Positive-type photosensitive resin composition, resist film, resist underlayer film, and resist permanent film

Abstract

To provide a positive photosensitive resin composition from which a resist film having high i-line transmittance, excellent developability and excellent heat resistance can be obtained, and which also exhibits good storage stability.SOLUTION: A positive photosensitive resin composition comprises the following components (A) to (C): (A) a novolac-type phenolic resin having acetal-based protecting groups and including a phenolic structural unit (a1) derived from m-cresol and / or o-cresol, an aldehyde structural unit (a2) derived from acetaldehyde, and an aldehyde structural unit (a3) derived from salicylaldehyde; (B) a photoacid generator; and (C) a solvent.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to a positive photosensitive resin composition, 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 packages has been progressing. Conventionally, for the production of semiconductor packages of ICs and LSIs, a positive photoresist for i-line using an alkali-soluble resin (for example, novolak-type phenol (phenol novolak) resin) and a naphthoquinonediazide compound-based photosensitizer has been widely used. However, the miniaturization using i-line is approaching its limit. In particular, in the plating resist for forming a redistribution layer used in advanced semiconductor packages, etc., the formation of fine wiring with a thick film of several tens of μm or more is required. In a thick film of several tens of μm, in the exposure process for a photosensitive resin composition using a conventional naphthoquinonediazide compound-based photosensitizer, sufficient light does not reach the bottom of the film, so the resist layer at the bottom of the pattern does not undergo alkali dissolution, and there is a problem that it is difficult to form a high aspect pattern.

[0003] In response to the above problems, instead of using a naphthoquinonediazide compound-based photosensitizer, it has been considered to use a chemically amplified positive photoresist used in photolithography using an excimer laser such as KrF, ArF, EUV, etc. in photolithography using i-line (for example, Patent Document 1). When light is irradiated on a photosensitive resin film using a chemically amplified positive photoresist, an acid is generated from a photoacid generator, and the generated acid (proton) acts as an acid catalyst to remove the protecting group of the acid-decomposable resin and expose an alkali-soluble group. In a chemically amplified positive photoresist, after the removal of the protecting group, the acid is catalytically regenerated and can remove another protecting group, so it is possible to produce a positive pattern having high alkali solubility even with a small amount of light. Therefore, alkali dissolution at the bottom of the film, which has been a problem in thick film production, becomes possible. However, the positive-type photosensitive resin composition using the m-cresol-based novolac-type phenolic 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 remains unresolved.

[0004] Therefore, in addition to m-cresol, chemically amplified positive-type photosensitive resin compositions consisting of o-cresol and p-cresol have also been investigated (for example, Patent Document 2). However, the photosensitive resin composition described in Patent Document 2 still suffers from insufficient alkali solubility, resulting in residual film formation at the bottom of the pattern after development, and also has low heat resistance. Furthermore, its low light transmittance at 365 nm, the wavelength of the i-line, limits the improvement of sensitivity.

[0005] Furthermore, the development of chemically amplified positive-type photosensitive resin compositions using hydroxyl-substituted aromatic aldehydes has also been investigated with the aim of improving sensitivity (for example, Patent Document 3). However, the positive-type photosensitive resin composition described in Patent Document 3 had the problem of poor storage stability, although sensitivity was improved. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2003-149816 [Patent Document 2] Japanese Patent Publication No. 2019-203097 [Patent Document 3] Japanese Patent Publication No. 2005-300820 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] The object of the present invention is to provide a positive-type photosensitive resin composition that yields a resist film with high i-line transmittance, excellent developability and heat resistance, and good storage stability. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the present inventors 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 are substituted with acetal-based protecting groups, a photoacid generator, and a solvent has good storage stability and can produce a desired resist film, thus completing the present invention.

[0009] In other words, the present invention relates to a positive-type photosensitive resin composition containing the following components (A) to (C). (A) A novolac-type phenolic resin comprising a phenolic structural unit (a1) derived from m-cresol and / or o-cresol, an aldehyde structural unit (a2) derived from acetaldehyde, and an aldehyde structural unit (a3) ​​derived from salicylaldehyde, and having an acetal group protecting group. (B) Photoacid generator (C) Solvent

[0010] The present invention further relates to a photosensitive film obtained by drying a positive-type photosensitive resin composition. The present invention further relates to a resist film obtained from a positive-type photosensitive resin composition. The present invention further relates to a resist underlayer film obtained from a positive-type photosensitive resin composition. The present invention further relates to a permanent resist film obtained from a positive-type photosensitive resin composition. [Effects of the Invention]

[0011] According to the present invention, a positive-type photosensitive resin composition can be provided that yields a resist film with high i-line transmittance, excellent developability and heat resistance, and good storage stability. [Modes for carrying out the invention]

[0012] The following describes embodiments for carrying out the invention. In this specification, "x~y" represents a numerical range of "greater than or equal to x and less than or equal to y". The upper and lower limits specified for the numerical range can be combined in any way. Moreover, a form in which two or more of the individual forms of the present invention described below are combined is also a form of the present invention.

[0013] [Positive photosensitive resin composition] The positive photosensitive resin composition according to an embodiment of the present invention contains the following components (A) to (C). (A) A novolak-type phenol resin containing a phenol structural unit (a1) derived from m-cresol and / or o-cresol, an aldehyde structural unit (a2) derived from acetaldehyde, and an aldehyde structural unit (a3) derived from salicylaldehyde, and having an acetal group-based protecting group (B) A photoacid generator (C) A solvent

[0014] In this embodiment, since the novolak-type phenol resin has an acetal group-based protecting group, a synergistic effect with the photoacid generator occurs when the positive photosensitive resin composition is used as a resist film or the like. Specifically, in the exposed portion, the acetal group-based protecting group is detached from the component (A) by the acid generated by the photoacid generator, while in the unexposed portion, the acetal group-based protecting group is not detached from the component (A). As a result, a positive photosensitive resin composition having excellent i-line transmittance and excellent developability, development contrast, and heat resistance when formed into a resist film or the like can be obtained. Moreover, since the novolak-type phenol resin contains an aldehyde structural unit (a2) derived from acetaldehyde, the storage stability of the positive photosensitive resin composition is improved in order to suppress the detachment of the acetal group-based protecting group over time.

[0015] · Component (A) The novolak-type phenol resin as the component (A) contains a phenol structural unit (a1) derived from m-cresol and / or o-cresol, an aldehyde structural unit (a2) derived from acetaldehyde, and an aldehyde structural unit (a3) derived from salicylaldehyde, and has an acetal group-based protecting group.

[0016] The aldehyde structural unit (a3) derived from salicylaldehyde can improve the alkali solubility of the novolak-type phenol resin which is the component (A).

[0017] The novolak-type phenol resin which is the component (A) preferably satisfies a molar ratio [(a1):(a2):(a3)] of the phenol structural unit (a1) derived from m-cresol, the aldehyde structural unit (a2) derived from acetaldehyde, and the aldehyde structural unit (a3) derived from salicylaldehyde of 1.0:0.3 to 0.99:0.01 to 0.7.

