Photosensitive resin composition, cured product, interlayer insulating film, cover coat layer, surface protective film, and electronic component

Abstract

To provide a photosensitive resin composition containing an organic solvent other than NMP and exhibiting excellent photosensitivity.SOLUTION: A photosensitive resin composition contains: a polyimide precursor having a polymerizable unsaturated bond; a photopolymerization initiator; and a solvent. The solvent contains at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a photosensitive resin composition, a cured product, an interlayer insulating film, a cover coat layer, a surface protective film, and an electronic component.

Background Art

[0002] In recent years, as a protective film material for semiconductor integrated circuits (LSIs), organic materials having high heat resistance such as polyimide resins have been widely applied. A protective film using a cured film of such a polyimide resin can be obtained by heating a resin film formed by applying and drying a polyimide precursor or a resin composition containing a polyimide precursor on a substrate to cure it.

[0003] While polyimide precursors have high resistance to organic solvents, they have low solubility in organic solvents. Therefore, the types of organic solvents that can be used for preparing a resin composition containing a polyimide precursor are limited. Further, in order to increase the concentration of the polyimide precursor in the resin composition, an organic solvent capable of dissolving the polyimide precursor at a high concentration is required. Generally, as an organic solvent for dissolving precursors of heat-resistant resins such as polyimide precursors, N-methyl-2-pyrrolidone (NMP) is often used because of its advantages of both high boiling point and flash point and large dissolving ability (see, for example, Japanese Patent Application Laid-Open No. 2013-40249).

Summary of the Invention

Problems to be Solved by the Invention

[0004] With the expansion of the uses of resin compositions containing polyimide precursors, there has been a demand for resin compositions using organic solvents other than NMP. Therefore, in order to increase the options of organic solvents, it is necessary to examine solvents other than NMP. However, especially when the polyimide precursor exhibits photosensitivity, the change of the organic solvent also affects the photosensitive properties of the polyimide precursor. Therefore, it is necessary to review the composition of various additives contained in the resin composition in order to obtain appropriate photosensitive properties of the polyimide precursor, and it may be difficult to switch to an alternative solvent. This disclosure has been made in view of the above conventional circumstances, and an object of one aspect of this disclosure is to provide a photosensitive resin composition containing an organic solvent other than NMP and having excellent photosensitive properties, and a cured product, an interlayer insulating film, a cover coat layer, a surface protective film, and an electronic component using this photosensitive resin composition.

Means for Solving the Problems

[0005] Specific means for achieving the above object are as follows. <1> A photosensitive resin composition containing a polyimide precursor having a polymerizable unsaturated bond, a photoinitiator, and a solvent, wherein the solvent contains at least one selected from the group consisting of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea. <2> The photosensitive resin composition according to <1>, wherein the total proportion of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea in the solvent is 50% by mass or more. <3> The photosensitive resin composition according to <1>, wherein the proportion of N-ethyl-2-pyrrolidone in the solvent is 50% by mass or more. <4> The photosensitive resin composition according to <1>, wherein the proportion of 1,3-dimethyl-2-imidazolidinone in the solvent is 50% by mass or more. <5> The photosensitive resin composition according to <1>, wherein the proportion of tetramethylurea in the solvent is 50% by mass or more. <6> The photosensitive resin composition according to any one of <1> to <5>, wherein the polyimide precursor has a structural unit represented by the following general formula (6).

[0006]

Chemical formula

[0007] (In general formula (6), X represents a tetravalent organic group, and Y represents a divalent organic group. R 6 and R 7 are each independently a hydrogen atom, a group represented by the following general formula (7), or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and at least one of R 6 and R 7 is a group represented by the following general formula (7).)

[0008]

Chemical formula

[0009] (In general formula (7), R 8 to R 10 each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and q represents an integer of 1 to 10.) <7> The proportion of 1,3-dimethyl-2-imidazolidinone in the solvent is 50% by mass or more, and the proportion of the group represented by the following general formula (G1) in the divalent organic group represented by Y in the general formula (6) is less than 100 mol% in the photosensitive resin composition according to <6>.

[0010]

Chemical formula

[0011] (In general formula (G1), each R independently represents an alkyl group, an alkoxy group, a halogenated alkyl group, a carboxy group, or a phenyl group, and each n independently represents an integer of 0 to 4.) <8> The photosensitive resin composition according to any one of <1> to <7>, wherein the photoinitiator contains an oxime derivative. <9> A cured product obtained by curing the photosensitive resin composition according to any one of <1> to <8>. <10> The cured product according to <9>, which is a patterned cured product. <11> The cured product according to <9> or <10>, which is used as an interlayer insulating film, a cover coat layer, or a surface protective film. <12> An interlayer insulating film containing the cured product according to <9>. <13> A cover coat layer containing the cured product according to <9>. <14> A surface protective film containing the cured product according to <9>. <15> An electronic component containing the cured product according to any one of <9> to <11>.

Advantages of the Invention

[0012] According to one embodiment of the present disclosure, there can be provided a photosensitive resin composition containing an organic solvent other than NMP and having excellent photosensitive characteristics, and a cured product, an interlayer insulating film, a cover coat layer, a surface protective film, and an electronic component using this photosensitive resin composition.

Brief Description of the Drawings

[0013]

Figure 1

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments for carrying out the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, which do not limit the present disclosure.

[0015] In the present disclosure, the term "step" includes, in addition to steps independent of other steps, also those steps that, even if they cannot be clearly distinguished from other steps, are included as long as the purpose of the step is achieved. In the numerical ranges indicated by using "~" in the present disclosure, the numerical values described before and after "~" are included as the minimum value and the maximum value, respectively. In the numerical ranges described step by step in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in other step-by-step descriptions. Also, in the numerical ranges described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples. In the present disclosure, each component may contain a plurality of corresponding substances. When there are a plurality of substances corresponding to each component in the composition, the content rate or content of each component means, unless otherwise specified, the total content rate or content of the plurality of substances present in the composition. In the present disclosure, the term "layer" or "film" includes, in addition to the case where it is formed over the entire region where the layer or film exists, also the case where it is formed only in a part of the region when observing the region where the layer or film exists.

[0016] <Photosensitive Resin Composition> The photosensitive resin composition of the present disclosure contains a polyimide precursor having a polymerizable unsaturated bond (hereinafter sometimes referred to as an unsaturated polyimide precursor), a photoinitiator, and a solvent, and the solvent contains at least one selected from the group consisting of N-ethyl-2-pyrrolidone (hereinafter sometimes referred to as NEP), 1,3-dimethyl-2-imidazolidinone (hereinafter sometimes referred to as DMI), and tetramethylurea (hereinafter sometimes referred to as TMU) (hereinafter, these solvents may be referred to as "specific solvents"). As a result of intensive studies, the inventors of the present invention have found that a photosensitive resin composition having excellent photosensitive properties can be obtained by using a specific solvent, and thus completed the present invention. Further, since the unsaturated polyimide precursor exhibits solubility equivalent to that of NMP in a specific solvent, even when the specific solvent is used, it is possible to secure the concentration of the unsaturated polyimide precursor in the photosensitive resin composition to the same extent as when NMP is used.

[0017] The photosensitive resin composition of the present disclosure is preferably a negative photosensitive resin composition. Hereinafter, each component contained in the photosensitive resin composition of the present disclosure will be described.

[0018] (Unsaturated polyimide precursor) The photosensitive resin composition of the present disclosure contains an unsaturated polyimide precursor. Examples of the polymerizable unsaturated bond include a carbon-carbon double bond. The unsaturated polyimide precursor may be, for example, a polyimide precursor having a structural unit represented by the following general formula (6). When the unsaturated polyimide precursor has a structural unit represented by the general formula (6), the transmittance of i-line is high, and a good cured product tends to be formed even during curing at 380 °C or lower. The content of the structural unit represented by the following general formula (6) in the unsaturated polyimide precursor is preferably 50 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more with respect to all the structural units contained in the unsaturated polyimide precursor. The upper limit is not particularly limited and may be 100 mol%.

[0019] The unsaturated polyimide precursor may be synthesized using a tetracarboxylic dianhydride and a diamine compound. In this case, X corresponds to a residue derived from the tetracarboxylic dianhydride, and Y corresponds to a residue derived from the diamine compound. Note that the unsaturated polyimide precursor may be synthesized using a tetracarboxylic acid instead of the tetracarboxylic dianhydride.

[0020] [Chemical formula]

[0021] In general formula (6), X represents a tetravalent organic group, and Y represents a divalent organic group. R 6 and R 7 are each independently a hydrogen atom, a group represented by the following general formula (7), or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and at least one of R 6 and R 7 is a group represented by the following general formula (7).

[0022] [Chemical formula]

[0023] In general formula (7), R 8 ~R 10 each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and q represents an integer of 1 to 10.

