Photosensitive resin composition, method for manufacturing a cured relief pattern, and semiconductor device.

Abstract

The present invention provides a photosensitive resin composition which contains (A) a polyimide precursor that has a repeating structure represented by formula (1), and (B) a photoradical initiator. (In formula (1), X1 represents a tetravalent organic group; Y1 represents a divalent organic group; m represents an integer of 1 or more; R1 and R2 each represent a hydrogen atom, a radically polymerizable group or an organic group represented by formula (2). In formula (2), R3, R4 and Rz each independently represent a monovalent organic group having 2 to 20 carbon atoms and not containing a fluorine atom, or alternatively, in cases where one of the R3, R4 and Rz moieties is a hydrogen atom, the other moieties are each a monovalent organic group having 2 to 20 carbon atoms and not containing a fluorine atom, and at least one of the other moieties has a branched chain or a cyclic structure.)

Description

[Technical Field]

[0001] The present invention relates to a polyimide precursor, a photosensitive resin composition containing the polyimide precursor, a method for producing a cured relief pattern obtained by curing the photosensitive resin composition, a cured relief pattern, and a semiconductor device and a display device having the cured relief pattern. [Background technology]

[0002] Conventionally, polyimide resins possessing excellent heat resistance, electrical properties, and mechanical properties have been used as insulating materials for electronic components, as well as for passivation films, surface protective films, and interlayer insulating films of semiconductor devices. Among these polyimide resins, those provided in the form of photosensitive polyimide precursor compositions allow for the easy formation of heat-resistant cured relief pattern coatings through thermal imidization treatment by coating, exposure, development, and curing of the composition. Such photosensitive polyimide precursor compositions have the advantage of enabling a significant reduction in process steps compared to conventional non-photosensitive polyimide materials.

[0003] As semiconductor miniaturization progresses, extremely low-κ (ELK) layers with low dielectric constants are being introduced into semiconductor devices to suppress signal delay. Materials with porous structures are used to reduce the dielectric constant of the ELK layer. However, a problem with such materials is their low mechanical strength. As a result, for example, in a solder reflow process requiring a high temperature of 260°C, the ELK layer may be destroyed by the stress applied to it from bumps on the semiconductor surface. From the viewpoint of i-line transmittance and low stress for pattern protective films used as protective films for interlayer insulating films, for example, Patent Document 1 describes a polyimide precursor having a specific structure with polymerizable groups in its side chains for forming a low-stress cured film.

[0004] Meanwhile, in recent years, the mounting methods for semiconductor devices onto printed circuit boards have also changed in order to improve integration density and functionality, as well as to reduce chip size. From the conventional mounting method using metal pins and lead-tin eutectic solder, structures where a polyimide coating directly contacts the solder bumps are now being used, such as BGA (Ball-Gripped Array) and CSP (Chip-Size Packaging), which enable higher density mounting. When forming such bump structures, the coating requires high heat resistance and mechanical properties. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-201696 [Overview of the project] [Problems that the invention aims to solve]

[0006] However, one problem with the photosensitive polyimide resin used in the ELK protective layer is its poor adhesion to the aluminum that forms the electrodes of the semiconductor. As a result, delamination can occur between the polyimide resin and the substrate, potentially reducing the reliability of the semiconductor device.

[0007] Furthermore, there is a growing demand for thicker ELK protective layers (e.g., 9 μm or more) to improve the reliability of semiconductor devices. On the other hand, the polyimide resin used in the ELK protective layer is composed of a linear structural framework to impart mechanical properties. The absorption of the polyimide precursor containing such a framework is high at the i-line (365 nm), which is the exposure wavelength, resulting in insufficient light reaching the bottom of the film during exposure. As a result, the crosslinking efficiency of the polymer at the bottom of the film is low, making it difficult to obtain a pattern with a good shape.

[0008] The present invention aims to provide a semiconductor device that can form a pattern with a good shape in a thick film, and further provides excellent protection for the semiconductor chip and adhesion between the surface protective film and the interlayer insulating film in the redistribution layer, as well as a method for manufacturing the same. [Means for solving the problem]

[0009] In view of the above problems, the present inventors conducted diligent studies and found that by partially introducing a specific chemical structure as a side chain of the polyimide precursor, a thick film pattern can be formed in a photosensitive resin composition using the polyimide precursor, and that it exhibits good adhesion to the substrate, thus completing the present invention. That is, the present invention is as follows.

[0010] <1> (A) A polyimide precursor having a repeating structure represented by the following formula (1): [ka] {In the formula, X1 is a tetravalent organic group, Y1 is a divalent organic group, m is an integer greater than or equal to 1, R1 and R2 are independently a hydrogen atom, a radical polymerizable group, or the following formula (2): [ka] (In the formula, R3, R4 and R z Each of these is independently a monovalent organic group with 2 to 20 carbon atoms that does not contain fluorine, or R3, R4 and R z If any one of them is a hydrogen atom, the others are monovalent organic groups with 2 to 20 carbon atoms that do not contain fluorine atoms, and at least one has a branched chain or cyclic structure.}, and (B) Photoradical initiator A photosensitive resin composition containing [a specific substance]. <2> The photosensitive resin composition according to item 1, wherein R3 is a monovalent organic group having 3 or fewer carbon atoms. <3> Said R3, R4 and R z is a photosensitive resin composition according to Item 1 or 2, which does not contain the radical polymerizable group. <4> The photosensitive resin composition according to any one of Items 1 to 3, wherein the radical polymerizable group is a group represented by the following formula (3): [Chemical formula] (In the formula, R5 is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, R6, R7 and R8 are each independently a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and p is an integer of 1 to 10.). <5> In the formula (1), at least one of R1 and R2 is a group represented by the formula (3), and the R7 and R8 do not contain a radical polymerizable group. The photosensitive resin composition according to Item 4. <6> In the formula (1), the group represented by the formula (3) is contained in an amount of 20 to 80 mol% based on the total of R1 and R2. The photosensitive resin composition according to Item 4 or 5. <7> Said R3, R4 and R z One of them is a hydrogen atom. The photosensitive resin composition according to any one of Items 1 to 6. <8> The photosensitive resin composition according to any one of Items 1 to 7, wherein Y^{1} is represented by the following formula (5) or formula (6): [Chemical formula] (In the formula, R 13 each independently represents any one of a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group.). [Chemical formula] (In the formula, R 14 each independently represents any one of a hydrogen atom or a methyl group.). <9> The photosensitive resin composition according to any one of items 1 to 8, wherein X1 is a group derived from at least one selected from the group consisting of the following formulas (7) to (12): [ka] . <10> The photosensitive resin composition according to item 9, wherein X1 is a group derived from at least one selected from the group consisting of formulas (7), (8), and (10). <11> (A) A polyimide precursor having a repeating structure represented by the following formula (1): [ka] {In the formula, X1 is a tetravalent organic group, Y1 is a divalent organic group, m is an integer greater than or equal to 1, R1 and R2 are, independently, a hydrogen atom, a radical polymerizable group, or a monovalent organic group having 2 to 20 carbon atoms that does not have a radical polymerizable group. (B) Photoradical initiator A photosensitive resin composition comprising, The structure represented by the following formula (13): [ka] {The definitions of X1, Y1, R1, and R2 in the formula are the same as in formula (1) above.} A photosensitive resin composition in which, after molecular dynamics calculations using Forcite, the lowest empty molecular orbital (LUMO) calculated with Dmol3 is -3.00 to -2.59 eV, and the band gap between the highest occupied molecular orbital (HOMO) and the LUMO is 1.52 to 2.00 eV. <12> A photosensitive resin composition according to any one of items 1 to 11, wherein the cured film obtained by coating and exposing a wafer and then thermally curing it at a temperature of 280°C under a nitrogen atmosphere has a Young's modulus of 6 GPa or more. <13> (1) A step of forming a photosensitive resin layer on a substrate by applying a photosensitive resin composition described in any one of items 1 to 12 onto the substrate, (2) A step of exposing the photosensitive resin layer, (3) A step of developing the photosensitive resin layer after exposure to form a relief pattern, (4) A step of forming a hardened relief pattern by heat treatment of the relief pattern, A method for manufacturing a hardened relief pattern, including [the specified element]. <14> A cured relief pattern comprising a cured product of a photosensitive resin composition described in any one of items 1 to 12. <15> A semiconductor device having the cured relief pattern described in item 14. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a photosensitive resin composition that exhibits excellent adhesion to a metal layer in a redistribution layer and can form a good thick film pattern, a method for manufacturing a cured relief pattern using the photosensitive composition, a cured relief pattern, and a semiconductor device and a display device having the cured relief pattern. [Modes for carrying out the invention]