[0018] The molar ratio [(a1):(a2):(a3)] of the phenol structural unit (a1) derived from m-cresol, the aldehyde structural unit (a2) derived from acetaldehyde, and the aldehyde structural unit (a3) derived from salicylaldehyde that the component (A) has is preferably 1.0:0.4 to 0.98:0.02 to 0.6, and more preferably 1.0:0.5 to 0.95:0.05 to 0.5, from the viewpoint of obtaining a resist film or the like having heat resistance in addition to high developability.

[0019] The component (A) may contain structural units other than the phenol structural unit (a1) derived from m-cresol and / or o-cresol, the aldehyde structural unit (a2) derived from acetaldehyde, and the aldehyde structural unit (a3) derived from salicylaldehyde. Examples of the structural units other than (a1) to (a3) include structural units derived from phenols and aldehydes other than m-cresol, o-cresol, acetaldehyde, and salicylaldehyde.

[0020] Examples of the above phenols include phenol, p-cresol, 2,3-xylenol, 2,5-xylenol, 3,4-xylenol, 3,5-xylenol, 2,3,5-trimethylphenol, 3,4,5-trimethylphenol, and the like.

[0021] Examples of the above-mentioned aldehydes include propionaldehyde, butanal, pentanal, hexanal, chloroacetaldehyde, benzaldehyde, 4-hydroxybenzaldehyde, 3-hydroxybenzaldehyde, 2-methoxybenzaldehyde, 3-nitrobenzaldehyde, phenylaldehyde, cinnamaldehyde, 1-naphthaldehyde, 2-naphthaldehyde, 2-methylbenzaldehyde, 3-methylbenzaldehyde, 4-methylbenzaldehyde, and 4-biphenylaldehyde.

[0022] With respect to the above-mentioned aldehydes, if the novolac-type phenolic resin, which is component (A), contains aldehyde structural units (a4) derived from formaldehyde, the content of the aldehyde structural units (a4) derived from formaldehyde is preferably 10% by mass or less of the total amount of repeating units of the novolac-type phenolic resin, more preferably 5% by mass or less, and even more preferably 3% by mass or less. The novolac-type phenolic resin, which is component (A), preferably does not contain aldehyde structural units (a4) derived from formaldehyde.

[0023] Regarding the above aldehydes, the novolac-type phenolic resin, which is component (A), preferably further contains an aldehyde structural unit (a5) derived from benzaldehyde. When the novolac-type phenolic resin, which is component (A), contains an aldehyde structural unit (a5) derived from benzaldehyde, the content of the aldehyde structural unit (a5) derived from benzaldehyde is preferably in the range of 5 to 50 mol% of the total amount of repeating units of the novolac-type phenolic resin, more preferably in the range of 5 to 30 mol% of the total amount of repeating units of the novolac-type phenolic resin, and even more preferably in the range of 5 to 20 mol%.

[0024] The total content of the above structural units (a1), (a2), (a3) ​​and any (a5) in the repeating units of the novolac-type phenolic resin, which is component (A), is preferably 50% by mass or more, more preferably 80% by mass or more, and even more preferably 90% by mass or more. The total content of the above structural units (a1), (a2), (a3) ​​and any (a5) may be substantially 100% by mass. Substantially 100% by mass includes cases where structural units other than the above structural units (a1), (a2), (a3) ​​and any (a5) are inevitably included.

[0025] The acetal protecting group of component (A) is preferably a group represented by the following formula (1). [ka] (In the formula, R1 and R2 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 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, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. R3 may be bonded to R1 or R2 to form a ring. *This symbol is bonded to the benzene ring that constitutes the main chain of the novolac-type phenolic resin.

[0026] In component (A), at least a portion of the phenolic hydroxyl groups of the novolac-type phenolic resin are protected by an acetal group protecting group represented by formula (1) above. The acetal group protecting group can be removed by an acid generated from a photoacid generator. The fact that component (A) has an acetal protecting group means that 13 This can be confirmed by 13C-NMR.

[0027] In formula (1), examples of linear alkyl groups having 1 to 20 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, and hexyl groups. Examples of branched alkyl groups having 3 to 20 carbon atoms include isopropyl group, sec-butyl group, tert-butyl group, neopentyl group, isopentyl group, 2-methylpentyl group, 3-methylpentyl group, and 2,3-dimethylbutyl group. Examples of cyclic alkyl groups having 3 to 20 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and adamantyl groups. Cyclic alkyl groups may have substituents such as the linear alkyl groups mentioned above. Examples of aryl groups having 6 to 20 carbon atoms include phenyl groups, naphthyl groups, and anthracenyl groups. The aryl group may have substituents such as the alkyl groups mentioned above.

[0028] The aralkyl group is an alkyl group (C n H 2n+1 This refers to an alkyl group in which one or more hydrogen atoms are substituted with an aryl group. The aryl group may have substituents such as the alkyl groups mentioned above. Specifically, examples include phenylmethyl group, tolylmethyl group, xylmethyl group, naphthylmethyl group, hydroxynaphthylmethyl group, dihydroxynaphthylmethyl group, phenylethyl group, hydroxyphenylethyl group, dihydroxyphenylethyl group, tolylethyl group, xylylethyl group, naphthylethyl group, hydroxynaphthylethyl group, and dihydroxynaphthylethyl group. The number of carbon atoms is preferably 7 to 15, for example.

[0029] R3 may bond with R1 or R2 to form a ring. Examples of rings include oxygen-containing heterocycles such as furan rings and pyran rings.

[0030] Examples of acetal protecting groups represented by formula (1) above include, specifically, 1-methoxyethoxy group, 1-ethoxyethoxy group, 1-propoxyethoxy group, 1-butoxyethoxy group, 2-methoxypropoxy group, 2-ethoxypropoxy group, 1-(2-methylpropoxy)ethoxy group, 1-(1-propoxy)propoxy group, 1-ethoxybutoxy group, 1-(2-methoxyethoxy)ethoxy group, 1-(2-acetoxyethoxy)ethoxy group, tetrahydrofuran-2-yl group, 1-[(1-adamantyloxy)ethoxy]ethyl group, 1-[2-(1-adamantanecarbonyloxy)ethoxy]ethyl group, tetrahydro-2-pyranyl group, tetrahydro-2-furyl group, 1-(cyclohexyloxy)ethoxy Examples include xy group, 1-phenoxyethoxy group, 1-(2-cyclohexyl)ethoxyethoxy group, (1-adamantyloxy)ethoxy group, (2-adamantyloxy)ethoxy group, (1-adamantylmethoxy)ethoxy group, (2-adamantylethoxy)ethoxy group, 1-(1-bicyclo[2.2.1]heptyloxy)ethoxy group, 1-(2-bicyclo[2.2.1]heptyloxy)ethoxy group, 1-(1-bicyclo[2.2.1]heptylmethoxy)ethoxy group, 1-(2-bicyclo[2.2.1]heptylmethoxy)ethoxy group, 2-(1,7,7-trimethylbicyclo[2.2.1]heptyloxy)ethoxy group, and 2-(1-isopropyl-4-methylcyclohexyloxy)ethoxy group. The protecting group represented by formula (1) above is preferably a 1-propoxyethoxy group.

