JP3137382B2 - Photosensitive resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive resin composition capable of suitably forming a polyimide film pattern having excellent adhesion to a semiconductor substrate and a sealing resin.

[0002]

2. Description of the Related Art Conventionally, in a resin-encapsulated semiconductor device, a protective film made of an inorganic material such as silicon dioxide, silicon nitride, or alumina is formed on the surface of a semiconductor substrate on which elements are formed. It has a structure sealed with an epoxy resin composition or the like. However, this resin-encapsulated semiconductor device has a property of transmitting moisture through a sealing resin such as an epoxy resin. In addition, cracks may occur in the protective film due to a difference in thermal expansion coefficient between the sealing resin and the semiconductor substrate. This crack is particularly likely to occur with the enlargement of the semiconductor pellet, and causes a problem that the aluminum wiring pattern present under the protective film is corroded by the invasion of moisture into the crack and the like.

[0003] In view of the above, a resin seal formed by sealing a semiconductor pellet having a second protective film made of a polyimide resin on the surface of the first protective film made of the inorganic material, with a sealing resin. 2. Description of the Related Art A fixed semiconductor device has been proposed.

On the other hand, in such semiconductor pellets, usually,
Since it is necessary to perform a pattern processing such as a through hole or a pad processing for conducting to external leads, a hole (relief pattern) corresponding to the pattern, the pad, and the like is formed in the second protective film made of a polyimide resin. There is a need. The formation of the second protective film having this relief pattern is usually performed by using PEP (ph
otoengraving process). That is, first, a polyimide film is formed on the first protective film. next,
A photoresist film is provided on the surface of the polyimide film, and the photoresist film is exposed and developed to form a resist pattern. Then, by selectively etching the underlying polyimide film using the resist pattern as an etching resistant mask, a polyimide film pattern as a second protective film having a desired relief pattern is formed.

However, when the second protective film (polyimide film pattern) having the relief pattern is formed by the method described above, the formation of the polyimide film and the PEP for forming the pattern are independent. It is necessary to perform it in one process, and the operation by the multi-step process has been complicated.

Therefore, in order to solve the above-mentioned problems, it has been studied to use various photosensitive materials described below as a material for the second protective film and perform film formation and pattern formation in one step. . For example, JP-A-49-115541 describes a light-sensitive material having a repeating unit represented by the following chemical formula 2.

[0007]

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This photosensitive material is a polyamic acid ester which is a polyimide precursor and has a negative photosensitive property in which an exposed portion becomes insoluble in a developing solution by light irradiation. Therefore, patterning can be performed simultaneously with the formation of the polyimide film, and the patterning of the polyimide film can be performed without using a conventional PEP.
However, this photosensitive material has a problem that the synthesis process is very complicated.

JP-B-59-52822 discloses a negative heat-resistant photosensitive material containing a compound containing a carbon-carbon double bond and an amino group which can be dimerized or polymerized by actinic radiation. . However, this material has poor adhesion to the first protective film made of an inorganic material on the surface of the semiconductor substrate, or the sealing resin for sealing the semiconductor pellet, and the reliability of the formed semiconductor device is impaired. is there.

In addition, Japanese Patent Application Laid-Open No. Sho 62-145240 proposes a positive photosensitive material containing a polymer having an isoimide structure. However, this polymer has drawbacks of low heat resistance and low exposure sensitivity, and has a problem in use as a protective film in a semiconductor device.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has as its object to provide a high exposure sensitivity and a sharp process by a simple process without using a separate photoresist. An object of the present invention is to provide a photosensitive resin composition capable of forming a relief pattern having contrast. Another object of the present invention is to provide a protective film (second protective film) having excellent adhesion to another protective film (first protective film) made of an inorganic material on the surface of a semiconductor substrate and a sealing resin, and excellent heat resistance. To provide a photosensitive resin composition capable of forming a protective film).

[0012]

Means for Solving the Problems The photosensitive resin composition of the present invention is obtained by dimerizing an oligoamic acid represented by the following general formula (1) having an end capped molecule with an energy ray. It is characterized by containing a compound having a polymerizable carbon-carbon double bond and an amino group, and a sensitizer.

[0013]

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However, in the formula, Ar ¹ Represents a divalent organic group, A
r ² Represents a tetravalent organic group, and Z represents a divalent organic group having a photopolymerizable double bond or triple bond. n is a number average degree of polymerization and is a positive integer of 30 or less. Hereinafter, the details of the photosensitive resin composition of the present invention will be described.

