Positive photosensitive resin composition, insulating resin film, method for forming insulating resin film, and semiconductor device

Abstract

A positive photosensitive resin composition according to the present invention comprises: (A) an alkali-soluble resin; (B) a photoacid generator that is a compound which uses light to generate an acid; and (C) a thermal crosslinking agent that is a compound which uses heat to facilitate crosslinking of the alkali-soluble resin. The alkali-soluble resin includes a constituent unit that is a group obtained by removing one or more hydrogen atoms from a bisphenol imide compound represented by general formula (I). R1 and R2 are each independently a hydroxyphenyl group represented by formula (1a) or (1b).

Description

Positive photosensitive resin composition, insulating resin film, method for forming insulating resin film, and semiconductor device

[0001] The present disclosure relates to a positive photosensitive resin composition, an insulating resin film having a pattern including openings, a method for forming an insulating resin film having a pattern including openings, and a semiconductor device.

[0002] Patent Document 1 discloses a positive photosensitive resin composition containing an alkali-soluble resin having an imide bond and a phenolic hydroxyl group as a material capable of forming a surface protective layer or an interlayer insulating layer of a semiconductor element.

[0003] International Publication No. 2021 / 261448

[0004] The present disclosure relates to a positive photosensitive resin composition that can form an insulating resin film that exhibits large elongation at break and has a surface with little tack immediately after development.

[0005] The present disclosure includes the following: [1] A composition comprising: (A) an alkali-soluble resin; (B) a photoacid generator that is a compound that generates an acid by light; and (C) a thermal crosslinker that is a compound that crosslinks the alkali-soluble resin by heat, wherein the alkali-soluble resin is represented by the following formula (I): a structural unit which is a group obtained by removing one or more hydrogen atoms from a bisphenolimide compound represented by the formula: １ is a tetravalent organic group, and R １ and R ２ are each independently represented by the following formula (1a) or (1b): is a hydroxyphenyl group represented by R ３ and R ４ [2] A positive photosensitive resin composition, wherein the bisphenolimide compound is a compound represented by the following formula (I'): is a compound represented by R １ and R ２ is R in formula (I) １ and R ２ is defined similarly to Z ２is a divalent organic group or a covalent bond. [3] The positive photosensitive resin composition according to [1] or [2], wherein the alkali-soluble resin comprises a novolak resin that is a reaction product of a phenolic compound, including the bisphenolimide compound, with one or more reactive compounds selected from an aldehyde compound, a compound having multiple methoxymethyl groups, and a compound having multiple hydroxymethyl groups. [4] The positive photosensitive resin composition according to [3], wherein the proportion of the bisphenolimide compound is 10 mol % or more and 100 mol % or less, based on the total amount of the phenolic compounds. [5] The positive photosensitive resin composition according to any one of [1] to [4], wherein the thermal crosslinking agent comprises an alkoxy compound having multiple alkoxy groups. [6] A method for forming an insulating resin film, comprising: exposing a portion of a photosensitive layer comprising the positive photosensitive resin composition according to any one of [1] to [5]; developing the photosensitive layer to remove a portion of the photosensitive layer to form an insulating resin film having a pattern including openings; and heating the insulating resin film. [7] An insulating resin film comprising a cured product of the positive photosensitive resin composition according to any one of [1] to [5], and having a pattern including openings. [8] A semiconductor device comprising: a semiconductor chip; and a wiring part comprising a conductor wiring layer connected to the semiconductor chip and one or more insulating layers, wherein at least a part of the one or more insulating layers is the insulating resin film according to [7].

[0006] The positive photosensitive resin composition according to the present disclosure can form an insulating resin film that exhibits a large elongation at break and has a surface with little tack immediately after development. The little or substantially no tack can be advantageous for, for example, the efficient formation of a redistribution layer including the insulating resin film.

[0007] 1 is a flowchart showing an example of a method for forming an insulating resin film having a pattern.

[0008] The present invention is not limited to the following examples. In this disclosure, the term "process" includes not only an independent process but also a process that cannot be clearly distinguished from other processes as long as the intended function of the process is achieved. The term "layer" encompasses not only a structure that is formed over the entire surface when observed in a plan view, but also a structure that is formed only on a portion of the surface. Numerical ranges indicated using "to" indicate ranges that include the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In numerical ranges described in stages in this specification, the upper or lower limit of a numerical range of a certain stage may be replaced with the upper or lower limit of a numerical range of another stage. In numerical ranges described in this specification, the upper or lower limit of the numerical range may be replaced with the value shown in the examples.

[0009] Photosensitive Resin Composition An example of a photosensitive resin composition includes (A) an alkali-soluble resin, (B) a photoacid generator that generates an acid when exposed to light, and (C) a thermal crosslinking agent that crosslinks the alkali-soluble resin when exposed to heat. The photosensitive resin composition according to the present disclosure can function as a positive-type photosensitive resin composition based on a change in solubility in an alkaline developer due to exposure to light. Furthermore, a film containing the photosensitive resin composition according to the present disclosure can be thermally cured mainly by a crosslinking reaction between the thermal crosslinking agent and the alkali-soluble resin to form an insulating resin film that is a cured film containing a cured product of the photosensitive resin composition.

