Radiation-sensitive composition, pattern formation method, and compound

Abstract

The purpose of the present invention is to provide: a radiation-sensitive composition that makes it possible to achieve sufficient levels of sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity during resist pattern formation; a pattern formation method; and a compound. This radiation-sensitive composition contains a polymer (A), a compound (B) represented by formula (1), an acid diffusion control agent (C), and a solvent (S). (In formula (1), Q is a quinone structure, and M+ is a monovalent organic cation.)

Description

Radiation-sensitive composition, pattern-forming method, and compound

[0001] The present invention relates to a radiation-sensitive composition, a pattern-forming method, and a compound.

[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 polymer in alkaline or organic developers between the exposed and unexposed areas, thereby forming a resist pattern on the substrate.

[0003] In the above photolithography techniques, from the perspective of pattern miniaturization, there is progress in replacing existing lasers with g-ray, i-ray, and KrF excimer lasers. Furthermore, there is also the use of short-wavelength radiation such as ArF excimer lasers, and liquid immersion lithography, in which exposure is performed with the space between the lens of the exposure apparatus and the resist film filled with a liquid medium. As next-generation technologies, lithography using even shorter-wavelength radiation such as electron beams, X-rays, and EUV (extreme ultraviolet) is also being considered.

[0004] Regarding photoacid generators, which are the main components of resist compositions, perfluoroalkyl sulfonic acid or its salts, which can generate strong acids, are widely used to improve sensitivity and resolution. On the other hand, in recent years, due to growing environmental awareness, photoacid generators that do not have a perfluoro structure (PFAS-free) are being investigated. Various photoacid generators that do not have a perfluoro structure are also known (Japanese Patent Publication No. 3-54059).

[0005] Japanese Patent Application Publication No. 3-54059

[0006] In order to achieve PFAS-free photoresists, the development of photoacid generators without perfluoroalkyl structures (PFAS-free PAGs) is key. PFAS-free resist compositions are required to have performance equivalent to or better than conventional PFAS-containing resists in terms of sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU (Critical Dimension Uniformity), and pattern circularity.

[0007] The present invention aims to provide a radiation-sensitive composition, a pattern-forming method, and a compound that can exhibit sufficient levels of sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity during resist pattern formation.

[0008] 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.

[0009] In other words, the present invention relates to a radiation-sensitive composition comprising, in one embodiment, a polymer (A), a compound (B) represented by the following formula (1), an acid diffusion control agent (C), and a solvent (S). (In equation (1), Q is a quinone structure. M) ＋ (This is a monovalent organic cation.)

[0010] The radiation-sensitive composition, by containing compound (B) represented by formula (1) above, can form a resist film that exhibits sufficient levels of sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity. The reason for this is presumed to be as follows, although it is not bound by any theory.

[0011] Since the compound (B) represented by the above formula (1) has a quinone structure, the electron-withdrawing property of the quinone structure enhances the acidity of the anion. As a result, the efficiency of the reaction catalyzed by an acid is increased, the dissolution contrast between the exposed and unexposed areas can be enhanced, and it is presumed that various performances such as pattern rectangularity can be improved. In addition, since the quinone structure possessed by the compound (B) is bulky, it becomes possible to control the diffusion length of the generated acid. It is presumed that due to these combined actions, given resist performances can be exhibited.

[0012] In another embodiment, the present invention relates to a pattern forming method including a step of directly or indirectly applying the above radiation-sensitive composition onto a substrate to form a resist film, a step of exposing the above resist film, and a step of developing the exposed resist film with a developer.

[0013] In this pattern forming method, since the above radiation-sensitive composition capable of forming a resist film excellent in sensitivity, exposure margin, depth of focus, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity is used, a high-quality resist pattern can be efficiently formed.

[0014] In yet another embodiment, the present invention relates to a compound represented by the following formula (10), formula (11), formula (12), or formula (13). (In formula (10), １１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxy group, a cyano group, or a nitro group. When a plurality of １１ R are present, the plurality of １１ R may be the same as or different from each other. １１ n is an integer of 0 to 2. １１ m is an integer of 0 to (3 + 2n １１ ). When １１ n is 0 or 2, １ ＋ M is a monovalent organic cation, and when １１ n is 1, １ + M is a monovalent organic cation represented by the following formula (10-1), formula (10-2), or formula (10-3). (In formula (10-1), R １２ and R １３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a cyano group, or a hydroxyl group. １２ , R １３ If multiple R １２ , R １３ They are either identical or different from each other. １２ , m １３ Each of these is an independent integer between 0 and 5. (In formula (10-2), R １４ ~R １６ Each of these is independently a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms other than a thiophenyl group, or R １４ ~R １６ It is a ring-shaped structure formed by the combination of two of them. １４ ~R １６ If multiple R １４ ~R １６ They are either identical or different from each other. １４ m is an integer between 1 and 5. １５ , m １６ Each of these is an independent integer between 0 and 5. (In formula (10-3), R １７ This is a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. １７ R is an integer between 0 and 5. １８ and R １９ Each of these is independently a monovalent organic group having 1 to 10 carbon atoms, or R １８ and R １９ They are combined with each other R １８ and R １９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded. (In formula (11), R ２１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ２１ If multiple R ２１ They are either identical or different from each other. r is an integer between 0 and 2. ２１M is an integer between 0 and (2r + 3). ＋ (This is a monovalent organic cation.) (In formula (12), R ３１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ３１ If multiple R ３１ They are either identical or different from each other. ３１ M is an integer between 0 and 7. ２ ＋ This is a monovalent organic cation represented by the following formula (12-1), formula (12-2), or formula (12-3). (In formula (12-1), R ３２ , R ３３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, or a hydroxyl group. ３２ , R ３３ If multiple R ３２ , R ３３ They are either identical or different from each other. ３２ , m ３３ Each of these is an independent integer between 0 and 5. (In formula (12-2), R ３４ ~R ３６ Each of these independently comprises a halogen atom, a hydroxyl group, a cyano group, a nitro group, or an organic group having 2 to 20 carbon atoms, or R ３４ ~R ３６ It is a ring-shaped structure formed by the combination of two of them. ３４ ~R ３６ If multiple R ３４ ~R ３６ They are either identical or different from each other. ３４ m is an integer between 1 and 5. ３５ , m ３６ Each of these is an independent integer between 0 and 5. (In formula (12-3), R ３７ This is a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. ３７ R is an integer between 0 and 5. ３８ and R ３９is, independently of each other, a monovalent organic group having 1 to 20 carbon atoms, or R ３８ and R ３９ are combined with each other and represent a cyclic structure formed together with a sulfur atom to which R ３８ and R ３９ are bonded.)) (In Formula (13), R ４１ is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxy group, a cyano group, or a nitro group. When a plurality of R ４１ are present, the plurality of R ４１ are the same as or different from each other. m ４１ is an integer of 0 to 7. M ３ ＋ is a monovalent organic cation represented by the following Formula (13-1), the following Formula (13-2), or the following Formula (13-3). (In Formula (13-1), R ４２ , R ４３ are, independently of each other, a fluorine atom, an iodine atom, a nitro group, a hydroxy group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. When a plurality of R ４２ , R ４３ are present, the plurality of R ４２ , R ４３ are the same as or different from each other. m ４２ , m<00oo092>are, independently of each other, an integer of 0 to 5. However, m ４２ + m ４３ ≧ 1.) (In Formula (13-2), R ４４ to R ４６ are, independently of each other, a halogen atom, a hydroxy group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms, or a cyclic structure formed by bonding two of R ４４ to R ４６ . When a plurality of R ４４ to R ４６ are present, the plurality of R ４４ to R ４６ are the same as or different from each other. m ４４ is an integer of 1 to 5. m ４５ , m ４６ are, independently of each other, an integer of 0 to 5.)) (In formula (13-3), R ４７ This is a halogen atom, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. ４７ R is an integer between 0 and 5. ４８ and R ４９ Each of these is independently a monovalent chain-like organic group having 1 to 10 carbon atoms, or R ４８ and R ４９ They are combined with each other R ４８ and R ４９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded.

[0015] By using a radiation-sensitive composition containing the compound, it is possible to form a resist film that is excellent in sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity.

[0016] In this specification, "organic group" means a group having at least one carbon atom (excluding groups that constitute a functional group or characteristic group on their own, such as -CN, -COOH, -CO-, -COO-, -O-CO-O-, etc.).

[0017] The embodiments of the present invention will be described in detail below, but the present invention is not limited to these embodiments. A preferred combination of embodiments is also preferable.

[0018] <<Radiation-Sensitive Composition>> The radiation-sensitive composition according to this embodiment (hereinafter also simply referred to as "the composition") contains a polymer (A), a compound (B) represented by the above formula (1), an acid diffusion control agent (C), and a solvent (S). It may also optionally contain a radiation-sensitive acid generator (P), a crosslinking agent (Q), etc. The above composition may contain other optional components as long as they do not impair the effects of the present invention.

[0019] <Compound (B)> Compound (B), represented by the following formula (1), functions as a radiation-sensitive acid generator that generates acid upon exposure. (In equation (1), Q is a quinone structure. M) ＋ (This is a monovalent organic cation.)

[0020] The quinone structure represented by Q above is a structure derived from a benzene ring having two C=O structures within the same ring.

[0021] The above compound (B) is preferably a compound represented by the following formula (1-1) or the following formula (1-2). (In formula (1-1), R １ is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group, or two R １ These elements are combined with each other to form a divalent alicyclic or heterocyclic structure with 3 to 20 carbon atoms, along with the carbon atoms to which they are bonded. １ If multiple R １ They are either identical or different from each other. n is an integer between 0 and 2. １ M is an integer between 0 and (2n+3). ＋ (This is a monovalent organic cation.) (In formula (1-2), R ２ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ２ If multiple R ２ p and q are either identical or different from each other. p and q are independently either 0 or 1. ２ M is an integer between 0 and (2p + 2q + 3). ＋ (This is a monovalent organic cation.)

[0022] The above R １ , R ２ Examples of organic groups having 1 to 20 carbon atoms represented by include monovalent hydrocarbon groups having 1 to 20 carbon atoms, groups (α) having a divalent heteroatom-containing group between carbon atoms (between two adjacent or non-adjacent carbon atoms) or at the terminal end of the hydrocarbon group, groups in which some or all of the hydrogen atoms of the hydrocarbon group or group (α) are replaced with monovalent heteroatom-containing groups, or combinations thereof.

[0023] Examples of the above-mentioned monovalent hydrocarbon groups having 1 to 20 carbon atoms include monovalent chain hydrocarbon groups having 1 to 20 carbon atoms, monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms, monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, or combinations thereof.

[0024] Examples of the above-mentioned monovalent linear hydrocarbon groups having 1 to 20 carbon atoms include monovalent linear or branched saturated hydrocarbon groups having 1 to 20 carbon atoms, or monovalent linear or branched unsaturated hydrocarbon groups having 2 to 20 carbon atoms. Examples of the above-mentioned monovalent linear or branched saturated hydrocarbon groups having 1 to 20 carbon atoms include alkyl groups such as methyl group, ethyl group, n-propyl group, i-propyl group, n-butyl group, 2-methylpropyl group, 1-methylpropyl group, t-butyl group, n-pentyl group, isopentyl group, and neopentyl group. Examples of the above-mentioned monovalent linear or branched unsaturated hydrocarbon groups having 2 to 20 carbon atoms include alkenyl groups such as ethenyl group, propenyl group, and butenyl group; and alkynyl groups such as ethynyl group, propynyl group, and butynyl group.

[0025] Examples of monovalent alicyclic hydrocarbon groups having 3 to 20 carbon atoms include monocyclic or polycyclic saturated hydrocarbon groups, or monocyclic or polycyclic unsaturated hydrocarbon groups. Examples of monocyclic saturated hydrocarbon groups include cycloalkyl groups such as cyclopentyl, cyclohexyl, cycloheptyl, and cyclooctyl groups. Examples of polycyclic saturated hydrocarbon groups include bridged alicyclic hydrocarbon groups such as norbornyl, adamantyl, tricyclodecyl, and tetracyclododecyl groups. Examples of monocyclic unsaturated hydrocarbon groups include monocyclic cycloalkenyl groups such as cyclopropenyl, cyclobutenyl, cyclopentenyl, and cyclohexenyl groups. Examples of polycyclic unsaturated hydrocarbon groups include polycyclic cycloalkenyl groups such as norborneyl, tricyclodecenyl, and tetracyclododecenyl groups. A bridged alicyclic hydrocarbon group is a polycyclic alicyclic hydrocarbon group in which two non-adjacent carbon atoms constituting the alicyclic ring are bonded together by a linking group containing one or more carbon atoms.

[0026] Examples of the monovalent aromatic hydrocarbon groups having 6 to 20 carbon atoms include aryl groups such as phenyl, tolyl, xyl, naphthyl, and anthyl groups; and aralkyl groups such as benzyl, phenethyl, and naphthylmethyl groups.

[0027] Examples of heteroatoms that constitute the monovalent heteroatom-containing groups and divalent heteroatom-containing groups mentioned above include oxygen atoms, nitrogen atoms, sulfur atoms, phosphorus atoms, silicon atoms, and halogen atoms. Examples of halogen atoms include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

[0028] Examples of the monovalent heteroatom-containing groups mentioned above include hydroxyl groups, carboxyl groups, sulfanyl groups, cyano groups, nitro groups, halogen atoms, and the like.

[0029] Examples of the above-mentioned divalent heteroatom-containing groups include -CO-, -C(=O)O-, -CS-, -NR'-, -O-, -S-, -SO-, and -SO ２ - or combinations thereof are examples. R' is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms.

[0030] The above R １ Preferred members include iodine atoms, alkoxy groups, groups containing ester bonds, fluorine atoms, hydroxyl groups, cyano groups, or nitro groups.

[0031] The above R ２ Preferred elements include fluorine atoms, iodine atoms, groups containing ester bonds, nitro groups, methylsulfonyl groups, and hydroxyl groups.

[0032] The two R's mentioned above １ As a divalent alicyclic structure having 3 to 20 carbon atoms, which can be formed by combining these with the carbon atoms to which they are bonded, a structure corresponding to the monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably adopted.