In the photosensitive resin composition of the present invention, the oligoamic acid represented by the general formula (1) and having a molecular end capped corresponds substantially to a resin component which is a main component of the composition. . In the general formula (1), A
r ¹ As an organic group represented by the following chemical formulas 4 and 5, Ar ² Is an organic group represented by the following chemical formula 6, and Z is an organic group represented by the following chemical formula 7, respectively.

[0016]

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[0017]

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[0018]

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[0019]

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The number average polymerization degree n of the oligoamic acid represented by the general formula (1) is 30 or less, and 4
-20 is preferred. The reason for this is that if n deviates from the above range, the adhesion between the obtained polyimide film pattern and the protective film made of an inorganic material on the surface of the semiconductor substrate may decrease, or the exposure sensitivity of the photosensitive resin composition may decrease. Because there is. Specifically, during the synthesis of oligoamic acid, for example, the intrinsic viscosity at 30 ° C. of a solution of 0.5 g of oligoamic acid dissolved in 100 ml of N-methyl-2-pyrrolidone is adjusted to be 0.2 to 1.5 dl / g. do it.

The oligoamic acid (1) is a precursor of an oligoimide and is synthesized by the following method. That is, a diamine represented by the following general formula (1-a), a tetracarboxylic dianhydride represented by the following general formula (1-b), and an acid anhydride represented by the following general formula (1-c): Can be synthesized by solution polymerization in the presence of an organic solvent. H ₂ N-Ar ¹ —NH ₂ (1-a) (wherein, Ar ¹ Is synonymous with general formula (1))

[0022]

Embedded image (Wherein, Ar ² Is synonymous with general formula (1))

[0023]

Embedded image (Wherein, Z is the same as general formula (1))

Examples of the diamine represented by the general formula (1-a) include m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, 3,3′-diaminodiphenyl ether, and 4,4 ′ -Diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminophenylsulfone, 4,4'-diaminodiphenylsulfone, 3,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylmethane, 4,4 '-Diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylketone, 4,4'-diaminodiphenylketone, 3,4'-diaminodiphenylketone, 2 2,2-bis (4-aminophenyl) propane, 2,2-bis (4-aminophenyl) hexafluoropropane, 1,3-bis (3-aminophenoxy) benzene, 1,3-
Bis (4-aminophenoxy) benzene, 1,4-bis (4-aminophenoxy) benzene, 4-methyl-2,4-bis (4-aminophenyl) -1-pentene, 4-methyl-2,4- Screw (4-
Aminophenyl) -2-pentene, 1,4-bis (α, α-dimethyl-4-aminobenzyl) benzene, imino-di-p-
Phenylenediamine, 1,5-diaminonaphthalene, 2,6-diaminonaphthalene, 4-methyl-2,4-bis (4-aminophenyl) pentane, 5 (or 6) -amino-1- (4-aminophenyl) -1,3,3-trimethylindane, bis (4-aminophenyl) phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-bis (4-aminophenoxy) biphenyl , 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 2,2-bis [4- (3-
Aminophenoxy) phenyl] benzophenone, 4,4'-
Bis (4-aminophenoxy) diphenyl sulfone, 4,
4'-bis [4- (α, α-dimethyl-4'-aminobenzyl)
Phenoxy] benzophenone, 4,4′-bis [4- (α, α
-Dimethyl-4'-aminobenzyl) phenoxy] diphenyl sulfone, bis (4-aminophenoxy) dimethylsilane, bis (4-aminophenyl) tetramethyldisiloxane, and other aromatic diamines, and hydrogen of aromatic nuclei in these aromatic diamines A compound in which an atom is substituted by at least one substituent selected from the group consisting of a chlorine atom, a fluorine atom, a bromine atom, a methyl group, a methoxy group, a cyano group, a hydroxyl group, and a phenyl group, dimethylene diamine;
Trimethylene diamine, tetramethylene diamine, hexamethylene diamine, heptamethylene diamine, octamethylene diamine, nonamethylene diamine, decamethylene _{diamine, H 2 N- (CH 2 -} ) 3 -O- (CH 2)
₃ -NH _2, 1,2-bis (3'-amino-propoxy) ethane,
1,4-diaminocyclohexane, 4,4'-diaminodicyclohexylmethane, 1,3-bisaminomethylcyclohexane, 1,4-bisaminomethylcyclohexane, 1,3-diaminocyclohexane, 4,4'-diaminodicyclohexylisopropane , 1,4-xylylenediamine, 2,6-diaminopyridine, 2,4-diamino-S-triazine, bis (γ-aminopropyl) -1,1,3,3-tetramethyldisiloxane, 1,4 -
Bis (γ-aminopropyldimethylsilyl) benzene,
Bis (4-aminobutyl) tetramethyldisiloxane, bis (γ-aminopropyl) tetraphenyldisiloxane and the like can be mentioned. These diamines can be used alone or in a mixture of two or more.