[0031] The acetal protecting group is not limited to those represented by formula (1) above. For example, it may be a group derived from a compound that forms a crosslinkable protecting group, as described later.

[0032] In component (A), the protection rate of phenolic hydroxyl groups in the novolac-type phenolic resin (the ratio of acetal group-based protecting groups to the total amount of phenolic hydroxyl groups in the novolac-type phenolic resin) is 1 to 50 mol%, preferably 2 to 40 mol%, more preferably 5 to 25 mol%, and even more preferably 7.5 to 15 mol%, from the viewpoint of appropriate dissolution rate in alkaline developer.

[0033] The weight-average molecular weight of component (A), a novolac-type phenolic resin, is preferably 1,000 or more, more preferably 1,500 or more. It is also preferably 10,000 or less, more preferably 6,000 or less, and even more preferably 3,000 or less. A weight-average molecular weight of 1,000 or more is preferable because it provides high heat resistance. On the other hand, a weight-average molecular weight of 10,000 or less is preferable because it provides high sensitivity. In this specification, the weight-average molecular weight is measured according to the conditions described in the examples.

[0034] Component (A) is preferably obtained by polycondensing m-cresol and / or o-cresol, acetaldehyde, and salicylaldehyde in an organic solvent using an acid catalyst in a molar ratio (m-cresol and / or o-cresol:acetaldehyde:salicyaldehyde) of 1.0:0.3 to 0.99:0.01 to 0.7 to obtain a novolac-type phenolic resin (a), and then further reacting it with a compound that forms an acetal group protecting group. The synthesis of novolac-type phenolic resin (a) and the introduction of acetal-based protecting groups will be described below.

[0035] (Synthesis of novolac-type phenolic resin (a)) Novolac-type phenolic resin (a) can be obtained, for example, by dissolving the raw material compounds in a reaction solvent according to a conventional method and carrying out a synthesis reaction using an acid catalyst.

[0036] Examples of reaction solvents used in the production of 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.

[0037] The molar ratio of m-cresol and / or o-cresol, acetaldehyde, and salicylaldehyde in the reaction solvent (m-cresol and / or o-cresol:acetaldehyde:salicyaldehyde) is preferably 1.0:0.4~0.98:0.02~0.6, and more preferably 1.0:0.5~0.95:0.05~0.5, from the viewpoint of obtaining a resist film that has high sensitivity and chemical resistance through low-temperature curing.

[0038] In the novolac-type phenolic resin (a), the monomers (starting compounds) constituting the phenolic structural unit (a1) derived from m-cresol, the aldehyde structural unit (a2) derived from acetaldehyde, and the aldehyde structural unit (a3) ​​derived from salicylaldehyde are not limited to m-cresol, o-cresol, acetaldehyde, and salicylaldehyde. For example, para-aldehyde (a trimer of acetaldehyde) may be used as the compound constituting the aldehyde structural unit (a2) derived from acetaldehyde.

[0039] When obtaining a novolac-type phenolic resin (a) by polycondensation of m-cresol and / or o-cresol, acetaldehyde, and salicylaldehyde in an organic solvent, as described above, other phenols and aldehydes other than m-cresol, o-cresol, acetaldehyde, and salicylaldehyde may be included in the organic solvent. Benzaldehyde is preferred as the other aldehyde.

[0040] The ratio of the total mass of m-cresol and / or o-cresol, acetaldehyde, salicylaldehyde, and any benzaldehyde in the reaction solvent to the total mass of all starting materials that can form structural units of component (A) is preferably 50% by mass or more, 70% by mass or more, 80% by mass or more, and 90% by mass or more, in that order, and more preferably substantially 100% by mass, from the viewpoint of obtaining a resist film that is highly sensitive and has heat resistance due to low-temperature curing.

[0041] From the viewpoint of reaction uniformity, the amount of the above-mentioned reaction solvent used is preferably 20 parts by mass or more, more preferably 50 parts by mass or more, per 100 parts by mass of the raw material for deriving the structural units constituting component (A). Furthermore, it is preferably 500 parts by mass or less, more preferably 300 parts by mass or less.

[0042] Examples of acid catalysts used in the production of 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. Among these, inorganic acids and p-toluenesulfonic acid are preferred, and p-toluenesulfonic acid is more preferred, as they promote the reaction more effectively. The amount of acid catalyst added is not particularly limited, but is preferably 5 parts by mass or more, more preferably 20 parts by mass or more, per 100 parts by mass of raw material for deriving the structural units constituting component (A). It is also preferably 150 parts by mass or less, more preferably 100 parts by mass or less.

[0043] The reaction temperature when polycondensing the raw materials for novolac-type phenolic resin (a) is preferably 30°C or higher, more preferably 40°C or higher, in order to promote the reaction and efficiently increase the molecular weight. It is also preferably 100°C or lower, more preferably 80°C or lower. The reaction time is preferably 4 hours or more, more preferably 12 hours or more. It is also preferably 32 hours or less, more preferably 24 hours or less.

[0044] (Introduction of acetal protecting groups) The method for introducing the acetal protecting group is not particularly limited. For example, one method involves adding a novolac resin (a) and a compound that forms the acetal protecting group to a reaction solvent and reacting them using an acid catalyst. The acetal group protecting group is generated in an acid catalyst by the reaction of a compound that forms an acetal group protecting group with a phenolic hydroxyl group in the novolac-type phenolic resin (a), thereby protecting the phenolic hydroxyl group in the novolac-type phenolic resin (a).

[0045] As the reaction solvent used for introducing the acetal group protecting group, the reaction solvent used in the synthesis of the novolac-type phenol resin (a) described above can be suitably used. Methyl isobutyl ketone is preferred as the reaction solvent used for introducing the acetal group protecting group.

[0046] The acid catalyst used in introducing the acetal group protecting group is preferably the same acid catalyst used in the synthesis of the novolac-type phenolic resin (a) described above. Among these, inorganic acids and p-toluenesulfonic acid are preferred, and p-toluenesulfonic acid is more preferred, in order to further promote the reaction.

[0047] When introducing an acetal protecting group, the reaction time is preferably 1 hour or more, more preferably 2 hours or more. It is also preferably 10 hours or less, more preferably 6 hours or less. When introducing the acetal group protecting group, the reaction temperature can be the same as that used for the synthesis of the novolac-type phenolic resin (a) described above.

[0048] In this embodiment, the compound that forms the acetal protecting group is preferably a compound represented by the following formula (2). [ka] (In the formula, R3 is 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, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms.) R4 to R6 are, 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.

[0049] In formula (2), specific examples of linear alkyl groups having 1 to 20 carbon atoms, branched alkyl groups having 3 to 20 carbon atoms, cyclic alkyl groups having 3 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms are the same as in formula (1) above. Any two of R3, R4, R5, and R6 may bond to form a ring; for example, R3 and R6 may bond to form a cyclic ether.

