Photosensitive resin composition, cured film, and semiconductor device

Abstract

To provide a negative photosensitive resin composition having low temperature curability and to provide a cured film having excellent strength obtained by curing the same.SOLUTION: There is provided a negative photosensitive resin composition used in a re-wiring layer of a semiconductor device, which comprises a phenol resin (A), a crosslinking agent (B) and a photosensitizing agent (C), wherein the phenol resin (A) includes a biphenyl-type phenol resin, the crosslinking agent (B) includes a tetrafunctional urea resin-based crosslinking agent and a bifunctional epoxy resin-based crosslinking agent and a cured product obtained by curing the negative photosensitive resin composition has a storage modulus at 250°C of 2500 MPa or less as measured by dynamic viscoelasticity measurement (DMA).SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition, a cured film thereof, and a semiconductor device comprising the cured film as an insulating layer. [Background Art]

[0002] In the electrical and electronic fields, photosensitive resin compositions containing a thermosetting resin are sometimes used for forming cured films such as insulating layers. Accordingly, photosensitive resin compositions containing a thermosetting resin have been studied to date. It is known that an insulating film in a rewiring layer or an insulating film in a portion other than a rewiring layer can be formed from a photosensitive resin composition containing a thermosetting resin.

[0003] As an example, Patent Document 1 describes a photosensitive resin composition containing an alkali aqueous solution-soluble resin, a crosslinking agent, a photopolymerization initiator, and an epoxy resin (thermosetting resin) represented by a specific general formula. Patent Document 1 describes that the photosensitivity of this photosensitive resin composition is favorable. Patent Document 1 also describes that a film formed from this photosensitive resin composition is excellent in flexibility, adhesiveness, pencil hardness, solvent resistance, acid resistance, heat resistance, gold plating resistance, and the like. [Prior Art Documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Unexamined Patent Publication No. 2016-80871 [Summary of the Invention] [Problem to be Solved by the Invention]

[0005] As electronic devices become more sophisticated and complex, they are required to have a higher level of reliability than ever before. Therefore, there is a need to improve the reliability of electronic devices through improvements to curing films and the photosensitive resin compositions used to form these films. Furthermore, in recent years, there has been a demand to lower the heating temperature during the formation of curing films (for example, to around 200°C) in order to reduce thermal damage to semiconductor chips.

[0006] This invention was made in view of the above problems, and in a positive-type photosensitive resin composition containing a phenolic resin, a photosensitive agent, and a specific phenolic resin and a specific crosslinking agent, it was discovered that a resin film can be obtained that is low-temperature curable, has excellent solubility in OK73 thinner, and therefore has excellent processability, thus completing the present invention. [Means for solving the problem]

[0007] According to the present invention, A positive-type photosensitive resin composition used in the redistribution layer of a semiconductor device, (A) Phenolic resin, (B) Crosslinking agent, and (C) Contains a photosensitive agent, The phenolic resin is Having a structure represented by formula (2) Biphenyl-type phenolic resin (a1) and a biphenyl-type phenolic resin (a2) having a structure represented by formula (1) Includes, [ka] In equation (2) above, R 41 , and R 42 Each of these is independently a monovalent substituent selected from the group consisting of a hydroxyl group, a halogen atom, a carboxyl group, a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 1 to 20 carbon atoms, a saturated or unsaturated alicyclic group having 3 to 20 carbon atoms, or an organic group having an aromatic structure having 6 to 20 carbon atoms, and these may be linked via ester bonds, ether bonds, amide bonds, or carbonyl bonds, and r and s are independently integers from 0 to 3, Y 4 , and Z 4 Each is independently selected from the group consisting of aliphatic groups having 1 to 10 carbon atoms that may have single or unsaturated bonds, alicyclic groups having 3 to 20 carbon atoms, and organic groups having an aromatic structure with 6 to 20 carbon atoms, Z 4 It is bonded to one of the two benzene rings, [ka] In equation (1), n ​​is between 6 and 72, The crosslinking agent (B) provides a positive-type photosensitive resin composition comprising a bifunctional phenoxy-type epoxy resin.

[0008] Further according to the present invention, there is provided a cured film obtained by curing the positive photosensitive resin composition described above.

[0009] Still further according to the present invention, a semiconductor element, a semiconductor device comprising: a rewiring layer provided on a surface of the semiconductor element, there is provided a semiconductor device, wherein an insulating layer in the rewiring layer is formed of the cured film described above. Effects of the Invention

[0010] According to the present invention, there are provided a positive photosensitive resin composition having low-temperature curability, and a cured film excellent in strength obtained by curing the same. Brief Description of the Drawings

[0011] [Figure 1] It is a cross-sectional view showing a configuration example of a semiconductor device in an embodiment. Mode for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described. In this specification, "x to y" representing a numerical range indicates "not less than x and not more than y", and includes both the lower limit x and the upper limit y. For example, "1 to 5 mass%" means "not less than 1 mass% and not more than 5 mass%". Also, in the following drawings, the same reference numerals are given to similar constituent elements, and descriptions thereof are omitted as appropriate. In addition, the drawings are schematic diagrams and do not correspond to actual dimensional ratios.

[0013] In the notation of groups (atomic groups) in this specification, a notation that does not specify whether it is substituted or unsubstituted includes both those having no substituent and those having a substituent. For example, the term "alkyl group" includes not only an alkyl group having no substituent (unsubstituted alkyl group) but also an alkyl group having a substituent (substituted alkyl group).

