Resin, composition, method for forming a resist pattern, method for forming a circuit pattern, and method for purifying a resin

Abstract

The present invention addresses the problem of providing a novel resin or the like that is particularly useful as a film-forming material for lithography. Said problem can be solved by a resin including a structural unit represented by formula (1) or (1)'. (In the formulae, the variable portions are as defined in the description.)

Description

[Technical Field]

[0001] The present invention relates to a resin, a composition, a method for forming a resist pattern, a method for forming a circuit pattern, and a method for purifying a resin. [Background technology]

[0002] In semiconductor device manufacturing, microfabrication is performed using lithography with photoresist materials. However, in recent years, with the increasing integration and speed of LSIs (large-scale integrated circuits), further miniaturization using pattern rules has become necessary. Furthermore, the light sources used for lithography in resist pattern formation have been shortened in wavelength from KrF excimer lasers (248 nm) to ArF excimer lasers (193 nm), and the introduction of extreme ultraviolet (EUV, 13.5 nm) light is also anticipated (see, for example, Non-Patent Document 1).

[0003] However, conventional lithography using resist materials results in roughness on the pattern surface, making it difficult to control the pattern dimensions and limiting miniaturization. Therefore, various techniques have been employed to produce resist patterns with higher resolution.

[0004] Furthermore, as resist patterns become finer, problems arise such as resolution issues or the resist pattern collapsing after development, making it desirable to thin the resist. However, simply thinning the resist makes it difficult to obtain a sufficient resist pattern thickness for substrate processing. Therefore, a process is needed to create a resist underlayer film between the resist and the semiconductor substrate to be processed, and to give this resist underlayer film the function of a mask during substrate processing (see, for example, Non-Patent Documents 2 and 3).

[0005] Currently, various types of resist underlayers are known for such processes. For example, unlike conventional resist underlayers with fast etching rates, a resist underlayer material for multilayer resist processes has been proposed that realizes a resist underlayer for lithography with a selectivity ratio for dry etching rates close to that of the resist itself. This material contains a resin component having at least one substituent that, when a predetermined energy is applied, detaches its terminal group to produce a sulfonic acid residue, and a solvent (see Patent Document 1). Furthermore, a resist underlayer material containing a polymer having a specific repeating unit has been proposed that realizes a resist underlayer for lithography with a selectivity ratio for dry etching rates smaller than that of the resist itself (see Patent Document 2). In addition, a resist underlayer material containing a polymer obtained by copolymerizing repeating units of acenaphthylenes with repeating units having substituted or unsubstituted hydroxyl groups has been proposed that realizes a resist underlayer for lithography with a selectivity ratio for dry etching rates smaller than that of a semiconductor substrate (see Patent Document 3).

[0006] On the other hand, amorphous carbon underlayers formed by Chemical Vapor Deposition (CVD) using methane, ethane, or acetylene gases as raw materials are well known as materials with high etching resistance in this type of resist underlayer. However, from a process perspective, there is a need for resist underlayer materials that can be formed by wet processes such as spin coating or screen printing.

[0007] Furthermore, the present inventors have proposed a lithography underlayer film-forming composition (see Patent Document 4) containing a compound with a specific structure and an organic solvent, which is a material that has excellent etching resistance, high heat resistance, is soluble in solvents, and can be applied to wet processes.

[0008] Regarding methods for forming the intermediate layer used in the formation of the resist underlayer in a three-layer process, for example, methods for forming silicon nitride films (see Patent Document 5) and methods for CVD formation of silicon nitride films (see Patent Document 6) are known. In addition, materials containing silsesquioxane-based silicon compounds are known as intermediate layer materials for three-layer processes (see Patent Documents 7 and 8). [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2004-177668 [Patent Document 2] Japanese Patent Publication No. 2004-271838 [Patent Document 3] Japanese Patent Publication No. 2005-250434 [Patent Document 4] International Publication No. 2013 / 024779 [Patent Document 5] Japanese Patent Publication No. 2002-334869 [Patent Document 6] International Publication No. 2004 / 066377 [Patent Document 7] Japanese Patent Publication No. 2007-226170 [Patent Document 8] Japanese Patent Publication No. 2007-226204 [Non-patent literature]

[0010] [Non-Patent Document 1] Shinji Okazaki, et al., "Lithography Technology: 40 Years," S&T Publishing Co., Ltd., December 2016, pp. 1-21. [Non-Patent Document 2] Shinji Okazaki, et al., "New Developments in Photoresist Material Development," CMC Publishing Co., Ltd., September 2009, pp. 273-275. [Non-Patent Document 3] Toray Research Center, Inc., Research and Development Division, "Microfabrication Technology Supporting Next-Generation Semiconductors," Toray Research Center, Inc., Research and Development Division, August 2006, pp. 178-180. [Overview of the project] [Problems that the invention aims to solve]

[0011] However, materials used for lithography film formation or optical component formation are required to simultaneously satisfy high levels of solubility in organic solvents, etching resistance, and resist pattern formation properties.

[0012] Therefore, the present invention aims to provide a novel resin and composition particularly useful as a film-forming material for lithography, a method for forming a resist pattern, a method for forming a circuit pattern, and a method for purifying the above resin. [Means for solving the problem]

[0013] As a result of diligent research to solve the above problems, the inventors of the present invention have found that a resin having a specific structure is particularly useful as a film-forming material for lithography, and have completed the present invention.

[0014] In other words, the present invention is as follows: [1] A resin containing a constituent unit represented by the following formula (1) or (1)'. [ka] (In formula (1), A is a single bond, a C1-C4 alkylene which may have substituents, or a heteroatom. R 1 It is a 2n valent group with 1 to 30 carbon atoms, R 2 ~R 5Each is independently a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a thiol group or a hydroxyl group, R 2 at least one of and / or R 3 at least one of is a hydroxyl group and / or a thiol group, m 2 and m 3 are each independently an integer from 0 to 8, m 4 and m 5 are each independently an integer from 0 to 9, n is an integer from 1 to 4, p 2 ~p 5 are each independently an integer from 0 to 2.)

Chemical formula

Chemical formula

[10] The resin according to [1], comprising a block unit including a constituent unit represented by formula (1) or formula (1)', wherein the block unit is represented by the following formula (4) or formula (4)'. [ka] (In formula (4), A, R 1 ~R 5 , m 2 ~m 5 , n, p 2 ~p 5 This is as defined in equation (1) above, L is a divalent group with 1 to 30 carbon atoms, or a single bond. k is a positive integer. [ka] (In formula (4)', R 1’ It is a divalent group with 1 to 30 carbon atoms, A, R 2 ~R 5 , m2 ~m 5 、p 2 ~p 5 is as defined in the above formula (1), L is a divalent group having 1 to 30 carbon atoms or a single bond, k is a positive integer, n 0 is an integer from 1 to 10.)

[11] The resin according to

[10] , wherein the formula (4) is the following formula (5). [Chemical formula] (In formula (5), R 1’ is a divalent group having 1 to 30 carbon atoms, A, R 2 ~R 5 、m 2 ~m 5 、p 2 ~p 5 、L, k are as defined in the above formula (4).)

[12] The resin according to

[10] , wherein the formula (4) is the following formula (5a). [Chemical formula] (In formula (5a), n A 、R 1A ~R 5A 、L, k are respectively synonymous with n, R 1 ~R 5 、L, k in the above formula (4), m 2A 及m 3A are each independently an integer from 0 to 3, m 4A 及m 5A are each independently an integer from 0 to 5.)

[13] The resin according to

[10] , wherein the formula (4) and the formula (4)' are respectively the following formula (5b) and the following formula (5b)'. <00​​ (In formula (5b), R 1A‘ is a divalent group having 1 to 30 carbon atoms, R 2A ~R 5A , L, and k are each synonymous with R 2 ~R 5 , L, and k in the said formula (4), m 2A and m 3A are each independently an integer of 0 to 3, m 4A and m 5A are each independently an integer of 0 to 5.)

Chemical formula

[14] The resin according to any one of

[10] to

[13] , comprising the block unit and one or two types of structural units different from the structural unit represented by the formula (1) or the formula (1)’.

[15] The resin according to any one of

[10] to

[14] , further comprising a structural unit represented by the following formula (U1) and / or a structural unit represented by the following (U2).

Chemical formula

[16] A composition comprising any of the resins described in [1] to

[15] .

[17] The composition according to

[16] , further comprising a solvent.

[18] The composition according to

[16] or

[17] , further comprising an acid generator.

[19] The composition according to any one of

[16] to

[18] , further containing a crosslinking agent.

[20] A composition according to any one of

[16] to

[18] , used for forming lithography films. [twenty one] The composition according to

[20] , used as a composition for forming a resist film. [twenty two] The composition described in

[20] , which is used as a composition for forming an underlying film. [twenty three] A photoresist layer formation step in which a photoresist layer is formed on a substrate using the composition described in

[21] , A developing step involves irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation to perform development, A method for forming a resist pattern, including the method described above. [twenty four] A base layer formation step in which a base layer is formed on a substrate using the composition described in

[22] , A photoresist layer formation step, in which at least one photoresist layer is formed on the lower layer film formed by the lower layer film formation step, A step of irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation and performing development, A method for forming a resist pattern, including the method described above. [twenty five] A base layer formation step in which a base layer is formed on a substrate using the composition described in

[22] , An intermediate layer film formation step is performed to form an intermediate layer film on the lower layer film formed by the lower layer film formation step, A photoresist layer formation step, in which at least one photoresist layer is formed on the intermediate layer formed by the intermediate layer formation step, A resist pattern formation step involves irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation and developing it to form a resist pattern, An intermediate layer pattern formation step is performed by using the resist pattern formed in the resist pattern formation step as a mask to etch the intermediate layer film and form an intermediate layer pattern, A lower layer pattern formation step is performed by using the intermediate layer pattern formed in the intermediate layer pattern formation step as a mask to etch the lower layer to form a lower layer pattern, A substrate pattern formation step involves etching the substrate using the underlying film pattern formed in the underlying film pattern formation step as a mask to form a pattern on the substrate, A method for forming a circuit pattern, including the method described above.

[26] A method for purifying a resin as described in any of [1] to

[15] , A method for purifying a resin, comprising an extraction step of contacting a solution containing the resin and an organic solvent that is not arbitrarily miscible with water with an acidic aqueous solution for extraction. [Effects of the Invention]

[0015] According to the present invention, it is possible to provide a novel resin, composition, resist pattern formation method, circuit pattern formation method, and a method for purifying the above resin, which are particularly useful as film-forming materials for lithography. [Modes for carrying out the invention]

[0016] The following describes embodiments of the present invention (also referred to as "these embodiments"). The following embodiments are illustrative examples for explaining the present invention, and the present invention is not limited to these embodiments.

