JPWO2017038828A1 - Positive photosensitive resin composition, uncured resin pattern formed from the resin composition, cured resin pattern, semiconductor device using the same, and manufacturing method thereof - Google Patents

Abstract

（一般式（１）中、Ａはヘテロ原子を含まない４価の単環式または二環式の芳香族炭化水素基を表し、２種類以上を用いてもよい。）
【化２】

（一般式（２）中、ＢはＯ、Ｓ、ＳＯ_２、ＣＨ_２、ＣＨ（ＣＨ_３）、Ｃ（ＣＨ_３）_２、Ｃ（ＣＦ_３）_２から選択される基を表し、これらを２種類以上用いてもよい。）
【化３】

【選択図】なしHigh sensitivity to i-line of mercury lamp, excellent chemical resistance to strong acidic aqueous solution and strong alkaline aqueous solution, especially to obtain cured resin pattern with excellent adhesion reliability with aluminum pad even in electroless plating process after O ₂ ashing It is an object of the present invention to provide a positive photosensitive resin composition that can be used, a resin pattern using the composition, and a semiconductor manufacturing method using the same.
(A) an alkali-soluble resin, (b) a quinonediazide compound, and (a) the alkali-soluble resin is
(A1) The tetracarboxylic acid residue represented by the general formula (1) is 5 to 50 mol% in the total tetracarboxylic acid residues, and the diamine residue represented by the general formula (2) is the total diamine. A polyimide precursor having 10 to 80 mol% in the residues and further having 10 to 90 mol% of the diamine residues represented by the formula (3) in all diamine residues,
And / or (a2) polyimide corresponding to (a1),
A positive photosensitive resin composition comprising:
[Chemical 1]

(In general formula (1), A represents a tetravalent monocyclic or bicyclic aromatic hydrocarbon group containing no hetero atom, and two or more types may be used.)
[Chemical formula 2]

(In the general formula (2), B represents _{O, S, SO 2, CH} 2, CH (CH 3), a _{C (CH 3) 2, C} (CF 3) groups selected from _2, these two More than one type may be used.)
[Chemical 3]

[Selection figure] None

Description

  The present invention relates to a positive photosensitive resin composition, an uncured resin pattern formed from the resin composition, a cured resin pattern, a semiconductor device using the same, and a method for manufacturing the same. Specifically, the present invention relates to a positive photosensitive resin composition that is suitably used for a surface protective film of a semiconductor element, an interlayer insulating film, an insulating layer of an organic electroluminescent element, and the like.

  For semiconductor device surface protection film and interlayer insulation film, organic electroluminescence device insulation layer and TFT substrate flattening film, polyimide resin, polybenzoxazole resin, polyamideimide resin with excellent heat resistance and mechanical properties, etc. Resins are widely used. Conventionally, a coating film is first formed in the state of a heat-resistant resin precursor having high solubility in an organic solvent, and then a desired pattern is formed using a photoresist based on a novolak resin or the like. A method has been adopted in which the body is heat-cured to obtain an insoluble and infusible heat-resistant resin.

  In recent years, the photoresist process has been simplified by using a negative-type or positive-type photosensitive resin composition that itself can be processed to form a desired pattern.

  In addition, from the viewpoint of reducing the size, weight, functionality, and cost of electronic devices, surface mount semiconductors that have introduced an electroless plating process that forms a nickel and gold layer on the pad portion of a semiconductor wafer by electroless plating. The number of wafers is increasing. In this electroless plating process, there is a zincate treatment in which the treatment is performed with a strong alkaline aqueous solution having a pH of 12 or more, and a positive photosensitive resin composition excellent in resistance to the strong alkaline aqueous solution is required.

  However, it has been difficult for conventional positive photosensitive resin compositions to simultaneously satisfy the performance of high sensitivity to i-line of a mercury lamp and excellent resistance to strong alkaline aqueous solution. In particular, in a structure in which the peripheral portion of the aluminum pad is covered with the cured resin pattern, there is a problem that peeling occurs between the aluminum pad and the cured resin pattern, and reliability is lowered.

  For such a problem, a positive photosensitive resin composition (see Patent Document 1) containing an alkali-soluble resin, a photosensitive agent, and a thermal base generator, a hydroxystyrene resin, a specific phenol resin, and a photoacid generator, A positive photosensitive resin composition containing a solvent (see Patent Document 2), an alkali-soluble resin, a photoacid generator, and a solvent, having a glass transition temperature after curing of 200 ° C. or higher and an internal stress of 40 MPa or less. Type photosensitive resin compositions (see Patent Document 3) have been proposed.

JP 2013-152381 A (page 1-2) JP 2014-211151 A (page 1-3) Japanese Patent Laying-Open No. 2015-7675 (page 1-3)

However, in actual manufacturing, in order to improve the yield of the zincate process, the O ₂ ashing process is performed before the electroless plating process, and the residue in the pad opening is removed.

In the prior art, since the O ₂ ashing resistance of the resin is insufficient, there has been a problem that peeling occurs between the aluminum pad and the cured resin pattern due to the zincate treatment in the subsequent electroless plating process.

The present invention has been made in view of the above problems, and is highly sensitive to i-line of a mercury lamp, excellent in chemical resistance to strong acidic aqueous solution and strong alkaline aqueous solution, and particularly in an electroless plating process that has undergone O ₂ ashing. It is an object to provide a positive photosensitive resin composition capable of obtaining a cured resin pattern having excellent adhesion reliability with a pad, a resin pattern using the resin composition, and a method for producing a semiconductor using the same. .

In order to solve the above problems, the positive photosensitive resin composition of the present invention has the following constitution.
[1] containing (a) an alkali-soluble resin, and (b) a quinonediazide compound, wherein (a) the alkali-soluble resin is
(A1) The tetracarboxylic acid residue represented by the general formula (1) is 5 to 50 mol% in the total tetracarboxylic acid residues, and the diamine residue represented by the general formula (2) is the total diamine. A polyimide precursor having 10 to 80 mol% in the residues and further having 10 to 90 mol% of the diamine residues represented by the general formula (3) in all diamine residues,
And / or (a2) polyimide corresponding to (a1),
A positive photosensitive resin composition comprising:

(In general formula (1), A represents a tetravalent monocyclic or bicyclic aromatic hydrocarbon group containing no hetero atom, and two or more types may be used.)

(In General Formula (2), B represents a group selected from O, S, SO ₂ , CH ₂ , CH (CH ₃ ), C (CH ₃ ) ₂ , and C (CF ₃ ) ₂ , Two or more types may be used.)

[2] The positive photosensitive resin composition according to [1], which includes the polyimide precursor (a1) as the alkali-soluble resin (a) and has an imide ring closure rate of 5 to 25%.
[3] The positive photosensitive resin composition according to [1] or [2], further comprising (c) a thermal crosslinking agent.
[4] An uncured resin pattern formed from the positive photosensitive resin composition according to any one of [1] to [3].
[5] A cured resin pattern obtained by curing the uncured resin pattern according to [4].
[6] A semiconductor device in which the cured resin pattern according to [5] is disposed on a semiconductor element.
[7] The semiconductor device according to [6], wherein the cured resin pattern has an opening, and at least one of the openings is disposed on a pad having aluminum or an aluminum alloy.
[8] The semiconductor device according to [7], wherein an under bump metal is disposed on an upper portion of the pad having aluminum or an aluminum alloy.
[9] The semiconductor device according to [8], wherein the under bump metal has a nickel element of 60 mass% or more and 99.9 mass% or less.
[10] The semiconductor device according to [8] or [9], wherein a protective layer of gold element is provided on the surface of the under bump metal.
[11] The pad having aluminum or aluminum alloy and the external electrode are connected to each other by any one of a solder bump, a gold wire, and a copper wire through the under bump metal. The semiconductor device described.
[12] The semiconductor device according to any one of [6] to [11], wherein the thickness of the cured resin pattern is 3.0 μm or more and 15.0 μm or less.
[13] A method for manufacturing the semiconductor device according to any one of [6] to [12],
A step of treating the semiconductor element having the cured resin pattern with a strongly acidic liquid having a pH of 2 or less, a step of treating with a strong alkaline liquid having a pH of 12 or more, a step of treating with a flux solution, and a step of treating with an electrolytic plating solution. And a method for manufacturing a semiconductor device, comprising at least one step selected from the step of treating with an electroless plating solution.
[14] The solution is an electrolytic plating solution or an electroless plating solution,
The method for manufacturing a semiconductor device according to [13], further including a step of plating growth of a first type of metal or alloy and a step of plating growth of a second type of metal or alloy different from the first type.

The positive photosensitive resin composition of the present invention is highly sensitive to i-line and excellent in chemical resistance against strong acidic aqueous solution and strong alkaline aqueous solution. In particular, it is in close contact with an aluminum pad even in an electroless plating process after O ₂ ashing. A resin pattern having excellent reliability and a semiconductor using the resin pattern can be obtained.

It is a schematic diagram of the cross section showing an example of the semiconductor device of this invention. It is a schematic diagram of the cross section showing another example of the semiconductor device of this invention.