[0050] Compounds that form the acetal protecting group represented by formula (2) above include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, cyclopentyl vinyl ether, cyclohexyl vinyl ether, cyclohexylmethyl vinyl ether, phenyl vinyl ether, benzyl vinyl ether, phenethyl vinyl ether, menthyl vinyl ether, 1-adamantyl vinyl ether, 2-adamantyl vinyl ether, [(adamantan-1-yl)methyl] vinyl ether, [(A Examples include damantan-2-yl)methyl vinyl ether, 1-methoxypropylene, 2-methoxy-2-butene, 2-methoxy-3-methyl-2-butene, 2-(ethenyloxy)bicyclo[2.2.1]heptane, 2-(ethenyloxy)-1,7,7-trimethylbicyclo[2.2.1]heptane, 2-[(vinyloxy)methyl]bicyclo[2.2.1]heptane, 2-[(vinyloxy)ethyl]bicyclo[2.2.1]heptane, 3-(ethenyloxy)-1,1-bicyclohexane, and 3,4-dihydropyran. Among these, ethyl vinyl ether, propyl vinyl ether, and butyl vinyl ether are preferred.

[0051] In this embodiment, the amount of the compound represented by formula (2) is preferably 1 part by mass or more, more preferably 5 parts by mass or more, per 100 parts by mass of novolac-type phenolic resin (a), in order to obtain good developability (sensitivity) and development contrast. Also preferably 20 parts by mass or less, more preferably 15 parts by mass or less.

[0052] Compounds other than those represented by formula (2) above may be used as compounds that form an acetal protecting group. For example, compounds that form a crosslinkable protecting group can be used. Examples of compounds that form a crosslinkable protecting group include ethylene glycol divinyl ether, triethylene glycol divinyl ether, 1,3-butanediol 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, and cyclohexanedimethanol divinyl ether.

[0053] ·Component (B) Component (B), the photoacid generator, is a compound that generates acid by causing bond cleavage upon exposure. By including the photoacid generator, the acid produced by the photoacid generator causes the acetal group-based protecting group to detach from component (A) in the exposed area. 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, thereby improving the developability (sensitivity) and development contrast when the positive-type photosensitive resin composition is used as a resist film.

[0054] The photoacid generator is not particularly limited, and known photoacid generators can be used. Examples include organic halogen compounds, sulfonic acid esters, onium salts (phosphonium salts, sulfonium salts, iodonium salts, etc.), diazonium salts, diazomethane compounds, nitrobenzyl compounds, disulfone compounds, and triazine-based photoacid generators. In one embodiment, the photoacid generator is not a naphthoquinone diazide compound.

[0055] Specific examples of photoacid generators include the following: Haloalkyl-containing s-triazine derivatives 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)ethenyl]-4,6-bis(trichloromethyl)-s-triazine);

[0056] Halogen-substituted paraffinic hydrocarbon compounds such as 1,2,3,4-tetrabromobutane, 1,1,2,2-tetrabromoethane, carbon tetrabromide, and iodoform; halogen-substituted cycloparaffinic hydrocarbon compounds such as hexabromocyclohexane, hexachlorocyclohexane, and hexabromocyclododecane;

[0057] Haloalkyl-containing benzene derivatives such as bis(trichloromethyl)benzene and bis(tribromomethyl)benzene; haloalkyl-containing sulfone compounds such as tribromomethylphenylsulfone and trichloromethylphenylsulfone; halogen-containing sulfolane compounds such as 2,3-dibromosulfolane; haloalkyl-containing isocyanurate compounds such as tris(2,3-dibromopropyl)isocyanurate;

[0058] Sulfonium salts such as triphenylsulfonium chloride, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl[4-(phenylthio)phenyl]sulfonium trifluoromethanesulfonate, triphenylsulfonium methanesulfonate, triphenylsulfonium p-toluenesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluoroarsenate, and triphenylsulfonium hexafluorophosphonate;

[0059] Iodonium salts such as diphenyliodonium trifluoromethanesulfonate, diphenyliodonium p-toluenesulfonate, diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, and diphenyliodonium hexafluorophosphonate;

[0060] Methyl p-toluenesulfonate, ethyl p-toluenesulfonate, p-toluenesulfonate Sulfonic acid ester compounds such as butyl nitrate, 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 diphenyldisulfone;

[0061] 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) (Fonyl) 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, Cyclohexyl Diazomethane (2-trifluoromethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl (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, Cyclopentylsulfonyl-(4-trifluoromethoxyphenylsulfonyl (2,4,6-trimethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl-(2,4,6-trimethylphenylsulfonyl) diazomethane, cyclohexylsulfonyl-(2,3,4-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, cyclopentylsulfonyl-(2,3,4-triethylphenylsulfonyl) diazomethane, phenylsulfonyl-(2-methoxyphenylsulfonyl) diazomethane, phenylsulfonyl-(3-methoxyphenylsulfonyl) diazomethane, phenylsulfonyl-(4-methoxyphenylsulfonyl) diazomethane, bis(2-methoxyphenylsulfonyl) diazomethane, bis(3-methoxyphenylsulfonyl) Phenylsulfonyl diazomethane, bis(4-methoxyphenylsulfonyl) diazomethane, phenylsulfonyl-(2,4,6-trimethylphenylsulfonyl) diazomethane, phenylsulfonyl-(2,3,4-trimethylphenylsulfonyl) diazomethane, phenylsulfonyl-(2,4,6-triethylphenylsulfonyl) diazomethane, phenylsulfonyl-(2,3,4-triethylphenylsulfonyl) diazomethane, 2,4-dimethylphenylsulfonyl-(2,4,6-trimethylphenylsulfonyl) diazomethane,Sulfone diazide compounds such as 2,4-dimethylphenylsulfonyl-(2,3,4-trimethylphenylsulfonyl)diazomethane, phenylsulfonyl-(2-fluorophenylsulfonyl)diazomethane, phenylsulfonyl-(3-fluorophenylsulfonyl)diazomethane, and phenylsulfonyl-(4-fluorophenylsulfonyl)diazomethane;

[0062] o-nitrobenzyl ester compounds such as o-nitrobenzyl-p-toluenesulfonate; Sulfone hydrazide compounds such as N,N'-di(phenylsulfonyl)hydrazide; Sulfonium salts are salts of sulfonium cations such as triarylsulfonium and triarylsulfonium with sulfonates such as fluoroalkanesulfonates, arenesulfonates, and alkanesulfonates;

[0063] Iodonium salts are salts of iodonium cations such as diaryliodonium and sulfonates such as fluoroalkanesulfonates, arenesulfonates, and alkanesulfonates; Bisulfonyl diazomethane compounds such as bis(alkylsulfonyl)diazomethane, bis(cycloalkylsulfonyl)diazomethane, bis(perfluoroalkylsulfonyl)diazomethane, bis(arylsulfonyl)diazomethane, and bis(aralkylsulfonyl)diazomethane;