[0017] [resin] The resin of this embodiment is a resin containing constituent units (repeating units) represented by the following formula (1) or (1)'. The resin of this embodiment has, for example, the following properties (1) to (3). (1) The resin of this embodiment has excellent solubility in organic solvents (especially safe solvents). For this reason, for example, if the resin of this embodiment is used as a lithography film-forming material, lithography films can be formed by wet processes such as spin coating or screen printing. (2) The resin of this embodiment has a relatively high carbon concentration and a relatively low oxygen concentration. Furthermore, because the resin of this embodiment has phenolic hydroxyl groups and / or phenolic thiol groups in its molecule, it is useful for forming cured products by reaction with a curing agent, but it can also form cured products on its own through crosslinking reactions of the phenolic hydroxyl groups and / or phenolic thiol groups during high-temperature baking. As a result, the resin of this embodiment can exhibit high heat resistance, and when the resin of this embodiment is used as a lithography film-forming material, film degradation during high-temperature baking is suppressed, and a lithography film with excellent etching resistance to oxygen plasma etching and the like can be formed. (3) As described above, the resin of this embodiment exhibits high heat resistance and etching resistance, as well as excellent adhesion to the resist layer and the resist intermediate layer material. Therefore, when the resin of this embodiment is used as a lithography film-forming material, a lithography film with excellent resist pattern formation properties can be formed. Herein, "resist pattern formation properties" refers to the property of having no major defects in the resist pattern shape and having excellent resolution and sensitivity. [ka]

[0018] [ka]

[0019] In the above formula (1) or (1)', A is a single bond, an alkylene having 1 to 4 carbon atoms which may have substituents, or a heteroatom, and R 1 It is a 2n valent group with 1 to 30 carbon atoms, and R 1’ R 1 The 2n-valent base of R is one in which n is 1. 2 ~R 5 Each of these is independently a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a thiol group, or a hydroxyl group, and R 2 at least one of and / or R 3 At least one of them is a hydroxyl group and / or a thiol group, 2 and m 3 Each of these is an integer from 0 to 8, and m 4 and m 5 Each of the integers is independently between 0 and 9, n is an integer between 1 and 4, and p 2 ~p 5 Each of these is an independent integer between 0 and 2, and n 0 This is an integer between 1 and 10.

[0020] In formula (1) or (1)', A is a single bond, a C1-C4 alkylene which may have substituents, or a heteroatom, where a heteroatom is an atom other than a carbon atom and a hydrogen atom that can form a divalent group, such as a sulfur atom or an oxygen atom. From the viewpoint of etching resistance, A is preferably a single bond or a heteroatom, and more preferably a single bond.

[0021] In formula (1), R 1 This is a 2n valent group with 1 to 30 carbon atoms, and this R 1 Each aromatic ring is bonded via this link. Specific examples of 2n-valent groups will be discussed later.

[0022] In equation (1) or (1)', R 2 ~R 5 Each of these is independently a monovalent group selected from the group consisting of linear alkyl groups having 1 to 10 carbon atoms, branched alkyl groups having 3 to 10 carbon atoms, cyclic alkyl groups having 3 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, alkenyl groups having 2 to 10 carbon atoms, thiol groups, and hydroxyl groups. Examples of the alkyl groups include linear or branched alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, tert-butyl, pentyl, and hexyl groups, and cyclic alkyl groups such as cyclopentyl and cyclohexyl groups. Examples of the aryl groups include phenyl, naphthyl, tolyl, and xylyl groups. Examples of the alkenyl groups include ethenyl, propenyl, butenyl, pentenyl, and hexenyl groups. However, R 2 at least one of and / or R 3 At least one of them is a hydroxyl group and / or a thiol group.

[0023] In formula (1) or (1)', m 2 and m 3 Each of these is an integer between 0 and 8, preferably between 0 and 4, and more preferably 1 or 2. 4 and m 5Each of these is an independent integer between 0 and 9, preferably between 0 and 4, and more preferably 1 or 2.

[0024] In equation (1), n ​​is an integer between 1 and 4, preferably between 1 and 2, and more preferably 1.

[0025] In equation (1) or (1)', p 2 ~p 5 Each of these is an integer between 0 and 2, preferably 0 or 1, and more preferably 0.

[0026] In formula (1)', n 0 is an integer between 1 and 10, preferably between 1 and 5, and more preferably between 1 and 4.

[0027] R 1 Examples of the 2n-valent group include, when n=1, a divalent hydrocarbon group having 1 to 30 carbon atoms (e.g., a linear or branched hydrocarbon group such as an alkylene group or a cyclic hydrocarbon group); when n=2, a tetravalent hydrocarbon group having 1 to 30 carbon atoms (e.g., a linear or branched hydrocarbon group such as an alkanetetrayl group or a cyclic hydrocarbon group); when n=3, a hexavalent hydrocarbon group having 2 to 30 carbon atoms (e.g., a linear or branched hydrocarbon group such as an alkanehexyl group or a cyclic hydrocarbon group); and when n=4, an octavalent hydrocarbon group having 3 to 30 carbon atoms (e.g., a linear or branched hydrocarbon group such as an alkaneoctile group or a cyclic hydrocarbon group). Here, the cyclic hydrocarbon group may have a bridged cyclic hydrocarbon group or an aromatic group.

[0028] Furthermore, the above-mentioned 2n-valent group (for example, a 2n-valent hydrocarbon group) may have a double bond or a heteroatom.

[0029] R 1It is preferable that the group is a 2n-valent hydrocarbon group having an aryl group having 6 to 30 carbon atoms (preferably 6 to 14 carbon atoms), which may have substituents. The 2n-valent hydrocarbon group is preferably a methylene group. The aryl group having 6 to 30 carbon atoms (preferably 6 to 14 carbon atoms) is preferably a phenyl group, a biphenyl group, or a naphthyl group.

[0030] Because the repeating units represented by formula (1) or (1)' have hydroxyl groups and / or thiol groups, resins containing the repeating units represented by formula (1) or (1)' have high solubility in organic solvents (especially safe solvents). Furthermore, because the repeating units represented by formula (1) or (1)' have high heat resistance due to the rigidity of their structure, resins containing the repeating units represented by formula (1) or (1)' can be used even under high-temperature baking conditions. In addition, since resins with relatively high carbon concentrations can be obtained, high etching resistance can also be achieved.

[0031] Furthermore, the repeating unit represented by formula (1) or (1)' has a tertiary or quaternary carbon in its molecule, and resins containing the repeating unit represented by formula (1) or (1)' have suppressed crystallization and are suitably used as lithography film-forming materials.

[0032] The repeating unit represented by the above formula (1) or (1)' is, from the viewpoint of ease of crosslinking reaction and solubility in organic solvents, R 2 at least one of and / or R 3 Preferably, at least one of them is a hydroxyl group and / or a thiol group.

[0033] The resin containing the repeating unit represented by formula (1) or (1)' above preferably further contains repeating units different from those represented by formula (1) or (1)' above in order to balance the properties required for lithography resins. Preferably, there are one or two types of repeating units different from those represented by formula (1) or (1)' above.

[0034] The properties required for the lithography resins mentioned above include solubility in organic solvents, solubility in developing and stripping solutions, change in solubility before and after exposure, film-forming ability, etching resistance, and planarization ability.

[0035] Repeating units other than those represented by formula (1) or (1)' above are not limited to those represented by formulas (U1) and (U2) below.

[0036] [ka] [ka]

[0037] In the above formulas (U1) and (U2), Ar U1 ~Ar U4 R represents a phenyl ring or a naphthalene ring (preferably a phenyl ring), U1 ~R U4 This represents a hydrogen atom, or a C1-C10 alkyl group which may contain a branched or cyclic structure, an unsaturated bond, or a heteroatom (for example, a hydrogen atom, a linear alkyl group having 1-10 carbon atoms, a branched alkyl group having 3-10 carbon atoms, a cyclic alkyl group having 3-10 carbon atoms, an alkenyl group having 2-10 carbon atoms, or an alkoxy group having 1-10 carbon atoms, preferably a hydrogen atom).

[0038] The molar ratio of the repeating unit represented by formula (1) or (1)' to the repeating unit represented by formula (U1) may be, for example, 1:1.5 to 3.5, 1:2.0 to 3.0, etc. The molar ratio of the repeating unit represented by formula (1) or (1)' to the repeating unit represented by formula (U2) may be, for example, 1:0.5 to 2.0, 1:0.5 to 1.5, etc.

[0039] Specific examples of the above formula (U1) include, but are not limited to, the following:

[0040] [ka] [ka]

[0041] Specific examples of the above formula (U2) include, but are not limited to, the following:

[0042] [ka]

[0043] From the viewpoint of ease of crosslinking and solubility in organic solvents, formula (2) is preferable to formula (1).

[0044] [ka]

[0045] In formula (2) above, R1' is a divalent group having 1 to 30 carbon atoms, specifically, the R in formula (1) above. 1 Examples of explanations given include the following: A, R 2 ~R 5 , m 2 , m 3 , m 4 , m 5 , p 2 ~p 5 This is as explained in equation (1) above.

[0046] From the viewpoint of raw material supply, the above formula (1) may also preferably be the following formula (2a) or (2b). [ka]

[0047] In the above formula (2a), n A , R1A ~R 5A n and R in equation (1) above are respectively. 1 ~R 5 It is synonymous with m 2A and m 3A Each of these is an independent integer between 0 and 3. 4A and m 5A Each of these is an independent integer between 0 and 5.

[0048] [ka]

[0049] In the above equation (2b), R 1A‘ R is a divalent group having 1 to 30 carbon atoms, specifically, R in formula (1) above. 1 This is an example of what was explained as follows: R 2A ~R 5A These are the R values ​​in equation (1) above. 2 ~R 5 It is synonymous with m 2A and m 3A Each of these is an independent integer between 0 and 3. 4A and m 5A Each of these is an independent integer between 0 and 5.

[0050] Furthermore, while not limited to specific examples, the following are examples of compounds that constitute the repeating unit represented by formula (2a) or (2b).

[0051] [ka] [ka] [ka] [ka] [ka]

[0052] From the viewpoint of raw material supply, it is preferable that formula (1)' be represented by the following formulas (2b)', (3a)', and (3b)'.

[0053] [ka] [In formula (2b)', R 1A‘ R is a divalent group having 1 to 30 carbon atoms, specifically, R in formula (1) above. 1 This is an example of what was explained as follows: R 2A ~R 5A These are the R values ​​in equation (1) above. 2 ~R 5 It is synonymous with m 2A and m 3A Each of these is an independent integer between 0 and 3. 4A and m 5A Each of these is an independent integer between 0 and 5. 0 This is as explained in equation (1)'.

[0054] [ka] [ka] [In formula (3a)' or (3b)', n 0 This is as explained in equation (1)'.

[0055] Specific examples of the above formula (3a)' or (3b)' include, but are not limited to, the following: (n 0 The definition is as explained in equation (1)').

[0056] [ka] [ka] [ka] [ka] [ka] [ka]

[0057] The resin of this embodiment preferably includes block units that include constituent units represented by formulas (1), (1)', etc. From the viewpoint of raw material supplyability, the block units are preferably represented by the following formulas (4), (4)', (5), (5a), (5b), or (5b)'. [ka] In formula (4), A, R 1 ~R 5 , m 2 ~m 5 , n, p 2 ~p 5 This is as explained in formula (1) above. L is a divalent group or single bond having 1 to 30 carbon atoms. k is a positive integer. L is preferably a 2n-valent hydrocarbon group having an aryl group with 6 to 30 carbon atoms (preferably 6 to 14 carbon atoms), which may have substituents. The 2n-valent hydrocarbon group is preferably a methylene group. The aryl group with 6 to 30 carbon atoms (preferably 6 to 14 carbon atoms) is preferably a phenyl group, a biphenyl group, or a naphthyl group. k is preferably an integer between 1 and 30, more preferably an integer between 2 and 30, and even more preferably an integer between 2 and 20.

[0058] [ka] [In formula (4)', R 1’ R is a divalent group having 1 to 30 carbon atoms, specifically, R in formula (1) above. 1 Examples of explanations include: A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 n is defined as in equation (1) above. L and k are as explained in equation (4). 0 This is as explained in equation (1)'.

[0059] [ka] [In formula (5), R 1’ R is a divalent group having 1 to 30 carbon atoms, specifically, R in formula (1) above. 1 Examples of explanations include: A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 L and k are as defined in equation (4) above.

[0060] [ka] [In formula (5a), n A , R 1A ~R 5A , L, and k are n and R in equation (4) above, respectively. 1 ~R 5 , is synonymous with L and k. 2A and m 3A Each of these is an independent integer between 0 and 3. 4A and m 5A Each of these is an independent integer between 0 and 5.