Examples of the tetracarboxylic dianhydride represented by the general formula (1-b) include pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ', 4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) methane dianhydride 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropane dianhydride, bis (3,4-dicarboxyphenyl) ) Sulfone dianhydride, 4,4′-oxyphthalic dianhydride, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3.4-dicarboxyphenyl) tetramethyldisiloxane dianhydride, 1 , 4,5,8-Naphthalenetetracarboxylic dianhydride, 2,3,6,7-Naphthalenetetracar Phosphate dianhydride, butane tetracarboxylic dianhydride, and the like. These tetracarboxylic dianhydrides can be used in one kind or in a mixture of two or more kinds.

Examples of the acid anhydride represented by the general formula (1-c) include maleic anhydride, 2,3-dimethylmaleic anhydride, 2-chloromaleic anhydride, and 2,3-dichloromaleic anhydride. Acid, 2-phenylmaleic anhydride, citraconic anhydride, itaconic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, ethynylphthalic anhydride, 2-propynylphthalic anhydride, 3,6- Endomethylene-1,2,3,6-tetrahydrophthalic anhydride, 4-trimethoxysilyl-1,
2,3,6-tetrahydrophthalic anhydride and the like.

Examples of the organic solvent used in the solution polymerization reaction include N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl-ε-caprolactam, and γ-butyrolactone. , Sulfolane, dimethylsulfoxide, sulfolane, tetramethylurea, hexamethylphosphamide, 1,3-dimethyl-2-imidazolidone and the like. The reaction temperature of this solution polymerization reaction ranges from about -10 to 60 ° C, and the reaction time ranges from about 0.5 to 30 hours.

The above solution polymerization reaction (oligoamic acid (1)
), The compounding amounts of the above-described diamine, tetracarboxylic dianhydride, and acid anhydride are set such that the -NH ₂ group and the acid anhydride group represented by the following formula 10 are equivalent. Although it is desirable, the amount may be set so that the —NH ₂ group falls within a range of 5 equivalent% or less than the equivalent.

[0029]

Embedded image The mixing ratio of the tetracarboxylic dianhydride to the acid anhydride is desirably set in the range of 90:10 to 99.5 to 0.5 in molar ratio.

Further, in the photosensitive resin composition of the present invention, in addition to the above-mentioned oligoamic acid (1) as a resin component,
It is preferable to blend a polyamic acid having a repeating unit represented by the following general formula (2).

[0031]

Embedded image However, in the formula, Ar ³ Represents a divalent organic group, Ar ⁴ Represents a tetravalent organic group, respectively.

In the repeating unit (2), Ar ³ As Ar ^{1 of the} oligoamic acid (1) The same organic group as Ar ⁴ As Ar of the oligoamic acid (1)
^Two And the same organic groups. The number average polymerization degree of the polyamic acid having the repeating unit (2) is 80 to 120.
And more preferably about 100. The reason is that if the average degree of polymerization of the polyamic acid deviates from the above range, the adhesion between the obtained polyimide film pattern and the protective film made of an inorganic material on the surface of the semiconductor substrate is reduced, or the exposure sensitivity of the photosensitive resin composition is reduced. This is because there is a case where is decreased. Specifically, during the synthesis of polyamic acid, for example, N-
The intrinsic viscosity at 30 ° C. of a solution of 0.5 g of polyamic acid dissolved in 100 ml of methyl-2-pyrrolidone is 0.4 to 2.0 dl.
It may be adjusted to be / g.

The polyamic acid having the repeating unit (2) is a diamine of the general formula (1-a) used in the synthesis of the oligoamic acid and a tetracarboxylic dianhydride of the general formula (1-b). Can be synthesized by similarly subjecting the product to a polycondensation reaction in the presence of an organic solvent.

When the photosensitive resin composition of the present invention contains, as a resin component, a polyamic acid having a repeating unit (2) in addition to the oligoamic acid (1), the mixing ratio thereof is preferably such that The amount of the oligoamic acid (1) is adjusted to be 50% by weight or more based on the total amount. The reason for this is that the amount of the oligoamic acid (1)
If the content is less than 50% by weight, the adhesion between the finally obtained polyimide film pattern and the protective film made of an inorganic material on the surface of the semiconductor substrate is likely to be reduced.