  The positive photosensitive resin composition of the present invention contains (a) an alkali-soluble resin and (b) a quinonediazide compound, and the (a) alkali-soluble resin is represented by (a1) the general formula (1). Having 5-50 mol% of tetracarboxylic acid residues in all tetracarboxylic acid residues, 10-80 mol% of diamine residues represented by the general formula (2) in all diamine residues, Furthermore, the polyimide precursor which has 10-90 mol% of diamine residues represented by the said General formula (3) in all diamine residues, and / or (a2) The polyimide corresponding to said (a1) is contained. Here, the polyimide corresponding to (a1) represents one in which (a1) is closed to become a polyimide. For convenience, hereinafter, “a polyimide precursor having a structure of (a1) and / or a polyimide having a structure of (a2)” will be referred to as “a polyimide of (a1,2) (precursor)”, and “polyimide precursor and / or Or “polyimide” is expressed as “polyimide (precursor)”, and the residues of tetracarboxylic acid and diamine constituting “polyimide (precursor) of (a1,2)” are represented by “(a1,2)”. This is expressed as “monomer residue of polyimide (precursor)”.

  In the present invention, (a) the monomer residues of (a1, 2) polyimide (precursor) contained as an alkali-soluble resin and their ratios are important, and the estimated mechanism and preferred ratios are described below.

The residue of tetracarboxylic acid represented by polyimide Formula contained in the (precursor) (1) of the (a1,2) does not include the rigid and the other functional groups, the resin film during O ₂ ashing It is thought that surface oxidation is suppressed, and this suppresses deterioration of chemical resistance after O ₂ ashing.

The tetracarboxylic acid residue represented by the general formula (1) is contained in an amount of 5 mol% or more in all tetracarboxylic acid residues from the viewpoint of expressing the effect of suppressing the surface oxidation of the resin film during O ₂ ashing. Preferably, it is contained in an amount of 7 mol% or more, more preferably 9 mol% or more. On the other hand, from the viewpoint of maintaining high sensitivity, it is preferably 50 mol% or less, more preferably 45 mol% or less, and even more preferably 40 mol% or less in the total tetracarboxylic acid residues. Any tetracarboxylic acid residue other than that represented by the general formula (1) may be used.

A diamine having a higher molecular weight was used because the residue of the diamine represented by the general formula (2) contained in the polyimide (precursor) of (a1, 2) was a dinuclear body and a relatively low molecular weight. The ratio of the imide (precursor) unit of the entire polyimide (precursor) resin (a1,2) compared to the case is kept high, which is the same as the residue of the general formula (1) during O ₂ ashing. It is thought to suppress the surface oxidation of the film, thereby suppressing the deterioration of chemical resistance after O ₂ ashing. Furthermore, the residue of the diamine represented by the general formula (2) also has the effect of suppressing light absorption by breaking the π-conjugated system of two benzene rings in the molecule, and the sensitivity during exposure is reduced. Suppressed, these contribute to both chemical resistance and high sensitivity after O ₂ ashing.

The diamine residue represented by the general formula (2) is preferably contained in an amount of 10 mol% or more in all diamine residues from the viewpoint of expressing the surface oxidation suppression effect of the resin film during O ₂ ashing. More preferably, it is contained in an amount of 12 mol% or more, more preferably 15 mol% or more. On the other hand, from the viewpoint of maintaining high sensitivity, it is preferably 80 mol% or less, more preferably 70 mol% or less, still more preferably 60 mol% or less, and particularly preferably 50 mol% or less in all diamine residues.

Residue of diamine represented by the general formula (3) contained in the polyimide (precursor) of (a1,2) is moderately alkaline developable and organic solvent for the polyimide (precursor) of resin (a1,2) Adding the solubility increases the sensitivity of the positive photosensitive resin composition and improves the storage stability. The diamine residue represented by the general formula (3) is preferably contained in an amount of 10 mol% or more in the total diamine residues from the viewpoint of expressing the effects of increasing sensitivity and improving storage stability, It is more preferably contained, more preferably 20 mol% or more, and particularly preferably 25 mol% or more. On the other hand, from the viewpoint of suppressing deterioration in chemical resistance after O ₂ ashing, it is preferably 90 mol% or less, more preferably 85 mol% or less, still more preferably 80 mol% or less, in all diamine residues, 75 A mol% or less is particularly preferred.

In the polyimide (precursor) of (a1, 2), the total amount of the diamine residue represented by the general formula (2) and the diamine residue represented by the formula (3) is based on the total diamine residue. 20 to 100 mol%. By being 20 mol% or more, it becomes possible to suppress high sensitivity and deterioration of chemical resistance after O ₂ ashing. From this viewpoint, it is preferably 30 mol% or more, more preferably 35 mol% or more, Preferably it is 40 mol% or more.

  In the structure of the general formula (1) contained in the polyimide (precursor) of (a1, 2), A represents a tetravalent monocyclic or bicyclic aromatic hydrocarbon group containing no hetero atom. Examples of these aromatic hydrocarbon groups include, but are not limited to, groups derived from a benzene ring, a cyclotetradecaheptaene ring, a cyclooctadecanaene ring, a naphthalene ring, and an azulene ring. Of these, groups derived from a benzene ring, a naphthalene ring, and an azulene ring are preferably used from the viewpoint of chemical stability.

  Preferable examples of the general formula (1) include, but are not limited to, the following (A-1) group structures, and two or more of these may be used.

  Among these, particularly preferable structures include the structures of the following group (A-2), and two or more of these may be used.

In the structure of the general formula (2) contained in the polyimide (precursor) of (a1, 2), B is O, S, SO ₂ , CH ₂ , CH (CH ₃ ), C (CH ₃ ) ₂ , C A group selected from (CF ₃ ) ₂ is represented, and two or more of these may be used. Preferred examples of B include O, S, SO ₂ , CH ₂ and C (CF ₃ ) ₂ , and particularly preferred examples include O, S, SO ₂ and CH ₂ .

  Examples of the alkali-soluble resin (a) that is an alkali-soluble resin of the present invention include, for example, polyimide, polybenzoxazole, polyamideimide, or a precursor thereof, a copolymer thereof, a carboxyl group-containing resin, and a novolac. Examples include, but are not limited to, phenolic resins such as polyhydroxystyrene and resole. These include (a1,2) polyimide (precursor). The polyimide (precursor) of (a1, 2) may be a copolymer of these resins. Two or more of these resins may be contained.

In the case of using an alkali-soluble resin that does not correspond to the polyimide (precursor) of (a1, 2), the content thereof is 60% of the total amount of (a) alkali-soluble resin in order to maintain chemical resistance after O ₂ ashing. It is preferably at most mass%, more preferably at most 50 mass%, further preferably at most 45 mass%. Among them, a phenol group resin such as carboxyl group-containing resin, novolak, polyhydroxystyrene, and resol has low chemical resistance after O ₂ ashing, and therefore the preferred amount used is (a) 45% by mass of the entire alkali-soluble resin. Hereinafter, it is more preferably 40% by mass or less, and further preferably 35% by mass or less.

  Examples of the polyimide precursor preferably used as the (a) alkali-soluble resin of the present invention include polyamic acid, polyamic acid ester, polyamic acid amide, and polyisoimide. For example, the polyamic acid can be obtained by reacting a tetracarboxylic acid, a corresponding tetracarboxylic dianhydride and the like with a diamine, a corresponding diisocyanate compound, and a trimethylsilylated diamine. In order to obtain an appropriate molecular weight, a part of the diamine may be replaced with a monoamine which is an end-capping agent, and similarly, a part of tetracarboxylic dianhydride is an acid anhydride or a mono-acid chloride which is an end-capping agent. A compound or a monoactive ester compound may be substituted. In addition, the polyamic acid ester is prepared by using a method using tetracarboxylic acid diester dichloride instead of tetracarboxylic acid in the above method, or N, N-dimethylformamide dimethyl acetal, N, N for the polyamic acid obtained by the above method. -It can obtain by alkylesterifying a part or all of carboxylic acid using well-known alkyl esterifying agents, such as a dimethylformamide diethyl acetal. The polyimide can be obtained, for example, by dehydrating and ring-closing the polyamic acid obtained by the above method by heating or chemical treatment such as acid or base.

  (A) As an example of the tetracarboxylic acid corresponding to the preferable tetracarboxylic acid residue contained in the polyimide (precursor) of the alkali-soluble resin, in addition to the structure of the group (A-1), 3, 3 ′, 4, 4'-biphenyltetracarboxylic acid, 2,3,3 ', 4'-biphenyltetracarboxylic acid, 2,2', 3,3'-biphenyltetracarboxylic acid, 3,3 ', 4,4'-benzophenone tetra Carboxylic acid, 2,2 ′, 3,3′-benzophenone tetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane, 2,2-bis (2,3-dicarboxyphenyl) Hexafluoropropane, 1,1-bis (3,4-dicarboxyphenyl) ethane, 1,1-bis (2,3-dicarboxyphenyl) ethane, bis (3,4-dicarboxy) Enyl) methane, bis (2,3-dicarboxyphenyl) methane, bis (3,4-dicarboxyphenyl) sulfone, bis (3,4-dicarboxyphenyl) ether, 2,3,5,6-pyridinetetra Aromatic tetracarboxylic acid such as carboxylic acid, 3,4,9,10-perylenetetracarboxylic acid, aliphatic tetracarboxylic acid such as butanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, etc. Can be mentioned. These tetracarboxylic acids can be used as they are or as acid anhydrides, active esters and the like. Moreover, you may use combining these 2 or more types of tetracarboxylic acid.

