Positive photosensitive resin composition, photosensitive film, resist film, resist under film and resist permanent film

Abstract

The invention provides a positive photosensitive resin composition, a photosensitive film, a resist film, a resist underlayer film, and a resist permanent film. The positive photosensitive resin composition contains the following components A to C. Component A: a novolac-type phenolic resin which contains a phenol structural unit a1 derived from m-cresol and / or o-cresol and an aldehyde structural unit a2 derived from salicylaldehyde, and which has an acetal group-based protecting group derived from a compound containing two or more vinyl ether groups / component B: a photoacid generator / component C: a solvent.

Description

Technical Field

[0001] The present invention relates to a positive photosensitive resin composition, a photosensitive film, a resist film, a resist underlayer film and a resist permanent film. Background Art

[0002] In recent years, with the miniaturization of electronic devices, the high density of semiconductor packaging has been continuously promoted. In the past, in the manufacture of semiconductor packaging for integrated circuits (ICs) or large-scale integrated circuits (LSIs), alkali-soluble resins (such as novolac-type phenol (phenol novolac) resins) and positive photoresists for i-rays using naphthoquinone diazide compound-based photosensitizers were widely used. However, the miniaturization using i-rays is reaching its limit. In particular, in plating resists for forming redistribution layers used in cutting-edge semiconductor packaging, the formation of fine wiring with a thick film of more than tens of μm is required. In the thick film of tens of μm, in the previous naphthoquinone type, since there was not enough light to reach the bottom of the film, there was a problem that the resist layer at the bottom of the pattern would not cause alkali dissolution, making it difficult to form a high vertical and horizontal pattern.

[0003] To address this problem, studies have been conducted on using chemically amplified positive photoresists used in lithography using excimer lasers such as KrF, ArF, and EUV in lithography using i-rays instead of naphthoquinonediazide compound-based photosensitizers (for example, Patent Document 1).

[0004] When a photosensitive resin film using a chemically amplified positive photoresist is irradiated with light, an acid is generated from the photoacid generator. The generated acid (proton) acts as an acid catalyst, detaching the protective groups of the acid-degradable resin, thereby exposing the alkali-soluble groups. In chemically amplified positive photoresists, after the protective groups are detached, the acid is catalytically regenerated, allowing the detachment of other protective groups. This allows the production of positive patterns with high alkali solubility even under minimal light. This makes it possible to achieve alkali dissolution of the film bottom, a challenge in thick film production.

[0005] However, the positive-type photosensitive resin composition using the m-cresol-based phenol novolac resin described in Patent Document 1 still suffers from insufficient sensitivity and the problem of residual film formation at the bottom of the pattern after development has not been resolved. Furthermore, due to low transmittance at a wavelength of 365 nm, i.e., i-rays, the composition has limited potential for improving sensitivity.

[0006] Therefore, with the goal of improving sensitivity, chemically amplified positive-type photosensitive resin compositions using hydroxyl-substituted aromatic aldehydes have been studied (for example, Patent Document 2). However, although the positive-type photosensitive resin composition described in Patent Document 2 has improved sensitivity, it has poor storage stability and insufficient heat resistance, thus lacking practical application.

[0007] In addition, studies have been conducted to improve storage stability by cross-linking and protecting the phenolic hydroxyl groups in novolacs using divinyl ether having two or more vinyl ether groups per molecule (e.g., Patent Document 3). However, even the photosensitive resin composition described in Patent Document 3 does not have sufficient storage stability.

[0008] As described above, with the increasing density of semiconductor packaging, there is a demand for the development of a phenol novolac resin and a photosensitive resin composition for chemically amplified positive photoresists that can develop thick film patterns with a high aspect ratio without generating residue and that exhibits storage stability, high heat resistance, and high i-ray transmittance.

[0009] [Prior art literature]

[0010] [Patent Document]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2003-149816

[0012] [Patent Document 2] Japanese Patent Application Laid-Open No. 2005-300820

[0013] [Patent Document 3] International Publication No. 2004 / 104702 Summary of the Invention

[0014] [Problems to be solved by the invention]

[0015] An object of the present invention is to provide a positive photosensitive resin composition that has high i-ray transmittance, can provide a resist film having excellent developability and heat resistance, and has good storage stability.

[0016] [Technical means to solve the problem]

[0017] The present inventors have conducted intensive studies to solve the above-mentioned problems and have found that a positive-type photosensitive resin composition comprising a novolac-type phenolic resin having specific structural units and in which at least a portion of the phenolic hydroxyl groups is substituted with an acetal-based protecting group derived from a compound containing two or more vinyl ether groups, a photoacid generator, and a solvent has good storage stability and can produce a desired resist film, thereby completing the present invention.

[0018] That is, the present invention relates to a positive photosensitive resin composition containing the following components (A) to (C).

[0019] (A) a novolac-type phenolic resin comprising a phenol structural unit (a1) derived from m-cresol and / or o-cresol and an aldehyde structural unit (a2) derived from salicylaldehyde, and having an acetal-based protective group derived from a compound containing two or more vinyl ether groups

[0020] (B) Photoacid generator

[0021] (C) Solvent

[0022] The present invention also relates to a photosensitive film obtained by drying a positive photosensitive resin composition.

[0023] The present invention also relates to a resist film obtained from the positive photosensitive resin composition.

[0024] The present invention also relates to a resist underlayer film obtained from a positive photosensitive resin composition.

[0025] The present invention also relates to a permanent resist film, which is obtained from a positive photosensitive resin composition.

[0026] [Effects of the Invention]

[0027] According to the present invention, there can be provided a positive-type photosensitive resin composition which has high i-ray transmittance, can provide a resist film having excellent developability and heat resistance, and has good storage stability. DETAILED DESCRIPTION

[0028] Hereinafter, modes for carrying out the invention will be described.

[0029] In addition, in this specification, "x to y" is used to represent a numerical range of "x or more and y or less." The upper limit value and the lower limit value described in the numerical range can be arbitrarily combined.

[0030] Furthermore, combinations of two or more of the various aspects of the present invention described below are also aspects of the present invention.

[0031] [Positive photosensitive resin composition]

[0032] The positive photosensitive resin composition according to one embodiment of the present invention contains the following components (A) to (C).

[0033] (A) a novolac-type phenolic resin comprising a phenol structural unit (a1) derived from m-cresol and / or o-cresol and an aldehyde structural unit (a2) derived from salicylaldehyde, and having an acetal-based protective group derived from a compound containing two or more vinyl ether groups

[0034] (B) Photoacid generator

[0035] (C) Solvent

[0036] In this embodiment, the novolac-type phenolic resin has an acetal-based protecting group derived from a compound containing two or more vinyl ether groups, which produces a synergistic effect with a photoacid generator when the positive photosensitive resin composition is used as a resist film, etc. Specifically, in the exposed area, the acetal-based protecting group is separated from component (A) by the acid generated by the photoacid generator, but on the other hand, in the unexposed area, the acetal-based protecting group is not separated from component (A). As a result, a positive photosensitive resin composition with excellent i-ray transmittance and excellent developability, development contrast, and heat resistance when formed into a resist film, etc. is obtained. In addition, the storage stability of the positive photosensitive resin composition is improved.

[0037] ·Ingredients (A)

[0038] The novolac-type phenol resin as the component (A) comprises a phenol structural unit (a1) derived from m-cresol and / or o-cresol and an aldehyde structural unit (a2) derived from salicylaldehyde, and has an acetal-based protective group.

[0039] The novolac-type phenol resin as the component (A) preferably further contains a structural unit (a3) ​​derived from benzaldehyde and / or acetaldehyde.