[0012] The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "this embodiment"). It should be noted that the present invention is not limited to the following embodiments, and can be implemented in various modifications within the scope of its gist.

[0013] In this embodiment, the photosensitive resin composition comprises (A) a polyimide precursor, (B) a photopolymerization initiator, optionally (C) a crosslinking agent, (D) a solvent, and optionally other components. Each component will be described in order below.

[0014] Throughout this specification, structures represented by the same symbols in a general formula may be identical or different from each other if multiple such structures exist in a molecule.

[0015] <Polyimide precursor composition> (A) Polyimide precursor As the polyimide precursor used in the photosensitive resin composition, a polyamidic acid ester containing repeating units represented by the following general formula (1) is used. [ka] In the formula, X1 is a tetravalent organic group, Y1 is a divalent organic group, m is an integer greater than or equal to 1, and R1 and R2 are independently a hydrogen atom, a radical polymerizable group, or the following formula (2): [ka] (In the formula, R3, R4 and R z Each of these is independently a monovalent organic group with 2 to 20 carbon atoms that does not contain fluorine, or R3, R4 and R z If any one of the atoms is a hydrogen atom, the others are monovalent organic groups having 2 to 20 carbon atoms and not containing fluorine atoms, and at least one of them has a branched chain or cyclic structure.) Or, monovalent organic groups having 2 to 20 carbon atoms that do not have radical polymerizable groups.

[0016] In this embodiment, multiple polyamic acid esters represented by general formula (1) may be mixed. Alternatively, polyamic acid esters obtained by copolymerizing polyamic acid esters represented by general formula (1) may be used.

[0017] In general formula (1), the tetravalent organic group represented by X1 is not particularly limited, but is preferably an organic group having 6 to 40 carbon atoms, and more preferably the -COOR1 group, the -COOR2 group and the -CONH- group are aromatic groups or alicyclic aliphatic groups located in the ortho position relative to each other.

[0018] In general formula (1), a specific example of X1 is a group derived from at least one selected from the group consisting of the following formulas (7) to (12). [ka]

[0019] From the viewpoint of the film physical properties of the cured relief pattern, in the general formula (1), the tetravalent organic group represented by X1 is preferably a group derived from at least one selected from the group consisting of the above formulas (7), (8) and (10), and more preferably contains a group derived from at least one of pyromellitic dianhydride (PMDA) and biphenyltetracarboxylic dianhydride (BPDA).

[0020] R3, R4 and R in the general formula (2) z are each independently a monovalent organic group having 2 to 20 carbon atoms and not containing fluorine, or when any one of R3, R4 and R z is a hydrogen atom, the others are monovalent organic groups having 2 to 20 carbon atoms and not containing fluorine, and at least one has a branched chain or a cyclic structure. From the viewpoint of photosensitive characteristics, it is preferable that any one of R3, R4 or R z is an organic group having 3 or more carbon atoms, and more preferably a monovalent organic group having 3 to 20 carbon atoms and not containing fluorine. Further, from the viewpoint of the preparation of the polyimide precursor described later, it is preferable that one of R3, R4 and R z is a hydrogen atom, or it is preferable that any one of R3, R4 or R z is an organic group having 3 or less carbon atoms, and more preferably a methyl group. Further, from the viewpoint of adhesion, it is preferable that R3, R4 and R z all do not contain a radical polymerizable group, and more preferably do not contain fluorine.

[0021] From the viewpoint of photosensitive characteristics, the radical polymerizable group in the general formula (1) is preferably a group represented by the following formula (3):

Chemical formula

[0022] In the above general formula (3), R5 is preferably a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms, and more preferably a hydrogen atom or a monovalent organic group having 1 to 5 carbon atoms from the viewpoint of the photosensitive properties of the photosensitive resin composition. In the above general formula (3), R6 is preferably a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and more preferably a hydrogen atom or a methyl group from the viewpoint of the photosensitive properties of the photosensitive resin composition. R7 and R8 are each preferably independently a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and more preferably a hydrogen atom from the viewpoint of the photosensitive properties of the photosensitive resin composition. In the above general formula (3), p is preferably an integer between 1 and 10, and more preferably an integer between 2 and 4 from the viewpoint of photosensitive properties.

[0023] The reason for the effects of this invention is not entirely clear, but the inventors believe it to be as follows: It is generally known that the light absorption of polyimide precursors originates from charge transfer from the diamine moiety to the acid anhydride moiety. Therefore, by using a secondary or tertiary alcohol when introducing the side chains R1 and R2 in formula (1) above, and introducing bulky functional groups, the planarity of -X1-CONH-Y1- in the polyamic acid main chain is inhibited, and the conjugated system is cleaved. This is thought to suppress charge transfer from the nitrogen atom to the aromatic ring of the acid anhydride, thereby suppressing the absorption of the polyamic acid.

[0024] To reduce the absorbance of the polyimide precursor, it is preferable that the energy level of the lowest empty molecular orbital (LUMO) of the polyimide precursor be high, and furthermore, it is preferable to increase the band gap between the LUMO and the highest occupied molecular orbital (HOMO). For the polyimide precursor represented by formula (1) to have an appropriate absorbance, the following formula (13) is required: [ka] {The definitions of X1, Y1, R1, and R2 in the formula are the same as in formula (1) above.} The structure represented by [formula] is preferably optimized by molecular dynamics calculations using Forcite, and then calculated in Dmol3, the (LUMO) is preferably -3.00 to -2.59 eV, and more preferably the HOMO-LUMO band gap is 1.52 to 2.00 eV, and more preferably the LUMO is -2.85 to -2.59 eV and the HOMO-LUMO band gap is 1.57 to 1.90 eV.