  (A) As an example of the diamine corresponding to the preferable diamine residue contained in the polyimide (precursor) of the alkali-soluble resin, in addition to the diamine having the structure of the general formula (2) and the formula (3), 2,2- Bis (3-amino-4-hydroxyphenyl) hexafluoropropane, bis (3-amino-4-hydroxyphenyl) sulfone, 2,2-bis (3-amino-4-hydroxyphenyl) propane, bis (3-amino -4-hydroxyphenyl) methane, bis (3-amino-4-hydroxyphenyl) ether, 3,3'-diamino-4,4'-biphenol, 9,9-bis (3-amino-4-hydroxyphenyl) Hydroxyl group-containing diamines such as fluorene, sulfonic acid groups such as 3-sulfonic acid-4,4′-diaminodiphenyl ether Thiol group-containing diamines such as amine and dimercaptophenylenediamine, 1,4-bis (4-aminophenoxy) benzene, benzidine, m-phenylenediamine, p-phenylenediamine, 1,5-naphthalenediamine, 2,6-naphthalene Diamine, bis (4-aminophenoxyphenyl) sulfone, bis (3-aminophenoxyphenyl) sulfone, bis (4-aminophenoxy) biphenyl, bis {4- (4-aminophenoxy) phenyl} ether, 2,2′- Dimethyl-4,4′-diaminobiphenyl, 2,2′-diethyl-4,4′-diaminobiphenyl, 3,3′-dimethyl-4,4′-diaminobiphenyl, 3,3′-diethyl-4,4 '-Diaminobiphenyl, 2,2', 3,3'-tetramethyl-4,4'-dia Aromatic diamines such as nobiphenyl, 3,3 ′, 4,4′-tetramethyl-4,4′-diaminobiphenyl, 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl, Compounds in which some of the hydrogen atoms of these aromatic rings are substituted with alkyl groups having 1 to 10 carbon atoms, fluoroalkyl groups, halogen atoms, etc., 2,4-diamino-1,3,5-triazine (guanamine) Nitrogen-containing heteroaromatics such as 2,4-diamino-6-methyl-1,3,5-triazine (acetoguanamine), 2,4-diamino-6-phenyl-1,3,5-triazine (benzoguanamine) Diamine having a ring, 1,3-bis (3-aminopropyl) -1,1,3,3-tetramethyldisiloxane, 1,3-bis (p-aminophenyl) -1,1,3,3- Tet Lamethyldisiloxane, 1,3-bis (p-aminophenethyl) -1,1,3,3-tetramethyldisiloxane, 1,7-bis (p-aminophenyl) -1,1,3,3 In addition to silicone diamines such as 5,5,7,7-octamethyltetrasiloxane, alicyclic diamines such as cyclohexyl diamine and methylenebiscyclohexylamine, aliphatic diamines may be used, for example, containing polyethylene oxide groups As diamines, Jeffamine (registered trademark) KH-511, Jeffamine ED-600, Jeffamine ED-900, Jeffamine ED-2003, Jeffamine EDR-148, Jeffamine EDR-176, D of polyoxypropylenediamine -200, D-400, D-2000, D-4000 (hereinafter In addition, trade names, available from HUNTSMAN Co., Ltd.) and the like.

  These diamines can be used as they are or as the corresponding diisocyanate compounds and trimethylsilylated diamines. These two or more diamines may be used in combination.

In order not to impair the chemical resistance after O ₂ ashing, it is preferable to use an aromatic diamine in an amount of 50 mol% or more of the total diamine.

  In order to improve the storage stability of the positive photosensitive resin composition, (a) the polyimide (precursor) resin of the alkali-soluble resin has a main chain terminal at the monoamine, acid anhydride, monocarboxylic acid, monoacid chloride compound. It is preferable to seal with a terminal blocking agent such as a monoactive ester compound.

  The introduction ratio of the monoamine used as the terminal blocking agent is preferably 0.1 mol% or more, particularly preferably 5 mol% or more, based on the total amine component. On the other hand, the molecular weight of the polyimide (precursor) is preferably 60 mol% or less, particularly preferably 50 mol% or less, in terms of maintaining a high molecular weight.

  The introduction ratio of the acid anhydride, monocarboxylic acid, monoacid chloride compound or monoactive ester compound used as the end-capping agent is preferably 0.1 mol% or more, more preferably 5 mol%, relative to the diamine component. Further, it is preferably 100 mol% or less, more preferably 90 mol% or less. A plurality of different end groups may be introduced by reacting a plurality of end-capping agents.

  For the purpose of improving the chemical resistance of the cured resin pattern obtained by baking, as these end-capping agents, monoamines having at least one alkenyl group or alkynyl group, acid anhydrides, monocarboxylic acids, monoacid chloride compounds, Mono-active ester compounds can also be used.

The end-capping agent introduced into the resin can be easily detected by the following method. For example, a resin into which a terminal blocking agent has been introduced is dissolved in an acidic solution and decomposed into an amine component and an acid component, which are constituent units of the resin, and this is decomposed into gas chromatography (GC) or nuclear magnetic resonance (NMR). By measuring, the end-capping agent can be easily detected. Apart from this, it is possible to detect the resin into which the end-capping agent has been introduced by directly measuring by pyrolysis gas chromatography (PGC), infrared spectrum and ¹³ C-NMR spectrum.

(A) In a polyimide (precursor) used as an alkali-soluble resin, when a molar ratio of imide ring-closing units to all imide (precursor) units is defined as an imide ring closing rate (R _IM (%)), R _IM Can be preferably used in the whole range of 0% to 100%. When using a polyamic acid ester, _RIM is preferably 3% or more, more preferably 5% or more from the viewpoint of increasing storage stability, and preferably 70% or less, more preferably 50%, from the viewpoint of increasing sensitivity. Hereinafter, it is more preferably 25% or less.

The imide ring closing rate (R _IM (%)) can be easily determined by the following method, for example. First, measuring the infrared absorption spectrum of the polymer, the absorption peak (1780 cm around ^-1, 1377 cm around ^-1) of an imide structure caused by a polyimide confirmed the presence of, determine the peak intensity at around 1377 cm ^-1 (X) . Next, the polymer is heat-treated at 350 ° C. for 1 hour, an infrared absorption spectrum is measured, and a peak intensity (Y) near 1377 cm ⁻¹ is obtained. These peak intensity ratios correspond to the content of imide groups in the polymer before heat treatment, that is, the imide ring closure rate (R _IM = X / Y × 100 (%)).

(A) As for the polyamic acid ester used as alkali-soluble resin, all of the carboxyl groups may be esterified, or only some of the carboxyl groups may be esterified. The term “carboxyl group” as used herein refers to a carboxyl group other than the carboxyl residue that constitutes the amide of the main chain of the polyamic acid corresponding to the polyamic acid ester that is neither esterified nor imide-cyclized. In order for the alkali solubility and organic solvent solubility of the resin to be moderate, if the molar ratio of esterified carboxyl groups to total carboxyl groups is defined as the esterification rate (R _E (%)), R _E is preferably It is 20% or more, more preferably 25% or more, preferably 100% or less, more preferably 95% or less.

(A) The ester group of the polyamic acid ester used as the alkali-soluble resin can be expressed as COO-R ₁ . Here, R ₁ represents a monovalent organic group having 1 to 10 carbon atoms. Examples of R ₁ include formyl group, methyl group, ethyl group, propyl group, isopropyl group, tertiary butyl group, tertiary butoxycarbonyl group, phenyl group, benzyl group, tetrahydrofuranyl group, tetrahydropyranyl group, trimethylsilyl group. , Triethylsilyl group and the like, but not limited thereto, and two or more of them may be used.

  The positive photosensitive resin composition of the present invention contains (b) a quinonediazide compound. By containing the quinonediazide compound, an acid is generated in the ultraviolet-exposed area, and the solubility of the exposed area in an alkaline aqueous solution is increased. Therefore, a positive pattern can be obtained by alkali development after the ultraviolet exposure.

  The (b) quinonediazide compound used in the present invention may contain two or more quinonediazide compounds. Thereby, the ratio of the dissolution rate of the exposed part and the unexposed part can be increased, and a highly sensitive positive photosensitive resin composition can be obtained.

  Examples of the (b) quinonediazide compound used in the present invention include those in which a sulfonic acid of quinonediazide is ester-bonded to a polyhydroxy compound, a sulfonic acid of quinonediazide to a sulfonamide bond to a polyamino compound, and a quinonediazide to a polyhydroxypolyamino compound. Examples of the sulfonic acid include ester bonds and / or sulfonamide bonds. Although all the functional groups of these polyhydroxy compounds and polyamino compounds may not be substituted with quinonediazide, it is preferable that 50 mol% or more of the entire functional groups are substituted with quinonediazide. By using such a quinonediazide compound, it is possible to obtain a positive photosensitive resin composition that is sensitive to i-line (365 nm), h-line (405 nm), and g-line (436 nm) of a mercury lamp that is a general ultraviolet ray. .