[0033] The two R's mentioned above １Examples of divalent heterocyclic structures having 3 to 20 carbon atoms, formed by combining these atoms with the carbon atoms to which they bond, include: oxygen-containing aliphatic heterocyclic structures such as oxiran, tetrahydrofuran, tetrahydropyran, dioxolane, and dioxane; nitrogen-containing aliphatic heterocyclic structures such as aziridine, pyrrolidine, piperidine, and piperazine; sulfur-containing aliphatic heterocyclic structures such as thiethane, thioran, and thian; aliphatic heterocyclic structures containing multiple types of heteroatoms such as morpholine, 1,2-oxathioran, and 1,3-oxathioran; oxygen-containing aromatic heterocyclic structures such as furan, benzofuran, and dibenzofuran; nitrogen-containing aromatic heterocyclic structures such as pyrrole, pyrazole, triazine, pyridine, pyrazine, pyrimidine, and pyridazine; sulfur-containing aromatic heterocyclic structures such as thiophene; and aromatic heterocyclic structures containing multiple types of heteroatoms such as oxazole, isothiazole, and thiazine.

[0034] Heterocyclic structures include lactone structures, cyclic carbonate structures, sultone structures, cyclic acetals, or combinations thereof.

[0035] The above value n is an integer from 0 to 2, preferably 1 or 2, and more preferably 1.

[0036] The above m １ x is an integer between 0 and (2n+3).

[0037] When n in the above equation (1-1) is 0, the structure is represented by the following equation (b1); when n is 1, the structure is represented by the following equation (b2); and when n is 2, the structure is represented by the following equation (b3).

[0038] (In formulas (b1) to (b3), R １ M ＋ This is equivalent to equation (1-1). １１ m is an integer between 0 and 3. １２ m is an integer between 0 and 5. １３ (This is an integer between 0 and 7.)

[0039] The above values ​​of p and q are each independently 0 or 1, and it is preferable that p is 1 and q is 0.

[0040] The above m ２ x is an integer between 0 and (2p + 2q + 3).

[0041] If p and q in the above formula (1-2) are 0, the structure is represented by the following formula (b4); if either p or q is 1 and the other is 0, the structure is represented by the following formula (b5); and if both p and q are 1, the structure is represented by the following formula (b6).

[0042] (In formulas (b4) to (b6), R ２ M ＋ This is equivalent to equation (1-2). ２１ m is an integer between 0 and 3. ２２ m is an integer between 0 and 5. ２３ (This is an integer between 0 and 7.)

[0043] Specific examples of anions of the compounds represented by the above formulas (1), (1-1), and (1-2) include, but are not limited to, the following structures.

[0044]

[0045]

[0046]

[0047]

[0048]

[0049] The above M ＋ The monovalent organic cation is not particularly limited, but a monovalent radiation-sensitive onium cation is preferred. Examples of radiation-sensitive onium cations include sulfonium cations and iodonium cations.

[0050] The sulfonium cation or iodonium cation is preferably represented by the following formulas (X-1) to (X-6).

[0051]

[0052] In the above equation (X-1), R ａ１, R ａ２ and R ａ３ Each of these independently comprises a substituted or unsubstituted linear or branched alkyl group, alkoxy group or alkoxycarbonyloxy group having 1 to 12 carbon atoms, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, a hydroxyl group, a nitro group, a halogen atom, or -OSO ２ -R Ｐ , -SO ２ -R Ｑ , -S-R Ｔ This represents a group formed by combining these groups with -O- and -CO-, or a ring structure formed by combining two or more of these groups. This ring structure may contain heteroatoms such as O and S between the carbon-carbon bonds that form the skeleton. Ｐ , R Ｑ and R Ｔ 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. k1, k2, and k3 are each independently integers from 0 to 5. R ａ１ ~R ａ３ And R Ｐ , R Ｑ and R Ｔ If each of them is multiple, then multiple R ａ１ ~R ａ３ And R Ｐ , R Ｑ and R Ｔ These may be the same or different.

[0053] In the above equation (X-2), R ｂ１ These are substituted or unsubstituted linear or branched alkyl or alkoxy groups having 1 to 20 carbon atoms, alkoxyalkyloxy groups, substituted or unsubstituted acyl groups having 2 to 8 carbon atoms, substituted or unsubstituted aromatic hydrocarbon groups having 6 to 8 carbon atoms, nitro groups, cyano groups, and hydroxyl groups. ｂ１ Examples include groups composed of the aforementioned alkyl group and at least one group selected from -CO-, -O-, -NH-, and -S-.ｋ n is either 0 or 1. ｋ When is 0, k4 is an integer from 0 to 4, and n ｋ When k4 is 1, k4 is an integer from 0 to 7. ｂ１ If there are multiple R ｂ１ They may be the same or different, and there may be multiple R's. ｂ１ R may represent a ring structure formed by combining with other elements. ｂ２ This is a substituted or unsubstituted linear or branched alkyl group having 1 to 7 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 or 7 carbon atoms. Ｃ k5 is a single bond or a divalent linking group. k5 is an integer from 0 to 4. ｂ２ If there are multiple R ｂ２ They may be the same or different, and there may be multiple R's. ｂ２ may represent a ring structure formed by combining with each other. q is an integer from 0 to 3. In the formula, S ＋ The ring structure containing may include heteroatoms such as O or S between the carbon-carbon bonds that form the skeleton.

[0054] In the above equation (X-3), R ｃ１ , R ｃ２ and R ｃ３ Each of these is independently a substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. However, R ｃ１ , R ｃ２ and R ｃ３ At least one of these is a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a group composed of the alkyl group and at least one of the groups -CO-, -O-, -NH-, and -S-.

[0055] In the above equation (X-4), R ｇ１ This is a substituted or unsubstituted linear or branched alkyl or alkoxy group having 1 to 20 carbon atoms, a substituted or unsubstituted acyl group having 2 to 8 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 8 carbon atoms, or a hydroxyl group. ｋ２ n is either 0 or 1. ｋ２ When is 0, k10 is an integer from 0 to 4, and n ｋ２When is 1, k10 is an integer from 0 to 7. ｇ１ If there are multiple R ｇ１ They may be the same or different, and there may be multiple R's. ｇ１ R may represent a ring structure formed by combining with other elements. ｇ２ and R ｇ３ Each of these independently represents a substituted or unsubstituted linear or branched alkyl group, alkoxy group or alkoxycarbonyloxy group having 1 to 12 carbon atoms, a substituted or unsubstituted monocyclic or polycyclic cycloalkyl group having 3 to 12 carbon atoms, a substituted or unsubstituted aromatic hydrocarbon group, hydroxyl group, halogen atom having 6 to 12 carbon atoms, or a ring structure formed by combining these groups. k11 and k12 are each independently integers from 0 to 4. R ｇ２ and R ｇ３ If each of them is multiple, then multiple R ｇ２ and R ｇ３ These may be the same or different.

[0056] In the above equation (X-5), R ｄ１ and R ｄ２ Each of these independently comprises a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, an alkoxy group or alkoxycarbonyl group, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms, a halogen atom, a halogenated alkyl group having 1 to 4 carbon atoms, a nitro group, a hydroxyl group, a cyano group, and a -CO-O-R group. Ｐ１ , -S-R Ｔ１ This represents a ring structure formed by combining two or more of these groups. Ｐ１ and R Ｔ１ 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 ｄ１ and R ｄ２ If each of them is multiple, then multiple R ｄ１ and R ｄ２ These may be the same or different.

[0057] In the above formula (X-6), R ｅ１ and R ｅ２ k8 and k9 are each independently a halogen atom, a substituted or unsubstituted linear or branched alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted aromatic hydrocarbon group having 6 to 12 carbon atoms.

[0058] Specific examples of organic cations used as radiation-sensitive onium cations include, but are not limited to, the structure shown in the following formula.

[0059]

[0060]

[0061]

[0062]

[0063]

[0064] Compound (B) can be obtained by appropriately combining the above anion and the above cation. Specific examples of compound (B) include, but are not limited to, structures represented by the following formula.

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] The above-mentioned radiation-sensitive composition may contain one or more compounds (B).

[0071] The lower limit of the content of compound (B) (total if multiple types are included) is preferably 0.1 parts by mass, and more preferably 1 part by mass, per 100 parts by mass of polymer (A). The upper limit of the above content is preferably 70 parts by mass, and more preferably 65 parts by mass. As a result, the composition can exhibit excellent sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity when forming a resist pattern.

[0072] <Polymer (A)> The polymer (A) described above is not particularly limited in terms of the structural units it contains, but it is preferably an aggregate of polymerization chains containing structural units (I) having phenolic hydroxyl groups (hereinafter this polymer will also be referred to as "base polymer (A)").

[0073] Examples of polymers (A) containing a structural unit (I) having a phenolic hydroxyl group include polymers (A-1) containing a structural unit (I-1) represented by formula (4) described later, or novolac polymers (A-2) containing a structural unit (I-2) represented by formula (10) described later.

[0074] (Polymer (A-1)) The base polymer (A-1) contains structural unit (I-1), and may also contain other structural units besides structural unit (I-1). Each structural unit is described below.

[0075] [Structural Unit (I-1)] Polymer (A-1) contains structural unit (I-1) having a phenolic hydroxyl group. Structural unit (I-1) is preferably represented by the following formula (4).

[0076] (In the above formula (4), R Ａ L is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ＣＡ This is a single bond, -COO- ＊Or -O-. * indicates a bond on the aromatic ring side. X is a halogen atom, cyano group, nitro group, alkyl group, alkoxy group, carboxy group, fluorinated alkyl group, alkoxycarbonyl group, acyl group, or acyloxy group. If multiple Xs exist, they are either identical or distinct from one another. p is an integer from 0 to 2, n is an integer from 1 to 8, and m is an integer from 0 to 8. (However, 1 ≤ n + m ≤ 2p + 5.)

[0077] The above R Ａ Preferably, it is a hydrogen atom or a methyl group.

[0078] L ＣＡ For example, a single bond or -COO- ＊ It is preferable.

[0079] The alkyl group in X is R in formula (1) above. １ The alkyl group in can be suitably adopted. The alkyl group portion of the alkoxy group and the alkyl group portion of the alkoxycarbonyl group in X are R in formula (1) above. １ The alkyl group in X can be suitably adopted. Examples of fluorinated alkyl groups in X include linear or branched fluorinated alkyl groups having 1 to 8 carbon atoms, such as trifluoromethyl groups and pentafluoroethyl groups. Examples of acyl groups in X include aliphatic or aromatic acyl groups having 2 to 12 carbon atoms, such as acetyl groups, propionyl groups, benzoyl groups, and acryloyl groups. The alkyl group may contain heteroatoms such as O or S between the carbon-carbon bonds.

[0080] Examples of acyloxy groups in X include aliphatic or aromatic acyloxy groups having 2 to 12 carbon atoms, such as acetyloxy groups, propionyloxy groups, benzoyloxy groups, and acryloyloxy groups.

[0081] Among these, halogen atoms are preferred for X, and iodine atoms and fluorine atoms are more preferred.

[0082] The above value of p is preferably 0 or 1, and more preferably 0.

[0083] The above n is preferably an integer from 1 to 3, and more preferably 1 or 2.

[0084] For the above value m, an integer between 0 and 3 is preferred, and an integer between 0 and 2 is more preferred.

[0085] The above structural unit (I-1) is more preferably a structural unit represented by the following formula (4-1). (In equation (4-1), q1 is an integer between 1 and 5. q2 is an integer between 0 and 4. However, q1 + q2 is less than or equal to 5. R Ａ X is equivalent to equation (4) above.

[0086] For q1, an integer from 1 to 3 is preferred, and 1 or 2 is more preferred.

[0087] For q2, an integer between 0 and 3 is preferred, and an integer between 0 and 2 is more preferred.

[0088] The above structural unit (I-1) is preferably a structural unit represented by the following formula. In the following formula, R Ａ This is the same as equation (4) above.

[0089]

[0090] The base polymer (A-1) may contain one or more structural units (I-1) in combination.

[0091] The lower limit of the content of the above structural unit (I-1) (total if there are multiple types of structural unit (I-1)) is preferably 20 mol%, more preferably 30 mol%, and even more preferably 35 mol%, relative to the total structural units constituting the polymer (A-1). The upper limit of the above content is preferably 100 mol%, more preferably 95 mol%, and even more preferably 90 mol%. By setting the content of structural unit (I-1) within the above range, the sensitivity of the radiation-sensitive composition can be further improved.

[0092] [Structural Unit (II)] From the viewpoint of etching resistance, it is preferable that polymer (A-1) contains structural unit (II) having an aromatic ring (excluding those corresponding to structural unit (I-1) above).

[0093] The structural unit (II) described above is preferably the structural unit represented by the following formula (5).

[0094] (In the above formula (5), R Ａ L is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ＣＡ This is a single bond, -COO- ＊ Or -O-. * indicates a bond on the aromatic ring side. X １ X is a halogen atom, cyano group, nitro group, alkyl group, alkoxy group, carboxy group, fluorinated alkyl group, alkoxycarbonyl group, acyl group, or acyloxy group. １ If there are multiple X １ They are either identical or different. q3 is an integer between 0 and 2, and q4 is an integer between 0 and 8.

[0095] The above R A Preferably, it is a hydrogen atom or a methyl group.

[0096] The above L ＣＡ For example, a single bond or -COO- ＊ A single bond is preferred, and a single bond is even more preferred.

[0097] X １ In this, the alkyl group, alkoxy group, fluorinated alkyl group, alkoxycarbonyl group, acyl group, and acyloxy group listed as X in formula (4) above can be suitably adopted. Among these, X １ Preferably, the group is an alkoxycarbonyl group (however, the alkyl group portion may contain heteroatoms such as O or S between the carbon-carbon bonds).

[0098] For q3, 0 or 1 is preferred, and 0 is more preferred.

[0099] For q4, an integer between 0 and 3 is preferred, and 0 or 1 is more preferred.

[0100] The above structural unit (II) is preferably a structural unit represented by the following formula. In the following formula, R Ａ This is the same as equation (5) above.

[0101]

[0102] The base polymer (A-1) may contain one or more structural units (II) in combination.

[0103] When the base polymer (A-1) contains the structural unit (II), the lower limit of the content of the structural unit (II) (total if there are multiple types of structural unit (II)) is preferably 1 mol%, more preferably 3 mol%, and even more preferably 5 mol%, relative to the total structural units constituting the polymer (A-1). The upper limit of the content is preferably 60 mol%, more preferably 50 mol%, and even more preferably 40 mol%. By setting the content of structural unit (II) within the above range, the radiation-sensitive composition can be made to further improve etching resistance and sensitivity.