[0025] A secondary alcohol usable in this embodiment is, for example, the following formula (4): [ka] {In the formula, R independently represents a linear or cyclic fluorine-free hydrocarbon group, which may be the same or different, preferably an independent monovalent organic group having 2 to 20 carbon atoms that does not contain a fluorine atom, and more preferably an linear or branched fluorine-free hydrocarbon group having 2 to 12 carbon atoms, which may be the same or different.} It can be represented as follows:

[0026] A tertiary alcohol usable in this embodiment is, for example, the following formula (14): [ka] {In the formula, R' independently represents a monovalent organic group, preferably a linear or cyclic hydrocarbon group that does not contain a fluorine atom, and more preferably, independently, a linear or branched hydrocarbon group having 2 to 20 carbon atoms that does not contain a fluorine atom, or a cyclic hydrocarbon group having 3 to 20 carbon atoms that does not contain a fluorine atom.} It can be represented as follows:

[0027] Furthermore, side chains of the polyimide precursor represented by R1 or R2 that have a polymerizable group represented by formula (3) form polymers through photopolymerization during exposure or thermal polymerization during curing, inhibiting the interaction of the polyimide with the substrate and reducing adhesion. Therefore, it is thought that by partially introducing side chains that do not have a polymerizable group represented by formula (2) into the polymer, the formation of polymers that reduce adhesion can be suppressed, and the adhesion of the photosensitive resin composition can be improved. From a similar viewpoint, it is preferable that at least one of R1 and R2 in formula (1) is a group represented by formula (3), and that R7 and R8 in formula (3) do not contain radical polymerizable groups.

[0028] In the above general formula (1), from the viewpoint of the photosensitive properties and mechanical properties of the photosensitive resin composition, it is preferable that the total ratio of the monovalent organic group represented by the above general formula (2) and the monovalent organic group represented by the above general formula (3) to all of R1 and R2 is 80 mol% or more. Furthermore, it is preferable that the ratio of the monovalent organic group represented by the above general formula (3) to all of R1 and R2 is 20 mol% to 80 mol%. Moreover, in the above general formula (1), it is more preferable that the total ratio of the monovalent organic group represented by the above general formula (2) and the monovalent organic group represented by the above general formula (3) to all of R1 and R2 is 90 mol% or more, and that the ratio of the monovalent organic group represented by the above general formula (3) to all of R1 and R2 is 30 mol% to 70 mol%.

[0029] In general formula (1), there are no particular limitations on Y1, but from the viewpoint of Young's modulus and chemical resistance, Y1 is preferably a divalent organic group containing an aromatic group. Specifically, Y1 is preferably a divalent organic group containing at least one structure represented by the following general formulas (5) and (6). Furthermore, the structure of Y1 may be one type or a combination of two or more types. [ka] (In the formula, R 13 Each of these independently represents either a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. [ka] (In the formula, R 14 Each of these independently represents either a hydrogen atom or a methyl group.

[0030] [(A) Method for preparing polyimide precursors] The polyimide precursor represented by the general formula (1) in this embodiment can be obtained, for example, by reacting a tetracarboxylic dianhydride containing the aforementioned tetravalent organic group X1 having 6 to 40 carbon atoms with (a) the hydroxyl group of a monovalent organic group represented by the general formula (2) or the general formula (3) to prepare a partially esterified tetracarboxylic acid (hereinafter also referred to as an acid / ester), and then polycondensing it with a diamine containing the aforementioned divalent organic group Y1 represented by the general formula (5) or the general formula (6).

[0031] (Preparation of acid / ester compounds) In this embodiment, examples of tetracarboxylic dianhydrides containing a tetravalent organic group X1 having 6 to 40 carbon atoms include pyromellitic anhydride, diphenyl ether-3,3',4,4'-tetracarboxylic dianhydride, benzophenone-3,3',4,4'-tetracarboxylic dianhydride, biphenyl-3,3',4,4'-tetracarboxylic dianhydride, 9,9-bis(3,4-dicarboxyphenyl)fluorene dianhydride, bis(1,3-dioxo-1,3-dihydroisobenzofuran-5-carboxylic acid)1,4-phenylene, diphenylsulfone-3,3',4,4'-tetracarboxylic dianhydride, diphenylmethane-3,3',4,4'-tetracarboxylic dianhydride, 2,2-bis(3,4-phthalic anhydride)propane, and 2,2-bis(3,4-phthalic anhydride)-1,1,1,3,3,3-hexafluoropropane. Furthermore, these can be used individually or in combination of two or more types.

[0032] In this embodiment, examples of compounds having a radical polymerizable group represented by the general formula (3) above 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, 2-hydroxy-3-t-butoxypropyl acrylate, and 2-H Examples include 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, and 2-hydroxy-3-cyclohexyloxypropyl methacrylate.

[0033] Secondary alcohols having a group represented by the above general formula (2), which do not contain a fluorine atom and do not contain a polymerizable group, include, for example, isopropyl alcohol, 2-butanol, 2-pentanol, 1-cyclopropylethanol, 3-pentanol, 2-hexanol, 3-hexanol, 2,4-dimethyl-3-pentanol, 2-heptanol, 3-heptanol, 4-heptanol, 3,3-dimethyl-2-butanol, 2-methyl-3-hexanol, 4-methyl-2-pentanol, 2,5-dimethyl-3-hexanol, 4-methyl-2-pentanol, and 2-methylhexanol. Examples include 3-methylhexanol, 4-methylhexanol, 3,5-dimethylhexanol, 2-methyl-3-octanol, 2-undecanol, 3-undecanol, 5-undecanol, cyclopentanol, cyclohexanol, cycloheptanol, 1-cyclohexyl-1-butanol, exo-norborneol, 1-phenylethyl alcohol, 1-phenyl-1-propanol, 2-methoxy-2-phenylethanol, 1,3-bis(benzyloxy)-2-propanol, 3-hydroxytetrahydrofuran, tetrahydro-4-pyranol, etc.

[0034] Examples of tertiary alcohols having a group represented by the above general formula (2), which do not contain a fluorine atom or a polymerizable group, include t-butyl alcohol, t-amyl alcohol, 1-ethynyl-1-cyclopropanol, and 1-adamantanol.

[0035] By dissolving and mixing the above-mentioned tetracarboxylic dianhydride and the alcohols of (a) in a reaction solvent in the presence of a basic catalyst such as pyridine, the half-esterification reaction of the acid dianhydride proceeds, and the desired acid / ester product can be obtained. The reaction conditions are preferably such that the mixture is stirred at a reaction temperature of 20 to 50°C for 4 to 30 hours.

[0036] The reaction solvent is preferably one that dissolves the acid / ester compound and the polyimide precursor, which is a polycondensation product of the acid / ester compound and diamines. Examples of reaction solvents include N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N,N-dimethylformamide, dimethyl sulfoxide, tetramethylurea, gamma-butyrolactone, ketones, esters, lactones, ethers, halogenated hydrocarbons, hydrocarbons, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, methyl acetate, ethyl acetate, butyl acetate, diethyl oxalate, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, chlorobenzene, o-dichlorobenzene, hexane, heptane, benzene, toluene, xylene, etc. These may be used individually or in combination of two or more as needed.

[0037] Examples of diamines containing the divalent organic group Y1 that can be suitably used in this embodiment include 2,2'-dimethyl-4,4-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethyl-4,4'-diaminodiphenylmethane, 2,2'-dimethitoxy-4,4'-diaminobiphenyl, 3,3'-dimethitoxy-4,4'-diaminobiphenyl, 2,2',3,3'-tetramethyl-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, p-phenylenediamine, 2,5-dimethyl-1,4-phenylenediamine, and the like. These may be used individually or in combination of two or more. Furthermore, among these, it is preferable to use 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethitoxy-4,4'-diaminobiphenyl, and p-phenylenediamine, and it is even more preferable to use 2,2'-dimethyl-4,4'-diaminobiphenyl and p-phenylenediamine.