[0040] When the novolac-type phenol resin further includes the structural unit (a3) ​​derived from benzaldehyde and / or acetaldehyde, the acetal-based protective group can be suppressed from being released over time, thereby improving the storage stability of the novolac-type phenol resin.

[0041] The novolac-type phenol resin as component (A) preferably comprises a structural unit (a1) derived from m-cresol, a structural unit (a2) derived from salicylaldehyde, and a structural unit (a3) ​​derived from benzaldehyde and / or acetaldehyde in a molar ratio [(a1):(a2):(a3)] satisfying 1.0:0.2-0.8:0.2-0.8.

[0042] From the viewpoint of obtaining a resist film having high developability and heat resistance, the molar ratio of the structural unit (a1) derived from m-cresol, the unit (a2) derived from salicylaldehyde, and the structural unit (a3) ​​derived from benzaldehyde and / or acetaldehyde possessed by component (A) [(a1):(a2):(a3)] is preferably 1.0:0.3-0.8:0.3-0.8, more preferably 1.0:0.35-0.75:0.35-0.75, and further preferably 1.0:0.4-0.65:0.4-0.65.

[0043] Component (A) may contain structural units other than the structural unit (a1) derived from m-cresol, the unit (a2) derived from salicylaldehyde, and the structural unit (a3) ​​derived from benzaldehyde and / or acetaldehyde.

[0044] Examples of the structural units other than (a1) to (a3) ​​include structural units derived from phenols or aldehydes other than m-cresol, benzaldehyde, acetaldehyde, and salicylaldehyde.

[0045] Examples of the phenols include phenol, o-cresol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, and 3,4,5-trimethylphenol.

[0046] Examples of the aldehydes include propionaldehyde, butyraldehyde, valeraldehyde, hexanal, chloroacetaldehyde, 4-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 2-methoxybenzaldehyde, 3-nitrobenzaldehyde, benzaldehyde, cinnamaldehyde, 1-naphthaldehyde, 2-naphthaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, and 4-biphenylaldehyde.

[0047] Regarding the aldehydes, the novolac-type phenol resin as the component (A) preferably does not contain an aldehyde structural unit (a4) derived from formaldehyde.

[0048] When the novolac-type phenol resin as component (A) contains an aldehyde structural unit (a4) derived from formaldehyde, the content of the aldehyde structural unit (a4) derived from formaldehyde is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably less than 3% by mass, based on the total amount of repeating units of the novolac-type phenol resin.

[0049] The total content of the structural unit (a1), the structural unit (a2), and the structural unit (a3) ​​in the repeating units of the novolac-type phenol resin as component (A) is preferably 30% by mass or more, more preferably 50% by mass or more, further preferably 80% by mass or more, and particularly preferably 90% by mass or more.

[0050] The total content of the structural unit (a1), the structural unit (a2), and the structural unit (a3) ​​may be substantially 100% by mass. In addition, the term "substantially 100% by mass" also includes the case where structural units other than the structural unit (a1), the structural unit (a2), and the structural unit (a3) ​​are inevitably contained.

[0051] The acetal-based protecting group possessed by component (A) has a structure derived from a compound containing two or more vinyl ether groups, and is preferably, for example, at least one of the groups represented by the following formula (1) and formula (2).

[0052] [Chemistry 1]

[0053]

[0054] (wherein, R1, R2, R7 and R8 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms;

[0055] R3 is a linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, a cyclic alkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group formed by bonding two or more groups selected from the group consisting of the linear alkylene group, branched alkylene group, cyclic alkylene group, and arylene group; R3 may bond with R1, R2, R7, or R8 to form a ring;

[0056] R4 to R6 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms;

[0057] *Bonded to the benzene ring constituting the main chain of the novolac type phenol resin)

[0058] In component (A), at least a portion of the phenolic hydroxyl groups of the novolac-type phenol resin are protected by acetal-based protecting groups represented by formula (1) and formula (2). The acetal-based protecting groups can be removed by an acid generated from a photoacid generator.

[0059] When component (A) has an acetal protective group, 13 The results were confirmed by C-NMR.

[0060] In formula (1) and formula (2), examples of the linear alkyl group having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl.

[0061] Examples of the branched alkyl group having 3 to 20 carbon atoms include isopropyl, sec-butyl, tert-butyl, neopentyl, isopentyl, 2-methylpentyl, 3-methylpentyl, and 2,3-dimethylbutyl.

[0062] Examples of the cyclic alkyl group having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl. The cyclic alkyl group may have a substituent such as the linear alkyl group described above.

[0063] Examples of the aryl group having 6 to 20 carbon atoms include phenyl, naphthyl, anthracenyl, etc. The aryl group may have a substituent such as the alkyl group described above.

[0064] Examples of the linear alkylene group having 1 to 20 carbon atoms, the branched alkylene group having 3 to 20 carbon atoms, the cyclic alkylene group having 3 to 20 carbon atoms, and the arylene group having 6 to 20 carbon atoms include divalent groups obtained by forming a single bond between one hydrogen atom of the linear alkyl group, branched alkyl group, cyclic alkyl group, and aryl group.

[0065] Examples of the group formed by bonding two or more groups selected from the above-mentioned linear alkylene groups, branched alkylene groups, cyclic alkylene groups, and arylene groups include divalent groups represented by the following formula (A).

[0066] -Ra-Cyc-Rb-(A)

[0067] (wherein, Ra and Rb are linear or branched alkylene groups, and Cyc is a cyclic alkylene group or an arylene group)

[0068] R3 may be bonded with R1, R2, R7 or R8 to form a ring. Examples of the ring include oxygen-containing heterocycles such as a furan ring and a pyran ring.

[0069] R1, R2, and R4 to R8 are each independently preferably a hydrogen atom or a linear alkyl group having 1 to 4 carbon atoms, and particularly preferably a hydrogen atom or a methyl group.

[0070] R3 is preferably a straight-chain alkylene group having 1 to 4 carbon atoms, a branched alkylene group having 3 to 6 carbon atoms, a cyclic alkylene group having 3 to 6 carbon atoms, an arylene group having 6 to 14 carbon atoms, or a group formed by bonding two or more groups selected from the above straight-chain alkylene groups, branched alkylene groups, cyclic alkylene groups and arylene groups. It is more preferably a group formed by bonding a straight-chain alkylene group having 1 to 4 carbon atoms and a cyclohexanediyl group, and is particularly preferably a group represented by -CH2-Cyhex-CH2- (Cyhex is cyclohexanediyl).

[0071] The protection ratio of the phenolic hydroxyl groups in the novolac-type phenol resin in component (A) (the ratio of the bonds of the acetal-based protecting groups relative to the total amount of phenolic hydroxyl groups in the novolac-type phenol resin) is 1 mol% to 50 mol%, preferably 2 mol% to 40 mol%, more preferably 5 mol% to 25 mol%, and still more preferably 7.5 mol% to 15 mol%, from the viewpoint of making the dissolution rate in the alkaline developer appropriate.

[0072] The weight average molecular weight of the novolac type phenol resin as component (A) is preferably 1,000 or more, more preferably 3,000 or more, and particularly preferably 5,000 or more. In addition, it is preferably 30,000 or less, more preferably 25,000 or less, further preferably 20,000 or less, and particularly preferably 15,000 or less. When the weight average molecular weight is 1,000 or more, it is preferred because it is highly heat-resistant. On the other hand, when the weight average molecular weight is 30,000 or less, it is preferred because it is highly sensitive. In addition, in this specification, the weight average molecular weight is measured according to the conditions described in the examples.

[0073] Component (A) is preferably obtained by polycondensing at least one of m-cresol, salicylaldehyde, benzaldehyde and / or acetaldehyde in an organic solvent at a molar ratio (m-cresol: salicylaldehyde: benzaldehyde + acetaldehyde) within the range of 1.0:0.2 to 0.8:0.2 to 0.8 using an acid catalyst to obtain a novolac-type phenol resin (a), and then further reacting it with a compound that forms an acetal-based protective group.