[0010] (A) Alkali-Soluble Resin In the present disclosure, an alkali-soluble resin refers to a resin that dissolves in a 2.38% by mass aqueous solution of tetramethylammonium hydroxide (TMAH) at 25° C. Whether a resin is alkali-soluble can be confirmed by a method that includes forming a resin film of the resin having a thickness of about 1 μm on a substrate and immersing the resin film in a 2.38% by mass aqueous solution of TMAH at 25° C. For example, if the resin film completely dissolves in the TMAH aqueous solution within 60 minutes of immersion while the TMAH aqueous solution is left stationary, the resin is considered to be an alkali-soluble resin.

[0011] The alkali-soluble resin of component (A) is a resin or polymer containing a structural unit that is a group obtained by removing one or more hydrogen atoms from a bisphenolimide compound represented by the following formula (I): The alkali-soluble resin may be a novolak resin containing a structural unit derived from the bisphenolimide compound represented by formula (I).

[0012] In formula (I), Z １ is a tetravalent organic group, and R １ and R ２ are each independently a hydroxyphenyl group represented by the following formula (1a) or (1b): ３ and R in formula (1b) ４ are each independently an alkyl group having 1 to 3 carbon atoms (for example, a methyl group).

[0013] The hydroxyphenyl group represented by formula (1a) or (1b) has one phenolic hydroxyl group and one hydrogen atom bonded to the ortho- or para-position relative to the phenolic hydroxyl group. Typically, in a hydroxyphenyl group, the hydrogen atom bonded to the ortho- or para-position relative to the phenolic hydroxyl group tends to be easily substituted by a reactive compound such as an aldehyde compound. The bisphenolimide compound of formula (I) has a hydroxyphenyl group represented by formula (1a) or (1b) and has two hydrogen atoms at positions that are easily substituted. Thus, when the number of hydrogen atoms at positions that are easily substituted is small, the polymer is less likely to have an excessively crosslinked structure, which is thought to contribute to improving the elongation at break of the insulating resin film. Furthermore, the hydroxyphenyl group represented by formula (1a) or (1b) also contributes to reducing tack on the surface of the insulating resin film.

[0014] The structural unit derived from the bisphenol compound represented by formula (I) can be, for example, a divalent group represented by the following formula (IA), (IB) or (IC). Z in formulas (IA) to (IC) １ , R ３ and R ４ represents Z in formula (I), (1a) or (1b). １ , R ３ and R ４is defined similarly.

[0015] Z in formula (I) １ may be one cyclic hydrocarbon group which may have a substituent (for example, an alkyl group having 1 to 3 carbon atoms), or a group having two or more cyclic hydrocarbon groups which may have a substituent (for example, an alkyl group having 1 to 3 carbon atoms) and a divalent organic group or a covalent bond bonding them together.

[0016] Z １ Examples of the cyclic hydrocarbon group include groups in which one or more hydrogen atoms have been removed from the following cyclic hydrocarbon compounds:

[0017] Z １ The divalent organic group linking the two cyclic hydrocarbon groups may be, for example, a divalent group selected from an oxy group (-O-), a thio group (-S-), a carbonyl group, an alkylene group having 1 to 3 carbon atoms, a phenylene group, an alkylphenylene group, and groups consisting of combinations thereof. Examples of the alkylene group having 1 to 3 carbon atoms include a methylene group, an ethylene group, an ethylidene group, a propane-1,3-diyl group, a propane-1,1-diyl group, and a propane-2,2-diyl group. Z １ Specific examples of the divalent organic group linking two cyclic hydrocarbon groups include alkylene groups having 1 to 3 carbon atoms as well as the following:

[0018] In these formulas, R １０ represents an alkyl group having 1 to 3 carbon atoms (e.g., a methyl group), and multiple R １０ may be the same or different. q represents an integer of 0 to 4, and multiple q's in one formula may be the same or different. R １１ represents an alkylene group (e.g., propane-2,2-diyl group, methylene group), an oxy group, a thio group, or a covalent bond. １２ represents an alkylene group (for example, an ethane-1,2-diyl group).

[0019] The bisphenolimide compound represented by formula (I) may be a compound represented by the following formula (I'): １ and R２ is R in (I) １ and R ２ is defined in the same way as Z. ２ is a divalent organic group or a covalent bond.

[0020] Z in formula (I') ２ Examples of divalent organic groups as １ The examples of the divalent organic group linking two cyclic hydrocarbon groups in Z include the same as those in Z. ２ When Z is a covalent bond, an insulating resin film having particularly excellent PCT resistance is easily formed. ２ When the group is an oxy group, an insulating resin film that exhibits particularly large elongation at break and strength at break is likely to be formed.

[0021] The alkali-soluble resin may be a novolak resin, which is a reaction product of a phenolic compound, including a bisphenolimide compound represented by formula (I), with one or more reactive compounds selected from an aldehyde compound, a compound having multiple methoxymethyl groups, and a compound having multiple hydroxymethyl groups. In this case, the phenolic compound may further include a compound having a phenolic hydroxyl group other than the bisphenolimide compound, examples of which include phenol and the above-mentioned phenol derivatives.