[0038] The alcohols used in the esterification reaction of the tetracarboxylic dianhydride described above are alcohols having an olefinic double bond. Specifically, examples include, but are not limited to, 2-hydroxyethyl methacrylate, 2-methacryloyloxyethyl alcohol, glycerin diacrylate, and glycerin dimethacrylate. These alcohols can be used individually or in combination of two or more.

[0039] Examples of organic dehydrating agents include dicyclohexylcarbodiimide (DCC), diethylcarbodiimide, diisopropylcarbodiimide, ethylcyclohexylcarbodiimide, diphenylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide, and 1-cyclohexyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride.

[0040] After the reaction is complete, any water-absorbing by-products of the dehydrating condensation agent present in the reaction solution are filtered off as needed. Then, a poor solvent such as water, an aliphatic lower alcohol, or a mixture thereof is added to the obtained polymer component to precipitate it. Further purification of the polymer is carried out by repeating the redissolution and reprecipitation operations, and the polymer is then vacuum-dried to isolate the target polyimide precursor. To improve the degree of purification, the solution of this polymer may be passed through a column packed with an anion-cation exchange resin swollen with a suitable organic solvent to remove ionic impurities.

[0041] (B) Photopolymerization initiator The (B) photopolymerization initiator in this embodiment will be described below. As the (B) photopolymerization initiator, any compound conventionally used as a photopolymerization initiator for UV curing can be arbitrarily selected, and for example, a photoradical polymerization initiator can be used. For example, benzophenone derivatives such as benzophenone, o-benzoylmethyl benzoate, 4-benzoyl-4'-methyldiphenyl ketone, dibenzyl ketone, and fluorenone; acetophenone derivatives such as 2,2'-diethoxyacetophenone, 2-hydroxy-2-methylpropiophenone, and 1-hydroxycyclohexylphenyl ketone; thioxanthone derivatives such as thioxanthone, 2-methylthioxanthone, 2-isopropylthioxanthone, and diethylthioxanthone; benzyl derivatives such as benzyl, benzyldimethyl ketal, and benzyl-β-methoxyethyl acetal; benzoin derivatives such as benzoin and benzoin methyl ether; and 1-phenyl-1,2-butane. Preferred oximes include dione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-methoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl)oxime, 1-phenyl-1,2-propanedione-2-(O-benzoyl)oxime, 1,3-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; and aromatic biimidazoles, but are not limited to these. These can be used individually or in combination of two or more. Among the above (B) photopolymerization initiators, oximes are particularly preferred in terms of photosensitivity.

[0042] (B) The amount of photopolymerization initiator added is 0.1 to 20 parts by mass per 100 parts by mass of (A) polyimide precursor, and is preferably 1 to 15 parts by mass from the viewpoint of photosensitivity characteristics. Adding 0.1 parts by mass or more of (B) photopolymerization initiator per 100 parts by mass of (A) polyimide precursor results in a photosensitive resin composition with excellent photosensitivity, while adding 20 parts by mass or less results in a photosensitive resin composition with excellent thick-film curing properties.

[0043] (C) Crosslinking agent The (C) crosslinking agent in this embodiment will be described. In order to improve the resolution of the relief pattern, monomers having photopolymerizable unsaturated bonds can be optionally blended into the negative-type photosensitive resin composition. Preferred monomers are (meth)acrylate compounds that undergo radical polymerization reactions with a photopolymerization initiator, and are not limited to the following, but include, for example, diethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, mono or diacrylate and methacrylate of ethylene glycol or polyethylene glycol, mono or diacrylate and methacrylate of propylene glycol or polypropylene glycol, mono, di or triacrylate and methacrylate of glycerol, silohexane diacrylate and dimethacrylate, 1,4-butanediol diacrylate and dimethacrylate, 1, Examples of compounds include diacrylates and dimethacrylates of 6-hexanediol, diacrylates and dimethacrylates of neopentyl glycol, mono- or diacrylates and methacrylates of bisphenol A, benzene trimethacrylate, isobornyl acrylate and methacrylate, acrylamide and its derivatives, methacrylamide and its derivatives, trimethylolpropane triacrylate and methacrylate, di- or triacrylate and methacrylate of glycerol, di, tri- or tetraacrylate and methacrylate of pentaerythritol, and ethylene oxide or propylene oxide adducts of these compounds. Among these, (meth)acrylate compounds with two or more functions are preferred, and (meth)acrylate compounds with two to six functions are more preferred.

[0044] From the viewpoint of improving the resolution of the relief pattern, the amount of (C) crosslinking agent, such as a photopolymerizable unsaturated bond monomer, is preferably 1 to 80 parts by mass per 100 parts by mass of (A) polyimide precursor.

[0045] (D) Solvent The photosensitive resin composition of this embodiment may contain a solvent as, for example, component (D). From the viewpoint of solubility in (A) the polyimide precursor, it is preferable to use a polar organic solvent as the solvent. Specifically, examples of solvents 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, N-cyclohexyl-2-pyrrolidone, 2-octanone, etc., which can be used alone or in combination of two or more.

[0046] The above solvent can be used in an amount ranging from 30 to 1500 parts by mass, preferably 100 to 1000 parts by mass, per 100 parts by mass of (A) polyimide precursor, depending on the desired coating film thickness and viscosity of the negative-type photosensitive resin composition.

[0047] Furthermore, from the viewpoint of improving the storage stability of the negative-type photosensitive resin composition, solvents containing alcohols are preferred. Suitable alcohols are typically alcohols that have an alcoholic hydroxyl group in the molecule and do not have an 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; 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-hydroxyisobutyrate esters; and dialcohols such as ethylene glycol and propylene glycol. Among these, lactic acid esters, propylene glycol monoalkyl ethers, 2-hydroxyisobutyrate esters, and ethyl alcohol are preferred, with ethyl lactate, propylene glycol-1-methyl ether, propylene glycol-1-ethyl ether, and propylene glycol-1-(n-propyl) ether being particularly preferred.

[0048] When the solvent contains an alcohol without an olefinic double bond, the content of the alcohol without an olefinic double bond in the total solvent is preferably 5% to 50% by mass, and more preferably 10% to 30% by mass, based on the mass of the total solvent. When the above content of the alcohol without an olefinic double bond is 5% by mass or more, the storage stability of the negative-type photosensitive resin composition is improved, while when it is 50% by mass or less, the solubility of the (A) polyimide precursor is improved, which is preferable.

[0049] <Other ingredients> In this embodiment, the negative-type photosensitive resin composition may further contain components other than those described above (A) to (D). Examples of other components include resin components other than the polyimide precursor (A), sensitizers, monomers having photopolymerizable unsaturated bonds, adhesion aids, thermal polymerization inhibitors, azole compounds, hindered phenol compounds, and organotitanium compounds.

[0050] In this embodiment, the negative-type photosensitive resin composition may further contain resin components other than the (A) polyimide precursor. Examples of resin components that can be included in the negative-type photosensitive resin composition include polyimide, polyoxazole, polyoxazole precursor, phenol resin, polyamide, epoxy resin, siloxane resin, and acrylic resin. The amount of these resin components blended is preferably in the range of 0.01 parts by mass to 20 parts by mass per 100 parts by mass of the (A) polyimide precursor.