[0074] Hereinafter, the synthesis of the novolac-type phenol resin (a) and the introduction of the acetal-based protective group will be described.

[0075] (Synthesis of Novolac-Type Phenolic Resin (a))

[0076] The novolac-type phenol resin (a) can be obtained, for example, by dissolving a raw material compound in a reaction solvent according to a conventional method and conducting a synthesis reaction using an acid catalyst.

[0077] Examples of the reaction solvent used in the production of the novolac-type phenolic resin (a) include methanol, ethanol, 1-propanol, 2-propanol, butanol, hexanol, ethylene glycol, ethylene glycol monomethyl ether, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone, and toluene. Among these, one or more selected from ethanol, 1-propanol, and 2-propanol are preferred, and ethanol or methyl isobutyl ketone is more preferred.

[0078] From the perspective of obtaining a resist film with high sensitivity and chemical resistance under low-temperature curing, the molar ratio of meta-cresol, salicylaldehyde, benzaldehyde and / or acetaldehyde in the reaction solvent (meta-cresol: salicylaldehyde: benzaldehyde + acetaldehyde) is preferably 1.0:0.3~0.8:0.3~0.8, more preferably 1.0:0.35~0.75:0.35~0.75, and further preferably 1.0:0.4~0.65:0.4~0.65.

[0079] Furthermore, derivatives may be used as starting compounds. For example, secondary aldehydes may be used as starting compounds for forming structural units derived from acetaldehyde.

[0080] When the novolac-type phenol resin (a) is obtained by polycondensing m-cresol, salicylaldehyde, and benzaldehyde in an organic solvent, the organic solvent may contain phenols and aldehydes other than m-cresol, salicylaldehyde, benzaldehyde, and acetaldehyde, as described above.

[0081] From the perspective of obtaining a film with high sensitivity and heat resistance under low-temperature curing, the ratio of the total mass of m-cresol, benzaldehyde, acetaldehyde and salicylaldehyde in the reaction solvent to the total mass of all starting materials that can become structural units constituting component (A) is preferably 50 mass% or more, 70 mass% or more, 80 mass% or more, and 90 mass% or more, in that order, and more preferably substantially 100 mass%.

[0082] The amount of the reaction solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, relative to 100 parts by mass of the raw material from which the structural units of component (A) are derived, from the viewpoint of reaction uniformity. Furthermore, it is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

[0083] Examples of the acid catalyst used in the production of the novolac-type phenolic resin (a) include inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, and boric acid; and organic acids such as oxalic acid, acetic acid, and p-toluenesulfonic acid. Of these, inorganic acids and p-toluenesulfonic acid are preferred, and p-toluenesulfonic acid is more preferred, in order to further promote the reaction.

[0084] The amount of the acid catalyst added is not particularly limited, but is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, relative to 100 parts by mass of the raw materials from which the structural units constituting component (A) are derived. Furthermore, it is preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

[0085] The reaction temperature for polycondensing the raw materials of the novolac-type phenol resin (a) is preferably 30°C or higher, more preferably 40°C or higher, and preferably 100°C or lower, more preferably 80°C or lower, in order to promote the reaction and efficiently increase the molecular weight.

[0086] The reaction time is preferably 4 hours or longer, more preferably 12 hours or longer, and preferably 32 hours or shorter, more preferably 24 hours or shorter.

[0087] (Introduction of acetal-based protecting group)

[0088] The method for introducing the acetal-based protecting group is not particularly limited, and one example includes a method in which the novolac resin (a) and a compound capable of forming an acetal-based protecting group are placed in a reaction solvent and reacted using an acid catalyst.

[0089] The acetal-based protecting group is generated by reacting the phenolic hydroxyl group in the novolac-type phenol resin (a) with a compound that forms an acetal-based protecting group in the presence of an acid catalyst, thereby protecting the phenolic hydroxyl group in the novolac-type phenol resin (a).

[0090] The reaction solvent used for the introduction of the acetal-based protecting group is preferably the reaction solvent used for the synthesis of the novolac-type phenol resin (a). The reaction solvent used for the introduction of the acetal-based protecting group is preferably methyl isobutyl ketone.

[0091] The acid catalyst used for the introduction of the acetal-based protecting group is preferably the acid catalyst used for the synthesis of the novolac-type phenol resin (a). Of these, inorganic acids and p-toluenesulfonic acid are preferred, and p-toluenesulfonic acid is more preferred, in order to further promote the reaction.

[0092] When introducing an acetal-based protecting group, the reaction time is preferably 1 hour or longer, more preferably 2 hours or longer, and preferably 10 hours or shorter, more preferably 6 hours or shorter.

[0093] When the acetal-based protecting group is introduced, the reaction temperature can be the same as that used in the synthesis of the novolac-type phenol resin (a).

[0094] In the present embodiment, the compound that forms an acetal-based protecting group is preferably a compound represented by the following formula (3).

[0095] [Chemistry 2]

[0096]

[0097] (wherein, R3 is a linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, a cyclic alkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group formed by bonding two or more groups selected from the group consisting of the linear alkylene group, the branched alkylene group, the cyclic alkylene group, and the arylene group;

[0098] R4~R6 and R9~R 11 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms)

[0099] In formula (3), specific examples of the linear alkyl group having 1 to 20 carbon atoms, the branched alkyl group having 3 to 20 carbon atoms, the cyclic alkyl group having 3 to 20 carbon atoms, the aryl group having 6 to 20 carbon atoms, the linear alkylene group having 1 to 20 carbon atoms, the branched alkylene group having 3 to 20 carbon atoms, the cyclic alkylene group having 3 to 20 carbon atoms, the arylene group having 6 to 20 carbon atoms, or the group formed by bonding two or more groups selected from the linear alkylene group, the branched alkylene group, the cyclic alkylene group and the arylene group are the same as those in formula (1) and formula (2).

[0100] R3, R4~R6 and R9~R 11 Any two of them can be bonded to form a ring, for example, R3 and R6 can be bonded to form a cyclic ether.

[0101] Examples of the compound forming an acetal-based protecting group include ethylene glycol divinyl ether, 1,2-propylene glycol divinyl ether, 1,3-propylene glycol divinyl ether, propylene glycol divinyl ether, triethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, 1,2-butanediol divinyl ether, 2,3-butanediol divinyl ether, 1,3-butanediol divinyl ether, 1,4-butanediol divinyl ether, 1,5-pentanediol divinyl ether, 1,6-hexanediol divinyl ether, and the like. Glycol divinyl ether, tetramethylene glycol divinyl ether, neopentyl glycol divinyl ether, trimethylolpropane trivinyl ether, trimethylolethane trivinyl ether, hexanediol divinyl ether, 1,4-cyclohexanediol divinyl ether, tetraethylene glycol divinyl ether, pentaerythritol divinyl ether, pentaerythritol trivinyl ether, cyclohexanedimethanol divinyl ether, 1-methyl-1,3-propanediol divinyl ether, 2-methyl-1,3-propanediol divinyl ether, 2-methyl-1,2-propanediol divinyl ether, etc. Among these, cyclohexanedimethanol divinyl ether is more preferred.

[0102] In this embodiment, in order to obtain good developability (sensitivity) and development contrast, the amount of the compound forming the acetal-based protecting group is preferably 1 part by mass or more, more preferably 5 parts by mass or more, per 100 parts by mass of the novolac-type phenol resin (a). Furthermore, it is preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

[0103] Component (B)

[0104] The photoacid generator, component (B), refers to a compound that generates an acid by cleaving bonds upon exposure. The inclusion of a photoacid generator allows the acid generated by the photoacid generator to dissociate the acetal-based protecting group from component (A) in the exposed areas. This reaction exposes the phenolic hydroxyl groups of the novolac-type phenol resin, creating a difference in alkali solubility between the unexposed and exposed areas. This improves developability (sensitivity) and development contrast when forming a resist film from the positive-type photosensitive resin composition.

