Radiation-sensitive composition and pattern forming process

Abstract

The present invention aims to provide a radiosensitive linear composition and a patterning method, wherein the radiosensitive linear composition is capable of forming a resist film that can fully exert its sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, and dry etching resistance. A radiosensitive linear composition comprises: a polymer (A) containing a structural unit (I) having a phenolic hydroxyl group and a structural unit (II) represented by the following formula (2); a compound (B) represented by the following formula (1); a crosslinking agent (Q); and a solvent (E). (In formula (1), R...) 11 R 14 R 15 and R 18 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms; R 12 and R 13 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 12 and R 13 Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form atomized ring structures; R 16 and R 17 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 16 and R 17 Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form atomized ring structures; R 21 It is a halogen atom, cyano group, nitro group, hydroxyl group, or a monovalent organic group having 1 to 40 carbon atoms; in R 21 In the case of multiple Rs, multiple Rs 21 They are either identical or different; n is an integer from 1 to 5; p is 0 or 1; R 22 It is a monovalent organic group with 1 to 40 carbon atoms; X is -O-, -S-, -SO2- or -CO-) (in formula (2), R A1 It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups; n1 is an integer from 0 to 5; X 1 It is a halogen atom, cyano group, nitro group, alkyl group, carboxyl group, or fluorinated alkyl group; in X 1 When there are multiple X's, multiple X's 1 (Same or different from each other).

Description

Technical Field

[0001] This invention relates to a radioactive linear composition and a method for patterning. Background Technology

[0002] Photolithography, which uses a resist composition, is used in the formation of fine circuits in semiconductor devices. A representative process involves, for example, generating an acid by exposing a resist composition film to a dielectric mask pattern and irradiating it with radiation. The acid is then used as a catalyst to create a difference in the solubility of the polymer in an alkaline or organic developer between the exposed and unexposed areas, thereby forming a resist pattern on the substrate.

[0003] In the aforementioned photolithography techniques, g-rays or i-rays, KrF excimer lasers, and recently, ArF excimer lasers, extreme ultraviolet (EUV) lasers, or electron beams have been used to miniaturize patterns. However, depending on the application, patterning of resist film thicknesses on the order of several μm and pattern sizes on the order of hundreds of nm has sometimes been performed. Among these, techniques utilizing negative resist patterns containing crosslinking agents with specific structures have been proposed (Japanese Patent No. 5927095, Japanese Patent No. 6485380).

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent No. 5927095

[0007] Patent Document 2: Japanese Patent No. 6485380 Summary of the Invention

[0008] The problem that the invention aims to solve

[0009] When the resist film is thick, light cannot fully penetrate to the bottom of the resist film, sometimes causing problems with various properties such as sensitivity and pattern formation. Therefore, there is a need for a radiometric composition that, even with a thick resist film, can form patterns that impart sufficient resist properties such as sensitivity, exposure latitude (EL), depth of focus, pattern rectangularity, storage stability, development defect resistance, and resistance to dry etching.

[0010] The present invention aims to provide a radiosensitive linear composition and a pattern forming method, wherein the radiosensitive linear composition is capable of forming a resist film that can fully exert its sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance and dry etching resistance.

[0011] Technical means to solve the problem

[0012] The inventors have made repeated efforts to solve this problem and have found that the objective can be achieved by adopting the following structure, thus completing this invention.

[0013] That is, in one embodiment of the present invention, therein relates to a radioactive linear composition comprising:

[0014] Polymer (A) comprising a structural unit (I) having phenolic hydroxyl groups and a structural unit (II) represented by the following formula (2).

[0015] The compound (B) represented by the following formula (1)

[0016] Crosslinking agent (Q), and

[0017] Solvent (E).

[0018] [Chemistry 1]

[0019]

[0020] (In formula (1),

[0021] R 11 R 14 R 15 and R 18 Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms;

[0022] R 12 and R 13 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 12 and R 13 Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form a ring structure.

[0023] R 16 and R 17 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 16 and R 17 Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form a ring structure.

[0024] R 21 It is a halogen atom, cyano group, nitro group, hydroxyl group, or a monovalent organic group having 1 to 40 carbon atoms; in R 21 In the case of multiple Rs, multiple Rs 21 They are the same or different;

[0025] n is an integer from 1 to 5;

[0026] p is 0 or 1;

[0027] R 22 It is a monovalent organic group with 1 to 40 carbon atoms;

[0028] X is -O-, -S-, -SO2-, or -CO-)

[0029] [Chemistry 2]

[0030]

[0031] (In formula (2),

[0032] R A1 It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups;

[0033] n1 is an integer from 0 to 5;

[0034] X 1 It is a halogen atom, cyano group, nitro group, alkyl group, carboxyl group, or fluorinated alkyl group; in X 1 When there are multiple X's, multiple X's 1 (Same or different)

[0035] The aforementioned radiosensitive linear composition, by its composition, can form a resist film that exhibits sufficient sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect resistance, and resistance to dry etching. The rationale for this is not bound by any theory, but is speculated as follows.

[0036] When the resist film is thick, light cannot fully penetrate to the bottom of the resist film, sometimes causing problems with sensitivity or pattern formation. It is speculated that the cation of compound (B) in this composition has high transparency to radiation due to its structure, thus allowing light to fully penetrate to the bottom of the resist film, resulting in good sensitivity and pattern formation. Furthermore, it is speculated that the cation of compound (B) has excellent acid generation efficiency and dispersibility, thus producing acid efficiently and uniformly throughout the entire thickness of the resist film during exposure, thereby maximizing the various properties of the resist. Furthermore, it is speculated that the presence of substituents on the benzene ring (or naphthalene ring) of the cation of compound (B) enhances the structural stabilization of compound (B), improving the storage stability of the radiosensitive composition containing said compound (B). Furthermore, it is speculated that the polymer (A) possesses specific structural units that combine developer solubility, resist film permeability, crosslinking promotion effect, and dry etching resistance, resulting in improved sensitivity, exposure latitude, depth of focus, pattern rectangularity, and development defects. Furthermore, it is speculated that the properties of the corrosion resist can be achieved through the combined effect of these factors.

[0037] In another embodiment, the present invention relates to a pattern forming method, comprising:

[0038] The process of directly or indirectly coating the radiosensitive linear composition onto a substrate to form a resist film;

[0039] The process of exposing the resist film; and

[0040] The process of developing the exposed resist film.

[0041] In the pattern forming method described above, since the photosensitive linear composition is used, which has excellent properties of forming a resist film with high sensitivity, exposure latitude, depth of focus, pattern rectangularity, preservation stability, development defect performance and dry etching resistance, high-quality resist patterns can be formed efficiently. Detailed Implementation

[0042] The embodiments of the present invention will now be described in detail, but the present invention is not limited to these embodiments. Furthermore, combinations of preferred embodiments are also preferred.

[0043] Radioactive linear compositions

[0044] The radiosensitive linear composition of this embodiment (hereinafter also simply referred to as the "composition") comprises: a compound (B) represented by formula (1), a polymer (A) containing a structural unit (I) having a phenolic hydroxyl group, a crosslinking agent (Q), and a solvent (E). The composition may also contain any other ingredients as long as the effects of the present invention are not impaired.

[0045] <Compound (B)>

[0046] The compound (B) represented by the following formula (1) functions as a radiosensitive linear acid generator that produces acid through exposure. The acid produced through exposure is used to carry out a crosslinking reaction of the base polymer (A) based on the crosslinking agent (Q).

[0047] [Chemistry 3]

[0048]

[0049] (In formula (1),

[0050] R 11 R 14 R 15 and R 18 Each can be independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms;

[0051] R 12 and R 13 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 12 and R 13Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form a ring structure.

[0052] R 16 and R 17 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 16 and R 17 Alicyclic structures with 3 to 10 carbon atoms that combine with each other and together with these bonded carbon atoms form a ring structure.

[0053] R 21 It is a halogen atom, cyano group, nitro group, hydroxyl group, or a monovalent organic group having 1 to 40 carbon atoms; in R 21 In the case of multiple Rs, multiple Rs 21 They are the same or different;

[0054] n is an integer from 1 to 5;

[0055] p is 0 or 1;

[0056] R 22 It is a monovalent organic group with 1 to 40 carbon atoms;

[0057] X is -O-, -S-, -SO2-, or -CO-)

[0058] As the R 11 ~R 18 Examples of monovalent organic groups with 1 to 40 carbon atoms include: monovalent hydrocarbon groups with 1 to 40 carbon atoms, groups having divalent heteroatoms between carbon atoms or at the end of the carbon chain of the hydrocarbon group, groups formed by substituting some or all of the hydrogen atoms of the hydrocarbon group with a monovalent heteroatomonic group, or combinations thereof.

[0059] As the R 11 ~R 18 The monovalent hydrocarbon groups represented by carbon numbers 1 to 40 can be exemplified by: monovalent chain hydrocarbon groups with carbon numbers 1 to 40, monovalent alicyclic hydrocarbon groups with carbon numbers 3 to 40, and monovalent aromatic hydrocarbon groups with carbon numbers 6 to 40.

[0060] As the R 11 ~R 18The monovalent chain hydrocarbon group representing 1 to 40 carbon atoms can be exemplified by, for example, monovalent straight-chain or branched saturated hydrocarbon groups with 1 to 40 carbon atoms, or monovalent straight-chain or branched unsaturated hydrocarbon groups with 2 to 40 carbon atoms. Examples of monovalent straight-chain or branched saturated hydrocarbon groups with 1 to 40 carbon atoms include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, 2-methylpropyl, 1-methylpropyl, tert-butyl, n-pentyl, isopentyl, and neopentyl. Examples of monovalent straight-chain or branched unsaturated hydrocarbon groups with 2 to 40 carbon atoms include alkenyl groups such as vinyl, propynyl, and butenyl; and alkynyl groups such as ethynyl, propynyl, and butynyl.

[0061] As the R 11 ~R 18 The monovalent alicyclic hydrocarbon groups representing 3 to 40 carbon atoms can be categorized as monocyclic or polycyclic saturated hydrocarbon groups, or monocyclic or polycyclic unsaturated hydrocarbon groups. Examples of monocyclic saturated hydrocarbon groups include cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and other cycloalkyl groups. Examples of polycyclic saturated hydrocarbon groups include norbornyl, adamantyl, tricyclic decyl, tetracyclic dodecyl, and other bridged alicyclic hydrocarbon groups. Examples of monocyclic unsaturated hydrocarbon groups include cyclopropenyl, cyclobutenyl, cyclopentenyl, cyclohexenyl, and other monocyclic cycloalkenyl groups. Examples of polycyclic unsaturated hydrocarbon groups include norbornyl, tricyclic decenyl, tetracyclic dodecenyl, and other polycyclic cycloalkenyl groups. Furthermore, bridged alicyclic hydrocarbon groups refer to polycyclic alicyclic hydrocarbon groups in which two non-adjacent carbon atoms constituting the alicyclic ring are bonded together by a linker containing one or more carbon atoms.