[0064] N-sulfonyl oxyimide compounds consisting of a dicarboxylic acid imide compound and a sulfonate such as a fluoroalkanesulfonate, arene sulfonate, or alkanesulfonate; Benzoin sulfonate compounds such as benzoin tosylate, benzoin mesylate, and benzoin butanesulfonate; Polyhydroxyarene sulfonate compounds are those in which all hydroxyl groups of a polyhydroxyarene compound are replaced with sulfonates such as fluoroalkane sulfonates, arene sulfonates, or alkane sulfonates;

[0065] Nitrobenzyl sulfonate compounds such as fluoroalkanesulfonic acid (poly)nitrobenzyl, arenesulfonic acid (poly)nitrobenzyl, and alkanesulfonic acid (poly)nitrobenzyl; Fluoroalkanebenzyl sulfonate compounds such as (poly)fluoroalkanebenzyl fluoroalkanesulfonic acid, (poly)fluoroalkanebenzyl arenesulfonic acid, and (poly)fluoroalkanebenzyl alkanesulfonic acid;

[0066] Bis(arylsulfonyl)alkane compounds; Bis-O-(arylsulfonyl)-α-dialkylglyoxime, bis-O-(arylsulfonyl)-α-dicycloalkylglyoxime, bis-O-(arylsulfonyl)-α-diarylglyoxime, 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-dialkylnioxime, bis-O-(arylsulfonyl)-α-dicycloalkylnioxime, bis-O-(arylsulfonyl)-α-diarylnioxime, bis-O-(alkylsulfonyl)-α-dicycloalkylnioxime, bis-O-(alkylsulfonyl)-α-diarylnioxime, bis-O-(fluoroalkylsulfonyl)-α-dialkylnioxime, bis-O-(fluoroalkylsulfonyl)-α-dicycloalkylnioxime, and bis-O-(fluoroalkylsulfonyl)-α-diarylnioxime;

[0067] 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)aryldiacetonitrile, bis(alkylsulfonyloxyimino)aryldiacetonitrile, bis(fluoroalkylsulfonyloxyimino)aryldiacetonitrile, arylfluoroalkanone-O-(alkylsulfonyl)oxime, arylfluoroalkanone-O-(arylsulfonyl)oxime, and arylfluoroalkanone-O-(fluoroalkylsulfonyl)oxime.

[0068] The photoacid generator may be used alone, or two or more may be used in combination. The amount of photoacid generator added is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, per 100 parts by mass of component (A), from the viewpoint of obtaining good i-line transmittance for the positive-type photosensitive resin composition and good developability (sensitivity) and heat resistance when the positive-type photosensitive resin composition is made into a resist film or the like. Furthermore, it is preferably 20 parts by mass or less, and more preferably 5 parts by mass or less.

[0069] ·Component (C) Examples of solvents that constitute 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 individually or in combination of two or more.

[0070] The amount of solvent blended in the positive-type photosensitive resin composition of this embodiment is such that the solid content concentration in the composition is preferably 5% by mass or more, in order to obtain a uniform coating film by a coating method such as spin coating, which ensures the fluidity of the composition. Furthermore, it is preferably 65% ​​by mass or less.

[0071] Other ingredients In one embodiment, the positive-type photosensitive resin composition may contain various additives in addition to the components (A) to (C) described above, as long as they do not hinder the effects of the present invention. Examples of additives include fillers, pigments, surfactants such as leveling agents, adhesion improvers, and dissolution accelerators.

[0072] The positive-type photosensitive resin composition of this embodiment can be prepared by stirring and mixing the above-mentioned components (A) to (C), and various additives as needed, in a conventional manner to obtain a homogeneous liquid. When solid materials such as fillers and pigments are incorporated into the composition, it is preferable to disperse and mix them using a dispersion device such as a dissolver, homogenizer, or three-roll mill. Furthermore, the composition can be filtered using a mesh filter, membrane filter, or the like to remove coarse particles and impurities.

[0073] The positive-type photosensitive resin composition of this embodiment can be suitably used for applications such as resist films, resist underlayer films, and resist permanent films.

[0074] The positive-type photosensitive resin composition of the present invention can be used in the same way as a general positive-type photosensitive resin composition to form a resist film, a resist underlayer film, and a resist permanent film (hereinafter, the resist film, resist underlayer film, and resist permanent film may be collectively referred to as a resist film, etc.). Specifically, by applying the positive-type photosensitive resin composition of the present invention to an object to be photolithographed and pre-baking it, a film of the photosensitive resin composition (photosensitive film) from which the solvent has been removed is obtained.

[0075] Coating methods include spin coating, roll coating, flow coating, dip coating, spray coating, and doctor blade coating. Pre-baking can be done by heating at a temperature of 60°C to 150°C for a time of 30 seconds to 600 seconds. Furthermore, the positive-type photosensitive resin composition of the present invention can be appropriately selected as the coating target, such as glass substrates, silicon substrates, aluminum substrates, silicon carbide substrates, silicon nitride substrates, gallium nitride substrates, transparent conductive films, copper substrates, and copper-plated substrates.

[0076] The catalytic reaction of the acid generated by exposure to the photosensitive film causes the elimination of the acetal group-based protecting group from component (A), significantly increasing the solubility of the exposed area in the alkaline developer. Examples of light sources used for exposure include infrared light, visible light, ultraviolet light, far ultraviolet light, X-rays, and electron beams. Among these light sources, ultraviolet light is preferred, and the g-line (wavelength 436 nm) and i-line (wavelength 365 nm) of a high-pressure mercury lamp are particularly suitable. After exposure, the material may be heat-treated at around 100°C to 150°C to promote the elimination reaction of the acetal protecting group from component (A).

[0077] The photosensitive film obtained from the positive-type photosensitive resin composition of the present invention has high alkali solubility in the exposed areas and a large difference in alkali solubility between the exposed and unexposed areas, enabling high-resolution patterning. Therefore, it can be suitably used for resist films and the like. In this application, resist films and the like include both photosensitive films before exposure and non-photosensitive films after exposure.

[0078] Examples of alkaline developers used for development after exposure 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 pyreridine. Alkaline developers may be used with alcohol, surfactants, etc., added as needed. The alkali concentration of the alkaline developer is usually preferably in the range of 2 to 5% by mass, and a 2.38% by mass aqueous solution of tetramethylammonium hydroxide is commonly used.

[0079] When using the positive-type photosensitive resin composition of the present invention for resist underlayer (BARC film) applications, the positive-type photosensitive resin composition of the present invention may be used as is as a resist underlayer composition, or various additives such as other resin components, surfactants, dyes, fillers, crosslinking agents, and dissolution accelerators may be added as needed.

[0080] Other resin components include, for example, 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 (Zyloc resins), naphthol aralkyl resins, trimethylol methane resins, tetraphenyloleethane resins, biphenyl-modified phenolic resins, biphenyl-modified naphthol resins, aminotriazine-modified phenolic resins, and various vinyl polymers. When other resin components are used, the blending ratio of the positive-type photosensitive resin composition of the present invention to the other resin can be arbitrarily set depending on the application. For example, it is preferable that the other resin is in a ratio of 0.5 to 100 parts by mass to 100 parts by mass of component (A).

