Resist composition, laminate, and pattern forming method

Abstract

The invention relates to a resist composition, a laminate, and a pattern forming method. The present invention addresses the problem of providing: a resist composition having excellent sensitivity and resolution in optical lithography using high-energy rays, such as EB and EUV lithography; a laminate using the resist composition; and a pattern forming method. The resist composition is characterized by containing a hypervalent iodine compound represented by formula (1), a carboxyl group-containing compound, and a solvent. [In the formula, R1 and R2 are each independently a halogen atom or a C1-10 hydrocarbon group which may contain a heteroatom, and may be bonded to each other to form a ring together with the carbonyloxy groups to which they are bonded and the atoms between the carbonyloxy groups. R3 and R4 are each independently a halogen atom or a hydrocarbon group which may contain a heteroatom, and may be bonded to each other to form a ring together with the iodine atoms to which R3 and R4 are bonded and the atoms between the iodine atoms.

Description

Technical Field

[0001] This invention relates to a resist composition, a laminate, and a method for forming a pattern using the aforementioned resist composition. 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 a processing size of less than 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, since chemically amplified resist compositions improve sensitivity and contrast through acid diffusion, if acid diffusion is suppressed to the limit by lowering the post-exposure baking (PEB) temperature or shortening the PEB time, 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, in the patterning of resist films with dimensions smaller than 16 nm, it is believed that chemically amplified resist compositions are no longer suitable for patterning, and the development of non-chemically amplified resist compositions is desired.

[0005] Materials used in non-chemically amplified resist compositions include polymethyl methacrylate (PMMA). PMMA is a positive resist material whose solubility in organic solvent developers is improved by breaking down the main chain and reducing the molecular weight through EUV irradiation.

[0006] Hydrosilsesquioxane (HSQ) is a cross-linked form obtained from the condensation reaction of silanols produced by EUV irradiation, thereby becoming a negative resist material insoluble in alkaline developers. Additionally, chlorinated calixarnes also function as negative resist materials. These negative resist materials, due to their small molecular size before cross-linking 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 practical sensitivity, resist compositions with PMMA and HSQ as the main components are greatly affected by randomness and may not achieve the desired resolution.

[0008] As a method to reduce shot noise in resists, introducing elements with high absorption for EUV light has attracted attention. Patent Document 1 proposes a chemically amplified resist composition containing iodine atoms with high absorption for EUV light. However, as mentioned earlier, chemically amplified resist compositions cannot achieve excellent resolution in EUV lithography, where the processing dimensions are becoming increasingly smaller. Especially in line and space patterns, as the pattern size decreases, pattern collapse and line breaks increase significantly, so reducing these issues is closely related to improving the limiting resolution.

[0009] Patent Document 2 claims the use of a negative resist composition of tin compounds. Since tin, which has high absorption under EUV light, is the main component, randomness can be improved, and high sensitivity and resolution can be achieved. However, such a metal resist has many problems, including insufficient solubility in the resist solvent, storage stability, and defects caused by etching residue. Furthermore, because the exposed portion of the metal resist is primarily a metal oxide, it becomes a negative resist that is insoluble in the developer. Therefore, when used for patterning contact holes, an additional inversion process is required, which also raises cost concerns.

[0010] Existing technical documents

[0011] Patent documents

[0012] [Patent Document 1] Japanese Patent Application Publication No. 2018-5224

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

[0014] Non-patent literature

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

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

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

[0018] The present invention was made in view of the foregoing circumstances, and aims to provide a non-chemically amplified resist composition with excellent sensitivity and limiting resolution in optical lithography using high-energy rays, especially in electron beam (EB) lithography and EUV lithography, as well as a method for forming a laminate and pattern using the resist composition.

[0019] [Methods for solving the problem]

[0020] To address the aforementioned issues, the present invention provides a resist composition characterized by comprising: a high-valent iodine compound represented by formula (1), a carboxyl-containing compound, and a solvent.

[0021] [Chemistry 1]

[0022]

[0023] In the formula, R 1 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 carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 3 R 4 Each group is a halogen atom, or may contain heteroatoms. Also, R 3 and R 4 They can also bond to each other and form rings together with the iodine atoms they are bonded to and the atoms between those iodine atoms.

[0024] If the resist composition of the present invention is used, it exhibits excellent sensitivity and limiting resolution in optical lithography using high-energy rays, especially in EB lithography and EUV lithography.

[0025] In this invention, the aforementioned high-valent iodine compound is preferably one or more selected from the group consisting of high-valent iodine compounds represented by formulas (2), (3), (4) and (5).

[0026] [Chemistry 2]

[0027]

[0028] In the formula, m1 is 0, 1, or 2. When m1 is 0, n1 is 0, 1, 2, 3, or 4; when m1 is 1, n1 is 0, 1, 2, 3, 4, 5, or 6; when m1 is 2, n1 is 0, 1, 2, 3, 4, 5, 6, 7, or 8; m2 is 0 or 1. When m2 is 0, n2 is 0, 1, 2, 3, or 4; when m2 is 1, n2 is 0, 1, 2, 3, 4, 5, or 6; m3 is 0 or 1. When m3 is 0, n3 is 0, 1, 2, 3, or 4; when m3 is 1, n3 is 0, 1, 2, 3, 4, 5, or 6. n4 and n5 are 0, 1, 2, 3, 4, 5, or 6; n6 and n7 are 0, 1, 2, or 3. R 11 ~R 18 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 11 and R 12 R 13 and R 14 R 15 and R 16 、or R 17 and R 18 They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 21 ~R 27 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, or may contain heteroatoms. When n1 is 2 or more, each R 21 They can be the same or different, and there are multiple Rs. 21 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n2 is 2 or more, each R 22 They can be the same or different, and there are multiple Rs. 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n3 is 2 or more, each R 23 They can be the same or different, and there are multiple Rs. 23 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n4 is 2 or more, each R 24 They can be the same or different, and there are multiple Rs. 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n5 is 2 or more, each R 25 They can be the same or different, and there are multiple Rs. 25 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n6 is 2 or more, each R 26 They can be the same or different, and there are multiple Rs. 26 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n7 is 2 or more, each R27 They can be the same or different, and there are multiple Rs. 27 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. L1 can be unbonded, single bonded, -O-, -S-, -NH-, or -CH2-.

[0029] The high-valent iodine compound contained in the resist composition of the present invention is preferably a tricoordinate high-valent iodine compound represented by the above formula. Such a tricoordinate iodine(III) compound having aryl and carboxylic acid ligands readily undergoes an equilibrium reaction with the carboxyl-containing compound through mixing. At this time, by removing the original carboxylic acid ligands from the reaction system, the equilibrium will shift towards the formation of a high-valent iodine compound with new ligands for ligand exchange. Thus, the carboxyl-containing compound becomes a polymer crosslinked with the high-valent iodine compound.

[0030] In this invention, the aforementioned carboxyl-containing compound may be any one or both of a polymer containing a repeating unit represented by formula (6) and a compound represented by formula (7).

[0031] [Chemistry 3]

[0032]

[0033] 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 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. 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, some or all of the hydrogen atoms in the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be substituted by a group containing a heteroatom, and a portion of the -CH2- group in the aforementioned p-valent hydrocarbon group can also be substituted by a group containing a heteroatom. R 32 It is a single bond or a hydrocarbon group with 1 to 20 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.

[0034] The carboxyl-containing compounds contained in the resist composition of the present invention are preferably polymers or monomeric compounds of such nature.

[0035] Furthermore, the present invention provides a laminate characterized by comprising: a substrate, and a resist film of the resist composition located on the substrate.

[0036] A laminate containing a resist film derived from the resist composition of the present invention has a wide range of applications and is highly useful in resist manufacturing technology because the resist film of the resist composition has high sensitivity and excellent resolution. It is effective in precision micro-processing and can be used for forming any pattern, whether positive or negative.

[0037] At this time, a lower resist film may also be provided between the aforementioned substrate and the aforementioned resist film. Furthermore, the aforementioned resist film preferably contains a laminate of the ligand exchange reaction product of the aforementioned high-valent iodine compound and a carboxyl-containing compound.

