JP3015430B2 - Photosensitive composition and resin-encapsulated semiconductor device - Google Patents

Description

The present invention relates to a photosensitive composition and a resin-sealed semiconductor device.

(Prior Art) An element formed on a semiconductor substrate is susceptible to an external environment, and thus receives a protective film to maintain reliability.
Conventionally, as such a protective film, inorganic materials such as silicon dioxide, silicon nitride, and alumina have been used.
On the other hand, among organic materials, polyimide resin can form a protective film by a simple process and can adopt a stabilization treatment method at a relatively low temperature. It has become to.

In addition, a conventional resin-encapsulated semiconductor device has a structure in which a protective film made of an inorganic material such as silicon dioxide, silicon nitride, or alumina is formed on a semiconductor substrate, and further sealed with an epoxy resin composition or the like. . However, sealing resin such as epoxy resin has the property of transmitting moisture, and cracks occur in the protective film due to the difference in thermal expansion coefficient between the sealing resin and the semiconductor substrate as the size of the element pellet increases. Therefore, the occurrence of corrosion of a wiring pattern made of aluminum or the like due to intrusion of moisture or the like has been recognized. As a countermeasure, a polyimide protective film is further formed on the protective film made of the inorganic material.

It is also considered that the use of a polyimide protective film as the layer-enhancing insulating film makes it possible to flatten the steps on the element surface and to form the protective film by a relatively simple process.

However, in these applications, it is usually necessary to form holes in the polyimide protective film by pattern processing such as through holes or pad processing for conducting with external leads. In this processing step, it is necessary to use a photoresist, and there is a disadvantage that a complicated step and a long time are required for forming a protective film.

In contrast, JP-A-49-115541 and JP-A-59-52
No. 822 describes a heat-resistant photosensitive material containing a carbon-carbon double bond which can be dimerized or polymerized by actinic radiation. However, these materials have low photosensitivity and have a problem in mass productivity. Also, since an organic solvent is used for the developer,
There is a problem that the transferred pattern expands and the resolution is poor. Moreover, the use of large amounts of organic solvents is
It is not preferable from the viewpoint of fire prevention.

(Problems to be Solved by the Invention) The present invention has been made in order to solve the above-described problems, and is capable of forming an element protective film having a sharp relief pattern excellent in heat resistance without using a photoresist. It is intended to provide a neutral composition. Another object of the present invention is to provide a resin-sealed semiconductor device which is easy to manufacture and has excellent reliability.

[Configuration of the Invention] (Means for Solving the Problems) (However, Z in the formula represents an at least tetravalent organic group,
Y represents a divalent organic group, and R ₁ and R ₂ may be the same or different and each represents n-butyl, t-butyl, tetrahydropyranyl, benzyl, methoxymethyl, isopropyl, or trimethylsilyl A photosensitive composition comprising a polyamic acid derivative having a repeating unit represented by formula (1) and a compound capable of generating an acid upon irradiation with light.

The polyamic acid derivative can be synthesized by reacting a tetracarboxylic dianhydride with an alcohol to synthesize a tetracarboxylic diester, and subjecting the tetracarboxylic diester to a diamine to undergo a condensation reaction. This condensation reaction can be carried out in the same manner as the condensation reaction between dicarboxylic acid and diamine. Specifically, the method is carried out via the state of an acid chloride (eg, Japanese Patent Publication No. 55-41422).
), A method using an organic dehydration condensing agent (for example,
No. 72022, JP-A-61-127731, JP-A-62-272724, JP-A-62-74931, and the like.

Examples of the tetracarboxylic dianhydride used for the synthesis of the polyamic acid derivative include, for example, pyromellitic dianhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, 2,3,3 ′ , 4'-benzophenonetetracarboxylic dianhydride, 2,2-bis (3,3 ', 4,4'-tetracarboxyphenyl) hexafluoropropane 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, bis (3,4-dicarboxyphenyl) dimethylsilane dianhydride, bis (3,4
-Dicarboxyphenyl) tetramethyldisiloxane dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride,
Butanetetracarboxylic dianhydride and the like. These can be used alone or in combination of two or more.