[0014] [Positive-type photosensitive resin composition] The positive-type photosensitive resin composition of this embodiment is a resin material used to form a redistribution layer in a semiconductor device. The positive-type photosensitive resin composition of this embodiment comprises (A) a phenolic resin, (B) a crosslinking agent, and (C) a photosensitive agent. Phenolic resin (A) contains biphenyl-type phenolic resin, The crosslinking agent (B) contains a bifunctional phenoxy epoxy resin.

[0015] The inventors of the present invention conducted studies to improve the low-temperature curing properties of positive-type photosensitive resin compositions and to improve the developability of the resulting cured films. As a result, they found that the above-mentioned problems can be solved by configuring the positive-type photosensitive resin composition to include specific components. The following describes each component used in the positive-type photosensitive resin composition of this embodiment.

[0016] (Phenolic resin (A)) The positive-type photosensitive resin composition of this embodiment contains a biphenyl-type phenolic resin (a1) as the phenolic resin. As the biphenyl-type phenolic resin (a1), a phenolic resin having a structural unit represented by the following formula (2) is preferred from the viewpoint of improving curability at low temperatures and the reliability of the cured film.

[0017] [ka]

[0018] In equation (2) above, R 41 , and R 42Each of these is independently a monovalent substituent selected from the group consisting of a hydroxyl group, a halogen atom, a carboxyl group, a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 1 to 20 carbon atoms, a saturated or unsaturated alicyclic group having 3 to 20 carbon atoms, or an organic group having an aromatic structure having 6 to 20 carbon atoms, and these may be linked via ester bonds, ether bonds, amide bonds, or carbonyl bonds, and r and s are independently integers from 0 to 3, and Y4 and Z4 are independently selected from the group consisting of an aliphatic group having 1 to 10 carbon atoms, a alicyclic group having 3 to 20 carbon atoms, and an organic group having an aromatic structure having 6 to 20 carbon atoms, which may each have a single bond or an unsaturated bond, and Z4 is bonded to either of the two benzene rings.

[0019] The weight-average molecular weight of the biphenyl-type phenolic resin (a1) may be, for example, 2000 or more, preferably 3000 or more, more preferably 4000 or more, and even more preferably 5000 or more, from the viewpoint of improving curability at low temperatures. Furthermore, the weight-average molecular weight of the biphenyl-type phenolic resin (a2) may be, for example, 50,000 or less, preferably 20,000 or less, more preferably 15,000 or less, and even more preferably 10,000 or less, from the viewpoint of solvent solubility.

[0020] A biphenyl-type phenolic resin (a1) having a structural unit represented by formula (2) can be specifically obtained using the method described in Japanese Patent Application Publication No. 2018-155938.

[0021] In the positive-type photosensitive resin composition of this embodiment, the content of biphenyl-type phenolic resin (a1) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass, from the viewpoint of improving curability at low temperatures. Furthermore, from the viewpoint of degrading toughness, the content of biphenyl-type phenol resin (a1) in the positive-type photosensitive resin composition is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass.

[0022] The positive-type photosensitive resin composition of this embodiment may further contain a phenolic resin (a2) other than the biphenyl-type phenolic resin (a1) described above, from the viewpoint of improving curability at low temperatures and the reliability of the cured film. Examples of phenolic resins (a2) include novolac-type phenolic resins such as phenol novolac resin, cresol novolac resin, bisphenol novolac resin, phenol-biphenyl novolac resin, allylated novolac-type phenolic resin, and xylylene novolac-type phenolic resin; reaction products of phenolic compounds such as novolac-type phenolic resin, resol-type phenolic resin, and cresol novolac resin with aldehyde compounds; and reaction products of phenolic compounds such as phenol aralkyl resin with dimethanol compounds.

[0023] In particular, the phenolic resin (a2) is preferably a resin having the structure represented by the following formula (1) from the viewpoint of obtaining a low-temperature curable resin composition.

[0024] [ka]

[0025] In the above formula (1), n ​​is preferably 6 or more, more preferably 10 or more, and even more preferably 14 or more, from the viewpoint of improving curability at low temperatures. Furthermore, from the viewpoint of solvent solubility, n is preferably 72 or less, more preferably 54 or less, and even more preferably 36 or less.

[0026] The weight-average molecular weight of the biphenyl-type phenolic resin (a2) may be, for example, 500 or more, preferably 2000 or more, more preferably 3000 or more, and even more preferably 4000 or more, from the viewpoint of improving curability at low temperatures. Furthermore, the weight-average molecular weight of the biphenyl-type phenolic resin (a2) may be, for example, 50,000 or less, preferably 20,000 or less, more preferably 15,000 or less, and even more preferably 10,000 or less, from the viewpoint of solvent solubility.

[0027] When the positive-type photosensitive resin composition contains a biphenyl-type phenolic resin (a2), the amount of biphenyl-type phenolic resin (a2) is preferably 5 parts by mass or more, more preferably 10 parts by mass or more, and even more preferably 15 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass, from the viewpoint of improving toughness during low-temperature curing. Furthermore, from the viewpoint of the mechanical properties of the resulting cured film, the content of biphenyl-type phenolic resin (a2) in the positive-type photosensitive resin composition is preferably 70 parts by mass or less, more preferably 60 parts by mass or less, and even more preferably 50 parts by mass or less, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass.

[0028] The positive-type photosensitive resin composition of this embodiment may also contain thermosetting resins other than phenolic resins. Specific examples of such resins include phenolic resins other than the biphenyl-type phenolic resins mentioned above, hydroxystyrene resins, polyamide resins, polybenzoxazole resins, polyimide resins, and cyclic olefin resins.