[0062] As the R 11 ~R 18 The monovalent aromatic hydrocarbon groups represented by carbon numbers from 6 to 40 include, for example, aryl groups such as phenyl, tolyl, xylyl, naphthyl, and anthracene; and aralkyl groups such as benzyl, phenethyl, and naphthylmethyl.

[0063] Examples of heteroatoms constituting the monovalent or divalent heteroatom-containing bases include: oxygen, nitrogen, sulfur, phosphorus, silicon, and halogen atoms. Examples of halogen atoms include: fluorine, chlorine, bromine, and iodine atoms.

[0064] Examples of monovalent heteroatom-containing groups include: hydroxyl, carboxyl, hydrogen sulfide, cyano, nitro, halogen atom, etc.

[0065] Examples of divalent heteroatom-containing bases include: -CO-, -C(=O)O-, -CS-, -NH-, -O-, -S-, -SO-, -SO2-, or combinations thereof.

[0066] As the R 12 and R13 The three- to ten-carbon alicyclic structures or R-shaped structures formed by the interaction of these carbon atoms and their bonds. 16 and R 17 The alicyclic structure with 3 to 10 carbon atoms that are combined with each other and together with these bonded carbon atoms can preferably be the alicyclic structure corresponding to the group with 3 to 10 carbon atoms in the monovalent alicyclic hydrocarbon group with 3 to 40 carbon atoms.

[0067] As the R 11 ~R 18 Preferably, it is a monovalent chain hydrocarbon group with hydrogen atoms and 1 to 40 carbon atoms, more preferably an alkyl group with hydrogen atoms and 1 to 10 carbon atoms, and even more preferably hydrogen atoms.

[0068] As R 21 The monovalent organic group representing carbon numbers from 1 to 40 can preferably be the R group. 11 ~R 18 The term represents a monovalent organogroup with 1 to 40 carbon atoms. As R 21 Preferably, it is a halogen atom, a hydroxyl group, or a monovalent organic group having 1 to 20 carbon atoms; more preferably, it is a fluorine atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, an alkoxy carbonyl group having 1 to 10 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, or a fluorinated alkyl group having 1 to 10 carbon atoms; and even more preferably, it is a fluorine atom, a hydroxyl group, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a fluorinated alkyl group having 1 to 10 carbon atoms.

[0069] Examples of alkyl groups having 1 to 10 carbon atoms include linear or branched alkyl groups such as methyl, ethyl, and propyl. Examples of alkoxy groups having 1 to 10 carbon atoms include linear or branched alkoxy groups such as methoxy, ethoxy, and propoxy. Examples of alkoxycarbonyl groups having 1 to 10 carbon atoms include alkoxycarbonyl groups such as methoxycarbonyl and ethoxycarbonyl. Examples of acyloxy groups having 1 to 10 carbon atoms include aliphatic or aromatic acyloxy groups such as acetyloxy, propionyloxy, benzoyloxy, and acryloyloxy. Examples of fluorinated alkyl groups having 1 to 10 carbon atoms include groups formed by substituting some or all of the hydrogen atoms of the alkyl groups having 1 to 10 carbon atoms with fluorine atoms.

[0070] The n is an integer from 1 to 5, preferably an integer from 1 to 3.

[0071] p is 0 or 1, preferably 0.

[0072] X is -O-, -S-, -SO2- or -CO-, preferably -O-, -S- or -CO-, and more preferably -O-.

[0073] In formula (1), the preferred compound is R. 12 R 13R 16 and R 17 R is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. 21 Compounds in which X is a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy carbonyl group having 1 to 10 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and X is -O-.

[0074] As the R 22 The monovalent organic group representing carbon numbers from 1 to 40 can preferably be the R group. 11 ~R 18 The monovalent organic groups represented have 1 to 40 carbon atoms.

[0075] The R 22 Preferably, it contains -O-, -CO-, cyclic structures, halogen atoms, or combinations thereof. Such combinations also include structures in which -O- or -CO- are incorporated as ring-forming parts (heterocyclic structures).

[0076] As a cyclic structure, it can be any of a monocyclic, polycyclic, or combination thereof. Furthermore, the cyclic structure can be any of an alicyclic, aromatic, heterocyclic, or combination thereof. In the case of combinations, it can be a structure formed by chain-like bonds between cyclic structures, or two or more cyclic structures can form a condensed ring structure, a bridged ring structure, or a spirocyclic structure. Divalent heteroatom-containing groups can exist between the carbon atoms in the carbon-carbon backbone forming the cyclic or chain structure, and some or all of the hydrogen atoms on the carbon atoms of the cyclic or chain structure can be substituted by other substituents.

[0077] As the alicyclic structure, it is preferably adopted to be the same as that of R. 11 ~R 18 The structures corresponding to monovalent alicyclic hydrocarbon groups with 3 to 40 carbon atoms.

[0078] As the aromatic ring structure, it can preferably be adopted with R 11 ~R 18 The structures corresponding to monovalent aromatic hydrocarbon groups with 6 to 40 carbon atoms.

[0079] Examples of heterocyclic structures include:

[0080] Aliphatic heterocyclic structures containing oxygen atoms, such as oxacyclopropane, tetrahydrofuran, tetrahydropyran, dioxacyclopentane, and dioxane;

[0081] Aliphatic heterocyclic structures containing nitrogen atoms, such as aziridine, pyrrolidine, piperidine, and piperazine;

[0082] aliphatic heterocyclic structures containing sulfur atoms, such as thiocyclobutane, thiocyclopentane, and thiazoline;

[0083] Morpholine, 1,2-oxathionecyclopentane, 1,3-oxathionecyclopentane, and other aliphatic heterocyclic structures containing multiple heteroatoms;

[0084] Aromatic heterocyclic structures containing oxygen atoms, such as furans and benzofurans;

[0085] Aromatic heterocyclic structures containing nitrogen atoms, such as pyrrole, pyrazole, and triazine;

[0086] Thiophene and other aromatic heterocyclic structures containing sulfur atoms;

[0087] Aromatic heterocyclic structures containing multiple heteroatoms, such as oxazoles, isothiazoles, and thiazides.

[0088] The heterocyclic structure includes lactone structures, cyclic carbonate structures, sulfonyl lactone structures, cyclic acetal structures, or combinations thereof. Examples of such structures include those represented by formulas (H-1) to (H-11).

[0089] [Chemistry 4]

[0090]

[0091] (In the formula, g is an integer from 1 to 3)

[0092] As the chain-like structure, R can preferably be used. 11 ~R 18 The monovalent chain hydrocarbon group having 1 to 40 carbon atoms or the divalent chain hydrocarbon group formed by removing one hydrogen atom from the monovalent chain hydrocarbon group.

[0093] As a divalent heteroatom-containing base, it can preferably be used in the R 11 ~R 18 The monovalent organic groups representing carbon numbers from 1 to 40 are shown as divalent groups containing heteroatoms.

[0094] Substituents that replace part or all of the hydrogen atoms on the carbon atoms of the cyclic or chain structure include, for example, halogen atoms such as fluorine, chlorine, bromine, and iodine; hydroxyl; carboxyl; cyano; nitro; alkyl; alkoxy; alkoxycarbonyl; alkoxycarbonyloxy; acyl; acyloxy or groups formed by replacing the hydrogen atoms of these groups with halogen atoms.

[0095] The alkyl, alkoxy, alkoxycarbonyl, or acyloxy groups used as the substituents can preferably be R. 21The alkoxycarbonyl group comprises alkyl groups having 1 to 10 carbon atoms, alkoxy groups having 1 to 10 carbon atoms, alkoxycarbonyl groups having 1 to 10 carbon atoms, and acyloxy groups having 1 to 10 carbon atoms. Examples of alkoxycarbonyloxy groups include methoxycarbonyloxy, butoxycarbonyloxy, and adamantylmethyloxycarbonyloxy, which are chain-like or alicyclic alkoxycarbonyloxy groups having 2 to 16 carbon atoms. Examples of acyl groups include acetyl, propionyl, benzoyl, and acryloyl, which are aliphatic or aromatic acyl groups having 2 to 12 carbon atoms.

[0096] In the R 22 In the selection of the sulfonate anion (SO3), it is preferred to be selected from the sulfonate anion (SO3). - In compound (B), the sulfur atom is bonded to at least one of the groups consisting of carbon atoms at the α-position and β-position, with a fluorine atom or a fluorinated hydrocarbon group attached to it. Thus, compound (B) can efficiently function as a radiosensitive linear acid generator.

[0097] As the fluorinated hydrocarbon group, R can be listed as an example. 11 ~R 18 The groups represented by monovalent hydrocarbon groups with 1 to 40 carbon atoms are formed by replacing some or all of the hydrogen atoms with fluorine atoms.

[0098] While there are no specific limitations on the cations of compound (B), structures such as those described below can be listed as examples.

[0099] [Chemistry 5]

[0100]

[0101] [Chemistry 6]

[0102]

[0103] While there are no specific limitations on the specific examples of anions of compound (B), structures such as those described below can be listed as examples.

[0104] [Chemistry 7]

[0105]

[0106] [Chemistry 8]

[0107]

[0108] [Chemistry 9]

[0109]

[0110] [Chemistry 10]

[0111]

[0112] [Chemistry 11]

[0113]

[0114] Compound (B) can be obtained by suitably combining the anion with the cation. The following structures are examples of compound (B).

[0115] [Chemistry 12]

[0116]

[0117] [Chemistry 13]

[0118]

[0119] [Chemistry 14]

[0120]

[0121] This composition may contain one or more compounds (B).

[0122] As a lower limit for the content of said compound (B) (total amount in the case of multiple compounds), it is preferably 0.1 parts by mass, more preferably 0.5 parts by mass, and even more preferably 1 part by mass relative to 100 parts by mass of polymer (A) described later. As an upper limit for the content ratio, it is preferably 20 parts by mass, more preferably 15 parts by mass, and even more preferably 10 parts by mass. Setting the content of compound (B) within the aforementioned range is preferable from the viewpoints of sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, and resistance to dry etching.

[0123] <Polymer (A)>

[0124] Polymer (A) is an aggregate of polymer chains containing structural units (I) having phenolic hydroxyl groups and structural units (II) represented by formula (2) (hereinafter, the polymer is also referred to as "basic polymer (A)"). The radiosensitive linear composition, by having structural units (I) in polymer (A), exhibits excellent patterning properties due to the thorough crosslinking reaction of polymer (A). Furthermore, by having structural units (II) in polymer (A), it exhibits excellent sensitivity, exposure latitude, depth of focus, pattern rectangularity, and development defect resistance.