[0022] The aldehyde compound constituting the novolac resin may be formaldehyde. The compound having multiple methoxymethyl groups may be a compound having an aromatic ring (e.g., a benzene ring) to which methoxymethyl groups are bonded. The compound having multiple hydroxymethyl groups may be a compound having an aromatic ring (e.g., a benzene ring) to which hydroxymethyl groups are bonded. Examples of compounds having multiple methoxymethyl groups include compounds represented by the following formula (21) or (22). In these formulas, R １０ represents an alkyl group having 1 to 3 carbon atoms (e.g., a methyl group). １０may be the same or different. p represents an integer of 0 to 4, and q and r each independently represent an integer of 0 to 4. The compound having multiple methoxymethyl groups may be bis(methoxymethyl)biphenyl, dimethoxymethylbenzene, or a combination thereof. An example of a compound having multiple hydroxymethyl groups includes 2,6-bis(hydroxymethyl)-p-cresol.

[0023] The residue derived from formaldehyde is usually a methylene group. The residue derived from a compound having two or more methoxymethyl groups can be, for example, a divalent group represented by the following formula (21A) or (22A). R in formula (21A) and (22A) １０ , p, q and r are R in formulas (21) and (22). １０ , p, q and r are defined similarly.

[0024] In the phenolic compounds that react with aldehyde compounds or the like in the reaction to produce a novolac resin, the proportion of the bisphenolimide compound may be 10 mol% or more and 100 mol% or less, 20 mol% or more and 100 mol% or less, 30 mol% or more and 100 mol% or less, or 40 mol% or more and 100 mol% or less, based on the total amount of the phenolic compounds. A high proportion of the bisphenolimide compound tends to provide particularly excellent effects in terms of the elongation at break, heat resistance, and suppression of thermal expansion of the insulating resin film. From the same perspective, the proportion of the bisphenolimide compound may be 50 mol% or more, 60 mol% or more, 70 mol% or more, 80 mol% or more, or 90 mol% or more, based on the total amount of the phenolic compounds, or may be substantially 100 mol%.

[0025] The novolac resin, which is an alkali-soluble resin, can be synthesized, for example, by a method similar to the method for synthesizing a general phenol novolac resin or cresol novolac resin.

[0026] The weight average molecular weight (Mw) of the alkali-soluble resin may be 1,000 to 500,000, 2,000 to 400,000, 3,000 to 350,000, or 5,000 to 300,000, from the viewpoint of the balance between solubility in an alkaline aqueous solution, photosensitive properties, and mechanical strength of the insulating resin film. In the present disclosure, the weight average molecular weight is a converted value measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

[0027] The alkali-soluble resin may have molecular chains derived from an elastomer, examples of which will be described later.

[0028] (B) Photoacid Generator The photoacid generator (B) contains one or more compounds that generate an acid upon exposure to light (e.g., ultraviolet light) and functions as a photosensitizer in the photosensitive resin composition. The action of the acid generated by the photoacid generator upon absorption of light selectively increases the solubility in an alkaline aqueous solution of the portion of the photosensitive layer that has been irradiated with light.

[0029] The compound constituting the photoacid generator may be selected from compounds generally used as photoacid generators. The compound that generates an acid when exposed to light may be, for example, an o-quinonediazide compound, an aryldiazonium salt, a diaryliodonium salt, or a triarylsulfonium salt, or a combination of two or more selected from these.

[0030] In order to improve the sensitivity of exposure, the photoacid generator may contain an o-quinone diazide compound. The o-quinone diazide compound contains an aromatic group, an oxo group (=O), and a diazide group (=N). ＋ = N － ) in which an oxo group and a diazido group are bonded to adjacent carbon atoms in an aromatic group. The aromatic group may be, for example, a group obtained by removing a hydrogen atom from naphthalene or benzene.

[0031] The o-quinonediazide compound may have, as a group containing an oxo group and a diazide group, for example, a group represented by the following formula (3a), (3b) or (3c).

[0032] The compound having a group represented by formula (3a), (3b), or (3c) may be, for example, a product of a condensation reaction between o-quinone diazide sulfonyl chloride and a hydroxy compound and / or an amino compound in the presence of a dehydrochlorinating agent. In this case, the o-quinone diazide compound may be a compound having a residue derived from a hydroxy compound or an amino compound and a group represented by formula (3a), (3b), or (3c). For example, a compound having a group represented by formula (3a) can be obtained from naphthoquinone-1,2-diazide-5-sulfonyl chloride. A compound having a group represented by formula (3b) can be obtained from naphthoquinone-1,2-diazide-6-sulfonyl chloride. A compound having a group represented by formula (3c) can be obtained from benzoquinone-1,2-diazide-4-sulfonyl chloride.

[0033] The o-quinonediazide compound may be a compound having a residue derived from a hydroxy compound or an amino compound and a group represented by formula (3a), (3b) or (3c).