[0024] In general formula (6), the tetravalent organic group represented by X preferably has 3 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, and even more preferably 7 to 13 carbon atoms. The tetravalent organic group represented by X may contain an aromatic ring. When the tetravalent organic group represented by X contains an aromatic ring, examples of the aromatic ring include a benzene ring, a naphthalene ring, and a phenanthrene ring. Among these, from the viewpoint of improving the light transmittance of the unsaturated polyimide precursor in the ultraviolet region, a benzene ring is preferred. When the tetravalent organic group represented by X contains an aromatic ring, each aromatic ring may have a substituent or may be unsubstituted. Examples of the substituent of the aromatic ring include an alkyl group, a fluorine atom, a halogenated alkyl group, a hydroxyl group, and an amino group. When the tetravalent organic group represented by X contains a benzene ring, the tetravalent organic group represented by X preferably contains 1 to 4 benzene rings, more preferably 1 to 3 benzene rings, and even more preferably 1 or 2 benzene rings. When the tetravalent organic group represented by X contains two or more benzene rings, each benzene ring may be linked by a single bond, or an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R A )2-; R A each independently represents a hydrogen atom, an alkyl group or a phenyl group.), a siloxane bond (-O-(Si(R B )2-O-) n ; R B each independently represents a hydrogen atom, an alkyl group or a phenyl group, and n represents an integer of 1 or 2 or more.), etc., or may be linked by a linking group such as a composite linking group formed by combining at least two of these linking groups. Further, two benzene rings may be linked at two positions by at least one of a single bond and a linking group, and a 5-membered or 6-membered ring containing a linking group may be formed between the two benzene rings.

[0025] In general formula (6), when the tetravalent organic group represented by X contains an aromatic ring, the -COOR 6 group and the -CONH- group are preferably ortho to each other, and the -COOR 7 group and the -CO- group are preferably ortho to each other.

[0026] Specific examples of the tetravalent organic group represented by X include groups represented by the following general formula (A) to the following general formula (E), but the present disclosure is not limited to the following specific examples.

[0027]

Chemical formula

[0028] In general formula (D), A and B each independently represent a single bond, a methylene group, a halogenated methylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-) or a silylene bond (-Si(R A )2-; R AEach independently represents a hydrogen atom, an alkyl group, or a phenyl group. ), and both A and B cannot be single bonds.

[0029] In general formula (E), C represents a single bond, or an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R A )2-; R A Each independently represents a hydrogen atom, an alkyl group, or a phenyl group. ), a siloxane bond (-O-(Si(R B )2-O-) n ; R B Each independently represents a hydrogen atom, an alkyl group, or a phenyl group, and n represents an integer of 1 or 2 or more. ) or a divalent group formed by combining at least two of these. Also, C may have a structure represented by the following formula (C1).

[0030] [Chemical formula]

[0031] The alkylene group represented by C in general formula (E) is preferably an alkylene group having 1 to 10 carbon atoms, more preferably an alkylene group having 1 to 5 carbon atoms, and even more preferably an alkylene group having 1 or 2 carbon atoms. Specific examples of the alkylene group represented by C in the general formula (E) include linear alkylene groups such as methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, etc.; branched-chain alkylene groups such as methylmethylene group, methylethylene group, ethylmethylene group, dimethylmethylene group (isopropylidene group), 1,1-dimethylethylene group, 1-methyltrimethylene group, 2-methyltrimethylene group, ethylethylene group, 1-methyltetramethylene group, 2-methyltetramethylene group, 1-ethyltrimethylene group, 2-ethyltrimethylene group, 1,1-dimethyltrimethylene group, 1,2-dimethyltrimethylene group, 2,2-dimethyltrimethylene group, 1-methylpentamethylene group, 2-methylpentamethylene group, 3-methylpentamethylene group, 1-ethyltetramethylene group, 2-ethyltetramethylene group, 1,1-dimethyltetramethylene group, 1,2-dimethyltetramethylene group, 2,2-dimethyltetramethylene group, 1,3-dimethyltetramethylene group, 2,3-dimethyltetramethylene group, 1,4-dimethyltetramethylene group, etc.; and the like. Among these, methylene group, ethylene group, etc. are preferable.

[0032] The halogenated alkylene group represented by C in the general formula (E) is preferably a halogenated alkylene group having 1 to 10 carbon atoms, more preferably a halogenated alkylene group having 1 to 5 carbon atoms, and even more preferably a halogenated alkylene group having 1 to 3 carbon atoms. Specific examples of the halogenated alkylene group represented by C in the general formula (E) include alkylene groups in which at least one hydrogen atom contained in the alkylene group represented by C in the above general formula (E) is substituted with a halogen atom such as a fluorine atom or a chlorine atom. Among these, fluoromethylene group, difluoromethylene group, hexafluorodimethylmethylene group, etc. are preferable.

[0033] R contained in the above silylene bond or siloxane bond A or R BThe alkyl group represented by [alkyl group formula] is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably an alkyl group having 1 or 2 carbon atoms. R A or R B Specific examples of the alkyl group represented by [alkyl group formula] include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, and the like.

[0034] The combination of A and B in the general formula (D) is not particularly limited, and combinations such as a combination of a methylene group and an ether bond, a combination of a methylene group and a sulfide bond, and a combination of a carbonyl group and an ether bond are preferred. As C in the general formula (E), a single bond, an ether bond, a carbonyl group, etc. are preferred.

[0035] R in the general formula (6) 6 and R 7 The aliphatic hydrocarbon group represented by has 1 to 4 carbon atoms, preferably 1 or 2 carbon atoms. R 6 and R 7 Specific examples of the aliphatic hydrocarbon group represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, and the like.

[0036] R in the general formula (7) 8 ~R 10 The aliphatic hydrocarbon group represented by has 1 to 3 carbon atoms, preferably 1 or 2 carbon atoms. R 8 ~R 10 Specific examples of the aliphatic hydrocarbon group represented by include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, etc., and a methyl group is preferred.

[0037] R in the general formula (7) 8 ~R 10 As the combination of, R 8 and R 9 are hydrogen atoms, and the combination where R 10 is a hydrogen atom or a methyl group is preferred.

[0038] In general formula (7), q is preferably an integer of 1 to 10, more preferably an integer of 2 to 5, and even more preferably 2 or 3.

[0039] In general formula (6), R 6 and R 7 It is preferable that at least one of them is a group represented by the general formula (7), and it is more preferable that both R 6 and R 7 are groups represented by the general formula (7).

[0040] When X corresponds to a residue derived from a tetracarboxylic dianhydride, specific examples of the tetracarboxylic dianhydride from which the residue is derived include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,3,5,6-pyridinetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, m-terphenyl-3,3′,4,4′-tetracarboxylic dianhydride, p-terphenyl-3,3′,4,4′-tetracarboxylic dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis{4′-(2,3-dicarboxyphenoxy)phenyl}propane dianhydride, 2,2-bis{4′-(3,4-dicarboxyphenoxy)phenyl}propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis{4′-(2,3-dicarboxyphenoxy)phenyl}propane dianhydride, 1,1,1,3,3,3-hexafluoro-2,2-bis{4′-(3,4-dicarboxyphenoxy)phenyl}propane dianhydride, 4,4′-oxydiphthalic dianhydride, 4,4′-sulfonyldiphthalic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, and the like.

[0041] In general formula (6), the divalent organic group represented by Y preferably has 1 to 30 carbon atoms, more preferably 5 to 25 carbon atoms, and even more preferably 10 to 20 carbon atoms. The divalent organic group represented by Y may be a divalent aliphatic group or a divalent aromatic group. From the viewpoint of heat resistance, the divalent organic group represented by Y is preferably a divalent aromatic group.

[0042] Specific examples of the divalent aromatic group represented by Y include groups represented by the following general formula (F) and the following general formula (G).

[0043]

Chemical formula

[0044] In general formula (F) or general formula (G), R each independently represents an alkyl group, an alkoxy group, a halogenated alkyl group, a carboxy group, or a phenyl group, and n each independently represents an integer of 0 to 4. In general formula (G), D represents a single bond, or an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R A )2-; R A each independently represents a hydrogen atom, an alkyl group, or a phenyl group. ), a siloxane bond (-O-(Si(R B )2-O-) n ; R B each independently represents a hydrogen atom, an alkyl group, or a phenyl group, and n represents an integer of 1 or 2 or more. ) or a divalent group formed by combining at least two of these. Also, D may have a structure represented by the above formula (C1).

[0045] The alkyl group represented by R in general formula (F) or general formula (G) is preferably an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms, and even more preferably an alkyl group having 1 or 4 carbon atoms. Specific examples of the alkyl group represented by R in general formula (F) or general formula (G) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, and the like.

[0046] The alkoxy group represented by R in general formula (F) or general formula (G) is preferably an alkoxy group having 1 to 10 carbon atoms, more preferably an alkoxy group having 1 to 5 carbon atoms, and even more preferably an alkoxy group having 1 or 4 carbon atoms. Specific examples of the alkoxy group represented by R in general formula (F) or general formula (G) include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, an isobutoxy group, an s-butoxy group, a t-butoxy group, and the like.

[0047] The halogenated alkyl group represented by R in general formula (F) or general formula (G) is preferably a halogenated alkyl group having 1 to 10 carbon atoms, more preferably a halogenated alkyl group having 1 to 5 carbon atoms, and even more preferably a halogenated alkyl group having 1 or 2 carbon atoms. Specific examples of the halogenated alkyl group represented by R in general formula (F) or general formula (G) include an alkyl group in which at least one hydrogen atom contained in the alkyl group represented by R in general formula (F) or general formula (G) is substituted with a halogen atom such as a fluorine atom or a chlorine atom. Among these, a fluoromethyl group, a difluoromethyl group, a trifluoromethyl group, and the like are preferable.

