxy-2-propanol (300 parts by mass). Then, methanol (500 parts by mass), triethylamine (50 parts by mass), and ultrapure water (10 parts by mass) were added, and the hydrolysis reaction was carried out at 70°C for 6 hours with stirring.

[0235] After the reaction was complete, the residual solvent was removed by distillation, and the resulting solid was dissolved in acetone (100 parts by mass) and added dropwise to water (500 parts by mass) to solidify the resin. The resulting solid was filtered off and dried at 50°C for 13 hours to obtain a white powdered resin (A-12) (yield: 79%). The Mw of resin (A-12) was 5,200, and the Mw / Mn ratio was 1.60. 13 1C-NMR analysis revealed that the content of each structural unit derived from (M-1) and (M-18) was 51.3 mol% and 48.7 mol%, respectively.

[0236] [Synthesis Examples 13-15] (Synthesis of resin (A-13) to resin (A-15)) Resins (A-13) to (A-15) were synthesized in the same manner as in Synthesis Example 12, except that the monomers used were of the types and proportions shown in Table 2 below. The content (mol%), yield (%), and physical properties (Mw and Mw / Mn) of each structural unit of the obtained resins are also shown in Table 2 below.

[0237] [Table 2]

[0238] [Synthesis Example 16] (Synthesis of high-fluorine content resin (E-1)) Monomer (M-1) and monomer (M-20) were dissolved in 200 parts by mass of 2-butanone to a molar ratio of 20 / 80 (mol%), and AIBN (4 mol%) was added as an initiator to prepare a monomer solution.

[0239] 100 parts by mass of 2-butanone was placed in a reaction vessel, and after purging with nitrogen for 30 minutes, the temperature inside the reaction vessel was raised to 80°C. The monomer solution was then added dropwise over 3 hours while stirring. The start of the dropwise addition was defined as the start time of the polymerization reaction, and the polymerization reaction was carried out for 6 hours. After the polymerization reaction was completed, the polymerization solution was cooled to below 30°C by water cooling. The solvent was replaced with acetonitrile (400 parts by mass), and then hexane (100 parts by mass) was added and stirred, and the acetonitrile layer was recovered. This process was repeated three times.

[0240] A solution of the high-fluorine-content resin (E-1) was obtained by substituting the solvent with propylene glycol monomethyl ether acetate (yield: 69%). The Mw of the high-fluorine-content resin (E-1) was 6,000, and the Mw / Mn ratio was 1.62. 13 13C-NMR analysis revealed that the content of each structural unit derived from (M-1) and (M-20) was 19.9 mol% and 80.1 mol%, respectively.

[0241] [Synthesis Examples 17-20] (Synthesis of high-fluorine content resins (E-2) to high-fluorine content resins (E-5)) High-fluorine-content resins (E-2) to (E-5) were synthesized in the same manner as in Synthesis Example 16, except that monomers of the types and proportions shown in Table 3 below were used. The content (mol%), yield (%), and physical properties (Mw and Mw / Mn) of each structural unit of the obtained high-fluorine-content resins are shown in accordance with Table 3 below.

[0242] [Table 3]

[0243] <Synthesis of acid diffusion control agent C> [Synthesis Example 21] (Synthesis of compound (C-1)) Compound (C-1) was synthesized according to the following synthesis scheme.

[0244] [ka]

[0245] 20.0 mmol of 1,1-cyclobutanedicarboxylic acid, 20.0 mmol of lithium hydroxide, and 20.0 mmol of diphenyl(p-tolyl)sulfonium bromide were added to a reaction vessel, and a mixture of water and dichloromethane (1:3 by mass ratio) was added to make a 0.5 M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was removed by distillation, and the compound (C-1) represented by the above formula (C-1) was obtained in good yield.

[0246] [Synthesis Examples 22-29] (Synthesis of compounds (C-2) to (C-9)) The onium salts represented by the following formulas (C-2) to (C-9) were synthesized in the same manner as in Synthesis Example 21, except that the raw materials and precursors were changed as appropriate.