[0104] [Structural Unit (III)] The polymer (A-1) preferably has a structural unit (III) having an acid-dissociable group. An "acid-dissociable group" is a hydrogen atom-substituting group such as a carboxyl group, phenolic hydroxyl group, alcoholic hydroxyl group, or sulfo group that dissociates upon the action of an acid. The radiation-sensitive composition exhibits excellent pattern-forming properties because the polymer has structural unit (III).

[0105] Structural unit (III) is a structural unit having an acid-dissociable group. Structural unit (III) is not particularly limited as long as it contains an acid-dissociable group, and examples include a structural unit having a tertiary alkyl ester moiety, a structural unit having a structure in which the hydrogen atom of a phenolic hydroxyl group is replaced by a tertiary alkyl group, and a structural unit having an acetal bond. However, from the viewpoint of improving the pattern-forming properties of the radiation-sensitive composition, a structural unit represented by the following formula (3) (hereinafter also referred to as "structural unit (III-1)") is preferred.

[0106]

[0107] In the above formula (3), R ｔ１ R is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. ｔ２ R is a monovalent substituted or unsubstituted hydrocarbon group having 1 to 20 carbon atoms. ｔ３ and R ｔ４Each of these independently represents either a monovalent substituted or unsubstituted linear hydrocarbon group having 1 to 10 carbon atoms, a monovalent substituted or unsubstituted alicyclic hydrocarbon group having 3 to 20 carbon atoms, or a divalent alicyclic group having 3 to 20 carbon atoms formed by combining these groups with the carbon atoms to which they are bonded. １１ teeth, ＊ -COO- ＊ -L １１ａ COO- or ＊ - COOL １１ａ Represents COO-. １１ａ * is a substituted or unsubstituted alkanediyl group or arenediyl group. ｔ１ This is the bonding site with the carbon atom to which it is bonded.

[0108] The above R ｔ１ From the viewpoint of copolymerization of the monomer that gives the structural unit (III-1), hydrogen atoms and methyl groups are preferred, and methyl groups are more preferred.

[0109] L １１ａ Examples of alkanediyl groups represented by include methylene groups, ethanediyl groups, 1,3-propanediyl groups, and 2,2-propanediyl groups, which have 1 to 10 carbon atoms. １１ａ Methylene groups and ethanediyl groups are preferred as the base group.

[0110] L １１ａ Examples of the arenediyl group represented by include divalent aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as benzenediyl groups and naphthalenediyl groups. １１ａ A benzenediyl group is preferred as the group.

[0111] L １１ａ Substituents that the alkanediyl group or arenediyl group represented by can have include halogen atoms, hydroxyl groups, carboxyl groups, cyano groups, nitro groups, alkyl groups, fluorinated alkyl groups, alkoxycarbonyloxy groups, acyl groups, acyloxy groups, and alkoxy groups.

[0112] The above R ｔ２ As a monovalent hydrocarbon group having 1 to 20 carbon atoms represented by the above formula (1), R １Monovalent hydrocarbon groups having 1 to 20 carbon atoms can be suitably used in this material.

[0113] The above R ｔ２ Preferably, it is a straight-chain or branched-chain saturated hydrocarbon group having 1 to 10 carbon atoms.

[0114] The above R ｔ３ and R ｔ４ As a monovalent chain hydrocarbon group having 1 to 10 carbon atoms represented by the above formula (1), R １ Among the monovalent chain hydrocarbon groups having 1 to 20 carbon atoms, those with the corresponding number of carbon atoms can be suitably adopted. Also, the above R ｔ３ and R ｔ４ As a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms represented by the above formula (1), R １ A monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably used in this material.

[0115] The above R ｔ３ and R ｔ４ The divalent alicyclic group having 3 to 20 carbon atoms, which is formed by combining these atoms with the carbon atoms to which they are bonded, is R in formula (1) above. １ A group obtained by removing one hydrogen atom from a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably adopted.

[0116] The above R ｔ３ and R ｔ４ Preferably, the alicyclic structure, which consists of an alkyl group having 1 to 4 carbon atoms, or these alkyl groups combined with the carbon atoms to which they are bonded, is a polycyclic or monocyclic cycloalkane structure.

[0117] The above R ｔ２ ~R ｔ４ The substituents that can be present are L １１ａ The substituents that the arenediyl group represented by can have can be suitably adopted.

[0118] Examples of structural units (III-1) include those represented by the following formulas (3-1) to (3-15) (hereinafter also referred to as "structural units (III-1-1) to (III-1-15)").

[0119]

[0120]

[0121] In the above formulas (3-1) to (3-15), R ｔ１ to R ｔ４ is synonymous with the above formula (3). R Ｌ１１ is a halogen atom, a hydroxy group, a carboxy group, a cyano group, a nitro group, an alkyl group, a fluorinated alkyl group, an alkoxycarbonyloxy group, an acyl group, an acyloxy group or an alkoxy group. i and j are each independently an integer of 1 to 4. k and l are 0 or 1. a3 is each independently an integer of 0 to 3. When a3 is 2 or more, the plurality of R Ｌ１１ are the same as or different from each other. a4 is an integer of 1 to 3.

[0122] As i and j, 1 or 2 is preferable. R ｔ２ is preferably a methyl group, an ethyl group, an isopropyl group, a t-butyl group, a cyclopentyl group, an ethenyl group, a phenyl group, an iodophenyl group. R ｔ３ and R ｔ４ are preferably a methyl group, an ethyl group, an isopropyl group.

[0123] Further, the polymer may contain a structural unit represented by the following formulas (1f) to (2f) as the structural unit (III).

[0124]

[0125] In the above formulas (1f) to (2f), R αｆ are each independently a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. R βｆ are each independently a hydrogen atom or a linear alkyl group having 1 to 5 carbon atoms. h １ is an integer of 1 to 4.

[0126] As the above R βｆ a hydrogen atom, a methyl group or an ethyl group is preferable. h １ is preferably 1 or 2.

[0127] Although not particularly limited as a specific example of the structural unit (III), for example, the structure represented by the following formula can be mentioned. In the formula, Rｔ１ is synonymous with the above formula (3).

[0128]

[0129]

[0130]

[0131]

[0132] The lower limit of the content ratio (total content ratio in the case of multiple types) of the above structural unit (III) in all the structural units constituting the above polymer (A-1) is preferably 1 mol%, more preferably 5 mol%, and even more preferably 8 mol% with respect to all the structural units constituting the base polymer (A-1). Further, the upper limit of the above content ratio is preferably 80 mol%, more preferably 70 mol%, and even more preferably 65 mol%. By setting the content ratio of the structural unit (III) within the above range, the pattern formation property of the radiation-sensitive composition can be further improved.

[0133] [Structural unit (IV)] The structural unit (IV) is a structural unit containing at least one selected from the group consisting of a lactone structure, a cyclic carbonate structure, and a sultone structure. By further having the structural unit (IV), the base polymer can adjust the solubility in the developer, and as a result, the radiation-sensitive composition can improve lithography performance such as resolution. In addition, the adhesion between the resist pattern formed from the base polymer and the substrate can be improved.

[0134] Examples of the structural unit (IV) include structural units represented by the following formulas (T-1) to (T-11).

[0135]

[0136] In the above formula, R Ｌ１ is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R Ｌ２ to R Ｌ５These 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 bonded together with the carbon atoms. 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.

[0137] The above R Ｌ４ and R Ｌ５ When these are combined with each other, the divalent alicyclic group having 3 to 8 carbon atoms, formed together with the carbon atoms to which they are bonded, is R in formula (3) above. ｔ３ and R ｔ４ Examples include divalent alicyclic groups with 3 to 20 carbon atoms, where these groups are combined with each other and formed together with the carbon atoms to which they are bonded, specifically groups with 3 to 8 carbon atoms. One or more hydrogen atoms on these alicyclic groups may be substituted with hydroxyl groups.

[0138] 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-.

[0139] Among these, structural units (IV) that include a lactone structure are preferred, structural units that include a γ-butyrolactone structure are more preferred, and structural units derived from γ-butyrolactone-yl-(meth)acrylate are even more preferred.

[0140] When the base polymer (A-1) has structural units (IV), the lower limit of the content of structural units (IV) (total content if multiple types are included) is preferably 3 mol%, more preferably 5 mol%, and even more preferably 10 mol%, relative to the total structural units constituting the base polymer (A-1). The upper limit of the above content is preferably 80 mol%, more preferably 70 mol%, and even more preferably 60 mol%. By setting the content of structural units (IV) within the above range, the radiation-sensitive composition can further improve lithography performance such as resolution and the adhesion of the formed resist pattern to the substrate.

[0141] (Structural unit (V)) Polymer (A-1) may contain structural unit (V) which includes an amide bond.

[0142] The above structural unit (V) is preferably a structural unit derived from a compound represented by the following formula (8). (In formula (8), R １００ L is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. １０１ R is a single bond or a divalent linking group. １０１ and R １０２ These are, independently, monovalent organic groups having 1 to 20 carbon atoms.

[0143] L １０１ The divalent linking group represented by is preferably a divalent aromatic hydrocarbon group having 6 to 20 carbon atoms, or a divalent chain hydrocarbon group having 1 to 10 carbon atoms, with benzenediyl groups, ethanediyl groups, propanediyl groups, etc., being more preferred. Some or all of the hydrogen atoms of these groups may be substituted with the monovalent heteroatom-containing group described above.

[0144] R １０１ and R １０２ As a monovalent organic group having 1 to 20 carbon atoms, R in formula (1) above is an example. １ A monovalent organic group having 1 to 20 carbon atoms, represented by , can be suitably used. Among these, R １０１ and R １０２ A C1-C5 alkyl group is preferred.

[0145] The base polymer (A-1) may contain one or more structural units (V) in combination.

[0146] When the base polymer (A-1) contains the structural unit (V), the lower limit of the content of the structural unit (V) (or the total content if multiple types are included) is preferably 1 mol%, more preferably 5 mol%, and even more preferably 8 mol% relative to the total structural units constituting the base polymer (A-1). The upper limit of the above content is preferably 50 mol%, more preferably 40 mol%, and even more preferably 30 mol%.

[0147] [Structural Unit (VI)] The base polymer (A-1) optionally contains structural unit (VI) which includes a polar group (excluding those corresponding to structural units (I) to (V)). By further containing structural unit (VI), the solubility in the developer can be adjusted, and as a result, the lithographic performance such as resolution of the radiation-sensitive composition can be improved. Examples of the above polar group include a hydroxyl group, a carboxyl group, a cyano group, a nitro group, a sulfonamide group, etc. Among these, a hydroxyl group and a carboxyl group are preferred, and a hydroxyl group is more preferred.

[0148] Examples of structural units (VI) include structural units represented by the following formula.

[0149]

[0150]

[0151] In the above formula, R Ｋ This is a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0152] When the base polymer (A-1) has the structural unit (VI) having the polar group, the lower limit of the content ratio of the structural unit (VI) (when plural types are included, the total content ratio) is preferably 1 mol%, more preferably 2 mol%, and still more preferably 3 mol% with respect to all the structural units constituting the base polymer. Further, the upper limit of the content ratio is preferably 30 mol%, more preferably 20 mol%, and still more preferably 15 mol%. By setting the content ratio of the structural unit (VI) within the above range, the lithography performance such as the resolution of the radiation-sensitive composition can be further improved.

[0153] [Other Structural Units] The base polymer (A-1) may contain, as structural units other than the above-listed structural units, a structural unit having an alicyclic structure represented by the following formula (6) (hereinafter, also referred to as "structural unit (VII)"). (In the above formula (6), １α R is a hydrogen atom, a fluorine atom, a methyl group or a trifluoromethyl group. ２α R is a monovalent hydrocarbon group having 1 to 20 carbon atoms.)

[0154] In the above formula (6), as the monovalent hydrocarbon group having 1 to 20 carbon atoms represented by R ２α the monovalent hydrocarbon group having 1 to 20 carbon atoms in R １ in the above formula (1) can be preferably employed.

[0155] When the base polymer (A-1) contains the structural unit (VII), the lower limit of the content ratio of the structural unit (VII) is preferably 1 mol%, more preferably 3 mol%, and still more preferably 5 mol% with respect to all the structural units constituting the base polymer (A-1). Further, the upper limit of the content ratio is preferably 50 mol%, more preferably 40 mol%, and still more preferably 30 mol%.

[0156] (Synthesis Method of Base Polymer (A-1)) The base polymer (A-1) can be synthesized, for example, by polymerizing monomers that give each structural unit in a suitable solvent using a radical polymerization initiator or the like.

[0157] 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.

[0158] Examples of solvents used in the above polymerization 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; lactones such as γ-butyrolactone and δ-valerolactone; ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, 2-heptanone, and cyclohexanone; and ethers such as tetrahydrofuran, dimethoxyethanes, and diethoxyethanes. Examples include alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, and 4-methyl-2-pentanol. The solvent used in these polymerizations may be used alone or in combination of two or more.

[0159] The reaction temperature in the polymerization described above is usually 40°C to 150°C, with 50°C to 120°C being preferred. The reaction time is usually 1 hour to 48 hours, with 1 hour to 24 hours being preferred.

[0160] The molecular weight of the base polymer (A-1) 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 2,000, more preferably 2,500, and even more preferably 3,000. The upper limit of Mw is preferably 30,000, and more preferably 20,000. By setting the Mw of the base polymer (A-1) within the above range, good developability can be imparted to the resulting resist film.

[0161] The ratio of Mw to the polystyrene-equivalent number-average molecular weight (Mn) (Mw / Mn) of the base polymer (A-1) determined by GPC is usually between 1 and 5, preferably between 1 and 3, and more preferably between 1 and 2.

[0162] In this specification, the Mw and Mn values ​​of polymers are measured using gel permeation chromatography (GPC) under the following conditions.

[0163] GPC columns: 2 x G2000HXL, 1 x G3000HXL, 1 x G4000HXL (all manufactured by Tosoh Corporation) Column temperature: 40°C Elution solvent: Tetrahydrofuran Flow rate: 1.0 mL / min Sample concentration: 1.0% by mass Sample injection volume: 100 μL Detector: Differential refractometer Standard material: Monodisperse polystyrene

[0164] The content of the base polymer (A-1) is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more, based on the total solid content of the radiation-sensitive composition.

[0165] (Polymer (A-2)) Polymer (A-2) contains structural unit (I-2) having a phenolic hydroxyl group. The base polymer (A-2) may also contain structural units other than structural unit (I-2). Each structural unit is described below.