[0105] The photoacid generator is not particularly limited, and known photoacid generators can be used, for example, organic halogen compounds, sulfonates, onium salts (phosphonium salts, sulfonium salts, iodonium salts, etc.), diazonium salts, diazomethane compounds, nitrobenzyl compounds, disulfone compounds, triazine-based photoacid generators, etc.

[0106] In one embodiment, the photoacid generator is not naphthoquinone diazide.

[0107] Specific examples of the photoacid generator include the following.

[0108] s-triazine derivatives containing a haloalkyl group, such as tris(trichloromethyl)-s-triazine, tris(tribromomethyl)-s-triazine, tris(dibromomethyl)-s-triazine, 2,4-bis(tribromomethyl)-6-p-methoxyphenyl-s-triazine, and (2-[2-(5-methylfuran-2-yl)vinyl]-4,6-bis(trichloromethyl)-s-triazine);

[0109] Halogen-substituted paraffin hydrocarbon compounds such as 1,2,3,4-tetrabromobutane, 1,1,2,2-tetrabromoethane, carbon tetrabromide, and triiodomethane; halogen-substituted cycloparaffin hydrocarbon compounds such as hexabromocyclohexane, hexachlorocyclohexane, and hexabromocyclododecane;

[0110] Benzene derivatives containing alkyl halide such as bis(trichloromethyl)benzene and bis(tribromomethyl)benzene; sulfone compounds containing alkyl halide such as tribromomethylphenylsulfone and trichloromethylphenylsulfone; halogen-containing sulfolane compounds such as 2,3-dibromosulfolane; isocyanurate compounds containing alkyl halide such as tris(2,3-dibromopropyl)isocyanurate;

[0111] Sulfonium salts such as triphenylsulfonium chloride, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate, triphenylsulfonium methanesulfonate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroarsenate, and triphenylsulfonium hexafluorophosphonate;

[0112] Iodine salts such as diphenyliodinium trifluoromethanesulfonate, diphenyliodinium p-toluenesulfonate, diphenyliodinium tetrafluoroborate, diphenyliodinium hexafluoroarsenate, and diphenyliodinium hexafluorophosphonate;

[0113] Sulfonate compounds such as methyl p-toluenesulfonate, ethyl p-toluenesulfonate, butyl p-toluenesulfonate, phenyl p-toluenesulfonate, 1,2,3-tris(p-toluenesulfonyloxy)benzene, benzoin p-toluenesulfonate, methyl methanesulfonate, ethyl methanesulfonate, butyl methanesulfonate, 1,2,3-tris(methanesulfonyloxy)benzene, phenyl methanesulfonate, benzoin methanesulfonate, methyl trifluoromethanesulfonate, ethyl trifluoromethanesulfonate, butyl trifluoromethanesulfonate, 1,2,3-tris(trifluoromethanesulfonyloxy)benzene, phenyl trifluoromethanesulfonate, and benzoin trifluoromethanesulfonate; disulfone compounds such as diphenyl disulfone;

[0114] Bis(phenylsulfonyl)diazomethane, bis(2,4-dimethylphenylsulfonyl)diazomethane, bis(cyclohexylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-fluorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-fluorophenylsulfonyl)diazomethane, cyclohexylsulfonyl- (4-Fluorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-fluorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-fluorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-fluorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-chlorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-chlorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-chlorophenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-chlorophenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-trifluoromethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl Acyl-(3-trifluoromethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-trifluoromethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-trifluoromethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-trifluoromethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(4-trifluoromethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2-trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(3-trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(4-trifluoromethoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2-trifluoromethoxyphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(3-trifluoromethoxyphenylsulfonyl)diazomethane, sulfonyl)diazomethane, cyclopentylsulfonyl-(4-trifluoromethoxyphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane, cyclohexylsulfonyl-(2,3,4-triethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, cyclopentylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane,4-triethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(3-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(4-methoxyphenylsulfonyl)diazomethane, bis(2-methoxyphenylsulfonyl)diazomethane, bis(3-methoxyphenylsulfonyl)diazomethane, bis(4-methoxyphenylsulfonyl)diazomethane, phenylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, Sulfone diazide compounds such as phenylsulfonyl-(2,4,6-triethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2,3,4-triethylphenylsulfonyl)diazomethane, 2,4-dimethylphenylsulfonyl-(2,4,6-trimethylphenylsulfonyl)diazomethane, 2,4-dimethylphenylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2-fluorophenylsulfonyl)diazomethane, phenylsulfonyl-(3-fluorophenylsulfonyl)diazomethane, and phenylsulfonyl-(4-fluorophenylsulfonyl)diazomethane;

[0115] o-Nitrobenzyl-p-toluenesulfonate and other o-nitrobenzyl ester compounds;

[0116] Sulfone hydrazide compounds such as N,N'-bis(phenylsulfonyl)hydrazide;

[0117] The salt formed by sulfonium cations such as triarylsulfonium and triaralkylsulfonium and sulfonates such as fluoroalkanesulfonates, arenesulfonates and alkanesulfonates is a sulfonium salt;

[0118] The salt formed by iodonium cations such as diaryliodonium and sulfonates such as fluoroalkanesulfonates, arenesulfonates, and alkanesulfonates is called iodonium salt;

[0119] Bissulfonyldiazomethane compounds such as bis(alkylsulfonyl)diazomethane, bis(cycloalkylsulfonyl)diazomethane, bis(perfluoroalkylsulfonyl)diazomethane, bis(arylsulfonyl)diazomethane, and bis(aralkylsulfonyl)diazomethane;

[0120] N-sulfonyloxyimide compounds formed by combining a dicarboxylic acid imide compound with a sulfonate such as a fluoroalkanesulfonate, an aromatic hydrocarbon sulfonate, or an alkanesulfonate;

[0121] Benzoin sulfonate (salt) compounds such as benzoin toluenesulfonate (salt), benzoin methanesulfonate (salt), and benzoin butanesulfonate (salt);

[0122] Polyhydroxy aromatic hydrocarbon sulfonate (salt) compounds obtained by replacing all hydroxyl groups of polyhydroxy aromatic hydrocarbon compounds with sulfonate (salt) such as fluoroalkane sulfonate (salt), aromatic hydrocarbon sulfonate (salt), alkane sulfonate (salt) and the like;

[0123] Nitrobenzyl sulfonate compounds such as nitrobenzyl fluoroalkanesulfonate (poly)nitrobenzyl ester, nitrobenzyl arenesulfonate (poly)nitrobenzyl ester, and nitrobenzyl alkanesulfonate (poly)nitrobenzyl ester;

[0124] Fluorinated alkane benzyl sulfonate compounds such as (poly)fluoroalkane benzyl sulfonate, (poly)fluoroalkane benzyl sulfonate, and (poly)fluoroalkane benzyl sulfonate;

[0125] Bis(arylsulfonyl)alkane compounds;