[0247] [ka]

[0248] [Synthesis Example 30] (Synthesis of compound (C-10)) Compound (C-10) was synthesized according to the following synthesis scheme.

[0249] [ka]

[0250] 20.0 mmol of ethyl bromoacetate, 25.0 mmol of zinc powder, 2.00 mmol of chlorotrimethylsilane, and 50 g of tetrahydrofuran were added to a reaction vessel and stirred at room temperature for 1 hour. Then, 20.0 mmol of cyclobutanone was added to the reaction solution and stirred for a further 8 hours at room temperature. After that, saturated aqueous ammonium chloride solution was added to the reaction solution to terminate the reaction, and then ethyl acetate was added for extraction, separating the organic layer. The obtained organic layer was washed with saturated aqueous sodium chloride solution and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the alcohol compound was obtained in good yield by column chromatography.

[0251] A 1 M solution was prepared by adding a mixture of ethanol and water (1:1 by mass) to the above alcohol mixture. Then, 20.0 mmol of lithium hydroxide was added, and the mixture was reacted at 50°C for 2 hours. The lithium salt derivative was obtained by extraction with acetonitrile and evaporation to remove the solvent. 20.0 mmol of tri-p-tolylsulfonium bromide was added to the lithium salt derivative, and a mixture of water and dichloromethane (1:3 by mass) was added. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was evaporated, and the compound (C-10) represented by the above formula (C-10) was obtained in good yield by recrystallization.

[0252] [Synthesis Examples 31-33] (Synthesis of compounds (C-11) to (C-13)) Except for appropriately changing the raw materials and precursors, the onium salts represented by the following formulas (C-11) to (C-13) were synthesized in the same manner as in Synthesis Example 30.

[0253] [ka]

[0254] [Synthesis Example 34] (Synthesis of compound (C-14)) Compound (C-14) was synthesized according to the following synthesis scheme.

[0255] [ka]

[0256] 20.0 mmol of compound (C-13), 25.0 mmol of acetyl chloride, 25.0 mmol of triethylamine, and 50 g of dichloromethane were added to a reaction vessel and stirred at room temperature for 10 hours. Then, saturated aqueous ammonium chloride solution was added to the reaction solution to terminate the reaction, and dichloromethane was added for extraction, separating the organic layer. The obtained organic layer was washed with saturated aqueous sodium chloride solution, and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the compound (C-14), represented by the above formula (C-14), was obtained in good yield.

[0257] [Synthesis Example 35] (Synthesis of compound (C-15)) Compound (C-15) was synthesized according to the following synthesis scheme.

[0258] [ka]

[0259] 20.0 mmol of ethyl bromodifluoroethyl acetate, 25.0 mmol of cyclobutanol, 30.0 mmol of 1,8-diazabicyclo[5,4,0]-7-undecene, and 50 g of dimethylformamide were added to a reaction vessel and stirred at 50°C for 4 hours. Then, saturated aqueous ammonium chloride solution was added to the reaction solution to terminate the reaction, followed by extraction with ethyl acetate to separate the organic layer. The obtained organic layer was washed with saturated aqueous sodium chloride solution and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the ester was purified by column chromatography to obtain the ester in good yield.

[0260] The above ester was mixed with ethanol and water (1:1 by mass) to make a 1 M solution, then 20.0 mmol of lithium hydroxide was added and the mixture was reacted at room temperature for 7 hours. The lithium salt derivative was obtained by extraction with acetonitrile and evaporation to remove the solvent. 20.0 mmol of triphenylsulfonium bromide was added to the lithium salt derivative, and a mixture of water and dichloromethane (1:3 by mass) was added. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was evaporated, and the compound (C-15) represented by the above formula (C-15) was obtained in good yield by recrystallization.