[0038] The laminate of the present invention can be configured in such a manner as required.

[0039] Furthermore, the present invention provides a pattern forming method, characterized by comprising the following steps:

[0040] 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 above-described resist composition.

[0041] The aforementioned resist film was exposed to high-energy rays, and

[0042] The previously exposed resist film was developed using a developer.

[0043] If the pattern forming method of the present invention is used, it is useful for forming finer patterns because it uses a resist composition with excellent sensitivity and resolution in optical lithography using high-energy rays, especially in electron beam (EB) lithography and EUV lithography.

[0044] 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.

[0045] The pattern forming method of the present invention can form finer patterns by using such high-energy rays.

[0046] In the pattern forming method of the present invention, the developer may be used to dissolve the exposed portion without dissolving the unexposed portion, or it may be used to dissolve the unexposed portion without dissolving the exposed portion.

[0047] The pattern forming method of the present invention can form positive or negative patterns by appropriately selecting the developing solution, and is therefore widely applicable to the formation of various fine patterns.

[0048] [The effects of the invention]

[0049] The resist composition of the present invention is particularly useful in optical lithography using i-rays, KrF excimer lasers, ArF excimer lasers, EB or EUV, where it combines high sensitivity and high resolution to form fine patterns. Detailed Implementation

[0050] After repeated and in-depth explorations to achieve the above objectives, the inventors have obtained the following insights and thus completed the present invention: a resist composition mainly composed of a predetermined high-valent iodine compound and a carboxyl-containing compound (polymer or monomer compound) can provide a resist film exhibiting excellent resolution, which is extremely effective in precision micro-machining.

[0051] That is, the present invention is a resist composition characterized by containing: a specific high-valent iodine compound described below, a carboxyl-containing compound, and a solvent.

[0052] The present invention will now be described in detail, but it is not limited thereto. Furthermore, in this specification, the endpoints of a numerical range are defined as encompassing all values ​​contained within that range (for example, "0 to 3" includes 0, 1, 2, and 3).

[0053] [Resist Composition]

[0054] The resist composition of the present invention contains a predetermined high-valent iodine compound, a carboxyl-containing compound, and a solvent as the main components.

[0055] [High-valent iodine compounds]

[0056] High-valence iodine compounds refer to the general term for iodine compounds that have valence electrons in a form that exceeds the octet rule. Examples include tricoordinate iodine compounds with an oxidation state of +3 (iodine(III) compounds) and pentacoordinate iodine compounds with an oxidation state of +5 (iodine(V) compounds).

[0057] The aforementioned high-valent iodine compound, which is the main component of the resist composition in this invention, is a tricoordinate high-valent iodine compound represented by the following formula (1).

[0058] [Chemistry 4]

[0059]

[0060] In the formula, R 1 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 carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 3 R 4Each group is a halogen atom, or may contain heteroatoms. Also, R 3 and R 4 They can also bond to each other and form rings together with the iodine atoms they are bonded to and the atoms between those iodine atoms.

[0061] R 1 R 2 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 1 R 2 The hydrocarbon groups representing 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.] 1 R 2 It should preferably be a hydrocarbon group with 1 to 4 carbon atoms. Also, R 1 and R 2 They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms (iodine atoms, oxygen atoms) between the carbonyl oxygen groups.

[0062] R 3 R 4 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 3 R 4The hydrocarbon group can be saturated or unsaturated, and can be linear, branched, or cyclic. There is no particular limitation on the number of carbon atoms; for example, it can be set to 1–50. 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 1–50 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 50 carbon atoms, such as decyl, adamantyl, and adamantylmethyl; aryl groups with 6 to 50 carbon atoms, such as phenyl, naphthyl, and anthracene. 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, and 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, and nitrogen atoms. As a result, these groups may contain hydroxyl, cyano, halogen, carbonyl, ether, thioether, ester, sulfonate, carbonate, carbamate, lactone ring, sulfonyl lactone ring, carboxylic anhydride (-C(=O)-OC(=O)-), etc.]

[0063] The high-valent iodine compound of formula (1) is preferably selected from one or more of the group consisting of high-valent iodine compounds represented by formulas (2), (3), (4) and (5).

[0064] [Chemistry 5]

[0065]

[0066] In the formula, m1 is 0, 1, or 2. When m1 is 0, n1 is 0, 1, 2, 3, or 4; when m1 is 1, n1 is 0, 1, 2, 3, 4, 5, or 6; when m1 is 2, n1 is 0, 1, 2, 3, 4, 5, 6, 7, or 8; m2 is 0 or 1. When m2 is 0, n2 is 0, 1, 2, 3, or 4; when m2 is 1, n2 is 0, 1, 2, 3, 4, 5, or 6; m3 is 0 or 1. When m3 is 0, n3 is 0, 1, 2, 3, or 4; when m3 is 1, n3 is 0, 1, 2, 3, 4, 5, or 6. n4 and n5 are 0, 1, 2, 3, 4, 5, or 6; n6 and n7 are 0, 1, 2, or 3. R 11 ~R 18 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 11 and R 12 R 13 and R 14 R 15 and R 16 、or R 17 and R 18They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 21 ~R 27 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, or may contain heteroatoms. When n1 is 2 or more, each R 21 They can be the same or different, and there are multiple Rs. 21 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n2 is 2 or more, each R 22 They can be the same or different, and there are multiple Rs. 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n3 is 2 or more, each R 23 They can be the same or different, and there are multiple Rs. 23 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n4 is 2 or more, each R 24 They can be the same or different, and there are multiple Rs. 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n5 is 2 or more, each R 25 They can be the same or different, and there are multiple Rs. 25 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n6 is 2 or more, each R 26 They can be the same or different, and there are multiple Rs. 26 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n7 is 2 or more, each R 27 They can be the same or different, and there are multiple Rs. 27 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. L1 can be unbonded, a single bond, -O-, -S-, -NH-, or -CH2-.

[0067] In equations (2) to (5), m1 is 0, 1 or 2. When m1 is 0, n1 is 0, 1, 2, 3 or 4; when m1 is 1, n1 is 0, 1, 2, 3, 4, 5 or 6; when m1 is 2, n1 is 0, 1, 2, 3, 4, 5, 6, 7 or 8.

[0068] m2 is 0 or 1. When m2 is 0, n2 is 0, 1, 2, 3 or 4. When m2 is 1, n2 is 0, 1, 2, 3, 4, 5 or 6.

[0069] m3 is 0 or 1. When m3 is 0, n3 is 0, 1, 2, 3 or 4. When m3 is 1, n3 is 0, 1, 2, 3, 4, 5 or 6. In addition, when m1, m2 and m3 are 0, the aromatic ring is a benzene ring.

[0070] n4 and n5 are 0, 1, 2, 3, 4, 5 or 6, and n6 and n7 are 0, 1, 2 or 3.

[0071] In equations (2) to (5), R 11 ~R 18 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 11 and R 12 R 13 and R 14 、or R 15 and R 16 They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms (iodine atoms, oxygen atoms) between the carbonyl oxygen groups.

[0072] R 11 ~R 18 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 11 ~R 18 The hydrocarbon groups representing 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.] 11 ~R 18 It should preferably be a hydrocarbon group with 1 to 4 carbon atoms.

[0073] In equations (2) to (5), R 21 ~R 27 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, or may contain heteroatoms. When n1 is 2 or more, each R 21 They can be the same or different, and there are multiple Rs. 21They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n2 is 2 or more, each R 22 They can be the same or different, and there are multiple Rs. 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n3 is 2 or more, each R 23 They can be the same or different, and there are multiple Rs. 23 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n4 is 2 or more, each R 24 They can be the same or different, and there are multiple Rs. 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n5 is 2 or more, each R 25 They can be the same or different, and there are multiple Rs. 25 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n6 is 2 or more, each R 26 They can be the same or different, and there are multiple Rs. 26 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n7 is 2 or more, each R 27 They can be the same or different, and there are multiple Rs. 27 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to.