[0034] Hydroxy compounds that can be used to synthesize o-quinone diazide compounds are compounds having one or more hydroxyl groups. The residue of a hydroxy compound can be a group obtained by removing one or more hydrogen atoms from the hydroxyl group of a hydroxy compound. Examples of hydroxy compounds include hydroquinone, resorcinol, pyrogallol, bisphenol A, bis(4-hydroxyphenyl)methane, 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane, 2,2-bis(4-hydroxyphenyl)hexafluoropropane, 2,3,4-trihydroxybenzophenone, 2,3,4,4'-tetrahydroxybenzophenone, and 2,2',4,4'-tetrahydroxybenzophenone. phenone, 2,3,4,2',3'-pentahydroxybenzophenone, 2,3,4,3',4',5'-hexahydroxybenzophenone, bis(2,3,4-trihydroxyphenyl)methane, bis(2,3,4-trihydroxyphenyl)propane, 4b,5,9b,10-tetrahydro-1,3,6,8-tetrahydroxy-5,10-dimethylindeno[2,1-a]indene, tris(4-hydroxyphenyl)methane, and tris(4-hydroxyphenyl)ethane.

[0035] Specific examples of the compound having a residue of a hydroxy compound and a group represented by formula (3a), (3b), or (3c) include compounds represented by the following formulas (31), (32), (33), (34), (35), or (36). These compounds tend to absorb light in an appropriate wavelength range for exposure of the photosensitive layer.

[0036] In formulas (31) to (36), Q represents a group represented by formula (3a), (3b), or (3c), or a hydrogen atom, and multiple Qs in the same molecule may be the same or different, and at least one of the multiple Qs in the same molecule is a group represented by formula (3a), (3b), or (3c). ３０ represents an alkyl group having 1 to 3 carbon atoms (e.g., a methyl group), and multiple R３０ may be the same or different. ３１ represents an alkanetriyl group having 1 to 3 carbon atoms (for example, a methanetriyl group or an ethane-1,1,1-triyl group), and each of the multiple p's independently represents an integer of 0 to 4. In formula (32), each of the multiple q's independently represents an integer of 0 to 4. In formula (33), each of the multiple r's independently represents an integer of 0 to 4, and each of the multiple s's independently represents an integer of 0 to 3. In formula (34), each of the multiple t's independently represents an integer of 0 to 4. In formula (35), each of the multiple u's independently represents an integer of 0 to 4, and each of the multiple v's independently represents an integer of 0 to 3. In formula (36), w represents an integer of 0 to 4, and x represents an integer of 0 to 2.

[0037] The amino compound that can be used to synthesize the o-quinonediazide compound is a compound having one or more amino groups. The residue of the amino compound can be a group in which one or more hydrogen atoms have been removed from the amino group of the amino compound. Examples of the amino compound include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfide, o-aminophenol, m-aminophenol, p-aminophenol, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, bis(3-amino-4-hydroxyphenyl)propane, bis(4-amino-3-hydroxyphenyl)propane, bis(3-amino-4-hydroxyphenyl)sulfone, bis(4-amino-3-hydroxyphenyl)sulfone, bis(3-amino-4-hydroxyphenyl)hexafluoropropane, and bis(4-amino-3-hydroxyphenyl)hexafluoropropane.

[0038] From the viewpoint of good sensitivity, the content of the photoacid generator may be 1 to 50 mass %, 3 to 35 mass %, or 5 to 20 mass % relative to the content of the alkali-soluble resin of the component (A).

[0039] (C) Thermal Crosslinking Agent The thermal crosslinking agent of component (C) contains one or more compounds that crosslink the alkali-soluble resin by heat. The compound constituting the thermal crosslinking agent may have multiple functional groups that can react with the alkali-soluble resin and bond to the molecular chain of the alkali-soluble resin. Examples of such functional groups include alkoxy groups, epoxy groups, and oxazoline groups. The thermal crosslinking agent may contain an alkoxy compound having multiple alkoxy groups.

[0040] The alkoxy compound that can be used as a thermal crosslinking agent is thought to function as a thermal crosslinking agent that crosslinks molecular chains of an alkali-soluble resin mainly through a reaction between an aromatic group (phenylene group) to which a phenolic hydroxyl group is bonded and an alkoxy group. The number of alkoxy groups in the alkoxy compound may be 2 or more, 3 or more, or 4 or more, and may be 20 or less, 15 or less, or 10 or less.

[0041] At least a portion of the two or more alkoxy groups of the alkoxy compound may be methoxy groups. In other words, the alkoxy compound may have multiple methoxy groups. The alkoxy compound may have four or more methoxy groups.

[0042] The alkoxy compound may have a cyclic group obtained by removing one or more hydrogen atoms from benzene, 1,3,5-triazine, glycoluril, 2-imidazolidinone, or urea, and an alkoxyalkyl group (e.g., a methoxymethyl group or a 1,3-dimethoxypropan-2-yl group) may be bonded to the cyclic group. An alkoxy compound having a cyclic group (benzene ring) obtained by removing a hydrogen atom from benzene may have a phenolic hydroxyl group bonded to the cyclic group. In the present disclosure, a compound having an alkoxy group and a phenolic hydroxyl group may be considered a thermal crosslinking agent for component (C) rather than an alkali-soluble resin. An alkoxy compound having an alkoxy group and a phenolic hydroxyl group may contribute to improving the sensitivity of the photosensitive resin composition.

