High-valent iodine compound, resist composition, laminate obtained from the resist composition, and pattern forming method

Abstract

The present invention relates to a high-valent iodine compound, a resist composition, a laminate obtained from the resist composition, and a pattern forming method. The object of the present invention is to provide a non-chemically amplified resist composition and a laminate obtained therefrom, which are excellent in sensitivity and resolution in high-energy ray, particularly in electron beam (EB) lithography and EUV lithography, and a pattern forming method using the resist composition. The means for solving the object is a high-valent iodine compound characterized by a structure represented by the following general formula (1). [Chemical Formula 1] wherein R 1 ~ R 2 are each independently a halogen atom, or a hydrocarbon group having a carbon number of 1 to 10 which can also contain a hetero atom. Also, R 1 and R 2 may be bonded to each other and form a ring together with the carbon atoms to which they are bonded and the atoms between the carbon atoms.

Description

Technical Field

[0001] This invention relates to a high-valent iodine compound, a resist composition, a laminate obtained from the resist composition, and a method for patterning. Background Technology

[0002] With the expansion of the IoT market, there is a growing demand for high integration, high speed, and low power consumption in LSI (Light Silica) technology, and the miniaturization of patterning is also progressing rapidly. In particular, logic devices are leading the way in miniaturization. Regarding the most advanced miniaturization technologies, mass production of 10nm node devices obtained through dual, triple, and quadruple patterning using ArF immersion lithography is already underway. Furthermore, research is progressing on 7nm node devices obtained through 13.5nm extreme ultraviolet (EUV) lithography.

[0003] As miniaturization progresses, image blurring caused by acid diffusion has become a problem (Non-Patent Literature 1). To ensure the resolution of fine patterns with dimensions below 45 nm, it has been proposed that not only is the improvement of dissolution contrast, as previously advocated, important, but also the control of acid diffusion is crucial (Non-Patent Literature 2). However, chemically amplified resist materials improve sensitivity and contrast through acid diffusion; therefore, if the post-exposure baking (PEB) temperature or time is shortened to suppress acid diffusion to the limit, sensitivity and contrast will be significantly reduced.

[0004] Adding acid-generating agents that produce bulky acids is effective in suppressing acid diffusion. Therefore, it has been proposed to use onium salts of polymerizable olefins as acid-generating agents in polymer copolymerization. However, considering acid diffusion, it is believed that chemically amplified resist films are no longer suitable for patterning in resist film patterning with dimensions smaller than 16 nm, thus necessitating the development of non-chemically amplified resist materials.

[0005] Non-chemically amplified photoresist materials include polymethyl methacrylate (PMMA). PMMA is a positive photoresist material whose main chain is broken and its molecular weight is reduced by EUV irradiation, thereby improving its solubility in organic solvent developers.

[0006] Hydrosilsesquioxane (HSQ) is a negative resist material that is insoluble in alkaline developers, resulting from the crosslinking reaction of silanols produced by EUV irradiation. Chlorinated calixarnes also function as negative resist materials. These negative resist materials, due to their small molecular size before crosslinking and the absence of blurring caused by acid diffusion, can be used as pattern transfer materials with low edge roughness and very high resolution, showcasing the resolving limits of exposure devices. However, the sensitivity of these materials is insufficient and further improvements are needed.

[0007] One of the main reasons hindering material development for EUV lithography applications is the low photon count in EUV exposure. EUV energy is significantly higher than ArF excimer lasers, and the photon count in EUV exposure is only one-fourteenth that of ArF exposure. Furthermore, the size of patterns formed by EUV exposure is less than half that of ArF exposure. Therefore, EUV exposure is susceptible to variations in photon count. These variations in photon count in extremely short wavelength emission regions constitute shot noise, a physical phenomenon that cannot be eliminated. Thus, so-called stochastics are a concern. While the effects of shot noise cannot be eliminated, we will discuss how to reduce them. Due to shot noise, not only do dimensional uniformity (CDU) and linewidth roughness (LWR) increase, but there is also a one in a million chance of observing hole blockage. Hole blockage leads to poor conductivity and transistor malfunction, thus negatively impacting overall device performance. When considering the use of photoresist for practical sensitivity, photoresist with PMMA and HSQ as the main components will be greatly affected by randomness and will not be able to achieve the desired resolution.

[0008] Regarding methods to reduce shot noise in resists, the introduction of elements with high EUV absorption has attracted attention. Patent Document 1 proposes a chemically amplified resist composition containing bismuth atoms with high EUV light absorption. However, as mentioned earlier, chemically amplified resists cannot achieve excellent resolution in future EUV lithography where the size is becoming increasingly smaller.

[0009] Patent document 2 claims to use an organic solvent negative resist composition containing tin compounds. This composition uses tin, which has high EUV light absorption, as the main component, thus improving randomness and achieving high sensitivity and resolution. However, such a metal resist suffers from many problems, including insufficient solubility in the resist solvent, excessive reactivity leading to insufficient storage stability, and defects caused by etching residue.

[0010] Existing technical documents

[0011] Patent documents

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2018-005224

[0013] [Patent Document 2] Japanese Patent Publication No. 2021-503482

[0014] Non-patent literature

[0015] [Non-Patent Literature 1] SPIE Vol.5039 p1 (2003)

[0016] [Non-Patent Literature 2] SPIE Vol.6520 p65203L-1 (2007) Summary of the Invention

[0017] [The problem that the invention aims to solve]

[0018] The present invention is made in view of the foregoing circumstances, and aims to provide a non-chemically amplified resist composition with excellent sensitivity and resolution in high-energy radiation, especially in electron beam (EB) lithography and EUV lithography, a laminate obtained therefrom, and a method for patterning using the resist composition.

[0019] [Methods for solving the problem]

[0020] To address the aforementioned issues, the present invention provides a high-valent iodine compound, represented by the following general formula (1).

[0021] [Chemistry 1]

[0022]

[0023] In the formula, R 1 and R 2 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 1 and R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0024] Resist compositions containing high-valent iodine compounds with SF5 groups exhibit excellent sensitivity to high-energy radiation, particularly to electron beam (EB) lithography and EUV lithography, and also improve solvent solubility. This allows for the formation of patterns with excellent roughness resolution.

[0025] Furthermore, the present invention can be used as a resist composition, comprising:

[0026] The high-valent iodine compounds described above,

[0027] Compounds containing carboxyl groups, and

[0028] Solvent.

[0029] Such a resist composition provides excellent sensitivity and resolution under high-energy radiation, especially in electron beam (EB) lithography and EUV lithography.

[0030] At this time, the aforementioned carboxyl-containing compound is preferably a polymer containing repeating units represented by the following general formula (2) and / or a compound represented by the following general formula (3).

[0031] [Chemistry 2]

[0032]

[0033] In the formula, R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group.

[0034] X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -. X A1 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0035] p can be 1, 2, 3 or 4.

[0036] R 31 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 31 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, or sulfonyl group. Furthermore, some or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be replaced by a group containing a heteroatom.

[0037] R 32 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group may be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group may also be replaced by a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They can be the same or different.

[0038] The carboxyl-containing compounds contained in the resist composition of the present invention are preferably polymers or monomeric compounds of such nature.

[0039] The aforementioned resist composition preferably also contains at least one of the high-valent iodine compounds represented by the following general formula (4) or the following general formula (5).

[0040] [Chemistry 3]

[0041]

[0042] In the formula, m1 and m2 are integers from 0 to 2. n1 is an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2. When m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, satisfying 1 ≤ (n2 + n3) ≤ 6. When m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, satisfying 1 ≤ (n2 + n3) ≤ 8. When m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, satisfying 1 ≤ (n2 + n3) ≤ 10. R 51A hydrocarbon group consisting of 1 to 10 carbon atoms, which may also contain heteroatoms. R 52 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n1 is 2 to 8, each R 52 They can be the same or different. Also, multiple R's... 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. R 53 It can be a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. *3 and *4 represent atomic bonds of carbon atoms in the aromatic ring in the formula. However, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring. R 61 and R 62 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 61 and R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms. When n2 is 2 to 3, each R 61 and R 62 They can be the same or different. R 63 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n3 is 2 to 9, each R 63 They can be the same or different. Also, multiple R's... 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0043] The high-valent iodine compound further contained in the resist composition of the present invention is preferably a tricoordinate high-valent iodine compound represented by the above-described general formula (4) or general formula (5). When such a tricoordinate high-valent iodine (III) compound having aryl and carboxylate ligands is mixed with a carboxyl-containing compound in the same manner as the high-valent iodine compound represented by the above-described general formula (1), the exchange of the compound with the carboxylate ligand readily occurs in an equilibrium reaction. At this time, by removing the original carboxylate ligand from the reaction system, the equilibrium will tend towards the formation of a high-valent iodine compound with new ligands for ligand exchange. In this manner, the carboxyl-containing compound becomes a polymer cross-linked by the high-valent iodine compound. Polymerization is even more preferably carried out by also containing at least one of the high-valent iodine compounds represented by the above-described general formula (4) or general formula (5).

[0044] Furthermore, the present invention provides a laminate comprising:

[0045] substrate, and

[0046] A resist film obtained on the substrate from the resist composition described above.

[0047] In a laminate containing a resist film obtained from the resist composition of the present invention, the resist film, which is the film-forming body of the resist composition, has high sensitivity and exhibits excellent limiting resolution, making it effective for precision micro-processing. In addition, it is applicable to the formation of any pattern, whether positive or negative, thus having a wide range of applications and high usefulness in resist processing technology.

[0048] At this time, a lower resist film may also be provided between the aforementioned substrate and the aforementioned resist film.

[0049] The laminates of the present invention can be made in such a manner as needed.

[0050] Furthermore, the aforementioned resist film should preferably contain the ligand exchange reaction product of the aforementioned high-valent iodine compound represented by the above general formula (1) and the carboxyl-containing compound.