Examples of the diamine used in the synthesis of the polyamic acid derivative include, for example, m-phenylenediamine, p-phenylenediamine, 2,4-tolylenediamine, 3,3′-diaminodiphenyl ether, 4,4′-diaminodiphenyl ether, 3, 4'-diaminodiphenyl ether, 3,3'-
Diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone,
3,3'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane,
4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl ketone, 4,4'-diaminodiphenyl ketone, 3,4'-diaminodiphenyl ketone, 2,2'-bis (p-aminophenyl) propane, 2,2'-bis (p-
Aminophenyl) hexafluoropropane, 1,3-bis (m-aminophenoxy) benzene, 1,3-bis (p-
Aminophenoxy) benzene, 1,4-bis (p-aminophenoxy) benzene, 4-methyl-2,4-bis (p-
Aminophenyl) -1-pentene, 4-methyl-2,4-
Bis (p-aminophenyl) -2-pentene, 1,4-bis (α, α-dimethyl-p-aminobenzyl) benzene, imino-di-p-phenylenediamine, 1,5-diaminonaphthalene, 2,6 -Diaminonaphthalene, 4-methyl-2,4-bis (p-aminophenyl) pentane, 5
(Or 6) -amino-1- (p-aminophenyl) -1,
3,3-trimethylindane, bis (p-aminophenyl) phosphine oxide, 4,4'-diaminoazobenzene, 4,4'-diaminodiphenylurea, 4,4'-bis (p
-Aminophenoxy) biphenyl, 2,2-bis [p-
(P'-aminophenoxy) phenyl] propane, 2,2
-Bis [p- (m-aminophenoxy) phenyl] benzophenone, 4,4'-bis (p-aminophenoxy) diphenylsulfone, 4,4'-bis [p- (α, α-dimethyl-p'-amino) Benzyl) phenoxy] benzophenone, 4,4'-bis [p- (α, α-dimethyl-p'-
Aminobenzyl) phenoxy] diphenylsulfone, bis (4-aminophenyl) dimethylsilane, bis (4-
Aromatic diamines such as aminophenyl) tetramethyldisiloxane; and the aromatic nucleus hydrogen atoms of these aromatic diamines are chlorine, fluorine, bromine, methyl, methoxy, cyano, phenyl, etc. Substituted with at least one substituent selected from the group;
3'-dihydroxy-4,4'-diaminobiphenyl, 3,
3'-diamino-4,4'-dihydroxybiphenyl, 2,2
-Bis (3-hydroxy-4-aminophenyl) hexafluoropropane, 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2- (3-hydroxy-4-aminophenyl) -2- (3-amino-4
-Hydroxyenyl) hexafluoropropane, bis (γ
-Aminopropyl) tetramethyldisiloxane, 1,4-
Bis (γ-aminopropyldimethylsilyl) benzene,
Bis (4-aminobutyl) tetramethyldisiloxane,
Bis (γ-aminopropyl) tetraphenyldisiloxane, (Wherein, is a positive number from 2 to 12), dicyclohexylcarbodiimide and the like. These can be used alone or in combination of two or more.

Examples of the alcohol used in the synthesis of the polyamic acid derivative include methanol, ethanol, n-propanol, n-butanol, isopropanol, 2-butanol, tert-butanol, benzyl alcohol,
-Acetoxyethanol, 2-methoxyethanol, methoxymethanol, 2-ethoxyethanol, 3-methoxy-1-propanol, 2,3-dimethoxy-1-propanol and the like.

The polyamic acid derivative may be prepared by reacting a tetracarboxylic dianhydride with a diamine in advance to synthesize a polyamic acid in addition to the above-described synthesis method. −2603
No. 3) and an epoxy compound (for example, JP-A-56-32524). Further, trimethylchlorosilane, hexamethyldisilazane, 2,3-dihydro-4H-
The polyamic acid derivative can also be synthesized by reacting pyran or the like.