[0051] In this embodiment, the negative-type photosensitive resin composition may optionally contain a sensitizer to improve photosensitivity. Examples of such sensitizers include Michla'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, and p-dimethylaminocinnamyridene indigo. Non, 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, 3,3'-carbonyl-bis(7-diethylaminocoumarin), 3-acetone Examples include ethyl-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, isoamyl dimethylaminobenzoate, isoamyl diethylaminobenzoate, 2-mercaptobenzimidazole, 1-phenyl-5-mercaptotetrazol, 2-mercaptobenzothiazole, 2-(p-dimethylaminostyryl)benzoxazole, 2-(p-dimethylaminostyryl)benzthiazole, 2-(p-dimethylaminostyryl)naphtho(1,2-d)thiazole, and 2-(p-dimethylaminobenzoyl)styrene. These can be used individually or in combination (for example, 2 to 5 types).

[0052] The amount of sensitizer added is preferably 0.1 to 25 parts by mass per 100 parts by mass of (A) polyimide precursor.

[0053] In this embodiment, an adhesion aid can be optionally added to the negative-type photosensitive resin composition to improve the adhesion between the film formed using the negative-type photosensitive resin composition and the substrate. Examples of adhesion aids 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 include silane coupling agents such as amidic acid, benzophenone-3,3'-bis(N-[3-triethoxysilyl]propylamide)-4,4'-dicarboxylic acid, benzene-1,4-bis(N-[3-triethoxysilyl]propylamide)-2,5-dicarboxylic acid, 3-(triethoxysilyl)propyl succinic anhydride, and N-phenylaminopropyltrimethoxysilane; and aluminum-based adhesion aids such as aluminum tris(ethyl acetate), aluminum tris(acetylacetonate), and ethyl acetate aluminum diisopropylate.

[0054] Among these adhesion aids, a silane coupling agent is preferred in terms of adhesion strength. The amount of adhesion aid added is preferably in the range of 0.5 to 25 parts by mass per 100 parts by mass of (A) polyimide precursor.

[0055] In this embodiment, a thermal polymerization inhibitor may be optionally added to improve the viscosity and photosensitivity stability of the negative-type photosensitive resin composition, particularly when stored in a solvent-containing solution. Examples of thermal polymerization inhibitors include hydroquinone, N-nitrosodiphenylamine, ptert-butylcatechol, phenothiazine, N-phenylnaphthylamine, ethylenediaminetetraacetic acid, 1,2-cyclohexanediaminetetraacetic acid, glycol etherdiaminetetraacetic 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.

[0056] The amount of thermal polymerization inhibitor added is preferably in the range of 0.005 parts by mass to 12 parts by mass per 100 parts by mass of (A) polyimide precursor.

[0057] For example, when using a substrate made of copper or a copper alloy, an azole compound can be optionally incorporated into the negative-type photosensitive resin composition to suppress substrate discoloration. Examples of azole compounds 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, and 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-benz Examples include zotriazole, 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-tetrazol, 5-methyl-1H-tetrazol, 5-phenyl-1H-tetrazol, 5-amino-1H-tetrazol, 1-methyl-1H-tetrazol, and the like. Particularly preferred are tolyltriazole, 5-methyl-1H-benzotriazole, and 4-methyl-1H-benzotriazole. Furthermore, these azole compounds may be used individually or as a mixture of two or more.

[0058] The amount of azole compound blended is preferably 0.1 to 20 parts by mass per 100 parts by mass of (A) polyimide precursor, and more preferably 0.5 to 5 parts by mass from the viewpoint of photosensitivity characteristics. When the amount of azole compound blended per 100 parts by mass of (A) polyimide precursor is 0.1 parts by mass or more, discoloration of the copper or copper alloy surface is suppressed when the negative-type photosensitive resin composition is formed on copper or a copper alloy, while when it is 20 parts by mass or less, it is preferable because it has excellent photosensitivity.

[0059] In this embodiment, a hindered phenol compound can be optionally incorporated into the negative-type photosensitive resin composition to suppress discoloration on copper. Examples of hindered phenol compounds 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'-thiobis(3-methyl-6-t-butylphenol), and 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], N,N'hexamethylenebis(3,5-di-t-butyl-4-hydroxyhydrocinnamamide), 2,2'-methylene-bis(4-methyl-6-t- Tris(3,5-di-t-butyl-4-hydroxybenzyl)-1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 1,3,5-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-4-isopropylbenzyl)-1,3,5-tri Zin-2,4,6-(1H,3H,5H)-trione, 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, 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-t (Dimethylbenzyl)-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, 1,3,5-Tris(4-t-butyl-3-hydroxy-2-methylbenzyl)-1,3,5- Examples include, but are not limited to, 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.

[0060] The amount of the hindered phenol compound is preferably 0.1 to 20 parts by mass per 100 parts by mass of the (A) polyimide precursor, and more preferably 0.5 to 10 parts by mass from the viewpoint of photosensitivity characteristics. When the amount of the hindered phenol compound per 100 parts by mass of the (A) polyimide precursor is 0.1 parts by mass or more, for example, when a negative-type photosensitive resin composition is formed on copper or a copper alloy, discoloration and corrosion of the copper or copper alloy are prevented, while when it is 20 parts by mass or less, it is preferable because it has excellent photosensitivity.

[0061] In this embodiment, an organotitanium compound can be used to improve elongation after a humid heat endurance test. There are no particular limitations on the usable organotitanium compound, as long as it is one in which an organic chemical substance is bonded to a titanium atom via covalent or ionic bonds.

[0062] Specific examples of organotitanium compounds are shown in I) to VII) below: I) Titanium chelate compounds: Among these, titanium chelates having two or more alkoxy groups are preferred because they provide good storage stability and a good pattern for negative-type photosensitive resin compositions. Specific examples include titanium bis(triethanolamine)diisopropoxide, titanium di(n-butoxide)bis(2,4-pentanedione), titanium diisopropoxidebis(2,4-pentanedione), titanium diisopropoxidebis(tetramethylheptanedione), and titanium diisopropoxidebis(ethylacetoacetate).

[0063] II) Tetraalkoxy titanium compounds: For example, titanium tetra(n-butoxide), titanium tetraethoxide, titanium tetra(2-ethylhexoxide), titanium tetraisobutoxide, titanium tetraisopropoxide, titanium tetramethoxide, titanium tetramethoxypropoxide, titanium tetramethylphenoxide, titanium tetra(n-nonyloxide), titanium tetra(n-propoxide), titanium tetrastearaloxide, titanium tetrakis[bis{2,2-(alyloxymethyl)butoxide}], etc.

[0064] III) Titanocene compounds: For example, pentamethylcyclopentadienyltitanium trimethoxide, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluorophenyl)titanium, bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium, etc.

[0065] IV) Monoalkoxy titanium compounds: For example, titanium tris(dioctyl phosphate) isopropoxide, titanium tris(dodecylbenzenesulfonate) isopropoxide, etc.

[0066] V) Titanium oxide compounds: For example, titanium oxide bis(pentanedione), titanium oxide bis(tetramethylheptanedione), phthalocyanine titanium oxide, etc.

[0067] VI) Titanium tetraacetylacetonate compounds: For example, titanium tetraacetylacetonate.

[0068] VII) Titanate coupling agents: For example, isopropyltridodecylbenzenesulfonyl titanate.

[0069] Among the above I) to VII), it is preferable from the viewpoint of achieving better chemical resistance that the organotitanium compound is at least one compound selected from the group consisting of I) titanium chelate compounds, II) tetraalkoxy titanium compounds, and III) titanocene compounds. In particular, titanium diisopropoxide bis(ethyl acetoacetate), titanium tetra(n-butoxide), and bis(η5-2,4-cyclopentadien-1-yl)bis(2,6-difluoro-3-(1H-pyrrole-1-yl)phenyl)titanium are preferred.