[0051] Through the ligand exchange reaction products contained above, the aforementioned carboxyl-containing compounds can become polymers cross-linked by the aforementioned high-valent iodine compounds.

[0052] Furthermore, the present invention provides a pattern forming method, comprising the following steps:

[0053] A resist film is formed on a substrate or on the resist underlayer film of a substrate having a resist underlayer film laminated thereon using the resist composition described above.

[0054] The aforementioned resist film was exposed using high-energy rays, and

[0055] The previously exposed resist film was developed using a developer.

[0056] If it is the pattern forming method of the present invention, it is useful in forming finer patterns because it uses optical lithography with high-energy rays, especially in electron beam (EB) lithography and EUV lithography, and uses a resist composition with excellent sensitivity and resolution.

[0057] At this time, the aforementioned high-energy rays should preferably be i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet rays.

[0058] The pattern forming method of the present invention can form fine patterns by using such high-energy rays.

[0059] Furthermore, in the pattern forming method of the present invention, the developer can be a solution that dissolves the exposed portion but does not dissolve the unexposed portion.

[0060] The pattern forming method of the present invention can form positive patterns by appropriately selecting the developing solution, and is therefore widely applicable to the formation of various fine patterns.

[0061] Furthermore, in the pattern forming method of the present invention, the developer solution described above may also be one that dissolves the unexposed portions without dissolving the exposed portions.

[0062] The pattern forming method of the present invention can form negative patterns by appropriately selecting the developing solution, and is therefore widely applicable to the formation of various fine patterns.

[0063] [The effects of the invention]

[0064] The resist composition of the present invention, which uses a specific high-valent iodine compound having an SF5 group as one of the main components, is particularly useful in EB lithography and EUV lithography, in achieving both high sensitivity and high resolution while forming fine patterns. Detailed Implementation

[0065] As mentioned above, there is a need to develop non-chemically amplified resist compositions with excellent sensitivity and resolution in high-energy rays, especially in electron beam (EB) lithography and EUV lithography.

[0066] After repeated and in-depth explorations to achieve the aforementioned objectives, the inventors obtained the following insights, and thus completed the present invention: a resist composition with a specific high-valent iodine compound having an SF5 group as one of the main components has good overall solubility in resists, and exhibits extremely high sensitivity in the aforementioned high-energy rays, especially in electron beam (EB) lithography and EUV lithography, and provides a resist film with excellent resolution, which is extremely effective for precision micro-machining.

[0067] That is, the present invention is a high-valent iodine compound, characterized by a structure represented by the following general formula (1).

[0068] [Chemistry 4]

[0069]

[0070] In the formula, R 1 and R 2 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 1 and R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0071] The present invention will now be described in detail, but it is not limited thereto. Furthermore, in this specification, descriptions using the endpoints of a numerical range are defined as including all values ​​contained within that range (for example, "0 to 3" includes 0, 1, 2, and 3).

[0072] [Resist Composition]

[0073] The resist composition of the present invention contains a predetermined high-valent iodine compound, a carboxyl-containing compound, and a solvent as main components. Furthermore, the carboxyl group is a functional group having the structure "-C(=O)OH".

[0074] [High-valent iodine compounds]

[0075] The necessary high-valent iodine compound in this invention is the high-valent iodine compound represented by the following general formula (1).

[0076] [Chemistry 5]

[0077]

[0078] In the formula, R 1 and R 2 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 1 and R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0079] In the above general formula (1), R 1 and R 2 A hydrocarbon group having 1 to 10 carbon atoms, which may contain halogen atoms or heteroatoms. Specific examples of the aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The aforementioned hydrocarbon groups having 1 to 10 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups having 1 to 10 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 [Cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms, such as decyl and adamantyl; alkenyl groups with 2 to 10 carbon atoms, such as vinyl and allyl; aryl groups with 6 to 10 carbon atoms, such as phenyl and naphthyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, groups may contain hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone, sulfonyl, or carboxylic anhydride (-C(=O)-OC(=O)-), etc. The above R...] 1 and R 2 It is preferable to use a hydrocarbon group with 1 to 4 carbon atoms or a fluorinated hydrocarbon group with 1 to 4 carbon atoms, with a hydrocarbon group with 1 to 4 carbon atoms being more preferred.

[0080] Specific examples of high-valent iodine compounds represented by the above general formula (1) are shown below, but are not limited thereto. Additionally, in the following formula, Me is a methyl group.

[0081] [Chemistry 6]

[0082]

[0083] [Chemistry 7]

[0084]

[0085] [Chemistry 8]

[0086]

[0087] [Chemistry 9]

[0088]

[0089] [Chemistry 10]

[0090]

[0091] [Chemistry 11]

[0092]

[0093] [Chemistry 12]

[0094]

[0095] [Chemistry 13]

[0096]

[0097] [Chemistry 14]

[0098]

[0099] [Chemistry 15]

[0100]

[0101] [Chemistry 16]

[0102]

[0103] [Chemistry 17]

[0104]

[0105] [Chemistry 18]

[0106]

[0107] [Chemistry 19]

[0108]

[0109] [Chemistry 20]

[0110]

[0111] [Chemistry 21]

[0112]

[0113] If the resist composition of the present invention uses a high-valent iodine compound having an SF5 group as one of its main components, it will improve the solubility in solvents, thus making it more ideal. Furthermore, the resist composition of the present invention using a high-valent iodine compound as its main component can be used in optical lithography using high-energy rays, especially in EB lithography and EUV lithography, to improve resolution and provide excellent roughness resolution in pattern formation methods.

[0114] [Preparation of high-valent iodine compounds]

[0115] The high-valent iodine compounds represented by the above general formula (1) used in this invention can be obtained using known methods. For example, when the desired high-valent iodine compound contains iodine (III) and SF5, it can be obtained by oxidizing and acetylating SF5-containing iodobenzamide with an oxidizing agent such as peracetic acid. For example, the synthetic method can be found in Japanese Patent Application Publication No. 2013-119541.

[0116] [Compounds containing carboxyl groups]

[0117] The aforementioned carboxyl-containing compounds are preferably polymers containing repeating units represented by the following general formula (2) and / or compounds represented by the following general formula (3).

[0118] [Chemistry 22]

[0119]

[0120] In the formula, R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group.

[0121] X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -. X A1 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0122] p can be 1, 2, 3 or 4.

[0123] R31 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 31 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, or sulfonyl group. Furthermore, some or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be replaced by a group containing a heteroatom.

[0124] R 32 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group may be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group may also be replaced by a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They can be the same or different.

[0125] In the above general formula (2), R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group. X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -. X A1 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0126] In the above general formula (3), p is 1, 2, 3 or 4.

[0127] In the above general formula (3), R 31 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 31 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, or sulfonyl group. Furthermore, some or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be replaced by a group containing a heteroatom.

[0128] In the above general formula (3), R 32 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group may be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group may also be replaced by a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They can be the same or different.

[0129] In the above general formula (3), R 31The p-valent hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. The aforementioned p-valent hydrocarbon group is a group obtained by removing p hydrogen atoms from a hydrocarbon. Examples of such hydrocarbons include: alkanes with 1-40 carbon atoms, alkenes with 2-40 carbon atoms, alkynes with 2-40 carbon atoms, cyclic saturated hydrocarbons with 3-40 carbon atoms, cyclic unsaturated hydrocarbons with 3-40 carbon atoms, and aromatic hydrocarbons with 6-40 carbon atoms.

[0130] The above R 31 Examples of alkanes with 1 to 40 carbon atoms in the aforementioned p-valent hydrocarbon groups include: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and their structural isomers.

[0131] The above R 31 Examples of alkenes with 2 to 40 carbon atoms in the aforementioned p-valent hydrocarbon groups include: ethylene, propylene, butene, pentene, hexene, heptene, octene, nonene, decene, and their structural isomers.

[0132] The above R 31 Examples of alkynes with 2 to 40 carbon atoms in the p-valent hydrocarbon group include: acetylene, propyne, butyne, pentyne, hexyne, heptyne, octyne, nonyne, decyne, and their structural isomers.

[0133] The above R 31 Examples of cyclic saturated hydrocarbons with 3 to 40 carbon atoms in the p-valent hydrocarbon group include: cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norcamphene, etc.

[0134] The above R 31 Examples of cyclic unsaturated hydrocarbons with 3 to 40 carbon atoms in their p-valent hydrocarbon groups include: cyclopropene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and norcamphene.

[0135] The above R 31 Aromatic hydrocarbons with 6 to 40 carbon atoms in the p-valent hydrocarbon group can be listed as: benzene, naphthalene, biphenyl, etc.

[0136] The above R 31 The p-valent heterocyclic group represents a group obtained by removing p hydrogen atoms from a heterocyclic compound. Examples of such heterocyclic compounds include furan, pyridine, pyrazole, and tetrahydrothiazole.

[0137] The above R 31In the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group, part or all of its hydrogen atoms may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, resulting in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, iodine, etc. Furthermore, in the aforementioned p-valent hydrocarbon group, a portion of its -CH2- group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms, resulting in the presence of carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, lactone rings, sulopentalide rings, carboxylic anhydrides (-C(=O)-OC(=O)-), etc.

[0138] In the above general formula (3), R 32 The derivatized hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,2-diyl, propane-1,3-diyl, butane-1,4-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, decane-1,10-diyl, undecane-1, Alkyl groups with 1 to 20 carbon atoms, such as 11-diyl and dodecane-1,12-diyl; cyclic saturated alkylene groups with 3 to 20 carbon atoms, such as cyclopentanediyl, cyclohexanediyl, norcamphenediyl, and adamantanediyl; unsaturated aliphatic alkylene groups with 2 to 20 carbon atoms, such as vinylene and propylene-1,3-diyl; aryl groups with 6 to 20 carbon atoms, such as phenylene and naphthylene; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned alkylene group may be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, nitrogen atoms, and halogen atoms, and a portion of the -CH2- constituting the aforementioned alkylene group may also be replaced by groups containing heteroatoms such as oxygen atoms, sulfur atoms, and nitrogen atoms. As a result, it may contain hydroxyl groups, cyano groups, fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, lactone rings, sulcinolone rings, carboxylic anhydrides, etc.