Examples of the compound (acid generator) that generates an acid upon irradiation with light include onium salts, diazonium salts, phosphonium salts, sulfonium salts, iodonium salts and the like, and CF ₃ SO _{3
^{-, p-CH 3 PhSO 3}} -, p-NO 2 PhSO 3 - salts with such organic halogen compounds, orthoquinone - such diazide sulfonic acid ester. The organic halogen compound,
Hydrohalic acid forming compounds such as those disclosed in U.S. Pat. No. 3,515,552, U.S. Pat. No. 3,779,778 and West German Offenlegungsschrift 2,224,621. Compounds that generate an acid upon irradiation with another light as described above are described in JP-A-54-74728, JP-A-55-24113, JP-A-55-77742, JP-A-60-3626, and JP-A-60-3626. 60-138539
And JP-A-56-17345 and JP-A-50-36209. Specific examples of such compounds include di (p-tert-butylbenzene) diphenyliodonium trifluoromethanesulfonate, benzoin tosylate, orthonitrobenzylp-toluenesulfonate, triphenylsulfonium trifluoromethanesulfonate, and tri (tert-butylphenyl). Sulfonium trifluoromethanesulfonate, benzenidiazonium paratoluenesulfonate, 4- (di-n-
Propylamino) -benzonium tetrafluoroborate, 4-p-tolyl-mercapto-2,5-diethoxy-
Benzenediazonium hexafluorophosphate, tetrafluoroborate, diphenylamine-4-diazonium sulfate, 4-methyl-6-trichloromethyl-2-pyrone, 4- (3,4,5-trimethoxy-styryl) -6-tricolomethyl 2-pyrone, 4- (4-
Methoxy-styryl) -6- (3,3,3-trichloro-propenyl) -2-pyrone, 2-trichloromethyl-benzimidazole, 2-tribromomethyl-quinone, 2,4
-Dimethyl-1-tribromoacetyl-benzene, 4-
Dibromoacetyl-benzoic acid, 1,4-bis-dibromomethyl-benzene, tris-dibromomethyl-S-triazine, 2- (6-methoxy-naphthyl-2-yl) -4,
6-bis-trichloromethyl-S-triazine, 2-
(Naphthyl-1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (naphthyl-2-yl) -4,
6-bis-trichloromethyl-S-triazine, 2-
(4-ethoxyethyl-naphthyl-1-yl) -4,6-
Bis-trichloromethyl-S-triazine, 2- (benzopyran-3-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (4-methoxy-anthracy-
1-yl) -4,6-bis-trichloromethyl-S-triazine, 2- (phenant-9-yl) -4,6-bis-
Trichloromethyl-S-triazine, o-naphthoquinonediazide-5-sulfonic acid ester and the like.

The compounding amount of the acid generator is the polyamic acid derivative 10
0.01 to 20 parts by weight with respect to 0 parts by weight, more preferably 0.1 to 20 parts by weight
It is desirable to use 10 parts by weight. The reason is that if the compounding amount is less than 0.01 parts by weight, sufficient photosensitivity cannot be imparted, while if the compounding amount exceeds 20 parts by weight, applicability, strength of the coating film, and adhesion to the substrate. May decrease.

The photosensitive composition according to the present invention is usually used in a state of being dissolved in an organic solvent. The organic solvent is not particularly limited as long as it dissolves the polyamic acid derivative and the acid generator. Specifically, ketone solvents such as cyclohexanone, acetone, methyl ethyl ketone and methyl isobutyl ketone; methyl cellosolve; Cellosolve solvents such as methyl cellosolve acetate, ethyl cellosolve acetate and butyl cellosolve acetate; ester solvents such as ethyl acetate, butyl acetate and isoamyl acetate; ether solvents such as tetrahydrofuran and dioxane; N, N-dimethylformamide, N, N- Dimethylacetamide, N-methyl-2-pyrrolidone, N-methyl-ε
-Caprolactam, γ-butyl lactone, sulfolane,
Solvents such as N, N, N ', N'-tetramethylurea and hexamethylphosphoramide can be mentioned. These solvents may be used alone or in the form of a mixture.

In addition, in the said photosensitive composition, you may mix | blend a sensitizer, a dye, a surfactant, etc. as needed.

Next, a pattern forming method using the above-described photosensitive composition will be described.

First, the photosensitive composition according to the present invention, which is dissolved in an organic solvent and fine dust is removed by filtration or the like, is applied on a substrate by a spin coating method or a dipping method, and then dried to form a photosensitive composition layer. Form. Subsequently, the photosensitive composition layer is exposed through a mask having a desired pattern. This exposure is performed by irradiating energy rays such as visible light, infrared light, and electron beam according to a conventional method. Subsequently, the exposed substrate was exposed to a hot plate or an oven at 70 to 150 ° C. for 10 seconds to 15 minutes, if necessary.
More preferably, heating at 80 to 120 ° C. for 30 seconds to 5 minutes promotes the reaction between the acid generated by light and the resin component. Then
The photosensitive composition layer after pattern exposure is developed using an alkaline aqueous solution by a dipping method, a spray method, or the like. Examples of the aqueous alkali solution used here include an aqueous organic alkali solution such as an aqueous tetramethylammonium hydroxide solution; and an aqueous inorganic alkali solution such as potassium hydroxide and sodium hydroxide. If necessary, after development, a rinsing treatment with water, alcohol, acetone or the like may be performed, followed by a treatment such as baking.