[0074] R 21 ~R 27 Examples of halogen atoms that can be represented include: fluorine, chlorine, bromine, and iodine atoms. R 21 ~R 27 The hydrocarbon groups representing 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 part 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. Also, R 21 ~R 27 It can replace any position of the aromatic ring in the above formula.

[0075] L1 can be unbonded (in which case the carbon atom on the aromatic ring is replaced by a hydrogen atom), single bond, -O-, -S-, -NH-, or -CH2-.

[0076] The high-valent iodine compounds represented by formulas (1) to (5) above have a μ-oxo group structure formed by cross-linking trivalent iodine atoms with oxygen atoms. Such oxygen-crosslinked high-valent iodine compounds are used as oxidants, but it is completely unknown whether the combination of tricoordinate high-valent iodine (III) compounds with carboxyl ester (acyloxy) ligands as described below with carboxyl-containing compounds can lead to an equilibrium-forming system, thereby preferentially carrying out ligand exchange reactions rather than oxidation reactions, and providing polymers of carboxyl-containing compounds cross-linked with high-valent iodine compounds.

[0077] Specific examples of high-valent iodine compounds represented by equation (2) are listed below, but are not limited thereto.

[0078] [Chemistry 6]

[0079]

[0080] [Chemistry 7]

[0081]

[0082] [Chemistry 8]

[0083]

[0084] [Chemistry 9]

[0085]

[0086] [Chemistry 10]

[0087]

[0088] [Chemistry 11]

[0089]

[0090] [Chemistry 12]

[0091]

[0092] [Chemistry 13]

[0093]

[0094] [Chemistry 14]

[0095]

[0096] [Chemistry 15]

[0097]

[0098] [Chemistry 16]

[0099]

[0100] [Chemistry 17]

[0101]

[0102] [Chemistry 18]

[0103]

[0104] [Chemistry 19]

[0105]

[0106] [Chemistry 20]

[0107]

[0108] [Chemistry 21]

[0109]

[0110] Specific examples of high-valent iodine compounds represented by equation (3) are listed below, but are not limited thereto. Furthermore, in the following equation, L1 is the same as described above.

[0111] [Chemistry 22]

[0112]

[0113] [Chemistry 23]

[0114]

[0115] [Chemistry 24]

[0116]

[0117] [Chemistry 25]

[0118]

[0119] [Chemistry 26]

[0120]

[0121] [Chemistry 27]

[0122]

[0123] [Chemistry 28]

[0124]

[0125] [Chemistry 29]

[0126]

[0127] [Chemistry 30]

[0128]

[0129] [Chemistry 31]

[0130]

[0131] [Chemistry 32]

[0132]

[0133] [Chemistry 33]

[0134]

[0135] [Chemistry 34]

[0136]

[0137] [Chemistry 35]

[0138]

[0139] [Chemistry 36]

[0140]

[0141] [Chemistry 37]

[0142]

[0143] The oxygen-crosslinked high-valent iodine compound represented by general formula (3) can be the compound shown above. For the biphenyl-type oxygen-crosslinked high-valent iodine compound with L1 as a single bond, compounds other than the oxygen-crosslinked high-valent iodine compound represented by the following general formula [1] can also be used. In addition, the symbols in the following general formulas [1] to [6] are only applicable to that formula.

[0144] [Chemistry 38]

[0145]

[0146] In the formula, n R 1 and m R 2 Each of the following groups independently represents a halogen atom, alkyl, haloalkyl, alkoxy, aryl, aryloxy, alkoxycarbonyl, acylamino, alkylsulfonyl, nitro, nitrile, carboxyl, sulfonyl, phosphate, group represented by general formula [2], and ammonio group represented by general formula [3]. Each of the two X1 groups independently represents a halogen atom, alkoxy, aryl, haloalkyl, alkenyl, alkynyl, heterocyclic, acylamino, group represented by general formula [4], sulfonyloxy group represented by general formula [5], group represented by general formula [6], bis(trifluoroamino) (-NTf2), hydroxyl, cyano, azide (-N3), thiocyanoxy (-NCS), nitrate (-NO3), chlorate (-OClO3), phthalimide, tetrafluoroborate (-FBF3) or hexafluorophosphate (-FPF5). n and m each independently represent an integer from 0 to 4. Furthermore, n and / or m are 2 to 4, and there are 2 R's. 1 and / or 2 Rs 2 When bonded to two adjacent carbon atoms, the two adjacent R atoms... 1 With these R 1 The two carbon atoms bonded together, and / or the two adjacent R atoms 2 With these R 2 The two bonded carbon atoms can also form a cyclohexane ring. Furthermore, n and / or m are 1–4, and one R... 1 and / or 1 R 2 When R is bonded to a carbon atom adjacent to the carbon atom bonded to the iodine atom, 1 X1 bonded to an iodine atom, and / or the R 2 X2 bonded to an iodine atom can also form a group represented by the following formula [7] or [8].

[0147] [Chemistry 39]

[0148]

[0149] In the formula, R 3 ~R 5 Each can be used independently to represent an alkyl group.

[0150] [Chemistry 40]

[0151]

[0152] In the formula, R 6 ~R 8 Each of these can be independently represented as an alkyl group, and X2 represents a halide anion, an anion from an inorganic strong acid, or an anion from a sulfonic acid.

[0153] [Chemistry 41]

[0154]

[0155] In the formula, R 9 It indicates alkyl, haloalkyl, alkoxy, aryloxy, or acylamino.

[0156] [Chemistry 42]

[0157]

[0158] In the formula, R 10 This indicates alkyl, haloalkyl, or aryl groups that can be substituted by alkyl groups.

[0159] [Chemistry 43]

[0160]

[0161] In the formula, R 11 and R 12 Each can be used independently to represent an alkyl group.

[0162] [Chemistry 44]

[0163]

[0164] Specific examples of high-valent iodine compounds represented by equation (4) are listed below, but are not limited thereto.

[0165] [Chemistry 45]

[0166]

[0167] [Chemistry 46]

[0168]

[0169] [Chemistry 47]

[0170]

[0171] [Chemistry 48]

[0172]

[0173] [Chemistry 49]

[0174]

[0175] [Transformation 50]

[0176]

[0177] [Chemistry 51]

[0178]

[0179] [Chemistry 52]

[0180]

[0181] Specific examples of high-valent iodine compounds represented by equation (5) are listed below, but are not limited thereto.

[0182] [Chemistry 53]

[0183]

[0184] [Chemistry 54]

[0185]

[0186] [Chemistry 55]

[0187]

[0188] [Chemistry 56]

[0189]

[0190] [Chemistry 57]

[0191]

[0192] [Chem.58]

[0193]

[0194] [Chemistry 59]

[0195]

[0196] [Transformation 60]

[0197]

[0198] The oxygen-crosslinked high-valent iodine compounds represented by general formulas (1) to (5) may also be selected from the oxygen-crosslinked high-valent iodine compounds represented by the following formulas, or other compounds may be selected. Ideally, oxygen-crosslinked high-valent iodine compounds represented by the following formulas I-1 to I-4 may be used. In addition, in the following formulas, Ac represents acetyl and Me represents methyl.

[0199] [Chemistry 61]

[0200]

[0201] [Preparation of high-valent iodine compounds]

[0202] The oxygen-crosslinked high-valent iodine compound used in this invention can be obtained using known methods. For example, 1 mole of a bis(iodoaryl) compound or a diiodoaryl compound (hereinafter also referred to as "precursor"), which is a precursor of the desired high-valent iodine compound, is dissolved in a suitable solvent. Then, 2 to 5 moles of an oxidant are added to the precursor, and the mixture is stirred at -40 to 80°C for 1 to 12 hours to allow it to react. After processing according to common methods, the above-mentioned oxygen-crosslinked high-valent iodine compound can be obtained.

[0203] The aforementioned precursors can be selected according to the high-valent iodine compound that is intended for use. Examples include: diiodobenzene, diiodonaphthalene, diiodobiphenyl, diiodobinaphthalene, diiodospirobadiene, etc.