[0166] The structural unit (I-2) is preferably represented by the following formula (10).

[0167] (In formula (10), R ２０１ R is a monovalent organic group having 1 to 20 carbon atoms. ２０１If multiple R ２０１ (These two values ​​are either identical or different. a is an integer between 0 and 3.)

[0168] R ２０１ As a monovalent organic group having 1 to 20 carbon atoms represented by the above formula (1), R １ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0169] Polymer (A-2) is a novolac polymer obtained by condensing a phenol compound and an aldehyde in the presence of a catalyst.

[0170] Examples of the phenol compounds mentioned above include phenol; o-, m- or p-cresol; 2,3-, 2,5-, 3,4- or 3,5-xylenol; 2,3,4- or 2,3,5-trimethylphenol; 2-,3- or 4-tert-butylphenol; 2-tert-butyl-4- or 5-methylphenol; 2-,4- or 5-methylresorcinol; 2-,3- or 4-methoxyphenol; 2,3-, 2,5- or 3,5-dimethoxyphenol; 2-methoxyresorcinol; 4-tert-butylcatechol; 2-,3- or 4-ethylphenol; 2,5- or 3,5-diethylphenol; 2,3,5-triethylphenol; 2-naphthol; 1,3-, 1,5- or 1,7-dihydroxynaphthalene; and polyhydroxytriphenylmethane compounds obtained by the condensation of xylenol with hydroxybenzaldehyde. These phenol compounds can be used individually or in combination of two or more. Among these, o-, m-, or p-cresol; 2,3-, 2,5-, 3,4-, or 3,5-xylenol; and 2,3,4-, or 2,3,5-trimethylphenol are preferred as phenol compounds.

[0171] Examples of aldehydes include aliphatic aldehydes such as formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, isobutyraldehyde, acrolein, or crotonaldehyde; alicyclic aldehydes such as cyclohexanealdehyde, cyclopentanaldehyde, or furylacrolein; aromatic aldehydes such as furfural, benzaldehyde, o-, m-, or p-methylbenzaldehyde, p-ethylbenzaldehyde, 2,4-, 2,5-, 3,4-, or 3,5-dimethylbenzaldehyde, or o-, m-, or p-hydroxybenzaldehyde; and aromatic aliphatic aldehydes such as phenylacetaldehyde or cinnamaldehyde. These aldehydes can be used individually or in combination of two or more. Among these, formaldehyde is preferred because it is readily available industrially.

[0172] The condensation reaction between the above phenol compound and aldehyde can be carried out according to conventional methods.

[0173] The polymer (A-2) mentioned above includes polymers containing structural units represented by the following formulas (10-1) to (10-6). In the following formulas, the arrangement of each structural unit may be block-like or random.

[0174] The lower limit of the content of the above structural unit (I-2) (total if there are multiple types of structural unit (I-2)) is preferably 20 mol%, more preferably 30 mol%, and even more preferably 40 mol%, relative to the total structural units constituting the polymer (A-2). The upper limit of the above content is preferably 100 mol%. By setting the content of structural unit (I-2) within the above range, the radiation-sensitive composition can be made even more sensitive.

[0175] The weight-average molecular weight (Mw), Mw / Mn, and content ratio of polymer (A-2) can be given within the same range as those for polymer (A-1) described above.

[0176] (Other polymers (E)) The radiation-sensitive composition of this embodiment may also contain, as other polymers, a polymer (E) having a higher mass content of fluorine atoms than the base polymer (A) (hereinafter also referred to as "high fluorine-content polymer (E)"). When the radiation-sensitive composition contains the high fluorine-content polymer (E), it can be unevenly distributed on the surface of the resist film relative to the base polymer (A), and as a result, the water repellency of the surface of the resist film during immersion exposure can be enhanced, and the surface modification of the resist film and the distribution of the composition within the film can be controlled during EUV exposure.

[0177] If the radiation-sensitive composition contains a high-fluorine content polymer, the lower limit of the high-fluorine content polymer is preferably 0.5 parts by mass, more preferably 1 part by mass, and even more preferably 1.5 parts by mass, per 100 parts by mass of the base polymer (A). The upper limit of the above content is preferably 15 parts by mass, more preferably 10 parts by mass, and even more preferably 6 parts by mass.

[0178] By setting the content of the high-fluorine polymer within the above range, the high-fluorine polymer can be more effectively distributed to the surface layer of the resist film. As a result, it is possible to improve the water repellency of the surface of the resist film during immersion exposure, and to control the surface modification of the resist film and the distribution of the internal composition during EUV exposure. The radiation-sensitive composition may contain one or more high-fluorine polymers.

[0179] <Acid Diffusion Control Agent (C)> The radiation-sensitive composition contains an acid diffusion control agent (C). The acid diffusion control agent (C) controls the diffusion phenomenon of acids generated from the above compound (B) and the radiation-sensitive acid generator (P) described later in the resist film upon exposure, and has the effect of suppressing undesirable chemical reactions in the non-exposed areas. In addition, the storage stability of the resulting radiation-sensitive composition is improved. Furthermore, the resolution of the resist pattern is further improved, and changes in the line width of the resist pattern due to variations in the holding time from exposure to development can be suppressed, resulting in a radiation-sensitive composition with excellent process stability.

[0180] Examples of acid diffusion control agents (C) include compounds represented by the following formula (7) (hereinafter also referred to as "nitrogen-containing compounds (I)"), compounds having two nitrogen atoms in the same molecule (hereinafter also referred to as "nitrogen-containing compounds (II)"), compounds having three nitrogen atoms (hereinafter also referred to as "nitrogen-containing compounds (III)"), amide group-containing compounds, urea compounds, nitrogen-containing heterocyclic compounds, and the like.

[0181]

[0182] In the above formula (7), R ２２ , R ２３ and R ２４ Each 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.

[0183] Examples of nitrogen-containing compounds (I) include monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and triamylamine; and aromatic amines such as aniline and 2,6-di-i-propylaniline.

[0184] Examples of nitrogen-containing compounds (II) include ethylenediamine, N,N,N',N'-tetramethylethylenediamine, and 1,1',1'',1'''-(ethylenedinitrilo)tetrakis(2-propanol).

[0185] Examples of nitrogen-containing compounds (III) include polyamine compounds such as polyethyleneimine and polyallylamine; and polymers such as dimethylaminoethylacrylamide.

[0186] 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.

[0187] Examples of urea compounds include urea, methyl urea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, and tributylthiourea.

[0188] Examples of nitrogen-containing heterocyclic compounds include pyridines such as pyridine, 2-methylpyridine, 2,6-di-t-butylpyridine, and 2,6-diisopropylpyridine; morpholines such as N-propylmorpholine and N-(undecylcarbonyloxyethyl)morpholine; and pyrazines, pyrazoles, terpyridines, and 2-phenylbenzimidazole.

[0189] Furthermore, compounds having an acid-dissociable group can also be used as the nitrogen-containing organic compound. Examples of nitrogen-containing organic compounds having an acid-dissociable group include N-t-butoxycarbonylpiperidine, 1-(tert-butoxycarbonyl)-4-hydroxypiperidine, N-t-butoxycarbonylimidazole, N-t-butoxycarbonylbenzimidazole, N-t-butoxycarbonyl-2-phenylbenzimidazole, N-(t-butoxycarbonyl)di-n-octylamine, N-(t-butoxycarbonyl Examples include (bonyl)diethanolamine, N-(t-butoxycarbonyl)dicyclohexylamine, N-(t-butoxycarbonyl)diphenylamine, N-t-butoxycarbonyl-4-hydroxypiperidine, N-(1,1-dimethylpropyl)butoxycarbonyl-4-hydroxypiperidine, N-t-butoxycarbonyl-4-acetoxypiperidine, and N-t-amyloxycarbonyl-4-hydroxypiperidine.

[0190] Furthermore, as the acid diffusion control agent (C), an onium salt compound (d) can be suitably used, which generates an acid with a higher pKa than the acid generated from the above compound (B) or the radiation-sensitive acid generator (P) described later, upon irradiation with radiation.

[0191] The onium salt compound (d) is preferably represented by the following formulas (8-1) to (8-4).

[0192] In the above formulas (8-1) to (8-4), J＋ It is a sulfonium cation, U ＋ This is an iodonium cation. － and G － Each of them is independent of OH － It may be R α -O － , R α - COO － , R α -SO ３ － It may also be an organic acid anion represented by the above formulas (8-1) to (8-2), α R is a monovalent organic group having 1 to 30 carbon atoms. In the above formulas (8-3) to (8-4), α R is a single bond or a divalent organic group having 1 to 30 carbon atoms. As an example of the monovalent organic group having 1 to 30 carbon atoms, R in formula (1) above is... １ A monovalent organic group having 1 to 20 carbon atoms, represented by [formula], can be suitably adopted as a group with 1 to 30 carbon atoms. As the above-mentioned divalent organic group having 1 to 30 carbon atoms, a group obtained by removing one hydrogen atom from the above-mentioned monovalent organic group having 1 to 30 carbon atoms can be suitably adopted.

[0193] Examples of organic acid anions for the above-mentioned acid diffusion control agent include, but are not limited to, those listed below.

[0194]

[0195]

[0196] The onium cation in the above acid diffusion control agent (C) is M of formula (1) above. ＋ The structure listed as a specific example of a monovalent organic cation represented by can be suitably adopted.

[0197] These acid diffusion control agents (C) may be used individually or in combination of two or more.

[0198] The lower limit of the content (total in the case of multiple types) of the above-mentioned acid diffusion control agent (C) is preferably 0.05 parts by mass, more preferably 0.1 parts by mass, and still more preferably 0.5 parts by mass, per 100 parts by mass of polymer (A). The upper limit of the above-mentioned content is preferably 60 parts by mass, more preferably 50 parts by mass, and still more preferably 40 parts by mass. This allows for excellent sensitivity and pattern formation during resist pattern formation.

[0199] (Solvent (S)) The radiation-sensitive composition according to this embodiment contains a solvent (S). The solvent (S) is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the polymer (A), compound (B), and any optional components that may be contained therein.

[0200] Examples of solvents include alcohol-based solvents, ether-based solvents, ketone-based solvents, amide-based solvents, ester-based solvents, and hydrocarbon-based solvents.

[0201] Examples of alcohol-based solvents include monoalcohol solvents having 1 to 18 carbon atoms, such as isopropanol, 4-methyl-2-pentanol, 3-methoxybutanol, n-hexanol, 2-ethylhexanol, furfuryl alcohol, cyclohexanol, 3,3,5-trimethylcyclohexanol, and diacetone alcohol; polyhydric alcohol solvents having 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; and polyhydric alcohol partial ether solvents, such as propylene glycol monomethyl ether, which are obtained by etherifying some of the hydroxyl groups in the above-mentioned polyhydric alcohol solvents.

[0202] In this embodiment, alcohol acid ester solvents such as methyl lactate, ethyl lactate, propyl lactate, butyl lactate, methyl 2-hydroxyisobutyrate, isopropyl 2-hydroxyisobutyrate, isobutyl 2-hydroxyisobutyrate, and n-butyl 2-hydroxyisobutyrate are also included in the alcohol-based solvents.

[0203] Examples of ether-based solvents include: dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether; glycol ether solvents such as dipropylene glycol dimethyl ether and dipropylene glycol methyl-n-propyl ether; cyclic ether solvents such as tetrahydrofuran and tetrahydropyran; aromatic ring-containing ether solvents such as diphenyl ether and anisole (methylphenyl ether); and polyhydric alcohol ether solvents obtained by etherifying the hydroxyl groups of the above-mentioned polyhydric alcohol solvents.

[0204] Examples of ketone solvents include linear ketone solvents such as acetone, butanone, and methyl-isobutyl ketone; cyclic ketone solvents such as cyclopentanone, cyclohexanone, and methylcyclohexanone; and 2,4-pentanedione, acetonylacetone, and acetophenone.

[0205] Examples of amide solvents include cyclic amide solvents such as N,N'-dimethylimidazolidinone and N-methylpyrrolidone; and chain-like amide solvents such as N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, and N-methylpropionamide.

[0206] Examples of ester solvents include monocarboxylic acid ester solvents such as n-butyl acetate; 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 solvents such as γ-butyrolactone and valerolactone; carbonate solvents such as diethyl carbonate, ethylene carbonate, and propylene carbonate; and polyhydric carboxylic acid diester solvents such as propylene glycol diacetate, methoxytriglycol acetate, diethyl oxalate, ethyl acetoethyl acetate, and diethyl phthalate.

[0207] Examples of hydrocarbon solvents include aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane; and aromatic hydrocarbon solvents such as benzene, toluene, diisopropylbenzene, and n-amylnaphthalene.

[0208] Among these, alcohol-based solvents, ester-based solvents, and ketone-based solvents are preferred, polyhydric alcohol partial ether-based solvents, alcoholic acid ester-based solvents, C1-C18 monoalcohol-based solvents, polyhydric alcohol partial ether acetate-based solvents, lactone-based solvents, and cyclic ketone-based solvents are more preferred, and propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, and 2-heptanone are even more preferred. The radiation-sensitive composition may contain one or more solvents.

[0209] <Crosslinking agent (T)> The radiation-sensitive composition may contain a crosslinking agent (T). The type of crosslinking agent (T) is not particularly limited, and examples include crosslinking agents having two or more crosslinking groups in one molecule. The number of crosslinking groups is two or more per molecule, preferably 2 to 10, and more preferably 2 to 6.

[0210] The above crosslinkable group is not particularly limited, but it is preferable to have at least one selected from the group consisting of a methylol group, an alkoxymethyl group, a glycidyl group, a (meth)acryloyl group, and a vinyl group, more preferably a methylol group or an alkoxymethyl group, and even more preferably an alkoxymethyl group.

[0211] The above composition can be used as a negative-type pattern forming composition by containing a crosslinking agent (T). Specifically, in the exposed area, the acid generated from compound (B) or the radiation-sensitive acid generator (P) described later causes a crosslinking reaction between the crosslinking agent (T) and the polymer (A), leading to curing and making it substantially insoluble in alkaline developer. On the other hand, by removing the unexposed area with alkaline developer, a negative-type pattern can be formed.

[0212] The crosslinking agent (T) is not particularly limited, but examples include amino-based crosslinking agents having one or more nitrogen atoms, and phenolic hydroxyl group-containing crosslinking agents.