[0029] Furthermore, the content of phenol resin (A) in the positive-type photosensitive resin composition is preferably 30 parts by mass or more, more preferably 45 parts by mass or more, even more preferably 50 parts by mass or more, and even more preferably 55 parts by mass or more, when the total solid content of the photosensitive resin composition is 100 parts by mass, from the viewpoint of improving curability at low temperatures and the reliability of the cured film. Furthermore, from the viewpoint of improving chemical resistance and photosensitivity, the content of component (A) in the photosensitive resin composition is preferably 95 parts by mass or less, more preferably 90 parts by mass or less, and even more preferably 85 parts by mass or less, when the total solid content of the photosensitive resin composition is 100 parts by mass. Here, phenol resin (A) is the total amount of phenol resin used in the positive-type photosensitive resin composition of this embodiment, and phenol resin (A) consists of the biphenyl-type phenol resin (a1) described above and phenol resin (a2) used as needed.

[0030] (Crosslinking agent (B)) The positive-type photosensitive resin composition of this embodiment contains an epoxy resin-based crosslinking agent (b1) as the crosslinking agent (B). By including such a crosslinking agent, the positive-type photosensitive resin composition of this embodiment exhibits excellent curability at low temperatures.

[0031] In this embodiment, it is preferable to use a bifunctional phenoxy epoxy resin as the bifunctional epoxy resin-based crosslinking agent (b1) used as a crosslinking agent in the positive-type photosensitive resin composition. Examples of bifunctional phenoxy epoxy resins that can be used include bisphenol A type phenoxy resin, bisphenol F type phenoxy resin, bisphenol S type phenoxy resin, bisphenol acetophenone type phenoxy resin, novolac type phenoxy resin, biphenyl type phenoxy resin, fluorene type phenoxy resin, dicyclopentadiene type phenoxy resin, norbornene type phenoxy resin, naphthalene type phenoxy resin, anthracene type phenoxy resin, adamantane type phenoxy resin, terpene type phenoxy resin, and trimethylcyclohexane type phenoxy resin. Specific examples of such phenoxy epoxy resins include resins JER-1256 and YX-7105 (both manufactured by Mitsubishi Chemical Corporation) and LX-01 (manufactured by Osaka Soda Co., Ltd.).

[0032] The crosslinking agent (B) may include, in addition to the epoxy resin-based crosslinking agent (b1) described above, a bifunctional or more urea resin-based crosslinking agent (b2). Examples of urea resin-based crosslinking agents (b2) with two or more functions include two to four-functional alkoxymethylated glycoluryl compounds. An alkoxymethylated glycoluryl compound is a compound in which the hydrogen atom of the amino group of a glycoluryl compound is replaced by an alkoxymethylol group. Specific examples of alkoxymethylated glycoluryls include, for example, 1,3,4,6-tetrakis(methoxymethyl) glycoluryl, 1,3,4,6-tetrakis(butoxymethyl) glycoluryl, 1,3,4,6-tetrakis(hydroxymethyl) glycoluryl, 1,3-bis(hydroxymethyl)urea, 1,1,3,3-tetrakis(butoxymethyl)urea, 1,1,3,3-tetrakis(methoxymethyl)urea, 1,3-bis(hydroxymethyl)-4,5-dihydroxy-2-imidazolinone, and 1,3-bis(methoxymethyl)-4,5-dimethoxy-2-imidazolinone.

[0033] The crosslinking agent (B) may include, in addition to the above-mentioned bifunctional epoxy resin-based crosslinking agent (b1) and bifunctional or more urea resin-based crosslinking agent (b1), other crosslinking agents (b3), to the extent that it does not impair the low-temperature curability of the positive-type photosensitive resin composition. Other crosslinking agents (b3) include, for example, compounds having a methylol group such as 1,2-benzenedimethanol, 1,3-benzenedimethanol, 1,4-benzenedimethanol (paraxylene glycol), 1,3,5-benzenetrimethanol, 4,4-biphenyldimethanol, 2,6-pyridinedimethanol, 2,6-bis(hydroxymethyl)-p-cresol, and 4,4'-methylenebis(2,6-dialkoxymethylphenol); phenols such as phloroglucides; compounds having an alkoxymethyl group such as 1,4-bis(methoxymethyl)benzene, 1,3-bis(methoxymethyl)benzene, 4,4'-bis(methoxymethyl)biphenyl, 3,4'-bis(methoxymethyl)biphenyl, 3,3'-bis(methoxymethyl)biphenyl, 2,6-naphthalenedicarboxylate methyl, and 4,4'-methylenebis(2,6-dimethoxymethylphenol); hexamethylmelamine, hexabutanol Examples include methylolmelamine compounds, such as lumelamine; alkoxymelamine compounds such as hexamethoxymelamine; methylolurea compounds such as methylolbenzoguanamine compounds and dimethylolethyleneurea; alkylated urea resins; cyano compounds such as dicyanoaniline, dicyanophenol, and cyanophenylsulfonic acid; isocyanate compounds such as 1,4-phenylenediisocyanate and 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate; epoxy group-containing compounds such as ethylene glycol diglycidyl ether, bisphenol A diglycidyl ether, isocyanurate triglycidyl, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene-based epoxy resin, biphenyl type epoxy resin, and phenol novolac resin type epoxy resin; and maleimide compounds such as N,N'-1,3-phenylenedimaleimide and N,N'-methylenedimaleimide.

[0034] From the viewpoint of improving toughness during low-temperature curing, the content of the bifunctional epoxy resin crosslinking agent (b1) is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 10 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass. Furthermore, from the viewpoint of maintaining thermomechanical properties during low-temperature curing, the content of the bifunctional epoxy resin-based crosslinking agent (b1) in the positive-type photosensitive resin composition is preferably 60 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 40 parts by mass or less, when the total solid content of the photosensitive resin composition is 100 parts by mass.