[0043] The weight average molecular weight of the alkoxy compound may be 3000 or less, 2000 or less, or 1500 or less, or may be 100 or more, from the viewpoint of the balance of solubility in an alkaline developer, photosensitive properties, and mechanical strength.

[0044] Specific examples of alkoxy compounds having a phenolic hydroxyl group include compounds represented by the following formula (41), (42), (43), (44), (45), or (46). Specific examples of alkoxy compounds having a cyclic group formed by removing one or more hydrogen atoms from 1,3,5-triazine, glycoluril, 2-imidazolidinone, or urea include compounds represented by the following formula (47), (48), (49), or (50).

[0045] In formulas (41) to (50), R ４０ represents an alkoxyalkyl group, and multiple R ４０ may be the same or different. ４０ may be a methoxyalkyl group or a dimethoxyalkyl group, an example of which is a methoxymethyl group (-CH ２ OCH ３ ), and a 1,3-dimethoxypropan-2-yl group represented by the following formula:

[0046] From the viewpoints of heat resistance of the insulating resin film (cured film) and suppression of warpage, the content of the thermal crosslinking agent (or alkoxy compound) may be 1 to 70 mass %, 2 to 50 mass %, or 3 to 40 mass % relative to the content of the alkali-soluble resin of the component (A).

[0047] In the photosensitive resin composition, the total content of the (A) alkali-soluble resin, the (B) photoacid generator, and the (C) thermal crosslinking agent may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, 90% by mass or more, or 95% by mass or more, based on the amount of the photosensitive resin composition. When the photosensitive resin composition contains a solvent, the amount of the photosensitive resin composition herein is the amount excluding the solvent.

[0048] Other Components In addition to components (A) to (C), the photosensitive resin composition may further contain other components such as an elastomer, an adhesion aid, a solvent, a compound that generates an acid upon heating, a dissolution promoter, a dissolution inhibitor, a Cu rust inhibitor, a coupling agent, a surfactant, and a leveling agent. The photosensitive resin composition may further contain, in addition to component (A), an alkali-soluble resin that does not fall under component (A).

[0049] The elastomer may be, for example, one or more selected from styrene-based elastomers, olefin-based elastomers, urethane-based elastomers, polyester-based elastomers, polyamide-based elastomers, acrylic-based elastomers, and silicone-based elastomers.

[0050] The elastomer may be an acrylic elastomer containing a (meth)acrylic acid alkyl ester as a monomer unit. The (meth)acrylic acid alkyl ester may have an alkyl group having 1 to 20 carbon atoms. The acrylic elastomer may further contain, as a monomer unit, one or more acrylic monomers selected from (meth)acrylic acid, an aliphatic alcohol and ester having an amino group, a (meth)acrylic acid alkyl ester having a hydroxyalkyl group having 4 to 20 carbon atoms, and (meth)acrylic acid. The content of the elastomer may be 0 to 50 mass%, 0.5 to 50 mass%, 1 to 30 mass%, or 2 to 20 mass% relative to the amount of the alkali-soluble resin. "(Meth)acrylic acid" means acrylic acid or methacrylic acid.

[0051] The adhesion promoter may include a nitrogen-containing aromatic compound, examples of which include 1H-tetrazole, 5-aminotetrazole, 5-phenyltetrazole, and 5-methyltetrazole. The content of the adhesion promoter may be 0 to 20 mass%, 0.01 to 20 mass%, 0.015 to 10 mass%, or 0.02 to 7 mass% relative to the content of the alkali-soluble resin of component (A).

[0052] Examples of solvents include γ-butyrolactone, ethyl lactate, propylene glycol monomethyl ether acetate, benzyl acetate, n-butyl acetate, ethoxyethyl propionate, 3-methylmethoxypropionate, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, hexamethylphosphorylamide, tetramethylene sulfone, diethyl ketone, diisobutyl ketone, methyl amyl ketone, cyclohexanone, propylene glycol monomethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, and dipropylene glycol monomethyl ether. These solvents can be used alone or in combination of two or more. The solvent may include ethyl lactate, γ-butyrolactone, or a combination thereof. In a photosensitive resin composition containing a solvent, the concentration of components other than the solvent (solid content) may be 1 to 80% by mass based on the mass of the photosensitive resin composition containing the solvent.

[0053] The compound that generates an acid upon heating promotes the thermal crosslinking reaction between the alkali-soluble resin and the oxazoline compound or alkoxy compound, which can result in further improved heat resistance of the cured film. The compound that generates an acid upon heating can also contribute to improved resolution. Examples of the compound that generates an acid upon heating include salts formed from a strong acid and a base, such as onium salts, and imide sulfonates. The content of the compound that generates an acid upon heating may be 0 to 30% by mass, 0.1 to 30% by mass, 0.2 to 20% by mass, or 0.5 to 10% by mass relative to the content of the alkali-soluble resin of component (A).

