Photosensitive resin composition, method for producing polyimide, method for producing cured relief pattern, and semiconductor device

Abstract

To provide a photosensitive resin composition capable of giving a polyimide layer that can achieve both of, at high levels, improved adhesion between a rewiring layer (Cu layer) and the polyimide layer and reduced voids at an interface in contact with the polyimide layer after a high-temperature storage test.SOLUTION: A photosensitive resin composition contains the following components: (A) a polyimide precursor of a specific structure having an unsaturated group; (B) a triazine compound; and (C) a photopolymerization initiator. The (B) triazine compound contains a triazine ring with at least one hydrogen atom being substituted by a substituent including at least one selected from the group consisting of an amino group, a mercapto group, a (trialkoxysilylpropyl)amino group, hydroxyethoxy group, a (hydroxyethyl)amino group, a hydroxymethylcarbonyloxyalkyl group, an alkyloxycarbonyl group and an alkylthioethyl group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a photosensitive resin composition used for forming relief patterns of insulating materials for electronic components, passivation films, buffer coat films, interlayer insulating films, and the like in semiconductor devices, a method for producing polyimides using the same, a method for producing cured relief patterns, and a semiconductor device. [Background technology]

[0002] Polyimide resins, which have excellent heat resistance, electrical properties, and mechanical properties, have traditionally been used as insulating materials for electronic components, and as passivation films, surface protective films, interlayer insulating films, and the like for semiconductor devices. Among these polyimide resins, those provided in the form of photosensitive polyimide precursor compositions can easily form heat-resistant relief pattern films by applying the composition, exposing it to light, developing it, and subjecting it to a thermal imidization treatment involving curing. Such photosensitive polyimide precursor compositions have the advantage of enabling significant process reduction compared to conventional non-photosensitive polyimide materials.

[0003] Semiconductor devices (hereinafter also referred to as "elements") are mounted on printed circuit boards using various methods depending on the purpose. Conventional elements were generally fabricated using wire bonding, which connects the external terminals (pads) of the element to the lead frame with thin wires. However, as elements have become faster and their operating frequencies have reached GHz, differences in the wiring length of each terminal during mounting have come to affect the operation of the element. Therefore, when mounting elements for high-end applications, it has become necessary to accurately control the length of the mounting wiring. However, it has been difficult to meet this requirement using wire bonding.

[0004] To address this issue, flip-chip mounting has been proposed, in which a rewiring layer is formed on the surface of a semiconductor chip, bumps (electrodes) are formed on the rewiring layer, and then the chip is flipped over and directly mounted on a printed circuit board (see, for example, Patent Document 1). This flip-chip mounting allows for precise control of the wiring distance. For this reason, flip-chip mounting is being adopted for high-end devices that handle high-speed signals, and for mobile phones and other devices due to its small mounting size, and demand for flip-chip mounting is rapidly expanding. When using a polyimide material for flip-chip mounting, a metal wiring layer formation process is performed after the polyimide layer pattern is formed. The metal wiring layer is typically formed as follows: First, the surface of the polyimide layer is roughened by plasma etching, and then a metal layer that serves as a plating seed layer is formed by sputtering to a thickness of 1 μm or less. Then, the metal layer is used as an electrode for electrolytic plating to form the metal wiring layer. In this process, Ti is typically used as the metal for the seed layer, and Cu is used as the metal for the rewiring layer formed by electrolytic plating.

[0005] Such a metal rewiring layer is required to have high adhesion between the rewired metal layer and the polyimide layer after a reliability test, such as a high-temperature storage test in which the layer is stored in air at 5% humidity and 150°C for 168 hours. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-338947 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the above-mentioned high-temperature storage test is performed using conventional polyimide resins, some of the Cu atoms in the redistribution layer migrate (migrate) into the polyimide layer. This causes a problem of voids (hereinafter also referred to as "voids") forming at the interface where the redistributed Cu layer contacts the polyimide layer. When voids form at the interface between the Cu layer and the polyimide layer, the adhesion between them decreases. Furthermore, when the Cu layer and the polyimide layer peel off, the possibility of short circuits or disconnections occurring in the redistribution layer increases.

[0008] Although it is desirable for the redistribution layer (Cu layer) to have high adhesion to the polyimide layer, high adhesion between the redistribution layer and the polyimide layer also makes the migration of Cu atoms more likely to occur, as described above. In other words, there is a trade-off between ensuring adhesion between the redistribution layer (Cu layer) and the polyimide layer and suppressing Cu atom migration, and it has been difficult to achieve both at a high level.

[0009] The present invention has been devised in view of the above-described conventional circumstances. That is, an object of the present invention is to provide a photosensitive resin composition that can provide a polyimide layer that can achieve, at a high level, both improved adhesion between a redistribution layer (Cu layer) and a polyimide layer and suppressed void generation at the interface in contact with the polyimide layer after a high-temperature storage test, a method for producing a polyimide using the photosensitive resin composition, a method for producing a cured relief pattern, and a semiconductor device that has high adhesion between a redistribution layer (Cu layer) and a polyimide layer, is less likely to generate voids at the interface where the Cu layer contacts the polyimide layer after a high-temperature storage test, and is less likely to suffer from short circuits or disconnections after the high-temperature storage test. [Means for solving the problem]

[0010] The present inventors have found that the above object can be achieved by combining a polyimide precursor, a triazine compound having a specific substituent, and a photopolymerization initiator, and have thus completed the present invention. [1] Ingredients: (A) a polyimide precursor represented by the following general formula (A1): (B) a triazine compound; and (C) photoinitiator; Including, The (B) triazine compound is a photosensitive resin composition in which at least one hydrogen atom of the triazine ring is substituted with a substituent containing at least one selected from the group consisting of an amino group, a mercapto group, a (trialkoxysilylpropyl)amino group, a hydroxyethoxy group, a (hydroxyethyl)amino group, a hydroxymethylcarbonyloxyalkyl group, an alkyloxycarbonyl group, and an alkylthioethyl group. [ka] In the formula, X is a tetravalent organic group, Y is a divalent organic group, and R1 and R2 each independently represent a hydrogen atom or a group represented by the following general formula (R1): [ka] (In general formula (R1), R3, R4, and R5 are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and p is an integer selected from 2 to 10), or a saturated aliphatic group having 1 to 4 carbon atoms. However, R1 and R2 cannot both be hydrogen atoms at the same time.) [2] The photosensitive resin composition according to [1], wherein in the general formula (A1), the X contains a structure represented by the following formula (2): [ka] [3] The photosensitive resin composition according to [1] or [2], wherein in the general formula (A1), the Y contains a structure represented by the following formula (8): [ka] [4] The photosensitive resin composition according to [1] or [2], wherein in the general formula (A1), the Y contains a structure represented by the following formula (9): [ka] [5] The photosensitive resin composition according to any one of [1] to [4], wherein the content of the component (B) is 0.05 to 5.0 parts by mass per 100 parts by mass of the component (A). [6] A method for producing a polyimide, comprising curing the photosensitive resin composition according to any one of [1] to [5]. [7] (1) A step of applying the photosensitive resin composition according to any one of [1] to [5] onto a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer to light; (3) developing the exposed photosensitive resin layer to form a relief pattern; (4) heat-treating the relief pattern to form a hardened relief pattern; 1. A method for producing a cured relief pattern, comprising: [8] A semiconductor device having a cured relief pattern obtained by the method for producing a cured relief pattern according to [7]. [Effects of the Invention]

[0011] According to the present invention, there are provided a photosensitive resin composition that can produce a polyimide layer that can achieve, at a high level, both improved adhesion between the redistribution layer (Cu layer) and the polyimide layer and suppression of void generation at the interface in contact with the polyimide layer after a high-temperature storage test; a method for forming a cured relief pattern using the photosensitive resin composition; and a semiconductor device that has high adhesion between the redistribution layer (Cu layer) and the polyimide layer, is less likely to produce voids at the interface where the Cu layer contacts the polyimide layer after a high-temperature storage test, and is less likely to suffer from short circuits or disconnections after the high-temperature storage test. DETAILED DESCRIPTION OF THE INVENTION

[0012] This embodiment will be specifically described below. Throughout this specification, when a plurality of structures represented by the same symbol in a general formula are present in a molecule, they may be the same or different from each other.