[0035] When a bifunctional or more urea resin-based crosslinking agent (b2) is used, its content is preferably 80 parts by mass or more, more preferably 85 parts by mass or more, and even more preferably 90 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass. Furthermore, from the viewpoint of maintaining thermomechanical properties during low-temperature curing, the content of the bifunctional or more urea resin-based crosslinking agent (b2) in the positive-type photosensitive resin composition is preferably 140 parts by mass or less, more preferably 120 parts by mass or less, and even more preferably 110 parts by mass or less, when the total solid content of the photosensitive resin composition is 100 parts by mass.

[0036] In the positive-type photosensitive resin composition of this embodiment, the content of the crosslinking agent (B) is preferably 120 parts by mass or more, more preferably 140 parts by mass or more, and even more preferably 160 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass, from the viewpoint of improving toughness during low-temperature curing. Furthermore, from the viewpoint of maintaining thermomechanical properties during low-temperature curing, the content of the crosslinking agent (B) in the positive-type photosensitive resin composition is preferably 250 parts by mass or less, more preferably 220 parts by mass or less, and even more preferably 200 parts by mass or less, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass. Here, the crosslinking agent (B) consists of the above-mentioned bifunctional epoxy resin-based crosslinking agent (b1), a bifunctional or more urea resin-based crosslinking agent (b2) used as needed, and other crosslinking agents (b3) used as needed.

[0037] (Photosensitive agent (C)) The positive-type photosensitive resin composition of this embodiment includes a photosensitive agent (C) from the viewpoint of stably forming a cured film. Specifically, the photosensitive agent (C) is an acid generator that generates acid by absorbing thermal energy or light energy.

[0038] From the viewpoint of improving curability at low temperatures and chemical resistance, the photosensitive agent (C) preferably comprises a sulfonium compound or a salt thereof (c1). The sulfonium compound or its salt (c1) is specifically a sulfonium salt having a sulfonium ion as the cation. In this case, the anionic portion of the sulfonium compound or its salt (c1) is specifically a sulfonic acid ion such as a boride ion, antimony ion, phosphorus ion, or trifluoromethanesulfonate ion, and from the viewpoint of improving the reaction rate at low temperatures, it is preferably a boride ion or antimony ion, and more preferably a boride ion. These anions may have substituents.

[0039] The sulfonium compound or its salt (c1) preferably includes a sulfonium salt represented by the following formula (4).

[0040] [ka]

[0041] In the above general formula (4), R 1 This is a hydrogen atom or a monovalent organic group, and from the viewpoint of improving reactivity at low temperatures, it is preferably a hydrogen atom or an acyl group, more preferably an acyl group, and even more preferably a CH3C(=O)- group. R 2The group is a monovalent organic group, and from the viewpoint of improving reactivity at low temperatures, it is preferably a hydrocarbon group having a chain or branched chain or a benzyl group which may have substituents, more preferably a benzyl group which may be substituted with an alkyl group having 1 to 4 carbon atoms, and even more preferably a benzyl group in which a methyl group or an aromatic ring portion which may be substituted with a methyl group. R 3 The group is a monovalent organic group, and from the viewpoint of improving reactivity at low temperatures, it is preferably a hydrocarbon group having a chain or branched chain, more preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

[0042] Other preferred examples of component (c1) include triphenylsulfonium salts such as triphenylsulfonium trifluoromethanesulfonate.

[0043] If the positive-type photosensitive resin composition contains a photosensitive agent (C), its content is preferably 0.005 parts by mass or more, more preferably 0.01 parts by mass or more, and even more preferably 0.02 parts by mass or more, when the total solid content of the positive-type photosensitive resin composition is 100 parts by mass, from the viewpoint of improving curability at low temperatures. Furthermore, from the viewpoint of suppressing a decrease in reliability, the content of the photosensitive agent (C) in the positive-type photosensitive resin composition is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 16 parts by mass or less, when the total solid content of the photosensitive resin composition is 100 parts by mass.

[0044] (Adhesion enhancer) The positive-type photosensitive resin composition of this embodiment preferably contains an adhesion aid. This can, for example, further improve adhesion to the substrate.

[0045] The adhesion aid is not particularly limited. For example, silane coupling agents such as amino group-containing silane coupling agents, epoxy group-containing silane coupling agents, (meth)acryloyl group-containing silane coupling agents, mercapto group-containing silane coupling agents, vinyl group-containing silane coupling agents, ureido group-containing silane coupling agents, and sulfide group-containing silane coupling agents can be used. When using silane coupling agents, one type may be used alone, or two or more types may be used in combination.

[0046] Examples of amino group-containing silane coupling agents include bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldiethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropyltrimethoxysilane, N-β(aminoethyl)γ-aminopropyltriethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldimethoxysilane, N-β(aminoethyl)γ-aminopropylmethyldiethoxysilane, and N-phenyl-γ-aminopropyltrimethoxysilane. Examples of epoxy group-containing silane coupling agents include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and γ-glycidylpropyltrimethoxysilane. Examples of silane coupling agents containing a (meth)acryloyl group include γ-((meth)acryloyloxypropyl)trimethoxysilane, γ-((meth)acryloyloxypropyl)methyldimethoxysilane, and γ-((meth)acryloyloxypropyl)methyldiethoxysilane. Examples of mercapto group-containing silane coupling agents include 3-mercaptopropyltrimethoxysilane. Examples of vinyl group-containing silane coupling agents include vinyltris(β-methoxyethoxy)silane, vinyltriethoxysilane, and vinyltrimethoxysilane. Examples of ureido group-containing silane coupling agents include 3-ureidopropyltriethoxysilane. Examples of sulfide group-containing silane coupling agents include bis(3-(triethoxysilyl)propyl) disulfide and bis(3-(triethoxysilyl)propyl) tetrasulfide. Examples of acid anhydride-containing silane coupling agents include 3-trimethoxysilylpropyl succinic anhydride, 3-triethoxysilylpropyl succinic anhydride, and 3-dimethylmethoxysilylpropyl succinic anhydride.