[0054] The dissolution promoter is a component that increases the dissolution rate of the exposed area in a developer, and can contribute to improving sensitivity and resolution. The dissolution promoter may include a compound having a carboxy group, a sulfo group, or a sulfonamide group. The content of the dissolution promoter may be 0 to 30% by mass, or 0.01 to 30% by mass, relative to the content of the alkali-soluble resin of component (A).

[0055] The dissolution inhibitor is a compound that inhibits the dissolution of exposed areas in an alkaline aqueous solution and is used to control the film thickness, development time, and contrast after development. Examples of dissolution inhibitors include diphenyliodonium nitrate, bis(p-tert-butylphenyl)iodonium nitrate, diphenyliodonium bromide, diphenyliodonium chloride, and diphenyliodonium iodide. The content of the dissolution inhibitor may be 0 to 20% by mass, 0.01 to 20% by mass, 0.01 to 15% by mass, or 0.05 to 10% by mass relative to the content of the alkali-soluble resin of component (A).

[0056] The coupling agent may include an organic silane compound (silane coupling agent), an aluminum chelate compound, or a combination thereof. Examples of commercially available organic silane compounds include KBM-403, KBM-803, and KBM-903 (trade names, manufactured by Shin-Etsu Chemical Co., Ltd.). The content of the coupling agent may be 0 to 20% by mass, 0.1 to 20% by mass, or 0.5 to 10% by mass relative to the content of the alkali-soluble resin of component (A).

[0057] Examples of surfactants or leveling agents include polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, and polyoxyethylene octylphenol ether. Examples of commercially available products include Megafac F-171, F-565, and RS-78 (trade names, manufactured by DIC Corporation). The content of the surfactant or leveling agent may be 0 to 5 mass%, 0.001 to 5 mass%, or 0.01 to 3 mass%, relative to the content of the alkali-soluble resin of component (A).

[0058]

[0023] Method for forming an insulating resin film having a pattern including openings can be formed by photolithography using the photosensitive resin composition according to the present disclosure. Fig. 1 is a flowchart showing an example of a method for forming an insulating resin film having a pattern including openings. The method shown in Fig. 1 includes a step S1 of forming a photosensitive layer including the photosensitive resin composition, a step S2 of exposing a portion of the photosensitive layer to light, a step S3 of removing a portion of the photosensitive layer through development to form an insulating resin film having a pattern including openings, and a step S4 of heating the insulating resin film.

[0059] The photosensitive layer containing the photosensitive resin composition can be applied to, for example, a glass substrate, a semiconductor substrate, a metal oxide insulating substrate (e.g., TiO ２ , SiO ２ The photosensitive layer may be formed on any substrate, such as a silicon nitride substrate, a silicon dioxide substrate, or the like. The photosensitive layer may be formed, for example, by a method including coating a solvent-containing positive photosensitive resin composition on a substrate and removing the solvent from the coating. The coating may be heated to remove the solvent. The thickness of the photosensitive layer may be 0.1 to 40 μm.

[0060] A portion of the photosensitive layer is exposed by irradiation with actinic rays through a mask. The actinic rays may be ultraviolet light, visible light, or radioactive rays, and may be g-rays, h-rays, i-rays, or a combination thereof.

[0061] By developing to remove a portion of the photosensitive layer, a resin film (insulating resin film) having a pattern including openings is formed. A developer may be used for the development. Examples of development using a developer include shower development, spray development, immersion development, and puddle development. The resin film (insulating resin film) after development may be washed with water or the like.

[0062] The developer may be an alkaline aqueous solution. The alkaline aqueous solution may contain one or more bases selected from sodium carbonate, sodium hydroxide, potassium hydroxide, sodium silicate, ammonia, ethylamine, diethylamine, triethylamine, triethanolamine, and tetramethylammonium hydroxide (TMAH). The concentration of the base in the alkaline aqueous solution may be 0.1 to 10% by mass based on the mass of the alkaline aqueous solution. The developer may contain alcohol or a surfactant.

[0063] By heating the resin film (insulating resin film) that is the photosensitive layer remaining after development, an insulating resin film that is a resin film containing a thermoset product of the photosensitive resin composition is formed mainly by a reaction between the alkali-soluble resin and the thermal crosslinking agent. The heating temperature may be 300°C or less, 270°C or less, or 250°C or less, or may be 160°C or more. The heating time may be, for example, 0.5 hours or more and 5 hours or less.

[0064] The resin film (insulating resin film) can be heated using a heating device such as a quartz tube furnace, a hot plate, a rapid thermal annealer, a vertical diffusion furnace, an infrared curing furnace, an electron beam curing furnace, a microwave curing furnace, a microwave curing device, a frequency-variable microwave curing device, etc. The heating atmosphere may be, for example, an air atmosphere or an inert gas atmosphere containing nitrogen or the like.