  In the present invention, the quinonediazide compound is preferably a 5-naphthoquinonediazidesulfonyl group or a 4-naphthoquinonediazidesulfonyl group. A compound having both of these groups in the same molecule may be used, or a compound using different groups may be used in combination.

  The (b) quinonediazide compound used in the present invention can be synthesized by a known method. For example, a method of reacting 5-naphthoquinonediazide sulfonyl chloride and a polyhydroxy compound in the presence of triethylamine can be mentioned.

  The content of the (b) quinonediazide compound used in the present invention is preferably 1 to 60 parts by mass with respect to 100 parts by mass of the (a) alkali-soluble resin. By making content of a quinonediazide compound into this range, high sensitivity can be achieved and mechanical properties such as elongation of a cured resin pattern can be maintained. In order to achieve higher sensitivity, it is preferably 3 parts by mass or more, and preferably 50 parts by mass or less, more preferably 40 parts by mass or less in order not to impair the mechanical properties of the cured resin pattern. Furthermore, you may contain a sensitizer etc. as needed.

  The positive photosensitive resin composition of the present invention preferably further contains (c) a thermal crosslinking agent. (C) As the thermal crosslinking agent, a compound having at least two alkoxymethyl groups and / or methylol groups and a compound having at least two epoxy groups and / or oxetanyl groups are preferably used, but are not limited thereto. By containing these compounds, at the time of baking after patterning, a condensation reaction is caused with (a) the alkali-soluble resin to form a crosslinked structure, and mechanical properties such as elongation of the cured resin pattern are improved. Further, two or more kinds of thermal cross-linking agents may be used, which enables a wider range of designs.

  Preferred examples of the compound having at least two alkoxymethyl groups and / or methylol groups include, for example, DML-PC, DML-PEP, DML-OC, DML-OEP, DML-34X, DML-PTBP, DML-PCHP, DML-OCHP, DML-PFP, DML-PSBP, DML-POP, DML-MBOC, DML-MBPC, DML-MTrisPC, DML-BisOC-Z, DML-BisOCHP-Z, DML-BPC, DML-BisOC-P, DMOM-PC, DMOM-PTBP, DMOM-MBPC, TriML-P, TriML-35XL, TML-HQ, TML-BP, TML-pp-BPF, TML-BPE, TML-BPA, TML-BPAF, TML-BPAP, TMOM-BP, TM M-BPE, TMOM-BPA, TMOM-BPAF, TMOM-BPAP, HML-TPPHBA, HML-TPHAP, HMOM-TPPHBA, HMOM-TPHAP (above, trade name, manufactured by Honshu Chemical Industry Co., Ltd.), NIKALAC (registered trademark) ) MX-290, NIKALAC MX-280, NIKALAC MX-270, NIKACALAC MX-279, NIKACALAC MW-100LM, NIKACALAC MX-750LM (above, trade name, manufactured by Sanwa Chemical Co., Ltd.) are available from each company. Is possible. Two or more of these may be contained.

  Preferred examples of the compound having at least two epoxy groups and / or oxetanyl groups include, for example, bisphenol A type epoxy resins, bisphenol A type oxetanyl resins, bisphenol F type epoxy resins, bisphenol F type oxetanyl resins, propylene glycol diesters. Examples thereof include, but are not limited to, epoxy group-containing silicones such as glycidyl ether, polypropylene glycol diglycidyl ether, and polymethyl (glycidyloxypropyl) siloxane. Specifically, EPICLON (registered trademark) 850-S, EPICLON HP-4032, EPICLON HP-7200, EPICLON HP-820, EPICLON HP-4700, EPICLON EXA-4710, EPICLON HP-4770, EPICLON EXA-859CRP, EPICLON EXA-1514, EPICLON EXA-4880, EPICLON EXA-4850-150, EPICLON EXA-4850-1000, EPICLON EXA-4816, EPICLON EXA-4822 (above trade names, manufactured by Dainippon Ink & Chemicals, Inc.), Rica Resin ( Registered trademark) BEO-60E (trade name, manufactured by Shin Nippon Rika Co., Ltd.), EP-4003S, EP-4000S (trade name, ADEKA CORPORATION) ) And the like, are available from each company. Two or more of these may be contained.

  The content of the (c) thermal crosslinking agent used in the present invention is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and still more preferably 10 parts per 100 parts by mass of the (a) alkali-soluble resin. From the viewpoint of maintaining mechanical properties such as elongation, it is preferably 300 parts by mass or less, more preferably 200 parts by mass or less.

  The positive photosensitive resin composition of the present invention may contain a solvent as necessary. Preferable examples of the solvent include polar aprotic solvents such as N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, tetrahydrofuran, dioxane, propylene glycol Ethers such as monomethyl ether and propylene glycol monoethyl ether, ketones such as acetone, methyl ethyl ketone and diisobutyl ketone, ethyl acetate, butyl acetate, isobutyl acetate, propyl acetate, propylene glycol monomethyl ether acetate, 3-methyl-3-methoxybutyl Esters such as acetate, ethyl lactate and methyl lactate, alcohols such as diacetone alcohol and 3-methyl-3-methoxybutanol, aroma such as toluene and xylene Such as hydrocarbons. Two or more of these may be contained.

  The content of the solvent is preferably 70 parts by mass or more, more preferably 100 parts by mass or more with respect to (a) 100 parts by mass of the alkali-soluble resin, from the viewpoint of obtaining an appropriate film thickness. The amount is preferably 1800 parts by mass or less, more preferably 1500 parts by mass or less.

  The positive photosensitive resin composition of the present invention may contain a thermal acid generator as necessary. By containing the thermal acid generator, a cured resin pattern having a high crosslinking rate, benzoxazole ring closure rate, and imide ring closure rate can be obtained even when firing at 150 to 300 ° C., which is lower than usual.

  The content of the thermal acid generator preferable for the purpose of manifesting the effect is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more with respect to 100 parts by mass of the (a) alkali-soluble resin. From the viewpoint of maintaining mechanical properties such as elongation, it is preferably 30 parts by mass or less, more preferably 15 parts by mass or less.

  The positive photosensitive resin composition of the present invention may contain a low molecular compound having a phenolic hydroxyl group as long as it does not reduce the shrinkage residual film ratio after curing. By containing the low molecular weight compound having a phenolic hydroxyl group, it is easy to adjust the alkali solubility during pattern processing.

  The content of the low molecular weight compound having a phenolic hydroxyl group that is preferable for the purpose of manifesting the effect is preferably 0.1 parts by mass or more, more preferably 1 part by mass with respect to 100 parts by mass of the (a) alkali-soluble resin. From the viewpoint of maintaining mechanical properties such as elongation, it is preferably 30 parts by mass or less, more preferably 15 parts by mass or less.

  The positive photosensitive resin composition of the present invention is a surfactant, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, alcohols such as ethanol, cyclohexanone for the purpose of improving the wettability with the substrate as necessary. , Ketones such as methyl isobutyl ketone, and ethers such as tetrahydrofuran and dioxane.

  The preferable content of the compound used for the purpose of improving the wettability with these substrates is 0.001 part by mass or more with respect to 100 parts by mass of (a) the alkali-soluble resin, and from the viewpoint of obtaining an appropriate film thickness, Preferably it is 1800 mass parts or less, More preferably, it is 1500 mass parts or less.

  The positive photosensitive resin composition of the present invention may contain inorganic particles. Preferred specific examples include, but are not limited to, silicon oxide, titanium oxide, barium titanate, alumina, talc and the like.

  The primary particle diameter of these inorganic particles is preferably 100 nm or less, particularly preferably 60 nm or less.

  Regarding the primary particle diameter of the inorganic particles, the number average particle diameter may be calculated from the specific surface area. Specific surface area is defined as the sum of the surface areas contained in a unit mass of powder. As a specific surface area measurement method, there is a BET method, which can be measured using a specific surface area measurement device (such as HM model-1201 manufactured by Mounttech).

  It also contains a silane coupling agent such as trimethoxyaminopropyl silane, trimethoxy epoxy silane, trimethoxy vinyl silane, trimethoxy thiol propyl silane as long as storage stability is not impaired in order to enhance adhesion to the silicon substrate. May be.

  The preferred content of the silane coupling agent used for enhancing the adhesion to these silicon substrates is (a) 0.01 parts by mass or more with respect to 100 parts by mass of the alkali-soluble resin, maintaining mechanical properties such as elongation. In view of the above, it is preferably 5 parts by mass or less.

  The viscosity of the positive photosensitive resin composition of the present invention is preferably 2 to 5000 mPa · s. By adjusting the solid content concentration so that the viscosity is 2 mPa · s or more, it becomes easy to obtain a desired film thickness. On the other hand, when the viscosity is 5000 mPa · s or less, it becomes easy to obtain a highly uniform coating film. The resin composition having such a viscosity can be easily obtained by setting the solid content concentration to 5 to 60% by mass, for example.