[0081] The resist underlayer composition can be prepared by blending the above components and mixing them using a stirrer or the like. Furthermore, if the resist underlayer composition 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.

[0082] To form a resist underlayer from a resist underlayer composition, for example, the above-mentioned resist underlayer composition is applied to an object to be photolithographed, such as a silicon substrate, dried under a temperature of 100 to 200°C, and then further heat-cured under a temperature of 250 to 400°C. Subsequently, a resist pattern can be formed on this underlayer by performing a normal photolithography operation, and then a resist pattern can be formed by a multilayer resist method by dry etching with a halogen-based plasma gas or the like.

[0083] When the positive-type photosensitive resin composition of the present invention is used for resist permanent film applications, in addition to components (A) to (C) of the present invention, other additives such as other resins, surfactants, dyes, fillers, crosslinking agents, and dissolution accelerators may be added as needed. Examples of other resins used here include those similar to those that can be used in resist underlayer film compositions.

[0084] A photolithography method using a resist permanent film composition involves, for example, dissolving and dispersing other resin components and additive components in the positive-type photosensitive resin composition of the present invention, coating it onto the object to be photolithographed, and pre-baking it at a temperature of 60 to 150°C. The coating method at this time can be any of the following: spin coating, roll coating, flow coating, dip coating, spray coating, doctor blade coating, etc. Next, the target resist pattern is exposed through a predetermined mask, and the exposed area is dissolved with an alkaline developer to form the resist pattern.

[0085] The resist permanent film of this embodiment can be suitably used, for example, in semiconductor devices as a solder resist, package material, underfill material, package adhesive layer for circuit elements, and adhesive layer between integrated circuit elements and circuit boards, and in thin-film displays such as LCDs and OLEDs as a thin-film transistor protective film, liquid crystal color filter protective film, black matrix, spacer, etc. [Examples]

[0086] The present invention will be explained in more detail below with specific examples. The weight-average molecular weight (Mw) of the synthesized resin was measured under the GPC measurement conditions described below. [GPC measurement conditions] Measurement device: Tosoh Corporation "HLC-8220 GPC" Column: Showa Denko Corporation "Shodex KF802": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF802": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF803": 8.0mm diameter × 300mm +Showa Denko Corporation "Shodex KF804": 8.0mm diameter x 300mm Column temperature: 40℃ Detector: RI (Differential Refractometer) Data processing: Tosoh Corporation's "GPC-8020 Model II Version 4.30" Developing solvent: tetrahydrofuran Flow rate: 1.0mL / min Sample: A tetrahydrofuran solution containing 0.5% by mass (based on resin solids content) filtered through a microfilter. Injection volume: 0.1mL Standard sample: Monodisperse polystyrene (see below) (Standard sample: monodisperse polystyrene) "A-500" manufactured by Tosoh Corporation "A-2500" manufactured by Tosoh Corporation "A-5000" manufactured by Tosoh Corporation "F-1" manufactured by Tosoh Corporation "F-2" manufactured by Tosoh Corporation "F-4" manufactured by Tosoh Corporation Tosoh Corporation's "F-10" F-20 manufactured by Tosoh Corporation

[0087] Synthesis Example 1 (Synthesis of a novolac-type phenolic resin (A-1) having an acetal-based protecting group) In a 2000 ml four-necked flask equipped with a condenser, 164 g (1.52 mol) of m-cresol, 40 g (0.30 mol) of para-aldehyde, 73 g (0.60 mol) of salicylaldehyde, and 8 g of para-toluenesulfonic acid were charged and dissolved in 300 g of ethanol as the reaction solvent. The mixture was heated with a mantle heater and stirred under reflux at 80°C for 16 hours. After the reaction, ethyl acetate and water were added and the mixture was subjected to five separatory washes. The solvent was removed from the remaining resin solution under reduced pressure, and then the mixture was vacuum-dried to obtain 243 g of a pale red novolac-type phenolic resin powder (a-1). Next, 80 g of novolac-type phenolic resin powder (a-1), 12 g of propyl vinyl ether, and 0.1 g of p-toluenesulfonic acid were charged into a 500 ml four-necked flask and dissolved in 120 g of methyl isobutyl ketone as the reaction solvent. The mixture was heated with a mantle heater and stirred at 40°C for 4 hours to allow the reaction to proceed. After the reaction, 0.4 g of dimethylaminoethanol was added and stirred well, then ethyl acetate and water were added and the mixture was subjected to five separate liquid-liquid washes. After removing the solvent from the remaining resin solution under reduced pressure, the mixture was vacuum-dried to obtain 55 g of pale red novolac-type phenolic resin powder (A-1). 13 1C-NMR confirmed that the novolac-type phenolic resin (A-1) possesses an acetal-based protecting group. The weight-average molecular weight (Mw) of the novolac-type phenolic resin (A-1) was 2,430.

[0088] Synthesis Example 2 (Synthesis of a novolac-type phenolic resin (A-2) having an acetal-based protecting group) Except for using 164 g (1.52 mol) of m-cresol, 46 g (0.35 mol) of para-aldehyde, and 55 g (0.45 mol) of salicylaldehyde as starting materials, 56 g of novolac-type phenolic resin powder (A-2) was obtained in the same manner as in Synthesis Example 1. The Mw of novolac-type phenolic resin (A-2) was 2,420.

[0089] Synthesis Example 3 (Synthesis of a novolac-type phenolic resin (A-3) having an acetal-based protecting group) Except for using 164 g (1.52 mol) of m-cresol, 53 g (0.40 mol) of para-aldehyde, and 37 g (0.30 mol) of salicylaldehyde as starting materials, 58 g of novolac-type phenolic resin powder (A-3) was obtained in the same manner as in Synthesis Example 1. The Mw of novolac-type phenolic resin (A-3) was 2,380.

[0090] Synthesis Example 4 (Synthesis of a novolac-type phenolic resin (A-4) having an acetal-based protecting group) Except for using 164 g (1.52 mol) of m-cresol, 60 g (0.45 mol) of para-aldehyde, and 18 g (0.15 mol) of salicylaldehyde as starting materials, 56 g of novolac-type phenolic resin powder (A-4) having an acetal group protecting group was obtained in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenolic resin (A-4) was 2,330.

[0091] Synthesis Example 5 (Synthesis of a novolac-type phenolic resin (A-5) having an acetal-based protecting group) Except for using 164 g (1.52 mol) of m-cresol, 20 g (0.15 mol) of para-aldehyde, and 128 g (1.05 mol) of salicylaldehyde as starting materials, 55 g of novolac-type phenolic resin powder (A-5) having an acetal protecting group was obtained in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenolic resin (A-5) was 2,480.

[0092] Synthesis Example 6 (Synthesis of a novolac-type phenolic resin (A-6) having an acetal-based protecting group) 59 g of novolac-type phenolic resin powder (A-6) having an acetal protecting group was obtained in the same manner as in Synthesis Example 1, except that m-cresol was replaced with o-cresol. The Mw of novolac-type phenolic resin (A-6) was 2,320.