[0061] [ka] [In formula (5b), R 1A‘ is a divalent group having 1 to 30 carbon atoms, and specifically, those described as R 1 in the above formula (1) can be mentioned. R 2A ~R 5A , L, and k are each synonymous with R 2 ~R 5 , L, and k in the above formula (4). m 2A and m 3A are each independently an integer of 0 to 3. m 4A and m 5A are each independently an integer of 0 to 5.]

[0062]

Chemical formula

[0063] Preferably, the resin of the present embodiment further includes a repeating unit represented by the above formula (U1) and / or (U2) in addition to the block unit.

[0064] The molar ratio of the block unit to the repeating unit represented by formula (U1) may be, for example, 1:1.5 to 3.5, 1:2.0 to 3.0, etc. The molar ratio of the block unit to the repeating unit represented by the formula (U2) may be, for example, 1:0.5 to 2.0, 1:0.5 to 1.5, etc.

[0065] Examples of the method for synthesizing the compound from which the repeating unit represented by the formula (1) is derived include, for example, the following method. That is, under normal pressure, the compound represented by the following formula (1-x), the compound represented by the following formula (1-y), and the compound represented by the following formula (z1) are subjected to a polycondensation reaction under an acid catalyst or a base catalyst, whereby a compound from which the repeating unit represented by the above formula (1) is derived is obtained. The above reaction may be carried out under pressure if necessary.

[0066]

Chemical formula

[0067] In the above formula (1-x), A, R [[ID=十七]] 2 、R 4 、m 2 、m 4 、p 2 and p 4 are respectively synonymous with A, R 2 、R 4 、m 三十二 2 、m 4 、p 2 and p 4 [[ID=四〇]]In the above formula (1-y), A, R 3 、R <000026�>、m 3 、m 5 、p 3 and p 5 are respectively synonymous with A, R 3 、R 5 、m 3 、m 5 、p 3 and p 5 and the compound represented by the above formula (1-x) and the compound represented by the above formula (1-y) may be the same.

[0068] In the above formulas (z1) and (z2), n is synonymous with n in the above formula (1), and in the above formulas (z1) and (z2), "R1 -CH" section and 'R 1b -CR 1a The parts marked with " in the above equation (1) are R 1 It corresponds to.

[0069] Specific examples of the polycondensation reaction described above include polycondensation of dihydroxyphenyl ethers, dihydroxyphenyl thioethers, dihydroxynaphthyl ethers, dihydroxynaphthyl thioethers, dihydroxyanthrasyl ethers, and dihydroxyanthrasyl thioethers with the corresponding aldehydes or ketones under an acid catalyst or a base catalyst, and optionally in the presence of a reaction solvent, to obtain compounds that are the origin of the repeating units represented by formula (1) above. Here, specific examples of dihydroxyphenyl ethers, dihydroxyphenyl thioethers, dihydroxynaphthyl ethers, dihydroxynaphthyl thioethers, dihydroxyanthrasyl ethers, dihydroxyanthrasyl thioethers, aldehydes, ketones, acid catalysts, base catalysts, and reaction solvents, as well as their amounts used, can be found, for example, in International Publication No. 2020 / 026879 and International Publication No. 2019 / 151400.

[0070] The reaction temperature in the above reaction can be appropriately selected depending on the reactivity of the reactants and is not particularly limited, but is usually in the range of 10 to 200°C.

[0071] To obtain the compound from which the repeating unit represented by formula (1) of this embodiment originates, a higher reaction temperature is preferable, specifically in the range of 60 to 200°C. The reaction method is not particularly limited, but for example, it can be a method of charging the raw materials (reactants) and catalyst all at once, or a method of sequentially adding the raw materials (reactants) dropwise in the presence of the catalyst. After the polycondensation reaction is complete, the isolation of the obtained compound can be carried out according to conventional methods and is not particularly limited. For example, the target compound can be obtained by employing general methods such as raising the temperature of the reaction vessel to 130 to 230°C and removing volatile components at a level of about 1 to 50 mmHg in order to remove unreacted raw materials and catalyst present in the system.

[0072] Preferred reaction conditions include using 1 mole to an excess amount of the compound represented by formula (1-x) and the compound represented by formula (1-y) for every mole of aldehydes or ketones represented by formula (z1) or (z2), and further using 0.001 to 1 mole of an acid catalyst, and reacting at atmospheric pressure at 50 to 150°C for about 20 minutes to 100 hours.

[0073] After the reaction is complete, the target product can be isolated by known methods. For example, the reaction mixture can be concentrated, pure water can be added to precipitate the reaction product, cooled to room temperature, and then filtered to separate it. The resulting solid can be filtered and dried, then separated and purified from by-products by column chromatography. After solvent removal, filtration, and drying, the compound represented by formula (0) below, which is the origin of the repeating unit represented by formula (1) above, can be obtained.

[0074] [ka]

[0075] Specific examples of the resin of this embodiment include, for example, novolac resins obtained by a condensation reaction between the compound represented by formula (0) and aldehydes or ketones, which are compounds with crosslinking reactivity.

[0076] Here, the aldehydes used when converting the compound represented by formula (0) above into a novolac are not particularly limited, and examples include formaldehyde, trioxane, paraformaldehyde, benzaldehyde, acetaldehyde, propylaldehyde, phenylacetaldehyde, phenylpropylaldehyde, hydroxybenzaldehyde, chlorobenzaldehyde, nitrobenzaldehyde, methylbenzaldehyde, ethylbenzaldehyde, butylbenzaldehyde, biphenylaldehyde, naphthaldehyde, anthracenecarbaldehyde, phenanthrenecarbaldehyde, pyrenecarbaldehyde, furfural, and the like. These aldehydes may be used individually or in combination of two or more. Among these, from the viewpoint of exhibiting high heat resistance, one or more selected from the group consisting of benzaldehyde, phenylacetaldehyde, phenylpropylaldehyde, hydroxybenzaldehyde, chlorobenzaldehyde, nitrobenzaldehyde, methylbenzaldehyde, ethylbenzaldehyde, butylbenzaldehyde, cyclohexylbenzaldehyde, biphenylaldehyde, naphthaldehyde, anthracenecarboaldehyde, phenanthrenecarboaldehyde, pyrenecarboaldehyde, and furfural is used. Preferably, and from the viewpoint of improving etching resistance, it is preferable to use one or more selected from the group consisting of benzaldehyde, hydroxybenzaldehyde, chlorobenzaldehyde, nitrobenzaldehyde, methylbenzaldehyde, ethylbenzaldehyde, butylbenzaldehyde, cyclohexylbenzaldehyde, biphenylaldehyde, naphthaldehyde, anthracenecarboaldehyde, phenanthrenecarboaldehyde, pyrenecarboaldehyde, and furfural, and more preferably formaldehyde. The amount of aldehydes used is not particularly limited, but is preferably 0.2 to 5 moles, and more preferably 0.5 to 2 moles, per mole of the compound represented by the above formula (0).

[0077] The ketones used when converting the compound represented by formula (0) above into a novolac are not particularly limited, and include, for example, acetone, methyl ethyl ketone, cyclobutanone, cyclopentanone, cyclohexanone, norbornanone, tricyclohexanone, tricyclodecanone, adamantanone, fluorenone, benzofluorenone, acenaphthenequinone, acenaphthene, anthraquinone, acetophenone, diacetylbenzene, triacetylbenzene, acetonaphthone, diphenylcarbonylnaphthalene, phenylcarbonylbiphenyl, diphenylcarbonylbiphenyl, benzophenone, diphenylcarbonylbenzene, triphenylcarbonylbenzene, benzonaphthone, diphenylcarbonylnaphthalene, phenylcarbonylbiphenyl, and diphenylcarbonylbiphenyl. These ketones may be used individually or in combination of two or more. Among these, from the viewpoint of exhibiting high heat resistance, the compounds represented by the following formula (U1-0), cyclopentanone, cyclohexanone, norbornanone, tricyclohexanone, tricyclodecanone, adamantanone, fluorenone, benzofluorenone, acenaphthenequinone, acenaphthene, anthraquinone, acetophenone, diacetylbenzene, triacetylbenzene, acetonaphthone, diphenylcarbonylnaphthalene, phenylcarbonylbiphenyl, diphenylcarbonylbiphenyl, benzophenone, diphenylcarbonylbenzene, triphenylcarbonylbenzene, benzonaphthone, diphenylcarbonylnaphthalene, phenylcarbonyl It is preferable to use one or more compounds selected from the group consisting of biphenyls and diphenylcarbonylbiphenyls, and from the viewpoint of improving etching resistance, it is more preferable to use one or more compounds selected from the group consisting of compounds represented by the following formula (U1-0), acetophenone, diacetylbenzene, triacetylbenzene, acetonaphthone, diphenylcarbonylnaphthalene, phenylcarbonylbiphenyl, diphenylcarbonylbiphenyl, benzophenone, diphenylcarbonylbenzene, triphenylcarbonylbenzene, benzonaphthone, diphenylcarbonylnaphthalene, phenylcarbonylbiphenyl, and diphenylcarbonylbiphenyl.The amount of ketones used is not particularly limited, but is preferably 0.2 to 5 moles, and more preferably 0.5 to 2 moles, per mole of the compound represented by formula (0) above.

[0078] [ka] In formula (U1-0), Ar U1 Ar U2 , R U1 , R U2 This follows the definition of equation (U1).

[0079] In the condensation reaction between the compound represented by formula (0) above and an aldehyde or ketone, a catalyst may also be used. The acid catalyst or base catalyst used here can be appropriately selected from known ones and is not particularly limited. Such acid catalysts are not particularly limited and include, for example, inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, and hydrofluoric acid; organic acids such as oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, citric acid, fumaric acid, maleic acid, formic acid, p-toluenesulfonic acid, methanesulfonic acid, trifluoroacetic acid, dichloroacetic acid, trichloroacetic acid, trifluoromethanesulfonic acid, benzenesulfonic acid, naphthalenesulfonic acid, and naphthalenedisulfonic acid; Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride; or solid acids such as silitungstic acid, phosphotungstic acid, silimlybdic acid, or phosphomolybdic acid. These catalysts can be used individually or in combination of two or more. Among these, organic acids and solid acids are preferred from a manufacturing standpoint, and hydrochloric acid or sulfuric acid are preferred from a manufacturing standpoint such as ease of availability and handling. The amount of acid catalyst used can be appropriately set according to the raw materials used, the type of catalyst used, and the reaction conditions, and is not particularly limited, but it is preferably 0.01 to 100 parts by mass per 100 parts by mass of reaction raw materials.

[0080] However, in the case of copolymerization reaction with compounds having non-conjugated double bonds such as indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, 5-vinylnorborn-2-ene, α-pinene, β-pinene, limonene, etc., aldehydes or ketones are not necessarily required.

[0081] In the condensation reaction between the compound represented by the above formula (0) and aldehydes or ketones, a reaction solvent can also be used. As the reaction solvent in this polycondensation reaction, it can be appropriately selected from known ones and is not particularly limited. For example, water, methanol, ethanol, propanol, butanol, tetrahydrofuran, dioxane, or a mixed solvent thereof, etc. are exemplified. The solvent can be used alone or in combination of two or more.

[0082] The amount of the solvent used can be appropriately set according to the raw materials used, the type of the catalyst used, and further reaction conditions, etc., and is not particularly limited. However, it is preferably in the range of 0 to 2000 parts by mass with respect to 100 parts by mass of the reaction raw materials. Furthermore, the reaction temperature can be appropriately selected according to the reactivity of the reaction raw materials and is not particularly limited. Usually, it is in the range of 10 to 200 °C. As the reaction method, there are methods of charging the compound represented by the above formula (1), aldehydes and / or ketones, and the catalyst all at once, and methods of sequentially dropping the compound represented by the above formula (0), aldehydes and / or ketones in the presence of the catalyst.