[0139] Among the compounds represented by the above general formula (3), it is preferable that p is 2, 3 or 4. In this case, when mixed with high-valent iodine compounds, it is easy to form a strong resist film with high molecular weight, which is ideal considering etching resistance and developer resistance.

[0140] Specific examples of the repeating unit represented by the above general formula (2) can be listed below, but are not limited to these. Additionally, in the following formula, R... A Same as above.

[0141] [Chemistry 23]

[0142]

[0143] [Chemistry 24]

[0144]

[0145] Compounds represented by the above general formula (3) may be listed below, but are not limited thereto. Compounds represented by the above general formula (3) may be commercially available or synthesized.

[0146] [Chemistry 25]

[0147]

[0148] [Chemistry 26]

[0149]

[0150] [Chemistry 27]

[0151]

[0152] [Chemistry 28]

[0153]

[0154] [Chemistry 29]

[0155]

[0156] [Chemistry 30]

[0157]

[0158] Polymers containing repeating units represented by the above general formula (2) may also contain other repeating units (hereinafter also referred to as "other repeating units"). There are no particular limitations on the aforementioned other repeating units, but they should preferably be those that can improve the solubility of polymers that are poorly soluble in solvents when they only contain repeating units with carboxyl groups. The aforementioned other repeating units should preferably be repeating units with cyclic structures that can be expected to have high etch resistance due to their rigid backbone, or repeating units containing a styrene backbone.

[0159] Specific examples of the aforementioned repeating units may be listed below, but are not limited to these. Additionally, in the following formula, R... A As mentioned above, X B They are either -CH2- or -O-, respectively.

[0160] [Chemistry 31]

[0161]

[0162] [Chemistry 32]

[0163]

[0164] [Chemistry 33]

[0165]

[0166] [Chemistry 34]

[0167]

[0168] [Chemistry 35]

[0169]

[0170] [Chemistry 36]

[0171]

[0172] [Chemistry 37]

[0173]

[0174] [Chemistry 38]

[0175]

[0176] [Chemistry 39]

[0177]

[0178] [Chemistry 40]

[0179]

[0180] [Chemistry 41]

[0181]

[0182] [Chemistry 42]

[0183]

[0184] [Chemistry 43]

[0185]

[0186] [Chemistry 44]

[0187]

[0188] [Chemistry 45]

[0189]

[0190] [Chemistry 46]

[0191]

[0192] [Chemistry 47]

[0193]

[0194] [Chemistry 48]

[0195]

[0196] [Chemistry 49]

[0197]

[0198] [Transformation 50]

[0199]

[0200] [Chemistry 51]

[0201]

[0202] [Chemistry 52]

[0203]

[0204] [Chemistry 53]

[0205]

[0206] [Chemistry 54]

[0207]

[0208] [Chemistry 55]

[0209]

[0210] [Chemistry 56]

[0211]

[0212] [Chemistry 57]

[0213]

[0214] [Chem.58]

[0215]

[0216] [Chemistry 59]

[0217]

[0218] [Transformation 60]

[0219]

[0220] In the aforementioned resist composition, the molar ratio of the aforementioned high-valent iodine compound to the aforementioned carboxyl-containing compound (polymer containing repeating units represented by the above general formula (2) and / or compound represented by the above general formula (3)) is preferably high-valent iodine compound: carboxyl-containing compound = 1:99 to 99:1, more preferably 10:90 to 90:10, and even more preferably 20:80 to 80:20. In the aforementioned resist composition, the aforementioned high-valent iodine compound may be used alone or in combination with two or more of the aforementioned high-valent iodine compounds. The aforementioned carboxyl-containing polymers may be used alone or in combination with two or more polymers having different composition ratios, weight-average molecular weights (Mw), and / or molecular weight distributions (Mw / Mn). The aforementioned monomolecular compounds may be used alone or in combination with two or more polymers. Either the aforementioned carboxyl-containing polymers or the aforementioned monomolecular compounds may be used, or in combination.

[0221] In the aforementioned carboxyl-containing polymers, the molar ratio of carboxyl-containing repeating units to other repeating units should preferably be 10:90 to 90:10, more preferably 15:85 to 85:15, and even more preferably 20:80 to 80:20.

[0222] The weight-average molecular weight (Mw) of the aforementioned carboxyl-containing polymers is preferably between 1,000 and 500,000, and more preferably between 3,000 and 100,000. Furthermore, in this invention, the weight-average molecular weight Mw and the number-average molecular weight Mn are converted values ​​of standard polystyrene obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and the dispersity Mw / Mn is a value derived from them.

[0223] Furthermore, when the aforementioned carboxyl-containing polymers have a wide molecular weight distribution (Mw / Mn), there may be both low-molecular-weight and high-molecular-weight polymers. This raises concerns about foreign matter and pattern shape deterioration observed on the pattern after exposure. Therefore, as the pattern becomes more regular and refined, the influence of Mw and Mw / Mn tends to increase. Thus, to obtain a resist composition ideally suited for fine pattern sizes, the aforementioned carboxyl-containing polymers should preferably have a narrow dispersion of Mw / Mn between 1.00 and 2.00. Mw / Mn should preferably be greater than 1.30, with a lower limit of 1.40, 1.50, or 1.60, and an upper limit of 1.70, 1.80, or 1.90.

[0224] Examples of methods for synthesizing the aforementioned carboxyl-containing polymers include: polymerizing a monomer that provides the aforementioned repeating unit in an organic solvent by adding a free radical polymerization initiator and heating it.

[0225] Specific examples of organic solvents used in the polymerization reaction include: toluene, benzene, THF, diethyl ether, dioxane, cyclohexane, cyclopentane, cyclopentanone, cyclohexanone, methyl ethyl ketone (MEK), propylene glycol monomethyl ether (PGME), propylene glycol monomethyl ether acetate (PGMEA), γ-butyrolactone (GBL), etc. Specific examples of polymerization initiators include: 2,2'-azobisisobutyronitrile (AIBN), 2,2'-azobis(2,4-dimethylpentanonitrile), dimethyl-2,2-azobis(2-methylpropionate), 1,1'-azobis(1-acetoxy-1-phenylethane), benzoyl peroxide, lauroyl peroxide, etc. The amount of the aforementioned polymerization initiator added, relative to the total amount of monomers used to polymerize, should preferably be 0.01–25 mol%. The reaction temperature should preferably be 50–150 °C, preferably 60–100 °C. The reaction time should be 2 to 24 hours, but from the perspective of production efficiency, 2 to 12 hours is better.

[0226] The aforementioned polymerization initiator can be added to the monomer solution and supplied to the reactor, or an initiator solution different from the monomer solution can be prepared and supplied to the reactor separately. Since there is a possibility that polymerization may proceed and generate ultrapolymers due to the generation of free radicals from the initiator during the waiting time, from a quality management perspective, the monomer solution and initiator solution should preferably be prepared separately and added dropwise. Furthermore, to adjust the molecular weight, known chain transfer agents such as dodecyl mercaptan and 2-mercaptoethanol can also be used in combination. In this case, the amount of the aforementioned chain transfer agent added, relative to the total amount of monomers used to polymerize it, should preferably be 0.01 to 20 mol%.

[0227] In addition, the amount of each monomer in the aforementioned monomer solution can be appropriately set, for example, in a manner that makes it an ideal content ratio for the aforementioned repeating units.

[0228] [Other high-valent iodine compounds]

[0229] The resist composition of the present invention may also contain a high-valent iodine compound represented by the following general formula (4) or general formula (5) (hereinafter also referred to as "other high-valent iodine compounds"). By adding other high-valent iodine compounds to the resist composition of the present invention, the reactivity to light can be controlled and the sensitivity adjusted.

[0230] [Chemistry 61]

[0231]

[0232] In the formula, m1 and m2 are integers from 0 to 2. n1 is an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2. When m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, satisfying 1 ≤ (n2 + n3) ≤ 6. When m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, satisfying 1 ≤ (n2 + n3) ≤ 8. When m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, satisfying 1 ≤ (n2 + n3) ≤ 10. R 51 A hydrocarbon group consisting of 1 to 10 carbon atoms, which may also contain heteroatoms. R 52 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n1 is 2 to 8, each R 52 They can be the same or different. Also, multiple R's... 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. R 53 It can be a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. *3 and *4 represent atomic bonds of carbon atoms in the aromatic ring in the formula. However, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring. R 61 and R 62 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 61 and R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms. When n2 is 2 to 3, each R 61 and R 62 They can be the same or different. R 63 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n3 is 2 to 9, each R 63 They can be the same or different. Also, multiple R's... 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0233] In the above general formulas (4) and (5), m1 and m2 are integers from 0 to 2.

[0234] When m1 is 0, n1 is an integer from 0 to 4; when m1 is 1, n1 is an integer from 0 to 6; and when m1 is 2, n1 is an integer from 0 to 8.

[0235] When m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, and satisfies 1≤(n2+n3)≤6.

[0236] When m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, and satisfies 1≤(n2+n3)≤8.

[0237] When m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, and satisfies 1≤(n2+n3)≤10.

[0238] R 51 It is a hydrocarbon group with 1 to 10 carbon atoms, which may contain halogen atoms or heteroatoms.