[0065] The insulating resin film may be, for example, an insulating layer constituting a wiring portion of a semiconductor device. The semiconductor device may have a semiconductor chip, a conductor wiring layer connected to the semiconductor chip, and a wiring portion (rewiring portion) including one or more insulating layers, and at least a portion of the one or more wiring layers may be an insulating resin film including a cured product of the photosensitive resin composition according to the present disclosure.

[0066] FIG. 2 is a partial cross-sectional view showing an example of a semiconductor device having an insulating layer. The semiconductor device 100 shown in FIG. 2 includes a semiconductor chip 10 and a wiring section 20 provided on the semiconductor chip 10. The wiring section 20 includes a conductor wiring layer 31 connected to the semiconductor chip 10, a surface protective layer 41, a cover coat layer 42, and conductive balls 50. The semiconductor device 100 may be a semiconductor package having a wafer-level package (WLP) configuration. The surface protective layer 41 and the cover coat layer 42 are stacked in this order from the semiconductor chip 10 side, and the conductive balls 50 are provided outside the cover coat layer 42. The surface protective layer 41 and the cover coat layer 42 are insulating layers, and one or both of them may be an insulating resin film containing a cured product of the photosensitive resin composition according to the present disclosure.

[0067] The semiconductor chip 10 has a chip main body 11 having a circuit surface, pads 12 provided on the circuit surface of the chip main body 11, and a protective film 13 having a pattern including openings through which the pads 12 are exposed. The conductor wiring layer 31 of the wiring section 20 is a rewiring layer connected to the pads 12 and extends to the inside of the conductive balls 50 between a surface protective layer 41 and a cover coat layer 42. A connection section 32 for connecting to the conductive balls 50 is provided on an end of the conductor wiring layer 31. A barrier metal 33 is provided between the connection section 32 and the conductive balls 50. The pads 12, conductor wiring layer 31, connection section 32, barrier metal 33, and conductive balls 50 are electrically connected in this order.

[0068] The wiring portion (rewiring portion) of the semiconductor device may have multiple conductor wiring layers, and an insulating resin film containing a cured product of the photosensitive resin composition according to the present disclosure may be provided as an interlayer insulating layer provided between adjacent conductor wiring layers. In the semiconductor device, the interlayer insulating layer, the surface protective layer, or both of them may be an insulating resin film containing a cured product of the photosensitive resin composition according to the present disclosure.

[0069] The semiconductor device may be a memory. Examples of electronic devices including the semiconductor device according to the present disclosure include mobile phones, smartphones, tablet terminals, personal computers, and hard disk drives.

[0070] The present invention is not limited to the following examples.

[0071] 1. Raw materials The following raw materials were prepared. (A) Alkali-soluble resin A1-1: Novolak resin having a phenolic hydroxyl group and an imide group (a reaction product of bis(2-hydroxy-5-methylphenyl)-4,4'-oxyphthalimide (a compound represented by formula (I-1)) and 1,4-bismethoxymethylbenzene using an acid catalyst, weight-average molecular weight: 30,000).

[0072] A1-2: Novolak resin having a phenolic hydroxyl group and an imide group (a reaction product of bis(2-hydroxyphenyl)-4,4'-oxyphthalimide (a compound represented by formula (II-1)) and 1,4-bismethoxymethylbenzene using an acid catalyst, weight average molecular weight: 36,000)

[0073] A1-3: Novolak resin having a phenolic hydroxyl group and an imide group (a reaction product of bis(3-hydroxyphenyl)-4,4'-oxyphthalimide (a compound represented by formula (II-2)) and 1,4-bismethoxymethylbenzene using an acid catalyst, weight average molecular weight: 72,000)

[0074] A2-1: Novolak resin having a phenolic hydroxyl group and an imide group (a reaction product of N,N'-bis(2-hydroxy-5-methylphenyl)-4,4'-biphthalimide (a compound represented by formula (I-2)) and 1,4-bismethoxymethylbenzene in the presence of an acid catalyst, weight average molecular weight: 13,000)

[0075] A2-2: Novolak resin having a phenolic hydroxyl group and an imide group (a reaction product of N,N'-bis(3-hydroxyphenyl)-4,4'-biphthalimide (a compound represented by formula (II-3)) and 1,4-bismethoxymethylbenzene using an acid catalyst, weight average molecular weight: 78,000)

[0076] (B) Photoacid generator B1: 1-naphthoquinone-2-diazide-5-sulfonic acid ester of 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane (esterification rate: approximately 90%, manufactured by Daito ChemiX Co., Ltd., product name "PA28")

[0077] (C) Thermal crosslinking agent C1: 4,4'-[1-[4-[1-[4-hydroxy-3,5-bis(methoxymethyl)phenyl]-1-methylethyl]phenyl]ethylidene]bis[2,6-bis(methoxymethyl)phenol] (represented by formula (42), R ４０ is a methoxymethyl group, manufactured by Honshu Chemical Industry Co., Ltd., trade name "HMOM-TPPA")

[0078] (D) Adhesion aid D1: 5-aminotetrazole (manufactured by Toyobo Co., Ltd., trade name "HAT")

[0079] (E) Silane coupling agent E1: 3-glycidyloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name "KBM403")

[0080] 2. Photosensitive Resin Composition Each component was mixed with ethyl lactate and γ-butyrolactone to obtain the compounding ratio (parts by mass) shown in Table 1 or Table 2. The mixture was filtered under pressure through a polytetrafluoroethylene filter with 0.2 μm pores to prepare a photosensitive resin composition.