In the photosensitive resin composition of the present invention, the compound having a carbon-carbon double bond and an amino group which can be dimerized or polymerized by the energy ray is a component having photosensitivity. As the compound, specifically, acrylate N, N-dimethylaminoethyl, acrylate N, N-diethylaminoethyl, methacrylate N, N-dimethylaminoethyl, methacrylate N, N-diethylaminoethyl, methacrylate N N, N-dimethylaminopropyl acrylamide, N, N-dimethylaminopropyl methacrylamide, N, N-diethylaminopropyl acrylamide, N, N-diethylaminopropyl methacrylamide, N-methyl methacrylate -N -Benzylaminoethyl,
Compounds (PS-1) and (PS-
2) and the like.

[0036]

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The compounding amount of the compound having a carbon-carbon double bond and an amino group which can be dimerized or polymerized by the energy ray is determined based on the oligoamic acid (1) and the polyamic acid (resin component) having the repeating unit (2). To the total amount of carboxyl groups in the case where the polyamic acid is contained), it can be set to 0.5 to 2.0 equivalents, preferably 0.8 to 1.5 equivalents. The reason for this is that the amount of the compound
If the amount is out of the range of 0.5 to 2.0 equivalents, the exposure sensitivity of the photosensitive resin composition may be reduced, and the heat resistance and adhesion when a protective film is formed may be reduced.

In the photosensitive resin composition of the present invention, the sensitizer has a function of enhancing the photosensitivity of the resin composition.
As the sensitizer, specifically, acetophenone, benzophenone, benzoin, 2-methylbenzoyl, anthracene, phenanthrenequinone, Michler-ketone, 4,4′-
Bis (diethylamino) benzophenone, benzoin methyl ether, benzoin ethyl ether, benzyldimethyl ketal, 2-methyl- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 1-hydroxycyclohexylphenyl ketone, N, N- Ethyl dimethylaminobenzoate, 2-t-butyl-9,10-anthraquinone, N-phenylmaleimide and the like can be used.

The amount of the sensitizer is from 1 to 30% by weight based on the total amount of the oligoamic acid (1) and the polyamic acid having the repeating unit (2) (when the polyamic acid is contained in the resin component). %, Preferably 2 to 20% by weight.
The reason for this is that if the compounding amount of the sensitizer deviates from the range of 1 to 30% by weight, the exposure sensitivity of the composition may be reduced, or the heat resistance and adhesion when the protective film is formed may be reduced. That's why.

The photosensitive resin composition of the present invention contains, in addition to the above-mentioned amide acids, photosensitive compounds, and sensitizers, for example, a reaction initiator such as an azide compound, a silane coupling agent, Modifiers such as surfactants may be included.

The photosensitive resin composition of the present invention is prepared as follows. That is, first, the solvent and the like used for the synthesis of these compounds are added to the solution of the oligoamic acid (1) synthesized as described above and the solution of the polyamic acid having the repeating unit (2) as necessary, and Adjust the concentration of the components. Next, a compound having a carbon-carbon double bond and an amino group, which can be dimerized or polymerized by a predetermined amount of energy rays, and a predetermined amount of a sensitizer are uniformly blended in the reaction system, and the photosensitive composition of the present invention is obtained. To obtain a conductive resin composition. In addition, as the organic solvent, for example, tetrahydrofuran, dioxane or the like can be used in addition to the solvent used for synthesizing the oligoamic acid (1). Furthermore, methyl ethyl ketone, xylene, toluene, methyl cellosolve, cellosolve, ethyl acetate, butyl acetate, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol methyl ether, 1-acetoxy-2-ethoxyethane, diethylene glycol dimethyl ether and the like can be used in combination. . Hereinafter, an example of a process of forming a protective film having a pattern on a semiconductor substrate using the photosensitive resin composition of the present invention will be described.

First, a first protective film made of an inorganic material such as silicon dioxide is formed on the surface of a semiconductor substrate, and a solution (varnish) of the photosensitive resin composition of the present invention adjusted to an appropriate viscosity is formed on the surface of the protective film. Is applied with a spinner or the like, and dried at a temperature of preferably about 120 ° C. or less to form a photosensitive resin composition layer.