[0048] In general formula (F) or general formula (G), n is preferably independently 0 to 2, more preferably 0 or 1, and even more preferably 0.

[0049] Furthermore, D may be a divalent group represented by the following formula (D1) or (D2). -Q-Ar-Q- (D1) -Q-Ar-Q-Ar-Q- (D2) In formula (D1) or formula (D2), Ar represents a phenylene group or a naphthylene group which may have a substituent. Q is independently a single bond, or an alkylene group, a halogenated alkylene group, a carbonyl group, a sulfonyl group, an ether bond (-O-), a sulfide bond (-S-), a silylene bond (-Si(R A )2-; RA each independently represents a hydrogen atom, an alkyl group or a phenyl group.), a siloxane bond (-O-(Si(R B )2-O-) n ; R B each independently represents a hydrogen atom, an alkyl group or a phenyl group, and n represents an integer of 1 or 2 or more.).) or a divalent group formed by combining at least two of these. In formulas (D1) and (D2), the positional relationship between the two Qs bonded to each Ar may be ortho, meta or para. Specific examples of the substituents that the phenylene group or naphthylene group represented by Ar may have are the same as the groups represented by R in general formula (F) or general formula (G). The number of substituents that the phenylene group or naphthylene group represented by Ar may have is not particularly limited.

[0050] Specific examples of D excluding formulas (D1) and (D2) in general formula (G) and specific examples of Q in formulas (D1) and (D2) are the same as the specific examples of C in general formula (E). As D in general formula (G), a single bond or an ether bond is preferred.

[0051] Specific examples of the divalent aliphatic group represented by Y include a linear or branched alkylene group, a cycloalkylene group, a divalent group having a polyalkylene oxide structure, a divalent group having a polysiloxane structure, and the like.

[0052] The linear or branched alkylene group represented by Y is preferably an alkylene group having 1 to 15 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and even more preferably an alkylene group having 1 to 3 carbon atoms. Specific examples of the alkylene group represented by Y include a tetramethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a 2-methylpentamethylene group, a 2-methylhexamethylene group, a 2-methylheptamethylene group, a 2-methyloctamethylene group, a 2-methylnonamethylene group, a 2-methyldecamethylene group, and the like.

[0053] The cycloalkylene group represented by Y is preferably a cycloalkylene group having 3 to 20 carbon atoms, more preferably a cycloalkylene group having 3 to 10 carbon atoms, and even more preferably a cycloalkylene group having 3 to 6 carbon atoms. Specific examples of the cycloalkylene group represented by Y include a cyclopropylene group, a cyclohexylene group, and the like.

[0054] The unit structure contained in the divalent group having a polyalkylene oxide structure represented by Y is preferably an alkylene oxide structure having 1 to 10 carbon atoms, more preferably an alkylene oxide structure having 1 to 8 carbon atoms, and even more preferably an alkylene oxide structure having 1 to 4 carbon atoms. Among them, the polyalkylene oxide structure is preferably a polyethylene oxide structure or a polypropylene oxide structure. The alkylene group in the alkylene oxide structure may be linear or branched. The unit structure in the polyalkylene oxide structure may be one type or two or more types.

[0055] Examples of the divalent group having a polysiloxane structure represented by Y include a divalent group having a polysiloxane structure in which a silicon atom in the polysiloxane structure is bonded to a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 18 carbon atoms. Specific examples of the alkyl group having 1 to 20 carbon atoms bonded to the silicon atom in the polysiloxane structure include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a t-butyl group, an n-octyl group, a 2-ethylhexyl group, an n-dodecyl group, and the like. Among these, a methyl group is preferred. The aryl group having 6 to 18 carbon atoms bonded to the silicon atom in the polysiloxane structure may be unsubstituted or substituted with a substituent. Specific examples of the substituent when the aryl group has a substituent include a halogen atom, an alkoxy group, a hydroxy group, and the like. Specific examples of the aryl group having 6 to 18 carbon atoms include a phenyl group, a naphthyl group, a benzyl group, and the like. Among these, a phenyl group is preferred. The alkyl group having 1 to 20 carbon atoms or the aryl group having 6 to 18 carbon atoms in the polysiloxane structure may be one kind or two or more kinds. The silicon atom constituting the divalent group having a polysiloxane structure represented by Y may be bonded to the NH group in the general formula (6) via an alkylene group such as a methylene group or an ethylene group, or an arylene group such as a phenylene group.

[0056] When Y corresponds to a residue derived from a diamine compound, specific examples of the diamine compound from which the residue is derived include 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 2,2'-difluoro-4,4'-diaminobiphenyl, 3,5-diaminobenzoic acid, p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, m-xylylenediamine, 1,5-diaminonaphthalene, benzidine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 2,2'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,4'-diaminodiphenyl sulfone, 2,2'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 2,4'-diaminodiphenyl sulfide, 2,2'-diaminodiphenyl sulfide, o-tolidine, o-tolidine sulfone, 4,4'-methylenebis(2,6-diethylaniline), 4,4'-methylenebis(2,6-diisopropylaniline), 2,4-diaminomesitylene, 1,5-diaminonaphthalene, 4,4'-benzophenonediamine, bis-{4-(4'-aminophenoxy)phenyl}sulfone, 2,2-bis{4-(4'-aminophenoxy)phenyl}propane, 2,2-bis{4-(4'-aminophenoxy)phenyl}hexafluoropropane, 4,4'-(m-phenylenediisopropylidene)dianiline, 4,4'-(p-phenylenediisopropylidene)dianiline, 1,7-bis(4-aminophenoxy)naphthalene, 4,4'-bis(4-aminophenoxy)biphenyl, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis{4-(3'-aminophenoxy)phenyl}sulfone, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 9,9-bis(4-aminophenyl)fluorene, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diaminodiphenyl sulfone, 1,4-diaminobutane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, 1,12-diaminododecane, 2-methyl-1,5-diaminopentane, 2-methyl-1,6-diaminohexane, 2-methyl-1,7-diaminoheptane, 2-methyl-1,8-diaminooctane, 2-methyl-1,9-diaminononane, 2-methyl-1,10-diaminodecane, 1,4-cyclohexanediamine, 1,3-cyclohexanediamine, diaminopolysiloxane and the like can be mentioned., The diamine compound may be used alone or in combination of two or more kinds.,

[0057] In general formula (6), the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y is not particularly limited., In one embodiment, in order to cause the cyclization reaction of the polyimide to proceed at a low temperature, from the viewpoint of low-temperature curability, as the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y in general formula (6), X is represented by general formula (E) and C in general formula (E) is a group represented by a single bond or an ether bond, and Y is represented by general formula (G) and D in general formula (G) is a group represented by a single bond or an ether bond. The combination is preferred., In another aspect, in order to allow the irradiation light to reach the bottom of the film during exposure, from the perspective of permeability, as the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y in the general formula (6), it is preferable that X is represented by the general formula (E) and C in the general formula (E) is a group represented by an ether bond, and Y is represented by the general formula (G) and D in the general formula (G) is a group represented by an ether bond. In this case, Y may contain a group represented by the general formula (F). When Y uses in combination a group represented by the general formula (G) where D in the general formula (G) is a group represented by an ether bond and a group represented by the general formula (F), the proportion of the group represented by the general formula (F) in Y is preferably 5 mol% to 30 mol%, and more preferably 6 mol% to 15 mol%. In another aspect, from the perspective of the toughness of the cured film, as the combination of the tetravalent organic group represented by X and the divalent organic group represented by Y in the general formula (6), at least a part of X is a group represented by the general formula (A), and examples of Y include combinations of any divalent organic groups. From the perspectives of low-temperature curability, permeability, and toughness, X may be a combination of a group represented by the general formula (A) and a group represented by the general formula (E). When X is a combination of a group represented by the general formula (A) and a group represented by the general formula (E), the proportion of the general formula (A) in X is preferably 10 mol% to 80 mol%, and more preferably 30 mol% to 70 mol%. In another aspect, when the proportion of 1,3-dimethyl-2-imidazolidinone in the solvent is 50% by mass or more, 70% by mass or more, 90% by mass or more, or 100% by mass, from the perspective of film thickness uniformity, the proportion of the group represented by the following general formula (G1) in the divalent organic group represented by Y in the general formula (6) is preferably less than 100 mol%, more preferably 95 mol% or less, still more preferably 80 mol% or less, and particularly preferably 50 mol% or less. When the proportion of the group represented by the following general formula (G1) in the divalent organic group represented by Y in the general formula (6) is less than 100 mol%, the divalent organic group represented by Y in the general formula (6) may contain at least one selected from the group consisting of the group represented by the general formula (F) and the group represented by the following general formula (G2). In this case, the total proportion of the group represented by the general formula (F) and the group represented by the following general formula (G2) in the divalent organic group represented by Y in the general formula (6) is preferably more than 0 mol%, more preferably 5 mol% or more, still more preferably 20 mol% or more, particularly preferably 50 mol% or more, and extremely preferably 100 mol%.