[0013] <Photosensitive resin composition> The photosensitive resin composition of the present invention contains (A) a polyimide precursor, (B) a triazine compound, and (C) a photopolymerization initiator. Such a photosensitive resin composition can provide a cured relief pattern that can achieve, at a high level, both improved adhesion between the rewiring layer (Cu layer) and the polyimide layer and suppression of void generation by suppressing migration at the interface in contact with the polyimide layer after a high-temperature storage test.

[0014] [(A) Polyimide precursor] The polyimide precursor (A) according to this embodiment will be described. The polyimide precursor (A) according to this embodiment is a polyimide precursor represented by the following general formula (A1). [ka] In the formula, X is a tetravalent organic group, Y is a divalent organic group, and R1 and R2 each independently represent a hydrogen atom or a group represented by the following general formula (R1): [ka] (In general formula (R1), R3, R4, and R5 are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and p is an integer selected from 2 to 10), or a saturated aliphatic group having 1 to 4 carbon atoms. However, R1 and R2 cannot both be hydrogen atoms at the same time.) The above structure of the polyimide precursor (A) makes it possible to obtain a cured relief pattern that allows the photopolymerization initiator (C) to act well.

[0015] In the general formula (A1), the tetravalent organic group represented by X is preferably an organic group having 6 to 40 carbon atoms, and more preferably a tetravalent aromatic group in which one of the -COOR1 group and the -CONH- group is bonded to the same aromatic ring and both are in the ortho position relative to each other, or an alicyclic aliphatic group. In the former case, the aromatic ring to which the -COOR1 group is bonded and the aromatic ring to which the -COOR2 group is bonded may be the same aromatic ring or different aromatic rings. In this context, the aromatic ring is preferably a benzene ring. The tetravalent organic group represented by X is more preferably a group represented by the following formula: [ka] Examples of the structure include, but are not limited to, the structure of X. The structure of X may be one type or a combination of two or more types.

[0016] In this embodiment, from the viewpoint of more effectively suppressing voids, it is preferable that the polyimide precursor (A) contains at least one structure where X is represented by any one of the following formulas (1) to (3). [ka] [ka] [ka]

[0017] In the general formula (A1), the divalent organic group represented by Y is preferably a C6 to C 40 and aromatic groups of the formula: [ka] {In the above formula, A is a methyl group (-CH3), an ethyl group (-C2H5), a propyl group (-C3H7), a butyl group (-C4H9), or a trifluoromethyl group (-CF3).} Examples of the structure include, but are not limited to, the structure represented by each of the following. Furthermore, the structure of Y may be one type or a combination of two or more types.

[0018] In this embodiment, from the viewpoint of more effectively suppressing voids, it is preferable that the polyimide precursor (A) contains at least one structure in which the above Y is represented by the following general formulas (4) to (7). [ka] [ka] [ka] [ka] {In the above formula, A is a methyl group (-CH), an ethyl group (-C2H5), a propyl group (-C3H7), a butyl group (-C4H9), or a trifluoromethyl group (-CF3).}

[0019] In the present embodiment, from the viewpoint of suppressing voids, it is preferable that X in the polyimide precursor (A) contains a structure represented by formula (2). That is, it is preferable that the polyimide precursor (A) contains a structure derived from ODPA (4,4'-oxydiphthalic anhydride). [ka] In the general formula (R1), R3 is preferably a hydrogen atom or a methyl group, and R4 and R5 are each preferably a hydrogen atom from the viewpoint of photosensitivity. From the viewpoint of photosensitivity, p is preferably an integer of 2 or more and 10 or less, more preferably an integer of 2 or more and 4 or less.

[0020] In this embodiment, the polyimide precursor (A) is a polyimide precursor represented by the general formula (A1), wherein X is a polyimide precursor represented by the following formula (2): [ka] and Y is represented by the following formula (8): [ka] It is particularly preferable that the resin composition contains the compound (I) because this can further improve adhesion and more reliably suppress voids.

[0021] In this embodiment, the polyimide precursor (A) is a polyimide precursor represented by the general formula (A1), wherein X is a polyimide precursor represented by the following formula (2): [ka] and Y is of the formula: [ka] Or the following chemical formula: [ka] It is particularly preferable that the resin composition contains the compound (I) because this can further improve adhesion and more reliably suppress voids.

[0022] From the viewpoint of the heat resistance and mechanical properties of the film obtained after heat treatment, the weight-average molecular weight of the (A) polyimide precursor is preferably 1,000 or more, as a polystyrene equivalent value determined by gel permeation chromatography. It is more preferably 5,000 or more. The upper limit is preferably 100,000 or less. From the viewpoint of solubility in a developer, the weight-average molecular weight is more preferably 50,000 or less. From the viewpoint of achieving both sensitivity and resolution, it is preferably 6,000 to 40,000, more preferably 7,000 to 30,000, and particularly preferably 8,000 to 22,000.

[0023] [(A) Method for preparing polyimide precursor] The ester-bonded polyimide precursor is prepared, for example, by first reacting a tetracarboxylic dianhydride having the desired tetravalent organic group X with an alcohol having a photopolymerizable group (e.g., an unsaturated double bond) to prepare a partially esterified tetracarboxylic acid (hereinafter also referred to as an acid / ester). The acid / ester is then subjected to amide polycondensation with a diamine having a divalent organic group Y. Saturated aliphatic alcohols may be used in combination with the alcohol having the photopolymerizable group.

[0024] (Preparation of Acid / Ester Forms) In the present invention, examples of tetracarboxylic acid dianhydrides having a tetravalent organic group X that are suitable for preparing an ester-bonded polyimide precursor include, but are not limited to, pyromellitic anhydride, diphenylether-3,3',4,4'-tetracarboxylic acid dianhydride, benzophenone-3,3',4,4'-tetracarboxylic acid dianhydride, biphenyl-3,3',4,4'-tetracarboxylic acid dianhydride, diphenylsulfone-3,3',4,4'-tetracarboxylic acid dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic acid dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane. These may be used alone or in combination.

[0025] In the present invention, examples of alcohols having a photopolymerizable group that are preferably used to prepare an ester bond type polyimide precursor include 2-acryloyloxyethyl alcohol, 1-acryloyloxy-3-propyl alcohol, 2-acrylamidoethyl alcohol, methylol vinyl ketone, 2-hydroxyethyl vinyl ketone, 2-hydroxy-3-methoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, 2-hydroxy-3-phenoxypropyl acrylate, 2-hydroxy-3-butoxypropyl acrylate, and 2-hydroxy-3-t-butoxypropyl acrylate. acrylate, 2-hydroxy-3-cyclohexyloxypropyl acrylate, 2-methacryloyloxyethyl alcohol, 1-methacryloyloxy-3-propyl alcohol, 2-methacrylamidoethyl alcohol, 2-hydroxy-3-methoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-phenoxypropyl methacrylate, 2-hydroxy-3-butoxypropyl methacrylate, 2-hydroxy-3-t-butoxypropyl methacrylate, 2-hydroxy-3-cyclohexyloxypropyl methacrylate, and the like.

[0026] The saturated aliphatic alcohols that can be optionally used together with the alcohols having a photopolymerizable group are preferably saturated aliphatic alcohols having 1 to 4 carbon atoms, such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol.

[0027] The tetracarboxylic dianhydride suitable for the present invention and the alcohol are mixed and stirred preferably in the presence of a basic catalyst such as pyridine, preferably in an appropriate reaction solvent, at a temperature of 20 to 50°C for 4 to 10 hours, whereby the esterification reaction of the acid anhydride proceeds, and the desired acid / ester can be obtained.