[0083] After the polycondensation reaction is completed, the isolation of the obtained compound can be carried out according to a conventional method and is not particularly limited. For example, in order to remove unreacted raw materials, catalysts, etc. present in the system, the temperature of the reaction kettle is raised to 130 to 230 °C, and general methods such as removing volatile components at about 1 to 50 mmHg are adopted to obtain the target product (for example, a novolak resin).

[0084] Furthermore, the resin of this embodiment is also obtained during the synthesis reaction of the compound represented by formula (0) above. This corresponds to the case where the same aldehyde or ketone used in the synthesis of the compound represented by formula (0) above and the same aldehyde or ketone used when polymerizing the compound represented by formula (0) above are used.

[0085] Here, the resin of this embodiment may be a homopolymer of the compound represented by formula (0) above, or it may be a copolymer with other phenols. The copolymerizable phenols are not particularly limited, and examples include the compound represented by the following formula (U2-0), phenol, cresol, dimethylphenol, trimethylphenol, butylphenol, phenylphenol, diphenylphenol, naphthylphenol, resorcinol, methylresorcinol, catechol, butylcatechol, methoxyphenol, methoxyphenol, propylphenol, pyrogallol, thymol, and the like.

[0086] [ka] In formula (U2-0), Ar U3 Ar U4 , R U3 , R U4 This follows the definition of equation (U2).

[0087] Furthermore, the resin of this embodiment may be copolymerized with polymerizable monomers other than the phenols described above. The copolymerized monomers are not particularly limited and include, for example, naphthol, methylnaphthol, methoxynaphthol, dihydroxynaphthalene, indene, hydroxyindene, benzofuran, hydroxyanthracene, acenaphthylene, biphenyl, bisphenol, trisphenol, dicyclopentadiene, tetrahydroindene, 4-vinylcyclohexene, norbornadiene, vinylnorbornaene, pinene, limonene, and the like. The resin of this embodiment may be a two- or more (e.g., a 2- to 4-component) copolymer of the compound represented by formula (0) and the phenols described above, a two- or more (e.g., a 2- to 4-component) copolymer of the compound represented by formula (0) and the copolymerized monomers described above, or a three- or more (e.g., a 3- to 4-component) copolymer of the compound represented by formula (0), the phenols described above, and the copolymerized monomers described above.

[0088] The weight-average molecular weight (Mw) of the resin in this embodiment is not particularly limited, but is preferably 500 to 30,000 in polystyrene equivalent as measured by GPC, and more preferably 750 to 20,000. Furthermore, from the viewpoint of improving crosslinking efficiency and suppressing volatile components during baking, the resin in this embodiment preferably has a degree of dispersion (weight-average molecular weight Mw / number-average molecular weight Mn) in the range of 1.2 to 7.

[0089] The resin obtained using the compound represented by formula (0) above as a monomer is preferably highly soluble in solvents, from the viewpoint of facilitating the application of wet processes. More specifically, when propylene glycol monomethyl ether (PGME) and / or propylene glycol monomethyl ether acetate (PGMEA) are used as the solvent, it is preferable that the solubility of these compounds and / or resins in the solvent is 10% by mass or more. Here, the solubility in PGME and / or PGMEA is defined as "mass of resin ÷ (mass of resin + mass of solvent) × 100 (mass%)". For example, 10 g of the compound represented by formula (0) and / or the resin obtained using the compound as a monomer is evaluated as soluble in 90 g of PGMEA when the solubility of the compound represented by formula (0) and / or the resin obtained using the compound as a monomer in PGMEA is "10% by mass or more", and it is evaluated as not soluble when the solubility is "less than 10% by mass".

[0090] As an example of the resin of this embodiment, when a compound represented by the following formula (BisP-1), a compound represented by the following formula (U1-1), and a compound represented by the following formula (U2-1) are polymerized, a resin represented by the following formula (A-0a) is obtained. However, the arrangement order of each repeating unit in (A-0a) is arbitrary. [ka]

[0091] [ka]

[0092] [ka]

[0093] [ka]

[0094] Furthermore, for example, when a compound represented by the following formula (PRBiF-1), a compound represented by the above formula (U1-1), and a compound represented by the above formula (U2-1) are polymerized, a resin represented by the following formula (A-0b) is obtained. However, the order of arrangement of each repeating unit in (A-0b) is arbitrary.

[0095] [ka]

[0096] [ka]

[0097] [Composition] The composition of this embodiment contains a resin comprising repeating units represented by the above formulas.

[0098] The composition of this embodiment contains the resin of this embodiment, making it suitable for wet processes and providing excellent heat resistance and planarization properties. Furthermore, because the composition of this embodiment contains resin, film degradation during high-temperature baking is suppressed, and a lithography film with excellent etching resistance to oxygen plasma etching and the like can be formed. Moreover, the composition of this embodiment also exhibits excellent adhesion to the resist layer, enabling the formation of a superior resist pattern. For these reasons, the composition of this embodiment is suitably used for forming lithography films.

[0099] In this embodiment, the lithography film refers to a film that has a higher dry etching rate compared to the photoresist layer. Examples of the lithography film include a film used to fill in and flatten steps in the workpiece layer, a resist upper layer film, a resist lower layer film, and the like.

[0100] The lithography film-forming material of this embodiment may, in addition to the resin of this embodiment, optionally contain organic solvents, crosslinking agents, acid generators, and other components. These optional components will be described below.

[0101] [solvent] The lithography film-forming material in this embodiment may contain a solvent. The solvent is not particularly limited as long as it is capable of dissolving the resin of this embodiment. Here, as described above, the resin of this embodiment has excellent solubility in organic solvents, so various organic solvents are suitably used.

[0102] The solvents are not particularly limited, but examples include ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; cellosolve solvents such as propylene glycol monomethyl ether and propylene glycol monomethyl ether acetate; ester solvents such as ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, isoamyl acetate, ethyl lactate, methyl methoxypropionate, and methyl hydroxyisobutyrate; alcohol solvents such as methanol, ethanol, isopropanol, and 1-ethoxy-2-propanol; and aromatic hydrocarbons such as toluene, xylene, and anisole. These solvents can be used individually or in combination of two or more.

[0103] Among the above solvents, from the viewpoint of safety, it is preferable to use one or more selected from the group consisting of cyclohexanone, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate, ethyl lactate, methyl hydroxyisobutyrate, and anisole.

[0104] The solvent content is not particularly limited, but from the viewpoint of solubility and film formation, it is preferably 100 to 10,000 parts by mass, more preferably 200 to 5,000 parts by mass, and even more preferably 200 to 1,000 parts by mass, per 100 parts by mass of lithography film-forming material.

[0105] [Crosslinking agent] The lithography film-forming material of this embodiment may contain a crosslinking agent from the viewpoint of suppressing intermixing, etc. The crosslinking agent is not particularly limited, but for example, one described in International Publication No. 2013 / 024779 can be used.

[0106] The crosslinking agent is not particularly limited and includes, for example, phenol compounds, epoxy compounds, cyanate compounds, amino compounds, benzoxazine compounds, acrylate compounds, melamine compounds, guanamine compounds, glycoluryl compounds, urea compounds, isocyanate compounds, and azide compounds. Specific examples of these compounds are described, for example, in International Publication No. 2020 / 026879 and International Publication No. 2019 / 151400. These crosslinking agents can be used individually or in combination of two or more. Among these, it is preferable to use one or more selected from the group consisting of benzoxazine compounds, epoxy compounds, and cyanate compounds, and from the viewpoint of improving etching resistance, benzoxazine compounds are more preferable.

[0107] The lithography film-forming material of this embodiment may use a crosslinking agent having at least one allyl group, from the viewpoint of improving crosslinkability. The crosslinking agent having at least one allyl group is not particularly limited and includes, for example, those described in International Publication No. 2020 / 026879, International Publication No. 2019 / 151400, etc.

[0108] In this embodiment, the crosslinking agent content is not particularly limited, but is preferably 0.1 to 100 parts by mass, more preferably 5 to 50 parts by mass, and even more preferably 10 to 40 parts by mass, per 100 parts by mass of lithography film-forming material. When the crosslinking agent content is within the above range, the occurrence of mixing with the resist layer tends to be suppressed, the anti-reflective effect is enhanced, and the film-forming ability after crosslinking tends to be improved.

[0109] [Crosslinking promoter] The lithography film-forming material of this embodiment may contain a crosslinking accelerator to accelerate the crosslinking reaction (curing reaction) as needed. Examples of crosslinking accelerators include radical polymerization initiators.

[0110] The radical polymerization initiator may be a photopolymerization initiator that initiates radical polymerization by light, or a thermal polymerization initiator that initiates radical polymerization by heat. Examples of radical polymerization initiators include at least one selected from the group consisting of ketone-based photopolymerization initiators, organic peroxide-based polymerization initiators, and azo-based polymerization initiators.

[0111] Such radical polymerization initiators are not particularly limited and include, for example, those described in International Publication No. 2019 / 151400, International Publication No. 2018 / 016614, etc.

[0112] These radical polymerization initiators can be used individually or in combination of two or more.

[0113] [Acid Generator] The lithography film-forming material of this embodiment may contain an acid generator to further promote the thermal crosslinking reaction. Known acid generators include those that generate acid by thermal decomposition and those that generate acid by light irradiation, and any of these can be used. As an acid generator, for example, one described in International Publication No. 2013 / 024779 can be used.

[0114] The content of the acid generator in the lithography film-forming material is not particularly limited, but is preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 40 parts by mass, per 100 parts by mass of the lithography film-forming material. When the content of the acid generator is within the above range, the crosslinking reaction tends to be enhanced, and the occurrence of mixing with the resist layer tends to be suppressed.

[0115] [Basic compounds] The lithography film-forming material of this embodiment may contain a basic compound, from the viewpoint of improving storage stability, etc.

[0116] Basic compounds play a role in preventing trace amounts of acid generated from the acid generator from advancing the crosslinking reaction; in other words, they act as quenchers against the acid. Examples of such basic compounds are not limited to those described in International Publication No. 2013 / 024779.

[0117] The content of the basic compound in the lithography film-forming material of this embodiment is not particularly limited, but is preferably 0.001 to 2 parts by mass, and more preferably 0.01 to 1 part by mass, per 100 parts by mass of the lithography film-forming material. Having the basic compound content within this range tends to improve storage stability without excessively impairing the crosslinking reaction.

[0118] [Other additives] The underlying film-forming material of this embodiment may contain other resins and / or compounds for the purpose of imparting curability by heat or light or controlling absorbance. Such other resins and / or compounds are not particularly limited and include, for example, naphthol resin, xylene resin naphthol-modified resin, phenol-modified resin of naphthalene resin; polyhydroxystyrene, dicyclopentadiene resin, (meth)acrylate, dimethacrylate, trimethacrylate, tetramethacrylate, resins containing heterocyclic rings such as naphthalene rings, phenanthrenequinone, fluorene, etc., and resins that do not contain aromatic rings; rosin-based resins, cyclodextrin, adamantane(poly)ol, tricyclodecane(poly)ol and their derivatives, etc., and resins or compounds containing alicyclic structures. The lithography film-forming material of this embodiment may contain known additives. Known additives include, but are not limited to, thermal and / or photocuring catalysts, polymerization inhibitors, flame retardants, fillers, coupling agents, thermosetting resins, photocuring resins, dyes, pigments, thickeners, lubricants, defoamers, leveling agents, UV absorbers, surfactants, colorants, nonionic surfactants, and the like.

[0119] [Underlayer film for lithography] The lithography underlayer film in this embodiment is formed from the lithography film-forming material of this embodiment.