[0204] The solvents mentioned above should preferably be solvents that are not easily oxidized, such as: halogenated hydrocarbons such as dichloromethane, dichloroethane, and chloroform; fluorinated alcohols such as hexafluoroisopropanol and 2,2,2-trifluoroethanol; hydrocarbons such as hexane and methylcyclohexane; aromatic hydrocarbons such as benzene and toluene; ethers such as diethyl ether, dimethoxyethane, tetrahydrofuran, and 1,4-dioxane; amides such as N,N-dimethylformamide and N,N-dimethylacetamide; acetonitrile, acetic anhydride, water, and mixtures thereof. Mixtures of halogenated hydrocarbons and fluorinated alcohols are particularly suitable.

[0205] The oxidizing agents used when oxidizing the precursor can be arbitrarily listed. Commonly used oxidizing reagents in this field include: peracetic acid (PAA), hydrogen peroxide, m-chloroperoxybenzoic acid (mCPBA), Selectfluor (registered trademark: 1-(chloromethyl)-4-fluoro-1,4-aza-onium bicyclo[2.2.2]octanebis(tetrafluoroborate)), sodium perborate (NaBO3), potassium persulfate (K2S2O8), sodium periodate (NaIO4), potassium peroxymonosulfate (Oxone) (registered trademark: 2KHSO5·KHSO4·K2SO4, manufactured by DuPont), etc.

[0206] The high-valent iodine compound represented by formula (1) is R. 3 and R 4When atoms do not bond to each other and do not form a ring with the iodine atoms they are bonded to or the atoms between those iodine atoms, such as μ-oxo-bis(acetoxyiodoaryl), they can be obtained by reacting diacetoxyiodoaryl with acetic acid in a solvent-free environment or in any solvent (dimerization). The same process can be used to convert the acetoxy form into a trifluoroacetoxy form. The reaction conditions are the same as described above.

[0207] [Compounds containing carboxyl groups]

[0208] The aforementioned carboxyl-containing compounds are preferably polymers containing repeating units represented by formula (6) or compounds represented by formula (7).

[0209] [Chemistry 62]

[0210]

[0211] In equation (6), 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.

[0212] In equation (7), p is 1, 2, 3 or 4.

[0213] In equation (7), 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.

[0214] In equation (7), R 32 It is a single bond or a hydrocarbon group with 1 to 20 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.

[0215] 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.

[0216] The aforementioned alkanes with 1 to 40 carbon atoms include: methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, and their structural isomers.

[0217] The aforementioned alkenes with 2 to 40 carbon atoms include: ethylene, propylene, butene, pentene, hexene, hepten, octene, nonene, decene, and their structural isomers.

[0218] The aforementioned alkynes with 2 to 40 carbon atoms can be listed as follows: acetylene, propyne, butyne, pentyne, hexyne, heptyne, octyne, nonyne, decyne, and their structural isomers.

[0219] Examples of cyclic saturated hydrocarbons with 3 to 40 carbon atoms include: cyclopropane, cyclobutane, cyclohexane, cycloheptane, cyclooctane, adamantane, norcamphene, etc.

[0220] Examples of cyclic unsaturated hydrocarbons with 3 to 40 carbon atoms include: cyclopropylene, cyclobutene, cyclopentene, cyclohexene, cycloheptene, cyclooctene, and norcamphene.

[0221] Aromatic hydrocarbons with 6 to 40 carbon atoms mentioned above include: benzene, naphthalene, biphenyl, etc.

[0222] 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.

[0223] In the aforementioned p-valent hydrocarbon groups or p-valent heterocyclic groups, some or all of the hydrogen atoms can be replaced by groups containing heteroatoms such as oxygen, sulfur, nitrogen, and halogen atoms, resulting in the presence of hydroxyl, cyano, fluorine, chlorine, bromine, and iodine atoms. Furthermore, in the aforementioned p-valent hydrocarbon groups, a portion of the -CH2- group can be replaced by groups containing heteroatoms such as oxygen, sulfur, and nitrogen atoms, resulting in the presence of carbonyl groups, ether bonds, thioether bonds, ester bonds, sulfonate bonds, carbonate bonds, carbamate bonds, lactone rings, sulfonyl lactone rings, and carboxylic anhydrides (-C(=O)-OC(=O)-), etc.

[0224] R 32The 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.

[0225] Among the carboxylic acid compounds represented by formula (7), it is preferable that the p-value 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 a high molecular weight, which is ideal considering etching resistance and developer resistance.

[0226] Specific examples of the repeating unit containing a carboxyl group represented by equation (6) are shown below, but are not limited thereto. Additionally, in the following equation, R... A Same as above.

[0227] [Chemistry 63]

[0228]

[0229] [Chemistry 64]

[0230]

[0231] The carboxylic acid compounds represented by formula (7) can be listed below, but are not limited to. The carboxylic acid compounds can be commercially available or synthesized.

[0232] [Chemistry 65]

[0233]

[0234] [Chemistry 66]

[0235]

[0236] [Chemistry 67]

[0237]

[0238] [Chemistry 68]

[0239]

[0240] [Chemistry 69]

[0241]

[0242] [Chemistry 70]

[0243]

[0244] Polymers containing carboxyl groups and repeating units represented by formula (6) 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 a ring structure that can be expected to have high etch resistance due to a rigid backbone, or repeating units containing a styrene backbone.

[0245] 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.

[0246] [Chemistry 71]

[0247]

[0248] [Chemistry 72]

[0249]

[0250] [Chemistry 73]

[0251]

[0252] [Chemistry 74]

[0253]

[0254] [Chemistry 75]

[0255]

[0256] [Chemistry 76]

[0257]

[0258] [Chemistry 77]

[0259]

[0260] [Chemistry 78]

[0261]

[0262] [Chemistry 79]

[0263]

[0264] [Chemistry 80]

[0265]

[0266] [Chemistry 81]

[0267]

[0268] [Chemistry 82]

[0269]

[0270] [Chemistry 83]

[0271]

[0272] [Chemistry 84]

[0273]

[0274] [Chemistry 85]

[0275]

[0276] [Chemistry 86]

[0277]

[0278] [Chemistry 87]

[0279]

[0280] [Chemistry 88]

[0281]

[0282] [Chemistry 89]

[0283]

[0284] [Chemistry 90]

[0285]

[0286] [Chemistry 91]

[0287]

[0288] [Chemistry 92]

[0289]

[0290] [Chemistry 93]

[0291]

[0292] [Chemistry 94]

[0293]

[0294] [Chem. 95]

[0295]

[0296] [Chemistry 96]

[0297]

[0298] [Chemistry 97]

[0299]

[0300] [Chem. 98]

[0301]

[0302] [Chemistry 99]

[0303]

[0304] [Chemistry 100]

[0305]

[0306] In the resist composition of the present invention, the molar ratio of the high-valent iodine compound to the carboxyl-containing compound (a polymer containing repeating units represented by formula (6) and / or a compound represented by formula (7)) is preferably 10:90 to 90:10, more preferably 20:80 to 80:20, and even more preferably 30:70 to 70:30. The high-valent iodine compound can be used alone or in combination with two or more. The carboxyl-containing polymer can be used alone or in combination with two or more polymers with 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 of two or more. The aforementioned carboxyl-containing polymers and the aforementioned monomolecular compounds may be used individually or in combination.

[0307] 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.

[0308] 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, Mw and number-average molecular weight Mn are converted values ​​of standard polystyrene obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0309] Furthermore, among the aforementioned carboxyl-containing polymers, when the molecular weight distribution (Mw / Mn) is broad, there may be both low-molecular-weight and high-molecular-weight polymers. Therefore, there are concerns about foreign matter being observed on the pattern after exposure and deterioration of the pattern shape. As the pattern becomes more regular and refined, the influence of Mw and Mw / Mn tends to increase. Thus, in order to obtain a resist composition that can be ideally used for fine pattern sizes, the aforementioned carboxyl-containing polymers should preferably have a narrow dispersion of Mw / Mn of 1.0 to 2.0.

[0310] 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.

[0311] 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.

[0312] 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%.

[0313] 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.