[0081] 3. Evaluation 3-1. Breaking elongation and breaking strength of insulating resin film (cured film) A photosensitive resin composition was applied to a silicon substrate by spin coating. The coating was heated at 120°C for 3 minutes to remove the solvent, forming a photosensitive layer with a film thickness of 8 to 9 μm. Next, the photosensitive layer was exposed to light of all wavelengths through a mask using an aligner (manufactured by SUSS MicroTec K.K., product name "MA-8"). The exposure dose was 1500 mJ / cm. ２After exposure, an insulating resin film having a pattern including 10 mm-wide linear portions was formed by development using a 2.38% TMAH aqueous solution. The formed insulating resin film was heated in an inert gas oven (INH-9CD-S) under a nitrogen atmosphere, with the temperature increased to 230°C over 1 hour and maintained at 230°C for 2 hours, thereby promoting curing of the insulating resin film. The thickness of the cured insulating resin film after heating was approximately 7 μm.

[0082] A 10 mm wide strip-shaped test piece was prepared from the cured film peeled from the silicon substrate. A tensile test of the test piece was performed using an autograph AGS-100NX manufactured by Shimadzu Corporation. In the tensile test, the chuck distance was 20 mm, the tensile speed was 5 mm / min, and the temperature of the measurement environment was room temperature (20°C to 25°C). From the results of the tensile test, the average values ​​measured for six test pieces obtained from cured films prepared under the same conditions were recorded as the breaking elongation and breaking strength.

[0083] 3-2. Tack after development The insulating resin film formed in "3-1. Breaking elongation and breaking strength of insulating resin film (cured film)" was checked for the presence or absence of tack by touch immediately after development and about 30 minutes after development. The degree of tack on the surface of the insulating resin film after development was judged according to the following criteria: A: No tack immediately after development B: Tack present immediately after development, but no tack after aging C: Tack present immediately after development and after aging

[0084]

[0085]

[0086] The evaluation results, along with the structures of the hydroxyphenyl groups of the bisphenolimide compounds constituting the alkali-soluble resins, are shown in Tables 1 and 2. As shown in Tables 1 and 2, it was confirmed that the photosensitive resin compositions of the examples exhibited large elongation at break and strength at break, and were capable of forming insulating resin films having surfaces with little tack immediately after development.

[0087] 10...semiconductor chip, 11...chip main body portion, 12...pad portion, 13...protective film, 20...wiring portion, 31...conductor wiring layer, 32...connection portion, 33...barrier metal, 41...surface protection layer (insulating resin film), 42...cover coat layer (insulating resin film), 50...conductive ball, 100...semiconductor device

Claims

1. A composition comprising: (A) an alkali-soluble resin; (B) a photoacid generator which is a compound that generates an acid by exposure to light; and (C) a thermal crosslinker which is a compound that crosslinks the alkali-soluble resin by heat, wherein the alkali-soluble resin is represented by the following formula (I): a structural unit which is a group obtained by removing one or more hydrogen atoms from a bisphenolimide compound represented by the formula: １ is a tetravalent organic group, and R １ and R ２ are each independently represented by the following formula (1a) or (1b): is a hydroxyphenyl group represented by R ３ and R ４ are each independently an alkyl group having 1 to 3 carbon atoms.

2. The bisphenolimide compound is represented by the following formula (I'): is a compound represented by R １ and R ２ is R in formula (I) １ and R ２ is defined similarly to Z ２ The positive photosensitive resin composition according to claim 1 , wherein is a divalent organic group or a covalent bond.

3. The positive photosensitive resin composition according to claim 1, wherein the alkali-soluble resin comprises a novolak resin which is a reaction product of a phenolic compound, including the bisphenolimide compound, with one or more reactive compounds selected from the group consisting of an aldehyde compound, a compound having multiple methoxymethyl groups, and a compound having multiple hydroxymethyl groups.

4. The positive photosensitive resin composition according to claim 3, wherein the proportion of the bisphenolimide compound is 10 mol % or more and 100 mol % or less based on the total amount of the phenol compounds.

5. The positive photosensitive resin composition according to claim 1, wherein the thermal crosslinking agent comprises an alkoxy compound having a plurality of alkoxy groups.

6. A method for forming an insulating resin film, comprising: exposing a part of a photosensitive layer containing the positive photosensitive resin composition according to any one of claims 1 to 5; forming an insulating resin film having a pattern including openings by developing to remove a part of the photosensitive layer; and heating the insulating resin film.

7. An insulating resin film comprising a cured product of the positive photosensitive resin composition according to any one of claims 1 to 5, and having a pattern including openings.

8. A semiconductor device comprising: a semiconductor chip; and a wiring section including a conductor wiring layer connected to the semiconductor chip and one or more insulating layers, wherein at least a portion of the one or more insulating layers is the insulating resin film according to claim 7.

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