Next, the photosensitive resin composition layer is exposed to energy rays through a photomask having a desired pattern to perform exposure. Such energy rays include visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray and the like. At this time, in the photosensitive resin composition layer in the exposed portion, the compound having a carbon-carbon double bond and an amino group that can be dimerized or polymerized by the energy ray is
The acid group in the oligoamic acid (1), that is, the carboxyl group is capped to crosslink the main chain of the oligoamic acid (1). The crosslinking of the oligoamic acid (1) also proceeds by the function of the organic group Z having a photopolymerizable double or triple bond at the molecular terminal of the oligoamic acid (1). Thus, the molecular weight of the resin component in the exposed portion increases. In particular, in the present invention, since the oligoamic acid (1) having the organic group Z has high sensitivity, the change in the exposed portion of the photosensitive resin composition layer as described above becomes remarkable.

Next, the exposed photosensitive resin composition layer is developed. The organic solvent used in the synthesis of the oligoamic acid (1) can be applied to the developing solution used in the developing treatment.
A mixed solvent with methanol, isopropyl alcohol, toluene, xylene, methyl ethyl ketone, dioxane, tetrahydrofuran, or the like can also be used.

Here, in the unexposed portion of the photosensitive resin composition layer, the oligoamic acid (1) is not changed, and a carboxyl group as a side group remains and has a low molecular weight. Dissolve in developer. On the other hand, in the exposed portion, the oligoamic acid (1)
The carboxyl group which is a side group is capped and crosslinked, has a high molecular weight, and does not dissolve in the above-mentioned developer. Therefore, only the exposed portion remains by the development process, and a desired pattern is formed by the remaining portion. That is, the photosensitive resin composition of the present invention functions as a negative type photosensitive material in which the photosensitive portion is insoluble in a developer. Before the above-mentioned development processing, if necessary, the photosensitive resin composition layer is heated at a temperature of 90 to 130 ° C. for 30 seconds to 5 seconds.
The heat treatment may be performed for minutes.

Subsequently, the patterned photosensitive resin composition layer is subjected to a heat treatment at 100 to 400 ° C., preferably 250 to 400 ° C. or higher, whereby the oligoamide acid is closed to form an oligoimide, and the second protective layer having a pattern is formed. A film is formed.

When the photosensitive resin composition of the present invention contains a polyamic acid having the above repeating unit (2) as a resin component, the polyamic acid becomes the above-described oligoamic acid (1) in the exposure and development treatments. The patterning is performed in the same manner as in (1), and finally the ring is closed to form a polyimide.

[0048]

The photosensitive resin composition of the present invention has two functions as a negative type photosensitive material and as a protective film in a semiconductor device. Therefore, when the photosensitive resin composition of the present invention is used, in forming a protective film having a pattern in a semiconductor device, PEP for film formation and pattern formation is used.
Can be continuously performed by applying one substance and performing each treatment on the substrate. Thus, a protective film having a pattern can be formed by a simple process.

Further, as described above, the photosensitive resin composition of the present invention has high sensitivity, and in particular, contains a photopolymerizable oligoamic acid (1) having a double bond or a triple bond, thereby making the photosensitive resin composition light-sensitive. The portion changes significantly, and finally a relief pattern having a very sharp contrast is formed.

On the other hand, the photosensitive resin composition of the present invention has a low molecular weight in which the oligoamic acid (1), which is a resin component thereof, is end-capped at a molecular terminal, and has high wettability because the molecular terminal has polarity. . Therefore, according to the photosensitive resin composition, adhesion of the semiconductor substrate surface to a protective film made of an inorganic material such as silicon dioxide, silicon nitride, alumina or phosphosilicate glass, and further to a metal such as aluminum or copper used for wiring. A protective film having excellent adhesiveness and excellent adhesion to the sealing resin, particularly excellent adhesion to the epoxy sealing resin can be obtained. Further, such a protective film has excellent heat resistance.

According to the performance as described above, the photosensitive resin composition of the present invention is used to form a second protective film on a first protective film made of an inorganic material on the surface of a semiconductor substrate. By sealing the pellet with the sealing resin, the second protective film having excellent heat resistance can be satisfactorily adhered to the first protective film and the sealing resin. The second protective film, by the above-described high adhesion, prevents water from entering from the interface between the semiconductor substrate and the sealing resin, and buffers the difference in the coefficient of thermal expansion between the sealing resin and the semiconductor substrate. In addition, the occurrence of cracks in the first protective film due to the difference in the coefficient of thermal expansion is suppressed. Thus, according to the photosensitive resin composition of the present invention, corrosion of metal such as aluminum wiring forming an LSI circuit is effectively prevented, and a resin-encapsulated semiconductor device having significantly improved humidity resistance reliability is provided. can get.