[0047] Examples of adhesion enhancers include not only silane coupling agents, but also titanium coupling agents and zirconium coupling agents.

[0048] When adhesion aids are used, they may be used alone or in combination of two or more adhesion aids. When an adhesion aid is used, its content is preferably 0.3 to 15 parts by mass, more preferably 0.4 to 12 parts by mass, and even more preferably 0.5 to 10 parts by mass, per 100 parts by mass of phenol resin (A).

[0049] (Surfactants) The positive-type photosensitive resin composition of this embodiment may contain a surfactant. By including a surfactant, wettability during coating can be improved, and a uniform resin film and cured film can be obtained. Examples of surfactants include fluorine-based surfactants, silicone-based surfactants, alkyl-based surfactants, and acrylic-based surfactants.

[0050] The surfactant preferably contains at least one of a fluorine atom and a silicon atom. This contributes to obtaining a uniform resin film (improved coatability), improved developability, and improved adhesive strength. Such a surfactant is preferably a nonionic surfactant containing at least one of a fluorine atom and a silicon atom. Examples of commercially available surfactants that can be used include the "MegaFac" series from DIC Corporation: F-251, F-253, F-281, F-430, F-477, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561, F-562, F-563, F-565, F-56 Examples include fluorine-containing oligomer surfactants such as F-569, F-570, F-572, F-574, F-575, F-576, R-40, R-40-LM, R-41, and R-94; fluorine-containing nonionic surfactants such as Futergent 250 and Futergent 251 manufactured by Neos Co., Ltd.; and silicone-based surfactants such as the SILFOAM® series (e.g., SD 100 TS, SD 670, SD 850, SD 860, SD 882) manufactured by Wacker Chemie.

[0051] If the positive-type photosensitive resin composition contains a surfactant, the photosensitive resin composition may contain one or more surfactants. If the photosensitive resin composition contains a surfactant, the amount is, for example, 0.001 to 1 part by mass, preferably 0.005 to 0.5 parts by mass, per 100 parts by mass of phenol resin (A).

[0052] (solvent) The positive-type photosensitive resin composition of this embodiment preferably contains a solvent. This allows for easy formation of a photosensitive resin film on a stepped substrate by a coating method. When the positive-type photosensitive resin composition of this embodiment contains a solvent, it is, for example, varnish-like. The solvent typically includes organic solvents. The organic solvent is not particularly limited, as long as it is capable of dissolving or dispersing each of the above-mentioned components and does not substantially react with each component.

[0053] Examples of organic solvents include acetone, methyl ethyl ketone, toluene, propylene glycol methyl ethyl ether, propylene glycol dimethyl ether, propylene glycol 1-monomethyl ether 2-acetate, diethylene glycol ethyl methyl ether, diethylene glycol monoethyl ether acetate, and diethylene glycol mo Examples include butyl ether acetate, benzyl alcohol, propylene carbonate, ethylene glycol diacetate, propylene glycol diacetate, propylene glycol monomethyl ether acetate, dipropylene glycol methyl-n-propyl ether, butyl acetate, and γ-butyrolactone. These may be used individually or in combination.

[0054] When using a solvent, the concentration of non-volatile components in the positive-type photosensitive resin composition is preferably 30 to 75% by mass, more preferably 35 to 70% by mass. This range allows for sufficient dissolution or dispersion of each component. It also ensures good coatability, which in turn leads to improved flatness during spin coating. Furthermore, the viscosity of the positive-type photosensitive resin composition can be appropriately controlled by adjusting the content of non-volatile components.

[0055] (Other ingredients) The positive-type photosensitive resin composition of this embodiment may, in addition to the above-mentioned components, optionally contain components other than those listed above. Examples of such components include antioxidants, fillers such as silica, sensitizers, and film-forming agents.

[0056] (Properties of positive-type photosensitive resin compositions) The positive-type photosensitive resin composition of this embodiment, by containing the above-mentioned components, can achieve a tensile elongation of the cured film of the positive-type photosensitive resin composition of 5% to 200% as measured under the following condition 1. (Condition 1) (i) The positive-type photosensitive resin composition is cured at 200°C for 180 minutes to form the cured film, and a sample measuring 6.5 mm × 20 mm × 10 μm in thickness is prepared from the cured film. (ii) Based on JIS K7161, a tensile test is performed on the sample at 23°C and a test speed of 5 mm / min to determine the tensile elongation. From the viewpoint of suppressing brittle fracture, the lower limit of the tensile elongation of the cured film of the positive-type photosensitive resin composition of this embodiment is 5% or more, preferably 6% or more, more preferably 7% or more, and even more preferably 8% or more. Furthermore, from the viewpoint of obtaining a more stable cured film, the upper limit of the tensile elongation of the cured film is 200% or less, preferably 150% or less, more preferably 125% or less, and even more preferably 100% or less.

[0057] The positive-type photosensitive resin composition of this embodiment, by containing the above-mentioned components, can achieve a solubility of 2 g / ml or more in OK73 thinner at 25°C. Such solubility results in good processability through exposure and development processes. Here, the solubility in OK73 thinner is measured under the following conditions. (Conditions) A predetermined amount of the positive-type photosensitive resin composition and 18 g of OK73 thinner are placed in a screw-top tube, stirred with a stirrer for 30 minutes, and then it is confirmed that there is no residue of the positive-type photosensitive resin composition and that it has completely dissolved.