[0239] R 52 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n1 is 2 to 8, each R 52 They can be the same or different. Also, multiple R's... 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0240] R 53 It may also contain alkylene groups with 1 to 10 carbon atoms and heteroatoms.

[0241] *3 and *4 represent the atomic bonds of the carbon atoms in the aromatic ring in the formula. However, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring.

[0242] R 61 and R 62 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 61 and R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0243] R 63 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n3 is 2 to 9, each R 63 They can be the same or different. Also, multiple R's... 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0244] In the above general formula (4), m1 is an integer from 0 to 2. When m1 is 0, n1 is an integer from 0 to 4; when m1 is 1, n1 is an integer from 0 to 6; and when m1 is 2, n1 is an integer from 0 to 8. n1 should preferably be 0, 1, 2, 3, or 4, with 0, 1, 2, or 3 being better, 0, 1, or 2 being even better, and 0 or 1 being the best.

[0245] In the above general formula (4), R 51A hydrocarbon group having 1 to 10 carbon atoms, which may contain halogen atoms or heteroatoms. Specific examples of the aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The aforementioned hydrocarbon groups having 1 to 10 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups having 1 to 10 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 [Cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms, such as decyl and adamantyl; alkenyl groups with 2 to 10 carbon atoms, such as vinyl and allyl; aryl groups with 6 to 10 carbon atoms, such as phenyl and naphthyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, groups may contain hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone, sulfonyl, or carboxylic anhydride (-C(=O)-OC(=O)-), etc. The above R...] 51 It is preferable to use a hydrocarbon group with 1 to 4 carbon atoms or a fluorinated hydrocarbon group with 1 to 4 carbon atoms, with a hydrocarbon group with 1 to 4 carbon atoms being more preferred.

[0246] In the above general formula (4), R 52 A hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. Specific examples of the aforementioned halogen atoms include: fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc. The aforementioned hydrocarbon group with 1 to 40 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6[Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, and anthracene. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulfonyl ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc. When n1 is 2 to 8, each R...] 52 They can be the same or different. Also, multiple R's... 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0247] In the above general formula (4), R 53 It may also contain heteroatoms and be a hydrocarbon group with 1 to 10 carbon atoms. The aforementioned hydrocarbon groups with 1 to 10 carbon atoms may be saturated or unsaturated, and may be linear, branched, or cyclic. Specific examples include: alkylene groups with 1 to 10 carbon atoms, such as methanediyl, ethane-1,1-diyl, ethane-1,2-diyl, propane-1,1-diyl, propane-1,2-diyl, propane-1,3-diyl, propane-2,2-diyl, butane-2,3-diyl, butane-1,4-diyl, 2-methylpropane-1,2-diyl, pentane-1,5-diyl, hexane-1,6-diyl, heptane-1,7-diyl, octane-1,8-diyl, nonane-1,9-diyl, and decane-1,10-diyl; cyclopentanediyl, cyclohexanediyl, norcamphenediyl, adamantanediyl, and tricyclic [5.2.1.0] 2,6 [Cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms, such as decanediyl; vinylidene, propenide, etc., with 2 to 10 carbon atoms; arylene groups with 6 to 10 carbon atoms, such as phenylene, methylphenylene, ethylphenylene, n-propylphenylene, isopropylphenylene, n-butylphenylene, naphthylene; and groups obtained by combining these. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, groups may contain hydroxyl, cyano, halogenated alkyl, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulpholactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc. The above R...] 53 It is preferable to use a carbonyl group, a hydrocarbon group with 1 to 4 carbon atoms, or a fluorinated hydrocarbon group with 1 to 4 carbon atoms.

[0248] In the above general formula (4), *3 and *4 represent atomic bonds with the carbon atoms of the aromatic ring in the above general formula (4). However, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring. Such combinations of *3, *4 and m1 can be considered in the following 7 states.

[0249] [Chemistry 62]

[0250]

[0251] In the formula, n1 and R 52 and R 53 Same as above. The dashed line represents R. 51 -C(=O)-O- atomic bonds.

[0252] In addition, the above R 52 and the above R 53 It can replace any position of the aromatic ring in the above formula.

[0253] Specific examples of high-valent iodine compounds represented by the above general formula (4) are shown below, but are not limited thereto. Additionally, in the following formula, Me is a methyl group.

[0254] [Chemistry 63]

[0255]

[0256] [Chemistry 64]

[0257]

[0258] [Chemistry 65]

[0259]

[0260] [Chemistry 66]

[0261]

[0262] [Chemistry 67]

[0263]

[0264] [Chemistry 68]

[0265]

[0266] [Chemistry 69]

[0267]

[0268] [Chemistry 70]

[0269]

[0270] [Chemistry 71]

[0271]

[0272] [Chemistry 72]

[0273]

[0274] [Chemistry 73]

[0275]

[0276] [Chemistry 74]

[0277]

[0278] [Chemistry 75]

[0279]

[0280] [Chemistry 76]

[0281]

[0282] [Chemistry 77]

[0283]

[0284] [Chemistry 78]

[0285]

[0286] [Chemistry 79]

[0287]

[0288] [Chemistry 80]

[0289]

[0290] [Chemistry 81]

[0291]

[0292] [Chemistry 82]

[0293]

[0294] [Chemistry 83]

[0295]

[0296] [Chemistry 84]

[0297]

[0298] [Chemistry 85]

[0299]

[0300] [Chemistry 86]

[0301]

[0302] [Chemistry 87]

[0303]

[0304] [Chemistry 88]

[0305]

[0306] [Chemistry 89]

[0307]

[0308] [Chemistry 90]

[0309]

[0310] [Chemistry 91]

[0311]

[0312] [Chemistry 92]

[0313]

[0314] [Chemistry 93]

[0315]

[0316] [Chemistry 94]

[0317]

[0318] [Chemistry 95]

[0319]

[0320] [Chemistry 96]

[0321]

[0322] [Chemistry 97]

[0323]

[0324] [Chem. 98]

[0325]

[0326] [Chemistry 99]

[0327]

[0328] [Chemistry 100]

[0329]

[0330] [Chemistry 101]

[0331]

[0332] [Chemistry 102]

[0333]

[0334] [Chemistry 103]

[0335]

[0336] [Chemistry 104]

[0337]

[0338] [Chemistry 105]

[0339]

[0340] [Chemistry 106]

[0341]

[0342] [Chemistry 107]

[0343]

[0344] [Chemistry 108]

[0345]

[0346] [Chemistry 109]

[0347]

[0348] [Chemical 110]

[0349]

[0350] [Chemistry 111]

[0351]

[0352] [Chemistry 112]

[0353]

[0354] [Chemistry 113]

[0355]

[0356] [Chemistry 114]

[0357]

[0358] [Chemistry 115]

[0359]

[0360] [Chemistry 116]

[0361]

[0362] [Chemistry 117]

[0363]

[0364] [Chemistry 118]

[0365]

[0366] In the above general formula (5), m2 is an integer from 0 to 2.

[0367] When m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, and satisfies 1≤(n2+n3)≤6.

[0368] When m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, and satisfies 1≤(n2+n3)≤8.

[0369] When m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, and satisfies 1≤(n2+n3)≤10.

[0370] In the above general formula (5), R 61 and R 62 Each of the above R groups consists independently of a halogen atom, or may contain heteroatoms, and comprises a hydrocarbon group having 1 to 10 carbon atoms. Furthermore, the aforementioned R... 61 and the above R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms. Examples of halogen atoms include: fluorine, chlorine, bromine, iodine, etc. The aforementioned hydrocarbon groups with 1 to 10 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 10 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6[Cyclic saturated hydrocarbon groups with 3 to 10 carbon atoms, such as decyl and adamantyl; alkenyl groups such as vinyl and allyl; aryl groups with 6 to 10 carbon atoms, such as phenyl and naphthyl; and groups obtained by combining them. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups may be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, or halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups may also be replaced by groups containing heteroatoms such as oxygen, sulfur, or nitrogen atoms. As a result, groups may contain hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc. The above R...] 61 and the above R 62 It should preferably be a hydrocarbon group with 1 to 4 carbon atoms.

[0371] In the above general formula (5), R 63 A hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. Examples of halogen atoms include fluorine, chlorine, bromine, and iodine. The hydrocarbon group with 1 to 40 carbon atoms can be saturated or unsaturated, and can be linear, branched, or cyclic. Specific examples include: methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, tert-pentyl, n-hexyl, n-octyl, 2-ethylhexyl, n-nonyl, n-decyl, etc., alkyl groups with 1 to 40 carbon atoms; cyclopentyl, cyclohexyl, cyclopentylmethyl, cyclopentylethyl, cyclopentylbutyl, cyclohexylmethyl, cyclohexylethyl, cyclohexylbutyl, norcamphenyl, tricyclic [5.2.1.0] 2,6 [Cyclic saturated hydrocarbon groups with 3 to 40 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups with 6 to 40 carbon atoms, such as phenyl, naphthyl, and anthracene. Furthermore, some or all of the hydrogen atoms in the aforementioned hydrocarbon groups can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, and a portion of the -CH2- group in the aforementioned hydrocarbon groups can also be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms. As a result, hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulopentalide ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc. When n3 is 2 to 9, each R...] 63 They can be the same or different. Also, multiple R's... 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0372] In addition, the above R 63 It can replace any position of the aromatic ring in the above formula.

[0373] Specific examples of high-valent iodine compounds represented by the above general formula (5) are listed below, but are not limited thereto.

[0374] [Chemistry 119]

[0375]

[0376] [Chemistry 120]

[0377]

[0378] [Chemistry 121]

[0379]

[0380] [Chemistry 122]

[0381]

[0382] When the resist composition of the present invention contains other high-valent iodine compounds, the other high-valent iodine compounds may be the high-valent iodine compounds represented by the above general formula (4), or the high-valent iodine compounds represented by the above general formula (5), or a combination of the high-valent iodine compounds represented by the above general formula (4) and the high-valent iodine compounds represented by the above general formula (5). Furthermore, the high-valent iodine compounds represented by the above general formula (4) and the high-valent iodine compounds represented by the above general formula (5) may each be used individually, or two or more different compounds may be used in combination.