  Next, a method for forming a resin pattern on a substrate using the positive photosensitive resin composition of the present invention will be described. In the present specification, an uncured pattern formed from the positive photosensitive resin composition of the present invention is referred to as an uncured resin pattern, and a pattern obtained by curing this is referred to as a cured resin pattern. In addition, when simply referred to as a resin pattern, the uncured resin pattern and the cured resin pattern are collectively referred to. The substrate on which the resin pattern is formed is not particularly limited, but the positive photosensitive resin composition of the present invention is preferably used in a semiconductor device, and when used in such applications, a circuit is formed as the substrate. It is preferable to form a resin pattern on a semiconductor element such as a silicon wafer.

First, the positive photosensitive resin composition of the present invention is applied to a substrate. As the substrate, a wafer made of silicon, ceramics, gallium arsenide, or the like on which a metal is formed as an electrode or wiring is used, but is not limited thereto. Examples of the metal used as the electrode and wiring include, but are not limited to, aluminum (Al), Al—Si, Al—Si—Cu, and Cu. In particular, the present invention provides a cured resin pattern having excellent adhesion reliability with an aluminum pad and a semiconductor using the same even in an electroless plating process after O ₂ ashing, and thus a substrate on which an aluminum pad is formed. It is more preferable to use As a coating method for coating the positive photosensitive resin composition of the present invention on a substrate, methods such as spin coating using a spinner, spray coating, and roll coating can be applied. Moreover, although the film thickness at the time of application varies depending on the application method, the solid content concentration of the positive photosensitive resin composition, the viscosity, etc., it is usually applied so that the film thickness after drying is 0.1 to 150 μm. It is preferable.

  In order to enhance the adhesion between the substrate and the positive photosensitive resin composition, the substrate can be pretreated with the above-mentioned silane coupling agent. For example, a silane coupling agent is dissolved in a solvent such as isopropanol, ethanol, methanol, water, tetrahydrofuran, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, ethyl lactate, diethyl adipate at a concentration of 0.5 to 20% by mass. The solution is subjected to surface treatment by spin coating, dipping, spray coating, steam treatment or the like. In some cases, it is also preferable to carry out a heat treatment at 50 to 300 ° C. to advance the reaction between the substrate and the silane coupling agent.

  Next, the substrate coated with the positive photosensitive resin composition is dried to obtain an uncured film (hereinafter also referred to as a pre-baked film) of the positive photosensitive resin composition. Drying is preferably performed using an oven, a hot plate, infrared rays, or the like at 50 to 150 ° C. for 1 minute to several hours.

  Next, exposure is performed by irradiating actinic radiation through a mask having a desired pattern on the uncured film of the positive photosensitive resin composition. As the actinic radiation used for exposure, there are ultraviolet rays, visible rays, electron beams, X-rays and the like. In the present invention, i rays (365 nm), h rays (405 nm) and g rays (436 nm) of a mercury lamp are preferably used. After the exposure, the exposed portion is removed using a developer to form an uncured resin pattern. Developers include tetramethylammonium hydroxide, choline hydroxide, diethanolamine, diethylaminoethanol, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, triethylamine, diethylamine, methylamine, dimethylamine, dimethylaminoethyl acetate, dimethyl An aqueous solution of a compound exhibiting alkalinity such as aminoethanol, dimethylaminoethyl methacrylate, cyclohexylamine, ethylenediamine, and hexamethylenediamine is preferred. In some cases, these alkaline aqueous solutions may contain polar solvents such as N-methyl-2-pyrrolidone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethyl sulfoxide, γ-butyrolactone, dimethylacrylamide, methanol, ethanol, Alcohols such as isopropanol, esters such as ethyl lactate and propylene glycol monomethyl ether acetate, ketones such as cyclopentanone, cyclohexanone, isobutyl ketone, and methyl isobutyl ketone may be added singly or in combination. Good. After development, it is preferable to rinse with water. Here, alcohols such as ethanol and isopropyl alcohol, and esters such as ethyl lactate and propylene glycol monomethyl ether acetate may be added to water for rinsing treatment.

  After development, a predetermined temperature is applied and heat treatment is performed, and a thermal crosslinking reaction, an imide ring-closing reaction, and an oxazole ring-closing reaction are advanced to form a cured resin pattern. By curing, the heat resistance and chemical resistance of the resin pattern can be improved. This heat treatment is preferably carried out for 5 minutes to 5 hours while selecting the temperature and raising the temperature stepwise, or selecting a certain temperature range and continuously raising the temperature. As an example, heat treatment is performed at 150 ° C., 220 ° C., and 320 ° C. for 30 minutes each. Alternatively, a method such as linearly raising the temperature from room temperature to 400 ° C. over 2 hours may be mentioned.

  The preferred thickness of the cured resin pattern formed using the positive photosensitive resin composition of the present invention is 0.1 μm or more and 150 μm or less, but in order to obtain sufficient chemical resistance, more preferably 3.0 μm or more, More preferably, it is 4.0 μm or more, and particularly preferably 4.5 μm or more. In order to increase sensitivity and resolution, it is more preferably 15.0 μm or less, further preferably 8.0 μm or less, particularly preferably 7.0 μm or less. is there.

  The cured resin pattern formed by the positive photosensitive resin composition of the present invention is used for a semiconductor passivation film, a protective film for a semiconductor element, an interlayer insulating film for multilayer wiring for high-density mounting, an insulating layer for an organic electroluminescent element, etc. Is preferably used.

When the resin pattern of the cured film has an opening, an ashing process may be performed using a gas such as O ₂ or Ar after the cured resin pattern is formed. By doing so, organic residue in the cured resin pattern opening can be removed, and for example, the connection reliability of the electrode pad can be improved. Examples of the ashing treatment include, but are not limited to, plasma treatment, reactive ion etching (RIE), and reverse sputtering.

The cured resin pattern of the present invention is particularly excellent in chemical resistance after O ₂ ashing, a strongly acidic liquid having a pH of 2 or less, a strong alkaline liquid having a pH of 12 or more, a flux solution, an electrolytic plating solution, and an electroless plating solution. It is used suitably for manufacture of a semiconductor including the process processed with 1 or more types of liquids selected from these.

  Examples of strongly acidic liquids having a pH of 2 or lower include, but are not limited to, hydrochloric acid, nitric acid, sulfuric acid and the like. In the semiconductor manufacturing process, for example, the zinc layer after the first zincate treatment is removed in the double zincate treatment in which zinc plating is performed on the surface of the aluminum pad in two steps as a pretreatment in the electroless plating on the aluminum pad. In doing so, a strong acid such as dilute nitric acid is used.

  Examples of strong alkaline liquids having a pH of 12 or more include sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, calcium hydroxide aqueous solution, barium hydroxide aqueous solution, tetramethylammonium hydroxide aqueous solution, choline hydroxide aqueous solution and the like. It is not limited to. The zincate treatment liquid described later is also widely used as a strong alkaline liquid having a pH of 12 or more.

  Examples of the flux liquid include, but are not limited to, a rosin-based flux, an organic water-soluble flux, an inorganic water-soluble flux, and the like.

  The electrolytic plating solution and electroless plating solution in the present invention include a solution for temporarily growing a metal or alloy as a pretreatment step. The alloy described in the present invention refers to a metal-like material composed of a plurality of metal elements or a metal element and a non-metal element, and there are various modes such as a solid solution, a eutectic, and an intermetallic compound. include.

  As an example of plating growth of a metal or an alloy as such a pretreatment step, for example, a zincate treatment performed before electroless nickel plating is performed on an aluminum surface.

  Examples of metals or alloys plated with an electrolytic plating solution include, but are not limited to, copper, nickel, gold, Sn-Ag, and the like.

  Examples of metals or alloys plated with the electroless plating solution and its pretreatment solution include, but are not limited to, zinc, nickel, tin, gold, palladium, and the like.

  When a metal or alloy is plated and grown using an electrolytic plating solution or an electroless plating solution, after the first type of metal or alloy is grown by plating, the treatment is performed one or more times immediately after that or with one or more other types of solutions. After that, it is preferable to perform plating growth of a second type of metal or alloy different from the first type, and further, three or more types of metal or alloy may be grown by plating. This makes it possible to perform plating with higher reliability in consideration of the plating growth rate of the metal or alloy, the denseness of the plating film, the magnitude of the ionization tendency, and the amount of expensive gold or palladium used. To reduce costs.

Since the cured resin pattern of the present invention is particularly excellent in adhesion reliability with an aluminum pad even in an electroless plating process after O ₂ ashing, when the resin pattern of the cured film has an opening, the opening of the cured resin pattern Preferably, at least one of the parts is disposed on top of a pad having aluminum or an aluminum alloy. By applying electroless nickel / displacement gold plating in such an arrangement, excellent adhesion reliability between the aluminum pad and the cured resin pattern, excellent wettability with wire bonding and solder balls, and solder diffusion prevention effect of the nickel layer Can be formed on the pad having aluminum or aluminum alloy, and can be used as an electrode pad with high connection reliability.

  Examples of the metal used as the under bump metal include, but are not limited to, nickel, nickel alloy, copper, copper alloy, chromium, titanium, titanium tungsten, gold, platinum, and palladium. Among these, nickel or a nickel alloy is preferably used mainly because it is relatively inexpensive, and the preferable content of nickel element in the under bump metal is 60% by mass or more and 99.9% by mass or less, more preferably 70% by mass. % Or more and 99.9% by mass or less, more preferably 80% by mass or more and 99.9% by mass or less.