[0314] [solvent]

[0315] The resist composition of the present invention contains a solvent. There are no particular limitations on the solvent being capable of dissolving the aforementioned high-valent iodine compounds, carboxyl-containing compounds, and other components described below, and forming a film. 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, etc. Ethers such as glycol monoethyl ether, propylene glycol dimethyl ether, and diethylene glycol dimethyl ether; esters such as propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, ethyl lactate, ethyl pyruvate, butyl acetate, methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, tert-butyl acetate, tert-butyl propionate, and propylene glycol monotert-butyl ether acetate; carboxylic acids such as formic acid, acetic acid, and propionic acid; lactones such as γ-butyrolactone; and their mixed solvents, etc.

[0316] 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.

[0317] [Other ingredients]

[0318] The aforementioned resist composition may also contain a surfactant. The surfactant is preferably a fluorinated and / or polysiloxane surfactant. Examples of such surfactants include those described in paragraph

[0276] of U.S. Patent Application Publication 2008 / 0248425. Alternatively, surfactants other than those described in paragraph

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

[0319] When the aforementioned resist composition contains the aforementioned surfactant, its content in the total solid components should preferably be 0.0001 to 2% by mass. The aforementioned surfactant may be used alone or in combination of two or more.

[0320] The aforementioned resist composition may also contain free radical scavengers. By adding free radical scavengers, the photoresist reaction in optical lithography can be controlled, and the sensitivity can be adjusted.

[0321] The aforementioned free radical scavengers include hindered phenols, quinones, hindered amines, and thiols. Specifically, hindered phenols include butylated hydroxytoluene (BHT) and 2,2'-methylenebis(4-methyl-6-tert-butylphenol). Quinones include 4-methoxyphenol (MEHQ) and hydroquinone. Hindered amines include 2,2,6,6-tetramethylpiperidine and 2,2,6,6-tetramethylpiperidine-N-oxy radical. Thiols include dodecyl mercaptan and hexadecyl mercaptan.

[0322] When the aforementioned corrosion resist composition contains the aforementioned free radical scavenger, its content in the total solid components should preferably be 0.01 to 10% by mass. The aforementioned free radical scavenger can be used alone or in combination of two or more.

[0323] The aforementioned resist composition may also contain a crosslinking agent. By adding a crosslinking agent, the crosslinking reaction in optical lithography can be promoted, the glass transition point of the pattern can be improved, and a pattern with excellent resolution at fine lines can be obtained.

[0324] The aforementioned crosslinking agents can include compounds with carbon-carbon unsaturated bonds as functional groups, such as vinyl, (meth)acrylate, allyl, alkynyl, and aromatic rings. Specifically, compounds with vinyl groups can include: chain alkenes, branched alkenes, cyclic alkenes, etc., which may also have substituents. Compounds with (meth)acrylate groups can include: acrylic acid, methacrylic acid, acrylates, methacrylates, etc., which may also have substituents. Compounds with allyl groups can include: allyl alcohols, allyl ethers, allyl esters, allyl amides, allylamines, isocyanurates containing allyl groups, etc. Compounds with alkynyl groups can include: chain alkynes, branched alkynes, cyclic alkynes, alkynyl alcohols, alkynyl ethers, alkynyl esters, alkynyl amides, alkynylamines, isocyanurates containing alkynyl groups, etc. Compounds with aromatic rings can include: aromatic hydrocarbons, heteroaromatic hydrocarbons, styrene, stilbene, phenylacetylene, acenaphthene, chalcone, etc., which may also have substituents. The crosslinking agent may have only one or more of the above-mentioned functional groups. The number of the above-mentioned functional groups contained in the crosslinking agent is preferably 1 or more and 10 or less, and more than 2 or 8 or less.

[0325] When the aforementioned resist composition contains the aforementioned crosslinking agent, its content in the total solid components should preferably be 0.01 to 50% by mass. The aforementioned crosslinking agent can be used alone or in combination of two or more.

[0326] When the aforementioned resist composition contains the aforementioned crosslinking agent, it may also contain a photopolymerization initiator. The photopolymerization initiator can generate free radicals by irradiation with high-energy rays and promote the crosslinking of the aforementioned crosslinking agent.

[0327] Specific examples of the aforementioned photopolymerization initiators include: benzophenone, methyl O-benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone, and other benzophenone derivatives; 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylphenylacetone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxycyclohexylphenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinylpropane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)-benzyl]-phenyl}-2-methylpropane-1-one, methyl phenylglyoxylate, and other acetophenone derivatives; thioxanthone, 2-methylthiophene... Thioxanone derivatives such as 2-isopropylthioxanone, 4-isopropylthioxanone, 2-chlorothioxanone, and diethylthioxanone; benzoyl derivatives such as benzoyl, benzoyl dimethyl ketal, and benzoyl-β-methoxyethyl acetal; benzoylin derivatives such as benzoylinium, benzoylinium methyl ether, and 2-hydroxy-2-methyl-1-phenylpropane-1-one; 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, and 1,3-diphenylpropane... Oxime compounds such as trione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, 1,2-octanedione-1-[4-(phenylthio)-2-(O-benzoyl oxime)], acetone-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl]-1-(O-acetyl oxime); α-hydroxy-2-methyl-1-phenylpropane-1-one, 1-[4-(2-hydroxyethoxy)phenyl]-2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-1-{4-[4-(2-hydroxy-2-methylpropanoyl)-benzyl]phenyl}-2-methylpropane, etc. Hydroxyketone compounds; α-aminoalkylphenyl ketone compounds such as 2-benzyl-2-dimethylamino-1-(4-morpholinylphenyl)-butanone-1, 2-dimethylamino-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)butane-1-one; phosphine oxide compounds such as bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, and 2,4,6-trimethylbenzoyl diphenylphosphine oxide; and titanoceramic compounds such as bis(η5-2,4-cyclopentadien-1-yl)-bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium.

[0328] When the aforementioned photopolymerization initiator is present in the aforementioned photoresist composition, its content in the total solid components should preferably be 0.1–10% by mass, more preferably 0.1–5% by mass, and optimally 0.1–1% by mass. If it is 0.1% by mass or more, sufficient blending effect can be obtained.

[0329] As previously described, the aforementioned resist composition contains high-valent iodine compounds and carboxyl-containing compounds as main components. However, polymers containing acid-instable groups and photoacid generators, as found in conventional chemically amplified resist compositions, are not necessary. Nevertheless, the resist composition of the present invention, especially when exposed to EB or EUV, can still form positive patterns where the exposed portions are soluble in the developer, or negative patterns where the exposed portions are insoluble in the developer. The mechanism is not fully elucidated, but it is speculated, for example, as follows.

[0330] The high-valent iodine compound represented by formula (1) is a compound having oxygen-crosslinked high-valent iodine (III) and a carboxylate group coordinated to the aforementioned high-valent iodine. The high-valent iodine compounds represented by formulas (2), (3), (4), or (5) are compounds having tricoordinated high-valent iodine with aryl and carboxylic acid ligands. It is believed that the exchange of carboxylic acid ligands occurs in an equilibrium reaction when such tricoordinated iodine compounds are mixed with carboxyl-containing compounds. At this time, if the original carboxylic acid ligands can be removed by any method, a high-valent iodine compound with new ligands will be generated. For example, if 1-iodonaphthalene diacetate, which is a high-valent iodine compound, is mixed with a carboxyl-containing compound 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.

[0331] 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.

[0332] In the resist film obtained from the resist composition of the present invention, the high-valent iodine compound, as its main component, decomposes under light, thereby changing its polarity and forming a pattern using a development step. The mechanism is not fully elucidated, but it is speculated, for example, as follows.

[0333] 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.

[0334] 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.

[0335] The high-valent iodine compounds represented by formulas (1), (2), (3), (4), or (5) are rigid frameworks with large molecular weights that are almost non-volatile even under vacuum conditions during EB or EUV exposure. When using high-valent iodine compounds with small molecular weights, the compounds that decompose during exposure will volatilize under vacuum, causing significant exposure shrinkage of the resist film, as well as contamination of the exposure machine by the volatile components, or dimensional changes due to shrinkage of the resist pattern. Therefore, the aforementioned problems are solved by using the high-valent iodine compounds used in this invention. Furthermore, by using high-valent iodine compounds with large molecular weights and rigid frameworks, the glass transition point of the pattern is improved, pattern distortion is prevented, resolution is improved, and etching resistance is also improved.