[0383] When the resist composition of the present invention contains other high-valent iodine compounds, the molar ratio of the aforementioned high-valent iodine compounds to the aforementioned carboxyl-containing compounds (when the aforementioned carboxyl-containing compounds are carboxyl-containing polymers, it is the molar ratio of the high-valent iodine compounds to the repeating units containing carboxylic acids in the aforementioned polymers) is preferably 1:99 to 99:1, more preferably 10:90 to 90:10, and even more preferably 20:80 to 80:20. Furthermore, the aforementioned other high-valent iodine compounds, relative to the high-valent iodine compounds represented by the above general formula (1), are preferably contained in a molar ratio of other high-valent iodine compounds: high-valent iodine compounds represented by general formula (1) = 1:99 to 99:1, and more preferably in a molar ratio of 1:99 to 50:50.

[0384] [solvent]

[0385] The resist composition of the present invention contains a solvent. There are no particular limitations on the solvent being capable of dissolving and forming a film from a high-valent iodine compound represented by general formula (1), a carboxyl-containing compound, other high-valent iodine compounds, and other components described below. Such a solvent is preferably an organic solvent, and specific examples include: ketones such as cyclohexanone, methyl-2-n-pentyl ketone, and methyl isopentyl ketone; alcohols such as 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, 4-methyl-2-pentanol, and methyl 2-hydroxyisobutyrate; and propylene glycol monomethyl ether, ethylene glycol monomethyl ether, propylene glycol monoethyl ether, and ethylene glycol monoethyl ether. Ethers such as monoethyl ether of alcohol, dimethyl propylene glycol, and dimethyl ethylene glycol; esters such as propylene glycol monomethyl ether acetate, monoethyl propylene glycol acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and monotert-butyl propylene glycol acetate; carboxylic acids such as formic acid, acetic acid, and propionic acid; lactones such as γ-butyrolactone; and their mixed solvents, etc.

[0386] In the resist composition of the present invention, the content of the aforementioned solvent is preferably such that the concentration of the solid component in the resist composition is 0.1% to 20% by mass, more preferably 0.1% to 15% by mass, and even more preferably 0.1% to 10% by mass. Furthermore, in the present invention, the solid component refers to all components of the resist composition other than the solvent. The aforementioned solvent may be used alone or in combination of two or more.

[0387] [Other ingredients]

[0388] The resist composition of the present invention may also contain a surfactant. The aforementioned surfactant is preferably a fluorinated and / or polysiloxane surfactant. Specific examples of such surfactants include the surfactant described in paragraph

[0276] of U.S. Patent Application Publication 2008 / 0248425. Alternatively, surfactants other than the fluorinated and / or polysiloxane surfactants described in paragraph

[0280] of U.S. Patent Application Publication 2008 / 0248425 may also be used.

[0389] When the resist composition of the present invention contains the aforementioned surfactant, its content in the total solid components is preferably 0.0001 to 2% by mass. The aforementioned surfactant may be used alone or in combination of two or more.

[0390] The resist composition of the present invention may also contain at least one selected from free radical scavengers and crosslinking agents. This allows for control of the photoresist reaction in optical lithography and adjustment of sensitivity.

[0391] Specific examples of the aforementioned free radical scavengers include hindered phenols, quinones, hindered amines, and thiols. Specifically, examples of hindered phenols include butylated hydroxytoluene (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). Examples of quinones include 4-methoxyphenol (MEHQ) and hydroquinone. Examples of hindered amines include 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethylpiperidine-N-oxy radical. Examples of thiols include dodecanethiol and hexadecanethiol.

[0392] When the corrosion resist composition of the present invention contains the aforementioned free radical scavenger, its content in the total solid components is preferably 0.01 to 10% by mass. The aforementioned free radical scavenger may be used alone or in combination of two or more.

[0393] Specific examples of the aforementioned crosslinking agents include compounds with carbon-carbon unsaturated bonds as functional groups, such as vinyl, (meth)acrylate, allyl, alkynyl, and aromatic rings. Specifically, examples of compounds with vinyl groups include: chain alkenes, branched alkenes, and cyclic alkenes, which may also have substituents. Examples of compounds with (meth)acrylate groups include: acrylic acid, methacrylic acid, acrylates, and methacrylates, which may also have substituents. Examples of compounds with allyl groups include: allyl alcohols, allyl ethers, allyl esters, allyl amides, allylamines, and isocyanurates containing allyl groups, which may also have substituents. Examples of compounds with alkynyl groups include: chain alkynes, branched alkynes, cyclic alkynes, alkynyl alcohols, alkynyl ethers, alkynyl esters, alkynyl amides, alkynylamines, and isocyanurates containing alkynyl groups, which may also have substituents. Specific examples of compounds containing aromatic rings include: aromatic hydrocarbons, heteroaromatic hydrocarbons, styrene, stilbene, phenylacetylene, acenaphthene, chalcone, etc., which may also have substituents. The crosslinking agent may have only one of the aforementioned functional groups or multiple functional groups. The number of the aforementioned functional groups in the crosslinking agent is preferably 1 to 10, and more preferably 2 to 8.

[0394] When the resist composition of the present invention contains the aforementioned crosslinking agent, its content in the total solid components is preferably 0.01 to 50% by mass. The aforementioned crosslinking agent may be used alone or in combination of two or more.

[0395] As described above, the resist composition of the present invention contains a high-valent iodine compound and a carboxyl-containing compound as its main components, but does not need to contain the base polymer containing acid-instable groups or the photoacid generator found in conventional chemically amplified resist compositions. However, the resist composition of the present invention, especially when exposed to EB or EUV, can still produce differences in solubility between exposed and unexposed areas, forming positive or negative patterns. The mechanism is not fully elucidated, but is hypothesized, for example, as follows.

[0396] The high-valent iodine compound represented by the above general formula (1) is a compound containing a tricoordinate high-valent iodine with a carboxylic acid ligand. It is believed that when such a tricoordinate iodine compound is mixed with a carboxylic acid compound, the exchange of carboxylic acid ligands occurs in an equilibrium reaction. At this time, if the original carboxylic acid ligand can be removed by any method, a high-valent iodine compound with a new ligand will be generated. For example, if Dess-Martinperiodinane, which is more easily obtained in the form of a high-valent iodine compound, is mixed with a carboxylic acid compound with a large molecular weight, and the low-boiling acetic acid generated is removed, the ligand exchange will be completed. Here, the carboxyl-containing compound becomes a polymer crosslinked with the high-valent iodine compound.

[0397] Polymers crosslinked with high-valent iodine compounds are formed during film formation. This is because even if such crosslinked polymers are synthesized beforehand, they are insoluble in most organic solvents, making solution preparation impossible. It is speculated that this is because the high-valent iodine compounds, which originally have high polarization and low solvent solubility, use carboxyl-containing compounds as ligands, further worsening their solubility. Therefore, it is advisable to remove the original low-molecular-weight carboxylic acid components during film formation and the subsequent baking step, thereby completing the ligand exchange reaction and simultaneously forming the resist film.

[0398] In the resist film of the present invention, which is formed on a substrate in this manner, the high-valent iodine compound, as its main component, decomposes under light, thereby changing its polarity and forming a pattern using a development step. Furthermore, by appropriately selecting the developer, positive or negative patterns can be formed.

[0399] The resist composition of this invention can be either positive or negative depending on the selection of its components. In the positive case, it contains a polymer bonded by hypervalent iodine compounds during film formation. This polymer decomposes under light, becoming a monovalent iodine compound, while the bonds between the carboxyl-containing compound and the hypervalent iodine compound break, resulting in a decrease in molecular weight. It is presumably the result of forming a positive pattern where the exposed areas are removed by organic solvents.

[0400] On the other hand, in the negative case, there is a polymer cross-linked with high-valent iodine compounds generated during film formation. This polymer decomposes under light, causing cross-linking or bond exchange, and resulting in increased molecular weight and polarity reversal. It is speculated that this will result in a negative pattern where the unexposed areas are removed by the alkaline solution.

[0401] Based on the foregoing, it can be inferred that the resist composition of the present invention is a non-chemically amplified resist composition. The resist composition of the present invention does not require a base polymer containing acid-instable groups or a photoacid generator as in known chemically amplified resist compositions, and therefore does not suffer from adverse effects caused by acid diffusion (e.g., image blurring), and fine patterns can be distinguished.

[0402] The resist composition of the present invention is particularly effective in EUV lithography. This is because the resist composition of the present invention has iodine atoms with high absorption capacity for EUV light, and the high-valent iodine compound represented by the above general formula (1) has a carboxylic acid ligand on one iodine atom that can cause the aforementioned ligand exchange. Therefore, after film formation, crosslinking with carboxyl-containing compounds occurs at a higher density, resulting in a greater difference in dissolution rate between unexposed and exposed areas compared to using only other high-valent iodine compounds, i.e., a greater dissolution contrast. In other words, the resist composition of the present invention can achieve high sensitivity, high resolution, and low LWR by virtue of these characteristics. Thus, using a non-chemically amplified resist containing a high-valent iodine compound with an SF5 group and a carboxylic acid compound (a carboxyl-containing compound) improves the overall solubility of the resist. This allows the formation of patterns with excellent sensitivity and roughness resolution.