[0093] Synthesis Example 7 (Synthesis of a novolac-type phenolic resin (A-7) having an acetal-based protecting group) 80 g of the novolac-type phenolic resin powder (a-1) obtained in Synthesis Example 1 was dissolved in 120 g of methyl isobutyl ketone. The mixture was heated to 100°C with stirring using a mantle heater. Then, 6 g of cyclohexanedimethanol divinyl ether was added and the mixture was reacted for 24 hours. After the reaction, the methyl isobutyl ketone was removed by distillation under reduced pressure, and the mixture was vacuum-dried to obtain 82 g of pale red powder novolac-type phenolic resin (A-7). The Mw of novolac-type phenolic resin (A-7) was 9,140.

[0094] Synthesis Example 8 (Synthesis of a novolac-type phenolic resin (A-8) having an acetal-based protecting group) Except for using 164 g (1.52 mol) of m-cresol, 20 g (0.15 mol) of para-aldehyde, 73 g (0.60 mol) of salicylaldehyde, and 48 g (0.45 mol) of benzaldehyde as starting materials, 58 g of novolac-type phenolic resin powder (A-8) having an acetal group protecting group was obtained in the same manner as in Synthesis Example 1. The Mw of the novolac-type phenolic resin (A-8) was 2,650.

[0095] Comparative Synthesis Example 1 (Synthesis of Novolac-type Phenolic Resin (A-9) Having an Acetal Group Protecting Group) Under a stream of dry nitrogen, 140 g (1.30 mol) of m-cresol, 76 g (0.7 mol) of p-cresol, 151 g (1.86 mol) of 37 wt% formaldehyde aqueous solution (formaldehyde), and 1 g (0.01 mol) of oxalic acid dihydrate were charged into a 2000 ml four-necked flask equipped with a condenser, and dissolved in 528 g of methyl isobutyl ketone. The mixture was heated with a mantle heater and stirred under reflux for 4 hours to allow the reaction to proceed. After the reaction, water was added and the mixture was washed five times by liquid-liquid washing. Methyl isobutyl ketone was removed by vacuum distillation at 60°C using an evaporator, and then vacuum-dried to obtain 212 g of pale red powder novolac-type phenolic resin (a-9). Next, 80 g of the obtained novolac-type phenolic resin powder (a-9), 8 g of ethyl vinyl ether, and 0.1 g of p-toluenesulfonic acid were charged into a 500 ml four-necked flask and dissolved in 120 g of methyl isobutyl ketone as the reaction solvent. The mixture was heated on a mantle heater and stirred at 40°C for 4 hours to allow the reaction to proceed. After the reaction, 0.4 g of dimethylaminoethanol was added and stirred well, then ethyl acetate and water were added and the mixture was subjected to five separatory washes. After removing the solvent from the remaining resin solution under reduced pressure, it was vacuum dried to obtain 58 g of pale red novolac-type phenolic resin powder (A-9). The Mw of the novolac-type phenolic resin (A-9) was 3,600.

[0096] Comparative Synthesis Example 2 (Synthesis of Novolac-type Phenolic Resin (A-10) with Acetal Protecting Group) The synthesis was carried out in the same manner as in Synthesis Example 1, except that m-cresol was replaced with phenol, and a gel-like resin (A-10) was obtained. Resin (A-10) was insoluble in the solvent and could not be evaluated.

[0097] Comparative Synthesis Example 3 (Synthesis of Novolac-type Phenolic Resin (A-11) with Acetal Protecting Group) The synthesis was carried out in the same manner as in Synthesis Example 1, except that m-cresol was replaced with 2,5-xylenol, and a suspension resin (A-11) was obtained. Resin (A-11) had poor solvent solubility and could not be evaluated.

[0098] Comparative Synthesis Example 4 (Synthesis of Novolac-type Phenolic Resin (A-12) Having an Acetal Group Protecting Group) 55 g of novolac-type phenolic resin powder (A-12) having an acetal protecting group was obtained in the same manner as in Synthesis Example 1, except that m-cresol was replaced with catechol. The Mw of the novolac-type phenolic resin (A-12) was 9,690.

[0099] Comparative Synthesis Example 5 (Synthesis of Novolac-type Phenolic Resin (A-13)) 53 g of novolac-type phenolic resin powder (A-13) having an acetal group protecting group was obtained in the same manner as in Synthesis Example 1, except that 40 g (0.30 mol) of paraaldehyde was replaced with 30 g (0.90 mol) of paraformaldehyde. The Mw of the novolac-type phenolic resin (A-13) was 4,730.

[0100] Comparative Synthesis Example 6 (Synthesis of Novolac-type Phenolic Resin (A-14)) 55 g of novolac-type phenolic resin powder (A-14) having an acetal protecting group was obtained in the same manner as in Synthesis Example 1, except that 52.3 g (0.90 mol) of propionaldehyde was used instead of 40 g (0.3 mol) of paraaldehyde. The Mw of the novolac-type phenolic resin (A-14) was 960.

[0101] Comparative Synthesis Example 7 (Synthesis of Novolac-type Phenolic Resin (A-15) Having an Acetal Group Protecting Group) Except for replacing salicylaldehyde with paraaldehyde, 54 g of novolac-type phenolic resin powder (A-15) having an acetal group protecting group was obtained in the same manner as in Synthesis Example 1. The Mw of novolac-type phenolic resin (A-15) was 2,210.

[0102] [Positive-type photosensitive resin composition] Example 1 1.98 g of the novolac-type phenolic resin (A-1) powder obtained in Synthesis Example 1, 0.02 g of a photoacid generator (manufactured by Sunapro Co., Ltd.: CPI-110TF), and 8 g of propylene glycol monomethyl ether (PGME) were dissolved in the solution, and the mixture was precisely filtered through a 0.1 μm PTFE disc filter to obtain a positive-type photosensitive resin composition.

[0103] Examples 2-8, Comparative Examples 1-5 A positive-type photosensitive resin composition was prepared in the same manner as in Example 1, except that the novolac-type phenolic resin shown in Tables 1 and 2 was used as component (A).

[0104] [evaluation] The transmittance to i-line 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. In addition, the storage stability of the positive-type photosensitive resin compositions was evaluated.

[0105] (1)I-ray transparency A positive-type photosensitive resin composition was diluted with propylene glycol monomethyl ether (PGME) to a solid content of 1% (parts by mass). The transmittance of the obtained 1% diluted positive-type photosensitive resin composition at the i-line wavelength (365 nm) was evaluated using a UV-vis absorbance spectrophotometer (Shimadzu Corporation: SolidSpec-3700 DUV). The evaluation criteria were as follows. ○: Transmittance (%) is 40% or higher ×: Transmittance (%) is less than 40% The evaluation results are shown in Tables 1 and 2. The numbers in parentheses in Tables 1 and 2 represent the transmittance values.