In the above-described pattern formation, when the photosensitive composition is applied to the passivation film or the interlayer insulating film, it is gradually heated and cured to 90 to 400 ° C. after development. Then,
A process such as bonding is performed, followed by sealing with a sealing resin to manufacture a resin-sealed semiconductor device.

Further, when applying the photosensitive composition to the photoresist for fine processing in the pattern formation described above, if necessary, after development, heat bake at 90 to 180 ° C., and dry-etch or wet-etch the substrate according to a conventional method. Is processed. When a fine pattern of 3 μm or less is formed, a dry etching method is preferable. As a wet etching agent, an aqueous solution of hydrofluoric acid, an aqueous solution of ammonium fluoride, or the like is used when a silicon oxide film is to be etched, and an aqueous solution of phosphoric acid, an aqueous solution of acetic acid, or an aqueous solution of nitric acid is used when an etching target is ammonium. When a chromium-based film is to be etched, a cerium ammonium nitrate aqueous solution or the like is used. CF ₄ , C ₂ F ₆ , CCl
₄ , BCl ₃ , Cl ₂ , HCl, H _{2 and the} like, and these gases are used in combination as needed. The etching conditions determine the concentration of the wet etching agent, the concentration of the dry etching gas, the reaction temperature, the reaction time, and the like in the reaction tank based on the combination of the type of the substance on which the fine pattern is formed and the photosensitive composition. However, the method is not particularly limited. After such etching,
The pattern consisting of the polymer material and the resist remaining on the substrate is removed by using, for example, a release agent such as J-100 manufactured by Nagase Kasei Co., Ltd., oxygen gas plasma or the like.

(Operation) The photosensitive composition of the present invention contains a polyamic acid derivative having a repeating unit represented by the general formula (I) and a compound (acid generator) that generates an acid by light irradiation. Thereby, an alkaline aqueous solution can be used as a developing solution in the developing process after the pattern exposure. That is, the polyamic acid derivative in the photosensitive composition has a terminal group of n-butyl, t-butyl-, tetrahydropyranyl, benzyl, methoxymethyl, isopropyl,
Or R ₁ which is a specific organic group consisting of trimethylsilyl
It has become insoluble state with respect to an aqueous solution since it and is R _2. When the photosensitive composition is subjected to pattern exposure, an acid is generated from an acid generator, and the acid replaces R ₁ and R ₂ in the polyamic acid derivative with a hydrogen atom to form a —COOH group. Is easily dissolved in an aqueous solution. As a result, an alkaline aqueous solution can be used without using an organic solvent as a developing solution in a developing process after pattern exposure. Therefore, swelling of the pattern due to the developer is prevented, and the resolution is improved. Furthermore, this photosensitive composition is excellent in exposure sensitivity and heat resistance. Therefore, with such a photosensitive composition, a protective film having a sharp relief pattern having excellent heat resistance can be formed without using a photoresist.

Further, the photosensitive composition is coated on a semiconductor substrate on which an element is formed to form a photosensitive composition layer, which is exposed,
By performing development and heat curing, a desired patterned protective film can be easily provided on the semiconductor substrate. By sealing such a semiconductor pellet with a sealing resin, a highly reliable resin-encapsulated semiconductor device in which an encapsulating resin layer is covered via the pattern-shaped protective film having excellent heat resistance. Can be obtained.

(Example) Hereinafter, an example of the present invention will be described in detail.

Synthesis Example 1 200 ml of n-dehydrated 21.8 g of pyromellitic dianhydride
While mixing and suspending in butanol, the mixture was stirred at 40 to 50 ° C. for 20 hours under a nitrogen atmosphere to react until no insolubles were found. Bring the reaction to room temperature and add 400 ml
Was added and n-butanol was distilled off under reduced pressure until crystals precipitated. After storing this solution in the refrigerator overnight,
The crystals were collected by filtration and dried in vacuo to obtain dibutyl pyromellitic acid ester. Subsequently, 18.3 g of this pyromellitic acid dibutyl ester and dicyclohexylcarbodiimide 2
5 g was dissolved in 100 ml of N-methyl-2-pyrrolidone (NMP). While cooling this solution to 0 to 5 ° C., 30 ml of NMP in which 10 g of P-oxydianiline (ODA) was dissolved was added dropwise over 15 minutes, and after returning to room temperature, the ester and dicyclohexylcarbodiimide were stirred for 5 hours. Was reacted. 5 ml of ethanol was added to the reaction solution, and the mixture was stirred for 1 hour to remove insoluble components by filtration.
In ethanol, and the resulting precipitate was dried under vacuum to obtain dibutyl polyamic acid (abbreviated as PA-1).