[0052]

Embodiments of the present invention will be described below in detail.
In the following description, the compounds used in the examples are indicated by the following abbreviations. PMDA: pyromellitic dianhydride BTDA: 3,3'4,4'-benzophenonetetracarboxylic dianhydride DSDA: bis (3,4-dicarboxyphenyl) sulfone dianhydride TSL: bis (γ-aminopropyl ) -1,1,3,3-Tetramethyldisiloxane ODA: 4,4'-diaminodiphenyl ether BAPS: bis [4- (4-aminophenoxy) phenyl]
Sulfone MA: maleic anhydride SiPA: 4-trimethoxy-silyl-1,2,3,6-tetrahydrophthalic anhydride Synthesis Example 1 (Synthesis of oligoamic acid)

In a reaction flask equipped with a stir bar, a thermometer, and a dropping funnel, 7.67 g (0.035 mol) of PMDA,
BTDA 33.87 g (0.105 mol) and N-methyl-2-
140 g of pyrrolidone was charged, sufficiently stirred, and cooled to 0 ° C. Subsequently, while maintaining the inside of the reaction flask at 0 ° C., 30.16 g (0.15 mol) of ODA and 2.38 g of TSL were obtained.
(0.0096 mol) in a solution of 160 g of N-methyl-2-pyrrolidone was gradually added dropwise using a dropping funnel, and the mixture was stirred for 30 minutes while maintaining the inside of the reaction flask at 0 to 10 ° C.
Next, 3.92 g (0.04 mol) of MA was added to the reaction solution.
Was dissolved in 12 g of N-methyl-2-pyrrolidone, and the mixture was stirred at the same time for 5 hours while keeping the inside of the reaction flask at 10 ° C. to obtain an oligoamic acid represented by the general formula (1). 0.5 g of the obtained oligoamic acid was added to 100 ml of N-methyl
After dissolving in 2-pyrrolidone and measuring the intrinsic viscosity at a temperature of 30 ° C., it was 0.80 dl / g. Synthesis Examples 2 and 3 (Synthesis of oligoamic acid)

An oligoamic acid was synthesized from the diamine, tetracarboxylic dianhydride, and acid anhydride compositions shown in Table 1 according to the same method and conditions as in Synthesis Example 1, and the intrinsic viscosity was determined. The results are shown in Table 1 below.

[0055]

[Table 1] Synthesis Example 4 (Synthesis of polyamic acid)

In a reaction flask equipped with a stir bar, a thermometer, and a dropping funnel, 10.92 g (0.05 mol) of PMDA,
22.60 g (0.07 mol) of BTDA and 140 g of N-methyl-2-pyrrolidone were charged, sufficiently stirred, and cooled to 0 ° C. Subsequently, while maintaining the inside of the reaction flask at 0 ° C., 1.79 g (0.0072 mol) of TSL and 22.62 g of ODA
(0.1128 mol) in 143 g of N-methyl-2-pyrrolidone was gradually added dropwise using a dropping funnel, and the mixture was stirred for 6 hours while maintaining the inside of the reaction flask at 0 to 10 ° C.
A polyamic acid having the repeating unit of the general formula (2) was obtained. 0.5 g of the obtained polyamic acid was added to 100 ml of N-methyl-2.
It was dissolved in pyrrolidone and the intrinsic viscosity was measured at a temperature of 30 ° C. to be 1.67 dl / g. Synthesis Examples 5 and 6 (Synthesis of Polyamic Acid)

A polyamic acid was synthesized with the composition of diamine and tetracarboxylic dianhydride shown in Table 2 below according to the same method and conditions as in Synthesis Example 4, and the intrinsic viscosity was determined. The results are shown in Table 2 below. Synthesis Example 7 (Synthesis of polyamic acid)

According to Synthesis Example 4, P
A solution prepared by dissolving 21.812 g (0.10 mol) of MDA and 120 g of dimethylacetamide, then adding 18.321 g (0.094 mol) of ODA and 1,49 g (0.006 mol) of TSL in 90 g of dimethylacetamide,
By reacting for 5 hours, a polyamic acid was obtained.
The intrinsic viscosity of the obtained polyamic acid was measured in the same manner as in Synthesis Example 1. The results are shown in Table 2 below.

[0059]

[Table 2] Example 1

Concentration of oligoamic acid obtained in Synthesis Example 1
10 g of a 20% by weight solution and 11 g of a 17% by weight solution of polyamic acid obtained in Synthesis Example 4 were mixed. The mixed solution is provided with carbon-
As a compound having a carbon double bond and an amino group, 2.9 g of N, N-dimethylaminoethyl methacrylate was added to homogenize, and 0.12 g of Michler's ketone and 0.08 g of benzyldimethylketal were added as sensitizers to N-methyl-2. -A solution dissolved in 2 g of pyrrolidone was added to homogenize the mixture, and the mixture was filtered through a 0.5 μm filter to prepare a photosensitive resin composition of the present invention in the form of a varnish.