[0106] (2) Alkaline developability A positive-type photosensitive resin composition was coated onto a 5-inch silicon wafer to a thickness of approximately 1 μm using a spin coater, and dried on a hot plate at 110°C for 60 seconds to obtain a resist film. Subsequently, the resist film was exposed to UV light at 200 mJ / cm² using a UV exposure apparatus (UVE-1001SD, manufactured by San-ei Electric Works Co., Ltd.). 2 The wafers were exposed to light, and after exposure, they were baked (PEB) on a hot plate at 130°C for 90 seconds. The resulting wafers with the resist film were 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 thickness of the resist film was measured before and after immersion in the developer, and the difference was divided by 60 to obtain the alkali solubility ADR1 (Å / s). The evaluation criteria are as follows. ◎: ADR1 is 1000 or higher ○: ADR1 is 500 or more, but less than 1000. ×: ADR1 is less than 500 The evaluation results are shown in Tables 1 and 2. The numbers in parentheses in Tables 1 and 2 represent the ADR1 values.

[0107] (3) Development contrast In (2) above, the value measured similarly without exposure of the resist film was defined as ADR2 (Å / s), and the ADR1 / ADR2 value was used as the development contrast. The evaluation criteria are as follows. ○: Development contrast is 50 or higher ×: Development contrast less than 50 The evaluation results are shown in Tables 1 and 2. The numbers in parentheses in Tables 1 and 2 represent the ADR1 / ADR2 values.

[0108] (4) Storage stability The evaluation was performed using the rate of change of ADR2 as described in (2) above. Positive-type photosensitive resin compositions with poor storage stability show a faster ADR2 due to the detachment of protective groups. Specifically, positive-type photosensitive resin compositions were 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. ADR2 change rate = (ADR2 after storage / ADR2 before storage) × 100 The evaluation criteria are as follows: ○: ADR2 change rate is less than 150% ×: ADR2 change rate is 150% or more The evaluation results are shown in Tables 1 and 2. The numbers in parentheses in Tables 1 and 2 represent the ADR2 change rate.

[0109] (5) Heat resistance A positive-type photosensitive resin composition was coated onto a 5-inch diameter silicon wafer using a spin coater, and then dried at 110°C for 60 seconds to obtain a thin film with a thickness of 1 μm. This thin film was scraped off, and the glass transition temperature (hereinafter abbreviated as "Tg") was measured. The Tg was measured using a differential thermal scanning calorimeter (DSC) Q100, manufactured by T.A. Instruments Co., Ltd., under conditions of a nitrogen atmosphere, a temperature range of -100 to 200°C, and a heating rate of 10°C / min. The evaluation criteria are as follows: ◎: Tg is 140℃ or higher ○: Tg is 130℃ or higher, but less than 140℃ ×: Tg is less than 130℃ The evaluation results are shown in Tables 1 and 2. The numbers in parentheses in Tables 1 and 2 represent the Tg values.

[0110] [Table 1]

[0111] [Table 2]

[0112] In Tables 1 and 2, "Cr" means cresol, "SA" means salicylaldehyde, "BA" means benzaldehyde, "AA" means acetaldehyde, "HA" means formaldehyde, "PA" means propionaldehyde, and "CC" means catechol. Furthermore, in Tables 1 and 2, "PVE" refers to propyl vinyl ether, and "CyHDMDVE" refers to cyclohexanedimethanol divinyl ether.

[0113] For example, the value of "m-Cr / AA / SA" in Example 1 being "1 / 0.59 / 0.4" means that the novolac-type phenolic resin, which is component (A) of Example 1, consists of units derived from m-cresol, units derived from acetaldehyde, and units derived from salicylaldehyde, and that the molar ratio of units derived from m-cresol:units derived from acetaldehyde:units derived from salicylaldehyde = 1:0.59:0.4.

[0114] The results in Tables 1 and 2 show that the positive-type photosensitive resin composition of the present invention exhibits excellent i-line transmittance and storage stability. Furthermore, the resist film using the positive-type photosensitive resin composition of the present invention exhibits excellent alkali solubility, development contrast, and heat resistance.

Claims

1. A positive-type photosensitive resin composition containing the following components (A) to (C). (A) A novolac-type phenolic resin comprising a phenolic structural unit (a1) derived from m-cresol and / or o-cresol, an aldehyde structural unit (a2) derived from acetaldehyde, and an aldehyde structural unit (a3) ​​derived from salicylaldehyde, and having an acetal group protecting group. (B) Photoacid generator (C) Solvent

2. The positive-type photosensitive resin composition according to claim 1, wherein the content of aldehyde structural units (a4) derived from formaldehyde in component (A) is 10% by mass or less.

3. The positive-type photosensitive resin composition according to claim 1 or 2, wherein the molar ratio [(a1):(a2):(a3)] of the phenol structural unit (a1) derived from m-cresol, the aldehyde structural unit (a2) derived from acetaldehyde, and the aldehyde structural unit (a3) ​​derived from salicylaldehyde in component (A) satisfies 1.0:0.3 to 0.99:0.01 to 0.

7.

4. The positive-type photosensitive resin composition according to claim 1 or 2, wherein the component (A) further comprises an aldehyde structural unit (a5) derived from benzaldehyde.

5. The positive-type photosensitive resin composition according to claim 1 or 2, wherein the acetal group protecting group is a group represented by the following formula (1). 【Transformation 3】 (In the formula, R １ and R ２ Each of these 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. R ３ R is 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, an aryl group having 6 to 20 carbon atoms, or an aralkyl group having 7 to 20 carbon atoms. ３ R １ or R ２ It may also combine with other elements to form a ring. *This symbol is bonded to the benzene ring that constitutes the main chain of the novolac-type phenolic resin.

6. The positive-type photosensitive resin composition according to claim 1 or 2, wherein component (A) is obtained by reacting a compound that forms an acetal group protecting group with a novolac-type phenol resin obtained by polycondensation of m-cresol, acetaldehyde, and salicylaldehyde in an organic solvent with an acid catalyst in a molar ratio of m-cresol:acetaldehyde:salicyaldehyde = 1.0:0.3 to 0.99:0.01 to 0.

7.

7. The positive-type photosensitive resin composition according to claim 6, wherein the compound forming the acetal group protecting group is a compound represented by the following formula (2). 【Chemistry 4】 (In the formula, R ３ These are linear alkyl groups having 1 to 20 carbon atoms, branched alkyl groups having 3 to 20 carbon atoms, cyclic alkyl groups having 3 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, or aralkyl groups having 7 to 20 carbon atoms. R ４ ~R ６ is 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.)

8. The positive-type photosensitive resin composition according to claim 6, wherein the compound forming the acetal group protecting group is propyl vinyl ether.

9. The positive-type photosensitive resin composition according to claim 1 or 4, wherein the total content of phenol structural units derived from m-cresol (a1), aldehyde structural units derived from acetaldehyde (a2), aldehyde structural units derived from salicylaldehyde (a3), and aldehyde structural units derived from benzaldehyde (a5) in component (A) is 50% by mass or more.

10. A photosensitive film obtained by drying the positive-type photosensitive resin composition according to claim 1 or 2.

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

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

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

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