[0028] The reaction solvent is preferably one that completely dissolves the raw material tetracarboxylic dianhydride and alcohols, as well as the resulting acid / ester. More preferably, it is a solvent that completely dissolves the polyimide precursor, which is an amide polycondensation product of the acid / ester and diamine. Examples of such solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, ketones, esters, lactones, ethers, halogenated hydrocarbons, and hydrocarbons. Specific examples of these solvents include: Ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; Esters such as methyl acetate, ethyl acetate, butyl acetate, and diethyl oxalate;

[0029] Lactones include, for example, γ-butyrolactone; Ethers such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and tetrahydrofuran; Halogenated hydrocarbons, for example, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, chlorobenzene, o-dichlorobenzene, etc.; Examples of hydrocarbons include hexane, heptane, benzene, toluene, and xylene. These may be used alone or in combination of two or more, as required.

[0030] (Preparation of Polyimide Precursor) The acid / ester compound (typically in solution in the reaction solvent) is mixed with an appropriate dehydration condensation agent, preferably under ice cooling, to convert the acid / ester compound into a polyanhydride. A diamine having a divalent organic group Y, which is suitable for use in the present invention, dissolved or dispersed in a separate solvent is then added dropwise to the acid / ester compound, and the two are subjected to amide polycondensation to obtain the desired polyimide precursor. Diaminosiloxanes may be used in combination with the diamine having a divalent organic group Y. Examples of the dehydration condensation agent include dicyclohexylcarbodiimide, 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline, 1,1-carbonyldioxy-di-1,2,3-benzotriazole, and N,N'-disuccinimidyl carbonate. In this manner, the intermediate polyanhydride is obtained.

[0031] In the present invention, examples of diamines having a divalent organic group Y that can be suitably used in the reaction with the polyacid anhydride obtained as described above include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobiphenyl, 3,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 4,4'-diaminobenzophenone, 3,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane,

[0032] 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, 4,4-bis(4-aminophenoxy)biphenyl, 4,4-bis(3-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, 1,4-bis(4-aminophen bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 9,10-bis(4-aminophenyl)anthracene, 2,2-bis(4-aminophenyl)propane, 2,2-bis(4-aminophenyl)hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(3-aminopropyldimethylsilyl)benzene, ortho-tolidine sulfone, 9,9-bis(4-aminophenyl)fluorene, etc.; and those in which some of the hydrogen atoms on the benzene ring are substituted with a methyl group, an ethyl group, a hydroxymethyl group, a hydroxyethyl group, a halogen atom, or the like; and mixtures thereof.

[0033] Specific examples of the substitution products include 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)benzidine, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dimethytoxy-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, and mixtures thereof. The diamines are not limited to the above examples.

[0034] For the purpose of improving adhesion between a coating film formed from the photosensitive resin composition of the present invention and various substrates, diaminosiloxanes are used in combination with the diamines containing the divalent organic group Y when preparing (A) the photosensitive polyimide precursor. Specific examples of such diaminosiloxanes include 1,3-bis(3-aminopropyl)tetramethyldisiloxane and 1,3-bis(3-aminopropyl)tetraphenyldisiloxane.

[0035] After the amide polycondensation reaction is completed, the water-absorbing by-product of the dehydrating condensing agent coexisting in the reaction solution is filtered off, if necessary. Then, a suitable poor solvent (e.g., water, aliphatic lower alcohol, or a mixture thereof) is added to the solution containing the polymer component to precipitate the polymer component. The polymer is further purified, if necessary, by repeated redissolution and reprecipitation procedures, followed by vacuum drying to isolate the desired polyimide precursor. To improve the degree of purification, the polymer solution may be passed through a column packed with an anion and / or cation exchange resin swollen with an appropriate organic solvent to remove ionic impurities.

[0036] From the viewpoint of the heat resistance and mechanical properties of the film obtained after heat treatment, the weight-average molecular weight of the ester-bonded polyimide precursor is preferably 1,000 or more, as a polystyrene equivalent value determined by gel permeation chromatography. It is more preferably 5,000 or more. The upper limit is preferably 100,000 or less. From the viewpoint of solubility in a developer, the weight-average molecular weight is more preferably 50,000 or less. From the viewpoint of achieving both sensitivity and resolution, it is preferably 6,000 to 40,000, more preferably 7,000 to 30,000, and particularly preferably 8,000 to 22,000. Tetrahydrofuran or N-methyl-2-pyrrolidone is recommended as the developing solvent for gel permeation chromatography. The molecular weight is determined from a calibration curve prepared using standard monodisperse polystyrene. It is recommended that the standard monodisperse polystyrene be selected from the organic solvent standard sample STANDARD SM-105 manufactured by Showa Denko K.K.

[0037] [(B) Triazine compound] In the triazine compound (B) according to the present embodiment, at least one hydrogen atom of the triazine ring is substituted with at least one substituent selected from the group consisting of an amino group, a mercapto group, a (trialkoxysilylpropyl)amino group, a hydroxyethoxy group, a (hydroxyethyl)amino group, a hydroxymethylcarbonyloxyalkyl group, an alkyloxycarbonyl group, and an alkylthioethyl group. These substituents may be further substituted with the above-mentioned substituents or other substituents. The triazine compound (B) is not particularly limited as long as at least one hydrogen atom of the triazine ring is substituted with a substituent such as those described above. It is preferable that all three hydrogen atoms of the triazine ring are substituted. The substituent selected from the above group may be bonded to a carbon atom or a nitrogen atom on the triazine ring.

[0038] The (B) triazine compound is not particularly limited as long as it has the above-described substituent bonded to the triazine ring, but the triazine ring may also have other substituents. Examples of other substituents include aliphatic groups such as a methyl group, an ethyl group, and an undecane group, alicyclic groups, and aromatic groups such as a phenyl group. Among these, methyl, ethyl, and phenyl are preferred from the viewpoint of ease of introduction into the triazine ring. Furthermore, other substituents may be absent, singular, or plural, and in the case of plural, it is preferred that they are different substituents. In the case of plural, a combination of methyl and ethyl, or a combination of methyl and phenyl is preferred.

[0039] As the (B) triazine compound, from the viewpoint of improving the adhesion between the rewiring layer (Cu layer) and the polyimide layer and from the viewpoint of suppressing the generation of voids at the interface in contact with the polyimide layer after a high-temperature storage test, it is preferable that the compound have one of the following structures: 2,4-Diamino-6-(2-{2-[(2-ethylhexyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine: [ka]

[0040] 2,4-Diamino-6-(2-{2-[(3-methoxybutyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine: [ka]

[0041] 2,4-Diamino-6-{2-[(2,3-dihydroxypropyl)thio]ethyl}-1,3,5-triazine: [ka]

[0042] 2-(4,6-diamino-[1,3,5]triazin-2-ylamino)ethanol: [ka]

[0043] N-(3-trimethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine: [ka]

[0044] N-(3-triethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine: [ka]

[0045] 2-mercapto-4,6-bis[(2-hydroxyethyl)amino]-1,3,5-triazine: [ka]

[0046] 2-mercapto-4,6-bis[(3-triethoxysilylpropyl)amino]-1,3,5-triazine: [ka]

[0047] 2,4-Diamino-6-[2-(hydroxyethoxy)ethyl]-1,3,5-triazine: [ka]

[0048] 2,4-Diamino-6-(2-hydroxyethyl)oxy-1,3,5-triazine: [ka]

[0049] 2,4-Diamino-6-[2-(hydroxymethylcarbonyloxy)ethyl]-1,3,5-triazine: [ka]

[0050] 2-(2-hydroxyethyl)amino-4,6-bis(dimethylamino)-1,3,5-triazine: [ka] These triazine compounds may be used alone or in combination of two or more, as required.

[0051] Among these, 2,4-diamino-6-(2-{2-[(2-ethylhexyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine, N-(3-triethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine, 2-mercapto-4,6-bis[(3-triethoxysilylpropyl)amino]-1,3,5-triazine, and 2-(2-hydroxyethyl)amino-4,6-bis(dimethylamino)-1,3,5-triazine are preferred.