[0403] Regarding resist compositions for EUV lithography capable of forming fine patterns, there have been reports of metal resists with tin compounds as the main component, which have a similar high absorption capacity for EUV light as iodine atoms (e.g., Patent Document 2). However, as mentioned above, such metal resists suffer from many problems, including insufficient solvent solubility, poor storage stability, and defects caused by etching residues due to the presence of metal elements. On the other hand, the resist composition of the present invention does not use metal elements, thus it is more advantageous than metal resists in terms of defects and does not have the problem of solvent solubility. Furthermore, the resist composition of the present invention is applicable to both positive and negative modes, thus having a wide range of applications. For example, in the contact hole formation step, metal resists implemented with negative development require a reversal process after the pillar pattern is formed, while positive resists do not require such a step. Therefore, from the viewpoint of process simplicity, the resist composition of the present invention can be considered more useful than metal resists.

[0404] Japanese Patent Application Publication Nos. 2015-180928 and 2018-95853 disclose resist compositions containing hypervalent iodine compounds as additives, and resist compositions formed by incorporating hypervalent iodine compounds into the polymer backbone of a base polymer. However, in these patent documents, regarding the characteristics of the aforementioned resist compositions, they only describe the ability to improve line edge roughness, but make no mention of the possibility of photodecomposition of the hypervalent iodine compounds, or the possibility of them functioning as materials in non-chemically amplified resist compositions. Furthermore, according to the descriptions and specific examples related to their doping amounts, the hypervalent iodine compounds are not the main component. Also, Patent Document 3 proposes a positive resist composition using hypervalent iodine compounds, but does not describe the hypervalent iodine compounds represented by the general formula (1) of this invention, and makes no mention of improving resolution and LWR by using such compounds. Therefore, it is impossible to conceive of a non-chemically amplified resist composition like that of this invention, which exhibits extremely high sensitivity and excellent resolution and is highly effective in precision micromachining, based on these patent documents. In other words, the present invention clearly provides novel resist compositions and patterning methods.

[0405] [Layered Body]

[0406] This invention provides a laminate comprising: a substrate, and a resist film formed from the aforementioned resist composition on the substrate. In such a laminate comprising a resist film derived from the non-chemically amplified resist composition of this invention, the resist film formed from the aforementioned resist composition exhibits extremely high sensitivity and excellent limiting resolution, making it highly effective for precision micro-machining. Furthermore, it is applicable to the formation of any pattern, whether positive or negative, thus having a wide range of uses and high usefulness in resist manufacturing technology.

[0407] At this time, a lower resist film may also be provided between the aforementioned substrate and the aforementioned resist film as needed.

[0408] Furthermore, in the laminate of the present invention, the resist film preferably contains the ligand exchange reaction product of the aforementioned high-valent iodine compound and a carboxyl-containing compound. That is, the laminate can be obtained by forming a resist film derived from the resist composition of the present invention on a substrate, and the aforementioned resist film preferably is formed by ligand exchange between the aforementioned high-valent iodine compound and a carboxyl-containing compound.

[0409] As described above, by removing the byproduct low-molecular-weight carboxylic acids during film formation and subsequent baking steps, the hypervalent iodine compound undergoes a ligand exchange reaction with the carboxyl-containing compound, forming a resist film containing the ligand exchange reaction products (i.e., providing the film-forming body). By completing the ligand exchange, the carboxyl-containing compound becomes a polymer cross-linked with the hypervalent iodine compound. It is preferable to complete the ligand exchange reaction simultaneously with the formation of the resist film in this way.

[0410] [Pattern Formation Method]

[0411] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be employed. The pattern forming method of the present invention provides a pattern forming method comprising the following steps:

[0412] A resist film is formed on a substrate or on a substrate having a resist underlayer film laminated thereon using the aforementioned resist composition.

[0413] The aforementioned resist film was exposed to high-energy rays, and

[0414] The previously exposed resist film was developed using a developer.

[0415] Hereinafter, the resist underlayer film will be referred to as "underlayer film".

[0416] First, the resist composition of the present invention is coated onto a substrate for integrated circuit manufacturing, or onto the lower layer film of a substrate with a stacked lower layer film (Si, SiO2, SiN, SiON, TiN, WSi, BPSG, SOG, organic antireflective film, etc.), or onto a substrate for mask circuit manufacturing, or onto the lower layer film of a substrate with a stacked lower layer film (Cr, CrO, CrON, MoSi2, SiO2, etc.), using a suitable coating method such as spin coating, roll coating, flow coating, dip coating, spray coating, or blade coating, with a coating film thickness of 0.01 to 2 μm. The substrate is then pre-baked on a hot plate, preferably at 60 to 200°C for 10 seconds to 30 minutes, and more preferably at 80 to 180°C for 30 seconds to 20 minutes, to form a resist film. Furthermore, the lower layer film refers to the film formed between the substrate and the resist film in a multilayer resist process; there are no particular limitations on the aforementioned lower layer film, and known types can be used.

[0417] Then, the aforementioned resist film is exposed using high-energy radiation. Examples of such high-energy radiation include: ultraviolet rays (gamma rays (436 nm), h-rays (405 nm), i-rays (365 nm), etc.), far ultraviolet rays, EB, EUV, X-rays, soft X-rays, excimer lasers (KrF excimer lasers, ArF excimer lasers, etc.), gamma rays, synchrotron radiation, etc. In the resist pattern forming method of the present invention, the aforementioned high-energy radiation preferably uses i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet radiation. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, synchrotron radiation, etc., the exposure dose is preferably about 1 to 300 mJ / cm², either directly or using a mask used to form the desired pattern. 2 And preferably, it should be approximately 10–200 mJ / cm³. 2Irradiation is performed in the following manner. When using EB (Extracorporeal Electrode) for high-energy radiation, it is done directly or using a mask to form the desired pattern, with an exposure dose preferably of approximately 0.1–2000 μC / cm. 2 And preferably, it is about 0.5 to 1500 μC / cm. 2 The resist composition of the present invention is particularly suitable for fine patterning using EB or EUV, especially in high-energy radiation.

[0418] After exposure, PEB should be applied as needed. In this case, it is advisable to apply the PEB on a heated plate or in an oven at 30–150°C for 10 to 30 minutes, or more preferably at 60–120°C for 30 to 20 minutes.

[0419] After exposure or PEB, development and patterning are performed using a developer solution as needed. Examples of developers used at this time include: alkaline aqueous solutions such as tetramethylammonium hydroxide; 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, methylcyclohexanone, acetophenone, methyl acetophenone, isopropanol, isoamyl alcohol, n-butanol, n-pentanol, cyclohexanol, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, cyclohexyl acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, ethyl crotonate, methyl propionate, ethyl propionate. Organic solvents such as ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, amyl lactate, isoamyl lactate, methyl 2-hydroxyisobutyrate, ethyl 2-hydroxyisobutyrate, methyl benzoate, ethyl benzoate, phenyl acetate, benzyl acetate, methyl phenylacetate, ethyl phenylacetate, benzyl formate, ethyl formate, methyl 3-phenylpropionate, benzyl propionate, 2-phenylethyl acetate, 1-propanol, 3-methoxybutanol, 3-methyl-3-methoxybutanol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, diacetone alcohol, and 4-methyl-2-pentanol are used. These developers can be used alone or in combination of two or more.

[0420] After development, rinsing should be performed as needed. The rinsing solution should ideally be miscible with the developer and not dissolve the resist film. Suitable solvents include: alcohols with 3 to 10 carbon atoms, ether compounds with 8 to 12 carbon atoms, alkanes, alkenes, alkynes, and aromatic solvents with 6 to 12 carbon atoms. Alternatively, water can be used as the rinsing solution instead of an organic solvent.

[0421] By performing rinsing, the collapse of the resist pattern and the occurrence of defects can be reduced. Furthermore, rinsing is not necessary; by not performing rinsing, the amount of solvent used can be reduced.

[0422] The resist composition of the present invention, as described above, utilizes the difference in solubility between exposed and unexposed areas during exposure to form positive or negative patterns. Therefore, a developer can be used that dissolves the exposed areas but not the unexposed areas, and vice versa. Thus, the pattern forming method of the present invention, by appropriately selecting the developer, can form positive or negative patterns, and is therefore widely applicable to the formation of various fine patterns.

[0423] [Example]

[0424] The present invention will be specifically described below using examples and comparative examples, but the present invention is not limited thereto.

[0425] [1] Preparation of high-valent iodine compounds

[0426] The high-valent iodine compounds used in the examples are represented by the following formulas I-1 and I-2.

[0427] [Chemistry 123]

[0428]

[0429] The above-mentioned I-1 and I-2 are synthesized as follows.

[0430] [Chemistry 124]

[0431]

[0432] [Synthetic Example 1-1] Synthesis of I-1

[0433] 20 mL of 2.0 M peracetic acid (acetic anhydride solution) was mixed with 5 g of 4-iodophenyl pentafluoride (15.1 mmol) and stirred at 40 °C for 12 h. After returning to room temperature, 100 mL of isopropyl ether (IPE) was added, and the solid was separated by filtration. The resulting solid was dried at 40 °C for 1 h to obtain I-1 (3.1 g, 46% yield). The NMR spectrum and mass analysis spectrum of the obtained I-1 are described below.

[0434] 1 H NMR: (500MHz, CDCl3) δ8.18(d,2H),7.85(d,2H),2.01(s,6H)ppm.

[0435] Single quadrupole mass spectrometry (ESI): POSITIVE M + H + 347.9 (equivalent to C) 11 H 11 INO4)

[0436] [Synthetic Example 1-2] Synthesis of I-2

[0437] I-2 was synthesized using the same method as I-1.

[0438] [2] Polymer synthesis

[0439] The monomers used in the synthesis of the polymer are described below.