[0126] Bis-O-(arylsulfonyl)-α-dialkylglyoxime, bis-O-(arylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(arylsulfonyl)-α-diarylglyoxime, bis-O-(alkylsulfonyl)-α-dialkylglyoxime, bis-O-(alkylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(alkylsulfonyl)-α-diarylglyoxime, bis-O-(fluoroalkylsulfonyl)-α-dialkylglyoxime, bis-O-(fluoroalkylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(fluoroalkylsulfonyl)-α-diarylglyoxime Oxime compounds such as bis-O-(arylsulfonyl)-α-dialkyldioxime, bis-O-(arylsulfonyl)-α-dicycloalkyldioxime, bis-O-(arylsulfonyl)-α-diaryldioxime, bis-O-(alkylsulfonyl)-α-dialkyldioxime, bis-O-(alkylsulfonyl)-α-dicycloalkyldioxime, bis-O-(alkylsulfonyl)-α-diaryldioxime, bis-O-(fluoroalkylsulfonyl)-α-dialkyldioxime, bis-O-(fluoroalkylsulfonyl)-α-dicycloalkyldioxime, and bis-O-(fluoroalkylsulfonyl)-α-diaryldioxime;

[0127] Modified oxime compounds such as arylsulfonyloxyiminoarylacetonitrile, alkylsulfonyloxyiminoarylacetonitrile, fluoroalkylsulfonyloxyiminoarylacetonitrile, ((arylsulfonyl)oxyimino-thiophene-ylidene)arylacetonitrile, ((alkylsulfonyl)oxyimino-thiophene-ylidene)arylacetonitrile, ((fluoroalkylsulfonyl)oxyimino-thiophene-ylidene)arylacetonitrile, bis(arylsulfonyloxyimino)arylenediacetonitrile, bis(alkylsulfonyloxyimino)arylenediacetonitrile, bis(fluoroalkylsulfonyloxyimino)arylenediacetonitrile, arylfluoroalkanone-O-(alkylsulfonyl)oxime, arylfluoroalkanone-O-(arylsulfonyl)oxime, and arylfluoroalkanone-O-(fluoroalkylsulfonyl)oxime.

[0128] The photoacid generators may be used alone or in combination of two or more.

[0129] The amount of the photoacid generator added is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, relative to 100 parts by mass of component (A), from the viewpoint of ensuring that the positive photosensitive resin composition has good i-ray transmittance and that good developability (sensitivity) and heat resistance are obtained when the positive photosensitive resin composition is formed into a resist film or the like. Furthermore, it is preferably 20 parts by mass or less, more preferably 5 parts by mass or less.

[0130] Component (C)

[0131] Examples of the solvent for component (C) include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N,N-dimethylformamide, N,N-dimethylacetamide, and dimethyl sulfoxide; ethers such as tetrahydrofuran, dioxane, propylene glycol monomethyl ether, and propylene glycol monoethyl ether; ketones such as acetone, methyl ethyl ketone, and diisobutyl ketone; esters such as ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, and 3-methyl-3-methoxybutyl acetate; alcohols such as ethyl lactate, methyl lactate, diacetone alcohol, and 3-methyl-3-methoxybutanol; and aromatic hydrocarbons such as toluene and xylene. These solvents may be used alone or in combination of two or more.

[0132] In order to obtain a uniform coating film by a coating method such as spin coating by utilizing the fluidity of the composition, the amount of solvent added to the positive photosensitive resin composition of this embodiment is preferably such that the solids concentration in the composition is 5% by mass or more. Furthermore, it is preferably such that the solids concentration in the composition is 65% by mass or less.

[0133] Other ingredients

[0134] In one embodiment, in addition to the components (A) to (C) described above, various additives may be added to the positive photosensitive resin composition within a range that does not impair the effects of the present invention. Examples of the additives include fillers, pigments, surfactants such as leveling agents, adhesion enhancers, and dissolution accelerators.

[0135] The positive photosensitive resin composition of the present embodiment can be prepared by stirring and mixing the components (A) to (C) and, if necessary, various additives by a common method to form a uniform liquid.

[0136] When solid substances such as fillers and pigments are mixed with the composition, they are preferably dispersed and mixed using a dispersing device such as a dissolver, a homogenizer, or a three-roll mill. Furthermore, the composition may be filtered using a mesh filter, a membrane filter, or the like to remove coarse particles or impurities.

[0137] The positive photosensitive resin composition of this embodiment can be suitably used for applications such as a resist film, a resist underlayer film, and a resist permanent film.

[0138] The positive photosensitive resin composition of the present invention can be formed into a resist film, a resist underlayer film, and a resist permanent film (hereinafter sometimes referred to collectively as a resist film, etc.) by the same method as a general positive photosensitive resin composition.

[0139] Specifically, by applying the positive photosensitive resin composition of the present invention onto an object to be photolithographically processed and pre-baking the composition, a film of the photosensitive resin composition (photosensitive film) from which the solvent has been removed can be obtained.

[0140] Examples of coating methods include spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. Prebaking may be performed by heating at a temperature of 60°C to 150°C for 30 seconds to 600 seconds. The positive-type photosensitive resin composition of the present invention can be applied to a glass substrate, a silicon substrate, an aluminum substrate, a silicon carbide substrate, a silicon nitride substrate, a gallium nitride substrate, a transparent conductive film, a copper substrate, or a copper-plated substrate.

[0141] The acid catalytic reaction generated by exposing the photosensitive film to light causes the acetal-based protecting group to dissociate from component (A), significantly increasing the solubility of the exposed portion in an alkaline developer. Examples of light sources used for exposure include infrared light, visible light, ultraviolet light, extreme ultraviolet light, X-rays, and electron beams. Among these light sources, ultraviolet light is preferred, and g-rays (wavelength 436 nm) and i-rays (wavelength 365 nm) from a high-pressure mercury lamp are suitable.

[0142] After exposure, a heat treatment at about 100° C. to 150° C. may be performed to promote the reaction of removing the acetal-based protective group from the component (A).

[0143] The photosensitive film obtained from the positive-type photosensitive resin composition of the present invention has high alkali solubility in the exposed portion and a large difference in alkali solubility between the exposed portion and the unexposed portion, enabling high-resolution patterning. Therefore, it is suitable for use as a resist film, etc. In this application, the term "resist film," etc., includes both the photosensitive film before exposure and the non-photosensitive film after exposure.

[0144] Examples of the alkaline developer used in post-exposure development include inorganic alkaline substances such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, and aqueous ammonia; primary amines such as ethylamine and n-propylamine; secondary amines such as diethylamine and di-n-butylamine; tertiary amines such as triethylamine and methyldiethylamine; alcohol amines such as dimethylethanolamine and triethanolamine; quaternary ammonium salts such as tetramethylammonium hydroxide and tetraethylammonium hydroxide; and alkaline aqueous solutions of cyclic amines such as pyrrole and piperidine.

[0145] The alkali developer may be added with alcohol, surfactant, etc. as needed. The alkali concentration of the alkali developer is preferably in the range of 2% to 5% by mass, and a 2.38% by mass tetramethylammonium hydroxide aqueous solution is generally used.

[0146] When the positive photosensitive resin composition of the present invention is used for a resist underlayer film (bottom anti-reflection coating (BARC) film), the positive photosensitive resin composition of the present invention can be used directly as a resist underlayer film composition. In addition, various additives such as other resin components, surfactants, dyes, fillers, crosslinking agents, and dissolution promoters can be added as needed.

[0147] Examples of other resin components include various novolac resins, addition polymerization resins of alicyclic diene compounds such as dicyclopentadiene and phenolic compounds, modified novolac resins of phenolic hydroxyl group-containing compounds and alkoxy group-containing aromatic compounds, phenol aralkyl resins (Xylock resins), naphthol aralkyl resins, trimethylolmethane resins, tetrahydroxyphenylethane resins, biphenyl-modified phenol resins, biphenyl-modified naphthol resins, aminotriazine-modified phenol resins, and various vinyl polymers.

[0148] When other resin components are used, the ratio of the positive photosensitive resin composition of the present invention to the other resin can be arbitrarily set according to the application. For example, the ratio of the other resin to 100 parts by mass of component (A) is preferably 0.5 to 100 parts by mass.