[0052] Although the reason why the addition of a triazine compound in this embodiment improves adhesion is not clear, it is presumed that the improved adhesion is due to the formation of hydrogen bonds between the carbonyl group of the polyimide resin and at least one group selected from the amino group, mercapto group, (trialkoxysilylpropyl)amino group, hydroxyethoxy group, (hydroxyethyl)amino group, hydroxymethylcarbonyloxyalkyl group, alkyloxycarbonyl group, and alkylthioethyl group of the triazine compound in this embodiment. Although it is not clear why the addition of a triazine compound in this embodiment can suppress copper voids, it is presumed that the copper atoms of the substrate and the nitrogen atoms of the triazine ring form coordinate bonds, thereby suppressing the migration of copper atoms and thus the formation of copper voids.

[0053] In particular, in the photosensitive resin composition of the present embodiment, the (B) triazine compound is contained in the resin composition, i.e., is encapsulated therein, thereby more firmly adhering the polyimide resin to the Cu layer and more effectively suppressing migration of Cu atoms than when the compound is applied to the substrate surface as a surface treatment agent, thereby achieving more significant effects.

[0054] In addition, in the photosensitive resin composition of this embodiment, the total content of the (B) triazine compound is preferably 0.05 to 5.0 parts by mass, and more preferably 0.1 to 3 parts by mass, relative to 100 parts by mass of the (A) polyimide precursor component. If the content of (B) triazine compound is too low, the above-mentioned effects of the present invention cannot be sufficiently obtained, whereas if it is too high, the adhesion will be reduced instead.

[0055] [(C) Photopolymerization initiator] The photopolymerization initiator (C) according to this embodiment will be described. As the photopolymerization initiator according to the present embodiment, a photopolymerization initiator that generates radicals by absorbing and decomposing light of a specific wavelength is preferably used. (C) Photopolymerization initiators include benzophenone derivatives such as benzophenone, methyl o-benzoylbenzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and fluorenone; acetophenone derivatives such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, and 1-hydroxycyclohexyl phenyl ketone; thioxanthone derivatives such as thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, and diethylthioxanthone; benzil derivatives such as benzil, benzil dimethyl ketal, and benzyl-β-methoxyethyl acetal; benzoin derivatives such as benzoin and benzoin methyl ether; and 1-phenyl-1,2-butanedione-2-(o-methoxycarbonyl)oxime. Preferred examples of the photopolymerization initiator include, but are not limited to, oximes such as 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, 1,3-diphenylpropanetrione-2-(o-ethoxycarbonyl)oxime, and 1-phenyl-3-ethoxypropanetrione-2-(o-benzoyl)oxime; N-arylglycines such as N-phenylglycine; peroxides such as benzoyl perchloride; aromatic biimidazoles; titanocenes; and photoacid generators such as α-(n-octanesulfonyloxyimino)-4-methoxybenzyl cyanide. Among the above photopolymerization initiators, oximes are more preferred, particularly in terms of photosensitivity.

[0056] Among the above oxime photopolymerization initiators, those having a structure represented by any one of the following formulae (C1) to (C6) are most preferred from the viewpoint of adhesiveness. [ka] (In the formula, R39 is a methyl group or a phenyl group, and each R40 independently represents a monovalent organic group having 1 to 12 carbon atoms.) [ka] (wherein Z is a sulfur or oxygen atom, and R 41 represents a methyl group, a phenyl group, or a divalent organic group, and R 42 ~R 44 each independently represents a hydrogen atom or a monovalent organic group. [ka] [ka] [ka] [ka]

[0057] [(D) Crosslinking agent] The crosslinking agent (D) optionally used in the present invention may be any compound having multiple functional groups in the molecule, such as acrylic, methacrylic, epoxy, methylol, allyl, vinyl, and maleimide groups.

[0058] The blending amount of the (D) crosslinking agent is preferably 1 to 40 parts by mass, more preferably 2 to 30 parts by mass, per 100 parts by mass of the (A) resin.

[0059] In the photosensitive resin composition of the present invention, the total content of the (D) crosslinking agent is preferably 0.1 to 20 parts by mass per 100 parts by mass of the (A) polyimide precursor component.

[0060] [(E) Other ingredients] The photosensitive resin composition of the present invention may further contain components other than the above components (A) to (D). The photosensitive resin composition of the present invention is typically used as a liquid photosensitive resin composition in the form of a varnish obtained by dissolving the above-mentioned components and any optional components to be used as needed in a solvent. Therefore, examples of the (D) other components include, in addition to the solvent, resins other than the (A) photosensitive polyimide precursor, sensitizers, monomers having a photopolymerizable unsaturated bond, adhesion aids, thermal polymerization inhibitors, azole compounds, hindered phenol compounds, etc.

[0061] Examples of the solvent include polar organic solvents and alcohols. As the solvent, a polar organic solvent is preferably used from the viewpoint of solubility in (A) the photosensitive polyimide precursor, and specific examples thereof include N,N-dimethylformamide, N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether, cyclopentanone, γ-butyrolactone, α-acetyl-γ-butyrolactone, tetramethylurea, 1,3-dimethyl-2-imidazolinone, and N-cyclohexyl-2-pyrrolidone, which may be used alone or in combination of two or more.

[0062] As the solvent in the present invention, a solvent containing an alcohol is preferred from the viewpoint of improving the storage stability of the photosensitive resin composition. Suitable alcohols are typically alcohols having an alcoholic hydroxyl group in the molecule and no olefinic double bond. Specific examples include alkyl alcohols such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, and tert-butyl alcohol; Lactic acid esters such as ethyl lactate;

[0063] propylene glycol monoalkyl ethers such as propylene glycol-1-methyl ether, propylene glycol-2-methyl ether, propylene glycol-1-ethyl ether, propylene glycol-2-ethyl ether, propylene glycol-1-(n-propyl) ether, and propylene glycol-2-(n-propyl) ether; Monoalcohols such as ethylene glycol methyl ether, ethylene glycol ethyl ether, and ethylene glycol-n-propyl ether; 2-hydroxyisobutyric acid esters; Dialcohols such as ethylene glycol and propylene glycol Among these, lactate esters, propylene glycol monoalkyl ethers, 2-hydroxyisobutyrate esters, and ethyl alcohol are preferred, and ethyl lactate, propylene glycol-1-methyl ether, propylene glycol-1-ethyl ether, and propylene glycol-1-(n-propyl) ether are particularly preferred.

[0064] The solvent can be used in an amount of, for example, 30 to 1,500 parts by mass, preferably 100 to 1,000 parts by mass, per 100 parts by mass of the (A) polyimide precursor, depending on the desired coating thickness and viscosity of the photosensitive resin composition. When the solvent contains an alcohol having no olefinic double bond, the content of the alcohol having no olefinic double bond in the total solvent is preferably 5 to 50% by mass, more preferably 10 to 30% by mass. When the content of the alcohol having no olefinic double bond is 5% by mass or more, the storage stability of the photosensitive resin composition is improved, and when it is 50% by mass or less, the solubility of the (A) polyimide precursor is improved.

[0065] The photosensitive resin composition according to the present embodiment may further contain a resin component other than the polyimide precursor (A). Examples of the resin component that can be contained include polyimide, polyoxazole, polyoxazole precursor, phenolic resin, polyamide, epoxy resin, siloxane resin, and acrylic resin. The amount of these resin components to be added is preferably in the range of 0.01 to 20 parts by mass per 100 parts by mass of the polyimide precursor (A).