[0440] [Chemistry 125]

[0441]

[0442] [Chemistry 126]

[0443]

[0444] [Chemistry 127]

[0445]

[0446] [Synthetic Example 2-1] Synthesis of Polymer (P-1)

[0447] Under nitrogen atmosphere, monomer (a-1) (56g), monomer (b-1) (105g), V-601 (manufactured by Fujifilm and Koimitsu Chemicals), 5.4g, and MEK (methyl ethyl ketone) (180g) were measured in a flask to prepare a monomer-polymerization initiator solution. In another flask already conditioned under nitrogen atmosphere, 55g of MEK was measured, and the mixture was heated to 80°C with stirring. The aforementioned monomer-polymerization initiator solution was then added dropwise over 4 hours. After the addition was complete, the polymerization solution was stirred continuously at 80°C for 2 hours, and then cooled to room temperature. The resulting polymerization solution was added dropwise to 4000g of vigorously stirred hexane, and the precipitated polymer was filtered and separated. The obtained polymer was then washed twice with 1200g of hexane and dried under vacuum at 50°C for 20 hours to obtain a white powdered polymer (P-1) (yield 155g, 96% yield). The Mw of polymer (P-1) was 7700, and the Mw / Mn ratio was 1.82. Furthermore, Mw and Mn are converted values ​​of polystyrene obtained by GPC using tetrahydrofuran (THF) as a solvent. The determination was performed under the following conditions (the same applies below). The results are shown in Table 1 below.

[0448] Device: HLC-8320GPC

[0449] Column: TSK Guardcolumn

[0450] +TSKgel G4000HXL

[0451] +TSKgel G2000HXL

[0452] +TSKgel superH5000

[0453] Pump and tubing constant temperature: 40℃

[0454] Extraction solution: THF

[0455] Detector: RI (Differential Refraction) Detector

[0456] Injection volume: 100μl

[0457] [Chemistry 128]

[0458]

[0459] [Synthetic Examples 2-2 to 2-10] Synthesis of Polymers (P-2 to P-10)

[0460] By changing the types and blending ratios of the monomers, but otherwise using the same method as in Synthesis Example 2-1, the polymers shown in Table 1 below were synthesized. Furthermore, polymer (P-10) is a polymer without carboxyl groups (-COOH) and is not a carboxyl-containing compound of the present invention.

[0461] [Table 1]

[0462]

[0463]

[0464] [3] Preparation of the resist composition

[0465] [Examples 1-1 to 1-22 and Comparative Examples 1-1 to 1-4]

[0466] High-valent iodine compounds, other high-valent iodine compounds, and carboxyl-containing compounds were dissolved in a solvent containing 0.01% by mass of a surfactant (PF-636, manufactured by OMNOVA) according to the compositions shown in Table 2 below. The resulting solutions were filtered through a 0.2 μm Teflon (registered trademark) filter to obtain resist compositions (R-01 to R-22) and comparative resist compositions (CR-01 to CR-02). Furthermore, polymers, photoacid generators, and sensitivity modifiers were dissolved in a solvent containing 0.01% by mass of a surfactant (PF-636, manufactured by OMNOVA) according to the compositions shown in Table 3 below. The resulting solutions were filtered through a 0.2 μm Teflon (registered trademark) filter to obtain comparative resist compositions (CR-03 and CR-04).

[0467] [Table 2]

[0468]

[0469]

[0470] [Table 3]

[0471]

[0472] In Tables 2 and 3 above, other high-valent iodine compounds (O-1) and carboxyl-containing compounds (m-1 to m-6) are listed.

[0473] The photoacid generator (PAG-1), sensitivity modifier (Q-1), and solvent are described below.

[0474] [Chemistry 129]

[0475]

[0476] [Chemistry 130]

[0477]

[0478] [Chemistry 131]

[0479]

[0480] [Chemistry 132]

[0481]

[0482] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[0483] AcOH (acetic acid)

[0484] HBM (methyl 2-hydroxyisobutyrate)

[0485] PA (propionic acid)

[0486] GBL (γ-butyrolactone)

[0487] [4] Evaluation of EUV lithography (line and space pattern, positive tone development)

[0488] [Examples 2-1 to 2-22 and Comparative Examples 2-1 to 2-4]

[0489] Each resist composition (R-01 to R-22, and CR-01 to CR-04) was spin-coated onto a Si substrate with a silicon-containing spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., having a film thickness of 20 nm. A photoresist film with a thickness of 40 nm was obtained by photocoating followed by baking (PAB) at the temperatures listed in Table 4 below for 60 seconds using a heated plate. A 36 nm line-to-spacing (LS) 1:1 pattern was then exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination). A PEB was then performed on the heated plate at the temperatures listed in Table 4 below for 60 seconds, followed by development for 30 seconds using the developer listed in Table 4, forming an LS pattern with a spacing width of 18 nm and a pitch of 36 nm.

[0490] The obtained resist pattern was evaluated as follows. The results are shown in Table 4 below.

[0491] [Sensitivity Evaluation]

[0492] The aforementioned LS pattern was observed using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), and the optimal exposure Eop (mJ / cm²) for obtaining an LS pattern with a spacing width of 18nm and a pitch of 36nm was determined. 2 ), and make it a sensitivity.

[0493] [LWR Evaluation]

[0494] The dimensions of 10 points on the LS pattern obtained by exposure to the optimal amount of light along the length direction of the pitch width were measured using a critical dimension SEM (CG-6300) manufactured by Hitachi Advanced Technology Co., Ltd., and the LWR was defined as three times the standard deviation (σ) obtained from the results (3σ). The smaller this value, the smaller and more uniform the pitch width pattern can be obtained.

[0495] [Limited Resolution Evaluation]

[0496] Using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), the limiting linewidth (nm) that can be resolved when forming a pattern by gradually increasing the exposure amount in small increments from the optimal exposure amount for forming the aforementioned LS pattern is determined, and this value is defined as the limiting resolution (nm). The smaller this value, the better the limiting resolution, and the finer the pattern can be formed.

[0497] [Table 4]

[0498]

[0499] Developer: nBA (Butyl acetate)

[0500] CHA (cyclohexyl acetate)

[0501] TMAH (2.38% by mass tetramethylammonium hydroxide aqueous solution)

[0502] [5] Evaluation of EUV lithography (line and spacing patterns, negative tone development)

[0503] [Examples 3-1 to 3-22 and Comparative Examples 3-1 to 3-4]

[0504] Each resist composition (R-01 to R-22, and CR-01 to CR-04) was spin-coated onto a Si substrate with a silicon-containing spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., having a film thickness of 20 nm. A photoresist film with a 40 nm thickness was obtained by photocoating followed by baking (PAB) at the temperatures listed in Table 5 below for 60 seconds using a heated plate. A 36 nm line-to-spacing (LS) 1:1 pattern was then exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9, 90-degree dipole illumination). A PEB was then performed on the heated plate at the temperatures listed in Table 5 below for 60 seconds, followed by development for 30 seconds using the developer listed in Table 5 below, forming an LS pattern with a spacing width of 18 nm and a pitch of 36 nm.

[0505] The obtained resist pattern was evaluated as follows. The results are shown in Table 5 below.

[0506] [Sensitivity Evaluation]

[0507] The aforementioned LS pattern was observed using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), and the optimal exposure Eop (mJ / cm²) for obtaining an LS pattern with a spacing width of 18nm and a pitch of 36nm was determined. 2 ), and make it a sensitivity.

[0508] [LWR Evaluation]

[0509] The dimensions of 10 points on the LS pattern obtained by exposure to the optimal amount of light along the length direction of the pitch width were measured using a critical dimension SEM (CG-6300) manufactured by Hitachi Advanced Technology Co., Ltd., and the LWR was defined as three times the standard deviation (σ) obtained from the results (3σ). The smaller this value, the smaller and more uniform the pitch width pattern can be obtained.

[0510] [Limited Resolution Evaluation]

[0511] Using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), the limiting linewidth (nm) that can be resolved when forming a pattern by gradually increasing the exposure amount in small increments from the optimal exposure amount for forming the aforementioned LS pattern is determined, and this value is defined as the limiting resolution (nm). The smaller this value, the better the limiting resolution, and the finer the pattern can be formed.

[0512] [Table 5]

[0513] As can be seen from Table 4 and the results shown in Table 5 above, the resist composition of the present invention exhibits excellent sensitivity, LWR and resolution in the formation of line and spacing patterns during EUV exposure, regardless of whether it is positive or negative tone development.

[0514] [6] Evaluation of EUV lithography (contact hole pattern)

[0515] [Examples 4-1 to 4-22, Comparative Examples 4-1 to 4-4]

[0516] Each resist composition (R-01 to R-22, and CR-01 to CR-04) was spin-coated onto a Si substrate with a silicon-containing spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., having a film thickness of 20 nm. A photoresist film with a thickness of 50 nm was obtained by photocoating followed by baking (PAB) at the temperatures described in Table 6 below for 60 seconds using a heated plate. Then, the resist film was exposed using an ASML EUV scanning exposure machine NXE3400 (NA 0.33, σ 0.9 / 0.6, quadrupole illumination, 64 nm pitch, +20% offset aperture pattern mask on wafer). A PEB was then performed on the heated plate at the temperatures described in Table 6 below for 60 seconds, followed by development for 30 seconds using the developer described in Table 6 below, to obtain an aperture pattern with a size of 32 nm.

[0517] The obtained resist pattern was evaluated as follows. The results are shown in Table 6 below.

[0518] [Sensitivity Evaluation]

[0519] The aforementioned contact hole pattern was observed using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), and the optimal exposure value Eop (mJ / cm²) for obtaining a hole pattern with a size of 32nm was determined. 2 ).

[0520] [CD Uniformity (CDU) Evaluation]

[0521] The dimensions of 50 hole patterns obtained by irradiation with the optimal exposure were measured, and the standard deviation (σ) of the results was defined as three times the value of 3σ (CDU). The smaller this value, the more uniform the hole diameter pattern can be obtained.