[0336] The high-valent iodine compounds represented by formulas (1), (2), (3), (4) or (5) have more than two iodine atoms in one molecule, so they have high EUV absorption. When used as a resist, they improve the randomness of the resist and can form patterns with excellent sensitivity and resolution.

[0337] Based on the foregoing, it can be inferred that the resist composition of the present invention is a non-chemically amplified resist composition. Since the resist composition of the present invention does not necessarily contain acid-instable polymers or photoacid generators as in known chemically amplified resist compositions, adverse effects caused by acid diffusion (e.g., image blurring) do not occur, and fine patterns can be distinguished.

[0338] The resist composition of this invention is particularly effective in EUV lithography. This is due to iodine atoms, which have a high absorption capacity for EUV light. That is, it reduces shot noise and achieves higher resolution and lower LWR.

[0339] Regarding EUV resist compositions capable of forming fine patterns, there are 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 residues after etching 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 it also has no problems with solvent solubility. Furthermore, the resist composition of the present invention is applicable in both positive and negative modes, thus its applications are wide-ranging. For example, in the contact hole formation step, metal resists implemented with negative development require a reversal process after the pillar pattern is formed, but positive resists do not require such a step. Therefore, considering the viewpoint of ease of processing, the resist composition of the present invention can also be considered more useful than metal resists.

[0340] 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, regarding the characteristics of the resist compositions described in these patent documents, there is only a description of improving line edge roughness, but no mention is made 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. Therefore, it is not conceivable from these patent documents that the resist composition can reduce shot noise in EUV lithography as in this invention, and that it is a material capable of forming fine patterns. In other words, this invention provides a clearly novel resist composition and a method for pattern formation.

[0341] [Layered Body]

[0342] This invention provides a laminate characterized by 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 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.

[0343] At this time, a lower resist film may also be provided between the aforementioned substrate and the aforementioned resist film as needed.

[0344] 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.

[0345] 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.

[0346] [Pattern Formation Method]

[0347] When the resist composition of the present invention is used in the manufacture of various integrated circuits, known photolithography techniques can be employed. For example, a patterning method may include the following steps:

[0348] A resist film is formed on a substrate or on a substrate having a resist underlayer layer laminated with the aforementioned resist composition.

[0349] The aforementioned resist film was exposed to high-energy rays, and

[0350] The previously exposed resist film was developed using a developer. Hereinafter, the underlying resist film will also be referred to as the "underlying film".

[0351] 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.

[0352] Then, the aforementioned photoresist 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 radiation, EB, EUV, X-rays, soft X-rays, excimer lasers (KrF excimer lasers, ArF excimer lasers, etc.), gamma rays, and synchrotron radiation. I-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet radiation are preferred for high-energy radiation. When using ultraviolet rays, far ultraviolet rays, EUV, X-rays, soft X-rays, excimer lasers, gamma rays, or synchrotron radiation, the exposure dose should be approximately 1–300 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. 2 Irradiation is performed in a manner that allows for direct exposure or by using a mask to form the desired pattern. When using EB (Extracorporeal Electrode) for high-energy radiation, the exposure should be approximately 0.1–8000 μC / cm². 2 And preferably, it is about 0.5 to 5000 μC / cm. 2 The resist composition of the present invention is particularly suitable for fine patterning under high-energy radiation, such as EB or EUV.

[0353] 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 30–200°C for 10 to 30 minutes, or more preferably at 60–180°C for 30 to 20 minutes.

[0354] After exposure or PEB, develop the surface and pattern it using a developer. The developing solutions used at this time can include: alkaline aqueous solutions such as tetramethylammonium hydroxide aqueous solution and tetrabutylammonium hydroxide aqueous solution; 2-octanone, 2-nonanone, 2-heptanone, 3-heptanone, 4-heptanone, 2-hexanone, 3-hexanone, diisobutyl ketone, 5-methyl-2-hexanone, methylcyclohexanone, acetophenone, methyl acetophenone, isopropanol, isoamyl alcohol, n-butanol, tert-butanol, tert-amyl alcohol, n-amyl alcohol, cyclohexanol, formic acid, acetic acid, propionic acid, propyl acetate, butyl acetate, isobutyl acetate, amyl acetate, butyl acetate, isoamyl acetate, butyl acetate, isoamyl acetate, cyclohexyl acetate, 4-tert-butylcyclohexyl acetate, octyl acetate, isoborneol acetate, propyl formate, butyl formate, isobutyl formate, amyl formate, methyl valerate, methyl valerate, methyl crotonate, ethyl crotonate, methyl propionate, propionic acid Organic solvents including ethyl acetate, ethyl 3-ethoxypropionate, methyl lactate, ethyl lactate, propyl lactate, butyl lactate, isobutyl lactate, pentyl 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, 3-methyl-1-butanol, diacetone alcohol, 4-methyl-2-pentanol, 3-methylcyclohexanol, 3,5,5-trimethylhexanol, 2,6-dimethyl-4-heptanol, toluene, anisole, ε-caprolactone, etc. These developers can be used alone or in combination of two or more.

[0355] After development, rinsing should be performed as needed. The rinsing solution should be a solvent that is miscible with the developer and does not dissolve the resist film. Ideal solvents to use 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.

[0356] 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.

[0357] 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.

[0358] [Example]

[0359] The present invention will be specifically described below with examples of synthesis, embodiments and comparative examples, but the present invention is not limited to the following embodiments.

[0360] [1] Synthesis of high-valent iodine compounds

[0361] [Synthetic Example 1-1] Synthesis of high-valent iodine compound I-1

[0362] 2,2-Diiodobiphenyl (3.0 g, 7.38 mmol) was dispersed in acetic acid (74 mL) and acetonitrile (236 mL), and 5 equivalents of Selectfluor (13.02 g, 36.8 mmol) were added. The mixture was stirred at room temperature for 24 hours. After the reaction was complete, the solvent was removed under reduced pressure, and 100 mL of water and 150 mL of dichloromethane were added for extraction. The organic layer was washed three times with 50 mL of water, and the solvent was distilled off under reduced pressure. 100 mL of n-hexane was added, and the mixture was stirred at room temperature for 30 minutes. The solid was then separated by filtration. The obtained solid was dried at 40 °C to obtain I-1 as white crystals (3.46 g, 90% yield).

[0363] [Chemistry 101]

[0364]

[0365] The nuclear magnetic resonance spectrum is as follows

[0366] 1 H NMR (500MHz, CDCl3): δ = 1.87 (s, 6H), 7.61 (m, 4H), 7.78 (dd, J = 1.0, 5.9Hz, 2H), 8.20 (dd, J = 1.0, 5.8Hz, 2H).

[0367] [Synthetic Examples 1-2] Synthesis of high-valent iodine compound I-2

[0368] [Chemistry 102]

[0369]

[0370] I-2 was synthesized using the same method as I-1. (Yield 92%)

[0371] The nuclear magnetic resonance spectrum is as follows

[0372] 1 H NMR (500MHz, CDCl3): δ = 2.04 (s, 6H), 7.52 (dd, J = 7.1, 8.1Hz, 2H), 8.04 (dd, J = 1.4, 7.1Hz, 2H), 8.46 (dd, J = 1.4, 8.1Hz, 2H).

[0373] [Synthetic Examples 1-3] Synthesis of high-valent iodine compound I-3

[0374] [Chemistry 103]

[0375]

[0376] I-3 was synthesized using the same method as I-1. (Yield 78%)

[0377] The nuclear magnetic resonance spectrum is as follows

[0378] 1 H NMR (500MHz, CDCl3): δ=2.08 (s, 6H), 7.62 (dd, J=6.1, 3.4Hz, 2H), 8.02 (dd, J=6.1, 3.4Hz, 2H).