[0066] The photosensitive resin composition according to this embodiment may optionally contain a sensitizer in order to improve photosensitivity. Examples of the sensitizer include Michler's ketone, 4,4'-bis(diethylamino)benzophenone, 2,5-bis(4'-diethylaminobenzal)cyclopentane, 2,6-bis(4'-diethylaminobenzal)cyclohexanone, 2,6-bis(4'-diethylaminobenzal)-4-methylcyclohexanone, 4,4'-bis(dimethylamino)chalcone, 4,4'-bis(diethylamino)chalcone, p-dimethylaminocinnamylideneindanone, p-dimethylaminobenzylideneindanone, 2-(p-dimethylaminophenylbiphenylene)benzothiazole, 2-(p-dimethylaminophenylvinylene)benzothiazole, 2-(p-dimethylaminophenylvinylene)isonaphthothiazole, 1,3-bis(4'-dimethylaminobenzal)acetone, 1,3-bis(4'-diethylaminobenzal)acetone,

[0067] 3,3'-Carbonyl-bis(7-diethylaminocoumarin), 3-acetyl-7-dimethylaminocoumarin, 3-ethoxycarbonyl-7-dimethylaminocoumarin, 3-benzyloxycarbonyl-7-dimethylaminocoumarin, 3-methoxycarbonyl-7-diethylaminocoumarin, 3-ethoxycarbonyl-7-diethylaminocoumarin, N-phenyl-N'-ethylethanolamine, N-phenyldiethanolamine, Np-tolyldiethanolamine, N-phenylethanolamine, 4-morpholinobenzophenone, dimethylamino Examples include isoamyl benzoate, isoamyl diethylaminobenzoate, 2-mercaptobenzimidazole, 1-phenyl-5-mercaptotetrazole, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, 2-(p-dimethylaminobenzoyl)styrene, diphenylacetamide, benzanilide, N-methylacetanilide, 3',4'-dimethylacetanilide, etc. These can be used alone or in combination of, for example, 2 to 5 types.

[0068] When the photosensitive resin composition contains a sensitizer for improving photosensitivity, the amount of the sensitizer added is preferably 0.1 to 25 parts by mass per 100 parts by mass of the (A) polyimide precursor.

[0069] The resin composition of the present invention may optionally contain a monomer having a photopolymerizable unsaturated bond in order to improve the resolution of the relief pattern. Such a monomer is preferably a (meth)acrylic compound that undergoes a radical polymerization reaction in the presence of a photopolymerization initiator. Examples of such a monomer include, but are not limited to, mono- or di(meth)acrylates of ethylene glycol or polyethylene glycol, such as diethylene glycol dimethacrylate and tetraethylene glycol dimethacrylate; Mono- or di(meth)acrylates of propylene glycol or polypropylene glycol; Mono-, di- or tri(meth)acrylates of glycerol; Cyclohexane di(meth)acrylate; Diacrylate and dimethacrylate of 1,4-butanediol, di(meth)acrylate of 1,6-hexanediol;

[0070] Neopentyl glycol di(meth)acrylate; Mono- or di(meth)acrylate of bisphenol A; Benzene trimethacrylate; Isobornyl (meth)acrylate; Acrylamide and its derivatives; methacrylamide and its derivatives; Trimethylolpropane tri(meth)acrylate; Di- or tri(meth)acrylates of glycerol; Di-, tri-, or tetra(meth)acrylates of pentaerythritol; and compounds such as ethylene oxide or propylene oxide adducts of these compounds.

[0071] When the photosensitive resin composition according to the present embodiment contains the above-mentioned monomer having a photopolymerizable unsaturated bond for improving the resolution of the relief pattern, the blending amount is preferably 1 to 50 parts by mass per 100 parts by mass of the (A) polyimide precursor.

[0072] In order to improve the adhesion between a film formed from the photosensitive resin composition according to this embodiment and a substrate, an adhesion promoter can be optionally blended into the photosensitive resin composition. Examples of the adhesion promoter include γ-aminopropyldimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, 3-methacryloxypropyldimethoxymethylsilane, 3-methacryloxypropyltrimethoxysilane, dimethoxymethyl-3-piperidinopropylsilane, diethoxy-3-glycidoxypropylmethylsilane, N-(3-diethoxymethylsilylpropyl)succinimide, and N-[3-(triethoxysilyl)propyl]phthalate. Examples of suitable adhesives include silane coupling agents such as amido acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamido)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamido)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, and N-phenylaminopropyltrimethoxysilane, and aluminum-based adhesion promoters such as aluminum tris(ethylacetoacetate), aluminum tris(acetylacetonate), and ethylacetoacetate aluminum diisopropylate.

[0073] Among these adhesion aids, it is more preferable to use a silane coupling agent in terms of adhesive strength. When the photosensitive resin composition contains an adhesion aid, the blending amount is preferably in the range of 0.5 to 25 parts by mass per 100 parts by mass of the (A) polyimide precursor.

[0074] When the photosensitive resin composition according to the present embodiment is in a solution state containing a solvent, a thermal polymerization inhibitor can be optionally blended into the photosensitive resin composition to improve the stability of its viscosity and photosensitivity during storage. Examples of the thermal polymerization inhibitor include hydroquinone, N-nitrosodiphenylamine, p-tert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycoletherdiaminetetraacetic acid, 2,6-di-tert-butyl-p-methylphenol, 5-nitroso-8-hydroxyquinoline, 1-nitroso-2-naphthol, 2-nitroso-1-naphthol, 2-nitroso-5-(N-ethyl-N-sulfopropylamino)phenol, N-nitroso-N-phenylhydroxylamine ammonium salt, and N-nitroso-N(1-naphthyl)hydroxylamine ammonium salt.

[0075] The amount of the thermal polymerization inhibitor to be added to the photosensitive resin composition is preferably in the range of 0.005 to 12 parts by mass per 100 parts by mass of the (A) photosensitive polyimide precursor.

[0076] When the substrate to which the resin composition according to the present embodiment is applied is made of, for example, copper or a copper alloy, an azole compound can be optionally blended to suppress discoloration of the copper surface. Examples of the azole compound include 1H-triazole, 5-methyl-1H-triazole, 5-ethyl-1H-triazole, 4,5-dimethyl-1H-triazole, 5-phenyl-1H-triazole, 4-t-butyl-5-phenyl-1H-triazole, 5-hydroxyphenyl-1H-triazole, phenyltriazole, p-ethoxyphenyltriazole, 5-phenyl-1-(2-dimethylaminoethyl)triazole, 5-benzyl-1H-triazole, hydroxyphenyltriazole, 1,5-dimethyltriazole, 4,5-diethyl-1H-triazole, 1H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benzotriazole, and the like. Examples of the benzotriazole include 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)benzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, hydroxyphenylbenzotriazole, tolyltriazole, 5-methyl-1H-benzotriazole, 4-methyl-1H-benzotriazole, 4-carboxy-1H-benzotriazole, 5-carboxy-1H-benzotriazole, 1H-tetrazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole, 5-amino-1H-tetrazole, and 1-methyl-1H-tetrazole. Particularly preferred is at least one selected from tolyltriazole, 5-methyl-1H-benzotriazole, and 4-methyl-1H-benzotriazole. These azole compounds may be used alone or in a mixture of two or more.

[0077] When the photosensitive resin composition according to the present embodiment contains the azole compound, the blending amount is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the (A) polyimide precursor, and more preferably 0.5 to 5 parts by mass from the viewpoint of photosensitivity characteristics. When the blending amount of the azole compound relative to 100 parts by mass of the (A) polyimide precursor is 0.1 part by mass or more, discoloration of the copper or copper alloy surface is suppressed when the photosensitive resin composition according to the present embodiment is formed on copper or a copper alloy. On the other hand, when the blending amount is 10 parts by mass or less, the excellent photosensitivity of the photosensitive resin composition is maintained.

[0078] In order to suppress discoloration of the copper surface, a hindered phenol compound can be optionally blended in place of or together with the azole compound. Examples of the hindered phenol compound include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butyl-hydroquinone, octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, isooctyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 4,4'-methylenebis(2,6-di-t-butylphenol), 4,4'-thio-bis(3-methyl-6-t- Butylphenol), 4,4'-butylidene-bis(3-methyl-6-t-butylphenol), triethylene glycol-bis[3-(3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol-bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate],

[0079] N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 2,2'-methylene-bis(4-methyl-6-t-butylphenol), 2,2'-methylene-bis(4-ethyl-6-t-butylphenol), pentaerythrityl-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], tris-(3,5-di-t-butyl-4-hydroxybenzyl)-isocyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-tris(3-hydroxy-2,6-dimethyl- 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-s-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris[4-(1-ethylpropyl)-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,

[0080] 1,3,5-tris[4-triethylmethyl-3-hydroxy-2,6-dimethylbenzyl]-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(3-hydroxy-2,6-dimethyl-4-phenylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5,6-trimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2,6-dimethylbenzyl) -1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-6-ethyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-5,6-diethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione,

[0081] Examples of the hydroxybenzoates include, but are not limited to, 1,3,5-tris(4-t-butyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, 1,3,5-tris(4-t-butyl-3-hydroxy-2,5-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione, and 1,3,5-tris(4-t-butyl-5-ethyl-3-hydroxy-2-methylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione. Among these, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-1,3,5-triazine-2,4,6-(1H,3H,5H)-trione is particularly preferred.