[0120] [Method for forming a resist pattern] The resist pattern formation method of this embodiment includes a base layer formation step of forming a base layer on a substrate using the composition of this embodiment, a photoresist layer formation step of forming at least one photoresist layer on the base layer formed in the base layer formation step, and a step of irradiating a predetermined area of ​​the photoresist layer formed in the photoresist layer formation step with radiation and performing development. The resist pattern formation method of this embodiment can be used to form various patterns, and is preferably a method for forming insulating film patterns.

[0121] [Circuit pattern formation method] The circuit pattern formation method of this embodiment includes: a base layer formation step of forming a base layer on a substrate using the composition of this embodiment; an intermediate layer formation step of forming an intermediate layer on the base layer formed in the base layer formation step; a photoresist layer formation step of forming at least one photoresist layer on the intermediate layer formed in the intermediate layer formation step; a resist pattern formation step of irradiating a predetermined area of ​​the photoresist layer formed in the photoresist layer formation step with radiation and developing it to form a resist pattern; an intermediate layer pattern formation step of etching the intermediate layer using the resist pattern formed in the resist pattern formation step as a mask to form an intermediate layer pattern; a base layer pattern formation step of etching the base layer using the intermediate layer pattern formed in the intermediate layer pattern formation step as a mask to form a base layer pattern; and a substrate pattern formation step of etching the substrate using the base layer pattern formed in the base layer pattern formation step as a mask to form a pattern on the substrate.

[0122] The lithography underlayer film of this embodiment is formed from the lithography film-forming material of this embodiment. The method of formation is not particularly limited, and known methods can be applied. For example, the lithography film-forming material of this embodiment can be applied to a substrate by known coating methods such as spin coating or screen printing, or by printing methods, and then the underlayer film can be formed by removing it by volatilizing the organic solvent.

[0123] When forming the underlayer film, it is preferable to bake it in order to suppress the mixing phenomenon with the resist upper layer film and to promote the crosslinking reaction. In this case, the bake temperature is not particularly limited, but is preferably in the range of 80 to 450°C, and more preferably in the range of 200 to 400°C. The bake time is also not particularly limited, but is preferably in the range of 10 to 300 seconds. The thickness of the underlayer film can be appropriately selected according to the required performance and is not particularly limited, but is preferably 30 to 20,000 nm, and more preferably 50 to 15,000 nm.

[0124] After fabricating the lower layer film, in the case of a two-layer process, it is preferable to fabricate a silicon-containing resist layer or a single-layer resist made of hydrocarbons on the lower layer film. In the case of a three-layer process, it is preferable to fabricate a silicon-containing intermediate layer on the lower layer film, and then to fabricate a silicon-free single-layer resist layer on the silicon-containing intermediate layer. In this case, known photoresist materials can be used to form this resist layer.

[0125] For silicon-containing resist materials used in two-layer processes, a positive-type photoresist material is preferably used, from the viewpoint of oxygen gas etching resistance, in which a silicon atom-containing polymer such as a polysilsesquioxane derivative or vinylsilane derivative is used as the base polymer, and further containing an organic solvent, an acid generator, and optionally a basic compound. Here, known polymers used in this type of resist material can be used as the silicon atom-containing polymer.

[0126] For a three-layer process, a polysilsesquioxane-based intermediate layer is preferably used as the silicon-containing intermediate layer. By giving the intermediate layer an anti-reflective effect, reflection can be effectively suppressed. For example, in a 193nm exposure process, if a material containing many aromatic groups and having high substrate etching resistance is used as the lower layer, the k value tends to increase and substrate reflection tends to increase. However, by suppressing reflection with the intermediate layer, substrate reflection can be reduced to 0.5% or less. While not limited to the following, polysilsesquioxane that can be crosslinked with acid or heat and into which phenyl groups or light-absorbing groups having silicon-silicon bonds are introduced is preferably used for 193nm exposure.

[0127] Furthermore, an intermediate layer formed by the Chemical Vapor Deposition (CVD) method can also be used. While not limited to the following, a highly effective anti-reflective intermediate layer fabricated by the CVD method is known, for example, a SiON film. Generally, forming the intermediate layer by wet processes such as spin coating or screen printing is simpler and more cost-effective than the CVD method. The top resist in the three-layer process can be either positive or negative, and the same type of single-layer resist commonly used can be used.

[0128] Furthermore, the underlayer film in this embodiment can also be used as an anti-reflective film for ordinary single-layer resists or as a base material for suppressing pattern deformation. Since the underlayer film has excellent etching resistance for base processing, it can also be expected to function as a hard mask for base processing.

[0129] When forming a resist layer using the above-mentioned photoresist material, a wet process such as spin coating or screen printing is preferably used, similar to the process used to form the underlying film. After applying the resist material by spin coating or the like, pre-baking is usually performed, preferably at 80-180°C for 10-300 seconds. Subsequently, exposure is performed according to a conventional method, followed by post-exposure baking (PEB) and development to obtain the resist pattern. The thickness of the resist film is not particularly limited, but is generally preferred to be 30-500 nm, and more preferably 50-400 nm.

[0130] Furthermore, the exposure light should be appropriately selected depending on the photoresist material being used. Generally, high-energy rays with wavelengths of 300 nm or less can be used, specifically excimer lasers at 248 nm, 193 nm, and 157 nm, soft X-rays, electron beams, and X-rays at 3 to 20 nm.

[0131] The resist pattern formed by the method described above has pattern distortion suppressed by the underlying film. Therefore, by using the underlying film in this embodiment, a finer pattern can be obtained, and the amount of exposure required to obtain that resist pattern can be reduced.

[0132] Next, etching is performed using the obtained resist pattern as a mask. In a two-layer process, gas etching is preferably used for etching the lower layer film. Gas etching using oxygen gas is preferred. In addition to oxygen gas, it is also possible to add inert gases such as He and Ar, or gases such as CO, CO2, NH3, SO2, N2, NO2, and H2. Furthermore, gas etching can be performed using only CO, CO2, NH3, N2, NO2, and H2 gases without using oxygen gas. The latter gases are particularly preferred for sidewall protection to prevent undercutting of the pattern sidewalls.

[0133] On the other hand, gas etching is also preferably used for etching the intermediate layer in the three-layer process. The same gas etching methods as those described in the two-layer process above can be applied. In particular, it is preferable to process the intermediate layer in the three-layer process using a fluorocarbon-based gas to mask the resist pattern. Subsequently, as described above, the underlying film can be processed by using the intermediate layer pattern as a mask and performing, for example, oxygen gas etching.

[0134] In this case, when forming an inorganic hard mask intermediate layer, a silicon oxide film, silicon nitride film, or silicon oxynitride film (SiON film) is formed by CVD or ALD. The method for forming the nitride film is not limited to the following, but for example, the methods described in Japanese Patent Application Publication No. 2002-334869 (Patent Document 6) and WO2004 / 066377 (Patent Document 7) can be used. A photoresist film can be formed directly on such an intermediate layer, but an organic anti-reflective coating (BARC) may be formed on the intermediate layer by spin coating, and then a photoresist film may be formed on top of that.

[0135] Polysilsesquioxane-based intermediate layers are also suitably used as intermediate layers. By giving the resist intermediate layer film an anti-reflective effect, reflections tend to be effectively suppressed. The specific materials for the polysilsesquioxane-based intermediate layer are not limited to those described below, but for example, those described in Japanese Patent Application Publication No. 2007-226170 (Patent Document 8) and Japanese Patent Application Publication No. 2007-226204 (Patent Document 9) can be used.

[0136] Furthermore, etching of the substrate can also be performed by conventional methods. For example, if the substrate is SiO2 or SiN, etching can be performed mainly with fluorocarbon gases, while etching can be performed mainly with chlorine-based or bromine-based gases for p-Si, Al, or W. When etching the substrate with fluorocarbon gases, the silicon-containing resist in a two-layer resist process and the silicon-containing intermediate layer in a three-layer resist process are stripped simultaneously with the substrate processing. On the other hand, when etching the substrate with chlorine-based or bromine-based gases, the silicon-containing resist layer or silicon-containing intermediate layer is stripped separately, and generally, dry etching stripping with fluorocarbon gas is performed after the substrate processing.

[0137] The underlying film in this embodiment is characterized by excellent etching resistance of the substrate. The substrate can be appropriately selected from known materials and is not particularly limited, but examples include Si, α-Si, p-Si, SiO2, SiN, SiON, W, TiN, and Al. The substrate may also be a laminate having a film to be processed (worked substrate) on a base material (support). Examples of such worked films include various low-k films and their stopper films, such as Si, SiO2, SiON, SiN, p-Si, α-Si, W, W-Si, Al, Cu, and Al-Si, and are usually made of a different material than the base material (support). The thickness of the substrate or worked film to be processed is not particularly limited, but is usually preferably around 50 to 1,000,000 nm, and more preferably 75 to 50,000 nm.

[0138] The composition of this embodiment can be prepared by blending the above-mentioned components and mixing them using a stirrer or the like. Furthermore, if the composition of this embodiment contains fillers or pigments, it can be prepared by dispersing or mixing them using a dispersion device such as a dissolver, homogenizer, or three-roll mill.

[0139] [Methods for refining resins] The resin purification method of this embodiment includes an extraction step of contacting a solution containing the resin of this embodiment and an organic solvent that is not arbitrarily miscible with water with an acidic aqueous solution for extraction. More specifically, the purification method of this embodiment involves dissolving the resin in an organic solvent that is not arbitrarily miscible with water, contacting the solution with an acidic aqueous solution for extraction, thereby transferring the metal components contained in the solution (A) containing the resin of this embodiment and the organic solvent to the aqueous phase, and then separating the organic phase and the aqueous phase for purification. The purification method of this embodiment can significantly reduce the content of various metals in the resin of this embodiment.

[0140] In this embodiment, "organic solvent that is not arbitrarily miscible with water" means an organic solvent whose solubility in water at 20 to 90°C is less than 50% by mass, and from the viewpoint of productivity, it is preferably less than 25% by mass. The organic solvent that is not arbitrarily miscible with water is not particularly limited, but an organic solvent that can be safely applied to semiconductor manufacturing processes is preferred. The amount of organic solvent used is usually about 1 to 100 times the weight of the resin in this embodiment.

[0141] Specific examples of solvents used include those described in International Publication WO2015 / 080240. These solvents may be used individually or in combination of two or more. Among these, toluene, 2-heptanone, cyclohexanone, cyclopentanone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, and ethyl acetate are preferred, with cyclohexanone and propylene glycol monomethyl ether acetate being particularly preferred.

[0142] The acidic aqueous solutions used are appropriately selected from aqueous solutions of generally known organic and inorganic compounds dissolved in water. For example, those described in International Publication WO2015 / 080240 can be used. These acidic aqueous solutions can be used individually or in combination of two or more. Among these, aqueous solutions of sulfuric acid, nitric acid, and carboxylic acids such as acetic acid, oxalic acid, tartaric acid, and citric acid are preferred, and aqueous solutions of sulfuric acid, oxalic acid, tartaric acid, and citric acid are even more preferred, with aqueous solutions of oxalic acid being particularly preferred. Polycarboxylic acids such as oxalic acid, tartaric acid, and citric acid are thought to be able to remove metals more effectively because they coordinate with metal ions and produce a chelating effect. Furthermore, the water used here should preferably have a low metal content, such as deionized water, in line with the objectives of the present invention.

[0143] The pH of the acidic aqueous solution used in this embodiment is not particularly limited, but if the acidity of the aqueous solution is too high, it may adversely affect the resin and is therefore undesirable. Typically, the pH range is about 0 to 5, and more preferably about 0 to 3.

[0144] The amount of acidic aqueous solution used in this embodiment is not particularly limited, but if the amount is too small, it will be necessary to perform many extractions to remove the metal, and conversely, if the amount of aqueous solution is too large, the total volume of liquid will be large, which may cause operational problems. The amount of aqueous solution used is usually 10 to 200% by mass relative to the solution of the resin of this embodiment dissolved in an organic solvent, and preferably 20 to 100% by mass.