[0058]

Chemical formula

[0059] In the general formula (G1) or the general formula (G2), each R independently represents an alkyl group, an alkoxy group, a halogenated alkyl group, a carboxy group or a phenyl group, and each n independently represents an integer of 0 to 4. Specific examples and preferred examples of R and n are the same as those in the case of the general formula (G).

[0060] The unsaturated polyimide precursor may have other structural units other than the structural unit represented by the general formula (6). Examples of other structural units other than the structural unit represented by the general formula (6) include structural units in which R 6 and R 7 are each independently a hydrogen atom or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, that is, structural units in which neither R 6 nor R 7 is a group represented by the general formula (7).

[0061] The unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH in an organic solvent such as N-methyl-2-pyrrolidone to form a diester derivative, and then subjecting the diester derivative and a diamine compound represented by H2N-Y-NH2 to a condensation reaction. Alternatively, the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a diamine compound represented by H2N-Y-NH2 in an organic solvent to obtain a polyamic acid, adding a compound represented by R-OH, and reacting in an organic solvent to introduce an ester group. Here, Y in the diamine compound represented by H2N-Y-NH2 is the same as Y in the general formula (6), and the specific examples and preferred examples are also the same. Further, R in the compound represented by R-OH represents a group represented by the general formula (7) or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and the specific examples and preferred examples are the same as R in the general formula (6). 6 and R 7 are the same as in the case of. The tetracarboxylic dianhydride represented by the formula (8), the diamine compound represented by H2N-Y-NH2, and the compound represented by R-OH may each be used alone or in combination of two or more. Alternatively, the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH to form a diester derivative, then reacting with a chlorinating agent such as thionyl chloride to convert it to an acid chloride, and then reacting the acid chloride with a diamine compound represented by H2N-Y-NH2. Furthermore, the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a compound represented by R-OH to form a diester derivative, and then reacting the diester derivative with a diamine compound represented by H2N-Y-NH2 in the presence of a carbodiimide compound. Furthermore, the unsaturated polyimide precursor can be obtained by reacting a tetracarboxylic dianhydride represented by the following general formula (8) with a diamine compound represented by H2N-Y-NH2 to form a polyamic acid, then isimidizing the polyamic acid in the presence of trifluoroacetic anhydride, and then reacting with a compound represented by R-OH. In this case, a compound represented by R-OH may be allowed to act on a part of the tetracarboxylic dianhydride in advance, and the partially esterified tetracarboxylic dianhydride may be reacted with a diamine compound represented by H2N-Y-NH2 to form a polyamic acid. The unsaturated polyimide precursor obtained as described above may be purified according to a conventional method.

[0062]

Chemical formula

[0063] In the general formula (8), X is the same as X in the general formula (6), and the specific examples and preferred examples are also the same.

[0064] Examples of the compound represented by R-OH used in the synthesis of the unsaturated polyimide precursor include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, and the like.

[0065] There is no particular limitation on the molecular weight of the unsaturated polyimide precursor, but it is preferably 10,000 to 200,000 in terms of weight average molecular weight (Mw). The weight average molecular weight can be measured, for example, by gel permeation chromatography and can be determined by conversion using a standard polystyrene calibration curve.

[0066] (Polymerizable monomer) The photosensitive resin composition of the present disclosure may contain a polymerizable monomer. The polymerizable monomer may be any compound containing at least one polymerizable unsaturated bond in the molecule, and it is preferably a compound containing two or more polymerizable unsaturated bonds in the molecule. Examples of the group containing a polymerizable unsaturated bond include an allyl group, an acryloyloxy group, a methacryloyloxy group, and the like. Among these, an acryloyloxy group or a methacryloyloxy group is preferable.

[0067] The molecular weight of the polymerizable monomer is preferably 50 to 1000, more preferably 75 to 800, and even more preferably 100 to 500.

[0068] As the polymerizable monomer, a compound containing at least one of an acryloyloxy group and a methacryloyloxy group in the molecule is preferable, and it is more preferable that the two acryloyloxy groups or methacryloyloxy groups contained in the molecule are compounds linked by a linear divalent organic group, and it is even more preferably a compound represented by the following general formula (4) or the following general formula (5) (hereinafter, may be referred to as a specific polymerizable monomer).

[0069]

Chemical formula

[0070] In general formula (4) or general formula (5), R 3 each independently represents a hydrogen atom or a methyl group, R 4 represents an alkylene group having 1 to 8 carbon atoms, R 5 represents an alkylene group having 1 to 8 carbon atoms, and p represents an integer of 2 to 5. A plurality of R 3 may be the same or different. A plurality of R 5 may be the same or different.

[0071] As R 3 in general formula (4) or general formula (5), a methyl group is preferable. R in general formula (4) 4 Specific examples of the alkylene group having 1 to 8 carbon atoms represented by 4 include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, and the like. R in general formula (5) 5 Specific examples of the alkylene group having 1 to 8 carbon atoms represented by 5 include a methylene group, an ethylene group, a trimethylene group, a methylethylene group, a dimethylmethylene group, a tetramethylene group, a hexamethylene group, an octamethylene group, and the like. As p in general formula (5), it is preferably an integer of 3 to 4.

[0072] Specific examples of the specific polymerizable monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, 1,4-butanediol dimethacrylate, 1,6-hexanediol dimethacrylate, and the like. Among these, tetraethylene glycol dimethacrylate is preferable.

[0073] As the polymerizable monomer, other polymerizable monomers other than the specific polymerizable monomer may be used. Examples of other polymerizable monomers include trimethylolpropane diacrylate, trimethylolpropane triacrylate, trimethylolpropane dimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, styrene, divinylbenzene, 4-vinyltoluene, 4-vinylpyridine, N-vinylpyrrolidone, 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate, 1,3-bis(acryloyloxy)-2-hydroxypropane, 1,3-bis(methacryloyloxy)-2-hydroxypropane, methylene bisacrylamide, N,N-dimethylacrylamide, N-methylolacrylamide, and the like. The polymerizable monomer may be used alone or in combination of two or more.

[0074] The content of the polymerizable monomer is not particularly limited. For example, it is preferably 1 to 50 parts by mass, more preferably 3 to 50 parts by mass, and still more preferably 5 to 35 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor. When the content of the polymerizable monomer is within the above range, a practical relief pattern is easily obtained and the residue after development of the unexposed portion is easily suppressed.

[0075] When a specific polymerizable monomer and other polymerizable monomers are used in combination, the content of the other polymerizable monomers is not particularly limited. For example, it is preferably 1 to 300 parts by mass, more preferably 10 to 200 parts by mass, and still more preferably 20 to 150 parts by mass with respect to 100 parts by mass of the specific polymerizable monomer.

[0076] (Photoinitiator) The photosensitive resin composition of the present disclosure contains a photoinitiator. By containing a photoinitiator in the photosensitive resin composition, photosensitivity can be imparted to a resin composition containing an unsaturated polyimide precursor and a polymerizable monomer. The photoinitiator is not particularly limited as long as it is a compound capable of generating radicals upon irradiation with actinic rays. Examples of actinic rays include ultraviolet rays such as i-line, visible light, and radiation.

[0077] Specific examples of the photoinitiator include benzophenone; benzophenone derivatives such as N,N'-tetramethyl-4,4'-diaminobenzophenone (Michler's ketone), N,N'-tetraethyl-4,4'-diaminobenzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 4-chlorobenzophenone, 4,4'-dimethoxybenzophenone, 4,4'-diaminobenzophenone, methyl o-benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, fluorenone; acetophenone; acetophenone derivatives such as 2,2-diethoxyacetophenone, 3'-methylacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropiophenone, 1-hydroxycyclohexyl phenyl ketone; thioxanthone; thioxanthone derivatives such as 2-methylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, diethylthioxanthone; benzyl; benzyl derivatives such as benzyldimethyl ketal, benzyl-β-methoxyethyl acetal; benzoin; benzoin derivatives such as benzoin methyl ether, benzoin ethyl ether, benzoin phenyl ether, methyl benzoin, ethyl benzoin, propyl benzoin; oxime derivatives such as 1-phenyl-1,2-butanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1-phenyl-1,2-propanedioxime-2-(O-benzoyl)oxime, 1,3-diphenylpropanetrione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-3-ethoxypropanetrione-2-(O-benzoyl)oxime, 1,2-octanedione, 1-[4-(phenylthio)phenyl]-, 2-(O-benzoyloxim), ethanone, 1-[9-ethyl-6(2-methylbenzoyl)-9H-carbazol-3-yl]-, 1-(O-acetoxyoxime); N-aryl glycines such as N-phenylglycine; peroxides such as benzoyl perchloride;Aromatic biimidazoles such as 2-(2-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(2-chlorophenyl)-4,5-di(methoxyphenyl)imidazole dimer, 2-(2-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(2- or 4-methoxyphenyl)-4,5-diphenylimidazole dimer, etc.; acylphosphine oxide derivatives such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc. are included. The photoinitiator may be used alone or in combination of two or more. Among these, an oxime derivative is preferable from the viewpoint of high sensitivity without containing a metal element and having high reactivity.