[0261] [Synthesis Example 36] (Synthesis of compound (C-16)) Compound (C-16) was synthesized according to the following synthesis scheme.

[0262] [ka]

[0263] 20.0 mmol of cyclobutanecarboxylic acid, 20.0 mmol of sodium isethionate, 30.0 mmol of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride, and 50 g of chloroform were added to a reaction vessel and stirred at 50°C for 8 hours. The reaction solution was then diluted with water, extracted with acetonitrile, and the solvent was removed by distillation to obtain the sodium salt derivative. 20.0 mmol of triphenylsulfonium bromide was added to the sodium salt derivative, and a mixture of water and dichloromethane (1:3 by mass) was added. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The obtained organic layer was dried over sodium sulfate, the solvent was removed by distillation, and the compound (C-16) represented by the above formula (C-16) was obtained in good yield.

[0264] [Synthesis Examples 37-39] (Synthesis of compounds (C-17) to (C-19)) The onium salts represented by the following formulas (C-17) to (C-19) were synthesized in the same manner as in Synthesis Example 34, except that the raw materials and precursors were changed as appropriate.

[0265] [ka]

[0266] [Synthesis Example 40] (Synthesis of compound (C-20)) Compound (C-20) was synthesized according to the following synthesis scheme.

[0267] [ka]

[0268] 20.0 mmol of cyclobutanemethanol, 20.0 mmol of bromoacetylbromide, 30.0 mmol of triethylamine, and 50 g of tetrahydrofuran were added to a reaction vessel and stirred at room temperature for 4 hours. Then, saturated aqueous ammonium chloride solution was added to the reaction solution to terminate the reaction, and ethyl acetate was added for extraction, separating the organic layer. The obtained organic layer was washed with saturated aqueous sodium chloride solution and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the brominated compound was obtained in good yield by column chromatography.

[0269] The above bromo compound was mixed with acetonitrile and water (1:1 by mass) to make a 1 M solution. Then, 40.0 mmol of sodium dithionite and 60.0 mmol of sodium bicarbonate were added, and the mixture was reacted at 70°C for 5 hours. After extraction with acetonitrile and removal of the solvent, a mixture of acetonitrile and water (3:1 by mass) was added to make a 0.5 M solution. 60.0 mmol of hydrogen peroxide and 2.00 mmol of sodium tungstate were added, and the mixture was heated and stirred at 50°C for 12 hours. The sodium sulfonate salt compound was obtained by extraction with acetonitrile and removal of the solvent. 20.0 mmol of diphenyl(p-tolyl)sulfonium bromide was added to the above sodium sulfonate salt compound, and a mixture of water and dichloromethane (1:3 by mass) was added to make a 0.5 M solution. After vigorous stirring at room temperature for 3 hours, dichloromethane was added for extraction, and the organic layer was separated. The resulting organic layer was dried over sodium sulfate, the solvent was removed by distillation, and the compound (C-20) represented by the above formula (C-20) was obtained in good yield by recrystallization.

[0270] [Synthesis Examples 41-43] (Synthesis of compounds (C-21) to (C-23)) The onium salts represented by the following formulas (C-21) to (C-23) were synthesized in the same manner as in Synthesis Example 38, except that the raw materials and precursors were changed as appropriate.

[0271] [ka]

[0272] [Onium salts other than compounds (C-1) to (C-21)] cc-1 to cc-10: Compounds represented by the following formulas (cc-1) to (cc-10) (Hereafter, compounds represented by formulas (cc-1) to (cc-10) may be referred to as "compound (cc-1)" to "compound (cc-10)," respectively.)

[0273] [ka]

[0274] [[B] Radiation-sensitive acid generator] B-1 to B-8: Compounds represented by the following formulas (B-1) to (B-8) (Hereafter, compounds represented by formulas (B-1) to (B-8) may be referred to as "compound (B-1)" to "compound (B-8)," respectively.)