[0213] The above-mentioned amino-based crosslinking agents are not particularly limited, as long as they have one or more nitrogen atoms, but examples include glycoluryl-type crosslinking agents having a glycoluryl skeleton, melamine-type crosslinking agents having a melamine skeleton, and urea-type crosslinking agents having a cyclic alkylene urea skeleton.

[0214] Among these, amino-based crosslinking agents are preferred as the crosslinking agent (T), and glycoluryl-type crosslinking agents and melamine-type crosslinking agents are more preferred.

[0215] Examples of the glycoluryl-type crosslinking agent mentioned above include the compound (T1) represented by the following formula (T1). (In formula (T1), R ３１ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. However, at least two R ３１ is, *-R ３３ -OR ３４ (R ３３ R is a divalent hydrocarbon group having 1 to 10 carbon atoms. ３４ R is a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates a bond with a nitrogen atom. ３２ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms.

[0216] The above R ３１ In this, the monovalent organic group having 1 to 20 carbon atoms is R in formula (1) above. １ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0217] The above R ３３ In this, the divalent hydrocarbon group having 1 to 10 carbon atoms is R in formula (1) above. １ In this context, a monovalent hydrocarbon group having 1 to 20 carbon atoms can be suitably selected, specifically one group with one hydrogen atom removed from the corresponding carbon number group.

[0218] The above R ３４In this, the monovalent hydrocarbon group having 1 to 10 carbon atoms is R in formula (1) above. １ Among the monovalent hydrocarbon groups having 1 to 20 carbon atoms, those with the corresponding number of carbon atoms can be suitably adopted.

[0219] The above R ３２ In this, the monovalent organic group having 1 to 10 carbon atoms is R in formula (1) above. １ Among the monovalent organic groups having 1 to 20 carbon atoms represented by [formula], those with the corresponding number of carbon atoms can be suitably adopted.

[0220] As the glycoluryl type crosslinking agent, the compound represented by the following formula (T1-1) (T1-1) is preferred. (In formula (T1-1), R ３２ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. ３３ Each of these is independently a divalent hydrocarbon group having 1 to 10 carbon atoms. ３４ These are, independently, monovalent hydrocarbon groups having 1 to 10 carbon atoms.

[0221] R ３２ A monovalent organic group having 1 to 10 carbon atoms, R ３３ A divalent hydrocarbon group having 1 to 10 carbon atoms, R ３４ As the monovalent hydrocarbon group having 1 to 10 carbon atoms in the above formula (T1), the monovalent organic group having 1 to 10 carbon atoms, the divalent hydrocarbon group having 1 to 10 carbon atoms, and the monovalent hydrocarbon group having 1 to 10 carbon atoms can be suitably adopted.

[0222] Among these, the above R ３２ As such, a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferred. ３３ As for the group, an alkylene group having 1 to 5 carbon atoms is preferred, and a methylene group or an ethylene group is more preferred. ３４ A C1-C5 alkyl group is preferred, and a methyl group or a butyl group is more preferred.

[0223] Examples of glycoluryl-type crosslinking agents include those with the following formulas.

[0224] (In the formula, Et is an ethyl group,ｎ Bu is an n-butyl group, ｉ Pr represents an isopropyl group.

[0225] Examples of the melamine-type crosslinking agent mentioned above include the compound (T2) represented by the following formula (T2). (In formula (T2), R ４ Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 20 carbon atoms. However, at least two R ４ is, *-R ４１ -OR ４２ (R ４１ R is a divalent hydrocarbon group having 1 to 10 carbon atoms. ４２ This represents a hydrogen atom or a monovalent hydrocarbon group having 1 to 10 carbon atoms. * indicates a bond with a nitrogen atom.

[0226] The above R ４ In this, the monovalent organic group having 1 to 20 carbon atoms is R in formula (1) above. １ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0227] The above R ４１ In this, the divalent hydrocarbon group having 1 to 10 carbon atoms is R in formula (1) above. １ Among the monovalent hydrocarbon groups having 1 to 20 carbon atoms, groups with one hydrogen atom removed from those with the corresponding number of carbon atoms can be suitably adopted.

[0228] The above R ４２ In this, the monovalent hydrocarbon group having 1 to 10 carbon atoms is R in formula (1) above. １ Among the monovalent hydrocarbon groups having 1 to 20 carbon atoms, those with the corresponding number of carbon atoms can be suitably adopted.

[0229] As the melamine-type crosslinking agent, a compound represented by the following formula (T2-1) (T2-1) is preferred. (In formula (T2-1), R ４１ Each of these is independently a divalent hydrocarbon group having 1 to 10 carbon atoms. ４２ These are, independently, monovalent hydrocarbon groups having 1 to 10 carbon atoms.

[0230] R４１ A divalent hydrocarbon group having 1 to 10 carbon atoms, R ４２ As the monovalent hydrocarbon group having 1 to 10 carbon atoms in the above formula (T2), the divalent hydrocarbon group having 1 to 10 carbon atoms and the monovalent hydrocarbon group having 1 to 10 carbon atoms listed above can be suitably adopted.

[0231] Among these, the above R ４１ As for the group, an alkylene group having 1 to 5 carbon atoms is preferred, and a methylene group or an ethylene group is more preferred. ４２ Preferably, the alkyl group has 1 to 5 carbon atoms, and a methyl group is more preferred.

[0232] Examples of melamine-type crosslinking agents include those with the following formulas.

[0233] (In the formula, Me is a methyl group, Et is an ethyl group, ｎ Bu is an n-butyl group, ｉ Pr represents an isopropyl group.

[0234] Furthermore, the following crosslinking agents can be cited as urea-type crosslinking agents having the above-mentioned cyclic alkylene urea skeleton.

[0235]

[0236] Furthermore, the following crosslinking agents can be listed as phenolic hydroxyl group-containing crosslinking agents.

[0237]

[0238] In the present invention, the above-mentioned crosslinking agent (T) can be used alone or in combination of two or more types.

[0239] When the above radiation-sensitive composition contains a crosslinking agent (T), the lower limit of the content of the crosslinking agent (T) (total of multiple types of crosslinking agents (T) if they are included) is preferably 0.5 parts by mass, more preferably 1 part by mass, and even more preferably 3 parts by mass per 100 parts by mass of polymer (A). The upper limit of the content is preferably 30 parts by mass, and more preferably 20 parts by mass. The content of the crosslinking agent (T) is appropriately selected depending on the type of polymer used, exposure conditions, and the required sensitivity. This makes it possible to exhibit excellent CDU, pattern circularity, and pattern rectangularity when forming a resist pattern.

[0240] <Radiation-sensitive acid generator (P)> The above composition may also be used in combination with compound (B) as the above-mentioned radiation-sensitive acid generator, as well as other radiation-sensitive acid generators (P). Examples of the above-mentioned radiation-sensitive acid generator (P) include a nonionic radiation-sensitive acid generator (P1) and an ionic radiation-sensitive acid generator (P2).

[0241] Examples of the above-mentioned nonionic radioactive acid generator (P1) include compounds represented by the following formula (P1-1) and compounds represented by the following formula (P1-2).

[0242] (In the above formula (P1-1), R ５１ R is a divalent hydrocarbon group having 1 to 10 carbon atoms. ５２ (This refers to a monovalent organic group having 1 to 20 carbon atoms.)

[0243] (In the above formula (P1-2), R ５３ These are, independently, monovalent organic groups having 1 to 20 carbon atoms.

[0244] The above R ５１ As a divalent hydrocarbon group having 1 to 10 carbon atoms, R in formula (1) above is １ Among the monovalent hydrocarbon groups having 1 to 20 carbon atoms, groups obtained by removing one hydrogen atom from the corresponding carbon number group can be suitably adopted. The above hydrocarbon group may have substituents. Examples of substituents include L １１ａ The substituents that the arenediyl group represented by can have can be preferably adopted. Among these, R ５１Preferably, the alkylene group has 1 to 3 carbon atoms, or a cycloalkylene group containing a cyclic skeleton with unsaturated bonds.

[0245] The above R ５２ As a monovalent organic group having 1 to 20 carbon atoms, R in formula (1) above is an example. １ A monovalent organic group having 1 to 20 carbon atoms, represented by R, can be suitably used. ５２ Preferably, the structure has at least one structure selected from the group consisting of an alicyclic structure, an ester bond, and a halogen atom.

[0246] The above R ５３ As a monovalent organic group having 1 to 20 carbon atoms, R in formula (1) above is an example. １ A monovalent organic group having 1 to 20 carbon atoms, represented by R, can be suitably used. ５３ Preferably, it has at least one structure selected from the group consisting of an alicyclic structure and an ether bond.

[0247] The above alicyclic structure is R in formula (1) above. １ A structure corresponding to a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably adopted.

[0248] Examples of compounds represented by the above formula (P1-1) or (P1-2) include the following structures.

[0249] Examples of the above-mentioned ionic radioactive acid generator (P2) include onium salt compounds (P2) represented by the following formula (P2). (In formula (P2), R ６０ R is a monovalent organic group having 1 to 40 carbon atoms. ｆ１ and R ｆ２ Each of these is independently a hydrogen atom, a cyano group, a fluorine atom, or a monovalent fluorinated hydrocarbon group. ｆ１ and R ｆ２ If multiple R ｆ１ and R ｆ２ These are either the same or different. t is an integer between 0 and 4. Z ＋ (This is a radiation-sensitive onium cation.)

[0250] R ６０ As a monovalent organic group having 1 to 40 carbon atoms represented by the above formula (1), R １ Groups with 1 to 20 carbon atoms represented by the monovalent organic group can be preferably adopted, with the number of carbon atoms extended from 1 to 40. Among these, R ６０ From the viewpoint of being able to appropriately control the diffusion length of the generated acid, it is preferable that the structure includes an alicyclic structure. The alicyclic structure is R in formula (1) above. １ A structure corresponding to a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably adopted.

[0251] R ｆ１ and R ｆ２ As a monovalent fluorinated hydrocarbon group represented by formula (1), R １ Examples include groups in which some or all of the hydrogen atoms of a monovalent hydrocarbon group having 1 to 20 carbon atoms are replaced with fluorine atoms.

[0252] Specific examples of anions in onium salt compounds (P2) include, but are not limited to, the structure shown in the following formula.

[0253]

[0254]

[0255]

[0256] The above Z of the onium salt compound (P2) ＋ The onium cation represented by the above formula (1) is M ＋ The structure listed as a specific example of a monovalent organic cation represented by can be suitably adopted.

[0257] The radiation-sensitive acid generator (P2) can be obtained by appropriately combining the above-mentioned anion and the above-mentioned radiation-sensitive onium cation.

[0258] In the present invention, the above-mentioned radiation-sensitive acid generator (P) can be used alone or in combination of two or more types.

[0259] When the above composition contains a radiation-sensitive acid generator (P), the lower limit of the content of the radiation-sensitive acid generator (P) (total in the case of multiple types) is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, and still more preferably 1 part by mass, per 100 parts by mass of polymer (A). The upper limit of the above content is preferably 30 parts by mass, more preferably 20 parts by mass, and still more preferably 10 parts by mass. This allows for excellent sensitivity during resist pattern formation.

[0260] (Other optional components) The above-mentioned radiation-sensitive composition may contain other optional components in addition to the components listed above. Examples of these other optional components include segregation accelerators, dissolution accelerators, surfactants, alicyclic skeleton-containing compounds, sensitizers, etc. These other optional components may be used individually or in combination of two or more types.

[0261] The surfactants mentioned above are not particularly limited, but non-fluorinated surfactants or non-silicone surfactants can be suitably used.

[0262] If the above radiation-sensitive composition contains the above optional component, the content of the above optional component is preferably 0.01 parts by mass or more, more preferably 0.03 parts by mass or more, per 100 parts by mass of the above polymer (A). Furthermore, it is preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 25 parts by mass or less.

[0263] <Method for preparing a radiation-sensitive composition> The above radiation-sensitive composition can be prepared by mixing a polymer (A), a compound (B), an acid diffusion control agent (C), a solvent (S), and, if necessary, a crosslinking agent (T), a radiation-sensitive acid generator (P), etc., in predetermined proportions. After mixing, the above radiation-sensitive composition is preferably filtered using, for example, a filter with a pore size of about 0.05 μm to 0.40 μm. The solid content concentration of the above radiation-sensitive composition is usually 0.1% to 50% by mass, preferably 0.5% to 30% by mass, and more preferably 1% to 20% by mass.

[0264] ≪Pattern Forming Method≫ A pattern forming method according to one embodiment of the present invention includes a step (1) of applying the above-mentioned radiation-sensitive composition directly or indirectly to a substrate to form a resist film (hereinafter also referred to as the "resist film forming step"), a step (2) of exposing the resist film (hereinafter also referred to as the "exposure step"), and a step (3) of developing the exposed resist film (hereinafter also referred to as the "development step").

[0265] According to the above resist pattern formation method, a high-quality resist pattern can be formed because it uses the above-mentioned radiation-sensitive composition that can form a resist film with excellent sensitivity in the exposure process, exposure margin, depth of field, pattern rectangularity, storage stability, development defect performance, CDU, and pattern circularity. Each step will be described below.

[0266] [Resist Film Formation Process] In this process (step (1) above), a resist film is formed using the radiation-sensitive composition described above. 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 150°C, with 80°C to 140°C being preferred. The PB time is usually 5 seconds to 600 seconds, with 10 seconds to 300 seconds being preferred.

[0267] The lower limit of the thickness of the formed resist film is preferably 10 nm, more preferably 15 nm, and even more preferably 20 nm. The upper limit of the thickness is preferably 9000 nm, and more preferably 4000 nm. In particular, when a thick resist film is exposed to KrF excimer laser light in the exposure process described later, the lower limit of the thickness may be 100 nm, 150 nm, or 200 nm.

[0268] [Exposure Process] In this process (process (2) above), the resist film formed in the resist film formation process, which is process (1) above, is exposed by irradiating it with radiation through a photomask (and, in some cases, through an immersion liquid such as water). Examples of radiation used for exposure include electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, KrF, EUV (extreme ultraviolet), X-rays, and gamma rays, depending on the line width of the desired pattern; and charged particle beams such as electron beams and alpha rays. Among these, the compositions of the present invention are best suited to using a KrF excimer laser, EUV, and i-rays.