[0078] The content of the photoinitiator is preferably 0.1 parts by mass to 20 parts by mass, more preferably 1 part by mass to 15 parts by mass, and still more preferably 5 parts by mass to 12 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor. When the content of the photoinitiator is within the above range, photocrosslinking is likely to be uniform in the film thickness direction, and a practical relief pattern is easily obtained.

[0079] (Coupling agent) The photosensitive resin composition of the present disclosure may contain a coupling agent. The coupling agent preferably contains a functional group capable of interacting with the unsaturated polyimide precursor, the polyimide resin or the substrate. Examples of the functional group that the coupling agent may contain include a hydroxy group, a glycidyl group, a phenyl group, a (meth)acryl group, a carboxy group, a group having a urea bond, etc. Further, the phenyl group may be substituted with a polar group such as a hydroxy group, a carboxy group, an amine group, etc. When the coupling agent is a silane coupling agent, by the coupling agent containing the above functional group, in the heat treatment after development, the functional group portion reacts with the unsaturated polyimide precursor, and the siloxane portion reacts with the substrate. Thereby, the adhesiveness between the obtained cured product and the substrate can be further improved.

[0080] Specific examples of the coupling agent are not particularly limited. Examples of the coupling agent include silane coupling agents such as 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, N-[3-(triethoxysilyl)propyl]phthalic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, N-phenylaminopropyltrimethoxysilane; aluminum-based adhesion aids such as aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), aluminum diisopropylate ethylacetoacetate; and the like.

[0081] The coupling agent may be used alone or in combination of two or more.

[0082] When the photosensitive resin composition of the present disclosure contains a coupling agent, the content of the coupling agent is preferably 0.1 part by mass to 20 parts by mass, more preferably 1 part by mass to 10 parts by mass, and still more preferably 3 parts by mass to 10 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor.

[0083] (Solvent) The photosensitive resin composition of the present disclosure contains a specific solvent. In one aspect, the total proportion of N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The upper limit is not particularly limited and may be 100% by mass. Also, in one aspect, from the viewpoint of film thickness uniformity, the proportion of N-ethyl-2-pyrrolidone in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The upper limit is not particularly limited and may be 100% by mass. Also, in one aspect, from the viewpoint of dissolution contrast, the proportion of 1,3-dimethyl-2-imidazolidinone in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The upper limit is not particularly limited and may be 100% by mass. Also, in one aspect, from the viewpoint of film thickness uniformity, the proportion of tetramethylurea in the solvent is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. The upper limit is not particularly limited and may be 100% by mass.

[0084] The photosensitive resin composition of the present disclosure may contain other solvents other than N-ethyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, and tetramethylurea. Examples of other solvents include N-methyl-2-pyrrolidone, γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, methyl 3-methoxypropionate, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphorylamide, tetramethylene sulfone, cyclohexanone, cyclopentanone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, N-methylmorpholine, and the like. From the viewpoint that when the content of the unsaturated polyimide precursor is kept constant, the viscosity of the photosensitive resin composition is improved and the thick film formability is improved, the solvent preferably contains at least one of NEP and TMU.

[0085] The solvent may be used alone or in combination of two or more. The content of the solvent is not particularly limited, but generally it is 50 parts by mass to 1000 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor.

[0086] (Thermal polymerization initiator) From the viewpoint of promoting the polymerization reaction, the photosensitive resin composition of the present disclosure may further contain a thermal polymerization initiator. As the thermal polymerization initiator, a compound that does not decompose under the conditions of heating and drying for removing the solvent during film formation, decomposes by heating during curing to generate radicals, and promotes the polymerization reaction between the polymerizable monomers or between the unsaturated polyimide precursor and the polymerizable monomers is preferable. The thermal polymerization initiator is preferably a compound having a decomposition point of 110°C to 200°C, and more preferably a compound having a decomposition point of 110°C to 175°C from the viewpoint of promoting the polymerization reaction at a lower temperature.

[0087] Specific examples of the thermal polymerization initiator include ketone peroxides such as methyl ethyl ketone peroxide, peroxyketals such as 1,1 - di(t - hexylperoxy)-3,3,5 - trimethylcyclohexane, 1,1 - di(t - hexylperoxy)cyclohexane, 1,1 - di(t - butylperoxy)cyclohexane, hydroperoxides such as 1,1,3,3 - tetramethylbutyl hydroperoxide, cumene hydroperoxide, p - menthane hydroperoxide, diisopropylbenzene hydroperoxide, dialkyl peroxides such as dicumyl peroxide, di - t - butyl peroxide, diacyl peroxides such as dilauroyl peroxide, dibenzoyl peroxide, peroxydicarbonates such as di(4 - t - butylcyclohexyl) peroxydicarbonate, di(2 - ethylhexyl) peroxydicarbonate, peroxy esters such as t - butyl peroxy - 2 - ethylhexanoate, t - hexyl peroxyisopropyl monocarbonate, t - butyl peroxybenzoate, 1,1,3,3 - tetramethylbutyl peroxy - 2 - ethylhexanoate, and bis(1 - phenyl - 1 - methylethyl) peroxide and the like.

[0088] When the photosensitive resin composition of the present disclosure contains a thermal polymerization initiator, the content of the thermal polymerization initiator is preferably 0.1 part by mass to 20 parts by mass, more preferably 0.2 part by mass to 20 parts by mass in order to ensure good flux resistance, and further preferably 0.3 part by mass to 10 parts by mass from the viewpoint of suppressing the decrease in solubility due to decomposition during drying, based on 100 parts by mass of the unsaturated polyimide precursor.

[0089] (Sensitizer) The photosensitive resin composition of the present disclosure may contain a sensitizer. By containing a sensitizer in the photosensitive resin composition, it is possible to achieve both maintenance of the residual film ratio and good resolution over a wide range of exposure amounts.

[0090] Examples of the sensitizer include Michler's ketone, benzoin, 2-methylbenzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, 2-t-butylanthraquinone, 1,2-benzo-9,10-anthraquinone, anthraquinone, methylanthraquinone, 4,4'-bis-(diethylamino)benzophenone, acetophenone, benzophenone, thioxanthone, 1,5-acephenanthrylene, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propanone, diacetylbenzyl, benzyl dimethyl ketal, benzyl diethyl ketal, diphenyl disulfide, anthracene, phenanthrenequinone, riboflavin tetrabutyrate, acridine orange, erythrosine, phenanthrenequinone, 2-isopropylthioxanthone, 2,6-bis(p-diethylaminobenzylidene)-4-methyl-4-azacyclohexanone, 6-bis(p-dimethylaminobenzylidene)-cyclopentanone, 2,6-bis(p-diethylaminobenzylidene)-4-phenylcyclohexanone, aminostyryl ketone, 3-ketocoumarin compound, biscoumarin compound, N-phenylglycine, N-phenyldiethanolamine, 3,3',4,4'-tetra(t-butylperoxycarbonyl)benzophenone, and the like.

[0091] The sensitizer may be used alone or in combination of two or more.

[0092] When the photosensitive resin composition of the present disclosure contains a sensitizer, the blending amount of the sensitizer is preferably 0.1 part by mass to 1.0 part by mass, more preferably 0.2 part by mass to 0.8 part by mass, based on 100 parts by mass of the unsaturated polyimide precursor.

[0093] (Stabilizer) The photosensitive resin composition of the present disclosure may contain a stabilizer. Examples of the stabilizer include radical scavengers. By containing a stabilizer in the photosensitive resin composition, the storage stability can be improved.

[0094] Examples of the stabilizer include p-methoxyphenol, diphenyl-p-benzoquinone, benzoquinone, hydroquinone, pyrogallol, phenothiazine, resorcinol, ortho-dinitrobenzene, para-dinitrobenzene, meta-dinitrobenzene, phenanthraquinone, N-phenyl-2-naphthylamine, cupferron, 2,5-xylenol, tannic acid, para-benzylaminophenol, nitrosoamines, and the like.

[0095] The stabilizer may be used alone or in combination of two or more.

[0096] When the photosensitive resin composition of the present disclosure contains a stabilizer, the content of the stabilizer is preferably 0.05 parts by mass to 1.0 parts by mass, more preferably 0.1 parts by mass to 0.8 parts by mass, based on 100 parts by mass of the unsaturated polyimide precursor.

[0097] (Surfactant and leveling agent) The photosensitive resin composition of the present disclosure may contain at least one of a surfactant and a leveling agent. By containing at least one of a surfactant and a leveling agent in the photosensitive resin composition, the developability can be improved, and further, unevenness in film thickness such as striation can be suppressed to improve the coatability.

[0098] Examples of the surfactant or the leveling agent include polyoxyethylene uralyl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octylphenol ether, and the like.

[0099] The surfactant and the leveling agent may be used alone or in combination of two or more.

[0100] When the photosensitive resin composition of the present disclosure contains at least one of a surfactant and a leveling agent, the total content of the surfactant and the leveling agent is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.05 part by mass to 5 parts by mass, and still more preferably 0.05 part by mass to 3 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor.

[0101] (Rust inhibitor) The photosensitive resin composition of the present disclosure may contain a rust inhibitor. By containing a rust inhibitor in the photosensitive resin composition, corrosion of copper and copper alloys can be suppressed and discoloration can be prevented. Examples of the rust inhibitor include triazole derivatives such as benzotriazole and tetrazole derivatives. The rust inhibitor may be used alone or in combination of two or more.