[0522] [Limited Resolution Evaluation]

[0523] Using a Hitachi Advanced Technology Co., Ltd. critical dimension SEM (CG-6300), the limiting aperture diameter (nm) was determined when forming the aforementioned aperture pattern by gradually reducing the exposure amount from the optimal exposure amount. This value was then designated as the limiting resolution (nm). The smaller this value, the better the limiting resolution, and the more fine the aperture diameter pattern can be formed.

[0524] [Table 6]

[0525]

[0526] As can be seen from the results shown in Table 6, the resist composition of the present invention exhibits excellent sensitivity, CDU, and resolution in the formation of contact hole patterns during EUV exposure.

[0527] This specification contains the following specifications.

[0528] [1]: A high-valent iodine compound characterized by a structure represented by the following general formula (1).

[0529] [Chemistry 133]

[0530]

[0531] In the formula, R 1 and R 2 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 1 and R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

[0532] [2]: A resist composition characterized by containing:

[0533] As described in [1], high-valent iodine compounds,

[0534] Compounds containing carboxyl groups, and

[0535] Solvent.

[0536] [3]: The resist composition described in [2], wherein the aforementioned carboxyl-containing compound is a polymer containing repeating units represented by the following general formula (2) and / or a compound represented by the following general formula (3).

[0537] [Chemistry 134]

[0538]

[0539] In the formula, R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group.

[0540] X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -. X A1 It is a saturated hydrocarbon group, phenylene group, or naphthylene group having 1 to 10 carbon atoms, and the saturated hydrocarbon group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring. * indicates an atomic bond with a carbon atom in the main chain.

[0541] p can be 1, 2, 3 or 4.

[0542] R 31 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 31 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group, or sulfonyl group. Furthermore, some or all of the hydrogen atoms of the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing a heteroatom, and part of the -CH2- of the aforementioned p-valent hydrocarbon group can also be replaced by a group containing a heteroatom.

[0543] R 32 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group may be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group may also be replaced by a group containing a heteroatom. When p is 2, 3 or 4, each R 32 They can be the same or different.

[0544] [4]: The resist composition as described in [2] or [3], wherein the aforementioned resist composition further contains at least one of the high-valent iodine compounds represented by the following general formula (4) or (5).

[0545] [Chemistry 135]

[0546]

[0547] In the formula, m1 and m2 are integers from 0 to 2. n1 is an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2. When m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, satisfying 1 ≤ (n2 + n3) ≤ 6. When m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, satisfying 1 ≤ (n2 + n3) ≤ 8. When m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, satisfying 1 ≤ (n2 + n3) ≤ 10. R 51 A hydrocarbon group consisting of 1 to 10 carbon atoms, which may also contain heteroatoms. R 52 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n1 is 2 to 8, each R 52 They can be the same or different. Also, multiple R's... 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. R 53 It can be a hydrocarbon group with 1 to 10 carbon atoms, which may also contain heteroatoms. *3 and *4 represent atomic bonds of carbon atoms in the aromatic ring in the formula. However, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring. R 61 and R 62 Each group consists independently of a halogen atom, or may contain heteroatoms, and is a hydrocarbon group with 1 to 10 carbon atoms. Also, R 61 and R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms. When n2 is 2 to 3, each R 61 and R 62 They can be the same or different. R 63 It is a hydrocarbon group with 1 to 40 carbon atoms, which may contain halogen atoms or heteroatoms. When n3 is 2 to 9, each R 63 They can be the same or different. Also, multiple R's... 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0548] [5]: A laminated body characterized by having:

[0549] substrate, and

[0550] A resist film obtained on the substrate from a resist composition as described in any one of [2] to [4].

[0551] [6]: As described in [5], a layered structure wherein a lower resist film is provided between the aforementioned substrate and the aforementioned resist film.

[0552] [7]: As described in [5] or [6], wherein the aforementioned resist film is formed by ligand exchange between the aforementioned high-valent iodine compound and the aforementioned carboxyl-containing compound.

[0553] [8]: A method for forming a pattern, characterized by comprising the following steps:

[0554] A resist film is formed on a substrate or on the resist underlayer of a substrate having a resist composition as described in any of [2] to [4].

[0555] The aforementioned resist film was exposed using high-energy rays, and

[0556] The previously exposed resist film was developed using a developer.

[0557] [9]: The pattern forming method described in [8], wherein the aforementioned high-energy rays are i-rays, KrF excimer lasers, ArF excimer lasers, electron beams or extreme ultraviolet rays.

[0558]

[10] : The pattern forming method described in [8] or [9], wherein the aforementioned developing solution is used to dissolve the exposed portion but not the unexposed portion.

[0559]

[11] : The pattern forming method described in [8] or [9], wherein the aforementioned developer is used to dissolve the unexposed portion and not the exposed portion.

[0560] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and those having substantially the same structure as the technical concept described in the claims of the present invention and performing the same effects are all intended to be included within the technical scope of the present invention.

Claims

1. A high-valent iodine compound, characterized by: The structure represented by the following general formula (1); In the formula, R 1 and R 2 Each of the following groups is a hydrocarbon group consisting of 1 to 10 carbon atoms, which may be independently composed of halogen atoms or may also contain heteroatoms; furthermore, R 1 and R 2 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms.

2. A resist composition, characterized by containing: According to claim 1, the high-valent iodine compound, Compounds containing carboxyl groups, and Solvent.

3. The resist composition according to claim 2, wherein, The carboxyl-containing compound is a polymer containing repeating units represented by the following general formula (2) and / or a compound represented by the following general formula (3); In the formula, R A It can be a hydrogen atom, a halogen atom, a methyl group, or a trifluoromethyl group; X A It is a single bond, phenylene, naphthylene, or *-C(=O)-OX A1 -;X A1 It is a saturated alkylene group, phenylene group, or naphthylene group with 1 to 10 carbon atoms, and the saturated alkylene group may also contain a hydroxyl group, ether bond, ester bond, or lactone ring; * indicates an atomic bond with a carbon atom in the main chain; p is 1, 2, 3 or 4; R 31 R is a p-valent hydrocarbon group with 1 to 40 carbon atoms or a p-valent heterocyclic group with 2 to 40 carbon atoms; when p is 2, R 31 It can also be an ether bond, carbonyl group, azo group, thioether bond, carbonate bond, carbamate bond, sulfinyl group or sulfonyl group; furthermore, part or all of the hydrogen atoms of the p-valent hydrocarbon group or p-valent heterocyclic group can be replaced by a group containing heteroatoms, and part of the -CH2- of the p-valent hydrocarbon group can also be replaced by a group containing heteroatoms. R 32 It is a single bond or a hydrocarbon group with 1 to 10 carbon atoms, and some or all of the hydrogen atoms of the hydrocarbon group may be replaced by a group containing a heteroatom, and part of the -CH2- of the hydrocarbon group may also be replaced by a group containing a heteroatom; when p is 2, 3 or 4, each R 32 They can be the same or different.

4. The resist composition according to claim 2, wherein, The resist composition also contains at least one of the high-valent iodine compounds represented by the following general formula (4) or (5); In the formula, m1 and m2 are integers from 0 to 2; n1 is an integer from 0 to 4 when m1 is 0, an integer from 0 to 6 when m1 is 1, and an integer from 0 to 8 when m1 is 2; when m2 is 0, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 5, and satisfies 1 ≤ (n2 + n3) ≤ 6; when m2 is 1, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 7, and satisfies 1 ≤ (n2 + n3) ≤ 8; when m2 is 2, n2 is an integer from 1 to 3, and n3 is an integer from 0 to 9, and satisfies 1 ≤ (n2 + n3) ≤ 10; R 51 It is a hydrocarbon group with 1 to 10 carbon atoms, which may contain halogen atoms or heteroatoms; R 52 The group consists of a halogen atom, or may contain heteroatoms, a hydrocarbon group with 1 to 40 carbon atoms; when n1 is 2 to 8, each R 52 They can be the same or different; also, multiple Rs 52 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; R 53 It can also contain 1 to 10 carbon-containing hydrocarbon groups, which may also contain heteroatoms; *3 and *4 represent atomic bonds of the carbon atoms in the aromatic ring in the formula; however, *3 and *4 are bonded to adjacent carbon atoms on the aromatic ring; R 61 and R 62 Each of the following groups is a hydrocarbon group consisting of 1 to 10 carbon atoms, which may be independently composed of halogen atoms or may also contain heteroatoms; furthermore, R 61 and R 62 They can also bond to each other and form rings together with the carbon atoms they are bonded to and the atoms between those carbon atoms; when n2 is 2 to 3, each R 61 and R 62 They can be the same or different; R 63 The group consists of a halogen atom, or may contain heteroatoms, a hydrocarbon group with 1 to 40 carbon atoms; when n3 is 2 to 9, each R 63 They can be the same or different; also, multiple Rs 63 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

5. A laminated body, characterized by having: substrate, and A resist film obtained on the substrate from the resist composition according to any one of claims 2 to 4.

6. The laminate according to claim 5, wherein, A photoresist underlayer is provided between the substrate and the photoresist film.

7. The laminate according to claim 5, wherein, The resist film is formed by ligand exchange between the high-valent iodine compound and the carboxyl-containing compound.

8. A method for forming a pattern, characterized by comprising the following steps: A resist film is formed on a substrate or on a substrate having a resist underlayer film laminated with the resist composition according to any one of claims 2 to 4. The resist film was exposed using high-energy rays, and The exposed resist film was developed using a developer.

9. The pattern forming method according to claim 8, wherein, This high-energy radiation uses i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet light.

10. The pattern forming method according to claim 8, wherein, This developer is used to dissolve the exposed areas but not the unexposed areas.

11. The pattern forming method according to claim 8, wherein, This developer is used to dissolve the unexposed areas but not the exposed areas.

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