[0275] [ka]

[0276] [[D] Solvent] D-1: Propylene glycol monomethyl ether acetate D-2: Propylene glycol monomethyl ether D-3: γ-Butyrolactone D-4: Ethyl lactate

[0277] [Preparation of negative-type radiation-sensitive resin composition for ArF exposure] [Example 1] A radiation-sensitive resin composition (J-1) was prepared by mixing [A] 100 parts by mass of (A-1) as a resin, [B] 10.0 parts by mass of (B-1) as a radiation-sensitive acid generator, [C] 5.0 parts by mass of (C-1) as an acid diffusion control agent, [E] 3.0 parts by mass (solids) of (E-1) as a high-fluorine-content resin, and [D] 3,230 parts by mass of a mixed solvent of (D-1) / (D-2) / (D-3) as a solvent, and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0278] [Examples 2-53 and Comparative Examples 1-10] Radiation-sensitive resin compositions (J-2) to (J-53) and (CJ-1) to (CJ-10) were prepared in the same manner as in Example 1, except that the components used were of the types and in the amounts shown in Table 4 below.

[0279] [Table 4]

[0280] <Formation of Resist Pattern Using Negative Radiation-Sensitive Resin Composition for ArF Exposure> On a 12-inch silicon wafer, using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Limited), the composition for forming a lower anti-reflective coating ("ARC66" manufactured by Brewer Science Inc.) was applied, followed by heating at 205°C for 60 seconds to form a lower anti-reflective coating with an average thickness of 100 nm.

[0281] On this lower anti-reflective coating, using the above spin coater, the above-prepared negative radiation-sensitive resin composition for ArF exposure was applied, and PB (pre-bake) was performed at 100°C for 60 seconds. Thereafter, by cooling at 23°C for 30 seconds, a resist film with an average thickness of 90 nm was formed. Next, this resist film was exposed through a mask pattern of 40 nm holes and 105 nm pitch under optical conditions of NA=1.35 and Dipole (σ=0.9 / 0.7) using an ArF excimer laser immersion exposure apparatus ("TWINSCAN XT-1900i" manufactured by ASML Holding N.V.).

[0282] After exposure, PEB (post-exposure bake) was performed at 100°C for 60 seconds. Thereafter, the resist film was subjected to organic solvent development using n-butyl acetate as an organic solvent developer, followed by drying, to form a negative resist pattern (40 nm holes, 105 nm pitch).

[0283] <Evaluation> With respect to the resist pattern formed using the above negative radiation-sensitive resin composition for ArF exposure, sensitivity, LWR performance and pattern rectangularity were evaluated according to the following methods. The results are shown in Table 5 below. A scanning electron microscope ("CG-5000" manufactured by Hitachi High-Technologies Corporation) was used for measuring the resist pattern dimensions.

[0284] [Sensitivity] In the formation of a resist pattern using the above negative radiation-sensitive resin composition for ArF exposure, the exposure dose that forms a 40 nm hole pattern was defined as the optimal exposure dose, and this optimal exposure dose was taken as the sensitivity (mJ / cm 2The sensitivity was set to 30 mJ / cm². 2 The following cases are considered "good" and 30 mJ / cm². 2 If it exceeded this value, it was rated as "poor."

[0285] [CDU performance] A resist pattern with 40 nm holes and a 105 nm pitch was measured at 1,800 arbitrary points from the top of the pattern using the scanning electron microscope described above. The dimensional variation (3σ) was determined and defined as the CDU performance (nm). A smaller CDU value indicates less variation in hole diameter over long periods, resulting in better performance. CDU performance was evaluated as "good" if it was 2.5 nm or less, and "poor" if it exceeded 2.5 nm.

[0286] [depth of focus] In the resist pattern resolved at the optimal exposure level determined by the sensitivity evaluation above, the dimensions were observed when the focus was changed in the depth direction. The margin in the depth direction where the pattern dimensions fall within 90% to 110% of the standard without bridging or residue was measured, and this measured value was defined as the depth of focus (nm). A larger depth of focus indicates a better result. A depth of focus of 70nm or more is evaluated as "good," and a depth of focus of less than 70nm is evaluated as "poor."