[0269] It is preferable to perform post-exposure baking (PEB) after the above exposure. This PEB creates a difference in solubility in the developer between the exposed and unexposed areas. The PEB temperature is usually 50°C to 180°C, with 80°C to 150°C being preferred. The PEB time is usually 5 seconds to 600 seconds, with 10 seconds to 300 seconds being preferred.

[0270] [Development Process] In this process (step (3) above), the resist film exposed in the exposure process, which is step (2) above, is developed. 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.

[0271] Examples of developers used in the above-mentioned development 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, and 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.

[0272] 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 composition. Among these, ether solvents, ester solvents, and ketone solvents are preferred. As for ether solvents, glycol ether solvents are preferred, and ethylene glycol monomethyl ether and propylene glycol monomethyl ether are more preferred. As for ester solvents, acetate 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 solvents 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.

[0273] As mentioned above, either an alkaline developer or an organic solvent developer may be used as the developing solution.

[0274] 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 puddling 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 while scanning a developer solution dispensing nozzle at a constant speed onto a substrate rotating at a constant speed (dynamic dispensing method).

[0275] <<Compounds>> Compounds according to another embodiment of the present invention are represented by the following formulas (10), (11), (12), or (13).

[0276] <Compound represented by formula (10)> (In formula (10), R １１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. １１ If multiple R１１ They are either identical or different from each other. １１ m is an integer between 0 and 2. １１ is 0 to (3 + 2n １１ n is an integer of the form n. １１ If it is 0 or 2, M １ ＋ is a monovalent organic cation, n １１ If it is 1, M １ + This is a monovalent organic cation represented by the following formula (10-1), formula (10-2), or formula (10-3). (In formula (10-1), R １２ and R １３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a cyano group, or a hydroxyl group. １２ , R １３ If multiple R １２ , R １３ They are either identical or different from each other. １２ , m １３ Each of these is an independent integer between 0 and 5. (In formula (10-2), R １４ ~R １６ Each of these is independently a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms other than a thiophenyl group, or R １４ ~R １６ It is a ring-shaped structure formed by the combination of two of them. １４ ~R １６ If multiple R １４ ~R １６ They are either identical or different from each other. １４ m is an integer between 1 and 5. １５ , m １６ Each of these is an independent integer between 0 and 5. (In formula (10-3), R １７ This is a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. １７ R is an integer between 0 and 5. １８ and R １９Each of these is independently a monovalent organic group having 1 to 10 carbon atoms, or R １８ and R １９ They are combined with each other R １８ and R １９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded.

[0277] The above R １１ ~R １８ , and R １９ As an organic group having 1 to 20 carbon atoms represented by the above formula (1), R １ A monovalent organic group having 1 to 20 carbon atoms, represented by , can be suitably used. However, R １４ ~R １６ The organic groups with 1 to 20 carbon atoms represented by do not contain thiophenyl groups.

[0278] The above M １ ＋ As a monovalent organic cation represented by the above formula (1), M ＋ The structure listed as a specific example of a monovalent organic cation represented by can be suitably adopted.

[0279] R １４ ~R １６ The cyclic structure formed by the bonding of two of these elements may be monocyclic, polycyclic, or a combination thereof. Furthermore, the cyclic structure may be alicyclic, aromatic, heterocyclic, or a combination thereof. In the case of a combination, the cyclic structure may be linked by a chain-like structure, and two or more cyclic structures may form a fused cyclic structure or a bridged cyclic structure.

[0280] The above alicyclic structure is R in formula (1) above. １ A structure corresponding to a monovalent alicyclic hydrocarbon group having 3 to 20 carbon atoms can be suitably adopted. As the aromatic ring structure, R of formula (1) above １ A structure corresponding to a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms can be suitably adopted. As the heterocyclic structure, R in formula (1) above is suitable. １ A divalent heterocyclic structure with 3 to 20 carbon atoms can be suitably adopted in this material.

[0281] The above chain-like structure is R in formula (1) above. １Among the monovalent organic groups represented by , those with a chain structure (excluding cyclic structures) can be suitably adopted.

[0282] The above R １８ and R １９ They are combined with each other R １８ and R １９ Examples of cyclic structures formed with the sulfur atom to which it is bonded include tetrahydrothiophene ring structures, benzothiophene ring structures, dibenzothiophene ring structures, pentamethylene sulfide ring structures, and 1,4-thioxane ring structures.

[0283] <Compound represented by formula (11)> (In formula (11), R ２１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ２１ If multiple R ２１ They are either identical or different from each other. r is an integer between 0 and 2. ２１ M is an integer between 0 and (2r + 3). ＋ (This is a monovalent organic cation.)

[0284] The above R ２１ As an organic group having 1 to 20 carbon atoms represented by the above formula (1), R １ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0285] The above M ＋ As a monovalent organic cation represented by the above formula (1), M ＋ The structure listed as a specific example of a monovalent organic cation represented by can be suitably adopted.

[0286] <Compound represented by formula (12)> (In formula (12), R ３１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ３１ If multiple R ３１ They are either identical or different from each other. ３１ M is an integer between 0 and 7. ２ ＋This is a monovalent organic cation represented by the following formula (12-1), formula (12-2), or formula (12-3). (In formula (12-1), R ３２ , R ３３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, or a hydroxyl group. ３２ , R ３３ If multiple R ３２ , R ３３ They are either identical or different from each other. ３２ , m ３３ Each of these is an independent integer between 0 and 5. (In formula (12-2), R ３４ ~R ３６ Each of these independently comprises a halogen atom, a hydroxyl group, a cyano group, a nitro group, or an organic group having 2 to 20 carbon atoms, or R ３４ ~R ３６ It is a ring-shaped structure formed by the combination of two of them. ３４ ~R ３６ If multiple R ３４ ~R ３６ They are either identical or different from each other. ３４ m is an integer between 1 and 5. ３５ , m ３６ Each of these is an independent integer between 0 and 5. (In formula (12-3), R ３７ This is a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. ３７ R is an integer between 0 and 5. ３８ and R ３９ Each of these is independently a monovalent organic group having 1 to 20 carbon atoms, or R ３８ and R ３９ They are combined with each other R ３８ and R ３９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded.

[0287] The above R ３１ ~R ３３ , R ３７ ~R ３９ As an organic group having 1 to 20 carbon atoms represented by the above formula (1), R１ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0288] R ３４ ~R ３６ As an organic group having 2 to 20 carbon atoms represented by the above formula (1), R １ Among the monovalent organic groups having 1 to 20 carbon atoms represented by [formula], those with the corresponding number of carbon atoms can be suitably adopted.

[0289] R ３４ ~R ３６ The cyclic structure formed by the combination of two of these is R in formula (10-2) above. １４ ~R １６ A ring structure formed by the bonding of two of the above can be suitably adopted.

[0290] R ３８ and R ３９ They are combined with each other R ３８ and R ３９ The cyclic structure formed together with the sulfur atom to which it is bonded is R in the above formula (10-3). １８ and R １９ They are combined with each other R １８ and R １９ The cyclic structure formed with the sulfur atom to which it is bonded can be suitably adopted.

[0291] <Compound represented by formula (13)> (In formula (13), R ４１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ４１ If multiple R ４１ They are either identical or different from each other. ４１ M is an integer between 0 and 7. ３ ＋ This is a monovalent organic cation represented by the following formula (13-1), formula (13-2), or formula (13-3). (In formula (13-1), R ４２ , R ４３ Each of these is independently a fluorine atom, an iodine atom, a nitro group, a hydroxyl group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. ４２, R ４３ If multiple R ４２ , R ４３ They are either identical or different from each other. ４２ , m ４３ Each of these is an independent integer between 0 and 5. However, m ４２ +m ４３ (≥ 1.) (In formula (13-2), R ４４ ~R ４６ Each of these independently comprises a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms, or R ４４ ~R ４６ It is a ring-shaped structure formed by the combination of two of them. ４４ ~R ４６ If multiple R ４４ ~R ４６ They are either identical or different from each other. ４４ m is an integer between 1 and 5. ４５ , m ４６ Each of these is an independent integer between 0 and 5. (In formula (13-3), R ４７ This is a halogen atom, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. ４７ R is an integer between 0 and 5. ４８ and R ４９ Each of these is independently a monovalent chain-like organic group having 1 to 10 carbon atoms, or R ４８ and R ４９ They are combined with each other R ４８ and R ４９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded.

[0292] The above R ４１ , R ４４ ~R ４７ As an organic group having 1 to 20 carbon atoms represented by the above formula (1), R １ A monovalent organic group having 1 to 20 carbon atoms, represented by [the formula shown], can be suitably used.

[0293] The above R ４２ , R ４３ As a hydrocarbon group having 1 to 20 carbon atoms represented by the above formula (1), R １A hydrocarbon group having 1 to 20 carbon atoms can be suitably used in this material.

[0294] The above R ３４ ~R ３６ As an organic group having 2 to 20 carbon atoms represented by the above formula (1), R １ Among the monovalent organic groups having 1 to 20 carbon atoms represented by [formula], those with the corresponding number of carbon atoms can be suitably adopted.

[0295] The above R ４４ ~R ４６ The cyclic structure formed by the combination of two of these is R in formula (10-2) above. １４ ~R １６ A ring structure formed by the bonding of two of the above can be suitably adopted.

[0296] The above R ４８ , R ４９ As a monovalent chain-like organic group having 1 to 10 carbon atoms represented by the above formula (1), R １ Among the monovalent organic groups having 1 to 20 carbon atoms represented by , those in a chain-like structure can be preferably adopted.

[0297] R ４８ and R ４９ They are combined with each other R ４８ and R ４９ The cyclic structure formed together with the sulfur atom to which it is bonded is R in the above formula (10-3). １８ and R １９ They are combined with each other R １８ and R １９ The cyclic structure formed with the sulfur atom to which it is bonded can be suitably adopted.

[0298] Specific examples of compounds represented by formulas (10) to (13) above include those exemplified in compound (B) represented by formula (1) above that match each formula, which can be suitably adopted.

[0299] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples. The methods for measuring various physical properties are shown below.

[0300] [Weight-average molecular weight (Mw) and number-average molecular weight (Mn)] The Mw and Mn of the polymer were measured under the conditions described above. The degree of dispersion (Mw / Mn) was calculated from the measured results of Mw and Mn.

[0301] [ １３ [C-NMR analysis] Polymer １３ C-NMR analysis was performed using a nuclear magnetic resonance spectrometer (JEOL Ltd.'s "JNM-Delta400").

[0302] <Synthesis of Polymers> The monomers used in the synthesis of each polymer 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%.

[0303]

[0304] [Synthesis Example 1] (Synthesis of Polymer (A-1)) Monomers (M-1), (M-5), (M-9), and (M-12) were dissolved in 1-methoxy-2-propanol (200 parts by mass) in a molar ratio of 60 / 15 / 20 / 5 (mol%), and AIBN (10 mol%) was added as an initiator to prepare monomer solutions. 100 parts by mass of 1-methoxy-2-propanol was placed in a reaction vessel, and after purging with nitrogen for 30 minutes, the reaction vessel was heated to 80°C, and the monomer solutions were 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. The filtered white powder was washed twice with methanol, 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. 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 hexane (500 parts by mass) to solidify the polymer. The resulting solid was filtered and dried at 50°C for 13 hours to obtain a white powdery polymer (A-1) (yield: 80%). The Mw of polymer (A-1) was 5,100, and the Mw / Mn ratio was 1.15. １３ ¹³C-NMR analysis revealed that the content percentages of structural units derived from (M-1), (M-5), (M-9), and (M-12) were 60.1 mol%, 14.6 mol%, 20.3 mol%, and 5.0 mol%, respectively. Furthermore, in the monomer that gives structural unit (I-1), in the polymer, １３ C-NMR measurements confirmed the disappearance of the carbonyl group peak of the acetyl group, indicating that virtually all alkali-dissociable groups had been hydrolyzed to form phenolic hydroxyl groups.

[0305] [Synthesis Examples 2-8] (Synthesis of Polymers (A-2) to (A-8)) Polymers (A-2) to (A-8) were synthesized in the same manner as in Synthesis Example 1, except that monomers of the types and proportions shown in Table 1 below were used. Note that in the monomer that gives structural unit (I-1), in the polymer,１３ 13C-NMR analysis confirmed the disappearance of the carbonyl group peak of the acetyl group, indicating that virtually all alkali-dissociable groups had been hydrolyzed to phenolic hydroxyl groups. The content percentage (mol%) and physical properties (Mw and Mw / Mn) of each structural unit of the obtained polymer are shown in Table 1 below. In Table 1, "-" indicates that the corresponding component was not used (the same applies to subsequent tables).

[0306]

[0307] <Synthesis of Radiation-Sensitive Acid Generator (B)> [Example B1] (Synthesis of Onium Salt Compound (B-1)) Onium salt compound (B-1) as a radiation-sensitive acid generator (B) was synthesized according to the following synthesis scheme.

[0308]

[0309] 20.0 mmol of sodium 1,2-naphthoquinone-4-sulfonate, 20.0 mmol of bis(4-tert-butyl)iodonium chloride, 50 g of dichloromethane, and 50 g of water were added to a reaction vessel and stirred at room temperature for 4 hours. Dichloromethane was added to the reaction mixture and extracted, and the organic layer was separated. The obtained organic layer was washed with saturated sodium chloride aqueous solution, and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the compound (B-1) represented by the above formula (B-1) was purified by column chromatography to obtain compound (B-1) in good yield.

[0310] [Examples B2 to B8] (Synthesis of onium salt compounds (B-2) to (B-8)) Onium salt compounds as radiation-sensitive acid generators (B) represented by the following formulas (B-2) to (B-8) were synthesized in the same manner as in Synthesis Example B1, except that the raw materials and precursors were appropriately changed.

[0311]

[0312] [Example B9] (Synthesis of Onium Salt Compound (B-9)) An onium salt compound (B-9) was synthesized as a radiation-sensitive acid generator (B) according to the following synthesis scheme.

[0313]

[0314] 20.0 mmol of sodium 1,2-naphthoquinone-4-sulfonate, 20.0 mmol of compound (B-9-a), 50 g of dichloromethane, and 50 g of water were added to a reaction vessel and stirred at room temperature for 4 hours. Dichloromethane was added to the reaction mixture and extracted, and the organic layer was separated. The obtained organic layer was washed with saturated sodium chloride aqueous solution, and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the compound (B-9) represented by the above formula (B-9) was purified by column chromatography to obtain compound (B-9) in good yield.