[0125] The structural unit (I) and structural unit (II) may be contained in the same polymer chain, or structural unit (I) may be contained in one polymer chain and structural unit (II) may be contained in another polymer chain. As a whole polymer chain constituting the base polymer (A), it is sufficient to include structural unit (I) and structural unit (II). The base polymer (A) may also contain other structural units besides structural unit (I) and structural unit (II). The structural units are described below.

[0126] [Structural Unit (I)]

[0127] The polymer (A) contains a structural unit (I) having a phenolic hydroxyl group. The structural unit (I) is preferably represented by the following formula (5).

[0128] [Chemistry 15]

[0129]

[0130] (In the aforementioned formula (5),

[0131] R A2 It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups;

[0132] L CA For single bond, -COO- Or -O-; These are bonds on the aromatic ring side;

[0133] X 2 It is a halogen atom, cyano group, nitro group, alkyl group, alkoxy group, alkoxycarbonyl group, acyl group, carboxyl group, fluorinated alkyl group, or acyloxy group; in X 2 When there are multiple X's, multiple X's 2 They are the same or different;

[0134] 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; where 1 ≦ n + m ≦ 2p + 5)

[0135] As the R A2 Preferably, it contains hydrogen atoms or methyl groups.

[0136] As L CA Preferably, a single bond or -COO- .

[0137] As X 2 The alkyl, alkoxy, acyl, acyloxy, and alkoxycarbonyl groups in the formula (1) can preferably be R. 22 The substituents shown are the groups listed in the diagram.

[0138] As X 2The fluorinated alkyl group in the formula (1) can preferably be R. 21 Fluorinated alkyl groups in the form of alkyl groups.

[0139] Among these, as X 2 Preferably, it is a halogen atom, more preferably an iodine atom or a fluorine atom, and even more preferably a fluorine atom.

[0140] p is preferably 0 or 1, more preferably 0.

[0141] The n is preferably an integer from 1 to 3, and more preferably 1 or 2.

[0142] The value of m is preferably an integer from 0 to 3, and more preferably an integer from 0 to 2.

[0143] The structural unit (I) is more preferably the structural unit represented by the following formula (5-1).

[0144] [Chemistry 16]

[0145]

[0146] (In equation (5-1),

[0147] m3 is an integer from 1 to 5;

[0148] m2 is an integer from 0 to 4; where m2+m3 is less than 5;

[0149] R A2 X 2 (This has the same meaning as equation (5) above)

[0150] The value of m3 is preferably an integer from 1 to 3, and more preferably 1 or 2.

[0151] The value of m2 is preferably an integer from 0 to 3, and more preferably an integer from 0 to 2.

[0152] As the structural unit (I), it is preferably the structural unit represented by the following formula. In the following formula, R A2 Same as Equation (5).

[0153] [Chemistry 17]

[0154]

[0155] The base polymer (A) may contain one or more structural units (I).

[0156] As a lower limit for the content ratio of the structural unit (I) (total if there are multiple structural units (I)), it is preferably 30 mol%, more preferably 40 mol%, and even more preferably 50 mol%, relative to all structural units constituting the polymer (A). As an upper limit for the content ratio, it is preferably 95 mol%, more preferably 90 mol%, and even more preferably 85 mol%. By setting the content ratio of the structural unit (I) within the above range, the sensitivity of the radiosensitive linear composition can be further improved.

[0157] [Structural Unit (II)]

[0158] The polymer (A) contains the structural unit (II) represented by the following formula (2).

[0159] [Chemistry 18]

[0160]

[0161] (In formula (2),

[0162] R A1 It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups;

[0163] n1 is an integer from 0 to 5;

[0164] X 1 It is a halogen atom, cyano group, nitro group, alkyl group, carboxyl group, or fluorinated alkyl group; in X 1 When there are multiple X's, multiple X's 1 (Same or different)

[0165] As the R A1 Preferably, it contains hydrogen atoms or methyl groups.

[0166] The n1 is an integer from 0 to 5, preferably an integer from 0 to 2.

[0167] As the X 1 The alkyl or fluorinated alkyl group represented may preferably be R of formula (1). 21 Alkyl and fluorinated alkyl groups.

[0168] As the X 1 Preferably, it is composed of halogen atoms, fluorinated alkyl groups, or carboxyl groups, and more preferably fluorine atoms, trifluoromethyl groups, or carboxyl groups.

[0169] As the structural unit (II), the structural unit preferably is represented by the following formula. In the following formula, R A1 Same as Equation (2).

[0170] [Chemistry 19]

[0171]

[0172] Of these, structural unit (II) is preferably a structural unit derived from unsubstituted styrene.

[0173] The base polymer (A) may contain one or more structural units (II).

[0174] As a lower limit for the content ratio of the structural unit (II) (total if there are multiple structural units (II)), it is preferably 1 mol%, more preferably 3 mol%, and even more preferably 5 mol%, relative to all structural units constituting polymer (A). As an upper limit for the content ratio, it is preferably 60 mol%, more preferably 50 mol%, and even more preferably 40 mol%. By setting the content ratio of structural unit (II) to the above range, sensitivity, exposure latitude, depth of focus, pattern rectangularity, and development defects can be improved.

[0175] [Structural Unit (III)]

[0176] Polymer (A) may contain structural unit (III) comprising at least one of the group consisting of lactone structures, cyclic carbonate structures, sulfonyl lactone structures, and cyclic sulfone structures. By having structural unit (III) in the base polymer (A), the solubility in the developer can be adjusted, resulting in improved photolithography properties such as resolution of the photosensitive linear composition. Furthermore, the adhesion between the resist pattern formed from the base polymer (A) and the substrate can be improved.

[0177] As a structural unit (III), for example, the structural units represented by the following equations (T-1) to (T-11) can be listed.

[0178] [Chemistry 20]

[0179]

[0180] In the formula, R L1 It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. R L2 ~R L5 Each of the following groups is independently composed of a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, a cyano group, a trifluoromethyl group, a methoxy group, a methoxycarbonyl group, a hydroxyl group, a hydroxymethyl group, a dimethylamino group, or a -COOR group. L6 R L6 It is a monovalent hydrocarbon group with 1 to 20 carbon atoms. R L4 and R L5 It can also be a divalent alicyclic hydrocarbon group with 3 to 8 carbon atoms, which are bonded together with each other. 2 It can be a single bond or a divalent linker. 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.

[0181] As the R L4 and R L5 The 3-8 carbon-numbered divalent alicyclic hydrocarbon groups formed by the combination of these bonded carbon atoms can preferably be derived from R in formula (1). 11 ~R 18 A group is formed by removing one hydrogen atom from a monovalent alicyclic hydrocarbon group with 3 to 40 carbon atoms. More than one hydrogen atom on the alicyclic hydrocarbon group may also be substituted with a hydroxyl group.

[0182] As the R L6 The monovalent hydrocarbon group representing 1 to 20 carbon atoms can preferably be represented by R in formula (1). 11 ~R 18 The number of carbon atoms represented by the monovalent hydrocarbon group with carbon number 1 to 40 is the number of carbon atoms corresponding to the group.

[0183] As the L 2 Examples of divalent linkages 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 consisting of one or more of these hydrocarbon groups and at least one of the groups selected from -CO-, -O-, -NH- and -S-.

[0184] As the L 2 The divalent linear or branched hydrocarbon group having 1 to 10 carbon atoms can preferably be derived from R in formula (1). 11 ~R 18 A group formed by removing one hydrogen atom from a monovalent chain hydrocarbon group with 1 to 40 carbon atoms.

[0185] As the L 2 The divalent alicyclic hydrocarbon group with 4 to 12 carbon atoms in the formula (1) can preferably be R from the formula. 11 ~R 18 The radical is formed by removing one hydrogen atom from a monovalent alicyclic hydrocarbon group with 3 to 40 carbon atoms.

[0186] As structural unit (III), these are preferably structural units containing a lactone structure, more preferably structural units containing a norbornene lactone structure, and even more preferably structural units derived from norbornene lactone-based esters of (meth)acrylate.

[0187] The base polymer (A) may contain one or more structural units (III).

[0188] When the base polymer (A) contains the structural unit (III), the lower limit of the content ratio of the structural unit (III) (which is the total content ratio when multiple structural units are included) relative to all structural units constituting the base polymer (A) is preferably 3 mol%, more preferably 5 mol%, and even more preferably 8 mol%. The upper limit of the content ratio is preferably 50 mol%, more preferably 40 mol%, and even more preferably 30 mol%. By setting the content ratio of the structural unit (III) within the above range, the photosensitive linear composition can further improve photolithographic properties such as resolution and the adhesion between the formed resist pattern and the substrate.

[0189] [Structural Unit (IV)]

[0190] The base polymer (A) may contain structural units (IV) containing polar groups (excluding structural units (I) to (III)). By also having structural units (IV), the base polymer (A) can have its solubility in the developer adjusted, thereby improving the photolithographic properties such as resolution of the radiosensitive linear composition. Examples of such polar groups include hydroxyl, carboxyl, cyano, nitro, and sulfonamide groups. Among these, hydroxyl and carboxyl groups are preferred, and hydroxyl groups are more preferred.

[0191] As a structural unit (IV), for example, structural units represented by the following formulas can be listed.

[0192] [Chemistry 21]

[0193]

[0194] [Chemistry 22]

[0195]

[0196] In the formula, R K It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.

[0197] The base polymer (A) may contain one or more structural units (IVs).

[0198] When the base polymer (A) contains the structural unit (IV), the lower limit of the content ratio of the structural unit (IV) (the total content ratio when multiple structural units are included) relative to all structural units constituting the base polymer (A) is preferably 0.5 mol%, more preferably 1 mol%, and even more preferably 3 mol%. Furthermore, the upper limit of the content ratio is preferably 50 mol%, more preferably 40 mol%, and even more preferably 30 mol%. By setting the content ratio of the structural unit (IV) within the aforementioned range, the lithographic properties, such as resolution, of the photosensitive linear composition can be further improved.

[0199] [Structural Unit (V)]

[0200] The base polymer (A) may contain structural units with aliphatic hydrocarbon groups as represented by the following formula (6) (hereinafter also referred to as "structural units (V)") as structural units other than the listed structural units.

[0201] [Chemistry 23]

[0202]

[0203] (In the aforementioned formula (6),

[0204] R 1α It consists of hydrogen atoms, fluorine atoms, methyl groups, or trifluoromethyl groups;

[0205] R 2α (A monovalent aliphatic hydrocarbon group with 1 to 40 carbon atoms)

[0206] In equation (6), R is used as 2α The monovalent aliphatic hydrocarbon group representing 1 to 40 carbon atoms can preferably be represented by R in formula (1). 11 ~R 18 The monovalent chain hydrocarbon group with 1 to 40 carbon atoms and the monovalent alicyclic hydrocarbon group with 3 to 40 carbon atoms are included.