[0287] [Pattern Rectangle] The resist patterns with 40 nm hole spaces, formed by irradiating with the optimal exposure dose determined in the sensitivity evaluation above, were observed using the scanning electron microscope described above, and the cross-sectional shape of the hole patterns was evaluated. The rectangularity of the resist patterns was evaluated as follows: if the ratio of the length of the upper side to the length of the lower side in the cross-sectional shape was 1 or more and 1.05 or less, it was "A" (excellent); if it was greater than 1.05 and 1.10 or less, it was "B" (good); and if it was greater than 1.10, it was "C" (poor).

[0288] [Table 5]

[0289] As is clear from the results in Table 5, the radiation-sensitive resin compositions of Examples exhibited good sensitivity, CDU performance, depth of focus and pattern rectangularity when used for ArF exposure, whereas each property of Comparative Examples was inferior to that of Examples. Therefore, when the radiation-sensitive resin compositions of Examples are used for ArF exposure, it is possible to form a resist pattern with high sensitivity, favorable CDU performance and depth of focus, and excellent rectangularity.

[0290] [[ID=4)][Preparation of Radiation-Sensitive Resin Composition for Extreme Ultraviolet (EUV) Exposure] [Example 54] 100 parts by mass of (A-12) as the [A] resin, 15.0 parts by mass of (B-7) as the [B] radiation-sensitive acid generator, 8.0 parts by mass of (C-1) as the [C] acid diffusion controller, 3.0 parts by mass (solid content) of (E-5) as the [E] high fluorine content resin, and 6,110 parts by mass of a mixed solvent of (D-1) / (D-4) as the [D] solvent were mixed, and the mixture was filtered through a membrane filter with a pore size of 0.2 μm to prepare a radiation-sensitive resin composition (J-54).

[0291] [Examples 55 to 66 and Comparative Examples 11 to 14] Radiation-sensitive resin compositions (J-55) to (J-66) and (CJ-11) to (CJ-14) were prepared in the same manner as in Example 54, except that the components of the types and contents shown in Table 6 below were used.

[0292] [Table 6]

[0293] <Formation of Resist Pattern Using Radiation-Sensitive Resin Composition for EUV Exposure> On a 12-inch silicon wafer, using a spin coater ("CLEAN TRACK ACT12" manufactured by Tokyo Electron Limited), a composition for forming an underlayer antireflective film ("ARC66" manufactured by Brewer Science, Inc.) was applied, followed by heating at 205°C for 60 seconds to form an underlayer antireflective film having an average thickness of 105 nm.

[0294] The radiation-sensitive resin composition for EUV exposure prepared above was applied to this lower anti-reflective film using the spin coater described above, and PB (Photon Blast) was performed at 130°C for 60 seconds. Subsequently, a resist film with an average thickness of 55 nm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using an EUV exposure apparatus (ASML's "NXE3300") with NA=0.33, illumination conditions: Conventional s=0.89, and mask: imecDEFECT32FFR02.

[0295] After exposure, PEB was performed at 120°C for 60 seconds. Subsequently, the resist film was alkaline developed using a 2.38% by mass aqueous TMAH solution as the alkaline developer. After development, it was washed with water and then dried to form a positive-type resist pattern (32 nm line and space pattern).

[0296] <Rating> The sensitivity and LWR performance of resist patterns formed using the above-described radiation-sensitive resin composition for EUV exposure were evaluated according to the method described below. The results are shown in Table 7. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG-5000") was used to measure the length of the resist patterns.