[0315] [Examples B9 to B16] (Synthesis of onium salt compounds (B-9) to (B-16)) Except for appropriately changing the raw materials and precursors, onium salt compounds as radiation-sensitive acid generators (B) represented by the following formulas (B-9) to (B-16) were synthesized in the same manner as in Example B8.

[0316]

[0317] [Example B17] (Synthesis of Onium Salt Compound (B-17)) An onium salt compound (B-17) was synthesized as a radiation-sensitive acid generator (B) according to the following synthesis scheme.

[0318]

[0319] 20.0 mmol of sodium 1,2-naphthoquinone-3-sulfonate, 20.0 mmol of compound (B-17-a), 50 g of dichloromethane, and 50 g of water were added to a reaction vessel and stirred at room temperature for 4 hours. Dichloromethane was added to the reaction mixture and extracted, and the organic layer was separated. The obtained organic layer was washed with saturated sodium chloride aqueous solution, and then with water. After drying over sodium sulfate, the solvent was removed by distillation, and the compound (B-17) represented by the above formula (B-17) was obtained in good yield by purification by column chromatography.

[0320] [Examples B18 to B24] (Synthesis of onium salt compounds (B-18) to (B-24)) Onium salt compounds as radiation-sensitive acid generators (B) represented by the following formulas (B-18) to (B-24) were synthesized in the same manner as in Example B17, except that the raw materials and precursors were appropriately changed.

[0321]

[0322] In addition to the synthesized components mentioned above, the following compounds were used.

[0323] [Radiation-sensitive acid generators other than (B-1) to (B-24)] b-1 to b-6: Compounds represented by the following formulas (b-1) to (b-6) (Hereafter, compounds represented by formulas (b-1) to (b-6) may be referred to as "compound (b-1)" to "compound (b-6)," respectively.)

[0324]

[0325] [Polymers other than polymers (A-1) to (A-8)] A-i-1 to A-i-2: Polymers represented by the following formulas (A-i-1) to (A-i-2) (Hereafter, polymers represented by formulas (A-i-1) to (A-i-2) may be referred to as "polymer (A-i-1)" to "polymer (A-i-2)," respectively.)

[0326]

[0327] [Acid Diffusion Control Agent (C)] C-1 to C-5: Compounds represented by the following formulas (C-1) to (C-5) (Hereafter, the compounds represented by formulas (C-1) to (C-5) may be referred to as "Compound (C-1)" to "Compound (C-5)," respectively.)

[0328]

[0329] [Crosslinking agent (T)] T-1 to T-3: Compounds represented by the following formulas (T-1) to (T-3) (Hereinafter, compounds (T-1) to (T-3) may be referred to as "compound (T-1)" to "compound (T-3)," respectively.)

[0330]

[0331] [Other Additives (W)] W-1 to W-5: Compounds represented by the following formulas (W-1) to (W-3) and additive compounds (W-4) to (W-5) (Hereinafter, compounds (W-1) to (W-5) may be referred to as "compound (W-1)" to "compound (W-5)," respectively.)

[0332]

[0333] W-4: MEGAFACE EFS-321 (manufactured by DIC Corporation) (non-fluorine-based) W-5: BYK-399 (manufactured by Bic Chemie Japan Co., Ltd.) (non-silicone-based)

[0334] [Solvent (S)] S-1: Propylene glycol monomethyl ether acetate S-2: Propylene glycol monomethyl ether S-3: Ethyl lactate S-4: 2-heptanone

[0335] [Preparation of positive-type radiation-sensitive composition for KrF exposure] [Example 1] 100 parts by mass of (A-1) as polymer (A), 5.0 parts by mass of (B-1) as radioactive acid generator (B), 1.0 part by mass of (C-1) as acid diffusion control agent (C), 0.05 parts by mass of (W-1) as other additive (W), and 450 parts by mass of a mixed solvent of (S-1) / (S-3) as solvent (S) were mixed and filtered through a membrane filter with a pore size of 0.45 μm to prepare a radiation-sensitive composition (J-1).

[0336] [Examples 2-40 and Comparative Examples 1-4] Radiation-sensitive compositions (J-2) to (J-40) and (CJ-1) to (CJ-4) were prepared in the same manner as in Example 1, except that the components of the types and amounts shown in Table 2 below were used.

[0337]

[0338] <Formation of a resist pattern using a positive-type radiation-sensitive composition for KrF exposure> The prepared positive-type radiation-sensitive composition for KrF exposure was applied to a 12-inch silicon wafer treated with hexamethyldisilazane using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited), and pre-bake (PB) was performed at 130°C for 60 seconds. Subsequently, a resist film with an average thickness of 1600 nm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using a KrF excimer laser scanner (PAS5500 / 850C wavelength 248 nm from ASML) under optical conditions of NA = 0.68 and σ = 0.60, through a 350 nm line-and-space mask pattern. After exposure, post-exposure bake (PEB) was performed at 130°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 (350 nm line, 700 nm pitch).

[0339] <Evaluation> The resist patterns formed using the above-mentioned positive-type radiation-sensitive composition for KrF exposure were evaluated for sensitivity, exposure margin, depth of field, pattern rectangularity, number of development defects, and storage stability according to the following method. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG-5000") was used to measure the length of the resist patterns. The results are shown in Table 3 below.

[0340] [Sensitivity] In forming a resist pattern using the above-mentioned positive-type radiation-sensitive composition for KrF exposure, the exposure amount used to form the 350 nm line and 700 nm pitch is defined as the optimal exposure amount, and this optimal exposure amount is defined as the sensitivity (mJ / cm²). ２ The sensitivity was set to 30 mJ / cm². ２ The following conditions are considered "extremely good" and 30 mJ / cm². ２ Super 40mJ / cm ２ In the following cases, it is considered "good" and 40 mJ / cm². ２ If it exceeded this value, it was rated as "poor."

[0341] [EL Performance (Exposure Margin)] Within the exposure range including the optimal exposure amount mentioned above, the exposure amount is 1 mJ / cm². ２ Each resist pattern was formed by varying the exposure dose, and the line width of each pattern was measured using the scanning electron microscope described above. From the relationship between the obtained line width and exposure dose, the exposure dose E(385) that resulted in a line width of 385 nm and the exposure dose E(315) that resulted in a line width of 315 nm were determined, and the exposure margin (EL) was calculated using the formula: Exposure margin (EL) = (E(315) - E(380)) × 100 / (Optimal exposure dose). The larger the exposure margin value, the smaller the variation in the dimensions of the pattern obtained when the exposure dose is varied, and the higher the yield during device fabrication. EL performance was evaluated as "good" if it was 15% or more, and as "poor" if it was below 15%.

[0342] [Depth of Focus] In the resist pattern resolved at the optimal exposure amount determined in 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 200 nm or more is evaluated as "good," and a depth of focus of less than 200 nm is evaluated as "poor."

[0343] [Pattern Rectangularity] Line and space patterns with 350 nm lines and a 700 nm pitch, formed by irradiating with the optimal exposure amount determined in the sensitivity evaluation above, were observed using a scanning electron microscope SU8220, and the cross-sectional shape of the line and space patterns was evaluated. The rectangularity of the resist pattern was evaluated as follows: if the ratio of the length of the lower side to the length of the upper side in the cross-sectional shape of the line portion was 1 or more and 1.05 or less, it was evaluated as "A" (very good); if it was greater than 1.05 and 1.10 or less, it was evaluated as "B" (good); and if it was greater than 1.10, it was evaluated as "C" (poor).

[0344] [Storage Stability] The above KrF exposure-positive radiosensitive composition was stored at 35°C for 30 days, and then the optimal exposure amount, i.e., sensitivity S30, for forming a line-and-space pattern with a 350 nm line and a 700 nm pitch was measured again. The ratio of the change in sensitivity after 30 days of storage was calculated based on the following formula, compared to the sensitivity S0 before storage. A change ratio of 0% or more and 1.0% or less was evaluated as "A" (good), a change ratio of more than 1.0% and 1.5% or less was evaluated as "B" (good), and a change ratio of more than 1.5% was evaluated as "C" (poor). Sensitivity change ratio (%) = {|S30 - S0| / S0} × 100

[0345] [Development Defect Count] A resist film was exposed at the optimal exposure level to form a line-and-space pattern with 350 nm lines and a 700 nm pitch, and this was used as a wafer for defect inspection. The number of defects on this wafer was measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 μm or less were judged to be originating from the resist film, and their number was calculated. After development, the number of defects judged to be originating from the resist film was evaluated as "good" if it was 150 or less, and as "poor" if it exceeded 150.

[0346]

[0347] As is clear from the results in Table 3, the radiation-sensitive compositions of the examples exhibited good sensitivity, exposure margin, depth of field, pattern rectangularity, storage stability, and development defect performance when used in KrF positive exposure. On the other hand, the comparative examples failed to satisfy all of these characteristics simultaneously. Therefore, when the radiation-sensitive compositions of the examples are used in KrF positive exposure, it is possible to form a resist pattern with optimal sensitivity, excellent roughness performance, pattern shape, and yield.

[0348] [Preparation of Negative-Type Radiation-Sensitive Composition for KrF Exposure] [Example 41] A radiation-sensitive composition (J-41) was prepared by mixing 100 parts by mass of (A-5) as a polymer (A), 5.0 parts by mass of (B-9) as a radiation-sensitive acid generator (B), 1.0 part by mass of (C-1) as an acid diffusion control agent (C), 5.0 parts by mass of (T-1) as a crosslinking agent (T), 0.05 parts by mass of (W-1) as other additives (W), and 300 parts by mass of a mixed solvent of (S-1) / (S-4) as a solvent (S), and filtering the mixture through a membrane filter with a pore size of 1.0 μm.

[0349] [Examples 42-58 and Comparative Examples 5-8] Radiation-sensitive compositions (J-42) to (J-58) and (CJ-5) to (CJ-8) were prepared in the same manner as in Example 41, except that the components of the types and amounts shown in Table 4 below were used.

[0350]

[0351] <Formation of a resist pattern using a negative-type radiation-sensitive composition for KrF exposure> The prepared negative-type radiation-sensitive composition for KrF exposure was applied to a 12-inch silicon wafer treated with hexamethyldisilazane using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited), and pre-bake (PB) was performed at 130°C for 60 seconds. Subsequently, a resist film with an average thickness of 4.0 μm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using a KrF excimer laser scanner (PAS5500 / 850C wavelength 248 nm from ASML) under optical conditions of NA = 0.68 and σ = 0.60, through a mask pattern with 600 nm holes and a 1200 nm pitch. After exposure, post-exposure bake (PEB) was performed at 130°C for 60 seconds. Subsequently, the resist film was alkaline-developed using a 2.38% by mass aqueous solution of TMAH as the alkaline developer. After development, it was washed with water and then dried to form a negative-type resist pattern (600 nm holes, 1200 nm pitch).

[0352] <Evaluation> The sensitivity, depth of field, pattern circularity, and number of development defects of the resist patterns formed using the above-mentioned negative-type radiation-sensitive composition for KrF exposure were evaluated according to the following method. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG-5000") was used to measure the length of the resist patterns. The results are shown in Table 5 below.

[0353] [Sensitivity] In forming a resist pattern using the above-mentioned negative-type radiation-sensitive composition for KrF exposure, the exposure amount used to form 600 nm holes and a 1200 nm pitch is defined as the optimal exposure amount, and this optimal exposure amount is defined as the sensitivity (mJ / cm²). ２ The sensitivity was set to 50 mJ / cm². ２ The following conditions are considered "good" and 50 mJ / cm². ２ If it exceeded this value, it was rated as "poor."

[0354] [Depth of Focus] In the resist pattern resolved at the optimal exposure amount determined in 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 300 nm or more is evaluated as "good," and a depth of focus of less than 300 nm is evaluated as "poor."

[0355] [Pattern Circularity] The 600 nm holes and 1200 nm pitch contact holes formed by irradiating with the optimal exposure amount determined in the sensitivity evaluation above were observed in plan view using the scanning electron microscope described above, and the vertical and horizontal sizes were measured. If the ratio of vertical size to horizontal size was 0.90 or more and 1.10 or less, it was evaluated as "A" (good), and if it was less than 0.90 or greater than 1.10, it was evaluated as "B" (poor).

[0356] [Development Defect Count] A resist film was exposed at the optimal exposure level to form a contact hole pattern with 600 nm holes and a 1200 nm pitch, and this was used as a wafer for defect inspection. The number of defects on this wafer was measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 μm or less were judged to be originating from the resist film, and their number was calculated. After development, the number of defects judged to be originating from the resist film was evaluated as "good" if it was 100 or less, and as "poor" if it exceeded 100.

[0357]

[0358] As is clear from the results in Table 5, the radiation-sensitive composition of the example exhibited good sensitivity, depth of field, pattern circularity, and development defect performance when used in KrF negative exposure, whereas the comparative example failed to satisfy all of these characteristics simultaneously. Therefore, when the radiation-sensitive composition of the example is used in KrF negative exposure, it is possible to form a resist pattern with optimal sensitivity and excellent roughness performance, pattern shape, and defect performance.

[0359] [Preparation of positive-type radiation-sensitive composition for extreme ultraviolet (EUV) exposure] [Example 59] A radiation-sensitive composition (J-59) was prepared by mixing 100 parts by mass of (A-7) as polymer (A), 60.0 parts by mass of (B-17) as radiation-sensitive acid generator (B), 40.0 parts by mass of (C-5) as acid diffusion control agent (C), and 6,800 parts by mass of a mixed solvent of (S-1) / (S-2) as solvent (S), and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0360] [Examples 60-66 and Comparative Examples 9-11] Radiation-sensitive compositions (J-60) to (J-66) and (CJ-9) to (CJ-11) were prepared in the same manner as in Example 59, except that the components of the types and amounts shown in Table 6 below were used.

[0361]

[0362] <Formation of a resist pattern using a positive-type radiation-sensitive composition for EUV exposure> An anti-reflective underlayer film (ARC66 from Brewer Sciences) was applied to a 12-inch silicon wafer using a spin coater (CLEAN TRACK ACT12 from Tokyo Electron Limited), and then heated at 205°C for 60 seconds to form an anti-reflective underlayer film with an average thickness of 105 nm. The prepared positive-type radiation-sensitive composition for EUV exposure was applied to this anti-reflective underlayer film using the spin coater, and PB (plate blot) was performed at 130°C for 60 seconds. Subsequently, a resist film with an average thickness of 70 nm was formed by cooling at 23°C for 30 seconds. Next, the resist film was exposed using an EUV lithography system (ASML's "NXE3300") with NA = 0.33, illumination conditions: Conventional s = 0.89, and mask: imecDEFECT32FFR02. After exposure, PEB was performed at 120°C for 60 seconds. Subsequently, the resist film was alkaline developed using a 2.38 mass% TMAH aqueous solution as the alkaline developer, washed with water after development, and then dried to form a positive-type resist pattern (35 nm contact hole pattern).