[0102] When the photosensitive resin composition of the present disclosure contains a rust inhibitor, the content of the rust inhibitor is preferably 0.01 part by mass to 10 parts by mass, more preferably 0.1 part by mass to 5 parts by mass, and still more preferably 0.5 part by mass to 3 parts by mass with respect to 100 parts by mass of the unsaturated polyimide precursor.

[0103] The photosensitive resin composition of the present disclosure contains an unsaturated polyimide precursor, a photopolymerization initiator and a solvent, and optionally a polymerizable monomer, a coupling agent, a thermal polymerization initiator, a sensitizer, a stabilizer, a surfactant, a leveling agent, and a rust inhibitor, and may contain other components and unavoidable impurities as long as the effects of the present disclosure are not impaired. For example, 80% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 100% by mass of the photosensitive resin composition of the present disclosure is an unsaturated polyimide precursor, a photopolymerization initiator and a solvent, an unsaturated polyimide precursor, a polymerizable monomer, a coupling agent, a photopolymerization initiator and a solvent, an unsaturated polyimide precursor, a polymerizable monomer, a coupling agent, a photopolymerization initiator, a solvent and a thermal polymerization initiator, or It may be composed of an unsaturated polyimide precursor, a polymerizable monomer, a coupling agent, a photoinitiator, and a solvent, and optionally a thermal polymerization initiator, a sensitizer, a stabilizer, a surfactant, a leveling agent, and a rust inhibitor.

[0104] <Hardened product, interlayer insulating film, cover coat layer, surface protective film, their manufacturing methods, and electronic components> The hardened product of the present disclosure can be obtained by curing the photosensitive resin composition of the present disclosure. The hardened product of the present disclosure may be a patterned hardened product having a predetermined pattern, or may be a hardened product without a pattern. Among the photosensitive resin compositions of the present disclosure, the hardened product of the present disclosure obtained by curing a photosensitive resin composition containing NEP or TMU as a solvent tends to have excellent film thickness uniformity. On the other hand, among the photosensitive resin compositions of the present disclosure, the photosensitive resin film before curing formed using a photosensitive resin composition containing DMI as a solvent tends to have a high residual film ratio. As a result, the hardened product obtained by curing a photosensitive resin composition containing DMI as a solvent tends to form a thick film. The average thickness of the hardened product of the present disclosure is preferably 5 μm to 20 μm. The interlayer insulating film of the present disclosure may contain the hardened product of the present disclosure. The cover coat layer of the present disclosure may contain the hardened product of the present disclosure. The surface protective film of the present disclosure may contain the hardened product of the present disclosure.

[0105] The method for manufacturing the patterned hardened product of the present disclosure includes a step of applying the photosensitive resin composition of the present disclosure onto a substrate and drying to form a photosensitive resin film, a step of pattern-exposing the photosensitive resin film to obtain a resin film, a step of developing the resin film after pattern exposure using a developer to obtain a patterned resin film, and a step of heat-treating the patterned resin film. Thereby, a patterned hardened product can be obtained.

[0106] A method for producing a cured product without a pattern includes, for example, a step of forming the photosensitive resin film of the present disclosure and a step of heat treatment. Further, an exposure step may be included.

[0107] Examples of the substrate include a glass substrate, a semiconductor substrate such as a Si substrate (silicon wafer), a metal oxide insulator substrate such as a TiO2 substrate and a SiO2 substrate, a silicon nitride substrate, a copper substrate, and a copper alloy substrate.

[0108] There is no particular limitation on the coating method of the photosensitive resin composition of the present disclosure, and it can be performed using a spinner or the like.

[0109] Drying can be performed using a hot plate, an oven, or the like. The drying temperature is preferably 80°C to 150°C, and more preferably 90°C to 135°C from the viewpoint of ensuring the dissolution contrast. The drying time is preferably 30 seconds to 5 minutes. Drying may be performed two or more times. When drying is performed two or more times, the drying time per time is preferably within the above range. When drying is performed two or more times, the drying times may be the same or different. Also, the drying temperatures may be the same or different. Thereby, a photosensitive resin film formed by forming the photosensitive resin composition of the present disclosure into a film shape can be obtained.

[0110] The average thickness of the photosensitive resin film is preferably 3 μm to 30 μm, more preferably 5 μm to 20 μm, and even more preferably 5 μm to 15 μm.

[0111] Pattern exposure is performed, for example, by exposing through a photomask to a predetermined pattern. Examples of the actinic ray to be irradiated include ultraviolet rays such as i-line, visible light, radiation, etc., but i-line is preferred. As the exposure apparatus, a parallel exposure machine, an aligner, a projection exposure machine, a stepper, a scanner exposure machine, etc. can be used.

[0112] By developing, a patterned resin film (patterned resin film) can be obtained. Generally, when a negative photosensitive resin composition is used, the unexposed portion is removed with a developer. As the developer, a good solvent for the photosensitive resin film can be used alone, or a good solvent and a poor solvent can be appropriately mixed and used. Examples of the good solvent include N-methyl-2-pyrrolidone, N-acetyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, γ-butyrolactone, α-acetyl-γ-butyrolactone, cyclopentanone, cyclohexanone, and the like. Examples of the poor solvent include toluene, xylene, methanol, ethanol, isopropanol, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, water, and the like.

[0113] A surfactant may be added to the developer. The addition amount is preferably 0.01 parts by mass to 10 parts by mass, more preferably 0.1 parts by mass to 5 parts by mass, based on 100 parts by mass of the developer.

[0114] The development time can be, for example, twice the time until the photosensitive resin film is immersed and completely dissolved. The development time varies depending on the unsaturated polyimide precursor used, but is preferably 10 seconds to 15 minutes, more preferably 10 seconds to 5 minutes, and even more preferably 20 seconds to 5 minutes from the viewpoint of productivity.

[0115] After development, washing may be performed with a rinse solution. As the rinse solution, distilled water, methanol, ethanol, isopropanol, toluene, xylene, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, etc. may be used alone or appropriately mixed, or may be used in a stepwise combination.

[0116] By heat-treating the patterned resin film, a patterned cured product can be obtained. The unsaturated polyimide precursor undergoes a dehydration ring-closure reaction through a heat treatment process to become the corresponding polyimide resin.

[0117] The temperature of the heat treatment is preferably 380 °C or lower, more preferably 250 °C to 350 °C, and even more preferably 270 °C to 320 °C. When the temperature of the heat treatment is within the above range, damage to the substrate or device can be greatly suppressed, enabling the production of devices with high yield, and realizing energy savings in the process.

[0118] The time of the heat treatment is preferably 5 hours or less, more preferably 30 minutes to 3 hours. When the time of the heat treatment is within the above range, the cross-linking reaction or dehydration ring-closure reaction can proceed sufficiently. The atmosphere of the heat treatment may be in the air or in an inert atmosphere such as nitrogen. From the viewpoint of preventing oxidation of the pattern resin film, a nitrogen atmosphere is preferred.

[0119] Examples of the apparatus used for the heat treatment include a quartz tube furnace, a hot plate, rapid thermal annealing, a vertical diffusion furnace, an infrared curing furnace, an electron beam curing furnace, a microwave curing furnace, etc.

[0120] The cured product of the present disclosure can be used as an interlayer insulating film, a cover coat layer, or a surface protective film. Furthermore, the cured product of the present disclosure can be used as a passivation film, a buffer coat film, etc. Using one or more selected from the group consisting of the above passivation film, buffer coat film, interlayer insulating film, cover coat layer, surface protective film, etc., highly reliable electronic components such as semiconductor devices, multilayer wiring boards, various electronic devices, and laminated devices such as multi-die fan-out wafer-level packages can be manufactured. Here, the interlayer insulating film of the present disclosure contains the cured product of the present disclosure. The interlayer insulating film of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing NEP or TMU as a solvent tends to have excellent film thickness uniformity. The interlayer insulating film of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing DMI as a solvent tends to form a thick film. Further, the cover coat layer of the present disclosure contains the cured product of the present disclosure. The cover coat layer of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing NEP or TMU as a solvent tends to have excellent film thickness uniformity. The cover coat layer of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing DMI as a solvent tends to form a thick film. Further, the surface protective film of the present disclosure contains the cured product of the present disclosure. The surface protective film of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing NEP or TMU as a solvent tends to have excellent film thickness uniformity. The surface protective film of the present disclosure containing the cured product obtained by curing a photosensitive resin composition containing DMI as a solvent tends to form a thick film.

[0121] An example of the manufacturing process of a semiconductor device which is an electronic component of the present disclosure will be described with reference to the drawings. FIG. 1 is a manufacturing process diagram of a semiconductor device with a multilayer wiring structure which is an electronic component according to an embodiment of the present disclosure. In FIG. 1, a semiconductor substrate 1 such as a Si substrate having circuit elements is coated with a protective film 2 such as a silicon oxide film except for a predetermined portion of the circuit elements, and a first conductor layer 3 is formed on the exposed circuit elements. Thereafter, an interlayer insulating film 4 is formed on the semiconductor substrate 1.

[0122] Next, a photosensitive resin layer 5 such as a chlorinated rubber type or a phenol novolak type is formed on the interlayer insulating film 4, and a window 6A is provided so that a predetermined portion of the interlayer insulating film 4 is exposed by a known photolithography technique.