[0082] The amount of the hindered phenol compound is preferably 0.1 to 20 parts by mass relative to 100 parts by mass of the (A) polyimide precursor, and from the viewpoint of photosensitivity, more preferably 0.5 to 10 parts by mass. When the amount of the hindered phenol compound relative to 100 parts by mass of the (A) polyimide precursor is 0.1 part by mass or more, for example, when the photosensitive resin composition of the present invention is formed on copper or a copper alloy, discoloration and corrosion of the copper or copper alloy are prevented. On the other hand, when the amount is 20 parts by mass or less, the excellent photosensitivity of the photosensitive resin composition is maintained.

[0083] The photosensitive resin composition of the present invention preferably contains 100 parts by mass of (A) polyimide precursor, 0.05 to 5.0 parts by mass of (B) triazine compound, and 0.1 to 20 parts by mass of (C) photopolymerization initiator, based on 100 parts by mass of (A) polyimide precursor, which allows the photosensitive resin composition to exhibit particularly good sensitivity and to provide a cured relief pattern that more effectively prevents a decrease in adhesion to copper or a copper alloy.

[0084] <Method for producing cured relief pattern> The present invention also provides a method for producing a cured relief pattern. The method for producing an effect relief pattern in the present invention includes, for example, the following steps: (1) a coating step of coating the above-described photosensitive resin composition of the present invention onto a substrate to form a photosensitive resin layer on the substrate; (2) an exposure step of exposing the photosensitive resin layer to light; (3) a development step of developing the exposed photosensitive resin layer to form a relief pattern; (4) a heating step of heat-treating the relief pattern to form a hardened relief pattern; The method is characterized in that the above steps are taken in the order described above. A typical embodiment of each step will be described below.

[0085] (1) Coating process In this step, the photosensitive resin composition of the present invention is applied onto a substrate, and then dried as necessary to form a photosensitive resin layer. Examples of the substrate include metal substrates made of silicon, aluminum, copper, copper alloys, etc.; Resin substrates such as epoxy, polyimide, and polybenzoxazole; a substrate in which a metal circuit is formed on the resin substrate; A substrate made of multiple layers of metal or metal and resin. etc. can be used. As the application method, a method that has conventionally been used for applying a photosensitive resin composition, such as a method of applying using a spin coater, a bar coater, a blade coater, a curtain coater, a screen printing machine, or the like, or a method of spray application using a spray coater, can be used.

[0086] If necessary, the photosensitive resin composition film can be dried. Drying methods include air drying, heat drying using an oven or a hot plate, vacuum drying, and the like. The coating film is preferably dried under conditions that do not cause imidization of the (A) polyimide precursor (polyamic acid ester) in the photosensitive resin composition. Specifically, when air drying or heat drying is performed, drying can be performed under conditions of 20°C to 140°C for 1 minute to 1 hour. In this manner, a photosensitive resin layer can be formed on the substrate.

[0087] (2) Exposure process In this step, the photosensitive resin layer formed above is exposed to light. Examples of the exposure device that can be used include a contact aligner, a mirror projection device, and a stepper. The exposure can be performed directly or through a photomask or reticle having a pattern. The light used for exposure is, for example, an ultraviolet light source.

[0088] After the exposure, post-exposure baking (PEB) and / or pre-development baking may be performed at any temperature and time combination as needed for the purpose of improving photosensitivity, etc. The baking conditions are preferably in the range of a temperature of 40 to 120°C and a time of 10 to 240 seconds, but are not limited to these ranges as long as they do not impair the properties of the photosensitive resin composition of the present embodiment.

[0089] (3)Developing process In this step, the unexposed portions of the exposed photosensitive resin layer are developed and removed. The developing method for developing the exposed (irradiated) photosensitive resin layer can be selected from conventionally known photoresist developing methods. Examples include the rotary spray method, the puddle method, and the immersion method accompanied by ultrasonic treatment. Furthermore, after development, post-development baking may be performed at any desired temperature and time combination, as needed, for the purpose of adjusting the shape of the relief pattern, etc. The post-development baking temperature can be, for example, 80 to 130°C, and the time can be, for example, 0.5 to 10 minutes.

[0090] The developer used for development is preferably a good solvent for the photosensitive resin composition, or a combination of the good solvent and a poor solvent. Examples of good solvents include N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, and α-acetyl-γ-butyrolactone. Examples of poor solvents include toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate, and water. When a mixture of a good solvent and a poor solvent is used, it is preferable to adjust the ratio of the poor solvent to the good solvent depending on the solubility of the polymer in the photosensitive resin composition. Furthermore, two or more types of each solvent, for example, several types, can be used in combination.

[0091] (4)Heating process In this step, the relief pattern obtained by the above development is heated to dissolve the photosensitive component and also imidize the (A) polyimide precursor, thereby converting it into a cured relief pattern made of polyimide. Various methods can be selected for heat curing, such as using a hot plate, an oven, or a temperature-programmable heating oven. Heating can be carried out, for example, at 200°C to 400°C for 30 minutes to 5 hours. The atmospheric gas used during heat curing may be air, or an inert gas such as nitrogen or argon. In this manner, a cured relief pattern can be produced. In particular, the cured relief pattern of the present invention can achieve, at a high level, both improved adhesion between the Cu layer and the polyimide layer and suppressed migration of Cu atoms and the generation of voids at the interface with the polyimide layer after a high-temperature storage test.

[0092] <Semiconductor device> The present invention also provides a semiconductor device having a cured relief pattern obtained by the above-described method for producing a cured relief pattern of the present invention. The semiconductor device may be, for example, a semiconductor device having a substrate that is a semiconductor element and a cured relief pattern formed on the substrate by the above-described method for producing a cured relief pattern. That is, the semiconductor device of the present invention has a substrate and a cured relief pattern formed on the substrate.

[0093] The semiconductor device can be manufactured, for example, by a method using a semiconductor element as a substrate and including the above-described method for manufacturing a cured relief pattern as part of its steps. The semiconductor device of the present invention can be manufactured by forming the cured relief pattern formed by the above-described method for manufacturing a cured relief pattern as, for example, a surface protective film, an interlayer insulating film, an insulating film for rewiring, a protective film for a flip-chip device, or a protective film for a semiconductor device having a bump structure, and combining the result with a known method for manufacturing a semiconductor device.

[0094] When the semiconductor device of the present invention is applied to, for example, a metal rewiring layer made of a Cu layer and a relief pattern made of a polyimide resin, it is possible to achieve a high level of both improved adhesion between the rewiring layer and the polyimide layer and suppression of the occurrence of voids at the interface, resulting in excellent properties such as being less likely to cause short circuits or breaks after high-temperature storage tests.

[0095] The photosensitive resin composition of the present invention is useful not only for application to the semiconductor devices described above, but also for applications such as interlayer insulation in multilayer circuits, cover coatings for flexible copper-clad boards, solder resist films, and liquid crystal alignment films. [Example]

[0096] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples. The physical properties of the photosensitive resin compositions in the Examples, Comparative Examples, and Production Examples were measured and evaluated according to the following methods.