[0070] The amount of these organotitanium compounds added is preferably 0.01 to 10 parts by mass, and more preferably 0.1 to 2 parts by mass, per 100 parts by mass of the polyimide precursor used as component (A). When the amount of organotitanium compounds added is 0.01 parts by mass or more, adhesion is easily achieved, and when it is 10 parts by mass or less, storage stability is easily improved.

[0071] In the photosensitive resin composition of this embodiment, it is preferable that the total amount of components excluding (A) polyimide precursor among the total solid content contained in the photosensitive resin composition is 26% by mass or more and less than 60% by mass relative to (A) polyimide precursor. By setting the total amount of components excluding (A) polyimide precursor to 26% by mass or more, the absolute value of the initial development time after the coating process and baking process can be shortened, leading to an improvement in throughput in the semiconductor manufacturing process. Furthermore, by setting the total amount of components excluding (A) polyimide precursor to less than 60% by mass, the film properties after the moist heat durability test can be maintained.

[0072] From the viewpoint of protecting the ELK layer of a semiconductor device, the photosensitive resin composition according to this embodiment preferably has a Young's modulus of 6 GPa or higher when the cured film obtained by coating and exposing a wafer and then heat-curing it at a temperature of 280°C in a nitrogen atmosphere is preferable.

[0073] In one embodiment, a cured relief pattern including a cured product of the photosensitive resin composition described above can also be provided, which exhibits excellent adhesion to the metal layer in the redistribution layer or thick film formation.

[0074] <Method for manufacturing hardened relief patterns> In this embodiment, the following steps (1) to (4): (1) A step of applying the photosensitive resin composition of the above embodiment onto a substrate to form a photosensitive resin layer on the substrate, (2) A step of exposing the photosensitive resin layer, (3) A step of developing the photosensitive resin layer after exposure to form a relief pattern, and (4) A process of heat-treating the relief pattern to form a hardened relief pattern. A method for manufacturing a hardened relief pattern can be provided, including the following:

[0075] The following describes each step. (1) A step of applying a negative-type photosensitive resin composition onto a substrate to form a photosensitive resin layer on the substrate. In this step, the photosensitive resin composition of the above-described embodiment is applied to a substrate, and if necessary, it is then dried to form a photosensitive resin layer. In the method for manufacturing a cured relief pattern, negative-type and positive-type photosensitive resin compositions may be used, and of the two types, it is preferable to apply the negative-type photosensitive resin composition to the substrate. As for the application method, methods that have been conventionally used for applying photosensitive resin compositions, such as application using a spin coater, bar coater, blade coater, curtain coater, screen printing machine, etc., or spray application using a spray coater, etc., can be used.

[0076] If necessary, the coating film made of the photosensitive resin composition can be dried, and drying methods such as air drying, heating with an oven or hot plate, or vacuum drying can be used. Furthermore, it is preferable to dry the coating film under conditions that prevent imidization of the (A) polyimide precursor in the negative-type photosensitive resin composition. Specifically, when air drying or heating drying is performed, drying can be carried out at 20°C to 140°C for 1 minute to 1 hour. Heating at 100°C to 120°C for 230 seconds to 250 seconds is preferable, and heating at 110°C for 240 seconds is more preferable. By performing step (1) as described above, a photosensitive resin layer can be formed on the substrate.

[0077] (2) Exposure of the photosensitive resin layer In this process, the photosensitive resin layer formed in step (1) above is exposed to ultraviolet light or the like using an exposure device such as a contact aligner, mirror projection, or stepper, either through a patterned photomask or reticle or directly.

[0078] Subsequently, if necessary, post-exposure baking (PEB) and / or pre-development baking may be performed using any combination of temperature and time to improve photosensitivity, etc. The baking conditions are preferably in the range of 40°C to 120°C and 10 seconds to 240 seconds, but are not limited to this range as long as they do not impair the properties of the photosensitive resin composition.

[0079] (3) A process of developing the photosensitive resin layer after exposure to form a relief pattern. In this process, the unexposed portion of the photosensitive resin layer after exposure is developed and removed. The development method for developing the photosensitive resin layer after exposure (irradiation) can be selected from any of the conventionally known photoresist development methods, such as the rotary spray method, the paddle method, or the immersion method with ultrasonic treatment. Furthermore, after development, a post-development bake may be performed using any combination of temperature and time, if necessary, for purposes such as adjusting the shape of the relief pattern.

[0080] The developer used for development is preferably a good solvent for the negative-type photosensitive resin composition, or a combination of the good solvent and a poor solvent. Preferred good solvents include, for example, N-methyl-2-pyrrolidone, N-cyclohexyl-2-pyrrolidone, N,N-dimethylacetamide, cyclopentanone, cyclohexanone, γ-butyrolactone, and α-acetyl-γ-butyrolactone. Preferred poor solvents include, for example, toluene, xylene, methanol, ethanol, isopropyl alcohol, ethyl lactate, propylene glycol methyl ether acetate, and water. When using a mixture of the good solvent and the poor solvent, it is preferable to adjust the ratio of the poor solvent to the good solvent according to the solubility of the polymer in the negative-type photosensitive resin composition. Furthermore, two or more types of solvents, for example, can be used in combination.

[0081] (4) A process of heat-treating the relief pattern to form a hardened relief pattern. In this process, the relief pattern obtained by the above development is heated to dilute the photosensitive component and the (A) polyimide precursor is imidized, 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, using an oven, or using a heating oven with a temperature programmable. Heating can be carried out, for example, at 200°C to 400°C for 30 minutes to 5 hours. Air may be used as the atmospheric gas during heat curing, or an inert gas such as nitrogen or argon may be used. From the viewpoint of controlling the Young's modulus of the cured film, heat curing can be carried out under a nitrogen atmosphere, preferably at a temperature of 200°C to 400°C, more preferably at 250°C to 300°C, and even more preferably at 270°C to 290°C.

[0082] <Semiconductor device> In this embodiment, a semiconductor device is also provided that has a cured relief pattern obtained by the cured relief pattern manufacturing method described above. Therefore, a semiconductor device can be provided that has a substrate which is a semiconductor element and a cured relief pattern of polyimide formed on the substrate by the cured relief pattern manufacturing method described above.

[0083] Furthermore, the present invention can also be applied to a method for manufacturing a semiconductor device that uses a semiconductor element as a substrate and includes the above-described method for manufacturing a cured relief pattern as part of the process. The semiconductor device of the present invention can be manufactured by forming the cured relief pattern formed by the above-described method as a surface protective film, an interlayer insulating film, an insulating film for redistribution, a protective film for a flip-chip device, or a protective film for a semiconductor device having a bump structure, and combining it with a known method for manufacturing a semiconductor device.

[0084] <Display device> In this embodiment, a display device is provided comprising a display element and a cured film provided on the upper part of the display element, wherein the cured film is the cured relief pattern described above. Here, the cured relief pattern may be laminated in direct contact with the display element, or it may be laminated with another layer in between. For example, the cured film can be a surface protective film, insulating film, and planarization film for TFT liquid crystal display elements and color filter elements, a projection for an MVA type liquid crystal display device, and a partition wall for the cathode of an organic EL element.