  In addition, it is preferable to have a protective layer such as gold or copper on the surface of the under bump metal from the viewpoint of improving connection reliability, and it is more preferable to have a protective layer of gold element. In terms of connection reliability, the under bump metal preferably has an element other than nickel, and the preferable content of nickel in the under bump metal is 99.9% by mass or less, more preferably 99.5% by mass or less. More preferably, it is 99.0 mass% or less. Examples of the aluminum alloy include, but are not limited to, Al—Si, Al—Si—Cu, and the like.

  The pad having the aluminum or aluminum alloy and the external electrode are connected through the under bump metal by any one of a solder bump, a gold wire, and a copper wire, which suppresses metal corrosion of the connection portion and is high. This is preferable from the viewpoint of obtaining connection reliability.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated, this invention is not limited by these examples.

  In the examples, a silicon wafer was used as a model of the semiconductor element, and a metal layer was formed directly on the silicon wafer or by sputtering, and then a positive photosensitive resin composition was applied to form a resin film for evaluation. It was. Whether the resin film (including an uncured resin pattern and / or a cured resin pattern) is a resin film directly formed on a silicon wafer or a resin film formed on a metal layer formed by sputtering. When it is not necessary to distinguish between the two, the silicon wafer and the silicon wafer on which the metal layer is formed are collectively referred to as a substrate.

  First, an evaluation method in each example and comparative example will be described. In the evaluation of the positive photosensitive resin composition (hereinafter referred to as “varnish”), a varnish previously filtered with a 1 μm polytetrafluoroethylene filter (manufactured by Sumitomo Electric Industries, Ltd.) was used.

(1) Film thickness measurement The film thickness of the resin film on a board | substrate was measured using the optical interference type film thickness measuring apparatus (Dainippon Screen Mfg. Co., Ltd. lambda ace VM-1030). The refractive index was measured as 1.629 for polyimide.

(2) Imido ring closure rate (R _IM (%))
A polyimide (precursor) resin is dissolved in γ-butyrolactone (hereinafter referred to as GBL) at 35% by mass and applied onto a 4-inch silicon wafer by a spin coater using a spinner (1H-DX manufactured by Mikasa Co., Ltd.). Then, it was baked at 120 ° C. for 3 minutes using a hot plate (D-SPIN manufactured by Dainippon Screen Mfg. Co., Ltd.) to prepare a pre-baked film having a thickness of 4 to 5 μm. This wafer with resin film was divided into two, and one side was cleaned using a clean oven (CLH-21CD-S manufactured by Koyo Thermo System Co., Ltd.) under nitrogen flow (oxygen concentration 20 ppm or less) at 140 ° C. for 30 minutes and then further increased. Warmed and cured at 320 ° C. for 1 hour. The transmission infrared absorption spectrum of the resin film before and after curing was measured using an infrared spectrophotometer (FT-720 manufactured by HORIBA, Ltd.), respectively, and the absorption peak (near 1780 cm ⁻¹⁾ of the imide structure attributed to polyimide. After confirming the presence of 1377 cm ⁻¹ ), the peak intensity around 1377 cm ⁻¹ (before curing: X, after curing: Y) was determined. These peak intensity ratios were calculated to determine the content of imide groups in the polymer before heat treatment, that is, the imide ring closure rate (R _IM = X / Y × 100 (%)).

(3) Evaluation of photosensitive characteristics Using a coating and developing apparatus (ACT-8 manufactured by Tokyo Electron Co., Ltd.) on an 8-inch silicon wafer so that the film thickness after pre-baking the varnish for 3 minutes at 120 ° C. is 10 μm. The varnish was applied by spin coating and prebaked. A silicon wafer on which a pre-baked resin film is formed is set with a reticle having a pattern cut on an exposure machine i-line stepper (NSR-2005i9C manufactured by Nikon Corporation), and an exposure dose of 100 to 1000 mJ / cm ² is 10 mJ. / Cm ² step for exposure. After exposure, using a developing device of ACT-8, development is performed by a paddle method using a 2.38 mass% aqueous solution of tetramethylammonium hydroxide (hereinafter referred to as TMAH) (ELM-D manufactured by Mitsubishi Gas Chemical Co., Ltd.). Development with a liquid discharge time of 10 seconds and a paddle time of 25 seconds was repeated twice, rinsed with pure water, shaken and dried, and the minimum exposure amount at which the exposed portion was completely dissolved was determined. As a result, the minimum exposure amount is 500 mJ / cm ² or more is insufficient (B), 300 mJ / cm ² or more and less than 500 mJ / cm ² is good (A), and the one with less than 300 mJ / cm ² is very good (S).

(4) Evaluation of chemical resistance Sputtered substrate (hereinafter referred to as Al sputtered substrate) in which sputtering of Ti and Al was successively performed in this order on a 4-inch silicon wafer, and the lower layer Ti was formed with a thickness of 50 nm and the upper layer Al was formed with a thickness of 200 nm. Prepared). The Al sputter substrate was used for chemical resistance against the zincate solution and the electroless Ni / substituted Au plating treatment, and a 4-inch silicon wafer was used as the substrate for chemical resistance against strong acid and flux solution. The varnish is applied onto the substrate by spin coating using a spinner (Mikasa Co., Ltd.), and then 3 minutes on a hot plate at 120 ° C. using a hot plate (D-SPIN made by Dainippon Screen Mfg. Co., Ltd.). Baking was performed to prepare a pre-baked film having a thickness of about 6 to 13 μm. The film thickness after pre-baking was appropriately adjusted according to the target film thickness after curing. A substrate with a resin coating and a reticle with a cut pattern were set on a mask aligner (PEM-6M manufactured by Union Optics Co., Ltd.) and exposed with broadband light at an exposure amount of 500 mJ / cm ^{2 in} terms of i-line. After the exposure, development was performed by a dipping method using a 2.38 mass% TMAH aqueous solution (manufactured by Tama Chemical Industry Co., Ltd.), and then rinsed with pure water to obtain a positive type resin pattern. Using a clean oven (CLH-21CD-S, manufactured by Koyo Thermo System Co., Ltd.), the substrate with the resin pattern was heated at 140 ° C. for 30 minutes under a nitrogen stream (oxygen concentration 20 ppm or less), then further heated to 320 ° C. It was cured for 1 hour to cure the polyimide resin pattern. Further, using an RIE apparatus (RIE-10N manufactured by Samco Co., Ltd.), O ₂ 13 Pa, 200 W, O ₂ ashing treatment for 5 minutes was performed. The film reduction due to the O ₂ ashing process was about 0.4 μm. The following chemical-resistance evaluation was performed using the board | substrate with a resin pattern after a process. For observation after the chemical resistance test, an optical microscope of an optical interference film thickness measuring device (Lambda Ace VM-1030 manufactured by Dainippon Screen Mfg. Co., Ltd.) was used.

(4-1) Zincate Treatment An Al sputtered substrate with a cured resin pattern subjected to O ₂ ashing treatment prepared by the above method (hereinafter referred to as a substrate in the description of the evaluation in this section) is used as a zincate solution (Melplate (registered trademark)). FZ-7350 (Meltex Co., Ltd.) / Melplate (registered trademark) Zincate F-Plus (Meltex Co., Ltd.) / Pure water = 20/1/79 (volume ratio)) at 22 ° C. 5 It was immersed for a minute, washed by immersing it in pure water for 30 seconds, and dried by air blow. The peripheral portion of the 100 μm square square-extracted pattern of the substrate after processing was observed, and the penetration width into the remaining pattern was measured. The measurement was performed at five locations, and the average value of 20 μm or more was insufficient (B), 10 μm or more but less than 20 μm was good (A), and the average value less than 10 μm was very good (S).

(4-2) Strong Acid Treatment A silicon substrate with a cured resin pattern that has been subjected to O ₂ ashing treatment prepared by the above method (hereinafter referred to as a substrate in the description of the evaluation in this section) is 5% sulfuric acid at 40 ° C. It was immersed for a minute, washed by immersing it in pure water for 30 seconds, and dried by air blow. The substrate after the treatment was observed, the presence or absence of cracks on the surface of the resin film was observed, and those with cracks were judged as insufficient (B) and those without cracks as good (A).

(4-3) Flux treatment A silicon substrate with a cured resin pattern subjected to O ₂ ashing treatment prepared by the above method (hereinafter referred to as a substrate in the description of the evaluation in this section) is used as a flux solution (Arakawa Chemical Industries, Ltd.). WHD-001) is applied, heated on a hot plate at 250 ° C. (HHP-170D manufactured by As One Co., Ltd.) for 1 minute, immersed in pure water, and then subjected to an ultrasonic cleaner (AU manufactured by Aiwa Medical Industry Co., Ltd.). -26C) and dried by air blow. The substrate after the treatment was observed, the presence or absence of cracks on the surface of the resin film was observed, and those with cracks were judged as insufficient (B) and those without cracks as good (A).