[0207] The base polymer (A) may contain one or more structural units (V).

[0208] When the base polymer (A) contains the structural unit (V), the lower limit of the content ratio of the structural unit (V) (the total content ratio when multiple structural units are included) relative to all structural units constituting the base polymer (A) is preferably 0.5 mol%, more preferably 1 mol%, and even more preferably 3 mol%. In addition, the upper limit of the content ratio is preferably 50 mol%, more preferably 40 mol%, and even more preferably 35 mol%.

[0209] (Synthesis method of basic polymer (A))

[0210] The basic polymer (A) can be synthesized, for example, by using a free radical polymerization initiator or the like, to polymerize monomers that provide each structural unit in a suitable solvent.

[0211] Examples of free radical polymerization initiators include: azobisisobutyronitrile (AIBN), 2,2'-azobis(4-methoxy-2,4-dimethylpentanonitrile), 2,2'-azobis(2-cyclopropylpropionitrile), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl 2,2'-azobisisobutyrate, and other azo-based free radical initiators; and peroxide-based free radical initiators such as benzoyl peroxide, tert-butyl hydroperoxide, and cumene hydroperoxide. Among these, AIBN and dimethyl 2,2'-azobisisobutyrate are preferred, and AIBN is more preferred. These free radical initiators can be used alone or in combination of two or more.

[0212] Examples of solvents used in the polymerization include:

[0213] Alkanes such as n-pentane, n-hexane, n-heptane, n-octane, n-nonane, and n-decane;

[0214] Cycloalkanes such as cyclohexane, cycloheptane, cyclooctane, decahydronaphthalene, and norbornene;

[0215] Aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene, and cumene;

[0216] Halogenated hydrocarbons such as chlorobutanes, bromohexanes, dichloroethanes, hexamethylene dibromide, and chlorobenzene;

[0217] Saturated carboxylic acid esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, and methyl propionate;

[0218] Lactones such as γ-butyrolactone and δ-valerolactone;

[0219] Ketones such as acetone, 2-butanone, 4-methyl-2-pentanone, 2-heptanone, and cyclohexanone;

[0220] Ethers such as tetrahydrofuran, dimethoxyethane, and diethoxyethane;

[0221] Alcohols such as methanol, ethanol, 1-propanol, 2-propanol, 1-methoxy-2-propanol, and 4-methyl-2-pentanol.

[0222] The solvents used in these polymerizations can be a single solvent or two or more solvents used in combination.

[0223] The reaction temperature in the polymerization is typically 40°C to 150°C, preferably 50°C to 120°C. The reaction time is typically 1 hour to 48 hours, preferably 1 hour to 24 hours.

[0224] The molecular weight of the base polymer (A) is not particularly limited, but as a lower limit for the converted weight average molecular weight (Mw) of polystyrene obtained by gel permeation chromatography (GPC), it is preferably 2,000, more preferably 2,500, and even more preferably 3,000. As an upper limit for Mw, it is preferably 30,000, more preferably 20,000, and even more preferably 15,000. By setting the Mw of the base polymer (A) within the aforementioned range, good developability can be imparted to the obtained resist film.

[0225] The ratio (Mw / Mn) of the base polymer (A) to the equivalent number average molecular weight (Mn) of polystyrene obtained based on GPC is typically 1 or more and 5 or less, preferably 1 or more and 3 or less, and more preferably 1 or more and 2 or less.

[0226] The Mw and Mn values ​​of the polymers in this specification are values ​​determined using gel permeation chromatography (GPC) under the following conditions.

[0227] GPC tubing: 2 G2000HXL, 1 G3000HXL, 1 G4000HXL (all manufactured by Tosoh Corporation)

[0228] Column temperature: 40℃

[0229] Dissolution solvent: Tetrahydrofuran

[0230] Flow rate: 1.0 mL / min

[0231] Sample concentration: 1.0% by mass

[0232] Sample injection volume: 100 μL

[0233] Detector: Differential refractometer

[0234] Standard material: Monodisperse polystyrene

[0235] The proportion of the base polymer (A) relative to the total solid content of the radiosensitive linear composition is preferably 60% by mass or more, more preferably 65% ​​by mass or more, and even more preferably 70% by mass or more.

[0236] <Crosslinking agent (Q)>

[0237] This composition contains a crosslinking agent (Q). The type of crosslinking agent (Q) is not particularly limited, but examples include crosslinking agents having two or more crosslinking groups per molecule. The number of crosslinking groups per molecule is two or more, preferably two to ten, and more preferably two to six.

[0238] The crosslinking group is not particularly limited, but preferably has at least one selected from the group consisting of hydroxymethyl, alkoxymethyl, glycidyl, (meth)acryloyl and vinyl, more preferably has hydroxymethyl or alkoxymethyl, and even more preferably has alkoxymethyl.

[0239] This composition, by containing a crosslinking agent (Q), can be formulated as a negative patterning composition. Specifically, in the exposed portion, the polymer (A) is hardened by an acid generated from the compound (B), which is described later as a radiosensitive linear acid generator, and by a crosslinking reaction based on the crosslinking agent (Q), thereby making it substantially insoluble in the alkaline developer. On the other hand, a negative pattern can be formed by removing the unexposed portion using the alkaline developer.

[0240] There are no particular limitations on the crosslinking agent (Q). Examples include amino-based crosslinking agents with one or more nitrogen atoms and crosslinking agents containing phenolic hydroxyl groups.

[0241] As an amino-based crosslinking agent, it is not particularly limited as long as it has one or more nitrogen atoms. Examples include: glycourea-type crosslinking agents with a glycourea skeleton, melamine-type crosslinking agents with a melamine skeleton, and urea-type crosslinking agents with a cyclic alkylene urea skeleton.

[0242] Among these, the crosslinking agent (Q) is preferably an amino-based crosslinking agent, and more preferably a glycourea-type crosslinking agent or a melamine-type crosslinking agent.

[0243] The glycourea-type crosslinking agent can be exemplified by compounds represented by the following formula (3) (Q1).

[0244] [Chemistry 24]

[0245]

[0246] (In formula (3),

[0247] R 31 Each is independently a hydrogen atom or a monovalent organogroup having 1 to 20 carbon atoms; wherein at least two R atoms are present. 31 for -R 33 -OR 34 (R) 33 It is a divalent hydrocarbon group with 1 to 10 carbon atoms; R 34 It consists of hydrogen atoms or a monovalent hydrocarbon group having 1 to 10 carbon atoms; (This indicates a bond with a nitrogen atom).

[0248] R 32 (Each is independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms)

[0249] As the R 31 The monovalent organic group with 1 to 20 carbon atoms in it can preferably be R of the formula (1). 11 ~R 18 The group corresponding to the number of carbons in a monovalent organic group with carbons from 1 to 40.

[0250] As the R 33 The divalent hydrocarbon group with 1 to 10 carbon atoms in the formula (1) can preferably be R from the formula. 11 ~R 18 A group is formed by removing one hydrogen atom from a monovalent hydrocarbon group with a carbon number of 1 to 40.

[0251] As the R 32 R 34 The monovalent hydrocarbon group with 1 to 10 carbon atoms in the formula (1) can preferably be R. 11 ~R 18 The group consisting of monovalent hydrocarbon groups with carbon numbers from 1 to 40.

[0252] As the glycourea-type crosslinking agent, the preferred option is the compound represented by the following formula (3-1) (Q1-1).

[0253] [Chemistry 25]

[0254]

[0255] (In equation (3-1),

[0256] R 32 Each can be independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms;

[0257] R 33 Each is independently a divalent hydrocarbon group having 1 to 10 carbon atoms;

[0258] R 34 (Each is an independent monovalent hydrocarbon group having 1 to 10 carbon atoms)

[0259] As R 32 Monovalent organic groups with carbon numbers 1 to 10, R 33 Divalent hydrocarbon groups with 1 to 10 carbon atoms, R 34 The monovalent hydrocarbon group with 1 to 10 carbons in the formula (3) can preferably be a monovalent organic group with 1 to 10 carbons, a divalent hydrocarbon group with 1 to 10 carbons, or a monovalent hydrocarbon group with 1 to 10 carbons listed in the formula (3).

[0260] Among these, as the R 32 Preferably, it is a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. As said R 33 Preferably, it is an alkylene group having 1 to 5 carbon atoms, more preferably a methylene or ethylene group. As the R... 34 Preferably, it is an alkyl group having 1 to 5 carbon atoms, and more preferably methyl or butyl.

[0261] Examples of glycourea-type crosslinking agents include those with the following formulas.

[0262] [Chemistry 26]

[0263]

[0264] (In the formula, Et represents ethyl, n Bu represents n-butyl. i Pr represents isopropyl)

[0265] The melamine-type crosslinking agent can be exemplified by compounds represented by the following formula (4) (Q2).

[0266] [Chemistry 27]

[0267]

[0268] (In formula (4),

[0269] R 4 Each is independently a hydrogen atom or a monovalent organogroup having 1 to 20 carbon atoms; wherein at least two R atoms are present. 4 for -R 41 -OR 42 (R) 41 It is a divalent hydrocarbon group with 1 to 10 carbon atoms; R 42 It consists of hydrogen atoms or a monovalent hydrocarbon group having 1 to 10 carbon atoms; (This indicates a bond with a nitrogen atom)

[0270] As the R 4 The monovalent organic group with 1 to 20 carbon atoms in it can preferably be R of the formula (1). 11 ~R 18 The group corresponding to the number of carbons in a monovalent organic group with carbons from 1 to 40.

[0271] As the R 41 The divalent hydrocarbon group with 1 to 10 carbon atoms in the R group can preferably be derived from the R group. 11 ~R 18 A group is formed by removing one hydrogen atom from a monovalent hydrocarbon group with a carbon number of 1 to 40.

[0272] As the R 42The monovalent hydrocarbon group with 1 to 10 carbon atoms in the formula (1) can preferably be R. 11 ~R 18 The group consisting of monovalent hydrocarbon groups with carbon numbers from 1 to 40.

[0273] The preferred melamine-type crosslinking agent is the compound represented by the following formula (4-1) (Q2-1).

[0274] [Chemistry 28]

[0275]

[0276] (In equation (4-1),)

[0277] R 41 Each is independently a divalent hydrocarbon group having 1 to 10 carbon atoms;

[0278] R 42 (Each is an independent monovalent hydrocarbon group having 1 to 10 carbon atoms)

[0279] As R 41 Divalent hydrocarbon groups with 1 to 10 carbon atoms, R 42 The monovalent hydrocarbon group with 1 to 10 carbons in the formula (4) can preferably be a divalent hydrocarbon group with 1 to 10 carbons or a monovalent hydrocarbon group with 1 to 10 carbons.