The obtained PA-1 was dissolved in NMP to prepare a solution having a concentration of 0.5 g / d, and the intrinsic viscosity at 30 ° C. was measured.
d / g.

Synthetic Examples 2 to 13 The protective groups (R ₁ , R ₂ ) shown in Table 1 were prepared in the same manner as in Synthetic Example 1 using tetracarboxylic dianhydride and diamine in the proportions shown in Table ₁ . Polyamic acid derivative (P
A-2 to PA-13) were synthesized to obtain PA-2 to PA
An intrinsic viscosity of -13 was measured. The measured values are also shown in Table 1.

 Here, the abbreviations used in Table 1 will be described.

PMDA: pyromellitic dianhydride BTDA: 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride BPDA: 3,3', 4,4'-bisphenyltetracarboxylic dianhydride HFDA: 2 , 2-bis (3,3 ', 4,4'-tetracarboxyphenyl) hexafluoropropane dianhydride DSDA: 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride ODA: 4,4 '-Diaminodiphenyl ether DDS: 4,4'-diaminodiphenyl sulfone BAPP: 2,2-bis [4- (4-aminophenoxy) phenyl] propane BAPH: 2,2-bis [4- (4-aminophenoxy) phenyl ] Hexafluoropropane TSL bis (γ-aminopropyl) tetramethyldisiloxane Example 1 20 g of NMP was prepared by combining 5 g of PA-15 obtained in Synthesis Example 1 and 0.25 g of triphenylsulfonium hexafluoroantimonate.
This solution was passed through a 0.5 μm filter to remove insolubles, thereby preparing a photosensitive composition.

This photosensitive composition was spin-coated on a 5-inch silicon wafer, and dried on a hot plate to obtain a coating film having a thickness of 6 μm. An ultra-high pressure mercury lamp (8mW / cm ² )
And exposed through a photomask having a test pattern. After exposure, the film was baked on a hot plate at 120 ° C. for 2 minutes, immersed in a 2.38% by weight aqueous solution of tetramethylammonium hydroxide for 60 seconds, washed with water and developed. After drying, the cross section of the pattern was observed with an electron microscope to check the resolution.
It was found that a fine pattern with a line width of The light irradiation amount required during this exposure was 50 mJ / cm ² .

Examples 2 to 13 Photosensitive compositions were prepared using the polyamic acid derivatives (PA-2 to PA-5 and acid generators (A1 to A8)) shown in Table 2,
A pattern was formed in the same manner as in Example 1 except that the exposure conditions, the heating bake conditions after exposure, and the development conditions shown in Table 2 were used. The resolution of this pattern was examined in the same manner as in Example 1. The results are also shown in Table 2.

 Here, the abbreviations used in Table 2 will be described.

As is clear from Table 2, the photosensitive compositions of Examples 2 to 13 can obtain a fine pattern similarly to the composition of Example 1 and have excellent resolution. This is because pattern swelling was prevented because an alkaline aqueous solution could be used for the developer. Further, it can be seen that this photosensitive composition has a small amount of light irradiation required for exposure and has excellent exposure sensitivity.

Example 14 The photosensitive composition of Example 9 was examined for adhesion to a phosphosilicate glass (PSG) film. That is, on a silicon wafer on which a PSG film is formed, a photosensitive composition is applied by a spin coating method, a 2 mm square silicon chip with a PSG film is placed thereon, dried at 90 ° C. for 30 minutes, and further heated at 150 ° C. 30 minutes, 250 ° C
Heat treatment for 1 hour and at 350 ° C for 30 minutes.
A protective film (modified polyimide film) adjusted to a thickness of about 5 μm was formed between the films, and this was used as a sample. For the sample immediately after production and the sample after standing in steam at 120 ° C. and 2.2 atm for 100 hours in a pressure cooker, a 2 mm square PS
The shear fracture strength of the silicon chip with the G film was measured. As a result, the shear fracture strength of the sample immediately after preparation was 3.3 kg / mm ² , PCT
The sample after the (pressure cracker test) had a shear fracture strength of 2.9 kg / mm ² .