The obtained varnish was spin-coated on a 5-inch silicon wafer so as to have a thickness of 4 μm,
It dried at 20 degreeC for 20 minutes, and formed the photosensitive resin composition layer.
Next, using an exposure machine (PLA501F: manufactured by Canon Inc.), ultraviolet rays (11.0 mW / cm ² ) were applied to the surface of the composition layer through a predetermined mask. , 405 nm) for 30 seconds. After ultraviolet irradiation, the wafer was developed for 70 seconds with a mixed solution of 80 ml of methyl-2-pyrrolidone and 20 ml of methanol.The exposed area was hardly corroded, and a fine and clear relief pattern having 5 μm lines and spaces was obtained. Was done. In addition, 90 ° C for 30 minutes, 150 ° C for 30 minutes, 250 ° C
When heat treatment was performed for 30 minutes and at 350 ° C. for 30 minutes to imidize the resin component, the relief pattern was not disturbed in any case, and the 5 μm line and space were maintained in a state where they could be sufficiently identified. Examples 2 to 4

Concentration of oligoamic acid obtained in Synthesis Example 2
10 g of a 20% by weight solution, 11 g of a 17% by weight solution of polyamic acid obtained in Synthesis Example 5, 1.9 g of N, N-dimethylaminoethyl methacrylate, 0.15 g of Michler's ketone, 2-methyl
Using 0.1 g of-[4- (methylthio) phenyl] -2-morpholino-1-propanone and 2 g of N-methyl-2-pyrrolidone, a photosensitive resin composition was prepared in the same manner and under the same conditions as in Example 1. It was prepared in the form of a varnish (Example 2).

In addition, 15 g of a 20% by weight solution of oligoamic acid obtained in Synthesis Example 3, 6 g of a 17% by weight solution of polyamic acid obtained in Synthesis Example 6, N, N-dimethylaminopropyl methacrylamide Using 3.0 g, 4,4'-bis (diethylamino) benzophenone 0.2 g, benzoin ethyl ether 0.1 g, and N-methyl-2-pyrrolidone 2 g, in the same manner and under the same conditions as in Example 1, the photosensitive resin composition was used. The product was prepared in the form of a varnish (Example 3).

Further, 20 g of the solution containing 20% by weight of the oligoamic acid obtained in Synthesis Example 1, 2.7 g of dimethylaminoethyl N, N-methacrylate, 0.12 g of Michler's ketone, 0.08 g of benzyldimethylketal, and N-methyl- Using 2 g of 2-pyrrolidone, in the same manner and under the same conditions as in Example 1,
A photosensitive resin composition was prepared in the form of a varnish (Example 4).

Using the varnish of the photosensitive resin composition obtained in each of Examples 2 to 4, a pattern was formed in the same manner and under the same conditions as in the case of the varnish of Example 1.
A good relief pattern with m lines and spaces was obtained. In addition, even when the same heat treatment as in Example 1 was performed, the relief pattern was not disturbed, and the 5 μm line and space were maintained in a state where they could be sufficiently identified.

Further, with respect to the photosensitive resin compositions of Examples 1 to 4, the phosphosilicate glass (PS
G) The adhesion to the film was evaluated. That is, first, PSG
The photosensitive resin composition was applied to the silicon wafer on which the film was formed by a spin coating method. Next, a silicon chip having a 2 mm square PSG film was placed on the surface of the photosensitive resin composition layer and dried at 90 ° C. for 30 minutes.
Heat treatment at 250 ° C. for 30 minutes and at 350 ° C. for 30 minutes to form a sample having an imide film adjusted to a thickness of about 4 μm between the PSG films. Samples immediately after preparation and in saturated steam at 120 ° C in a pressure cooker
With respect to the samples left for 00 hours, the shear fracture strength of the silicon chips each having a 2 mm square PSG film was measured. The results are shown in Table 3 below.