[0363] <Evaluation> The sensitivity, CDU, and number of development defects of the resist patterns formed using the above-mentioned positive-type radiation-sensitive composition for EUV exposure were evaluated according to the following method. The results are shown in Table 7 below. A scanning electron microscope (Hitachi High-Technologies Corporation's "CG-5000") was used to measure the length of the resist patterns.

[0364] [Sensitivity] In forming a resist pattern using the above-mentioned positive-type radiation-sensitive composition for EUV exposure, the exposure amount used to form a 35 nm contact hole pattern is defined as the optimal exposure amount, and this optimal exposure amount is defined as the sensitivity (mJ / cm²). ２ The sensitivity was set to 45 mJ / cm². ２ The following conditions are considered "good": 45 mJ / cm² ２ If it exceeded this value, it was rated as "poor."

[0365] [CDU] The mask size was adjusted to form a 35 nm contact hole pattern by irradiating with the optimal exposure amount determined in the sensitivity evaluation 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 hole diameter was measured at 16 points in the range of 500 nm and the average value was calculated. This average value was measured at a total of 500 points at arbitrary points, and the 1 sigma value was calculated from the distribution of the measured values, and this was defined as CDU (nm). A smaller CDU value indicates less variation in hole diameter over long periods and is therefore better. A CDU of 2.5 nm or less was evaluated as "good," and a value greater than 2.5 nm was evaluated as "poor."

[0366] [Development Defect Count] A 35 nm contact hole pattern was formed by exposing a resist film with the optimal exposure dose, and this was used as a wafer for defect inspection. The number of defects on this wafer for defect inspection was measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 μm or less were judged to be originating from the resist film, and their number was calculated. After development, the defect count was evaluated as "good" if the number of defects judged to be originating from the resist film was 100 or less, and as "poor" if it exceeded 100.

[0367]

[0368] As is clear from the results in Table 7, the radiation-sensitive composition of the example showed good sensitivity, CDU, and development defect performance when used in EUV positive exposure, whereas the comparative example exhibited inferior characteristics compared to the example. Therefore, when the radiation-sensitive composition of the example is used in EUV positive exposure, it is possible to form a resist pattern with optimal sensitivity, excellent roughness performance, and superior defect performance.

[0369] [Preparation of negative-type radiation-sensitive composition for i-ray exposure] [Example 67] A radiation-sensitive composition (J-67) was prepared by mixing 100 parts by mass of (A-i-1) as a polymer (A), 2.0 parts by mass of (B-1) as a radiation-sensitive acid generator (B), 1.0 part by mass of (C-2) as an acid diffusion control agent (C), 15.0 parts by mass of (T-1) as a crosslinking agent (T), 20.0 parts by mass of (W-3) as other additives (W), and 250 parts by mass of a mixed solvent of (S-3) / (S-4) as a solvent (S), and filtering the mixture through a membrane filter with a pore size of 0.2 μm.

[0370] [Examples 68-74 and Comparative Examples 12-14] Radiation-sensitive compositions (J-68) to (J-74) and (CJ-12) to (CJ-14) were prepared in the same manner as in Example 67, except that the components of the types and amounts shown in Table 8 below were used.

[0371]

[0372] <Formation of a resist pattern using a negative-type radiation-sensitive composition for i-line lithography> The prepared negative-type radiation-sensitive composition for i-line lithography was applied to an 8-inch silicon wafer treated with hexamethyldisilazane using a spin coater (CLEAN TRACK ACT8 from Tokyo Electron Limited), and pre-bake (PB) was performed at 110°C for 60 seconds. Subsequently, a resist film with an average thickness of 5.5 μm was formed by cooling at 23°C for 30 seconds. Next, this resist film was exposed using an i-line lithography machine (Nikon 2205i14E2, wavelength 365 nm) under optical conditions of NA = 0.50 and σ = 0.60, through a mask pattern with 2.5 μm lines and 5.0 μm spaces. After exposure, post-exposure bake (PEB) was performed at 106°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 negative-type resist pattern (2.5 μm lines, 5.0 μm spaces).

[0373] <Evaluation> The sensitivity, pattern rectangularity, exposure margin, and depth of field of the resist patterns formed using the above i-line exposure negative radiation-sensitive composition were evaluated according to the following method. A scanning electron microscope (Hitachi High-Technologies Corporation's "CS-4800") was used. The results are shown in Table 9 below.

[0374] [Sensitivity] In forming a resist pattern using the above i-line exposure negative radiation-sensitive composition, the exposure amount used to form a 2.5 μm line and a 5.0 μm space was defined as the optimal exposure amount, and this optimal exposure amount was defined as the sensitivity (msec). Sensitivity was evaluated as "good" if it was 200 msec or less, and as "poor" if it exceeded 200 msec.

[0375] [EL Performance (Exposure Margin)] Within the exposure range including the optimal exposure amount described above, resist patterns were formed by changing the exposure amount every 5 msec, and the CD of each pattern was measured using the scanning electron microscope described above. From the relationship between the obtained dimensions and exposure amount, the exposure amount E(2.3) at which the line dimension is 2.3 μm and the exposure amount E(2.7) at which the line width is 2.7 μm were determined, and the exposure margin (EL) was calculated using the formula: Exposure margin (EL) = (E(2.3) - E(2.7)) × 100 / (Optimal exposure amount). The larger the exposure margin value, the smaller the variation in the dimensions of the pattern obtained when the exposure amount is varied, and the higher the yield during device fabrication. EL performance was evaluated as "good" if it was 35% or higher, and as "poor" if it was below 35%.

[0376] [Depth of Focus] In the resist pattern resolved at the optimal exposure amount determined in 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 1.8 μm or more was evaluated as "good," and a depth of focus of less than 1.8 μm was evaluated as "poor."

[0377] [Pattern Rectangularity] The patterns of 2.5 μm lines and 5.0 μm spaces formed by irradiating with the optimal exposure amount determined in the sensitivity evaluation above were observed using the scanning electron microscope described above, and the cross-sectional shape of the line patterns was evaluated. The rectangularity of the resist pattern was evaluated as follows: if the difference between the length of the lower side and the length of the upper side in the cross-sectional shape of the line portion was 100 nm or less, it was evaluated as "A" (excellent); if it was between 100 nm and 200 nm, it was evaluated as "B" (good); and if it was greater than 200 nm, it was evaluated as "C" (poor).

[0378]

[0379] As is clear from the results in Table 9, the radiation-sensitive composition of the example exhibited good sensitivity, exposure margin, depth of field, and pattern rectangularity when used in i-line negative exposure, whereas the comparative example failed to satisfy all of these characteristics simultaneously. Therefore, when the radiation-sensitive composition of the example is used in i-line negative exposure, it is possible to form a resist pattern with optimal sensitivity, excellent roughness performance, and superior pattern shape.

[0380] The radiation-sensitive composition and resist pattern formation method described above allow for the formation of resist patterns with good sensitivity to exposure light and excellent roughness performance, yield performance, pattern shape, and defect 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. A radiation-sensitive composition comprising a polymer (A), a compound (B) represented by the following formula (1), an acid diffusion control agent (C), and a solvent (S). (In equation (1), Q is a quinone structure. M) ＋ (This is a monovalent organic cation.) 2. The radiation-sensitive composition according to claim 1, wherein the compound (B) is a compound represented by the following formula (1-1) or the following formula (1-2). (In formula (1-1), １ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxy group, a cyano group, or a nitro group, or two Rs １ are combined with each other to represent a divalent alicyclic structure or heterocyclic structure having 3 to 20 carbon atoms formed together with the carbon atom to which they are attached. When there are a plurality of Rs １ , the plurality of Rs １ are the same as or different from each other. n is an integer of 0 to 2. m １ is an integer of 0 to (2n + 3). M ＋ is a monovalent organic cation.) (In formula (1-2), ２ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxy group, a cyano group, or a nitro group. When there are a plurality of Rs ２ 0], the plurality of Rs ２ are the same as or different from each other. p and q are each independently 0 or 1. m ２ is an integer of 0 to (2p + 2q + 3). M ＋ is a monovalent organic cation.) 3. The radiation-sensitive composition according to claim 2, wherein n is 1 in the above formula (1-1).

4. The radiation-sensitive composition according to claim 2, wherein in formula (1-2) above, p is 1 and q is 0.

5. M ＋ The radiation-sensitive composition according to any one of claims 1 to 4, wherein is a sulfonium cation or an iodonium cation.

6. The radiation-sensitive composition according to any one of claims 1 to 4, wherein the content of compound (B) is 0.1 parts by mass or more and 60 parts by mass or less per 100 parts by mass of polymer (A).

7. The radiation-sensitive composition according to any one of claims 1 to 4, wherein the polymer (A) comprises a structural unit having an acid-dissociable group.

8. The radiation-sensitive composition according to any one of claims 1 to 4, wherein the polymer (A) comprises a structural unit having a phenolic hydroxyl group.

9. The radiation-sensitive composition according to any one of claims 1 to 4, wherein the content of the acid diffusion control agent (C) is 0.05 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the polymer (A).

10. A pattern forming method comprising the steps of: applying a radiation-sensitive composition according to any one of claims 1 to 4 directly or indirectly to a substrate to form a resist film; exposing the resist film to light; and developing the exposed resist film with a developer.

11. The pattern formation method according to claim 10, wherein the exposure is performed using a KrF excimer laser or extreme ultraviolet light.

12. Compounds represented by the following formulas (10), (11), (12), or (13). (In formula (10), R １１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. １１ If multiple R １１ They are either identical or different from each other. １１ m is an integer between 0 and 2. １１ is 0 to (3 + 2n １１ n is an integer of the form n. １１ If it is 0 or 2, M １ ＋ is a monovalent organic cation, n １１ If it is 1, M １ + This is a monovalent organic cation represented by the following formula (10-1), formula (10-2), or formula (10-3). (In formula (10-1), R １２ and R １３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a cyano group, or a hydroxyl group. １２ , R １３ If multiple R １２ , R １３ They are either identical or different from each other. １２ , m １３ Each of these is an independent integer between 0 and 5. (In formula (10-2), R １４ ~R １６ Each of these is independently a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms other than a thiophenyl group, or R １４ ~R １６ It is a ring-shaped structure formed by the combination of two of them. １４ ~R １６ If multiple R １４ ~R １６ They are either identical or different from each other. １４ m is an integer between 1 and 5. １５ , m １６ Each of these is an independent integer between 0 and 5. (In formula (10-3), R １７ This is a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. １７ R is an integer between 0 and 5. １８ and R １９ Each of these is independently a monovalent organic group having 1 to 10 carbon atoms, or R １８ and R １９ They are combined with each other R １８ and R １９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded. (In formula (11), R ２１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ２１ If multiple R ２１ They are either identical or different from each other. r is an integer between 0 and 2. ２１ M is an integer between 0 and (2r + 3). ＋ (This is a monovalent organic cation.) (In formula (12), R ３１ R is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxyl group, a cyano group, or a nitro group. ３１ If multiple R ３１ They are either identical or different from each other. ３１ M is an integer between 0 and 7. ２ ＋ This is a monovalent organic cation represented by the following formula (12-1), formula (12-2), or formula (12-3). (In formula (12-1), R ３２ , R ３３ Each of these is independently an organic group having 1 to 20 carbon atoms, a halogen atom, a nitro group, a cyano group, or a hydroxyl group. ３２ , R ３３ If multiple R ３２ , R ３３ They are either identical or different from each other. ３２ , m ３３ Each of these is an independent integer between 0 and 5. (In formula (12-2), R ３４ ~R ３６ is, independently of one another, a halogen atom, a hydroxy group, a cyano group, a nitro group, or an organic group having 2 to 20 carbon atoms, or R ３４ ~R ３６ is a cyclic structure formed by bonding of two of them. When there are a plurality of R ３４ ~R ３６ the plurality of R ３４ ~R ３６ are the same as or different from one another. m ３４ is an integer of 1 to 5. m ３５ , m ３６ are, independently of one another, an integer of 0 to 5.) (In formula (12-3), R ３７ is a halogen atom, a hydroxy group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. m ３７ is an integer of 0 to 5. R ３８ and R ３９ are, independently of one another, a monovalent organic group having 1 to 20 carbon atoms, or R ３８ and R ３９ are combined with each other to represent a cyclic structure formed by the sulfur atom to which R ３８ and R ３９ are bonded.)) (In formula (13), R ４１ is an organic group having 1 to 20 carbon atoms, a halogen atom, a hydroxy group, a cyano group, or a nitro group. When there are a plurality of R ４１ the plurality of R ４１ are the same as or different from one another. m ４１ is an integer of 0 to 7. M ３ ＋ is a monovalent organic cation represented by the following formula (13-1), the following formula (13-2), or the following formula (13-3). (In formula (13-1), R ４２ , R ４３ are, independently of one another, a fluorine atom, an iodine atom, a nitro group, a hydroxy group, a cyano group, or a hydrocarbon group having 1 to 20 carbon atoms. When there are a plurality of R ４２ , R ４３ the plurality of R ４２ , R ４３ are the same as or different from one another. m ４２ , m ４３ Each of these is an independent integer between 0 and 5. However, m ４２ +m ４３ (≥ 1.) (In formula (13-2), R ４４ ~R ４６ Each of these independently comprises a halogen atom, a hydroxyl group, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms, or R ４４ ~R ４６ It is a ring-shaped structure formed by the combination of two of them. ４４ ~R ４６ If multiple R ４４ ~R ４６ They are either identical or different from each other. ４４ m is an integer between 1 and 5. ４５ , m ４６ Each of these is an independent integer between 0 and 5. (In formula (13-3), R ４７ This is a halogen atom, a nitro group, a cyano group, or an organic group having 1 to 20 carbon atoms. ４７ R is an integer between 0 and 5. ４８ and R ４９ Each of these is independently a monovalent chain-like organic group having 1 to 10 carbon atoms, or R ４８ and R ４９ They are combined with each other R ４８ and R ４９ This represents a cyclic structure formed by the sulfur atoms to which it is bonded.

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