[0145] In this embodiment, for example, the metal component is extracted by contacting an acidic aqueous solution as described above with a solution (A) containing the resin of this embodiment and an organic solvent that is not arbitrarily miscible with water.

[0146] The temperature during the extraction process is typically 20 to 90°C, preferably in the range of 30 to 80°C. The extraction operation is carried out by thoroughly mixing the solution, for example by stirring, and then allowing it to stand. This causes the metal components contained in the solution containing the resin and organic solvent of this embodiment to migrate to the aqueous phase. This operation also reduces the acidity of the solution, which helps to suppress the deterioration of the resin of this embodiment.

[0147] The resulting mixture separates into a solution phase containing the resin and organic solvent of this embodiment and an aqueous phase. The solution containing the resin and organic solvent of this embodiment is then recovered by decantation or the like. The standing time is not particularly limited, but if the standing time is too short, the separation of the solution phase containing the organic solvent and the aqueous phase will be poor, which is undesirable. Typically, the standing time is 1 minute or more, more preferably 10 minutes or more, and even more preferably 30 minutes or more. In addition, the extraction process can be performed only once, but it is also effective to repeat the operations of mixing, standing, and separating multiple times.

[0148] When such an extraction process is performed using an acidic aqueous solution, it is preferable to further extract the solution (A) containing the resin and organic solvent of this embodiment, which has been extracted and recovered from the aqueous solution after the process, with water. The extraction operation is carried out by thoroughly mixing the solution by stirring or the like, and then allowing it to stand. The resulting solution will separate into a solution phase containing the resin and organic solvent of this embodiment and an aqueous phase, so the solution phase containing the resin and organic solvent of this embodiment will be recovered by decantation or the like. Furthermore, the water used here should preferably have a low metal content, such as deionized water, in line with the objectives of the present invention. The extraction process may be performed only once, but it is also effective to repeat the operations of mixing, standing, and separating multiple times. Furthermore, there are no particular restrictions on the ratio of the two components used in the extraction process, as well as the temperature, time, and other conditions, but they may be the same as in the case of the contact treatment with the acidic aqueous solution described above.

[0149] Any water mixed into the solution containing the resin and organic solvent obtained in this embodiment can be easily removed by operations such as vacuum distillation. Furthermore, the concentration of the resin in this embodiment can be adjusted to any desired concentration by adding an organic solvent as needed.

[0150] The method for obtaining only the resin of this embodiment from a solution containing the obtained resin of this embodiment and an organic solvent can be carried out by known methods such as vacuum removal, separation by reprecipitation, and combinations thereof. If necessary, known treatments such as concentration, filtration, centrifugation, and drying can be performed. [Examples]

[0151] The embodiment will be described in more detail below with reference to synthesis examples and embodiments, but the embodiment is not limited in any way by these examples.

[0152] (molecular weight) The molecular weight of the compound or resin was determined by LC-MS analysis using Water's "Acquity UPLC / MALDI-Synapt HDMS" product.

[0153] (Solubility evaluation) At 23°C, the compound or resin was dissolved in propylene glycol monomethyl ether (PGME) to a 5% by mass solution. The solubility was then evaluated according to the following criteria after standing at 5°C for 30 days. Evaluation A: No precipitates were confirmed by visual inspection. Evaluation C: Precipitates were confirmed by visual inspection.

[0154] (Synthesis Example 1) Synthesis of BiF-1 A 200 mL container equipped with a stirrer, condenser, and burette was prepared. 30 g (161 mmol) of 4,4-biphenol (reagent from Tokyo Chemical Industry Co., Ltd.), 15 g (82 mmol) of 4-biphenylaldehyde (reagent from Mitsubishi Gas Chemical Co., Ltd.), and 100 mL of butyl acetate were charged into this container. 3.9 g (21 mmol) of p-toluenesulfonic acid (reagent from Kanto Chemical Co., Ltd.) was added to prepare the reaction solution. The reaction solution was stirred at 90°C for 3 hours. Next, the reaction solution was concentrated, 50 g of heptane was added to precipitate the reaction product, and after cooling to room temperature, the product was separated by filtration. After drying the solid obtained by filtration, separation and purification by column chromatography yielded 5.8 g of the target compound represented by the following formula (BiF-1). Furthermore, the following peaks were found by 400 MHz-1H-NMR, confirming that it has the chemical structure shown in the formula below. 1H-NMR: (d-DMSO, internal standard TMS) δ(ppm)9.4(4H,OH), 6.8~7.8(22H,Ph-H), 6.2(1H,CH)

[0155] [ka]

[0156] (Synthesis Example 2) Synthesis of TeF-1 A 500 mL container equipped with a stirrer, condenser, and burette was prepared. 30 g (161 mmol) of 4,4-biphenol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 5.4 g (40 mmol) of terephthalaldehyde (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), and 300 g of ethylglyme (reagent grade manufactured by Tokyo Chemical Industry Co., Ltd.) were charged into this container. 3.9 g (21 mmol) of p-toluenesulfonic acid (reagent manufactured by Kanto Chemical Co., Ltd.) was added to prepare the reaction solution. The reaction solution was stirred at 90°C for 3 hours. Next, the reaction solution was concentrated, 50 g of heptane was added to precipitate the reaction product, and after cooling to room temperature, the product was separated by filtration. After drying the solid obtained by filtration, separation and purification by column chromatography yielded 3.2 g of the target compound (TeF-1), represented by the following formula. Furthermore, the following peaks were found by 400 MHz-1H-NMR, confirming that it has the chemical structure shown in the formula below. 1H-NMR: (d-DMSO, internal standard TMS) δ(ppm)9.4(8H,OH), 6.8~7.8(32H,Ph-H), 6.2(2H,CH)

[0157] [ka]

[0158] (Synthesis Example 3) Synthesis of PBiF-1 The reaction was carried out in the same manner as in Synthesis Example 1, except that BiF-1 obtained in Synthesis Example 1 was used instead of 4,4'-biphenol, and 30 g of the target resin (PBiF-1) represented by the following formula (PBiF-1) was obtained.

[0159] [ka]

[0160] (Synthesis Example 4) Synthesis of RBiF-1 A 200 mL container equipped with a stirrer, condenser, and burette was prepared. 30 g (161 mmol) of 4,4-biphenol (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 15 g (82 mmol) of 4-biphenylaldehyde (manufactured by Mitsubishi Gas Chemical Co., Ltd.), and 100 mL of butyl acetate were charged into this container. 3.9 g (21 mmol) of p-toluenesulfonic acid (reagent manufactured by Kanto Chemical Co., Ltd.) was added to prepare the reaction solution. The reaction solution was stirred at 90°C for 3 hours. Next, the reaction solution was concentrated, 50 g of heptane was added to precipitate the reaction product, and after cooling to room temperature, the product was separated by filtration. The solid obtained by filtration was dried to obtain 21 g of the target compound represented by the following formula (RBiF-1).

[0161] [ka]

[0162] (Synthesis Example 5) Synthesis of BisP-1 In a 500 mL container equipped with a stirrer, condenser, and burette, 34.0 g (200 mmol) of o-phenylphenol (Sigma-Aldrich reagent), 18.2 g (100 mmol) of 4-biphenylaldehyde (Mitsubishi Gas Chemical Co., Ltd.), and 200 mL of 1,4-dioxane were charged. 10 mL of 95% sulfuric acid was added, and the mixture was stirred at 100°C for 6 hours to carry out the reaction. Next, the reaction mixture was neutralized with a 24% sodium hydroxide aqueous solution, 100 g of pure water was added to precipitate the reaction product, and after cooling to room temperature, the product was separated by filtration. After drying the obtained solid, separation and purification by column chromatography yielded 25.5 g of the target compound (BisP-1), represented by the following formula. Note: 400MHz- 1 The following peaks were observed by 1H-NMR, confirming that the chemical structure is as shown in the formula below. 1 H-NMR: (d-DMSO, internal standard TMS) δ(ppm)9.1(2H,OH), 7.2~8.5(25H,Ph-H), 5.6(1H,CH)

[0163] [ka]

[0164] (Synthesis Examples 6-9) Synthesis of BisP-2 to BisP-5 The procedure was carried out in the same manner as in Synthesis Example 5, except that benzaldehyde, p-methylbenzaldehyde, 1-naphthaldehyde, and 2-naphthaldehyde were used instead of 4-biphenylaldehyde, respectively, to obtain the target compounds (BisP-2), (BisP-3), (BisP-4), and (BisP-5) represented by the following formulas.

[0165] [ka]

[0166] (Synthesis Example 10) Synthesis of BisP-6 The synthesis was carried out in the same manner as in Synthesis Example 5, except that 4-phenylphenol (reagent manufactured by Kanto Chemical Co., Ltd.) was used instead of o-phenylphenol (reagent manufactured by Sigma-Aldrich). The target compound (BisP-6) represented by the following formula was obtained.

[0167] [ka]

[0168] (Synthesis Comparison Example 1) A 10 L four-necked flask with a removable bottom was prepared, equipped with a Liebig condenser, thermometer, and stirring blade. Into this flask, 1.09 kg (7 mol, manufactured by Mitsubishi Gas Chemical Co., Ltd.) of 1,5-dimethylnaphthalene, 2.1 kg (28 mol as formaldehyde, manufactured by Mitsubishi Gas Chemical Co., Ltd.) of 40% formalin aqueous solution, and 0.97 mL (98% sulfuric acid, manufactured by Kanto Chemical Co., Ltd.) were charged under a nitrogen stream. The reaction was carried out under atmospheric pressure at 100°C under reflux for 7 hours. Subsequently, 1.8 kg of ethylbenzene (reagent grade, manufactured by Wako Pure Chemical Industries, Ltd.) was added to the reaction mixture as a diluent, and after standing, the aqueous phase was removed. Further neutralization and washing with water were performed, and ethylbenzene and unreacted 1,5-dimethylnaphthalene were removed by distillation under reduced pressure to obtain 1.25 kg of light brown solid dimethylnaphthaleneformaldehyde resin. The molecular weight of the obtained dimethylnaphthaleneformaldehyde was Mn: 562.

[0169] Next, a 0.5 L four-necked flask equipped with a Liebig condenser, thermometer, and stirring blade was prepared. In this four-necked flask, 100 g (0.51 mol) of the dimethylnaphthaleneformaldehyde resin obtained as described above and 0.05 g of p-toluenesulfonic acid were charged under a nitrogen stream, and the temperature was raised to 190°C and heated for 2 hours, after which it was stirred. Subsequently, 52.0 g (0.36 mol) of 1-naphthol was added, and the temperature was further raised to 220°C and the reaction was carried out for 2 hours. After solvent dilution, neutralization and washing with water were performed, and the solvent was removed under reduced pressure to obtain 126.1 g of a dark brown solid modified resin (CR-1). The obtained resin (CR-1) had Mn: 885, Mw: 2220, and Mw / Mn: 4.17. The Mn, Mw, and Mw / Mn of the resin (CR-1) were determined in polystyrene equivalents by gel permeation chromatography (GPC) analysis under the following measurement conditions. Equipment: Shodex GPC-101 (Showa Denko Corporation product) Columns: KF-80M x 3 Eluent: THF 1mL / min Temperature: 40℃

[0170] (Synthesis Example 1) A 500 mL container equipped with a stirrer, condenser, and burette was prepared. In this container, 10.7 g (20 mmol) of BiF-1 obtained in Synthesis Example 1, 9.0 g (50 mmol) of 9-fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), and 7.0 g (20 mmol) of 9,9-bis(4-hydroxyphenyl)fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) were charged along with 150 g of ethylglyme (reagent grade manufactured by Tokyo Chemical Industry Co., Ltd.). 1.3 g (7 mmol) of p-toluenesulfonic acid (reagent manufactured by Kanto Chemical Co., Ltd.) was added to prepare the reaction solution. The reaction solution was stirred at 90°C for 3 hours. Next, the reaction solution was concentrated, 50 g of heptane was added to precipitate the reaction product, and after cooling to room temperature, the product was separated by filtration. The solid obtained by filtration was dried to obtain resin (A-1).