[0297] [sensitivity] In forming a resist pattern using the above-mentioned radiation-sensitive resin composition for EUV exposure, the exposure amount for forming a 32nm line-and-space pattern is defined as the optimal exposure amount, and this optimal exposure amount is set to the sensitivity (mJ / cm²). 2 The sensitivity was set to 25 mJ / cm². 2 The following cases are considered "good" and 25 mJ / cm². 2 If it exceeded this value, it was rated as "poor."

[0298] [LWR performance] The mask size was adjusted to form a 32nm line-and-space pattern by irradiating with the optimal exposure amount determined in the sensitivity evaluation described above, and a resist pattern was formed. The formed resist pattern was observed from the top of the pattern using the scanning electron microscope described above. The line width variation was measured at a total of 500 points, and the 3-sigma value was determined from the distribution of these measurements. This 3-sigma value was defined as LWR (nm). A smaller LWR value indicates less line jaggedness and better performance. LWR performance was evaluated as "good" if it was 2.5nm or less, and "poor" if it was greater than 2.5nm.

[0299] [Table 7]

[0300] As is clear from the results in Table 7, the radiation-sensitive resin composition of the example showed good sensitivity and LWR performance when used in EUV exposure, whereas the comparative example exhibited inferior characteristics compared to the example.

[0301] [Preparation of positive-type radiation-sensitive resin composition for ArF exposure] [Example 67] A radiation-sensitive resin composition (J-67) was prepared by mixing [A] 100 parts by mass of (A-6) as a resin, [B] 10.0 parts by mass of (B-2) as a radiation-sensitive acid generator, [C] 8.0 parts by mass of (C-1) as an acid diffusion control agent, [E] 5.0 parts by mass of (E-2) as a high-fluorine-content resin (solids), and [D] 3,230 parts by mass of a mixed solvent of (D-1) / (D-2) / (D-3) as a solvent, and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0302] [Examples 68-79 and Comparative Examples 15-18] Radiation-sensitive resin compositions (J-68) to (J-79) and (CJ-15) to (CJ-18) were prepared in the same manner as in Example 66, except that the components used were of the types and in the amounts shown in Table 8 below.

[0303] [Table 8]

[0304] An anti-reflective underlayer film with an average thickness of 100 nm was formed on a 12-inch silicon wafer by applying an anti-reflective underlayer film formation composition ("ARC66" from Brewer Science) using a spin coater ("CLEAN TRACK ACT12" from Tokyo Electron Limited), and then heating at 205°C for 60 seconds.

[0305] The ArF exposure positive-type radiation-sensitive resin composition prepared above was applied to this lower anti-reflective layer using the spin coater, and pre-bake (PB) was performed at 100°C for 60 seconds. Subsequently, a resist film with an average thickness of 90 nm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using an ArF excimer laser immersion lithography system (ASML's "TWINSCAN XT-1900i") under optical conditions of NA=1.35 and Annular (σ=0.8 / 0.6) through a 50 nm line-and-space mask pattern.

[0306] After exposure, post-exposure baking (PEB) was performed at 100°C for 60 seconds. Subsequently, the resist film was alkaline developed using a 2.38% by mass aqueous TMAH solution as the alkaline developer. After development, it was washed with water and then dried to form a positive-type resist pattern (50 nm line and space pattern).

[0307] <Rating> The sensitivity and LWR performance of resist patterns formed using the above-described radiation-sensitive resin composition for ArF exposure were evaluated according to the method described below. The results are shown in Table 9 below. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG-5000") was used to measure the length of the resist patterns.

[0308] [sensitivity] In forming a resist pattern using the above-mentioned radiation-sensitive resin composition for ArF exposure, the exposure amount used to form a 50 nm line-and-space pattern is defined as the optimal exposure amount, and this optimal exposure amount is set to the sensitivity (mJ / cm²). 2 The sensitivity was set to 30 mJ / cm². 2 The following cases are considered "good" and 30 mJ / cm². 2 If it exceeded this value, it was rated as "poor."