[0058] In this embodiment, the glass transition temperature (Tg) of the cured product of the positive-type photosensitive resin composition is preferably 150°C or higher, and more preferably 200°C or higher, from the viewpoint of improving heat resistance. Furthermore, from the viewpoint of suppressing deterioration of brittleness, the glass transition temperature of the cured product of the positive-type photosensitive resin composition is preferably 260°C or lower, more preferably 240°C or lower, and even more preferably 230°C or lower.

[0059] Here, the Tg of the cured product of the positive-type photosensitive resin composition is calculated from the results obtained by measuring a predetermined test piece (width 3 mm × length 10 mm × thickness 0.005 to 0.015 mm) using a thermomechanical analyzer (TMA) under the conditions of a starting temperature of 30°C, a measurement temperature range of 30 to 440°C, and a heating rate of 10°C / min.

[0060] [Cured resin film] A resin film is obtained by curing the photosensitive resin composition in this embodiment. The resin film in this embodiment is a dried or cured film of the photosensitive resin composition. That is, the resin film is obtained by drying or curing the photosensitive resin composition, preferably by curing the photosensitive resin composition. This resin film is used, for example, to form resin films for electronic devices such as permanent films and resists. Among these, it is preferable to use it in applications where a permanent film is used, from the viewpoint of obtaining a resin film at low temperatures, having excellent processability, and obtaining a resin film with excellent reliability. According to this embodiment, for example, it is possible to obtain a resin film using a photosensitive resin composition that exhibits excellent processability or reliability, which are required for resin films useful in manufacturing electronic devices and the like.

[0061] The above-mentioned permanent film is composed of a resin film obtained by pre-baking, exposing, and developing a photosensitive resin composition, patterning it into a desired shape, and then curing it by post-baking. The permanent film can be used as a protective film for electronic devices such as a buffer coat film, an interlayer film such as an insulating film for rewiring, a dam material, and the like.

[0062] The resist is composed of a resin film obtained by, for example, applying a negative-type photosensitive resin composition to an object to be masked by the resist using methods such as spin coating, roll coating, flow coating, dip coating, spray coating, or doctor coating, and then removing the solvent from the negative-type photosensitive resin composition.

[0063] Figure 1 is a cross-sectional view showing an example of the configuration of an electronic device having a resin film in this embodiment. The electronic device 100 shown in Figure 1 can be an electronic device equipped with the above-mentioned resin film. Specifically, one or more of the group consisting of the passivation film 32, insulating layer 42, and insulating layer 44 in the electronic device 100 can be a resin film. Here, it is preferable that the resin film is the permanent film described above.

[0064] The electronic device 100 is, for example, a semiconductor chip. In this case, a semiconductor package can be obtained by mounting the electronic device 100 on a wiring substrate via bumps 52. The electronic device 100 comprises a semiconductor substrate on which semiconductor elements such as transistors are provided, and a multilayer wiring layer (not shown) provided on the semiconductor substrate. The uppermost layer of the multilayer wiring layer is provided with an interlayer insulating film 30 and an uppermost wiring 34 provided on the interlayer insulating film 30. The uppermost wiring 34 is made of, for example, aluminum Al. A passivation film 32 is also provided on the interlayer insulating film 30 and the uppermost wiring 34. An opening is provided in a part of the passivation film 32 through which the uppermost wiring 34 is exposed.

[0065] A rewiring layer 40 is provided on the passivation film 32. The rewiring layer 40 includes an insulating layer 42 provided on the passivation film 32, rewiring 46 provided on the insulating layer 42, and an insulating layer 44 provided on the insulating layer 42 and the rewiring 46. The insulating layer 42 has openings formed therein that connect to the uppermost wiring 34. The rewiring 46 is formed on the insulating layer 42 and within the openings provided in the insulating layer 42 and is connected to the uppermost wiring 34. The insulating layer 44 has openings that connect to the rewiring 46.

[0066] Bumps 52 are formed within the openings provided in the insulating layer 44, for example, via a UBM (Under Bump Metallurgy) layer 50. The electronic device 100 is connected to a wiring board or the like via the bumps 52.

[0067] The embodiments of the present invention have been described above, but these are merely examples, and various other configurations can also be adopted. Examples of embodiments are provided below. 1. A positive-type photosensitive resin composition used in the redistribution layer of a semiconductor device, (A) Phenolic resin, (B) Crosslinking agent, and (C) Contains a photosensitive agent, The crosslinking agent (B) is a positive-type photosensitive resin composition comprising a bifunctional phenoxy-type epoxy resin. 2. The positive-type photosensitive resin composition according to 1, wherein the weight-average molecular weight of the phenol resin is 2,000 or more and 50,000 or less. 3. The positive-type photosensitive resin composition according to 1. or 2., wherein the crosslinking agent (B) further comprises a urea resin-based crosslinking agent with two or more functionalities. 4. The positive-type photosensitive resin composition according to 3., wherein the urea resin crosslinking agent has two or more functionalities and includes an alkoxymethylated glycoluryl compound. 5. The positive-type photosensitive resin composition according to any one of 1 to 4, wherein the amount of the bifunctional phenoxy epoxy resin is 0.1% by mass or more and 60% by mass or less based on the total solid content of the positive-type photosensitive resin composition. 6. The photosensitive agent (C) is a positive-type photosensitive resin composition according to any one of 1 to 5, comprising a thermal acid generator. 7. A positive-type photosensitive resin composition according to any one of 1 to 6, wherein the tensile elongation of the cured film of the positive-type photosensitive resin composition, as measured under the following condition 1, is 5% or more and 200% or less. (Condition 1) (i) The positive-type photosensitive resin composition is cured at 200°C for 180 minutes to form the cured film, and a sample measuring 6.5 mm × 20 mm × 10 μm in thickness is prepared from the cured film. (ii) Based on JIS K7161, a tensile test is performed on the sample at 23°C and a test speed of 5 mm / min to determine the tensile elongation. 8. A positive-type photosensitive resin composition according to any one of 1 to 7, wherein the solubility in OK73 thinner at 25°C is 2 g / ml or more. 9. A cured film obtained by curing a positive-type photosensitive resin composition as described in any of 1 to 8. 10. Semiconductor devices and, A semiconductor device comprising a redistribution layer provided on the surface of the semiconductor element, A semiconductor device wherein the insulating layer in the redistribution layer is made of the cured film described in 9. [Examples]