[0171] (Synthesis Example 2) Resin (A-2) was obtained by reacting in the same manner as in Synthesis Example 1, except that 16.8 g (20 mmol) of TeF-1 obtained in Synthesis Example 2 was used instead of 10.7 g (20 mmol) of BiF-1.

[0172] (Synthesis Example 3) The reaction was carried out in the same manner as in Synthesis Example 1, except that 10 g of PBiF-1 obtained in Synthesis Example 3 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-3).

[0173] (Synthesis Example 4) Resin (A-4) was obtained by reacting in the same manner as in Synthesis Example 1, except that 10 g of RBiF-1 obtained in Synthesis Example 4 was used instead of 10.7 g (20 mmol) of BiF-1.

[0174] (Synthesis Example 5) The reaction was carried out in the same manner as in Synthesis Example 1, except that 10.1 g (20 mmol) of BisP-1 obtained in Synthesis Example 5 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-5).

[0175] (Synthesis Example 6) The reaction was carried out in the same manner as in Synthesis Example 1, except that 8.6 g (20 mmol) of BisP-2 obtained in Synthesis Example 6 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-6).

[0176] (Synthesis Example 7) The reaction was carried out in the same manner as in Synthesis Example 1, except that 8.8 g (20 mmol) of BisP-3 obtained in Synthesis Example 7 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-7).

[0177] (Synthesis Example 8) The reaction was carried out in the same manner as in Synthesis Example 1, except that 9.5 g (20 mmol) of BisP-4 obtained in Synthesis Example 8 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-8).

[0178] (Synthesis Example 9) The reaction was carried out in the same manner as in Synthesis Example 1, except that 9.5 g (20 mmol) of BisP-5 obtained in Synthesis Example 9 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-9).

[0179] (Synthesis Example 10) The reaction was carried out in the same manner as in Synthesis Example 1, except that 10.1 g (20 mmol) of BisP-6 obtained in Synthesis Example 10 was used instead of 10.7 g (20 mmol) of BiF-1, to obtain resin (A-10).

[0180] (Synthesis Example 11) Resin (A-11) was obtained by reacting the two components in the same manner as in Synthesis Example 1, except that BiF-1, 10.7 g (20 mmol) was replaced with BisP-1, 5.05 g (10 mmol) obtained in Synthesis Example 5, and 9,9-bis(4-hydroxyphenyl)fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 7.0 g (20 mmol) was replaced with 9,9-bis(4-hydroxyphenyl)fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.), 10.5 g (30 mmol).

[0181] (Synthesis Example 12) Resin (A-12) was obtained by reacting the two components in the same manner as in Synthesis Example 1, except that 15.1 g (30 mmol) of BisP-1 obtained in Synthesis Example 5 was used instead of 10.7 g (20 mmol) of BiF-1, and 3.50 g (10 mmol) of 9,9-bis(4-hydroxyphenyl)fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was used instead of 7.0 g (20 mmol) of 9,9-bis(4-hydroxyphenyl)fluorenone (reagent manufactured by Tokyo Chemical Industry Co., Ltd.).

[0182] [Examples 1A-18A, 21A-29A, Comparative Example 1] Solubility tests were conducted on the resins A-1 to A-12 and CR-1 mentioned above. The results are shown in Table 1. In addition, lithography underlayer forming materials (lithography underlayer forming compositions) with the compositions shown in Table 1 were prepared. Next, these lithography underlayer forming materials were rotary coated onto a silicon substrate, and then baked at 240°C for 60 seconds, and then at 400°C for 120 seconds, to produce underlayer films with a thickness of 200 nm. The following acid generators, crosslinking agents, and organic solvents were used. Acid generator: Midori Chemical Co., Ltd. product "Diter-butyldiphenyliodonium nonafluoromethanesulfonate" (indicated as "DTDPI" in the table), or Kanto Chemical Co., Ltd. product "Pyridinium p-toluenesulfonate" (indicated as "PPTS" in the table). Crosslinking agent: Sanwa Chemical Co., Ltd. product "Nicalac MX270" (indicated as "Nicalac" in the table), or Honshu Chemical Industry Co., Ltd. product "TMOM-BP" (compound name 3,3',5,5'-tetrakis(methoxymethyl)-[1,1'-biphenyl]-4,4'-diol; indicated as "TMOM-BP" in the table). Organic solvent: Propylene glycol monomethyl ether acetate (indicated as "PGMEA" in the table), or a mixture of propylene glycol monomethyl ether acetate and propylene glycol monomethyl ether in a 1:1 (mass ratio) ratio (indicated as "PGMEA / PGME" in the table).

[0183] Etching tests were performed on each of the obtained underlayer films under the conditions described below to evaluate their etching resistance. The evaluation results are shown in Table 1.

[0184] [Etching test] Etching equipment: Samco International product "RIE-10NR" Output: 50W Pressure: 20 Pa Time: 2 min Etching gas Ar gas flow rate:CF4 gas flow rate:O2 gas flow rate = 50:5:5 (sccm) [Evaluation of etching resistance] Etching resistance was evaluated using the following procedure. First, a base layer containing phenol novolac resin was prepared under the same conditions as in Example 1A, except that phenol novolac resin (PSM4357, manufactured by Gun-ei Chemical Co., Ltd.) was used instead of the resin (A-1) used in Example 1A. Then, the etching test described above was performed on this base layer containing phenol novolac resin, and the etching rate (etching speed) was measured. Next, the etching test described above was performed on the base layer of each example and comparative example, and the etching rate was measured. Then, using the etching rate of the base layer containing phenol novolac resin as a reference, the etching resistance of each example and comparative example was evaluated according to the following evaluation criteria. [Evaluation Criteria] S: Etching rate less than -14% compared to the underlying novolac film. A: The etching rate is -14% to -10% compared to the underlying novolac film. B: Etching rate is -10% to +5% compared to the underlying novolac film. C: Compared to the underlying novolac film, the etching rate is more than +5%.

[0185] [Table 1]

[0186] [Examples 1B-18B, 21B-29B] Each of the lithography underlayer-forming material solutions prepared in Examples 1A-18A and 21A-29A above was applied to a 300 nm thick SiO2 substrate and baked at 240°C for 60 seconds, and then at 400°C for 120 seconds, to form a 70 nm thick underlayer film. An ArF resist solution was applied to this underlayer film and baked at 130°C for 60 seconds, to form a 140 nm thick photoresist layer. The ArF resist solution used was prepared by combining 5 parts by mass of the compound represented by the following formula (R-0), 1 part by mass of triphenylsulfonium nonafluoromethanesulfonate, 2 parts by mass of tributylamine, and 92 parts by mass of PGMEA. The compound represented by the following formula (R-0) was prepared by dissolving 4.15 g of 2-methyl-2-methacryloyloxyadamantane, 3.00 g of methacryloyloxy-γ-butyrolactone, 2.08 g of 3-hydroxy-1-adamantyl methacrylate, and 0.38 g of azobisisobutyronitrile in 80 mL of tetrahydrofuran to prepare the reaction solution. This reaction solution was polymerized under a nitrogen atmosphere at a reaction temperature of 63°C for 22 hours, after which the reaction solution was added dropwise to 400 mL of n-hexane. The resulting resin was coagulated and purified, and the resulting white powder was filtered and dried overnight under reduced pressure at 40°C.

[0187] [ka]

[0188] The numbers in the above formula (R-0) represent the ratio of each constituent unit.

[0189] Next, the photoresist layer was exposed using an electron beam lithography system (ELS-7500, 50 keV, manufactured by Elionix Corporation), baked (PEB) at 115°C for 90 seconds, and developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds to obtain a positive-type resist pattern.

[0190] Table 2 shows the results of observing defects in the obtained 55 nmL / S (1:1) and 80 nmL / S (1:1) resist patterns. In the table, "Good" indicates that no major defects were observed in the formed resist pattern, and "Poor" indicates that major defects were observed in the formed resist pattern.

[0191] [Comparative Example 2] A photoresist layer was directly formed on the SiO2 substrate in the same manner as in Example 1B, except that the underlying film was not formed, to obtain a positive-type resist pattern. The results are shown in Table 2.

[0192] [Table 2]

[0193] As is clear from Table 1, Examples 1A to 18A and 21A to 29A, which used any of the resins A-1 to A-12 of this embodiment, were confirmed to have good solubility and etching resistance. On the other hand, Comparative Example 1, which used CR-1 (phenol-modified dimethylnaphthaleneformaldehyde resin), had poor etching resistance.

[0194] Furthermore, as is clear from Table 2, in Examples 1B to 18B and 21B to 29B, which used any of the resins A-1 to A-12 of this embodiment, the resist pattern shape after development was good and no major defects were observed. Moreover, each of Examples 1B to 18B and 21B to 29B was found to be significantly superior in both resolution and sensitivity compared to Comparative Example 2, which did not have an underlayer film formed. Here, the good resist pattern shape after development indicates that the lithography underlayer film forming material used in Examples 1A to 18A and 21A to 29A has good adhesion to the resist material (photoresist material, etc.).

[0195] [Examples 1C-18C, 21C-29C] Solutions of the lithography underlayer-forming materials from Examples 1A-18A and 21A-29A were applied to a 300 nm thick SiO2 substrate and baked at 240°C for 60 seconds, and then at 400°C for 120 seconds to form an 80 nm thick underlayer film. A silicon-containing intermediate layer material was applied to this underlayer film and baked at 200°C for 60 seconds to form an intermediate layer film with a thickness of 35 nm. Furthermore, the above-mentioned ArF resist solution was applied to this intermediate layer film and baked at 130°C for 60 seconds to form a 150 nm thick photoresist layer. As the silicon-containing intermediate layer material, a silicon atom-containing polymer described in <Synthesis Example 1> of Japanese Patent Application Publication No. 2007-226170 was used. Next, the photoresist layer was mask-exposed using an electron beam lithography system (ELS-7500, 50 keV, manufactured by Elionix Corporation), baked (PEB) at 115°C for 90 seconds, and developed with a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution for 60 seconds to obtain a positive resist pattern of 55 nm / S (1:1). Subsequently, using a RIE-10NR manufactured by Samco International Corporation, the obtained resist pattern was used as a mask for dry etching of the silicon-containing interlayer film (SOG). Following this, the obtained silicon-containing interlayer film pattern was used as a mask for dry etching of the underlying film, and then the obtained underlying film pattern was used as a mask for dry etching of the SiO2 film.

[0196] The etching conditions for each are as follows: Etching conditions for resist patterns onto the resist interlayer film Output: 50W Pressure: 20 Pa Time: 1 min Etching gas Ar gas flow rate:CF4 gas flow rate:O2 gas flow rate = 50:8:2 (sccm) Etching conditions for resist interlayer patterns into the resist underlayer. Output: 50W Pressure: 20 Pa Time: 2 min Etching gas Ar gas flow rate:CF4 gas flow rate:O2 gas flow rate = 50:5:5 (sccm) Etching conditions for resist underlayer pattern onto SiO2 film Output: 50W Pressure: 20 Pa Time: 2 min Etching gas Ar gas flow rate: C5F 12 Gas flow rate: C2F6 Gas flow rate: O2 Gas flow rate =50:4:3:1(sccm)

[0197] [evaluation] The cross-sections of the patterns obtained as described above (i.e., the shape of the SiO2 film after etching) were observed using an electron microscope (S-4800) manufactured by Hitachi, Ltd. The observation results are shown in Table 3. In the table, "Good" indicates that no major defects were observed in the formed cross-section of the pattern, and "Poor" indicates that major defects were observed in the formed cross-section of the pattern.