[0309] [LWR performance] The mask size was adjusted to form a 50nm line-and-space pattern by irradiating with the optimal exposure amount determined in the sensitivity evaluation described above, and a resist pattern was formed. The formed resist pattern was observed from the top of the pattern using the scanning electron microscope described above. The line width variation was measured at a total of 500 points, and the 3-sigma value was determined from the distribution of these measurements. This 3-sigma value was defined as LWR (nm). A smaller LWR value indicates less line jaggedness and better performance. LWR performance was evaluated as "good" if it was 2.0nm or less, and "poor" if it was greater than 2.0nm.

[0310] [Table 9]

[0311] As is clear from the results in Table 9, the radiation-sensitive resin composition of the example showed good sensitivity and LWR performance when used in ArF exposure, whereas the comparative example exhibited inferior characteristics compared to the example.

[0312] [Preparation of negative-type radiation-sensitive resin composition for EUV exposure, formation and evaluation of resist patterns using this composition] [Example 80] A radiation-sensitive resin composition (J-80) was prepared by mixing [A] 100 parts by mass of (A-13) as a resin, [B] 18.0 parts by mass of (B-1) as a radiation-sensitive acid generator, [C] 10.0 parts by mass of (C-11) as an acid diffusion control agent, [E] 1.0 part by mass (solids) of (E-5) as a high-fluorine-content resin, and [D] 6,110 parts by mass of a mixed solvent of (D-1) / (D-4) as a solvent, and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0313] An anti-reflective underlayer film with an average thickness of 105 nm was formed on a 12-inch silicon wafer by applying an anti-reflective underlayer film formation composition ("ARC66" from Brewer Science) using a spin coater ("CLEAN TRACK ACT12" from Tokyo Electron Limited), and then heating at 205°C for 60 seconds.

[0314] The radiation-sensitive resin composition (J-80) prepared for EUV exposure, as described above, was applied to this underlayer anti-reflective coating using the spin coater, and PB (Photon Blast) was performed at 130°C for 60 seconds. Subsequently, a resist film with an average thickness of 55 nm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using an EUV exposure apparatus (ASML's "NXE3300") with NA=0.33, illumination conditions: Conventional s=0.89, and mask: imecDEFECT32FFR02.

[0315] After exposure, PEB was performed at 120°C for 60 seconds. Subsequently, the resist film was developed using n-butyl acetate as the organic solvent developer and dried to form a negative-type resist pattern (40 nm holes, 105 nm pitch).

[0316] The resist patterns using the above-mentioned negative-type radiation-sensitive resin composition for EUV exposure were evaluated in the same manner as the resist patterns using the above-mentioned negative-type radiation-sensitive resin composition for ArF exposure. As a result, the radiation-sensitive resin composition of Example 80 showed good sensitivity and CDU performance even when a negative-type resist pattern was formed by EUV exposure. [Industrial applicability]

[0317] The radiation-sensitive resin composition and resist pattern formation method described above allow for the formation of resist patterns with good sensitivity to exposure light and excellent CDU performance. Therefore, these can be suitably used in semiconductor device processing processes and the like, where further miniaturization is expected in the future.

Claims

1. Compound A, represented by the following formula (3), 【Chemistry 1】 (In the formula, R3 is a monovalent organic group, a fluorine atom, or a hydroxyl group. L1 and L2 are independently divalent organic groups having 1 to 3 carbon atoms. X １ This is a group represented by the following formula (1-1) or a group represented by the following formula (1-2). X ２ This is a group represented by the following formula (2-1) or the following formula (2-2). Z is a divalent group represented as -C(R4)2- or -CO-. Each of the R4 components is independently a hydrogen atom, a monovalent organic group, a fluorine atom, or a hydroxyl group. Y ＋ This is a monovalent onium cation. m is an integer between 1 and 2. m' is an integer between 0 and 1. q is an integer between 0 and 1. p is an integer between 0 and (6 - m - m'). 【Chemistry 2】 (In the formula, * represents a bond with another group.) Resin B containing a structural unit having an acid-dissociable group, A radiation-sensitive acid generator other than compound A, and solvent A radiation-sensitive resin composition containing [a specific substance].