(4-4) Electroless Ni / Substituted Au Plating Treatment An Al sputtered substrate with a cured resin pattern that has been subjected to O ₂ ashing treatment prepared by the above method (hereinafter referred to as a substrate in the description of the evaluation in this section) is shown in Table 1. A dipping process was carried out in order from step 1 to step 8 in the solution. However, after immersion in each solution, cleaning by immersion in pure water and drying by air blow were performed each time. In the table, Mel Cleaner and Mel Plate are both registered trademarks and manufactured by Meltex.

  The substrate after each chemical solution treatment was observed, and the presence or absence of cracks on the surface of the resin film and the permeation into the remaining pattern at the peripheral edge of the 100 μm square pattern was observed.

[Synthesis Example 1] Synthesis of diamine compound (HA) 164.8 g (0.45 mol) of 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane (hereinafter referred to as BAHF) was added to 900 mL of acetone and propylene. It was dissolved in 156.8 g (2.7 mol) of oxide and cooled to −15 ° C. A solution prepared by dissolving 183.7 g (0.99 mol) of 3-nitrobenzoyl chloride in 900 mL of acetone was added dropwise thereto. After completion of dropping, the mixture was reacted at −15 ° C. for 4 hours and then returned to room temperature. The precipitated white solid was filtered off and vacuum dried at 50 ° C.

  270 g of solid was placed in a 3 L stainless steel autoclave, dispersed in 2400 mL of methyl cellosolve, and 5 g of 5% palladium-carbon was added. Hydrogen was introduced here with a balloon and the reduction reaction was carried out at room temperature. After 2 hours, the reaction was terminated by confirming that the balloons did not squeeze any more. After completion of the reaction, filtration was performed to remove the palladium compound as a catalyst, and the mixture was concentrated with a rotary evaporator to obtain a diamine compound (hereinafter referred to as HA) represented by the following formula.

Synthesis Example 2 Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-1) 1.09 g (0.005 mol) of pyromellitic dianhydride (hereinafter referred to as PMDA) and bis (3,4) in a dry nitrogen stream -Dicarboxyphenyl) ether dianhydride (hereinafter referred to as ODPA) 13.96 g (0.045 mol) was dissolved in 120 g of N-methyl-2-pyrrolidone (hereinafter referred to as NMP). Here, HA 18.18 g (0.03 mol), 4,4′-diaminodiphenyl ether (hereinafter referred to as DAE) 2.80 g (0.014 mol) and 1,3-bis (3-aminopropyl) tetramethyldisiloxane 0.50 g (0.002 mol) (hereinafter referred to as SiDA) was added together with 40 g of NMP, reacted at 20 ° C. for 1 hour, and then reacted at 50 ° C. for 2 hours. Next, 0.87 g (0.008 mol) of 3-aminophenol (hereinafter referred to as MAP) as an end-capping agent was added together with 10 g of NMP, and reacted at 50 ° C. for 2 hours. Thereafter, a solution obtained by diluting 10.72 g (0.09 mol) of N, N-dimethylformamide dimethyl acetal (hereinafter referred to as DMFDMA) with 20 g of NMP was added dropwise over 10 minutes. After dropping, the mixture was stirred at 50 ° C. for 3 hours. After completion of stirring, the solution was cooled to room temperature, and then the solution was poured into 1 L of water to obtain a precipitate. The precipitate was collected by filtration, washed three times with water, and then dried for 20 hours in a vacuum dryer at 80 ° C. to obtain a powder of an alkali-soluble polyimide precursor resin (A-1).

[Synthesis Example 3] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-2) Synthesis except that acid dianhydride addition amount is changed to PMDA 2.18 g (0.01 mol) and ODPA 12.41 g (0.04 mol). A polymerization reaction was carried out in the same manner as in Example 2 to obtain an alkali-soluble polyimide precursor resin (A-2) powder.

Synthesis Example 4 Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-3) The acid dianhydride addition amount was changed to PMDA 4.36 g (0.02 mol) and ODPA 9.31 g (0.03 mol), and DMFDMA was added. A polymerization reaction was carried out in the same manner as in Synthesis Example 2 except that the amount was changed to 9.53 g (0.08 mol) to obtain an alkali-soluble polyimide precursor resin (A-3) powder.

[Synthesis Example 5] Synthesis of alkali-soluble polyimide precursor resin (A-4) The acid dianhydride addition amount was changed to PMDA 2.18 g (0.01 mol) and ODPA 12.41 g (0.04 mol), except for SiDA The polymerization reaction was carried out in the same manner as in Synthesis Example 2 except that the amount of diamine added was changed to 22.67 g (0.0375 mol) HA and 1.30 g (0.0065 mol) DAE, and an alkali-soluble polyimide precursor resin (A -4) powder was obtained.

[Synthesis Example 6] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-5) The amount of diamine other than SiDA was changed to 6.05 g (0.01 mol) and 6.01 g (0.03 mol) of DAE, and DMFDMA was added. A polymerization reaction was performed in the same manner as in Synthesis Example 2 except that the amount was changed to 9.53 g (0.08 mol) to obtain an alkali-soluble polyimide precursor resin (A-5) powder.

[Synthesis Example 7] Synthesis of alkali-soluble polyimide precursor resin (A-6) 1.34 g (0.005 mol) of 1,4,5,8-naphthalenetetracarboxylic dianhydride and ODPA13. The amount of diamine other than SiDA was changed to 17.53 g (0.029 mol) of HA and 2.40 g (0.012 mol) of DAE, and the amount of DMFDMA added was 9.53 g (0 Except for changing to 0.08 mol), a polymerization reaction was carried out in the same manner as in Synthesis Example 2 to obtain a powder of alkali-soluble polyimide precursor resin (A-6).

[Synthesis Example 8] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-7) Polymerization reaction in the same manner as in Synthesis Example 3 except that DAE was changed to 3.03 g (0.014 mol) of 4,4′-thiodianiline. To obtain a powder of alkali-soluble polyimide precursor resin (A-7).

[Synthesis Example 9] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A-8) The polymerization reaction was carried out in the same manner as in Synthesis Example 3 except that the reaction after addition of DMFDMA was changed to stirring at 80 ° C. for 3 hours, and alkali-soluble. A powder of polyimide precursor resin (A-8) was obtained.

[Synthesis Example 10] Synthesis of alkali-soluble polyimide resin (A-9) 4.53 g (0.0075 mol) HA, 1.50 g (0.0075 mol) DAE, 10.26 g (0.028 mol) BAHF under a dry nitrogen stream. In addition, 0.50 g (0.002 mol) of SiDA and 1.09 g (0.01 mol) of MAP as an end-capping agent were dissolved in 140 g of NMP. PMDA1.09g (0.005mol) and ODPA13.96g (0.045mol) were added with NMP20g here, it was made to react at 20 degreeC for 1 hour, and it was made to react at 50 degreeC then for 4 hours. Thereafter, 10 g of xylene was added, and the mixture was stirred at 150 ° C. for 5 hours while azeotropically distilling water with xylene. After completion of stirring, the mixture was allowed to cool, and the solution was poured into 1 L of water to obtain a white precipitate. The precipitate was collected by filtration, washed three times with water, and then dried for 20 hours in a vacuum dryer at 80 ° C. to obtain an alkali-soluble polyimide resin (A-9) powder.

[Synthesis Example 11] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A′-10) The acid dianhydride addition amount was changed to 6.54 g (0.03 mol) PMDA and 6.20 g (0.02 mol) ODPA, and SiDA The diamine addition amount other than HA was changed to 17.53 g (0.029 mol) and DAE 2.40 g (0.012 mol), and the terminal blocker addition amount was changed to MAP 1.53 g (0.014 mol), DMFDMA A polymerization reaction was carried out in the same manner as in Synthesis Example 2 except that the amount added was changed to 9.53 g (0.08 mol) to obtain an alkali-soluble polyimide precursor resin (A′-10) powder.

[Synthesis Example 12] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A′-11) A polymerization reaction was performed in the same manner as in Synthesis Example 2 except that acid dianhydride was changed to 15.51 g (0.05 mol) of ODPA. The powder of the alkali-soluble polyimide precursor resin (A′-11) was obtained.

[Synthesis Example 13] Synthesis of Alkali-Soluble Polyimide Precursor Resin (A′-12) A polymerization reaction is carried out in the same manner as in Synthesis Example 3 except that diamine other than SiDA is changed to 26.60 g (0.044 mol) of HA. The powder of alkali-soluble polyimide precursor resin (A′-12) was obtained.

Synthesis Example 14 Synthesis of Alkali-Soluble Polyimide Precursor Resin (A′-13) The acid dianhydride was changed to 15.51 g (0.05 mol) of ODPA, and 26.60 g (0.044 mol) of diamine other than SiDA. The polymerization reaction was carried out in the same manner as in Synthesis Example 2 except that the powder was changed to) to obtain an alkali-soluble polyimide precursor resin (A′-13) powder.