[0280] Among these, as the R 41 Preferably, it is an alkylene group having 1 to 5 carbon atoms, more preferably a methylene or ethylene group. As the R... 42 Preferably, it is an alkyl group having 1 to 5 carbon atoms, and more preferably a methyl group.

[0281] As melamine-type crosslinking agents, the following crosslinking agents can be listed.

[0282] [Chemistry 29]

[0283]

[0284] (In the formula, Me represents methyl and Et represents ethyl.) n Bu represents n-butyl. i Pr represents isopropyl)

[0285] In addition, the following crosslinking agents can be listed as urea-type crosslinking agents having a cyclic alkylene urea backbone.

[0286] [Chemistry 30]

[0287]

[0288] In addition, the following crosslinking agents can be listed as crosslinking agents containing phenolic hydroxyl groups.

[0289] [Chemistry 31]

[0290]

[0291] In this invention, one or more of the crosslinking agents (Q) may be used alone or in combination.

[0292] The lower limit of the content of the crosslinking agent (Q) (total of various crosslinking agents (Q)) relative to 100 parts by weight of polymer (A) is preferably 0.5 parts by weight, more preferably 1 part by weight, and even more preferably 3 parts by weight. The upper limit of the content is preferably 20 parts by weight, more preferably 10 parts by weight. The content of the crosslinking agent (Q) can be appropriately selected according to the type of polymer used, exposure conditions, or required sensitivity. As a result, excellent pattern rectangularity can be achieved when forming the resist pattern.

[0293] <Radiosensitive linear acid generator (b)>

[0294] This composition may contain, in addition to the compound (B) represented by the formula (1), a radiosensitive linear acid generator (b) that generates acid by exposure.

[0295] Examples of radiosensitive linear acid generators (b) include nonionic radiosensitive linear acid generators (b1) and ionic radiosensitive linear acid generators (b2).

[0296] As the nonionic, sensual, radioactive linear acid generator (b1), compounds represented by formula (b1-1) or formula (b1-2) can be listed.

[0297] [Chemistry 32]

[0298]

[0299] (In the aforementioned formula (b1-1),

[0300] R 51 It is a divalent hydrocarbon group with 1 to 10 carbon atoms.

[0301] R 52 (A monovalent organic group with 1 to 20 carbon atoms)

[0302] [Chemistry 33]

[0303]

[0304] (In the aforementioned formula (b1-2),

[0305] R 53 (Each is an independent monovalent organogroup with 1 to 20 carbon atoms)

[0306] As the R 51 The divalent hydrocarbon group having 1 to 10 carbon atoms can preferably be R from the formula (1). 11 ~R 18 These are groups formed by removing one hydrogen atom from the corresponding carbon number of a monovalent hydrocarbon group with carbons ranging from 1 to 40. Among these, R... 51 Preferably, it is an alkylene group having 1 to 3 carbon atoms, or an alkylene group containing a cyclic skeleton with unsaturated bonds.

[0307] As the R 52 The monovalent organic group with 1 to 20 carbon atoms can preferably be the R group of formula (1). 11 ~R 18 The radical with carbon numbers from 1 to 40 in a monovalent organic group. As R 52 Preferably, it has at least one structure selected from the group consisting of alicyclic structures, ester bonds and halogen atoms.

[0308] As the R 53 The monovalent organic group with 1 to 20 carbon atoms can preferably be the R group of formula (1). 11 ~R 18 The group corresponding to the number of carbons in a monovalent organic group with carbons from 1 to 40.

[0309] Examples of compounds represented by formula (b1-1) or formula (b1-2) include the following structures.

[0310] [Chemistry 34]

[0311]

[0312] As the ionotropic radioactive linear acid generator (b2), the following salt compounds (b2) represented by the formula (b2) can be listed.

[0313] [Chemistry 35]

[0314]

[0315] (in formula (b2),

[0316] R 60 It is a monovalent organic group with 1 to 40 carbon atoms;

[0317] R f1 and R f2 Each can be independently a hydrogen atom, a fluorine atom, or a monovalent fluorinated hydrocarbon group; in R f1 and R f2 In the case of multiple Rs, multiple Rs f1 and R f2 They are the same or different;

[0318] t is an integer from 0 to 4;

[0319] Z + (for radiosensitive linear cations)

[0320] As R 60 The monovalent organic group representing carbon 1 to 40 can preferably be R of formula (1). 11 ~R 18 The monovalent organic groups with 1 to 40 carbon atoms.

[0321] As R f1 and R f2 The monovalent fluorinated hydrocarbon group represented can be listed as R. 11 ~R 18 The groups represented by monovalent hydrocarbon groups with 1 to 40 carbon atoms are formed by replacing some or all of the hydrogen atoms with fluorine atoms.

[0322] While not limited to specific examples of anions of the salt compound (b2), for example, anions listed in the compound (B) represented by the formula (1) may preferably be used.

[0323] The Z as the salt compound (b2) + The radiosensitive linear cations represented include, for example, sulfonium cations, tetrahydrothiophene cations, monazine cations, etc.

[0324] The sulfonium cation is preferably represented by the following formula (Q-1).

[0325] [Chemistry 36]

[0326]

[0327] In equation (Q-1), Ra1 to Ra3 each independently represent a substituent. n11 represents an integer from 0 to 5; when n11 is 2 or more, multiple Ra1s can be the same or different. n12 represents an integer from 0 to 5; when n12 is 2 or more, multiple Ra2s can be the same or different. n13 represents an integer from 0 to 5; when n13 is 2 or more, multiple Ra3s can be the same or different. Ra1 and Ra2 can be linked together to form a ring. When n11 is 2 or more, multiple Ra1s can be linked together to form a ring. When n12 is 2 or more, multiple Ra2s can be linked together to form a ring.

[0328] The substituents represented by Ra1, Ra2, and Ra3 are preferably alkyl, cycloalkyl, alkoxy, cycloalkyloxy, alkoxycarbonyl, alkylsulfonyl, cycloalkylsulfonyl, hydroxyl, cyano, halogen atom, or halogenated hydrocarbon group.

[0329] As alkyl and cycloalkyl groups of Ra1, Ra2, and Ra3, R of formula (1) can be preferably used respectively. 11 ~R 18 The monovalent straight-chain or branched saturated hydrocarbon group with 1 to 40 carbon atoms, and R of formula (1) 11 ~R 18 The monocyclic saturated hydrocarbon group in it.

[0330] The alkyl portion of the alkoxy group in Ra1, Ra2, and Ra3 can be, for example, the alkyl portions previously listed as alkyl groups in Ra1, Ra2, and Ra3. The cycloalkyl portion of the cycloalkyloxy group in Ra1, Ra2, and Ra3 can be, for example, the cycloalkyl portions previously listed as cycloalkyl groups in Ra1, Ra2, and Ra3. The alkoxy portion of the alkoxycarbonyl group in Ra1, Ra2, and Ra3 can be, for example, the alkoxy portions previously listed as alkoxy groups in Ra1, Ra2, and Ra3. The alkyl portion of the alkylsulfonyl group in Ra1, Ra2, and Ra3 can be, for example, the alkyl portions previously listed as alkyl groups in Ra1, Ra2, and Ra3. Additionally, the cycloalkyl portion of the cycloalkylsulfonyl group in Ra1, Ra2, and Ra3 can be, for example, the cycloalkyl portions previously listed as cycloalkyl groups in Ra1, Ra2, and Ra3.

[0331] Each of the groups Ra1, Ra2, and Ra3 may also have substituents. Preferably, R from formula (1) can be used as the substituent. 22 The substituents shown in the figure.

[0332] The halogenated hydrocarbon groups Ra1, Ra2, and Ra3 are preferably halogenated alkyl groups. Examples of alkyl and halogen atoms constituting the halogenated alkyl groups are the same as those described above.

[0333] As described above, Ra1 and Ra2 can be linked together to form a ring (i.e., a heterocycle containing sulfur atoms). In this case, it is preferable that Ra1 and Ra2 are bonded together to form a single bond or a divalent linker. Examples of divalent linkers include -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO2-, alkylene, cycloalkylene, alkenyl, or combinations of two or more of these, preferably divalent linkers with a total carbon number of 20 or less. When Ra1 and Ra2 are linked together to form a ring, Ra1 and Ra2 are preferably bonded together to form -COO-, -OCO-, -CO-, -O-, -S-, -SO-, -SO2-, or a single bond. More preferably, -O-, -S-, or a single bond is formed, and particularly preferably, a single bond is formed. Furthermore, when n11 is 2 or more, multiple Ra1s can be linked together to form a ring, and when n12 is 2 or more, multiple Ra2s can be linked together to form a ring. As an example, one could cite the morphology of two Ra1 rings linked together to form a naphthalene ring together with these bonded benzene rings.

[0334] n11, n12 and n13 are each preferably integers from 0 to 3, and more preferably integers from 0 to 2.

[0335] As specific examples of the cation represented by the formula (Q-1) described herein, the following cations can be listed.

[0336] [Chemistry 37]

[0337]

[0338] (In the formula, tBu represents tert-butyl and Me represents methyl)

[0339] [Chemistry 38]

[0340]

[0341] [Chemistry 39]

[0342]

[0343] (In the formula, Me represents methyl)

[0344] [Chemistry 40]

[0345]

[0346] [Chemistry 41]

[0347]

[0348] [Chemistry 42]

[0349]

[0350] (In the formula, Me represents methyl)

[0351] [Chemistry 43]

[0352]

[0353] [Chemistry 44]

[0354]

[0355] (In the formula, Me represents methyl)

[0356] [Chemistry 45]

[0357]

[0358] Specific examples of the ferrocations mentioned above include the following ferrocations.

[0359] [Chemistry 46]

[0360]

[0361] As a radiosensitive linear acid generator (b2), it can be obtained by appropriately combining the anion with the radiosensitive linear cation.

[0362] When the radiosensitive linear composition comprises both compound (B) and radiosensitive linear acid generator (b), the upper limit of the content (total in various cases) of the radiosensitive linear acid generator (b) relative to 100 parts by mass of polymer (A) is preferably 10 parts by mass, more preferably 8 parts by mass, and even more preferably 5 parts by mass. The lower limit of the content is not particularly limited, but in this invention, it is preferable that it is not included.

[0363] <Acid Diffusion Control Agent (C)>

[0364] The radiosensitive linear composition may also contain an acid diffusion control agent (C) if necessary. The acid diffusion control agent (C) controls the diffusion of acid generated by the compound (B) or the radiosensitive linear acid generator (b) in the resist film during exposure, and suppresses undesirable chemical reactions in non-exposed areas. Furthermore, the storage stability of the obtained radiosensitive linear composition is improved. Consequently, the resolution of the resist pattern is further improved, and linewidth variations in the resist pattern caused by changes in storage time from exposure to development are suppressed, thereby obtaining a radiosensitive linear composition with excellent process stability.