[0149] The resist underlayer film composition can be prepared by blending the above-mentioned components and mixing them using a stirrer, etc. If the resist underlayer film composition contains a filler or a pigment, it can be adjusted by dispersing or mixing them using a dispersing device such as a dissolver, a homogenizer, or a three-roll mill.

[0150] To form a resist underlayer film from a resist underlayer film composition, for example, there is a method in which the resist underlayer film composition is applied to an object to be photolithographically processed, such as a silicon substrate, dried at a temperature of 100°C to 200°C, and then cured by heating at a temperature of 250°C to 400°C. Subsequently, a conventional photolithography operation is performed on the underlayer film to form a resist pattern, and dry etching is performed using a halogen plasma gas or the like to form a resist pattern using a multilayer resist method.

[0151] When the positive photosensitive resin composition of the present invention is used for resist permanent film applications, in addition to the components (A) to (C) of the present invention, additives such as other resins, surfactants, dyes, fillers, crosslinking agents, and dissolution accelerators may be added as needed. Examples of the other resin used herein include the same resins as those used in the resist underlayer film composition.

[0152] In a photolithography method using a resist permanent film composition, for example, other resin components and additive components are dissolved and dispersed in the positive-type photosensitive resin composition of the present invention. The composition is then applied to the object to be photolithographically processed and prebaked at a temperature of 60°C to 150°C. The coating method may be any of spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. Next, the target resist pattern is exposed through a predetermined mask, and the exposed areas are dissolved with an alkaline developer to form a resist pattern.

[0153] The permanent resist film of this embodiment can be suitably used in, for example, solder resists, packaging materials, bottom filling materials, packaging adhesive layers of circuit elements, and adhesive layers between integrated circuit elements and circuit substrates for semiconductor devices. In addition, it can be suitably used in thin-film transistor protective films, liquid crystal color filter protective films, black matrices, spacers, and the like for thin-film displays represented by liquid crystal displays (LCDs) and organic light-emitting diodes (OELDs).

[0154] [Example]

[0155] The present invention will be described in further detail below with reference to specific examples. The weight average molecular weight (Mw) of the synthesized resin was measured under the following gel permeation chromatography (GPC) conditions.

[0156] [GPC measurement conditions]

[0157] Measuring device: HLC-8220GPC manufactured by Tosoh Corporation

[0158] Tube: "Shodex KF802" manufactured by Showa Denko Co., Ltd.: 8.0mm φ × 300mm

[0159] + "Shodex KF802" manufactured by Showa Denko Co., Ltd.: 8.0 mm φ × 300 mm

[0160] + "Shodex KF803" manufactured by Showa Denko Co., Ltd.: 8.0 mm φ × 300 mm

[0161] + "Shodex KF804" manufactured by Showa Denko Co., Ltd.: 8.0 mm φ × 300 mm

[0162] Column temperature: 40°C

[0163] Detector: RI (differential refractometer)

[0164] Data processing: "GPC-8020 Model II Version 4.30" manufactured by Tosoh Corporation

[0165] Developing solvent: tetrahydrofuran

[0166] Flow rate: 1.0 mL / min

[0167] Sample: A tetrahydrofuran solution containing 0.5% by mass in terms of resin solid content was filtered through a microfilter.

[0168] Injection volume: 0.1mL

[0169] Standard sample: Monodisperse polystyrene as follows

[0170] (Standard sample: monodisperse polystyrene)

[0171] "A-500" manufactured by Tosoh Co., Ltd.

[0172] "A-2500" manufactured by Tosoh Co., Ltd.

[0173] "A-5000" manufactured by Tosoh Co., Ltd.

[0174] "F-1" manufactured by Tosoh Co., Ltd.

[0175] "F-2" manufactured by Tosoh Co., Ltd.

[0176] "F-4" manufactured by Tosoh Co., Ltd.

[0177] "F-10" manufactured by Tosoh Co., Ltd.

[0178] "F-20" manufactured by Tosoh Co., Ltd.

[0179] Synthesis Example 1 (Synthesis of Novolac-Type Phenolic Resin (A-1) Having an Acetal Protective Group)

[0180] Into a 2000ml four-necked flask equipped with a cooling tube, 164g (1.52mol) of m-cresol, 103g (0.97mol) of benzaldehyde, 74g (0.61mol) of salicylaldehyde, and 8g of p-toluenesulfonic acid were charged and dissolved in 300g of ethanol as a reaction solvent. The mixture was then heated with a hooded heater and stirred at 80°C under reflux for 16 hours to allow the reaction to proceed. After the reaction, ethyl acetate and water were added and the mixture was subjected to five liquid separation and washing operations. After the solvent was removed by vacuum distillation from the remaining resin solution, the mixture was vacuum dried to obtain 243g of a novolac-type phenolic resin powder (a-1) as a light red powder.

[0181] Next, in a 500ml four-necked flask, 80g of the obtained novolac type phenol resin powder (a-1) was dissolved in 120g of methyl isobutyl ketone. The mixture was heated to 100°C while stirring using a hooded heater. Next, 6g of cyclohexanedimethanol divinyl ether was added and allowed to react for 24 hours. After the reaction, the methyl isobutyl ketone was removed by distillation under reduced pressure, and then vacuum dried to obtain 82g of novolac type phenol resin (A-1) as a light red powder. The weight average molecular weight (Mw) of the novolac type phenol resin (A-1) is 8,940. Using 13 C-NMR confirmed that the novolac-type phenol resin (A-1) had an acetal-based protective group.

[0182] Synthesis Example 2 (Synthesis of Novolac-type Phenolic Resin (A-2))

[0183] 35 g of a novolac-type phenol resin powder (A-2) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that the starting materials were charged in the amounts of 164 g (1.52 mol) of m-cresol, 80 g (0.75 mol) of benzaldehyde, and 81 g (0.75 mol) of salicylaldehyde. The novolac-type phenol resin (A-2) had an Mw of 9,120.

[0184] Synthesis Example 3 (Synthesis of Novolac-type Phenolic Resin (A-3))

[0185] 81 g of a novolac-type phenol resin powder (A-3) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that the starting materials were charged in the amounts of 164 g (1.52 mol) of m-cresol, 117 g (1.10 mol) of benzaldehyde, and 58 g (0.47 mol) of salicylaldehyde. The novolac-type phenol resin (A-3) had an Mw of 10,750.

[0186] Synthesis Example 4 (Synthesis of Novolac-type Phenolic Resin (A-4))

[0187] 35 g of a novolac-type phenol resin powder (A-4) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that the starting materials were charged in the amounts of 164 g (1.52 mol) of m-cresol, 82 g (0.63 mol) of benzaldehyde, and 115 g (0.94 mol) of salicylaldehyde. The novolac-type phenol resin (A-4) had an Mw of 11,920.

[0188] Synthesis Example 5 (Synthesis of Novolac-type Phenolic Resin (A-5))

[0189] 81 g of phenol novolac resin powder (A-5) having an acetal protective group was obtained in the same manner as in Synthesis Example 1, except that the reaction solvent was changed to 250 g of ethanol, 30 g of 1-propanol, and 15 g of 2-propanol. The Mw of the novolac phenol resin (A-5) was 9,200.

[0190] Synthesis Example 6 (Synthesis of Novolac-type Phenolic Resin (A-6))

[0191] 82 g of a novolac-type phenol resin powder (A-6) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that o-cresol was used instead of m-cresol. The Mw of the novolac-type phenol resin (A-6) was 9,080.

[0192] Synthesis Example 7 (Synthesis of Novolac-type Phenolic Resin (A-7))

[0193] 81 g of a novolac-type phenol resin powder (A-7) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that benzaldehyde was replaced with salicylaldehyde. The Mw of the novolac-type phenol resin (A-7) was 25,190.