[Synthesis Example 15] Synthesis of novolak resin (A'-14) 70.2 g (0.65 mol) of m-cresol, 37.8 g (0.35 mol) of p-cresol, 37% by mass formaldehyde under a dry nitrogen stream 75.5 g of aqueous solution (0.93 mol of formaldehyde), 0.63 g (0.005 mol) of oxalic acid dihydrate and 264 g of methyl isobutyl ketone were charged, and then immersed in an oil bath, while the reaction solution was refluxed. A time polycondensation reaction was performed. Thereafter, the temperature of the oil bath is raised over 3 hours, and then the pressure in the flask is reduced to 40 to 67 hPa, volatile components are removed, the dissolved resin is cooled to room temperature, and alkali-soluble. Of a novolac resin (A′-14) was obtained.

[Synthesis Example 16] Synthesis of polyhydroxystyrene resin (A'-15) To a mixed solution of 2400 g of tetrahydrofuran and 2.6 g (0.04 mol) of sec-butyllithium as an initiator, pt-butoxystyrene 63 was added. 0.5 g (0.36 mol) and 25.0 g (0.24 mol) of styrene were added and polymerized with stirring for 3 hours, and then 12.8 g (0.4 mol) of methanol was added to terminate the polymerization reaction. Went. Next, in order to purify the polymer, the reaction mixture was poured into 3 L of methanol, the precipitated polymer was dried, further dissolved in 1.6 L of acetone, 2 g of concentrated hydrochloric acid was added at 60 ° C., stirred for 7 hours, and then poured into water. The polymer was precipitated with, pt-butoxystyrene was deprotected to convert to hydroxystyrene, washed with water three times, and then dried in a vacuum dryer at 50 ° C. for 24 hours to obtain an alkali-soluble polyhydroxystyrene resin. (A′-15) was obtained.

[Synthesis Example 17] Synthesis of phenol resin (A'-16) Under a dry nitrogen stream, 61.1 g (0.5 mol) of 2,3-xylenol, 58.0 g (0.475 mol) of salicylaldehyde, and p- A polycondensation reaction was carried out for 4 hours at 100 ° C. while 1.7 g (0.01 mol) of toluenesulfonic acid was refluxed in an oil bath. After cooling to room temperature, 50 g of acetone and 1.0 g (0.01 mol) of triethylamine were added and stirred for 30 minutes, and then 150 g of pure water was further added and stirred for 30 minutes. After removing the separated aqueous layer, 10 g of GBL was added, the temperature was raised to 200 ° C., the pressure in the flask was then reduced to 40 hPa or less, volatiles were removed, and the mixture was cooled to room temperature and alkali-soluble phenol resin (A'-16) was obtained.

[Synthesis Example 18] Synthesis of quinonediazide compound (B-1) 42.45 g (0.1 mol) of TrisP-PA (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) and 5-naphthoquinonediazidesulfonyl chloride under a dry nitrogen stream. 75.23 g (0.28 mol) (NAC-5, manufactured by Toyo Gosei Co., Ltd.) was dissolved in 1000 g of 1,4-dioxane. While cooling the reaction vessel with ice, a liquid obtained by mixing 150 g of 1,4-dioxane and 30.36 g (0.3 mol) of triethylamine was added dropwise so that the temperature inside the system would not exceed 35 ° C. It stirred at 30 degreeC after dripping for 2 hours. The triethylamine salt was filtered, and the filtrate was poured into 7 L of pure water to obtain a precipitate. The precipitate was collected by filtration and further washed with 2 L of 1% by mass hydrochloric acid. Thereafter, it was further washed twice with 5 L of pure water. The precipitate was dried in a vacuum dryer at 50 ° C. for 24 hours, and quinonediazide compound (B-1) represented by the following formula in which 2.8 of Q were converted into 5-naphthoquinonediazidesulfonic acid ester on average was obtained. Obtained.

  The thermal crosslinking agent (C-1) HMOM-TPHAP (trade name, manufactured by Honshu Chemical Industry Co., Ltd.) used in the examples is shown below.

  The thermal base generator (D-1) (R) -t-butyl-2- (hydroxymethyl) pyrrolidine-1-carboxylate (manufactured by Wako Pure Chemical Industries, Ltd.) used in the comparative example is shown below.

About the alkali-soluble polyimide (precursor) resin obtained in Synthesis Examples 2 to 14, the tetracarboxylic acid residue represented by the general formula (1) and the total diamine residue in the total tetracarboxylic acid residue calculated from the addition amount The diamine residue represented by the general formula (2) in the group, the ratio (mol%) of the diamine residue represented by the formula (3) in the total diamine residue, and the imide determined by the above method Table 2 shows the ring closure rate (R _IM (%)), the polyimide precursor having the structure (a1), the polyimide having the structure (a2), or the other classification. In addition, alkali-soluble resin (A'-14-16) as described in the synthesis examples 15-17 which is not a polyimide (precursor) is classified into others.

[Production of varnish]
Each component was put into a polypropylene vial with a capacity of 32 mL according to the composition shown in Table 3, and mixed using a stirring defoaming device (ARE-310, manufactured by Shinky Co., Ltd.) under the conditions of stirring for 10 minutes and defoaming for 1 minute. Filtration was performed to remove fine foreign matters to prepare varnishes (W-1 to 21). In Table 3, “GBL” represents γ-butyrolactone.

[Examples 1-12, Comparative Examples 1-9]
Table 4 shows the results of evaluating the photosensitivity and chemical resistance against zincate treatment using the prepared varnish by the above method. In Comparative Example 1, the photosensitive properties were insufficient. In Comparative Examples 2 to 9, the penetration width into the remaining pattern at the time of the zincate treatment was large, and the chemical resistance was insufficient.

[Examples 13 to 21, Comparative Examples 10 to 11]
Table 5 shows the results of chemical resistance evaluation with respect to strong acid treatment and flux treatment using varnishes W-1 to 7, 11, 12, 16, and 21 by the above-described methods. In Comparative Example 11, cracks occurred on the resin surface in any treatment.

[Examples 22 and 23]
Using varnish W-4 (Example 22) and W-11 (Example 23), chemical resistance evaluation for electroless Ni / substituted Au plating treatment was performed by the above method. In all cases, no permeation into the remaining pattern of the peripheral portion of the 100 μm square cut-out pattern occurred throughout the entire process, and no cracks occurred on the surface of the resin film, and the chemical resistance was good.

1 Hardened resin pattern 2 Semiconductor element 3A Under bump metal (main material)
3B Under bump metal (surface material)
4 Electrode pad 5 Solder bump 6 Metal wire

Claims (14)

(A) an alkali-soluble resin, and (b) a quinonediazide compound, wherein (a) the alkali-soluble resin is
(A1) The tetracarboxylic acid residue represented by the general formula (1) is 5 to 50 mol% in the total tetracarboxylic acid residues, and the diamine residue represented by the general formula (2) is the total diamine. A polyimide precursor having 10 to 80 mol% in the residues and further having 10 to 90 mol% of the diamine residues represented by the general formula (3) in all diamine residues,
And / or (a2) polyimide corresponding to (a1),
A positive photosensitive resin composition comprising:

(In general formula (1), A represents a tetravalent monocyclic or bicyclic aromatic hydrocarbon group containing no hetero atom, and two or more types may be used.)

(In the general formula (2), B represents _{O, S, SO 2, CH} 2, CH (CH 3), a _{C (CH 3) 2, C} (CF 3) groups selected from _2, these two More than one type may be used.)

2. The positive photosensitive resin composition according to claim 1, wherein the (a) alkali-soluble resin contains the polyimide precursor (a1) and has an imide ring ring closure rate of 5 to 25%. The positive photosensitive resin composition according to claim 1, further comprising (c) a thermal crosslinking agent. An uncured resin pattern formed from the positive photosensitive resin composition according to claim 1. A cured resin pattern obtained by curing the uncured resin pattern according to claim 4. A semiconductor device in which the cured resin pattern according to claim 5 is arranged on a semiconductor element. The semiconductor device according to claim 6, wherein the cured resin pattern has an opening, and at least one of the openings is disposed on an upper portion of a pad having aluminum or an aluminum alloy. The semiconductor device according to claim 7, wherein an under bump metal is disposed on an upper portion of the pad having the aluminum or aluminum alloy. The semiconductor device according to claim 8, wherein the under bump metal has a nickel element of 60 mass% or more and 99.9 mass% or less. The semiconductor device according to claim 8, further comprising a protective layer of gold element on a surface of the under bump metal. The semiconductor device according to claim 8, wherein the pad having the aluminum or aluminum alloy and the external electrode are connected to each other by any one of a solder bump, a gold wire, and a copper wire through the under bump metal. The semiconductor device according to claim 6, wherein a thickness of the cured resin pattern is 3.0 μm or more and 15.0 μm or less. A method for manufacturing the semiconductor device according to claim 6,
A step of treating the semiconductor element having the cured resin pattern with a strongly acidic liquid having a pH of 2 or less, a step of treating with a strong alkaline liquid having a pH of 12 or more, a step of treating with a flux solution, and a step of treating with an electrolytic plating solution. And a method for manufacturing a semiconductor device, comprising at least one step selected from the step of treating with an electroless plating solution. The solution is an electrolytic plating solution or an electroless plating solution;
14. The method of manufacturing a semiconductor device according to claim 13, further comprising a step of plating growth of a first type of metal or alloy and a step of plating growth of a second type of metal or alloy different from the first type.

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