Further, the photosensitive compositions of Examples 1 to 4 were examined for adhesion to an epoxy-based sealing resin. That is, first, on a silicon wafer with a PSG film formed on the surface,
The photosensitive resin composition was applied by a spin coating method. Next, dry at 90 ° C for 30 minutes, and further at 150 ° C for 30 minutes, 250
Heat treatment at 350 ° C for 30 minutes and 350 ° C for 30 minutes.
A protective film was formed on the SG film. The silicon wafer having the protective film is diced to a size of 10 mm × 30 mm, and a low-pressure transfer molding machine is used by using a semiconductor sealing epoxy resin (KE-600JZ: manufactured by Toshiba Chemical Corporation).
175 ℃, 80kg / cm ² Under a condition of 3 minutes, a 2 mm square sealing resin was formed on the protective film of the silicon wafer to obtain a sample. The shear fracture strength of a 2 mm square sealing resin was measured for each of the sample immediately after preparation and the sample left for 200 hours in saturated steam at 120 ° C. in a pressure cooker. The results are shown in Table 3 below. Comparative Example 1

The polyamic acid solution 20 obtained in Synthesis Example 4
g, N, N-dimethylaminoethyl methacrylate 2.3 g, Michler's ketone 0.18 g, benzyldimethyl ketal 0.11 g
g, and 2 g of N-methyl-2-pyrrolidone, and a photosensitive resin composition corresponding to a comparative example of the present invention was prepared in the form of a varnish in the same manner and under the same conditions as in Example 1. Using this varnish, the adhesion between the PSG film and the epoxy-based sealing resin was evaluated in the same manner as in the case of the photosensitive resin compositions of Examples 1 to 4. The results are shown in Table 3 below. Comparative Example 2

The polyamic acid solution 30 obtained in Synthesis Example 7
g, N, N-dimethylaminoethyl methacrylate 4.4 g, Michler's ketone 0.6 g, bis (4-N-maleimidophenyl)
A photosensitive resin composition corresponding to a comparative example of the present invention was prepared in the form of a varnish using 1.0 g of methane and 20 g of dimethylacetamide in the same manner and under the same conditions as in Example 1.

When a pattern was formed using the varnish obtained in Comparative Example 2 under the same method and conditions as in the case of the varnish of Example 1, a good relief pattern having lines and spaces of 10 μm was obtained. . Even when the same heat treatment as in Example 1 was performed, the relief pattern was not disturbed, and the lines and spaces of 10 μm were maintained in a state in which they could be discriminated sufficiently.

Further, using the varnish obtained in Comparative Example 2, in the same manner as in the photosensitive resin compositions of Examples 1 to 4,
The adhesion between the PSG film and the epoxy-based sealing resin was evaluated. The results are shown in Table 3 below.

[0072]

[Table 3]

From the results shown in Table 3, it was found that the photosensitive resin composition of the present invention, that is, the photosensitive resin composition containing the oligoamic acid (1) as a resin component was used and formed on a semiconductor substrate. It can be seen that the protective film has excellent adhesion to an inorganic material such as a PSG film and a sealing resin.

[0074]

As described in detail above, according to the present invention,
A photosensitive resin composition capable of forming a polyimide film pattern by a simple process without separately using a photoresist can be provided. Further, according to the present invention, it is possible to form a protective film made of an inorganic material on the surface of a semiconductor substrate and a protective film having excellent adhesion to a sealing resin, excellent heat resistance, excellent exposure sensitivity, and a sharp relief pattern. A photosensitive composition can be provided. Further, by forming a second protective film on the first protective film made of an inorganic material on the surface of the semiconductor substrate using such a photosensitive composition, and sealing with a sealing resin material, production is easy, A high-performance resin-encapsulated semiconductor device having excellent moisture resistance reliability can be provided.

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI G03F 7/075 511 G03F 7/075 511 H01L 21/027 H01L 21/312 B 21/312 D 21/30 575 (56) JP-A-59-68332 (JP, A) JP-A-1-118513 (JP, A) JP-A-49-16797 (JP, A) JP-B-45-36917 (JP, B1) (58) (Int.Cl. ⁷ , DB name) C08F 290/00-290/14 C08F 299/00-299/08 C08F 2/46-2/50 C08G 73/10-73/14 G03F 7/027 H01L 21/027 H01L 21/312

Claims (2)

(57) [Claims] 1. An oligoamic acid having a molecular terminal end-capped represented by the following general formula (1) and having a carbon-carbon double bond and an amino group which can be dimerized or polymerized by an energy ray. A photosensitive resin composition comprising a compound and a sensitizer. Embedded image In the formula, Ar ¹ represents a divalent organic group, Ar ² represents a tetravalent organic group, and Z represents a divalent organic group having a photopolymerizable double bond or triple bond. n is a number average degree of polymerization,
Indicates a positive integer of 30 or less. 2. Z in the general formula (1) is as follows:
The photosensitive material according to claim 1, which is a group selected from the group shown in the following.
Resin composition. Embedded image