[0068] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited thereto.

[0069] (Example 1~ 3, Reference example 1 Comparative Example 1) A photosensitive resin composition was prepared according to the formulations listed in Table 1. Specifically, each component formulated according to Table 1 was first stirred and mixed under a nitrogen atmosphere, and then filtered through a polyethylene filter with a pore size of 0.2 μm to obtain a varnish-like photosensitive resin composition. Details of each component listed in Table 1 are shown below.

[0070] ((A) Phenolic resin) • Phenolic resin a1: Phenolic aralkyl type resin, manufactured by Nippon Kayaku Co., Ltd., KAYAHARD GPH-103 • Phenolic resin a2: Biphenyl-type phenolic resin, manufactured by Sumitomo Bakelite Co., Ltd., PR-X18121 (Crosslinking agent (B)) (Epoxy resin-based crosslinking agent (b1)) • Crosslinking agent b1-1: Phenoxy epoxy resin, manufactured by Mitsubishi Chemical Corporation, YX-7105 • Crosslinking agent b1-2: Bisphenol A type epoxy resin, manufactured by Osaka Soda Co., Ltd., LX-01 • Crosslinking agent b1-3: Rubber-modified epoxy resin, manufactured by DIC Corporation, TSR960 • Crosslinking agent b1-4: Polypropylene glycol diglycidyl ether, manufactured by Daito Chemix, PG207GS (Urea resin-based crosslinking agent (b2)) • Crosslinking agent b2-1: 1,3,4,6-tetrakis(methoxymethyl) glycoluryl, manufactured by Daito Chemix, CROLIN-318 ((C) Photosensitive material) • Acid generator c1: Photoacid generator, manufactured by Daito Chemix Co., Ltd., DS-427. • Acid generator c2: 4-acetoxyphenyldimethylsulfonium tetrakis(pentafluorophenyl)borate, manufactured by Sanshin Chemical Industry Co., Ltd., SI-B5 • Acid generator c3:4-acetoxyphenylmethylbenzylsulfonium tetrakis(pentafluorophenyl)borate, manufactured by Sanshin Chemical Industry Co., Ltd., SI-B3A (Adhesion enhancer) • Adhesion enhancer 1:3-Glycidyloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd., KBM-503P

[0071] (Surfactants) • Surfactant 1: Fluorine-based surfactant, manufactured by 3M Japan, FC4432 (10% GBL) (solvent) Solvent 1: γ-butyrolactone, manufactured by Sanwa Oil & Chemical Industries Co., Ltd.

[0072] The following physical properties were measured for the obtained resin composition.

[0073] (Low temperature curability (curing temperature)) The photosensitive resin composition obtained above was spin-coated onto an 8-inch silicon wafer to a dry film thickness of 10 μm, and then cured by heat treatment in an inert oven (Koyo Thermo Systems Co., Ltd., part number CLH-21CD-(V)-S) under a nitrogen atmosphere, according to the temperature settings and measured internal temperature described below. The curing temperatures are shown in Table 1. • 220°C curing: Room temperature (30°C) → Heat to 220°C over 30 minutes → Maintain at 180°C for 2 hours → Cool down to room temperature over 30 minutes

[0074] (Solubility in OK73 thinner) Two g of photosensitive resin composition and eighteen g of OK73 thinner were placed in a screw-cap tube and stirred with a stirrer for 30 minutes. The resulting solution was then visually inspected and evaluated according to the following criteria. ○: There was no residue of the photosensitive resin composition; it was completely dissolved. △: The solid content of the photosensitive resin composition was visually confirmed. (Growth rate) The photosensitive resin compositions obtained in each example were cured at 200°C for 180 minutes to form a cured film. From the resulting cured films, samples measuring 6.5 mm × 20 mm × 10 μm thick were prepared. Tensile tests were conducted on the samples according to JIS K7161, using an Orientec Co., Ltd. tensile testing machine (Tensilon RTA-100), at 23°C and a test speed of 5 mm / min. Eight measurements were taken for each sample, and the average value ("ave." in Table 1) was defined as the tensile elongation (%). The results are shown in Table 1.

[0075] (Tg, coefficient of thermal expansion (CTE))) Cured films of the photosensitive resin compositions obtained in each example were prepared under conditions of 200°C for 180 minutes, and test specimens measuring 3 mm in width, 10 mm in length, and 10 mm in thickness were obtained from the resulting cured films. For each example specimen, measurements were performed using a thermomechanical analyzer (TMA, Seiko Instruments Inc., SS6000) under the conditions of a starting temperature of 30°C, a measurement temperature range of 30–440°C, and a heating rate of 10°C / min. From the measurement results, Tg (°C) and the coefficient of linear expansion (ppm / °C) in the temperature range of 50–100°C were determined. The results are shown in Table 1.