[0365] 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)"), compounds containing amide groups, urea compounds, nitrogen-containing heterocyclic compounds, etc.

[0366] [Chemistry 47]

[0367]

[0368] In equation (7), R q1 R q2 and R q3 Each of the following 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.

[0369] Examples of nitrogen-containing compounds (I) include: monoalkylamines such as n-hexylamine; dialkylamines such as di-n-butylamine; trialkylamines such as triethylamine and tripentylamine; aromatic amines such as aniline and 2,6-diisopropylaniline.

[0370] Examples of nitrogen-containing compounds (II) include ethylenediamine, N,N,N',N'-tetramethylethylenediamine, etc.

[0371] Examples of nitrogen-containing compounds (III) include polyamine compounds such as polyethyleneimine and polyallylamine; polymers such as dimethylaminoethylacrylamide.

[0372] Examples of compounds containing an amide group include: formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, propionamide, benzamide, pyrrolidone, N-methylpyrrolidone, etc.

[0373] Examples of urea compounds include: urea, methylurea, 1,1-dimethylurea, 1,3-dimethylurea, 1,1,3,3-tetramethylurea, 1,3-diphenylurea, tributylthiourea, etc.

[0374] Examples of nitrogen-containing heterocyclic compounds include: pyridines such as pyridine, 2-methylpyridine, and 2,6-di-tert-butylpyridine; morpholines such as N-propylmorpholine and N-(undecylcarbonyloxyethyl)morpholine; and pyrazines and pyrazoles.

[0375] Alternatively, compounds with acid-dissociable groups may be used as the nitrogen-containing organic compounds mentioned above. Examples of such nitrogen-containing organic compounds with acid-dissociable groups include: N-tert-butoxycarbonylpiperidine, N-tert-butoxycarbonylimidazolium, N-tert-butoxycarbonylbenzimidazole, N-tert-butoxycarbonyl-2-phenylbenzimidazole, N-(tert-butoxycarbonyl)di-n-octylamine, N-(tert-butoxycarbonyl)diethanolamine, N-(tert-butoxycarbonyl)dicyclohexylamine, N-(tert-butoxycarbonyl)diphenylamine, N-tert-butoxycarbonyl-4-hydroxypiperidine, N-tert-butoxycarbonyl-4-acetoxypiperidine, and N-tert-pentyloxycarbonyl-4-hydroxypiperidine.

[0376] Alternatively, as an acid diffusion control agent (C), a salt compound (c) of an acid that produces an acid with a higher pKa than that produced by said compound (B) or a radiosensitive linear acid generator (b) may preferably be used.

[0377] The salt compound (c) is preferably represented by the following formulas (8-1) to (8-4).

[0378] [Chemistry 48]

[0379]

[0380] In equations (8-1) and (8-2), J + It is a sulfonium cation, U + It is a ferric cation. The E in formulas (8-1) and (8-2) - and Q - Each independently selects the option R. 8 SO3 - R 8 COO - and (R) 8 SO2)N - At least one of the groups formed, more preferably R 8 COO - Additionally, examples include compounds represented by formula (8-3) containing both sulfonium cations and anions within the same molecule, or compounds represented by formula (8-4) containing both sulfonium cations and anions within the same molecule. In formulas (8-3) and (8-4), J' + U' is a monovalent group with a sulfonium cation structure. + It is a monovalent group having a monazine cation structure. E' in formulas (8-3) and (8-4) - and Q' - Each independently selects the free choice -R 81 SO3 - -R 81 COO- and -R 81 SO2N - SO2R 8 At least one of the groups formed, more preferably -R 81 COO - The R 8 As a monovalent organic group, the R 81 It is a single bond or a divalent organic group.

[0381] As the monovalent organic group, R of formula (1) can preferably be used. 11 ~R 18 The monovalent organic group it represents.

[0382] As the divalent organic group, R from formula (1) can preferably be used. 11 ~R 18 The radical represented is formed by removing one hydrogen atom from a monovalent organic radical.

[0383] Examples of compounds represented by the following formulas can be listed as the salt compounds (c).

[0384] [Chemistry 49]

[0385]

[0386] [Transformation 50]

[0387]

[0388] The salt compound (c) can also be synthesized by known methods, particularly salt exchange reactions. Other known acid diffusion control agents besides those described can also be used, provided that the effects of the invention are not compromised.

[0389] These acid diffusion control agents (C) can be used alone or in combination of two or more. The lower limit of the content (total in multiple cases) of the acid diffusion control agent (C) relative to 100 parts by weight of polymer (A) is preferably 0.1 parts by weight, more preferably 0.5 parts by weight, and even more preferably 0.8 parts by weight. The upper limit of the content is preferably 50 parts by weight, more preferably 40 parts by weight, and even more preferably 30 parts by weight. This results in excellent sensitivity or pattern-forming properties during resist pattern formation.

[0390] <Solvent (E)>

[0391] The radiosensitive linear composition of this embodiment contains a solvent (E). The solvent (E) is not particularly limited as long as it is a solvent capable of dissolving or dispersing at least the polymer (A), compound (B), crosslinking agent (Q), and radiosensitive linear acid generator (b) as needed.

[0392] Examples of solvents include: alcohol solvents, ether solvents, ketone solvents, amide solvents, ester solvents, and hydrocarbon solvents.

[0393] Examples of alcohol-based solvents include:

[0394] Monohydric alcohol solvents with 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.

[0395] Polyol solvents with 2 to 18 carbon atoms, such as ethylene glycol, 1,2-propanediol, 2-methyl-2,4-pentanediol, 2,5-hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, and tripropylene glycol.

[0396] Polyol partial ether solvents, etc., are formed by etherifying a portion of the hydroxyl groups in the polyol solvent.

[0397] In this embodiment, 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 solvent.

[0398] Examples of ether-based solvents include:

[0399] Dialkyl ether solvents such as diethyl ether, dipropyl ether, and dibutyl ether;

[0400] Tetrahydrofuran, tetrahydropyran, and other cyclic ether solvents;

[0401] Ether solvents containing aromatic rings, such as diphenyl ether and anisole (methyl phenyl ether);

[0402] Polyol ether solvents, etc., are formed by etherifying the hydroxyl groups of the polyol solvent.

[0403] Examples of ketone solvents include: acetone, butanone, methyl isobutyl ketone, and other chain-like ketone solvents.

[0404] Cyclic ketone solvents such as cyclopentanone, cyclohexanone, and methylcyclohexanone;

[0405] 2,4-Pentanedione, acetone, acetophenone, etc.

[0406] Examples of amide solvents include cyclic amide solvents such as N,N'-dimethylimidazolium ketone and N-methylpyrrolidone.

[0407] N-methylformamide, N,N-dimethylformamide, N,N-diethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, N-methylpropionic acid, and other chain amide solvents.

[0408] Examples of ester-based solvents include:

[0409] Monocarboxylic acid ester solvents such as n-butyl acetate;

[0410] Diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, and other polyol partial ether acetates are solvents;

[0411] Lactone solvents such as γ-butyrolactone and valproic acid;

[0412] Carbonate solvents such as diethyl carbonate, ethylene carbonate, and propylene carbonate;

[0413] Solvents based on polycarboxylic acid diesters, such as propylene glycol diacetate, methoxytriethylene glycol acetate, diethyl oxalate, ethyl acetoacetate, and diethyl phthalate.

[0414] Examples of hydrocarbon solvents include:

[0415] Aliphatic hydrocarbon solvents such as n-hexane, cyclohexane, and methylcyclohexane;

[0416] Aromatic hydrocarbon solvents such as benzene, toluene, diisopropylbenzene, and n-pentylnaphthalene.

[0417] Among these, ester-based solvents and ether-based solvents are preferred, more preferably polymethyl ether acetate-based solvents, lactone-based solvents, monocarboxylic acid ester-based solvents, and ketone-based solvents, and even more preferably propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, γ-butyrolactone, ethyl lactate, cyclohexanone, cyclopentanone, and propylene glycol monomethyl ether. The radiosensitive composition may contain one or more solvents.

[0418] (Any other ingredients)

[0419] The radiosensitive linear composition may contain any other components besides the aforementioned ingredients. Examples of such other components include: pre-existing accelerators, solubility accelerators, surfactants, compounds containing alicyclic skeletons, sensitizers, etc. One or more of these other components may be used individually or in combination.

[0420] There are no particular limitations on the surfactant used, but non-fluorinated surfactants or non-silicone surfactants are preferred.

[0421] When the radiosensitive linear composition contains the arbitrary component, the content of the arbitrary component is preferably 0.05 parts by mass or more, more preferably 0.08 parts by mass or more, relative to 100 parts by mass of the base polymer (A). Furthermore, it is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less.

[0422] <Preparation Method of Radiosensitive Linear Composition>

[0423] The radiosensitive linear composition can be prepared, for example, by mixing a polymer (A), a compound (B), a crosslinking agent (Q), a solvent (E), and, if desired, a radiosensitive linear acid generator (B) or a radiosensitive linear acid generator (b) in a predetermined ratio. The radiosensitive linear composition is preferably filtered, for example, using a filter with a pore size of approximately 0.05 μm to 0.40 μm after mixing. The concentration of the solid component in the radiosensitive linear composition is typically 0.1% to 50% by mass, preferably 0.5% to 30% by mass, and more preferably 1% to 20% by mass.

[0424] Pattern Formation Methods

[0425] A pattern forming method according to one embodiment of the present invention includes:

[0426] The process (1) of directly or indirectly coating the radiosensitive linear composition onto a substrate to form a resist film (hereinafter also referred to as the "resist film formation process").

[0427] The process of exposing the resist film (2) (hereinafter also referred to as the "exposure process"); and

[0428] The process of developing the exposed resist film (3) (hereinafter also referred to as the “development process”).

[0429] According to the resist patterning method described above, since the radiosensitive linear composition is used, which can form a resist film with excellent sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, and dry etching resistance in the exposure process, high-quality resist patterns can be formed. The following describes each step.

[0430] [Resist film formation process]

[0431] In this process (process (1)), a photoresist film is formed using the aforementioned photosensitive linear composition. Examples of substrates for forming the photoresist film include, for example, silicon wafers, silicon dioxide, aluminum-clad wafers, and other known substrates. Alternatively, organic or inorganic antireflective films disclosed in, for example, Japanese Patent Application Publication No. 6-12452 or Japanese Patent Application Publication No. 59-93448 may be formed on the substrate. Examples of coating methods include, for example, spin coating, cast coating, and roll coating. After coating, a pre-bake (PB) may be performed as needed to allow the solvent in the coating to evaporate. The PB temperature is typically 60°C to 150°C, preferably 80°C to 140°C. The PB time is typically 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.