[0085] In addition to applications in semiconductor devices as described above, the photosensitive resin composition of the present invention is also useful for applications such as interlayer insulating films in multilayer circuits, cover coats for flexible copper-clad sheets, solder resist films, and liquid crystal alignment films. [Examples]

[0086] The following describes examples taken to clarify the effects of the present invention, but the present invention is not limited to the embodiments described in the examples. The following materials and measurement methods were used in the examples.

[0087] <Measurement and Evaluation Methods>

[0088] (1) i-line absorbance measurement The i-line absorbance of polyimide precursors was measured using a Shimadzu UV-1800 instrument with a medium scan speed and a sampling pitch of 0.5 nm after preparing an NMP solution containing 0.1% (wt%) of the polyimide precursor and filling it into a 1 cm quartz cell. The i-line absorbance of the polyimide precursors was evaluated as polymer samples according to the following criteria: A: Absorbance is less than 1.0; B: Absorbance is between 1.0 and 1.2; C: Absorbance exceeds 1.2.

[0089] (2) Pattern formation (lithography) evaluation The resin composition prepared in the example formulation was spin-coated onto a 6-inch silicon wafer substrate to a cured film thickness of 9 μm, and pre-baked at 110°C for 4 minutes. The resulting coating was then exposed to an exposure dose of 450 mJ / cm² using a stepper NSR2005i8A (Nikon Corporation) with an i-line (365 nm) exposure wavelength through a reticle with a test pattern. 2 The material was exposed by irradiating it with the i-line. Next, using a D-SPIN developing machine (manufactured by SOKUDO), rotary spray development was performed at 23°C with cyclopentanone as the developer for a time equal to 1.4 times the time until the unexposed areas were completely dissolved and disappeared. Subsequently, a rotary spray rinse was performed with propylene glycol monomethyl ether acetate for 10 seconds to obtain a relief pattern consisting of a resin film. Subsequently, curing was performed in a vertical curing furnace VF200B (manufactured by Koyo Thermo Systems) under a nitrogen atmosphere at 280°C for 2 hours to obtain a cured relief pattern.

[0090] For each obtained pattern, the pattern shape was observed using a scanning electron microscope (Hitachi High-Technos S-4800). Regarding resolution, patterns with multiple apertures of different areas were formed in the same manner as described above by exposure through a reticle with a test pattern. Among the obtained patterns, those with no residue at the bottom and normal taper angles on the sidewalls were identified, and the length of the opening side of the mask corresponding to the smallest area was defined as the minimum aperture. Furthermore, the photosensitive resin compositions prepared in the formulation examples were evaluated according to the following criteria: A: Minimum aperture less than 8 μm; B: Minimum aperture is between 8 μm and 10 μm; C: Minimum aperture exceeds 10 μm.

[0091] (3) Adhesion evaluation (peel test) The resin composition prepared in the example formulation was spin-coated onto a 6-inch silicon wafer substrate having an aluminum (Al) vapor-deposited layer on its surface, so that the cured film thickness would be 9 μm. The wafer was then pre-baked at 110°C for 4 minutes. Subsequently, a heat curing treatment was performed at 280°C for 2 hours using a vertical curing furnace (Koyo Lindbergh, model VF-2000B) to produce a wafer with a polyimide resin film. The peel strength may be the peel strength between the glass substrate and the polyimide film, measured according to the 180° peel method of JIS K6854-1 using a sample in which a polyimide film was formed on a glass substrate. The peel strength was measured under the following conditions: Device name: RTG-1210 (manufactured by A&D Company, Limited) Measurement temperature: room temperature Peeling speed: 50 mm / min Atmosphere: Atmosphere Measurement sample width: 5 mm. Furthermore, the Al adhesion of the photosensitive resin composition was evaluated according to the following criteria: A: Peel strength exceeds 0.3 N / mm; B: Peel strength of 0.2 to 0.3 N / mm; C: Peel strength is less than 0.2 N / mm.

[0092] <Manufacturing Example 1> (Polymer A: Synthesis of polyimide precursor) (Reaction solution I) 19.63 g (0.09 mol) of pyromellitic anhydride (PMDA) as acid anhydride 1 and 19.13 g (0.19 mol) of 3,3-dimethyl-2-butanol as side chain 1 were placed in a 200 mL three-necked flask, 53 g of γ-butyrolactone and 14.24 g (0.18 mol) of pyridine were added, and the mixture was stirred at room temperature for 24 hours to obtain reaction solution I.

[0093] (Reaction solution II) 18.61 g (0.06 mol) of 4,4'-oxydiphthalic acid dianhydride (ODPA) as acid anhydride 2 and 16.24 g (0.12 mol) of 2-hydroxyethyl methacrylate (HEMA) as side chain 2 were placed in a 1-liter separable flask, 44.35 g of γ-butyrolactone and 9.49 g (0.12 mol) of pyridine were added, and the mixture was stirred at room temperature for 16 hours to obtain reaction solution II.

[0094] Next, reaction solution I and reaction solution II were mixed and cooled to below 0°C. A solution of 60.98 g (0.15 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 60.00 g of γ-butyrolactone was then added to the reaction mixture over 20 minutes with stirring.

[0095] Next, while maintaining the reaction temperature below 2°C, a solution of 2,2'-dimethylbiphenyl-4,4'-diamine (m-TB) 27.86 g (0.13 mol) dissolved in 80.00 g of γ-butyrolactone was added dropwise over 30 minutes.

[0096] Subsequently, the reaction mixture was heated to room temperature and stirred at room temperature for 4 hours. Then, 13.66 g of ethanol was added as a terminal sealant and stirred for 30 minutes. The precipitate formed in the reaction mixture was removed by filtration to obtain the reaction solution.

[0097] To the resulting reaction solution, 3 L of ethanol was added to produce a precipitate consisting of the crude polymer. The crude polymer was filtered off and dissolved in 600 g of γ-butyrolactone to obtain a crude polymer solution. The obtained crude polymer solution was added dropwise to 6 L of water to precipitate the polymer, and the resulting precipitate was filtered off and vacuum-dried at 40°C for 72 hours to obtain a powdered polymer (polyimide precursor (polymer A)). The i-line absorbance of the polymer was 0.92, and it was evaluated as A. Furthermore, the structure of the obtained polymer represented by the above general formula (13) was simulated using the simulation software "Forcite" under the conditions described in Table 1 below: [Table 1] Structural optimization is performed, and further, the calculation program "Dmol3" is used under the conditions listed in Table 2 below: [Table 2] The lowest empty molecular orbital (LUMO) and the band gap between the highest occupied molecular orbital (HOMO) and the LUMO were calculated.

[0098] <Manufacturing Examples 2-10> (Polymers B-J: Synthesis of polyimide precursors) The acid anhydrides, side chains, and diamines in reaction solutions I and II of Production Example 1 were replaced with the combinations shown in Table 3, and polymers B to J were synthesized following the same procedure as the synthesis example in Production Example 1. The i-line absorbance of the polymers was then evaluated.

[0099] <Production Example 11> (Polymer K: Synthesis of polyimide precursor) 18.61 g (0.06 mol) of 4,4'-oxydiphthalic acid dianhydride (ODPA) and 19.63 g (0.09 mol) of pyromellitic acid anhydride (PMDA) as acid anhydrides, and 40.61 g (0.15 mol) of 2-hydroxyethyl methacrylate (HEMA) as a side chain were placed in a 1-liter separable flask, and 102.58 g of γ-butyrolactone and 23.73 g (0.30 mol) of pyridine were added and the mixture was stirred at room temperature for 16 hours.