2. The radiation-sensitive resin composition according to claim 1, wherein the compound A is represented by the following formula (4-1) or the following formula (4-2). 【Transformation 3】 (In the formula, L １ , L ２ , X １ , X ２ , Y ＋ Z, m, m', p, and q are the same as in equation (3). R3 is a monovalent organic group having 1 to 5 carbon atoms, a fluorine atom, or a hydroxyl group.

3. Y ＋ The radiation-sensitive resin composition according to claim 1 or 2, wherein is a monovalent radiation-decomposable onium cation.

4. The radiation-sensitive resin composition according to claim 1 or 2, wherein the radiation-sensitive acid generator comprises a compound represented by the following formula (10). R ｂ１ -R ｂ２ -SO ３ － M ＋ (10) (In the formula, R ｂ１ This refers to a monovalent group containing an alicyclic structure or a monovalent group containing an aliphatic heterocyclic structure. R ｂ２ This is a fluorinated alkanediyl group having 1 to 10 carbon atoms. M ＋ (This is a monovalent radiodegradable onium cation.)

5. The radiation-sensitive resin composition according to claim 4, wherein the radiation-sensitive onium cation in formula (10) is a sulfonium cation or an iodonium cation.

6. The radiation-sensitive resin composition according to claim 1 or 2, wherein the structural unit having an acid-dissociable group in the resin B is represented by the following formula (6). 【Chemistry 4】 (In the formula, R ５ This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R ６ It is a monovalent hydrocarbon group having 1 to 20 carbon atoms. R ７ and R ８ Each of these independently comprises a monovalent linear hydrocarbon group having 1 to 10 carbon atoms or a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, or R ７ and R ８ These are divalent alicyclic groups with 3 to 20 carbon atoms, formed by combining them with the carbon atoms to which they are bonded.

7. The radiation-sensitive resin composition according to claim 1 or 2, wherein the resin B further comprises a structural unit comprising at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure.

8. A step (1) of applying the radiation-sensitive resin composition according to claim 1 or 2 directly or indirectly onto a substrate to form a resist film, The steps of (2) exposing the resist film and A method for forming a pattern, comprising the step (3) of developing the exposed resist film.

9. The pattern forming method according to claim 8, wherein the radiation used in the exposure step (2) is ArF excimer laser light, extreme ultraviolet (EUV), X-rays, or electron beam (EB).

10. The method for forming a pattern according to claim 8, wherein in step (3) above, the pattern is developed with an organic solvent to form a negative type pattern.

11. The method for forming a pattern according to claim 8, wherein in step (3) above, the pattern is developed with an alkaline developer to form a positive type pattern.

12. A method for manufacturing a substrate, comprising the step (4) of forming a pattern on a substrate using a pattern formed by the method of claim 8 as a mask.

13. Compound A represented by the following formula (3), 【Transformation 5】 (In the formula, R3 is a monovalent organic group, a fluorine atom, or a hydroxyl group. L1 and L2 are, independently, single-bonded or divalent organic groups. X1 is a group represented by the following formula (1-1) or a group represented by the following formula (1-2). X2 is a group represented by the following formula (2-1) or the following formula (2-2). Z is a divalent group represented as -C(R4)2- or -CO-. Each of the R4 components is independently a hydrogen atom, a monovalent organic group, a fluorine atom, or a hydroxyl group. Y+ is a monovalent onium cation. m is an integer between 1 and 2. m' is 1. q is an integer between 0 and 1. p is an integer between 0 and (6 - m - m'). 【Transformation 6】 (In the formula, * represents a bond with another group.) Resin B containing a structural unit having an acid-dissociable group, A radiation-sensitive acid generator other than compound A, and solvent A radiation-sensitive resin composition containing [a specific substance].

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