[0097] (1) Fabrication of hardened relief patterns on Cu A 6-inch silicon wafer (manufactured by Fujimi Electronics Co., Ltd., thickness 625±25 μm) was sputtered with a 200 nm thick Ti layer and a 400 nm thick Cu layer, in that order, using a sputtering device (Model L-440S-FHL, manufactured by Canon Anelva Corporation). Subsequently, a photosensitive resin composition prepared by the method described below was spin-coated onto the wafer using a coater developer (Model D-Spin60A, manufactured by SOKUDO Co., Ltd.), and dried to form a 10 μm thick coating film. A test patterned mask was used to apply 300 mJ / cm to this coating film using a parallel light mask aligner (Model PLA-501FA, manufactured by Canon Inc.). 2 The coating was then spray-developed with a coater developer (D-Spin 60A, manufactured by SOKUDO Co., Ltd.) using cyclopentanone as the developer for negative-tone coatings, and rinsed with propylene glycol methyl ether acetate to obtain a relief pattern on Cu.

[0098] The wafer with the relief pattern formed on Cu was heat-treated in a temperature-programmable curing furnace (VF-2000 model, manufactured by Koyo Lindberg) at 230°C for 2 hours in a nitrogen atmosphere to obtain a cured relief pattern made of resin approximately 6 to 7 μm thick on Cu.

[0099] (2) Copper adhesion test The cured relief pattern film prepared in (1) was evaluated for adhesion properties between the copper substrate and the cured resin coating film according to the cross-cut method of JIS K 5600-5-6 standard, based on the following criteria. "◎": The lattice number of the cured resin coating adhered to the substrate is 100 "Good": The lattice number of the cured resin coating adhered to the substrate is 70 to 99. "△": The lattice number of the cured resin coating adhered to the substrate is 40 to 69 "×": The number of lattices of the cured resin coating film adhered to the substrate is less than 40

[0100] (3) High temperature storage test of hardened relief patterns on Cu and subsequent void area evaluation The wafer with the cured relief pattern formed on Cu was heated in air at 150°C for 168 hours using a temperature-programmable curing furnace (VF-2000, manufactured by Koyo Lindberg). Subsequently, the resin layer on Cu was entirely removed by plasma etching using a plasma surface treatment device (EXAM, manufactured by Shinko Seiki Co., Ltd.). The plasma etching conditions were as follows: Output: 133W Gas type and flow rate: O2: 40 mL / min + CF4: 1 mL / min Gas pressure: 50Pa Mode: Hard Mode Etching time: 1800 seconds The Cu surface from which the resin layer had been completely removed was observed using a FE-SEM (S-4800 model, manufactured by Hitachi High-Technologies Corporation), and the area of ​​voids on the surface of the Cu layer was calculated using image analysis software (Azo-kun, manufactured by Asahi Kasei Corporation). When the photosensitive resin composition described in Comparative Example 1 was evaluated, assuming the total area of ​​voids to be 100%, a void area ratio of less than 50% was evaluated as "◎", a void area ratio of 50% or more but less than 75% was evaluated as "◯", a void area ratio of 75% or more but less than 100% was evaluated as "△", and a void area ratio of 100% or more was evaluated as "X".

[0101] <Production Example 1> (A) Synthesis of Polyimide Precursor (Polymer A-1) 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) was placed in a 2-liter separable flask, 134.0 g of 2-hydroxyethyl methacrylate (HEMA) and 400 ml of γ-butyrolactone were added, and 79.1 g of pyridine was added while stirring at room temperature to obtain a reaction mixture. After the heat generated by the reaction had ceased, the mixture was allowed to cool to room temperature and then left to stand for a further 16 hours.

[0102] Next, under ice cooling, a solution of 206.3 g of dicyclohexylcarbodiimide (DCC) in 180 ml of γ-butyrolactone was added to the reaction mixture over 40 minutes with stirring, followed by a suspension of 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) in 350 ml of γ-butyrolactone over 60 minutes with stirring. After further stirring at room temperature for 2 hours, 30 ml of ethyl alcohol was added and stirred for 1 hour, after which 400 ml of γ-butyrolactone was added. The precipitate that formed in the reaction mixture was removed by filtration to obtain the reaction solution.

[0103] The resulting reaction solution was added to 3 L of ethyl alcohol to produce a crude polymer precipitate. The crude polymer was collected by filtration and dissolved in 1.5 L of tetrahydrofuran to produce a crude polymer solution. The crude polymer solution was added dropwise to 28 L of water to precipitate the polymer. The precipitate was collected by filtration and then vacuum dried to produce powdered polymer A-1. The weight average molecular weight (Mw) of this polymer A-1 was measured and found to be 20,000.

[0104] <Production Example 2> (Synthesis of Polyimide Precursor (Polymer A-2)) Polymer A-2 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that 147.1 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) was used instead of 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) in Production Example 1. The weight average molecular weight (Mw) of this polymer A-2 was measured and found to be 22,000.

[0105] <Production Example 3> (Synthesis of Polyimide Precursor (Polymer A-3)) Polymer A-3 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) was replaced with 190.7 g of 2,2-bis[4-(4-aminophenoxy)phenyl]propane (BAPP). The weight average molecular weight (Mw) of this polymer A-3 was measured and found to be 21,000.

[0106] <Production Example 4> (Synthesis of Polyimide Precursor (Polymer A-4)) Polymer A-4 was obtained by carrying out the reaction in the same manner as in Production Example 1, except that 98.6 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB) was used instead of 93.0 g of 4,4'-diaminodiphenyl ether (DADPE). The weight average molecular weight (Mw) of this polymer A-4 was measured and found to be 21,000.

[0107] <Production Example 5> (Synthesis of polyimide precursor (polymer A-5)) Polymer A-5) was obtained by carrying out the reaction in the same manner as in Production Example 1, except that p-phenylenediamine (p-PD) (50.2 g) was used instead of 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) in Production Example 1. The weight average molecular weight (Mw) of this polymer A-5 was measured and found to be 21,000.

[0108] <Production Example 6> (Synthesis of polyimide precursor (polymer A-6)) Polymer A-6 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that in Production Example 1, 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) was replaced with 54.5 g of pyromellitic anhydride (PMDA) and 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA), and 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) was replaced with 98.6 g of 2,2'-dimethyl-4,4'-diaminobiphenyl (m-TB). The weight average molecular weight (Mw) of this polymer A-6 was measured and found to be 21,000.

[0109] <Production Example 7> (Synthesis of polyimide precursor (polymer A-7)) Polymer A-7 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) was replaced with 77.6 g of 4,4'-oxydiphthalic dianhydride (ODPA) and 73.6 g of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA). The weight average molecular weight (Mw) of this polymer A-7 was measured and found to be 20,000.

[0110] <Production Example 8> (Synthesis of polyimide precursor (polymer A-8)) Polymer A-8 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that 2,2'-bis(trifluoromethyl)benzidine (TFMB) (160.1 g) was used instead of 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) in Production Example 1. The weight average molecular weight (Mw) of this polymer A-8 was measured and found to be 21,000.

[0111] <Production Example 9> (Synthesis of polyimide precursor (polymer A-9)) Polymer A-9 was obtained by carrying out a reaction in the same manner as in Production Example 1, except that in Production Example 1, 155.1 g of 4,4'-oxydiphthalic dianhydride (ODPA) was replaced with 109.1 g of pyromellitic anhydride (PMDA) and 93.0 g of 4,4'-diaminodiphenyl ether (DADPE) was replaced with 50.2 g of p-phenylenediamine (p-PD). The weight average molecular weight (Mw) of this polymer A-9 was measured and found to be 20,000.

[0112] Example 1 (A) Polymer A-1 (100 g) as a polyimide precursor, (B) B1 (0.5 g) as a triazine compound, (C) O-benzoyl-N-(1-methyl-2-oxo-2-phenylethylidene)hydroxylamine (4 g) as a photopolymerization initiator C-1, and other components such as tetraethylene glycol dimethacrylate (abbreviated as M4G, 8 g), N-phenyldiethanolamine (abbreviated as DEA, 4 g), gamma-butyrolactone, and DMSO were dissolved in a mixed solvent (weight ratio 75:25), and the amount of solvent was adjusted so that the viscosity became approximately 35 poise, thereby preparing a photosensitive resin composition solution. This composition was evaluated by the methods described above, and the evaluation results are shown in Table 1.