[0194] Synthesis Example 8 (Synthesis of Novolac-type Phenolic Resin (A-8))

[0195] 54 g of novolac-type phenol resin powder (A-8) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that 103 g (0.97 mol) of benzaldehyde was replaced with 42 g (0.32 mol) of secondary aldehyde. The Mw of the novolac-type phenol resin (A-8) was 2,210.

[0196] Comparative Synthesis Example 1 (Synthesis of Novolac-Type Phenolic Resin (A-9))

[0197] Under a dry nitrogen stream, a 2000 ml four-necked flask equipped with a cooling tube was charged with 140 g (1.30 mol) of m-cresol, 76 g (0.7 mol) of p-cresol, 151 g of a 37 wt% aqueous formaldehyde solution (1.86 mol of formaldehyde), and 1 g (0.01 mol) of oxalic acid dihydrate. The mixture was dissolved in 528 g of methyl isobutyl ketone. The mixture was then heated with a hooded heater and stirred for 4 hours while refluxed to allow the reaction to proceed. After the reaction, water was added and the mixture was separated and washed five times. The methyl isobutyl ketone was removed by vacuum distillation at 60°C using an evaporator, followed by vacuum drying to obtain 212 g of a novolac-type phenolic resin (a-9) as a light red powder.

[0198] 81 g of novolac-type phenol resin powder (A-9) was obtained by crosslinking the novolac-type phenol resin (a-9) powder with cyclohexanedimethanol divinyl ether in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenol resin (A-9) was 14,400.

[0199] Comparative Synthesis Example 2 (Synthesis of Novolac-Type Phenolic Resin (A-10))

[0200] 82 g of a novolac-type phenol resin (A-10) powder having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that salicylaldehyde (2-hydroxybenzaldehyde) was replaced with 3-hydroxybenzaldehyde. The novolac-type phenol resin (A-10) had an Mw of 38,250.

[0201] Comparative Synthesis Example 3 (Synthesis of Novolac-Type Phenolic Resin (A-11))

[0202] 80 g of a novolac-type phenol resin powder (A-11) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that salicylaldehyde (2-hydroxybenzaldehyde) was replaced with 4-hydroxybenzaldehyde. The novolac-type phenol resin (A-11) had an Mw of 8,600.

[0203] Comparative Synthesis Example 4 (Synthesis of Novolac-Type Phenolic Resin (A-12))

[0204] 82 g of a novolac-type phenol resin powder (A-12) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that salicylaldehyde (2-hydroxybenzaldehyde) was replaced with benzaldehyde. The Mw of the novolac-type phenol resin (A-12) was 9,520.

[0205] Comparative Synthesis Example 5 (Synthesis of Novolac-Type Phenolic Resin (A-13))

[0206] A novolac-type phenol resin (A-13) was obtained in the same manner as in Synthesis Example 1, except that m-cresol was replaced with phenol. The novolac-type phenol resin (A-13) was in a gel state and did not dissolve in the solvent, so the evaluation described below could not be performed.

[0207] Comparative Synthesis Example 6 (Synthesis of Novolac-Type Phenolic Resin (A-14))

[0208] A novolac-type phenol resin (A-14) was obtained in the same manner as in Synthesis Example 1, except that m-cresol was replaced with 2,5-xylenol. The novolac-type phenol resin (A-14) had poor solubility in the solvent, and the evaluation described below could not be performed.

[0209] Comparative Synthesis Example 7 (Synthesis of Novolac-Type Phenolic Resin (A-15))

[0210] 55 g of a novolac-type phenol resin powder (A-15) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that catechol was used instead of m-cresol. The Mw of the novolac-type phenol resin (A-15) was 38,760.

[0211] Comparative Synthesis Example 8 (Synthesis of Novolac-Type Phenolic Resin (A-16))

[0212] 82 g of a novolac-type phenol resin powder (A-16) having an acetal-based protective group was obtained in the same manner as in Synthesis Example 1, except that 32 g (0.90 mol) of paraformaldehyde was used instead of 103 g (0.97 mol) of benzaldehyde. The Mw of the novolac-type phenol resin (A-16) was 18,920.

[0213] Comparative Synthesis Example 9 (Synthesis of Novolac-Type Phenolic Resin (A-17))

[0214] In a 500ml four-necked flask, 80g of novolac-type phenolic resin powder (a-1), 8g of ethyl vinyl ether and 0.1g of p-toluenesulfonic acid synthesized in the same manner as in Synthesis Example 1 were placed and dissolved in 120g of methyl isobutyl ketone as a reaction solvent. Then, the mixture was heated with a hooded heater and stirred at 40°C for 4 hours to allow it to react. After the reaction, 0.4g of dimethylaminoethanol was added, and after sufficient stirring, ethyl acetate and water were added to carry out liquid separation and washing 5 times. After removing the solvent by reduced pressure distillation from the residual resin solution, vacuum drying was carried out to obtain 36g of novolac-type phenolic resin powder (A-17) as a light red powder. The Mw of the novolac-type phenolic resin (A-17) was 3,140.

[0215] [Positive photosensitive resin composition]

[0216] Example 1

[0217] 1.98 g of the novolac-type phenol resin (A-1) powder obtained in Synthesis Example 1 and 0.02 g of a photoacid generator (CPI-110TF, manufactured by San-Apro Co., Ltd.) were dissolved in 8 g of propylene glycol monomethyl ether (PGME). The mixture was then finely filtered using a 0.1 μm polytetrafluoroethylene (PTFE) disk filter to obtain a positive photosensitive resin composition.

[0218] Examples 2 to 8, Comparative Examples 1 to 7

[0219] A positive photosensitive resin composition was prepared in the same manner as in Example 1 except that the novolac-type phenol resin shown in Table 1 and Table 2 was used as the component (A).

[0220] [evaluate]

[0221] The i-ray transmittance of the positive-type photosensitive resin compositions prepared in the Examples and Comparative Examples was evaluated. Furthermore, resist films were prepared using the positive-type photosensitive resin compositions, and the alkali solubility, development contrast, and heat resistance of the resist films were evaluated. Furthermore, the storage stability of the positive-type photosensitive resin compositions was evaluated.

[0222] (1) I-ray transparency

[0223] A positive-type photosensitive resin composition was diluted with propylene glycol monomethyl ether (PGME) to a solids content of 1% (mass fraction). The transmittance of the resulting 1% diluted positive-type photosensitive resin composition at an i-ray wavelength (365 nm) was evaluated using an ultraviolet (UV)-visible spectrophotometer (SolidSpec-3700 DUV manufactured by Shimadzu Corporation). The evaluation criteria are as follows.

[0224] ○: Transmittance (%) is 40% or more

[0225] ×: Transmittance (%) less than 40%

[0226] The evaluation results are shown in Tables 1 and 2. In addition, the numerical values ​​in parentheses in Tables 1 and 2 are transmittance values.

[0227] (2) Alkali developability

[0228] A positive photosensitive resin composition was applied to a 5-inch silicon wafer using a spin coater to a thickness of about 1 μm and dried on a hot plate at 110°C for 60 seconds to obtain a resist film. The resist film was then exposed to UV light at 200 mJ / cm² using a UV exposure device (UVE-1001SD manufactured by Sanei Electric Co., Ltd.). 2 After exposure, post-exposure baking (PEB) was performed on a hot plate at 130°C for 90 seconds. The obtained wafer with the resist film was immersed in a developer (2.38% tetramethylammonium hydroxide aqueous solution) for 60 seconds and then dried on a hot plate at 110°C for 60 seconds. The film thickness of the resist film before and after immersion in the developer was measured, and the difference was divided by 60 to obtain the value of the alkali solubility ADR1. The evaluation criteria are as follows.