[0379] [Synthetic Examples 1-4] Synthesis of high-valent iodine compound I-4

[0380] [Chemistry 104]

[0381]

[0382] I-4 was synthesized using the same method as I-1. (Yield 90%)

[0383] The nuclear magnetic resonance spectrum is as follows

[0384] 1 H NMR (500MHz, CDCl3): δ = 1.85 (s, 6H), 2.30-2.49 (m, 4H), 3.13-3.16 (m, 4H), 7.41 (t, J = 7.8Hz, 2H), 7.54 (d, J = 7.5Hz, 2H), 7.99 (d, J = 7.8Hz, 2H).

[0385] [2] Synthesis of carboxyl-containing polymers

[0386] The monomers a-1 to a-3, b-1 to b-3, and c-1 to c-3 used in the synthesis of carboxyl-containing polymers are described below.

[0387] [Chemistry 105]

[0388]

[0389] [Chemistry 106]

[0390]

[0391] [Chemistry 107]

[0392]

[0393] [Synthetic Example 2-1] Synthesis of Polymer P-1

[0394] Under nitrogen atmosphere, monomer a-1 (56g), monomer b-1 (36g), V-601 (manufactured by Fujifilm and Koei Tecmo Chemicals), 5.4g, and MEK (180g) were measured in a flask to prepare a monomer-polymerization initiator solution. In another flask 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 washed twice with hexane (1200g) and then vacuum dried at 50°C for 20 hours to obtain a white powder polymer P-1 (yield 90g, 98% yield). The Mw of polymer P-1 was 8000, and the Mw / Mn ratio was 1.42. Additionally, Mw is the converted value of standard polystyrene obtained by GPC using THF as a solvent.

[0395] [Chemistry 108]

[0396]

[0397] [Synthetic Examples 2-2 to 2-13] Synthesis of Polymers P-2 to P-13

[0398] By changing the types and blending ratios of the monomers, the polymers shown in Table 1 below were synthesized using the same method as in Synthesis Example 2-1.

[0399] [Table 1]

[0400]

[0401]

[0402] [3] Preparation of the resist composition

[0403] [Examples 1-1 to 1-22, Comparative Examples 1-1 to 1-4]

[0404] 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 solution was filtered through a 0.2 μm Teflon (registered trademark) filter to obtain photoresist compositions (R-01 to R-22, 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 solution was filtered through a 0.2 μm Teflon (registered trademark) filter to obtain photoresist compositions (CR-03 to CR-04).

[0405] [Table 2]

[0406]

[0407]

[0408] [Table 3]

[0409]

[0410] In Tables 2 and 3, the high-valent iodine compound I-5, carboxyl-containing compounds m-1 to m-6, photoacid generator PAG-1, sensitivity modifier Q-1, and solvent are described below.

[0411] [Chemistry 109]

[0412]

[0413] [Chemical 110]

[0414]

[0415] [Chemistry 111]

[0416]

[0417] [Chemistry 112]

[0418]

[0419] Solvent: PGMEA (Propylene Glycol Monomethyl Ether Acetate)

[0420] AcOH (acetic acid)

[0421] GBL (γ-butyrolactone)

[0422] [4] Evaluation of EUV lithography (line and spacing patterns)

[0423] [Examples 2-1 to 2-22, Comparative Examples 2-1 to 2-4]

[0424] Each resist component (R-01 to R-22, CR-01 to CR-04) was spin-coated onto a Si substrate containing a silicon-containing spin-coated hard mask SHB-A940 (43% by mass) manufactured by Shin-Etsu Chemical Co., Ltd., with 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 for 60 seconds using a heated plate. The aforementioned resist film was then exposed to a 36 nm line-to-spacing (LS) 1:1 pattern 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 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.

[0425] The obtained resist pattern was evaluated as follows. The results are shown in Table 4.

[0426] [Sensitivity Evaluation]

[0427] The aforementioned LS pattern was observed using a Hitachi Advanced Technology Co., Ltd. (GAD) CG-6300 measuring SEM, 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.

[0428] [LWR Evaluation]

[0429] The dimensions of 10 points on an LS pattern obtained by exposure to the optimal amount of light along the length direction of the pitch width were measured using a Hitachi Advanced Technology Co., Ltd. The LWR was defined as three times the standard deviation (σ) obtained from the results (3σ). The smaller this value, the more uniform and less rough the pitch width pattern can be obtained.

[0430] [Limited Resolution Evaluation]

[0431] Using a Hitachi Advanced Technologies (AG) CG-6300 long-range SEM, the linewidth (nm) that can be resolved by gradually increasing the exposure amount to form the aforementioned LS pattern from the optimal exposure amount is determined, and this is set as the limiting resolution (nm). The smaller this value, the better the limiting resolution, and the finer the pattern can be formed.

[0432] [Table 4]

[0433]

[0434]

[0435] Developer: nBA (Butyl acetate)

[0436] TMAH (2.38% by mass tetramethylammonium hydroxide aqueous solution)

[0437] As shown in Table 4, depending on the developer used, both positive and negative patterns can be formed. Furthermore, comparing the resist compositions of Comparative Examples 2-1 and 2-2 with the resist composition of the present invention, it is evident that the present invention exhibits excellent resolution and LWR. Comparing it with Comparative Examples 2-3 and 2-4, which are chemically amplified resist compositions using an acid catalyst reaction, it is also evident that the present invention exhibits excellent sensitivity, resolution, and LWR. Therefore, it can be concluded that the resist composition of the present invention provides excellent resolution when forming LS patterns obtained through EUV exposure.

[0438] [5] Evaluation of EUV lithography (contact hole pattern)

[0439] [Examples 3-1 to 3-22, Comparative Examples 3-1 to 3-4]

[0440] Each resist composition (R-01 to R-22, 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 PAB process was then performed for 60 seconds at the temperatures listed in Table 5 using a heated plate to obtain a resist film with a thickness of 50 nm. The resist film was then 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 process was performed for 60 seconds at the temperatures listed in Table 5 using a heated plate, followed by 30 seconds of development using the developer listed in Table 5 to obtain an aperture pattern with a size of 32 nm.

[0441] The obtained resist patterns were evaluated as follows. The results are shown in Table 5.

[0442] [Sensitivity Evaluation]

[0443] The aforementioned contact hole pattern was observed using a Hitachi Advanced Technology Co., Ltd. (HIT) CG-6300 SEM, and the optimal exposure value Eop (mJ / cm²) for obtaining a hole pattern with a size of 22nm was determined. 2 And make it a sensitivity.

[0444] [CDU Evaluation]

[0445] 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 of the pattern can be obtained.

[0446] [Limited Resolution Evaluation]

[0447] Using a Hitachi Advanced Technologies (AGT) CG-6300 long-range SEM, the limiting aperture diameter (nm) was determined by gradually decreasing the exposure amount to form the aforementioned aperture pattern from the optimal exposure amount. This value was then defined as the limiting resolution (nm). The smaller this value, the better the limiting resolution, and the more fine the aperture pattern can be formed.

[0448] [Table 5]

[0449]

[0450]

[0451] As shown in Table 5, depending on the developer used, both positive and negative patterns can be formed. Furthermore, comparing the resist compositions of Comparative Evaluation Examples 3-1 and 3-2 with the resist composition of the present invention, it is evident that the present invention exhibits excellent resolution and CDU. Comparing it with Comparative Evaluation Examples 3-3 and 3-4, which utilize a chemically amplified resist using an acid catalyst reaction, it is also evident that the present invention exhibits excellent sensitivity, resolution, and CDU. Therefore, it can be concluded that the resist composition of the present invention provides excellent resolution when forming contact hole patterns obtained through EUV exposure.

[0452] This specification contains the following specifications.

[0453] [1]: An anti-corrosion composition characterized by containing: a high-valent iodine compound represented by formula (1), a carboxyl-containing compound, and a solvent.

[0454] [Chemistry 113]

[0455]

[0456] In the formula, R 1 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 carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 3 R 4 Each group is a halogen atom, or may contain heteroatoms. Also, R 3 and R 4They can also bond to each other and form rings together with the iodine atoms they are bonded to and the atoms between those iodine atoms.

[0457] [2]: The resist composition of [1], wherein the aforementioned high-valent iodine compound is selected from one or more of the group consisting of high-valent iodine compounds represented by the following formulas (2), (3), (4) and (5).