[0123] The interlayer insulating film 4 exposed from the window 6A is selectively etched to provide a window 6B. Next, the photosensitive resin layer 5 is removed using an etching solution that etches the photosensitive resin layer 5 without etching the first conductor layer 3 exposed from the window 6B.

[0124] Furthermore, a second conductor layer 7 is formed using a known photolithography technique and electrically connected to the first conductor layer 3. When forming a multilayer wiring structure of three or more layers, the above-described steps can be repeated to form each layer.

[0125] Next, using the photosensitive resin composition of the present disclosure, a window 6C is opened by pattern exposure to form a surface protective film 8. The surface protective film 8 protects the second conductor layer 7 from external stress, α-rays, etc., and the resulting semiconductor device has excellent reliability. In addition, in the above example, it is also possible to form the interlayer insulating film 4 using the photosensitive resin composition of the present disclosure.

Example

[0126] Hereinafter, based on examples, the present disclosure will be described more specifically. Note that the present disclosure is not limited to the following examples.

[0127] [Details of Materials] Details of various materials used in the examples are as follows. · Polymerizable monomer: tetraethylene glycol dimethacrylate · Photoinitiator: 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime (PDO, Lambson) · Rust inhibitor: benzotriazole (BTA) · Unsaturated polyimide precursor A1 synthesized by the following method · Unsaturated polyimide precursor A2 synthesized by the following method · Unsaturated polyimide precursor A3 synthesized by the following method

[0128] (Synthesis of Unsaturated Polyimide Precursor A1) 7.07 g of 4,4'-oxydiphthalic dianhydride (ODPA), 3.6 g of 4,4'-diaminodiphenyl ether (ODA), and 0.2 g of m-phenylenediamine were dissolved in 30 g of N-methyl-2-pyrrolidone (NMP), stirred at 30 °C for 4 hours, and then stirred overnight at room temperature to obtain a polyamic acid. 9.45 g of trifluoroacetic anhydride was added thereto under water cooling, and the mixture was stirred at 45 °C for 3 hours. After adding 7.08 g of 2-hydroxyethyl methacrylate (HEMA), the mixture was stirred. This reaction solution was dropped into distilled water, and the precipitate was collected by filtration and dried under reduced pressure to obtain an unsaturated polyimide precursor A1. Using gel permeation chromatography (GPC) method, the number average molecular weight of the unsaturated polyimide precursor A1 was determined under the following conditions in terms of standard polystyrene conversion. The number average molecular weight of the unsaturated polyimide precursor A1 was 25,000. The ratio of the group represented by the general formula (G1) (residue derived from ODA) to the residue derived from the diamine compound (divalent organic group represented by the general formula (6)) in the unsaturated polyimide precursor A1 was 90.6 mol%.

[0129] 0.5 mg of the unsaturated polyimide precursor A1 was dissolved in 1 mL of a solvent [tetrahydrofuran (THF) / dimethylformamide (DMF) = 1 / 1 (volume ratio)] to obtain a measurement sample.

[0130] Measuring device: Detector Prominence SPD-M20A manufactured by Shimadzu Corporation Pump: Prominence LC-20AD manufactured by Shimadzu Corporation Standard monodisperse polystyrene: TSKgel standard Polystyrene Mw = 2350, 10200, 37900, 190000, 706000 manufactured by Tosoh Corporation Measurement conditions: Column: Two Gelpack GL-8300 MDT-5 in series (manufactured by Showa Denko Materials & Technology Service Co., Ltd.) Eluent: THF / DMF = 1 / 1 (volume ratio) LiBr (0.03 mol / L), H3PO4 (0.06 mol / L) Flow rate: 1.0 mL / min Detection wavelength: 270 nm Injection volume: 5 μL Measurement temperature: 40 °C

[0131] (Synthesis of unsaturated polyimide precursor A2) 7.07 g of ODPA and 4.12 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (DMAP) were dissolved in 30 g of NMP, and the mixture was stirred at 30 °C for 4 hours and then overnight at room temperature to obtain a polyamic acid. 9.45 g of trifluoroacetic anhydride was added thereto under water cooling, and the mixture was stirred at 45 °C for 3 hours. After adding 7.08 g of HEMA, the mixture was stirred. This reaction solution was dropped into distilled water, and the precipitate was collected by filtration and dried under reduced pressure to obtain an unsaturated polyimide precursor A2. The number average molecular weight of the unsaturated polyimide precursor A2 was determined in the same manner as that of the unsaturated polyimide precursor A1, and it was 30,000. The ratio of the group represented by the general formula (G1) (residue derived from ODA) to the residue derived from the diamine compound (divalent organic group represented by the general formula (6)) in the unsaturated polyimide precursor A2 was 0 mol%.

[0132] (Synthesis of unsaturated polyimide precursor A3) 31.02 g of ODPA and 26.24 g of HEMA were dissolved in 80 mL of γ-butyrolactone, and 16.30 g of pyridine was added while stirring at room temperature to obtain a reaction mixture. Regarding this reaction mixture, after the exotherm due to the reaction ended, it was allowed to cool to room temperature and further allowed to stand for 16 hours. Next, under ice cooling, a solution prepared by dissolving 41.26 g of dicyclohexylcarbodiimide (DCC) in 36 mL of γ-butyrolactone was added dropwise to the reaction mixture over 40 minutes while stirring, and then a suspension prepared by suspending 18.60 g of ODA in 70 mL of γ-butyrolactone was added dropwise over 60 minutes while stirring. Stirring was continued at room temperature for 2 hours, 6 mL of ethyl alcohol was added and stirred for 1 hour, and then 80 mL of γ-butyrolactone was added. The precipitate formed in this reaction mixture was removed by filtration to obtain a reaction solution. The obtained reaction solution was poured into 3 liters of ethyl alcohol to form a precipitate composed of a crude polymer. The formed crude polymer was collected by filtration, dissolved in 1.5 liters of tetrahydrofuran to obtain a crude polymer solution. The obtained crude polymer solution was dropped into 28 liters of water to precipitate the polymer, and the obtained precipitate was collected by filtration and dried under reduced pressure to obtain an unsaturated polyimide precursor A3. When the number average molecular weight of the unsaturated polyimide precursor A3 was determined in the same manner as the unsaturated polyimide precursor A1, it was 40,000. The ratio of the group represented by the general formula (G1) (residue derived from ODA) in the residue derived from the diamine compound (divalent organic group represented by the general formula (6)) in the unsaturated polyimide precursor A3 was 100 mol%.

[0133] [Solubility] The solubility of the unsaturated polyimide precursors A1 to A3 in a specific solvent was evaluated by the following method. For comparison with the specific solvent, NMP was also evaluated. 10 g of the unsaturated polyimide precursors A1 to A3 were put into a predetermined amount of the solvent and stirred at 23°C. After 30 minutes from the start of stirring, it was visually confirmed whether the unsaturated polyimide precursors A1 to A3 were dissolved or not. The above operation was repeated while increasing the solvent amount by 0.5 g each time, and the minimum amount of the solvent required to dissolve the unsaturated polyimide precursors A1 to A3 was determined. The obtained results are shown in Table 1. In addition, the viscosity of the solution at 25°C when the unsaturated polyimide precursors A1 to A3 were dissolved with the minimum amount of the solvent required was measured using an E-type viscometer (DV-2+Pro, manufactured by BROOKFIELD). Based on the viscosity of Reference Example 1 or 2 using NMP as the solvent, the viscosity of each example was evaluated according to the following criteria. For Examples 1 to 3, the viscosity of Reference Example 1 (standard 1) was used as the standard. For Example 4, the viscosity of Reference Example 2 (standard 2) was used as the standard. For Example 5, the viscosity was not evaluated. A: There was a viscosity increase of more than 20% compared to the viscosity of Reference Example 1 or 2. B: The viscosity change was within ±20% compared to the viscosity of Reference Example 1 or 2.

[0134] [Film thickness uniformity] A solution in which unsaturated polyimide precursors A1 to A3 were dissolved with the necessary minimum amount of solvent was used as a coating solution for evaluating film thickness uniformity. After the obtained coating solution was spin-coated onto a 6-inch silicon wafer, it was heated at 100°C for 5 minutes to remove the solvent, thereby forming a coating film having the average film thickness shown in Table 1. Next, the film thickness of this coating film was measured at 41 points selected from the following criteria on the wafer. Film thickness measurement was performed using an optical interference film thickness measurement device (VM-2200, manufactured by SCREEN). The film thickness uniformity of the unsaturated polyimide precursors A1 to A3 was estimated from the following formula. Film thickness uniformity [%] = (maximum film thickness of 41 points of film thickness after coating - minimum film thickness of 41 points of film thickness after coating) / average film thickness of 41 points × 100 Selection criteria for measurement points: Excluding the region 10 mm from the outer peripheral edge of the wafer, 41 points set concentrically at equal intervals from the remaining entire region were used as measurement points. The average film thickness was taken as the average value of each film thickness measured at 41 measurement points.