[0229] ○: ADR1 is 200 or more

[0230] ×: ADR1 is less than 200

[0231] The evaluation results are shown in Tables 1 and 2. In addition, the numerical values ​​in parentheses in Tables 1 and 2 are the values ​​of ADR1.

[0232] (3) Development contrast

[0233] In the above (2), the value measured in the same manner without performing exposure of the resist film is referred to as ADR2. The value of ADR1 / ADR2 was defined as the development contrast. The evaluation criteria were as follows.

[0234] ○: Development contrast is 10 or more

[0235] ×: Development contrast is less than 10

[0236] The evaluation results are shown in Tables 1 and 2. In addition, the numerical values ​​in parentheses in Tables 1 and 2 are the values ​​of ADR1 / ADR2.

[0237] (4) Storage stability

[0238] The evaluation was conducted based on the change rate of ADR2 in (2). Positive-type photosensitive resin compositions with poor storage stability experience a rapid change in ADR2 due to the removal of protective groups. Specifically, the positive-type photosensitive resin composition was stored at room temperature for one month, and the storage stability was evaluated using the following formula based on the ADR2 before and after storage.

[0239] ADR2 change rate = (ADR2 after storage / ADR2 before storage) × 100

[0240] The evaluation criteria are as follows.

[0241] ○: ADR2 change rate is less than 120%

[0242] ×: ADR2 change rate is 120% or more

[0243] The evaluation results are shown in Tables 1 and 2. In addition, the numerical values ​​in parentheses in Tables 1 and 2 are the values ​​of the ADR2 change rate.

[0244] (5) Heat resistance

[0245] A positive photosensitive resin composition was applied to a 5-inch diameter silicon wafer using a spin coater and then dried at 110°C for 60 seconds to obtain a 1 μm thick film. This film was scraped and the glass transition temperature (hereinafter referred to as "Tg") was measured. Tg was measured using a differential scanning calorimeter (TA Instruments: Differential Scanning Calorimeter (DSC) Q100) in a nitrogen atmosphere at a temperature range of -100°C to 200°C and a heating rate of 10°C / minute.

[0246] The evaluation criteria are as follows.

[0247] ○: Tg is 150°C or higher

[0248] ×: Tg less than 150°C

[0249] The evaluation results are shown in Tables 1 and 2. In addition, the numerical values ​​in parentheses in Tables 1 and 2 are Tg values.

[0250] [Table 1]

[0251]

[0252] * In Example 1 and Example 5, the solvents used in the synthesis of component (A) were different.

[0253] [Table 2]

[0254]

[0255] In Tables 1 and 2, “Cr” refers to formaldehyde, “SA” refers to salicylaldehyde, “BzA” refers to benzaldehyde, “AA” refers to acetaldehyde, “3HyBzA” refers to 3-hydroxybenzaldehyde, “4HyBzA” refers to 4-hydroxybenzaldehyde, “HA” refers to formaldehyde, and “CC” refers to catechol.

[0256] In Tables 1 and 2, "CyHDMDVE" refers to cyclohexanedimethanol divinyl ether, and "EVE" refers to ethyl vinyl ether.

[0257] For example, "m-Cr / BzA / SA" of Example 1 is "1 / 0.64 / 0.4", which means that the novolac-type phenolic resin as component (A) of Example 1 contains units derived from m-cresol, units derived from salicylaldehyde, and units derived from benzaldehyde, and the molar ratio satisfies the following: units derived from m-cresol: units derived from salicylaldehyde: units derived from benzaldehyde = 1:0.64:0.4.

[0258] The results in Tables 1 and 2 show that the positive photosensitive resin composition of the present invention has excellent i-ray transmittance and storage stability. It also shows that the resist film using the positive photosensitive resin composition of the present invention has excellent alkali solubility, development contrast, and heat resistance.

Claims

1. A positive photosensitive resin composition comprising the following components A to C, Component A: a novolac-type phenolic resin comprising a phenol structural unit a1 derived from m-cresol and / or o-cresol and an aldehyde structural unit a2 derived from salicylaldehyde, and having an acetal-based protecting group derived from a compound containing two or more vinyl ether groups; Ingredient B: a photoacid generator; and Ingredient C: solvent.

2. The positive photosensitive resin composition according to claim 1, wherein The novolac-type phenol resin further includes a structural unit a3 derived from benzaldehyde and / or acetaldehyde.

3. The positive photosensitive resin composition according to claim 1 or 2, wherein The novolac-type phenolic resin comprises: a phenolic structural unit a1 derived from m-cresol and / or o-cresol, a structural unit a2 derived from salicylaldehyde, and a structural unit a3 derived from benzaldehyde and / or acetaldehyde, and the molar ratio of the structural units, i.e., the structural unit a1 derived from m-cresol: the structural unit a2 derived from salicylaldehyde: the structural unit a3 derived from benzaldehyde and / or acetaldehyde, satisfies 1.0:0.2-0.8:0.2-0.

8.

4. The positive photosensitive resin composition according to claim 1, wherein The content of the aldehyde structural unit a4 derived from formaldehyde in the component A is less than 3% by mass.

5. The positive photosensitive resin composition according to claim 1 or 2, wherein The acetal protecting group is at least one of the groups represented by the following formula (1) and formula (2), wherein R1, R2, R7, and R8 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms; R3 is a linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, a cyclic alkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group formed by bonding two or more groups selected from the group consisting of the linear alkylene group, branched alkylene group, cyclic alkylene group, and arylene group; R3 may bond with R1, R2, R7, or R8 to form a ring; R4 to R6 are each independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms; *Bonded to the benzene ring constituting the main chain of the novolac type phenol resin.

6. The positive photosensitive resin composition according to claim 1 or 2, wherein The component A is obtained by reacting a novolac-type phenolic resin with a compound having two or more vinyl ether groups and forming an acetal-based protective group. The novolac-type phenolic resin is obtained by polycondensing m-cresol, salicylaldehyde, and benzaldehyde in an organic solvent using an acid catalyst in a molar ratio of m-cresol: salicylaldehyde: benzaldehyde = 1.0:0.2-0.8:0.2-0.

8.

7. The positive photosensitive resin composition according to claim 6, wherein The compound forming the acetal-based protecting group is a compound represented by the following formula (3): In the formula, R3 is a linear alkylene group having 1 to 20 carbon atoms, a branched alkylene group having 3 to 20 carbon atoms, a cyclic alkylene group having 3 to 20 carbon atoms, an arylene group having 6 to 20 carbon atoms, or a group formed by bonding two or more groups selected from the linear alkylene group, branched alkylene group, cyclic alkylene group, and arylene group; R4~R6 and R9~R 11 Each of them is independently a hydrogen atom, a linear alkyl group having 1 to 20 carbon atoms, a branched alkyl group having 3 to 20 carbon atoms, a cyclic alkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

8. The positive photosensitive resin composition according to claim 6, wherein The compound forming the acetal-based protecting group is cyclohexanedimethanol divinyl ether.

9. The positive photosensitive resin composition according to claim 2, wherein The total content of the phenol structural unit a1 derived from m-cresol and / or o-cresol, the structural unit a2 derived from salicylaldehyde, and the structural unit a3 derived from benzaldehyde and / or acetaldehyde in the component A is 30% by mass or more. 10 . A photosensitive film obtained by drying the positive photosensitive resin composition according to claim 1 .

11. A resist film obtained from the positive photosensitive resin composition according to claim 1 or 2.

12. A resist underlayer film obtained from the positive photosensitive resin composition according to claim 1 or 2.

13. A resist permanent film obtained from the positive photosensitive resin composition according to claim 1 or 2.

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