[0458] [Chemistry 114]

[0459]

[0460] In the formula, m1 is 0, 1, or 2. When m1 is 0, n1 is 0, 1, 2, 3, or 4; when m1 is 1, n1 is 0, 1, 2, 3, 4, 5, or 6; when m1 is 2, n1 is 0, 1, 2, 3, 4, 5, 6, 7, or 8; m2 is 0 or 1. When m2 is 0, n2 is 0, 1, 2, 3, or 4; when m2 is 1, n2 is 0, 1, 2, 3, 4, 5, or 6; m3 is 0 or 1. When m3 is 0, n3 is 0, 1, 2, 3, or 4; when m3 is 1, n3 is 0, 1, 2, 3, 4, 5, or 6. n4 and n5 are 0, 1, 2, 3, 4, 5, or 6; n6 and n7 are 0, 1, 2, or 3. R 11 ~R 18 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 11 and R 12 R 13 and R 14 R 15 and R 16 、or R 17 and R 18 They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms between those carbonyl oxygen groups. R 21 ~R 27 Each R is an independent hydrocarbon group with 1 to 40 carbon atoms, or may contain heteroatoms. When n1 is 2 or more, each R 21 They can be the same or different, and there are multiple Rs. 21 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n2 is 2 or more, each R 22 They can be the same or different, and there are multiple Rs. 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n3 is 2 or more, each R 23 They can be the same or different, and there are multiple Rs. 23 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n4 is 2 or more, each R 24 They can be the same or different, and there are multiple Rs. 24They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n5 is 2 or more, each R 25 They can be the same or different, and there are multiple Rs. 25 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n6 is 2 or more, each R 26 They can be the same or different, and there are multiple Rs. 26 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n7 is 2 or more, each R 27 They can be the same or different, and there are multiple Rs. 27 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. L1 can be unbonded, single bonded, -O-, -S-, -NH-, or -CH2-.

[0461] [3]: such as [1] or [2] of the resist composition, wherein the aforementioned carboxyl-containing compound is any or both of a polymer containing a repeating unit represented by the following formula (6) and a compound represented by the following formula (7).

[0462] [Chemistry 115]

[0463]

[0464] 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 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. 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, some or all of the hydrogen atoms in the aforementioned p-valent hydrocarbon group or p-valent heterocyclic group can be substituted by a group containing a heteroatom, and a portion of the -CH2- group in the aforementioned p-valent hydrocarbon group can also be substituted by a group containing a heteroatom. R 32 It is a single bond or a hydrocarbon group with 1 to 20 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.

[0465] [4]: A laminate characterized by comprising: a substrate, and a resist film of a resist composition such as [1] to [3] located on the substrate.

[0466] [5]: As in [4], a laminated body, wherein a lower resist film is provided between the aforementioned substrate and the aforementioned resist film.

[0467] [6]: such as [4] or [5], wherein the aforementioned resist film contains the ligand exchange reaction product of the aforementioned high-valent iodine compound and the carboxyl-containing compound.

[0468] [7]: A method for forming a pattern, characterized by comprising the following steps:

[0469] 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 [1] to [3].

[0470] The aforementioned resist film was exposed using high-energy rays, and

[0471] The previously exposed resist film was developed using a developer.

[0472] [8]: The pattern forming method as in [7], wherein the aforementioned high-energy rays are i-rays, KrF excimer lasers, ArF excimer lasers, electron beams or extreme ultraviolet rays.

[0473] [9]: The pattern forming method as in [7] or [8], wherein the aforementioned developing solution is used to dissolve the exposed portion but not the unexposed portion.

[0474]

[10] : The pattern forming method, such as [7] or [8], wherein the aforementioned developer is used to dissolve the unexposed portion and not the exposed portion.

[0475] Furthermore, the present invention is not limited to the embodiments described above. The embodiments described above are illustrative examples, and any embodiment having a substantially the same structure and performing the same effect as the technical concept described in the claims of the present invention is intended to be included within the technical scope of the present invention.

Claims

1. A resist composition, characterized in that it contains: a high-valent iodine compound represented by formula (1), a carboxyl-containing compound, and a solvent; In the formula, R 1 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 carbonyl oxygen groups they are bonded to and the atoms between the carbonyl oxygen groups; R 3 R 4 Each is a hydrocarbon group that is independently composed of a halogen atom, or may also contain heteroatoms; furthermore, R 3 and R 4 They can also bond to each other and form rings together with the iodine atoms they are bonded to and the atoms between those iodine atoms.

2. The resist composition according to claim 1, wherein, The high-valent iodine compound is selected from one or more of the group consisting of high-valent iodine compounds represented by formulas (2), (3), (4) and (5); In the formula, m1 is 0, 1, or 2; when m1 is 0, n1 is 0, 1, 2, 3, or 4; when m1 is 1, n1 is 0, 1, 2, 3, 4, 5, or 6; when m1 is 2, n1 is 0, 1, 2, 3, 4, 5, 6, 7, or 8; m2 is 0 or 1; when m2 is 0, n2 is 0, 1, 2, 3, or 4; when m2 is 1, n2 is 0, 1, 2, 3, 4, 5, or 6; m3 is 0 or 1; when m3 is 0, n3 is 0, 1, 2, 3, or 4; when m3 is 1, n3 is 0, 1, 2, 3, 4, 5, or 6; n4 and n5 are 0, 1, 2, 3, 4, 5, or 6; n6 and n7 are 0, 1, 2, or 3; R 11 ~R 18 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 11 and R 12 R 13 and R 14 R 15 and R 16 、or R 17 and R 18 They can also bond to each other and form rings together with the carbonyl oxygen groups they are bonded to and the atoms between the carbonyl oxygen groups; R 21 ~R 27 Each R is an independent hydrocarbon group consisting of halogen atoms, or may contain heteroatoms, with 1 to 40 carbon atoms; when n1 is 2 or more, each R 21 They can be the same or different, and there are multiple Rs. 21 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n2 is 2 or more, each R 22 They can be the same or different, and there are multiple Rs. 22 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n3 is 2 or more, each R 23 They can be the same or different, and there are multiple Rs. 23 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; when n4 is 2 or more, each R 24 They can be the same or different, and there are multiple Rs. 24 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n5 is 2 or more, each R 25 They can be the same or different, and there are multiple Rs. 25 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n6 is 2 or more, each R 26 They can be the same or different, and there are multiple Rs. 26 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to. When n7 is 2 or more, each R 27 They can be the same or different, and there are multiple Rs. 27 They can also bond to each other and form rings together with the carbon atoms of the aromatic rings they are bonded to; L1 is unbonded, single bond, -O-, -S-, -NH- or -CH2-.

3. The resist composition according to claim 1, wherein, The carboxyl-containing compound is any one or both of a polymer containing a repeating unit represented by formula (6) and a compound represented by formula (7). In the formula, R A It is 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; 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 a heteroatom, and part of the -CH2- of the p-valent hydrocarbon group can also be replaced by a group containing a heteroatom; R 32 It is a single bond or a hydrocarbon group with 1 to 20 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. A laminate, characterized in that it comprises: a substrate, and a resist film of a resist composition according to any one of claims 1 to 3 located on the substrate.

5. The laminated body according to claim 4, wherein, A lower resist film is also provided between the substrate and the resist film.

6. The laminate according to claim 4, wherein, The resist film contains the ligand exchange reaction products of the high-valent iodine compound and the carboxyl-containing compound.

7. A method for forming a pattern, characterized by comprising the following steps: A resist film is formed on a substrate or on the resist underlayer film of a substrate having a resist underlayer film laminated using the resist composition according to any one of claims 1 to 3. The resist film was exposed using high-energy rays, and The exposed resist film was developed using a developer.

8. The pattern forming method according to claim 7, wherein, This high-energy radiation uses i-rays, KrF excimer lasers, ArF excimer lasers, electron beams, or extreme ultraviolet light.

9. The pattern forming method according to claim 7, wherein, This developer is used to dissolve the exposed areas but not the unexposed areas.

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 7, wherein, This developer is used to dissolve the unexposed areas but not the exposed areas.

12. 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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