[0432] 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 film thickness is preferably 9000 nm, more preferably 4000 nm. However, for thick resist films, when exposure using a KrF excimer laser is performed in the exposure process described later, the lower limit of the film thickness can be 100 nm, 150 nm, or 200 nm.

[0433] [Exposure Process]

[0434] In this step (step (2)), a photomask (which may be a liquid immersion medium such as water) exposes the resist film formed in step (1), i.e., the resist film formation step, to radiation. The radiation used for exposure can be, for example, electromagnetic waves such as visible light, ultraviolet light, far ultraviolet light, extreme ultraviolet light (EUV), X-rays, and gamma rays, depending on the linewidth of the target pattern; or charged particle beams such as electron beams and alpha rays. Among these, the composition of the present invention is suitable for use with a KrF excimer laser.

[0435] Preferably, a post-exposure bake (PEB) is performed after the initial exposure. The PEB creates a difference in the solubility of the developer between the exposed and unexposed areas. The PEB temperature is typically 50°C to 180°C, preferably 80°C to 150°C. The PEB time is typically 5 seconds to 600 seconds, preferably 10 seconds to 300 seconds.

[0436] [Developing process]

[0437] In this step (step (3)), the resist film exposed in step (2), i.e., the exposure step, is developed. Thus, a predetermined resist pattern can be formed. Generally, after development, the film is rinsed with a solution such as water or alcohol and then dried.

[0438] As the developing solution used in the aforementioned development, in the case of alkaline development, examples include alkaline aqueous solutions containing at least one of the following alkaline compounds: sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, methyl diethylamine, ethyl dimethylamine, triethanolamine, tetramethyl ammonium 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 solution of TMAH is preferred, and a 2.38% by mass aqueous solution of TMAH is more preferred.

[0439] In addition, when developing with an organic solvent, examples of organic solvents include hydrocarbon-based solvents, ether-based solvents, ester-based solvents, ketone-based solvents, alcohol-based solvents, and solvents containing organic solvents. Examples of such organic solvents include one or more solvents listed as solvents for the radiosensitive linear composition. Among these, ether-based solvents, ester-based solvents, and ketone-based solvents are preferred. As an ether-based solvent, glycol ether-based solvents are preferred, more preferably ethylene glycol monomethyl ether or propylene glycol monomethyl ether. As an ester-based solvent, acetate-based solvents are preferred, more preferably n-butyl acetate or amyl acetate. As a ketone-based solvent, chain ketones are preferred, more preferably 2-heptanone. The content of organic solvent in the developing solution is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, particularly preferably 99% by mass or more. Other components in the developing solution besides the organic solvent include, for example, water and silicone oil.

[0440] As described above, the developer can be any of an alkaline developer or an organic solvent developer. The radiosensitive linear composition of the present invention is preferably used for negative patterning.

[0441] Examples of development methods include: immersing a substrate in a tank filled with developer for a fixed time (immersion method); developing a substrate by using surface tension to accumulate developer on the substrate surface and then allowing it to stand still for a fixed time (puddle method); spraying developer onto the substrate surface (spraying method); and continuously spraying developer onto a substrate rotating at a fixed speed while scanning the developer nozzle at a fixed speed (dynamic distribution method), etc.

[0442] Example

[0443] The present invention will now be described in detail based on embodiments, but the present invention is not limited to these embodiments. Methods for determining various physical properties are shown below.

[0444] [Weight-average molecular weight (Mw) and number-average molecular weight (Mn)]

[0445] The Mw and Mn of the polymer were determined under the conditions described above. Furthermore, the dispersity (Mw / Mn) was calculated based on the results of the Mw and Mn measurements.

[0446] [ 13 C-NMR ( 13 C-Nuclear Magnetic Resonance, 13 [C-NMR analysis]

[0447] polymers 13 C-NMR analysis was performed using a nuclear magnetic resonance apparatus (JNM-Delta400 of Nippon Electron Ltd).

[0448] <Polymer Synthesis>

[0449] The following shows the monomers used in the synthesis of each polymer in each embodiment and comparative example. Furthermore, in the following synthesis examples, unless otherwise specified, parts by mass refer to the value when the total mass of the monomers used is set to 100 parts by mass, and mol% refers to the value when the total number of moles of the monomers used is set to 100 mol%.

[0450] [Chemistry 51]

[0451]

[0452] [Synthesis example 1]

[0453] (Synthesis of polymer (A-1))

[0454] Monomers (M-1), (M-5), (M-9), and (M-14) were dissolved in 200 parts by mass of 1-methoxy-2-propanol in a molar ratio of 70 / 10 / 10 / 10 (mol%), and AIBN (10 mol%) was added as an initiator to prepare a monomer solution. 100 parts by mass of 1-methoxy-2-propanol were placed in a reaction vessel, purged with nitrogen for 30 minutes, and the reaction vessel was set to 80°C. The monomer solution was added dropwise over 3 hours with 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 water-cooled to below 30°C. The cooled polymerization solution was then 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 a hydrolysis reaction was carried out at 70°C for 6 hours with stirring. After the reaction, the residual solvent was removed by distillation, and the obtained solid was dissolved in acetone (100 parts by mass) and added dropwise to hexane (500 parts by mass) to solidify the polymer. The obtained solid was filtered and dried at 50°C for 13 hours to obtain a white powder polymer (A-1) (yield: 80%). The Mw of polymer (A-1) was 3,200, and the Mw / Mn ratio was 1.18. Additionally, 13 C-NMR analysis showed that the content of each structural unit derived from (M-1), (M-5), (M-9), and (M-14) was 71.0 mol%, 10.3 mol%, 9.1 mol%, and 9.6 mol%, respectively. Furthermore, regarding the monomer providing structural unit (I), in the polymer, through... 13 C-NMR measurements confirmed the disappearance of the carbonyl peak of the acetyl group, indicating that all the base-dissociated groups were hydrolyzed to become phenolic hydroxyl groups.

[0455] [Synthesis Examples 2 to 14]

[0456] (Synthesis of polymers (A-2) to (A-9) and polymers (a-1) to (a-5))

[0457] Using the monomers of the types and proportions shown in Table 1 below, polymers (A-2) to (A-9) and polymers (a-1) to (a-5) were synthesized in the same manner as in Synthesis Example 1. Furthermore, regarding the monomers providing structural unit (I), in the polymers, by... 13C-NMR measurements confirmed the disappearance of the carbonyl peak at the acetyl group, indicating that all the base-dissociated groups had been hydrolyzed to form phenolic hydroxyl groups. The content (mol%) and physical properties (Mw and Mw / Mn) of each structural unit of the obtained polymer are shown in Table 1 below. Furthermore, "-" in Table 1 indicates that the corresponding component was not used (the same applies to subsequent tables).

[0458] [Table 1]

[0459]

[0460] The following compounds are used as components other than those used in the synthesis.

[0461] [Compounds (B-1) to (B-14): Radiosensitive linear acid generators]

[0462] B-1 to B-14: Compounds represented by formulas (B-1) to (B-14) below (hereinafter, the compounds represented by formulas (B-1) to (B-14) are sometimes referred to as "compound (B-1)" to "(B-14)" respectively).

[0463] [Chemistry 52]

[0464]

[0465] [Radiosensitive linear acid generators (b-1) to (b-7)]

[0466] b-1 to b-7: The compounds represented by formulas (b-1) to (b-7) below (hereinafter, the compounds represented by formulas (b-1) to (b-7) are sometimes referred to as "compound (b-1)" to "compound (b-7)" respectively).

[0467] [Chemistry 53]

[0468]

[0469] [Acid diffusion control agent (C)]

[0470] C-1 to C-3: Compounds represented by formulas (C-1) to (C-3) below (hereinafter, the compounds represented by formulas (C-1) to (C-3) are sometimes referred to as "compound (C-1)" to "compound (C-3)" respectively).

[0471] [Chemistry 54]

[0472]

[0473] [Crosslinking agent (Q)]

[0474] Q-1 to Q-7: Compounds represented by formulas (Q-1) to (Q-7) below (hereinafter, compounds of formulas (Q-1) to (Q-7) are sometimes referred to as "compound (Q-1)" to "compound (Q-7)" respectively).

[0475] [Chemistry 55]

[0476]

[0477] [Other Additives (D)]

[0478] D-1 to D-5: Compounds represented by formulas (D-1) to (D-3) and additive compounds (D-4) to (D-5) (Hereinafter, compounds (D-1) to (D-5) are sometimes referred to as "compound (D-1)" to "compound (D-5)" respectively).

[0479] [Chemistry 56]

[0480]

[0481] D-4: MEGAFACE EFS-321 (manufactured by DIC) (non-fluorine based)

[0482] D-5: BYK-399 (manufactured by BYK Chemical Co., Ltd., Japan) (non-silicon based)

[0483] [Solvent (E)]

[0484] E-1: Propylene glycol monomethyl ether

[0485] E-2: Propylene glycol monomethyl ether

[0486] E-3: γ-Butyrolactone

[0487] E-4: Cyclopentanone

[0488] [Preparation of negative-type radiometric linear compositions for KrF exposure]

[0489] [Example 1]

[0490] 100 parts by mass of (A-1) as polymer (A), 10.0 parts by mass of (B-1) as compound (B) (radiosensitive linear acid generator), 1.0 parts by mass of (C-1) as acid diffusion control agent (C), 5.0 parts by mass of (Q-1) as crosslinking agent (Q), 0.10 parts by mass of (D-1) as other additive (D), and 300 parts by mass of a mixed solvent of (E-1) / (E-2) as solvent (E) were mixed and filtered using a membrane filter with a pore size of 0.2 μm to prepare a radiosensitive linear composition (J-1).

[0491] [Examples 2-42 and Comparative Examples 1-12]

[0492] Using the types and amounts of each component shown in Table 2 below, except that, the radiosensitive linear compositions (J-2) to (J-42) and (CJ-1) to (CJ-12) were prepared in the same manner as in Example 1.

[0493] [Table 2]

[0494]

[0495] <Formation of resist patterns using KrF exposure negative-type radiometric linear composition>

[0496] Using a spin coater (Tokyo Electron Inc.'s "CLEAN TRACK ACT12"), the prepared KrF exposure negative-type radiosensitive linear composition was coated onto a 12-inch silicon wafer treated with hexamethyldisilazane and pre-baked at 130°C for 60 seconds (PB). Afterward, it was cooled at 23°C for 30 seconds, thereby forming a resist film with an average thickness of 9 μm. Next, the resist film was exposed using a KrF excimer laser scanner (Nikon Inc.'s "S210DASML wavelength 248 nm") with optical conditions of numerical aperture (NA) = 0.60 and σ = 0.80, using a mask pattern with a line-space separation of 3.5 μm. After exposure, it was post-baked at 130°C for 60 seconds (PEB). Subsequently, the resist film was developed using a 2.38% by mass TMAH aqueous solution as an alkaline developer. After development, the film was washed with water and then dried to form a negative resist pattern (3 μm lines and spaces).