Further, the photosensitive composition of Example 9 was examined for adhesion to an epoxy-based semiconductor sealing resin. That is, a photosensitive composition is applied on a silicon wafer on which a PSG film is formed by a spin coating method, dried at 90 ° C. for 30 minutes, and further dried at 150 ° C. for 3 minutes.
A heat treatment was performed for 0 minute, at 250 ° C. for 1 hour, and at 320 ° C. for 30 minutes to form a protective film. The silicon wafer with the protective film is diced to a size of 10 mm × 30 mm, and a low-pressure transfer molding machine is used at 175 ° C. and 80 kg / c using an epoxy resin for semiconductor encapsulation (KE-300TS: trade name of Toshiba Chemical Corporation).
m ² , 3m on the silicon wafer protective film under the conditions of 3 minutes
An m-square sealing resin was formed and used as a sample. The shear fracture strength of a 2 mm square PSG film-attached silicon chip was measured for the sample immediately after the preparation and for the sample that had been left in water vapor at 120 ° C. and 2.2 atm for 100 hours in a pressure cooker.
As a result, the shear fracture strength of the sample immediately after preparation was 4.0 kg / m
m ² , the shear fracture strength of the sample after PCT was 3.7 kg / mm ² .

Comparative Example 1 21.8 g of pyromellitic dianhydride and 26 g of 2-hydroxyethyl methacrylate were mixed in 100 ml of γ-butyl lactone, and 20.2 g of triethylamine was added while cooling with ice. After stirring for 20 hours at room temperature, a solution of 20.0 g of 4,4'-diaminodiphenyl ether dissolved in 80 g of NMP was added, and then 45 g of dicyclohexylcarbodiimide was added to 3 g of the solution.
A suspension in 0 ml of γ-butyl lactone was added over 15 minutes. Further, 80 ml of NMP was added, and the mixture was stirred for 2 hours to remove insoluble components by filtration.
The precipitate was collected by filtration and dried to obtain a polymer.

The obtained polymer was dissolved in 10 g, Michler's ketone 0.2 g and NMP, and this solution was passed through a 0.5 μm filter to remove insolubles, thereby preparing a photosensitive composition. This photosensitive composition is spin-coated on a 5-inch silicon wafer and heated at 90 ° C.
And dried on a hot plate for 5 minutes to obtain a coating film having a thickness of 5 μm. The coating film was exposed through a photomask on which a test pattern was formed using an ultra-high pressure mercury lamp (8 mW / cm ² ). After the exposure, a mixture of NMP and isopropyl alcohol (IPA) (NMP: IPA = 3: 1) was used as a developer to develop a pattern.

The resulting pattern swelled due to development with an organic solvent. The light irradiation amount required at the time of the exposure is 400 mJ / cm.
² , which was inferior in sensitivity.

[Effects of the Invention] As described in detail above, according to the present invention, it is possible to provide a photosensitive composition capable of forming an element protective film having a sharp relief pattern excellent in heat resistance without using a photoresist. . Further, by forming a protective film on a semiconductor substrate on which an element is formed using such a photosensitive composition, a resin-encapsulated semiconductor device which is easy to manufacture and has excellent reliability can be provided.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI H01L 23/29 H01L 23/30 C 23/31 (56) References JP-A-2-181149 (JP, A) JP-A Sho56 -17345 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 79/00-79/08 C08G 73/00-73/26 C09D 179/00-179/08 G03F 7 / 004,7 / 038 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] (1) General formula (However, Z in the formula represents an at least tetravalent organic group,
Y represents a divalent organic group, and R ₁ and R ₂ may be the same or different and each represents n-butyl, t-butyl, tetrahydropyranyl, benzyl, methoxymethyl, isopropyl, or trimethylsilyl A photosensitive composition comprising a polyamic acid derivative having a repeating unit represented by formula (1) and a compound capable of generating an acid upon irradiation with light. 2. A pattern-like protective film is formed by coating the photosensitive composition according to claim 1 on a semiconductor substrate on which an element is formed, and exposing, developing and heat-curing, and further comprises a sealing resin material. A resin-encapsulated semiconductor device, characterized in that the semiconductor device is sealed.