[0100] Next, the reaction mixture was cooled to below 0°C, and a solution of 60.98 g (0.15 mol) of dicyclohexylcarbodiimide (DCC) dissolved in 60.00 g of γ-butyrolactone was added over 20 minutes while stirring.

[0101] Next, while maintaining the reaction temperature below 2°C, a solution of 2,2'-dimethylbiphenyl-4,4'-diamine (m-TB) 27.29 g (0.13 mol) dissolved in 80.00 g of γ-butyrolactone was added dropwise over 30 minutes.

[0102] Subsequently, the reaction mixture was heated to room temperature and stirred at room temperature for 4 hours. Then, 13.66 g of ethanol was added as a terminal sealant and stirred for 30 minutes. The precipitate formed in the reaction mixture was removed by filtration to obtain the reaction solution.

[0103] To the resulting reaction solution, 3 L of ethanol was added to produce a precipitate consisting of crude polymer. The crude polymer was filtered off and dissolved in 600 g of γ-butyrolactone to obtain a crude polymer solution. The obtained crude polymer solution was added dropwise to 6 L of water to precipitate the polymer, and the resulting precipitate was filtered off and then vacuum-dried at 40°C for 72 hours to obtain a powdered polymer (polyimide precursor (polymer K)). The i-line absorbance of the polymer was measured and evaluated as C.

[0104] <Production Example 12> (Polymer M: Synthesis of polyimide precursor) The acid anhydride and diamine in Production Example 11 were replaced with the combinations shown in Table 3, and polymer M was synthesized following the same procedure as in the synthesis example of Production Example 11. The i-line absorbance of the polymer was then evaluated.

[0105] [Table 3]

[0106] <Examples 1-8, Comparative Examples 1-4> A photosensitive resin composition was prepared by dissolving 10.00 g of polymers A to M obtained in the production example, 0.50 g of 1-phenyl-2-[(benzoyloxy)imino]-1-propanone as a photopolymerization initiator, 1.40 g of tetraethylene glycol dimethacrylate as a crosslinking agent, and 1.20 g of N-phenyldiethanolamine and 0.05 g of 7-(diethylamino)coumarin-3-carboxylate ethyl in 18.49 g of γ-butyrolactone, and filtering the mixture using a microfilter with a pore size of 1 μm. The results of the evaluation of pattern formation and adhesion of the polymers used in each example and comparative example, and the photosensitive resin composition, are summarized in Table 4.

[0107] [Table 4]

[0108] As is clear from the above examples, the i-line absorbance was suppressed by introducing side chains with a branched structure into the polymer. The photosensitive resin composition using this polymer showed good pattern-forming performance in thick films. Furthermore, a significant improvement was observed in the adhesion to aluminum of the photosensitive resin composition using a polymer with non-crosslinked side chains. [Industrial applicability]

[0109] By using the photosensitive resin composition according to the present invention, it is possible to form an insulating layer that exhibits excellent adhesion to the substrate after curing treatment of the coating film, and to stably open via patterns. This makes it suitably applicable in the field of photosensitive materials useful for the manufacture of electrical and electronic materials such as semiconductor devices and multilayer wiring boards.

Claims

1. (A) A polyimide precursor having a repeating structure represented by the following formula (1): 【Chemistry 1】 {During the ceremony, X 1 It is a tetravalent organic group, Y 1 It is a divalent organic group, m is an integer greater than or equal to 1, R 1 and R 2 Each of these independently comprises a hydrogen atom, a radical polymerizable group, or the following formula (2): 【Chemistry 2】 (wherein, R 3 , R 4 and R ｚ are each independently a monovalent organic group having 1 to 20 carbon atoms and not containing fluorine, or when any one of R 3 , R 4 and R ｚ is a hydrogen atom, the others are monovalent organic groups having 1 to 20 carbon atoms and not containing fluorine atoms, and at least one has a branched chain or a cyclic structure.), and is an organic group represented by, provided that at least one R 1 is the radical polymerizable group, and at least one R 2 is the organic group represented by the above formula (2) not containing a radical polymerizable group.}, and (B) Photoradical initiator A photosensitive resin composition containing [a specific substance].

2. The aforementioned R 3 The photosensitive resin composition according to claim 1, wherein is a monovalent organic group having 3 or fewer carbon atoms.

3. The aforementioned R 3 , R 4 and R ｚ The photosensitive resin composition according to claim 1 or 2, wherein it does not contain radical polymerizable groups.

4. The photosensitive resin composition according to claim 1 or 2, wherein R1 and R2 in formula (1) are each independently a hydrogen atom, a radical polymerizable group represented by the following formula (3), or an organic group represented by the formula (2): 【Transformation 3】 (In the formula, R 5 R is a hydrogen atom or a monovalent organic group having 1 to 10 carbon atoms. 6 , R 7 and R 8 Each of these is independently a hydrogen atom or a monovalent organic group having 1 to 3 carbon atoms, and p is an integer from 1 to 10.

5. R in formula (1) 1 is a group represented by the above formula (3), and R 7 and R 8 The photosensitive resin composition according to claim 4, wherein it does not contain radical polymerizable groups.

6. In the above formula (1), R 1 and R 2 The photosensitive resin composition according to claim 4, wherein the group represented by formula (3) is contained in an amount of 20 to 80 mol% of the total.

7. The aforementioned R 3 , R 4 and R ｚ The photosensitive resin composition according to claim 1 or 2, wherein one of the atoms is a hydrogen atom.

8. The aforementioned Y 1 The photosensitive resin composition according to claim 1 or 2, represented by the following formula (5) or formula (6): 【Chemistry 4】 (In the formula, R 13 Each of these independently represents either a hydrogen atom, a fluorine atom, a methyl group, or a trifluoromethyl group. 【Transformation 5】 (In the formula, R 14 Each of these independently represents either a hydrogen atom or a methyl group.

9. The aforementioned X 1 The photosensitive resin composition according to claim 1 or 2, wherein the group is derived from at least one selected from the group consisting of the following formulas (7) to (12): 【Transformation 6】 。

10. The aforementioned X 1 The photosensitive resin composition according to claim 9, wherein the group is derived from at least one selected from the group consisting of formulas (7), (8), and (10).

11. A structure represented by the following formula (13): 【Transformation 8】 {X in the formula} 1 , Y 1 , R 1 and R 2 The definition is the same as in equation (1) above. The photosensitive resin composition according to claim 1 or 2, wherein, after molecular dynamics calculations using Forcite, the lowest empty molecular orbital (LUMO) calculated with Dmol3 is -3.00 to -2.59 eV, and the band gap between the highest occupied molecular orbital (HOMO) and the LUMO is 1.52 to 2.00 eV.

12. The photosensitive resin composition according to claim 1 or 2, wherein the cured film obtained by coating and exposing a wafer and then thermally curing it at a temperature of 280°C in a nitrogen atmosphere has a Young's modulus of 6 GPa or more.

13. (1) A step of forming a photosensitive resin layer on a substrate by applying the photosensitive resin composition according to claim 1 or 2 onto the substrate, (2) A step of exposing the photosensitive resin layer, (3) A step of developing the photosensitive resin layer after exposure to form a relief pattern, (4) A step of forming a hardened relief pattern by heat treatment of the relief pattern, A method for manufacturing a hardened relief pattern, including [the specified element].

14. A cured relief pattern comprising a cured product of the photosensitive resin composition according to claim 1 or 2.

15. A semiconductor device having the cured relief pattern described in claim 14.

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