[0497] <Evaluation>

[0498] For the resist patterns formed using the aforementioned KrF exposure negative-sensitive radiometric linear composition, sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, number of development defects, and resistance to dry etching were evaluated according to the following methods. Furthermore, the length of the resist patterns was measured using a scanning electron microscope (Hitachi High-Technologies, Inc.'s "CG-5000"). The results are shown in Table 3 below.

[0499] [sensitivity]

[0500] In the formation of a resist pattern using the aforementioned KrF exposure negative-sensitive linear composition, the exposure amount for forming a 3 μm line and space is set as the optimal exposure amount, and the optimal exposure amount is set as the sensitivity (mJ / cm). 2 Regarding sensitivity, 50 mJ / cm 2 The following conditions are rated as "good" and will exceed 50 mJ / cm 2 The situation was rated as "poor".

[0501] [Exposure tolerance (EL)]

[0502] Within the range of exposure levels that include the optimal exposure, at 1 mJ / cm 2 Resist patterns were formed by varying the exposure amount, and the linewidths were measured using the aforementioned scanning electron microscope. Based on the relationship between the obtained linewidth and exposure amount, the exposure amount E(3.3) for a diameter of 3.3 μm and the exposure amount E(2.7) for a linewidth of 2.7 μm were calculated. The exposure latitude (EL) was then calculated using the formula: EL = (E(2.7) - E(3.3)) × 100 / (optimal exposure amount). A higher exposure latitude value results in less variation in pattern size when the exposure amount changes, thus improving the yield during device fabrication. Regarding EL, a value above 10% was rated as "good," and a value below 10% was rated as "bad."

[0503] [Focus Depth]

[0504] In the resist pattern resolved at the optimal exposure determined in the sensitivity evaluation, the size of the focal point changes in the depth direction. The tolerance of the pattern size entering 90% to 110% of the reference depth direction in a state free of bridging or residue is measured. This measured value is set as the focal depth (nm). A larger focal depth value indicates better performance. Regarding focal depth, a value of 200 nm or more is evaluated as "good," and a value less than 200 nm is evaluated as "poor."

[0505] [Pattern Rectangularity]

[0506] The 3 μm line and spatial pattern formed by irradiation with the optimal exposure determined in the sensitivity evaluation is observed using the scanning electron microscope, and the cross-sectional shape of the line and spatial pattern is evaluated. Regarding the rectangularity of the resist pattern, 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 is greater than or equal to 1 and less than 1.05, it is rated "A" (extremely good); if it exceeds 1.05 and is less than 1.10, it is rated "B" (good); and if it exceeds 1.10, it is rated "C" (poor).

[0507] [Maintain stability]

[0508] After storing the KrF exposure negative-type radiometric linear composition at 35°C for 30 days, the optimal exposure level, i.e., sensitivity S, for forming 3 μm lines and spatial patterns was determined again. 30 The change ratio of sensitivity after 30 days of storage to sensitivity S0 before storage is calculated based on the following formula. If the change ratio is 0% or more and 1.0% or less, it is rated as "A" (extremely good); if it is 1.0% or more and 1.5% or less, it is rated as "B" (good); if it exceeds 1.5%, it is rated as "C" (poor).

[0509] The percentage change in sensitivity (%) = {|S 30 -S0| / S0}×100

[0510] [Number of development defects]

[0511] A 3 μm line and spatial pattern is formed by exposing the resist film at the optimal exposure level, and this is designated as a defect inspection wafer. The number of defects on the defect inspection wafer is measured using a defect inspection device (KLA-Tencor's "KLA2810"). Defects with a diameter of 50 μm or less are identified as originating from the resist film, and their number is calculated. Regarding the number of defects after development, if the number of defects identified as originating from the resist film is 100 or less, it is evaluated as "good"; if it exceeds 100, it is evaluated as "bad".

[0512] [Resistance to dry etching]

[0513] 3 μm lines and spatial patterns were formed by exposing the resist film to the optimal exposure level. A dry etching apparatus (Pinnacle 8000) manufactured by PMT was used, with CF4 as the etching gas. Dry etching was performed at a gas flow rate of 75 sccm, a pressure of 2.5 mTorr, and an output of 2500 W, and the etching rate was measured. The etching rate using the resist composition (J-1) was set as 1, and the relative etching rate was evaluated based on the relative value. A lower etching rate indicates better resistance to dry etching.

[0514] [Table 3]

[0515]

[0516] Based on the results in Table 3, it is clear that the linearly induced resist composition of the embodiments exhibits excellent sensitivity, exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, and dry etching resistance when used for KrF negative exposure. In contrast, the comparative examples did not simultaneously meet all these characteristics. Therefore, when the linearly induced resist composition of the embodiments is used for KrF negative exposure, a resist pattern with optimal sensitivity, excellent exposure latitude, depth of focus, pattern rectangularity, storage stability, development defect performance, and dry etching resistance can be formed.

[0517] Industrial availability

[0518] According to the described radiosensitive linear composition and patterning method, resist patterns exhibit excellent sensitivity to exposure light and can be formed with superior exposure latitude, depth of focus, pattern rectangularity, storage stability, resistance to development defects, and resistance to dry etching. Therefore, these are preferably suitable for use in the fabrication processes of semiconductor devices that are envisioned to be further miniaturized in the future.

Claims

1. A radiosensitive composition comprising: Polymer (A) comprising a structural unit (I) having phenolic hydroxyl groups and a structural unit (II) represented by the following formula (2). The compound (B) represented by the following formula (1) Crosslinking agent (Q), and Solvent (E). [Chemistry 1] (In formula (1), R 11 R 14 R 15 and R 18 Each can be a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. R 12 and R 13 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 12 and R 13 Alicyclic structures with 3 to 10 carbon atoms are formed by the combination of these carbon atoms. R 16 and R 17 Each is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms, or represents R. 16 and R 17 Alicyclic structures with 3 to 10 carbon atoms are formed by the combination of these carbon atoms. R 21 It can be a halogen atom, cyano group, nitro group, hydroxyl group, or a monovalent organic group having 1 to 40 carbon atoms. In R 21 In the case of multiple Rs, multiple Rs 21 They are the same or different. n is an integer from 1 to 5. p is 0 or 1. R 22 It is a monovalent organic group with 1 to 40 carbon atoms. X can be -O-, -S-, -SO2-, or -CO-. [Chemistry 2] (In formula (2), R A1 It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. n1 is an integer from 0 to 5. X 1 It can be a halogen atom, cyano group, nitro group, alkyl group, carboxyl group, or fluorinated alkyl group. In X 1 When there are multiple X's, multiple X's 1 (Same or different from each other).

2. The radiosensitive linear composition according to claim 1, wherein, The crosslinking agent (Q) comprises at least one selected from the group consisting of the compound (Q1) represented by formula (3) and the compound (Q2) represented by formula (4). [Chemistry 3] (In formula (3), R 31 Each is independently a hydrogen atom or a monovalent organogroup having 1 to 20 carbon atoms. At least two of them are R. 31 for -R 33 -OR 34 (R) 33 It is a divalent hydrocarbon group having 1 to 10 carbon atoms. R 34 It consists of hydrogen atoms or monovalent hydrocarbon groups with 1 to 10 carbon atoms. (This indicates a bond with a nitrogen atom). R 32 Each can be independently a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. [Chemistry 4] (In formula (4), R 4 Each is independently a hydrogen atom or a monovalent organogroup having 1 to 20 carbon atoms. At least two of them are R. 4 for -R 41 -OR 42 (R) 41 It is a divalent hydrocarbon group having 1 to 10 carbon atoms. R 42 It consists of hydrogen atoms or monovalent hydrocarbon groups with 1 to 10 carbon atoms. (This indicates a bond with a nitrogen atom).

3. The radiosensitive linear composition according to claim 1, wherein, The crosslinking agent (Q) comprises at least one selected from the group consisting of compounds represented by formula (3-1) (Q1-1) and compounds represented by formula (4-1) (Q2-1). [Chemistry 5] (In equation (3-1), R 32 Each can be a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. R 33 Each is an independent divalent hydrocarbon group having 1 to 10 carbon atoms. R 34 Each group is an independent monovalent hydrocarbon group having 1 to 10 carbon atoms. [Chemistry 6] (In equation (4-1),) R 41 Each is an independent divalent hydrocarbon group having 1 to 10 carbon atoms. R 42 Each is an independent monovalent hydrocarbon group having 1 to 10 carbon atoms.

4. The radiosensitive linear composition according to claim 1, wherein, In the above formula (1), R 12 R 13 R 16 and R 17 R is independently a hydrogen atom or a monovalent organic group having 1 to 40 carbon atoms. 21 It is a halogen atom, an alkyl group having 1 to 10 carbon atoms, an alkoxy carbonyl group having 1 to 10 carbon atoms, an acyloxy group having 1 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms, and X is -O-.

5. The radiosensitive linear composition according to claim 1, wherein, The structural unit (II) represented by the formula (2) is a structural unit derived from unsubstituted styrene.

6. The radiosensitive linear composition according to claim 1, wherein, The structural unit (I) is represented by the following equation (5-1). [Chemistry 7] (In equation (5-1), R A2 It can be a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. m3 is an integer from 1 to 5. m2 is an integer from 0 to 4. Where m2+m3 is less than or equal to 5. X 2 It can be a halogen atom, cyano, nitro, alkyl, alkoxy, alkoxycarbonyl, acyl, carboxyl, fluorinated alkyl, or acyloxy. In X 2 When there are multiple X's, multiple X's 2 (Same or different from each other).

7. The radiosensitive linear composition according to claim 1, wherein, The content of compound (B) is 0.1 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of polymer (A).

8. The radiosensitive linear composition according to claim 1, wherein, The content of the crosslinking agent (Q) is 0.5 parts by mass or more and 20 parts by mass or less relative to 100 parts by mass of the polymer (A).

9. The radiosensitive linear composition according to claim 1, further comprising an acid diffusion control agent (C).

10. The radioactive linear composition according to claim 1, used for forming a negative pattern.

11. A method for forming a pattern, comprising: The process of directly or indirectly coating a substrate with the radiosensitive linear composition as described in any one of claims 1 to 10 to form a resist film; The process of exposing the resist film; and The process of developing the exposed resist film.

12. The pattern forming method according to claim 11, wherein, The exposure is performed using a KrF excimer laser.

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