[0113] <Examples 2 to 24 and Comparative Examples 1 to 5> The evaluation was carried out in the same manner as in Example 1, except that the resin composition solutions were prepared in the proportions shown in Tables 1 to 3. The evaluation results are shown in Tables 1 and 2.

[0114] Triazine compound B1: 2,4-diamino-6-(2-{2-[(2-ethylhexyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine [ka]

[0115] Triazine compound B2: 2,4-diamino-6-(2-{2-[(3-methoxybutyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine [ka]

[0116] Triazine compound B3: 2,4-diamino-6-{2-[(2,3-dihydroxypropyl)thio]ethyl}-1,3,5-triazine [ka]

[0117] Triazine compound B4: 2-(4,6-diamino-[1,3,5]triazin-2-ylamino)ethanol [ka]

[0118] Triazine compound B5: N-(3-trimethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine [ka]

[0119] Triazine compound B6: N-(3-triethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine [ka]

[0120] Triazine Compound B7: 2-Mercapto-4,6-bis[(2-hydroxyethyl)amino]-1,3,5-triazine [ka]

[0121] Triazine Compound B8: 2-Mercapto-4,6-bis[(3-triethoxysilylpropyl)amino]-1,3,5-triazine [ka]

[0122] Triazine compound B9: 2,4-diamino-6-[2-(hydroxyethoxy)ethyl]-1,3,5-triazine [ka]

[0123] Triazine compound B10: 2,4-diamino-6-(2-hydroxyethyl)oxy-1,3,5-triazine [ka]

[0124] Triazine compound B11: 2,4-diamino-6-[2-(hydroxymethylcarbonyloxy)ethyl]-1,3,5-triazine [ka]

[0125] Triazine compound B12: 2-(2-hydroxyethyl)amino-4,6-bis(dimethylamino)1,3,5-triazine [ka]

[0126] Nitrogen-containing compound a: 2,4,6-triamino-1,3,5-triazine [ka]

[0127] Nitrogen-containing compound b: 3-aminopropyltriethoxysilane: [ka]

[0128] <Comparative Example 6> The evaluation was carried out in the same manner as in Example 1, except that triazine compound B1 was directly applied to the surface of a copper substrate. Triazine compound B1 (0.5 g) was dissolved in gamma-butyrolactone (10 g), and a Cu wafer was immersed in the solution for 10 minutes to apply B1 to the substrate. The evaluation results are shown in Table 2.

[0129] [Table 1]

[0130] [Table 2]

[0131] [Table 3]

[0132] As is clear from Tables 1 to 3, the examples containing a triazine compound had superior adhesion between copper and polyimide compared to the comparative examples not containing a triazine compound, and also effectively suppressed the generation of copper voids in a high-temperature environment.

[0133] Although the embodiment of the present invention has been described above, the present invention is not limited to this and can be modified as appropriate within the scope of the invention. [Industrial Applicability]

[0134] By using the photosensitive resin composition of the present invention, no voids are generated at the interface where the Cu layer contacts the polyimide layer, and high adhesion is achieved, even after a high-temperature storage test. Therefore, the composition can be suitably used in the field of photosensitive materials that are useful for producing electrical and electronic materials such as semiconductor devices and multilayer wiring boards.

Claims

1. Ingredients: (A) a polyimide precursor represented by the following general formula (A1): (B) a triazine compound; and (C) a photopolymerization initiator; Including, The triazine compound (B) is any one of the following: 2,4-Diamino-6-(2-{2-[(2-ethylhexyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine: 【Chemistry 1】 2,4-Diamino-6-(2-{2-[(3-methoxybutyl)oxycarbonyl]ethylthio}ethyl)-1,3,5-triazine: 【Chemistry 2】 2,4-Diamino-6-{2-[(2,3-dihydroxypropyl)thio]ethyl}-1,3,5-triazine: 【Transformation 3】 2-(4,6-diamino-[1,3,5]triazin-2-ylamino)ethanol: 【Chemistry 4】 N-(3-trimethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine: 【Transformation 5】 N-(3-triethoxysilanyl-propyl)-[1,3,5]triazine-2,4,6-triamine: 【Transformation 6】 2-mercapto-4,6-bis[(2-hydroxyethyl)amino]-1,3,5-triazine: 【Transformation 7】 2-mercapto-4,6-bis[(3-triethoxysilylpropyl)amino]-1,3,5-triazine: 【Transformation 8】 2,4-Diamino-6-[2-(hydroxyethoxy)ethyl]-1,3,5-triazine: 【Chemistry 9】 2,4-Diamino-6-(2-hydroxyethyl)oxy-1,3,5-triazine: 【Chemistry 10】 2,4-Diamino-6-[2-(hydroxymethylcarbonyloxy)ethyl]-1,3,5-triazine: 【Chemistry 11】 2-(2-hydroxyethyl)amino-4,6-bis(dimethylamino)-1,3,5-triazine: 【Chemistry 12】 It has a structure represented by A photosensitive resin composition used to form a surface protective film for a semiconductor element or an insulating film for a rewiring layer. 【Chemistry 13】 wherein X is a tetravalent organic group, Y is a divalent organic group, and R １ and R ２ are each independently a hydrogen atom or a group represented by the following general formula (R1): 【Chemistry 14】 (In general formula (R1), R ３ , R ４ , and R ５ are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and p is an integer selected from 2 to 10.) or a saturated aliphatic group having 1 to 4 carbon atoms. １ and R ２ Both cannot be hydrogen atoms at the same time.

2. Ingredients: (A) a polyimide precursor represented by the following general formula (A1): (B) a triazine compound; and (C) a photopolymerization initiator; Including, The triazine compound (B) has at least one hydrogen atom of the triazine ring substituted with a substituent containing at least one selected from the group consisting of a (trialkoxysilylpropyl)amino group, a hydroxyethoxy group, a (hydroxyethyl)amino group, a hydroxymethylcarbonyloxyalkyl group, an alkyloxycarbonyl group, and an alkylthioethyl group; A photosensitive resin composition used to form a surface protective film for a semiconductor element or an insulating film for a rewiring layer. 【Chemistry 15】 In the formula, X is a tetravalent organic group, Y is a divalent organic group, and R 1 and R 2 each independently represent a hydrogen atom or a group represented by the following general formula (R1): 【Chemistry 16】 (In general formula (R1), R 3 , R 4 , and R 5 are each independently a hydrogen atom or an organic group having 1 to 3 carbon atoms, and p is an integer selected from 2 to 10), or a saturated aliphatic group having 1 to 4 carbon atoms. However, R 1 and R 2 cannot both be hydrogen atoms at the same time.)

3. The photosensitive resin composition according to claim 1 or 2, wherein in the general formula (A1), the X includes a structure represented by the following formula (2): 【Chemistry 17】

4. The photosensitive resin composition according to claim 1 or 2, wherein in the general formula (A1), the Y includes a structure represented by the following formula (8): [Chemistry 18]

5. The photosensitive resin composition according to claim 1 or 2, wherein in the general formula (A1), the Y includes a structure represented by the following formula (9): 【Chemistry 19】

6. 6. The photosensitive resin composition according to claim 1, wherein the content of the component (B) is 0.05 to 5.0 parts by mass per 100 parts by mass of the component (A).

7. A method for producing a polyimide, which comprises curing the photosensitive resin composition according to any one of claims 1 to 6.

8. (1) applying the photosensitive resin composition according to any one of claims 1 to 6 onto a substrate to form a photosensitive resin layer on the substrate; (2) exposing the photosensitive resin layer to light; (3) developing the exposed photosensitive resin layer to form a relief pattern; (4) heat-treating the relief pattern to form a hardened relief pattern; 1. A method for producing a cured relief pattern, comprising:

9. A semiconductor device comprising a cured relief pattern obtained by the method for producing a cured relief pattern according to claim 8.

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