[0076] (swellability) The photosensitive resin compositions obtained above were applied to 8-inch silicon wafers using a spin coater, and then pre-baked on a hot plate at 120°C for 3 minutes to obtain a coating film with a thickness of approximately 7.5 μm. The coated film was heated in an oven at 200°C for 60 minutes while maintaining an oxygen concentration of 1000 ppm or less to obtain a cured film of the resin composition. The cured film was immersed in a 30 wt% ammonia solution at 50°C for 10 minutes, then thoroughly washed with pure water and air-dried, and the film thickness after treatment was measured. The rate of change in film thickness between the film thickness after treatment and the film thickness before treatment was calculated using the following formula and was defined as the swelling rate of the cured product. Swelling rate of the cured material (%) {(film thickness after immersion - film thickness before immersion) / film thickness before immersion} × 100 (%) The cured material was evaluated as follows: a swelling rate of 5% or less was marked "○", and a rate exceeding 5% was marked "×". A lower swelling rate for cured materials is preferable in order to minimize changes in film thickness during semiconductor manufacturing processes and eliminate process abnormalities.

[0077] (Developability) The photosensitive resin compositions obtained above were then placed on an 8-inch silicon wafer using a spin-coating method. After applying with a microwave, pre-bake on a hot plate at 120°C for 3 minutes to achieve a film thickness of approximately A 9.0 μm thick coating film was obtained. A mask manufactured by Toppan Printing Co., Ltd. (Test Chart No. 1: width) was applied to this coating film. (Through patterns of remaining and removed areas of 0.88 to 50 μm, i-line The exposure was varied using a tapered filter (Nikon NSR-4425i). Next, a 2.38% aqueous solution of tetramethylammonium hydroxide was used as the developer. Adjust the development time so that the difference between the film thickness after pre-baking and the film thickness after development is 1.0 μm. After dissolving and removing the exposed areas by paddle development twice, the film was rinsed with pure water for 10 seconds. The minimum exposure required to form a pattern of 100 μm square via holes is +100 mJ / c m 2 The resolution of the line pattern was evaluated using a pattern exposed with energy . Resolution was determined by checking whether the line pattern was open at 10 μm intervals. If it was open, it was marked with "○"; if it was not open, it was marked with "×" as shown in Table 1.

[0078] [Table 1] [Explanation of Symbols]

[0079] 30 Interlayer insulating film 32 Passivation membrane 34 Top layer wiring 40 Redistribution layer 42, 44 Insulating layer 46 Rewiring 50 UBM layers 52 Bump 100 Electronic equipment

Claims

1. A positive-type photosensitive resin composition used in the redistribution layer of a semiconductor device, (A) Phenolic resin, (B) Crosslinking agent, and (C) Contains a photosensitive agent, The phenol resin comprises a biphenyl-type phenol resin (a1) having a structure represented by formula (2) and a biphenyl-type phenol resin (a2) having a structure represented by formula (1). 【Chemistry 1】 In formula (2) above, R 41 and R 42 are each independently monovalent substituents selected from the group consisting of a hydroxyl group, a halogen atom, a carboxyl group, a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, an alkyl ether group having 1 to 20 carbon atoms, a saturated or unsaturated alicyclic group having 3 to 20 carbon atoms, or an organic group having an aromatic structure having 6 to 20 carbon atoms, and these may be linked via ester bonds, ether bonds, amide bonds, or carbonyl bonds, and r and s are each independently integers from 0 to 3, and Y 4 and Z 4 are each independently selected from the group consisting of an aliphatic group having 1 to 10 carbon atoms which may have single bonds or unsaturated bonds, an alicyclic group having 3 to 20 carbon atoms, and an organic group having an aromatic structure having 6 to 20 carbon atoms, and Z 4 is bonded to either of the two benzene rings. 【Chemistry 2】 In equation (1), n ​​is between 6 and 72, The crosslinking agent (B) is a positive-type photosensitive resin composition comprising a bifunctional phenoxy epoxy resin.

2. The positive-type photosensitive resin composition according to claim 1, wherein the weight-average molecular weight of the phenol resin is 2,000 or more and 50,000 or less.

3. The positive-type photosensitive resin composition according to claim 1 or 2, wherein the crosslinking agent (B) further comprises a urea resin-based crosslinking agent with two or more functionalities.

4. The positive-type photosensitive resin composition according to claim 3, wherein the urea resin-based crosslinking agent with two or more functionalities comprises an alkoxymethylated glycoluryl compound.

5. The positive-type photosensitive resin composition according to any one of claims 1 to 4, wherein the amount of the bifunctional phenoxy epoxy resin is 0.1% by mass or more and 60% by mass or less based on the total solid content of the positive-type photosensitive resin composition.

6. The photosensitive agent (C) comprises a thermal acid generator, as described in any one of claims 1 to 5, in the positive-type photosensitive resin composition.

7. The positive-type photosensitive resin composition according to any one of claims 1 to 6, wherein the tensile elongation of the cured film of the positive-type photosensitive resin composition, as measured under the following condition 1, is 5% or more and 200% or less. (Condition 1) (i) The positive-type photosensitive resin composition is cured at 200°C for 180 minutes to form the cured film, and a sample measuring 6.5 mm × 20 mm × 10 μm thick is prepared from the cured film. (ii) Based on JIS K7161, a tensile test is performed on the sample at 23°C and a test speed of 5 mm / min to determine the tensile elongation.

8. A cured film obtained by curing the positive-type photosensitive resin composition according to any one of claims 1 to 7.

9. Semiconductor elements and A semiconductor device comprising a redistribution layer provided on the surface of the semiconductor element, A semiconductor device wherein the insulating layer in the redistribution layer is made of the cured film described in claim 8.

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