[0135]

Table 1

[0136] As is clear from Reference Example 1 and Examples 1 to 3 in Table 1, it can be seen that unsaturated polyimide precursor A1 exhibits solubility equivalent to NMP in a specific solvent. Also, when a specific solvent was used instead of NMP, the film thickness uniformity was improved. As is clear from Reference Example 2 and Example 4 in Table 1, it can be seen that unsaturated polyimide precursor A2 exhibits solubility and film thickness uniformity equivalent to NMP in a specific solvent. A high-viscosity coating solution is excellent in thick film formability. The fact that the viscosity of the coating solution adjusted with the minimum necessary amount of solvent is high indicates that a thicker film can be formed during film formation. Thin film formation can be achieved by adding a solvent to reduce the viscosity of the coating solution. The high viscosity of the coating solution can be said to be excellent as a "material with a wide film thickness film formation margin". Since the solvent can be removed by heating during film formation and curing, this method of increasing the viscosity by a special combination of the solvent and the unsaturated polyimide precursor is different from the method of improving the viscosity of the coating solution by using additives such as thickeners, and there is an advantage that additives are less likely to remain in the polyimide film and do not inhibit the properties of the polyimide film. If spin coating during film formation can be performed at a high rotation speed, it is possible to improve the film thickness uniformity. However, if the viscosity of the coating solution is low, it may be difficult to ensure the minimum required film thickness of the coating film when spin coating is performed at a high rotation speed. In the examples of the present application, due to the increased viscosity of the coating solution, the film thickness is less likely to become thin even when spin coating is performed at a high rotation speed. Therefore, it is presumed that spin coating during film formation can be performed at a high rotation speed, and the film thickness uniformity is improved.

[0137] [Composition properties] The properties of the photosensitive resin composition were evaluated as follows. The photosensitive resin composition was obtained by blending each component described in Table 2 in the blending amounts described in Table 2. The blending amounts of the components in Table 2 are based on parts by mass.

[0138] (Dissolution contrast) The obtained photosensitive resin composition was spin-coated on a 6-inch silicon wafer using a coating apparatus Act8 (manufactured by Tokyo Electron Limited), dried at 90°C for 200 seconds, and then dried (pre-baked) at 100°C for 200 seconds to form a photosensitive resin film. The rotation conditions for spin coating were fixed with a rotation time of 30 seconds, and the rotation speed was adjusted so that the dry film thickness was about 15 μm. In this evaluation, the range was 2000 rotations / minute to 2500 rotations / minute. Table 2 shows the actually measured value (film thickness) of the dry film thickness. The obtained photosensitive resin film was immersed in cyclopentanone, and the dissolution rate (DR1) of the unexposed portion was calculated by measuring the time (development time) until the photosensitive resin film was completely dissolved. DR1 = (film thickness after pre-baking) / development time Also, a photosensitive resin film was prepared in the same manner as above. Using an i-line stepper FPA-3000iW (manufactured by Canon Inc.), i-line of 700 mJ / cm 2 was irradiated onto the entire surface of the obtained photosensitive resin film to perform exposure. After the exposure, the photosensitive resin film was paddle-developed with cyclopentanone for the above development time using Act8, and then rinsed with propylene glycol monomethyl ether acetate (PGMEA). The dissolution rate (DR2) of the exposed portion was calculated using the following formula. DR2 = (film thickness after pre-baking - film thickness after development) / development time Based on the dissolution rate DR1 of the unexposed portion and the dissolution rate DR2 of the exposed portion of the photosensitive resin film obtained as described above, the dissolution contrast (DR1 / DR2) was calculated. The results obtained are shown in Table 2.

[0139] (Residual film ratio) The obtained photosensitive resin composition was spin-coated onto a 6-inch silicon wafer using a coating apparatus Act8 (manufactured by Tokyo Electron Limited), dried at 90°C for 200 seconds, and then dried (pre-baked) at 100°C for 200 seconds to form a photosensitive resin film. The rotation conditions for spin coating were fixed with a rotation time of 30 seconds, and the rotation speed was adjusted so that the dry film thickness was approximately 15 μm. In this evaluation, the range was 2000 rotations / minute to 2500 rotations / minute. The obtained photosensitive resin film was immersed in cyclopentanone, and twice the time until the photosensitive resin film was completely dissolved was set as the development time. Also, a photosensitive resin film was prepared in the same manner as above. Using an i-line stepper FPA-3000iW (manufactured by Canon Inc.), i-line of 100 mJ / cm 2 ~1100 mJ / cm 2 of i-line was irradiated at 100 mJ / cm 2Exposure was performed by irradiating a predetermined pattern with the exposure dose of the stepwise exposure amount. After the exposure, the photosensitive resin film was paddle-developed with cyclopentanone for the above-mentioned development time using Act8, and then rinsed with propylene glycol monomethyl ether acetate (PGMEA) to obtain a predetermined pattern resin film. When the exposure dose was 300 mJ / cm 2 or 700 mJ / cm 2 the remaining film ratio was calculated using the following calculation formula. The obtained results are shown in Table 2. Remaining film ratio (%) = 100 × (film thickness after development) / (film thickness after pre-baking)

[0140] (Resolution) The obtained photosensitive resin composition was spin-coated onto a 6-inch silicon wafer using a coating apparatus Act8 (manufactured by Tokyo Electron Limited), dried at 90°C for 200 seconds, and then dried (pre-baked) at 100°C for 200 seconds to form a photosensitive resin film. The rotation conditions for spin coating were fixed with a rotation time of 30 seconds, and the rotation speed was adjusted so that the dry film thickness was approximately 15 μm. In this evaluation, the range was set to 2000 revolutions per minute to 2500 revolutions per minute. The obtained photosensitive resin film was immersed in cyclopentanone, and the development time was set to twice the time until the photosensitive resin film was completely dissolved. Also, a photosensitive resin film was produced in the same manner as above, and the obtained photosensitive resin film was irradiated with i-line of 700 mJ / cm 2 using an i-line stepper FPA-3000iW (manufactured by Canon Inc.) through a photomask. (In Example 3, 800 mJ / cm 2 ) After the exposed photosensitive resin film was paddle-developed with Act8 in cyclopentanone for the above-described development time, it was rinsed with propylene glycol monomethyl ether acetate (PGMEA) to obtain a predetermined pattern resin film. The predetermined patterns were a hole pattern and a line-and-space pattern with a line width ratio of 1:1. The minimum hole diameter and line width that could be patterned without peeling and residue were defined as the resolution and evaluated according to the following criteria. In Table 2, "Resolution (L / S)" indicates the resolution of the line-and-space pattern, and "Resolution (hole)" indicates the resolution of the hole pattern. A: The diameter of the smallest hole or the line width was in the range of 20 μm or less. B: The diameter of the smallest hole or the line width was in the range exceeding 20 μm and 50 μm or less. C: The diameter of the smallest hole or the line width was in the range exceeding 50 μm.

[0141]

Table 2

[0142] As is clear from Reference Example 1 and Examples 1 to 3 in Table 2, it can be seen that the photosensitive resin composition containing a specific solvent exhibits photosensitive characteristics equivalent to or superior to those of the photosensitive resin composition containing NMP. As is clear from the comparison of Examples 2, 4, and 5 in Table 2, when DMI is used as a solvent, as the ratio of the group represented by the general formula (G1) (residue derived from ODA) in the residue derived from the diamine compound in the unsaturated polyimide precursor (divalent organic group represented by the general formula (6)) decreases, the dissolution contrast improves.

[0143] The disclosure of International Application No. PCT / JP2020 / 047736 filed on December 21, 2020 is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards described in this specification are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard were specifically and individually indicated to be incorporated by reference.

Explanation of Reference Signs

[0144] 1 Semiconductor substrate 2 Protective film 3 First conductor layer 4 Interlayer insulating film 5 Photosensitive resin layer 6A, 6B, 6C Windows 7 Second conductor layer 8 Surface protective film

Claims

1. A photosensitive resin composition containing a polyimide precursor having a conjugated unsaturated bond, a photoinitiator, and a solvent, wherein the proportion of tetramethylurea in the solvent is 50% by mass or more.

2. The photosensitive resin composition according to Claim 1, wherein the polyimide precursor has a structural unit represented by the following general formula (6). 【Chemical 1】 (In general formula (6), X represents a tetravalent organic group, and Y represents a divalent organic group. R ６ and R ７ each independently represents a hydrogen atom, a group represented by the following general formula (7), or an aliphatic hydrocarbon group having 1 to 4 carbon atoms, and at least one of R ６ and R ７ is a group represented by the following general formula (7).) [Chemical Formula 2] (In general formula (7), R ８ to R １０ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and q represents an integer of 1 to 10.)

3. The photosensitive resin composition according to Claim 1 or Claim 2, wherein the photoinitiator contains an oxime derivative.

4. A cured product obtained by curing the photosensitive resin composition according to Claim 1 or Claim 2.

5. The cured product according to Claim 4, which is a patterned cured product.

6. The cured product according to Claim 4 or Claim 5, which is used as an interlayer insulating film, a cover coat layer, or a surface protective film.

7. An interlayer insulating film containing the cured product according to Claim 4.

8. A cover coat layer containing the cured product according to Claim 4.

9. A surface protective film containing the cured product according to Claim 4.

10. An electronic component containing the cured product according to any one of Claims 4 to 6.

Images