[0198] [Table 3]

[0199] (Example 19) Acidic purification of RBiF-1 In a 1000 mL four-necked flask (bottomless type), 150 g of a solution (10% by mass) of RBiF-1 dissolved in PGMEA, obtained in Synthesis Example 4, was placed and heated to 80°C while stirring. Next, 37.5 g of oxalic acid aqueous solution (pH 1.3) was added, stirred for 5 minutes, and then allowed to stand for 30 minutes. This separated the oil phase and aqueous phase, and the aqueous phase was removed. After repeating this operation once, 37.5 g of ultrapure water was added to the obtained oil phase, stirred for 5 minutes, and then allowed to stand for 30 minutes to remove the aqueous phase. After repeating this operation three times, residual water and PGMEA were concentrated and removed by reducing the pressure inside the flask to below 200 hPa while heating to 80°C. Subsequently, EL grade PGMEA (reagent manufactured by Kanto Chemical Co., Ltd.) was diluted and the concentration was adjusted to 10% by mass to obtain a PGMEA solution of RBiF-1 with reduced metal content.

[0200] (Example 20) Acidic purification of BisP-1 The procedure was carried out in the same manner as in Example 19, except that BisP-1 was used instead of RBiF-1, and a BisP-1 PGMEA solution was obtained by adjusting the concentration to 10% by mass.

[0201] (Comparative Example 3) Purification of RBiF-1 using ultrapure water The procedure was carried out in the same manner as in Example 19, except that ultrapure water was used instead of oxalic acid aqueous solution, and the concentration was adjusted to 10% by mass to obtain a PGMEA solution of RBiF-1.

[0202] The metal content of various metals was measured by ICP-MS in the 10% PGMEA solution of RBiF-1 before treatment, the 10% PGMEA solution of BisP-1 before treatment, and the solutions obtained in Example 19, Example 20, and Comparative Example 3. The measurement results are shown in Table 4.

[0203] [Table 4] [Industrial applicability]

[0204] The resin of the present invention has high heat resistance and high solvent solubility, and is applicable to wet processes. Therefore, lithography film-forming materials and lithography films using the resin of the present invention can be widely and effectively used in various applications where these properties are required. Accordingly, the present invention can be widely and effectively used in, for example, electrical insulating materials, resist resins, semiconductor encapsulating resins, adhesives for printed circuit boards, electrical laminates mounted in electrical equipment, electronic equipment, industrial equipment, etc., matrix resins for prepregs mounted in electrical equipment, electronic equipment, industrial equipment, etc., build-up laminate materials, resins for fiber-reinforced plastics, encapsulating resins for liquid crystal display panels, paints, various coatings, adhesives, coatings for semiconductors, resist resins for semiconductors, and resins for forming underlayer films. In particular, the present invention can be used particularly effectively in the field of lithography films.

Claims

1. A resin comprising a constituent unit represented by the following formula (1) or (1)' and a constituent unit represented by the following formula (U2). 【Chemistry 1】 (In formula (1), A is a single bond, a C1-C4 alkylene which may have substituents, or a heteroatom. R 1 This is a 2n valent group with 1 to 30 carbon atoms. R 2 ~R 5 Each of these is independently a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, a thiol group, or a hydroxyl group. R 2 at least one of and / or R 3 At least one of them is a hydroxyl group and / or a thiol group, I understand 2 and m 3 Each of these is an independent integer from 0 to 8, m 4 and m 5 are each independently an integer from 0 to 9, n is an integer between 1 and 4. p 2 ~p 5 (Each of these is an independent integer between 0 and 2.) 【Chemistry 2】 (In formula (1)', R 1' It is a divalent group having 1 to 30 carbon atoms. n 0 These are integers from 1 to 10, A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 This is defined as in formula (1) above. 【Chemistry 10】 (In formula (U2), Ar U3 and Ar U4 Each of these is independently a phenyl ring or a naphthalene ring. R U3 and R U4 Each of these is independently a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an alkoxy group having 2 to 10 carbon atoms, or a carbon 1 to 10 carbon atoms.

2. The resin according to claim 1, wherein formula (1) is the following formula (2). 【Transformation 3】 (In formula (2), R 1' It is a divalent group having 1 to 30 carbon atoms. A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 This is defined as in formula (1) above.

3. p 2 ~p 5 The resin according to claim 1 or 2, wherein is 0.

4. The resin according to any one of claims 1 to 3, wherein A is a single bond.

5. The resin according to claim 1, wherein formula (1) is formula (2a) below. 【Chemistry 4】 (In formula (2a), n A , R 1A ~R 5A n and R in formula (1) above are respectively. 1 ~R 5 It is synonymous with, I understand 2A and m 3A Each of these is an independent integer between 0 and 3, I understand 4A and m 5A (Each of these is an independent integer between 0 and 5.)

6. The resin according to claim 1, wherein formula (1) and formula (1)' are formula (2b) and formula (2b)', respectively. 【Transformation 5】 (In formula (2b), R 1A` It is a divalent group having 1 to 30 carbon atoms. R 2A ~R 5A These are R in formula (1) above, respectively. 2 ~R 5 It is synonymous with, I understand 2A and m 3A Each of these is an independent integer between 0 and 3, I understand 4A and m 5A (Each of these is an independent integer between 0 and 5.) 【Transformation 6】 (In formula (2b)', R 1A` It is a divalent group having 1 to 30 carbon atoms. R 2A ~R 5A These are R in formula (1) above, respectively. 2 ~R 5 It is synonymous with, I understand 2A and m 3A Each of these is an independent integer between 0 and 3, I understand 4A and m 5A These are each an independent integer between 0 and 5, n 0 (This is an integer between 1 and 10.)

7. The resin according to claim 1, wherein formula (1)' is formula (3a)' or formula (3b)' below. 【Transformation 7】 【Transformation 8】 [In formulas (3a)' and (3b)', n 0 [This is an integer between 1 and 10.]

8. A resin according to any one of claims 1 to 7, comprising a constituent unit defined in any one of claims 1 to 7 and one or two constituent units different from the constituent units defined in any one of claims 1 to 7.

9. The resin according to any one of claims 1 to 8, further comprising a constituent unit represented by the following formula (U1). 【Chemistry 9】 (In formula (U1), Ar U1 and Ar U2 Each of these is independently a phenyl ring or a naphthalene ring. R U1 and R U2 Each of these is independently a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

10. The resin according to claim 1, comprising a block unit including a constituent unit represented by formula (1) or formula (1)' and a constituent unit represented by the following formula (U2), wherein the block unit is represented by the following formula (4) or formula (4)'. 【Chemistry 11】 (In formula (4), A, R 1 ~R 5 , m 2 ~m 5 , n, p 2 ~p 5 This is as defined in formula (1) above, L is a divalent group having 1 to 30 carbon atoms, or a single bond. k is a positive integer. 【Chemistry 12】 (In formula (4)', R 1' It is a divalent group having 1 to 30 carbon atoms. A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 This is as defined in formula (1) above, L is a divalent group having 1 to 30 carbon atoms, or a single bond. k is a positive integer, n 0 (This is an integer between 1 and 10.) [Chemistry 18] (In formula (U2), Ar U3 and Ar U4 Each of these is independently a phenyl ring or a naphthalene ring. R U3 and R U4 Each of these is independently a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an alkoxy group having 2 to 10 carbon atoms, or a carbon 1 to 10 carbon atoms.

11. The resin according to claim 10, wherein formula (4) is the following formula (5). 【Chemistry 13】 (In formula (5), R 1' It is a divalent group having 1 to 30 carbon atoms. A, R 2 ~R 5 , m 2 ~m 5 , p 2 ~p 5 , L, k are as defined in the above formula (4).)

12. The resin according to claim 10, wherein formula (4) is formula (5a) shown below. 【Chemistry 14】 (In formula (5a), n A , R 1A ~R 5A , L, and k are n and R in formula (4) above, respectively. 1 ~R 5 , is synonymous with L and k, m 2A and m 3A are each independently an integer from 0 to 3, I understand 4A and m 5A (Each of these is an independent integer between 0 and 5.)

13. The resin according to claim 10, wherein formula (4) and formula (4)' are formula (5b) and formula (5b)', respectively. 【Chemistry 15】 (In formula (5b), R 1A` It is a divalent group having 1 to 30 carbon atoms. R 2A ~R 5A L and k are respectively R in formula (4) above. 2 ~R 5 , is synonymous with L and k, I understand 2A and m 3A Each of these is an independent integer between 0 and 3, I understand 4A and m 5A (Each of these is an independent integer between 0 and 5.) 【Chemistry 16】 (In formula (5b)', R 1A` It is a divalent group having 1 to 30 carbon atoms. R 2A ~R 5A L and k are respectively R in formula (4) above. 2 ~R 5 , is synonymous with L and k, I understand 2A and m 3A Each of these is an independent integer between 0 and 3, I understand 4A and m 5A These are each an independent integer between 0 and 5, n 0 (This is an integer between 1 and 10.)

14. The resin according to any one of claims 10 to 13, comprising the block unit and one or two constituent units different from the constituent units represented by formula (1) or formula (1)'.

15. The resin according to any one of claims 10 to 14, further comprising a constituent unit represented by the following formula (U1). 【Chemistry 17】 (In formula (U1), Ar U1 and Ar U2 Each of these is independently a phenyl ring or a naphthalene ring. R U1 and R U2 Each of these is independently a hydrogen atom, a linear alkyl group having 1 to 10 carbon atoms, a branched alkyl group having 3 to 10 carbon atoms, a cyclic alkyl group having 3 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or an alkoxy group having 1 to 10 carbon atoms.

16. A composition comprising the resin according to any one of claims 1 to 15.

17. The composition according to claim 16, further comprising a solvent.

18. The composition according to claim 16 or 17, further comprising an acid generator.

19. The composition according to any one of claims 16 to 18, further comprising a crosslinking agent.

20. A composition according to any one of claims 16 to 18, used for forming lithography films.

21. The composition according to claim 20, which is used as a composition for forming a resist film.

22. The composition according to claim 20, which is used as a composition for forming an underlying film.

23. A photoresist layer formation step of forming a photoresist layer on a substrate using the composition described in claim 21, A developing step involves irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation to perform development, A method for forming a resist pattern, including the method described above.

24. A base layer formation step of forming a base layer on a substrate using the composition described in claim 22, A photoresist layer formation step, in which at least one photoresist layer is formed on the lower layer film formed by the lower layer film formation step, A step of irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation and performing development, A method for forming a resist pattern, including the method described above.

25. A base layer formation step of forming a base layer on a substrate using the composition described in claim 22, An intermediate layer film formation step is performed to form an intermediate layer film on the lower layer film formed by the lower layer film formation step, A photoresist layer formation step, in which at least one photoresist layer is formed on the intermediate layer formed by the intermediate layer formation step, A resist pattern formation step involves irradiating a predetermined area of ​​the photoresist layer formed by the photoresist layer formation step with radiation and developing it to form a resist pattern, An intermediate layer pattern formation step is performed by using the resist pattern formed in the resist pattern formation step as a mask to etch the intermediate layer film and form an intermediate layer pattern, A lower layer pattern formation step is performed by using the intermediate layer pattern formed in the intermediate layer pattern formation step as a mask to etch the lower layer to form a lower layer pattern, A substrate pattern formation step involves etching the substrate using the underlying film pattern formed in the underlying film pattern formation step as a mask to form a pattern on the substrate, A method for forming a circuit pattern, including the method described above.

26. A method for purifying a resin according to any one of claims 1 to 15, A method for purifying a resin, comprising an extraction step of contacting a solution containing the resin and an organic solvent that is not arbitrarily miscible with water with an acidic aqueous solution for extraction.

Images